Diffusion Sheet Reflection Patterns for LCD Light Uniformity
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Solution Overview
Problem
The decreasing distance between lamps and diffusion plates in LCD devices, combined with reduced lamp numbers for efficiency, leads to degraded light uniformity, necessitating additional diffusion sheets that compromise the slim model design.
Innovation Solution
A diffusion sheet with reflection patterns extending parallel to the lamps' length, featuring reflection beads and a diffusion layer, is used to enhance light uniformity by reflecting and diffusing light, reducing the need for multiple optical sheets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the distance between lamps and diffusion plate is decreased to achieve a slim model, then the thickness of the LCD device is reduced, but the uniformity of light supplied to the liquid crystal panel is degraded
Solution Approach 1:
The diffusion sheet is designed with spatially varying properties: the first region (adjacent to lamps) has a first diffusion coefficient while the second region (away from lamps) has a second diffusion coefficient. This local variation in diffusion characteristics allows the sheet to compensate for the non-uniform light distribution caused by the reduced distance between lamps and diffusion plate, thereby maintaining both slim profile and light uniformity.
2Use of energy by moving object
If the number of lamps is reduced to improve efficiency, then the power consumption is reduced, but the uniformity of light supplied to the liquid crystal panel is degraded
Solution Approach 1:
The diffusion sheet employs region-specific diffusion coefficients to compensate for the non-uniform light distribution resulting from reduced lamp count. The first region with its specific diffusion coefficient addresses the lighting deficiencies in areas adjacent to the fewer lamps, while the second region handles the opposite area, collectively restoring light uniformity without requiring additional lamps.
3Illumination intensity
If additional diffusion sheets are provided to enhance light uniformity, then the uniformity of light is improved, but the number of optical sheets increases compromising the slim model design
Solution Approach 1:
The diffusion sheet is segmented into a first region and a second region with different diffusion coefficients. This segmentation allows a single sheet to perform the function that would otherwise require multiple sheets, as each region independently addresses specific uniformity requirements in different areas of the display.
Solution Approach 2:
The diffusion sheet is designed to simultaneously perform multiple functions: it diffuses light while maintaining the slim profile, and its region-specific diffusion coefficients allow it to compensate for both reduced lamp distance and reduced lamp count effects. This multi-functionality eliminates the need for additional separate optical sheets.
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 configuration provides a uniform luminance distribution to the liquid crystal panel, improving screen display quality while minimizing the number of optical sheets, thus maintaining a slim model design.
Implementation Method 1
a diffusion plate disposed above the lamps and diffusing light emitted from the lamps
Implementation Method 2
including reflection patterns formed on a region of a rear surface adjacent to the lamps and including reflection beads reflecting a portion of light from the diffusion plate
Data Source
AI summary
A liquid crystal display (LCD) device includes: a liquid crystal panel; a plurality of lamps disposed under the liquid crystal panel, supplying light to the liquid crystal panel; a diffusion plate disposed above the lamps and diffusing light emitted from the lamps; a diffusion sheet disposed on the diffusion plate and including a plurality of reflection patterns formed on a region of a rear surface adjacent to the lamps and including reflection beads reflecting a portion of light from the diffusion plate, wherein the respective reflection patterns of the diffusion sheet are formed to extend in a direction parallel to a lengthwise direction of the lamps.