The present invention is directed to a highly-integrated MEMS-based miniaturized transceiver. The transceiver utilizes a low band front-end to direct sample low band signals and a high band front-end to translate high band signals that cannot be directly sampled to low band before low band front-end processing. The low band front-end comprises an array of High-Q MEMS (microelectromechanical systems)-based filters/resonators separated by isolation amplifiers in selectable cascade with narrower bandwidth filters. Dynamic tuning ability is provided through the isolation amplifiers and the sample frequency of the analog-to-digital converter. This architecture is amenable to monolithic fabrication. The input frequency range is scalable with analog-to-digital conversion sampling rate improvements. Re-utilization of filters is spatially efficient and cost effective. Tuning time is limited only by the analog-to-digital conversion and digital signal processing, not synthesizer settling times. This architecture eliminates major sources of traditional intermodulation distortion and reduces complex hardware, increasing reliability.

Radio/microwave frequency receivers and transmitting systems typically rely on a superheterodyne architecture to couple high-frequency signals from the antenna to a base-band processor. Superheterodyne frequency receivers and transmitting systems spanning many octaves of frequency coverage typically require multiple conversion steps and intermediate frequencies to down-convert to a final processing frequency. Frequency filters are heavily relied upon to channelize bands of operation and reject interference. Unfortunately, these filters typically comprise a large volume of the overall system size and are not amenable to monolithic fabrication, requiring extensive and costly touch labor (also direct labor, factory labor costs that can be easily traced to individual units of product). Radio/microwave frequency receivers and transmitting systems also rely on highly linear and low-loss switches to select between channels.
Conventional approaches to reducing transceiver complexity include direct-conversion transceivers, SAW filters, high-Dk distributed element filters, varactor-based agile filters, and FET semiconductor switches. However, direct-conversion transceivers suffer from DC offset errors and poor second order intermodulation performance. SAW filters are inherently narrow band, lossy, have poor group delay response, and are not amenable to monolithic integration. High-Dk distributed element filters are lossy and still consume appreciable size at lower frequencies. Varactor-based agile filters typically have high loss, modest intermodulation performance, limited tuning range, and complex biasing requirements. FET semiconductor switches are lossy, exhibit poor isolation, and are prone to intermodulation distortion.
Consequently, it would be desirable to reduce the size and complexity of transceivers with highly linear, low-loss filters which can be monolithically integrated.

Highly-integrated MEMS-based miniaturized transceiver


Multistep process for the preparation of alkyl mono and diisocyanates consisting in reacting the corresponding aliphatic amine or diamine with dimethylcarbonate and, substantially, in partially vaporizing and converting the urethane thus formed in an evaporator to subsequently terminate the cracking in a II.degree. reactor, and finally subjecting the cracking product to fractional distillation at reduced pressure, recycling the unconverted part to the partial vaporization step.

Various procedures for the preparation of isocyanates starting from aminic compounds via dialkylcarbonate are already described in literature for example, patent applications EQU WO 8805430; JP 2066-261; JP 2311-452
disclose a two-step procedure consisting in:
1) reacting a diamine with dimethylcarbonate in the presence of an alkaline alcoholate to produce urethane which is recovered from the mixture; PA1 2) the decomposition of the latter at 230.degree. C. in an organic solvent having a high boiling point in the presence of a metal and continuously removing the reaction products, by distillation. PA1 1) reacting a diamine with urea in the presence of dialkylcarbonate and alcohol to give the corresponding alkyl diurethane; PA1 2) subjecting the latter to partial vaporization and be then fed to a cracking reactor packed with a metallic filling with a low pressure loss which operates at a temperature which is higher than 300.degree. C.
Between 1) and 2) the catalyst is neutralized by treatment with acid, and then removed; the urethane is then purified by distillation.
This procedure has a problem in step 1) concerning the recovery of the dialkylurethane by distillation with the conventional methods, which is difficult to perform with good yields, and in step 2) various problems due to the purification of the liquid flows from the catalytic residues.
U.S. Pat. Nos. 4,596,678 and 4,596,679 also describe a two-step process consisting in:
Between 1) and 2) the urethane, which however contains synthetic by-products, which have a negative influence on the final result, is isolated.
U.S. Pat. No. 4,613,466 discloses a one-step process wherein dialkylurethane urethane is partially vaporized without decomposition and fed as such to a cracking reactor packed with a specific metallic filling having a catalytic function.
The products are then recovered by fractional condensation.
The above two-step process has, as already mentioned, the serious disadvantage of insufficient selectivity in the synthesis of the urethane during which are formed complex mixtures which are difficult to separate; the second step of the process and also the procedure described in the last patent have problems deriving from the presence of polymeric byproducts in the alkyl diurethane, which must be removed from the vaporization chamber by the liquid current discharged (partial evaporization) and from which it is difficult to recover the alkyl diurethane. This weighs heavily on the specific consumption of the process.

Procedure for the preparation of alkyl isocyanates


An apparatus configured to a downhole tubular to a pump. The apparatus comprises: a body portion having a bore; a locking assembly comprising at least one locking member pivotally mounted to the body portion so as to permit the locking member to be pivoted between an open position in which the downhole tubular can be inserted into the bore of the body portion, and a closed position in which the locking member engages the downhole tubular so as to lock the downhole tubular in the bore of the body portion. Fixing means is provided for fixing the looking member in the closed position. A method of drilling a wellbore using a borehole casing.

1. Field of the Invention
The present invention relates to coupling apparatus for coupling a downhole tubular (such as a borehole casing) to a pump, conventionally known as a circulating head. The invention also relates to a method of pumping fluid into a downhole tubular, and to a method of drilling.
2. Description of the Related Art
A conventional circulating head is described by LeFleur et al in U.S. Pat. No. 5,282,653, U.S. Pat. No. 5,152,554 and U.S. Pat. No. 5,348,351. As described by LeFleur et al, when casing is being run in connection with the drilling of an oil or gas well, it sometimes becomes necessary to connect surface pumping equipment to circulate drilling fluid down the well. Typically, this need arises when a tight spot is encountered and drilling fluid is circulated down the well to run the casing past the tight spot and avoid the need for removing the casing and redrilling the hole.
The circulating head described by LeFleur et al uses a segmented ring of eight dogs to lock a cylindrical member in place. The dogs are fixed in place by rotating a bottom end cap.
This arrangement suffers from a number of problems. Firstly the apparatus has a large number of working parts. Secondly it can be difficult and time consuming to rotate the bottom end cap.


The embodiments of the present invention enable novel methods, non-transitory mediums, and systems for encoding and generating haptic effects. According to the various embodiments, a media object is retrieved. The media object is analyzed to determine one or more time periods for rendering haptic effects. The haptic effects for rendering during the time periods are determined. The haptic effects are encoded as a haptic effect pattern that identifies a start time and duration for each of the haptic effects.

Electronic device manufacturers strive to produce a rich interface for users. Conventional devices use visual and auditory cues to provide feedback to a user. In some interface devices, kinesthetic feedback (e.g., active and resistive force feedback) and/or tactile feedback (e.g., vibration, texture, temperature variation, and the like) are provided to the user. In general, such feedback is collectively known as "haptic feedback" or "haptic effects." Haptic feedback provides cues that intuitively enhance and simplify a user's interaction with an electronic device. For example, the haptic effects may provide cues to the user of the electronic device to alert the user to specific events, or provide realistic feedback to generate greater sensory immersion within a simulated or virtual environment.
Haptic feedback has also been increasingly incorporated in a variety of portable electronic devices, such as cellular telephones, smart phones, tablets, portable gaming devices, and a variety of other portable electronic devices. In addition, some known devices modify or generate haptic effects in real-time or based on an audio file.

Haptic effect encoding and rendering system


Methods for optimizing the routing of customer communications include receiving a customer communication; identifying a customer associated with the customer communication; accessing a profile of the identified customer to determine customer data; receiving customer metric scores for a plurality of customer metrics; identifying available agents; accessing a profile of each available agent to determine agent data; predicting interaction outcome metric values for a plurality of customer metrics based on the customer data and the agent data; calculating, in real-time, an aggregate agent-customer pairing score for each available agent; selecting a responding agent from the available agents with the highest aggregate agent-customer pairing score; and providing a routing recommendation to a communication distributor to route the customer communication to the responding agent with the highest aggregate agent-customer pairing score.

