Backlight Device LED Placement Interval Optimization
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Solution Overview
Problem
The non-uniformity of luminous intensity caused by the placement interval of LEDs in backlight devices emitting light to an end face of a light guide plate, which is exacerbated by the need for thinning and larger display sizes, requires a solution to ensure consistent light distribution.
Innovation Solution
A backlight device design where white light-emitting diodes are arranged side by side with specific placement intervals, with the light guide plate positioned such that the distance between the LEDs and the end face meets the condition P1≤H≤P2, where P1 is the interval between LEDs and P2 is the interval between groups, to mitigate luminance non-uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If LEDs are arranged side by side around the end face of the light guide plate to increase light output for larger displays, then the amount of light emitted increases, but the non-uniformity of luminous intensity caused by placement intervals worsens
Solution Approach 1:
The patent segments the LED arrangement into multiple groups with different placement intervals. Within each group, LEDs are spaced at interval P1, while between groups they are spaced at interval P2 (where P2 > P1). This segmentation allows the system to maintain high light output through multiple LEDs while reducing luminous intensity non-uniformity by varying the spacing pattern, thereby resolving the contradiction between increasing light emission and maintaining uniformity.
2Use of energy by moving object
If LEDs are placed closer to the light guide plate end face to improve light coupling efficiency, then light emission efficiency improves, but the thickness of the backlight device increases
Solution Approach 1:
The patent changes the parameter of LED placement distance from the light guide plate end face, denoting it as H. By optimizing this distance parameter, the system achieves effective light coupling into the light guide plate while maintaining a compact overall structure. This parameter optimization allows the backlight device to remain thin while preserving light emission efficiency, resolving the contradiction between these two requirements.
3Ease of manufacture
If LEDs are grouped and assembled to facilitate manufacturing, then ease of assembly improves, but the non-uniformity of luminous intensity due to varying placement intervals worsens
Solution Approach 1:
The patent segments LEDs into multiple groups that can be assembled separately and then combined. Each group maintains consistent internal spacing (P1) for uniform light distribution, while the groups themselves are spaced at larger intervals (P2). This segmentation enables modular assembly that is easier to manufacture while preserving luminous intensity uniformity within each group, resolving the contradiction between ease of assembly and uniformity of light output.
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 effectively suppresses luminance non-uniformity while maintaining efficient light distribution and supporting the thinning and expansion of display sizes by optimizing the placement and spacing of LEDs.
Implementation Method 1
a plurality of white light-emitting diodes, placed side by side in a direction extending along an end face of the light guide plate
Data Source
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AI summary
In an LED unit (34) of a backlight device (20), LEDs (38) are placed side by side at intervals of first placement interval P1. The LED unit (34) are installed in a flexible substrate (32) with a space of a second placement interval P2 apart from the flexible substrate (32). A light guide plate (22) is arranged such that an end face of the light guide plate (22) is spaced apart from the LEDs (38) by a distance H. The light guide plate (22) is so arranged as to meet a condition that P1≤H≤P2. Specifically, a plurality of LEDs (38) are placed side by side such that P1 is in a range of 0.1 mm to 3 mm and P2 in a range of 5 mm and 15 mm. The light guide plate (22) is arranged such that that H is in a range of 1 mm to 7 mm.