Display Backlight Timing to Reduce Power and Image Persistence
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Solution Overview
Problem
Conventional electronic devices face issues with high power consumption and poor image display quality due to the timing of backlight activation relative to liquid crystal reactions, leading to problems such as image persistence and rough edges.
Innovation Solution
The electronic device incorporates a display module and a backlight module with coordinated operation periods, including an overlapping backlight driving period with the display charging period, and adjustable or variable frame rates and frequencies to balance power consumption and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the backlight is turned on when the liquid crystals react, then the image display can be continuous, but image persistence and rough edges occur leading to poor visual effect
Solution Approach 1:
The backlight is turned on in advance during the display charging period before the liquid crystal switching is complete, so that when the liquid crystals finish switching, the backlight is already on and ready to illuminate the stable image, avoiding image persistence and rough edges
Solution Approach 2:
The backlight driving period is made dynamically adjustable and is staggered relative to the liquid crystal switching period, allowing the system to optimize the timing between backlight illumination and liquid crystal response to achieve both continuous display and high image quality
2Manufacturing precision
If the backlight is turned on after the liquid crystals react to avoid reaction time issues, then image display quality improves, but the backlight is limited to very short time resulting in high instantaneous current and high power consumption
Solution Approach 1:
The backlight is activated in advance during the display charging period rather than waiting until after liquid crystal switching, which allows the backlight to run for a longer duration spread across multiple periods, reducing instantaneous current peaks and overall power consumption while still ensuring the image is stable when illuminated
Solution Approach 2:
The system dynamically adjusts the backlight driving period to overlap with the display charging period of the next frame, creating a staggered timing arrangement that extends the effective backlight on time and distributes power consumption more evenly
3Use of energy by moving object
If the backlight driving period is extended to reduce instantaneous current, then power consumption decreases, but it may overlap with liquid crystal rotating period causing image persistence
Solution Approach 1:
The backlight driving period is dynamically staggered to overlap with the display charging period rather than the liquid crystal rotating period, allowing extended backlight duration for reduced power consumption while maintaining image quality by avoiding illumination during liquid crystal switching
Solution Approach 2:
The backlight is activated during the display charging period in advance, which allows the system to extend the backlight on time for lower power consumption while ensuring the backlight is already stable when the liquid crystal image is complete, avoiding image persistence
Data Source
AI summary
An electronic device including a display module and a backlight module is disclosed. The display module includes a display charging period and a liquid crystal rotating period in one frame. The backlight module is configured to provide a light source to the display module, and the backlight module includes a backlight driving period corresponding to one frame of the display module. A portion of the backlight driving period of an Nth frame is overlapped with the display charging period of an (N+1)th frame, and N is a positive integer. The backlight module includes a backlight driving circuit, the backlight driving circuit is capable of providing commands with different driving frequencies according to an operation state of the display module, and the backlight module is operated in the backlight driving period in one frame according to the commands with different driving frequencies.