Patent application number | Description | Published |
20100181985 | Regulator Circuit and RFID Tag Including the Same - One object of the present invention is to provide a regulator circuit with an improved noise margin. In a regulator circuit including a bias circuit generating a reference voltage on the basis of the potential difference between a first power supply terminal and a second power supply terminal, and a voltage regulator outputting a potential to an output terminal on the basis of a reference potential input from the bias circuit, a bypass capacitor is provided between a power supply terminal and a node to which a gate of a transistor included in the bias circuit is connected. | 07-22-2010 |
20110063803 | Semiconductor Device - The problem of damage on an antenna or a circuit (electrostatic breakdown) due to discharge of electric charge accumulated in an insulator is solved; and the problem of NAKANUKE failure is solved. A pair of conductive layers, a pair of insulators provided between the pair of conductive layers, and a chip which is provided between the pair of insulators and includes an antenna, an analog circuit, and a digital circuit are provided, in which an opening is provided for at least one of the pair of conductive layers, and the opening is provided at a position which overlaps at least the analog circuit. | 03-17-2011 |
20110121911 | MODULATION CIRCUIT AND SEMICONDUCTOR DEVICE INCLUDING THE SAME - A modulation circuit includes a load and a transistor serving as a switch. The transistor has an oxide semiconductor layer in which hydrogen concentration is 5×10 | 05-26-2011 |
20110122673 | SEMICONDUCTOR DEVICE INCLUDING MEMORY CELL - A nonvolatile memory includes a memory cell including a first transistor and a second transistor. The first transistor includes a first channel, a first gate electrode, a first source electrode, and a first drain electrode. The second transistor includes a second channel made of oxide semiconductor material, a second gate electrode, a second source electrode, and a second drain electrode. One of the second source electrode and the second drain electrode is electrically connected to the first gate electrode. Data writing in the memory cell is done by raising the potential of a node between one of the second source electrode and the second drain electrode and the first gate electrode. Data erasure in the memory cell is done by irradiating the second channel with ultraviolet light and lowering the potential of the node. | 05-26-2011 |
20110187435 | SEMICONDUCTOR DEVICE - To prevent damage on an element even when a voltage high enough to break the element is input. A semiconductor device of the invention operates with a first voltage and includes a protection circuit which changes the value of the first voltage when the absolute value of the first voltage is higher than a reference value. The protection circuit includes: a control signal generation circuit generating a second voltage based on the first voltage and outputting the generated second voltage; and a voltage control circuit. The voltage control circuit includes a transistor which has a source, a drain, and a gate, and which is turned on or off depending on the second voltage input to the gate and thus controls whether the value of the first voltage is changed based on the amount of current flowing between the source and the drain. The transistor also includes an oxide semiconductor layer. | 08-04-2011 |
20110216566 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - In a rectifier circuit, by using a transistor whose off-state current is small as a so-called diode-connected MOS transistor included in the rectifier circuit, breakdown which is caused when a reverse bias is applied is prevented. Thus, an object is to provide a rectifier circuit whose reliability is increased and rectification efficiency is improved. A gate and a drain of a transistor are both connected to a terminal of the rectifier circuit to which an AC signal is input. In the transistor, an oxide semiconductor is used for a channel formation region and the off-state current at room temperature is less than or equal to 10 | 09-08-2011 |
20110254095 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to reduce the number of manufacturing steps of a semiconductor device, to improve yield of a semiconductor device, or to reduce manufacturing cost of a semiconductor device. One embodiment of the present invention relates to a semiconductor device and a method for manufacturing the semiconductor device. The semiconductor device includes, over a substrate, a first transistor having a single crystal semiconductor layer in a channel formation region, a second transistor that is isolated from the first transistor with an insulating layer positioned therebetween and has an oxide semiconductor layer in a channel formation region, and a diode having a single crystal semiconductor layer and a oxide semiconductor layer. | 10-20-2011 |
20110279144 | METHOD FOR EVALUATING SEMICONDUCTOR DEVICE - To provide a simple method for evaluating reliability of a transistor, a simple test which correlates with a bias-temperature stress test (BT test) is performed instead of the BT test. Specifically, a gate current value is measured in the state where a voltage lower than the threshold voltage of an n-channel transistor whose channel region includes an oxide semiconductor is applied between a gate and a source of the transistor and a potential applied to a drain is higher than a potential applied to the gate. The evaluation of the gate current value can be simply performed compared to the case where the BT test is performed; for example, it takes short time to measure the gate current value. That is, reliability of a semiconductor device including the transistor can be easily evaluated. | 11-17-2011 |
