A controller for a three-phase AC motor includes a current sensor and a current estimation section. The current sensor detects current flowing through one phase of the motor. The one phase is defined as a sensor phase. The current estimation section calculates a current phase relative to an axis of the sensor phase based on α-axis current and β-axis current in a stationary coordinate system defined by a α-axis parallel to the sensor phase axis and a β-phase perpendicular to the sensor phase axis. The current estimation section estimates current flowing through another phase of the motor based on the current phase and the detected current. The current estimation section calculates the α-axis current based on the detected current. The current estimation section calculates the β-axis current based on the detected current and a command value for the current flowing through the other phase of the motor.

In recent years, from social demands for low-fuel consumption and low exhaust emission, there has been an increased attention to an electric vehicle or a hybrid vehicle which has an alternate-current (AC) motor to run. For example, in a hybrid vehicle, an AC motor is connected to a direct-current (DC) power source such as a rechargeable battery unit through a power converter such as an inverter. The inverter converts a DC voltage supplied from the DC power source to an AC voltage and drives the AC motor with the AC voltage.
A typical control system for controlling an AC motor mounted on an electric vehicle or a hybrid vehicle uses two or three current sensors to detect two or three of three phases of the AC motor. The AC motor is controlled based on outputs (i.e., current detection values) of the current sensors. In this type of motor control system, two or three current sensors are provided to one AC motor. Therefore, the size and cost of the control system may be increased.
A method of reducing the number of current sensors used to control an AC motor has been known. For example, in JP-A-2004-64903, one current sensor is provided to a DC power line to detect a bus current. However, if a current sensor is provided to a DC power line in a control system for controlling a high-powered motor mounted on a vehicle, conduction noise may be increased due to an extension of the DC power line. JP-A-10-225199, JP-A-2001-145398 corresponding to U.S. Pat. No. 6,229,719, JP-A-2004-159391, and JP-A-2008-86139 corresponding to US 2008/0079385 disclose a method of controlling an AC motor by using a current sensor that detects an electric current flowing through one of three phases of the AC motor.
In JP-A-10-225199, a d-axis current Id and a q-axis current Iq are calculated from a state equation, which is derived from a motor constant, using a current detection value of one of three phases of an AC motor. However, the motor constant changes with a temperature. Therefore, the d-axis current Id and the q-axis current Iq, which are calculated from the state equation, may have large estimation errors so that control may become unstable. Further, since the calculation is complex, it may be difficult to cause an electronic control unit (ECU) to perform the calculation.
In JP-A-2001-145398, a d-axis current Id and a q-axis current Iq of an AC motor are calculated by dq transformation of a current detection value of one of three phases of the AC motor and current estimation values of the other phases. Then, averaging is performed through a first order lag filter, and then inverse dq transformation is performed. However, a lag may occur in the current estimation values due to the first order lag filter so that control may become unstable.
In JP-A-2004-159391, an electric current flowing through one (e.g., U-phase) of three phases of an AC motor is detected by a current sensor. Then, current estimation values of the other phases (e.g., V-phase and W-phase) are calculated based on a current detection value detected by the current sensor, a d-axis current command value, a q-axis current command value, and an electrical angle of the AC motor.
Specifically, a U-phase current phase angle θ1 (=α+θ) is calculated by adding a command current phase angle α, which is formed by a q-axis and a combined vector of a d-axis current command value Id* and a q-axis current command value Iq*, to an angle θ, which is formed by an U-phase axis of a stator and a rotor of the AC motor. Then, a current amplitude Ia is calculated from a formula (A) using the U-phase current phase angle θ1 and a current detection value Iu detected by the current sensor. Then, current estimation values Iv and Iw of the other phases are calculated from the respective formulas (B) and (C) using the current amplitude Ia and the U-phase current phase angle θ1.Ia=Iu/{√{square root over (⅓)}×[−sin(θ1)]}  (A)Iv=√{square root over (⅓)}×Ia×[−sin(θ1+120°)]  (B)Iw=√{square root over (⅓)}×Ia×[−sin(θ1+240°)]  (C)
A d-axis current Id and a q-axis current Iq are calculated based on the current detection value Iu and the current estimation values Iv and Iw. Then, the current flowing through the AC motor is feedback-controlled by calculating a voltage command value of the AC motor so that the d-axis current Id and the q-axis current Iq can be equal to the d-axis current command value Id* and the d-axis current command value Iq*, respectively.
It is noted that a current vector of an AC motor changes with a command current vector (current vector corresponding to a current command value). However, due to effects of the control error and the feedback control, there is a deviation (i.e., difference) between the current vector and the command current vector. Accordingly, a command current phase differs from an actual current phase and does not actually reflect the actual current phase.
However, according to JP-A-2004-159391, by using the U-phase current phase angle calculated from the command current phase angle, the current estimation values of the other phases are calculated without consideration of the actual current phase. As a result, there is a possibility that the current estimation values do not have accuracy high enough to control the AC motor.
In JP-A-2008-86139, an electric current flowing through one (e.g., U-phase) of three phases of an AC motor is detected by a current sensor. Then, current estimation values of the other phases (e.g., V-phase and W-phase) are calculated based on a current detection value detected by the current sensor and three-phase current command values of the AC motor.
Specifically, the AC motor is controlled by dq transformation using an electrical angle based on a current detection value Iu detected by the current sensor and three-phase electric command values Iv* and Iw* of the other phases. The electric command values Iv* and Iw* are calculated by transformation using an electrical angle based on a d-axis current command value Id* and a d-axis current command value Iq* of the AC motor. However, since the electric command values are simply used as a substitute for current detection values of the other phases, a command current phase does not actually reflect an actual current phase. Therefore, in a vehicle, in which a torque and a rotation speed are required to change from time to time, estimated currents will not be calculated sufficiently accurately, and hence the AC motor will not be controlled properly.
As described above, there remains a technical difficulty in controlling a high-powered AC motor by using one current sensor.


An unauthorized usage monitoring system for image processing devices of the present invention sets a higher information storage ratio for a smaller number of people present in an office when determining, based on an information storage ratio, whether or not to store to a storage portion 15 information in which a user ID code and image data are associated. The information ratio is compared with a random number, and information in which the image data and the ID code of the user who requested image processing are associated is stored to the storage portion 15 only when the information storage ratio is higher than the random number.

Many offices and the like in recent years are configured as systems in which terminals such as personal computers are connected via a network to image processing devices such as digital multifunctional machines. It is typical for these kinds of image processing devices to be configured as multifunctional machines that serve such roles as a printer, a scanner, and a copying machine. In functioning as a printer, such a multifunctional machine receives print data (image data or text data) via the network from a terminal and, based on the print data, records the images and text onto recording paper. Or, when functioning as a scanner, it displays an image of a scanned original on the display of a terminal. Moreover, when functioning as a copying machine, it records onto recording paper the image of the original that was scanned with the scanning function.
Image processing devices such as these greatly contribute to improved work efficiency in offices. However, as they can be used simply and easily, they are sometimes subjected to unauthorized usage for private (personal) purposes other than work.
Conventional technology that focuses on inhibiting such unauthorized usage of image processing devices is disclosed in Japanese Laid-Open Patent Publication No. Hei 11-24859 (hereafter "patent document 1") and Japanese Laid-Open Patent Publication No. 2002-116901 (hereafter "patent document 2").
A configuration is disclosed in patent document 1 in which a plurality of personal cards are provided on which individual information corresponding to users of a system is recorded, and a key counter with a plurality of insertion slots for the personal cards is connected to a multifunction printer. One of the insertion slots is for the copying function of the printer, and another insertion slot is for the printing function of the printer, and when a personal card is read at the insertion slot of the key counter for the printing function, the individual information that is read out is verified against the individual information at the time of logging on to the network. The result of this verification is that the print data saved by a server can be printed by a printer on the condition that the individual information is in agreement. Furthermore, the number of sheets printed by each user can be recorded in a data storage portion when a print operation is carried out.
The invention in patent document 2 has been proposed by the inventor of the present invention. When data is to be recorded onto recording paper, the ID code of the user who requested the data to be recorded is stored in association with the recorded data, thus enabling an administrator to know which users have recorded which data, and making it possible to ascertain unauthorized usage of an image processing device. Furthermore, in patent document 2, whether or not to store data in which the ID code of the user is associated with the recorded image data is determined based on preset storage ratios for each user.
However, with the techniques disclosed in the above-described patent documents, it is possible that a large volume of image data that does not need to be recorded, that is, even information that does not involve unauthorized usage, is nonetheless recorded. And for this reason, not only is a storage device with a large storage capacity required, but numerous tasks become required to carry out the job of monitoring with an administrator distinguishing whether or not unauthorized usage has been made of recorded information, thus increasing the burden on the administrator.
It should be noted that consideration is given in patent document 2 to presetting storage ratios on a per-user basis and recording information that has a high probability for unauthorized usage, but the effectiveness therein was as yet insufficient and further improvements were required.