Call-routing ability and efficiency is important. The time it takes to connect a caller to a suitable agent affects customer satisfaction and hence business image. Mistakes in routing, connecting callers for example to overloaded centers or to agents not prepared to help with the customer's difficulty or desire, can be troublesome.
Automatic communication distribution (ACD) systems are known. Often an organization disseminates a single telephone number to its customers and to the public in general as a means of contacting the organization. As calls are directed to the organization from the public switch telephone network, the ACD system directs the calls to its agents based upon some type of criteria. For example, where all agents are considered equal, the ACD may distribute the calls based upon which agent has been idle the longest.
In addition, ACD systems generally require predefined and static distribution strategies that are unable to adapt in real-time. This limitation forces a "one size fits all" distribution approach optimized for a single customer metric, as opposed to a dynamic approach based on employee, customer, and interaction information. For example, an agent may be selected based on customer satisfaction where the available agents all perform similarly on customer satisfaction, but optimizing average handling time where the agents vary greatly is not analyzed. In another example, a customer is eligible for a new product offer so the customer could be routed to the agent most likely to upsell, rather than the global treatment based on customer satisfaction. In yet another example, a customer has contacted the contact center multiple times, but the company is optimizing all interactions for average handling time. This customer, however, would be better served by an agent with the highest resolution rate.
Accordingly, a need exists for improved methods and systems for routing customer communications.

This patent is subject to a terminal disclaimer.

Dynamic metric optimization in predictive behavioral routing


In annealing a non-single crystal silicon film through the use of a linear laser beam emitted by a YAG laser of a light source, it is the object of the present invention to prevent heterogeneity in energy caused by an optical interference produced in the linear laser beam from having an effect on the silicon film. The laser beam is divided by a mirror 604 shaped like steps into laser beams which have an optical path difference larger than the coherence length of the laser beam between them. The divided laser beams are converged on an irradiate surface 611 by the action of a cylindrical lens array 605 and a cylindrical lens 606 to homogenize the energy of the laser beam in the length direction and to determine the length of the linear laser beam. On the other hand, the laser beams divided by a cylindrical lens array 607 are converged on the irradiate surface 611 by a cylindrical lens 608 and a doublet cylindrical lens 609 to homogenize the energy in the width direction of the laser beam and to determine the width of the linear laser beam. Interference fringes parallel to the width direction of the linear laser beam disappears in the linear laser beam by the action of a mirror 604 shaped like steps. If the silicon film is annealed by the linear laser beam while the linear laser beam is being shifted in the width direction of the linear laser beam, the silicon film is remarkably homogenized as compared with a conventional silicon film.

