LCD Backlight White Balance Adjustment via Shutter Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid crystal display apparatuses face challenges in accurately adjusting white balance due to variations in backlight luminance, which affect video image quality, as the detection of light emission luminance is unstable due to the liquid crystal display panel's optical shutter function.
Innovation Solution
A liquid crystal display apparatus with a backlight luminance detection portion that measures light emission luminance with the optical shutter closed, and a control portion that adjusts the backlight's luminance based on detected values, ensuring accurate and stable detection by comparing detected luminance with stored data to maintain constant white balance, and also considers ambient illuminance and time-based adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the backlight is turned on for white balance adjustment, then white balance can be adjusted, but light from the backlight is transmitted through the liquid crystal display panel to the front side, causing unstable detection and reduced detection accuracy
Solution Approach 1:
The patent extracts the harmful transmitted light from the detection path by closing the optical shutter during backlight luminance detection. This separates the detection function from the normal display function, allowing accurate measurement without interference from the liquid crystal panel's light modulation.
Solution Approach 2:
The patent performs preliminary action by closing the optical shutter before backlight luminance detection begins. This preparatory step ensures that no light is transmitted through the liquid crystal panel during detection, establishing stable detection conditions in advance.
2Measurement precision
If the optical shutter is closed during detection, then detection accuracy is improved, but the liquid crystal display panel cannot display video images during this period
Solution Approach 1:
The patent implements periodic action by intermittently closing the optical shutter at specific intervals to perform backlight luminance detection, rather than keeping it closed continuously. This allows the system to alternate between detection mode and normal display mode, maintaining both detection accuracy and display functionality.
Solution Approach 2:
The patent performs preliminary action by closing the optical shutter briefly before detection to prepare the detection environment, then opens it again after detection completes. This time-limited preliminary action minimizes impact on display functionality while ensuring accurate detection.
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 enables accurate and effective white balance adjustment, maintaining consistent video image quality by stabilizing light emission luminance detection and correcting errors, even in varying ambient conditions or specific time slots, without causing discomfort to viewers.
Implementation Method 1
a backlight luminance detection portion for detecting light emission luminance of the backlight on the back side of the liquid crystal display panel
Implementation Method 2
on the liquid crystal display panel, in displaying an input video image signal, an oriented state of liquid crystal is changed according to gradation of the input video image signal
Data Source
AI summary
Adjustment of white balance based on a measurement result of light emission luminance of a backlight is allowed to be executed accurately and effectively. A backlight luminance detection portion detects light emission luminance of an LED backlight in a state where an optical shutter of a liquid crystal display panel is closed. A main control portion adjusts light emission luminance of the LED backlight according to light emission luminance detected by the backlight luminance detection portion. Here, the main control portion compares light emission luminance of LEDs of RGB detected by the backlight luminance detection portion with light emission luminance of RGB in white balance adjustment that is stored in advance in the storage portion, and adjusts, when an error occurs between the compared light emission luminance, the light emission luminance of each of the LEDs of RGB so as to eliminate the error.