The invention is directed to an arrangement for clock supply of a high bit-rate switching network structures in a digital narrowband switching system such as EWSD. A clock frequency signal (CLK2) traditionally generated with a crystal-controlled oscillator (11) as well as a corresponding frame clock signal (FMB2) are converted into low-voltage CMOS level signals and supplied to a system PLL (2) for high frequencies. This contains a discretely constructed VCO 6 with a sine oscillator that derives a higher-frequency signal from the supplied clock signal and converts this into a high-frequency clock signal (CLK92) of the output side. A feedback signal derived in this part serves as an input-side feedback signal for a phase detector (8) in low-voltage CMOS technology. The feedback signal as well as the output-side high-frequency signal (CLK92) also serve for phase decoupling of the input-side frame clock signal (FMB2) from the output-side frame clock signal (FMB92) and for the phase-coupling thereof to the output-side high-frequency signal (CLK92). The output-side clock signals (CLK92, FMB92) are distributed in pairs via a clock distribution system (3) dimensioned within narrow tolerances and are supplied to respective application-specific or customized ICs (4) in low-voltage CMOS technology. This division onto various stages and onto components of different technologies in low-voltage technology allow the dimensioning and configuration with cost-beneficial components.

1. Field of the Invention
The invention is directed to an arrangement for a clock supply of high bit rate switching network structures in a digital narrowband switching system such as EWSD with a PLL system comprising a crystal-controlled oscillator.
2. Description of the Related Art
The previously mentioned switching networks work with a transmission speed of (128xc3x9764 kB/s)=8.192 MB/s (colloquially, xe2x80x9c8 MB/sxe2x80x9d). In such switching networks, the required synchronizing clock is achieved proceeding from a centrally generated 8 MHz system clock, namely with rigid synchronism. The necessary frame positions are also defined and forced in the various switching stages by a frame clock FMB2 that is generated phase-locked relative to the 8 MHz system clock. Due to the adequate phase reserves at the data interfaces, a synchronization on site is not required. Jitter problems are not critical; on the contrary, the jitter demands made of the generated system parts lie in the easily doable range. Traditionally, a PLL system employing a commercially obtainable crystal-controlled oscillator is used. The PLL system is provided in order to assure the phase-locked linking of the switching network clock to the clock that is generated by the central clock generator, the crystal-controlled oscillator, and converted. The required 8 MHz system clock, CLK8, and the 2 KHz frame marking or the 2 KHz frame clock, FMB2, are offered on symmetrical lines in the narrowband switching system at the traditional TTL level. The stable crystal-controlled oscillator of the PLL system achieves high-quality phase and frequency stability.
High bit rate switching network structures, however, must work with significantly higher serving speeds. It is desirable to have a serving speed of (2304xc3x9780 kB/s)=184.320 MB/s (xe2x80x9c184 MB/sxe2x80x9d), which could use correspondingly dimensioned crystal-controlled oscillators. Crystals that oscillate with the required frequencies, however, are extremely expensive, by which only the harmonics can be employed. Moreover, a central circuit-synchronous clock can no longer be employed for distribution-oriented reasons. The necessity of having to adhere to an extremely narrow frequency follow-up range is also disadvantageous.
It must be taken into consideration that clock signal edges having a spacing of 0.7 ns must be selected, by which a high-frequency phase stability of 300-400 ps (peak-to-peak) must be achieved to reliably function and to consider unavoidable jitter accumulation at the various transitions.
Thus, an object of the present invention is to specify an arrangement for a clock supply of high bit rate switching network structures with which high phase and frequency stability can also be assured in the high-frequency range.
This object is achieved by an arrangement for a clock supply of high bit-rate switching network structures in a digital narrowband switching system, comprising: a PLL system comprising a crystal-controlled oscillator that locks the switching network clock to a clock phase generated by a central clock generator and outputs a low-voltage normal bit-rate, low frequency, clock signal and a low-voltage frame clock signal for normal bit-rate switching network structures; an analog, discrete sine oscillator in a phase-locked loop that converts the normal bit-rate clock signal into a high-frequency clock signal; and a low-voltage pseudo-ECL arrangement, that, after stabilization with a reference clock, generates a high bit-rate, high frequency, clock signal suitable for high bit-rate switching network structures by division and outputs it, the low-voltage pseudo-ECL arrangement also outputting an output-side high bit-rate, high frequency, frame clock signal of the same frequency decoupled in phase position from an input-side frame clock signal that has a predetermined phase relation relative to the high bit-rate output-side clock signal. The arrangement may further comprise a feedback path via which a clock signal, that is a feedback signal, that has been stepped-down in frequency as well as converted in level can be fed back to an input-side phase detector contained within a low-voltage CMOS arrangement that also receives the input-side normal bit-rate clock signal. The arrangement may also comprise an ultra-fast comparator with a high analog gain, the ultra-fast comparator comprising a following, integrated frequency divider with two differing division rates for an output of the high bit-rate output-side clock signal and of the feedback signal. The comparator may have a high steepness for a sine signal in a zero-axis crossing at a steepness of approximately 1V/ns. This arrangement may further comprise a level converter in the feedback path, the level converter consisting of passive components and serving for a conversion of low-voltage pseudo-ECL level onto low-voltage CMOS level. The phase detector may comprise an exclusive-OR element; and a step-down device in the low-voltage CMOS structure may be provided in the form of an electrically programmable gate array that further-converts the feedback and level-converted signal into a signal having a pulse-duty factor 1:1 that is supplied to the exclusive-OR element.
The arrangement may further comprise a two-stage, passive low-pass filter preceding the analog sine oscillator and having a xe2x88x923 dB limit frequency of at least 2 times the corner frequency of a pure proportion control element part of a control loop of the arrangement without a low-pass filter. It also may comprise a clock distributor arrangement in the low-voltage pseudo-ECL arrangement that receives the high bit-rate clock signal and the high bit-rate frame clock signal coupled to it in phase position at its input side and divides these in pairs onto numerous output pairs. The arrangement may further comprise low-voltage pseudo-ECL components with low skew that are selected such that a required system jitter that is reached in the low-voltage pseudo-ECL arrangement, the low-voltage CMOS arrangement, and the clock distributor arrangement lies on the order of magnitude of xc2x1200 ps. The arrangement may further comprise a low-voltage ASIC in a low-voltage CMOS arrangement, the ASIC having integrated into it: a gate array arrangement; an analog PLL; and a comparator that is supplied by the high bit-rate clock signal and the high bit-rate frame clock signal coupled to it in phase position, the comparator having difference outputs that supply the analog PLL for converting an input-side clock frequency to double that and for, in turn, its distribution of this clock frequency with the gate array arrangement. In the arrangement, the low-frequency clock signal frequency may be approximately 2048 KHz; the output side high-frequency clock frequency may be approximately 92.162 MHz; and the high frequency frame clock signal frequency may be approximately 8 KHz.
The invention is based on the idea that the noise influence as well as the creation and accumulation of jitter in the overall clock path can be kept low with a suitable selection and dimensioning of component parts. This, on the one hand, is based on the use of low-voltage technology (in the area of 3.3 V) in the high-frequency level, particularly a low-voltage CMOS technology and a low-voltage pseudo-ECL technology. Critical sources of noise influences or sources for the creation of jitter can thus be eliminated to the farthest-reaching extent. Critical noise sources in the high-frequency range are the supply voltage, the signal level employed, the edge steepness, the entire signal spectrum, and high-impedance components.

Arrangement for clock supply of high bit rate switching network structures


A resin composition for laser engraving, including: a binder polymer; and a metal compound containing a metal selected from the group consisting of metals in Group 1 to Group 15 in the periodic table.

