Global Oled Technology LLC

Kyocera Corporation

International Business Machines Corporation

Chi Mei Optoelectronics Corporation

Koichi Miwa

Takatoshi Tsujimura

Yuichi Maekawa

Shinya Ono

Mitsuo Morooka

Donald P Seraphim

Kuniaki Sueoka

Ho Chong Lee

Dean W Skinner

Shunji Suzuki

Hajime Nakamura

Hiroshi Suzuki

Koji Murayama

Keigo Kanoh

Mototsugu Oohata

Nami Ikeda

Michikazu Noquchi

Checking failures in transistors including driving transistors, switching transistors, and sampling transistors before light emitting elements are formed in a display device. I-V characteristics including threshold voltage of the driving transistorC in one pixel circuit can be detected. In a pixel circuit, the sampling transistorA and switching transistorD are made conductive and the signal potential is given to the gate electrode of the driving transistorC from the signal line DTCm. At this time, the current which flows between the drain electrode and source electrode of driving transistorC flows through the switching transistorD and a reference potential line Vref_r to a test point, and is measured by a current measuring device connected to the test point.

Pixel circuit, display device, and inspection method

Compensate for the variations of threshold voltage of a driving transistor. During the period of the reference signal voltage Vref being set to the signal line DTC, voltage between the gate and source of the driving transistorC is made equal to or greater than the threshold voltage of the driving transistorC, and the difference in voltage of the reference signal voltage Vref and the reference power supply voltage Vref_r is charged to the retentive capacitanceB. At the same time, the voltage of the source of the said driving transistorC is set to the reference power supply voltage Vref_r to make the voltage applied to the light emitting elementE equal to or lower than its threshold voltage, a voltage corresponding to the threshold voltage of the driving transistorC is held in the retentive capacitanceB. During a period of time when a display signal voltage is set to the signal line DTC, the sampling transistorA is conducting, so as to sample the signal voltage, and this signal voltage is superposed on the threshold voltage held in the retentive capacitance.

To compensate for a change of light emission intensity caused by deterioration of a light emitting element, provided is a display device including a drive element (T) which controls a drive current to be supplied to a light emitting element (EL) in accordance with a data signal representing a target luminance of the light emitting element (EL). The light emitting element (EL) emits light in accordance with a current flowing through the light emitting element (EL). The data signal is corrected in accordance with a voltage applied at both terminals of the light emitting element (EL) so that the drive current to be supplied to the light emitting element (EL) increases with an increase in an amount of a voltage drop of the light emitting element (EL).

Display device

A display device in which a plurality of pixels are arranged in a matrix form, corresponding to intersections of a plurality of data lines and a plurality of scan lines, wherein each pixel includes a light emitting element having a first electrode connected to a first power supply and which emits light according to a current that flows; a driving transistor having a source electrode connected to a second power supply and which supplies a drain current to a second electrode of the light emitting element; a data storage capacitor having a first electrode connected to a gate electrode of the driving transistor; and a first switch which is switched ON during a pixel selection period so that data of a data line is written to the data storage capacitor, and wherein a potential of a second electrode of the data storage capacitor is changed.

Display device and pixel circuit

In each pixel, a current-driven type light emitting element OLED, and a driving element Twhich controls an electric current to be supplied to the light emitting element in accordance with a data signal representing a target brightness, are provided. The mutual conductance of the driving element T, or a parameter reflecting the mutual conductance, is detected, and the data signal to be supplied to the driving element is corrected in accordance with a detection result. More specifically, the data signal is corrected such that a driving current to be supplied to the light emitting element in accordance with the data signal increases as the mutual conductance of the driving element Tdecreases.

Electroluminescent pixel with efficiency compensation by threshold voltage overcompensation

To efficiently compensate a threshold value of a driving transistor. In a state where a first switching transistor is non-conductive and a second switching transistor in conductive, a sampling transistor is made conductive and a reference voltage is supplied from a signal line to write a threshold voltage of a driving transistor to a first capacitance. After that, in a state where first and second switching transistors and are non-conductive, the sampling transistor is made conductive and a signal voltage from the signal line is written to the first capacitance. Further, after that the sampling transistor is put into a non-conductive state, and the first and second switching transistors are put in a conductive state, to drive the driving transistor and supply current to a light emitting element.

