Light Source Module Aspherical Collimator for LCD Backlight Uniformity
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Solution Overview
Problem
Current direct type backlight modules for LCDs face challenges in achieving high brightness and uniformity while maintaining a thin light cavity and low cost, often requiring a trade-off between the number of LEDs, light cavity height, and system reliability.
Innovation Solution
A light source module design incorporating an optical film, a light source unit with a reflecting device, a collimated unit, and a side reflection unit, where the collimated unit features aspherical reflective portions and varying pitch and brightness of LEDs to enhance central brightness and uniformity, and a processor adjusts power based on display modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the number of LEDs is decreased or light cavity height is decreased by configuring a secondary optical lens, then the light cavity becomes thinner, but product cost is increased
Solution Approach 1:
The patent removes the secondary optical lens from the system entirely, extracting the unnecessary component that increases cost while achieving the same thin light cavity goal through alternative structural design of the reflective lampshade
Solution Approach 2:
The patent employs an aspherical reflective surface in the lampshade with specific curvature characteristics to optimize light reflection and achieve uniform brightness distribution without requiring additional optical lenses, thereby maintaining thin light cavity while controlling costs
2Ease of manufacture
If a direct type backlight module without secondary optical lens is used, then product cost is reduced, but light cavity becomes thicker or more LEDs are required
Solution Approach 1:
The aspherical reflective surface design optimizes light reflection efficiency and distribution, enabling the system to achieve uniform brightness with fewer LEDs and thinner light cavity without requiring expensive secondary optical lenses
Solution Approach 2:
The patent modifies the geometric parameters of the reflective lampshade, specifically using an aspherical surface with defined curvature radius and vertex position, to optimize light reflection and achieve thin light cavity with reduced component count
3Quantity of substance
If the number of LEDs is limited, then cost is reduced, but it becomes difficult to improve center point brightness while maintaining uniformity
Solution Approach 1:
The patent implements non-uniform pitch arrangement of LEDs with different spacing in different regions, and uses an aspherical reflective surface with varying curvature to concentrate light reflection toward the center, achieving high center point brightness while maintaining overall uniformity with limited LEDs
Solution Approach 2:
The aspherical reflective surface is specifically designed with curvature that concentrates reflected light toward the center region, enhancing center point brightness without requiring additional LEDs, while the gradual curvature change maintains overall light uniformity
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 increases central brightness, improves light-emitting uniformity, and allows for cost-effective production by omitting a light guide plate, enabling flexible brightness adjustments without replacing other components.
Implementation Method 1
The collimated unit extends along a direction parallel to the third direction, and includes an upper reflective portion and a lower reflective portion
Implementation Method 2
The light bar includes a plurality of light-emitting elements, where a direction of an optical axis of the light-emitting elements is defined as a first direction
Data Source
AI summary
A light source module including an optical film and at least one light source unit is provided. The light source unit and the optical film enclose a space. The light source unit includes a reflecting device, at least one light bar, and a collimated unit. The reflecting device is disposed under the optical film. The light bar includes a plurality of light-emitting elements arranged along a third direction. The collimated unit extends along a direction parallel to the third direction and includes an upper reflective portion and a lower reflective portion. A shortest distance between one end of the lower reflective portion located adjacent to the reflecting device and the optical axis of the light-emitting elements along a second direction is defined as a first half light-emitting width, which is gradually increased along the third direction from a center portion of the collimated unit towards two sides thereof.