A circuit with a large load driving capability, which is structured by single polarity TFTs, is provided. With a capacitor (154) formed between a gate electrode and an output electrode of a TFT (152), the electric potential of the gate electrode of the TFT (152) is increased by a boot strap and normal output with respect to an input signal is obtained without amplitude attenuation of an output signal due to the TFT threshold value. In addition, a capacitor (155) formed between a gate electrode and an output electrode of a TFT (153) compensates for increasing the electric potential of the gate electrode of the TFT (152), and a larger load driving capability is obtained.

1. Field of the Invention
The present invention relates to an inverter, buffer, and level shifter, and to a semiconductor device using them. Note that the term display device used within this specification includes a liquid crystal display device which employ liquid crystal elements in pixels, and a light emitting device which employ light emitting elements such as electroluminescence (EL) elements. The term semiconductor device indicates circuits that perform processing for inputting video signals into pixels disposed in the display device and displaying images. Pulse output circuits such as shift registers, inverters, buffers, and level shifters, and amplification circuits such as amplifiers are included in the category of semiconductor devices.
2. Description of the Related Art
In recent years, display devices manufactured by forming semiconductor thin films on an insulator such as a glass substrate, in particular, active matrix display devices such as LCDs (liquid crystal displays) using thin film transistors (hereinafter referred to as TFTs), are being utilized in many manufactured products, and are spreading. The active matrix display devices using TFTs have from several hundred thousands to several million pixels arranged in a matrix shape, and display of images is performed by controlling the electric charge of each pixel with TFTs disposed in the respective pixels.
In addition, techniques related to polysilicon TFTs for TFTs have been developed recently, and a driver circuit using TFTs is formed in a peripheral region of a pixel portion on a substrate simultaneously with pixel TFTs structuring pixels. The techniques contribute greatly to making a device small size and to reducing electric power consumption, and accordingly, a display device has come to be indispensable for a portion such as a display portion of a mobile information terminal, which has remarkably been applied to the extensive fields in recent years.
In general, a CMOS circuit in which an n-channel TFT and a p-channel TFT are combined are used as a circuit for structuring semiconductor devices. A CMOS inverter is shown in FIG. 11A as one example of the CMOS circuit. A p-channel TFT 1101 and an n-channel TFT 1102 are combined, and an output signal is obtained by inverting the polarity of an input signal (see FIG. 11B).
Now, as shown in FIG. 11C, there is a state in which a certain load (Load) is attached to the later stage of the CMOS inverter. If the load is excessive with respect to the size of the TFTs structuring the CMOS inverter at this point and a pulse is input from an input (In), there will be a case in which an output pulse, namely an output (Out i) of an inverter (Inv1) in FIG. 11C, is greatly dulled in both rise and fall of the pulse, compared to the waveform of the input signal, as shown in FIG. 11E. This is because the CMOS itself inverter does not have the capability of supplying a sufficient amount of electric charge for driving the load.
There normally is lot of weight given to low electric power consumption with semiconductor devices, and logical circuits are structured using relatively small size TFTs. On the other hand, display regions are becoming larger in size, and in addition, the number of pixels is increasing. The load due to pixels is therefore large. As stated above, pulses are not output normally if a large load is present in the later stage of an inverter with a small driving capability.
A buffer is normally formed between a driver circuit portion and a pixel portion. Typically, a plurality of inverter stages are disposed in series as shown in FIG. 11D, and driving of the final load can be performed without problem by driving the inverters that are gradually increased in size. Compared to the structure of FIG. 11C, the waveform of an output (Out ii) of a buffer in the final stage (Inv4) is not greatly dulled and thus is output as a normal pulse, and the load in the later stage can be driven.
Display devices have come to be employed in the display portion of many types of electronic devices in recent years, and there is steady expansion in the number of fields in which display devices are used. Display devices are recently being actively employed even in relatively low cost electronic equipment, and therefore further cost reductions are desirable.
A multiple-layer structure is formed for a display device by repeatedly performing processes of film formation, exposure to light using a photomask, and etching. The extreme complexity of the processes therefore invites an increase in manufacturing costs. In addition, in the case in which the driver circuit and the pixel portion are formed integrally on the substrate as discussed above, some defects become a problem which affects the entire manufactured product, and has a large influence on yield.
A method in which the number of processes is reduced as much as possible, and manufacturing can be performed simply in a short period of time can be given as one method of achieving the cost reduction. A display device is manufactured with a structure that uses TFTs with a single polarity type, n-channel TFTs or p-channel TFTs, instead of a CMOS structure for the driver circuit. Processes for adding an impurity which imparts a conductivity to a semiconductor layer can thus be simply cut in half, and in addition, the number of photomasks can be reduced. This is extremely effective from the view point of cost-related merits.
A conventionally known single polarity type circuit is explained here.
FIG. 12A shows an example in which an inverter is structured by two n-channel TFTs. The inverter is a two input type inverter with signals input to gate electrodes of TFTs 1201 and 1202. An inverted signal of one input is used as the other input.
Operation of the inverter shown in FIG. 12A is explained simply here. Note that the terms "gate electrode, input terminal, and output terminal", and the term "gate electrode, source region, and drain region" are used separately in this specification for the names of the three electrodes of the TFT in explaining the circuit structure and operation. This is because, although there are many cases in which the voltage between the gate and the source is considered in explaining TFT operation, it is difficult to clearly differentiate the source region and the drain region of the TFT based upon the structure of the TFT and the use of unified names may, instead of being helpful, lead to confusion developing. The terms input terminal and output terminal are used in explaining the input and output of signals. The input terminal or the output terminal is referred to as the source region, and the other is referred to as the drain region, in explaining the relationship of the electric potential between the electrodes of the TFT.
First, operation of the two input inverter of FIG. 12A is explained. When H level is input to a first input (In) and L level is input to a second input (Inb),, the TFT 1201 turns off and the TFT 1202 turns on. L level therefore appears in an output (Out) and the electric potential of the output becomes VSS. On the other hand, when L level is input to the first input (In), and H level is input to the second input (Inb), the TFT 1201 turns on and the TFT 1202 turns off. H level therefore appears in the output (Out) to pulled up to the VDD side.
At this point, the electric potential is considered when the output (Out) becomes the H level.
The L level is input to the gate electrode of the TFT 1202 when the H level is input to the gate electrode of the TFT 1201 in FIG. 12A. The TFT 1201 is therefore on, and the TFT 1202 is therefore off. Accordingly, the electric potential of the output (Out) begins to rise, and the voltage between the gate and the source of the TFT 1201 becomes equal to the threshold value VthN when the electric potential of the output (Out) becomes (VDD−VthN). That is, the TFT 1201 turns off at this instant, and therefore the electric potential of the output (Out) cannot rise any further.
A circuit in which a plurality of stages of the inverters shown in FIG. 12A are connected in series is shown in FIG. 12B. The output of a certain stage becomes the input of the next stage with this type of circuit. As discussed above, waveforms in which the amplitude is attenuated by VthN with respect to the input signal appear in an output (Out i) of a first stage and an output (Out ii) of the next stage. An output (Out ii) of a third stage is additionally attenuated by VthN compared with the first stage output (FIG. 12C). Similarly, attenuation of the amplitude due to the threshold voltage continues to develop and overlap throughout the stages, the amplitude of the waveform shrinks rapidly, and the circuit cannot function as a satisfactory circuit.
A boot strap method is known in order to resolve this problem in structuring the circuit by using single polarity type TFTs. A basic circuit which functions by using the boot strap method is shown in FIG. 13A.
FIG. 13A is an inverter structured by three n-channel TFTs 1301 to 1303 and a capacitor means 1304, as disclosed in JP 3092595 B. A signal is input to a gate electrode of the TFT 1303, and the inverted signal of the signal is input to an input terminal of the TFT 1301.
Operation is explained. The amplitude of the input signal is VDD to VSS here. Refer to FIG. 13A and FIG. 13B. FIG. 13B is a diagram showing an input signal (In), an electric potential (Vf) of a gate electrode of the TFT 1302, and an output signal (Out).
When a H level signal is input to the input (In), and a L level signal is input to the inverted input (Inb), the electric potential of the gate electrode of the TFT 1301 is VDD to be in an on state, and therefore the electric potential of the gate electrode of the TFT 1302 is L level to turn off. On the other hand, the H level is input to the gate electrode of the TFT 1303 to turn on, and L level appears at the output (Out).
When a L level signal is input to the input (In), and an H level signal is input to the inverted input (Inb), the electric potential of the gate electrode of the TFT 1301 is VDD to be in an on state, and therefore the electric potential of the gate electrode of the TFT 1302 is H level. However, the electric potential of the gate electrode of the TFT 1301 is VDD, and therefore the electric potential of an output terminal of the TFT 1301, that is the electric potential of the gate electrode of the TFT 1302, becomes (VDD−VthN) to place the TFT 1301 in an off state. The gate electrode of the TFT 1302 is thus placed in a floating state at this instant. On the other hand, the TFT 1303 turns off.
The voltage between the gate and the source of the TFT 1302 rises above the TFT threshold voltage, the TFT 1302 therefore turns on, and the electric potential of an output terminal of the TFT 1302 is pulled up the to VDD side. However, the electric potential of the gate electrode of the TFT 1302 is (VDD−VthN) at this point, and the electric potential of the output terminal of the TFT 1302 can thus only increase to (VDD−2VthN).
The capacitor 1304 is formed between the output terminal and the gate electrode of the TFT 1302, however, and the gate electrode of the TFT 1302 is in a floating state. Therefore the electric potential of the gate electrode of the TFT 1302 rises by ΔVf shown in (ii) of FIG. 13B due to capacitive coupling along with the rise in the electric potential of the output terminal of the TFT 1302. The electric potential of the gate electrode of the TFT 1302 is thus greater than (VDD+VthN), and therefore the electric potential of the output terminal of the TFT 1302 then becomes equal to VDD. Note that a dotted line denoted by reference numeral 1350 in (iii) of FIG. 13B is an output example in the case of using the inverter shown in FIGS. 12A and 12B.
The inverter shown in FIG. 13A outputs an inverted signal without amplitude attenuation due to the threshold value of the TFT by the aforementioned procedure. A method of operating the electric potential of a node in a floating state by utilizing capacitive coupling between two nodes is referred to as a boot strap method.
It takes time for charging a load in the case in which the load attached to the later stage is large in an inverter that uses a boot strap method, and therefore the rise time becomes long. It is possible to increase the effect of the boot strap by making the capacitor 1304 larger. Conversely, however, a delay in the increase of the electric potential of the output with respect to the input becomes long if the capacitor is made too large, thus the size of the capacitor is limited.
The rise time may become long, or the boot strap may not function sufficiently and the amplitude of the output signal may not be able to be normalized (specifically, H level may not be sufficiently brought up), in the cases in which the load attached to the later stage of the output is additionally large, the amplitude of the input signal is small (H level is low), the threshold value of the TFT is large, and parasitic capacitance in the gate electrode of the TFT in a floating state is large during boot strap operations, and similar cases.