20110286256 | SEMICONDUCTOR DEVICE AND METHOD FOR DRIVING SEMICONDUCTOR DEVICE - A semiconductor device with a reduced area and capable of higher integration and larger storage capacity is provided. A multi-valued memory cell including a reading transistor which includes a back gate electrode and a writing transistor is used. Data is written by turning on the writing transistor so that a potential according to the data is supplied to a node where one of a source electrode and a drain electrode of the writing transistor and a gate electrode of the reading transistor are electrically connected to each other, and then turning off the writing transistor and holding a predetermined potential in the node. Data is read by supplying a reading control potential to a control signal line connected to one of a source electrode and a drain electrode of the reading transistor, and then detecting potential change of a reading signal line. | 11-24-2011 |
20110286290 | DRIVING METHOD OF SEMICONDUCTOR DEVICE - A period (inverted period) in which a high negative potential is applied to a gate of the transistor is provided between a writing period and a retention period. In the inverted period, supply of positive electric charge from the drain of the transistor to the oxide semiconductor layer is promoted. Thus, accumulation of positive electric charge in the oxide semiconductor layer or at the interface between the oxide semiconductor layer and a gate insulating film can converge in a short time. Therefore, it is possible to suppress a decrease in the positive electric charge in the node electrically connected to the drain of the transistor in the retention period after the inverted period. That is, the temporal change of data stored in the semiconductor device can be suppressed. | 11-24-2011 |
20110303953 | GAS SENSOR AND METHOD FOR MANUFACTURING THE GAS SENSOR - It is an object to provide a gas sensor which is formed by a simple manufacturing process. Another object is to provide a gas sensor whose manufacturing cost is reduced. A transistor which includes an oxide semiconductor layer in contact with a gas and which serves as a detector element of a gas sensor, and a transistor which includes an oxide semiconductor layer in contact with a film having a gas barrier property and which forms a detection circuit are formed over one substrate by the same process, whereby a gas sensor using these transistors may be formed. | 12-15-2011 |
20110309689 | ELECTRIC POWER TRANSMITTING DEVICE, ELECTRIC POWER RECEIVING DEVICE, AND POWER SUPPLY METHOD USING ELECTRIC POWER TRANSMITTING AND RECEIVING DEVICES - In electric power supply through wireless signals, electric power is supplied efficiently, even when distance fluctuation is caused between an electric power transmitting device and an electric power receiving device. Even when distance fluctuation is caused between the electric power transmitting device for supplying electric power with the use of wireless signals and the electric power receiving device for receiving electric power supplied from the electric power transmitting device, the Q value of the electric power transmitting device is adjusted to optimize the transmission efficiency. The impedance of a resonance circuit of the electric power transmitting device is fluctuated at a constant frequency, the resulting reflected wave is detected as a response signal by the electric power transmitting device, and the Q value of the electric power transmitting device is adjusted to optimize the transmission efficiency. | 12-22-2011 |
20110310381 | PHOTOSENSOR, SEMICONDUCTOR DEVICE INCLUDING PHOTOSENSOR, AND LIGHT MEASUREMENT METHOD USING PHOTOSENSOR - An object is to provide a photosensor utilizing an oxide semiconductor in which a refreshing operation is unnecessary, a semiconductor device provided with the photosensor, and a light measurement method utilizing the photosensor. It is found that a constant gate current can be obtained by applying a gate voltage in a pulsed manner to a transistor including a channel formed using an oxide semiconductor, and this is applied to a photosensor. Since a refreshing operation of the photosensor is unnecessary, it is possible to measure the illuminance of light with small power consumption through a high-speed and easy measurement procedure. A transistor utilizing an oxide semiconductor having a relatively high mobility, a small S value, and a small off-state current can form a photosensor; therefore, a multifunction semiconductor device can be obtained through a small number of steps. | 12-22-2011 |
20110317500 | SEMICONDUCTOR DEVICE AND METHOD FOR DRIVING THE SAME - Disclosed is a semiconductor device having a memory cell which comprises a transistor having a control gate and a storage gate. The storage gate comprises an oxide semiconductor and is able to be a conductor and an insulator depending on the potential of the storage gate and the potential of the control gate. Data is written by setting the potential of the control gate to allow the storage gate to be a conductor, supplying a potential of data to be stored to the storage gate, and setting the potential of the control gate to allow the storage gate to be an insulator. Data is read by supplying a potential for reading to a read signal line connected to one of a source and a drain of the transistor and detecting the change in potential of a bit line connected to the other of the source and the drain. | 12-29-2011 |