1. Field of the Invention
The present invention relates to a resin composition for laser engraving, an image forming material, a relief printing plate precursor for laser engraving, a relief printing plate, and a method of producing a relief printing plate.
2. Description of the Related Art
As a method of forming a printing plate by forming concavities and convexities on a photosensitive resin layer laminated on the surface of a support, a method called "analogue plate making" is well known in which a relief forming layer that is formed using a photosensitive composition is exposed to UV-light through an original image film so as to cure selectively image portions, and then uncured portions are removed with a liquid developer.
The relief printing plate is a printing plate with a relief layer having concavities and convexities. Such a relief layer having concavities and convexities is obtained by patterning a relief forming layer containing a photosensitive composition containing as a main component an elastic polymer such as synthetic rubber, a resin such as thermoplastic resin, or a mixture of resin and plasticizer, to form concavities and convexities thereon. Among these relief printing plates, a printing plate having a soft relief layer is referred to as a flexographic printing plate in some cases.
When the relief printing plate is produced by the analogue plate making, an original image film using a silver salt material is usually required, so that cost and time for the production of the original image film are also required. Further, a chemical treatment is required for the development of the original image film, and disposal of the waste liquid of the development process is also needed. Therefore, a still simpler method of producing the printing plate such as, for example, a method using no original image film or a method requiring no development process has been studied.
In recent years, a method of plate making by scanning light exposure of a relief forming layer, in which no original image film is required, has been studied.
As a technique that does not require an original image film, a relief printing plate precursor having a laser sensitive mask layer element that is capable of forming an image mask on a relief forming layer has been proposed (for example, see Japanese Patent No. 2773847 and Japanese Patent Application Laid-Open (JP-A) No. 9-171247). According to these methods of plate making of a plate precursor, an image mask having a function similar to that of an original image film is formed from the mask layer element by laser beam irradiation in accordance with image data, so that the method is called a "Mask CTP method", in which no original image film is needed, but in subsequent processes of plate making, light exposure using UV-light through the image mask is carried out, and uncured portions are removed by development. In view of the fact that a development process is still needed, there is room for improvement.
As a method of producing a printing plate that does not need a development process, there are many proposals about a so-called "direct engraving CTP method" in which a relief forming layer is engraved directly with a laser beam to produce a printing plate. In the direct engraving CTP method, engraving is carried out literally with a laser beam so as to form concavities and convexities that provide relief. The method has an advantage of controlling freely the shape of the relief as opposed to a method of forming relief using an original image film. Owing to this advantage, when an image like a cutout character is formed, the area thereof is engraved deeply as compared with the other areas, or in the case of a fine halftone dot image, engraving so as to form shoulders can be carried out considering the resistance to printing pressure.
However, when a relief having concavities and convexities that are resistant to printing pressure is formed on a relief forming layer that has a predetermined thickness, a high energy is required, and also, the speed of laser engraving is slow. Therefore, a problem of lower productivity as compared with a method of forming an image with a mask is brought about.
For this reason, improvement in the sensitivity of a relief printing plate precursor has been tried. For example, a flexo printing plate precursor for laser engraving that contains an elastomer foam has been proposed (see JP-A No. 2002-357907, for example). In this proposed technology, improvement in the engraving sensitivity is tried by using a low density foam for a relief forming layer. However, the resulting printing plate lacks strength because a low density material is used, thereby bringing about a problem of largely lowering the printing durability.
Further, for example, in Japanese Patent No. 2846954, and JP-A Nos. 11-338139 and 11-170718, a flexo printing plate precursor capable of being engraved with a laser beam or a flexo printing plate obtained by laser engraving is disclosed. In these documents, a flexo printing plate is obtained by mixing a monomer with an elastomer rubber as a binder, curing the resulting mixture by a heat-polymerization mechanism or a photo-polymerization mechanism, and then performing laser engraving.
As a problem of the direct engraving CTP method, slow speed in laser engraving may be mentioned. This is because the engraving depth is required to be at least 100 μm in the direct engraving CTP method in order to directly form relief, as opposed to the mask CTP method in which the thickness of the mask layer element to be ablated is about 1 μm to 10 μm.
For this reason, there are some proposals for improving the laser engraving sensitivity as described below.
For example, a flexo printing plate precursor for laser engraving that contains an elastomer foam has been proposed (for example, see JP-A No. 2000-318330). In this proposed technology, improvement in the engraving sensitivity is tried by using a low density foam. However, the resulting printing plate lacks strength because a low density material is used, thereby bringing about a problem of largely lowering the printing durability.
For example, a flexo printing plate precursor for laser engraving that contains microspheres encapsulating a hydrocarbon gas has been proposed (for example, see U.S. Patent Application Publication No. 2003/180636). In this proposed technology, improvement in the engraving sensitivity is tried by applying a system in which the gas encapsulated in the microspheres is expanded by heat generated with a laser beam and the material to be engraved is collapsed. However, a material containing gas bubbles is used, so that the strength as a printing plate is likely to be insufficient. In addition, since gas has a property of easily expanding by heat as compared with a solid, even if microspheres having a high thermal deformation initiation temperature are selected, changes in volume caused by changes in atmospheric temperature are unavoidable. For this reason, the material containing gas bubbles is not appropriate for a printing plate in which stable accuracy in thickness is required.
For example, a resin relief printing plate precursor for laser engraving that contains a polymer filler having a ceiling temperature lower than 600 K has been proposed (for example, see JP-A No. 2000-168253). In this proposed technology, improvement in the engraving sensitivity is tried by adding a polymer filler having a low depolymerization temperature. However, the polymer filler brings about unevenness on the surface of a resulting printing plate precursor, thereby providing a problem of having a significant influence on the printing quality.
As mentioned above, regarding a resin composition that can be appropriately applied to a relief forming layer of a relief printing plate precursor for laser engraving, various technologies have been proposed, but a technology having a high engraving sensitivity upon laser engraving has not yet been proposed.

Resin composition for laser engraving, image forming material, relief printing plate precursor for laser engraving, relief printing plate, and method of producing relief printing plate


A transmission device includes: a wavelength detector configured to detect a first wavelength of a first optical signal; a wavelength selective switch to which the first optical signal is input; and a controller configured to detect a direction toward which a central wavelength of a passband of the wavelength selective switch is shifted from the first wavelength detected by the wavelength detector and to control the wavelength selective switch so as to increase a width of the passband toward an opposite direction of the direction toward which the central wavelength of the passband is shifted from the first wavelength.

With an increase in demand for communication, optical networks that use wavelength division multiplexing (WDM) are widely used. WDM is a technique for multiplexing a plurality of optical signals with different wavelengths and transmitting the optical signals. For example, WDM enables 88 optical signals to be multiplexed and transmitted as a wavelength multiplexed optical signal (hereinafter referred to as multiplexed optical signal).
As a transmission device using WDM, an optical add-drop multiplexer (OADM) that is referred to as a reconfigurable optical add-drop multiplexer (ROADM) or the like is known. The optical add-drop multiplexer has a transceiver that transmits and receives optical signals. The transceiver is referred to as a transponder or the like.
The optical add-drop multiplexer multiplexes optical signals received from a transceiver and having arbitrary wavelengths and transmits the multiplexed signals to another node. The optical add-drop multiplexer separates an optical signal with an arbitrary wavelength from multiplexed optical signals received from the other node and outputs the optical signal through the transceiver. In other words, the optical add-drop multiplexer adds and drops an optical signal with an arbitrary wavelength.
The optical add-drop multiplexer has an optical amplifier and a wavelength selective switch (WSS) for each path.
The wavelength selective switch selects a specific wavelength from among received multiplexed optical signals and outputs an optical signal with the selected wavelength from an arbitrary port. The wavelength selective switch multiplexes optical signals input from an arbitrary port and outputs the optical signals as a multiplexed optical signal.
The wavelength selective switch has a filter for a passband of which the central wavelength is the selected wavelength (frequency). When a plurality of optical add-drop multiplexers are connected to each other, the width of a passband is reduced due to accumulated errors of the filters, and the spectrums of optical signals are narrowed.
The spectral width of an optical signal depends on a scheme for modulating the optical signal. The higher the bit rate, the larger the spectral width of the optical signal. For example, the spectral width of an optical signal transmitted at a high rate of 40 Gbps, 100 Gbps, or the like is large. When the large spectral width is reduced by filtering at multiple stages, an error rate may increase. Thus, the number of optical add-drop multiplexers that transmit an optical signal while maintaining the quality of the transmission at a certain level is limited.
Regarding narrowing of a spectrum, Japanese Laid-open Patent Publication No. 2010-98544 discloses that if a path is not assigned to wavelengths that are next shorter and longer than a wavelength of a certain path, a passband of a filter for the certain path is maximized for a wavelength selective switch. transmission device

Transmission device, transmission system, and method for adjusting passband


Boron nitride green sheets are made of boron nitride powder in an organic binder which leaves no undesirable residue upon pyrolysis in the absence of oxygen. These boron nitride green sheets can be placed on each side of the ceramic green sheet to form a composite for hot pressing ceramic green sheets containing ceramic powder to produce dense ceramic sheets suitable for electronic substrates.

When hot pressing ceramic green sheets, the binders for the green sheets must impart strength (and handleability) to the green ceramic sheet. In addition, a successful organic binder system must meet the requirement that it can be removed during heating such that no undesirable properties result from residues (e.g. carbon) which would be left in the ceramic after densification. This attribute of a binder is commonly referred to as "clean-burning" even if the binder removal does not involve oxidation. Note that the property of clean-burning is dependent upon the environmental conditions during firing. For instance, if conventional sintering is performed in air, the binder removal is assisted by the presence of oxygen, which provides the potential for oxidation of carboneous residues from thermal decomposition. Clean-burning of the binder becomes more difficult to achieve when sintering under non-oxidizing or reducing conditions, where oxidation is effectively eliminated. Hot pressing with graphite tooling (in non-oxidizing atmospheres) exacerbates the binder removal problem, since the graphite will compete with the binder residues for any oxygen in the atmosphere. Hence, the benefits from adding small quantities of oxygen or water vapor to facilitate binder removal (as is sometimes done through the addition of water vapor) is minimized. The problem of binder removal is further exacerbated during hot pressing by the fact that the green body is enclosed by the tooling, thus requiring the binder volatiles to escape through the crack between the rams and the die. Hence, there are long diffusion paths through the green compact for the binder volatiles. There is also little chance for control of the local atmosphere in this encapsulated system. From consideration of the remarks above, it is concluded that hot pressing places more constraints on the successful binder system than conventional sintering, and thus eliminates from consideration some organics which are considered to be clean-burning when employed for conventional sintering processes.
Another common problem to be overcome in hot pressing of ceramics is sticking of the ceramic to the graphite tooling after densification. Boron nitride (BN) powder is often used as an effective release agent for hot pressing ceramics with graphite tooling. It is commonly applied to the graphite surfaces (which would contact with ceramic powder) by painting or spraying a BN-containing slurry (e.g. U.S. Pat. No. 4,518,736). BN powder is useful because it does not readily react with either graphite nor many refractory ceramics and does not readily densify itself. This, coupled with its plate-like particle morphology, allows easy delamination of the ceramic from the graphite after hot pressing.
If a thicker BN layer is necessary (because of slight reactions between the BN and other materials or because of the need for a better barrier to carbon diffusion into the ceramic), BN powder can be formed into a green sheet using the same procedures as described previously for making green ceramic sheets. The binder system used for making the BN green sheet must meet the same criteria of strength and clean-burning nature as mentioned above for the ceramic green sheets. In Japanese Published Patent Application 61-10074 to Sadakata a boron nitride mold releasing sheet material is used for SiC hot press sintering. The sheet material has a binder containing thermoplastic resins as its major component such as polyvinyl butyral (PVB) or polyvinyl alcohol (PVA) and a plasticizer such as butyl butylphthalylacrylate or polyethylene glycol and peptidizer such as glycerin or octadecylamine. In order for the sheet to maintain a required strength and flexibility the approximate range of the composition is given as 82-88weight % of the mold-releasing material, 8-12 weight % of the binder, 4-6 weight % of the plasticizer, and less than 5 weight % of the peptidizing agent. For some applications, the PVB and PVA binders suggested by this Japanese patent may not be effective since they leave substantial residue upon pyrolysis in non-oxidizing atmospheres (see Figure). Residues from these binders could migrate to the material to be hot pressed and affect its resultant properties.


