IP Library Granted Patent US 9,704,427
Granted Patent B2
US 9,704,427 · App. 14/723,633 · Granted Jul 11, 2017

Method and device for adjusting grayscale brightness and 3D display device

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Quick Facts
Patent No.
US 9,704,427
App. No.
14/723,633
Granted
Jul 11, 2017
Kind
B2
Abstract

The disclosure discloses a method and device for adjusting grayscale brightness and a 3D display device. In the present disclosure, an initial gray level and a target gray level are determined, and it is determined whether the target gray level is too low or too high, so that it is determined whether over-voltage driving can be applicable, and in the case that it is not appropriate to adjust grayscale brightness through over-voltage driving, a backlight brightness adjustment table is searched, and backlight brightness is adjusted up or down using a found adjustment parameter to thereby adjust the grayscale brightness so as to reduce crosstalk in liquid crystal display.

Claims (48)

1. A method for adjusting grayscale brightness, applicable to a 3D display device, the method comprising:

determining an initial gray level corresponding to a preceding frame, and a target gray level corresponding to a current frame, for a backlight zone corresponding to a zone of a display image;

determining whether the target gray level is less than a first threshold gray level or greater than a second threshold gray level, wherein the first threshold gray level is less than the second threshold gray level; and

if not, then in response to determining the target gray level is not less than the first threshold gray level and not greater than the second threshold gray level, adjusting the grayscale brightness of the backlight zone through over-voltage driving,

in response to determining the target gray level is less than the first threshold gray level or greater than the second threshold gray level, determining a value of an adjustment parameter corresponding to the initial gray level and the target gray level according to a preset backlight brightness adjustment table, and adjusting backlight brightness of the current frame according to the determined value of the adjustment parameter so that grayscale brightness of the current frame substantially equals grayscale brightness corresponding to the target gray level,

wherein the adjustment parameter is a duty cycle of backlight or a reference current of backlight.

2. The method according to claim 1 , wherein determining the value of the adjustment parameter corresponding to the initial gray level and the target gray level according to the preset backlight brightness adjustment table comprises:

searching the preset backlight brightness adjustment table for the value of the adjustment parameter corresponding to the initial gray level and the target gray level when the initial gray level and the target gray level are present in the backlight brightness adjustment table; and

calculating the value of the adjustment parameter corresponding to the initial gray level and the target gray level according to the backlight brightness adjustment table using an interpolation algorithm when the initial gray level and the target gray level are not present in the backlight brightness adjustment table.

3. The method according to claim 2 , wherein when the adjustment parameter is the duty cycle of backlight, adjusting the backlight brightness of the current frame according to the determined value of the duty cycle of backlight so that the grayscale brightness of the current frame substantially equals the grayscale brightness corresponding to the target gray level comprises:

if the target gray level is less than the initial gray level, then adjusting down the backlight brightness of the current frame according to the determined value of the duty cycle of backlight so that the grayscale brightness of the current frame substantially equals the grayscale brightness corresponding to the target gray level; and

if the target gray level is more than the initial gray level, then adjusting up the backlight brightness of the current frame according to the determined value of the duty cycle of backlight so that the grayscale brightness of the current frame substantially equals the grayscale brightness corresponding to the target gray level.

4. The method according to claim 2 , wherein when the adjustment parameter is the reference current of backlight, adjusting the backlight brightness of the current frame according to the determined value of the reference current of backlight so that the grayscale brightness of the current frame substantially equals the grayscale brightness corresponding to the target gray level comprises:

if the target gray level is less than the initial gray level, then adjusting down the backlight brightness of the current frame according to the determined value of the reference current of backlight so that the grayscale brightness of the current frame substantially equals the grayscale brightness corresponding to the target gray level; and

if the target gray level is more than the initial gray level, then adjusting up the backlight brightness of the current frame according to the determined value of the reference current of backlight so that the grayscale brightness of the current frame substantially equals the grayscale brightness corresponding to the target gray level.

