Liquid Crystal Display Driving Control Circuit for Flicker Reduction
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Solution Overview
Problem
Conventional liquid crystal display devices experience flicker and blurring when using LED backlights due to the rapid response time of LEDs, which worsens image quality, especially when displaying still images at normal frame frequencies.
Innovation Solution
The liquid crystal display device divides each frame into multiple sub-frames for overdriving and normal driving operations, with the backlight flashing at a higher frequency than the frame frequency, and inverting the voltage polarity during each sub-frame to reduce flicker and blurring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the backlight is made to flash at the same frequency as the frame frequency to reduce liquid crystal response blurring, then moving image quality is improved, but a flicker occurs on the display screen
Solution Approach 1:
The patent applies periodic action by making the backlight flash at a frequency that is an integer multiple (2 or more times) of the frame frequency. This periodic flashing strategy transforms the single-frequency backlight operation into multi-frequency operation, which prevents flicker while maintaining sharp moving image display by synchronizing with the liquid crystal response characteristics.
2Object-affected harmful factors
If the backlight flashes at a higher frequency to prevent flicker, then flicker is reduced, but the complexity of the driving control increases
Solution Approach 1:
The patent segments the backlight driving control into multiple independent flashing periods within one frame period. By dividing the frame period into multiple sub-periods with distinct backlight flashing operations, the control is simplified into repeatable modular units, reducing overall control complexity while achieving flicker-free display through multiple synchronized flashing events.
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 prevents flicker and blurring of moving images by synchronizing the backlight flashes with the liquid crystal response, improving image quality by reducing the impact of LED response times.
Implementation Method 1
a liquid crystal display panel having scanning electrodes and data electrodes to apply a specified voltage to a corresponding pixel region and to control orientation of a liquid crystal to obtain a displayed image
Implementation Method 2
When an LED is used as a backlight source, a response of the LED in its turning-on to its turning-off states or vice versa is more rapid than that of a CRT
Data Source
AI summary
A liquid crystal display device is provided which improves quality of images made up of moving images and images having moving images and still images in a mixed manner. Each frame of an input video signal having a specified frame frequency (60 Hz) is divided into four sub-frames each having a frequency being four times as large as the specified frame frequency and, after an overdriving operation is performed in the first sub-frame on each pixel region of a liquid crystal display panel, a normal driving operation is performed in the second sub-frame and thereafter, and in which a backlight flashes two times at a frequency being two times as large as a frame frequency (120 Hz) of the first frame frequency during one frame period in specified time intervals.