Abstract: An output circuit for gray scale control includes a low-side current mirror unit, a low-side gray scale control circuit, a high-side current mirror unit, a high-side gray scale control circuit, a current increment control circuit and a selective precharge control circuit. A gray scale control circuit for outputting gray scale signals is separated into the high side and the low side, thereby enabling the output-current characteristics to be controlled to be close to the ? characteristics of a light emitting device. In addition, variations in the current for each output unit can be suppressed by using multistage current mirrors.

Abstract: A switching-controlling section turns ON one of a transfer gate for high voltages or a transfer gate for low voltages and subsequently turns ON the other one of the transfer gates according to the outputs from the data latches only when the outputs from data latches are different from each other. Source lines are sequentially connected to a capacitor element for high voltages or a capacitor element for low voltages. For those source lines in which applied voltages change in a previous period and a subsequent period, an electric charge is stored and supplied effectively and power consumption is reduced, whereas for those source lines in which the applied voltages do not change, retained voltages do not vary so power is not consumed when subsequent voltages are applied. Power consumption in a liquid crystal panel driving device is reduced, and the time required for storing and supplying an electric charge is shortened. The circuit scale is also reduced.

Abstract: A current driver outputs an output current according to a reference current. The current driver includes: a current-voltage converter; a bias-voltage generating transistor; a differential amplifier; and a driving transistor. The converter has a given resistance value and is connected between a first node and a second node. The bias-voltage generating transistor is provided between the first and second nodes and connected in series with the converter. The amplifier outputs a voltage according to the difference between a voltage at an interconnecting node between the converter and the bias-voltage generating transistor and a voltage according to the reference current at a third node. The driving transistor is connected between an output current node outputting an output current and the second node and receives, at its gate, the voltage from the amplifier. The bias-voltage generating transistor receives, at its gate, the voltage from the amplifier.

Abstract: An output circuit for gray scale control includes a low-side current mirror unit, a low-side gray scale control circuit, a high-side current mirror unit, a high-side gray scale control circuit, a current increment control circuit and a selective precharge control circuit. A gray scale control circuit for outputting gray scale signals is separated into the high side and the low side, thereby enabling the output-current characteristics to be controlled to be close to the ? characteristics of a light emitting device. In addition, variations in the current for each output unit can be suppressed by using multistage current mirrors.

Abstract: The grayscale voltage generation device includes a first line, a second line and a plurality of serial digital analog converters (DACs). A first reference voltage having a first voltage value is supplied to the first line, and a second reference voltage having a second voltage value is supplied to the second line. Each of the plurality of serial DACs receives grayscale information representing a grayscale level and generates a grayscale voltage having a voltage value corresponding to the grayscale information using the reference voltages supplied to the first and second lines.

Abstract: In the process of transferring a clock signal and a plurality of data signals which are in synchronization with the clock signal, a driving pulse width of a driver switch is feedback-controlled by a clock transmission system (12), whereby the clock signal is transmitted at a small amplitude. A control signal having the pulse width is used for controlling the driver switch in each data transmission system (13), whereby transfer of each data signal at a small amplitude is realized at the same time. Further, in a clock reception system (10), the control signal having the pulse width is used in delay control of a clock delay circuit, whereby an optimum latch timing of received data in each data reception system (11) is realized.

Abstract: A level shift circuit having a latch function includes a precharging PMOS transistor MP1 which is turned on in a precharge period to interrupt a through current of an input stage, an NMOS transistor MN1 which inputs data and performs discharging in a data input period, and a transistor MP2 for holding data after level shifting. Thus, each of the transistors can have a minimum configuration. Since the level shift circuit has a latch function, it is possible to omit a circuit for latching input data, thereby reducing a circuit area.

Abstract: In a current drive system for current-driving a display panel such as an organic EL panel, display crosstalk caused by a bias-voltage variation due to induction from the display panel is prevented. For this prevention, the current drive system includes: a plurality of drivers for current-driving a plurality of display element circuits in the display panel; and a bias circuit with a low output impedance for generating a bias voltage and supplying the bias voltage to each of the drivers through a bias line. The output impedance of the bias circuit is set sufficiently low so that a voltage variation caused on the bias line due to switching operation of each switch in the drivers converges within a period during which display data is written.

Abstract: A current driver generates an output current according to an input signal. The current driver includes R current copy circuits and an output current generator where R is a natural number. Each of the current copy circuits stores a current having a given current value and input from the outside in a storage mode and outputs the stored current in an output mode. The output current generator obtains a current or the sum of currents from a non-negative integer number of the current copy circuits selected in accordance with the input signal, and thereby generates an output current.

Abstract: A display driver comprises second and third MOSFETs for supplying reference currents equal to each other, a first current-input MOSET connected to the second MOSFET, a second current-input MOSFET connected to the third MOSFET, a plurality of mirroring devices which are placed between the first current-input MOSFET and the second current-input MOSFET and to which a current fed to each of the first and second current-input MOSFETs is distributed, and current adding means for changing the output current value by adding currents produced in the plurality of mirroring devices.

