Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.

The present invention applies to communications systems, all of which are inherently limited in their capacity (or rate) of information transfer by channel impairments. One example of an impairment is often referred to by the generic term "noise." Noise sometimes emanates, for example, from within electrical components themselves, such as amplifiers and even passive resistors. Another example of an impairment is referred to as "interference," which is usually taken to be some unwanted manmade emission perhaps for another communications system such as radio, or perhaps from switching circuits in a home or automobile. "Distortion" is a further example of an impairment, and includes linear distortion in the channel, such as pass-band ripple or non-flat group delay, and nonlinear distortion, such as compression in an overdriven amplifier. Of course, there are many other types of impairments that may adversely affect communications in a channel.
Often in communications channels, the impairments may by dynamic in nature. In many cases, the impairment level may be at one level of severity most of the time, and the communications system may be designed or optimized (in some fashion) to operate at that level of impairment. Occasionally, however, one or more of the impairments may rise to so severe an amount as to preclude the operation of the communications system optimized for the more ordinary level of impairments.
In prior art, in some applications where a large interferer or burst of noise occasionally impinges upon the receiver, the received signal is simply blanked during increased power to mitigate large out-of-the ordinary bursts of received power. Often, analog processing means are used, almost at, if not right at, the receiver input. Sometimes this is done especially to protect sensitive receiver front-ends from damage. While this technique may provide some benefit in circumstances where the noise or interference power dwarfs the signal-of-interest power, it does not protect against the many other impairments which have power more on the order of the signal-of-interest power (or even much less). Also, by itself, this blanking does not provide the receiver with a means to improve its overall performance in the presence of the lost information, i.e., the information content concurrent with the large noise burst.
Other prior art that may have been applied to this problem, even unknowingly, is the use of forward error correction (FEC) techniques that incorporate soft-decision decoding, such as is common with convolutional error correction codes and the Viterbi decoding algorithm. In this prior art, as the error power in the received signal is increased, this increase is passed directly into the decision process. Such encoding and decoding techniques have been in common practice for years, and are widely applied without thought to temporary fidelity changes in the channel. Fortunately, in the event of a change in the channel fidelity, the soft-decision decoding will automatically take into consideration the larger error power in making signal decisions. However, unfortunately, often with a change in channel conditions, there is a duration of multiple symbol intervals (in a digital communications system example) where the degradation persists, and during this time some symbols may be erred so severely that they actually appear close to another possible (but wrong) symbol. In this event, which becomes much more likely as the constellation density (of a QAM constellation, for example) is increased for high rate communications, the soft-decision decoder actually "thinks" it has received a low error power, and may rate the wrong signal with a high confidence.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.

Detection and mitigation of temporary impairments in a communications channel


A thermal balance conversion circuit includes a voltage conversion circuit, a temperature detection circuit, a PWM controller, and a signal integration controller. The voltage conversion circuit includes a plurality of voltage conversion units, and each of the voltage conversion units converts the DC voltage of a external power to a driving voltage. The temperature detection circuit includes a plurality of temperature detection units, and the plurality of temperature detection units detects temperatures of the plurality of voltage conversion units. The pulse width modulation controller outputs a plurality of different phase PWM signals according to each of the voltage conversion units. The signal integrated controller receives the PWM signals from the PWM controller to control the voltage conversion of each of the voltage conversion unit.

1. Technical Field
The disclosure relates to thermal balance circuits, and particularly to a multiphase thermal balance conversion circuit.
2. Description of Related Art
In a multiphase power supply, a plurality of voltage conversion return circuits are used to convert voltage. The plurality of voltage conversion return circuits may not meet requirements because of the dissipating heat caused by a change of external environment or circuit layout of a printed circuit board. The one or more voltage conversion return circuits can overheat and damage the elements of the voltage conversion return circuits. Therefore, a multiphase power that can overcome the described limitations is needed.


The process for analyzing an ovine animal carcase comprises capturing an image of a dorsal view to generate color image data for the carcase (10). Predetermined anatomical points (21–24) of the carcase are identified to then derive dimensional measurements for the carcase. Also characterizing parameters such as yield and fat depth of the carcase are derived by processing color data included in the captured image data in conjunction with the derived dimensional measurements. The color data processed are the color data for predetermined selected surface areas, especially the chump, the loin and the shoulder areas (30–32) of the carcase (10) known or determined to have significant correlation to the characterizing parameter related to fatness. Desirably the tail (17) of the animal carcase is identified and its width determined since this is useful as a variable in a carcase yield predictive equation. The color data comprises average RGB values representing red, green and blue color components which are intensity normalized color values.

In the meat industry, specialist trained and skilled operators are employed, in abattoirs for example, in order to inspect each animal carcase and to provide estimates or gradings of various parameters, such as the predicted saleable meat yield of each carcase. Such predictions of meat yield and gradings are very important for fixing a fair value for the carcase and for determining uses to which the carcase and meat cuts will be destined. Obviously it is very important for the meat industry generally including producers, processors and consumers that such operators are consistent both within a particular abattoir or processing facility and between different facilities at different places and different times.
In the case of ovine carcases, particularly sheep carcases, the analyses commonly used include both quantitative and qualitative measurements or assessments such as dimensional measurements, yield, particularly "lean meat yield", and fat depths.
There have been proposed and developed automated systems for image capture and colour analysis for automating beef carcase yield predictions or gradings, or at least for providing some objective replacement or supplement to human operators. However, such automated analysis and yield predicting systems for beef have not been applicable to sheep carcases both in their physical construction and arrangement, and also in the analyses performed and data output.


There are disclosed an assembling apparatus and an assembling method of a nuclear fuel assembly by which flaws or scratches to be formed on the surfaces of the fuel rods can be reduced. The fuel rods are inserted into the grid cells of the supporting grids under the state where the supporting grids are disposed in proximity to each other. Therefore, it is possible to remarkably reduce the fall-down movement of the tip portion of the fuel rod. Conventionally, the tip portion or lower surface of the fuel rod inevitably comes in contact with the grid cell of the supporting grid, so that the scratches might be formed on the surface of the fuel rod, which deteriorates the quality of the fuel assembly. However, according to the present method and apparatus, it is possible to avoid the interference between them so that the scratches to be formed on the surface of the fuel rods can be reduced remarkably.

1. Field of the Invention
The present invention relates to an assembling method and an assembling apparatus for a nuclear fuel assembly which is used in nuclear reactors such as a pressurized water reactor.
2. Conventional Art
An existing conventional nuclear fuel assembly is illustrated in FIG. 6.
In FIG. 6, numerals 1 and 2 respectively designate a top nozzle and a bottom nozzle which are positioned apart from each other in a vertical direction and disposed so as to face each other. A plurality of control-rod guide pipes 3 are extended between and securely fixed to the top and bottom nozzles 1, 2. A plurality of supporting grids 4 are secured to intermediate portions of the respective control-rod guide pipes 3 such that they are vertically positioned apart from each other.
As illustrated in FIGS. 7 to 9, the foregoing supporting grid 4 is formed such that a plurality of straps 7 are assembled perpendicularly to each other into a grid form by the mutual fitting of slits 8 which are formed and equally spaced in the longitudinal direction in the strap, and consequently, a plurality of grid cells 5 are formed in each grid. On the walls of the prescribed grid cells 5, there is provided a pair of dimples 9 and springs 10 which are arranged to face each other, for holding a fuel rod 6. The fuel rod 6 inserted in the grid cell 5 is held in the grid 5 by being pressed against the dimples 9 by the springs 10.
According to the conventional method for inserting the fuel rod 6 into the grid cell 5 in the above-mentioned fuel assembly, a plurality of supporting grids 4 (normally, eight supporting grids) of which grid cells 5 are directed in a horizontal direction are disposed into a line in a horizontal direction such that they are disposed apart from each other by the predetermined equal spacing; key members are inserted into the supporting grid 4 so as to deflect the springs 10 away from the dimples 9; and then, a plurality of fuel rods 6 are inserted horizontally into the grid cells 5, thus assembling the fuel assembly.
Meanwhile, the fuel rod generally in use comprises a zircaloy-clad tube having a cylindrical shape of 4 m length or less, and an outer diameter of approximately 10 mm. For this reason, when inserting the fuel rod 6 into the grid cell 5 horizontally in accordance with the foregoing method, the tip of the fuel rod 6 drops down slightly by its own weight such that it may interfere with the supporting grid 4, or that scratches may be formed on the surface of the fuel rod 6 because the lower surface of the fuel rod 6 comes in contact with the supporting grid 4. This is undesirable for producing a fuel assembly of high quality and reliability.

Method for assembling nuclear fuel assembly and apparatus therefor


A two-dimensional silicon controlled rectifier (2DSCR) having the anode and cathode forming a checkerboard pattern. Such a pattern maximizes the anode to cathode contact length (the active area) within a given SCR area, i.e., effectively increasing the SCR width. Increasing the physical SCR area, increases the current handling capabilities of the SCR.