20120025611 | WIRELESS POWER FEEDING SYSTEM AND WIRELESS POWER FEEDING METHOD - A power feeding device which wirelessly supplies power to a power receiver receives a position and resonant frequency detection signal from the power receiver, detects the position and the resonant frequency of the power receiver, and controls the frequency of a power signal to be transmitted to the power receiver on the basis of the information. As the power signal for power transmission, two signals having different frequencies, which are generated using a mixer by mixing a base carrier (a first signal) with a conversion carrier (a second signal) generated on the basis of the resonant frequency, are used. | 02-02-2012 |
20120025627 | WIRELESS POWER FEEDING SYSTEM AND WIRELESS POWER FEEDING METHOD - An object is to provide a power feeding system and a power feeding method which are more convenient for a power feeding user at the power receiving end. An object is to provide a power feeding system and a power feeding method which also allow a power feeding provider (a company) which feeds power (at the power transmitting end) to supply power without waste. A power feeding device which wirelessly supplies power to a power receiver detects the position and the resonant frequency of the power receiver to be supplied with power, and controls the frequency of a power signal to be transmitted to the power receiver on the basis of the information. | 02-02-2012 |
20120025631 | WIRELESS POWER FEEDING SYSTEM AND WIRELESS POWER FEEDING METHOD - An object is to provide a power feeding system and a power feeding method which are more convenient for a power feeding user at the power receiving end, without causing increases in complexity and size of devices. An object is to provide a power feeding system and a power feeding method which also allow a power feeding provider (a company) which feeds power (at the power transmitting end) to supply power without waste. A power feeding device which wirelessly supplies power to a power receiver detects the position and the resonant frequency of the power receiver by receiving a position and resonant frequency detection signal using a plurality of sub-carriers having different frequencies from the power receiver, and controls the frequency of a power signal to be transmitted to the power receiver on the basis of the information. An efficient power feeding service can be offered by transmitting a power signal to the power receiver at an optimum frequency for high power transmission efficiency. | 02-02-2012 |
20120026787 | SEMICONDUCTOR DEVICE AND METHOD FOR DRIVING THE SAME - A transistor includes first and second control gates, and a storage gate. The storage gate is made to be a conductor, supplied with a specific potential, and then made to be an insulator, thereby holding the potential. Data is written by making the storage gate a conductor, supplying a potential of data to be stored, and making the storage gate an insulator. Data is read by making the storage gate an insulator, supplying a potential to a read signal line connected to one of a source and a drain of the transistor, supplying a potential for reading data to the first control gate, and then detecting a potential of a bit line connected to the other of the source and the drain. | 02-02-2012 |
20120032785 | SEMICONDUCTOR DEVICE - A protection circuit is designed to operate when the level of a DC power supply potential which is generated in a rectifier circuit is equal to or greater than a predetermined level (a reference level), so as to decrease the level of the generated DC power supply potential. On the other hand, the protection circuit is designed not to operate when the DC power supply potential which is generated in the rectifier circuit is equal to or less than the predetermined level (the reference level), so as to use the generated DC power supply potential without change. A transistor of the protection circuit includes an oxide semiconductor layer, which enables a reduction in the off-state current of the transistor and a reduction in power consumption of the protection circuit. | 02-09-2012 |
20120062039 | POWER FEEDING DEVICE, WIRELESS POWER FEEDING SYSTEM USING THE SAME AND WIRELESS POWER FEEDING METHOD - An object is to provide a power feeding device, a power feeding system, and a power feeding method which are more convenient for a power feeding user at the power receiving end. The power feeding device includes a means of controlling a frequency of a power signal transmitted to a power receiver, based on a proportion of signals, among power signals output to an antenna circuit, that return from the power receiver to the antenna circuit without feeding power to the power receiver. | 03-15-2012 |
20120062174 | POWER RECEIVING DEVICE AND WIRELESS POWER FEED SYSTEM - An electric field coupling type wireless power feed system including a power transmitting device and a power receiving device which is unlikely to be affected by a noise and which has a reduced size is provided. A capacitive coupling type wireless power feed system includes a power receiving device including a first electrode using an oxide semiconductor film, and a battery and a power transmitting device including a second electrode, wherein the battery is charged by a voltage generated based on an electric field generated between the first electrode and the second electrode. The charging of the battery may be stopped by applying a positive direct-current voltage from a charge control circuit to the first electrode. | 03-15-2012 |
20120063204 | SEMICONDUCTOR DEVICE - One object is to provide a novel semiconductor device which can hold stored data even when not powered and which has an unlimited number of writing operations. Another object is to reduce a circuit size and to improve reliability of writing and reading of data. When a memory cell using a transistor including an oxide semiconductor layer is subjected to the verification operation and reading of data, a dual-gate transistor showing different threshold voltages is used as a resistor; thus, stable verification operation and reading operation can be performed by only a reference potential circuit. | 03-15-2012 |