1. Field of the Invention
The present invention relates to a device for manufacturing a semiconductor device having a circuit constituted by a thin film and, or example, to a device for manufacturing an electro-optical device typified by a liquid display device and an electric device having the electro-optical device as a part. In this connection, in the present specification, a semiconductor device designates in general a device capable of functioning by the use of semiconductor characteristics and includes the above electro-optical device and electric device.
2. Description of the Related Art
In recent years, research and development have been widely conducted on the technologies for performing a laser annealing processing to an amorphous semiconductor film or a crystalline semiconductor film (semiconductor film which is not a single crystal but a polycrystal or a micro-crystal), that is, non-single crystal semiconductor film formed on an insulating substrate such as a glass substrate or the like to crystallize the non-single crystal semiconductor film or to improve its crystallinity. A silicon film is often used as the above semiconductor film.
A glass substrate has advantages that it is cheap and has good workability and is easy to make a large area substrate in comparison with a quartz substrate which has been conventionally used. This is because the above research and development have been carried out. Also, it is because the melting point of the glass substrate is low that a laser is widely used for crystallizing the semiconductor film. The laser can apply high energy only to a non-single crystal film without increasing the temperature of the substrate too much.
The crystalline silicon film is called a polycrystalline silicon film or a polycrystalline semiconductor film because it is made of many crystal grains. Since the crystalline silicon film subjected to a laser annealing processing has high mobility, a thin film transistor (hereinafter referred to as TFT) is formed by the use of the crystalline silicon film and, for example, is widely used for a monolithic liquid crystal electro-optical device having a glass substrate and TFTs for driving a pixel and for a driving circuit.
Also, a laser annealing method of transforming the high-power laser beam of a pulse oscillation such as an excimer laser into a square spot several cm square or a linear beam 10 cm or more in length at an irradiate surface by the use of an optical system and of scanning a semiconductor film with the laser beam (or moving a spot irradiated with the laser beam relatively to an irradiate surface) has been widely used because it increases mass productivity and is excellent in an industrial view point.
In particular, when a linear laser beam is used, the whole irradiate surface is irradiated with the linear laser beam only by scanning the irradiate surface in the direction perpendicular to the direction of the line of the linear laser beam, which therefore produces high mass productivity. In contrast to this, when a spot-like laser beam is used, the irradiate surface needs to be scanned with the laser beam in the back-and-forth direction and in the right-and-left direction. The irradiate surface is scanned with the linear laser beam in the direction perpendicular to the direction of the line of the linear laser beam because the direction is the most efficient scanning direction. The method of using the linear laser beam into which the laser beam emitted from the excimer laser of pulse oscillation is transformed by the use of a suitable optical system for the laser annealing processing has become a mainstream technology.
In FIG. 1 is shown an example of the constitution of an optical system for transforming the cross section of the laser beam into a linear shape at an irradiate surface. This constitution is extremely ordinary and all the above optical systems are similar to FIG. 1. This constitution not only transforms the cross section of the laser beam into the linear shape but also homogenizes the energy of the laser beam at the irradiate surface. In general, an optical system homogenizing the energy of the beam is called a beam homogenizer.
In the case where an excimer laser which is ultraviolet radiation is used as a light source, it is recommended that the base material of the above optical system be quartz because the quartz can produce a high transmittance. Also, it is recommended to use a coating capable of producing a transmittance of 99% or more to the wavelength of the excimer laser.
First, a side view in FIG. 1 will be described. A laser beam emitted by a laser oscillator 101 is divided into the direction orthogonal to the direction of travel of the laser beam by cylindrical lens arrays 102a and 102b. The applicable direction is called a vertical direction in the present specification. When a mirror is arranged in the middle of the optical system, the above vertical direction is bent in the direction of the light bent by the mirror. In this constitution, the laser beam is divided into four portions. These divided laser beams are once unified to one laser beam by a cylindrical lens 104. The unified laser beam is reflected by a mirror 107 and then is again focused on one laser beam at an irradiate surface 109 by a doublet cylindrical lens 108. The doublet cylindrical lens means the one constituted by two cylindrical lenses. The doublet lens homogenizes the energy in the width direction of the linear laser beam and determines a length in the width direction of the laser beam.
Next, a top view will be described. The laser beam emitted by the laser oscillator 101 is divided by cylindrical lens arrays 103 into the direction orthogonal to the direction of travel of the laser beam and in the direction orthogonal to the vertical direction. The applicable direction is called a lateral direction in the present specification. When a mirror is arranged in the middle of the optical system, the above lateral direction is bent in the direction of the light bent by the mirror. In this constitution, the laser beam is divided into seven portions. These divided laser beams are once converged on one laser beam at the irradiate surface 109 by the cylindrical lens 105. This homogenizes the energy in the length direction of the linear laser beam and determines the length of the linear laser beam.
The above lenses are made of synthetic quartz to respond to the excimer laser. Also, their surfaces are coated such that they well transmit the excimer laser, whereby the transmittance of one lens to the excimer laser is made 99% or more.
The linear laser beam transformed by the above constitution is applied to the non-single crystal silicon film while it is gradually shifted and superposed in the direction of the width of the linear laser beam to subject the whole surface of the non-single crystal silicon film to laser annealing to thereby crystallize the non-single crystal silicon film or to improve the crystallinity thereof
Next, a typical method of forming a semiconductor film to be irradiated with the laser beam will be described.
First, a Corning 1737 substrate 0.7 mm thick and 5 inch square was prepared as a substrate. A SiO2 film (silicon oxide film) having a thickness of 200 nm was formed on the substrate with a plasma CVD device and the amorphous silicon film (hereinafter referred to as "a-Si film") having a thickness of 50 nm was formed on the surface of the SiO2 film.
The substrate was heated at 500° C. in a nitrogen atmosphere for 1 hour to reduce the concentration of hydrogen in the film, whereby the resistance to laser of the film was remarkably improved.
A XeCl excimer laser L3308 (wavelength=308 nm, pulse width=30 ns) made by Ramda Corp. was used as a laser device. The laser device generates a pulse oscillation laser and has a capacity producing an energy of 500 mJ/pulse. The size of the laser beam is 10–30 mm (both in full width at half maximum) at the exit of the laser beam. The exit of the laser beam is defined, in the present specification, as a plane perpendicular to the direction of travel of the laser beam right after the laser beam is emitted by the laser irradiation device.
In general, the shape of the laser beam generated by the excimer laser is rectangular and ranges from 3 to 5 when expressed in aspect ratio, and as the position is nearer to the center of the laser beam, the intensity of the laser beam is stronger, that is, the intensity of the laser beam shows a Gaussian distribution. The size of the above laser beam was transformed into a linear laser beam of 125 mm×0.4 mm having a uniform energy distribution by an optical system having a constitution shown in FIG. 1.
According to the experiment of the present inventor, it was found that the pitch of superposition of 1/10 times the width (full width at half maximum) of the linear laser beam was most suitable in the case where the above semiconductor film was irradiated with the linear laser beam. This improved homogeneity in crystallinity in the film. In the above example, the above full width at half maximum was 0.4 mm and hence the semiconductor film was scanned and irradiated with the laser beam of the excimer laser at a pulse frequency of 30 Hz, at a scanning speed of 1.0 mm/sec, at an energy density of 420 mJ/cm2 at the surface irradiated with the laser beam. The above-described method is an extremely ordinary method used for crystallizing a semiconductor film by the use of the linear laser beam.
When the silicon film annealed with the above linear laser beam was very carefully observed, very weak interference fringes were observed. This is because when the divided laser beams were again converged on one region, the divided laser beams interfered with each other. However, since the excimer laser has a coherence length ranging from about several micron to several tens micron, it does not produce strong interference.
The state of the art in the excimer laser can oscillate high-power, high-repetition pulses (about 300 Hz) and hence is widely used for crystallizing the semiconductor film. When the liquid crystal display using a low-temperature polysilicon TFT, which has been brought to a commercial stage in recent years, was manufactured, the excimer laser is widely used in the crystallization process of the semiconductor film.
In recent years, the maximum power of a YAG laser has been remarkably increased. Since the YAG laser is a solid state laser, it is easy to handle and maintain as compared with the excimer laser which is a gas laser. The present inventor considered the possibility of the YAG laser being used for crystallizing the semiconductor film in consideration of the increasing power of the YAG laser.
It is well known that the YAG laser emits a laser beam having a wavelength of 1065 nm as a fundamental wave. The absorption coefficient of the silicon film to the laser beam is very low and hence can not be used in this state for crystallizing the a-Si film which is one of the silicon films. However, the laser beam can be converted into the laser beams having shorter wavelengths by the use of the non-linear optical crystal. The converted laser beams are called the second harmonic (533 nm), the third harmonic (355 nm), the fourth harmonic (266 nm), and the fifth harmonic (213 nm), depending on the converted wavelength.
Since the second harmonic has a wavelength of 533 nm and has a sufficient absorption coefficient to the a-Si film, it can be used for crystallizing the a-Si film. However, its absorption coefficient to the a-Si film is not so high as that of the excimer laser. The third harmonic, the fourth harmonic, and the fifth harmonic are very high in the absorption coefficient to the a-Si film and hence can crystallize the semiconductor film with a high degree of energy efficiency.
The maximum power of the third harmonic of the state-of-the-art YAG laser is about 750 mJ/pulse. Also, the maximum power of the fourth harmonic is about 200 mJ/pulse. The maximum power of the fifth harmonic is lower than the above maximum power and hence the fifth harmonic is not suitable for crystallizing the semiconductor film. From the viewpoint of both the power and the absorption coefficient to the a-Si film of the laser beam, it is best at the present time to use the second harmonic or the third harmonic.
Next, in the case where the YAG laser is used for crystallizing the semiconductor film, it is preferable for mass production that the shape of the laser beam at the irradiate surface is linear. It is preferable that the above optical system is applied to the YAG laser as it is. This possibility will be considered in the following.
First, the difference between the YAG laser and the excimer laser will be described. The shape of the laser beam emitted by the excimer laser is generally rectangular and the shape of the laser beam emitted by the excimer laser is generally circular. The dominating size of the laser beam having large power exceeding 500 mJ/pulse and high repetition over 200 Hz is about 10–30 mm and the above optical system is tailored to the size of the laser beam. On the other hand, the size of the laser beam of the YAG laser over 500 mJ/pulse is a circle having a diameter of about 10 mm. In order to tailor the YAG laser 10 mm in diameter to the above optical system, it is recommended that the circular laser beam be transformed into an ellipsoidal one by the use of the beam expander capable of changing the size of the laser beam. In this case, it is recommended that the above circular laser beam be elongated by three times to an ellipsoidal laser beam 30 mm in long diameter and 10 mm in short diameter by the use of the beam expander constituted by cylindrical lenses capable of elongating the size of the laser beam in one direction.
An example of an optical system in which the above beam expander is built in the optical system shown in FIG. 1 to be adapted to the YAG laser 300 will be shown in FIG. 3. FIG. 3 shows only a top view. In FIG. 3 and FIG. 1, the same reference numerals designate the lenses having the same shape.
A cylindrical lens 301 has a focal length of 100 mm, a length and a width of 50 mm, and a thickness of 10 mm. A laser beam enters the cylindrical lens 301. A cylindrical lens 302 has a focal length of 200 mm, a length and a width of 50 mm, and a thickness of 10 mm. These lenses are arranged at a distance of 400 mm from each other. This elongates the laser beam three times in one direction.
Next, the difference in coherence length between the YAG laser and the excimer laser will be described. As described above, the excimer laser has a coherence length of about several micron to several tens micron and hence produces a very weak optical interference when the laser beam emitted by the excimer laser passes through an optical system for dividing the laser beam and then converging it on one point. On the other hand, the YAG laser has a very long coherence length of 1 cm and hence the effect of interference produced by the YAG laser is not negligible.
If the laser beam emitted by the YAG laser is passed through the optical system shown in FIG. 3 to be transformed into a linear laser beam 200, the linear laser beam 200 has an energy distribution in which energy is repeatedly increased or decreased like a grid pattern.
The energy distribution shaped like a grid pattern is produced by an optical interference. In FIG. 2A, dark lines 201 designate regions having comparatively high energy and blank lines 202 between the dark lines 201 designate regions having comparatively low energy.
If the a-Si film is crystallized with the linear laser beam 200 having the energy distribution shaped like a grid pattern, the a-Si film is heterogeneously crystallized. FIG. 2B shows the surface of a silicon film 203 crystallized with the linear laser beam. As described above, since the a-Si film is irradiated with the linear laser beam while the linear laser beam is shifted and superposed by 1/10 times in the width direction of the laser beam, interference fringes parallel to the line direction of the linear laser beam cancel each other to become light, but interference fringes 204, 205 parallel to the width direction of the linear laser beam remain strongly dark. In FIG. 2B, dark lines 204 designate regions having comparatively high energy and blank lines 205 between the dark lines 204 designate regions having comparatively low energy.

Method of fabricating a semiconductor device incorporating crystallizing by laser irradiation

Semiconductor Energy Laboratory Co., Ltd.


A method is provided for fabricating memory devices on a semiconductor substrate using a dual damascene process. The method includes the steps of forming at least one dummy gate structure for at least one memory device on the semiconductor substrate, depositing dielectric material on surroundings of the at least one dummy gate structure, etching the dielectric material and the at least one dummy gate structure to form at least one control gate void and at least one floating gate void, forming a gate dielectric layer on a bottom surface of the at least one floating gate void, depositing floating gate material on the gate dielectric layer in the at least one floating gate void to form a floating gate, depositing a dielectric layer on the floating gate, and depositing control gate material on the dielectric layer in the at least one control gate void to form a control gate. Support devices may be fabricated on the semiconductor substrate by a single damascene process this is integrated with the processes of fabricating the memory devices, so that top surfaces of the support devices and the memory devices are substantially coplanar.

