System and method for providing a wide aspect ratio flat panel display monitor independent white-balance adjustment and gamma correction capabilities

• US 7,136,076 B2
• Filed: 08/25/2003
• Issued: 11/14/2006
• Est. Priority Date: 05/29/1998
• Status: Expired due to Fees

• Current Assignee: RPX Corporation
• Original Assignee: Silicon Graphics Incorporated (Graphics Properties Holdings, Inc.)
• Inventors: Evanicky, Daniel E., Medina, Oscar Ivan
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): Nguyen, Kevin M.
• Application Number:
  US10/650,030
• Publication Number:
  US 20040036708A1
• Time in Patent Office: 1,177 Days
• Field of Search: 345/87, 345/88, 345/589, 345/691, 345/89, 345/600, 345/690, 345/904, 348/180, 348/189, 324/121.R
• US Class Current: 345/600
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2370/04 Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2092 Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165
• CPC Class Codes: G09G 3/3413 : Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3611 : Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/006 : Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/06 : using colour palettes, e.g. look-up tables
• CPC Class Codes: H04N 17/045 : Self-contained testing apparatus
• CPC Class Codes: H04N 5/66 : Transforming electric information into light information scanning details H04N3/00
• CPC Class Codes: H04N 9/73 : Colour balance circuits, e.g. white balance circuits or colour temperature control camera processing pipelines for colour balance H04N23/88
• CPC Class Codes: Y10S 345/904 : Display with fail/safe testing feature

Abstract

A system and method are described herein for controlling the white balance and providing gamma correction without compromising gray-scale dynamic range in a flat panel liquid crystal display (LCD). According to one embodiment of the present invention, the flat panel LCD includes electronic circuitry for coupling to a host computer to receive a white-balance adjustment control signal, and electronic circuitry for receiving image data to be rendered on the flat panel LCD. Further, the flat panel LCD of one embodiment is configured for coupling to a color-sensing device to receive optical characteristics data of the flat panel LCD detected by the color-sensing device. The white balance adjustment mechanisms include the provision of two or more light sources of differing color temperature, whose brightness can be independently varied (and distributed through a light distribution mechanism) to adjust color temperature without altering the grayscale resolution of the RGB colors. The present invention further includes white balance adjustment software and gamma correction software for generating white-balance adjustment control signals and appropriate gamma correction curves.

Claims

1. A flat panel monitor for displaying information originated by a host computer, said flat panel monitor comprising:

a graphics controller operable to receive a gamma correction control signal, the graphics controller operable to adjust a gamma value of a liquid crystal display screen displaying a representation of image data in response to the gamma correction control signal, the graphics controller operable to adjust the gamma value without substantially affecting a grayscale resolution of the liquid crystal display screen.

2. The flat panel monitor of claim 1, wherein the graphics controller includes a color look up table to match a gamma response for the liquid crystal display screen, the graphics controller operable to adjust the gamma response of the color look up table in response to the gamma correction control signal.

3. The flat panel monitor of claim 1, wherein the graphics controller is operable to generate color values in response to receipt of the image data and the gamma correction control signal.

4. The flat panel monitor of claim 3, further comprising:

a frame rate modulator operable to generate an intermediate grayscale value for the liquid crystal display screen in response to the color values generated by the graphics controller.

5. The flat panel monitor of claim 3, further comprising:

a frame rate controller operable to receive a synchronization signal from the graphics controller, the frame rate controller operable to control modulation performed by the frame rate modulator in response to the synchronization signal.

6. The flat panel monitor of claim 5, wherein the synchronization signal includes horizontal synchronization and vertical synchronization values.

7. The flat panel monitor of claim 1, further comprising:

a controller circuit operable to receive a white balance adjustment control signal, the controller circuit operable to adjust a white balance of the liquid crystal display screen in response to the white balance control signal.

8. The flat panel monitor of claim 7, wherein the controller circuit adjusts the white balance of the liquid crystal display screen without substantially affecting a grayscale resolution of the liquid crystal display screen.

9. The flat panel monitor of claim 1, wherein the graphics controller is operable to provide a backlight control signal to control a backlight of the flat panel monitor.

10. The flat panel monitor of claim 1, wherein the gamma correction control signal is generated in response to a comparison of optical characteristics of the liquid crystal display screen and reference optical characteristics.

11. A method for displaying information on a flat panel monitor, comprising:

receiving a gamma correction control signal;

adjusting a gamma value for a liquid crystal display screen in response to the gamma correction control signal, the gamma value being adjusted without substantially affecting a grayscale resolution of the liquid crystal display screen.

12. The method of claim 11, further comprising:

comparing optical characteristics of the liquid crystal display screen to reference optical characteristics;

generating the gamma correction control signal in response to the comparison.

13. The method of claim 11, further comprising:

generating color values in response to receipt of image data and the gamma correction control signal.

14. The method of claim 13, further comprising:

generating an intermediate grayscale value for the liquid crystal display screen in response to the color values.

15. The method of claim 11, further comprising:

adjusting a white balance of the liquid crystal display screen without substantially affecting a grayscale resolution of the liquid crystal display screen.

16. A method for providing image data to a flat panel monitor, comprising:

generating an uncorrected color value in response to receipt of image data;

translating an uncorrected color value to a corrected color value according to an actual gamma response for a liquid crystal display screen;

displaying the image data with the corrected color value without substantially affecting a grayscale resolution of the liquid crystal display screen.

17. The method of claim 16, further comprising:

determining grayscale ramps for the liquid crystal display screen;

determining the actual gamma response for the liquid crystal display screen from the grayscale ramps.

18. The method of claim 16, further comprising:

comparing the gamma response for the liquid crystal display screen to a reference gamma response;

generating a transfer function to map the reference gamma response to the actual gamma response.

19. The method of claim 16, further comprising:

maintaining the gamma response for the liquid crystal display screen in a look up table.

20. The method of claim 16, further comprising:

modulating the corrected color value to produce an intermediate grayscale value.