System and method for reducing power consumption by a display controller

• US 7,570,238 B2
• Filed: 04/01/2004
• Issued: 08/04/2009
• Est. Priority Date: 04/01/2004
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Van Dyke, Phil
• Primary Examiner(s): Abdulselam; Abbas I
• Application Number:
  US10/815,317
• Publication Number:
  US 20050219174A1
• Time in Patent Office: 1,951 Days
• Field of Search: 345/98, 345/690, 345/87, 345/100, 345/204, 345/89, 345 92- 93, 345/99, 345/213, 345/214, 345/589, 348/489, 348/511, 348/516
• US Class Current: 345/87
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters

Abstract

A display controller and method for reducing power consumption of an electro-optical image display while still providing a useful display. A source of a set of image data words corresponding to individual pixels of an image is provided. A control circuit is adapted to substitute for a selected subset of the set of image data words the image data words from one or more contiguous pixels and to provide the resulting modified set of image data words to an output port to be made available to the electro-optical image display. The method provides a set of image data words corresponding to individual pixels of an image, substitutes for a selected subset of the set of image data words the image data words from one or more contiguous pixels, and makes available to the electro-optical image display the modified set of data words resulting from the substitution.

Claims

1. A method for reducing power consumption, comprising:

producing an electrical representation of an image, wherein a resolution of the image is equivalent to the resolution of a display, and the apparent resolution of the image is a first fraction of the resolution of the display, wherein the first fraction is a ratio of the apparent resolution of the image divided by the resolution of the display; and

producing an output, in which a data line is held constant for a period of time that is equivalent to a multiple of an inverse of the first fraction and a period of time required to transmit data representing a single pixel, wherein power consumption is reduced by reducing data toggling on the data line by the first fraction.

2. The method of claim 1 further comprising retrieving from memory a selective first fraction of data stored in memory that is an electrical representation of the image.

3. The method of claim 1, wherein the output is parallel-bit data words, each data word representing a single pixel, each bit of the data word is held constant for a period of time that is equivalent to a multiple of the inverse of the first fraction and the period of time required to transmit a single data word.

4. A display controller for performing the method of claim 1.

5. A digital image display system for performing the method of claim 1 including the display.

6. The digital image display system of claim 5 wherein the display is an electro-optic display and circuitry performs the method.