1. Field of the Invention
The present invention relates to a method of manufacturing memory devices, and more particularly, to a method for fabricating memory devices using a dual damascene process and support devices using a single damascene process on a common semiconductor substrate.
2. Description of the Related Art
Flash memory devices, such as erasable and programmable read-only memory (EPROM) devices and electrically erasable and programmable read-only memory (EEPROM) devices, generally have a structure such that a control gate of a flash memory device is disposed on top of a floating gate of the flash memory device. In a conventional flash memory device, a floating gate is first formed and then a control gate is formed on top of the floating gate. Due to such a structure, a conventional flash memory device has a non-planar surface. In other words, the surface (particularly, the top surface of a control gate) of a flash memory device is higher than that of a support device. When patterning a control gate of a flash memory device, the surface of the flash memory device is not planar due to existence of a floating gate of the flash memory device. Such a non-planar surface of a flash memory device causes a patterning problem in lithography and/or an etching process for fabricating flash memory devices. For example, in lithography for a flash memory device, lithography resolution is deteriorated due to non-planar (i.e., high topography) surface of the flash memory device. Such a lithography resolution can be improved when the surface of the flash memory device has relatively less topography. Also, it is difficult in an etching process to optimize an etching selectivity between materials to be removed. and not to be removed due to a high topography of a memory device surface. The etching selectivity may be improved as the surface of a flash memory device is flatter, and be optimized in case of having a flat surface.
Thus, in a process of fabricating a conventional flash memory device, an extra process is required to planarize the non-planar surface of a flash memory device. The planarization of the surface of a flash memory device may advantageously induce a high quality metallic interconnection between a flash memory device and support devices, thereby achieving a high-density integration of the devices.
In a conventional flash memory device, properties of a gate dielectric layer of a flash memory device are different from those of support devices. A support device is a device disposed outside a memory array area. The support devices may include, for example, decoder circuits, sense amplifiers, drivers, and so on. Such differences in the properties between a flash memory device and support devices are inevitable because a flash memory device requires either hot-carrier injection or electron tunneling to program a floating gate of the flash memory device. In this case, the gate dielectric layer of a flash memory device has to be constantly programmed for an injection of electrons, whereas supporting devices do not require such a constraint.
In a conventional approach, this problem may be solved by fabricating each device independently on a common semiconductor substrate by separate processes. For example, a support device is formed by a first process, and then a flash memory device is formed by another process. This approach generally causes a significant increase in the process cost. Also, the conventional approach is highly complex for fabricating a flash memory integrated with support devices. Thus, it is difficult to improve yield for such a process.
Therefore, a need exists for a method of fabricating flash memory devices and support devices through an integrated process on a common semiconductor substrate, where the surfaces of the flash memory devices and the support devices are substantially coplanar. Further, it will be advantageous to enhance density and capability of integration of memory and support devices by employing the present invention for fabricating the devices together in an integrated process.
It is an object of the present invention to provide a method for fabricating memory devices on a common semiconductor substrate using a dual damascene process.
It is another object of the present invention to provide a method for fabricating memory devices and support devices together by an integrated process, wherein the memory devices and the support devices are formed by a dual damascene process and a single damascene process, respectively.
It is also another object of the present invention to provide a method for fabricating memory devices of which surfaces are substantially coplanar with those of support devices interconnected with the memory devices.
To achieve the above and other objects, the present invention provides a method for fabricating a flash memory by use of a dual damascene process, comprising the steps of forming at least one dummy gate structure for at least one memory device on the common semiconductor substrate, depositing dielectric material surrounding the at least one dummy gate structure on the common semiconductor substrate, etching the dielectric material and the at least one dummy gate structure to form at least one control gate void and at least one floating gate void for the at least one memory device, forming a gate dielectric layer on a bottom surface of the at least one floating gate void, depositing floating gate material on the gate dielectric layer in the at least one floating gate void to form a floating gate of the at least one memory device, depositing a dielectric layer on the floating gate, and depositing control gate material on the dielectric layer in the at least one control gate void to form a control gate of the at least one memory device. The etching step preferably includes the steps of recessing the at least one dummy gate structure to form a recessed dummy floating gate with a predetermined height from the common semiconductor substrate, forming resist masks on the dielectric material deposited at the surroundings of the at least one dummy gate structure, selectively etching the dielectric material to form the at least one control gate void, and removing the recessed dummy floating gate to form the at least one floating gate void. The etching step may alternatively include the steps of removing the at least one dummy gate structure by an etching to form at least one void area, forming an oxide layer on a bottom surface of the at least one void area, depositing polysilicon material on the oxide layer to form a dummy floating gate with a predetermined height in the at least one void area, forming resist masks on the dielectric material deposited at the surroundings of the at least one dummy gate structure, selectively etching the dielectric material to form the at least one control gate void, and removing the dummy floating gate to form the at least one floating gate void. The etching step may also include the step of forming step edges between the at least one control gate void and the at least one floating gate void.
The method of the present invention may further include the steps of forming at least one gate conductor structure for at least one support device on the common semiconductor substrate, and depositing dielectric material at surroundings of the at least one gate conductor structure on the common semiconductor substrate. The step of forming the at least one gate conductor structure preferably includes the steps of forming a gate oxide layer of the at least one support device on the common semiconductor substrate, depositing control gate material on the gate oxide layer to form a control gate of the at least one support device, and forming a cap layer of the at least one support device on a top surface of the control gate material. The at least dummy gate structure for the at least one memory device and the at least one gate conductor structure for the at least one support device are formed an integrated process, including the steps of forming a gate oxide layer of the at least one dummy gate structure and the gate oxide layer of the at least one support device by a same process flow, depositing dummy material of the at least one dummy gate structure and the control gate material of the at least one support device by a same process flow, and forming a cap layer of the at least one dummy gate structure and the cap layer of the at least one support device by a same process flow.
The present invention also provides a method for fabricating memory devices on a common semiconductor substrate, comprising the steps of forming at least one dummy gate structure for at least one memory device on the semiconductor substrate, depositing dielectric material at surroundings of the at least one dummy gate structure on the common semiconductor substrate, removing the at least one dummy gate structure to form a void area on the common semiconductor substrate, forming a gate dielectric layer on a bottom surface of the void area, depositing floating gate material on the gate dielectric layer in the void area, forming resist masks on the dielectric material deposited at the surroundings of the at least one dummy gate structure, non-selectively etching the dielectric material and the floating gate material to form a floating gate and a control gate void, depositing a dielectric layer on the floating gate, and depositing control gate material on the dielectric layer in the control gate void to form a control gate.
The present invention further provides a memory circuit having a plurality of memory cells formed on a common semiconductor substrate, wherein a memory cell comprising a channel region for the memory cell formed in the common semiconductor substrate, a gate oxide layer formed on the channel region, the gate oxide layer having a thickness unique to the memory cell, a floating gate formed on the gate oxide layer, where the floating gate having a predetermined thickness, a dielectric layer formed on the floating gate, and a control gate formed on the dielectric layer. The memory circuit preferably further includes at least one support device formed on the common semiconductor substrate by a process integrated with forming the memory device, wherein the at least support device includes a gate oxide layer having properties substantially equal to those of the gate oxide layer of the memory cell, a control gate formed on the gate oxide layer, the control gate having properties substantially equal to those of the floating gate of the memory cell, and a cap layer formed on the control gate. Preferably, top surfaces of the memory cells and the support devices are substantially coplanar.

Method for fabricating flash memory device using dual damascene process

International Business Machines Corporation


Provided is an optical filter and a display device. In the optical filter, patterns of first and second regions therein may be stably maintained, and therefore the optical filter capable of ensuring excellent light division characteristics for a long time may be provided.

A technique of dividing light into at least two kinds of light having different polarized states from each other may be available in various fields.
The light division technique may be applied in manufacturing a three-dimensional (3D) image. 3D images may be realized using binocular disparity. For example, when two of two-dimensional images are respectively input to a left eye and a right eye of a human, input data is delivered to the brain and fused, and thus he/she experiences 3D perspective and reality. In such a process, the light division technique may be used.
A technique of generating a 3D image may be available in 3D measurement, a 3D TV, a camera or computer graphics.
Examples of applying the light division technique to generation of a 3D image are disclosed in Korean Patent No. 0967899 and Korean Patent Publication No. 2010-0089782.


A mass analyzer includes: an ion trap device including an ion trapping space surrounded by a plurality of electrodes; a time-of-flight mass analyzer for determining a mass to charge ratio of ions ejected from the ion trapping space; a trapping voltage generator for generating an ion trapping RF voltage to at least one of the plurality of electrodes; an ejecting voltage generator for generating an ejecting voltage to at least one of the plurality of electrodes to form an ion ejection electric field for ejecting ions trapped in the ion trapping space; and a controller for stopping the ion trapping RF voltage at a timing when ions are trapped in the ion trapping space and the ion trapping RF voltage is at a predetermined phase, and for applying the ion ejecting voltage a predetermined period after the ion trapping RF voltage is stopped. Here the predetermined phase and the predetermined period are predetermined so that, when the ion trapping RF voltage is stopped at the predetermined phase and the predetermined period passes, the voltage of said at least one of the electrodes to which the ion trapping voltage is generated becomes almost a certain fixed value irrespective of the amplitude of the ion trapping RF voltage when it is stopped. Thus, by stopping the ion trapping RF voltage and applying the ion ejecting voltage at such a timing, the initial kinetic energy of the ejected ions does not vary with the amplitude of the ion trapping voltage before it is stopped, and a precise determination of the mass to charge ratio of the ions becomes possible.

