Global Oled Technology LLC

Eastman-kodak Company

Lg Display Co., Ltd.

Other

Semiconductor Manufacturing International (shanghai) Corporation

Seiichi Mizukoshi

Makoto Kohno

Kouichi Onomura

Nobuyuki Mori

Kenneth Alan Parulski

Masaki Izumi

Nobuyki Mori

Kazuyoshi Kawabe

Clay A Dunsmore

Seishi Ohmori

John J Uebelacker

Warren D Severin

Tomonori Satoh

John K Lynch

An Organic Light Emitting Diode (OLED) display device can include a display panel, a pixel circuit, and a data line and a power line connected in parallel and to the pixel circuit; a data driver for supplying a data voltage to the data line in display and sensing modes; and a sensing unit for supplying a high-potential voltage to the power line to drive the pixel circuit, cutting off supplying the high-potential voltage to the power line in a sensing duration of the sensing mode, sensing a voltage corresponding to a pixel current of the pixel circuit using the power line. A capacitor can be connected in parallel with the power line is charged according to the pixel current flowing through the power line, and the sensing unit senses the sensing voltage on the power line by sampling and holding the charged voltage in the capacitor.

Organic light emitting diode display device for pixel current sensing in the sensing mode and pixel current sensing method thereof

An object of the invention is to convert input RGB data to R'G&#x2032;B&#x2032;W data without suffering loss of gradations of the input RGB data. A display panelis configured having unit pixels made up of subpixels of RGBW (red, green, blue, white). In an RGB&#x2192;R&#x2032;G&#x2032;B&#x2032;W conversion section, conversion is carried out under conditions that usage rate of W is less than 100%, and a bit width of input RGB data us larger than a bit width of R&#x2032;G&#x2032;B&#x2032;W data after conversion. In the RGB&#x2192;R&#x2032;G&#x2032;B&#x2032;W conversion section, R1G1B1values and W values are determined so that an absolute value of a sum of values obtained by multiplying differences between respective RGB data input and respective RGB components in R&#x2032;G&#x2032;B&#x2032;W data after conversion by a weight, becomes minimum.

Display device

An organic light emitting display device including a display panel including a first pixel connected with a first data line and first and second scan lines, a second pixel connected with a second data line and the first and second scan lines, and a reference line connected in common with the first and second pixels; a source driver configured to operate first and second sensing modes for sensing driving characteristic values of the first and second pixels through the reference line; and a scan driver configured to drive the first and second scan lines so as to drive only the first pixel for the first sensing mode or only the second pixel for the second sensing mode.

Organic light emitting display device

Provided are an organic light emitting display and a method of manufacturing the same. The organic light emitting display includes: a display panel including a plurality of pixels, each pixel including: a light emitting element, and a driving element to drive the light emitting element, a data driving circuit to, within one horizontal display period: write sensing data to a pixel on a horizontal display line through a data line, sense the pixel current of the pixel through a reference line, and then write display data compensated by a first offset compensation value to the pixel, an offset calculator to calculate a second offset compensation value for compensating changes in the driving element over time based on the sensed value of the pixel current, and an offset memory to update the pre-stored first offset compensation value with the second offset compensation value when display data writing is stopped.

Organic light emitting display capable of compensating for luminance variations caused by changes in driving element over time and method of manufacturing the same

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.

To alleviate an afterimage phenomenon caused by a hysteresis characteristic of a drive transistor. Current driven type light emitting elementsare provided for each of pixelsthat are arranged in a matrix shape, and current of the light emitting elementsis controlled using drive TFTsthat operate by receiving data voltage on a gate. At least two power supply voltages (PVDDa, PVDDb) for supply to each pixel are provided, one being set to a voltage such that current corresponding to a data voltage flows in the drive TFT, the other being set to a voltage beyond a variation range of data voltage and that reverse biases the drive TFT, and the two power supply voltages are switched and supplied to each pixel

An OLED display device which can sense a current of each pixel at high speed by a simple structure in order to compensate for luminance non-uniformity and a pixel current sensing method thereof are discussed. The OLED display device includes a display panel including pixels, each including a light emitting element and a pixel circuit for independently driving the light emitting element, a data driver for driving a data line connected to the pixel circuit using a data voltage, floating one of the data line, a reference line for supplying a reference voltage to the pixel circuit, and a power line for supplying a power to the pixel circuit to use the floated line as a current sensing line, sensing a voltage corresponding to a pixel current of the pixel circuit flowing to the current sensing line, and outputting the sensing voltage, in a sensing mode.

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.

There is provided a display device in which disadvantageous effects due to unnecessary operations of an image lag alleviating function are minimized. In a display device of active matrix type, for each of the pixels arranged in a matrix, a current-driven emissive element is provided, and the current of the emissive element is controlled using a drive TFT so as to perform display. While a black display period during which an opposite bias voltage is applied between the gate electrode and the source electrode of the drive TFT is inserted in order to alleviate image lag, this insertion is performed only when a predetermined condition is satisfied, and is performed for a certain duration according to a command by a microcomputer ().

Display unevenness is suppressed. A display device includes pixels () arranged in matrix, each including a current-driven type light emitting element (EL) and a drive transistor (Tr) for supplying a current to the current-driven type light emitting element (EL). The current-driven type light emitting element (EL) is driven by dividing each frame period into a plurality of sub-frame periods for lighting time. The drive transistor is controlled under current write driving using two write currents having a ratio of 1:1/2and a sum of the two write currents.

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

In order to maintain a high visual image quality and save power, a display device includes: R sub-pixels, G sub-pixels, B sub-pixels, and W sub-pixels; and a human detection sensor () for detecting whether or not a person is present within a predetermined range. A use rate of the W sub-pixels is changed depending on whether or not a person is present within the predetermined range.

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

Noise on a current to be measured is removed. Horizontal power supply lines (PVDD) are arranged in a horizontal direction and supply a current to pixels in respective corresponding horizontal lines. A switch () connects a group of the horizontal power supply lines (PVDD) to a first power supply line (PVDDa) or a second power supply line (PVDDb) disposed outside a pixel region in a switchable manner. Only the horizontal power supply lines (PVDD) in a group to which a pixel to be measured belongs are supplied with power from the second power supply line (PVDDb) so as to measure a current of each pixel in the group, and a current flowing into a power source (PVDDa) connected to a group to which other pixels than the pixel to be measured belong is measured, to thereby calculate a pixel current based on a difference between the two measured currents.

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.

Growing community of inventors

Kanagawa, Japan

Seiichi Mizukoshi