Gamma curve adjustment method and gamma curve adjustment apparatus

• US 9,704,425 B2
• Filed: 09/26/2013
• Issued: 07/11/2017
• Est. Priority Date: 05/31/2013
• Status: Expired due to Fees

• Current Assignee: Beijing BOE Display Technology Co Ltd (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Original Assignee: Beijing BOE Display Technology Co Ltd (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Inventors: Zhang, Zhi, Xiao, Lijun, Wang, Liyan, Huo, Weiwei
• Primary Examiner(s): Sasinowski, Andrew
• Assistant Examiner(s): WOO, KUO-KONG
• Application Number:
  US14/373,982
• Publication Number:
  US 20150243198A1
• Time in Patent Office: 1,384 Days
• Field of Search: 345 88, 345 89, 345102, 345204, 345690
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• 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 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• 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 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

A Gamma curve adjustment method and a Gamma curve adjustment apparatus for a display apparatus. The method includes: obtaining correspondence relationship between current grayscale voltages and first transmittances of the display apparatus, the first transmittances being the transmittances of the display apparatus driving by the current grayscale voltages; determining a target grayscale voltage corresponding to each gray scale based on the correspondence relationship between the current grayscale voltages and the first transmittances and an ideal Gamma curve; generating and outputting the target grayscale voltage corresponding to each gray scale to the display apparatus; and obtaining an actual Gamma curve of the display apparatus driven by the target grayscale voltages as a final Gamma curve. The Gamma curve adjustment method improves the speed and efficiency of adjusting the Gamma curve.

Claims

1. A Gamma curve adjustment method for a display apparatus, comprising:

obtaining correspondence relationship between current grayscale voltages and first transmittances of the display apparatus, the first transmittances being the transmittances of the display apparatus driven by the current grayscale voltages;

wherein obtaining correspondence relationship between current grayscale voltages and first transmittances of the display apparatus comprises;

determining the current grayscale voltage corresponding to each gray scale based on the original correspondence relationship between voltages and transmittances of the display apparatus and an ideal Gamma curve;

generating and outputting the current grayscale voltage corresponding to each gray scale to the display apparatus;

testing the first transmittances of the display apparatus driven by the current grayscale voltages; and

establishing the correspondence relationship between the current grayscale voltages and the first transmittances based on the first transmittances obtained by the testing;

determining a target grayscale voltage corresponding to each gray scale based on the correspondence relationship between the current grayscale voltages and the first transmittances and the ideal Gamma curve, wherein an ideal transmittance T corresponding to the gray scale of the target grayscale voltage to be determined currently is determined based on the ideal Gamma curve, and two adjacent transmittances T1 and T2 are selected from the first transmittances, wherein T2>

T>

T1, and the target grayscale voltage corresponding to the ideal transmittance T is determined from the current grayscale voltages V1 and V2 corresponding to T1 and T2 respectively, based on a linear relationship;

generating and outputting the target grayscale voltage corresponding to each gray scale to the display apparatus; and

obtaining an actual Gamma curve of the display apparatus driven by the target grayscale voltages as a final Gamma curve.

2. The Gamma curve adjustment method according to claim 1, wherein the linear relationship is as follows:

(V2−

V1)*(T−

T1)/(T2−

T1)+V1.

3. The Gamma curve adjustment method according to claim 1, wherein obtaining an actual Gamma curve of the display apparatus driven by the target grayscale voltages comprises:

testing second transmittances of the display apparatus driven by the target grayscale voltages;

establishing correspondence relationship between the target grayscale voltages and the second transmittances based on the second transmittances obtained by the testing; and

determining the actual Gamma curve describing correspondence relationship between gray scales and the second transmittances based on the correspondence relationship between the target grayscale voltages and the second transmittances and correspondence relationship between the target grayscale voltages and the gray scales.

4. The Gamma curve adjustment method according to claim 2, wherein obtaining an actual Gamma curve of the display apparatus driven by the target grayscale voltages comprises:

testing second transmittances of the display apparatus driven by the target grayscale voltages;

establishing correspondence relationship between the target grayscale voltages and the second transmittances based on the second transmittances obtained by the testing; and

determining the actual Gamma curve describing correspondence relationship between gray scales and the second transmittances based on the correspondence relationship between the target grayscale voltages and the second transmittances and correspondence relationship between the target grayscale voltages and the gray scales.

5. A Gamma curve adjustment apparatus for a display apparatus, comprising:

an upper computer configured to obtain correspondence relationship between current grayscale voltages and first transmittances of the display apparatus, the first transmittances being the transmittances of the display apparatus driven by the current grayscale voltages;

wherein the upper computer is configured to determine the current grayscale voltage corresponding to each gray scale based on the original correspondence relationship between voltages and transmittances of the display apparatus and an ideal Gamma curve;

a voltage supplying chip configured to generate and output the current grayscale voltage corresponding to each gray scale to the display apparatus;

an optical test equipment configured to test the first transmittances of the display apparatus driven by the current grayscale voltages;

wherein the upper computer is further configured to establish the correspondence relationship between the current grayscale voltages and the first transmittances based on the first transmittances obtained by the optical test equipment, and

to determine a target grayscale voltage corresponding to each gray scale based on the correspondence relationship between the current grayscale voltages and the first transmittances and the ideal Gamma curve;

the voltage supplying chip is further configured to generate and output the target grayscale voltage corresponding to each gray scale to the display apparatus; and

the upper computer is configured to obtain an actual Gamma curve of the display apparatus driven by the target grayscale voltages as a final Gamma curve;

wherein the upper computer is configured to

determine an ideal transmittance T corresponding to the gray scale of the target grayscale voltage to be determined currently based on the ideal Gamma curve;

select two adjacent transmittances T1 and T2 from the first transmittances, wherein T2>

T>

T1;

determine the current grayscale voltages V1 and V2 corresponding to T1 and T2 respectively; and

determine the target grayscale voltage corresponding to the ideal transmittance T from the current grayscale voltages V1 and V2, corresponding to T1 and T2 respectively, based on a linear relationship.

6. The Gamma curve adjustment apparatus according to claim 5, wherein the linear relationship is as follows:

(V2−

V1)*(T−

T1)/(T2−

T1)+V1.

7. The Gamma curve adjustment apparatus according to claim 5, wherein

the optical test equipment is further configured to test second transmittances of the display apparatus driven by the target grayscale voltages;

the upper computer is configured to establish correspondence relationship between the target grayscale voltages and the second transmittances based on the second transmittances obtained by the optical test equipment; and

determine the actual Gamma curve describing correspondence relationship between gray scales and the second transmittances based on the correspondence relationship between the target grayscale voltages and the second transmittances and correspondence relationship between the target grayscale voltages and the gray scales.

8. The Gamma curve adjustment apparatus according to claim 6, wherein

the optical test equipment is configured to test second transmittances of the display apparatus driven by the target grayscale voltages;

the upper computer is configured to establish correspondence relationship between the target grayscale voltages and the second transmittances based on the second transmittances obtained by the optical test equipment; and

determine the actual Gamma curve describing correspondence relationship between gray scales and the second transmittances based on the correspondence relationship between the target grayscale voltages and the second transmittances and correspondence relationship between the target grayscale voltages and the gray scales.