Liquid Crystal Display Black Insertion Controller for Residual Image Reduction
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Solution Overview
Problem
Liquid crystal displays (LCDs) suffer from residual image and flicker phenomena when using black insertion driving methods, which impair display quality by causing afterimages and perceived skipping or jumping of images during still image display.
Innovation Solution
A liquid crystal panel with a black insertion controller that generates control signals to alternate between normal and black image units within each frame period, ensuring that each pixel displays a normal image in one sub-frame and a black image in the next, thereby eliminating residual images and averaging flicker effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If black insertion driving method is used to eliminate residual images, then residual image phenomenon is reduced, but flicker phenomenon is generated
Solution Approach 1:
The frame period is divided into multiple sub-frame periods (first, second, third, fourth sub-frames) rather than using a simple two-subframe black insertion method. This segmentation allows different regions of the display to be updated at different times, eliminating residual images while maintaining image stability and reducing flicker through progressive scanning.
Solution Approach 2:
The patent implements periodic updating of pixel data across multiple sub-frame periods, where each pixel is updated in a systematic sequence through the different sub-frames. This periodic action ensures that all pixels receive their final image data by the end of the frame period, eliminating residual images while maintaining stable display.
2Object-affected harmful factors
If black insertion driving is implemented by inserting black frames between normal frames, then afterimage is removed, but display quality is impaired due to flicker and perceived skipping
Solution Approach 1:
The display frame is segmented into multiple sub-frames with different updating patterns. Some pixels are updated in earlier sub-frames while others are updated in later sub-frames, creating a progressive scanning effect that eliminates afterimages without causing the flicker and skipping associated with complete black frame insertion.
Solution Approach 2:
Different regions or groups of pixels are assigned different update timings within the frame period. This local quality approach allows the display to eliminate residual images in each region without requiring complete black frames, thereby maintaining overall display quality and avoiding flicker.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces residual image phenomena and minimizes flicker, enhancing display quality by ensuring alternating normal and black image units across sub-frames, thus improving overall image stability and clarity.
Implementation Method 1
an electric field is generated between the pixel electrode 132 and the common electrode 134 of each pixel 130. The electric field drives the liquid crystal molecules of the pixel 130 to tilt to a corresponding angle, so as to control the light transmission of the pixel 130
Implementation Method 2
When the discharging process is finished, the electric field is removed. Thereby, the liquid crystal molecules of the pixel 130 return to the original positions, so as to prevent light beams from transmitting therethrough
Data Source
AI summary
An exemplary liquid crystal display (300) includes a liquid crystal panel (301), a data circuit (303), and a black insertion controller (305). The liquid crystal panel includes a plurality of pixels (330). The black insertion controller receives a display signal of the pixel, and generates a black insertion control signal according to an address of the pixel, and the data circuit drives the pixel to display one of a black image unit and a normal image unit according to the black insertion control signal in a first sub-frame period of a frame period. The displayed black image unit of the pixel or the displayed normal image unit is converted into a normal image unit or a black image unit in a second sub-frame period of the frame period. A method for driving the liquid crystal display is also provided.