Method for driving display device

• US 7,439,965 B2
• Filed: 03/05/2004
• Issued: 10/21/2008
• Est. Priority Date: 03/05/2004
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Anderson, Daryl E.
• Primary Examiner(s): Shankar, Vijay
• Application Number:
  US10/794,621
• Publication Number:
  US 20050195175A1
• Time in Patent Office: 1,691 Days
• Field of Search: 345 11- 34, 345204-215, 345690-699
• US Class Current: 345/204
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• 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 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/2077 by a combination of two or more gradation control methods

Abstract

A method is provided for reducing power consumption in a digital display including an array of pixels. The method includes reducing a switching frequency for driving the array of pixels and dividing the array of pixels into groups of a predefined size. A representative value of the input data for the group of pixels may be obtained using a weighting function and the group of pixels are driven to display the representative value.

Claims

1. A multi-mode display device including a display comprising an array of pixels, comprising:

means for driving the display in a first display mode that provides high image quality; and

means for driving the display in a second display mode that provides reduced power consumption and lower screen resolution, wherein the means for driving the display in the second display mode comprises;

means for dividing the array of pixels into groups of pixels;

means for receiving image data for one of the pixel groups;

means for calculating a representative value of the image data; and

means for driving the one group of pixels to display the representative value of the image data.

2. The device of claim 1, wherein the representative value is an average of the image data and the calculating means converts the average of the image data into a halftoned set of pixel colors.

3. The device of claim 1, wherein the calculating means calculates an average intensity level for each primary color in the image data.

4. The device of claim 3, further including means for converting the average intensity level for each primary color into a separate halftoned set of pixels.

5. The device of claim 1, wherein the one group of pixels is a rectangular array.

6. The device of claim 1, wherein the display is capacitively driven.

7. The device of claim 6, wherein the display is selected from a liquid-crystal display device, a digital micro-mirror display device, and an interferometric display device.

8. The device of claim 1, further including means for switching between the first and second display modes.

9. The device of claim 1, wherein the means for driving the display in the second display mode switches the array of pixels only once per frame.

10. The device of claim 1, wherein the means for driving the display in the second display mode switches the array of pixels only once for each primary color per frame.

11. A multi-mode display device, comprising:

a display including a pixel display area;

a controller configured to drive the display in accordance with first and second display modes, the first display mode providing high image quality and the second display mode providing reduced power consumption at lower image quality;

a memory containing image data, and wherein the controller operating in the second display mode is configured to;

receive image data for one group of pixels from the memory;

calculate a representative value of the image data; and

driving the one group of pixels to display the representative value of the image data.

12. The device of claim 11, wherein the representative value is an average of the image data and the controller operating in the second display mode is configured to convert the average into a halftoned set of pixel colors for each primary color.

13. The device of claim 11, wherein the display is capacitively driven,.

14. The device of claim 11, further including a switch configured to placing the controller in the first display mode and the second display mode.

15. The device of claim 14, wherein the switch is user selectable.

16. The device of claim 11, wherein the controller is configured to suggest a display mode to a user based on at least one of battery power remaining and a type of image data to be displayed.