An investigative system uses positioning information, such as global position system information, from a non-resident device used for communication with a correctional facility inmate. Therein, a correctional facility communications application program upon installation on a non-resident communication device, prompts the non-resident to grant a waiver for an investigative data aggregation and analysis system associated with at least one correctional facility to access positioning information provided by the non-resident communication device, and prompts the non-resident to grant location reporting permission on the non-resident communication device, prior to use of the non-resident communication device to communicate with a correctional facility inmate. The investigative data aggregation and analysis system, thereafter, captures position data collected by the non-resident communication device. The investigative data aggregation and analysis system may analyze captured position data for a location of an event of investigative interest and provide an alert to an investigator, with the location.

According to the International Centre for Prison Studies, the United States has the highest prison population per capita in the world. In 2009, for example, 1 out of every 135 U.S. residents was incarcerated. Generally, inmates convicted of felony offenses serve long sentences in prison (e.g., federal or state prisons), whereas those convicted of misdemeanors receive shorter sentences to be served in jail (e.g., county jail). In either case, while awaiting trial, a suspect or accused may remain incarcerated. During his or her incarceration, an inmate may have opportunities to communicate with the outside world.
By allowing prisoners to have controlled contact with friends and family while incarcerated, the justice system aims to facilitate their transition back into society upon release. Traditional forms of contact include telephone calls, in-person visitation, conjugal visits, etc. More recently, technological advances have allowed jails and prisons to provide other types of visitation, including individual-to-individual videoconferences, which may be typically referred to as "video visitation," and online chat sessions.
Traditional communication services provide residents (inmates) of controlled-environment facilities (such as correctional facilities) a way to place outbound phone calls to non-residents of the controlled-environment facility. Additionally, non-residents can typically schedule video visitation with residents (inmates) of the controlled-environment facility. Other types of communication available to controlled-environment residents include the ability to exchange email and text messages between residents and non-residents of the controlled-environment facility. Basically, all of these forms of communication aim to facilitate communication between a resident of a controlled-environment facility and a non-resident.
Cellular phones are becoming the only home phones in an increasing number of U.S. households, a trend intensified by challenging economic conditions. The percentage of "wireless-only" phone use continues to grow on a national level. For example, preliminary results from the January-June 2017 National Health Interview Survey (NHIS) indicate more than one-half of American homes (52.5%) had only wireless telephones during the first half of 2017. Nearly three-quarters of all adults aged 25-34 were living in wireless-only households, and more than two-thirds (70.7%) of adults renting their homes were living in wireless-only households.
Additionally, over the past several years, the sharp increase in the U.S. inmate population has not been followed by a proportional increase in the number of prison or jail staff. To the contrary, budget pressures in local, state, and federal governments have made it difficult for correctional facilities to maintain an adequate number of wardens, officers, and other administration personnel. Hence, many correctional facilities are often unable to perform investigations with respect to their own inmates.

Investigation systems and methods employing positioning information from non-resident devices used for communications with controlled-environment facility residents


To improve energy efficiencies, supply circuits (1) for supplying switch circuits (2) have first supply modes for receiving first amounts of input power from sources (7) and providing first amounts of output power to output circuits (5) comprising control parts (3) of the switch circuits (2) and have second supply modes for receiving second amounts of input power and providing second amounts of output power. The first amounts of output power are larger than the second amounts of output power. The second amounts of input power are larger than zero and smaller than amounts of switch power necessary for operating the switch circuits (2). The switch circuits (2) may comprise relays for switching loads (8). The first amounts of input power may arrive via main contacts of the relays. Switches (47) may switch output signal levels. The relays may be bistable relays.

A prior art supply circuit receives first energy from a source and dissipates second energy and provides third energy to an output circuit. The output circuit may comprise a switch circuit for switching a load on and off. When being switched off, the load cannot consume energy. When being switched on, the load may consume energy. So, the switch circuit improves an energy efficiency of the load.

Supply circuit for supplying power to a switch circuit


In an optical connector having a housing defining an area surrounding a connection axis of the optical connector, the housing has a pair of slits spaced from each other and defining an elastic portion therebetween. A protruding portion protrudes from the elastic portion outward in a radial direction of the housing. A mounting portion is faced to the protruding portion with a space left therebetween.

This invention relates to an optical connector and, in particular, to an optical connector having a housing defining an area surrounding a connection axis. In the present specification and the appended claims, the "optical connector" should be broadly understood so as to include an adapter, a splicing module, and the like used in optical connection.
For example, Japanese Unexamined Patent Application Publication (JP-A) No. 2004-45622 discloses, as an optical adapter, an optical connector for use in connecting optical fibers. In the optical adapter, end portions of a pair of optical fibers are inserted into a pair of cylindrical ferrules, respectively. Axial end faces of the ferrules are faced to each other so that the optical fibers are spliced and optically connected to each other. The optical adapter is mounted to a panel by the use of a fitting bracket attached to a housing of the optical adapter.
In such a structure comprising the fitting bracket attached to the housing, the number of components is increased and an operation of attaching the fitting bracket is required. Since the fitting bracket is attached, it is difficult to reduce the size of the optical adapter. Further, in case where the housing is changed in design, it is necessary to change mold components for use in production of the housing and to use a new fitting bracket adapted to a new design of the housing. If the thickness of the panel is changed, it is necessary to alter the mold components in order to produce the housing adapted to the thickness of the panel. Thus, there is no degree of freedom with respect to the thickness of the panel.

Optical connector improved in mountability without an increase in number of components

Japan Aviation Electronics Industry, Limited


A first capacitive circuit is coupled to an output of a low drop-out (LDO) regulator. A second capacitive circuit is selectively coupled to a power supply signal circuit and arranged to store charge when the LDO regulator is deactivated. When the LDO regulator is activated, a portion of the charge on the second capacitive circuit is transferred to the first capacitive circuit. The LDO regulator provides an output when the charge associated with the first capacitive circuit reaches a predetermined level. The power-on time of the LDO regulator depends on the time required to increase the charges of the first capacitance circuit to the predetermined level from a level associated with the transferred charge from the second capacitive circuit. Also, the presence of the first capacitive circuit prevents noise associated with the power supply from being reflected at the output of the LDO regulator.

The present invention is generally related to voltage regulators. More particularly, the present invention is related to a circuit for improving power-on speed and power supply rejection ratio (PSRR) characteristics for a low drop out voltage (LDO) regulator.
Voltage regulators are often used to provide a relatively constant voltage source to other electronic circuits. Some regulators are limited in their effectiveness in a particular application. For example, some regulators have a high xe2x80x9cdrop-outxe2x80x9d voltage. A xe2x80x9cdrop-outxe2x80x9d voltage is the minimum voltage difference between the input voltage and the output voltage that is necessary to maintain proper regulation. Large drop-out voltages result in wasted power, and raise the minimum power supply requirements for maintaining regulation.
A low-drop-out regulator (hereinafter referred to as an xe2x80x9cLDO regulatorxe2x80x9d) is useful in applications where it is desired to maintain a regulated voltage that is sufficiently close to the input voltage. For example, LDO regulators are useful in battery-powered applications where the power supply voltage is exceedingly low.
A typical LDO regulator (500) is shown in FIG. 5. The LDO regulator (500) includes a PMOS transistor (MP50), a first resistor (R50), a second resistor (R51), and a voltage control block (510). The PMOS transistor (MP50) has a drain that is connected to an output terminal (VREG), a gate that is connected to node N50, and a source that is connected to an input voltage (VIN). The first resistor (R51) is series connected between the output terminal (VREG) and node N51. The second resistor (R52) is series connected between node N51 and a circuit ground (GND). The voltage control block (510) has three input terminals (VIN, VREF, SENSE) and an output terminal (PCTL). In the voltage control block (510), the first input terminal (VIN) is connected to the input voltage (VIN), the second input terminal (VREF) is connected to a reference voltage (VREF), and the third input terminal (SENSE) is connected to node N51. The output terminal (PCTL) of the voltage control block (510) is connected to node N50.
A load (ZL) is connected to the output terminal (VREG) of the LDO regulator (500). The LDO regulator (500) controls the gate of the PMOS transistor (MP50) to ensure that regulation of the output voltage (VREG) is maintained. The voltage control block (510) monitors the SENSE input terminal and controls the gate of the PMOS transistor (MP50) through the PCTL output terminal. Resistors R51 and R52 form a resistor divider that produces a signal that is related to the regulated output voltage (VREG). When the SENSE input terminal and the reference signal (VREF) are substantially the same, the LDO is properly maintaining regulation of the output voltage to the load (ZL).
Briefly stated, the present invention is arranged to provide an enhanced power-on speed for a low drop-out (LDO) voltage regulator while improving power supply rejection ratio (PSRR) performance. A first capacitive circuit is coupled to the output of the LDO regulator. A second capacitive is selectively coupled to a power supply signal circuit and arranged to store charge when the LDO regulator is deactivated. When the LDO regulator is activated, a portion of the charge on the second capacitive circuit is transferred to the first capacitive circuit. The configuration decreases the power-on time of the LDO regulator, and provides for improved PSRR characteristics.
In accordance with the present invention, an apparatus for providing improved power-on speed and power supply rejection ratio (PSRR) characteristics for a low drop-out (LDO) voltage regulator includes a low drop-out (LDO) voltage regulator that is configured to provide an output voltage to an output when activated. A first capacitive circuit is coupled to the output of the low drop-out (LDO) voltage regulator. A second capacitive circuit is selectively coupled to a power supply during a first cycle and selectively coupled to the first capacitive circuit during a second cycle. The first cycle corresponds to when the low drop-out (LDO) voltage regulator is deactivated, and the second cycle corresponds to when the low drop-out (LDO) voltage regulator is activated.
In accordance with another aspect of the invention, a first switch circuit is coupled between the second capacitive circuit and the power supply. A second switch circuit is coupled between the first capacitive circuit and the second capacitive circuit. The first switch circuit is closed and the second switch circuit is open during the first cycle. The first switch circuit is open and the second switch circuit is closed during the second cycle. A first resistor is coupled between the first switch circuit and the power supply. Current is provided to the second capacitive circuit across the first resistor when the first switch circuit is closed. The first switch circuit is responsive to a first control signal and the second switch circuit is responsive to a second control signal.
The invention may also be implemented as methods that perform substantially the same functionality as the embodiments of the invention discussed above and below.
A more complete appreciation of the present invention and its improvements can be obtained by reference to the accompanying drawings, which are briefly summarized below, to the following detail description of presently preferred embodiments of the invention, and to the appended claims.