Unauthorized usage monitoring system for image processing devices and method for controlling unauthorized usage monitoring system


A device for providing a storage mechanism to an assistive device is presented. The assistive device has a handle, a shaft and a ferrule. The assistive device provides the means for transferring of weight from a person to the ferrule. The storage mechanism, has a frame, a plurality of sides, a bottom and a top. The storage mechanism provides an area storing items while using the assistive device. The device has a coupling means that has a first clip and a second clip. The first clip is coupled to the second clip. Further, the first clip is securely coupled to the assistive device and the second clip is securely coupled to the storage mechanism. The storage mechanism may have a strap, preferably Velcro, that can be used to securely couple the bottom of the storage mechanism to the shaft of the assistive device.

An assistive cane is a walking stick used as a crutch or mobility aid.
Canes can help redistribute weight from a lower leg that is weak or painful, improve stability by increasing the base of support, and provide tactile information about the ground to improve balance. In the US, ten percent of adults older than 65 years use canes, and 4.6 percent use walkers.
In contrast to crutches, canes are generally lighter, but, because they transfer the load through the user's unsupported wrist, are unable to offload equal loads from the legs.
Another type of crutch is the walker, a frame held in front of the user and which the user leans on during movement. Walkers are more stable due to their increased area of ground contact, but are larger and less wieldy and, like canes, pass the full load through the user's wrists in most cases.
Assistive canes and walkers provide much needed support for those with walking disabilities, but it is not easy for one using an assistive cane or walker to also carry items when they are alone. Therefore, there is a need for an assistive device, such as a walker or cane, to have a storage mechanism.

Storage attachment for an assistive device


A fuel delivery system for use in combination with a fuel delivery truck, said system having a dye additive injector for selectively adding a predetermined amount of dye into a main fuel delivery line, comprising: a dye additive storage tank, having an inlet and outlet, adapted to receive a dye additive; a dye flow line for passage of said dye additive out of the storage tank and into the fuel delivery line; and a means for selectively initiating and terminating the flow of said dye additive out of the storage tank, through the dye flow line and into the fuel delivery line.

Liquid fuels, and in particular diesel fuels, are colour coded for governmental tax purposes. For example, the amount of tax charged by governmental bodies on diesel fuel destined for agricultural use is different than diesel fuel destined for use by transport trucks. The tax on fuel is collectible by the fuel supplier, usually the petroleum company, and in order for the governmental bodies to be able to monitor that the correct taxes have been paid by the user the fuel is colour coded.
The fuel dye is usually provided to petroleum companies by the governmental body responsible for levying taxes on fuel. Usually, a volume of a known concentration of dye is provided to the petroleum company to be mixed with undyed fuel in a particular ratio to produce the dyed fuel. Since the governmental body specifies the final concentration of dye in the fuel, they can collect taxes based upon the amount of concentrate provided to the petroleum company as a measure of the amount of dyed fuel sold. Governmental authorities routinely check on the concentration of dye in dyed fuels to ensure that it meets with their specifications and thus provides an accurate measure of dyed fuels sold. Precise calibration of the mixing of fuel and dye is therefore extremely important. The amount of undyed fuel sold is calculated for tax purposes by taking the measurement of total fuel sold and subtracting from it the amount of dyed fuel that the known volume of dye provided to the supplier would have made.
Presently, it is necessary to maintain separate storage tanks at bulk terminals for dyed and undyed fuel. It is also necessary for trucks delivering the fuel to the end user to either carry only one variety of fuel at a time or to have multiple tanks on the truck. This creates a number of logistical problems as well as requiring increased storage capacity and a relatively large fleet of delivery trucks to ensure sufficient delivery capacity. Furthermore, when a tank-truck has been used to deliver one particular fuel, and it is needed to deliver another, the tank, hose and pump must be completely flushed and this adds to both time and overhead in the delivery process. A need therefore exists for a delivery system which is capable of carrying unmarked (i.e. undyed) fuel and at the point of delivery to the user providing either dyed or undyed fuel. Furthermore, because of the taxes levied on the fuel is based upon the amount of dye provided to the fuel supplier, extremely precise measurement of the amount of dye added to the fuel is required. Additionally, for security purposes, the driver delivering the fuel should not be able to access the dye injection system. He should only be able to select either dyed or undyed fuel.
A variety of additive injection systems are presently known. For example, U.S. Pat. No. 3,225,962 discloses a method specifically directed to adding odorants to liquid propane gas at bulk facilities when using automatic dispensing to a tank truck. The additive flow is metered and automatic shut-off of the main flow is provided where additive flow is too low. The additive is maintained under pressure and driven by a compressed gas. This system is of unknown accuracy and does not solve the problem of requirement of multiple products at the point of delivery.
U.S. Pat. No. 3,964,294 discloses a system for adding active tags to petroleum products for identification of the source of the product should they be involved in a spill. The system does not teach or suggest a constant metered addition of an additive into a stream of fuel, instead a bulk crudely measured amount of tracer is added.
U.S. Pat. No. 4,005,803 discloses a sprayer apparatus in which chemical concentrates are added to water for spraying behind a moving piece of farm equipment. Water pressure range determines whether the injection is terminated. A constant water flow rate is provided with the amount of injection, which is not metered, but which varies with the ground speed of the implement.
U.S. Pat. No. 4,276,997 discloses a system which injects anti icing additives into aircraft fuel tanks. It utilizes a series of discreet additive injections each time a measured amount of fuel is delivered. The calibration of this system is controlled by the operator and the additive is added prior to the delivery hose.
U.S. Pat. No. 5,222,027 discloses a system for remote control and monitoring of additive injection at a fuel terminal. It is a stationary system in which the concentrations are set by the users.

Tank truck fuel delivery system having a selective dye injection system


A disposable device for controlling the rate of suction to and from a bodily organ, such as the stomach, during a lavage procedure that involves the use of a movable controller that slides back and forth over an opening in the main body of the device. The interior opening of the device which is placed in a flowline that extends from the stomach upstream to a downstream collection vessel has a tapered flow path that allows for the uninterrupted flow of pill fragments or stomach contents through the flowline. A lateral flow path that extends from an opening in the exterior of the main body to the main flow path enables an operator to vary the suction pressure to or from the patient by varying the size of the exterior opening through the use of the movable controller.

Acute poisoning remains a common cause of morbidity and even mortality in children and adults. However, if ingested poison can be removed from the gastrointestinal tract before being absorbed, the risk of severe poisoning is prevented or reduced. Stomach emptying is among the most time-honored and widely accepted medical treatments for ingested poisons. Because of this, physicians have routinely treated poison and overdose patients by performing gastric lavage.
A major problem associated with gastric lavage involves the clogging of the evacuation devices used to perform the procedure. Additionally, in-wall vacuum systems used in the procedure generally provide more steady suction than is necessary. Because of this, a valve is required to regulate the flow from the patient to the vacuum source.
The problem resulting from the use of a suction control valve is that the valve and hose connectors tend to clog and plug-up with stomach contents or pill fragments. Because of this, many hospitals have abandoned the in-wall vacuum units in favor of a hand plunger device. Use of the hand plunger, however, creates its own unique problems in that the plunger unit is costly, difficult to operate, and requires the use of an additional technician.
U.S. Pat. No. 4,790,832 (Lopez) describes a system for administering medication nasally to a patient and involves the use of a plastic connector having a series of flanges of increasing diameter that allows it to be inserted into flexible plastic gastric tubes of different sizes. The plastic connector used with this system--which can also be connected to suction when it is desired to remove fluid from a patient's stomach--highlights some of the problems identified above in that the tapering of the connection ends results in a void between the inside wall of the gastric tube and the outside wall of the connector. This void often fills with pill fragments or stomach contents that clog the evacuation tube.
A device that would reduce the number of qualified personnel required to perform a gastric lavage, allow an operator to vary the degree of suction to or from a patient, reduce the possibility of line obstruction, provide for easy clearing of pill fragments or stomach contents, be less costly, and disposable would be an important advancement in the art.


An injection protocol for a cable includes selecting a cable for testing, selecting a pre-injection electrical discharge test for determining if electrical discharge activity occurs at or about operating voltage of the cable, configuring the cable for the pre-injection electrical discharge test; running the pre-injection electrical discharge test on the cable, and determining whether to inject the cable with a restorative fluid based upon electrical discharge activity detected at or about operating voltage of the cable.

