Liquid Crystal Display Polarity Frequency Control for Image Sticking
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Solution Overview
Problem
Liquid crystal display devices suffer from display quality degradation due to DC image sticking and flicker phenomena, which are caused by residual image accumulation and visual perception of brightness differences.
Innovation Solution
A liquid crystal display device and driving method that utilize a data voltage polarity frequency control system, where two liquid crystal cell groups operate at different frequencies within two frame periods, with one group inverting polarity every frame period and the other every two frame periods, to prevent DC image sticking and flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If interlace data voltages are supplied to liquid crystal cells, then display capability is improved, but DC image sticking occurs due to polarity dominance
Solution Approach 1:
The liquid crystal display panel is divided into first and second liquid crystal cell groups that are driven at different data voltage polarity frequencies. The first group is driven at a lower frequency (every two frame periods) while the second group is driven at a higher frequency (every frame period), segmenting the display into zones with different driving characteristics to prevent DC image sticking while maintaining display capability
Solution Approach 2:
The patent changes the data voltage polarity frequency parameter for different liquid crystal cell groups. By controlling the first group at a lower polarity frequency and the second group at a higher polarity frequency, the system prevents polarity dominance and DC image sticking while preserving the ability to display interlace data
2Object-generated harmful factors
If data voltage polarity frequency is increased to prevent DC image sticking, then residual images are reduced, but flicker phenomenon increases due to brightness difference perception
Solution Approach 1:
The display is segmented into two liquid crystal cell groups with different driving frequencies. The first group driven at lower frequency (every two frame periods) provides stability and reduces flicker perception, while the second group driven at higher frequency (every frame period) prevents DC image sticking and residual images, achieving a balance between both requirements
Solution Approach 2:
By changing the data voltage polarity frequency parameter for different cell groups, the patent optimizes the trade-off between residual image prevention and flicker reduction. The differential frequency driving allows each group to contribute differently: one group addresses DC components while the other addresses flicker components
Data Source
AI summary
A liquid crystal display device includes a liquid crystal display panel including a plurality of data lines, a plurality of gate lines, and a plurality of liquid crystal cells, the plurality of liquid crystal cells associated to a first and second liquid crystal cell groups, a data drive circuit to supply a data voltage to the data lines in response to a polarity control signal, a gate drive circuit to supply a scan pulse to the gate lines, and a polarity control circuit to generate different polarity control signals for each frame period and to control data voltage frequencies of the first and second liquid crystal cell groups to be different from each other.