Lighting Device Corner Brightness via Wall Passing Portion
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Solution Overview
Problem
Liquid crystal display devices with direct type backlight units experience uneven brightness, particularly in the corner portions, due to a lower number of LEDs surrounding the outer peripheral areas, leading to decreased brightness and dark corners.
Innovation Solution
A lighting device with a reflection member having a rectangular plan view shape and insertion holes for LEDs, where wall portions surround the holes and include passing portions that allow light from adjacent LEDs to pass through, enhancing light distribution and brightness in corner areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a reflection member with a grid of wall portions is used to direct light from LEDs, then light directionality is improved, but brightness in outer peripheral portions decreases
Solution Approach 1:
The reflection member applies different structural characteristics to different regions: the first reflection area at the corner portion has a wall portion with a passing portion to allow light passage, while other reflection areas have complete wall portions for light reflection. This local differentiation resolves the contradiction by providing both light directionality and enhanced brightness in the outer peripheral corner area.
2Illumination intensity
If wall portions completely surround insertion holes to direct light, then light control is improved, but light distribution to corner areas decreases
Solution Approach 1:
The wall portion in the first reflection area is designed with a passing portion that creates a local structural difference. This allows light from adjacent LEDs to pass through to the corner area while maintaining the light control function in other regions, thus improving light distribution to corner areas without compromising overall light control precision.
3Illumination intensity
If LEDs are arranged in a standard grid pattern, then manufacturing is simplified, but brightness uniformity deteriorates
Solution Approach 1:
The patent maintains a standard grid arrangement for most LEDs to simplify manufacturing, but introduces a specific structural modification at the corner reflection area with a passing portion in the wall. This localized structural change improves brightness uniformity by directing additional light to the corner area without requiring a complete redesign of the LED arrangement, thus maintaining ease of manufacture while improving brightness 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 solution effectively reduces uneven brightness by ensuring that light from adjacent LEDs is directed towards corner areas, thereby enhancing brightness in these regions and minimizing the dark spots typically found in liquid crystal display devices.
Implementation Method 1
The reflection member includes insertion holes in which the LEDs are inserted, respectively, and side walls that surround the LEDs that are inserted in the insertion holes. The side walls of the reflection member are arranged to form a grid and surround the respective LEDs in a plan view. With such a reflection member, light rays emitted by the LEDS are likely to be directed toward the liquid crystal panel evenly by the side walls of the reflection member.
Implementation Method 2
The reflection areas include a first reflection area at a corner portion of the reflection member. The wall portions include one wall portion that is included in the first reflection area and the one wall portion includes a passing portion through which light from one of the light sources that is adjacent to the reflection area via the one wall portion passes.
Data Source
AI summary
A lighting device includes light sources, a board having a mount surface on which the light sources are arranged, and a reflection member disposed on the mount surface of the board and having a rectangular plan view shape. The reflection member includes insertion holes in each of which at least one of the light sources is disposed and wall portions defining a surface area of the reflection member into reflection areas in a grid. Some of the wall portions surround at least one of the insertion holes. The reflection areas include a first reflection area at a corner portion of the reflection member. The wall portions include one wall portion that is included in the first reflection area and the one wall portion includes a passing portion through which light from one of the light sources that is adjacent to the reflection area via the one wall portion passes.