Semiconductor Energy Laboratory Co., Ltd.


A projection screen includes a reflector and a plurality of compound lenses. The compound lenses are arranged at the same side of the reflector in an array manner. Each of the compound lenses has a first lens portion and a second lens portion. The first lens portion is disposed between the second lens portion and the reflector. A surface of the first lens portion opposite to the reflector has a first radius of curvature, and a surface of the second lens portion opposite to the reflector has a second radius of curvature. The first radius of curvature has a length greater than the second radius of curvature.

1. Field of Invention
The present invention relates to a projection screen.
2. Description of Related Art
Currently, projection screens generating stereoscopic images with lens pupil scanning method are mostly transmission screens. FIG. 7 is a schematic diagram of a conventional transmission projection screen. In general, the transmission projection screen includes a Fresnel lens 910, double lenticular lenses 920 and 930, and a diffuser 940. The Fresnel lens 910 converges the diffusing light emitted from a projector (not shown) to parallel light, and the lenticular lens 920 images the parallel light onto the diffuser 940. Subsequently, the lenticular lens 930 images the images on the diffuser 940 to different views. This method faces problems such as the Fresnel lens 910 itself refracts different color lights (such as red, blue, and green lights) to different positions due to its chromatic aberration, such that the lights are unable to be projected on the correct views. For an image system including the lenticular lens 920, the F number must be greater to maintain an acceptable image quality. Therefore, the back focus of the lenticular lens 920 is increased, resulting in a large screen thickness. Moreover, since the Fresnel lens 910 is a thin lens composed by many tiny surfaces, which generates moire with the lenticular lenses 920 and 930. The diffuser 940 decreases the image quality, thereby creating a deteriorating crosstalk problem. In addition, the diffuser 940 repeats views, and as a result, view reversion area unavoidably occurs on the projection screen.

Projection screen and projection system using the same


The disclosure provides methods, systems, and kits for assaying an agent for mutagenic properties. The methods systems and kits utilize a DEL selectable marker and a colorimetric detection systems. Also included are methods systems and kits that utilize a DEL selectable marker and a regent that detects mitochondrial activity.

It is generally accepted that the mutagenic potential of a chemical agent is roughly proportional to the agent's carcinogenic potential. An early determination of whether a particular agent presents a hazard of mutagenicity is fundamental to the development of products for the chemical, cosmetic, food additive and pharmaceutical industries.
Mutagens are agents that cause an increase in the rate of mutation, i.e. detectable and heritable structural changes in the genetic material of an organism. Such changes may include the addition or deletion of a whole chromosome, a structural change to a chromosomes (e.g., a translocation) and a structural change to a portion of the genomic sequence (e.g., point mutations, mutations to multiple sequential nucleotides and deletions of portions of the genomic sequence). Because genetic changes can damage or otherwise interfere with the action of genes, mutagens are characterized as genotoxins, i.e. agents that are toxic to genes.

The Regents of the University of California


A headband for retaining and positioning an object is adapted to have an active configuration and an alternative passive configuration. In the active configuration, the headband can be made to encircle a user's head such that the object is retained on an exterior surface ready for use. In the passive configuration, the headband can be made to close around the object such that the object is retained on an interior surface, protected against damage, with the headband retained in a compact form. In this passive configuration, the headband can releasably engage a belt so as to form a holster for the object, thereby rendering both the object and the headband ready for rapid deployment.

Headbands for retaining and positioning flashlights are known. Typical of such devices is the one shown in U.S. Pat. No. 5,053,932, granted on Oct. 1, 1991, to Richard N. Case for a "Flashlight Retainer". The '932 patent describes an elongated band having two ends adapted to releasably engage each other so as to form a circular headband having an outside face and an inside face. The inside face fits snugly against the head of the user while the outside face includes an elastic loop for retaining and positioning a flashlight.
Other similar devices are known. Typically, these devices differ by their means for retaining the flashlight or by their means for adjusting the headband to fit different head sizes. Examples of such other devices are shown in U.S. Pat. No. 4,797,793, granted on Jan. 10, 1989, to Tom R. Fields for a "Headband for Holding a Flashlight", U.S. Pat. No. 5,217,294, granted on Jun. 8, 1993, to James W. Liston for a "Head Mounted Multi-Position Flashlight Holder", and U.S. Pat. No. 4,970,631, granted on Nov. 13, 1990, to Timothy E. Marshall for a "Headband Device for Holding Flashlight".
Unfortunately, known flashlight-retaining headbands have a number of disadvantages.
Although these devices are suitable for retaining a flashlight on a person's head, this arrangement is not the normal state for either the flashlight or the person. People generally do not walk about with flashlights on their heads and flashlights are generally found in places other than on people's heads.
The known headbands do not assist a person to carry a flashlight anywhere except on the head. Designed for active flashlight use, these devices expose the flashlight to damage during passive carriage.
When not worn, the headband is loose and susceptible to snagging on objects. To avoid snagging the headband, the user must either wrap it cumbersomely around the flashlight or remove it entirely and store it separately from the flashlight. In either case, over time the user will be prone to forget the headband, to lose it, or to intentionally leave it behind. Without the headband, the user must either carry the flashlight in hand or find an alternative device for retaining or carrying the flashlight.
Similarly, the known devices are not suitable for storing a flashlight between uses. They leave the flashlight exposed and susceptible to damage, and their elongated, flexible structure is prone to becoming a tangled mess.
What is needed is a flashlight-retaining headband that is also suitable for carrying the flashlight during passive use and for storing the flashlight between uses. The present invention is directed to such a device.


The inventions relate to security systems for securely accessing accounts and avoiding identity-theft scams. They include object-based passwords and passphrases. For example, the invention relates to method of verifying a user's identity to allow that user to gain access to an account. The method includes creating a first matrix of characters of size X; and upon logon, displaying a second matrix of characters of size Z, wherein Y characters represent a preselected password of the user and X>Z>Y. In this equation, X is greater than the number of letters, numbers and characters on a keyboard.

There is a need to improve the security of commerce over the Internet, for example, in commerce that involves finances such as stocks, bonds, cash, credit cards, bank accounts, and brokerage accounts. Programs have been developed to monitor key strokes and send people to faux websites designed to look like a legitimate institution, e.g., financial; both programs are designed for the purpose of capturing password information to either commit identity theft or break into the account.

User identity security system for computer-based account access


The invention relates to a riser pipe section comprising a main tube (2), at least one auxiliary line element (3) arranged substantially parallel to said tube (2), characterized in that the ends of main tube (2) comprise connecting means (8) allowing longitudinal stresses to be transmitted and in that the ends of auxiliary line element (3) comprise linking means (5-6) allowing longitudinal stresses to be transmitted.

