| Patent application number | Description | Published |
|---|
| 20080231617 | Display Device - To provide a display device in which reliability of a driver circuit can be improved by suppressing shift of the threshold voltage of a TFT. The minimum power supply voltage that is optimal for driving a transistor used in the driver circuit is found by actually changing voltage applied to a gate of the transistor. Specifically, voltage that is output from an output circuit included in the driver circuit when a value of power supply voltage applied to a shift register is changed is monitored. Then, a value of the power supply voltage is found such that a value of the voltage output from the output circuit satisfies a value enough to operate a pixel portion, and the driver circuit is operated using the power supply voltage. | 09-25-2008 |
| 20080246716 | Display Device - To provide a display device which can ensure high reliability of a driver circuit even when a threshold voltage of a TFT shifts. The display device includes a power supply control circuit which can apply a forward bias voltage or a reverse bias voltage to a gate of a transistor included in an output circuit, a monitor transistor which is formed to monitor the amount of change of a threshold voltage of the transistor included in the output circuit, and a threshold control circuit which controls the power supply control circuit so as to apply the reverse bias voltage to the gate of the transistor in order to compensate the threshold voltage of the transistor included in the output circuit. | 10-09-2008 |
| 20080246717 | Display Device - The display device includes an output circuit, a threshold control circuit which sequentially selects one of a forward bias voltage and a reverse bias voltage, and a power supply control circuit which applies one of the forward bias voltage and the reverse bias voltage which is selected to a gate of a transistor included in the output circuit. Time in which the reverse bias voltage is applied to the gate of the transistor is determined in accordance with time in which the forward bias voltage is applied to the gate of the transistor. | 10-09-2008 |
| 20080284710 | SEMICONDUCTOR DEVICE AND DISPLAY DEVICE - A single-crystal semiconductor layer is separated from a single-crystal semiconductor substrate and is fixed to an insulating substrate to form a TFT over the insulating substrate. Then, a driver circuit is formed using the TFT. The TFT has excellent current characteristics because an active layer is almost in a single-crystal state. Accordingly, a small thin display device with low power consumption can be manufactured. Further, a controller and a shift register which is included in a source driver are operated at the same power supply voltage. Thus, power consumption can be reduced. | 11-20-2008 |
| 20080284934 | LIQUID CRYSTAL DISPLAY DEVICE - To reduce the number of components such as IC chips so that decrease in size and thickness of a display module and an electronic device on which the display module is mounted is achieved. Further, to reduce the number of components such as IC chips so that an inexpensive display module and an electronic device on which the display module is mounted are provided. An electronic device or a display module includes two display panels. One of the display panels (i.e., a peripheral portion of a display region of the one of the display panels) is provided with circuits which are necessary for operating the display panels or circuits which are necessary for an electronic device in which the display panels are incorporated. Then, the display panels or the electronic device in which the display panels are incorporated are/is driven by the circuits incorporated in the display panels. | 11-20-2008 |
| 20090027083 | SEMICONDUCTOR DEVICE AND ELECTRONIC APPARATUS HAVING THE SAME - With an offset circuit including transistors of the same conductivity type, offset of an input signal is performed. Then, the input signal after the offset is supplied to a logic circuit including transistors of the same conductivity type as that of the offset circuit, thereby H and L levels of the input signal can be shifted at the same time. Further, since the offset circuit and the logic circuit are formed using the transistors of the same conductivity type, a display device can be manufactured at a low cost. | 01-29-2009 |
| 20090303219 | DISPLAY DEVICE, LIQUID CRYSTAL DISPLAY DEVICE AND ELECTRONIC DEVICE INCLUDING THE SAME - A liquid crystal display device includes a pixel having a first to nth (n is a natural number of 2 or more) subpixels and a circuit. To the circuit N (N is a natural number of 2 or more) wirings for supplying a digital signal with N bits and first to nth wiring groups having M (M is a natural number of 2 or more) wirings for supplying M different voltages are electrically connected. The liquid crystal display device has a function of converting the digital signal into n analog signals by using the M voltages supplied to the first to nth wiring groups and inputting the n analog signals to first to nth subpixels. The first to nth subpixels each include an electrode for driving a liquid crystal element. | 12-10-2009 |
