Liquid crystal display and the backlight indicating apparatus and method thereof

• US 20090040172A1
• Filed: 04/01/2008
• Published: 02/12/2009
• Est. Priority Date: 08/06/2007
• Status: Abandoned Application

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Hung, Chi-Mao, Lien, Shui-Chih
• Application Number:
  US12/078,504
• Publication Number:
  US 20090040172A1
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

A liquid crystal display has a backlight module and an indicator. The indicator is used to detect the light brightness of the backlight module, and announces a warning when the light brightness is lower than a predetermined value. The indicator has at least one color light detection unit that includes a detector, an analog-to-digital converter (ADC), a controller and a warning display. The detector detects the brightness of a color light from the backlight module to generate a light brightness voltage. The ADC converts the light brightness voltage into a digital signal. The controller determines whether the brightness of the color light is lower than the predetermined value or not according to the digital signal. When the brightness of the color light is lower than the predetermined value, the controller makes the warning display announce the warning.

Claims

1. A liquid crystal display (LCD), comprising:

a backlight module; and

an indicating apparatus for detecting the light brightness of the backlight module and issuing a warning when the light brightness is below a predetermined value.

2. The LCD of claim 1, wherein the indicating apparatus has at least one color light detection unit that includes:

a detector for detecting the light brightness of a color light of the backlight module and generates a light brightness voltage;

an analog-to-digital converter (ADC) for converting the light brightness voltage into a digital signal;

a controller for determining whether the color light brightness is below the predetermined value according to the digital signal; and

a warning display adapted to be controlled by the controller to issue the warning when the color light brightness is below the predetermined value.

3. The LCD of claim 2, wherein the ADC is adapted to convert the light brightness voltage into the digital signal according to a reference voltage for the color light.

4. The LCD of claim 2, wherein the controller is configured to adjust the output light brightness of the backlight module according to the digital signal.

5. The LCD of claim 2, wherein the warning display comprises a light-emitting diode, an on-screen-display image generator, or a warning program.

6. The LCD of claim 2, wherein the indicating apparatus further includes at least one multiplexer to switch between different modes for detecting the light brightness of different colors of the backlight module.

7. The LCD of claim 1, wherein the backlight module comprises a cold cathode fluorescent lamp, or a light-emitting diode.

8. The LCD of claim 1, further comprising a printed circuit board, wherein the indicating apparatus is disposed on the printed circuit board.

9. The LCD of claim 1, further comprising a data driver chip, wherein the indicating apparatus is disposed in the data driver chip.

10. The LCD of claim 1, further comprising a scanning driver chip, wherein the indicating apparatus is disposed in the scanning driver chip.

11. An indicating apparatus for use in a liquid crystal display (LCD), comprising:

at least one color light detection unit that include;

a detector configured to detect the light brightness of a color light of the backlight module and generates a light brightness voltage;

an analog-to-digital converter (ADC) adapted to convert the light brightness voltage into a digital signal;

a controller configured to determine whether the color light brightness is below the predetermined value according to the digital signal; and

a warning display adapted to be controlled by the controller to issue the warning when the color light brightness is below the predetermined value.

12. The indicating apparatus of claim 11, wherein the ADC is adapted to convert the light brightness voltage into the digital signal according to a reference voltage for the color light.

13. The indicating apparatus of claim 11, wherein the controller is configured to adjust the output light brightness of the backlight module according to the digital signal.

14. The indicating apparatus of claim 11, wherein the backlight module comprises a cold cathode fluorescent lamp, or a light-emitting diode.

15. The indicating apparatus of claim 11, wherein the warning display comprises a light-emitting diode, an on-screen-display image generator, or a warning program.

16. The indicating apparatus of claim 11, further comprising at least one multiplexer to switching among different modes for detecting the light brightness of different colors of the backlight module.

17. A method for indicating the light brightness of a liquid crystal display (LCD), comprising the steps of:

detecting the brightness of a color light of a backlight module and generating a light brightness voltage accordingly;

converting the light brightness voltage into a digital signal;

determining whether the light brightness of the color light is below a predetermined value; and

issuing a warning when the color light brightness is below the predetermined value.

18. The method of claim 17, wherein the step of converting the light brightness voltage into a digital signal is performed according to a reference voltage associated with the color light.

19. The method of claim 17, wherein issuing the warning comprises utilizing a light-emitting diode, an on-screen-display image generator, or a warning program to realize the warning.

20. The method of claim 17, further comprising the step of switching among different modes for detecting the light brightness of different colors of the backlight module.