An in-situ interferometer includes an image modifying optic that produces light ray bundles. The light ray bundles are projected onto a reticle with a plurality of measurement fiducials encoded onto a face of the reticle. The measurement fiducials are exposed onto a sensing plane and their locations measured. Aberrations in the projection system are determined from the measurements of the exposed reticles.

1. Field of the Invention
The present invention relates generally to processes for semiconductor manufacturing and more particularly to characterizing and monitoring lithographic projection lenses in-situ.
2. Description of the Related Art
Projection imaging systems, also referred to as lithographic projection systems, have many uses in various industries. For example, lithographic projection systems are used to produce patterns on semiconductor materials for use as integrated circuits and flat panel displays. The performance of lithographic projection systems greatly influences the manufacturability and cost of manufacturing semiconductor chips and flat panel displays.
In general, the performance of lithograph projection systems is limited because of aberrations, which are the deviation of a projection lens' performance from a "perfect" lens or from the diffraction limit. As the resolution required from lithography projection systems increases, for example as low as 100 nm and below, the ability to measure the state of the optical aberration of projection lenses becomes increasingly important. For example, aberrations as small as 10 milliwave (mλ) or less can cause significant shifts and distortions in patterns.
Techniques have been developed to compensate for aberrations in lithography projection systems. For example, distortion and field curvature data from images exposed using a lithography projection system are used to design "figured" optical surfaces that are placed in the optical path of the projection system to compensate for aberrations of projection systems. A drawback to these techniques is that they only consider distortion and field curvature aberrations. Distortion and field curvature correspond to the lowest order aberrations of an imaging system, namely field dependent tilt and focus. In order to ascertain the degree of correction and method of correction useful for higher order aberrations, data in addition to distortion and field curvature are needed.
Application of a conventional interferometer to a projection imaging system can provide high quality wavefront data. However, a drawback to use of a conventional interferometer is that it requires removing, or significantly altering or disturbing, the lens column of the lithographic projection system. Removal of the lens column can introduce uncertainties into the measurement and require significant downtime from productive operation.
Due, at least in part, to the drawbacks in using a conventional interferometer in-situ, techniques have been developed for determining distortion, field curvature, best focus, astigmatism, and the aerial image of a projection imaging system in-situ. Of these various in-situ techniques, the greatest amount of information is usually provided by in-situ aerial image measurements. However, a drawback to in-situ aerial image measurements is that the light level is generally low, leading to long exposure times or poor signal to noise ratios. In addition, the reconstruction of the aberrated wavefront is ambiguous unless several out of focus exposures are performed.
Thus, there is a need for an improved technique to measure the optical aberrations of lithography projection systems. The present invention satisfies this need


A method for establishing a connection is provided. The method includes the following steps. A mobility management entity generates a create bearer context request message and sends the message to a selected serving gateway. The create bearer context request message at least includes address information of at least one packet data network gateway and corresponding indication information of the protocol type of connection establishment. The serving gateway receives and analyzes the create bearer context request message, and determines the protocol type of the connection according to the indication information of the protocol type of connection establishment. The serving gateway processes the create bearer context request message with the determined protocol type of connection. A mobility management entity, a serving gateway, and a network system which are able to reduce time delay when connection is established are further provided.

In order to increase the competitiveness of future mobile networks, the 3rd generation partnership project (3GPP) is researching a future network architecture. The network architecture includes an SAE at a network side and an evolved universal terrestrial radio access network (E-UTRAN) (i.e. LTE) at a wireless side. The structure of an evolved packet system (EPS) is as shown in FIG. 1, and includes at least three logical function entities, i.e., a mobility management entity, a serving gateway, and a packet data network gateway. The mobility management entity is in charge of mobility management of control-plane, which includes management of user context and mobility status, temporary user identity assignment, security function, etc. The serving gateway is a mobile anchor point for local inter base station handover and inter 3GPP access system handover, and is in charge of managing and storing IP bearer parameters and network routing information, lawful interception, etc. The packet data network gateway is a gateway towards the external network, and is in charge of realizing policy-based management, user-based packet filtering, accounting, lawful interception, user IP address assignment, etc., and therefore serves as a user-plane anchor point among different access systems. Subscription information of users is stored in a home subscriber server (HSS).
A protocol used for an interface between the serving gateway and the packet data network gateway may be the general packet radio service (GPRS) tunneling protocol (GTP), or the proxy mobile IP protocol (PMIP).
Although manners for establishing connections by using different protocols are defined in different transfer services (TS) respectively, in a process of practical network deployment and upgrade, the serving gateway may support multiple connection protocols (for example, the GTP and the PMIP) at the same time, while the packet data network gateway only supports one of them (for example, the GTP). Under this situation, a connection between the serving gateway and the packet data network gateway is usually established by using the following manners.
The serving gateway uses one connection protocol to initiate a connection establishment request to the packet data network gateway. When the packet data network gateway does not support such a protocol, no response is received. After timeout, the serving gateway considers to use another connection protocol again to initiate the connection establishment request. When implementing the present invention, the inventor discovers a disadvantage of such a manner: if the connection protocol selected by the serving gateway first time is a connection protocol not supported by the packet data network gateway, a time delay when the connection is established successfully will be extended.
Or, the serving gateway may use multiple protocols supported by the serving gateway at the same time to initiate the connection establishment request to the packet data network gateway. The packet data network gateway selects one or all of the protocols for responses according to its own ability. The serving gateway selects one response message that first reaches to establish a connection. When implementing the present invention, the inventor of the present invention discovers a disadvantage of such a manner: for a serving gateway that supports multiple protocols, more processing is required. Also, such a mechanism that a sender sends multiple messages of the same function but with different protocols regardless of the ability of the receiver will consume more processing resources.

This patent is subject to a terminal disclaimer.

Method, apparatus and system for establishing connection


An optical device has at least one reflector disposed in an optical cavity. The reflector has a plurality of mirror pairs each comprising a pair of layers, each layer of each mirror pair having an index of refraction different than that of the other layer of the respective mirror pair. A tuning layer is disposed in the reflector, the tuning layer having an index of refraction different from that of the layers of the mirror pairs. In another embodiment, the reflector has first and second adjacent reflector sections, each reflector section having a respective plurality of mirror pairs where the difference in refractive index of a mirror pair""s layers defines a refractive index contrast for the mirror pair. The mirror pairs of the first reflector section have a refractive index contrast different than that of the second reflector section, and a tuning layer is disposed in the optical cavity adjacent to the second reflector section and having an index of refraction different from that of the layers of the mirror pairs of the second reflector section.