20120099368 | METHOD FOR DRIVING SEMICONDUCTOR DEVICE - It is an object to obtain a memory element (DRAM) storing multilevel data easily. The amount of charge accumulated in a capacitor of a memory element (DRAM) is controlled by changing the potential of a wiring (a bit line), which is used for writing data to the memory element (DRAM), in a period in which a transistor included in the memory element (DRAM) is on. Thus, multilevel data stored in the memory element (DRAM) can be obtained without a complex configuration of a semiconductor device including the memory element (DRAM). | 04-26-2012 |
20120105130 | RECEIVING CIRCUIT, LSI CHIP, AND STORAGE MEDIUM - A receiving circuit with a simple circuit structure for performing wireless communication utilizing electromagnetic induction is provided. An LSI chip and a storage medium where wireless communication utilizing electromagnetic induction is performed and the circuit scale and circuit size can be reduced are provided. The following receiving circuit may be used: a parallel circuit where two diode elements whose directions are opposite are connected in parallel is used, one end of the parallel circuit is connected to the other end of a coil whose one end is connected to a ground potential line, and a capacitor is connected in series with the other end of the parallel circuit. A transistor whose leakage current is markedly reduced may be used as a diode in the receiving circuit. Such a receiving circuit may be used in an LSI chip or a storage medium. | 05-03-2012 |
20120126863 | ELECTRONIC CIRCUIT, SEMICONDUCTOR DEVICE, AND ELECTRONIC DEVICE - The electronic circuit includes a first comparator and a second comparator in which an induced electromotive force of a coil are compared with each of a first reference potential and a second reference potential and which output a pulse signal in accordance with conditions; the first signal processing circuit which outputs a first receiving rectangular wave signal and a first error signal in accordance with conditions of the pulse signal output from the first comparator and in which data held in accordance with conditions of pulse signal output from the second comparator is reset; and the second signal processing circuit which outputs a second receiving rectangular wave signal and a second error signal in accordance with conditions of the pulse signal output from the second comparator and in which data held in accordance with conditions of pulse signal output from the first comparator is reset. | 05-24-2012 |
20120133212 | POWER TRANSMISSION DEVICE AND WIRELESS POWER TRANSMISSION SYSTEM INCLUDING THE SAME - Not a structure in which a resonance frequency of a power transmission device is set after a resonance frequency of a power receiving device is directly measured but a structure in which the resonance frequencies of the power receiving device and the power transmission device are estimated after reflection of an electromagnetic field for transmitting electric power to the power receiving device is monitored by the power transmission device is employed. After a capacitance value of a variable capacitor in a resonance coil of the power receiving device is once set to 0, an S11 parameter is detected while a frequency of an electromagnetic wave is changed, and the resonance frequency of the power transmission device is estimated on the basis of the S11 parameter. | 05-31-2012 |
20120153276 | SEMICONDUCTOR DEVICE - An object is to provide a semiconductor memory device capable of shortening writing operation by concurrently determining potentials of memory cells on one word line. A plurality of transistors having switching characteristics are connected to one potential control circuit, whereby writing potentials are determined concurrently. A potential continues to be changed (raised or decreased) stepwise, a desired potential is determined while changing the potential, and whether data resulted from reading with respect to written data is correct or not is continuously checked, so that high-precision writing operation and high-precision reading operation can be achieved. In addition, favorable switching characteristics and holding characteristics of a transistor including an oxide semiconductor are utilized. | 06-21-2012 |
20120161529 | POWER FEEDING DEVICE, POWER RECEIVING DEVICE, AND WIRELESS POWER FEED SYSTEM - A wireless power feed system with high transfer efficiency of electric power is disclosed. The wireless power feed system includes a power feeding device and a power receiving device, wherein the power feeding device includes a first electromagnetic coupling coil that is connected to an AC power source via a directional coupler; a first resonant coil; a switch connected to the opposite ends of the first resonant coil; a control circuit which conducts switching on/off of the switch based on a parameter of an amplitude of a reflective wave detected by the directional coupler; and an analog-digital converter provided between the first electromagnetic coupling coil and the control circuit; and the power receiving device includes a second resonant coil; and a second electromagnetic coupling coil, and wherein the first electromagnetic coupling coil is provided between the first resonant coil and the second resonant. | 06-28-2012 |
