Backlight Control for Display Apparatus Subframe Flicker
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Solution Overview
Problem
Liquid crystal display apparatuses experience luminance errors and subframe flicker due to misalignment between light source turn-on timing and liquid crystal pixel rewriting timing, leading to unintended light emission and increased frequency of subframe flicker, especially when multiple subframe light emissions occur.
Innovation Solution
A display apparatus with a determination section that calculates light source control information based on subframe average luminances to control the backlight in each subframe period, ensuring synchronized light emission with the liquid crystal panel's scanning process, thereby reducing subframe flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all light sources are subjected to scanning turn-on during one subframe period, then the frame flicker is reduced, but the luminance error increases causing subframe flicker
Solution Approach 1:
The patent divides the backlight control into multiple independent BL control areas (first, second, third areas) that are controlled separately with different turn-on timings. This segmentation allows each area's light emission to be synchronized with the corresponding liquid crystal pixel rewriting timing, preventing luminance errors while maintaining frame flicker reduction through coordinated control of all areas.
2Reliability
If subframe light emission is performed multiple times, then the frame flicker is reduced, but the frequency of subframe flicker increases
Solution Approach 1:
The patent performs preliminary calculation of the statistic (average luminance) for each BL control area before determining the light source control information. This preliminary action ensures that the light emission timing and amount are pre-synchronized with the liquid crystal pixel rewriting timing, preventing luminance errors that would cause subframe flicker even when multiple subframe emissions are performed.
3Ease of operation
If light source turn-on timing does not coincide with liquid crystal rewrite timing, then the sequential scanning is simplified, but luminance error occurs
Solution Approach 1:
The patent dynamically adjusts the turn-on timing of light sources in different BL control areas to coincide with the liquid crystal pixel rewriting timing for each area. Instead of using a fixed timing for all areas, the system adapts the timing dynamically based on the sequential scanning progress, maintaining luminance accuracy while preserving the simplicity of sequential scanning through coordinated dynamic control.
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 effectively reduces subframe flicker by accurately controlling light source brightness in each subframe period, ensuring that the displayed luminance matches the input video signal, thereby minimizing luminance errors and flicker occurrences.
Implementation Method 1
a panel configured to display the video by modulating light from the backlight
Data Source
AI summary
An apparatus that displays a video in accordance with an input signal, the apparatus includes a backlight including a plurality of light sources, a panel configured to display the video by modulating light from the backlight, a determination section configured to determine an amount of light of each of the plurality of light sources subframe by subframe, a controller configured to control the plurality of light sources in accordance with the determined amounts of light, and an acquisition section configured to acquire a statistic in a plurality of areas subframe by subframe in accordance with the input signal. The determination section is configured to determine the amount of light of each of the plurality of light sources in accordance with the statistic.