PREDICTIVE POWER CONTROL IN A FLAT PANEL DISPLAY

• US 20130314391A1
• Filed: 05/23/2012
• Published: 11/28/2013
• Est. Priority Date: 05/23/2012
• Status: Active Grant

• Current Assignee: Dialog Semiconductor Incorporated (Renesas Electronics Corporation)
• Original Assignee: iWatt, Inc. (Renesas Electronics Corporation)
• Inventors: Jin, Xuecheng
• Granted Patent: US 9,224,340 B2
• Time in Patent Office: Days
• US Class Current: 345/212
• 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, future image property information related to a future image to be displayed on a display during a second cycle, said second cycle occurring after said first cycle;

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

precharging the power regulator output voltage, during said second cycle based on the power regulator control signal, prior to the 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 the predicted 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 step of precharging the power regulator begins prior to the output voltage dropping below a target voltage level during said second cycle.

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

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

7. A method for controlling a power regulator comprising:

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

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

modifying a duty cycle of a power regulator for said second cycle, based on said power regulator control signal to reduce a maximum voltage ripple of said output voltage based upon the 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.

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

9. The method of claim 8, 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).

10. The method of claim 7, 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 target voltage level during said second cycle.

11. The method of claim 7, wherein said power regulator controls a liquid crystal display (LCD) panel.

12. The method of claim 7, wherein said future image property information can include information about the intensity of the future image.

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

a precharge module coupled to receive, during a first cycle, future image property information related to a future image to be displayed on a display during a second cycle, said second cycle occurring after said first cycle, and to generate 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 during said second cycle 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.

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

15. The system of claim 13, wherein said future image property information is the predicted load on at least a portion of said display when displaying said future image during said second cycle.

16. The system of claim 15, 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).

17. The system of claim 13, wherein said power regulator output voltage increases prior to the output voltage dropping below a target voltage level during said second cycle.

18. The system of claim 13, wherein said power regulator controls a liquid crystal display (LCD) panel.

19. The system of claim 13, wherein said future image property information can include information about the intensity of the future image.

20. The system of claim 13, wherein said power regulator modifies a duty cycle for said second cycle based on said power regulator control signal to reduce a maximum voltage ripple of said output voltage based upon the power regulator control signal.

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

22. The system of claim 21, 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).

23. The system of claim 20, 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 target voltage level during said second cycle.

24. The system of claim 20, wherein said power regulator controls a liquid crystal display (LCD) panel.

25. The system of claim 20, wherein said power regulator controls a liquid crystal display (LCD) panel.

26. The system of claim 20, wherein said future image property information can include information about the intensity of the future image.