Nec Electronics Corporation

Renesas Electronics Corporation

Teru Yoneyama

Yoshiharu Hashimoto

Yutaka Saeki

A drive circuit which outputs an output signal to an output terminal, includes a drive transistor configured to output a gradation current to the output terminal; a single differential amplifier; a resistance element connected with the drive transistor; and a plurality of switches. The plurality of switches are controlled such that a precharge voltage is outputted from the differential amplifier to the output terminal in a first period while blocking off an output from the drive transistor and such that a gradation current is outputted from the drive transistor to the output terminal in a second period after the first period.

Display apparatus, and driving circuit for the same

A display data receiving circuit of the present invention includes a PLL circuitwhich generates internal clock signal ICLK having an integral multiple of the frequency of differential clock signals CLK and /CLK in response to differential clock signals CLK and /CLK, and a serial/parallel conversion circuitwhich receives serial data signal transmitting display data in synchronization with the internal clock signal ICLK, and generates parallel data signal by executing serial/parallel conversion for the serial data signal. The serial/parallel conversion circuitis configured to be able to execute either a single edge operation, which receives serial data signals in response to one of a rising edge and a falling edge of the internal clock signal ICLK, or a double edge operation, which receives serial data signals in response to both of a rising edge and a falling edge of the internal clock signal ICLK. Further, the PLL circuitis configured to be able to change the frequency of the internal clock signal ICLK.

Display data receiving circuit and display panel driver having changeable internal clock and sychronization mechanisms

A drive circuit for a display apparatus includes a gradation voltage generation circuit and a D/A conversion circuit. The gradation voltage generation circuit generates a plurality of different first gradation voltages and a plurality of different second gradation voltages. The D/A conversion circuit drives a light emitting element of a pixel through a data line with a gradation voltage based on one of the first gradation voltages as a first specific gradation voltage in a precharge period and drives the light emitting element of the pixel through the data line with a gradation current based on one of the second gradation voltages as a second specific gradation voltage. The D/A conversion circuit includes a voltage driver to drive the light emitting element, and a current driver to drive the light emitting element.

Disclosed is a display driver that includes a first current driver circuit, a second current driver circuit and a reference current source circuit. The first current driver circuit, which has plural current sources the output current values of which are determined based on a reference current, and switch circuits for on/off controlling the current path between the plural current sources and the current output terminal based on video signal composed of plural bits. The first current driver circuit outputs a first output current conforming to the video signal. The second current driver circuit outputs the second output current conforming to the video signal, while the reference current source circuit variably controls the reference current based on the value of the video signal. A current that is the result of combining the first and second output currents from the first and second current driver circuits is output as an output current. An amount of change in the output current that corresponds to a change of one LSB of the video signal, is varied in accordance with the value of the video signal, the gamma characteristic is approximated by piece-wise linear approximation and the overall luminance of the display pane is variably controlled based on a control signal from a panel luminance adjustment circuit.

Driver circuit for light emitting element

A current drive circuit is provided with a bias generator and a current output unit; wherein the bias generator is provided with: p-channel MOS transistor, p-channel MOS transistor, and reference current source; and the current output unit is provided with: p-channel MOS transistor, switch means, p-channel MOS transistor, and output terminal.

Growing community of inventors

Kanagawa, Japan

Teru Yoneyama