A drilling riser is made up of an assembly of tubular elements whose length ranges between 15 and 25 m, assembled by connectors. The weight of these risers borne by an offshore platform can be very great, which requires suspension means of very high capacity at the surface and suitable dimensions for the main tube and the linking subs.
So far, the auxiliary lines: kill lines, choke lines, booster lines and hydraulic lines are arranged around the main tube and they comprise subs that fit together, fastened to the riser element connectors in such a way that these high-pressure lines can allow a longitudinal relative displacement between two successive line elements, without any disconnection possibility however. Owing to these elements mounted sliding into one another, the lines intended to allow high-pressure circulation of an effluent coming from the well or from the surface cannot take part in the longitudinal mechanical strength of the structure consisting of the entire riser.
Now, in the perspective of drilling at water depths that can reach 3500 m or more, the dead weight of the auxiliary lines becomes very penalizing. This phenomenon is increased by the fact that, for the same maximum working pressure, the length of these lines requires a larger inside diameter considering the necessity to limit pressure drops.
Document FR-2,799,789 aims to involve the auxiliary lines, kill lines, choke lines, booster lines or hydraulic lines, in the longitudinal mechanical strength of the riser. According to this document, a riser element comprises a main tube, connecting means at both ends thereof, at least one auxiliary line length arranged substantially parallel to the main tube. The auxiliary line length is secured at both ends to the main tube connecting means so that the longitudinal mechanical stresses undergone by the connecting means are distributed in the tube and in the line.
One difficulty in making the riser according to document FR-2,799,789 lies in the fastening means for joining the auxiliary line length to the main tube. The tensional stresses undergone by the auxiliary line length are transmitted by these fastening means. The assembly and design requirements impose a distance to be provided between the main tube and the auxiliary line. This distance acts as a lever arm for the tensional stresses transmitted to the auxiliary line. As a result of the tensional stresses associated with the lever arm, the fastening means are subject to bending strains that may be harmful to the good working order of the riser.
The present invention provides a riser made according to a principle that is an alternative to the principle disclosed by document FR-2,799,789. According to the present invention, all of the auxiliary lines contribute, together with the main tube, to taking up the longitudinal stresses applied to the riser.


A needle assembly includes a housing having proximal and distal ends, an IV cannula projecting distally from the housing, and an IV shield having an engagement. The housing has a shield seat and the IV cannula has a distal tip. The IV shield has a pre-use position where the IV shield covers the distal tip of the IV cannula and the engagement is disengaged from the shield seat, and a use position where the engagement is engaged with the shield seat and the IV shield is adapted to move between a non-shielded position, in which the distal tip is exposed, and a shielded position, in which the distal tip is shielded by the IV shield.

Field of the Invention
The present invention relates to a needle assembly and, more particularly, to a shieldable blood collection needle assembly.
Description of Related Art
Needle assemblies are used for collecting specimens of fluid, such as blood, from a patient. Some such needle assemblies are intended for use with an evacuated tube and include a housing with a proximal end, a distal end, and a passage extending between the ends. Such needle assemblies further include at least one needle cannula mounted to the housing. The needle cannula includes a sharply pointed distal end that projects distally beyond the housing, a proximal end that projects proximally beyond the housing, and a lumen that provides communication between the opposed ends of the needle cannula. Some needle assemblies include separate proximal and distal cannulas and rely upon a portion of the housing to provide communication between the lumens of the respective cannulas. The distal end of the needle cannula typically is beveled to a tip that is sufficiently sharp for piercing the skin of the patient and accessing the vein or other source of fluid that is to be collected. The proximal end of the needle cannula is configured for piercing the rubber stopper on an evacuated tube. The proximal end of the needle cannula typically is covered by a needle pierceable resealable multi-sample sleeve. The sleeve is compressed by the rubber stopper of the evacuated tube and punctured by the proximal end of the needle cannula as the proximal end of the needle cannula is urged into communication with the evacuated tube. The evacuated tube is typically received by a needle holder secured to the proximal end of the housing.
Prior to use, the needle assembly also typically includes an IV shield and a non-patient shield mounted respectively over the distal end of the needle cannula and the proximal end of the needle cannula. The IV shield and the non-patient shield are frictionally retained on the housing and can be separated through axial movement of the shields away from the housing. The combined needle assembly and evacuated tube is employed by initially urging the pointed distal end of the needle cannula into a blood vessel of a patient. Once the targeted blood vessel has been accessed, the evacuated tube is urged into the needle holder such that the proximal point of the needle cannula pierces the septum of the tube. Low pressure conditions within the evacuated tube, as well as the patient's own vasculature pressure, generate a flow of blood from the patient through the needle cannula and into the evacuated tube. The evacuated tube may be removed from the needle holder after a sufficient quantity of blood has been collected. One or more additional evacuated tubes may similarly be urged into the open end of the needle holder for drawing one or more additional samples of blood to be analyzed. The needle cannula is then withdrawn from the patient after a sufficient volume of blood has been collected for the required analytical procedure.
Many fluid collection needle assemblies are provided with a flashback chamber that communicates with the needle cannula. The flashback chamber typically is formed at least partly from a transparent or translucent material and is intended to receive a portion of the blood flow shortly after a vein has been accessed properly. The flashback chamber gives a positive indication of venous entry after a vein is entered with the distal end of the needle cannula.
In order to reduce the risk of an accidental needle stick, or contact that could transmit pathogens from the patient to the medical practitioner, the needle cannula is shielded after contact with the patient. Shields have taken many different forms. For example, some shields telescope over the needle cannula and frictionally engage the housing. Other shields are telescoped over the housing and can be moved distally over the needle cannula to effect shielding. Other shields are hingedly mounted to or near the housing and can be rotated from an open position, where the needle cannula is exposed, to a closed position, where the needle cannula is shielded.

Blood collection assembly having a multi-function shield


An image recording apparatus, including a tray configured to support a sheet; a chassis defining a first conveyer path, in which the sheet on the tray is conveyed in a first conveying direction, and a second conveyer path, through which the sheet is conveyed in a second conveying direction through a branch point to be inverted to reenter the first conveyer path through a merging point; a base member integrally formed of resin and including a guiding section to define a form of a part of the second conveyer path; a recording unit to record an image on the sheet conveyed in the first conveyer path; a drive shaft supported by the base member; and a return-conveyer roller disposed in the second conveyer path and configured to convey the sheet to be guided on the guiding section in the second conveying direction by rotation of the drive shaft, is provided.

Technical Field
The present invention relates to an image recording apparatus capable of recording an image on either side of a sheet.
Related Art
An image recording apparatus capable of recording an image on either side of a sheet is known. The image recording apparatus may have a first conveyer path, along which a recording unit is disposed, and a second conveyer path, which inverts the sheet with the image recorded on a first side and directs the inverted sheet to the first conveyer path so that another image may be recorded on second side of the sheet. In the first and second conveyer paths, a plurality of rollers may be disposed to convey the sheet.
Meanwhile, in order to reduce a size, a quantity of parts, and manufacturing cost of the image recording apparatus, a paper chute serving as a part of a conveyer path to guide the sheet may be integrally formed in a base member, which is made of a resin.


Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

The commercial production of portlandite (Ca(OH)2) and brucite (Mg(OH)2) presently involves calcination-based methods, which require a significant amount of thermal energy. To produce portlandite, calcite (CaCO3) is heated to about 800° C. to produce lime (CaO) and carbon dioxide (CO2). The lime produced is then reacted with water to form Ca(OH)2 by a slaking process. Commercial Mg(OH)2 is produced by adding portlandite to seawater rich in Mg2+, thereby precipitating Mg(OH)2. Alternatively, hydrated magnesium chloride (MgCl2) from seawater is recrystallized several times, and then calcined at about 1000° C., before reacting with water to form a hydroxide slurry.
Also, brines from various industrial processes, such as desalination operations and oil and gas production, are hypersaline streams typically treated as waste. However, such brines are actually a potential sink for CO2 as they are rich in divalent ions such as Ca2+ and Mg2+ which react with aqueous CO32− from the dissolution of CO2 in water to form relatively insoluble carbonate solids. Carbonate precipitates formed in this manner can have a wide range of industrial applications. An example of a brine waste stream is produced water, which refers to the water generated during oil and gas production, and which can have divalent ion concentrations of up to about 100,000 parts per million (ppm). Such process can provide an effective route to mitigate the increasing anthropogenic CO2 emissions at a gigaton-scale, since brines are generated at large quantities annually around the world (e.g., about 22 billion barrels of produced water was generated in 2014 in the United States alone). However, effective extraction of divalent ions from hypersaline and complex aqueous matrices in brines as carbonate solids at low cost and energy expense remains a significant challenge.
It is against this background that a need arose to develop the embodiments described herein.

Facile, low-energy routes for the production of hydrated calcium and magnesium salts from alkaline industrial wastes


A system detects targets located within patterns. It operates in the pupil plane by filtering the received signal from the surrounding pattern. A method includes illuminating a target and a surrounding pattern with radiation, detecting the radiation reflected by the target and the surrounding pattern and forming a first set of data based on the detected radiation, removing portions of the first set of data which correspond to the target to form reduced data, interpolating the remaining portions of the reduced data over the removed portions to form product data, and subtracting the product data from the first set of data to form target data.