In a TOF-MS, accelerated ions are injected into a flight space where no electric field or no magnetic field is present, and the ions are separated by their mass to charge ratios with the flight time of the ions in the flight space. For the ion source of a TOF-MS, an ion trap device is used in many cases.
As shown in FIG. 4, a typical ion trap device 1 is composed of a ring electrode 11, and a pair of end cap electrodes 12, 13 placed opposing each other with the ring electrode 11 between them. Usually, an RF (radio frequency) voltage is applied to the ring electrode 11 to form a quadrupole electric field in the ion trapping space 14 surrounded by the electrodes 11, 12, 13, whereby ions are trapped within the ion trapping space 14. In one case, ions are generated outside of the ion trap device 1 and introduced into it, and in another case they are generated within the ion trap device 1. The theory of such an ion trapping method is described in detail in, for example, "Quadrupole Storage Mass Spectrometry" by R. E. March and R. J. Hughes, John Wiley & Sons, 1989, pp. 31–110.
A wide variety of samples are analyzed by such mass analyzers, and the range of mass to charge ratio to be analyzed depends on the sample. In an ion trap device, ions are not only trapped and stored in the ion trapping space, but also manipulated in various processes such as cooling their vibrational motion, selection of ions with specific mass to charge ratio and excited for collisional dissociation to perform structural analysis of the sample. The amplitude of the RF voltage is controlled so that the trapping potential appropriate for each process is established.
When ions are to be analyzed in the TOF-MS, the RF voltage applied to the ring electrode 11 is stopped after various processings as mentioned above are done and object ions are prepared in the ion trapping space 14. Then an ejecting voltage is applied to the end cap electrodes 12, 13 to form an ion ejection electric field in the ion trap device. Owing to the ion ejection electric field, ions are accelerated and ejected through a hole 13a in an end cap electrode to the TOF-MS, where a mass analysis of the ions are achieved.
The RF voltage applied to the ring electrode 11 just before ions are ejected from the ion trapping space 14 differs depending on the mass to charge ratio of the ejected ions and the processings that the ions have undergone in the ion trap device 1. For example, as shown in FIG. 5, when the RF voltage is stopped using a high-speed switch at tc, the actual voltage of the ring electrode 11 (which will be referred to as "the ring voltage") does not instantaneously become that of the end cap electrodes 12, 13 (which will be referred to as "the end cap voltage", and is zero in the case of FIG. 5), but gradually approaches it with an oscillation (which is called a "ringing"), because an RF resonance coil and an RF resonance capacitor are connected to the ring electrode 11. That is, a certain period of time is necessary until the ring voltage subsides to the end cap voltage.
If, before the ring voltage subsides to the end cap voltage, an ion ejecting voltage is applied to the end cap electrodes 12, 13 to eject ions from the ion trap device 1 to the TOF-MS 3, the ion ejection electric field in the ion trap device 1 has a variation from the calculated target field, and there arises an error in the initial kinetic energy of the ejected ions. Since the amplitude of the ringing depends on the amplitude of the RF voltage before the stop, variation in the ejection electric field when ions are ejected, a certain period after the stop time tc, also changes with it.
If the error in the initial kinetic energy is small, the width of the peak changes little in the mass spectrum, and it does not affect the resolution in the mass to charge ratio. But the error in the kinetic energy affects the flight time of the ions, which results in a shift in the peak in the mass spectrum and makes it difficult to accurately determine the mass to charge ratio of the ions.
On the other hand, if enough time is allotted from the stop time tc to the ion ejecting time (i.e., enough time is taken until the ringing subsides), the ring voltage stabilizes and the above problem does not arise. In this case, however, the state where no quadrupole electric field exists in the ion trapping space lasts longer, so that ions may disperse before the ion ejection electric field is formed. This decreases the number of ions to be used in the analysis, and deteriorates the sensitivity of the analysis.
An object of the present invention is therefore to provide a mass analyzer and a mass analyzing method in which the shift of a peak or peaks in a mass spectrum is minimized while maintaining a high analyzing sensitivity, and the mass to charge ratio can be determined at high accuracy.
In the first aspect of the present invention, a mass analyzer comprises:
an ion trap device including an ion trapping space surrounded by a plurality of electrodes;
a time-of-flight mass analyzer for determining a mass to charge ratio of ions ejected from the ion trapping space;
a trapping voltage generator for generating an ion trapping RF voltage to at least one of the plurality of electrodes;
an ejecting voltage generator for generating an ejecting voltage to at least one of the plurality of electrodes to form an ion ejection electric field for ejecting ions trapped in the ion trapping space; and
a controller for stopping the ion trapping RF voltage at a timing when ions are trapped in the ion trapping space and the ion trapping RF voltage is at a predetermined phase, and for applying the ion ejecting voltage a predetermined period after the ion trapping RF voltage is stopped.
In the second aspect of the present invention, a mass analyzing method comprises the steps of:
trapping ions in an ion trapping space surrounded by a plurality of electrodes by applying an ion trapping RF voltage to at least one of the plurality of electrodes;
stopping the ion trapping RF voltage at a timing when ions are trapped in the ion trapping space and the ion trapping RF voltage is at a predetermined phase; and
applying an ion ejecting voltage to at least one of the plurality of electrodes for forming an ion ejection electric field to eject ions trapped in the ion trapping space to a time-of-flight mass analyzer a predetermined period after the ion trapping RF voltage is stopped.
In the present invention, in both aspects, the phase and the timing are predetermined under the condition that the voltage of the electrode or electrodes to which the ion trapping RF voltage was applied becomes almost the same the predetermined period after the ion trapping RF voltage is stopped at the predetermined phase, irrespective of the amplitude of the ion trapping RF voltage when it is stopped.
In the present invention, in both aspects, the electrode to which the ion trapping RF voltage is applied is normally the ring electrode, and the electrode to which the ion ejecting voltage is applied is normally the end cap electrodes. Other voltage configuration is of course possible in the present invention.
In the present invention, the ion ejection electric field is formed at the timing when the voltage of the ring electrode is the same as that of the end cap electrodes while the voltage of the ring electrode is still ringing after the ion trapping RF voltage is stopped. Since the frequency of the ringing is low, the voltage of the end cap electrodes can be regarded as constant while the ions are being ejected. Thus the kinetic energy of the ions ejected from the ion trapping space to the TOF-MS does not vary, and the flight time of the ions in the TOF-MS does not vary, either. This brings the peak of the ions to the same place in the mass spectrum, and makes it possible to determine the mass to charge ratio of the ions precisely.
If the amplitude of the ion trapping RF voltage before it is stopped is changed according to the mass to charge ratio of the ions to be analyzed, the amplitude of the ringing after the stop of the RF voltage also changes. The inventor of the present invention has found out that, if the ion trapping RF voltage is stopped at a certain phase, the voltage of the ring electrode becomes the same as the voltage of the end cap electrodes or, at least, becomes a certain fixed voltage after a certain time period irrespective of the amplitude of the ringing. The phase and the time period depend on the electric parameters of the electric circuit around the ion trap including the ion trap itself and its power source, but they are determined if the constitution of the device is fixed. Thus the phase and the time period can be experimentally determined beforehand, and the controller can use the values to stop the ion trapping RF voltage and to start applying the ion ejecting voltage.
In the present invention, by precisely controlling the stopping time of the the ion trapping RF voltage to come to a predetermined phase of the RF voltage, the voltage of the ring electrode can be adjusted to be the same as that of the end cap electrodes a certain time period after the ion trapping RF voltage is stopped, irrespective of the amplitude of the ion trapping RF voltage when it is stopped. Thus, by applying the ion ejecting voltage at such a timing, the initial kinetic energy of the ejected ions does not vary, and a precise determination of the mass to charge ratio of the ions becomes possible.
Even if the voltage of the ring electrode cannot be brought to be the same as that of the end cap electrodes, it suffices if the voltage of the ring electrode can be brought to a certain predetermined value, because the same ion ejection electric field can be formed by adjusting the ejecting voltage of the end cap electrodes by the difference between the predetermined value and the end cap voltage. In this case also a precise determination of the mass to charge ratio of the ions becomes possible.


