Lighting Device Self-Positioning Board for Brightness Uniformity

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Solution Overview

Problem

Existing lighting devices for electro-optical devices, such as liquid crystal display devices, face issues with light source dispersion and reduced brightness due to misalignment between the light source and the light guide, leading to gaps that attenuate the light and result in uneven brightness.

Innovation Solution

The lighting device incorporates a board with a first hole and a projecting part that presses a protrusion on the light guide, allowing the board to move closer to the light receiving plane, ensuring efficient light introduction and maintaining the light source's position, thereby preventing dispersion and enhancing brightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If LED is positioned using notches and ribs with size differences, then the positioning structure is simple, but the LED may be dislocated from the predetermined position causing brightness dispersion

Engineering Contradiction:

Improvepositioning structureVSAvoidLED position accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The FPC board's projecting part automatically presses the light guide's protrusion to self-adjust and self-position the LED board relative to the light guide, eliminating the need for complex external positioning mechanisms while ensuring precise alignment

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The positioning mechanism transitions from a static rigid structure (notches and ribs) to a dynamic adjustable structure where the projecting part can elastically deform to press the protrusion, allowing for tolerance compensation and precise positioning

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If there is a gap between the light guide and LED due to positioning errors, then the positioning structure is tolerant, but the brightness of the light introduced into the light guide is lowered

Engineering Contradiction:

Improvepositioning toleranceVSAvoidlight brightness

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The projecting part is pre-configured to press the protrusion before final assembly, ensuring that the light guide and LED board are firmly positioned together in advance, preventing any gaps from forming during operation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The contact interface between the projecting part and protrusion is designed with curved surfaces that allow for point or line contact, concentrating the pressing force effectively to eliminate gaps while accommodating positioning tolerances

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Manufacturing precision

If a special shape is formed on the emitting plane of LED for positioning, then the positioning is achieved, but the brightness of the lighting device is dispersed

Engineering Contradiction:

ImproveLED positioningVSAvoidlight brightness uniformity

Core Design Contradiction:

Manufacturing precisionVSIllumination intensity

Solution Approach 1:

The positioning function is extracted from the LED's emitting plane itself and transferred to dedicated positioning structures (projecting part and protrusion) on the FPC board and light guide, preserving the emitting plane's integrity and brightness uniformity

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS7490973B2Lighting device, electro-optical device and electronic apparatus

Publication Date: 2009.02.17 BOE TECHNOLOGY GROUP CO LTD

AI summary

A lighting device includes a board mounting a light source, a first hole provided in the board, a projecting part protruded inside the first hole from a periphery of the first hole, a light guide which receives a light emitted from the light source through a light receiving plane, and transmits the light from a light transmitting plane, and the first protrusion which is integrally formed in the light guide and is inserted into the first hole, wherein the projecting part presses a side of the first protrusion so that the board can move toward the light receiving plane.