A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that instance, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g. including part of, one, or several dies) on a substrate (e.g. a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the "scanning"-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.
In order to monitor the lithographic process, it is desirable to measure parameters of the patterned substrate, for example the overlay error between successive layers formed in or on it. There are various techniques for making measurements of the microscopic structures formed in lithographic processes, including the use of scanning electron microscopes and various specialized tools. One form of specialized inspection tool is a scatterometer in which a beam of radiation is directed onto a target on the surface of the substrate and properties of the scattered or reflected beam are measured. By comparing the properties of the beam before and after it has been reflected or scattered by the substrate, the properties of the substrate can be determined. This can be done, for example, by comparing the reflected beam with data stored in a library of known measurements associated with known substrate properties. Two main types of scatterometer are known. Spectroscopic scatterometers direct a broadband radiation beam onto the substrate and measure the spectrum (intensity as a function of wavelength) of the radiation scattered into a particular narrow angular range. Angularly resolved scatterometers use a monochromatic radiation beam and measure the intensity of the scattered radiation as a function of angle.
In scatterometers and lithographic apparatus, targets are used in the determination of overlay errors. These are conventionally positioned in the scribe lanes between the patterns. The overlay error at the target site is thus measured. However, the overlay error at the position of the pattern is therefore an interpolation between the overlay at different points surrounding the pattern.
Although the targets could be positioned within the patterns themselves, this is not desirable because the targets used are relatively large and therefore take up too much of the area that is designed for product patterns, thereby compromising device functionality.

Inspection apparatus to detect a target located within a pattern for lithography


Disclosed is a circuit substrate supporting structure including: a base; a cover to cover over the base; a circuit substrate accommodated in the cover in a state standing on the base; a projecting section provided on the circuit substrate in a state projecting from a bottom edge section of the circuit substrate and placed on the base; an elastic piece placed on the projecting section; and a pressurizing section convexly provided on an inner wall of the cover above the projecting section to be pressed against the projecting section from above the elastic piece.

1. Field of the Invention
The present invention relates to a circuit substrate supporting structure and an antenna apparatus, and in particular, a circuit substrate supporting structure where a circuit substrate is supported in a standing state and an antenna apparatus.
2. Description of Related Art
In an electrical apparatus such as an antenna apparatus, etc., a circuit substrate is accommodated inside a case and a circuit substrate is supported inside the case. A case main body and a base are set together as a case. The base is provided in a plate-shape and the bottom of the case main body is open to cover over the base so that the opening of the case main body is closed by the base (for example, see Japanese Patent Application Laid-Open Publication No. 2000-68722 and Japanese Patent Application Laid-Open Publication No. 2002-94320).
In order to make the apparatus smaller, the circuit substrate is accommodated in the case in a standing state with respect to the base (see Japanese Patent Application Laid-Open Publication No. 2000-68722 and Japanese Patent Application Laid-Open Publication No. 2002-94320). In order to set the circuit substrate standing with respect to the base, two ribs are convexly provided on the top face of the base, and the circuit substrate is nipped between the ribs. In order to fix the circuit substrate, the circuit substrate is nipped between the ribs and the ribs are crimped. Alternatively, another method to fix the circuit substrate is to fix the circuit substrate in a standing state to a bracket other than the base and then the bracket is fixed to the base (see Japanese Patent Application Laid-Open Publication No. 2000-68722).
However, when the rib is crimped, there is a possibility that the circuit substrate is damaged in crimping. Also, in addition to a step of setting the base to the case main body, a step to crimp the ribs is necessary and the number of steps necessary for assembly increases. When a bracket is used, in addition to a step of setting the circuit substrate to the bracket, a step to set the bracket to the base is necessary and the number of steps necessary for assembly increases.

Circuit substrate supporting structure and antenna apparatus


A composition comprising a Type 1 clathrate of silicon having a Si46 framework cage structure wherein the silicon atoms on said framework are at least partially substituted by carbon atoms, said composition represented by the formula CySi46-y with 1≦y≦45. The composition of may include one or more guest atoms A within the cage structure represented by the formula AxCySi46-y wherein A=H, Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca. Sr, Ba, Ra, Eu, Cl, Br, or I or any metal or metalloid element and x is the number of said guest atoms within said cage structure.

Silicon clathrate Si46 refers to crystalline Si with a regular arrangement of 20-atom and 24-atom cages fused together through 5 atom pentagonal rings (Type I clathrate). It has a simple cubic structure with a lattice parameter of 10.335 Å and 46 Si atoms per unit cell. FIG. 1 illustrates the cage structure of the Si46, which belongs to the Space Group Pm3n and Space Group Number 223. The crystal structure of the silicon clathrate (Si46) is different from the common form of crystalline Si (c-Si), which is diamond cubic with a lattice parameter of about 5.456 Å and belongs to the Space Group Fd3m, Number 227.
Another form of silicon clathrate is Si34 (Type II clathrate) that consists of crystalline Si with a regular arrangement of 20 atoms and 28 atom cages fused together through five-atom pentagonal rings. Type II Si34 clathrate has a face-centered cubic (fcc) structure, with 34 Si atoms per fcc unit cell. The Si34 clathrate has a lattice parameter of 14.62 Å and belongs to the Space Group Fd3m, Number 227. Type II silicon clathrate is sometimes referred to as Si136 since the compound contains four fcc unit cells. A third form of silicon clathrate is a modification of the Si46 type formed by removing four atoms from the 24-atom cages.


The present invention relates to thin film retardation plates, such as cholesteric and A-plate compensators, for improving the viewing angle and contrast of liquid crystal displays. The A-plate is fabricated using a single substrate onto which a layer of polymerizable reactive mesogens (RMs) is solvent cast. Included in the RMs solution is an additive that migrates to the RM/air interface to lower the surface energy and generate an additive-rich surface layer, which in turn lowers the intrinsic tilt angle of the RMs at the air interface to between 25 degrees (25.degree.) and about zero degrees (0.degree.). The solvent is evaporated and the resulting film is polymerized in the liquid crystal phase to permanently orient the liquid crystal. The resulting film may be readily separated from the substrate and shaped into any desired pattern and combined to form novel compensators. In an alternative embodiment, a tilt may be provided by treating the substrate with an oblique alignment layer to form a compensator having a defined splay through the bulk of the thin film.

(1) Field of the Invention
The present invention relates to optical retardation means and more particularly to thin film retarders for improving the viewing angle and brightness of liquid crystal displays.
(2) Description of Related Art
Tremendous advances in liquid crystal display technology has created advanced display devices that are brighter, lighter, and capable of displaying information with high resolution. Due to the lightweight, smaller form factor and low power requirements of liquid crystal displays, they offer several advantages over alternative displays such as cathode ray tube displays. However, liquid crystal displays suffer from poor contrast and/or chromaticity at wide viewing angles such that viewing the display is often difficult in many viewing environments.
The primary factor limiting the contrast ratio achievable in a liquid crystal display arises from light that leaks through portions of the display that are supposed to be in the dark state. The contrast ratio of a liquid crystal also depends on the viewing angle of the observer. As is well known, the contrast ratio in a typical liquid crystal display is a maximum only within a narrow viewing angle centered about the normal incidence and drops off as the viewing angle increases. This viewing angle related decrease in the contrast ratio is caused by light leaking through dark state pixel elements at large viewing angles. Large viewing angles may also cause color shifts in color displays.
To improve both the contrast and viewing angle, optical compensator layers may be included in the liquid crystal display. The need for such compensators increases for supertwisted nematic (STN) liquid crystal displays where it is common practice to include a second STN display panel having an opposite twist to compensate for the birefringence of the first panel. Since it is expensive to provide a second liquid crystal display panel solely as a compensator, many displays include optical compensators such as phase retardation films. The use of such retardation films have been disclosed in U.S. Pat. Nos. 5,196,953 (issued to Yeh et al.), 5,504,603 (issued to Winker et al.), 5,557,434 (issued to Winker et al.), 5,589,963 (issued to Gunning, III et al.), 5,619,352 (issued to Koch et al.), 5,612,801 (issued to Winker) and 5,638,197 (issued to Gunning, III et al.). A liquid crystal layer is sandwiched between a pair of polarizer layers with one polarizer having an absorbing layer perpendicular to the absorbing axis of the other. With the addition of one or more compensator layers, the contrast ratio is improved over a wide range of viewing angles by careful orientation of the optic axis of the compensator. The combined retardation effect of the compensator cancels the phase retardation inherent in liquid crystal displays. All of the above referenced patents are either commonly assigned with this application or assigned to the assignee's parent corporation, Rockwell International Corporation.
One type of compensator included in the compensator layers discussed in these patents is known as A-plate compensator. An A-plate is a birefringent layer with its extraordinary axis (i.e. its c-axis) oriented parallel to the surface of the layer and its a-axis oriented normal to the surface (parallel to the direction of normally incident light). Prior art A-plates may be fabricated by the use of uniaxially stretched polymer films, such as polyvinyl alcohol or other suitable oriented organic birefringent material.
Unfortunately, the quality and uniformity of the optical properties of such prior art A-plates are generally poor. Further, the A-plate must be held under tension and the material must be relatively thick to obtain sufficient anisotropy. Further still, lamination of such A-plates with other retardation films often results in stress-induced birefringence when exposed to elevated temperatures.
Recently, it has been reported that retardation films may be obtained from ultraviolet (UV) curable liquid crystals. See, for example, H. Hasebe, K. Takeuchi and H. Takatsu, J.SID, 3/3, 139 (1995). As shown in FIG. 5, two substrates are provided so that traditional alignment techniques may be used to eliminate any splay in the crystal structure that may otherwise be introduced by the intrinsic tilt of the liquid crystal at the liquid crystal/air interface. However, since polyimide alignment material is very expensive, it is undesirable to apply alignment layers to two substrates. It is also undesirable to incur the expense associated with aligning and spacing the two substrates if one or both of the substrates are to be discarded after photopolymerization of the UV-curable liquid crystal. It is further still undesirable to rely on spaced parallel substrates to establish the orientation of the liquid crystal prior to photopolymerization since there is a practical limitation on the size and uniformity achievable with spaced substrates.
Clearly, it is desirable to minimize the number of substrates required to orient the UV-curable liquid crystal material. As noted in the above-referenced U.S. Pat. No. 5,619,352, polymerizable liquid crystals may be used in a process that coats a single substrate surface to create thin film compensators. This process eliminates the need to provide a second substrate having an alignment layer for aligning the liquid crystal. However, most polymerizable liquid crystals have an intrinsic non-zero tilt angle at the polymerizable liquid crystal/air interface that makes it difficult to achieve the planar orientation of the liquid crystal needed for A-plate compensators. Accordingly, an efficient and economical method is needed for achieving a tilt angle at the nematic /air interface necessary that is lower than the intrinsic tilt angle of the polymerizable liquid crystal.