A drive circuit that compensates for the dispersion of the characteristics of drive transistors is disclosed. A switch SWis turned off, and switches SWand SWare turned on. Thereby, a constant current from a constant current source CCis flown in a drive transistor T. Consequently, a gate voltage corresponding to the constant current Is written in the gate of the drive transistor T. Then, the switches SWand SWare turned off, and the switch SWis turned on. Simultaneously, the voltage of a capacitor Con the side of the switch SWis varied according to a signal voltage, and thereby the voltage is added to the gate of the drive transistor Tto flow a current corresponding to the signal voltage in the drive transistor T

Drive circuit for electroluminescent device

A thin film transistor according to the present invention includes a gate electrode, a semiconductor layer having a channel forming region arranged on the gate electrode and an impurity region arranged on a part of the channel forming region, source and drain electrodes electrically connected to the impurity region, and a gate insulating film that electrically insulates the gate electrode and the semiconductor layer, wherein the distance between the upper end of the gate electrode and the upper end of the impurity region is larger than the distance between the upper end of the gate electrode and the upper end of the channel forming region.

Thin film transistor in which fluctuations in current flowing therethrough are suppressed, and image display apparatus

A image display device includes a light-emitting device that emits light with a luminance depending on an electric current flowing therethrough, a driver that includes at least a first terminal and a second terminal and that supplies an electric current whose value is defined based on a potential difference between the first terminal and the second terminal to the light-emitting device, a potential difference supply unit that supplies the potential difference between the first terminal and the second terminal, a potential adjusting unit that adjusts so that the potential of the second terminal becomes reference potential while the potential difference supply unit supplies the potential difference, and a capacitor that is arranged between the first terminal and the second terminal and that holds the potential difference supplied from the potential difference supply unit.

Image display device

A transparent substrate is provided thereon with a first thin film transistor and a second thin film transistor to configure a driver circuit; a conductive layer to be connected to a data line or a scan line; a conductive layer to connect the first thin film transistor with the second thin film transistor; and an anode wire layer connected to the second thin film transistor. The anode wire layer is provided thereon with a light emitting diode including a plurality of light emitting layers and electron-hole pair generating layers alternately interposed between the light emitting layers.

Image display apparatus

Thin-film transistor in which fluctuations in current flowing therethrough are suppressed, and image display apparatus

An organic light emitting diode (OLED) display comprises: an insulating substrate; common electrodes; a first electrode layer formed in a region adjacent to the common electrodes formed on the insulating substrate electrically isolated from the common electrodes; an insulating layer which coats the insulating substrate and respectively opens a first opening window exposing a part of the common electrodes and a second opening window exposing at least a part of the first electrode layer; ribs or walls which form a cell area by crossing the common electrodes on the insulating substrate and surround each of the opening windows; a material layer formed on the first electrode layer exposed by the second opening window; and a second electrode layer which coats the cell area surrounded by the ribs and is electrically connected to the common electrodes through the first opening window.

OLED display and method of manufacturing such display

An electrophoretic display is mounted on the surface of the housing of a notebook type personal computer. When an event that requires the user to operate a member occurs, the member and operation information corresponding to that event are searched for, and the searched-for operation information is displayed in a region of the electrophoretic display in the vicinity of the searched-for member. For example, when a termination switch is in a corner of the exterior surface of the cover, for a system termination event, information indicating that the termination switch should be operated is displayed in a region of the electrophoretic display in the vicinity of the termination switch.

Electronic apparatus and electronic apparatus information display method

A system and method of displaying an image on a liquid crystal display equipped with a crystal panel which comprise a plurality of gate lines, a plurality of data lines, and pixel cells disposed in the shape of a matrix corresponding to the intersections of the gate lines and the data lines, the method comprising the steps of: (a) selecting the gate line for the display of an image on the liquid crystal panel in a first term during a frame period for displaying one image and moreover supplying an image signal to display the image to the data line; and (b) selecting the gate line again in a second term during the same frame period as that of the first term, the first term and the second term being in the same frame period, and supplying a non-image signal having a predetermined potential and different from the image signal to the data line during the second term, whereby supply of the non-image signal is for displaying a blanking image.

Method of displaying an image on liquid crystal display and a liquid crystal display

A method for applying the sealing material onto the corner regions of the substrate to realize the liquid crystal cell with large display region. A protrude region,is formed on each of the side regions adjacent to a display region of a first substrate,. A difference of level is formed at each boundary of the side region and the corner region on one surface of the first substrate,for providing the corner region with a height which is lower than a height of the side region. A sealing material,is applied on the side regions and the corner regions on the one surface of the first substrate,by a tool for dispensing the sealing material,. When a second substrate,is positioned on the applied sealing material,on one surface of the first substrate,, a distance between the first substrate,and the second substrate,is decreased and the sealing material,applied on the first substrate,is collapsed.

Growing community of inventors

Kanagawa, Japan

Koichi Miwa