A filament using a high melting point metal compound such as tantalum carbide is provided. As the filament, a filament comprising a tungsten base material, a tantalum layer coating the tungsten base material, and a tantalum carbide layer coating the tantalum layer is used. The tantalum layer and the tantalum carbide layer may be replaced with a hafnium layer and a hafnium carbide layer, respectively, or may be formed of a combination of tantalum and hafnium.

There are widely used incandescent light bulbs which produce light with a filament such as tungsten filament heated by an electric current flown through it. Incandescent light bulbs have various advantages, for example, (a) they are inexpensive, (b) they show superior color rendering properties, (c) they can be used with any operating voltage (they can work with either alternating current or direct current), (d) they can be lightened with a simple lighting implement, (e) they are used worldwide, and so forth. However, efficiency of incandescent light bulbs for conversion from electric power to visible light is about 15 lm/W, which is lower than that of fluorescent lamps (conversion efficiency, 90 lm/W), and therefore they impose larger environmental loads.
Patent document 1 suggests use of tantalum carbide having a higher melting point than that of tungsten for the filament. Patent document 1 discloses a method for producing a sintered body of a carbon compound containing tantalum carbide, which comprises mixing impalpable powder TaC, powdery carbide of Zr, Hf, or the like, and the like, molding the mixture, and heating the molded body at a temperature of 1600° C. or higher.
Patent document 2 discloses a method for manufacturing a coil-shaped tantalum carbide electrode. In this manufacturing method, tantalum is first processed into a coil shape, this coil is subjected to a heat treatment to remove the surface oxide film, and after a carbon source is introduced, the coil is further subjected to a heat treatment. Carbon is thereby made to permeate into the tantalum from the surface to form a coil-shaped electrode fully consisting of tantalum carbide or consisting of tantalum carbide and tantalum.
Patent document 3 discloses that if a TaC film is formed on a surface of a tungsten filament by an ion-plating method, superior heat resistance and stable thermionic or field emission current can be obtained.

Light source device, method for manufacturing the same and filament


An attachment mechanism for use with a portable electronic device (101) includes a case (110) having a first surface (211) and a second surface (111), where the first surface and the second surface define therebetween a space (105) capable of receiving the portable electronic device. The attachment mechanism further includes a clip (120) attached to the second surface of the case. The clip includes a body (221) adjacent to the second surface, a first extension (222) spaced apart from and extending toward the second surface, and a second extension (223) also spaced apart from and extending toward the second surface. The second piece creates a first pocket (231) between the case and the clip, and the second piece creates a second pocket (232) between the case and the clip.

Cellular telephones, MP3 players, pocket computers, and other portable electronic devices have become so popular and are in such widespread use that it is now almost unusual to encounter a person who is not carrying at least one such device. Many portable electronic devices, including all of those mentioned above, are at least capable of emitting sound, and thus are quite often equipped with headphones that enable the sound to be listened to privately. Other cables or cords in addition to those connected to headphones are sometimes also used in conjunction with portable electronic devices. These headphone and other cords are easily tangled and broken, and are, in general, hard to manage. Accordingly, there exists a need for a mechanism capable of safely and conveniently storing and carrying a portable electronic device while also managing any cords that are used therewith.
For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. The same reference numerals in different figures denote the same elements.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprise," "include," "have," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
The terms "left," "right," "front," "back," "top," "bottom," "over," "under," and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. The term "coupled," as used herein, is defined as directly or indirectly connected in an electrical, mechanical, or other manner.

Attachment mechanism for use with a portable electronic device, and method of manufacturing same


The invention relates to a wing, a wing, a tail unit or grid fins for a flying object moving with supersonic speeds. The wing comprises leading edges and tailing edges.

The drag of air leads to energy losses that increase exponentially with increasing speed of a flying object. Furthermore, the drag leads to mechanical loads and stresses acting upon the constructive elements of the flying object. These loads and stresses have to be considered when dimensioning the flying object. Accordingly, the drag influences the minimal dimension of the constructive elements. However, increased dimensions due to the acting loads and stresses lead to an increased consumption of the energy source of the propulsion when changing or maintaining the speed of the aircraft. Additionally, under certain conditions the increased drag could reduce the payload of the flying object. Investigations have shown that a change of the total drag of 1% may correlate to a change of the payload of approximately 5 to 10% in a modern commercial aircraft, cp.    [1]. D. Bushnell, Supersonic Aircraft Drag Reduction, AIAA Paper 90–1596, June 1990[1].
Document [1], which is incorporated entirely herein by reference, contains an overview on common technologies for reducing the drag of an aircraft.
Due to an exponential dependence of the drag on the flight speed for supersonic flying object a reduction of the total drag of 1% leads to a further increase of the payload.
Usually the outer shape of wings located in the airflow is the result of an optimization depending on a lot of different requirements. One such requirement is that the wing has to provide high performance throughout a large range of speeds. The aforementioned requirement is commonly fulfilled for wings used for transonic or supersonic aircrafts by variable sweep wings (swing-wings) or by providing cranked delta planform. Both these applications may lead to a low wave drag for a use of the wing during cruise speeds as well as a sufficient lift force during take-off and landing.
In a lot of cases the basic aerodynamic design of the wings is determined by means of theoretical or numerical models requiring wings of different known types of basic designs, cp. [1]. Examples for such simple shapes of wings are those being describable by means of a two-dimensional analysis.    [2] Bertin J. & Smith M., Aerodynamics for Engineers, Prentice-Hall, 1979, 410 p. [2], which is incorporated entirely herein by reference, contains an overview concerning the knowledge for the reduction of the drag for planar wings.

Abstract: According to the invention, the contour of at least one of the leading contour and the tailing contour has a meandered shape.

Abstract: By means of the inventive meandered contours the wave drag of the flying object may be decreased. The inventive design of the leading or tailing edges of a wing can be used for aircrafts, spacecrafts, missiles, projectiles and the like.


A power source switching apparatus is provided. The example power source switching apparatus may include a voltage adjuster outputting a first power source voltage having a voltage level, corresponding to the output voltage of a battery, during an external power source mode where the battery is being charged, the first power source voltage based at least in part on the external power source and the output voltage of the battery, a controller outputting a first control signal and a second control signal, the first control signal enabled if the battery is operating in the external power source mode and the second control signal is enabled if the battery is not operating in the external power source mode, a first switch outputting the first power source voltage if the first control signal is enabled and a second switch outputting the output voltage of the battery if the second control signal is enabled.

