Power Supply Voltage Controller for Display IR Drop Compensation
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Solution Overview
Problem
Display devices, such as LED and LCD devices, face image quality impairment due to voltage drops caused by IR drops, leading to uneven voltage distribution across the panel, especially in large high-resolution displays.
Innovation Solution
A power supply system that includes a voltage controller capable of performing constant voltage and constant current driving, using vertical synchronization signals and current feedback to boost and regulate the high-level voltage supplied to the display panel, ensuring uniform voltage distribution through the use of control transistors and a compensation capacitor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If high-level voltage is supplied to the display panel from a single power supply area, then the power supply structure is simple, but voltage drop causes uneven voltage distribution across different areas of the panel
Solution Approach 1:
The power supply function is segmented into multiple independent voltage controllers distributed across different areas of the display panel. Each voltage controller independently manages voltage supply to its local region, preventing voltage drops from affecting the entire panel. This segmentation resolves the contradiction by maintaining simple individual controller structures while achieving uniform voltage distribution across the whole panel through distributed architecture.
Solution Approach 2:
Each voltage controller is designed to provide locally optimized voltage compensation based on its specific position and load conditions. The controllers adjust their output characteristics to match local requirements, ensuring uniform voltage distribution across different areas of the panel while keeping each controller's structure relatively simple.
2Stability of the object's composition
If constant voltage driving is used during the display period, then voltage stability is improved, but current variation affects brightness uniformity
Solution Approach 1:
The voltage controllers dynamically switch between constant voltage driving mode during the display period and constant current driving mode during the blanking period. This dynamic adaptation allows the system to maintain voltage stability when needed while ensuring current stability for brightness uniformity, resolving the contradiction through temporal mode switching.
Solution Approach 2:
The voltage controllers operate in periodic cycles, alternating between constant voltage mode during the active display period and constant current mode during the vertical blanking period. This periodic action enables the system to achieve both voltage stability and brightness uniformity by applying different control strategies at appropriate times.
3Manufacturing precision
If voltage boosting is performed during the vertical blanking period, then voltage compensation is improved, but the response time to the next frame is reduced
Solution Approach 1:
The voltage controllers perform voltage boosting and compensation during the vertical blanking period before the next frame's display begins. By completing voltage adjustments in advance during the blanking interval, the controllers ensure that optimal voltage levels are already established when the next frame starts, achieving effective compensation without delaying the response time.
Data Source
AI summary
A light emitting display device can include a display panel configured to display an image, a driver configured to drive the display panel, and a power supply configured to supply a high-level voltage to a first power line of the display panel. Also, the power supply includes a voltage controller configured to receive, from the driver, a vertical synchronization signal and current amount information of the high-level voltage for driving of the display panel, and boost the high-level voltage to be supplied to the display panel during a vertical blank period, based on the vertical synchronization signal and the current amount information of the high-level voltage.