Thin film compensators having planar alignment of polymerized liquid crystals at the air interface


A program partial linking system includes an assigned program existence judgement section, an assigned program linkage section, and a specific program linkage section. The assigned program existence judgement section judges whether the program assigned by linkage information input during program linkage exists in a program library. The assigned program linkage section links the assigned program when the judgement section judges that the assigned program exists in the program library. The specific program linkage section links a specific program prepared in advance when the judgement section judges that the assigned program does not exist in the program library.

The present invention relates to a program linking system and, more particularly, to a system for partially linking a plurality of unit programs.
In a conventional computer system, in order to link a plurality of unit programs to form a single program having one execution format and to execute the single program, names of unit programs and names of means storing the unit programs are given to the computer system during linking. In conventional linking systems, if a unit program to be linked to a given unit program does not exist in the program storing means such as a program library, the program having an execution format is generated while the assigned program is not linked to the given program. During execution of the program, when control is shifted to the unit program assigned by control shift information such as a call instruction, an execution error occurs and the subsequent operation cannot be performed. When the execution error occurs, if the error is caused by nonlinkage of the assigned program or the error is caused by another cause cannot be determined.
The following schemes must be employed to execute only other linked unit programs without causing an execution error when the unit program assigned by the control shift information does not exist in the conventional program linking system.
(1) An original program is corrected so as not to call the unit program and then, linkage operation is performed again, and PA1 (2) A dummy program having a given name is generated for each nonexistent unit program and is stored in the program storing unit.
In a conventional scheme (1) described above, however, the original program must be corrected, and the operations are cumbersome. At the same time, errors may occur during correction.
In a conventional scheme (2) described above, the dummy program having a given name must be generated in units of nonexistent unit programs. When the number of nonexistent unit programs is increased, the number of dummy programs is increased, and preparation procedures are complicated. In addition, if the name is to be changed, the dummy program must be corrected.

Program partial linking system for linking a specific program prepared in advance when an assigned program is not in a program library


A method of assembling a bent circuit chip package and a circuit chip package having a bent structure. The circuit chip package includes: a substrate having a first coefficient of thermal expansion (CTE); a circuit chip, having a second CTE, mounted onto the substrate; a metal foil disposed on the circuit chip in thermal contact with the chip; a metal lid having (i) a third CTE that is different from the first CTE and (ii) a bottom edge region, where the metal lid is disposed on the metal foil in thermal contact with the metal foil; and an adhesive layer along the bottom edge of the metal lid, cured at a first temperature, bonding the lid to the substrate, producing an assembly which, at a second temperature, is transformed to a bent circuit chip package.

1. Field of the Invention
The present invention relates to the packaging of circuit chips and more particularly to providing a method of assembly and an apparatus for cooling circuit chip packages.
2. Description of Related Art
U.S. Pat. No. 6,292,369 describes a thermally conductive lid structure having a customized lid understructure and shim. This structure uses thermally conductive compliant or non-rigid materials in the primary heat dissipation path.
U.S. Patent Publication 2008-0165502, describes a patterned metal deformable thermal interface placed between a circuit chip and a heat dissipative structure to improve the quality of the heat dissipation path.
To reduce the stress placed on package elements resulting from temperature changes through various assembly steps and operation of the package, U.S. Pat. No. 5,821,617 teaches enhancing performance by providing a package which uses materials that are matched in CTE to each other and to a silicon circuit chip. This is because using different coefficients of thermal expansion (CTEs) of the materials of the package components increases stress. Accordingly, the use of materials having different coefficients of thermal expansion (CTEs) is discouraged by the industry, as taught by U.S. Pat. No. 5,821,617. Thus, there is a need for a package that provides good thermal coupling between a chip and a heat spreader or heat sink through excursions in the temperature of the package.

Method and package for circuit chip packaging

International Business Machines Corporation


In a computer-implemented method for information retrieval and a processing system of a computer-implemented information retrieval system, an input text is received by a Natural Language Processing, NLP, suite, wherein the NLP suite comprises a plurality of models. At least one of the plurality of models is a model trained using selected features. The selected features are determined using a feature selection process. The input text is processed by each one of the plurality of models. An intermediate representation of the input text is generated by each one of the plurality of models. An enhanced representation of the input text is generated by combining a plurality of the generated intermediate representations. Information is retrieved based on the enhanced representation of the input text.

In the HR, industry or staffing industry, it is essential to have a reliable information retrieval system that may assist in matching candidates to vacancies, and vice versa. In recent years the prevalence of fast computers helped the development of automated and computer-implemented information retrieval systems.
Despite the increasing computational power, determining relevant keywords and phrases in texts for application specific domains is still a challenging problem. Usually, information retrieval systems analyze keyword search logs, leverage known keywords and phrases, known tags, or other types of labels. These are then used to assist in weighting processes for ranking search results.
However, there exists a need for an information retrieval system in the HR industry which can identify informative keywords and phrases without prior information, i.e., from unstructured HR data. Various existing approaches have relied on labelled data, wherein recorded data and logs of job seeker data is used to correlate job seekers with vacancies of employers, and to filter candidate profiles from search results. However, obtaining labelled data may not always be possible and is generally work intensive. Therefore, information retrieval systems have been developed that do not rely on labelled data.
For example, U.S. Pat. No. 8,117,024 B2 discloses systems and methods for automatically processing candidate resumes and job specifications expressed in natural language into a normalized form using frequency analysis. A database of elements is provided in which each element is expressed in natural language and at least some of which are associated with a corresponding set of synonymous words or phrases. Candidate resumes and job specifications are received in electronic form and expressed in natural language. The candidate resumes and job specifications are analyzed to extract elements expressed in candidate resumes and job specifications. The extracted elements are compared to the database. For each extracted element, the most frequent element or synonym is identified and used as a common form for the extracted element. A set of candidate resumes is matched with a corresponding job specification by comparing the set of elements expressed in common form for the resumes with the set of elements expressed in common form for the job specification.
However, the existing methods and systems for information retrieval in the HR industry that do not rely on labelled data have the drawback that elements in a determined representation associated to e.g. a vacancy or a candidate may not be very informative or may contain noise. Said representations therefore require unnecessary storage space and unnecessary computational power to provide informative information retrieval results, if even possible.

Method, system and computer-readable medium for information retrieval


Resistor elements are formed by doping impurity into a single crystal film formed on a substrate such as a silicon-on-insulator substrate. A semiconductor device having such resistor elements is used as a detector for detecting an amount of airflow, for example. The impurity density in the single crystal silicon is made lower than 1×1020/cm3 to suppress a resistance change by aging especially at a temperature higher than 310° C. To obtain a high temperature coefficient of the resistor element as well as a low resistance change by aging, the impurity density is set in a range from 4×1019/cm3 to 1×1020/cm3, and more preferably in a range from 7×1019/cm3 to 1×1020/cm3. As the impurity, N-type impurity such as phosphorus or P-type impurity such as boron may be used. It is preferable to use the impurity having a low diffusion coefficient to attain a low resistance change by aging.

1. Field of the Invention
The present invention relates to a semiconductor device including a resistor element doped with impurity.
2. Description of Related Art
A thermal type flow sensor for detecting a flow amount of fluid has been known hitherto. This type of flow sensor includes a heater element and a temperature-sensitive element, both made by doping impurity into silicon semi-conductor layer. Examples of this type of sensor are shown in Japanese Patents No. 3468731 and No. 3698679. In this sensor device, a heater element and a temperature-sensitive element are made by doping impurity into a semiconductor layer. Both of the heater element and the temperature-sensitive element are resistor elements, and the specific resistance thereof is made 8×10−4 Ωcm or lower, and an impurity density is made 2×1020/cm3 or higher. In another example shown in JP-A-2004-205498, the impurity density in the resistor element made by doping the impurity into a semiconductor layer is set to 1×1020/cm3 or higher.
Tests conducted by inventors of the present invention revealed the fact that a resistance change by aging in the resistor having a high impurity density is high when the resistor is at a high temperature, e.g., a temperature higher than 310° C.