1. Field of the Invention
Example embodiments of the present invention are directed generally to a power source switching apparatus and method thereof, and more particularly to a power source switching apparatus and method of providing power.
2. Description of the Related Art
A portable mobile device may be used in places where an external power source voltage may not be available because the portable mobile device may be configured to operate with an internal power source voltage applied by a battery. Portable mobile devices may be configured to use rechargeable batteries and/or disposable batteries. Rechargeable batteries may typically be charged by external power source voltages. A charge capacity of rechargeable batteries may typically be relatively limited, and therefore rechargeable batteries may need to be recharged from time to time as charges stored therein are exhausted.
For example, a user may charge a rechargeable battery during a period where the portable mobile device may be powered by an external power source voltage. In other words, the portable mobile device may draw power from the external power source to both power the portable mobile device as well as charge the rechargeable battery.
FIG. 1 is a block diagram illustrating a conventional portable mobile device. Referring to FIG. 1, the portable mobile device may include a voltage drop diode 120, a controller 130, a battery charger 140, a battery 150, a direct current (DC)-DC converter 160, a system load 170, and a switch SW1.
Referring to FIG. 1, the voltage drop diode 120 may be used if charges are supplied to the battery 150 via the battery charger 140 while the portable mobile device is powered by an external power source 110. An operating voltage of the system load 170 may be lower than a voltage of the external power source 110 in order to reduce power consumption of the system load 170. Accordingly, the voltage of the external power source 110 may be reduced or dropped using at least one voltage drop diode 120 connected in series, and the reduced voltage may then be supplied to the system load 170. The controller 130 may generate a control signal CON for selecting one of the voltage of the external power source 110 (e.g., applied through the voltage drop diode 120) and the voltage of the battery 150.
Referring to FIG. 1, the battery charger 140 may charge the battery 150 using the external power source 110. During charging, the battery 150 may receive charges from the battery charger 140. The battery 150 may output a voltage corresponding to a voltage level at which the battery 150 is charged. The switch SW1 may supply one of the output voltage of the battery 150 and the output voltage of the voltage drop diode 120 to the DC-DC converter 160, in response to the control signal CON output from the controller 130. The DC-DC converter 160 may convert the voltage supplied through the switch SW1 into a voltage having a level which may be sufficient to power the system load 170. The system load 170 may indicate a functional block which may perform a specific function using the voltage supplied from the DC-DC converter 160.
FIG. 2 is a block diagram illustrating another conventional portable mobile device. Referring to FIG. 2, the output voltage of a voltage drop diode 220 may be directly supplied to a system load 270 through a switch SW2, and the output voltage of a battery 250 may be supplied to a DC-DC converter 260 through a second switch SW3. The two switches SW2 and SW3 may be controlled by a control signal CON output from a controller 230 and a signal which may be obtained by inverting a phase of the control signal CON through an inverter 280, respectively. Accordingly, the first switch SW2 and the second switch SW3 may be turned on and off, respectively, or vice versa.
The conventional portable mobile devices illustrated in FIGS. 1 and 2 may each have (i) a battery mode in which the portable mobile device may be powered by a battery and (ii) an external power source mode in which the battery may be charged via the external power source while the portable mobile device is either operating via the external power source or not operating. During a transition between the battery mode and the external power source mode (e.g., in response to plugging in or unplugging the portable mobile device), a voltage supplied to the DC-DC converter 160 or the system load 270 may change at a relatively high rate.
FIGS. 3A, 3B and 3C illustrate a supplied voltage during a first transition from a battery mode to an external power source mode and a second transition from the external power source mode back to the battery mode. In an example, the supplied voltage illustrated in FIG. 3 may represent a voltage applied to the DC-DC converter 160 and/or the system load 270.
FIG. 3A illustrates a theoretical voltage level fluctuation of the power source voltage applied during a transition between the battery mode and the external power source mode. The theoretical voltage level of FIG. 3A is not intended to represent a capability of the conventional art, but is rather intended to illustrate a conceptual "ideal" voltage transition having a linear or "smooth" voltage change during a power source transition.
Referring to FIG. 3A, in a battery mode Bat_mode, a level of the power source voltage applied to the system may gradually be reduced over time. The external power source mode Recharge_mode for charging may be initiated before the voltage reaches a lower threshold voltage VRL. In the external power source mode Recharge_mode, the voltage of the battery may increase, and the external power source mode Recharge_mode may be switched to the battery mode Bat_mode before the voltage reaches a higher threshold voltage VRH. In an example, the lower threshold voltage VRL may represent a minimum voltage level required to power the portable mobile device and the higher threshold VRH may represent a voltage level above which the portable mobile device may not be capable of safe operation.
However, in a real-world environment, the external power source may have a voltage level at least equal to the lower voltage VRH because, typically, a voltage used to charge a battery may be set to a voltage level higher than a voltage level to which the battery is configured to be charged. Hereinafter, it may be assumed that the external power source voltage may be set to Vpp.
FIG. 3B illustrates a conventional voltage level fluctuation of the power source voltage applied during a transition between the battery mode and the external power source mode.
Referring to FIG. 3B, in the instant when the battery mode is switched to the external power source mode or the instant when the external power source mode is switched to the battery mode, a voltage level of the external power source voltage may spike (e.g., rapidly change). Furthermore, because the power source voltage may be set to Vpp, which may be higher than the lower voltage VRH, in the external power source mode Recharge_mode, the battery may be charged by the power source voltage Vpp but the power source voltage Vpp may be too high to safely supply power to the portable mobile device. Accordingly, the portable mobile device may be inoperable during battery charging because the voltage used to charge the battery may be unsuitable to power the portable mobile device.
FIG. 3C illustrates another conventional voltage level fluctuation of the power source voltage applied during a transition between the battery mode and the external power source mode.
Referring to FIG. 3C, if the external power source voltage is reduced to the same voltage as the lower voltage VRH using a plurality of voltage drop diodes which are connected to each other in series, the power source voltage (e.g., set to VRH) may be supplied to a system load of the portable mobile device. Accordingly, because the external power source voltage may be maintained at the lower voltage VRH, the external power source voltage may be applied to the system while the battery is charged (e.g., although the charging of the battery may take a longer period of time due to the lower charging voltage). However, in FIG. 3C, similar to FIG. 3B, in the instant of switching the battery mode to the external power source mode or switching the external power source mode to the battery mode, the power source voltage may spike or change rapidly, thereby degrading a performance of the portable mobile device.

Power source switching apparatus and method thereof


A method and apparatus for obtaining the planar location with sub-pixel resolution and corrected energy of a gamma or X-ray photon interacting with a room temperature solid state detector of given thickness. The detector comprises two electrodes of negative and positive polarities. One of the electrodes is common, and the other is segmented being formed with segmented readout elements. Each of the readout elements defines a pixel size. Depending on that the negative or positive electrode is segmented, respectively, negative-induces charge signals are induced on the readout elements or both a positive-induced charge signal is induced on a central readout element and negative-induced charge signals are induced on adjacent readout elements. Accordingly, respective induced-charge signals are simultaneously measured and statistically correlated on the respective readout elements with detector response templates so as to obtain a best fit template, thereby determining the photon's energy, location and depth of interaction.

