Display device and driving circuit thereof

• US 20110242112A1
• Filed: 03/31/2010
• Published: 10/06/2011
• Est. Priority Date: 03/31/2010
• Status: Abandoned Application

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Technology Corporation (Renesas Electronics Corporation)
• Inventors: Shoji, Takashi, KATAYAMA, Yukari, Akai, Akihito, Kurokawa, Yoshiki
• Application Number:
  US12/750,794
• Publication Number:
  US 20110242112A1
• Time in Patent Office: Days
• US Class Current: 345/501
• CPC Class Codes: G09G 2340/02 Handling of images in compressed format, e.g. JPEG, MPEG
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 5/36 characterised by the display of a graphic pattern, e.g. using an all-points-addressable [APA] memory
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513
• CPC Class Codes: H04N 19/198 including smoothing of a sequence of encoding parameters, e.g. by averaging, by choice of the maximum, minimum or median value

Abstract

The display driver includes: a display data compression circuit; a recording circuit; a display data decompression circuit; and an output circuit. Further, the display driver is provided with a compressibility setting circuit. The display data compression circuit has the function of compressing the display data according to a compressibility set by the compressibility setting circuit. With the display driver arranged like this, the power consumption can be reduced by increasing the compressibility for a displayed image such that the image quality is not noticeably deteriorated even with the compressibility increased. Further, for the displayed image such that the image quality is noticeably deteriorated with the compressibility increased, a sufficient image quality after data decompression can be secured by lowering the compressibility.

Claims

1. A display driver comprising:

a display data compression circuit operable to compress display data of an image thereby to reduce a data amount of the display data;

a recording circuit operable to store the display data compressed by the display data compression circuit;

a display data decompression circuit operable to decompress the display data read from the recording circuit; and

an output circuit operable to output the display data decompressed by the display data decompression circuit to a display section,

wherein the display driver includes a compressibility setting circuit operable to set a compressibility of the display data, and

the display data compression circuit includes a function for compressing the display data with the compressibility set by the compressibility setting circuit.

2. The display driver according to claim 1, further comprising a display area setting circuit operable to set a plurality of display area,

wherein the compressibility setting circuit includes a function for setting a compressibility corresponding to each display area, and

the display data compression circuit includes a function for switching the compressibility and compressing the display data according to a value set by the display area setting circuit, and a display position of the display data.

3. The display driver according to claim 2, further comprising a compression-mode setting circuit operable to set a compression mode corresponding to each display area,

wherein the display data compression circuit switches the compression mode and compresses the display data according to a value set by the compression-mode setting circuit and a display position of the display data.

4. The display driver according to claim 1, further comprising a circuit operable to update a value set by the compressibility setting circuit,

wherein the compression of display data of an image includes at least the step of performing quantization using a quantization parameter, and

the update is conducted depending on a value taken by the quantization parameter.

5. A display unit, comprising:

a display driver including a CPU having a display data compression circuit operable to compress display data of an image thereby to reduce a data amount of the display data,

a recording circuit operable to store the compressed display data,

a display data decompression circuit operable to decompress the display data read from the recording circuit, and

an output circuit operable to output the display data decompressed by the display data decompression circuit; and

a display section operable to display the display data output through the output circuit,

wherein the CPU includes a compressibility setting circuit operable to set a compressibility of the display data,

the display data compression circuit includes a function for compressing the display data according to a compressibility set by the compressibility setting circuit, and

the display data compressed by the display data compression circuit is transmitted to the display data decompression circuit through the recording circuit.