Scanning Line Signal Timing Correction for Display Panel
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Solution Overview
Problem
In display apparatus using the active matrix-type driving method, display unevenness occurs due to waveform distortion of the scanning line clock signal as it propagates through the wiring on the display panel, leading to inconsistent timing of level transitions among scanning line drive units, which affects the voltage held in liquid crystal layers and results in luminance unevenness across pixels.
Innovation Solution
A display apparatus with a timing control unit generating a scanning line clock signal and a signal correcting unit that adjusts the timing of level transitions in the scanning line signal output by scanning line drive units to match the intended timing, using shift times set for each unit to synchronize the level transitions and reduce waveform distortion effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of pixels and frame rate are increased to improve image definition and video smoothness, then the display quality is improved, but the time allowed to set each pixel to desired luminance becomes shorter, making it difficult to maintain consistent voltage in liquid crystal layers
Solution Approach 1:
The patent applies preliminary action by adjusting the timing of scanning line signals in advance to compensate for waveform distortion that will occur during signal propagation. The timing control unit predicts the distortion and pre-adjusts the signal timing so that when the signal reaches the liquid crystal layer, the TFT switching and voltage application occur at the correct moments despite the shortened time window caused by high frame rates and pixel density
2Manufacturing precision
If multiple scanning line drive units are arranged along the outer edge of the display panel to drive high-resolution displays, then the pixel density is improved, but waveform distortion occurs in the scanning line clock signal as it propagates through the wiring, leading to display unevenness
Solution Approach 1:
The patent applies local quality by providing different timing adjustments to different scanning line drive units based on their specific positions and signal propagation characteristics. Each drive unit receives customized timing correction parameters from the timing control unit, allowing local compensation for waveform distortion that varies across different regions of the display panel, thereby maintaining signal timing consistency despite the long wiring paths required for high pixel density
3Area of stationary object
If the scanning line clock signal is propagated through long wiring to reach scanning line drive units arranged along the outer edge, then the display area coverage is improved, but waveform distortion occurs leading to inconsistent level transition timing among drive units
Solution Approach 1:
The patent applies feedback by having the timing control unit receive timing information from each scanning line drive unit and adjust the scanning line clock signal timing based on the actual propagation characteristics. The system measures or predicts the timing offset caused by long wiring propagation and feeds this information back to the timing control unit, which then compensates by adjusting the clock signal timing to ensure all drive units achieve level transitions at the correct moments
Data Source
AI summary
A display apparatus is disclosed. The display apparatus according to one embodiment comprises: a display panel comprising a plurality of pixels arranged in a matrix, a plurality of scanning lines, and a plurality of data lines; a timing control unit to generate a scanning line clock signal in which a level transition is repeated; a plurality of scanning line drive units to successively output a scanning line signal based on the scanning line clock signal to the scanning lines; and a signal correcting unit to correct either one of the scanning line clock signal and the scanning line signal such that time differences between a timing of one level transition of the scanning line clock signal and a timing of a level transition of the scanning line signal based on the one level transition substantially match among the scanning line signals output by respective scanning line drive units.