20120161536 | WIRELESS POWER FEEDING SYSTEM - A wireless power feeding system includes a power feeding device and a power receiving device. The power feeding device includes a first resonance coil connected to a high-frequency power source through a first matching circuit, and a first control circuit connected to the first matching circuit and a first transmitter-receiver circuit. The power receiving device includes a second resonance coil configured to be in magnetic resonance with the first resonance coil, and a second control circuit connected to a load, a second matching circuit, and a second transmitter-receiver circuit. | 06-28-2012 |
20120161537 | POWER FEEDING DEVICE AND CONTACTLESS POWER FEEDING SYSTEM PROVIDED WITH POWER FEEDING DEVICE - A power feeding device utilizing an electromagnetic resonance coupling method and a contactless power feeding system can be provided. A coupling coefficient of electromagnetic induction coupling in the power feeding device and/or the inside of a power receiving device is optimized to improve electric power transmission efficiency of a resonance frequency regardless of positions of the power feeding device and the power receiving device. Provided is a power feeding device or a contactless power feeding system in which an S11 parameter which is a reflection component of electric power output from a high-frequency power source of the power feeding device is monitored, and one or both of positions of a transmission coil and a first resonant coil in the power feeding device and positions of a reception coil and a second resonant coil in a power receiving device are changed to adjust a coupling coefficient of electromagnetic induction coupling. | 06-28-2012 |
20120187771 | POWER FEEDING DEVICE AND WIRELESS POWER FEEDING SYSTEM - A resonant power feeding system that can provide high power transmission efficiency between a power feeding device and a power reception device without dynamically controlling the oscillation frequency in accordance with the distance between the power feeding device and the power reception device. High power transmission efficiency between the power feeding device and the power reception device is obtained by addition of a structure for adjusting the matching condition to both the power reception device and the power feeding device. Specifically, a transmission-reception circuit and a matching circuit are provided in both the power reception device and the power feeding device, and wireless signals for adjusting the matching circuit are transmitted and received through a resonant coil. Thus, the power feeding device can efficiently supply power to the power reception device without adjusting the oscillation frequency. | 07-26-2012 |
20120193994 | POWER RECEIVING DEVICE, POWER SUPPLY SYSTEM, AND METHOD FOR SUPPLYING POWER - A power transmitting system in which power can be successfully supplied by magnetic resonance from a power transmitting device to a selected power receiving device among a plurality of power receiving devices. The power receiving device includes a variable unit which can change the self resonant frequency of a resonance coil in accordance with an invalidation signal transmitted from the power transmitting device. Thus, even in the case where the plurality of power receiving devices are provided for one power transmitting device, the self resonant frequencies of the resonance coils included in the power receiving devices which are not to be supplied with power are changed to avoid resonance with the power transmitting device. Consequently, power can be successfully and selectively supplied to the power receiving devices to be supplied with power. | 08-02-2012 |
20120223592 | METHOD FOR DRIVING POWER SUPPLY SYSTEM - The frequency of high-frequency voltage which is output by a variable high frequency power source included in a power transmitting device is controlled in accordance with the value of electric power received by a power receiving device. That is to say, the frequency of the high-frequency voltage is controlled in accordance with data directly relating to power supply. Thus, electric power is accurately supplied with high transmission efficiency in the power supply system. | 09-06-2012 |
20120223593 | POWER RECEIVING DEVICE AND WIRELESS POWER SUPPLY SYSTEM - A power receiving device used for wirelessly supplying power from a power supply device using electromagnetic resonance to an electronic apparatus which receives power by electromagnetic induction is provided. The power receiving device includes a first antenna coupled with an antenna of the power supply device by electromagnetic resonance, a second antenna coupled with the first antenna by electromagnetic induction, a load, a switching circuit, a control circuit, and an input device. A signal for selecting switching of the switching circuit is generated in the control circuit in response to a command from the input device. A connection between the second antenna and the load is controlled by switching of the switching circuit in response to the signal. | 09-06-2012 |
20120228956 | POWER-RECEIVING DEVICE, WIRELESS POWER-FEEDING SYSTEM INCLUDING POWER-RECEIVING DEVICE, AND WIRELESS COMMUNICATION SYSTEM INCLUDING POWER-RECEIVING DEVICE - When a portable electronic appliance is provided with two systems, a wireless power-feeding system and a wireless communication system, each system requires two power-receiving devices, a coil and an antenna, leading to a problem of increased electronic appliance size and cost. Wireless power feeding employs the resonance method and uses a resonance coil using the resonance method and a power-receiving coil that receives power from the resonance coil. At least one of the resonance coil and the power-receiving coil can also be used as an antenna for wireless communication. Thus, a power-receiving device that can be used for two systems, wireless power feeding and wireless communication, can be provided. | 09-13-2012 |