| 20090310734 | DRIVER CIRCUIT, DISPLAY DEVICE, AND ELECTRONIC DEVICE - To suppress malfunctions in a shift register circuit. A shift register having a plurality of flip-flop circuits is provided. The flip-flop circuit includes a transistor | 12-17-2009 |
| 20100026619 | SHIFT REGISTER, SEMICONDUCTOR DEVICE, DISPLAY DEVICE, AND ELECTRONIC DEVICE - The invention provides a semiconductor device and a shift register, in which low noise is caused in a non-selection period and a transistor is not always on. First to fourth transistors are provided. One of a source and a drain of the first transistor is connected to a first wire, the other of the source and the drain thereof is connected to a gate electrode of the second transistor, and a gate electrode thereof is connected to a fifth wire. One of a source and a drain of the second transistor is connected to a third wire and the other of the source and the drain thereof is connected to a sixth wire. One of a source and a drain of the third transistor is connected to a second wire, the other of the source and the drain thereof is connected to the gate electrode of the second transistor, and a gate electrode thereof is connected to a fourth wire. One of a source and a drain of the fourth transistor is connected to the second wire, the other of the source and the drain thereof is connected to the sixth wire, and a gate electrode thereof is connected to the fourth wire. | 02-04-2010 |
| 20100084650 | DISPLAY DEVICE - A pixel portion and a driver circuit driving the pixel portion are formed over the same substrate. At least a part of the driver circuit is formed using an inverted staggered thin film transistor in which an oxide semiconductor layer is used and a channel protective layer is provided over the oxide semiconductor layer serving as a channel formation region which is overlapped with the gate electrode. The driver circuit as well as the pixel portion is provided over the same substrate to reduce manufacturing costs. | 04-08-2010 |
| 20100084651 | DISPLAY DEVICE - With an increase in the definition of a display device, the number of pixels is increased, and thus the numbers of gate lines and signal lines are increased. Due to the increase in the numbers of gate lines and signal lines, it is difficult to mount an IC chip having a driver circuit for driving the gate and signal lines by bonding or the like, which causes an increase in manufacturing costs. A pixel portion and a driver circuit for driving the pixel portion are formed over one substrate. At least a part of the driver circuit is formed using an inverted staggered thin film transistor in which an oxide semiconductor is used. The driver circuit as well as the pixel portion is provided over the same substrate, whereby manufacturing costs are reduced. | 04-08-2010 |
| 20100133533 | DISPLAY DEVICE - By applying an AC pulse to a gate of a transistor which easily deteriorates, a shift in threshold voltage of the transistor is suppressed. However, in a case where amorphous silicon is used for a semiconductor layer of a transistor, the occurrence of a shift in threshold voltage naturally becomes a problem for a transistor which constitutes a part of circuit that generates an AC pulse. A shift in threshold voltage of a transistor which easily deteriorates and a shift in threshold voltage of a turned-on transistor are suppressed by signal input to a gate electrode of the transistor which easily deteriorates through the turned-on transistor. In other words, a structure for applying an AC pulse to a gate electrode of a transistor which easily deteriorates through a transistor to a gate electrode of which a high potential (VDD) is applied, is included. | 06-03-2010 |
| 20100134396 | DISPLAY DEVICE AND ELECTRONIC DEVICE INCLUDING THE SAME - It is an object to decrease the number of transistors connected to a capacitor. In a structure, a capacitor and one transistor are included, one electrode of the capacitor is connected to a wiring, and the other electrode of the capacitor is connected to a gate of the transistor. Since a clock signal is input to the wiring, the clock signal is input to the gate of the transistor through the capacitor. Then, on/off of the transistor is controlled by a signal which synchronizes with the clock signal, so that a period when the transistor is on and a period when the transistor is off are repeated. In this manner, deterioration of the transistor can be suppressed. | 06-03-2010 |
| 20100134708 | SEMICONDUCTOR DEVICE AND ELECTRONIC APPARATUS HAVING THE SAME - With an offset circuit including transistors of the same conductivity type, offset of an input signal is performed. Then, the input signal after the offset is supplied to a logic circuit including transistors of the same conductivity type as that of the offset circuit, thereby H and L levels of the input signal can be shifted at the same time. Further, since the offset circuit and the logic circuit are formed using the transistors of the same conductivity type, a display device can be manufactured at a low cost. | 06-03-2010 |
