Backlight Unit Barrier Rib Light Interference Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing direct light type backlight units using CCFLs face challenges with motion blur due to light interference between division areas, especially when switching between images, as CCFLs are poor at instant lighting and have low color reproducibility.
Innovation Solution
A backlight unit with a base substrate, point light sources arranged in lines, a diffusion plate, and barrier ribs that form division areas by reflecting light and preventing interference between adjacent areas, allowing sequential lighting in synchronization with the liquid crystal panel's scanning time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light diverging from a selected lighting area is allowed to pass through the diffusion plate, then light can be uniformly distributed, but light invades adjacent lighting areas causing motion blur
Solution Approach 1:
The diffusion plate is divided into multiple light transmission regions by non-light transmission regions (barrier ribs). This segmentation prevents light from one lighting area from invading adjacent areas while maintaining uniform light distribution within each area. The barrier ribs create physical boundaries that separate the light paths of different LED lines.
Solution Approach 2:
The harmful light interference is extracted and removed by introducing barrier ribs that block the diverging light from reaching adjacent lighting areas. The barrier ribs selectively remove the unwanted light paths while allowing the desired light to pass through the diffusion plate to the liquid crystal panel.
2Duration of action of stationary object
If CCFL is used as light source, then continuous lighting is achieved, but instant lighting capability and color reproducibility are poor
Solution Approach 1:
The light source type is changed from CCFL to LED, which fundamentally changes the lighting characteristics. LEDs provide both continuous lighting capability and instant response time, along with superior color reproducibility. This parameter change in the light source technology resolves the contradiction between continuous lighting and instant response.
3Ease of manufacture
If barrier rib is not inserted into diffusion plate, then manufacturing is simpler, but light interference between division areas occurs
Solution Approach 1:
The barrier ribs are pre-formed as integral parts of the diffusion plate structure, with insertion grooves already prepared in the diffusion plate. This preliminary preparation allows the barrier ribs to be easily inserted during assembly without requiring complex post-processing or alignment procedures, thus maintaining ease of manufacture while effectively preventing light interference.
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
Effectively eliminates motion blur by preventing light interference between division areas, enhancing image display clarity and contrast by ensuring precise light irradiation to each area.
Implementation Method 1
having a wall surface reflecting light incident from the plurality of point light sources
Implementation Method 2
a diffusion plate disposed on the plurality of point light sources to diffuse and transmit incident light
Data Source
AI summary
A backlight unit and an LCD employing the backlight unit are provided. The backlight unit includes: a base substrate; a plurality of point light sources arranged in two or more lines on the base substrate; a diffusion plate disposed over the plurality of point light sources to diffuse and transmit incident light; and at least one barrier rib forming two or more division areas by being disposed between the base substrate and the diffusion plate to be upright with respect to the base substrate between the lines and having a wall surface reflecting light incident from the plurality of point light sources, at least a portion of an end portion of the barrier rib being inserted into the diffusion plate.