IP Library › Granted Patent US 10,115,353
Granted Patent B2
US 10,115,353 · App. 14/915,236 · Granted Oct 30, 2018

Backlight adjustment method, liquid crystal display device and electronic apparatus

Inventors: Zhenzhou Xing (Guangdong, CN); Qingcheng Zuo (Guangdong, CN); Xingling Guo (Guangdong, CN)
Assignee: Wuhan China Star Optoelectronics Technology Co., Ltd
G09G3/3406G09G3/36G09G2320/062G09G2320/064G09G2320/0646G09G2330/021G09G2330/023
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Quick Facts
Patent No.
US 10,115,353
App. No.
14/915,236
Granted
Oct 30, 2018
Kind
B2
Abstract

The present invention provides a liquid crystal display device, comprising a backlight part, and the liquid crystal display device includes an image collection circuit, a gray scale judgment circuit, a PWM signal generation circuit and a LED driving circuit, and the backlight part is electrically coupled to the LED driving circuit; the image collection circuit obtains a gray scale of a target image and transmits the gray scale of the target image to the gray scale judgment circuit, and the gray scale judgment circuit compares the gray scale of the target image with a preset gray scale threshold to generate a control signal to be transmitted to the PWM signal generation circuit; the PWM signal generation circuit generates a PWM signal of which a duty ratio is zero to be transmitted to the LED driving circuit, and the LED driving circuit cuts off an input current of the backlight part.

Claims (21)

1. A liquid crystal display device, comprising a backlight part, wherein the liquid crystal display device comprises an image collection circuit, a gray scale judgment circuit, a Pulse Width Modulation (PWM) signal generation circuit and a LED driving circuit, which are electrically coupled in order, and the backlight part is electrically coupled to the LED driving circuit; the image collection circuit obtains a gray scale of a target image and transmits the gray scale of the target image to the gray scale judgment circuit, and the gray scale judgment circuit compares the gray scale of the target image with a preset gray scale threshold to generate a control signal, and transmits the control signal to the PWM signal generation circuit; the PWM signal generation circuit responds with the control signal to generate a PWM signal of which a duty ratio is zero, and transmits the PWM signal to the LED driving circuit, and the LED driving circuit responds with the PWM signal to cut off an input current of the backlight part; and

wherein as the gray scale judgment circuit judges that the gray scale of the target image is smaller than the preset gray scale threshold, the gray scale judgment circuit outputs the control signal to the PWM signal generation circuit, and the PWM signal generation circuit adjusts the duty ratio of the PWM signal to be zero after receiving the control signal, and the LED driving circuit cuts off the input current of the backlight part according to the PWM signal; as the gray scale judgment circuit judges that the gray scale of the target image is larger than or equal to the preset gray scale threshold, the backlight part is inputted with a backlight current and is in an activation state.

2. The liquid crystal display device according to claim 1 , wherein the preset gray scale threshold is 10.

3. The liquid crystal display device according to claim 1 , wherein the PWM signal generation circuit adjusts the duty ratio of the PWM signal in real time according to the input current of the backlight part currently transmitted by the LED driving circuit as the PWM signal is generated.

4. The liquid crystal display device according to claim 1 , wherein the PWM signal generation circuit comprises a square wave generator.

5. The liquid crystal display device according to claim 2 , wherein the PWM signal generation circuit comprises a square wave generator.

6. An electronic apparatus, comprising a liquid crystal display device, and the liquid crystal display device comprises a backlight part, wherein the liquid crystal display device comprises an image collection circuit, a gray scale judgment circuit, a Pulse Width Modulation (PWM) signal generation circuit and a LED driving circuit, which are electrically coupled in order, and the backlight part is electrically coupled to the LED driving circuit; the image collection circuit obtains a gray scale of a target image and transmits the gray scale of the target image to the gray scale judgment circuit, and the gray scale judgment circuit compares the gray scale of the target image with a preset gray scale threshold to generate a control signal, and transmits the control signal to the PWM signal generation circuit; the PWM signal generation circuit responds with the control signal to generate a PWM signal of which a duty ratio is zero, and transmits the PWM signal to the LED driving circuit, and the LED driving circuit responds with the PWM signal to cut off an input current of the backlight part;

wherein as the gray scale judgment circuit judges that the gray scale of the target image is smaller than the preset gray scale threshold, the gray scale judgment circuit outputs the control signal to the PWM signal generation circuit, and the PWM signal generation circuit adjusts the duty ratio of the PWM signal to be zero after receiving the control signal, and the LED driving circuit cuts off the input current of the backlight part according to the PWM signal; as the gray scale judgment circuit judges that the gray scale of the target image is larger than or equal to the preset gray scale threshold, the backlight part is inputted with a backlight current and is in an activation state; and

wherein the PWM signal generation circuit comprises a square wave generator.

7. The electronic apparatus according to claim 6 , wherein the preset gray scale threshold is 10.

8. The electronic apparatus according to claim 6 , wherein the PWM signal generation circuit adjusts the duty ratio of the PWM signal in real time according to the input current of the backlight part currently transmitted by the LED driving circuit as the PWM signal is generated.

9. A backlight adjustment method, wherein the backlight adjustment method comprises:

obtaining a gray scale of a target image with an image collection circuit and transmitting the gray scale of the target image to a gray scale judgment circuit;

comparing the gray scale of the target image with a preset gray scale threshold with a gray scale judgment circuit;

outputting a corresponding control signal to a Pulse Width Modulation (PWM) signal generation circuit with a gray scale judgment circuit as the gray scale of the target image is smaller than a preset gray scale threshold, and the PWM signal generation circuit generates a PWM signal of which a duty ratio is zero, and outputs the PWM signal to a LED driving circuit;

cutting off an input current of a backlight part with the LED driving circuit according to the PWM signal of which the duty ratio is zero;

wherein the preset gray scale threshold is 10; and

wherein as the gray scale judgment circuit judges that the gray scale of the target image is larger than or equal to the preset gray scale threshold, the PWM signal generation circuit adjusts the duty ratio of the PWM signal in real time according to the input current of the backlight part currently transmitted by the LED driving circuit as the PWM signal is generated, and the LED driving circuit adjusts the input current outputted to the backlight part in real time according to the PWM signal.

10. The backlight adjustment method according to claim 9 , wherein as the gray scale judgment circuit judges that the gray scale of the target image is larger than or equal to the preset gray scale threshold, the PWM signal generation circuit adjusts the duty ratio of the PWM signal in real time according to the input current of the backlight part currently transmitted by the LED driving circuit as the PWM signal is generated, and the LED driving circuit adjusts the input current outputted to the backlight part in real time according to the PWM signal.

11. The backlight adjustment method according to claim 10 , wherein as the duty ratio of the PWM signal is not zero, the input current transmitted to the backlight part is positively correlated with the duty ratio of the PWM signal, and as the duty ratio of the PWM signal is zero, the input current of the backlight part is not transmitted to the backlight part.

12. The backlight adjustment method according to claim 9 , wherein as the duty ratio of the PWM signal is not zero, the input current transmitted to the backlight part is positively correlated with the duty ratio of the PWM signal, and as the duty ratio of the PWM signal is zero, the input current of the backlight part is not transmitted to the backlight part.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 28, 2016
From: XING, ZHENZHOU; ZUO, QINGCHENG; GUO, XINGLING
To: WUHAN CHINA STAR OPTOELECTRONICS TECHNOLOGY CO., LTD
Reel/Frame 037846/0582 →
Priority Claims (1)
CN 2015 1 0963790 · Dec 21, 2015 · national
Continuity (1)
Related Publication 20180047346A1 · Feb 15, 2018