1. Field of the Invention
Embodiments of the present invention generally relate to a silicon controlled rectifier (SCR) layout within an integrated circuit (IC) and, more particularly, to an SCR layout that maximizes the width/area ratio of an SCR layout.
2. Description of the Related Art
Silicon-controlled rectifiers (SCRs) find widespread use in many applications where a switched resistive path is desired. For example, SCRs find particular use in electrostatic discharge (ESD) circuits or devices that are placed between an output or input pad of an IC and ground. The ESD circuits provide a high resistance path through an SCR when the circuit being protected is operating normally, and provides a low resistance path from the pad to ground when an ESD event occurs. The ESD event triggers the SCR into a low resistance state that shunts ESD generated current from the pad to ground. In this manner, the circuit being protected is not damaged by the ESD event.
There are many variations of ESD circuits that utilize SCRs in this manner. Commonly assigned U.S. Pat. Nos. 6,768,616, 6,791,122, 6,850,397 and 6,909,149, which are incorporated herein by reference, describe a number of such ESD circuits.
In conventional SCRs, the amount of current that can be handled by an SCR is proportional to the width of the SCR. FIG. 1 depicts a simplified top plan view of a 1-sided SCR 100. The SCR comprises an anode 102 and a cathode 104 that abut one another along an active area 106. As is well known in the art, the SCR 100 is generally formed of a PNPN device, the details of which are well-known and not shown in this simplified view. The SCR 100 has a length L and a width W. When the SCR 100 is not triggered, the SCR has a high resistive path from the anode 102 to cathode 104. Conversely, when the SCR 100 is triggered in a low resistance state, current I flows from the anode 102 to the cathode 104 along the width W of the SCR 100, i.e., along the active area 106. The wider the SCR width W, the wider the active area 106 and the higher the current handling capability of the SCR. Since the depth of the SCR 100 is fixed by the IC manufacturing parameters, the current handling ability of the SCR is solely controlled by the SCR width W. In an ESD circuit, an ESD circuit designer selects an SCR width that provides a suitable level of ESD protection against an ESD event.
To increase the current handling capability without increasing the physical width of the SCR, a 2-sided SCR may be used. FIG. 2 depicts a simplified top plan view of a 2-sided SCR 200 comprising a first anode 202, a cathode 204 and a second anode 206. The two anodes 202 and 206 abut the cathode 204 along active areas 208 and 210. When the SCR is active, current flows from both anodes 202, 206 into the cathode 204. As such, the effective width of the SCR is double that of the 1-sided SCR. As with the 1-sided SCR, an ESD designer controls the current handling level by adjusting the physical width W of the SCR 200.
If the region of the circuit in which the SCR is formed has limited space for the SCR width, the designer may not be able to achieve the width of the SCR that is necessary for the desired current handling capability. The result will be a compromised design.
Therefore, there is a need in the art for increasing the current handling capability of an SCR without increasing the physical width of the SCR, i.e., increasing the current handling for a given SCR area.

Two-dimensional silicon controlled rectifier


There is disclosed a housing for a centrifugal fan or blower or the like. The housing includes a wedge member for reducing the tonal noise generated during operation of the fan or blower. The wedge member is disposed on an interior surface of the housing chamber.

1. Field of the Invention
The present invention relates generally to a housing for a centrifugal fan, blower or the like. More particularly, the present invention relates to a volute housing for a centrifugal fan, blower or the like which reduces noise generated during operation.
2. Disclosure Information
Centrifugal fans or blowers are commonly used in the automotive, air handling and ventilation industries for directing a forced flow of air through a variety of air conditioning components. In a typical centrifugal blower, air is drawn into a housing through an aperture by a rotating blower or fan. This air is then forced around the housing and out an air exit end. In some situations, an undesirable whistling or other tonal noise may be generated by this flow of air. (As used herein, tonal noise means noise at frequencies equal to (nBN/60) where n equals 1, 2, 3, . . . , B equals the number of blades on the fan wheel and N is the rotational speed per minute of the fan wheel.) This noise is primarily due to a pressure pulse generated when fan blades pass the blower cut-off region, the necked down portion immediately adjacent the exit end of the blower housing. Various modifications to the housing have been proposed for reducing this noise.
The most common method for reducing this noise has been to modify the shape of the cut-off region of the blower. This has been done by inclining or altering the sides of the housing in this region, to effectively reduce the sudden increase in pressure (pulse shape) when rotating blades pass the cut-off region. More gradual cut-off inclinations are required for tonal noise reductions but these may affect airflow performance and manufacturability of the housing and its assembly.
Therefore, it would be desirable to reduce the tonal noise generated by a centrifugal blower without affecting its performance. It is an object of the present invention to reduce tonal noise in an economical manner without affecting the performance of the blower.


A reel driving apparatus for a video camera, which is constructed with a minimum of structural elements, resulting in achieving simplicity in construction and reducing the manufacturing cost and weight of the product. The apparatus comprises an idle gear mounted on a support plate to be pivotally movable therewith between a feed reel and a take-up reel gears to selectively transmit power from a motor to the reel gears, direction rotating gear disposed in intermeshing engagement with the take-up reel gear, and a stopper protruding from the support plate to control rotation of the direction rotating gear, thereby preventing a tape from instantaneously slackening during a change of the direction of the travel in the tape in the tape during winding and unwinding operations.

1. Field of the Invention
This invention relates to a reel driving apparatus for a miniature video camera in which a tape frequently needs to be instantaneously advanced backward reversed during its forward advance.
2. Description of the Prior Art
The prior reel driving apparatus for a miniature video camera is of the type shown in FIGS. 1 and 2 of the accompanying drawings, in which a drive unit functioning to wind and unwind a tape (not shown) extending between a feed reel and a take-up reel comprises, as shown in FIG. 1, a belt pulley (2) rotated by a belt(1) transmitting power from a motor (not shown) to the pulley, and an idle gear(3) being in intermeshing engagement with a gear of the belt pulley (2) to be rotated thereby. The belt pulley and the idle gear are mounted on a single support plate(4) which is pivotally movable about a center shaft(5) of the belt pulley (2) between a feed reel gear(6) and a take-up reel rear(7), which gears are disposed each on the opposite sides of the center shaft.
With this arrangement, when the support plate(4) is rotated in a counter-clockwise direction as viewed in FIG. 1 so that the idle gear (3) mounted thereon is engaged with the feed reel gear (6), the tape feed reel may be rotated via a gear train comprising the gear of the belt pulley(2), the idle gear(3) and the feed reel gear(6), thereby unwinding the tape therefrom.
Conversely, when the support plate(4) is rotated in a clockwise direction, the take-up reel may be rotated via a gear train comprising the gear of the belt pulley (2), the idle gear(3) and the take-up reel gear(7), thereby winding the tape thereon.
In addition, in contrast to a common video cassette recorder, the miniature video camera is provided with a rotary gear assembly (9) comprising a direction rotating gear(8) disposed in intermeshing engagement with the take-up reel gear(7) so as to control the rotation of the take-up reel depending upon a rotational direction of the take-up reel gear(7). In the miniature video camera, the reason for controlling the rotation of the take-up reel by means of the rotary gear assembly is as follows. Generally, the miniature video camera repeatedly carries out picture-taking and stop operations for the purpose of its use. Every time the camera is operated, the tape needs to be repeatedly advanced forward and reversed depending upon various modes of the operation.
Therefore, in the course of such forward advances and reverses of the tape, especially when the forward advancing tape is temporarily stopped, thereafter is slightly moved backward and remains in the pause condition according to a change of the operation from a picture recording mode to a temporary stop or pause mode, because the inertia force disappears and then acts again on the tape, the tape is not unwound uniformly from the take-up reel. In such case, the amount of the tape being wound again on the feed reel is not as great as the amount of tape excessively unwound from the take-up reel due to temporary over-rotation of the take-up reel. In order to prevent the slackening of the tape, therefore, an attempt has been made to apply tension to the tape on the take-up reel by controlling the rotation of the reel.
The construction and operation of the rotary gear assembly functioning to prevent the tape from slackening due to the temporary over-rotation of the take-up reel as discussed above will now be described in more detail below.
As shown in FIG. 2, the rotary gear assembly(9) having the one-way rotating gear(8) held in intermeshing engagement with the take-up reel gear(7) comprises three tapered rectangular holes(10) formed in the rotary gear assembly in circumferentially spaced relation to each other, cylindrical bearings (11) received one in each of the taper holes (10) and a compression spring (12) disposed in each one of the taper holes(10) to apply its biasing force to each one of bearings(11). With this construction, in the picture recording mode and a play mode of the video camera, in which the idle gear (3) is engaged with the take-up reel gear(7), as the take-up reel gear is rotated in a clockwise direction, the bearings (11) are moved to and positioned at the wide portions of the taper holes(10). Thus, the one-way rotating gear(8) may be rotated without interference, and therefore the take-up reel gear(7) may be rotated smoothly. In this condition, when the mode of the operation is changed to a review mode in which the tape is reversed, or the pause mode in which the tape must be slightly reversed the idle gear (3) is engaged with the feed reel gear (6) to rotate the feed reel in a counter-clockwise direction, and thus the take-up reel (14) is rotated in a counter-clockwise direction through a cassette tube (not shown). At this point, because the one-way rotating gear(8) of the rotary gear assembly (9) has a tendency to rotate in a clockwise direction contrary to the counter-clockwise rotation of the take-up reel, the bearings (11) are moved to the narrow portions of the taper holes (10), thereby impeding the rotation of the one-way rotating gear(8).
Consequently, the take-up reel gear(7) engaged with the rotating gear(8) is also prevented from rotating, and only the take-up reel(14) is rotated while being subjected to frictional force by a friction clutch (13) disposed between the take-up reel(14) and the take-up reel gear(7). As a result, the take-up reel tightens the tape wound thereon, thereby preventing the tape from slackening. This prior apparatus is however disadvantageous in that the rotary gear assembly is complex in construction and requires a large number of parts, resulting in increasing the manufacturing cost and weight of a product.