Semiconductor device having impurity-doped resistor element


An orthogonal frequency division multiplexed signal generator comprises a data sequence conversion means, a power changing means, an inverse discrete Fourier transform part, and an orthogonal modulation means, and modulates a first data and a second data using modulation systems independent of each other, into an orthogonal frequency division multiplexed signal. The data sequence conversion means arranges the first data to be transmitted, in a predetermined order correspondingly to two or more sub-carriers orthogonal to each other on a frequency axis. The power changing means changes powers of the sub-carriers in accordance with the second data to be transmitted which is independent of the first data. The inverse discrete Fourier transform means generates a time-base waveform by synthesizing the individual sub-carriers. The orthogonal modulation means performs orthogonal modulation on a real axis signal and an imaginary axis signal which are orthogonal to each other to synthesize them.

1. Field of the Invention
The present invention relates to an apparatus for and method of generating orthogonal frequency division multiplexed signal, a demodulator, and a communication apparatus.
2. Description of the Related Art
Commercializing of the OFDM (Orthogonal Frequency Division Multiplexing) system is promoted as a modulation method of digital communication.
An example of a system to which OFDM is applied is the EUREKA-147 SYSTEM. Generally, this is referred to as DAB (Digital Audio Broadcasting) or the EUREKA-147 DAB system. This EUREKA-147 DAB system was approved by ITU-R (International Telecommunication Union-Radio communication sector) on November 1994 as System-A and becomes an international standard. This standard has been issued as "ETS 300401".
In the EUREKA-147 DAB system, each sub-carrier in the OFDM is subjected to phase modulation. As a phase modulation system, is employed the differential QPSK (Quadrature Phase Shift Keying) system, in which main data is transmitted by phase differences of respective sub-carriers between an OFDM symbol duration and the just preceding OFDM symbol duration.
In the EUREKA-147 DAB system, since data is transmitted by phase differences of respective sub-carriers between OFDM symbols, a demodulation means in a receiver requires phase information that becomes a reference. For this purpose, phase reference symbols are periodically inserted into an OFDM signal being transmitted. Each phase reference symbol is constituted by sub-carriers having predetermined reference phases.
Further, in demodulating operation at receiving, each OFDM symbol duration should be specified in order that each OFDM symbol duration is converted onto a frequency axis to extract sub-carrier components on the frequency axis. To that end, in the EUREKA-147 DAB system, a symbol for coarse synchronization, called a null symbol, is inserted just before a phase reference symbol.
The null symbol is a "null" signal having no sub-carrier for transmitting main data. Usually, on the receiving side, a null symbol duration is specified from change of an envelope of the received signal, in order to decide roughly each OFDM symbol duration.
In the EUREKA-147 DAB system, it is possible to optionally superimpose a TII (Transmitter Identification Information) signal on a null symbol duration to identify a transmitting station. The TII signal is transmitted by transmission of only some predetermined sub-carriers out of the sub-carriers of an OFDM symbol. In that case, a null symbol duration is not a null signal but has a waveform of slight amplitude. However, it is suppressed to relatively small amplitude as compared to the amplitude of other OFDM symbol durations transmitting the phase reference symbol or main data.
Taking an example of the mode 2 of the EUREKA-147 DAB system, arrangement of the sub-carriers on the frequency axis in a null symbol duration will be described in the case that a TII signal is added. In the mode 2 of the EUREKA-147 DAB system, information is transferred by 384 sub-carriers.
FIG. 1 shows an arrangement of the sub-carriers on the frequency axis in a null symbol duration in the case that a TII signal is added. As shown in FIG. 1, a TII signal is constituted by some pairs of adjacent sub-carriers of predetermined frequencies in accordance with an identification code defined for each transmitting station. As compared to other OFDM symbols, the number of the sub-carriers is very small. Accordingly, when observed, it has such a waveform that a signal of relatively small amplitude is superimposed on a null symbol duration.
As described above, when a TII signal is superimposed on a null symbol duration, the null symbol duration is actually not a null signal but has a waveform of slight amplitude. Thus, it is possible that superimposition of a TII signal on a null symbol duration makes detection of the null symbol difficult in a receiver. For example, in a location of bad receiving conditions, it is difficult to discriminate between a null symbol and the other OFDM symbols. Further, depending on receiving conditions, a transmitting station expressed by a TII signal may become difficult to be discriminated.
Such situation is not limited to the transmission of a TII signal, and it is possible that similar difficulty is caused when a null symbol duration is utilized for transmitting other data, in addition to data transmitted by phase modulation.

Communication system using orthogonal frequency division multiplexed signal


A system and method for autonomous flight control with mode selection an electric aircraft is illustrated. The system comprises an altitude-related sensor and a computing device. The altitude-related sensor is coupled to the electric aircraft and is configured to detect an altitude value. The computing device is communicatively connected to the altitude-related sensor and is configured to receive the altitude value from the altitude-related sensor, to determine a flight mode as a function of the altitude value and an altitude threshold, to determine an aircraft adjustment as a function of a determine flight mode, and to generate an autonomous function configured to enact the determined flight mode and an aircraft adjustment automatically.

While performing takeoff, landing, or any sort of flight maneuver, the altitude of the aircraft is an important piece of information. Some sensors that detect altitude have a "dead zone" near the ground where the sensors render unreliable and inaccurate altitude readings. These malfunctions could cause catastrophic damage to the aircraft and its workers during takeoff, landing, and flight in general. To compensate for this, new techniques for some aircrafts use different sensors to measure different ranges of altitude, such as one for lower altitudes and one for higher altitudes.

System and method for autonomous flight control with mode selection for an electric aircraft


An X-ray CT imaging apparatus includes an X-ray generating section, an X-ray image capturing section, a supporting section, a holding section, a rotation driving section, and an X-ray controlling section, wherein the X-ray generating section generates an X-ray cone beam, the X-ray image capturing section detects the X-ray cone beam having passed through an object, the supporting section supports the X-ray generating section and the X-ray image capturing section with the object positioned therebetween, the holding section holds the object, the rotation driving section rotates the supporting section relatively to the object, and the X-ray controlling section alleviates an influence of a high X-ray absorption region, present inside the object, in the X-ray image capturing section by means of a control model formed based upon information on the high X-ray absorption region.

1. Field of the Invention
The present invention relates to an X-ray CT imaging apparatus and an imaging control method therefor, and particularly relates to an X-ray CT imaging apparatus and an imaging control method therefor, which are capable of alleviating an influence of a high X-ray absorption region that is present inside an object and has an influence on an imaging result.
2. Description of the Background Art
In the field of X-ray diagnosis for medical use, an X-ray CT (computerized tomography) imaging apparatus for tomographically imaging an arbitrary region of a human body is widely known. In this X-ray CT imaging apparatus, an X-ray generating section and an X-ray imaging means being opposed thereto are rotated 360 degrees around an object, and obtained image information is subjected to computer processing, to obtain an CT image of an arbitrary region of a head, a body or the like having been cut off.
Especially in the field of dental treatment, at the time of an implant operation or the like, grasping a thickness, a structure and the like of a cervical spine beforehand facilitates the operation, and hence a small-sized X-ray CT imaging apparatus capable of performing X-ray CT imaging of a specific tooth and its vicinity has been considered.
In this small-sized X-ray CT imaging apparatus, a supporting means supports the X-ray generating section and the X-ray image capturing means in a mutually opposed manner with an object positioned therebetween, and is rotated 360 degrees around the object, to obtain image information. The obtained image information is stored in a storage means, and the stored image information is subjected to image processing such as reconstruction by a computer, to obtain a desired CT image.
Specifically, the X-ray CT imaging apparatus for use in the dental field is described in Japanese Patent Application Laid-Open No. H10-225454 and Japanese Patent Application Laid-Open No. 2003-245277.

X-ray CT imaging apparatus and imaging control method therefor


In a head loading/unloading type disk apparatus, accurate velocity feedback control is implemented by correcting any error in a VCM velocity detection value, which is caused by a temperature change or the like. At the start of loading control for loading a head from a ramp onto a disk, a carriage is pushed against an outer-periphery stopper to set the actual velocity of a VCM to zero. In this state, a VCM velocity detection value detected by a VCM velocity detection circuit is read out. On the basis of this velocity detection value, calibration for correcting the relationship between the VCM current value and the VCM velocity detection value is performed. In the period of head positioning control after the loading, an operation using a timer is periodically performed in which the carriage is pushed against an inner-periphery stopper, the calibration is reexecuted, and the head is returned to the original head position.

