Special-Shaped Reflector Assembly Holes for Lens Misalignment Tolerance
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Solution Overview
Problem
Conventional reflectors have poor fault tolerance, leading to misalignment issues between the PCB board and the lens, which results in the lens falling off due to heat expansion, affecting the lighting effect of the backlight.
Innovation Solution
A reflector with a special-shaped assembly hole featuring an irregular rhombus design, including symmetrical axes and arc-shaped sides, allows for gaps that accommodate misalignment and prevent weld legs from being cut during thermal expansion, ensuring the lens remains securely attached.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the reflector is designed with a standard-shaped assembly hole for accommodating the lamp bead and lens, then the manufacturing process is simple, but the misalignment between the PCB board and the reflector causes the weld legs of the lens to be too close to the edge, resulting in poor fault tolerance
Solution Approach 1:
The patent applies asymmetry by designing an irregular rhombus-shaped assembly hole instead of a standard symmetric shape. The hole features four sides of different lengths and four angles of different measures, creating an asymmetric geometry that provides better clearance margins. This asymmetric design ensures that even with misalignment between the PCB board and reflector, the weld legs of the lens maintain sufficient distance from the hole edges, thereby improving fault tolerance while remaining manufacturable.
2Area of stationary object
If the reflector is positioned close to the PCB board to reduce space, then the backlight structure is compact, but thermal expansion of the reflector cuts the weld legs of the lens, causing the lens to fall off
Solution Approach 1:
The asymmetric irregular rhombus shape creates non-uniform clearance zones around the assembly hole. This asymmetric geometry strategically positions greater clearance distances in directions where thermal expansion is most likely to occur, allowing the reflector to expand without cutting the weld legs. The design maintains compact overall dimensions while providing targeted clearance where needed most for reliability.
Solution Approach 2:
The design incorporates beforehand cushioning by pre-establishing sufficient clearance distances between the weld legs and the assembly hole edges. This clearance acts as a cushion or buffer zone that absorbs the dimensional changes caused by thermal expansion. The irregular rhombus geometry is specifically configured to provide this protective cushioning margin before any potential contact between the expanding reflector and the weld legs can occur.
3Device complexity
If the assembly hole is designed with uniform clearance from the center, then the design is simple, but it cannot accommodate misalignment between components during assembly
Solution Approach 1:
The patent rejects uniform clearance in favor of asymmetric clearance distribution. The irregular rhombus shape creates varying clearance distances from the center to each side and corner, with strategically larger clearances in directions prone to misalignment. This asymmetric approach provides superior misalignment tolerance compared to uniform clearance, while the overall design remains relatively simple and manufacturable.
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
The design enhances fault tolerance by preventing lens detachment from the PCB board, maintaining a stable connection even under thermal stress, thus improving the reliability of the backlight.
Implementation Method 1
the reflector is provided with a special-shaped assembly hole for accommodating the lamp bead and the lens
Implementation Method 2
the reflector will focus light emitted by the lamp bead, and will emit a lot of heat
Implementation Method 3
since the PCB board generates heat during operation, the reflector will be also heated up accordingly
Implementation Method 4
After heated up, the reflector will expand to a certain extent, and will stretch when expanding
Data Source
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AI summary
The present disclosure provides a reflector and a backlight having the same. The reflector is provided with a special-shaped assembly hole. The special-shaped assembly hole comprises a first included angle and a second included angle opposite to each other, two sides forming the first included angle are respectively a first upper side and a second upper side, and two sides forming the second included angle are respectively a first lower side and a second lower side. The special-shaped assembly hole further comprises a first arc-shaped side and a second arc-shaped side opposite to each other. The special-shaped assembly hole further comprises a first limiting side and a second limiting side, and further comprises a third limiting side and a fourth limiting side. Through arranging gaps of the first upper side, the second upper side, the first lower side and the second lower side relative to the first limiting side, the second limiting side, the third limiting side and the fourth limiting side in a direction away from the center, when the PCB board and the reflector are misaligned, there can be still a space between the weld leg of the lens and the side edge of the special-shaped assembly hole. When the reflector expands, the weld leg of the lens will not be easily cut, thereby reducing the probability of the lens falling off from the PCB board, and improving the fault tolerance effect of the special-shaped assembly hole.