Tape hub driving system with mechanism to prevent tape slackening during mode change


A method includes receiving a metal component including a raw surface that includes a metal base, a first native oxide disposed on the metal base, and hydrocarbons disposed on the metal base. The method further includes machining the raw surface of the metal component to remove the first native oxide and a first portion of the hydrocarbons from the metal base. The machining generates an as-machined surface of the metal component including the metal base without the first native oxide and without the first portion of the hydrocarbons. The method further includes performing a surface machining of the as-machined surface of the metal component to remove a second portion of the hydrocarbons. The method further includes surface treating the metal component to remove a third portion of the hydrocarbons. The method further includes performing a cleaning of the metal component and drying the metal component.

In semiconductor processing and other electronics processing, objects, such as substrates, are transported between portions of the system. The different portions of the system include storage areas, transfer areas, processing areas, and so forth. Such storage areas, transfer areas, processing areas, and so on are generally composed of metals that have contaminants therein. Such contaminants are known to migrate onto substrates stored in, processed by and/or passed through the storage areas, transfer areas, processing areas, and so on.

Organic contamination free surface machining


Disclosed is a container for containing a beverage and a grommet for use with a container, and a method of retaining liquid in a container and preventing reverse flow out of the container. The container is of the type for retaining a quantity of beverage including at least one wall containing a cavity therein, a rim defining a mouth, and a lid extending at least partially over the mouth. A valve port is provided in the lid. A grommet is provided for retention in the valve port including a flange and structures for retaining the grommet in the valve port. The grommet defines an aperture extending therethrough which communicates with the valve port. The beverage is passed through the aperture and valve port for retention in the cavity of the container. A tongue extends from the grommet into the valve port for movably blocking a portion of the valve port. The tongue is movably displaced as beverage is dispensed into the container and is positioned over a portion of the valve port for preventing reverse flow of beverage from the container out through the valve port.

Beverage containers for receiving beverage from a brewer or other source of beverage and for thereafter serving the beverage are known in the art. Such beverage containers typically include a vessel for receiving the beverage, a top opening for receiving the beverage from the source and into the vessel, a spout for dispensing the beverage from the vessel, and a handle for facilitating the dispensing of the beverage.

Beverage container with one-way valve assembly


An intelligent control system and method of thin plate dryer for cut tobacco are provided. The system includes a factor searching and screening unit, a control unit, an early warning unit. The control unit adopts a dual-model control method and establishes a process parameter control model and an energy balance model, the control unit calculates the moisture discharge opening value in real time according to the dual-model; the early warning unit is configured to connected with the control unit, and send out an alarm information based on early warning signal. The present disclosure is designed to transform the traditional control into intelligent precision control, improve product quality, reduce product differences between batches and build an intelligent early warning function.

In the process of tobacco production, the process of making cut tobacco is a very important link, in which the tobacco is made into qualified cut tobacco step by step through a variety of processing procedures in accordance with certain procedures, according to the physical and chemical characteristics of tobacco raw materials. Therefor in the process of tobacco production, making cut tobacco has the longest and the most complicated process, with most kinds of equipment.
The thin plate drier (a cut tobacco dryer of thin plate type) is an important equipment for cut tobacco production, which has the characteristics of low processing strength, high original flavor retention rate and the like. But in prior art, the production and operation control method of the equipment is semi-automatic production mode, that is: when the feeding material moisture is stable, the equipment is automatically controlled by PID control system; when the feeding material moisture fluctuates greatly, manual intervention is needed to adjust the parameters since automatic adjustment is usually represent delay.
At present, the early warning system of a thin plate drier is relatively simple. Early warning is given based on the moisture information feedback from the moisture meter at the outlet of the thin plate drier. The moisture exceeds the upper and lower limits of the process is regarded as an early warning information, the early warning information is limited by the accuracy of the moisture meter and the working principle of the moisture meter.
An invention patent application with publication number CN111109643A discloses a control method and system for cut tobacco moisture content of thin plate cut tobacco drier. The method includes: setting hot air temperature of the sheet cut tobacco drier according to a set value, and setting a target value of outlet moisture content of the sheet cut tobacco drier; obtaining an actual measurement value of the outlet moisture content of the sheet cut tobacco drier, and obtaining a target deviation value of the outlet moisture content according to the target value and the actual measurement value; establishing a PID feedback control model to adjust the hot air speed according to the target deviation value so as to carry out feedback control over the outlet moisture content, which enables the outlet moisture content of the sheet cut tobacco drier within a batch to be controlled according to the target value.
An invention patent application with publication number CN111103854A discloses a system and method for improving the production stability of cut tobacco drier, belonging to the technical field of cut tobacco production. The system includes a data acquisition module, a data processing module, a stability evaluation module, an early warning and optimization module, a steady-state real-time analysis and evaluation module, an unsteady-state automatic control judgment module, an unsteady-state real-time analysis and evaluation module and the like. The invention is supported by new-generation information technologies such as industrial big data and artificial intelligence to shorten the unsteady-state time and improve the steady-state control quality, so as to effectively improve the quality stability of the whole production process of the cut tobacco drier.

Intelligent control system and method of thin plate drier for cut tobacco


A DC circuit breaker includes: a first current section of a first electrical polarity from a first supply terminal of the DC circuit breaker to a first load terminal of the DC circuit breaker; a second current section of a second electrical polarity from a second supply terminal of the DC circuit breaker to a second load terminal of the DC circuit breaker; a mechanical bypass switch arranged in the first current section or the second current section, the mechanical bypass switch having at least one bypass switch excitation coil; a first semiconductor circuit arrangement connected in parallel with the mechanical bypass switch; an electronic control unit of the DC circuit breaker for actuating the first semiconductor circuit arrangement; a second semiconductor circuit arrangement to be actuated by the electronic control unit, which second semiconductor circuit arrangement is connected to the bypass switch excitation coil by circuitry.

So-called hybrid circuit breakers for DC applications are known. Circuit breakers of this kind have a so-called bypass switch as a central or functionally essential component. This bypass switch is intended to open particularly quickly in the case of a safety-relevant deactivation process in order to cause the current to commutate to the power semiconductors before the current over the breaker rises too much, which power semiconductors then deactivate the current in question. A bypass switch is a relay having mechanical switching contacts. In order to actuate this relay, hybrid circuit breakers of this kind have a driver circuit which is powered by a power supply unit of the circuit breaker.
The required particularly quick opening of the contacts of the bypass switch necessitates a correspondingly large amount of electrical energy which has to be quickly available or quickly output to the driver circuit. This requires correspondingly powerful power supply units and energy storage devices, in particular electrolytic capacitors, for supplying the corresponding driver circuits. However, such powerful power supply units and capacitors require a considerable amount of space and contribute significantly to the spatial enlargement of such circuit breakers. Furthermore, a power supply unit draws a closed-circuit current such that, in addition to the space required within the circuit breaker, there is also a considerable power loss, which has to be dissipated via corresponding cooling surfaces. The capacitors also have to be constantly recharged, otherwise they lose their charge over time. The resulting power loss leads to a temperature increase within the circuit breaker, which can reduce the service life of the safety-relevant semiconductors of the circuit breaker.
Although the use of a drive of the bypass switch with a high number of turns would reduce the required current, this would also lead—due to the higher inductance of such a coil having a high number of turns—to a larger time constant and thus to a slowing down of the opening process of the bypass switch.
Circuit breakers often carry out only very few deactivation processes due to dangerous electrical states. Most of the time, therefore, a correspondingly powerful power supply unit and the corresponding capacitors are not required since the maximum power that can be output is not required, and the power loss which has to be continuously dissipated is disadvantageous. In order, therefore, to be able to deactivate short-circuits with a reasonable space requirement and power loss to be dissipated, known breakers have a choke, which is also referred to as "time buyer inductance," in the current path, which naturally only acts on changes in the current flow, and reduces the rate at which the current rises in the case of a short-circuit. Nevertheless, a choke also requires a lot of space and exhibits ohmic losses.


A process for producing cyclic thioether compounds and their synthetic intermediates. The process produces a compound represented by formula (5):

1. Field of the Invention
The present invention relates to a novel process for producing cyclic thioethers, and more particularly, to novel compounds for producing cyclic thioethers, production processes therefor and methods of use.
2. Background Information
The following processes are known as processes for synthesizing cyclic thioethers.
W. E. Parham et al. in J. Org. Chem., 41, 2628 (1976) disclose a process for synthesizing cyclic thioethers by reacting thiourea with 1-bromo-2-(bromomethyl)benzene and hydrolysis thereof to obtain (2-bromophenyl)methanethiol, and then following lithium-halogen exchange of (2-bromophenyl)methanethiol with butyl lithium, reacting the resulting product with a ketone (G represents NMe or CH2) to obtain mercapto alcohol followed finally by a dehydration reaction with sulfuric acid.
(In the above formula, Bu represents n-butyl, and G represents >CH2 or >NCH3.)
Japanese Patent Application (Kokai) No. Hei 10-182649 discloses a process for synthesizing a cyclic thioether by converting the hydroxyl group of (2-bromophenyl)methanol to a leaving group with a sulfonyl halide such as methanesulfonyl chloride or p-toluenesulfonyl chloride, and after converting to an acetylthio group, removing the acetyl group by hydrolyzing to obtain (2-bromophenyl)methanethiol, and then carrying out a lithium-halogen exchange by reacting with butyl lithium, followed by reacting with a ketone to obtain a mercaptoalcohol compound followed by a dehydration reaction.
(In the above formula, Ac represents acetyl. Bu represents n-butyl, tBu represents tert-butyl, and R represents methyl or p-tolyl.)
Hirokazu Kubota et al., Chem. Pharm. Bull., 46, 242 (1998) disclose a process for synthesizing a cyclic thioether by reacting (2-bromophenyl)methanethiol or 2-(2-bromophenyl)ethanethiol with butyl lithium to carry out a lithium-halogen exchange, followed by reaction of the resulting product with a ketone to obtain a mercapto alcohol and finally carrying out a dehydration reaction with trifluoroacetic acid.
(In the above formula, Bu represents n-butyl, Et represents ethyl, and m represents 1 or 2.)The (2-bromophenyl)methanethiol used as the starting material in the process of Hirokazu Kubota et al. is known to be synthesized by reacting 1-bromo-2-(bromomethyl)benzene with thiourea or derivatives thereof followed by hydrolysis (Overberger et al., J. Amer. Chem. Soc., 78, 666 (1956) and T. Annalisa et al., Farmaco, 45, 617 (1990)), and the process requires at least two steps.
These processes have the disadvantages of requiring two equivalents of organic lithium reagent (resulting in high costs), having a large number of steps and having a low synthetic yield, and none of the processes are suited for industrial production of cyclic thioethers from the viewpoint of economic feasibility.
As a result of conducting extensive studies for the purpose of overcoming these disadvantages and establishing an industrial process for the production of cyclic thioethers, the inventors of the present invention found that cyclic thioethers can be obtained, by going through the compounds of the general formulae (3) and (5), in fewer steps and less expensively than the known processes, thereby leading to completion of the present invention.

