Optical Substrate with Light Selection Units for Color Display
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Solution Overview
Problem
Current display devices using extraction gratings for LED light sources suffer from high light-loss rates due to the need for a color film structure to achieve color display, as they can only extract light of a single color at a collimation angle.
Innovation Solution
An optical substrate with a light guide plate and periodic light selection units, including light-filtering films and gratings, that selectively extract and emit monochromatic light of different colors from multiple regions, eliminating the need for a color film structure and enhancing light utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If extraction gratings are used to extract monochromatic light at a collimation angle, then light can be extracted from the light guide plate, but a color film structure is required to achieve color display, resulting in high light-loss rates
Solution Approach 1:
The light guide plate is divided into multiple light-exiting regions, each corresponding to a specific light selection unit. Each region independently extracts and emits monochromatic light of different colors, eliminating the need for a color film structure and reducing light loss through segmented functional zones.
Solution Approach 2:
Different regions of the light guide plate are assigned different optical properties through light selection units with specific extraction gratings and light-filtering films. Each region is optimized for its specific function of extracting monochromatic light of a particular color, achieving color display without uniform color filtering across the entire plate.
2Adaptability or versatility
If a color film structure is used to achieve color display, then color can be displayed, but light utilization efficiency decreases due to high light-loss rates
Solution Approach 1:
The invention extracts monochromatic light directly from the light guide plate at multiple wavelengths simultaneously through specially designed extraction gratings in different light-exiting regions. This eliminates the need to pass light through color film structures, thereby extracting only the needed light components and avoiding the light loss associated with color film absorption.
Solution Approach 2:
Instead of using a color film structure to filter white light to produce color display (which causes light loss), the invention inverts the approach by directly extracting monochromatic light of different colors from the light guide plate through multiple light selection units. This produces color display through selective extraction rather than selective filtering, significantly improving light utilization efficiency.
3Loss of energy
If multiple light selection units are used to emit monochromatic light of different colors from multiple light-exiting regions, then color backlight effect is achieved without color film, but device complexity increases
Solution Approach 1:
The invention combines multiple functions into the light guide plate itself: light guidance, light extraction, color separation, and light filtering are all integrated into single optical substrate with multiple light selection units. Each unit combines extraction grating and light-filtering film structures, merging what would traditionally be separate components into a unified integrated system that reduces overall device complexity.
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 enables a color backlight effect with high light utilization efficiency, allowing for color display without a polarizer or color film, promoting transparent display and reducing light loss.
Implementation Method 1
each of the multiple light-filtering films is configured to reflect monochromatic light of a preset color among monochromatic light of the different colors to exit from the light-exiting surface and is configured to transmit monochromatic light of a color other than the preset color among monochromatic light of the different colors
Implementation Method 2
monochromatic light emitted from a Light-Emitting Diode (LED) light source is coupled into a light guide plate; an extraction grating is on or under the light guide plate since total reflection transmission occurs within the light guide plate
Implementation Method 3
the extracting grating extracts, at a collimation angle, the monochromatic light propagating in a total reflection manner in the light guide plate
Data Source
AI summary
An optical substrate and a display device are provided. The optical substrate includes a light guide plate and a plurality of light selection units, wherein, the light guide plate includes a light-incident surface and a light-exiting surface, and the light-exiting surface includes a plurality of light-exiting regions; each light selection unit is configured to select light incident from the light-incident surface and propagating in the light guide plate, such that monochromatic light of different colors are emitted from multiple light-exiting regions corresponding to the each light selection unit, and each of the multiple light-exiting regions emits monochromatic light of a single color.