1. Field of the Invention
This invention relates generally to laser manufacturing and, more particularly, to vertical cavity surface-emitting lasers (VCSELs).
2. Description of the Related Art
In many applications, it is desirable to have lasers capable of producing light at several different wavelengths that are closely spaced. In particular, for optical communication applications, such as wavelength division multiplexing (WDM), many wavelengths spaced a few nanometers apart are useful. There are several possible ways to make wavelength-selectable arrays with edge-emitting semiconductor lasers. However, edge-emitting semiconductor lasers that meet specifications for telecommunication applications are typically complex and expensive to manufacture. Monolithic edge-emitting semiconductor laser arrays with large numbers of wavelengths are impractical technically and economically.
Vertical cavity surface-emitting lasers (VCSELs) provide a more cost effective solution for many applications. Vertical cavity surface-emitting lasers (VCSELs) can be made using wafer-scale processing and testing, dramatically lowering the cost in comparison to edge-emitting semiconductor lasers, for example. In a vertical cavity surface-emitting laser (VCSEL), the wavelength may be determined by the optical cavity length. The optical cavity length is the effective distance between the two generally parallel mirrors, typically distributed Bragg reflectors (DBRs), enclosing the active region of the vertical cavity surface-emitting laser (VCSEL). Since the optical cavity length is typically set by the epitaxial growth, which should be uniform across the entire wafer or workpiece, the wavelength is uniform.
Tunable vertical cavity surface-emitting lasers (VCSELs) are desired in order to provide different wavelengths on the same wafer or workpiece. One conventional approach to providing tunable vertical cavity surface-emitting lasers (VCSELs) uses a top mirror that is suspended on a micromachined cantilever. With this conventional structure, any given vertical cavity surface-emitting laser (VCSEL) can be tuned to any wavelength within the tuning range. However, this conventional approach involves a micromachined structure that is difficult to fabricate, has reliability problems and is susceptible to mechanical vibrations. A more reliable way of providing monolithically integrated vertical cavity surface-emitting laser (VCSEL) arrays is still needed.
In a vertical cavity surface-emitting laser (VCSEL), the lasing wavelength may be determined by the length of a Fabry-Perot cavity formed by two distributed Bragg reflectors (DBRs) separated by the semiconductor optical cavity active region that includes layers with optical gain. The optical gain in a vertical cavity surface-emitting laser (VCSEL) is typically provided by quantum wells. Each quantum well has a gain spectrum with a single peak wavelength, and some spectral width over which gain is present. Each distributed Bragg reflector (DBR) is composed of quarter-wave layers of alternating high and low refractive indices. The distributed Bragg reflector (DBR) reflectivity is characterized by a complex amplitude and phase spectrum. The amplitude spectrum exhibits a high reflectivity region at the center of which the reflectivity is highest. The width of the high reflectivity region is referred to as the distributed Bragg reflector (DBR) stop-band width. The phase characteristic of the distributed Bragg reflector (DBR) varies approximately linearly over the stop-band width. The lasing wavelength of a vertical cavity surface-emitting laser (VCSEL) is determined by the optical length of the semiconductor cavity and the phase characteristics of the distributed Bragg reflectors (DBRs). The gain provided by the active layer, necessary to achieve lasing (threshold gain) is determined by the roundtrip cavity loss that includes material absorption and the distributed Bragg reflector (DBR) transmission. A monolithic multiple-wavelength vertical cavity surface-emitting laser (VCSEL) array requires side-by-side fabrication of vertical cavity surface-emitting lasers (VCSELs) with varying lasing wavelengths, but otherwise uniform laser characteristics, such as threshold gain and current, and efficiency. This implies that the vertical structure of the lasers must vary from device to device on the same wafer, while the cavity losses, material gain, and the distributed Bragg reflector (DBR) transmission remain largely unchanged. The lasing wavelength variation is most commonly realized by changing the optical length of the semiconductor cavity.
One conventional method of making a monolithic multiple wavelength vertical cavity surface-emitting laser (VCSEL) array uses non-uniform growth due to a thermal gradient. The backside of a substrate is patterned prior to epitaxial growth in a molecular beam epitaxy (MBE) reactor. The resulting backside pattern produces a thermal gradient on the surface of the substrate when the wafer is heated. Because growth rate is temperature dependent, there is a variable material thickness and, hence, a variable laser wavelength along the thermal gradient. One disadvantage of this conventional approach is the fact that the arrays are limited to linear geometries. To date, it has been difficult to control the wavelengths precisely and repeatedly over large areas of the wafer.
Another conventional method is to grow a partial vertical cavity surface-emitting laser (VCSEL) structure including the lower distributed Bragg reflector (DBR), the active region, and some part of the upper distributed Bragg reflector (DBR). The wafer is masked and anodically oxidized to some controlled oxide thickness over the exposed portions. A selective etch is then used to remove the oxide. This process is repeated to create different effective cavity lengths for each laser in an array. The remainder of the vertical cavity surface-emitting laser (VCSEL) structure is regrown over the patterned wafer. However, each selective etch is sensitive to voltage and concentration variations that may affect the depth, resulting in reduced control over wavelength spacing between devices in the array.
Yet another conventional method of making a monolithic multiple wavelength vertical cavity surface-emitting laser (VCSEL) array is described, for example, in U.S. Pat. No. 6,117,699 to Lemoff et al. (xe2x80x9cthe Lemoff et al. ""699 patentxe2x80x9d), describing an array of N-wavelength vertical cavity surface-emitting lasers (VCSELs) that can be grown with wavelength control. First, as shown in FIG. 1, a foundation vertical cavity surface-emitting laser (VCSEL) structure 100 is grown on a gallium arsenide (GaAs) substrate 105. The foundation vertical cavity surface-emitting laser (VCSEL) structure 100 includes a lower distributed Bragg reflector (DBR) 110 in an optical cavity 145. The lower distributed Bragg reflector (DBR) 110 includes M pairs of layers 115, 120, 125, 130, 135 and 140 (M=6, in FIG. 1), each member of each pair having an index of refraction differing from the other member of each pair. For example, the lower member 115a of the pair 115 may comprise aluminum arsenide (AlAs) and the upper member 115b of the pair 115 may comprise aluminum gallium arsenide (AlxGalxe2x88x92xAs, where 0.15 less than x less than 1).
The optical cavity 145 also includes a first intrinsic (non-doped) layer 150, an optical gain layer 155 and a second intrinsic (non-doped) layer 160. The optical cavity 145 also includes N-paired semiconductor phase shift epitaxially grown layers 165, 170, 175 and 180 (N=4 in FIG. 1) of aluminum gallium arsenide (AlGaAs) and indium gallium phosphide (InGaP), where N is the desired number of different wavelengths.
Next, a region of one of the N-paired semiconductor phase shift layers is lithographically patterned (masked and etched). For example, as shown in FIG. 1, a mask 185 is formed and portions 190 and 195 (shown in phantom) of the paired semiconductor phase shift epitaxially grown layer 180 are removed by selective etching. The steps of patterning (masking and etching) are repeated for a total of at least (Nxe2x88x921)/2 patterning (masking and etching) steps until regions of at least Nxe2x88x921 of the N-paired semiconductor phase shift layers are etched. For example, as shown in FIG. 2, a mask 200 is formed and portions 205 and 210 (shown in phantom) of the paired semiconductor phase shift epitaxially grown layers 170, 175 and 180 are removed by selective etching, forming 4 different effective optical cavity lengths corresponding to 4 different lasing wavelengths.
Finally, an upper vertical cavity surface-emitting laser (VCSEL) structure (not shown) is grown. The upper vertical cavity surface-emitting laser (VCSEL) structure may include an upper distributed Bragg reflector (DBR) similar to the lower distributed Bragg reflector (DBR) 110, but typically having fewer than M pairs of layers, each member of each pair having an index of refraction differing from the other member of each pair. The upper distributed Bragg reflector (DBR) typically has fewer than M pairs of layers so that the reflectivity of the upper distributed Bragg reflector (DBR) is less than the reflectivity of the lower distributed Bragg reflector (DBR) 110. Equivalently, the transmissivity of the upper distributed Bragg reflector (DBR) is greater than the transmissivity of the lower distributed Bragg reflector (DBR) 110. Consequently, more laser photons are emitted from the upper surface (not shown) of the vertical cavity surface-emitting laser (VCSEL) than into the substrate 105.
However, this Lemoff et al. ""699 patent method necessarily requires at least (N-1)/2 masking steps, to produce an array of N-wavelength vertical cavity surface-emitting lasers (VCSELs). For a large number N of wavelengths, such methods may become expensive, unwieldy, impractical and inefficient and may suffer from a loss of yield.
For example, as shown in FIG. 3, a foundation vertical cavity surface-emitting laser (VCSEL) structure 300 is grown on the gallium arsenide (GaAs) substrate 105. The foundation vertical cavity surface-emitting laser (VCSEL) structure 300 includes the lower distributed Bragg reflector (DBR) 110 and an optical cavity 345. The optical cavity 345 includes the first intrinsic (non-doped) layer 150, the optical gain layer 155 and the second intrinsic (non-doped) layer 160. The optical cavity 345 also includes N-paired semiconductor phase shift epitaxially grown layers 165, 170, 175, 180, 365, 370, 375 and 380 (N=8 in FIG. 3) of aluminum gallium arsenide (AlGaAs) and indium gallium phosphide (InGaP), where N is the desired number of different wavelengths.
Next, a region of one of the N-paired semiconductor phase shift layers is lithographically patterned (masked and etched). For example, as shown in FIG. 3, a mask 305 is formed and portions 390 and 395 (shown in phantom) of the paired semiconductor phase shift epitaxially grown layer 380 are removed by selective etching. The steps of patterning (masking and etching) are repeated for a total of at least (Nxe2x88x921)/2 patterning (masking and etching) steps until regions of at least Nxe2x88x921 of the N-paired semiconductor phase shift layers are etched. For example, as shown in FIG. 4, a mask 400 is formed and portions 405 and 410 (shown in phantom) of the paired semiconductor phase shift epitaxially grown layers 370, 375 and 380 are removed by selective etching. Then, as shown in FIG. 5, a mask 500 is formed and a portion 505 (shown in phantom) of the paired semiconductor phase shift epitaxially grown layer 365 is removed by selective etching. Finally, two more patterning steps (similar to those shown in FIGS. 1 and 2) may be performed to remove respective portions (similar to the portions 190, 195, 205 and 210 shown in FIGS. 1 and 2) from the paired semiconductor phase shift epitaxially grown layers 170, 175 and 180 by selective etching, forming 8 different effective optical cavity lengths corresponding to 8 different lasing wavelengths, but using as many as 5 patterning steps.
Resonant optical cavities are used in many devices including vertical cavity surface-emitting lasers (VCSELs), optical filters (such as band-pass filters), resonant cavity-based optical devices, resonant cavity-based opto-electronic devices and resonant cavity-enhanced photodetectors. The general structure of such a device consists of a cavity region including a reflector on each end of the device. These reflectors are often distributed Bragg reflectors (DBRs) that are made from multiple pairs of material with alternating refractive indices. The higher the contrast in material index of refraction, the lower the number of mirror pairs that are required to achieve the desired reflectivity. For many structures these layers are made from semiconductors whose refractive indices tend to be similar. It is also possible, and in some cases desirable, to fabricate the top reflector using dielectric materials with a greater contrast than is available using distributed Bragg reflectors (DBRs) made entirely of semiconducting materials.
There are also applications, in optical communication for instance, where it is desirable to have arrays of lasers, filters, or detectors with closely-spaced wavelengths. The wavelength may be changed by altering the effective cavity length of the device. The effective cavity length at a given wavelength is determined by the layer thicknesses and material properties in the optical cavity and the phase shift due to the reflectors. There are previous approaches (U.S. Pat. No. 6,117,699) in which the optical cavity length is adjusted by varying the thickness of material within the optical cavity. This can be achieved by depositing and selectively removing layer thicknesses within the optical cavity. This approach relies on the epitaxial growth of a specific pair of semiconductor materials to achieve the precision and etch selectivity required. However, this approach limits the technique to a specific range of wavelengths.
The sensitivity of the resonant (for example, the lasing) wavelength depends in part on the distributed Bragg reflector (DBR) materials utilized. However, the choice of distributed Bragg reflector (DBR) materials is often dictated by other concerns (compatibility with device operation, compatibility with the processing, reliability, and the like). Since the required sensitivity depends on the desired wavelength spacing for the particular application, it would be desirable to be able to adjust the sensitivity of the optical cavity to the thickness of the tuning layers. In particular, for improved process control, it would often be desirable to decrease the sensitivity of the wavelength to variations in the tuning layer thickness.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
In one aspect of the present invention, a method is provided, the method comprising forming an optical cavity for an optical device and forming at least one reflector for the optical cavity for the optical device, the at least one reflector having at least two sections. The method also comprises providing at least one of a tuning layer between the at least two sections of the at least one reflector and different refractive index contrasts for the at least two sections of the at least one reflector.
In another aspect of the present invention, a device is provided, the device comprising an optical cavity for an optical device, the optical cavity having at least one reflector having at least two sections. The device also comprises at least one of a tuning layer between the at least two sections of the at least one reflector and different refractive index contrasts for the at least two sections of the at least one reflector.

