Granted Patent B2

US 8,436,632 · App. 12/164,000 · Granted May 7, 2013

Abstract

Claims (66)

1. A method for selecting Vcom for a liquid crystal display comprising the steps of:

A. covering at least a first portion of the display with a diffusing unit;

B. applying a first gamma voltage to the display;

C. normalizing the light exiting the first portion of the display with said diffusing unit;

D. measuring the flicker of the light exiting the diffusing unit; and

E. adjusting the Vcom of the display until the minimum flicker is measured and results in a first Vcom for the display.

2. The method of claim 1 further comprising the steps of:

repeating steps A-D with a second gamma voltage;

adjusting the Vcom of the display until the minimum flicker is measured and results in a second Vcom for the display; and

averaging said first and second Vcom values to determine an average Vcom for the display.

3. The method of claim 1 further comprising the steps of:

covering a second portion of the display with said diffusing unit;

repeating steps B-D with the second portion;

adjusting the Vcom of the display until the minimum flicker is measured and results in a second Vcom for the display; and

averaging the first and second Vcom values to determine an average Vcom for the display.

4. The method of claim 1 wherein said at least first portion is the entire viewable area of the display.

5. The method of claim 2 further comprising the steps of:

repeating steps A-D with a third and fourth gamma voltage;

adjusting the Vcom of the display until the minimum flicker is measured and results in a third and fourth Vcom for the display; and

averaging said first, second, third, and fourth Vcom values to determine an average Vcom for the display.

6. The method of claim 3 further comprising the steps of:

covering a third portion of the display with said diffusing unit;

repeating steps B-D with the third portion;

adjusting the Vcom of the display until the minimum flicker is measured and results in a third Vcom for the display;

covering a fourth portion of the display with said diffusing unit;

repeating steps B-D with the fourth portion;

adjusting the Vcom of the display until the minimum flicker is measured and results in a fourth Vcom for the display; and

averaging the first, second, third, and fourth Vcom values to determine an average Vcom for the display.

7. The method of claim 6 further comprising the step of preventing ambient light from entering the diffusing unit.

8. The method of selecting a Vcom for a liquid crystal display comprising the steps of:

A. covering a first quadrant of the display with a diffusing unit;

B. applying a first gamma voltage to the display;

C. normalizing the light exiting the first quadrant of the display with said diffusing unit;

D. measuring the flicker of the light exiting the diffusing unit;

E. adjusting the Vcom of the display until the minimum flicker is measured and results in a Vcom for the first quadrant

F. covering a second, third, and fourth quadrant of the display with a diffusing unit;

G. repeating steps B-E resulting in a Vcom for the second, third, and fourth quadrant; and

H. averaging the Vcoms for the first, second, third, and fourth quadrants resulting in a first average Vcom for the display.

9. The method of claim 8 further comprising the steps of:

I. covering the center portion of the display with a diffusing unit;

J. repeating steps B-E resulting in a Vcom for the center portion of the display; and

K. averaging the Vcoms for the first, second, third, and fourth quadrants with the Vcom for the center portion of the display resulting in a first average Vcom for the display.

10. The method of claim 8 further comprising the steps of:

I. covering the center portion of the display with a diffusing unit;

J. repeating steps B-E resulting in a Vcom for the center portion of the display;

K. weighting the Vcom for the center portion of the display resulting in a weighted value for the center portion Vcom; and

L. averaging the Vcoms for the first, second, third, and fourth quadrants with the weighted value for the center portion Vcom resulting in a first weighted-average Vcom for the display.

11. The method of claim 8 further comprising the steps of:

repeating steps A-H for a plurality of gamma voltages resulting in a plurality of average Vcoms for the display; and

averaging the first average and the plurality of average Vcoms resulting in an ideal Vcom for the display.

12. The method of claim 9 further comprising the steps of:

repeating steps A-K for a plurality of gamma voltages resulting in a plurality of average Vcoms for the display; and

averaging the first average and the plurality of average Vcoms resulting in an ideal Vcom for the display.

13. The method of claim 10 further comprising the steps of:

repeating steps A-L for a plurality of gamma voltages resulting in a plurality of weighted-average Vcoms for the display; and

averaging the first weighted-average Vcom and the plurality of weighted-average Vcoms resulting in an ideal Vcom for the display.

14. The method of claim 9 further comprising the step of preventing ambient light from entering the diffuser.

15. A system for determining Vcom for a liquid crystal display having a display surface and a LCD control board, said system comprising:

a diffuser having a first opening with a first area and a second opening with a second area where said first opening is against the display surface and said first area is larger than the second area;

a light sensing device adjacent to the second opening of said diffuser; and

a microprocessor receiving electrical signals from said light sensing device and in electrical communication with the LCD control board.

16. The system of claim 15 further comprising an analog-digital converter between the light sensing device and the microprocessor.

17. The system of claim 15 wherein said diffuser prevents ambient light from entering said first opening.

18. The system of claim 15 wherein the internal surfaces of said diffuser are highly reflective.

19. The system of claim 15 wherein the diffuser covers the entire display surface.

20. The system of claim 15 wherein the diffuser covers a quadrant of the display surface.

Assignments (10)