Pioneer Corporation

Panasonic Corporation

Jun Kamiyamaguchi

Masahiro Suzuki

Tetsuya Shigeta

Hirofumi Honda

Tetsuro Nagakubo

Akira Gotoda

The object is to provide a display device in which high-quality image display that is free from luminance nonuniformity can be obtained with a simplified structure. A magnitude of load corresponding to the light emission state of each pixel cell on a display line is measured for each display line based on a video signal, and correction of the luminance level according to the magnitude of load corresponding to the display line is conducted for the interval of the video signal corresponding to each display line.

Display device

An improved driving device for a display panel. In the display panel, pixel cells serving as pixels are positioned in a plurality of display lines. The driving device drives the display panel according to pixel data derived from an input image signal. The display lines are divided into a plurality of display line groups, and each group includes a plurality of neighboring display lines. The driving device has a light emission driving circuit. This circuit causes the pixel cells in each of the neighboring display lines in the respective display line groups to emit light at different brightness levels based on weighting values assigned to the display lines. The weighting values are assigned to the display lines such that bias in brightness differences between the pixel cells positioned in neighboring display lines falls within a prescribed range for all neighboring display lines in the display panel.

Driving device for a display panel

A driver device for a display panel. Pixel cells are arranged on respective display lines of the display panel. Each N adjacent display lines makes one display line group. N is an integer of two or more. The pixels in each display line group are driven to emit light at different luminance levels based on one of M different dither patterns. One of the M dither patterns is selected sequentially and in predetermined periods, and the selected dither pattern is used. M is less than N. In the dither processing, N different weighting values are allocated to the N display lines in the display line group, respectively.

Display panel driver device

A method of grayscale-driving a display panel in accordance with pixel data derived from a video signal. The display panel includes a plurality of display lines, with a plurality of pixel cells serving as pixels being arranged on each display line. A display period of a single field of the video signal is divided into a plurality of subfields. The method includes dividing one subfield into M lower subfields. M is an integer greater than one. M groups of display lines are prepared by sequentially taking every M display lines from the display lines. First to Mth address steps are performed in the M lower subfields respectively and sequentially. Each address step sets the pixel cells belonging to the display lines of the display line group concerned, to a drive mode determined by the pixel data. A first light emission step is performed to cause the pixel cells whose drive mode is a lit mode, to emit light directly before or after the address step concerned. Another subfield is divided into N lower subfields. N is smaller than M. N groups of L continuos address steps are prepared from the first to Mth address steps. L is an integer greater than one. The N groups of L continuous address steps are performed in the N lower subfields respectively and sequentially. A second light emission step is performed to cause the pixel cells whose drive mode is the lit mode, to emit light directly before or after the address step group concerned.

Display panel driving method

A display device with a dithering circuit is provided which can perform dithering on an input video signal without causing flicker and dither noise. A correction value is provided to reduce the difference (average error value) between an average value of brightness levels represented by pixel data corresponding to each of pixels in a pixel group and an average value of brightness levels represented by dither added pixel data corresponding to each of the pixels in the pixel group. This correction value is added to the dither added pixel data for correction. This prevents flicker from being produced even when the assignment of dither coefficients in the pixel group is changed in each field to reduce dither noise. Also provided is a gray scale processing system which can perform gray scale processing on an input video signal without causing problems such as flicker. Control is provided to the operation of a gray scale processing circuit that performs gray scale processing on the input video signal in response to the frequency of the input video signal. This makes it possible to prevent a problem such as flicker even when an input video signal of a relatively high frequency is supplied.

Growing community of inventors

Yamanashi-ken, Japan

Jun Kamiyamaguchi