As an electrical power cable ages, the dielectric strength of its insulation is reduced, thereby shortening its life expectancy. As is well known in the art, a primary mechanism for the reduction of insulation strength with cable age is a phenomenon commonly referred to as water-treeing. Over time, water, on a molecular scale and in the presence of high electrical stresses and ionic contamination, can degrade the cable insulation's structure. This degradation typically occurs at discreet points along the cable length where point defects have increased the localized electrical stress level in the insulation. The degradation further increases discreet point electrical stresses and decreases insulation strength leading to a progressive condition. As the condition grows out from the initial defect site, it often takes on a bush-like appearance giving rise to its common name: a water-tree.
Water-trees are slow growing structures which lead to cable failure, but they are not themselves the mechanism of cable failure. Failure occurs when a voltage perturbation of some sort, i.e., a lightning surge, a switching surge, etc., causes a partial breakdown in the cable's insulation at the sight of reduced strength and increased stress. That partial breakdown forms a new structure commonly referred to as an electrical-tree. The electrical-tree defect propagates through the insulation very quickly, often failing a cable within hours or days of initial inception. Thus, in summary, water-trees develop slowly, degrading the cables insulation until that degradation gives rise to an electrical-tree, which quickly propagates and fails the cable. Water-tree growth can occur on a timescale of decades but electrical-tree growth often leads to failure in a time frame of hours or days.
Water-tree growth can be stopped through any process which removes the ionic laden water from the site. The deleterious effects of the remaining water-tree structure can be reduced if the electrical stresses associated with the discontinuity of the water-tree structure are stress graded. There are chemical solutions (restorative or injection fluids) which, when injected into the conductor strands of a cable, diffuse into the cable's insulation and chemically combine with the water existing in the insulation's structural defect, thereby removing the fuel for further water tree development. In some restorative fluid processes the by-product of this reaction may serve to stress grade the point defects of the structural defect, thereby reducing its deleterious effects on the cable's insulation. In the most refined restorative fluid solutions, those by-products can be chosen such that they remain in place within the water tree structure forming a pseudo-permanent solution to the water-tree degradation.
Restorative fluid solutions intended only to mitigate the deleterious effects of water-tree growth have little effect on cables that contain electrical-tree structures. However, if a cable has been functioning properly and it has not been subjected to any service disruptions or any conditions that vary from its standard operating condition, it is very unlikely that the cable will contain an electrical-tree structure at the time it is chosen for restorative fluid injection. Because an electrical-tree typically fails a cable in a matter of hours or days, it is statistically very unlikely that any particular cable with a lifespan of 15 or more years of life will be, coincidentally, in its last days of life at the time it is selected for injection. A cable injection, when performed on a cable that has been functioning properly at standard operating conditions, is typically referred to as a pro-active cable injection.
However, if the aged cable has recently been subjected to any conditions outside of its standard operating conditions, the statistical safety net described above no longer applies. Moreover, because of the aged condition of cables being considered for chemical injection, it is impossible to estimate the specific factor of safety between the operating conditions under which the cable is currently functioning and the actual, unknown value of the ultimate dielectric strength of the cable's insulation. Without knowing the exact extent of the cable insulation's degradation it is not possible to know what level of perturbation above its standard operating condition it is able to withstand. Examples of such perturbations are:                surges due to switching the cable out and into service        application of voltages in excess of system voltage for analytical purposes        surges that occur during cable failures and fault location        application of DC voltage testing, resulting in space charge development
A cable injection, when performed on a cable which has recently been subjected to any non-standard conditions or perturbations outside of its standard operating condition, is typically referred to as a re-active cable injection. Often the 'non-standard condition' is an actual cable fault. In that case the decision to inject the cable is a reaction to the obvious weakness of the cable indicated by the fact that it has already faulted at least once. However, any one of a number of perturbations or deviations from standard operating conditions, such as those listed above, would classify the injection as a re-active cable injection.
As one would expect, the failure rate for cables injected in a re-active manner is significantly higher than the failure rate for cables injected in a pro-active manner.
Injecting a cable that already contains an electrical tree is undesirable since ultimately the materials and labor are wasted on the effort. Detecting the presence of an electrical tree before injection is; therefore, highly desirable. Fortunately, between the inception of an electrical tree structure and the time that the electrical tree actually fails the cable, its presence can be detected using any test methodology that can detect the presence of an active partial discharge within the cable insulation. Additionally, tests which are sensitive enough to detect the partial discharging of an active electrical tree are also typically able to detect other electrical system discharge activities such as arcing, surface discharging, etc. These discharges also indicate issues that one would want to be aware of and perhaps address before injecting a cable.
The cable rejuvenation injection protocol of the present disclosure incorporates analytical methods of detecting active partial or full discharge activity; hereinafter sometimes collectively referred to as an "electrical discharge" or "discharge" occurring at system voltage into a cable rejuvenation injection process. Such methods include specialized test procedures aimed at eliminating the possibility of injecting a cable that already contains an electrical tree discharging at or about system voltage. The cable rejuvenation injection protocol may also include a step for checking the cable immediately after it has been chemically injected and returned to service in order to assure that any craftwork or switching process performed in the standard course of the cable rejuvenation injection process did not incite a new electrical-tree or other cable or system defect.
The testing performed as a part of this overall cable rejuvenation injection protocol should be distinguished from test protocols that are designed to evaluate the general condition of a cable for the purpose of prioritizing the replacement sequence of a population of cables. Currently there are a number of testing devices and procedures available that are used to try to ascertain a qualitative analysis of a cable insulation's health. Often, the goal is to prioritize cables for replacement. The cables that have the most degraded insulation are prioritized for replacement while the cables with the least aging are allowed to remain in service.
A typical test isolates the cable from the rest of the system and then uses an exterior power supply to incrementally raise the voltage of the cable in multiples of its operating voltage. Many of these tests use some indicator to determine at what voltage an electrical discharge occurs. In the specific case of water tree evaluation, different technologies take advantage of different phenomenon to make this determination. But most tests that work on this principle ultimately incite a discharge event by increasing the test voltage and then drawing conclusions about the cable's condition based largely on the size of the gap between the operating voltage of the cable and the inception voltage of the discharge incited by the test.
Unfortunately, these tests are not helpful at determining cable injection suitability. These tests typically require that the cable be switched out of service for the testing to be performed. Additionally, they require that overvoltage be applied to the cable to incite a discharge event. Therefore, the tests themselves create circumstances that take a cable from its proactive state to a reactive state. Moreover, the objective of these tests is to identify and replace the cables in the most aged, water treed condition. These are the cables that are the most likely to be seriously damaged by this testing approach. However, since the test is being used to determine the priority for cable replacement, the potential damage to the cable caused by the test can be considered a reasonable risk. In comparison, an objective of the injection protocol of the present disclosure is to rejuvenate the most aged (highly water-treed) cables, which are the cables most likely to be damaged by the overvoltage testing and rendered un-suitable for injection. Thus, it can be appreciated from the foregoing that there is a need for an improved method for determining cable injection suitability performed at the time, and as a part of the cable rejuvenation injection process.


A seal assembly for canal hearing devices including a dynamic pressure vent formed and defined by diaphragmatic flaps configured to open in response to a pressure gradient across the diaphragm. The seal assembly comprises a compliant seal element configured to be positioned generally concentrically around the canal hearing device for providing comfortable contact with the ear canal and for acoustically sealing the residual volume of the ear canal. The seal assembly is preferably made of an elastomeric material. The dynamic pressure vent is substantially closed in the normal position to minimize feedback, while momentarily opening inside the ear canal during insertion or removal of the canal hearing device into or from the ear canal.

The ear canal 10 (FIGS. 1 & 2) is generally narrow and tortuous and is approximately 26 millimeters (mm) long from the canal aperture 11 to the tympanic membrane 15 (eardrum). The lateral part is flexible and referred to as the cartilaginous canal 16 due to the underlying cartilaginous tissue beneath the skin 5. The medial part, proximal to the tympanic membrane, is rigid and referred to as the bony region 13 due to the underlying bone tissue. A characteristic first bend occurs roughly at the aperture 11 of the ear canal. A second characteristic bend 8 occurs roughly at the bony-cartilaginous junction and separates the cartilaginous region and the bony region. The dimensions and contours of the ear canal may vary significantly among individuals, but are generally narrow with little space for accommodating miniaturized components therewithin. The ear canal is generally sensitive to touch and pressure, particularly in the deeper region, which can readily experience discomfort, abrasion and trauma with pressure and rigid contact. Abrasion of the skin inside the ear canal due to hearing aid use is common and generally limits insertions to the lateral (outer) portions of the ear canal.
Placement of a hearing device inside the ear canal 10 (FIG. 1) is generally desirable for various electroacoustic advantages such as reduction of the acoustic occlusion effect, improved energy efficiency, reduced distortion, reduced receiver vibrations, and improved high frequency response. Placement inside the ear canal may also be desirable for cosmetic reasons, with many of the hearing impaired preferring to wear inconspicuous hearing devices. A canal hearing device can be inserted entirely or partially inside the ear canal. In the context of this application, a "canal hearing device" refers to any hearing device with sound delivery inside the ear canal, whether partially or fully inserted therein. This includes what is known in the hearing aid industry as Completely-In-the-Canal (CIC), In-The-Canal (ITC), invisible extended wear deep canal, as well as Receiver-In-the-Canal (RIC) devices.

