Vehicle Meter Illumination via Slit Light Guide
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Solution Overview
Problem
Conventional combination vehicle meters experience illumination unevenness due to the shading effect of the lateral edge portions of the liquid crystal display, which affects the external appearance quality by preventing backlight illumination from reaching the outer rim portions of the analogue meters.
Innovation Solution
The implementation of long and short slits with cutout corner shapes in the case lateral edge portions of the liquid crystal display, allowing illumination light to pass through and illuminate the overlapped circular rings, reducing illumination unevenness and enhancing the external appearance quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the liquid crystal display is positioned between the analogue meters to increase displayable area, then the display surface utilization is improved, but illumination unevenness occurs due to shading of the lateral edge portions
Solution Approach 1:
The lateral edge portions of the liquid crystal display case are segmented with long and short slits that have cutout corner shapes. This segmentation allows illumination light to pass through specific regions, creating illuminated portions that compensate for the shading effect and achieve uniform illumination across the dial portions.
Solution Approach 2:
The illumination structure is designed with different local qualities: the long slits with cutout corner shapes are positioned to illuminate specific regions, creating localized illumination zones that match the display requirements of different areas, particularly the outer rim portions that were previously shaded.
2Area of stationary object
If the lateral edge portions of the liquid crystal display case overlap with the outer rim portions of the analogue meters, then the displayable area is increased, but the outer rim portions are shaded and do not receive sufficient illumination
Solution Approach 1:
The long and short slits with cutout corner shapes act as intermediaries between the illumination light source and the dial portions. These slits selectively transmit light to the outer rim portions of the analogue meters that would otherwise be shaded by the liquid crystal display case, mediating the illumination distribution to achieve uniformity.
3Device complexity
If a single integral light-guiding member is used for backlight illumination, then the device complexity is reduced, but the illumination light does not reach the outer rim portions due to the integrated structure
Solution Approach 1:
The light-guiding member is segmented with long and short slits featuring cutout corner shapes. This segmentation allows the single integral structure to perform multiple illumination functions, directing light to both the central and outer rim portions of the display, thereby maintaining structural simplicity while achieving comprehensive illumination coverage.
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 solution ensures even backlight illumination across the dial portions, increasing the displayable area and improving the external appearance quality by effectively using the limited display surface and reducing illumination unevenness.
Implementation Method 1
The implementation of long and short slits with cutout corner shapes in the case lateral edge portions, allowing illumination light to pass through and illuminate the overlapped circular rings
Data Source
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AI summary
A meter includes a liquid crystal display having a liquid crystal display surface and a case housing the liquid crystal display surface, an analogue meter device including a dial portion having a plurality of translucent indicators, a light source configured to illuminate the dial portion from a back side of the dial portion, and an illumination light-passing section formed in a lateral edge portion of the case, configured to pass light from the light source toward the translucent indicator.