Process for producing cyclic thioether and synthetic intermediate thereof

Abstract: wherein G1 is an alkylene group, R1 is a thiol protecting group, R2 is hydrogen or an amino protecting group, and Ar is an aryl group or a 5- to 7-membered heteroaryl group.


An image forming apparatus of the present invention includes a fixing device for fixing a toner image formed on a recording medium. A heat source is applied with power for generating heat to thereby heating the heating device. A drive circuit includes a storage capable of being selectively charged or discharged and a charger for charging the storage by being supplied with power from a commercial power supply. A discharging device discharges the storage in a non-use mode in which the apparatus is not used.

1. Field of the Invention
The present invention relates to a copier, printer, facsimile apparatus or similar image forming apparatus capable of insuring user's safety when the apparatus is not used.
2. Description of the Background Art
It is a common practice with an image forming apparatus to use a fixing device of the type having a heat roller heated by a heat source and a press roller pressed against the heat roller. In this type of heating device, while the heat roller being heated is in rotation, a sheet or recording medium carrying a toner image thereon is passed through a nip between the heat roller and the press roller and has the toner image fixed thereon by heat and pressure. A heater for heating the heat roller has customarily been implemented by a halogen heater using a halogen lamp.
A current trend in the imaging art is toward a power saving type of image forming apparatus constructed to shut off power supply to a heater when the apparatus is not used from the environment standpoint. In this type of image forming apparatus, it is necessary for the heater to immediately raise the surface temperature of a heat roller to preselected temperature at the time of image formation. In practice, however, power is applied from a commercial power supply to one or more heaters, so that power available for the individual heater is limited. Moreover, a certain period of time is necessary for a halogen heater to heat the heat roller to the preselected temperature.
In light of the above, it has been customary with a fixing device of the type using a halogen heater to reduce the wall thickness of a heat roller to 1 mm or below. Such a small wall thickness is successful to reduce the thermal capacity of the heat roller and therefore to sharply heat the heat roller to preselected temperature. The small wall thickness, however, brings about the following problems. A heat roller with a thin wall lacks mechanical strength and is therefore apt to collapse, warp or otherwise deform. Further, as the wall thickness of the heat roller decreases, machining becomes technically more difficult to practice and requires higher accuracy, resulting in an increase in cost.
To solve the problems stated above, there has been proposed a fixing device configured to apply power greater than power available with a commercial power supply to a heater, thereby accelerating the warm-up of a heat roller. This is contrastive to the above-stated scheme that reduces the thermal capacity of a heat roller in order to reduce power consumption losses. Japanese Patent Laid-Open Publication No. 3-36579, for example, discloses a heating device for a fixing device that includes a heater configured to generate heat on receiving power via heater drive means. The heater drive means includes a rechargeable battery and a charger connected to a commercial power supply for charging the battery. The heater is made up of a main heater receiving power from the commercial power supply and an auxiliary heater receiving power from the battery. The battery is selectively connectable to the charger to form a charge circuit or connectable to the auxiliary heater to form a discharge circuit. The discharge circuit serves to reduce the warm-up time of the heater.
Japanese Utility Model Laid-Open Publication No. 63-150967 teaches a fixing device including heating means implemented as a first heater powered by an AC power supply and a second heater powered by a battery rechargeable by charging means.
Japanese Patent Laid-Open Publication No. 3-5779 discloses an image forming apparatus including a thermal fixing device in which a heat roller accommodates a main heater and a subheater therein. More specifically, the apparatus taught in this document includes a main power supply for heating the main heater, first switching means for selectively turning on or turning off the main power supply, a battery for heating the subheater, charging means for charging the battery, second switching means for selectively connecting the battery to the subheater or the charging means, temperature sensing means responsive to the temperature of the heat roller, and control means for controlling the first and second switching means in accordance with the output of the temperature sensing means. When the temperature of the heat roller being heated by the main power supply drops to reference temperature related to a fixing ability, the subheater is heated via the battery. When the temperature of the heat roller rises above the reference temperature, the heating of the subheater is interrupted.
Japanese Patent Laid-Open Publication No. 2000-315567 proposes a heating device including a heating section and a main and an auxiliary power supply unit. The heating section includes a heat generating body to be applied with power from the main and auxiliary power supply units. The auxiliary power supply unit is implemented by a capacitor.
Japanese Patent Laid-Open Publication No. 2000-98799 discloses a heating device for a fixing device that includes a heater for generating heat when applied with power and heater drive means for feeding power to the heater. The heater drive means includes a rechargeable battery and a charger for charging the battery by being applied with power from a commercial power supply. The heater is made up of a main heater powered by the commercial power supply and an auxiliary heater powered by the battery. The battery is charged when the main heater is turned off.
The precondition with any one of the conventional heating devices, fixing devices and image forming apparatuses discussed above is that the capacitor, rechargeable battery or similar auxiliary power supply can store electric energy great enough to implement rapid warm-up. Despite that such a precondition involves risks as to user's safety, no safety measures have been taken with the conventional devices as to troubles ascribable to the auxiliary power supply. Particularly, when the image forming apparatus enters a non-use mode with great energy remaining in the auxiliary power supply, dangers unexpected with the conventional image forming apparatus are apt to occur. The non-use mode mentioned above refers to a condition wherein the apparatus is transported for disposal or maintained by way of example.

This patent is subject to a terminal disclaimer.

Image forming apparatus with an energy storage that can be discharged, and with a display of residual energy in the storage


A method of measuring echo path delay in a circuit having echo cancellers after enabling an echo signal to pass through the echo cancellers. The known time for a given echo canceller to disable is subtracted from the overall test signal duration. This quantity can be subtracted from the overall echo duration to compute the echo path delay.

As is known in the art, echo in networks, such as telephone circuits, is primarily caused by the reflection of energy due to impedance mismatches at 4-to-2 wire junctions, which are commonly known as hybrids. In conventional telephone circuits, echo cancellers (ECs) are placed at various locations in the network to cancel this echo. In Internet Protocol (IP) networks, echo cancellers are placed inside the network gateways. It is often desirable to characterize echo path(s). Parameters of interest include the delay associated with the echo path (EPD) of the canceller and the echo return loss (ERL). This information is useful for troubleshooting field echo control problems and network characterizations.
Field-deployed echo cancellers can fail to control echo for a number of reasons. Two reasons for such failures include the EPD exceeding the operating range of the canceller, and the ERL associated with the echo path being so low that the canceller categorizes the echo as the speech signal of the party nearer to the EC and thus, allows the echo to pass through. However, when troubleshooting complaints of echo in conventional or IP telephone networks using known techniques, collecting information on these two parameters is difficult.
It would, therefore, be desirable to overcome the aforesaid and other disadvantages.

Method for remote measurement of echo path delay


The present invention provides a rubber composition for a studless tire and a high-performance studless tire produced therefrom, which achieve good braking force and handling stability on ice and snow. The rubber composition for a studless tire includes: a rubber component; a zinc salt of a C4-C12 aliphatic carboxylic acid, or a C4-C12 aliphatic carboxylic acid and zinc oxide; and an oil or a plasticizer. The rubber component contains 40% by mass or more of butadiene rubber per 100% by mass of the rubber component.