Dynamic pressure vent for canal hearing devices


A semiconductor device includes a latency signal generating circuit for generating a latency signal corresponding CAS latency by measuring a delay amount reflected at a delay locked loop and reflecting the measured delay amount at a read command signal, and a delay locked loop for controlling an internal clock signal applied to the latency signal generating circuit corresponding to the read command and the latency signal. The semiconductor device includes an internal clock signal generating block configured to generate an internal clock signal, a latency generating block configured to generate a latency signal by synchronizing a read command signal with the internal clock signal at a time corresponding to a CAS latency value and a measured delay value, and an input controlling block configured to activate the reference clock signal using an external clock signal in response to the read command signal and the latency signal.

The present invention relates to semiconductor design, and more particularly, to a latency signal generating circuit for outputting a latency signal by synchronizing a read command signal, which is synchronized with an external clock signal, with an internal clock signal, and an internal clock signal generating circuit for outputting an internal clock signal by compensating an received external clock signal for an internal delay time of a semiconductor device.
In general, a semiconductor device such as a Double Data Rate Synchronous DRAM (DDR SDRAM) receives an external clock signal, generates an internal clock signal based on the received external clock signal, and uses the generated internal clock signal as a reference to synchronize various operation timings in a semiconductor device. Accordingly, the semiconductor device includes an internal clock signal generating circuit for generating an internal clock signal. Since a skew is generally generated between an external clock signal and an internal clock signal due to an internal delay of a semiconductor device, the internal clock signal generating circuit receives an external clock signal, compensates the external clock signal for the internal delay, and outputs the compensated external clock signal as an internal clock signal. A phase locked loop (PLL) or a delay locked loop (DLL) are representative internal clock signal generating circuits.
A semiconductor device receives a read command that is synchronized with an external clock signal and outputs stored data to an external device in response to an internal clock signal. That is, a semiconductor device uses an internal clock signal, not an external clock signal, to output data. Therefore, in a read operation, a semiconductor device needs to synchronize a read command, which is synchronized with an external clock signal, with an internal clock signal. That is, the synchronized clock signal is changed from an external clock signal to an internal clock signal based on the read command. Changing a synchronization target signal from a clock signal to another clock signal is referred to as domain crossing.
A semiconductor device includes various circuits for performing the domain crossing operation. Such circuits for the domain crossing include a latency generating circuit. The latency generating circuit synchronizes a read command, which was synchronized with an external clock signal, with an internal clock signal and outputs the synchronized signal as a latency signal. Herein, the latency signal, wherein the domain crossing is completed, includes CAS latency (CL) information. The semiconductor device uses the latency signal to output data to be synchronized with an external clock signal at desired point after a corresponding read command. Herein, the CAS latency includes time information from a time point of applying a corresponding read command to a time point of outputting data using one cycle of an external clock signal as a unit time. In general, the CAS latency is stored in a mode register set included in a semiconductor device.
FIG. 1 is a block diagram illustrating a delay locked loop (DLL) which is an internal clock signal generating circuit according to a prior art.
Referring to FIG. 1, the delay locked loop includes a phase comparator 110, a control signal generator 130, a variable delay unit 150, and a delay replica model 170.
The phase comparator 110 compares an external clock signal CLK_EXT with a feedback clock signal CLK_FED and outputs a detection signal DET. For example, if a phase of the feedback clock signal CLK_FED lags behind that of the external clock signal CLK_EXT, the detection signal DET becomes logic high. If a phase of the feedback clock signal CLK_FED is ahead of that of the external clock signal CLK_EXT, the detection signal DET becomes logic low.
The control signal generator 130 generates delay control signals CTR_DLY in response to the detection signal. Herein, the control signal generator 130 generates n delay control signals CTR_DLY corresponding to the number of unit delay cells included in the variable delay unit 150 where n is an integer number.
The variable delay unit 150 outputs a DLL clock signal CLK_DLL by delaying an external clock signal CLK_EXT according to the delay control signals CTR_DLY. The variable delay unit 150 includes a plurality of unit delay cells and each of the unit delay cells is enabled in response to a corresponding delay control signal CTR_DLY. Therefore, a delay amount of the external clock signal CLK_EXT is decided according to the number of enabled unit delay cells.
The delay replica model 170 generates a feedback clock signal CLK_FED by mirroring (for example, substantially identically) an internal delay of the semiconductor device to the DLL clock signal CLK_DLL outputted from the variable delay unit 150. In general, the delay replica model 170 is formed identically to a circuit of a path transferring the DLL clock signal CLK_DLL inside the semiconductor device.
The delay locked loop performs operations for making the external clock signal CLK_EXT and the feedback clock signal CLK_FED to have the same phase. Herein, making the external clock signal CLK_EXT and the feedback clock signal CLK_FED to have the same phase is referred to as locking. The locked DLL clock signal CLK_DLL is used to synchronize data. Accordingly, the data outputted after being synchronized with the DLL clock signal CLK_DLL is equivalent to data outputted after being synchronized with the external clock signal CLK_DLL.
FIG. 2 is a block diagram illustrating a latency signal generating circuit according to the prior art.
Referring to FIG. 2, the latency signal generating circuit includes a counter reset signal generator 210, an initializing unit 220, a DLL clock counter 230, an OE delay replica model 240, an external clock counter 250, a counter value latch unit 260, and a counting value comparator 270.
The counter reset signal generator 210 generates a DLL clock counter reset signal RSTb_DLL for resetting the DLL clock counter 230 by synchronizing the latency reset signal RSTb with the DLL clock signal CLK_DLL. The latency reset signal RSTb is activated by decoding external command signals such as a chip select signal /CS, a row address strobe signal /RAS, a column address strobe signal /CAS, and a write enable signal /WE. Or, the latency reset signal RSTB is activated at a time of ending a locking operation of the delay locked loop (see FIG. 1).
The initializing unit 220 provides an initial counting value INT<0:2> corresponding to CAS latency CL to the DLL clock counting unit 230. Herein, it is embodied that the initial counting unit value INT<0:2> is a 3-bit code signal. The following Table 1 shows initial counting setup values set in the initializing unit 220 corresponding to CAS latency CL3 and CAS latency CL6 and initial counting values INT<0:2> outputted from the initializing unit 220 corresponding to the initial counting setup values.
TABLE 1Initial countingCLsetup valueINT<2>INT<1>INT<0>35101441005301162010
The DLL clock counter 230 is reset in response to the DLL clock counter reset signal RSTb_DLL and counts the DLL clock signal CLK_DLL from the initial counting value INT<0:2> outputted from the initializing unit 220. That is, the DLL clock counting unit 230 generates a DLL clock counting value CNT_DLL<0:2> by counting the DLL clock signal CLK_DLL from an initial counting value set according to the CAS latency CL. For example, if the initial counting value INT<0:2> is set to 4 according to CAS latency CL, the DLL clock counter 230 outputs the DLL clock counting value CNT_DLL<0:2> counted from 4 in response to the DLL clock signal CLK_DLL.
The OE delay replica model 240 models a delay amount between the DLL clock signal CLK_DLL and the external clock signal CLK_EXT. That is, the OE delay replica model 240 generates an external clock counter reset signal RSTb_EXT by delaying the DLL clock counter reset signal RSTb_DLL. Herein, the external clock counter reset signal RSTb_EXT is synchronized with the external clock signal CLK_EXT.
The external clock counter 250 performs a counting operation in response to the external clock counter reset signal RSTb_EXT. That is, the external clock counter 250 outputs an external clock counting value CNT_EXT<0:2> counted in response to an external clock signal CLK_EXT according to the external clock counter reset signal RSTb_EXT. The initial counting value of the external clock counter 250 is set to 0 unlike the DLL clock counter 230. In other words, the external clock counter 250 outputs an external clock counting value CNT_EXT<0:2> counted from 0 in response to the external clock signal CLK_EXT after enabled according to the external clock counter reset signal RSTb_EXT.
The counting value latch unit 260 latches the external clock counting value CNT_EXT<0:2> in response to a read command signal RD_EN and outputs the latched external clock counting value LAT_CNT<0:2>. The read command signal RD_EN is a pulse signal that is activated in response to a read command. Herein, the read command is applied after being synchronized with the external clock signal CLK_EXT.
The counting value comparator 270 compares the DLL clock counting value CNT_DLL<0:2> with the latched external clock counting value LAT_CONT<0:2> and outputs a latency signal LTC activated at a time when the two values become identical. The latency signal LTC is synchronized with the DLL clock signal CLK_DLL and includes CAS latency information. In other words, the latency signal LTC is a signal generated by synchronizing a read command, which is applied after being synchronized with an external clock signal CLK_EXT, with a DLL clock signal CLK_DLL wherein CAS latency is reflected. That is, the latency signal LTC is a result of domain crossing of the read command. The latency signal LTC is used to output data with burst length information in later.
FIG. 3 is a waveform for describing an operation timing of a latency signal generating circuit of FIG. 2. For illustration purposes, CL4 indicates when CAS latency CL is 4, CL5 indicates when CAS latency CL is 5, and CL6 indicates when CAS latency CL is 6.
At first, an operation timing of a latency signal generating circuit of FIG. 2 when CAS latency CL is 4 will be described.
The initial counting value of the initializing unit 220 is set to 4 according to Table 1. Then, when a DLL clock counter reset signal RSTb_DLL is shifted to logic high, the DLL clock counting unit 230 outputs a DLL clock counting value CNT_DLL<0:2> counted from 4 which is an initial counting value in response to the DLL clock signal CLK_DLL.
Meanwhile, the OE delay replica model 240 outputs an external clock counter reset value RSTb_EXT by mirroring a delay time D to the DLL clock counter reset signal RSTb_DLL. Then, when the external clock counter reset signal RSTb_EXT is shifted to logic high, the external clock counter 250 outputs an external clock counting value CNT_EXT<0:2> counted from 0 in response to the external clock signal CLK_EXT.
If the read command signal RD_EN is activated because the read command RD is applied, the counting value latch unit 260 outputs 3 which is an external clock counting value CNT_EXT<0:2> as the latched external clock counting value LAT_CNT<0:2>. The counting value comparator 270 compares the DLL clock counting value CNT_DLL<0:2> with the latched external clock counting value LAT_CNT<0:2> and activates the latency signal LTC when the two values become identical, that is, when the DLL clock counting value CNT_DLL<0:2> becomes 3. A semiconductor device outputs data using the activated latency signal LTC when the external clock signal CLK_EXT becomes 4.
In case of CL5, the latency signal LCT is activated when the DLL clock signal CLK_DLL is 4. A semiconductor device outputs data using the activated latency signal LCT when the external clock signal CLK_EXT becomes 5. In case of CL6, the latency signal LCT is activated when the DLL clock signal CLK_DLL becomes 5. A semiconductor device outputs data using the activated latency signal LTC when the external clock signal CLK_EXT becomes 6.
Meanwhile, semiconductor devices are being manufactured for high speed operation, low power consumption, and miniaturization. However, such a semiconductor device may have the following problems.
At first, the increment of an operation frequency of a semiconductor device causes increasing CAS latency CL. Since the counting circuit having the DLL clock counter 230 and the external clock counter 250 is designed corresponding to CAS latency CL, it is necessary to design the counter circuit big if the CAS latency CL becomes large. Furthermore, it is also necessary to design a comparing circuit of the counting value comparator 270 big according to the counter. That is, a chip size of a semiconductor device disadvantageously increases.
Also, since a 4-bit counter circuit has a slower operation speed than that of a 3-bit counter circuit, the operation speed of the counter circuit become slow as the CAS latency CL increases. Then, an operation speed of the comparing circuit becomes slow as the number of bits increases. That is, a data processing speed of a semiconductor device becomes slow.
A latency signal generating circuit according to the prior art latches an external clock counting value CNT_EXT<0:2> when a read command signal RD_EN is activated. Therefore, the DLL clock counter 230 and the external clock counter 250 perform a reset operation and a counting operation before the read command signal RD_EN is activated. That is, before the read command signal RD_EN is activated, the external clock counter 250 receiving the external clock signal CLK_EXT and the DLL clock counter 230 receiving the DLL clock signal CLK_DLL continuously perform counting operations. It means a semiconductor device may waste power until the read command RD is applied. In this view, the delay locked loop DLL circuit may continuously generate the DLL clock signal CLK_DLL for the smooth operation of the latency signal generating circuit. Thus, the delay locked loop DLL circuit may waste power continuously.