5. The method according to claim 1 , wherein the backlight brightness adjustment table is preset as follows:

for the backlight zone, the reference current of backlight for the backlight zone is maintained, and when the initial gray level corresponding to the preceding frame is adjusted to the target gray level corresponding to the current frame, the duty cycle of backlight for the backlight zone is adjusted so that the grayscale brightness of the current frame equals the grayscale brightness corresponding to the target gray level, and a value of the duty cycle of backlight at the grayscale brightness is recorded; and wherein the initial gray level ranges from 0 to 255, and the target gray level ranges throughout gray levels which are less than the first threshold gray level and gray levels which are greater than the second threshold gray level in the preset set of gray levels.

6. The method according to claim 1 , wherein the backlight brightness adjustment table is preset as follows:

for the backlight zone, the duty cycle of backlight for the backlight zone is maintained, and when the initial gray level corresponding to the preceding frame is adjusted to the target gray level corresponding to the current frame, the reference current of backlight for the backlight zone is adjusted so that the grayscale brightness of the current frame equals the grayscale brightness corresponding to the target gray level, and the value of the reference current of backlight at the grayscale brightness is recorded; and wherein the initial gray level ranges from 0 to 255, and the target gray level ranges throughout gray levels which are less than the first threshold gray level and gray levels which are greater than the second threshold gray level.

7. A 3D display device, comprising a device for adjusting grayscale brightness, wherein the device for adjusting grayscale brightness comprising:

one or more processors; and

a non-transitory memory,

wherein one or more computer readable program codes are stored in the non-transitory memory, and the one or more processors are configured to execute the one or more computer readable program codes to:

determine an initial gray level corresponding to a preceding frame, and a target gray level corresponding to a current frame, for a backlight zone corresponding to a zone of a display image;

determine whether the target gray level is less than a first threshold gray level or greater than a second threshold gray level, wherein the first threshold gray level is less than the second threshold gray level; and

in response to determining the target gray level is not less than the first threshold gray level and not greater than the second threshold gray level, adjust the grayscale brightness of the backlight zone through over-voltage driving,

in response to determining the target gray level is less than the first threshold gray level or greater than the second threshold gray level, determine a value of an adjustment parameter corresponding to the initial gray level and the target gray level according to a preset backlight brightness adjustment table, and adjust backlight brightness of the current frame according to the determined value of the adjustment parameter so that grayscale brightness of the current frame substantially equals grayscale brightness corresponding to the target gray level,

wherein the adjustment parameter is a duty cycle of backlight or a reference current of backlight.

8. The 3D display device according to claim 7 , wherein the one or more processors are further configured to execute the one or more computer readable program codes to:

search the backlight brightness adjustment table for the value of the adjustment parameter corresponding to the initial gray level and the target gray level when the initial gray level and the target gray level are present in the backlight brightness adjustment table; and

calculate the value of the adjustment parameter corresponding to the initial gray level and the target gray level according to the backlight brightness adjustment table using an interpolation algorithm when the initial gray level and the target gray level are not present in the backlight brightness adjustment table.

9. The 3D display device according to claim 8 , wherein the one or more processors are further configured to execute the one or more computer readable program codes to:

if the target gray level is less than the initial gray level, adjust down the backlight brightness of the current frame according to the determined value of the duty cycle of backlight so that the grayscale brightness of the current frame equals the grayscale brightness corresponding to the target gray level; and

if the target gray level is more than the initial gray level, adjust up the backlight brightness of the current frame according to the determined value of the duty cycle of backlight so that the grayscale brightness of the current frame substantially equals the grayscale brightness corresponding to the target gray level.

10. The 3D display device according to claim 8 , wherein the one or more processors are further configured to execute the one or more computer readable program codes to:

if the target gray level is less than the initial gray level, adjust down the backlight brightness of the current frame according to the determined value of the reference current of backlight so that the grayscale brightness of the current frame equals the grayscale brightness corresponding to the target gray level; and

if the target gray level is more than the initial gray level, adjust up the backlight brightness of the current frame according to the determined value of the reference current of backlight so that the grayscale brightness of the current frame substantially equals the grayscale brightness corresponding to the target gray level.