20120262432 | LIGHT-EMITTING DEVICE, DISPLAY DEVICE, LIGHT-EMITTING SYSTEM, AND DISPLAY SYSTEM - A highly reliable light-emitting device is provided. A lighting device or a display device with a high level of safety and without an exposed electrode is provided. A lighting device or a display device with high layout flexibility is provided. A light-emitting system or a display system to which the light-emitting device or the display device can be applied is provided. An electrode for receiving power and a rectifier circuit are provided in a light-emitting device including an organic EL element and arranged so as to face an electrode for transmitting power, whereby alternating-current power is supplied to the light-emitting device. The alternating-current power is rectified by the rectifier circuit to direct-current power so that the organic EL element in the light-emitting device is driven. | 10-18-2012 |
20120319646 | WIRELESS POWER FEEDING SYSTEM - An object is to provide a wireless power feeding system using the resonance method, which can increase power transmission efficiency. The wireless power feeding system includes a power transmission coil electrically connected to a high-frequency power supply, a power transmission resonance coil for transmitting power by electromagnetic induction with the power transmission coil, a power reception resonance coil for exciting high-frequency power by magnetic resonance, a load coil for exciting high-frequency power by electromagnetic induction with the power reception resonance coil, a load, and a variable element. The load includes a microprocessor for controlling the impedance of the load, a battery charger, and a battery. The battery charger is configured to charge the battery with the high-frequency power excited by the load coil. | 12-20-2012 |
20130002036 | CONTACTLESS POWER SUPPLY DEVICE - A contactless power supply device capable of appropriately supplying power to a plurality of power supplied devices at the same time without contact is provided. A contactless power supply device capable of supplying power without contact even when the positional flexibility of a plurality of power supplied devices is increased is provided. The contactless power supply device determines a power supply condition that power can be most appropriately supplied to a plurality of power supplied devices that need power supply in a short time. The contactless power supply device can appropriately supply power to a plurality of power supplied devices at the same time without contact by controlling the resonant capacitance of a power transmission coil in an optimized power supply condition. The positional flexibility of the plurality of power supplied devices with respect to the contactless power supply device can be increased. | 01-03-2013 |
20130069585 | CONTACTLESS POWER FEEDING SYSTEM - The contactless power feeding system includes a power transmitting device including an AC power source, a power transmitting element transmitting an AC power and a first microprocessor generating a transmission signal, and a power receiving device including a power receiving element receiving the AC power, a rectifier circuit, a smoothing circuit, a voltage conversion circuit, a second microprocessor generating a response signal in accordance with the transmission signal, a charge control circuit changing a charging rate for a power storage device in accordance with the response signal and the power storage device whose charging is controlled by the charge control circuit. Then, a resistance value of the power storage device changes, an impedance changes, and a modulation signal is generated. The generated modulation signal is transmitted from the power receiving device to the power transmitting device and is processed by the first microprocessor. | 03-21-2013 |
20130082648 | POWER RECEIVING DEVICE AND CONTACTLESS POWER FEEDING SYSTEM - A power receiving device includes a resonant coil, an electromagnetic coupling coil, a rectifier circuit, a smoothing circuit, a voltage converter circuit which converts a voltage value of DC power into another voltage value, a control circuit which obtains voltage and current values of the DC power input to the voltage converter circuit, calculates an impedance from the obtained voltage and current values, and generates a pulse width modulation signal for controlling an output voltage and an output current of the voltage converter circuit, and a load to which the output voltage and the output current of the voltage converter circuit are input. The duty ratio of the pulse width modulation signal is determined so that the impedance calculated by the control circuit becomes close to an impedance for the maximum efficiency in transferring the AC power. The power receiving device is included in a contactless power feeding system. | 04-04-2013 |
20130119776 | POWER RECEIVING DEVICE, POWER TRANSMISSION DEVICE, AND POWER FEEDING SYSTEM - A novel power receiving device and a novel power transmission device are provided. Power feeding and communication are performed using a magnetic resonance method. Specifically, in one embodiment of the present invention, power feeding is performed by generating a second high-frequency voltage based on a first high-frequency voltage induced in a resonant coil and communication is performed by modulating amplitude of the first high-frequency voltage induced in the resonant coil. Thus, it is possible to perform communication and power feeding based on data obtained by the communication in pseudo-parallel. | 05-16-2013 |
