Planar Lighting Device with Segmented Conduction Pattern for High Density Mounting
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Solution Overview
Problem
Current side light-type backlights for liquid crystal display devices face challenges in achieving high brightness and uniform lighting due to limitations in the number of LEDs that can be mounted, excessive driving voltage when all LEDs are serially driven, and difficulties in providing adequate coverlay between adjacent LEDs, leading to potential breakage and adhesion issues.
Innovation Solution
A planar lighting device configuration featuring a light guide plate with LEDs arranged in a line along its side end face, a mounting substrate with a conduction pattern and cover member that exposes lands for adjacent LEDs, and extension parts to secure the LEDs and prevent peeling, allowing for high-density mounting and independent driving control of LEDs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If more LEDs are arranged on the light incidence face to increase brightness, then the brightness of the backlight is improved, but the driving voltage is excessively increased when all LEDs are serially driven
Solution Approach 1:
The patent divides the plurality of LEDs into multiple independent groups, where each group can be driven separately. This segmentation allows the backlight to achieve high brightness by activating all LEDs while avoiding excessive driving voltage by only requiring sufficient voltage for each individual group, thus resolving the contradiction between brightness and driving voltage requirements.
2Illumination intensity
If more LEDs are arranged on the light incidence face to increase brightness, then the brightness of the backlight is improved, but it is difficult to provide adequate coverlay between adjacent LEDs due to processing limits and adhesion precision
Solution Approach 1:
By dividing LEDs into separate groups with independent connection wirings, the patent creates distinct mounting regions that can be processed independently. This segmentation allows adequate coverlay placement within each group while maintaining manufacturing feasibility, thus enabling high LED density without compromising adhesion precision.
Solution Approach 2:
The patent transitions from a single continuous wiring structure to multiple discrete wiring groups arranged in a modular fashion. This dimensional reorganization of the connection structure allows for better spatial distribution of coverlay application areas, improving adhesion precision while accommodating higher LED densities.
3Illumination intensity
If more LEDs are arranged on the light incidence face to increase brightness, then the brightness of the backlight is improved, but the connection wiring may break due to insufficient adhesion strength without adequate coverlay
Solution Approach 1:
The patent segments the connection wiring into multiple independent groups, each with its own coverlay protection. This segmentation ensures that each wiring group has sufficient adhesion strength and coverlay coverage, preventing breakage while allowing a higher overall density of LEDs to be mounted on the light incidence face.
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 enhances the reliability and stability of the lighting device by ensuring high brightness and uniformity, while preventing peeling and breakage, and allowing for precise self-alignment and increased LED density.
Implementation Method 1
a plurality of light sources 1 which are mounted on an FPC 3 and arranged with contacting a side end face 2s of a light guide plate 2
Implementation Method 2
extension parts that are respectively connected to the pair of lands, the cover member has an opening that exposes together the two lands
Data Source
AI summary
A planar lighting device includes a light guide plate, a plurality of light sources arranged in a line shape along a longitudinal direction of a side end face of the light guide plate, and a mounting substrate, on which the light sources are mounted. The mounting substrate has a base material, a conduction pattern formed on the base material, and a cover member arranged on the conduction pattern. The conduction pattern includes pairs of lands corresponding to a plurality of electrode terminals of each light source and to which the pair of electrode terminals is respectively connected, and first and second extension parts that are respectively connected to the pair of lands, extend from a first end portion of the lands, which faces the land of the adjacent light source, extend toward opposite sides of the light guide plate and to extend under the cover member.