DRIVING METHOD, COMPENSATION PROCESSOR AND DRIVER DEVICE FOR LIQUID CRYSTAL DISPLAY

• US 20090243986A1
• Filed: 11/10/2008
• Published: 10/01/2009
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.)
• Original Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.)
• Inventors: JUNG, Chulgyu
• Granted Patent: US 8,766,895 B2
• Time in Patent Office: Days
• US Class Current: 345/94
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/064 by time 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 2320/0653 Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

The invention relates to a driving method, compensation processor and driver device for liquid crystal display. The driving method includes steps of receiving data signal of a present frame; obtaining an average brightness value of the present frame; comparing the previous frame with the present frame, and when the difference between the average brightness values is larger than or equal to a set threshold, generating at least two back light driver pulse signals of which the duty ratios gradually changing, and outputting them to drive the back lights. The compensation processor includes a data analysis module, a data compensation module, a back light linear filtering module and a pulse generator module. The driver device employs the compensation processor of the present invention. The present invention employs the technical means of generating a plurality of back light driver pulse signals, realizes the gradual changing of the brightness of the back lights, and overcomes the picture flickering problem due to the sudden changing of the brightness of the back lights, thus improving the display effect of the LCD.

Claims

1. A driving method for LCD, characterized in that comprising:

Step 1 of receiving data signal of a present frame, making spectrum analysis on the data signal, and obtaining and recording an average brightness value of the present frame;

Step 2 of acquiring the average brightness value of the present frame, and querying an average brightness value of the previous frame to compare with the average brightness value of the present frame;

Step 3 of when the result of the comparison is that the difference between the average brightness value of the previous frame and the average brightness value of the present frame is larger than or equal to a set threshold, generating a pulse generation instruction indicating to generate at least two back light driver pulse signals in sequence, wherein the relation between the duty ratios of the respective back light driver pulse signals is a unidirectional gradual changing, and the direction of the unidirectional gradual changing is the same as the direction of the average brightness value of the previous frame gradually changing to the average brightness value of the present frame; and

Step 4 of generating the back light driver pulse signals according to the pulse generation instruction, and outputting each of the back light driver pulse signals in sequence to drive the back lights.

2. The driving method for LCD according to claim 1, characterized in that said step 3 comprising:

Step 31 of obtaining the difference between the average brightness value of the previous frame and the average brightness value of the present frame;

Step 32 of comparing the difference with a plurality of decrementing set thresholds; and

Step 33 of when it is judged that the difference is larger than or equal to the set threshold for current comparison, generating the pulse generation instruction corresponding to the set threshold for current comparison, for indicating to generate a set number of the back light driver pulse signals in sequence, wherein the relation between the duty ratios of the respective back light driver pulse signals is a unidirectional gradual changing, and the direction of the unidirectional gradual changing is the same as the direction of the average brightness value of the previous frame gradually changing to the average brightness value of the present frame.

3. The driving method for LCD according to claim 1, characterized in that the range of the number of the generated back light driver pulse signals is 10 to 20.

4. The driving method for LCD according to claim 2, characterized in that the range of the number of the generated back light driver pulse signals is 10 to 20.

5. A compensation processor for LCD, characterized in that comprising:

a data analysis module for receiving data signal of a present frame, making a spectrum analysis on the data signal, and obtaining and recording an average brightness value of the present frame;

a data compensation module connected with the data analysis module, for generating data compensation signal according to the result of the spectrum analysis and outputting the generated data compensation signal to a data driver of the LCD;

a back light linear filtering module connected with the data analysis module, for obtaining an average brightness value of the previous frame to compare with the average brightness value of the present frame, and when the result of the comparison is that a difference between the average brightness value of the previous frame and the average brightness value of the present frame is larger than or equal to a set threshold, generating a pulse generation instruction indicating to generate at least two back light driver pulse signals in sequence, wherein the relation between the duty ratios of the respective back light driver pulse signals is unidirectional gradual changing, and the direction of the unidirectional gradual changing is the same as the direction of the average brightness value of the previous frame gradually changing to the average brightness value of the present frame; and

a pulse generator module connected with the back light linear filtering module, for generating the back light driver pulse signals according to the pulse generation instruction, and outputting each of the back light driver pulse signals in sequence to drive the back lights.

6. The compensation processor for LCD according to claim 5, characterized in that the back light linear filtering module comprising:

a brightness value comparison unit connected with the data analysis module, for obtaining the average brightness value of the previous frame and the average brightness value of the present frame to compare for obtaining a difference;

an instruction control unit for storing a plurality of decrementing set thresholds in sequence, and storing the pulse generation instruction indicating the number of the generated back light driver pulse signals corresponding to each of the set thresholds; and

an instruction generation unit connected with the brightness value comparison unit and the instruction control unit, for comparing the difference with the plurality of decrementing set thresholds in sequence, and when it is judged that the difference is larger than or equal to the set threshold for current comparison, querying and obtaining a corresponding pulse generation instruction corresponding to the set threshold for current comparison, for indicating to generate a set number of back light driver pulse signals in sequence, wherein the relation between the duty ratios of the respective back light driver pulse signals is unidirectional gradual changing, and the direction of the unidirectional gradual changing is the same as the direction of the average brightness value of the previous frame gradually changing to the average brightness value of the present frame.

7. A driver device utilizing the compensation processor for LCD of claim 5, comprising:

a data driver;

a scan driver;

an inverter;

a timing controller connected with the data driver and the scan driver respectively;

a transformer, characterized in that the data compensation module of the compensation processor being connected with the data driver;

the pulse generator module of the compensation processor being connected with the inverter.

8. A driver device utilizing the compensation processor for LCD of claim 6, comprising:

a data driver;

a scan driver;

an inverter;

a timing controller connected with the data driver and the scan driver respectively;

a transformer, characterized in that the data compensation module of the compensation processor being connected with the data driver;

the pulse generator module of the compensation processor being connected with the inverter.