Liquid crystal display driver and method thereof

• US 7,843,414 B2
• Filed: 07/09/2004
• Issued: 11/30/2010
• Est. Priority Date: 08/27/2003
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: Chi Mei Innolux Corporation (InnoLux Corporation)
• Inventors: Shih, Ming-Chia, Hsu, Ying-Hao, Li, Wang-Yang
• Primary Examiner(s): Awad; Amr
• Assistant Examiner(s): Pervan; Michael
• Application Number:
  US10/887,088
• Publication Number:
  US 20050057473A1
• Time in Patent Office: 2,335 Days
• Field of Search: 345/55, 345/84, 345 87-104, 345/690, 345/694, 348/674, 382/167, 349/106, 349/141, 349/164, 349/144
• US Class Current: 345/89
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

A system comprises a liquid crystal display viewable from front and side view points, and comprising a plurality of pixels having corresponding original luminance values, a plurality of data lines in the display, a plurality of data drivers for driving the data lines, and an adjusted gray scale generator for adjusting gray scales of the pixels and outputting adjusted gray scales to the data drivers for driving the data lines.

Claims

1. A system comprising:

a display element having an original luminance value in a frame period

corresponding to an input data between a minimum gray scale and a maximum gray scale;

an adjusted gray scale generator for receiving the input data and outputting a plurality of adjusted gray scale signals including a first adjusted gray scale signal and a second adjusted gray scale signal; and

a driving unit for driving the display element according to the first adjusted gray scale signal in a first subframe period and driving the display element according to the second adjusted gray scale signal in a second subframe period to result in an adjusted luminance value of the display element, wherein the first subframe period and the second subframe period are within the frame period and the second subframe period follows the first subframe period;

wherein when the input data is between a first gray scale and a second gray scale, wherein the first gray scale and the second gray scale are predetermined values both higher than the minimum gray scale and lower than the maximum gray scale, the first adjusted gray scale signal is higher than the second adjusted gray scale signal and the first adjusted gray scale signal is substantially equal to a third gray scale and is lower than the maximum gray scale, wherein the third gray scale is lower than the second gray scale, and

wherein when the input data is between the second gray scale and the maximum gray scale value, the first adjusted gray scale signal is equal to the second adjusted gray scale signal.

2. The system of claim 1 wherein the original luminance value and the adjusted luminance value of the display element when the display element is viewed from a front view point are generally the same.

3. The system of claim 1 wherein the original luminance value is corresponding to a gray scale of the display element in the frame period, the adjusted luminance value is corresponding to one of a plurality of adjusted gray scales of the display element in one of a plurality of subframe periods, and the gray scale is between two of the adjusted gray scales corresponding to two of the subframe periods within the frame period.

4. The system of claim 1 further comprising a lookup table storing the input data and the adjusted gray scale signals.

5. The system of claim 1 wherein the display element is a multi-domain vertically aligned liquid crystal pixel.

6. The system of claim 1 wherein when the input data is between 0 and the first gray scale, the first adjusted gray scale signal is higher than the second adjusted gray scale signal and approaches the third gray scale.

7. The system of claim 6 wherein the second adjusted gray scale signal is 0.

8. The system of claim 1 wherein when the input data is between the second gray scale and the maximum gray scale, the first adjusted gray scale signal is equal to the second adjusted gray scale signal.

9. A method for driving a display comprising:

obtaining an original luminance value in a frame period corresponding to an input data between a minimum gray scale and a maximum gray scale;

receiving the input data and outputting a plurality of adjusted gray scale signals including a first adjusted gray scale signal and a second adjusted gray scale signal; and

driving a display element according to the first adjusted gray scale signal in a first subframe period and driving the display element according to the second adjusted gray scale signal in a second subframe period to result in an adjusted luminance value of the display element, wherein the first subframe period and the second subframe period are within the frame period and the second subframe period follows the first subframe period;

wherein when the input data is between a first gray scale and a second gray scale, wherein the first gray scale and the second gray scale are predetermined values both higher than the minimum gray scale and lower than the maximum gray scale, the first adjusted gray scale signal is higher than the second adjusted gray scale signal and the first adjusted gray scale signal is substantially equal to a third gray scale and is lower than the maximum gray scale, wherein the third gray scale is lower than the second gray scale, and

wherein when the input data is between the second gray scale and the maximum gray scale value, the first adjusted gray scale signal is equal to the second adjusted gray scale signal.

10. The method of claim 9 wherein the original luminance value is corresponding to a gray scale of the display element in the frame period, the adjusted luminance value is corresponding to one of a plurality of adjusted gray scales of the display element in one of the plurality of subframe periods, the gray scale is between two of the adjusted gray scales corresponding to two of the subframe periods within the frame period.

