Global Oled Technology LLC

Eastman-kodak Company

Semiconductor Manufacturing International (shanghai) Corporation

Kouichi Onomura

Seiichi Mizukoshi

Makoto Kohno

Nobuyuki Mori

Kazuyoshi Kawabe

The rate of reading from a memory for storing display irregularity correction data is lowered. At the time of display, calculation is carried out in a correction calculation section using an input signal and correction data in one or more memory units, and brightness inconsistency correction is carried out. The way in which correction calculation is carried out in the correction calculation section is changed for every frame.

Display device

The rate of reading from a memory for storing display irregularity correction data is lowered. At the time of display, calculation is carried out in a correction calculation sectionusing an input signal and correction data in RAM, and brightness inconsistency correction is carried out. The way in which correction calculation is carried out in the correction calculation sectionis changed for every frame.

To compensate for voltage drop on a power supply line. In a display device, pixel data is supplied to each of a plurality of pixels arranged in a matrix form and display is performed. Each pixel has a self-emissive element. A horizontal direction power supply line (horizontal direction PVDD) which supplies a power supply to each pixel is provided, and one end of the horizontal PVDD line is connected to a vertical power supply line (vertical PVDD line) that is connected to an external power supply terminal. Correction data corresponding to a voltage drop to the horizontal PVDD line due to a resistance in the vertical PVDD line is then obtained through a calculation based on pixel data, and the input pixel data is corrected using the correction data so as to reduce the influence of the voltage drop on the pixel current.

Compensating voltage drop for display device

Nonuniformity in an organic EL display device is effectively detected. All display pixels of an organic EL panel are turned on and the display is photographed with a digital camera. A computer performs image processing of the photographed image to detect an area in which unevenness exists. Then, a V-I curve of each pixel in the area is measured to calculate necessary correction values. The calculated correction values are stored in a memory for use in correcting a signal input to the organic EL panel.

Method of correcting nonuniformity of pixels in an OLED

A method of measuring a panel current in an active matrix organic electroluminescence display panel, wherein when a current flowing through a display panel when one or a plurality of pixels are caused to emit light is measured, a flow-in current flowing into the display panel from a side of a high voltage and a flow-out current flowing out from the display panel toward a side of a low voltage are simultaneously measured, and a value of a panel current is determined using both obtained measurement results.

Method and device for measuring panel current

An electroluminescent display device having a first and a second power supply; a respective power supply line for each row, wherein each power supply line is placed along a horizontal direction and is connected to the respective first electrodes of the driving TFTs of the pixels in the corresponding row; a plurality of switches, each connected to one or more power supply lines, for selectively connecting the corresponding one or more power supply lines to either the first or the second power supply; a gate driver for selecting a gate line; and a selecting circuit for controlling the plurality of switches, wherein the selecting circuit causes the power supply line corresponding to the selected gate line to be connected to the first power supply, and the one or more power supply lines not corresponding to the selected gate line to be connected to the second power supply.

Current controlled electroluminescent display device

An OLED display having a correction circuit for producing corrected image data in response to the first image data and in response to correction data to correct for brightness unevenness due to TFT variations; a memory for storing first image data or correction data; a switch effective in first and second states in response to a function switching signal having first and second conditions, respectively; and circuitry for causing the switch to be in the first state to connect the memory to the image input signal interface and to provide the stored first image data to the panel as the second image data; and for causing the switch to be in the second state to connect the memory to the correction circuit, provide the stored correction data to the correction circuit, and provide the corrected image data to the panel as the second image data.

Correcting brightness variations in organic electroluminescent panel

During image display, pixel current measurement for brightness irregularity correction is carried out. Display is carried out by sequentially writing pixel data in a horizontal direction to pixel sections that are arranged in a matrix shape. Horizontal power supply lines PVDD are arranged for each horizontal line, and power is supplied from these power supply lines to corresponding pixel sections. When carrying out measurement of pixel current by lighting pixel sections one at a time, a horizontal power supply line PVDD of a horizontal line to which the lit pixel belongs is connected to a power supply PVDDb by a switch, and other horizontal power supply lines PVDD are connected to PVDDa.

Measurement of pixel current in display device

After a look-up table applies &#x3b3; correction to each of R, G, and B signals, a multiplier multiplies a &#x3b3; corrected signal by a gain. An adder adds an offset to an output of the multiplier and supplies a resultant gain/offset corrected signal to a display panel. Memories store entropy coded correction data, which can be expanded by corresponding expansion circuits and supplied to the multiplier and the adder, respectively.

Display apparatus

Displaying an image with unevenness correction by measuring Vgs-Id characteristics of the transistors in a subset of pixels; approximating each characteristic using an equation of the form=(());calculating a value c' using the approximations; measuring the characteristics of the remaining pixels; approximating each of those characteristics by an equation of the same form, using c&#x2032; as the power for all of the approximations, calculating corrected image signals for each pixel using the respective approximations of the corresponding pixels of the display device to correct for unevenness; and applying the corrected image signals to the corresponding pixels of the display device to display a corresponding image with unevenness correction.

Brightness unevenness correction for OLED

On a panel, a plurality of PVDD lines, each of which corresponds to a horizontal line of pixels and supplies power to the pixels of the horizontal line, are provided. A voltage drop correction unit that obtains a voltage drop before reaching the pixel, based on resistance in the plurality of power supply lines and currents flowing therein, and corrects display data so as to cancel the obtained voltage drop of the pixel. A display unevenness correction unit that corrects uneven brightness caused by a variation in a TFT characteristic of the pixel by performing a calculation using display data of the pixel and obtained correction data of the pixel.

Organic EL display module and manufacturing method of the same

An organic EL display apparatus including in each display pixel an organic EL element. A drive transistor supplies a drive current that depends on brightness data and having the display pixels arranged in a matrix form. The display includes a correction gain storage unit for storing display pixel positions and a correction gain for correcting the slope of the brightness-data-based drive current of the drive transistors in the display pixels; and a correction unit for correcting pixel-by-pixel brightness data depending on the pixel position using the correction gain stored in the correction gain storage unit into brightness data for the pixel to generate corrected brightness data, each of the display pixels is displayed by driving its drive transistor in response to the data generated by the correction gain storage unit and the correction unit and supplying the corresponding organic EL element with the drive current.

Organic electroluminescent display apparatus

A display device, for carrying out image display on a display panel by controlling current flowing in display elements for each pixel based on image data, including display setting circuitry for setting a relationship between image data and current values for current flowing in display elements in response to an input adjustment signal, to set contrast or brightness; estimation circuitry for estimating panel current flowing in all pixels when carrying out display for the display panel based on the image data; and current control circuitry for controlling actual panel current by correcting the set contrast or brightness based on the panel current estimated by the estimation circuitry.

Controlling current in display device

An organic electroluminescent display device in which display pixels containing organic electroluminescent elements are arranged in a matrix, comprising:

Correction of pixels in an organic EL display device

To appropriately adjust luminance and a black level even when characteristics of an organic EL display element should be changed due to an environmental change or heat self-generation, to display a stable image. A current detector detects a level of a total panel current flowing in an organic EL panel. The detected level is subjected to A/D conversion before being supplied to an adder. Meanwhile, a video signal is supplied to a current calculatorto be converted into data corresponding to the level of a total panel current, before being supplied to the adder. The adder then compares an average total panel current level, estimated based on a video signal, and an actual total panel current level, to obtain a difference so that a black level for image data to be supplied to the panel is adjusted according to the difference.

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Yokohama, Japan

Kouichi Onomura