Display Panel Drive Blocks for Threshold Voltage Correction
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Solution Overview
Problem
Conventional image display devices using organic electroluminescence (EL) elements face issues with luminance unevenness due to variations in drive transistor characteristics, leading to increased drive circuit output load and reduced display quality, especially as the display area increases.
Innovation Solution
The image display device is configured with luminescence pixels arranged in rows and columns, forming drive blocks where each pixel includes a luminescence element and a current controller, with switches and capacitors to convert signal voltage into signal current, allowing for uniform threshold voltage correction within a drive block, reducing signal switching frequency and increasing the threshold voltage correction period to a significant part of the frame period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the display area is increased, then the number of luminescence pixels increases, but the signal switching frequency increases and the threshold voltage correction period is reduced
Solution Approach 1:
The display panel is divided into multiple drive blocks, where each drive block independently manages a subset of luminescence pixels. This segmentation allows the threshold voltage correction to be performed simultaneously across multiple drive blocks, effectively parallelizing the correction process and maintaining sufficient correction time even as the overall display area increases.
Solution Approach 2:
The threshold voltage correction is performed during the signal voltage storing period of the previous drive block, before the actual display operation begins. This preliminary correction ensures that drive transistor threshold voltages are compensated in advance, eliminating luminance unevenness without encroaching on the display time of the current frame.
2Device complexity
If conventional drive circuits are used, then the circuit structure is simple, but the drive circuit output load increases and display quality deteriorates
Solution Approach 1:
The drive circuit is segmented into multiple independent drive blocks, each with its own control lines and switching elements. This segmentation distributes the output load across multiple channels, preventing any single drive circuit from becoming overloaded while maintaining uniform threshold voltage correction across the entire display panel.
Solution Approach 2:
Each drive block is equipped with local control capabilities, including dedicated control lines for threshold voltage correction and signal voltage storage. This local quality enhancement allows each drive block to independently manage its luminescence pixels with precise control, improving overall display quality without requiring a globally complex circuit architecture.
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 configuration reduces the drive circuit output load, improves image display quality by ensuring precise drive current flow to luminescence elements, and maintains high luminance duty even with increased display area without reducing the threshold voltage correction period.
Implementation Method 1
image display devices using organic electroluminescence (EL) elements... the luminance of the respective luminescence elements is controlled according to the value of the current flowing thereto
Data Source
AI summary
An image display device includes luminescence pixels arranged in rows and columns. The image display device includes a first and second signal lines, first control lines, and at least two drive blocks. Each drive block is composed of luminescence pixels in at least two rows. Each luminescence pixel includes a luminescence element and a current controller. Each luminescence pixel that belongs to a kth drive block further includes a first switch provided between the first signal line and the current controller. Each luminescence pixel that belongs to a (k+1)th drive block further includes a second switch provided between the second signal line and the current controller. Each first control line is connected to all of the luminescence pixels in one of the drive blocks and not connected to the luminescence pixels in a different drive block.