The present invention relates to a calibration method for use in a head loading/unloading type disk apparatus and, more particularly, to a calibration method suited to automatic adjustment of the velocity detection value used in unloading.
Recently, some disk apparatuses for recording and reproducing information by using a head, e.g., some small magnetic disk apparatuses use a head retraction method called a loading/unloading method. The characteristic feature of this loading/unloading method is as follows. When no data read/write operation is performed, e.g., when the rotation of a disk (recording media) is stopped, a head stops on a ramp mechanism positioned outside the outer periphery of the disk. In this state, the head is moved from a retraction position on the ramp mechanism onto the disk by an instruction from a host to thereby perform a read/write operation. When the read/write operation is complete, the head is returned from the disk onto the ramp mechanism.
The operation of moving the head from the ramp mechanism onto the disk is called loading, and the operation of moving the head from the disk onto the ramp mechanism is called unloading.
Jpn. Pat. Appln. KOKAI Publication No. 8-63920 has disclosed an apparatus for loading and unloading an arm having a head slider to and from a rotary information recording disk by driving the arm by an actuator. In this apparatus, the back electromotive force of a voice coil type driving mechanism of the actuator is detected and fed back to a driving control circuit, and this control circuit controls the position and velocity of the actuator. That is, this reference describes that when loading or unloading is performed, velocity feedback control is performed by detecting the VCM velocity by using the back electromotive force generated in the voice coil motor (VCM).
In this prior art, however, which performs velocity feedback control by detecting the VCM velocity by using the back electromotive force generated in the voice coil motor (VCM), if the resistance of the coil of the VCM changes due to temperature change or the like, the relationship between the value (VCM current value) of current flowing through the VCM and the VCM velocity detection value also changes. This makes accurate velocity feedback control impossible to perform. The above reference does not describe the nature of the problem and a method of solving the problem when the resistance of the coil of the VCM changes due to temperature change or the like and the relationship between the VCM current value and the VCM velocity detection value changes.
Accordingly, it is an object of the present invention to provide a calibration method capable of accurately correcting the relationship between the value of a voice coil motor current flowing through a voice coil motor and a voice coil motor detection value detected by a voice coil motor velocity detection circuit, thereby performing accurate feedback control during loading/unloading.
It is another object of the present invention to provide a calibration method capable of improving the accuracy of a detected velocity by detecting a state in which the VCM resistance changes due to temperature change or the like and this may change the relationship between the VCM current value and the VCM velocity detection value, thereby performing more accurate velocity feedback control.
According to one aspect of the present invention, there is provided a calibration method for use in a head loading/unloading type disk apparatus having a voice coil motor for driving a carriage to move a head in a direction of radius of a disk, a voice coil motor velocity detection circuit for detecting a voice coil motor velocity corresponding to a back electromotive force of the voice coil motor, and a ramp mechanism arranged outside an outer periphery of the disk to retract the head, comprising the steps of: executing, at the start of loading control for loading the head from the ramp mechanism onto the disk, calibration for correcting a relationship between a value of a voice coil motor current flowing through the voice coil motor and the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit, the calibration being executed by obtaining a voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit in a state where an actual velocity of the voice coil motor is set to zero and a current is supplied to the voice coil motor; and periodically reexecuting the calibration after the head is loaded.
In the present invention, a relationship between a value of a voice coil motor current flowing through the voice coil motor and the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit is accurately corrected by the calibration. The calibration is executed by obtaining a voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit in a state where an actual velocity of the voice coil motor is set to zero and a current is supplied to the voice coil motor. With this the calibration, the velocity detection value detected by the VCM velocity detection circuit can be accurately corrected by velocity feedback control during unloading. This makes accurate unloading possible.
Generally, when a predetermined time or more has elapsed from loading, the resistance of the VCM coil changes due to temperature change, and this causes an error in the aforementioned relationship corrected by the calibration. So, (velocity feedback control during) unloading may not be accurately performed. In the present invention, however, the calibration is periodically reexecuted after loading. Accordingly, unloading can be accurately performed regardless of the reception timing of an unload instruction.
According to another aspect of the present invention, there is provided a calibration method for use in a head loading/unloading type disk apparatus having a voice coil motor for driving a carriage to move a head in a direction of radius of a disk, a voice coil motor velocity detection circuit for detecting a voice coil motor velocity corresponding to a back electromotive force of the voice coil motor, and a ramp mechanism arranged outside an outer periphery of the disk to retract the head, comprising the steps of: executing, at the start of loading control for loading the head from the ramp mechanism onto the disk, calibration for correcting a relationship between a value of a voice coil motor current flowing through the voice coil motor and the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit, the calibration being executed by obtaining a voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit in a state where an actual velocity of the voice coil motor is set to zero and a current is supplied to the voice coil motor; and if it is detected that a change in a temperature of the voice coil motor or an ambient temperature thereof from a temperature during loading is not less than a prescribed value after the head is loaded, reexecuting the calibration.
When the VCM coil resistance changes due to temperature change, the aforementioned relationship corrected during loading cannot reflect the present state any longer, and the error increases. This may make accurate unloading impossible. In the present invention, however, if the change in the VCM temperature from that during loading is equal to or larger than a prescribed value, the calibration is reexecuted. Consequently, accurate unloading can be performed.
According to still another aspect of the present invention, there is provided a calibration method for use in a head loading/unloading type disk apparatus having a voice coil motor for driving a carriage to move a head in a direction of radius of a disk, a voice coil motor velocity detection circuit for detecting a voice coil motor velocity corresponding to a back electromotive force of the voice coil motor, and a ramp mechanism arranged outside an outer periphery of the disk to retract the head, comprising the steps of: executing, at the start of loading control for loading the head from the ramp mechanism onto the disk, calibration for correcting a relationship between a value of a voice coil motor current flowing through the voice coil motor and the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit, the calibration being executed by obtaining a voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit in a state where an actual velocity of the voice coil motor is set to zero and a current is supplied to the voice coil motor; reading out the voice coil motor velocity detection value immediately after loading control is switched to on-track control from the voice coil motor velocity detection circuit and storing the readout value in a memory; and monitoring the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit while the head is positioned on the disk and, if an absolute value of a difference between the monitored voice coil motor velocity detection value and the voice coil motor velocity detection value stored in the memory is not less than a prescribed value, reexecuting the calibration.
If the absolute value of the difference between the VCM velocity detection value detected immediately after loading control is switched to on-track control and the VCM velocity detection value monitored while the head is positioned on the disk (in the head positioning control state), i.e., the VCM velocity detection value difference is equal to or larger than a prescribed value, it is highly likely that the VCM coil resistance has changed. If this is the case, the error in the aforementioned relationship corrected during loading increases, so unloading may not be accurately performed. In the present invention, however, if the VCM velocity detection value difference is equal to or larger than a prescribed value, the calibration is reexecuted. Consequently, accurate unloading can be performed.
The calibration can also be reexecuted by moving the carriage to the inner-periphery stopper position. If this is the case, the carriage is pushed against the inner-periphery stopper to realize zero VCM velocity, so the calibration can be done with high accuracy.
It is also possible to reexecute the calibration by moving the carriage to the outer-periphery stopper position by unloading and to reload after the calibration. If this is the case, the carriage is pushed against the outer-periphery stopper to realize zero VCM velocity, so the calibration can be done with high accuracy.
According to still another aspect of the present invention, there is provided a calibration method for use in a head loading/unloading type disk apparatus having a voice coil motor for driving a carriage to move a head in a direction of radius of a disk, a voice coil motor velocity detection circuit for detecting a voice coil motor velocity corresponding to a back electromotive force of the voice coil motor, and a ramp mechanism arranged outside an outer periphery of the disk to retract the head, comprising the steps of: executing, at the start of loading control for loading the head from the ramp mechanism onto the disk, calibration for correcting a relationship between a value of a voice coil motor current flowing through the voice coil motor and the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit, the calibration being executed by obtaining a voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit in a state where an actual velocity of the voice coil motor is set to zero and a current is supplied to the voice coil motor; and if a predetermined time has elapsed since the head is loaded when an unload instruction is received, reexecuting the calibration and performing unloading thereafter.
As already described above, when a predetermined time or more has elapsed from loading, the VCM coil resistance changes due to temperature change, and this increases an error in the aforementioned relationship corrected during loading. So, unloading may not be accurately performed. In the present invention, however, the elapsed time from loading is checked when an unload instruction is received. If a predetermined time or more has elapsed, the calibration is reexecuted, and then unloading is performed. Therefore, accurate unloading can be performed.
According to still another aspect of the present invention, there is provided a calibration method for use in a head loading/unloading type disk apparatus having a voice coil motor for driving a carriage to move a head in a direction of radius of a disk, a voice coil motor velocity detection circuit for detecting a voice coil motor velocity corresponding to a back electromotive force of the voice coil motor, and a ramp mechanism arranged outside an outer periphery of the disk to retract the head, comprising the steps of: executing, at the start of loading control for loading the head from the ramp mechanism onto the disk, calibration for correcting a relationship between a value of a voice coil motor current flowing through the voice coil motor and the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit, the calibration being executed by obtaining a voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit in a state where an actual velocity of the voice coil motor is set to zero and a current is supplied to the voice coil motor; and if a change in a temperature of the voice coil motor or an ambient temperature thereof from the temperature during loading is not less than a prescribed value when an unload instruction is received, reexecuting the calibration and performing unloading thereafter.
As already described above, if the VCM coil resistance changes due to temperature change, the aforementioned relationship corrected during loading cannot reflect the present state any longer, and the error increases. This may make accurate unloading impossible to perform. In the present invention, however, if the change in the VCM temperature from that during loading is equal to or larger than a prescribed value, the calibration is reexecuted, and then unloading is performed. Therefore, accurate unloading can be performed.
According to still another aspect of the present invention, there is provided a calibration method for use in a head loading/unloading type disk apparatus having a voice coil motor for driving a carriage to move a head in a direction of radius of a disk, a voice coil motor velocity detection circuit for detecting a voice coil motor velocity corresponding to a back electromotive force of the voice coil motor, and a ramp mechanism arranged outside an outer periphery of the disk to retract the head, comprising the steps of: executing, at the start of loading control for loading the head from the ramp mechanism onto the disk, calibration for correcting a relationship between a value of a voice coil motor current flowing through the voice coil motor and the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit, the calibration being executed by obtaining a voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit in a state where an actual velocity of the voice coil motor is set to zero and a current is supplied to the voice coil motor; reading out the voice coil motor velocity detection value immediately after loading control is switched to on-track control from the voice coil motor velocity detection circuit and storing the readout value in a memory; and monitoring the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit when an unload instruction is received and, if an absolute value of a difference between the monitored voice coil motor velocity detection value and the voice coil motor velocity detection value stored in the memory is not less than a prescribed value, reexecuting the calibration and performing unloading thereafter.
As already described above, if the difference between the VCM velocity detection values is equal to or larger than a prescribed value, it is highly likely that the VCM coil resistance has changed. So, the aforementioned relationship corrected during loading can no longer reflect the present state, and the error increases. This may make accurate unloading impossible. In the present invention, however, if the difference between the VCM velocity detection values is equal to or larger than a prescribed value, the calibration is reexecuted, and then unloading is performed. Therefore, accurate unloading can be performed.
The reexecution of the calibration when the unload instruction is received can also be performed by moving the carriage to the inner-periphery stopper position. If this is the case, the carriage is pushed against the inner-periphery stopper to realize zero VCM velocity, so the calibration can be done with high accuracy.
According to still another aspect of the present invention, there is provided a calibration method for use in a head loading/unloading type disk apparatus having a voice coil motor for driving a carriage to move a head in a direction of radius of a disk, a voice coil motor velocity detection circuit for detecting a voice coil motor velocity corresponding to a back electromotive force of the voice coil motor, and a ramp mechanism arranged outside an outer periphery of the disk to retract the head, comprising the steps of: executing, at the start of loading control for loading the head from the ramp mechanism onto the disk, calibration for correcting a relationship between a value of a voice coil motor current flowing through the voice coil motor and the voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit, the calibration being executed by obtaining a voice coil motor velocity detection value detected by the voice coil motor velocity detection circuit in a state where an actual velocity of the voice coil motor is set to zero and a current is supplied to the voice coil motor; when an unload instruction is received, performing unloading by using a result of the calibration during loading; and if the unloading indicates abnormality, moving the carriage to an inner-periphery stopper position, reexecute the calibration, and again performing unloading by using a result of the reexecuted calibration.
When unloading control is performed in accordance with an unload instruction, unloading may not be accurately performed depending on the error in the aforementioned relationship corrected during loading. Unloading abnormality occurs if the VCM current value during unloading control does not reach a current value by which the head can be unloaded to the ramp mechanism. If this is the case, it is highly likely that the head is not present on the ramp mechanism. In the present invention, therefore, if unloading abnormality occurs, the carriage is moved to the inner-periphery stopper position and pushed against the inner-periphery stopper. In this state, the calibration is reexecuted, and unloading is again performed by using this updated velocity correction value. This makes accurate unloading feasible.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.