Latency signal generating circuit and semconductor device having the same


Systems, apparatus, methods, and articles of manufacture for Artificial Intelligence (AI) driving analysis and incentives, by utilizing on-board image object analysis to classify driving events and provide driving-based awards.

Driver safety, particularly among new or teen drivers, continues to be a problem. As reported by the U.S. Department of Transportation National Highway Traffic Safety Administration (NHTSA)1, motor vehicle accidents remain the leading cause of death for teens, and likely due to increased opportunities for distracted driving (on-board or hand-held navigation systems, hand-held phone dialing or texting, etc.), overall roadway fatalities are currently increasing. 1 See, https://www.nhtsa.gov/road-saftey/teen-driving#topic-parental-influence
Currently, three (3) overall types of solutions may be utilized in an attempt to alleviate teen driving issues. First, passive safe driving programs and websites allow teens to learn about safe driving and safe driving habits. Second, various "black box", telematic device, and mobile device applications utilize Global Positioning System (GPS) data and/or accelerometers to measure driving parameters, such as hard braking, speeding, and the like. And third, on-board cameras (either built-in or removable dash-cams) allow recording of video footage (e.g., for after-event review) or allow for certain real-time alerts, such as drifting from a lane or approaching another vehicle too quickly. Many modern vehicles now also include proactive safety features, such as lane-keeping assistive steering and automatic braking to help avoid collisions.
Each of these solutions, however, suffer from deficiencies. Passive driver safety programs are important to help young drivers understand what they should be doing behind the wheel, for example, but are not tied to actual driving performance and accordingly cannot provide guidance or corrections for specific actions a driver has taken in the real world. GPS and accelerometer devices provide good insight into driving behaviors, such as speeding and hard braking, but do so in a vacuum. GPS and accelerometer readings are disembodied from the outside environment of the vehicle, for example, and therefore cannot distinguish between events that provide similar measurements, but that occur in different driving scenarios. And vehicle or dash-cam devices may be programmed to provide some basic guidance (e.g., lane keeping), but do not capture data descriptive of a driver's overall performance. Both GPS/accelerometer and camera-based systems raise significant privacy concerns as well.

This patent is subject to a terminal disclaimer.

Systems and methods for artificial intelligence (AI) driving analysis and incentives


A method for manufacturing a dielectric thin film capacitor of the present invention includes the steps of coating a liquid raw material on a substrate and performing a first heat treatment to form an adhesive layer, forming a lower electrode on the adhesive layer, coating a liquid raw material on the lower electrode and performing a second heat treatment to form a dielectric thin film by crystallization, forming an upper electrode on the dielectric thin film, and performing a third heat treatment at a temperature higher than those of the first and second heat treatments. The adhesive layer and the dielectric thin film are formed by using materials having the same composition system or using the same material.

1. Field of the Invention
The present invention relates to a method for manufacturing a dielectric thin film capacitor.
2. Description of the Related Art
A dielectric thin film capacitor used in a semiconductor device such as DRAM or a noise filter has a structure in which a substrate, a lower electrode, a dielectric thin film, and an upper electrode are stacked in order. The dielectric thin film can be deposited by a sputtering process, a CVD process (chemical vapor deposition), a MBE process (molecular beam epitaxy), a sol-gel process, or a MOD process (metalorganic decomposition). However, the sol-gel process and the MOD process are advantageous from the viewpoint of manufacturing cost.
In the sol-gel process or the MOD process for depositing the dielectric thin film, a raw material solution prepared by dissolving an organic compound used as a dielectric raw material in an organic solvent is coated and then heat-treated in an oxidizing atmosphere. Therefore, an non-oxidizable noble metal, for example, Pt, is often used for the lower electrode.
Although a Si substrate is generally used as the substrate of the dielectric thin film capacitor, a Si oxide layer is formed on the surface of the Si substrate because Si becomes oxidized when being allowed to stand in air.
When a dicing-cut process is performed after the dielectric thin film capacitor is formed, an adhesive layer must be formed between the substrate and the lower electrode in order to improve the low adhesion between the Si oxide layer on the surface of the substrate and the noble metal of the lower electrode. The adhesive layer often comprises Ti (refer to Japanese Unexamined Patent Application Publication No. 8-78636).
Japanese Unexamined Patent Application Publication No. 8-78636 discloses that the use of Ti for the adhesive layer has the problem of causing warping of the substrate due to oxidation of the Ti layer and thus causing cracking in the dielectric thin film. This publication also discloses that warping of the substrate can be suppressed by limiting the thickness of the Ti layer functioning as the adhesive layer.
However, another problem occurs even if the thickness of the Ti layer is limited. Namely, even a limited Ti layer is inevitably oxidized in an annealing process or the like. When Ti is oxidized and diffuses at the interface between the lower electrode and the dielectric thin film, two additional problems described below occur.
First, when barium titanate (BaTiO3), strontium titanate (SrTiO3) or strontium barium titanate ((Ba,Sr)TiO3, abbreviated to "BST" hereinafter) is used for the dielectric thin film, the Ti oxide diffusing at the interface between the dielectric thin film and the lower electrode causes a crystal structure deviation at the interface which causes disturbance in crystallinity of the dielectric thin film. When the crystallinity of the dielectric thin film is disturbed, a sufficient dielectric constant cannot be obtained.
Second, the Ti oxide has a high resistance and a low dielectric constant and thus creates a state in which a layer having a high resistance and a low dielectric constant is present at the interface between the lower electrode and the dielectric thin film to significantly degrade the characteristics of the capacitor.
The above document further discloses that the dielectric thin film is preliminarily burned at a temperature lower than the crystallization temperature to planarize its surface, and then the upper electrode is formed on the dielectric thin film, followed by final burning at a temperature higher than the crystallization temperature. As shown in FIG. 2 of the document, the dielectric constant of the dielectric thin film formed by the production method is about 220, which is relatively low for BST. Under the present situation in which circuit integration is strongly demanded, a capacitor capable of achieving a high capacity with a small area is required, and thus a dielectric thin film having a higher dielectric constant must be formed.
While, the technique disclosed in the above document is capable of suppressing the occurrence of cracking, which causes a leakage current, to some extent, it has the problem of impairing the characteristics of the capacitor and causing difficulty in achieving a high dielectric constant.

