Method and device for reducing power consumption in a display

• US 8,471,808 B2
• Filed: 05/11/2009
• Issued: 06/25/2013
• Est. Priority Date: 09/27/2004
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Sampsell, Jeffrey B.
• Primary Examiner(s): SHERMAN, STEPHEN G
• Application Number:
  US12/463,900
• Publication Number:
  US 20090219309A1
• Time in Patent Office: 1,506 Days
• Field of Search: 345/204, 345/108, 345/698, 345/699, 345/87, 345/76, 345/82, 359/245
• US Class Current: 345/108
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G09G 2310/04 Partial updating of the display screen
• 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 3/3466 based on interferometric effect
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127

Abstract

A method and system for reducing power consumption in a display includes driving a display comprising a plurality of display elements characterized by a display state. In a first mode of operation, the display state of substantially all the display elements is periodically re-set so as to display a first series of image frames. Upon changing to a second mode of operation, a second mode of operations comprises re-setting the display state of only a portion of the display elements so as to display a second series of image frames at a display element resolution which is less than said display element resolution used to display said first series of image frames.

Claims

1. A method of updating a display, the method comprising:

applying a series of row voltage strobes to a first set of rows of display elements during a first display write operation so as to configure one or more display elements in said first set of rows to a first selected state, wherein the display elements are arranged as a plurality of pixels of the display, each pixel having at least a first display element and a second display element; and

skipping subsequent row voltage strobes to a subset of said first set of rows during subsequent display write operations that set the remaining rows of the display in accordance with received display data, in order to apply voltage strobes to the first display elements while skipping voltage strobes to the second display elements.

2. The method of claim 1, wherein skipping said subsequent row voltage strobes is performed under low battery conditions.

3. The method of claim 1, wherein skipping said subsequent row voltage strobes comprises displaying a reduced color gamut.

4. The method of claim 1, wherein skipping said subsequent row voltage strobes comprises displaying a reduced gray scale.

5. The method of claim 1, further comprising determining said first selected state based at least in part on image data.

6. The method of claim 1, wherein said skipping is triggered by a power level condition.

7. The method of claim 1, further comprising applying row voltage strobes to all of the remaining rows of the display during the subsequent display write operations.

8. The method of claim 1, further comprising skipping subsequent row voltage strobes to rows in the remaining rows of the display during the subsequent display write operations.

9. The method of claim 8, wherein a frequency of skipping row voltage strobes to rows in the remaining rows is different than a frequency of skipping row voltage strobes to the subset of the first set of rows.

10. The method of claim 8, wherein the number of rows skipped depends on available battery power.

11. The method of claim 8, wherein an increasing number of rows are skipped as a battery power becomes lower.

12. The method of claim 1, further comprising maintaining the display elements in the subset of the first set of rows in a second selected state.

13. The method of claim 12, wherein the second selected state is based on an average brightness or color for at least some of the display elements in the display calculated over at least one image frame portion.

14. The method of claim 12, further comprising receiving the second selected state from an image source.

15. The method of claim 1, further comprising receiving motion video data, wherein the method comprises applying row voltage strobes to the first set of rows only when reference frames of the motion video data are displayed.

16. The method of claim 1, wherein a frequency of applying the series of row voltage strobes to the first set of rows is non-constant.

17. The method of claim 1, wherein each pixel additionally comprises a third display element, and wherein skipping subsequent row voltage strobes to said first set of rows applies voltage strobes to the first and third display elements while skipping voltage strobes to the second display elements.

18. A method of updating a display, the method comprising:

transitioning a set of column voltages to a first set of columns of display elements during a first display write operation so as to configure one or more display elements in said first set of columns to a selected state, wherein the display elements are arranged as a plurality of pixels, each pixel having at least a first display element and a second display element; and

skipping subsequent column transitions to a subset of said first set of columns during subsequent display write operations that set the remaining columns of the display in accordance with received display data, in order to transition voltages to the first display elements without transitioning voltages to the second display elements.

19. The method of claim 18, wherein skipping said subsequent column transitions is performed under low battery conditions.

20. The method of claim 18, wherein skipping said subsequent column transitions comprises displaying a reduced color gamut.

21. The method of claim 18, wherein skipping said subsequent column transitions comprises displaying a reduced gray scale.

22. The method of claim 18, further comprising determining said selected state based at least in part on image data.

23. The method of claim 18, further comprising skipping subsequent column transitions to columns in the remaining columns of the display during the subsequent display write operations, wherein the number of transitions skipped depends on available battery power.

24. The method of claim 18, wherein each pixel additionally comprises a third display element, and wherein skipping subsequent column transitions to said first set of columns transitions voltages to the first and third display elements without transitioning voltages to the second display elements.

25. A display device, comprising:

an array of display elements configured as a plurality of rows, wherein the array of display elements is arranged as a plurality of pixels of the display, each pixel having at least a first display element and a second display element;

a battery configured to provide power to the array; and

an array controller configured to apply a series of row voltage strobes to a first set of rows of the array during a first display write operation so as to configure one or more display elements in said first set of rows to a first selected state;

wherein the array controller is further configured to skip subsequent row voltage strobes to one or more of the rows in the first set of rows based on a power level condition of the battery during subsequent display write operations that set the remaining rows of the display in accordance with received display data, in order to apply voltage strobes to the first display elements while skipping voltage strobes to the second display elements.

26. The device of claim 25, wherein the array controller is configured to skip said subsequent row voltage strobes under low battery conditions.

27. The device of claim 25, wherein an increasing number of rows are skipped as the battery power becomes lower.

28. The device of claim 25, wherein a reduced color gamut or a reduced gray scale is displayed when the array controller skips said subsequent row voltage strobes.

29. The device of claim 25, wherein each pixel additionally comprises a third display element, and wherein the array controller is configured to apply voltage strobes to the first and third display elements while skipping voltage strobes to the second display elements.

30. The device of claim 29, wherein the array controller is further configured to apply voltage strobes to the first display elements while skipping voltage strobes to the second and third display elements.

31. The device of claim 30, wherein the array controller is configured to skip voltage strobes to the second display elements at a frequency that is lower than a frequency at which voltage strobes to the third display elements are skipped.