# US 12,002,433 B2 · Brightness adjustment method, device and display apparatus

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- Number: US 12,002,433 B2
- Document ID: US12002433B2
- Status: Granted
- Kind: B2
- Application number: 18/026,578
- Filed: 2021-05-18
- Published: 2023-10-19
- Granted: 2024-06-04
- Earliest claimed: 2020-09-15
- Assignees: Chipone Technology (Beijing) Co., Ltd.
- Applicants: Chipone Technology (Beijing) Co., Ltd.
- Inventors: Aqiang Liu
- Web page: https://patentgrep.com/patent/US12002433B2

## CPC

- G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)}
- G09G 3/3426: {the different display panel areas being distributed in two dimensions, e.g. matrix}
- G09G 3/2096: {Details of the interface to the display terminal specific for a flat panel (suitable for both CRT and flat panel G09G5/006; specific for a CRT G09G1/167)}
- G09G 3/36: using liquid crystals
- G09G 2320/0626: for control of overall brightness
- G09G 2320/064: by time modulation of the brightness of the illumination source
- G09G 2354/00: Aspects of interface with display user
- G09G 2360/144: the light being ambient light
- G09G 2360/16: Calculation or use of calculated indices related to luminance levels in display data
- Y02B 20/40: Control techniques providing energy savings, e.g. smart controller or presence detection
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

Disclosed is a brightness adjustment method, a device and a display apparatus. The method comprises: acquiring a brightness adjustment instruction and a target display brightness value of a display panel, a display brightness value representing backlight brightness of the display panel; adjusting a duty cycle of the light-emitting control signal based on the target display brightness value of the display panel; driving LEDs of a corresponding row in a backlight source to emit light by the adjusted light-emitting control signal. Each time the duty cycle of the light-emitting control signal needs to be adjusted, a duty cycle of each pulse cycle of a part of N pulse cycles of the light-emitting control signal is selected for corresponding adjustment, thus backlight brightness adjustment accuracy of the display panel is effectively improved, and an adjustable range of backlight brightness of the display panel is wider.

## Claims

### Claim 1

A brightness adjustment method, comprising:
acquiring a brightness adjustment instruction and a target display brightness value of a display panel, the display brightness value being used to represent backlight brightness of the display panel;
adjusting a duty cycle of a light-emitting control signal based on the target display brightness value of the display panel;
driving LEDs of a corresponding row in a backlight source to emit light by use of the adjusted light-emitting control signal, wherein for each row of LEDs in the backlight source of the display panel, the light-emitting control signal corresponding to that row of LEDs comprises N pulse cycles; and
each time the duty cycle of the light-emitting control signal needs to be adjusted, performing corresponding adjustment on a duty cycle of each pulse cycle of a selected part of the N pulse cycles of the light-emitting control signal, within a corresponding to-be-adjusted frame period,
wherein,
N is a positive integer greater than 2; and
during the corresponding to-be-adjusted frame period together with an adjacent frame period before the corresponding to-be-adjusted frame period, a duty cycle of the at least one of the N pulse cycles of the light-emitting control signal is prevented from being adjusted.

### Claim 2 (depends on 1)

The brightness adjustment method according to claim 1, wherein, step of performing corresponding adjustment on the duty cycle of each pulse cycle of the selected part of the N pulse cycles of the light-emitting control signal comprises:
selecting each odd-numbered pulse cycle or each even-numbered pulse cycle of the N pulse cycles of the light-emitting control signal as the selected part of the N pulse cycles of the light-emitting control signal, and performing corresponding adjustment on the duty cycle of each pulse cycle of the selected part of the N pulse cycles of the light-emitting control signal.

### Claim 3 (depends on 1)

The brightness adjustment method according to claim 1, wherein, step of performing corresponding adjustment on the duty cycle of each pulse cycle of the selected part of the N pulse cycles of the light-emitting control signal comprises:
selecting i-th pulse cycle to k-th pulse cycle of the N pulse cycles of the light-emitting control signal as the selected part of the N pulse cycles of the light-emitting control signal, and performing corresponding adjustment on the duty cycle of each pulse cycle of the selected part of the N pulse cycles,
wherein i is a positive integer greater than or equal to 1, k is a positive integer greater than i and less than or equal to N, and k-i is less than N−1.

### Claim 4 (depends on 1)

The brightness adjustment method according to claim 1, wherein step of performing corresponding adjustment on the duty cycle of each pulse cycle of the selected part of the N pulse cycles of the light-emitting control signal comprises:
selecting a pulse cycle, which has a duty cycle less than a first threshold value or greater than a second threshold value, of the N pulse cycles of the light-emitting control signal as the selected part of the N pulse cycles of the light-emitting control signal, and performing corresponding adjustment on the duty cycle of each pulse cycle of the selected part of the N pulse cycles,
wherein a method for setting the first threshold value comprises: sorting duty cycles of the N pulse cycles in an order from high to low, and selecting a duty cycle of a j-th pulse cycle in that order as the first threshold value;
wherein a method for setting the second threshold value comprises: sorting the duty cycles of the N pulse cycles in an order from low to high, and selecting a duty cycle of a j-th pulse cycle in that order as the second threshold value, where j is a positive integer less than N−1.

### Claim 5 (depends on 1)

The brightness adjustment method according to claim 1, wherein step of performing corresponding adjustment on the duty cycle of each pulse cycle of the selected part of the N pulse cycles of the light-emitting control signal comprises:
randomly selecting a part of the N pulse cycles as the selected part of the N pulse cycles of the light-emitting control signal, and performing corresponding adjustment on the duty cycle of each pulse cycle of the selected part of the N pulse cycles.

### Claim 6 (depends on 2)

The brightness adjustment method according to claim 2, wherein,
the selected part of the N pulse cycles required for corresponding adjustment and corresponding to LEDs of each of adjacent rows in the backlight source are odd-numbered pulse cycles or even-numbered pulse cycles; or
the selected part of the N pulse cycles required for corresponding adjustment and corresponding to one of the adjacent rows of LEDs in the backlight source are odd-numbered pulse cycles, and the selected part of the N pulse cycle required for corresponding adjustment and corresponding to the other one of the adjacent rows of LEDs in the backlight source are even-numbered pulse cycles.

### Claim 7 (depends on 3)

The brightness adjustment method according to claim 3, wherein,
the selected part of the N pulse cycles required for corresponding adjustment and corresponding to LEDs of each of adjacent rows in the backlight source are from i-th pulse cycle to k-th pulse cycle; or
the selected part of the N pulse cycles required for corresponding adjustment and corresponding to LEDs of one of the adjacent rows of LEDs in the backlight source are from the i-th pulse cycle to the k-th pulse cycle, and the selected part of the N pulse cycles required for corresponding adjustment and corresponding to LEDs of the other one of the adjacent rows are from (i+m)-th pulse cycle to (k+m)-th pulse cycle,
where m is an integer, (i+m) is greater than or equal to 1, and (k+m) is less than or equal to N.

### Claim 8 (depends on 1)

The brightness adjustment method according to claim 1, wherein the duty cycle of each pulse cycle of the selected part of the N pulse cycles for corresponding adjustment is adjusted by a same adjustment quantity.

### Claim 9 (depends on 1)

The brightness adjustment method according to claim 1, wherein step of acquiring the brightness adjustment instruction and the target display brightness value of the display panel comprises:
generating the brightness adjustment instruction according to an operation instruction of a user, and taking a display brightness value set by the user as the target display brightness value of the display panel; or
generating the brightness adjustment instruction according to brightness variation of external ambient light, and generating the target display brightness value of the display panel according to sensed brightness of the external ambient light.

### Claim 10 (depends on 1)

A brightness adjustment device used for executing the brightness adjustment method according to claim 1, wherein, when the display panel displays each frame image, for each row of light emitting diodes in the backlight source of the display panel, the light-emitting control signal received by that row comprises N pulse cycles, N is a positive integer greater than 2, and the brightness adjustment device comprises:
a processor, configured to generate the brightness adjustment instruction and the target display brightness value of the display panel;
a timing controller, connected with the processor, and configured to receive the brightness adjustment instruction and the target display brightness value, and adjust the duty cycle of the outputted light-emitting control signal according to the brightness adjustment instruction and the target display brightness value;
a backlight driver, connected with the controller, and configured to receive the adjusted light-emitting control signal, so as to generate a corresponding driving current, which is used to drive the backlight source to emit light,
wherein, each time the duty cycle of the light-emitting control signal needs to be adjusted, corresponding adjustment is performed on a duty cycle of each pulse cycle of a selected part of the N pulse cycles of the light-emitting control signal.

### Claim 11 (depends on 10)

The brightness adjustment device according to claim 10, wherein the timing controller, configured to:
calculate a duty cycle of each pulse cycle of the outputted light-emitting control signal according to the target display brightness value of the display panel, so as to obtain a calculation result; and
generate the light-emitting control signal according to the calculation result.

### Claim 12 (depends on 10)

The brightness adjustment device according to claim 10, further comprising:
a memory, respectively connected with the processor and the timing controller, and configured to establish and store a mapping relationship between a duty cycle of the light-emitting control signal and a corresponding display brightness value.

### Claim 13 (depends on 10)

A display apparatus, comprising: the brightness adjustment device according to claim 10.

### Claim 14 (depends on 1)

The brightness adjustment method according to claim 1, wherein,
for each time the duty cycle of the light-emitting control signal needs to be adjusted, the at least one of the N pulse cycles of the light-emitting control signal that has the duty cycle prevented from being adjusted comprises a pulse cycle that has a maximum/minimum duty cycle among the N pulse cycles of the light-emitting control signal, within the corresponding to-be-adjusted frame period.