Method for manufacturing dielectric thin film capacitor


User interface devices, such as displays and keyboards, are automatically deployed using pulse-width-modulated controlled force in a first safety period. Once safe, force and speed are increased to full deployment. At full deployment, electrical braking dissipates mechanical energy and power is throttled down to hold device against deployment stop.

The notion of providing retractable devices is not new. For many years, a wide variety of industries have used retractable devices such as keyboards and displays. These are just two examples of user interface devices that may be used in a deployed position and then retracted when they are not needed or otherwise intrude into a cluttered space.
The aircraft industry has long used retractable user interface devices because of the limited operational space that is available either in the cockpit or in the passenger compartment of an aircraft. It is not uncommon to discover retractable keyboards that are used to control equipment disposed in the flight deck. Once the keyboard is not needed, it can be stowed so that it does not continue to clutter the operating space. This helps to promote the operational safety of the aircraft. Although not as common, retractable display devices may also be used in the flight deck.
In the passenger compartment of an aircraft, retractable display devices are much more prevalent. In many cases, retractable display devices may comprise an in-flight entertainment (IFE) system. For instance, retractable display devices may be used to present entertainment content to passengers. Retractable display devices that may be used in IFE systems may take on many different forms. One example of a retractable display device is that of a personal display unit that may be stowed in the arm of a passenger seat. When the display is in use, it may be deployed outward from the passenger seat arm and articulated into a comfortable viewing position. Another form of retractable display device that may be used in IFE applications is that of an overhead monitor. An overhead monitor is typically installed in the ceiling of the passenger compartment or it may be disposed at the bottom surface of luggage compartments. When an overhead monitor is installed in either of these manners, it typically deploys downward into the passenger space.
Other example applications of retractable display devices and keyboards may be found in the automotive industry. Here, stereo systems, navigation systems and automotive control systems may benefit from the application of retractable displays and keyboards. For instance, a deployable heads-up-display may be disposed above the control console of an automobile. The heads-up-display may be used to enhance night vision. In this type of an application, it would be beneficial to retract the heads-up-display when it is not needed. Even some stereo systems meant for use in cars may comprise deployable keyboards because of the limited amount of space available on the console for conventional controls.
The most advanced of these deployable user interface devices comprise mechanisms for automatic deployment and retraction of the user interface assembly. It is not uncommon to find a retractable overhead display installed in the passenger compartment of an aircraft that automatically responds to a deployment signal. When the deployment signal is active, this type of overhead display deploys the functional-end of the display screen into the passenger space. Likewise, when the deployment signal becomes inactive, the display screen may be retracted; promoting passenger comfort and safety.
In all of these cases, automatic deployment and retraction of a user interface provides a significant level of convenience. However, as with any mechanized assembly, there exists the potential to harm human life and limb. Up until now, deployable user interface devices that are automatically driven into the user's space have done so using a constant force. If allowed to operate in this type of an unrestrained fashion, deployment of a user interface assembly may inadvertently apply harmful pressure to an innocent bystander.
Despite the convenience they offer, automatically deployed user interface devices such as keyboards and displays rigidly maintain their deployment position. There may be situations where a deployed user interface assembly must be retracted in an exigent circumstance. One such situation is commonly encountered in an aircraft application of an overhead display; a passenger inadvertently collides with the deployed display screen comprising the display assembly. In this case, it is likely that the passenger will sustain physical injury if the fully deployed position is rigidly maintained.

Method and apparatus for controlled force deployment of user interface devices


A solid oxide fuel cell including a flat plate-shaped solid oxide fuel cell element. The cell element is composed of an ion-conductive ceramic plate formed with ribs connected with each other in a plane, an air electrode formed on one main surface of the ion-conductive ceramic plate, and a fuel electrode formed on the other main surface of the ion-conductive ceramic plate. In producing the fuel cell, a flat plate-shaped green sheet made of an ion-conductive ceramic molding material is press contacted with a rib-forming green sheet made of a material of the same kind and having a unitary shape formed by connecting elongated portions to each other. The contacted green sheets are sintered together to form an ion-conductive ceramic plate. In an alternative, a flat plate-shaped green sheet and a rib-forming green sheet may be separately sintered and then bonded with each other to form an ion-conductive ceramic plate. The ion-conductive ceramic plate is formed with an air electrode surface and a fuel electrode on opposite main surfaces, respectively.

1. Field of the Invention
The present invention relates to a solid oxide fuel cell which generates electric power by the use of a flat plate-shaped solid oxide fuel cell element and a method for producing the solid oxide fuel cell.
2. Related Art Statement
Recently, fuel cells have been recognized as power generating equipment. The fuel cell is capable of directly converting chemical energy possessed by fuel to electric energy. Since the fuel cell is free from limitation of Carnot's cycle, the cell is a very promising technique owing to its high energy conversion efficiency, wide latitude of fuels to be used (naphtha, natural gas, methanol, coal reformed gas, heavy oil and the like), less public nuisance, and high electric power generating efficiency without being affected by scale of installation.
Particularly, since the solid electrolyte fuel cell (hereinafter referred to as "SOFC") operates at high temperatures of 1,000.degree. C. or so, activity of electrodes is very high. Thus, no catalyst of a noble metal such as expensive platinum is necessary. In addition, since the SOFC has low polarization and relatively high output voltage, its energy conversion efficiency is conspicuously much higher than those of the other fuel cells. Furthermore, since their constituent materials are all solid, the SOFC is stable and has long service life.
Since such fuel cells can be constructed by solid structural materials, various kinds of cell structures have been proposed. Among the so-called flat plate-shaped solid oxide fuel cells are structurally very promising because their electric power per unit volume can be easily increased.
With the flat plate-shaped SOFC and monolithic SOFC, however, there are problems in producing techniques and the like as follows.
An ion-conductive film of zirconia has been formed on a flat plate-shaped porous support by means of chemical vapor deposition (CVD), physical vapor deposition (PVD) or electrochemical vapor deposition (EVD). However, apparatuses for use in CVD, PVD and EVD are generally expensive and large in size. Moreover, film forming speeds are low so that these methods are low in productivity and not suitable for mass production and it is difficult to obtain films of wide areas. Furthermore, internal resistance in the cells is high owing to diffusion resistance of fuel gases passing through porous supports.
A method has been proposed to form corrugated green sheets of an ion-conductive film of zirconia, an air electrode film and a fuel electrode film, press contact these green sheets and sinter them. In this method, however, since green sheets of different materials are sintered together, it is difficult to adjust their shrinkages during firing. Further, when the green sheets are press contacted with one another, the green sheets are likely to be cracked or fractured. Moreover, insulating layers tend to be produced at interfaces between the ion-conductive film and the electrode films after they are sintered together.
In order to overcome these problems, Japanese Patent Application Laid-open No. 1-128,359 disclosed a method in which an ion-conductive plate of zirconia is formed by sintering, electrodes are formed on its both surfaces to form a flat plate-shaped SOFC element, and such SOFC elements and insulating spacers are alternately laminated to form a SOFC.
However, inventor's investigations revealed that these methods involved the following problems.
That is, in the SOFC using such so-called self-standing ion-conductive ceramic plates, the green sheet of the flat plate-shaped ion-conductive ceramic plate are formed by the tape-casting method. In operating such a laminated SOFC, the ion-conductive ceramic plate undergoes a difference in pressure between a fuel gas and an oxidizing gas in a fuel gas chamber and an oxidizing gas chamber provided on both sides of the ceramic plate, respectively In order to resist emergency gas purging, the ion-conductive ceramic plate must be made thick to prevent any cracks and fracture
On the other hand, in order to restrain an increase in resistance to the ion-conduction, the ion-conductive ceramic plate must be made thin. It is difficult, however, to fulfill the contradictory requirements. Therefore, the structural strength and internal resistance of the flat plate-shaped SOFC element are not sufficient up to now.

Solid oxide fuel cell and method for producing the same


A low-level light detector includes an avalanche photodiode (APD) to which is applied a bias voltage adjusted to produce a multiplication factor of not more than 30, and a capacitor for accumulating carriers produced by light in the APD and multiplied using the APD characteristics, the capacitor being connected to the avalanche photodiode. The detector detects the intensity of light impinging on the avalanche photodiode by periodically reading the capacitor voltage and obtaining time-based differences in the voltage, or by resetting the capacitor voltage to a predetermined voltage each time the capacitor voltage is read.

