RGBW DISPLAY APPARATUS AND CONTROL METHOD THEREOF

• US 20120001947A1
• Filed: 01/24/2011
• Published: 01/05/2012
• Est. Priority Date: 06/30/2010
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Cheng, Sheng-Wen, CHU-KE, Hui
• Granted Patent: US 8,730,273 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• 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 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3688 suitable for active matrices only
• CPC Class Codes: G09G 5/026 Control of mixing and/or overlay of colours in general G09G5/022 and G09G5/024 take precedence

Abstract

In an exemplary RGBW display apparatus, a plurality of four-color image output signals and a plurality of mapping scale ratios are generated according to a plurality of three-color image input signals. Furthermore, a backlight output intensity outputted from a backlight module is dynamically adjusted according to the mapping scale ratios and a white color signal adjust ratio is generated. In addition, a white color signal in each of the four-color image output signals is adjusted to be an updated white color signal according to the white color signal adjust ratio.

Claims

1. A four-primary-color display apparatus comprising:

a four-color mapping unit for receiving a plurality of three-color image input signals and generating a plurality of corresponding mapping scale ratios and thereby generating a plurality of corresponding four-color image output signals, wherein each of the four-color image output signals comprises a first color signal, a second color signal, a third color signal and a white color signal;

a dynamic backlight control unit electrically connected to the four-color mapping unit and for receiving and computing the mapping scale ratios and thereby outputting a backlight adjust signal and a white color signal adjust ratio, wherein the four-color mapping unit adjusts the white color signal to be an updated white color signal according to the white color signal adjust ratio;

a backlight module electrically connected to the dynamic backlight control unit and for receiving the backlight adjust signal and thereby generating a backlight output intensity;

a source driver electrically connected to the four-color mapping unit and for receiving the first color signal, the second color signal, the third color signal and the updated white color signal and thereby generating a plurality of data signals; and

a pixel array electrically connected to the source driver and for displaying an image according to the data signals and the backlight output intensity.

2. The four-primary-color display apparatus according to claim 1, wherein the first color signal, the second color signal and the third color signal respectively are a red color signal, a green color signal and a blue color signal.

3. The four-primary-color display apparatus according to claim 1, wherein the dynamic backlight control unit comprises:

a scale ratio analyzing unit for computing the mapping scale ratios and thereby outputting an analyzing value and the white color signal adjust ratio; and

a backlight adjust lookup table electrically connected to the scale ratio analyzing unit and for receiving the analyzing value and converting the analyzing value into the backlight adjust signal.

4. The four-primary-color display apparatus according to claim 1, wherein the backlight module comprises:

a backlight driving unit for receiving the backlight adjust signal and generating a pulse width modulation signal; and

a backlight generating unit electrically connected to the backlight driving unit and for receiving the pulse width modulation signal and thereby generating the backlight output intensity.

5. The four-primary-color display apparatus according to claim 1, further comprising:

a gate driver for outputting a plurality of gate signals to enable the pixel array to receive the data signals and thereby cooperative with the backlight output intensity to display the image.

6. A control method of a four-primary-color display apparatus comprising steps of:

receiving a plurality of three-color image input signals;

generating a plurality of mapping scale ratios and a plurality of four-color image output signals according to a pre-mapping lookup table and the three-color image input signals, wherein each of the four-color image output signals comprises a first color signal, a second color signal, a third color signal and a white color signal;

computing the mapping scale ratios and thereby outputting a backlight adjust signal and a white color signal adjust ratio;

controlling a backlight module to generate a backlight output intensity according to the backlight adjust signal;

adjusting the white color signal to be an updated white color signal according to the white color signal adjust ratio; and

displaying an image on a pixel array according to the backlight output intensity and the first color signal, the second color signal, the third color signal and the updated white-color signal.

7. The control method of a four-primary-color display apparatus according to claim 6, wherein the first color signal, the second color signal and the third color signal respectively are a red color signal, a green color signal and a blue color signal.

8. A four-primary-color display apparatus comprising:

a four-color mapping unit for receiving a plurality of three-color image input signals and generating a plurality of four-color image output signals, wherein each of the four-color image output signals comprises a first color signal, a second color signal, a third color signal and a white color signal;

a saturation mapping unit for receiving the three-color image input signals and mapping the received three-color image input signals to be a plurality of saturation values;

a dynamic backlight control unit electrically connected to the saturation mapping unit and for receiving and computing the saturation values and thereby outputting a backlight adjust signal and a white color signal adjust ratio, wherein the four-color mapping unit adjusts the white color signal to be an updated white color signal according to the white color signal adjust ratio;

a backlight module electrically connected to the dynamic backlight control unit and for receiving the backlight adjust signal and thereby generating a backlight output intensity;

a source driver electrically connected to the four-color mapping unit and for receiving the first color signal, the second color signal, the third color signal and the updated white color signal outputted from the four-color mapping unit and thereby generating a plurality of data signals; and

a pixel array electrically connected to the source driver and for displaying an image according to the data signals and the backlight output intensity.

9. The four-primary-color display apparatus according to claim 8, wherein the first color signal, the second color signal and the third color signal respectively are a red color signal, a green color signal and a blue color signal.

10. The four-primary-color display apparatus according to claim 8, wherein the dynamic backlight control unit comprises:

a saturation value analyzing unit for computing the saturation values and thereby outputting an analyzing value and the white color signal adjust ratio; and

a backlight adjust lookup table electrically connected to the saturation value analyzing unit and for receiving the analyzing value and converting the analyzing value into the backlight adjust signal.

11. The four-primary-color display apparatus according to claim 8, wherein the backlight module comprises:

a backlight driving unit for receiving the backlight adjust signal and thereby generating a pulse width modulation signal; and

a backlight generating unit electrically connected to the backlight driving unit and for receiving the pulse width modulation signal and thereby generating the backlight output intensity.

12. The four-primary-color display apparatus according to claim 8, wherein the saturation mapping unit is for mapping each of the three-color image input signals to be a hue saturation luminance (HSL) color gamut.

13. The four-primary-color display apparatus according to claim 8, further comprising:

a gate driver for outputting a plurality of gate signals to enable the pixel array to receive the data signals and thereby cooperative with the backlight output intensity to display the image.

14. A control method of a four-primary-color display apparatus comprising steps of:

receiving a plurality of three-color image input signals;

mapping the three-color image input signals to be a plurality of four-color image output signals according to a pre-mapping lookup table, wherein each of the four-color image output signals comprises a first color signal, a second color signal, a third color signal and a white color signal;

mapping the three-color image input signals to be a plurality of saturation values;

computing the saturation values and thereby outputting a backlight adjust signal and a white color signal adjust ratio;

controlling a backlight module to generate a backlight output intensity according to the backlight adjust signal;

adjusting the white color signal to be an updated white color signal according to the white color signal adjust ratio; and

displaying an image on a pixel array according to the backlight output intensity and the first color signal, the second color signal, the third color signal and the updated white color signal.

15. The control method of a four-primary-color display apparatus according to claim 14, wherein the first color signal, the second color signal and the third color signal respectively are a red color signal, a green color signal and a blue color signal.