Lapis Semiconductor Co., Ltd.

Lapis Technology Co., Ltd.

Yukinobu Watanabe

Yuichi Matsushita

An interface circuit comprises a timing signal generating unit that generates a timing signal indicating a timing to switch between a data input period and a non-input period, a plurality of driver error detection circuits that detects an error in source drivers, a selector circuit that selects one of the driver error detection circuits in the non-input period and that outputs a driver error detection signal indicating an error detection result, an input error detection circuit that detects an input error of a data signal and outputs an input error detection signal indicating the result, an OR circuit that outputs an OR of the driver error detection signal and the input error detection signal, and a signal output unit connected to an output part of the OR circuit.

Interface circuit, source driver, and display device

In the present invention, output circuits are connected to respective external terminals. Each output circuit includes an operational amplifier that outputs a current to one external terminal until a voltage of the external terminal becomes equal to a gradation voltage received by an input terminal thereof, and a disconnection detection circuit that detects whether a wiring connected to the one external terminal is disconnected or not. The disconnection detection circuit supplies a test voltage instead of the gradation voltage to the input terminal of the operational amplifier in a non-display period and measures a time period taken from then until the voltage of the one external terminal exceeds a reference voltage as a rise time. The disconnection detection circuit detects whether the wiring connected to the one external terminal is disconnected or not based on the rise time measured in one frame and the rise time measured in another frame.

Display driver and display device

A display device which can suppress erroneous display of a display panel is provided. A source driver receives a serial data signal in which a preamble and video data of the display panel are alternately continuous via an interface from a display controller. The source driver controls timing of supply of a gate signal from a gate driver based on the video data included in the serial data signal, and supplies a gradation voltage signal which corresponds to the video data to a plurality of data lines of the display panel. The source driver has a detection portion which detects that the interface is in an unstable state, and a gate reset signal output portion which outputs a gate reset signal for stopping an operation of the gate driver when the unstable state of the interface is detected at the time of the supply of the video data.

Display device and display driver

An interface circuit generates a timing signal indicating the timing at which to switch between a data input period and a non-input period, and outputs a second start pulse signal obtained by delaying a first start pulse signal. Anomaly detection circuits detect an anomaly that has occurred in source drivers, and a detection result selection circuit selects one of the anomaly detection circuits during the non-input period and outputs a detection result signal indicating detection results. A selector selectively outputs the second start pulse signal or the detection result signal on the basis of the timing signal.

A display driver includes a driving voltage generation part that generates a voltage as a pixel driving voltage by inverting a polarity of a voltage representing a luminance level of each pixel based on a video signal according to a polarity inversion signal received via a transmission line, the polarity inversion signal alternately indicating either one of positive and negative polarities, and a polarity inversion abnormality detection part that generates an abnormality detection signal indicating an abnormality of the transmission line when the polarity inversion signal indicates only one constant polarity for a period of N frames (N is an integer greater than or equal to 2) of the video signal.

Display driver and display apparatus

An A/D conversion device includes: a level shifter circuit configured to level-shift an analog voltage of an input voltage signal to generate a conversion signal; an A/D converter configured to A/D-convert a voltage of the conversion signal supplied from the level shifter circuit. The level shifter circuit subtracts an instantaneous voltage value of the input voltage signal from a reference voltage so as to output a signal value as the conversion signal.

A/D conversion device having level shifter circuit

A display device includes display panel includes a first source driver including a first input terminal and a first output terminal connected to the display panel; a first gate driver including a first input-output terminal, a second input-output terminal connected to the first input-output terminal, and a second output terminal connected to the display panel; a timing controller including a first terminal for outputting or inputting a first signal to or from the first input-output terminal and a second terminal; a first signal line connected to the first terminal; a second signal line connected to the second terminal; and a third signal line connected to the first source driver and the timing controller for transmitting a second signal indicating a display direction of the image data. The first source driver operates according to the first signal from the first terminal or the second terminal selected.

Growing community of inventors

Yokohama, Japan

Yukinobu Watanabe