Display Device Driving Blocks for Luminance Uniformity
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Solution Overview
Problem
Conventional display devices face issues with luminance unevenness due to variations in driving transistor characteristics, leading to increased signal output load and manufacturing costs, as well as limitations in high-precision correction of threshold voltage for each pixel row.
Innovation Solution
A display device is configured with pixels arranged in driving blocks, where each block includes multiple rows, using a signal line driving circuit that outputs standard and signal voltages to two signal lines, and a selector to apply these voltages selectively, allowing for uniform initialization and threshold voltage correction within a driving block, reducing the frequency of signal switching and output load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If active-matrix organic EL display device is used to maintain luminance when number of scanning lines increases, then luminance is maintained, but variation in driving transistor characteristics causes luminance unevenness
Solution Approach 1:
The display device divides the pixel array into multiple driving blocks, where each block is independently driven. This segmentation allows for localized compensation of transistor characteristics within each block, reducing luminance unevenness caused by manufacturing variations while maintaining overall luminance levels.
Solution Approach 2:
The invention applies gamma correction and threshold voltage compensation techniques to adjust the electrical parameters of driving transistors. By dynamically changing these parameters based on measured characteristics, the system compensates for manufacturing variations and achieves uniform luminance across all pixels.
2Measurement precision
If threshold voltage correction and initialization are performed for each pixel row individually, then correction precision is improved, but signal switching frequency increases and output load increases
Solution Approach 1:
The pixel array is divided into driving blocks that can be processed in groups rather than individually row-by-row. This allows threshold voltage correction and initialization to be performed for multiple rows simultaneously within each block, reducing the overall signal switching frequency while maintaining correction precision through block-level compensation.
Solution Approach 2:
The invention combines threshold voltage correction and initialization operations into unified driving periods for each driving block. By merging these operations and executing them simultaneously for multiple rows within a block, the system reduces the total number of signal switching events while achieving the necessary correction precision.
3Manufacturing precision
If frequent signal switching is performed for threshold voltage correction and initialization, then correction precision is improved, but driving circuit output load and manufacturing costs increase
Solution Approach 1:
By segmenting the display into driving blocks with independent control, the system performs correction operations at the block level rather than row-by-row. This reduces the frequency of signal switching events from the driving circuit, lowering output load and simplifying circuit design while maintaining precision through block-level compensation mechanisms.
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 ensures precise correction of driving current to luminescence elements, improves image display quality, reduces driving circuit output load and costs, and enhances manufacturing yield by allocating more time to threshold voltage correction and initialization periods.
Implementation Method 1
a luminescence element configured to produce luminescence according to a flow of a signal current corresponding to the signal voltage
Data Source
AI summary
A display device including pixels has formed therein at least two driving blocks each made up of pixel rows, and includes: a signal line driving circuit that outputs a signal voltage to an output line disposed in each of pixel columns; and a selector circuit that controls a selector disposed in each of the columns for providing a signal voltage outputted from the output line to one of a first signal line and second signal line disposed in each of the columns, and selectively provides a standard voltage or the signal voltage outputted from the output line to one of the first signal line or the second signal line. Each of the pixels includes a current control unit and an organic EL element. Pixels in the k-th driving block are connected to the first signal line and pixels in the (k+1)-th driving block are connected to the second signal line.