Vehicle LCD Uniform Illumination via Diffuser and Reflectors
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Solution Overview
Problem
Existing liquid crystal display devices in vehicle measuring instruments face issues with uniform illumination due to non-uniform distribution of light from the indicating needle illuminating light source.
Innovation Solution
Incorporating a diffuser panel between the light guide member and the liquid crystal panel, along with a first and second reflector, to diffuse and redirect light for uniform illumination, and using spacers to maintain a distance between the diffuser and liquid crystal panels for improved light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If illuminating light is distributed from the indicating needle illuminating light source to the liquid crystal display panel, then the device structure is simplified by reusing the existing light source, but the luminance uniformity across the display panel deteriorates
Solution Approach 1:
A diffuser panel is introduced as an intermediary component between the light guide member and the liquid crystal display panel. This diffuser panel receives light from the indicating needle illuminating light source and redistributes it uniformly across the display panel area, thereby improving luminance uniformity while maintaining the simplified structure of reusing the existing light source.
Solution Approach 2:
The invention introduces a spatial dimension by positioning the diffuser panel at a specific distance from the liquid crystal display panel using spacers. This dimensional arrangement allows light to be distributed from a point source (light guide member) to cover the entire panel area uniformly, transforming the light distribution pattern from concentrated to diffuse across the two-dimensional panel surface.
2Illumination intensity
If a dedicated light source is added for the liquid crystal display panel, then the luminance uniformity can be improved, but the device structure becomes more complex and the number of components increases
Solution Approach 1:
The indicating needle illuminating light source is designed to serve multiple functions: it provides illumination for both the indicating needle and the liquid crystal display panel. By making this light source universal, the invention eliminates the need for a dedicated light source for the display panel, thereby maintaining structural simplicity while achieving uniform luminance distribution through the diffuser panel.
3Device complexity
If light is directly emitted from the light guide member to the liquid crystal panel, then the device structure is simplified, but the light intensity distribution becomes non-uniform across the panel
Solution Approach 1:
The diffuser panel serves as a mediator between the light guide member and the liquid crystal display panel. It receives non-uniform light from the light guide member and transforms it into uniform illumination across the panel, thereby improving light intensity distribution without adding complex structural elements or requiring precise manufacturing tolerances.
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 achieves uniform luminance across the liquid crystal display device, enhancing visibility and reducing light intensity differences, while also simplifying the device structure by utilizing the indicating needle illuminating light source as the primary light source without adding a dedicated light source.
Implementation Method 1
a diffuser panel configured to be disposed between the light guide member and the liquid crystal panel, extend over an entire area of the back surface of the liquid crystal panel, and diffuse the light received from the light guide member to illuminate the light to the liquid crystal panel
Implementation Method 2
a first reflector configured to be provided on a back surface of the diffuser panel close to the light guide member side and on an optical axis of the light received from the light guide member, and reflect the light towards the light guide member side
Implementation Method 3
a second reflector configured to reflect the light reflected on the first reflector to the diffuser panel side
Data Source
AI summary
A liquid crystal display device includes a liquid crystal panel; a light source; a light guide member that guides light emitted from the light source to a back surface side of the liquid crystal panel; a diffuser panel that is disposed between the light guide member and the liquid crystal panel, extended over an entire area of the back surface of the liquid crystal panel, and diffuses the light received from the light guide member to illuminate the light to the liquid crystal panel; a first reflector that is provided on a back surface of the diffuser panel close to the light guide member side and on an optical axis of the light received from the light guide member, and reflects the light towards the light guide member side; and a second reflector that reflect the light reflected on the first reflector to the diffuser panel side.