Predictive power control in a flat panel display

• US 9,224,340 B2
• Filed: 05/23/2012
• Issued: 12/29/2015
• Est. Priority Date: 05/23/2012
• Status: Active Grant

• Current Assignee: Dialog Semiconductor Incorporated (Renesas Electronics Corporation)
• Original Assignee: Dialog Semiconductor Incorporated (Renesas Electronics Corporation)
• Inventors: Jin, Xuecheng
• Primary Examiner(s): Merkoulova, Olga
• Application Number:
  US13/479,071
• Publication Number:
  US 20130314391A1
• Time in Patent Office: 1,315 Days
• Field of Search: 345/102, 345/94, 345/98, 345/84, 345/48, 345 52- 54, 345/212, 315/169.3, 349/70, 349/61
• US Class Current: 1/1
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02M 1/14 Arrangements for reducing ripples from dc input or output
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

A Predictive Power Control (PPC) device within a TCON Bias IC that addresses an overdesign inefficiency and enables a low cost solution. A PPC block utilizes the next frame image data and interacts with a pulse width modulation (PWM) control block of internal regulators to proactively prepare the output voltages of a power regulator for the power requirements in one or more future frames, for example.

Claims

1. A method for controlling a power regulator comprising:

receiving, during a first cycle corresponding to a display duration of a current image, future image property information related to a future image to be displayed on a display during a second cycle after display of the current image, said second cycle occurring after said first cycle;

generating a power regulator control signal, prior to said second cycle and prior to display of the future image, based upon the future image property information; and

precharging a power regulator output voltage based on the power regulator control signal, prior to said second cycle by a duration of time that depends on the future image property information, and prior to the power regulator output voltage dropping below a threshold value, said power regulator output voltage coupled to a switch that assists in displaying said future image on said display during said second cycle.

2. The method of claim 1, wherein said future image property information is a load on at least a portion of said display when displaying said future image during said second cycle.

3. The method of claim 2, wherein said portion of said display includes at least one of a row or a column of a thin film transistor liquid crystal display (TFT LCD).

4. The method of claim 1, wherein said power regulator controls a liquid crystal display (LCD) panel.

5. The method of claim 1, wherein said future image property information can include information about the intensity of the future image.

6. A method for controlling a power regulator comprising:

receiving, during a first cycle corresponding to a display duration of a current image, future image property information related to a future image to be displayed on a display during a second cycle after display of the current image, said second cycle occurring after said first cycle;

generating a power regulator control signal, prior to said second cycle and prior to display of the future image, based upon the future image property information; and

modifying a duty cycle of a power regulator for said second cycle to turn on the power regulator prior to said second cycle by a duration of time that depends on the future image property information, the duty cycle modified based on said power regulator control signal to reduce a maximum voltage ripple of an output voltage of the power regulator, said power regulator output voltage coupled to a switch that assists in displaying said future image on said display during said second cycle.

7. The method of claim 6, wherein said future image property information is a load on at least a portion of said display when displaying said future image during said second cycle.

8. The method of claim 7, wherein said portion of said display includes at least one of a row or a column of a thin film transistor liquid crystal display (TFT LCD).

9. The method of claim 6, wherein said step of modifying the duty cycle of the power regulator results in an increase in the output voltage prior to the output voltage dropping below a voltage threshold during said second cycle.

10. The method of claim 6, wherein said power regulator controls a liquid crystal display (LCD) panel.

11. The method of claim 6, wherein said future image property information can include information about the intensity of the future image.

12. A predictive power control system for controlling a power regulator comprising:

a precharge module coupled to receive, during a first cycle corresponding to a display duration of a current image, future image property information related to a future image to be displayed on a display during a second cycle after display of the current image, said second cycle occurring after said first cycle, and to generate, prior to the second cycle and prior to display of the future image, a power regulator control signal based upon the future image property information; and

a power regulator, coupled to said precharge module, to generate a power regulator output voltage signal prior to said second cycle by a duration of time that depends on the future image property information, the power regulator output voltage signal generated based upon said power regulator control signal, said power regulator output voltage coupled to a switch that assists in displaying said future image on said display during said second cycle.

13. The system of claim 12, wherein said power regulator output voltage signal increases prior to the output voltage dropping below a threshold value.

14. The system of claim 12, wherein said future image property information is a load on at least a portion of said display when displaying said future image during said second cycle.

15. The system of claim 14, wherein said portion of said display includes at least one of a row or a column of a thin film transistor liquid crystal display (TFT LCD).

16. The system of claim 12, wherein said power regulator output voltage increases prior to the output voltage dropping below a voltage threshold during said second cycle.

17. The system of claim 12, wherein said power regulator controls a liquid crystal display (LCD) panel.

18. The system of claim 12, wherein said future image property information includes information about the intensity of the future image.

19. The system of claim 12, wherein said power regulator modifies a duty cycle for said second cycle to turn on the power regulator prior to said second cycle by the duration of time that depends on the future image property information, the duty cycle modified based on said power regulator control signal to reduce a maximum voltage ripple of said output voltage based upon the power regulator control signal.

20. The system of claim 19, wherein said future image property information is a load on at least a portion of said display when displaying said future image during said second cycle.

21. The system of claim 20, wherein said portion of said display includes at least one of a row or a column of a thin film transistor liquid crystal display (TFT LCD).

22. The system of claim 19, wherein modifying the duty cycle of the power regulator results in an increase in the output voltage prior to the output voltage dropping below a voltage threshold during said second cycle.

23. The system of claim 19, wherein said power regulator controls a liquid crystal display (LCD) panel.

24. The system of claim 19, wherein said future image property information includes information about the intensity of the future image.

25. The system of claim 12, wherein said future image property information includes a weighted sum of image intensities of two or more images, including said future image, to be displayed after display of the current image, the two or more images weighted differently in the weighted sum.