LCD Pixel Driving Using Alternating Gamma Curves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display (LCD) devices face challenges in increasing viewing angle and preventing afterimages due to the complexity of patterning pixel electrodes and the limitations of existing time division voltage-applying methods.
Innovation Solution
A method of driving pixels using alternating A-gamma and B-gamma curves for image data conversion, where pixel polarity is inverted every frame or every two frames, to improve viewing angle and eliminate afterimages, employing a timing controller and gamma memory to manage the gamma curves and output converted image data to the display unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If each pixel includes a first pixel electrode and a second pixel electrode to increase viewing angle, then viewing angle is improved, but patterning process becomes more complicated and aperture ratio is reduced
Solution Approach 1:
The patent extracts the dual-electrode structure from each pixel and replaces it with a single pixel electrode that receives different voltage levels through data signaling. Instead of having first and second pixel electrodes in each pixel, the invention uses one pixel electrode per pixel that is driven by different voltage levels (first voltage or second voltage) according to the display method, thereby eliminating the complex patterning requirements while maintaining the viewing angle improvement benefit
Solution Approach 2:
The patent inverts the conventional approach by not having different electrode structures for different voltage applications. Instead of structurally differentiating electrodes, it inverts the control strategy: a single electrode structure is used, but the voltage level applied to it is inverted or switched based on the frame timing, thereby achieving the same effect with simpler structure
2Adaptability or versatility
If time division voltage-applying method is used to increase viewing angle, then viewing angle is improved, but afterimages occur due to same polarity pixels having same voltage level
Solution Approach 1:
The patent applies local quality by differentiating the voltage levels applied to pixels based on their polarity. Pixels with the same polarity are driven by different voltage levels (first voltage for one polarity, second voltage for opposite polarity), while pixels with different polarities receive different voltage levels. This localized differentiation in voltage application prevents afterimages while maintaining the viewing angle benefit of the time division method
Solution Approach 2:
The patent changes the voltage level parameter based on pixel polarity and frame timing. Instead of applying the same voltage level to all pixels of the same polarity, it dynamically adjusts the voltage level (first voltage or second voltage) according to the pixel's polarity and the current frame number, thereby eliminating afterimages while maintaining viewing angle improvement
Data Source
AI summary
A pixel is driven by first converted image data having a first polarity and being converted by an A-gamma curve during an (N)th frame where ‘N’ is a natural number. The pixel is driven by second converted image data having a second polarity opposite to the first polarity and being converted using the A-gamma curve during an (N+1)th frame. The pixel is driven by third converted image data having the first polarity and being converted using a B-gamma curve different from the A-gamma curve during an (N+2)th frame. The pixel is driven by fourth converted image data having the second polarity and being converted by the B-gamma curve during an (N+3)th frame.