Local-Dimming Display Gaussian Tapering Halo Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle instrument panel displays suffer from 'bleed through' or 'halo' effects due to large zone backlighting, making rear displays less noticeable and aesthetically unpleasing.
Innovation Solution
A local-dimming display system with a light source, a monochrome display, and a color display, where pixels are controlled to pass or block backlight at varying transmission levels to create a Gaussian tapering intensity pattern, reducing the visibility of backlight transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If large zone backlighting is used to increase contrast ratio, then white and black areas have better contrast, but bleed through glow or halo appears around lit pixels
Solution Approach 1:
The backlighting system is segmented into multiple independently controllable zones rather than using large uniform zones. Each zone can be dimmed or brightened independently, allowing precise control over light distribution to eliminate bleed through effects while maintaining contrast in displayed areas.
Solution Approach 2:
Different regions of the display backlight are assigned different illumination characteristics. Areas requiring high contrast are brightly illuminated, while peripheral or non-display areas are dimmed to prevent glow. This local differentiation of light quality resolves the contradiction between contrast and bleed through.
2Object-generated harmful factors
If local dimming with multiple transmit levels is implemented, then halo effect is reduced, but device complexity increases
Solution Approach 1:
Instead of implementing full local dimming control across all pixels, the system applies partial dimming control only to specific boundary zones where halo effects occur. This selective approach reduces the halo effect while minimizing the increase in device complexity by limiting the scope of controlled zones.
Solution Approach 2:
The patent introduces intermediary control elements between the light source and display pixels that manage the transition zones. These intermediaries handle the complex dimming control, isolating the complexity from the main display control system while still achieving reduced halo effects.
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 system effectively minimizes the 'halo' effect by creating a gradual backlight transition, enhancing the visibility of the rear display and reducing the noticeability of backlight demarcations.
Implementation Method 1
Each of the plurality of first pixels is configured to selectively pass and block the backlight
Implementation Method 2
The plurality of the first pixels cooperating at the first transmit level and the one or more second transmit levels selectively presents the backlight to the second display with a declining intensity pattern in the plurality of neighboring pixels. In one or more embodiments of the local-dimming display, the declining intensity pattern is a Gaussian tapering in the one or more second transmit levels.
Data Source
AI summary
A local-dimming display generally includes a light source configured to generate a backlight, a first display aligned with the light source and having multiple first pixels, wherein each first pixel is configured to selectively pass and block the backlight, and a second display aligned with the first display and having multiple second pixels. A particular pixel is controlled to pass the backlight. The particular pixel corresponds with an aligned pixel and multiple parallax pixels of the first pixels controlled at a first transmit level, and multiple neighboring pixels of the first pixels controlled at one or more second transmit levels. The one or more second transmit levels are less than or equal to the first transmit level. The first pixels cooperating at the first transmit level and the second transmit levels selectively presents the backlight to the second display with a declining intensity pattern in the neighboring pixels.