Calibration method for use in head loading/unloading type disk apparatus


An electrical circuit for use as a string of lights in one embodiment includes a rectifier for converting AC into DC; and a plurality of lamps connected in series, each lamp having an LED, and wherein at least one of the lamps each has a Zener diode connected in series with the LED, a positive terminal of the lamp proximate the rectifier is connected to a positive terminal of an output of the rectifier, and a negative terminal of the lamp distal the rectifier is connected to a negative terminal of the output of the rectifier. In another embodiment, the Zener diode is replaced with a resistor. Hence, no resistors are provided externally of the lamp.

1. Field of Invention
The invention relates to providing electrical power to a plurality of low voltage electrical loads, and more particularly to a string of LED (light-emitting diode) light having a plurality of lamps wired in series, each lamp having an LED and some or all lamps having an additional one of a Zener diode and a resistor connected in series with the LED, thereby eliminating the provision of any additional resistors externally of the lamp.
2. Description of Related Art
LEDs are renowned for their long life and their ability to resist shock. Also, an LED consumes much less electrical power than fluorescent lamps (i.e., energy saving). Therefore, LED lighting devices are gaining popularity worldwide.
A conventional string of lights including a plurality of LED bulbs arranged electrically in a series circuit is shown in FIGS. 1 and 2. AC 120V is rectified by a full-wave rectifier (not shown) to convert into DC (e.g., DC 120V) to be consumed by the plurality of LED bulbs. Each LED bulb is wired in series with a resistor 1. For example, the LED bulb is a blue LED bulb of 3.2V 0.02A. The number of the blue LED bulbs is 25. The light string has a nominal operating voltage of DC 80V. The light string will be damaged if DC 120V is directly applied thereto without any voltage reduction. Resistance (R) of additional resistor(s) other than the LED bulbs of the light string is equal to 40V (i.e., 120V−80V) divided by 0.02 A according to Ohm's Law. Hence, the resistance (R) is 2,000 Ω. Resistor is an electrical component that may generate much heat when energized. 40V power may be applied to a single resistor of 2,000 Ω inserted in series with one of the LED bulbs. Disadvantageously excessive heat generated by the resistor will burn out the LED bulb, thereby killing the circuit. Hence, it is typical to arrange five resistors 1 of 400 Ω each to connect in series to one LED bulb, i.e., five connected LED bulbs in total. Each resistor 1 has a voltage component of 8V and is adapted to generate much less heat. Therefore, the light string is protected.
Another conventional string of lights including a plurality of LED bulbs arranged electrically in a series circuit is shown in FIGS. 3 and 4. AC 120V is rectified by a full-wave rectifier in a plug (not shown) to convert into DC (e.g., DC 120V) which is to be consumed by the plurality of LED bulbs. A resistor 1 is interconnected to the rectifier output and the adjacent LED bulb (i.e., the load). For example, the LED bulb is a blue LED bulb of 3.0V 0.02 A. The number of the blue LED bulbs is 30. The light string has a nominal operating voltage of DC 90V. The light string will be damaged if DC 120V is directly applied thereto without any voltage reduction. Resistance (R) of the additional resistor 1 other than the LED bulbs of the light string is equal to 30V (i.e., 120V−90V) divided by 0.02 A according to Ohm's Law. Hence, the resistance (R) of the resistor 1 is 1,500 Ω. DC 30V is applied to the resistor 1. Also, the resistor 1 is adapted to generate much less heat. Therefore, the light string is protected.
However, both the well known light strings suffer from a number of disadvantages. In detail, each resistor is required to dispose in the light string by soldering which may pollute the environment if sufficient care is not taken. LED bulbs may be damaged due to high temperature and electrostatic discharge (ESD) while soldering. Soldering is a manual, laborious task such that these light strings cannot be mass produced easily. Heat generated by the resistor may damage the adjacent LED bulb and even cause a fire hazard. Moreover, the manufacturing cost is very high.
There have been numerous suggestions in prior patents for light string. For example, U.S. Pat. No. 6,344,716 discloses a Christmas light string. Thus, continuing improvements in the exploitation of light string employing LED bulbs are constantly being sought.

LED light string without additional resistors


A pseudo-synchronous temporary storage element transports data between two system blocks with different clock systems by pseudo-synchronizing the clock edges of the two clock signals. The pseudo-synchronization circuit may be an integral part of a storage element, a separate pseudo-synchronization device, or a discrete add-on circuit to an off the shelf storage element device.

A FIFO is a first in, first out, temporary data storage device. It is useful for sharing data between real-time tasks and user-level applications. A FIFO is often used to connect a non-real-time machine interface to a real-time application (e.g. to log messages to disk files).
A FIFO in its simplest form is a queue of raw storage units. Typically, fixed-size data structures are written to a FIFO, so that a device reading the data is not burdened with message boundaries. The queued nature of a FIFO makes it best suited for ordered streams of data such as: messages or error diagnostics where the message can include a timestamp for later analysis; data logs for performance metrics; and configuration information at system start-up, among others.
A FIFO, on a higher level, is an array of registers that stores data. The data is often read from and written to devices with different clock domains. The conventional way to transfer data in different clock domains is to synchronize the read and write clocks in the control logic. However, when the read control signal and the write control signal are synchronized, penalties are incurred in the form of delays. The read and write blocks, which are sharing the data, are often clocked at different frequencies, which introduces unwanted delays in the transfer of data between the blocks.
The delays are normally incurred in the control circuit. The control circuit involves the FIFO write control signal and FIFO read control signal. Based on the read and write control signals, a status signal is produced, such as non-limiting examples of FIFO empty or FIFO full. An overflow signal is another status signal, but it is more like an error condition. A status signal can be used to control the transfer of data.
A delay is incurred when the read control signal is synchronized with the write control signal. The read signal is processed some number of clocks later than the write signal. Since the write signal fills the FIFO faster than the read signal can empty it, some delay is incurred.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.

Pseudo-synchronization of the transportation of data across asynchronous clock domains