1. Field of the Invention
This invention relates to a low-level light detector and low-level light imaging apparatus using an avalanche photodiode, having a linear sensitivity to the intensity of the low-level light.
2. Description of the Prior Art
Light detectors used to detect low-level light include avalanche photodiodes (APDs), photomultiplier tubes (PMT) and CCD cameras. However, in fields such as nanotechnology and other leading-edge areas of biology and chemistry that involve the handling of DNA and environmental endocrine disruptors and the like, it is necessary to detect light that is of a weakness that is difficult to measure using the above light detectors. Moreover, there are a number of problems that limit the methods of using the above detectors. The low multiplication noise light detector developed has excellent characteristics that enable higher-sensitivity in light detection than the above light detectors and also enable the problems of the above light detectors to be solved.
An APD or PMT multiplies a photoelectric current comprised of electrons produced from light, and can even enable detection of single photons if the current can be multiplied to a high enough level compared with the noise of the amplification stage. A detector that detects photons one by one is called a photon counter, and represents the most sensitive light detection method known. However, photon counters using APDs and PMTs have a number of problems that make this a less-than-perfect detection method. For example, these photon counters cannot measure low-level light in which only one photon per second hits the detector. The reason for this is as follows.
Dark current exists in APDs and PMTs, which is a current that flows when no light falls incident on the photodetector. Dark current is not constant, but is always varying. If the dark current reaches a high level that is higher than the current produced by incident light, it can result in an output that seems to be produced by the impinging of light. When an APD or PMT is used to constitute a photon counter, the dark current can therefore give rise to a photon count even when there is no incident light. This is known as the dark count. In the case of a PMT, the dark count is a relatively low few counts per second, but in the case of an APD the dark count is 100 or more per second. Quantum efficiency is another factor that hinders detection of low-level light. In the case of a photon counter, the quantum efficiency shows the proportion of incident light in terms of the photon count. If all of incident light is counted, the quantum efficiency is 100%. Thus, the lower the quantum efficiency is, the higher the possibility becomes that a single incident photon will not be counted, lowering the sensitivity. A PMT has a low dark current but also a low quantum efficiency of around 20% at most. In the case of longer wavelengths over 600 nm, the efficiency decreases sharply to 1% or less. PMTs are being developed having a relatively high quantum-efficiency in the near-infrared region, but due to the increase in the dark current, there is no outstanding improvement in the detection sensitivity. Generally, compared with PMTs, APDs have a higher quantum efficiency that can reach 90%. The quantum efficiency is especially high in the wavelength range of 600 nm to 1 μm, which can make it possible to achieve a higher sensitivity with an APD, even after taking the higher dark current into account.
A problem common to both APDs and PMTs is multiplication noise. Neither an APD nor a PMT can multiply the photoelectric current at a fixed rate; the multiplication factor always has a certain distribution. This fluctuation in the multiplication is termed the multiplication noise. A high multiplication noise makes it difficult to distinguish between events when the number of photons incident on the APD is one or two or more. That is, existing APD-based photon counters cannot distinguish the number of simultaneously incident photons. There are reports of PMTs having a lower multiplication noise than an APD that can distinguish between several levels of incident photon numbers, but only after extensive statistical calculations; on a real time basis, distinguishing between the numbers of incident photons is difficult.
Generally lowering the multiplication factor reduces the multiplication noise. So, a desirable method of using an APD or PMT as a photon counter is to reduce the multiplication factor and to decrease the multiplication noise until the output current is proportional to the number of incident photons. This method is done using what is called the linear mode or the gain mode. However, it becomes impossible to detect single photons due to the low multiplication factor, resulting in reduced sensitivity.
It therefore follows that these photon counters cannot be used for a short-pulse light source to measure how much light is produced per pulse. This shows that it is very difficult to measure high-speed phenomena requiring the use of short pulses, or optical non-linear phenomena using an APD or PMT. For this purpose, a camera, such as a CCD camera as described below, is used.
Recently available on the market are CCD cameras that are capable of measuring single photons. With their very highly linear output with respect to the number of incident photons, these cameras are being extensively used as light detectors that complement APDs and PMTs. Because of their linearity with respect to the number of incident photons, CCD cameras can also be used for pulsed-source measurement, which is difficult using an APD- or PMT-based photon counter. However, the small area of each CCD pixel (10 to 20 square μm) makes a CCD camera unsuited in cases where there is a relatively large-area light source when it is not necessary to capture an image, or where as much as possible of the light radiating in various directions is to be collected. Because it is so difficult to cram into a small area light from a large area light source or light radiating at a large angle, such light unavoidably becomes dispersed over a number of CCD pixels. When this happens, in order to measure the overall intensity of the incident light it is necessary to add together the outputs from the pixels on which the light fell, which also results in an increase in the noise. This is because the noise from the individual pixels is also added together. If the outputs from the pixels on which the light did not fall are also added, the intensity of the incident light will stay the same but the noise will increase. Thus, it is necessary to choose the pixels that are added together in line with the spatial spread of the incident light. This being the case, with respect to a large-area light source, the sensitivity of a CCD camera is not necessarily good.
The characteristics of an APD can be readily understood from the multiplication factor or by using the distribution of the pulse height in the APD output when photons fall incident thereon. To compare the pulse height with the noise level, pulse-height distribution will now be used to explain amplifier noise and APD sensitivity. FIG. 6 shows the probability distribution with respect to the height of a current pulse produced when a single photon falls incident on the APD. The horizontal axis is pulse height and the vertical axis is the probability of a pulse of that height being produced. Looking at FIG. 6, it can be seen that the probability grows as the pulse height decreases, with the probability reaching a maximum when the pulse height is at its smallest, meaning it has not been amplified at all. In principle, photon detection is determined by the presence or absence of a photoelectric current. In this case, the pulse height is not used in the determination, so the distribution thereof is unrelated to the sensitivity. However, since, as described above, photon detection is determined by the presence or absence of a photoelectric current, as in the case of an ordinary photodiode, the quantum efficiency that is the probability of the incident light generating one photoelectron can be applied with no modification to the APD.
The present invention uses an APD in which the avalanche effect is used to amplify the number of electrons. It is characterized by using a concatenated generation of electrons to multiply the number of carrier electrons. The higher the energy of each electron means the higher the overall number of electrons that are produced. So, in order to increase the multiplication factor, it is necessary to apply a high field.
However, there is a drawback by increasing the speed of the electrons. Excessively speeding up electrons decreases the excitation scattering cross-section (the probability of carrier electrons being produced). Therefore, in the case of an APD which uses the avalanche effect, the highest probability is that the first photoelectron produced by incident light will be output without any amplification. That is the reason for the high probability at minimum pulse height shown in FIG. 6.
In conventional APDs, the photoelectric current is multiplied to surpass the subsequent amplifier noise. When multiplication factor and pulse height are low, a pulse output by the APD in response to a single photon will be buried in the amplifier noise. Therefore, inputting APD output pulses to the counter as they are, after they have been input to the amplifier, will generate a lot of erroneous counts, due to the amplifier noise. Generally, in order to prevent this happening, a threshold value that is higher than the amplifier noise is used, so that only output pulses that exceed the threshold value are counted. As shown in FIG. 9, which shows output relative to multiplication factor, amplifier output includes thermal noise and shot noise. The point at which the detected signal exceeds this noise at which the signal-to-noise ratio is at a maximum is selected as the operating point.
Also, a photon falling incident on the APD when the multiplication factor happens to be low is discarded. It is usual for this non-counting of photons that are thus discarded to be thought of as included in the quantum efficiency. That means that the quantum efficiency of a conventional APD is that much worse than a conventional photodiode.
As described above, in an APD or PMT, the multiplication noise decreases with the decrease in the multiplication factor, so that if the amplifier noise can be reduced, it will also be possible to reduce the multiplication factor, thereby reducing the multiplication noise. However, as shown in FIG. 6, reducing the multiplication factor does not have much of an effect on the shape of the multiplication factor distribution: the probability of occurrence is still higher when the multiplication factor is low. Therefore, as can be understood from FIG. 6, even if the multiplication factor is reduced (decreasing output pulse height), along with the threshold value, no major improvement in quantum efficiency can be expected. In fact, from the standpoint of improving the quantum efficiency, it would be better to decrease the threshold value and not change the multiplication factor. That is to say, as long as a conventional APD is to be used without modification, virtually the only way the sensitivity can be improved is to reduce the amplifier noise. And, since reducing just the amplifier noise will leave the multiplication noise unchanged, the linearity of the output current relative to the number of incident photons cannot be improved.
Due to such problems, the present invention employs an APD multiplier that utilizes slow electrons. That is, in contrast to the prior art in which electrons accelerated to a high speed are used to produce a strong avalanche effect, slow electrons are prepared in the acceleration voltage region where there is a high excitation cross-section. Normally, the slower the electrons, the larger the excitation scattering cross-section, but below a fixed excitation energy above that required to produce new carrier electrons, a sharp decrease takes place. Therefore, as a function relative to electron speed, the scattering cross-section peaks at around a speed at which the kinetic energy is around several times the excitation energy. If the electron speed is brought to within this vicinity, electrons excitation takes place with a high probability, ensuring the photoelectrons generate the next carrier electrons. Ensuring the electrons thus generated are all, also low-speed ensures the further generation of carrier electrons, reducing the fluctuations in the multiplication factor.
An object of this invention is to provide a low-level light detector and low-level light imaging apparatus that in low-level light regions maintain a linear relationship between light intensity and detection sensitivity, using an APD that can readily increase the light receiving area per element and in which the light receiving element itself has an amplifying action.
Another object is to provide a low-level light detector and low-level light imaging apparatus that can detect voltage that is proportional to the number of incident photons when irradiated by low-level light, and which also have a high quantum efficiency.