Abstract: In the process of transferring a clock signal and a plurality of data signals which are in synchronization with the clock signal, a driving pulse width of a driver switch is feedback-controlled by a clock transmission system (12), whereby the clock signal is transmitted at a small amplitude. A control signal having the pulse width is used for controlling the driver switch in each data transmission system (13), whereby transfer of each data signal at a small amplitude is realized at the same time. Further, in a clock reception system (10), the control signal having the pulse width is used in delay control of a clock delay circuit, whereby an optimum latch timing of received data in each data reception system (11) is realized.

Abstract: A display driver comprises second and third MOSFETs for supplying reference currents equal to each other, a first current-input MOSET connected to the second MOSFET, a second current-input MOSFET connected to the third MOSFET, a plurality of mirroring devices which are placed between the first current-input MOSFET and the second current-input MOSFET and to which a current fed to each of the first and second current-input MOSFETs is distributed, and current adding means for changing the output current value by adding currents produced in the plurality of mirroring devices.

Abstract: In a current driving apparatus for driving a display panel, allocation of some of transistors used for constructing current sources is exchanged between first and second DA converter circuits. For example, a current source corresponding to the most significant bit of the first DA converter circuit is composed of transistors disposed on the first, third, fifth and seventh rows of a first transistor group and transistors disposed on the second, fourth, sixth and eighth rows of a second transistor group adjacent to the first transistor group. Similarly, a current source corresponding to the most significant bit of the second DA converter circuit is composed of transistors disposed on the second, fourth, sixth and eighth rows of the first transistor group and transistors disposed on the first, third, fifth and seventh rows of the second transistor group.

Abstract: A display driver comprises second and third MOSFETs for supplying reference currents equal to each other, a first current-input MOSET connected to the second MOSFET, a second current-input MOSFET connected to the third MOSFET, a plurality of mirroring devices which are placed between the first current-input MOSFET and the second current-input MOSFET and to which a current fed to each of the first and second current-input MOSFETs is distributed, and current adding means for changing the output current value by adding currents produced in the plurality of mirroring devices.

Abstract: A current driver to which image data including a plurality of grayscale values is input and which outputs an electric current according to the grayscale values of the image data, the current driver comprising: a first input section to which a first reference current is input, a current value of the first reference current being changed according to the grayscale values of the image data; a second input section to which a second reference current is input, the second reference current having a current value different from that of the first reference current; and a current divider circuit which uses the second reference current and the first reference current to output an electric current, the electric current having a value equal to or higher than that of the first reference current and equal to or lower than that of the second reference current.

Abstract: The first and second chips are provided side by side. The first chip includes: a current supply section for outputting a drive current, the current supply section including a current mirror; a current distribution MISFET; a current input MISFET for transmitting an electric current to the current supply section, the current input MISFET being connected to the current distribution MISFET; and a second current distribution MISFET. The current distribution MISFET and the second current distribution MISFET constitute a current mirror. The second chip includes a second current input MISFET which is connected to the second current distribution MISFET. The ratio between the W/L ratio of the current distribution MISFET and the W/L ratio of the current input MISFET connected thereto is the same in the first and second chips.

Abstract: A current driving device includes a reference current source, a first MISFET connected to the reference current source, a plurality of current distribution MISFETs which constitutes a current mirror together with the first MISFET and distributes a reference current, a current input MISFET connected to the current distribution MISFETs, and a plurality of current supply sections each of which includes MISFETs constituting a current mirror circuit together with the current input MISFET and supplies a driving current for a pixel circuit. With the plurality of current distribution MISFETs provided, change in gate the potential of MISFETs in the current supply section can be suppressed, so that the generation of a crosstalk in a display device can be suppressed.

Abstract: An organic EL display apparatus includes: a display panel on which a plurality of pixel sections are provided; source drivers provided with pixel drivers, which includes current drivers for supplying drive currents to the pixel sections, registers for latching data signals and timing control units; signal lines for supplying the drive currents from the current drivers to the pixel sections. Each of the current drivers is controlled by the associated timing control unit to allow a current larger than or equal to a current which is set in accordance with the data signal to flow only during a given period in a current setting mode, so that the value of a current flowing in the pixel section reaches a target value in a short time.

Abstract: In a current drive system for current-driving a display panel such as an organic EL panel, display crosstalk caused by a bias-voltage variation due to induction from the display panel is prevented. For this prevention, the current drive system includes: a plurality of drivers for current-driving a plurality of display element circuits in the display panel; and a bias circuit with a low output impedance for generating a bias voltage and supplying the bias voltage to each of the drivers through a bias line. The output impedance of the bias circuit is set sufficiently low so that a voltage variation caused on the bias line due to switching operation of each switch in the drivers converges within a period during which display data is written.

Abstract: An output circuit for gray scale control includes a low-side current mirror unit, a low-side gray scale control circuit, a high-side current mirror unit, a high-side gray scale control circuit, a current increment control circuit and a selective precharge control circuit. A gray scale control circuit for outputting gray scale signals is separated into the high side and the low side, thereby enabling the output-current characteristics to be controlled to be close to the &ggr; characteristics of a light emitting device. In addition, variations in the current for each output unit can be suppressed by using multistage current mirrors.