摘要:
In each pixel formation portion of a display device, an amplification electrode is provided which is connected to a drain electrode of a thin-film transistor whose gate electrode is connected to a gate bus line and whose source electrode is connected to a source bus line. A second-capacitor is formed by the amplification electrode and a pixel electrode. A selection period is constituted by a precharge period and an amplification period. In the precharge period, a video signal potential is applied to the pixel electrode and a potential of a control wire is applied to the amplification electrode. In the amplification period, a video signal potential is applied to the amplification electrode with the pixel electrode being in a floating state.
摘要:
A semiconductor device in which a transistor can supply an accurate current to a load (EL pixel and signal line) without being influenced by variations is provided.A voltage at each terminal of a transistor is adjusted by a feedback circuit using an amplifier circuit. A current Idata is input from a current source circuit to the transistor, and a gate-source voltage is set by the feedback circuit so that the transistor can flow the current Idata. The feedback circuit controls the transistor to operate in a saturation region. Thus, a gate voltage required for flowing the current Idata is set. With the use of the set transistor, a current can be supplied to a load (EL pixel and signal line) with accuracy. Note that a desired gate voltage can be set quickly since the amplifier circuit is utilized.
摘要:
A pixel circuitry of a display device is provided to make a voltage level transmitted to a display element be close to a voltage level of a received data voltage, such that the pixel circuitry faithfully transmits the data voltage to the display element. The pixel circuitry of a display device includes a first write switch, a first write memory unit, a first voltage following module, and a display element. The first voltage following module is to detect a first data voltage stored in the first write memory unit, and to generate a corresponding first output voltage at a terminal of the display element based on a detection result. A first output terminal of the first voltage following module is controlled by a switching voltage.
摘要:
An amplification circuit comprises a capacitor arrangement (42) and a switching arrangement. The capacitor arrangement has a first capacitor (C2) which has a voltage-dependent capacitance and a second capacitor (C1) (which may also be voltage-dependent). The circuit is operable in two modes, a first mode in which the input voltage is provided to one terminal of at least the first capacitor, and a second mode in which the switching arrangement causes charge to be redistributed between the first and second capacitors such that the voltage across the first capacitor changes to reduce the capacitance of the first capacitor, the output voltage being dependent on the resulting voltage across the first capacitor. The invention uses a voltage controlled capacitance in combination with charge sharing between capacitors, which has the result of providing a voltage amplification characteristic. This arrangement can thus be used for the amplification of an analogue voltage, or the boosting of a fixed level (i.e. digital voltage). Thus, the circuit of the invention can be used for level shifting or amplification, for example for use in the pixels of an active matrix array device.
摘要:
A driving circuit for an organic light emitting display apparatus includes first and second switching elements and a driving element. The first switching element is controlled by a scan signal supplied from a scan line. The second switching element is controlled by the scan signal. The driving element provides an end of an organic electroluminescent element with a first reference voltage via the second switching element. The driving element has amorphous silicon thin film transistors so that the manufacturing cost of the organic light emitting display apparatus may be reduced.
摘要:
The invention relates to an active-matrix image display device that comprises an array of light emitters. Each light emitter is controlled by a current modulator having a particular trip threshold voltage. The device also includes compensation means for compensating for the trip threshold voltage of the modulators. These compensation means comprise at least one operational amplifier connected between the gate electrode and the source electrode of the modulator. The feedback of this operational amplifier compensates for the trip threshold voltage of at least one modulator whatever the value of the said voltage.
摘要:
An amplification circuit comprises a capacitor arrangement (42) and a switching arrangement The capacitor arrangement has a first capacitor (C2) which has a voltage-dependent capacitance and a second capacitor (C1) (which may also be voltage-dependent). The circuit is operable in two modes, a first mode in which the input voltage is provided to one terminal of at least the first capacitor, and a second mode in which the switching arrangement causes charge to be redistributed between the first and second capacitors such that the voltage across the first capacitor changes to reduce the capacitance of the first capacitor, the output voltage being dependent on the resulting voltage across the first capacitor. The invention uses a voltage controlled capacitance in combination with charge sharing between capacitors, which has the result of providing a voltage amplification characteristic. This arrangement can thus be used for the amplification of an analogue voltage, or the boosting of a fixed level (i.e. digital voltage). Thus, the circuit of the invention can be used for level shifting or amplification, for example for use in the pixels of an active matrix array device.
摘要:
When light emitting elements have the same luminance, luminosity obtained from one pixel can be higher as area of a light emitting region in the pixel (also called an aperture ration) is increased. The aperture ratio of a pixel is low if the number of transistors and wires constituting the pixel is large. Thus, the invention is to decrease the number of transistors and wires constituting a pixel to increase the aperture ratio. Instead of a power supply line to which a certain potential is set, a potential supply line which controls a potential by a signal is provided; supplying an applied voltage to a light emitting element can be controlled by a signal of the potential supply line without providing a switch.
摘要:
A transistor has variation in a threshold voltage or mobility due to accumulation of factors such as variation in a gate insulating film which is caused by a difference of a manufacturing process or a substrate to be used and variation in a crystal state of a channel formation region. The present invention provides an electric circuit which is arranged such that both electrodes of a capacitance device can hold a voltage between the gate and the source of a specific transistor. Further, the present invention provides an electric circuit which has a function capable of setting a potential difference between both electrodes of a capacitance device so as to be a threshold voltage of a specific transistor.
摘要:
To ensure uniformity of display regardless of a characteristics difference and temporal deterioration of a light-emitting element. An optical feedback type pixel circuit having a photoelectric transducer therein comprises a capacitor C1 for storing as an electric charge an integral value of the photoelectric current output from the photoelectric transducer; a comparator for changing a level of an output voltage Vout at a timing when a first voltage set according to the electric charge stored in the capacitor C1 reaches a second voltage set according to data supplied through a data line X; and a transistor T2 electrically controlled according to the output voltage Vout from the comparator for making an organic EL element OLED emit light when the first voltage has not reached the second voltage and for making the organic EL element OLED stop emitting the light when the first voltage reaches the second voltage.