| 20100182226 | Liquid Crystal Display Device and Electronic Device Including the Same - A driver circuit includes first to third transistors, a first circuit, and a second circuit. In the first transistor, a first terminal is electrically connected to a second wiring, a second terminal is electrically connected to a first wiring, and a gate is electrically connected to the second circuit and a first terminal of the third transistor. In the second transistor, a first terminal is electrically connected to the first wiring, a second terminal is electrically connected to a sixth wiring, a gate is electrically connected to the first circuit and a gate of the third transistor. A second terminal of the third transistor is electrically connected to the sixth wiring. The first circuit is electrically connected to a third wiring, a fourth wiring, a fifth wiring, and the sixth wiring. The second circuit is electrically connected to the first wiring, the second wiring, and the sixth wiring. | 07-22-2010 |
| 20100182306 | METHOD FOR DRIVING DISPLAY DEVICE - To suppress degradation of a transistor. A method for driving a liquid crystal display device has a first period and a second period. In the first period, a first transistor and a second transistor are alternately turned on and off repeatedly, and a third transistor and a fourth transistor are turned off. In the second period, the first transistor and the second transistor are turned off, and the third transistor and the fourth transistor are alternately turned on and off repeatedly. Accordingly, the time during which the transistor is on can be reduced, so that degradation of characteristics of the transistor can be suppressed. | 07-22-2010 |
| 20100245304 | Semiconductor Device - One of the objects is to improve display quality by reduction in malfunctions of a circuit. In a driver circuit formed using a plurality of pulse output circuits having first to third transistors and first to fourth signal lines, a first clock signal is supplied to the first signal line; a preceding stage signal is supplied to the second signal line; a second clock signal is supplied to the third signal line; an output signal is output from the fourth signal line. Duty ratios of the first clock signal and the second clock signal are different from each other. A period during which the second clock signal is changed from an L-level signal to an H-level signal after the first clock signal is changed from an H-level signal to an L-level signal is longer than a period during which the preceding stage signal is changed from an L-level signal to an H-level signal. | 09-30-2010 |
| 20100245307 | Liquid Crystal Display Device and Electronic Device Including the Same - A driver circuit includes a circuit | 09-30-2010 |
| 20100245335 | LIQUID CRYSTAL DISPLAY DEVICE, DRIVING METHOD OF THE SAME, AND ELECTRONIC DEVICE INCLUDING THE SAME - It is an object to suppress deterioration of characteristics of a transistor in a driver circuit. A first switch for controlling whether to set a potential state of an output signal by being turned on and off in accordance with the first input signal, and a second switch for controlling whether to set a potential state of an output signal by being turned on and off in accordance with the second input signal are included. A first wiring and a second wiring are brought into electrical continuity by turning on and off of the first switch or the second switch. | 09-30-2010 |
| 20100246750 | Semiconductor Device and Electronic Device Including Semiconductor Device - It is an object to suppress deterioration in characteristics of a transistor in a driver cricuit. A driver circuit includes a first transistor, a second transistor including a gate and one of a source and a drain to which a second signal is inputted, a third transistor whose gate is electrically connected to one of a source and a drain of the first transistor and which controls whether a voltage state of an output signal is set or not by being turned on/off, and a fourth transistor whose gate is electrically connected to the other of the source and the drain of the second transistor and which controls whether a voltage state of an output signal is set or not by being turned on/off. | 09-30-2010 |
| 20100252826 | DISPLAY DEVICE AND METHOD FOR MANUFACTURING THE SAME - With an increase in the definition of a display device, the number of pixels is increased, and thus the numbers of gate lines and signal lines are increased. The increase in the numbers of gate lines and signal lines makes it difficult to mount an IC chip having a driver circuit for driving the gate line and the signal line by bonding or the like, which causes an increase in manufacturing costs. A pixel portion and a driver circuit driving the pixel portion are provided over the same substrate. The pixel portion and at least a part of the driver circuit are formed using thin film transistors in each of which an oxide semiconductor is used. Both the pixel portion and the driver circuit are provided over the same substrate, whereby manufacturing costs are reduced. | 10-07-2010 |
