Shift Register Compensation for OLED Scanning Line Elimination
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Solution Overview
Problem
Existing display technologies face issues with non-uniformity in brightness and scanning lines due to line-by-line scanning, which affect the display quality of OLED panels, particularly due to variations in threshold voltage and mobility of drive transistors and aging of OLEDs.
Innovation Solution
A shift register unit incorporating a display sub-shift-register and a detection sub-shift-register is used, where the detection sub-shift-register outputs compensation signals based on random pulse signals to address non-uniformity and aging, eliminating the need for sequential scanning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If line-by-line scanning is used to drive gate lines, then gate lines can be sequentially controlled, but brightness non-uniformity and scanning lines occur due to threshold voltage variations and OLED aging
Solution Approach 1:
The patent performs threshold voltage detection during the programming phase before the actual display operation. By detecting the threshold voltage of each pixel's drive transistor in advance and storing this information, the system can compensate for threshold voltage variations during subsequent scanning operations, thereby eliminating scanning lines and brightness non-uniformity without affecting the sequential gate line control capability.
2Productivity
If sequential scanning of gate lines is implemented, then image display can be achieved, but display quality deteriorates due to non-uniform brightness and scanning artifacts
Solution Approach 1:
The patent implements a feedback mechanism where the threshold voltage detected during programming is fed back to the scanning control circuit. This feedback information is used to adjust the scanning timing and voltage signals dynamically during the display phase, allowing real-time compensation for threshold voltage variations and OLED aging effects, thus maintaining high display quality throughout the operational period.
Solution Approach 2:
By performing threshold voltage detection and compensation data preparation during the programming phase (before display), the system eliminates the need for complex real-time adjustments during scanning. This preliminary action ensures that all compensation data is ready in advance, allowing sequential scanning to proceed smoothly without introducing artifacts or non-uniformity.
3Manufacturing precision
If threshold voltage compensation is performed, then brightness uniformity improves, but additional detection circuits and complexity are required
Solution Approach 1:
The patent designs the detection circuit to serve multiple functions: it detects threshold voltage during programming, stores compensation data, and provides feedback for scanning control. By making this single circuit unit multi-functional, the patent avoids adding separate dedicated circuits for each function, thereby achieving brightness uniformity compensation while minimizing the increase in overall device complexity.
Solution Approach 2:
The patent merges the threshold voltage detection function with the existing programming circuitry and scanning control functions. Instead of adding completely separate detection circuits, the system integrates detection capabilities into the existing transistor and capacitor structures, combining multiple functions into unified circuit blocks to reduce overall complexity while achieving compensation.
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 1E~2
AI summary
A shift register unit, a grid drive circuit, a display device and a driving method are disclosed. The shift register unit (10) includes a display sub-shift-register (200) and a detection sub-shift-register (100). The display sub-shift-register (200) includes a display output terminal, and the display sub-shift-register is configured to output a display output signal of the shift register unit (10) from the display output terminal at a display stage; the detection sub-shift-register (100) is connected to a display output terminal of the display sub-shift-register (200) to receive a display output signal, and includes a first random pulse signal terminal (OE1) to receive a first random pulse signal. The detection sub-shift-register (100) is configured to output a detection output signal of the shift register unit (10) when the display output signal is at a turn-on level and the first random pulse signal is at a turn-on level. The shift register unit can eliminate scanning lines occurring in the display process and solve the brightness difference problem of the display panel.