Backlight Module Brightness Control for Red Afterimage Suppression
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Solution Overview
Problem
The existing methods for reducing motion blur in image displays, such as black frame insertion, are hindered by the persistence of backlight afterimages, particularly red afterimages which have the longest duration and significantly interfere with visual perception, requiring costly hardware changes to adjust the color gamut range of phosphor powders.
Innovation Solution
The image display device controls its backlight module to provide different intensities of white light sources during various intervals of an image frame cycle, with a higher intensity in the first interval, a lower intensity in the second interval to cover red afterimages, and turning off the backlight in the third interval to simulate black frame insertion, thereby reducing afterimages without altering the hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the color gamut range of phosphor powder of backlight sources is reduced to change spectral components of red light source, then red afterimage duration is reduced, but hardware costs increase
Solution Approach 1:
The patent changes the operating parameters of the existing backlight hardware by adjusting the drive current intensity over time. Instead of modifying the phosphor material properties (which would require hardware changes), the system varies the backlight intensity parameter dynamically - using high intensity during display intervals and low or zero intensity during intervals when red afterimages would interfere with the next frame, thereby reducing red afterimage duration without increasing hardware costs
Solution Approach 2:
The patent implements periodic variation of backlight intensity synchronized with the display frame rate. The backlight operates in cycles matching the image frame cycle, alternating between active periods (providing full illumination) and inactive or reduced-intensity periods (minimizing red afterimage generation). This periodic action allows the system to achieve motion blur reduction and afterimage suppression using the existing hardware without modification
2Object-affected harmful factors
If black frame insertion is implemented to reduce motion blur, then motion blur is reduced, but backlight afterimages still interfere with visual perception
Solution Approach 1:
The patent applies preliminary anti-action by reducing or turning off the backlight intensity during the interval between frames, specifically targeting the red light component that causes the longest afterimage. By preemptively minimizing red backlight emission before the next frame displays, the system prevents red afterimages from forming and interfering with visual perception, while still maintaining the motion blur reduction benefits of black frame insertion
Data Source
AI summary
An image display device is provided. The image display device includes a display unit and a backlight module. The display unit is used for displaying pictures in an image frame cycle. The backlight module includes a plurality of light sources of different colors. The image frame cycle is divided into a first interval, a second interval and a third interval in sequence, and the second interval is adjacent to the first interval. The backlight module provides a white light source with a first intensity in the first interval and provides a white light source with a second intensity in the second interval, and the second intensity is smaller than the first intensity. The backlight module is turned off in the third interval.