US 6,583,779 B1Granted

Display device and drive method thereof

AssigneeSony Corporation

InventorJunichi Ushirono

Life of this patent

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Abstract

Displaying an image at different aspect ratios requires incorporating circuits such as memory and scan converters into the drive system driving the display thus increasing the cost. In an active matrix liquid crystal display device a logic control circuit is added to the vertical drive circuit, and when a black display pulse BLK for switching the aspect ratio is applied, the pixels in a specified range at the top and bottom (or left and right) of the pixel section are set to active status and, a black level signal written for all pixels of the area set to active status and, pixels of all other areas are set by line to active status in sequence in the pixel section by vertical scanning performed by a vertical scanner and display signals are written for each line by horizontal scanning with a horizontal scanner, to allow displaying different aspect ratios with a simple design, low cost and low power consumption.

Claims24

Dependent claims

A display device comprising:

a pixel section having pixels arrayed in lines;
a vertical drive system for sequentially setting each pixel of the pixel section by lines to active status;
a control circuit for setting pixels of a specified area on the left and right or upper and lower of the pixel section to active status by applying a control signal;
and
a horizontal drive system for writing a specified luminance level signal for all pixels of an area set in active status by the control circuit, and also writing for pixels of all other areas, display signals in each line sequentially set to active status by the vertical drive system, wherein:
said control circuit comprises a plurality of two-input gate circuits formed for each line to set each pixel to active status according to output of said gates,
each of a specified number of gate circuits corresponding to said specified areas from among said plurality of gate circuits has two inputs for said control signal and vertical scanning signal to scan each pixel in the pixel section in the line direction, and
each of said plurality of gate circuits corresponding to areas other than said specified areas has two inputs for a vertical scanning signal for scanning each pixel of said pixel section in the line direction and a signal of a fixed level to pass the vertical scanning signal unchanged.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/584,141Filed 31 May 2000
Priority: JP 11-1547182 Jun 1999
Granted: 24 Jun 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G09G 3/3688
Details of drivers for data electrodes: suitable for active matrices only
G09G 3/20
Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes: for presentation of an…
G09G 3/30
Using controlled light sources: using electroluminescent panels
G09G 2300/08
Aspects of the constitution of display devices: active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal…