Display Backlight Flickering Suppression via Cycle Ratio Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices with light-emitting members that change their lighting cycle experience flickering due to changes in the length of the lighting cycle, which affects the perceived luminance, even when the duty ratio is kept constant.
Innovation Solution
A display device with a light-emitting member that controls the lighting cycle by setting intermediate points within the lighting period as start and end points of subsequent cycles, ensuring the absolute difference in the ratio of the lighting period to the synchronization cycle remains within 0.1, thereby minimizing flickering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the length of the lighting cycle is changed, then the adaptability of the display device is improved, but flickering is generated due to changes in the ratio of lighting period to lighting cycle
Solution Approach 1:
The patent applies parameter changes by carefully adjusting the lighting period length and lighting cycle length parameters. When changing the lighting cycle from a first length to a second length, the patent modifies the lighting period length accordingly to maintain the ratio within 0.1 of the target duty ratio, thereby suppressing flickering while achieving adaptability.
Solution Approach 2:
The patent implements feedback control by calculating the ratio of the lighting period length to the lighting cycle length and comparing it against the target duty ratio. The light emitting control unit adjusts the lighting period length based on this feedback to ensure the ratio remains within 0.1 of the target value, preventing flickering during cycle changes.
2Stability of the object's composition
If the duty ratio is kept constant, then the luminance stability is improved, but flickering still occurs when the lighting cycle length is changed
Solution Approach 1:
The patent extends parameter changes beyond just maintaining a constant duty ratio. It introduces a new constraint by controlling the ratio of lighting period length to lighting cycle length to be within 0.1 of the target duty ratio. This additional parameter control prevents flickering even when the lighting cycle length changes, while maintaining luminance stability.
3Illumination intensity
If the lighting period length is extended, then the illumination intensity is improved, but the ratio change causes perceived flickering
Solution Approach 1:
The patent applies parameter changes by coordinating the lighting period length extension with a proportional extension of the lighting cycle length. By maintaining the ratio of lighting period to lighting cycle within 0.1 of the target duty ratio, the patent achieves higher illumination intensity without causing perceived flickering, as the ratio change remains below the human perception threshold.
Data Source
AI summary
A display device includes a control circuit. By setting an intermediate point between a start point and an end point of a lighting period as a start point of the lighting cycle, and setting an intermediate point between a start point and an end point of a lighting period of the next lighting period as an end point of the lighting cycle, the control circuit controls a backlight such that an absolute value of a difference value between a first ratio of a sum of a length of a first lighting period in the first lighting cycle and a length of the next second lighting period in the first lighting cycle to a length of the first lighting cycle and the target duty ratio is 0.1 or less.