Modified distributed bragg reflector (DBR) for vertical cavity surface-emitting laser (VCSEL) resonant wavelength tuning sensitivity control


A mobile X-ray apparatus including a main body portion, a mobile dolly on which the main body portion is mounted, a support pole that is erectly provided on the mobile dolly, an X-ray generator supported on the support pole, and an image reading device for reading image information from an imaging plate in which X-ray image information is stored, and further including detecting means for detecting whether the mobile dolly is being moved, and reading control means for prohibiting reading of the image reading device when it is detected by the detecting means that the mobile dolly is being moved.

Needs for picking up images of patients who are difficult to move from hospital rooms, urgently picking up images in an operating room, etc. have recently increased in medical fields, and a mobile X-ray apparatus which is movable to a hospital room or the like to perform X-ray imaging has been broadly popular. Recently, a mobile X-ray apparatus having an image reading device for reading image information from IP is being put into practical use so that a picked up X-ray image is immediately checked at an image pickup place to determine at that place whether re-imaging is required or not.
For example, Patent Document 1 discloses an X-ray apparatus for doctor's round visits which is equipped with an image information reading device for reading image information accumulated in IP. According to this X-ray apparatus for doctor's round visits, image information read out by the image information reading device is transmitted to a CRT display fixed on a top surface of a main body to display an X-ray image.
The image reading device scans a laser beam in a main scan direction (a direction perpendicular to an auxiliary scan direction) while feeding IP in the auxiliary scan direction to successively scan the whole IP surface and detect photostimulable emission light at each point, thereby reading image information. In order to obtain an accurate image, it is important to perform the feeding of IP and the laser scanning accurately with high precision, and it is not preferable that vibration, impact or inclination is applied when image information is read.    Patent Document 1: JP-A-4-190224


The invention relates to imaging, such as in situ imaging by expansion microscopy, labelling, and analyzing biological samples, such as formalin fixed paraffin embedded (FFPE) cells and tissues, as well as reagents and kits for doing so.

In situ transcriptional profiling of clinical formalin fixed paraffin embedded (FFPE) tissues has the potential to contribute to the development of accurate and reliable diagnoses for diseases, such as cancer. However the analysis of ribonucleic acid (RNA) within clinical samples is currently constrained by the diffraction limit of conventional microscopes which reduce the accuracy of RNA spot count quantification. Additionally, the limited number of transcripts (typically 3-4 depending on the number of available fluorescent channels) further reduces the ability to systematically map transcriptional variations across a large number of genes.
Current imaging technologies for analyzing RNA in clinical samples include RNA fluorescent in situ hybridization combined with conventional paraffin removal (e.g., Hughes et al., Anal. Methods [2014] 6:1028) and antigen retrieval, followed by widefield or confocal imaging. Techniques for transcriptional profiling of complex tissues include confocal microscopy or super-resolution microscopy of RNA in situ hybridization targets, either via RNA fluorescence in situ hybridization (FISH) (e.g., Chaumeil et al., "Combined Immunofluorescence, RNA Fluorescent In Situ Hybridization, and DNA Fluorescent In Situ Hybridization to Study Chromatin Changes, Transcriptional Activity, Nuclear Organization, and X-Chromosome Inactivation" (ch. 18, pp. 297-308) in R. Hancock (ed), The Nucleus: Vol. 1: Nuclei and Subnuclear Components [Humana Press 2008]), or via RNA hybridization chain reaction (HCR) (e.g., Dirks & Pierce, Proc. Natl. Acad. Sci. [2004] 101(43): 15275; U.S. Pat. Nos. 7,727,721, 8,124,751, and 8,507,204; Choi et al., ACS Nano. [2014] 8(5): 4284; Shah et al., Development [2016] 143:2862).
In expansion microscopy (ExM), 3-dimensional imaging with nanoscale precision is performed on cells and tissues. This is accomplished by physically expanding the biological sample using a dense polymer matrix. The first step of this process involves treating the tissue with a fluorescent protein-binding-group (typically an antibody) that selectively binds to the protein being analyzed. Next the sample is infused with a monomer solution that permeates into the tissue. Free radical polymerization of this solution creates a polymer network that is physically connected to the protein-binding-groups through customized bioconjugation chemistry. Lastly, the tissue is digested and the hydrogel (and fluorescent dyes) expands uniformly. The result is a polymer network that contains fluorescent dyes where the target proteins were located. This process has many advantages. Notably, it allows pseudo super-resolution imaging with conventional confocal microscopy because the imaging targets are no longer diffraction limited. Additionally, the tissue digestion clears the sample allowing imaging deep into thick tissues samples. (See, e.g., LeGoff et al., Eur. Polym. J. [2015] http://dx.doi.org/10/1016/j.eurpolymj.2015.02.022)
Critical to the success of the ExM process is the ability to physically connect the fluorescent protein-binding-groups to the polymer network. Current ExM attachment chemistry uses a trifunctional, double-stranded DNA linker to accomplish this. Because the tissue digestion enzymes are also capable of digesting the antibodies typically used as protein-binding-groups, the fluorescent dyes must be attached to the DNA and not the antibody. Also needed is the presence of a chemical group that can polymerize into the gel matrix. Current examples of ExM use a chemical arrangement in which one strand of DNA is connected to the protein-binding-group while the complementary strand possesses both the dye and the polymerizable group. Using this strategy, cells and brain tissue were successfully stained with up to 3 different protein-binding-groups, expanded, and imaged (Chen et al., Science 347:543 [2015]; Chen et al., "Nanoscale Imaging of RNA with Expansion Microscopy," Nature Methods 13:679 [2016]). However, because the number of fluorescent dyes that can be used is small (typically <6), this strategy is limited to imaging only a small number of proteins per sample. Additionally, the polymerization process dampens the fluorescence of the dyes, which are permanently connected to the gel matrix. By rearranging the location of the three chemical groups (dye, gel binding group, and protein-binding-group) on the DNA linker, previous limitations in protein imaging some previous limitations have been overcome.
However, use of DNA/antibody conjugates has also had several disadvantages. Buffers with uncommon additives are necessary in order to prevent the DNA on the antibody from binding to the nuclear DNA in the sample. Also, the presence of the DNA on the antibody reduces the extent and the rate at which it binds to the target. The result is that the current ExM processes are lengthy, and the staining is commonly dim compared to controls, making this approach laborious, time consuming, and inefficient for RNA detection due to the limited number of transcripts which can be resolved within a single specimen.
Alternatively, attempts have been made to overcome problems of ExM with respect to dim staining by utilizing an improved bioconjugation strategy or by utilizing turbo-expansion microscopy (TurboExM), which does not use DNA as a linker, and samples can be rapidly stained. TurboExM relies on antibodies, which can be directly acrylated (and hence suitable for polymerization), either before, after, or at the same time as attachment with a detectable label, but also that the detectable label will remain after the tissue digestion step, which is necessary for ExM. However, this approach is suitable for protein targets but not RNA detection.
The interrogation of RNA in clinical samples in a highly multiplexed and efficient manner remains a challenge in structural biology and medicine.
Surprisingly, it has been found that by combining serial RNA hybridization strategies with ExM, it is possible to read multiplexed RNA transcript data from FFPE clinical tissue samples. This approach allows for high speed transcriptional profiling of a large number of genes in clinical samples for diagnostic, prognostic and other purposes.

