Nec Corporation

Konica-Minolta Holdings, Inc.

Yuichi Iketsu

Yoshikazu Sakaguchi

Hironori Imura

Kouichi Ishida

Yuji Kondo

Eiichi Kitazume

Kouji Miyawaki

An organic EL element driving device that drives an organic EL element with a constant current is provided. The organic EL element driving device includes a power supply connected in series with the organic EL element, and a current control unit connected in series with the organic EL element. The current control unit includes a current detection circuit having a resistor for detecting the value of the current passing through the organic EL element. The current control unit sets a prescribed value for the current to be passed through the organic EL element in accordance with the luminance control, and performs control such that the current passing through the organic EL element has the prescribed value in accordance with an output from the current detection circuit. A value of the resistor in the current detection circuit is varied in accordance with the luminance control.

Organic EL element driving device and organic EL lighting apparatus

Disclosed is an illumination apparatus, which is constituted by a plurality of OLED devices and makes it possible to improve an accuracy of a dimming control operation. The apparatus is provided with a driving electric power source including: a pulse generating section; an OLED driving section; a first voltage source; a second voltage source; a current source; a switchover section that conducts a switchover operation between the first voltage source and the current source during the time when the duty ratio of the driving pulses is increasing, and also conducts another switchover operation between the first voltage source and the current source during the time when the duty ratio of the driving pulses is decreasing; and an OLED illumination disabling section that makes the second voltage source supply the second electric power to the OLED unit, only during the time when each of the pulses is the OFF state.

Illumination apparatus

An active matrix organic EL display device includes pixels each having an organic EL element () and a pixel circuit () including a polysilicon TFT for controlling the organic EL element () arranged adjacently in each of the regions partitioned into a matrix shape by data line () and gate line () that intersect each other. The organic EL element () has a cathode () arranged in at least a region that excludes a space above the polysilicon TFT. The cathode () is arranged continuously over two or more adjacent pixels in the direction of gate line ().

Active matrix organic EL display device and manufacturing method thereof

A color organic EL display is provided with first electrodes extending in a column direction, second electrodes extending in a row direction, pixels arranged in a row direction and a column direction, and an organic luminescence layer between the first electrode and the second electrode which emits luminescence by applying a voltage to the first and the second electrodes to make an electric current flow therebetween. The number of the first electrodes is twice of the number of displaying columns. The second electrode is provided at every two displaying rows. Each of the pixels consists of three sub pixels for three luminescence colors arranged in order in the row direction. Each of the sub pixels is provided in each of regions where the first electrodes intersect with the second electrodes in a plan view. The sub pixels are arranged while being shifted to each other by a half pitch in the row direction between adjacent two displaying rows. Luminescence color of sub pixels provided for the same first electrode is unified as a single color. The luminescence colors of three adjacent sub pixels arranged at three triangle positions in two adjacent displaying rows are different from each other.

Color organic EL display and method for driving the same

A comparator compares the signal voltage S (i, j) applied to the display element P(i, j) on a predetermined data electrode Xi on the scanning electrode Yj for the current display period and the signal voltage S(i, j&plus;1) applied to the display element P(i, j&plus;1) on the data electrode Xi on the scanning electrode Y (j&plus;1) during the next display period. A controller controls a discharge of residual electric charges or a quantity of residual electric charges discharged from the data electrode Xi during a blanking period immediately before the next display period depending on the comparison result by the comparator.

Driving device and driving method of organic thin film EL display

A method of manufacturing an organic EL panel, in which an organic electroluminescent material is formed between a pair of opposing electrodes, is provided. At least one of the electrodes is transparent or opaque. An emission pixel is obtained through the steps of forming a photoconductor having a charge generation layer and a charge transport layer on the transparent electrode side, charging the photoconductor and thereafter exposing the photoconductor to form an electrostatic latent image at the prospective emission pixel portion, developing the electrostatic latent image by using toner kneaded with an electroluminescent medium, and fixing the toner on the photoconductor after development. An EL panel manufactured by the above method is also disclosed.

Organic EL panel and method of manufacturing the same

When a forward bias is applied between a selected unit electrode of scanning electrodes and a selected unit electrode of data electrodes to cause a selected pixel concerning both of the selected unit electrodes to emit light, and a reverse bias is applied between nonselected unit electrodes of the scanning electrodes and nonselected unit electrodes of the data electrodes, thereby preventing crosstalk caused by a semi-excited state of the nonselected pixels, all of the scanning electrodes and all of the data electrodes are short-circuited once, immediately before a predetermined unit electrode of the data electrode, which should be selected in accordance with selection of each of the unit electrodes of the scanning electrodes, is selected, to set all of the pixels at a zero bias.

Driving organic thin-film EL display by first zero biasing by short circuiting all pixels and then forward biasing selected pixels and reverse biasing nonselected pixels to prevent crosstalk

A two-dimensional organic thin film electroluminescence (EL) display unit has a plurality of one-dimensional organic EL arrays extending in a first direction and adhered together in a second direction perpendicular to the first direction. The EL array has a transparent substrate having a main surface directed to the second direction, and a multilayer EL structure formed on the main surface and including a plurality of first layer transparent electrodes extending perpendicular to the array, an organic EL thin film and a second layer metallic electrode extending along the array. The EL array emits luminescence in the third direction perpendicular to the first and second directions. The first layer electrodes and the second layer electrode drive the EL array in a matrix drive. The organic EL display unit exhibits excellent image quality, contrast and brightness.

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Tokyo, Japan

Yuichi Iketsu