11. The method of claim 9 wherein when the input data is between 0 and the first gray scale, the first adjusted gray scale signal is higher than the second adjusted gray scale signal and approaches the third gray scale.

12. The method of claim 11 wherein the second adjusted gray scale signal is 0.

13. The method of claim 9 wherein when the input data is between the second gray scale and the maximum gray scale, the first adjusted gray scale signal is equal to the second adjusted gray scale signal.

14. A display device comprising:

a plurality of first pixels;

a plurality of second pixels;

a circuit for receiving an original signal corresponding to a first intensity value between a minimum gray scale and a maximum gray scale for a first pixel at a first frequency in a frame period consisting of a plurality of subframe periods;

a converter for converting the original signal into two adjusted signals, including a first adjusted gray scale signal and a second adjusted gray scale signal, corresponding to a second intensity value and a third intensity value, respectively, at a second frequency wherein the second frequency is larger than the first frequency, wherein the first intensity value is between the second and the third intensity values; and

a memory for storing and outputting the two adjusted signals to the first pixel;

wherein each of the first pixels and the second pixels has a pair of first color sub-pixels, a pair of second color sub-pixels, and a pair of third color sub-pixels, and the first pixels and the second pixels are interlaced in an alternating fashion horizontally and vertically to compose the display device;

wherein the first color sub-pixels, the second color sub-pixels, and the third color sub-pixels in each of the first pixels are arranged in a first shape, the first color sub-pixels, the second color sub-pixels, and the third color sub-pixels in each of the second pixels are arranged in a second shape, wherein the first shape and the second shape are symmetrical to each other;

wherein each pair of the first color sub-pixels are arranged along a first diagonal line, and each pair of the second color sub-pixels are arranged along a second diagonal line, wherein the first diagonal line is substantially perpendicular to the second diagonal line,

wherein one of the first color sub-pixels in each first pixel is directly adjacent to one of the first color sub-pixels in one of the second pixels adjacent to the first pixel, and one of the second color sub-pixels in the first pixel is directly adjacent to one of the second color sub-pixels in the other one of the second pixels adjacent to the first pixel, and

wherein when the original signal is between a first gray scale and a second gray scale, wherein the first gray scale and the second gray scale are predetermined values both higher than the minimum gray scale and lower than the maximum gray scale, the first adjusted gray scale signal is higher than the second adjusted gray scale signal and the first adjusted gray scale signal is substantially equal to a third gray scale and is lower than the maximum gray scale, wherein the third gray scale is lower than the second gray scale, and

wherein when the input data is between the second gray scale and the maximum gray scale value, the first adjusted gray scale signal is equal to the second adjusted gray scale signal.

15. The display device of claim 14, wherein the first color is red, the second color is blue, and the third color is green.

16. A display device comprising:

a plurality of first pixels;

a plurality of second pixels;

a circuit for receiving an original signal corresponding to a first intensity value between a minimum gray scale and a maximum gray scale for a first pixel at a first frequency in a frame period consisting of a plurality of subframe periods;

a converter for converting the original signal into two adjusted signals, including a first adjusted gray scale signal and a second adjusted gray scale signal, corresponding to a second intensity value and a third intensity value, respectively, at a second frequency wherein the second frequency is larger than the first frequency, wherein the first intensity value is between the second and the third intensity values; and

a memory for storing and outputting the two adjusted signals to the first pixel,

wherein each of the first pixels and the second pixels has a pair of first color sub-pixels, a pair of second color sub-pixels, and a pair of third color sub-pixels, and the first pixels and the second pixels are interlaced in an alternating fashion horizontally and vertically to compose the display device,

wherein the first color sub-pixels, the second color sub-pixels, and the third color sub-pixels in each of the first pixels are arranged in a first shape, the first color sub-pixels, the second color sub-pixels, and the third color sub-pixels in each of the second pixels are arranged in a second shape, wherein the first shape and the second shape are symmetrical to each other,

wherein each pair of the first color sub-pixels are arranged along a first diagonal line, and each pair of the second color sub-pixels are arranged along a second diagonal line, wherein the first diagonal line is substantially perpendicular to the second diagonal line,

wherein when the original signal is between a first gray scale and a second gray scale, wherein the first gray scale and the second gray scale are predetermined values both higher than the minimum gray scale and lower than the maximum gray scale, the first adjusted gray scale signal is higher than the second adjusted gray scale signal and the first adjusted gray scale signal is substantially equal to a third gray scale and is lower than the maximum gray scale, wherein the third gray scale is lower than the second gray scale, and

wherein when the input data is between the second gray scale and the maximum gray scale value, the first adjusted gray scale signal is equal to the second adjusted gray scale signal.

17. The display device of claim 16 wherein the first color is red, the second color is blue, and the third color is green.