Use of spike tires has been banned by law in Japan so as to prevent powder dust pollution resulting from the use of spike tires. As a result, studless tires are now used instead of the spike tires in cold regions. The studless tires can have better grip performance on ice and snow when they have a lower elastic modulus at low temperatures and have higher traction, for example. In particular, the braking force on ice is largely affected by the effective contact area between rubber and ice. There is therefore a demand for a vulcanized rubber composition that is flexible at low temperatures, which can provide a larger effective contact area.
Disadvantageously, decrease in only the hardness of a vulcanized rubber composition by, for example, increasing the oil amount causes poor handling stability.
Generally, tread rubber of studless tires is often produced from natural rubber or butadiene rubber as a main ingredient (for example, see Patent Document 1). This is because these rubbers have a low glass transition temperature and flexibility, as well as high strength. However, natural rubber and butadiene rubber suffer reversion upon sulfur vulcanization. This phenomenon causes degradation of the rubber or deterioration of the cross-linking state of the rubber, and thereby the elastic modulus at low temperatures of the rubber is decreased. Further, the inventors of the present invention have found from their studies that the phenomenon causes excessive decrease in the hardness of the rubber, resulting in poor handling stability and poor abrasion resistance. In addition, reversion may excessively increase tan δ at high temperatures, which may cause poor fuel economy.
In some cases, tires, not limited to studless tires, are vulcanized at higher temperatures so as to be produced at higher productivity. In such cases, the aforementioned phenomenon more remarkably occurs. Accordingly, there is an additional problem of decrease in abrasion resistance caused by the reversion.
Conventionally, vulcanizable rubber compositions used in rubber products such as tires are prevented from suffering reversion and are allowed to have better heat resistance in the case of containing a vulcanization accelerator in a proportion higher than that of sulfur (a vulcanizing agent), or containing a thiuram vulcanization accelerator as a vulcanization accelerator, for example. Further, rubber compositions are known to be prevented from suffering reversion in the case of containing a cross-linking agent that is capable of forming a long chain cross-linking structure represented by formulas such as —(CH2)6—S—. Examples of the cross-linking agent include PERKALINK 900 and Duralink HTS (each produced by Flexsys), and Vulcuren KA9188 (produced by Bayer AG). These techniques effectively inhibit the reversion of natural rubber or isoprene rubber; however, the techniques disadvantageously have a less or no inhibiting effect on the reversion of butadiene rubber.
Patent Document 1: JP 2007-169500 A

Rubber composition for studless tire and studless tire


A reference voltage generator uses a conventional forward junction voltage generating device and a conventional thermal generator to generate a thermal voltage. The forward junction voltage and the thermal voltages have respective thermal sensitivities that act oppositely to each other so that, when the forward junction voltage is combined with the thermal voltage to produce a reference voltage, the reference voltage is substantially insensitive to temperature. The forward junction voltage and the thermal voltage are combined to produce the reference voltage in a manner that avoids generating any voltage having a magnitude that is greater than the magnitude of the sum of the forward voltage and the thermal voltage.

A variety of electronic devices and circuits must be supplied with a voltage having a magnitude that is precisely controlled using a voltage regulator, charge pump or other voltage source. The magnitude of the voltage supplied by the voltage regulator, charge pump or other source is often set by the magnitude of a reference voltage. Various reference voltage generators are well known in the art.
A common reference voltage generator is a diode voltage generator, a typical example of which is shown in FIG. 1. The diode voltage generator 10 includes a reference current source 14 directing a reference current IR through a bipolar PNP transistor 20 having its base and collector interconnected in a diode configuration. A PN junction diode forward voltage VEB is produced at the emitter of the transistor 20. Of course, other designs for a diode voltage generator can be used, such as one having a bipolar NPN transistor.
The current-voltage characteristics of the diode voltage generator 10 are shown in FIG. 2. As shown in FIG. 2, as the current flowing through the transistor 20 increases from zero, the emitter-base voltage VEB increases quite dramatically until the "knee" 22 of the curve is reached. Thereafter as the current increases further, the emitter-base voltage VEB is fairly constant despite large changes in the magnitude of the current. The current source 14 maintains the reference current IR at a magnitude that is greater than the magnitude of the current at the knee 22. As a result, the diode reference voltage VEB is maintained at a relatively constant value despite slight fluctuations in the magnitude of the reference current IR. A typical value for the diode reference voltage VBG is 0.65 volts, and the diode voltage generator 10 is able to maintain that voltage to within a few millivolts.
Diode voltage generators are often exposed to environments in which the temperature can vary widely, and yet it is important to maintain the reference voltage constant despite these temperature variations. Unfortunately, although the diode reference voltage VEB is substantially insensitive to small variations in the magnitude of the reference current IR, the voltage VEB is not insensitive to variations in the temperature of the transistor 20. In particular, the magnitude of the diode reference voltage VEB varies with temperature at about −2 mV/° C., as shown in the graph of FIG. 3. Circuits have therefore been developed to temperature compensate the diode reference voltage VEB shown in FIG. 1. An example of a temperature compensated diode voltage generator 30 is shown in FIG. 4. The reference voltage generator 30 uses a summing amplifier 34 to sum VEB from the PN junction diode of FIG. 1 with a thermal reference voltage VT generated by a thermal voltage source 36 to produce a reference voltage VR at its output. The thermal reference voltage VT is generated from a voltage generated by the thermal voltage source 36 after being boosted by a factor of K using an amplifier 38 having a gain of K.
The thermal reference voltage VT is 0.026V varying with temperature at 0.085 mV/° C. After this value is adjusted by a constant K to make the thermal voltage equal to 0.6 V, a temperature sensitivity of 1.96 mV/° C. is obtained (i.e., K=0.06 V/0.026 V). The sum of the 1.96 mV/° C. thermal sensitivity of the thermal reference voltage VT and the −2 mV/° C. thermal sensitivity of the diode forward voltage VEB results in a terminal sensitivity of the reference voltage VR of only about −0.04 mV/° C., which is substantially insensitive to temperature variations. A graph of the reference voltage VR, i.e., the sum of the thermal reference voltage VT and the diode forward voltage VEB, is shown in FIG. 6.
Although the temperature compensated diode voltage generator 30 can provide a precise reference voltage that is substantially insensitive to temperature, it is not without its limitations. In particular, as is apparent from FIG. 6, the diode voltage generator 30 generates a reference voltage VR of about 1.25 volts, which inherently requires a supply voltage of at least 1.25 volts. However, electronic devices are increasingly being powered by supply voltages of less than 1.25 volts, thus making the temperature compensated diode voltage generator 30 unsuitable for use in such devices. As a result, there is no relatively simple and inexpensive means to provide a precise, temperature compensated reference voltage in low voltage devices.
There is therefore a need for a method and system for generating a precise reference voltage that is substantially insensitive to temperature and that can be powered by a relatively low supply voltage.

Low supply voltage temperature compensated reference voltage generator and method


A rigid intersection connection including three intersecting elongated wood structural members and a rigid connector made from a single sheet metal blank which requires no welding. The rigid connector includes a pair of angular members joined in angular relationship and joined at a common outer edge. The rigid connector more specifically includes structure for engaging two sides of one of the elongated wood structural members and three sides of two of the elongated wood structural members. The disclosure includes a log holder, a table, a bunk bed, and a greenhouse or garden structure as examples of structures which can be readily constructed from the rigid intersection connections.

This invention relates to a rigid intersection connection including a rigid sheet metal one piece connector for joining three intersecting wood elongated members in a rigid embrace.
Rigid intersection connections are common in metal structures, but are seldom used in wood frame construction because of the lack of a suitable metal connector.
Cast iron connectors have been used, but they are heavy, expensive, and difficult to work with and have not found use in today's high cost labor environment.
Attempts have been made in the past to provide connectors for rigidly joining two intersecting members, but these connectors have proven difficult to work with in joining three intersecting elongated wood members.
Several connectors have been created to join intersecting panels, but these connectors have not been adaptable for joining intersecting elongated wood members.
Molded plastic connectors which encapsulate the ends of intersecting elongated wood members have been taught, but these connectors are expensive, difficult to manufacture and install and have not found general acceptance in the building trades.


A configuration and method are disclosed for recyclably using a fixing roller cleaning device in an electrostatographic fixing station. In a principal embodiment, the cleaning device includes a cleaning web unit 13 installable in cassette fashion into a corresponding unit loading receptacle 14(15) disposed axially adjacent either fixing roller in the top and bottom ends of the fixing station. On the heating roller 3 end, the cleaning web unit 13 contains an unused disposable cleaning web 12. Therein side A of the cleaning web 12 winding between feed and take-up sections 16 and 17 of a web winding mechanism 18 serves in heavy-duty cleaning of, and application of sheet-parting agent to, the surface of the heating roller 3. Afterwards, the cleaning web unit 13 is withdrawn from location on the heating roller 3 end, turned round horizontally, and installed in location beneath the pressure roller 4 end of the fixing station. Therein reverse side B of the cleaning web 12 serves in light duty cleaning of, and application of parting agent to, the surface of the pressure roller 4.

1. Technical Field
The present invention relates to cleaning web devices in the fixing station of electrostatographic printing apparatuses, such as electrostatic photocopying machines, printers, and facsimile machines; in particular the present invention relates to the recycling use of such cleaning web devices.
2. Description of Related Art
In electrostatographic printing devices, printing sheets carrying a toner-developed image are conveyed to a fixing station typically having a heating roller against which a pressure roller presses. The toner image is fuse-fixed onto the printing sheets as they are nipped by the pair of rollers in conveyance to the fixing station. In the fixing process, toner particles thus cling to the surface of the heating roller, and consequently a cleaning device is provided in the fixing station for cleaning the heating roller.
Toner that does not get cleaned from the surface of the heating roller may stick to the surface of the pressure roller due to its different separative properties from the heating roller. Further, in double-sided image fixing processes in electrostatographic printing devices, toner may stick to the surface of the pressure roller. Consequently, a cleaning device for the pressure roller is also provided.
Examples of such cleaning devices include unit devices in which a cleaning web that is prepared by impregnating a heat-resistant paper or the like with a parting agent such as silicone oil is stretched from a web feed reel to a web take-up real, bringing one surface of the cleaning web into contact with the roller surface to be cleaned. The cleaning web is wound at a predetermined rate, and as the roller it contacts rotates, toner sticking to the roller surface is stripped off by the cleaning web.
A problem in thus employing a cleaning web, however, is that in bringing the web into cleaning contact with the roller a major portion of the parting agent contained in the web is applied to the roller surface. Accordingly, wherein after using one side of a cleaning web, the other side is to be used for another roller cleaning, the amount of parting agent applied to the surface of the roller is insufficient. Therefore, under the present circumstances only one side of the cleaning web is generally used and then it discarded.
Thus disposing of the cleaning web is, however, quite uneconomical.
Toward overcoming the forgoing problems, JP-A-140830/1995, in pursuing economy of use, discloses a technique in which a used cleaning web is reversed and re-extended between web feed and web take-up sections, and in order to compensate for the lack of parting agent remaining for application to the roller surface to be cleaned, the winding speed after reversing the web is increased over that prior to reversing, in order to equalize the quantity of parting agent applied by either side of the web. Unfortunately, it is very difficult to adjust the amount of parting agent applied in this manner; moreover the structure entailed is complex, increase the overall cost of the cleaning web unit.