Expansion microscopy compatible and multiplexed in situ hybridization of formalin fixed paraffin embedded tissue sections for spatially resolved transcriptomics


In a constant rate discharge pump, a rotary drive source is disposed on an end of a housing, and on the other end of the housing, a pump head is provided, having a pump chamber into which a fluid is drawn, and a filling chamber filled with an indirect medium. Further, a displacement mechanism having a displacement nut which is displaced under a driving action of the rotary drive source is disposed in the interior of the housing. A bellows is interposed between a tubular body connected to the displacement nut and a first block of the pump head, wherein the interior of the bellows also is filled with the indirect medium, which is made up from an incompressible fluid. Furthermore, a flexible diaphragm is disposed in the pump head between the fluid and the indirect medium.

1. Field of the Invention
The present invention relates to a pump apparatus, which is capable of discharging a fluid continuously at a constant rate through a displacement mechanism under a driving operation of a driving element.
2. Description of the Related Art
Heretofore, a constant rate ejection pump has been adopted for supplying a medicinal, a coating, a cleaning solution or the like at a constant rate in a manufacturing apparatus of a semiconductor or the like, a coating apparatus, a medical device, etc.
The present applicant, as disclosed in Japanese Laid-Open Patent Publication No. 2006-029302, has proposed a pump apparatus in which a pump chamber is formed in the interior of a body having a suction port through which a fluid is drawn in and a discharge port through which the fluid is discharged. A piston is displaced along a first chamber inside the body under the action of a pilot pressure. Together therewith, an indirect medium formed from an incompressible fluid is pressed by the piston, and a diaphragm, which is disposed alongside the indirect medium, is flexed, whereupon the fluid filled in the pump chamber is pressed on by the diaphragm and discharged.


Provided is a leg retention clip for a leg of a tripod and a tripod assembly that includes the leg retention clip. The leg retention clip can be inserted inside a hollow-out inside of a first leg section with slots/holes which output protruding edges of the leg retention clip. When a second leg section is fitted over the first leg section, the protruding edges of the leg retention clip can stop movement of the second leg section and help lock the second leg section in place with respect to the first leg section. If the leg of the tripod includes more than two leg sections, the leg can be provided with multiple leg retention clips.

A tripod is often used to stabilize and elevate an object such as a camera, a scope, a rifle, and the like. In some cases, the legs of the tripod may be retractable. Here, the legs may include a plurality of tubular sections with different diameters. For example, an upper tubular section at the top of the leg may have the largest diameter enabling the upper tubular section to slide over and hide the lower tubular sections of the leg. When in use, the lower tubular sections may be pulled out to a desired length and locked using leg locks. When finished, the lower tubular sections may be collapsed into the upper tubular section allowing the tripod to be compactly stored.
Shims are commonly used on the exterior of the tubular sections of the leg to prevent the leg sections from becoming completely detached from one another. For example, one or more shims may be attached around an exterior of a lowest tubular leg section to stop the lower leg section at its longest point of extension. However, plastic shims are not durable. In cold temperatures, a plastic shim can become brittle and break. Furthermore, plastic shims are attached to an outer surface of the lower tubular section. This requires the next/upper tubular section to loosely fit around the lower tubular section to make room for the shims. Because of the loose fit, the tripod can wiggle when in use.


A guide wire for a catheter is inserted for use into the catheter and has a wire body, a reshapeable shaping ribbon (wire material) mounted such that a part of the base end side of the shaping ribbon is fixed to the front end side (small diameter section) of the wire body and a part of the front end side of the shaping ribbon extends in the direction to the front end of the guide wire from the front end of the wire body, and a helical coil installed so as to cover both the front end side of the wire body and the shaping ribbon. The coil is divided into a first coil and a second coil, and the first coil is divided into a fine pitch section and a rough pitch section. The bending rigidity of the fine pitch section is greater than that of the rough pitch section.

In the past, a catheter has been introduced into a blood vessel in order to examine or cure a heart disease or the like. To introduce such a catheter to a target site in a body, a guide wire is inserted into the catheter and a distal end of the guide wire is allowed to go ahead. The distal end of the guide wire is allowed to reach the target site and thereafter the catheter is guided to the target site.
In particular, in PCI (Percutaneous Coronary Intervention), while selecting a branch of a coronary artery under radiographic guidance, the distal end of the guide wire is allowed to reach a vascular narrowing portion as a target site and passed through it. Thereafter, an expansion catheter equipped with a balloon at a distal end is inserted along the guide wire and the balloon of the expansion catheter is located at the vascular narrowing portion. The balloon is expanded to push and widen the vascular narrowing portion to ensure blood flow. In this way, a treatment for angina or the like can be performed.
In such an treatment, to insert the guide wire from a femoral artery and advance it to an aorta, an aortic arc and a coronary artery, the guide wire requires the following: flexibility and restoring performance for following the shape of a blood vessel, indentation performance and torque transmissibility (generically referred to as "operability") for reliably transmitting to a distal end force encountered when a proximal portion of the guide wire is pressed, anti-kink performance (anti-bending performance), etc.
To advance the guide wire from a branch portion of the coronary artery to a desired branch, shaping in which the distal end of the guide wire is shaped to conform to the shape of the branch portion is performed with fingers. Such work is called reshaping.
For example, if a guide wire is inserted into a peripheral side coronary artery, a conventional distal shape such as an angle-type or J-type preliminarily molded cannot select a desired branch. Because of this, the distal end of the guide wire is formed in advance into a desired shape for insertion in many cases. If such a shape still does not conform to the desired branch, the guide wire is once removed from the catheter and reshaped.
As the reshapeable guide wire, a guide wire is proposed that includes e.g. a superelastic core material; a reshaping member secured to the vicinity of the distal end of the core material; and a coil obtained by helically forming a raw-wire and installed to cover the distal end of the core material and the reshaping member. (See e.g. patent document 1.) In this guide wire, also the coil is secured to the vicinity of the distal end of the core material together with the reshaping member. The guide wire described above is such that the distal end can be reshaped by the function of the reshaping member.
The reshaping member disclosed in patent document 1 is formed rectangular in transverse section; therefore, it is called a shaping ribbon. This shaping ribbon is formed of a material tending to be plastically deformed, such as stainless steel or the like.
However, the guide wire provided with such a shaping ribbon has a large difference between the bendability (bending rigidity) of the superelastic core material and the bendability (bending rigidity) of the shaping ribbon, which results in that the joint portion between both causes stress resulting from the difference of the bendability (bending rigidity). If the stress concentrates, the shaping ribbon is bent in the vicinity of the joint portion so that the function as the guide wire is impaired.
The guide wire described in patent document 1 is provided with a coil obtained by helically forming a raw-wire. The raw-wire is different in pitch between both sides of the joint portion mentioned above. However, in the coil, the pitch of the raw-wire is rough on the distal end side of the joint portion but fine on the proximal end side thereof. Therefore, the difference in the pitch of the raw-wire in the coil described above acts to further increase the stress resulting from the difference in the bendability (bending rigidity) between the core material and the shaping ribbon described above.
Because of this, the guide wire described in patent document 1 has a concern that because of bending, the shaping ribbon does not sufficiently function in a bent blood vessel.    Patent Document 1: Japanese Patent Laid-open No. Hei 4-292174


A method for establishing a radio connection between radio communication devices, has the operations of (1) operating a first connection switch in a first radio communication device, (2) operating a second connection switch in a second radio communication device, and (3) establishing a radio connection between the first radio communication device and the second radio communication device when a time difference between each operation of the first connection switch and the second connection switch is within a predetermined time period.

1. Field
This invention relates to a radio communication device that communicates with an external device over a radio connection, and a method for establishing the radio connection between radio communication devices.
2. Description of the Related Art
Recently, radio connection techniques have been developed between electronic devices of different types by using, for example, a BLUETOOTH™ (hereinafter "BT") standard radio communication system. Specifically, there are developed electronic devices such as wireless phones that receive digital audio signals over radio communication from, for example, portable audio players and replay the signals.
Meanwhile, BT-standard radio communication systems employ a radio communication connection method in which an electronic device such as an audio player, working as a master device, conducts a search for slave devices and selects an electronic device such as a headphone, from a plurality of detected slave devices for use as a communication connection.
According to conventional radio communication connection methods, such as BT-standard, an electronic device operating as a master device is configured with an operation method for establishing communication connection with slave devices. The operation method, however, requires the user to have access to an interface for inputting data or menu selection. Examples of-different types of interfaces may include a display device to display information, a mouse and/or a keyboard.
However, for certain devices, such as an audio headphone, it is very difficult to implement the operation method for the establishing communication connection therein. The reason is that the interface for certain devices may only a few LEDs (light emitting diodes) for a display device and a few buttons for an input device. Even when the operation method could be implemented, the small and limited interface makes users difficult to operate it.

Radio communication device and a method for establishing radio connection


New dual temperature electrochemical methods and systems for the production of sodium metal from sodium polysulfides have been discovered. The technology provides high conductivity for sodium ions and extended service life for the electrochemical cell.