Solid state gamma and X-ray detectors are used for many applications which require precise spectroscopic measurements. These applications include security, medical, space and astrophysical research, reactor safety, and host of others. A gamma or X-ray interacting with a solid state detector produces secondary ionizing radiation which create electron-hole pairs. The number of electron-hole pairs produced is directly proportional to the energy of the absorbed gamma or X-ray. Under the influence of the electric field existing between the electrodes of the detector the electrons and holes drift towards the positive and negative electrodes, respectively, where they are collected. The drifting electrons and holes induce signals on the electrodes which are amplified. The induced are proportional to the energy of the absorbed gamma or X-ray, and thus good spectroscopic measurements are obtained. Solid state detectors and their associated electronics tend to be compact, require little power, and their stabilization time is small.
For very accurate spectroscopic measurements, germanium detectors (i.e. Ge(Li) ) are used (see, for example, F. S. Goulding, Nuclear Instruments and Methods, Vol. 43, pp. 1-54, 1966). These detectors provide very accurate energy measurements because of the low energy required to produce an electron-hole pair, and the correspondingly large number of electron-hole pairs produced per gamma or X-ray interaction. Germanium detectors must be operated at liquid nitrogen temperatures because of the very small energy band gap. Since they operate at liquid nitrogen temperatures, mobilities are high and charge collection efficiencies are effectively unity for both electrons and holes. Imaging systems with germanium detectors exist, but are costly because the whole imaging system needs to be at liquid nitrogen temperature.
Gamma and X-ray detectors and imaging system have also been made from silicon. For gamma or X-rays with energy above 20 keV, silicon suffers from its low photoelectric absorption probability, due to its low atomic number, Z=14. Nonetheless, silicon detectors are very useful for gamma and X-rays with energies less than 20 keV. Recently, imaging system prototypes have been made from silicon with readout segmented onto strips or pads of 50-100 .mu.m spacing (see, for example, A. Czermak, et al., Nuclear Instruments and Methods, Vol. A360, pp. 290-296, 1995.). Spatial resolutions of several .mu.m have been achieved by determining the centroid of collected charge distribution on the strips or pads. The physical effect which distributes the collected charge (electrons or holes) among several strips or pads is the diffusion of the charges as they drift in the electric field towards the electrodes. The transverse diffusion of the charge carriers typically expands over an area of about 50-100 .mu.m.
Much effort has gone to developing room temperature solid state detectors with medium to high atomic number. Some of the materials which have shown promise are: CdTe, CdZnTe, Hgl2GaAs, PbI2 (M. Cuzin Nuclear Instruments and Methods, Vol. A253, pp. 407-417, 1987; Y. Elisen, Workshop on Solid State Gamma and X-ray Detectors, Grenoble, September 1995, to be published in Nuclear Instruments and Methods). These materials have a high absorption probability, even for gamma rays with energies above 100 keV. Room temperature operation is a very important consideration in many applications. However, these materials suffer from bad to poor charge transport properties for the holes. As a result, detectors from these materials exhibit incomplete charge collection properties, whereby only a fraction of the photoelectric conversions appears in a distinct photopeak, and the rest of the events show up in a broad "incomplete" low energy region. To correct for this many techniques, both in hardware and software, have been developed. One of the more popular schemes, especially for CdTe detectors, involves correlating lower charge collection with longer risetimes of the pulses. The longer risetimes indicates a deeper interaction of the gamma or X-ray in the crystal which requires a larger fraction of the collected charge to be induced by the holes (see, for example, Y. Eisen and Y. Horowitz, Nuclear Instruments and Methods, Vol. A353, pp. 60-66, 1994).
A lot of emphasis has been placed on developing imaging systems utilizing room temperature solid state detectors. Imaging systems have been constructed with an array of individual detector elements, where each detector element forms a pixel of the imaging systems. Monolithic solid state detectors with segmented readout, usually with pad segmentation, with each pad serving as a pixel in the imaging system, have also been developed. Segmentation of the readout in monolithic detectors is convenient and economic in that it saves a lot of processing and machining of the detector material during production.
More recently, attention has been focused on CdZnTe as a promising material for room temperature solid state gamma and X-ray detectors (see, for example, J. F. Butler, C. L. Lingren, and F. P. Doty, IEEE Trans. Nuclear Science, Vol. 39, No. 4, pp. 605-609, 1992). CdZnTe has relatively high mean atomic number (Z-50 as compared Z=32 for germanium). It also has very high resistivity, p.apprxeq.10.sup.11 .OMEGA.-cm, and as a result very low leakage current. Low leakage current means very little noise, and insensitivity to changes in temperature (i.e. dark current).
CdZnTe detectors, despite exhibiting excellent charge transport properties for electrons, show fair to poor charge transport properties for holes. As a result techniques for obtaining good spectroscopy using only the induced signals from the electrons have been developed, irrespective of the holes or depth of interaction. A scheme employing parallel grids at the anode, which is sensitive to the electron signal only has been developed (P. Luke, Applied Phys.Lett., Vol. 65, pp. 2884-2886, 1994). This scheme requires fine segmentation of the positive electrode into strips with a small difference in bias between alternating strips. The electrons are collected on the strips with the slightly higher bias.
An approach using small segmented readout elements at the anode has also been developed (H. H. Barrett, J. D. Eskin, and H. B. Barber, Phys.Rev,Lett., Vol. 75, pp. 156-159, 1995). In this approach, the smaller the readout element size the less the sensitivity to incomplete charge collection of the holes, since the small readout element would only feel induced charge from electrons drifting in close vicinity to the readout element. This approach obviously also benefits from the very fine spatial resolution accorded by the small readout elements, although at the cost of large number of channels of electronics and also the corresponding slowness in readout acquisition time.
Solid state detectors hold the potential of very fine spatial resolution, and therefore very good imaging capabilities. The compactness of solid state detectors and the readout electronics enable fabrication of small detector elements, where each detector element in an array of detectors can comprise a pixel of the image formed. Imaging systems have been constructed with individual solid state detector elements of sizes as small as 1 mm. A more economical solution, which avoids individual processing of each detector element at the manufacturing stage, is to fabricate monolithic solid state detectors with segmented readouts, where either the positive or negative electrode is segmented in any desired fashion dictated by the readout requirements. Each detector readout element has its own charge sensitive electronics. Readout electrodes in monolithic solid state detectors are typically segmented into pad (i.e., square) elements or strip elements, although other segmentation geometries can be applied. Usually, in a pad segmentation configuration, the position of the incident X-ray or gamma ray in the image is obtained from the planar location of the pad which received the signal within the array. In such a case, the spatial resolution of the image is limited to the size of the pad. Smaller pad elements can therefore lead to better spatial resolution, but with an quadratic increase in detector segmentation and a correspondingly quadratic increase in cost of readout electronics and readout complexity. Readout from segmented electrodes, especially in silicon detectors, has also been configured in strip geometry. Strip geometry enables a finer spatial resolution with only a linear increase in segmentation (and therefore price of electronics), but at the cost of requiring projective readout with the ambiguities and slow readout inherent in projective readout. Additional shortcomings of strip readout include inability to handle high counting rates, and growth of noise with increased detector area. Simultaneous x and y measurement can be accomplished by using double sided strip readout, with the strips on one side of the detector perpendicular to the strips on the other side.
It is an object of the present invention to provide a method for obtaining image spatial resolution smaller than the readout element size (i.e., sub-pixel resolution) of a segmented room temperature solid state detector, thereby affording improved image resolution without incurring the costs involved in using smaller readout elements.
It is a further object of the present invention to provide a method for correcting the incomplete charge collection and improving the energy resolution of a room temperature solid state detector, provided the detector has segmented readout. This will lead to much better spectroscopic performance of the detector. An imaging system comprising of superior spectroscopic detectors will provide for improved image contrast.

Technique for obtaining sub-pixel spatial resolution and corrected energy determination from room temperature solid state gamma and X-ray detectors with segmented readout

The State of Israel, Atomic Energy Commission Soreq Nuclear Research Center


An image forming apparatus includes a movable member equipped with an operating unit for operating the image forming apparatus, wherein the movable member can be a first state and a second state by changing its position with respect to an main body of the apparatus, and a holding unit configured to hold the movable member, wherein the direction in which the operating unit is depressed in order to operate the image forming apparatus is the direction in which the movable member is depressed when the position of the movable member is changed from the first state to the second state, and wherein the holding unit holds the movable member so that the requisite force for changing the movable member from the first state to the second state is larger than the requisite force for changing the movable member from the second state to the first state.

1. Field of the Invention
The present invention relates to an image forming apparatus equipped with a movable member capable of changing its position with respect to a main body of the apparatus.
2. Description of the Related Art
An image forming apparatus is provided with an operating unit equipped with a button, touch panel, and the like allowing the user to operate the apparatus, and an indicating unit displaying the condition of the apparatus, etc. In recent years, there is a demand for securing the operability and visibility of such an operating unit and a indicating unit, and adjustability of the operability and visibility according to the user's usage while keeping the size of the entire main body of the apparatus during transportation and storage.
Thus, Japanese Patent Application Laid-Open No. 2007-163812 discusses a configuration in which an operating unit and a indicating unit are provided on the movable member held so as to allow a change in its position with respect to the main body of the apparatus through a change in angle and height.
Further, in order to allow the cartridge for image formation to be replaced and jamming generated within the apparatus to be dealt with, the image forming apparatus is provided with an opening and closing member that can be opened and closed with respect to the main body of the apparatus, revealing the interior of the apparatus when opened with respect to the main body of the apparatus.
Japanese Utility Model Application Laid-Open No. 59-167269 discusses a configuration in which the user can open such an opening and closing member to a predetermined position, with the opening and closing member being held at that position so as to be capable of changing its position with respect to the main body of the apparatus.
A holding configuration for the conventional movable member as mentioned above will be described. FIGS. 10A through 10C are schematic sectional diagrams illustrating a holding configuration. A rotatable arm 51 is connected integrally with the movable member rotatably supported by the main body of the apparatus. The arm 51 is provided with a plurality of engaging grooves 51b.
On the main body of the apparatus side, there are provided an engagement pin 52 that can be fit-engaged with the engaging grooves 51b, a compression spring 53 urging the engagement pin 52, and a spring holder 54 serving as a seat for the compression spring 53. An arrow C indicates the direction in which the compression spring 53 expands and contracts. The arm 51 is rotated to fit-engage the engagement pin 52 with one of the plurality of engaging grooves 51b, and urging in the fit-engagement direction is effected by compression spring 53, whereby the arm 51 and the movable member are maintained in a predetermined position.
In a case where the operating unit is provided on the movable member, when the user depresses the operating unit backwards from the front surface of the operating unit in order to operate the operating unit, it is necessary for the movable member to be firmly held so that the movable member may not be allowed to move backward due to the depressing force. In this regard, it might be possible to enhance the spring force of the compression spring 53 and to enhance the resistance force to the movement of the movable member, thereby strengthening the holding force with which the movable member is held.
However, also when moving the movable member from the rear side to the front side, it is necessary to move the movable member against this resistance force (holding force), so that an unnecessarily large operation force is required, which can impair the usability of the apparatus. Further, the way the weight of the movable member itself affects differs between the case where the movable member is started to be moved against the gravitational force and the case where it is started to be moved along the gravitational force, so that if the resistance force (holding force) is adjusted to the movement in one direction of the movable member, the usability of the apparatus may be impaired.
In this way, in a holding configuration in which the resistance force (holding force) with respect to the movement of the movable member is fixed independent of the moving direction of the holding member, the usability of the apparatus may be impaired.
However, the conventional movable member holding configuration leaves room for an improvement in terms of operability. Therefore, the present invention aims to provide an image forming apparatus having a movable member holding configuration improved in terms of usability.