Backlight Device Lens Array for Uniform Brightness
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Solution Overview
Problem
Conventional backlight devices for large-sized liquid crystal displays using light emitting diodes (LEDs) face challenges in achieving uniform brightness while maintaining low cost, as they require a large number of LEDs, leading to increased costs and potential luminance unevenness.
Innovation Solution
A backlight device design featuring a light source element with a plurality of LEDs and lenses arrayed in rows, where the lenses are configured to spread light uniformly across the liquid crystal display panel, using a housing, diffuser plate, and reflection sheet to ensure even luminance distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple light emitting diodes are arranged to achieve uniform brightness, then brightness uniformity is improved, but cost increases due to the large number of LEDs needed
Solution Approach 1:
Multiple lenses are combined in an array configuration where their light-spreading functions are merged to collectively illuminate the liquid crystal panel uniformly, replacing the need for numerous individual LEDs
Solution Approach 2:
Lenses are introduced as intermediary optical elements between the LEDs and the liquid crystal panel to redistribute and uniformize the light output, allowing fewer LEDs to achieve the same uniformity效果
2Quantity of substance
If the output of each individual light emitting diode is increased to decrease the number of LEDs, then the number of LEDs is reduced, but luminance unevenness occurs
Solution Approach 1:
Different regions of the liquid crystal panel are illuminated by different lens rows with optimized light distribution characteristics, where each lens row provides tailored local illumination to compensate for distance and angle variations
Solution Approach 2:
The problem of luminance uniformity is solved by transitioning from a single-row linear arrangement to a two-dimensional array of lenses, where multiple rows work together to distribute light more evenly across the panel surface
3Illumination intensity
If a large number of light emitting diodes are used to achieve sufficient brightness, then brightness is improved, but device complexity increases
Solution Approach 1:
The mechanical/optical system is simplified by replacing numerous discrete LED sources with a fewer-number LED array combined with passive optical lenses, where the lenses perform the light distribution function that would otherwise require many more LEDs
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 simple, cost-effective backlight device and liquid crystal display apparatus with sufficient brightness, reducing luminance unevenness by overlapping luminance distributions from multiple lens rows and optimizing light distribution across the panel.
Implementation Method 1
a lens that spreads out light from the light emitting diodes
Implementation Method 2
a reflection sheet configured to reflect light emitted from the light source element, toward the diffuser plate
Data Source
AI summary
Provided is a backlight device having: a light source element having light emitting diodes and a lens expanding light from the light emitting diodes; a housing containing the light source element; a diffuser plate covering an opening portion of the housing; and a reflection sheet reflecting light emitted from the light source element, toward the diffuser plate. In the light source element, a plurality of the lenses are arranged at a central zone, the plurality of lenses being arranged in a plurality of rows.