Liquid Crystal Display Backlight Zoning to Reduce Black Floating
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Solution Overview
Problem
Existing display devices exhibit black floating, where black areas appear slightly brighter than perfect black due to slight backlight transmission, making the boundary between the display area and frame area visually noticeable.
Innovation Solution
A display device design featuring a liquid crystal panel with a front surface plate that transmits and reflects light, and a backlight with adjustable luminance, where the frame area luminance is 50% or less of the display area luminance, and a front surface plate with a design layer that overlaps the display area, allowing for reduced interface reflection and high luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the liquid crystal panel displays black, then the display area shows black content, but the backlight light transmits through slightly causing black floating and making the boundary with frame area noticeable
Solution Approach 1:
The patent applies local quality by setting different luminance levels for different regions of the backlight. Specifically, the fourth area (frame area) has luminance that is 50% or less of the third area (display area), creating a local luminance gradient that reduces the visibility of the boundary between display and frame areas when black is displayed.
2Object-generated harmful factors
If the luminance of the fourth area is reduced to 50% or less of the third area, then the boundary between display area and frame area becomes less noticeable, but the overall brightness of the display may be affected
Solution Approach 1:
The patent implements local quality differentiation in the backlight structure, where the third area (overlapping display area) maintains high luminance for optimal display brightness, while the fourth area (surrounding the third area) has reduced luminance at 50% or less to minimize boundary visibility. This localized luminance control achieves both goals simultaneously.
3Object-generated harmful factors
If a design layer is added to the front surface plate to transmit and reflect light, then aesthetic integration is improved, but the optical path and light transmission characteristics change
Solution Approach 1:
The design layer in the front surface plate is designed to perform multiple functions simultaneously: it transmits at least part of the backlight light to maintain display visibility, reflects at least part of incident light from the observer side to enhance aesthetic appearance, and integrates the display area with surrounding frame areas. This multi-functionality reduces the need for separate components.
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 design minimizes the visibility of the boundary between the display and frame areas, enhancing the aesthetic integration of the display device by reducing black floating and maintaining high luminance.
Implementation Method 1
configured to transmit at least a part of light incident from the liquid crystal panel and to reflect at least a part of light incident from the observer side
Data Source
AI summary
Provided is a display device in which a boundary between a display area and a frame area is less noticeable even when a liquid crystal panel is in a black display state. A display device includes: a liquid crystal panel and a backlight. The liquid crystal panel includes: a display area; and a frame area, the front surface plate includes a design layer that overlaps the display area and is configured to transmit at least a part of light incident from the liquid crystal panel and to reflect at least a part of light incident from the observer side, the backlight includes: a third area that overlaps the display area; and a fourth area that overlaps the display area, and a luminance of the fourth area is 50% or less of a luminance of the third area when the backlight is turned on.