Local Dimming Backlight Control for Motion Flicker and Raised Blacks
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Solution Overview
Problem
Conventional liquid crystal display devices using local dimming experience flickering due to rapid movement of objects on the screen, leading to reduced display quality and difficulty in achieving deep blacks.
Innovation Solution
A display device with a backlight controller that divides the backlight into areas and adjusts the light-emission luminance of adjacent areas based on the motion vector of the image, ensuring the luminance of adjacent areas is higher than the indicated luminance to reduce flickering and suppress raised blacks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the area of the illumination area is increased to improve flickering in motion scenes, then flickering is reduced, but deep blacks are lost and display quality deteriorates
Solution Approach 1:
The backlight is divided into multiple illumination areas that can be independently controlled. The controller selectively adjusts the luminance of specific areas based on motion detection, allowing flickering reduction in motion areas while maintaining deep blacks in static areas.
Solution Approach 2:
The illumination area boundaries are dynamically adjusted based on detected motion vectors. When motion is detected, the controller expands illumination areas in the direction of motion to prevent flickering, while contracting them when motion is minimal to maintain deep blacks.
2Reliability
If the light-emission luminance of adjacent illumination areas is increased to reduce flickering, then flickering is improved, but raised blacks occur and display quality is reduced
Solution Approach 1:
Different illumination areas are assigned different luminance levels based on their position relative to motion vectors. Areas adjacent to the motion direction receive enhanced luminance to prevent flickering, while other areas maintain lower luminance to preserve deep blacks and avoid raised blacks.
Data Source
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AI summary
A display device according to an embodiment is provided with a display panel, a backlight, and a backlight controller which divides the backlight into a plurality of areas, and controls a light-emission luminance of the backlight for each of the plurality of areas on the basis of an image signal. The backlight controller causes the light-emission luminance of the backlight in a first adjacent illumination area which is adjacent, in a direction in which an image included in the image signal moves, to the image to be changed from a luminance indicated by the image signal.