11. The device according to claim 7 , wherein the backlight brightness adjustment table is preset as follows:

for the backlight zone, the reference current of backlight for the backlight zone is maintained, and when the initial gray level corresponding to the preceding frame is adjusted to the target gray level corresponding to the current frame, the duty cycle of backlight for the backlight zone is adjusted so that the grayscale brightness of the current frame equals the grayscale brightness corresponding to the target gray level, and a value of the duty cycle of backlight at the grayscale brightness is recorded; and wherein the initial gray level ranges from 0 to 255, and the target gray level ranges throughout gray levels which are less than the first threshold gray level and gray levels which are greater than the second threshold gray level.

12. The device according to claim 7 , wherein the backlight brightness adjustment table is preset as follows:

for the backlight zone, the duty cycle of backlight for the backlight zone is maintained, and when the initial gray level corresponding to the preceding frame is adjusted to the target gray level corresponding to the current frame, the reference current of backlight for the backlight zone is adjusted so that the grayscale brightness of the current frame equals the grayscale brightness corresponding to the target gray level, and the value of the reference current of backlight at the grayscale brightness is recorded; and wherein the initial gray level ranges from 0 to 255, and the target gray level ranges throughout gray levels which are less than the first threshold gray level and gray levels which are greater than the second threshold gray level.

13. A display device, comprising a device for adjusting grayscale brightness, wherein the device for adjusting grayscale brightness comprising:

one or more processors; and

a non-transitory memory,

wherein one or more computer readable program codes are stored in the non-transitory memory, and the one or more processors are configured to execute the one or more computer readable program codes to:

determine an initial gray level corresponding to a preceding frame, and a target gray level corresponding to a current frame, for a backlight zone corresponding to a zone of a display image;

adjust the grayscale brightness of the backlight zone through over-voltage driving, when the target gray level is not less than a first threshold gray level and not greater than a second threshold gray level; and

determine a value of an adjustment parameter corresponding to the initial gray level and the target gray level according to a preset backlight brightness adjustment table, and adjust backlight brightness of the current frame according to the determined value of the adjustment parameter, when the target gray level is less than the first threshold gray level or greater than the second threshold gray level.

Assignments (7)
CHANGE OF NAME Recorded Dec 3, 2021
From: MAXELL HOLDINGS, LTD.
To: MAXELL, LTD.
Reel/Frame 058666/0407 →
MERGER Recorded Nov 29, 2021
From: MAXELL, LTD.
To: MAXELL HOLDINGS, LTD.
Reel/Frame 058255/0579 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 25, 2021
From: HISENSE VISUAL TECHNOLOGY CO., LTD.
To: MAXELL, LTD.
Reel/Frame 056681/0441 →
CHANGE OF NAME Recorded May 27, 2021
From: HISENSE ELECTRIC CO., LTD.
To: HISENSE VISUAL TECHNOLOGY CO., LTD.
Reel/Frame 056408/0336 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 27, 2021
From: HISENSE USA CORPORATION; HISENSE INTERNATIONAL CO., LTD.
To: HISENSE VISUAL TECHNOLOGY CO., LTD.
Reel/Frame 056371/0923 →
ASSIGNMENT OF UNDIVIDED 66% INTEREST Recorded Aug 14, 2015
From: HISENSE ELECTRIC CO., LTD.
To: HISENSE USA CORPORATION; HISENSE INTERNATIONAL CO., LTD.
Reel/Frame 036354/0816 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 28, 2015
From: HUANG, SHUNMING; ZHANG, YUXIN; YANG, JIA; YANG, JIE
To: HISENSE ELECTRIC CO., LTD.
Reel/Frame 035731/0020 →