20130147281 | CONTACTLESS POWER FEEDING SYSTEM - A contactless power feeding system includes a power transmitting device and a power receiving device. The power transmitting device includes a first AC power source configured to generate an AC power with a first frequency, a second AC power source configured to generate an AC power with a second frequency which is different from the first frequency, a first electromagnetic induction coil, and a first resonant coil. The power receiving device includes a second resonant coil, a second electromagnetic induction coil, and a power storage unit. Power is wirelessly supplied to the power storage unit at the second frequency by a magnetic resonance phenomenon which occurs between the first resonant coil and the second resonant coil. | 06-13-2013 |
20130154556 | DC-DC CONVERTER, POWER RECEIVING DEVICE, AND POWER FEEDING SYSTEM - A circuit capable of keeping input impedance constant is provided. Further, a circuit which can contribute to improvement in power feeding efficiency in power feeding by a magnetic resonance method is provided. A voltage (a former voltage) proportional to a direct-current voltage input to a DC-DC converter from the outside and a voltage (a latter voltage) proportional to a current input from the outside are detected, and the ratio of the former voltage and the latter voltage are held constant. Accordingly, input impedance can be kept constant. Further, impedance conversion is performed in the DC-DC converter. Thus, even when the battery in which power feeding is performed exists on an output side of the DC-DC converter, input impedance can be kept constant. Consequently, power can be supplied to a power receiving device including the DC-DC converter and the battery with high power feeding efficiency by a magnetic resonance method. | 06-20-2013 |
20130162203 | POWER RECEIVING DEVICE AND WIRELESS POWER SUPPLY SYSTEM - Provided is a power receiving device in which supply of power from a power supply device can be stopped while a reduction in Q-value is suppressed. The power receiving device includes a first antenna which forms resonant coupling with an antenna of the power supply device; a second antenna which forms electromagnetic induction coupling with the first antenna; a rectifier circuit including a plurality of switches and performing a first operation or a second operation depending on whether the plurality of switches is ON or OFF, the first operation being an operation in which voltage applied from the second antenna is rectified to be outputted, and the second operation being an operation in which a pair of power supply points is short-circuited; a load to which the voltage is applied; and a control circuit which generates a signal for selecting ON or OFF of the plurality of switches. | 06-27-2013 |
20130241301 | POWER TRANSMISSION DEVICE AND POWER FEEDING SYSTEM - There is provided a power transmission device which includes an antenna receiving a reflected power from a power receiving device, a power detection unit detecting a value of the reflected power received by the antenna, a control circuit determining a power adjustment value in accordance with the value of the reflected power, a power adjustment unit to which the reflected power whose value is detected is input and which adjusts impedance in accordance with the power adjustment value determined by the control circuit, and a demodulation circuit to which the reflected power having the power adjustment value determined by the control circuit is input via the power adjustment unit having the adjusted impedance, and relates to a power feeding system including the power transmission device. | 09-19-2013 |
20130249309 | POWER RECEIVING DEVICE AND POWER FEEDING SYSTEM - A power receiving device and a power feeding system which are capable of performing communication and power feeding at the same time are provided. Further, a power receiving device and a power feeding system which are capable of stably performing communication during power feeding are provided. One embodiment of the present invention relates to a power receiving device which includes an antenna for communication and power feeding that receives AC power, a rectifier circuit that rectifies the received AC power including the modulation signal into DC power, a smoothing circuit that smoothes the resulting DC power, a power storage device that stores the smoothed DC power, a communication control unit that analyzes the modulation signal included in the AC power, and a transformer that is positioned between the antenna and the rectifier circuit and changes a reference potential of the AC power, and a power feeding device. | 09-26-2013 |
20130285464 | POWER FEEDING SYSTEM AND POWER FEEDING METHOD - To provide a power feeding system and the like with which charging can be performed without a decrease in the power supply efficiency. To provide a power feeding system and the like with which can offer a power feeding service which is efficient to both a power feeding user and a power feeding provider. The power transmission state in each of power transmitting portions is monitored, the power transmitting portion having the highest power transmission efficiency is selected based on positional advantage, and the power transmitting resonance coil included in the selected power transmitting portion is kept at a first resonance frequency, whereby power transmission continues. The resonance frequency of the power transmitting resonance coil included in the non-selected power transmitting portion (the number of the non-selected power transmitting portions may be plural) is set to a second resonance frequency, whereby power transmission is stopped. | 10-31-2013 |