Liquid hydrocarbons, including many oil feedstocks, often contain difficult to remove sulfur in the form of organosulfur compounds as well as metals and other heteroatom-containing compounds that hinder usage of the hydrocarbons. Sulfur can cause air pollution and can poison catalysts used in petroleum processing or catalysts designed to remove hydrocarbons and nitrogen oxide from motor vehicle exhaust. There has been a worldwide trend to limit the amount of sulfur in hydrocarbon fuels, such as gasoline, diesel, and fuel oils, including marine bunker fuels. Metals contained in the hydrocarbon stream can also poison the hydroprocessing catalysts typically utilized for removal of sulfur whereby hydrogen reacts under extreme conditions to break down the sulfur bearing organosulfur molecules.
Sodium metal has been recognized as potentially effective for the treatment of high-sulfur hydrocarbons, including petroleum oil distillate, crude, heavy oil, bitumen, and shale oil. Sodium is capable of reacting with the oil and its contaminants to dramatically reduce the sulfur, nitrogen, oxygen, and metal content of the oil through the formation of sodium sulfide compounds (sulfide, polysulfide and hydrosulfide) as well as other sodium-containing byproducts. To make such desulfurization techniques economically viable, the sodium metal must be regenerated from the sodium sulfides/polysulfides and other sodium-containing byproducts. Although metallic sodium may be electrochemically regenerated from such sulfides/polysulfides and by-products, short service life of the electrochemical cells used in these methods has stymied their commercial use. Thus, cost-effective and robust electrochemical systems and methods for producing sodium metal from sulfides/polysulfides have not been available, until now.

Production of sodium metal by dual temperature electrolysis processes


An electrical assembly for a motor controller is disclosed that includes an electrical lead. The electrical lead has a conductive trace within an insulating material and that extends a length between first and second ends. An electrical pad is in electrical continuity with and extends from the conductive trace through the insulating material at the first end. The pad includes an aperture providing a securing feature. An electrical component is supported by and integral with the second end, in one example. The electrical component is in electrical continuity with the conductive trace at the second end. A bus bar provides a joint having a first cross-sectional area. The electrical lead is flexible and is removably secured to the joint by the securing feature to provide electrical continuity from a capacitor to the bus bar. The flexible electrical lead has a second cross-sectional area substantially less than the first cross-sectional area.

This disclosure relates to a motor controller suitable for an aircraft electric starter motor, such as main and APU engine start, cabin air compressor motor, nitrogen gas generation system motor, and hydraulic motor applications, for example. More particularly, the disclosure relates to an apparatus and method for electrically connecting a thermally sensitive electrical component to a bus bar.
Electric starter motors are used in the aircraft industry to rotationally drive a gas turbine engine during a starting procedure. The motor controller includes inductors used in input filter and output filters that are connected to input or output bus bars. In one example, the bus bar typically conducts 220-240 amps, and up to 480 amps for brief periods, which generates heat within the bus bar. Bus bar temperature can reach up to of approximately 130-150° C. during these periods.
A motor controller houses the input and output filters which include inductors and capacitors. In one example, a printed wiring board (PWB) is mounted to a chassis. One or more capacitors are supported on the PWB and are typically only provided a few amps of current. The bus bar is secured directly to the printed wiring board. As result, a significant amount of heat is transmitted from the bus bar to the PWB and the capacitors. A typical maximum operating temperature capacity of the capacitors is 105° C. The bus bars may conduct heat to the capacitors such that they operate beyond their maximum temperature limit.

Motor controller assembly with capacitor thermal isolation


A sculptable, decorative light system includes a number of modules of differing lengths which can respond to commands either in parallel or time delay to create pre-selected light colors and sequences. Three miniature connectors are used to create a direct current fed system which has the potential to even out a current demand. Interconnectable lamp modules are provided in sets of 1, 2, 3, 4, and more lengths to create decorative light displays. Each lamp module or string of modules may include a male/plug end and a female/receptacle end.

Currently available light sets that may be utilized both indoors and out-of-doors are limited. For holiday lighting, one available option for outdoor lighting is a large-bulb incandescent light set. Such light sets are still available on the market and are often necessary where a user wishes to create a bright and dramatic display. One advantage of large-bulb light sets is that they are typically wired in parallel so that failure of a single bulb does not prevent the rest of the strand from lighting. There are, however, numerous disadvantages to this type of light set. Because each bulb in a given string of lights consumes approximately 5 to 10 watts of power, a single string of 25 to 50 bulbs consumes a significant amount of power and can therefore be expensive to light on a regular basis. Additionally, the large-bulb incandescent light sets generate appreciable amounts of heat which can lead to fire hazards. For this reason, large-bulb incandescent light sets are not properly usable indoors. Finally, large-bulb light sets are costly both to purchase and to maintain.
Another option for outdoor lighting available in the current market is known as a miniature incandescent light set. While this type of light set can be used indoors and out-of-doors and is less expensive to purchase and maintain than the large-bulb incandescent light set, there are several drawbacks associated with miniature light sets.
Lamps on miniature light sets may be connected in series and can be extremely difficult to maintain. In some sets, a single burned-out lamp results in an open circuit that prevents operation of other lamps in the strand until the defective lamp is replaced. In newer sets, a shunt may be present to allow current to pass to the rest of the strand even when a bulb burns out, but the shunt does not prevent malfunction of the entire strand where a bulb becomes slightly dislodged from its socket. In that case, the user must locate the loose bulb and either secure or replace it. This may mean systematically checking each lamp on the strand, which can be both time-consuming and frustrating. Most users are likely to conduct such a search while the strand remains plugged into the power source, thereby risking electrical shock. Moreover, the lamps themselves are small, difficult to grasp, difficult to remove, and delicate to handle. Consequently, time spent searching for a defective lamp and the associated risk of injury from shock or from crushing the glass portion of the lamps while removing and replacing them is burdensome at best. Sometimes, entire light sets are often discarded even if only a single lamp is defective, making repeated purchases of conventional decorative light sets less cost effective than their price would indicate.
The lamps in miniature incandescent light sets are typically driven by low voltage alternating current (AC), which is usually achieved through a step-down transformer that converts standard 120 volt AC power to 12 volt AC power. While this reduces potential danger from voltage as compared to the large-bulb incandescent light systems, it also means that a user must have access to an AC outlet, necessarily limiting the use of conventional light sets to certain applications where AC power is convenient.
Further, if multiple extension cords are necessary, a display can quickly become both unattractive and hazardous with respect to circuit overload and fire. Moreover, although miniature light sets allow a user to connect multiple strands of lamps to one another to create longer strands for more extensive applications or for the convenience of avoiding multiple extension cords in a single application, a user is still constrained by high current draws that could overload the circuit and permanently damage the light set.
Another practical problem with miniature light sets is the difficulty of creating dense or intricate light displays because the lamps on miniature light sets have a fixed space, usually 4 to 6 inches or more from one another. In order to create clusters of lights or complex light displays, a user must re-wrap or double back on multiple times to achieve the desired results. This often leads to problems with tangling and breakage, especially if a bulb is loose or needs replacing or if the light strands must be taken down often, such as in a seasonal or temporary applications. Where a user has completed decoration of one portion of an object and has lights on a string which have not been utilized, extending the string to extend the power to the next object removes the ability to eliminate the presence of lights between objects.
A further issue with miniature light sets is the limited range of available light colors. Even assuming that a user might be satisfied with the few lamp colors available on the market for miniature light sets, changing the color scheme on even a single strand of conventional lights is problematic, and more so for multiple strands of lights. Again, because the lights are small, delicate, and difficult to remove and replace, a user is likely to decide against changing color schemes to avoid the extra effort required to change colors. Further, a change in color scheme would require that a user separately purchase as many lamps as he desires to change, since most miniature light sets only come with 2 or 3 extra replacement bulbs. Although the cost of purchasing all-new replacement lamps is not necessarily prohibitive, the difficulty of finding enough replacement lamps in the desired replacement color is often difficult if not impossible. Practically, then, a user is more likely to purchase an entire new light set when new colors are desired, but even then, the selection of available colors remains small.
Similarly, the range of flashing patterns available in miniature lighting systems is narrow. Available options usually only include full-on, twinkling, blinking, chasing, or a few other similar variations. Flashing patterns in miniature light sets are generally pre-set and cannot be overridden or changed by the user. In fact, in many light sets, the user may have only two choices, either full-on or blinking. In the more basic miniature light sets, the blinking pattern is usually be achieved by replacing a regular lamp with a "flasher" lamp containing a bi-metallic strip. The strip responds to the heat of the bulb's filament and either closes or opens the circuit, turning on or off the bulbs, respectively. Unfortunately, the strand will not light at all when the blinker bulb burns out. Because most light sets only come with one flasher or two at most, any defect or damage to the flasher bulb may further limit a user's options with respect to flashing patterns. Even in the more advanced miniature light sets run by a controller, available flashing patterns are usually preset and the selection is limited.
Finally, transitioning from structure to another, when lighting a series of structures is almost always problematic. For example, where a user wishes to frame multiple windows in decorative lights using a conventional light set, the user must either (1) use separate strands with separate extension cords for each window, or (2) use multiple strands connected together and powered by a single extension cord for multiple windows. In the former case, a user must purchase multiple extension cords and is limited by the number of AC power outlets available. In the latter case, a user must move from one window to the next by extending lighted portions of strands between the two windows, thus detracting from the aesthetic quality of the display.
Control protocol is another major problem. The communications highway in any system has a width which is proportional to its length. It is difficult to provide a high level of control in most systems without knowing the size of the system. Systems which have a variable size are almost impossible to provide with distributed control.
What is therefore needed is a modular decorative light system having components which are connectable in parallel, which are capable of efficient arrangement in any number of different configurations, and which have virtually unlimited programmable flashing and color display capabilities. The optimal modular decorative light system should operate safely using low voltage, use little energy, and have an independent power source allowing it to be used without regard to the location of an AC power source, and is simple and cost-effective to use, maintain, and upgrade.