Backlight Current Control Circuit for Flicker-Free Luminance
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Solution Overview
Problem
Backlight devices for LCD panels face challenges in maintaining light emission for one frame to prevent flicker and achieving uniform luminance control across different luminance areas, particularly in low and high luminance regions.
Innovation Solution
A backlight device and current control integrated circuit that utilize a combination of linear control and pulse width control to manage driving current, employing a backlight driving board and backlight board with light emitting blocks grouped into control units, each with current control integrated circuits to maintain light emission and uniform luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light emitting blocks are controlled to emit light for one frame or more, then flicker is reduced or eliminated, but maintaining sufficient light emission becomes difficult
Solution Approach 1:
The patent applies preliminary action by pre-charging capacitors during a first period before the actual light emission period. This allows the light emitting blocks to maintain sufficient light emission during the second period (one frame or more) without requiring continuous current supply, thereby preventing flicker while ensuring adequate illumination intensity.
Solution Approach 2:
The patent implements periodic action by dividing the operation into distinct periods: a first period for capacitor charging and a second period for light emission. This periodic structure allows the system to prepare energy in advance and then release it during the frame duration, maintaining stable light output without flicker.
2Manufacturing precision
If precise luminance control is achieved across entire luminance change area, then uniformity is improved, but control complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the backlight system into multiple independently controllable light emitting blocks arranged in a matrix. Each block can be controlled individually through separate row and column signals, allowing precise luminance adjustment across different regions while maintaining overall uniformity through coordinated control.
Solution Approach 2:
The patent implements dynamics by enabling independent control of luminance for each light emitting block through dynamic row and column signal timing. The system can adjust the duration and intensity of signals sent to different blocks, allowing adaptive luminance control across the entire display area to achieve uniformity despite variations in block characteristics.
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 ensures light emitting blocks maintain emission for one frame or more, reducing or eliminating flicker and achieving precise, uniform luminance control across luminance changes.
Implementation Method 1
The backlight board may include light emitting blocks using LEDs as light sources, and the light emitting blocks may emit light to provide a backlight.
Implementation Method 2
controls an amount of driving current for light emission of the light emitting block
Data Source
AI summary
Disclosed are a backlight device for a display that provides a backlight for displaying an image and a current control integrated circuit thereof. According to the backlight device and the current control integrated circuit thereof, a driving current can be controlled so as to allow light emitting blocks to maintain light emission for one frame or more, and the luminance of a backlight can be uniformly and precisely controlled in an entire luminance change area.