Electrostatographic recyclable cleaning unit and use method


A process is presented to treat a process gas stream containing hydrogen sulfide using a reverse jet absorber with a liquid treatment solution containing a chelated metal catalyst. A treat gas substantially free of the hydrogen sulfide is separated from a spent liquid treatment solution containing elemental sulfur which can then be regenerated in an oxidation vessel where it is contacted with an oxygen containing gas to convert the spent liquid treatment solution to a regenerated liquid treatment solution that can be recycled for introduction into the reverse jet absorber.

Hydrogen sulfide is a major source of pollution of gas streams since it is liberated as a waste by-product in a number of chemical processes, such as sulfate or kraft paper pulp manufacture, viscose manufacture, sewage treatment, the production of organic sulfur compounds, as well as during petroleum refining and in the production of natural gas and combustible gases from coal, such as in coking operations. Hydrogen sulfide is also present in geothermal steam, which is captured for use in power generating plants.
To eliminate these polluting sulfur gases the art has developed several reduction-oxidation ("Redox") processes that use an aqueous liquid chelated metal catalyst solution for removing hydrogen sulfide from a gas stream. In those prior art processes, a hydrogen sulfide-containing gas, known as "sour gas," is contacted with a chelated metal catalyst to effect absorption. Subsequent oxidation of the hydrogen sulfide to elemental sulfur and concurrent reduction of the metal to a lower oxidation state also occurs. The catalyst solution is then regenerated for reuse by contacting it with an oxygen-containing gas to oxidize the metal back to a higher oxidation state. The elemental sulfur is continuously removed from the process as a solid product with high purity. Illustrative, but not exclusive, of these oxidation-reduction processes is the description contained in U.S. Pat. Nos. 4,622,212; 8,372,365 and the references cited therein.
Known sulfur removal processes use bubble column type of absorbers for H2S absorption where the sour gas is sparged or bubbled into the liquid catalytic treatment solution. Such absorber designs are chosen because bubble columns are less prone to sulfur plugging. However, the disadvantages of bubble column absorber are low gas velocity, high gas pressure drop, and low mass transfer coefficient, resulting in absorber designs that are very large in size. Other types of absorber designs include counter-current flow packed beds and co-current flow static mixers that achieve higher gas velocities (200 ft/min-1000 ft/min). Absorbers using packed bed are prone to flooding at high velocity because of the counter-current gas-liquid flow. Static mixer absorber designs are chosen when a high pressure operations is needed since a bubble column absorber would become prohibitively expensive due to the needed size and vessel wall thickness. Additionally, both the packed bed absorber and the static mixer absorber are also known to suffer elemental sulfur plugging.
Accordingly, there is a need in the technical area of H2S removal for an absorber design that allows large gas flow and gas velocity, with small pressure drop across the absorber, and yet will not be plugged by product sulfur after a prolonged operation. The present disclosure provides a reverse jet absorber design and a process of operating an H2S removal process that uses such an absorber, which design avoids the above-noted issues with conventional H2S removal processes. These and other advantages will become evident from the following more detailed description of the present disclosure.


The methods involve selectively depositing a resist containing a solid hydrogenated rosin resin and a liquid hydrogenated rosin resin ester as a mixture on a semiconductor followed by etching uncoated portions of the semiconductor and simultaneously inhibiting undercutting of the resist. The etched portions may then be metallized to form current tracks.

The manufacture of semiconductor devices, such as photovoltaics and solar cells, involves the formation of electrically conductive contacts or current tracks on front and back sides of semiconductors. The metal coating must be able to establish ohmic contact with the semiconductor in order to ensure that charge carriers emerge from the semiconductor into the electrically conductive contacts without interference. In order to avoid current loss, metallized contact grids must have adequate current conductivities, i.e. a high conductivity or a sufficiently high conductor track cross section.
Numerous processes which meet the above requirements exist for metal coating the back side of solar cells. For example, in order to improve current conduction at the back side of solar cells, p-doping directly under the back side is reinforced. Usually aluminum is used for this purpose. The aluminum is applied, for example, by vapor deposition or by being printed onto the back side and being driven in or, respectively, alloyed in. Metal coatings using thick-film techniques are conventional methods for metallizing conductor tracks. Pastes used include metal particles and are electrically conductive as a result. The pastes are applied by screen, mask, pad printing or paste writing. A commonly used process is the screen printing process where finger-shaped metal coating lines having a minimum line width of 80 μm to 100 μm are made. Even at this grid width electrical conductivity losses are evident in comparison with a pure metal structure. This can have an adverse effect on the series resistance and on the filling factor and efficiency of the solar cell. This effect is intensified at smaller printed-on conductor track widths because the process causes the conductor tracks to become flatter. Nonconductive oxide and glass components between the metal particles constitute a fundamental cause of this reduced conductivity.
When metal coating the front sides, or light incidence sides, the objective is to achieve the least amount of shading of the active semiconductor surface in order to use as much of the surface as possible for capturing photons. Complex processes for producing the front side contacts make use of laser and other imaging techniques for the definition of the conductor track structures. The front side of the wafer may optionally be subjected to crystal-oriented texture etching in order to impart to the surface an improved light incidence geometry which reduces reflections. To produce the semiconductor junction, phosphorus diffusion or ion implantation takes place on the front side of the wafer to produce an n-doped (n+ or n++) region and provides the wafer with a PN junction. The n-doped region may be referred to as the emitter layer.
An anti-reflective layer is added to the front side or emitter layer of the wafer. In addition the anti-reflective layer may serve as a passivation layer. Suitable anti-reflective layers include silicon oxide layers such as SiOx, silicon nitride layers such as Si3N4, or a combination of silicon oxide and silicon nitride layers. In the foregoing formulae, x is the number of oxygen atoms, typically x is the integer 2. Such anti-reflective layers may be deposited by a number of techniques, such as by various vapor deposition methods, for example, chemical vapor deposition and physical vapor deposition.
An opening or pattern is then defined on the front side. The pattern reaches through the antireflective layer to expose the surface of the semiconductor body of the wafer. A variety of processes may be used to form the pattern, such as, but not limited to, laser ablation, mechanical means, chemical and lithographic processes. Such mechanical means include sawing and scratching. Typical photolithographic processes include disposing an imageable material on the surface of the wafer, patterning the imageable material to form openings in the anti-reflective layer, transferring the pattern to the wafer, depositing a metal layer in the openings and removing the imageable material. An example of a chemical method of forming an opening on the front side is etching with an etching composition, such as a buffered oxide etch. Such buffered oxide etches may include one or more inorganic acids in combination with a buffering agent, such as an ammonium compound. Prior to the etching step, a mask which is resistant to the etching activity of the etchant is applied in a pattern negative to that of the sites of the current tracks. After etching the mask is usually removed prior to metallization of the current tracks.
A major problem which often arises during formation of the current tracks is undercutting. This results in defective and inefficient semiconductor devices. This problem is common when the current tracks are formed using an etching method in combination with a mask, also known as an etch resist. Upon application of the etch to the selectively masked semiconductor, the etch may not only remove portions of the antireflective layer not covered by the mask but by capillary action seep under the mask at the interface of the mask and the antireflective layer causing portions of the antireflective layer covered by the mask to be undesirably etched away. This results in current tracks having irregular widths which results in irregular and non-uniform current flow in the final metalized device. In addition, such undercutting may form tributaries which adjoin adjacent current tracks resulting in electrical shorts.
Another problem in the formation of current tracks involves the hydrophilic nature of the surface of the semiconductor wafer. Many conventional masking materials used in the manufacture of photovoltaic devices adhere poorly to hydrophilic surfaces. The more hydrophilic the wafer surface the more compromised is the adhesion of the mask to the wafer surface, thus aggravating undercutting of the mask by the etchant. While monocrystalline and polycrystalline wafers and antireflective layers, in general, tend to be more hydrophobic in nature than hydrophilic, there is still some degree of hydrophilic character which may compromise adhesion of masks to their surfaces. In addition, mono cast wafers, also known as hybrid mono wafers, are becoming more common in the photovoltaic industry. These wafers are combinations of both multicrystalline and monocrystalline silicon. They are becoming more desirable for use in the photovoltaic industry because they have a higher potential efficiency than conventional multicrystalline wafers and are less costly than conventional monocrystalline wafers. However, such mono cast wafers are substantially more hydrophilic than the multicrystalline and monocrystalline wafers and many conventional masks do not adhere to their surfaces to the degree desired to prevent undercutting.
As the industry seeks to manufacture semiconductor devices using thinner and more delicate semiconductor wafers and at the same time increase the plurality of current tracks on the front side of the wafers to increase electrical out-put, the problem becomes compounded by difficulty of working with smaller and more delicate materials. In addition, current tracks with smaller dimensions reduce shadowing. When the semiconductor is used as a means of collecting incident radiation, such as in photovoltaic devices and solar cells, large current tracks may block incident light from impinging on the antireflection layer, thus reducing the amount of incident light which is absorbed by the semiconductor with the result of compromising the efficiency of the photovoltaic device or solar cell. Accordingly, there is a need for a method and etch resist which substantially reduces or eliminates the problem of undercutting in the formation of current tracks on semiconductor wafers and permits the formation of fine line current tracks.


