Joled Inc.

Toshiba Matsushita Display Technology Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Hitoshi Tsuge

Hiroshi Takahara

Masafumi Matsui

Kouhei Ebisuno

Shinya Ono

Kohei Ebisuno

Atsuhiro Yamano

Shigeo Homura

Kenji Kokuda

Tetsuro Yamamoto

Arinobu Kanegae

Yoshito Date

Kunio Sekimoto

Takashi Osako

Katsumi Adachi

Teppei Tanaka

Ryoichi Yasuda

A pixel circuit driving method is a method for driving a pixel circuit that includes a drive transistor that supplies a current corresponding to a signal voltage supplied via a signal line, a write transistor connected between the signal line and a gate electrode of the drive transistor, and an organic EL element that emits light in accordance with the current. The pixel circuit driving method includes supplying a reference potential to the gate electrode of the drive transistor before a threshold correction preparation operation of making a gate-source voltage of the drive transistor higher than a threshold voltage of the drive transistor.

Pixel circuit driving method, pixel circuit, and display device

An EL display apparatus is provided. A display screen includes pixels arranged in a matrix, with each pixel including an EL device and a pixel circuit. A source driver circuit is configured to output an analog video signal to each pixel. A gate driver circuit is on at least one side of the display screen, with the gate driver circuit including first and second gate driver circuits. Each pixel includes a driving transistor, a first switch transistor, and a second switch transistor. A gate terminal of the first switch transistor is connected to a first gate signal line of the first gate driver circuit, and a gate terminal of the second switch transistor is connected to a second gate signal line of the second gate driver circuit. The first and second switch transistors are on/off controlled, independently, by the first and second gate driver circuits.

El display apparatus

A light emitting display panel includes a plurality of pixel circuits arranged in a matrix. Each of the plurality of pixel circuits includes a light emitting element, a capacitor that is connected to a gate of a drive transistor and the light emitting element, a first switch transistor that is connected to a first electrode of the capacitor, a first wire that is connected to the first electrode of the capacitor via the first switch transistor, a second switch transistor that is connected to a second electrode of the capacitor and the light emitting element, and a second wire that is connected to the second electrode of the capacitor via the second switch transistor. A voltage of the first wire and a voltage of the second wire are the same during a power off operation or during a non-light emission period.

Power off method of display device, and display device

EL display apparatus

A display apparatus has an image display unit having a plurality of arrayed pixel circuits, and an image signal compensation circuit compensating an image signal and outputs the compensated signal to the image display unit. Each of the pixel circuits has a compensating capacitor which compensates the threshold voltage of the driving transistor. The image signal compensation circuit has a compensation memory storing a compensation data for compensating the current variation of the driving transistors, a first comparison circuit which compares the image signal and first threshold value, and an arithmetic circuit compensating the image signal. When the image signal has a luminance larger than the threshold value, the compensation is performed.

Display apparatus

A display panel includes a contact area which includes an upper conductive layer forming first electrodes of the organic EL elements, a lower conductive layer disposed below the upper conductive layer, a middle layer between the upper conductive layer and the lower conductive layer, and an insulating layer between the lower conductive layer and the middle layer. The middle layer includes a first area and a second area which are conductive and electrically connected to the upper conductive layer, and an insulating separating area which separates the first area and the second area. The lower conductive layer includes a first line which is electrically connected to the first area via a first contact hole, and a second line which is electrically connected to the second area via a second contact hole.

Display panel and display device

A display device includes a plurality of pixels arranged in rows and columns, a plurality of first power lines that extend in a pixel column direction and through which a power supply voltage is supplied to the pixels, and a plurality of second power lines that extend in the pixel column direction and through which an initialization voltage different from the power supply voltage is to the pixels. The number of first power lines is greater than the number of second power lines.

Active matrix display device for reducing unbalanced voltage drop

An electroluminescent (EL) display apparatus and corresponding method of control are provided. A display screen includes gate signal lines which are arranged to intersect source signal lines. A pixel provided with an EL device corresponds to each intersection of the gate signal lines and the source signal lines. A driving transistor is provided for each pixel to supply a current to the EL device. A first switch transistor is provided for each pixel on a current path through which the current is supplied to the EL device. A gate driver circuit is connected to the gate signal lines. The gate driver circuit is configured to turn the first switch transistor on and off to simultaneously generate band-shaped non-display regions and band-shaped display regions on the display screen and to move the band-shaped non-display regions and the band-shaped display regions relative to the display screen.

A power off method of a display device includes: detecting a power off operation on the display device; setting, when the power off operation is detected, a same potential in one electrode and an other electrode of a capacitance element in each of a plurality of pixel circuits; and stopping power supply to a display panel immediately after the same potential is set.

An electroluminescent (EL) display apparatus and method of controlling are provided. A display screen includes gate and source signal lines. A pixel corresponds to each intersection of the gate and source signal lines. Each pixel includes: an EL device including anode and cathode terminals, the cathode terminal being connected to a common reference voltage; a driving transistor to flow a current to the EL device; a first switch transistor provided on a current path through which the current flows from a power line through the driving transistor to the EL device; a second switch transistor to supply, to the driving transistor, an image signal from one source signal line; and a third switch transistor provided between the anode terminal of the EL device and a voltage line. The voltage line is configured to supply a reverse bias voltage for reverse biasing the anode terminal of the EL device.

Pixel circuits each include a write transistor having a gate electrode connected to a write control line, one of a drain electrode and a source electrode connected to a data line for transmitting data voltage corresponding to luminance of the pixel circuit, and the other of the drain electrode and the source electrode connected to a gate electrode of a drive transistor. A compensation circuit includes a compensation transistor connected to a compensation signal line and the write control line. A compensation voltage generation circuit outputs compensation control voltage in accordance with a representative value of data voltage for the pixel circuits. A capacitance of the write control line caused by the compensation transistor and a capacitance of the write control line caused by the write transistors of the pixel circuits have mutually opposite voltage dependence with respect to the representative value of the data voltage for the pixel circuits.

Display device

A plurality of pixel circuits included in a display device each includes: a drive transistor; a capacitor connected to a gate electrode and a source electrode of the drive transistor; a light-emitting element which is driven by the drive transistor; a write transistor having a gate electrode connected to a write control line for transmitting a write signal, one of a drain electrode and a source electrode connected to a data line for transmitting a data voltage corresponding to luminance, and the other of the drain electrode and the source electrode connected to the gate electrode of the drive transistor; and a compensation transistor having a gate electrode connected to the data line, and at least one of a drain electrode and a source electrode connected to the write control line, the compensation transistor being of same conductivity type as the write transistor.

Growing community of inventors

Osaka, Japan

Hitoshi Tsuge