Liquid Crystal Display Backlight Integration for Downsized NIR-ToF Cameras
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
NIR-ToF camera units in liquid crystal display devices require a large distance from the light source to avoid being blocked, leading to non-display regions and difficulty in downsizing, especially for wide-angle views.
Innovation Solution
A diffusion structural unit is positioned above and distant from the light source emission surface, reducing the distance between the light source and reception unit, and using a diffusion sheet that is smaller than the display region to diffuse NIR light effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the NIR-ToF camera unit is disposed behind the cover panel, then the light source can emit NIR light without being blocked, but the region where the camera is disposed becomes a non-display region
Solution Approach 1:
The patent moves the light source from the traditional position behind the cover panel to inside the backlight unit, changing the spatial dimension of light source placement. This allows the light source to be positioned in a different spatial layer that does not conflict with the display region, eliminating the need for non-display regions while maintaining reliable NIR light emission.
2Reliability
If a large distance is maintained from the light source to avoid blocking, then the camera unit can function properly, but downsizing becomes difficult
Solution Approach 1:
The patent merges the light source with the backlight unit structure, integrating both the visible light backlight function and the NIR light source function into a single unified structure. This integration eliminates the need for separate camera unit components and large spacing, enabling significant downsizing while maintaining proper function.
Solution Approach 2:
The backlight unit is designed to serve multiple functions: it provides visible light for display illumination and simultaneously houses the NIR light source for the ToF camera function. This multi-functionality reduces the overall system complexity and size by eliminating redundant structures.
3Area of stationary object
If the diffusion sheet is made smaller than the display region, then the display region can be expanded, but the diffusion of NIR light must be optimized
Solution Approach 1:
The diffusion sheet is designed with non-uniform properties, being smaller than the display region and strategically positioned to optimize NIR light diffusion only in the necessary areas. This local optimization allows the display region to be maximized while maintaining effective NIR light diffusion for camera functionality.
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 allows for a downsized NIR-ToF camera unit without blocking light, expanding the display region and minimizing interference with the display.
Implementation Method 1
a diffusion structural unit located in front of the light source, the diffusion structural unit being configured to diffuse non-visible light from the light source
Implementation Method 2
a lens unit configured to condense light that is diffused by the diffusion structural unit, hits an object and is reflected off the object onto a sensor
Implementation Method 3
The plurality of optical sheets include a diffusion sheet configured to diffuse visible light
Data Source
AI summary
A liquid crystal display device includes a liquid crystal display panel including a display region, a backlight unit located behind the liquid crystal panel and including layered optical sheets, a light source of non-visible light disposed inside or behind the backlight unit, a diffusion structural unit located in front of the light source and configured to diffuse non-visible light from the light source, and a lens unit configured to condense light that is diffused by the diffusion structural unit, hits an object and is reflected off the object onto a sensor. The optical sheets include a diffusion sheet. The diffusion structural unit is smaller in size than the display region and selectively disposed at a location to be irradiated with non-visible light from the light source. At least one of the optical sheets is interposed between the diffusion structural unit and the light source.