A highly efficient PET breast imager for detecting lesions in the entire breast including those located close to the patient's chest wall. The breast imager includes a ring of imaging modules surrounding the imaged breast. Each imaging module includes a slant imaging light guide inserted between a gamma radiation sensor and a photodetector. The slant light guide permits the gamma radiation sensors to be placed in close proximity to the skin of the chest wall thereby extending the sensitive region of the imager to the base of the breast. Several types of photodetectors are proposed for use in the detector modules, with compact silicon photomultipliers as the preferred choice, due to its high compactness. The geometry of the detector heads and the arrangement of the detector ring significantly reduce dead regions thereby improving detection efficiency for lesions located close to the chest wall.

Breast cancer biology seems to indicate that breast cancer metastasis starts at the lesion size of about 2 mm. While X-ray mammography offers much better intrinsic spatial resolution, on the order of 50 micrometers, this anatomical imaging modality suffers from poor specificity to the type (cancerous or benign, etc.) of the suspicious structure seen on the mammogram. In some patients this X-ray imaging technique is not useful at all due to dense breast tissue, implants, or scars as the result of previously performed surgery. Breast MRI can provide more structural information than mammography but it also provides nonspecific information about the type of tissue imaged. Imaging techniques offering information as to the type or biology of the anatomical structures present in the breast and especially any suspicious lesions are based on biomarkers sensitive to molecular species present in the tissue. Examples of these functional or molecular imagers are Positron Emission Tomography (PET) scanners and gamma cameras. These standard imaging instruments are not capable of achieving spatial resolution in breast at the range of 2 mm or better, as is desirable, as mentioned above. It is therefore crucial to develop functional imaging techniques that can produce imaging power on the 1 mm resolution scale.
Although there has been proposed breast-specific functional imagers including dedicated compact gamma cameras placed close to breast, physical limits are imposed on their resolution by the parallel-hole mechanical collimator and the effect of distance between the imaged feature to the surface of the collimator. Radiotracer used in single gamma breast imaging with standard gamma cameras and with specialized breast-specific instruments is typically Tc-99m-Sestamibi, labeled with Tc99m, which emits gamma rays at 140 keV. Typically, the best average linear spatial resolution obtained in a compressed breast with these instruments using parallel-hole collimators is on the order of 5-6 mm. A partial remedy to this problem is imaging the compressed breast simultaneously from both sides, therefore reducing the average distance from any feature in the volume of the breast to the nearest collimator. However, even in this case the 2 mm limit is practically not obtainable due to interrelation between the collimator resolution and sensitivity. While parallel collimators offering 2 mm spatial resolution at a 2.5 cm distance can be made available, their sensitivity will be too low and the resulting images will exhibit too much statistical noise to allow efficient detection of small cancerous lesions. Other imaging schemes with pinhole collimators were proposed to attain better spatial resolution, but they still suffer from poor sensitivity due to the function of the pinhole gamma collimator.
FDA-approved dedicated breast PET imagers are available from Naviscan PET Systems of San Diego, Calif. These instruments are capable of achieving spatial resolution of <2 mm FWHM with F-18 positron-emitting radiolabels used for example in the F-18-fluorodeoxyglucose (FDG) biomarker. However, they suffer from another problem, related to the physics process of coincidence PET coincidence imaging, which results in poor sensitivity in the region of the breast close to chest wall. PET detection efficiency drops quickly off at the detector edges because of the geometrical requirement of simultaneous detection of two back to back 511 keV annihilation gamma rays produced in the act of positron annihilation with one of the electrons of the surrounding breast tissue. This produces a dead edge or sharp drop in detection efficiency when approaching the edge plane of the system. In comparison, single photon imaging does not suffer to the same extent from the chest wall effect and in addition one can use for example the slant collimator solution that will further reduce the dead region effect. This geometrical effect was defined in a recent clinical trial study as the cause of missing lesions placed at the base of the breast, close to the wall chest region. It is therefore a serious limitation and recognized deficiency of the dedicated PET breast imaging procedure as currently implemented with planar scanning modules.
Another example of a prior art breast imaging PET system is that described by RR Raylman, et al. in Development of a Dedicated Positron Emission Tomography System for the Detection and Biopsy of Breast Cancer, NIMA, 2006; 564(2):291-295. The imaging system includes two pairs of planar PET imager modules mounted on a rotating gantry under a patient's bed. The two pairs of modules in this proposed system have only limited reach towards the patient's chest wall and therefore, are unable to image the breast region closest to the chest wall.

High resolution PET breast imager with improved detection efficiency


Displaying font names is disclosed. A list of font names is obtained, where each font name is divided into a prefix portion, if any, and a remainder portion. The list is sorted without considering the prefix portion. The prefix portions are displayed, for those font names that have them, using a first display property and the remainder portions are displayed using a second display property.

Some typographically advanced applications have a rich selection of fonts where a user is able to select from hundreds or thousands of fonts. For example, designers who develop web pages or advertisements may be extremely concerned about visual aesthetics and font selection may be an important consideration. Simple sort and prefix savvy sort are two techniques for sorting a list of fonts. In simple sort, a list is sorted in alphabetical order using all of the words in a font name. In prefix savvy sort, a prefix portion of a font name is not considered during alphabetizing, and the sort is based on a remaining portion of a name. For example, the font New Caledonia Std includes a prefix of New and a remaining portion of Caledonia Std. Using prefix savvy sort, the font New Caledonia Std would be sorted or grouped under the letter C.
Existing techniques for presenting fonts can be cumbersome or confusing to some users. For example, in some cases, a list of fonts is presented using simple sort but a user prefers prefix savvy sort. When presented with a list of fonts that has been prefix savvy sorted, some users do not understand how the order came about and/or it is difficult to visually detect the sort order. It is particularly inconvenient or frustrating when thousands of fonts are presented to a user. It would be desirable to develop improved techniques for presenting a list of fonts to a user.

Prefix savvy displays in font enumeration user interfaces


A print buffer for storing recording data is divided into a plurality of segments and the amount of recording data causing a recording head to perform a recording operation is counted on a segment-by-segment basis. A recording medium is compared to the print buffer with respect to a scanning direction of the recording head and segments not corresponding to the inside of the recording medium are selected from the plurality of segments. The amount of recording data included in the selected segments and causing a recording operation to occur is counted and added up to estimate the amount of ink ejected outside the recording medium.

