LCD Backlight Light Characteristics Changing Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display (LCD) devices with edge-type backlight units face challenges in achieving uniformly distributed luminance due to light degradation, and direct-type units face issues with increased size and cost associated with limited color gamut and chromaticity coordinates, requiring advanced optical solutions to minimize light loss and adjust color viewing sensations.
Innovation Solution
Incorporating an optical member with a light characteristics changing layer, comprising a diffusion plate, prism sheet, and reflection plates coated with dyes or pigments, to adjust the spectrum distribution and chromaticity coordinates of light emitted from the backlight, allowing for improved color viewing sensations and reduced unit costs by shifting the color region of LEDs within the available range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If edge-type backlight unit is used to reduce size, then device thickness is reduced, but luminance uniformity deteriorates due to light degradation
Solution Approach 1:
A light guide plate is introduced as an intermediary component between the edge-mounted LED light source and the liquid crystal panel. The light guide plate distributes light from the edge source across the entire panel surface, achieving both thin profile and uniform luminance distribution throughout the display area.
Solution Approach 2:
The light source is positioned at the edge (one-dimensional line source) rather than across the entire back surface (two-dimensional area source). The light guide plate transforms this edge-mounted linear light source into uniform area illumination, solving the contradiction between compact thickness and luminance uniformity.
2Illumination intensity
If direct-type LED backlight unit is used to improve luminance uniformity, then light distribution is improved, but device size and cost increase
Solution Approach 1:
The light guide plate serves as a mediator that enables edge-mounted LEDs to achieve uniform area illumination without requiring a large array of LEDs across the entire back surface, thus reducing both component count and overall device thickness.
Solution Approach 2:
Instead of using multiple LED sources across the panel, a single edge-mounted LED array is used to generate light that is then copied and distributed uniformly across the entire panel surface through the light guide plate, reducing component complexity and cost.
3Manufacturing precision
If conventional color filters are used to adjust chromaticity coordinates, then color accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The patent changes the approach from using conventional color filters to using phosphor materials with specific emission characteristics. By selecting phosphors with appropriate peak wavelengths and bandwidths, the desired chromaticity coordinates are achieved through material property selection rather than complex filter manufacturing, reducing production cost.
Solution Approach 2:
The invention uses composite phosphor materials combining different phosphor types (e.g., yellow phosphor with blue LED, or red-green phosphors with blue LED) to achieve precise chromaticity control. This composite approach provides both color accuracy and manufacturing simplicity through material science rather than complex optical filtering.
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 enhances luminance uniformity and color accuracy by adjusting the spectrum distribution and chromaticity coordinates, reducing the need for costly color filters and expanding the color gamut, thereby improving the overall performance and cost-effectiveness of LCD devices.
Implementation Method 1
an optical member with a light characteristics changing layer for changing a spectrum distribution and chromaticity coordinates of light emitted from a back light
Implementation Method 2
comprising a diffusion plate, prism sheet, and reflection plates coated with dyes or pigments, to adjust the spectrum distribution and chromaticity coordinates
Implementation Method 3
The diffusion sheet 34 is disposed on the light guide plate 32 and uniformly distributes light that has transmitted through the light guide plate 32
Implementation Method 4
prism sheet 55 including first and second prism sheets 52 and 54 is disposed on the diffusion sheet 34. The prism sheet 55 guides light from the diffusion sheet 34 to a certain region
Implementation Method 5
The prism sheet 55 guides light from the diffusion sheet 34 to a certain region, namely, to an image region
Implementation Method 6
A reflection plate 30 disposed below the light guide plate 32 increases light reflection efficiency
Data Source
AI summary
Disclosed is a liquid crystal display device including an optical member with a region using an optical component such as a light emitting diode (LED) used as a backlight source, namely, a light characteristics changing layer for changing a spectrum distribution and chromaticity coordinates of light emitted from a back light. The LCD device including: a liquid crystal panel that displays an image; a backlight unit provided on a rear surface of the liquid crystal panel and providing light; and an optical member provided between the liquid crystal panel and the backlight unit and having a light characteristics changing layer for changing a spectrum distribution of light outputted from the backlight unit and chromaticity coordinates and providing the same to the liquid crystal panel.