20130335056 | Regulator Circuit and RFID Tag Including the Same - One object of the present invention is to provide a regulator circuit with an improved noise margin. In a regulator circuit including a bias circuit generating a reference voltage on the basis of the potential difference between a first power supply terminal and a second power supply terminal, and a voltage regulator outputting a potential to an output terminal on the basis of a reference potential input from the bias circuit, a bypass capacitor is provided between a power supply terminal and a node to which a gate of a transistor included in the bias circuit is connected. | 12-19-2013 |
20140003146 | SIGNAL PROCESSING CIRCUIT | 01-02-2014 |
20140071768 | SEMICONDUCTOR DEVICE AND METHOD FOR DRIVING SEMICONDUCTOR DEVICE - A semiconductor device with a reduced area and capable of higher integration and larger storage capacity is provided. A multi-valued memory cell including a reading transistor which includes a back gate electrode and a writing transistor is used. Data is written by turning on the writing transistor so that a potential according to the data is supplied to a node where one of a source electrode and a drain electrode of the writing transistor and a gate electrode of the reading transistor are electrically connected to each other, and then turning off the writing transistor and holding a predetermined potential in the node. Data is read by supplying a reading control potential to a control signal line connected to one of a source electrode and a drain electrode of the reading transistor, and then detecting potential change of a reading signal line. | 03-13-2014 |
20140093992 | GAS SENSOR AND METHOD FOR MANUFACTURING THE GAS SENSOR - It is an object to provide a gas sensor which is formed by a simple manufacturing process. Another object is to provide a gas sensor whose manufacturing cost is reduced. A transistor which includes an oxide semiconductor layer in contact with a gas and which serves as a detector element of a gas sensor, and a transistor which includes an oxide semiconductor layer in contact with a film having a gas barrier property and which forms a detection circuit are formed over one substrate by the same process, whereby a gas sensor using these transistors may be formed. | 04-03-2014 |
20140124778 | SEMICONDUCTOR DEVICE AND METHOD FOR DRIVING THE SAME - Disclosed is a semiconductor device having a memory cell which comprises a transistor having a control gate and a storage gate. The storage gate comprises an oxide semiconductor and is able to be a conductor and an insulator depending on the potential of the storage gate and the potential of the control gate. Data is written by setting the potential of the control gate to allow the storage gate to be a conductor, supplying a potential of data to be stored to the storage gate, and setting the potential of the control gate to allow the storage gate to be an insulator. Data is read by supplying a potential for reading to a read signal line connected to one of a source and a drain of the transistor and detecting the change in potential of a bit line connected to the other of the source and the drain. | 05-08-2014 |
20140131705 | PHOTOSENSOR, SEMICONDUCTOR DEVICE INCLUDING PHOTOSENSOR, AND LIGHT MEASUREMENT METHOD USING PHOTOSENSOR - An object is to provide a photosensor utilizing an oxide semiconductor in which a refreshing operation is unnecessary, a semiconductor device provided with the photosensor, and a light measurement method utilizing the photosensor. It is found that a constant gate current can be obtained by applying a gate voltage in a pulsed manner to a transistor including a channel formed using an oxide semiconductor, and this is applied to a photosensor. Since a refreshing operation of the photosensor is unnecessary, it is possible to measure the illuminance of light with small power consumption through a high-speed and easy measurement procedure. A transistor utilizing an oxide semiconductor having a relatively high mobility, a small S value, and a small off-state current can form a photosensor; therefore, a multifunction semiconductor device can be obtained through a small number of steps. | 05-15-2014 |
20140347777 | SEMICONDUCTOR DEVICE - To prevent damage on an element even when a voltage high enough to break the element is input. A semiconductor device of the invention operates with a first voltage and includes a protection circuit which changes the value of the first voltage when the absolute value of the first voltage is higher than a reference value. The protection circuit includes: a control signal generation circuit generating a second voltage based on the first voltage and outputting the generated second voltage; and a voltage control circuit. The voltage control circuit includes a transistor which has a source, a drain, and a gate, and which is turned on or off depending on the second voltage input to the gate and thus controls whether the value of the first voltage is changed based on the amount of current flowing between the source and the drain. The transistor also includes an oxide semiconductor layer. | 11-27-2014 |
20140375263 | WIRELESS POWER FEEDING SYSTEM AND WIRELESS POWER FEEDING METHOD - An object is to provide a power feeding system and a power feeding method which are more convenient for a power feeding user at the power receiving end. An object is to provide a power feeding system and a power feeding method which also allow a power feeding provider (a company) which feeds power (at the power transmitting end) to supply power without waste. A power feeding device which wirelessly supplies power to a power receiver detects the position and the resonant frequency of the power receiver to be supplied with power, and controls the frequency of a power signal to be transmitted to the power receiver on the basis of the information. An efficient power feeding service can be offered by transmitting a power signal to the power receiver at an optimum frequency for high power transmission efficiency. | 12-25-2014 |