1. Field of the Invention
The present invention relates to inkjet recording apparatuses for recording by ejecting ink from a recording head onto a recording medium, and to methods in the inkjet recording apparatuses for estimating the amount of waste ink not used for recording. In particular, the present invention relates to a recording apparatus capable of recording by ejecting ink onto the entire surface of a recording medium, and to a method for estimating the amount of waste ink ejected outside a recording medium.
2. Description of the Related Art
Known recording apparatuses, including printers, copiers, and facsimiles, record images by forming dot patterns, based on image information, on a recording medium, such as paper or a thin plastic plate. Examples of recording methods used in such recording apparatuses include an inkjet method, a wire dot recording method, a thermal recording method, and a laser beam recording method.
These days, such recording apparatuses are required to offer high-speed printing capability, high image quality (high resolution), and less noise. Examples of recording apparatuses meeting these requirements include a recording apparatus using an inkjet method (inkjet recording apparatus). An inkjet recording apparatus allows ink (recording liquid) to be ejected from ejection outlets of a recording head, causes ink droplets to adhere to a recording medium, thereby forming images thereon. Since it is not necessary in the inkjet method to bring a recording head into contact with a recording medium, images can be recorded with a constant quality on various types of recording media.
Among inkjet recording apparatuses, a serial-type recording apparatus causing the recording head to reciprocate in a direction (main scanning direction) differing from the feed direction of a recording medium is widely known. The serial-type recording apparatus is capable of recording on recording media of various sizes even with a small recording head. With a plurality of recording heads or with a plurality of nozzle arrays on a recording head, the serial-type recording apparatus can easily accommodate multiple color recording. Moreover, with a recording method in which a recording head scans the same area of a recording medium multiple times, the serial-type recording apparatus can easily adjust the recording speed and image quality by varying the number of scans on the same area. This serial recording method has become widespread rapidly in the market because of its various advantages as described above.
Another type of recording apparatus that is known these days is capable of performing full-surface recording (also called non-blank recording), in which a recording area over which a carriage reciprocates for ejecting ink extends outside a recording medium, and thus recording on the entire surface of the recording medium can be achieved without leaving blank space on the edge of the medium.
This full-surface recording involves recording on the entire surface of a recording medium, and is also called "borderless recording" in contrast with a method of recording on a recording medium, with a border left on the edge thereof. In such a recording apparatus that can accommodate full-surface recording, a platen supporting a recording medium must be prevented from being contaminated with ink ejected outside the recording medium, that is, ink off the edge of the recording medium. Therefore, a waste ink absorber is disposed on a platen or under an opening in a platen to absorb ink ejected outside the recording medium. Such a waste ink absorber provided to achieve full-surface recording is hereinafter referred to as "platen absorber".
However, there is a limit to the amount of ink that can be absorbed in the platen absorber. A problem thus arises in that an increase in the number of sheets for full-surface recording causes ink to overflow from a platen absorber and causes the platen to be contaminated.
For such a recording apparatus capable of performing full-surface recording, some control methods have been proposed to prevent ink from overflowing from a platen absorber.
For example, Japanese Patent Laid-Open No. 2001-301201 (corresponding to U.S. Pat. No. 6,709,088) discloses a structure where a guide unit for a recording medium is provided with an ink receiving hole in which an ink absorber is placed. This document proposes a recording apparatus having amount-of-waste-liquid summing means for summing to calculate the amount of ink ejected to an ink absorber. This document also proposes amount-of-waste-liquid summing means for summing predetermined values instead of the amount of ejected ink.
This document further proposes amount-of-waste-ink measuring means for dividing the size of a recording medium into segments in the direction of movement of a carriage (in the main scanning direction), determining the size of a dot count window, performing a dot count on each dot count window on a print buffer provided in a control circuit of the inkjet recording apparatus, thereby measuring the amount of ink in a borderless area.
To calculate the total amount of ink ejected to the ink absorber, the above-described known techniques require accurate measurement of the width of a recording medium and the size of overflow areas on the left and right sides of the recording medium, and calculation every time a recording operation is performed. Therefore, these known techniques require complex and expensive sensors and mechanisms for accurate detection and measurement of the width of a recording medium and the size of overflow areas. However, if a method for summing predetermined values is used instead to reduce the costs involved in producing the recording apparatus, accuracy in estimating the amount of waste liquid is degraded.
In another method proposed to avoid such problems, the amount of ink ejected to the ink absorber is not calculated by summing, but is estimated based on recording data (that is, data to be used for recording) stored in the print buffer. However, the method for estimating the amount of ink based on recording data in the print buffer has a problem in that sufficient accuracy cannot be maintained in some cases, depending on the size of the recording medium.
This problem will be described in detail.
The above-described Japanese Patent Laid-Open No. 2001-301201 discloses a structure in which control means creates bitmap data based on recording data transmitted from the host computer, and causes head drive means to generate driving signals based on the bitmap data. This document also discloses an apparatus supplying driving signals to a recording head on a carriage, allowing ink to be ejected through the recording head, thereby recording images on a recording medium.
During image recording, print control means sends control signals to amount-of-waste-liquid counting means. Thus, during full-surface recording, the number of ink droplets ejected to the waste ink absorber on the platen is counted. Such a structure for counting the number of ejected ink droplets requires an extremely complex and expensive control device, as the total number of ejected ink droplets must be counted at every ejection.
The above-described Japanese Patent Laid-Open No. 2001-301201 also proposes a recording apparatus for adding a predetermined value, instead of performing complex control, every scan of a carriage or every time recording is performed on a recording medium. Since the sum of predetermined values is calculated, this recording apparatus does not require a complex control mechanism, as there is no need to count the number of ejected ink droplets. However, since the same value regardless of the image to be recorded is added, the accuracy in the calculation of the amount of waste ink is low. This particularly poses a problem when the platen absorber is independently structured and cannot allow ink to be discharged therefrom.
For example, if a predetermined value to be added is set to be large, it is determined that the maximum amount of ink that can be absorbed in the absorber has been reached at a stage earlier than the number of recording media on which full-surface recording can actually be performed is reached. In this case, even if the absorber is actually capable of absorbing more ink, the recording operation is restricted so that full-surface recording can no longer be performed. On the other hand, if a predetermined value to be added is set to be small, and if images causing a large number of ink droplets to be ejected to the absorber are continuously recorded, ink may overflow from an absorber before a set value is reached. In this case, the amount of ink actually discharged is larger than the sum of the predetermined values. A problem thus arises in that the platen and the reverse side of the recording medium are contaminated with ink.
A method for estimating the amount of ink based on recording data stored in the print buffer is provided to solve the problems described above. However, accuracy in dot count for estimating the amount of ink ejected off the recording medium is significantly degraded, depending on the size of recording. The degradation in accuracy will be described in detailed in an embodiment below.

Inkjet recording apparatus and method for estimating the amount of waste ink in the inkjet recording apparatus


A wager for casino craps which allows a player to win when a come out shooter makes a hard point (e.g. rolls 2/2 or 3/3 or 4/4 or 5/5), and then the shooter makes the point (before the shooter rolls a seven) with the same hard point (e.g. 2/2 or 3/3 or 4/4 or 5/5). If the shooter does not roll a hard point (1/1 and 6/6 are considered ‘craps’ and are not points) or the shooter rolls a hard point on the come out roll but does not make the same hard point before rolling a seven (or makes the point without rolling the hard point), then the player loses the wager.

1. Field of the Invention
The present inventive concept relates to a casino table game, and more particularly, to a variation of casino craps which includes a new wager.
2. Description of the Related Art
Although games involving dice are extremely popular in non-gaming environments, only craps has been successful in a gaming environment. The game of craps is offered in nearly all casinos. Craps involves two six sided dice which are rolled two or more times by a designated player (the "shooter"). The fundamental bet in craps is known as the "pass" bet. The pass line bet is lost on a first roll ("come out") of 2, 3, or 12. Each pass bet wagerer is paid even money on a come out roll of 7 or 11. In either case, the pass bet is resolved and a new wager must begin. Should the shooter's come out roll be a 4, 5, 6, 8, 9, or 10, that number is identified as the "point." Thereafter, the shooter continues to roll the dice until the point is repeated or a seven is rolled, whichever occurs first. If the point is repeated ("making the point"), each pass wagerer is paid even money on their pass bets and a new game begins with the same shooter. If a seven is rolled ("seven-out") prior to making the point, each pass bet wagerer loses their pass bet and the shooter must relinquish the dice to another participant. Craps also includes a host of additional wager opportunities related to each roll of the dice. For example, players may wager that any number will be rolled on a subsequent roll, bet that the value of each die will match (i.e snake eyes), and so on.
In craps, a "hard way" or "hard" number is one of 4, 6, 8, or 10, rolled with both dice showing the same number. The dice show a hard 4 if each die displays a 2. The dice show a hard 6 if each die displays a 3. The dice show a hard 8 if each die displays a 4. The dice show a hard 10 if each die displays a 5.
Also in craps, a "proposition" bet is any of the rolls displayed in the center of the casino craps layout, usually with high payouts and correspondingly high house advantages. Examples of proposition bets include a single-roll bet on the number 12, the single-roll "Any-7" bet, and the single-roll "Any Craps" bet. In addition, there are four "hard way" wagers based on the proposition that the shooter will roll a given hard number before either the non-hard version of that number or a seven appears.
Several other dice games have been attempted in casinos, but without great, or even moderate, success. One such game is known as "Chuck-a-Luck." Chuck-a-Luck is a game involving a single roll of three six sided dice having associated payouts related to one, two, or three of the dice faces showing a selected number from one to six. Another dice game is known as "Under and Over 7. " Under and Over 7 allows players to wager whether the sum of two dice will be less than, more than or equal to seven.
Casino craps is the only significantly successful casino dice game. The game of craps is exciting, but traditionally has payouts only as high as 31-1. Moreover, the wagers that pay the highest multiples also tend to have the worst odds for the player.
A side wager for craps known as the Fire Bet (U.S. Pat. No. 6,655,689) has payouts as high as 2500-1, although that wager has up to a 20% house advantage. Furthermore, based on the rules, one Fire Bet can be made per shooter. Since each shooter rolls an average of 8.5 rolls before relinquishing the dice, many fewer Fire Bets can be made per hour, thereby decreasing the casino's revenue potential when compared to other, more frequently-made wagers.
Therefore, what is needed, is a craps wager that overcomes the limitations in the prior art by providing a wager for casino craps with a high payout, a fast rate of resolution, and a reasonable house advantage.


An imaging system including a multi-mode fiber and a gradient index (GRIN) lens. The invention also relates to a system including a multi-mode fiber, such as a double-clad photonic crystal fiber, for transmitting an excitation signal to a sample for the purpose of imaging, and a scanning mechanism, which preferably includes a microelectromechanical system (MEMS) mirror, for reflecting the excitation signal in varying directions in order to scan the sample.

It is known to use a single-mode fiber in a two-photon fluorescence endoscope. The fiber has a core with a small numerical aperture (NA), which acts as both the source and detection aperture. Transmission characteristics of the single-mode fiber allow for relatively high excitation efficiencies and resolution to be achieved but low collection efficiency results.
Multi-mode fibers, such as double-clad photonic crystal fibers (DCPCFs) have recently been used for imaging. Such fibers have a single-mode inner core, with a small NA to provide a high efficiency excitation signal. A larger NA multi-mode layer surrounds the core, within an outer cladding, to provide high collection efficiency, although somewhat reduced resolution as compared to the single-mode fiber.
The advantages of DCPCFs have been demonstrated for optical imaging in endoscopy, as disclosed in an article D. Yelin, et al, "Double-clad fiber for endoscopy", Optics Letters, Vol. 29, No. 20, 2408 (2004). Further, improved detection efficiency has been investigated in relation to two-photon fluorescence detection, as disclosed in M. Myaing, et al, "Enhanced two-photon biosensing with double-clad photonic crystal fibers", Optics Letters, Vol. 28, No. 14, 1224 (2003).