Low-level light detector and low-level light imaging apparatus

National Institute of Information and Communications Technology Incorporated Administrative Agency


An underground housing contains a netting that is retractably attached inside the housing. The netting is used to cover rubbish positioned at curbside, to keep dogs and children away from the rubbish. The netting also acts to hide the rubbish until it is picked up.

A critical ingredient in community waste programs is proper segregation/preparation packaging of the waste materials for curbside collection. Outdoor placement of any such recycling collectables still-retaining or suggesting a food odor can invite scavenging animals, or, the items themselves can be an irresistible object of interest to curious children. Efficient tamper-proofing measures of some citizens such as, walls, fence/gates, eternally-residual boxes, platforms, etc., have met with minimal success. Retractably removed from underground storage, net protectively encompasses and tamper-proofs the waste placement until collected. With application of the instant invention to waste collection, no reminder of unsightly garbage necessarily remains all day(s) to mar(i.e., empty cans, bins, bags, boxes, etc.) the visual ambiance.


A transfer device is provided for an image forming apparatus designed such that toner images formed on a plurality of image bearing members are transferred one over another on a transfer body disposed in contact with each of the image bearing members with predetermined pressure and thus a toner image in two or more colors is formed on the transfer body. The transfer device includes a pressure varying mechanism which is capable of separating the transfer body from at least some of the image bearing members, and capable of varying transfer pressure between the image bearing members and the transfer body in contact with said image bearing members.

1. Field of the Invention
The present invention relates to a transfer device mounted in an image forming apparatus, such as a copying machine, a printer, or a facsimile apparatus, which uses an electrophotographic technology.
2. Description of the Related Art
Currently, a single-drum type image forming apparatus and a tandem type image forming apparatus are known. The single-drum type image forming apparatus includes a single image bearing member (i.e., photoreceptor drum), whereas the tandem type image forming apparatus includes two or more image bearing members. Since the tandem type image forming apparatus provides high productivity in comparison with the single-drum type image forming apparatus, the tandem type has become widespread in recent years.
Examples of the tandem type image forming apparatus include one that directly transfers a toner image from an image bearing member onto a transfer material on a transfer conveying body, and one that first transfers a toner image from an image bearing member onto an intermediate transfer body and finally transfers the toner image onto the transfer material. Each type is configured such that some of the image bearing members can be separated from the transfer conveying body or intermediate transfer body respectively. This is because constant contact of each image bearing member with the transfer conveying body or intermediate transfer body may lead to scratching or wear after long use and, therefore, it is necessary that image bearing members for colors not involved in an image formation be separated from the transfer body or the like in order to prolong the life of the components. Generally, such a separation is switched between a monochrome mode and full-color mode. For example, in the case of an apparatus in which four image stations are arranged in tandem, image forming units for the four generally-used colors (black, cyan, magenta, and yellow) are designed such that only the image bearing member for black and the transfer body are brought into contact with each other in monochrome mode whereas image bearing members for all the colors and the transfer body are brought into contact with each other in full-color mode (refer to Japanese Patent Application Laid-Open No. H9-146383).
Meanwhile, such a tandem type image forming apparatus suffers from image defects caused by banding. Banding occurs when a toner image is blurred or a dot image is distorted due to unstable rotating speed of the transfer body or an image bearing member during the formation of toner images on the image bearing members or during the transfer of toners from the image bearing members to the transfer body.
The causes of banding with respect to components involved in the image transfer reside in unstable rotating speed of the transfer body. Factors contributing to unstable rotating speed of the transfer body may be shock from starting or stopping of a rotating body provided in the apparatus, shock from the operation of a contact/separation member, shock from a transfer material, such as paper, entering or exiting the transfer body, etc.
In order to prevent image defects caused by banding, a conventional technique increases electrostatic attraction between an image bearing member and the transfer body, thereby making the speed of the transfer body less susceptible to disturbance.
An example of such a technique is described in Japanese Patent Application Laid-Open No.2005-128230. The application discloses an image forming apparatus including: a latent image forming unit that forms an electrostatic latent image on an image bearing member; a development unit that develops the electrostatic latent image into a toner image; a primary transfer unit that transfers the toner image to an intermediate transfer body; and a secondary transfer unit that transfers the toner image, transferred to the intermediate transfer body, to a recording medium, and the apparatus includes a member for a contact/separation operation or driving/stopping operation, which is performed in the non-image formation area on the intermediate transfer body or in an area of the image bearing member, which area corresponds to the non-image formation area. This image forming apparatus sets primary transfer bias to high while the position on the intermediate transfer body, where the separation/contact operation or driving/stopping operation is performed, is passing through a primary transfer position.
However, the inventors of the present invention discovered that such countermeasures are not enough to prevent image defects caused by banding, and examined the factors contributing to banding in detail. It has been found that more defects arose while the image bearing members and the transfer body are partially separated from each other. Further analysis revealed that a decrease in electrostatic attraction in the area where the image bearing member and the transfer body are separated results in a decrease in the overall electrostatic attraction between the image bearing members and the transfer body. This increases instability of the transfer body.
In order to avoid such defects, transfer bias is further increased using conventional techniques. This reduces banding. However, the excessively high transfer bias results in inconveniences such as formation of an abnormal discharge image, a reverse transfer image, etc., and thus desirable image quality cannot be obtained.

Transfer device and image forming apparatus


A device and method for transmitting sound waves between a signal source and a user's ears, wherein the sound waves bypass the air. The invention generally comprises an edible substance and a signal source operatively associated with the edible substance and configured to produce sound waves for transmission through the edible substance to a user's mouth, from which they are conducted by teeth and bones to the user's ears to be perceived as sound. The signal source may produce sound waves directly, or it may do so with the assistance of a transducer. The invention provides for the construction of a nearly limitless number of novel amusement devices that simultaneously combine appeal to taste and sound.

Amusement devices delight and entertain by appealing to the senses in novel and unexpected ways. For example, a figure may spring out of a jack-in-the-box at the end of a song, providing a visual surprise after a period of auditory stimulation. Alternatively, an aerial fireworks display may conclude with a loud bang, providing an auditory surprise after a period of visual stimulation.
Although novelty is fundamental to amusement devices, generating novelty is difficult because humans perceive their environment through a limited number of senses, namely sight, hearing, taste, smell, and touch. Yet, a successful amusement device should employ a novel combination of these senses, and it should appeal to that combination in a novel way.
Amusement devices most commonly appeal to sight and hearing, as with the jack-in-the-box and fireworks. Amusement devices less commonly appeal to other senses, such as taste. The relatively few amusement devices relating to edible substances primarily have combined appeal to taste with appeal to sight and/or touch. For example, a few patents have disclosed lollipop holders that cause a lollipop to jiggle, wobble, or spin. These devices combine the taste of the lollipop with the amusing sight and feel of a moving lollipop. Others have developed various mechanical or electrical candy dispensers.
Even less common are amusement devices that combine appeal to taste with appeal to hearing. Nevertheless, one patent has disclosed an amusement device that simultaneously appeals to taste, hearing, and sight. In this device, a lollipop holder plays preprogrammed sounds using a standard speaker integrated into the holder. The lollipop holder also flashes pulses of light that are synchronized with the sounds.
Despite their novelty in combining appeal to taste with appeal to other senses, each of the amusement devices described above has significant shortcomings. For example, although these devices appeal to a variety of senses, they generally do so in simple and repetitive ways, such as spinning a lollipop or dispensing a piece of candy. Yet, an amusement device designed to appeal to a variety of senses should offer complex stimulation, not mindless repetition. More importantly, each of the devices described above appeals to the senses in very conventional ways. For example, the device that simultaneously appeals to taste, hearing, and sight generates sound using a conventional speaker and transmits that sound to the ears through the air. Yet, for greatest novelty, an amusement device should appeal to a given sense in an unexpected or even startling way, such as with sound waves that are not transmitted through the air.
Recently, a mechanism for transmitting sound to the ears that bypasses the air has been determined. Through this mechanism, sound waves are transmitted directly to the ears, without traveling through air, by conduction through an object to the mouth, from which the sound waves travel through the teeth and bones to the ears to be perceived as sound. This process is termed denta-mandibular conduction. Several devices have been designed based on this principle, including a teeth-held head tilt alarm and an underwater communication device. Significantly, none of these devices is directed at amusement. More significantly, none combines appeal to hearing with appeal to taste in the construction of an amusement device or method.

Sound-transmitting amusement device and method