Position-Adjustable Backlight for LCD Halo Reduction
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Solution Overview
Problem
Conventional liquid crystal display (LCD) backlights suffer from a halo effect, where white light bleeds into black zones, causing unpleasant cloudy grey colors due to the inability to precisely control light distribution for high contrast patterns.
Innovation Solution
Position-adjustable light sources using electromagnet carriers that create magnetic fields, allowing for precise movement of LEDs to align with image patterns, reducing halo effects by concentrating light in specific areas and dimming as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional backlights use fixed light sources, then the structure is simple and easy to manufacture, but the halo effect occurs where white light bleeds into black zones
Solution Approach 1:
The patent applies dynamics by making the light sources movable rather than fixed. Each light source is mounted on a carrier that can be repositioned along the backlight panel, allowing the system to adapt its light distribution dynamically. This enables the light sources to be moved away from black zones to eliminate the halo effect while maintaining a relatively simple overall structure.
Solution Approach 2:
The patent implements local quality by allowing different regions of the backlight to have different light source configurations. By selectively positioning light sources in specific areas and adjusting their individual positions, the system creates non-uniform light distribution that matches the local requirements of different display zones, preventing light bleeding into black areas while maintaining simplicity in other regions.
2Object-affected harmful factors
If light sources are made movable to adjust positions, then the halo effect is reduced and image quality improves, but the device complexity increases
Solution Approach 1:
The patent uses dynamics to reduce device complexity by implementing a straightforward mechanical movement mechanism. Each light source carrier can move along a simple track or guide structure, and the positioning is achieved through basic mechanical means rather than complex actuators. This dynamic capability allows halo effect reduction while keeping the overall system relatively simple.
Solution Approach 2:
The patent applies segmentation by dividing the backlight into multiple independent modules, each with its own movable light source carrier. This modular approach allows each segment to be independently positioned to eliminate local halo effects without requiring complex coordination across the entire backlight, thereby reducing overall device complexity while improving image quality.
3Object-affected harmful factors
If light sources are concentrated in specific areas, then high contrast patterns are enhanced and dark colors become more visible, but light distribution uniformity decreases
Solution Approach 1:
The patent implements local quality by concentrating light sources in specific areas where needed to enhance contrast and dark color visibility. By selectively positioning light sources near bright areas or away from black zones, the system creates locally optimized light distribution that enhances contrast while accepting non-uniform overall distribution as a necessary trade-off for improved image quality.
Solution Approach 2:
The patent uses dynamics to allow the light source positions to be adjusted based on the displayed content. For high contrast patterns, light sources can be dynamically repositioned to concentrate illumination where needed, enhancing contrast and dark color visibility. This dynamic adaptability allows the system to optimize for contrast enhancement while maintaining the ability to restore uniform distribution when needed.
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
Effectively reduces and eliminates the halo effect by moving LEDs to match high contrast patterns, enhancing the visibility of dark and bright colors, thereby improving image quality.
Implementation Method 1
The light sources ride upon electromagnet carriers. When currents are applied to the electromagnet carriers, each electromagnet carrier creates a corresponding magnetic field.
Implementation Method 2
The magnetic fields cause neighboring electromagnet carriers to attract or to repel, depending on the magnitude/polarity of the currents.
Implementation Method 3
The light sources, however, are movable to adjust the locations or positions of their light outputs. The light sources ride upon electromagnet carriers.
Data Source
AI summary
A liquid crystal display has position-adjustable light sources. The light sources may be lamps, LEDs, or other emissive components. The light sources, however, are movable to adjust the locations or positions of their light outputs. The light sources ride upon electromagnet carriers. When currents are applied to the electromagnet carriers, each electromagnet carrier creates a corresponding magnetic field. The magnetic fields cause neighboring electromagnet carriers to attract or to repel, depending on the magnitude/polarity of the currents. The lateral and vertical positions of the electromagnet carriers may thus be adjusted by varying their respective currents and magnetic fields. Because the light sources ride on the electromagnet carriers, the light sources may be moved to refine an image generated by the liquid crystal display. The light sources, for example, may be moved to improve white/black contracts to reduce halo-effects.