OLED Pixel Drive Circuit Area Reduction via Merged Reset Switch
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Solution Overview
Problem
The large number of Thin Film Transistors (TFTs) in existing OLED display pixel drive circuits occupies a significant area, reducing the number of light-emitting elements per unit area and hindering resolution improvement in display screens.
Innovation Solution
A drive circuit with multiple pixel drive circuits and a signal processing circuit, where the pixel drive circuits include a light-emitting element, energy-storage capacitor, capacitor-reset loop, light-emitting element reset loop, and data-writing loop, configured to reduce the area occupied by the pixel drive circuit and eliminate the need for a separate reset circuit for the energy-storage capacitor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a 7T1C pixel drive circuit is used, then the drive circuit can complete capacitor reset and light-emitting element reset functions, but the pixel drive circuit occupies a relatively large area
Solution Approach 1:
The patent merges the capacitor reset function and light-emitting element reset function into a single shared switch tube T7. The switch tube T7 is controlled by scan signal SCAN(n-1) to simultaneously perform both reset operations through the same control node, eliminating the need for separate reset circuits and reducing the overall pixel drive circuit area while maintaining complete reset functionality.
2Area of stationary object
If the pixel drive circuit area is reduced, then the layout area of the light-emitting element OLED is reduced, but the number of light-emitting elements per unit area is reduced
Solution Approach 1:
By merging multiple reset functions into a single switch tube T7 and using shared control signals, the patent significantly reduces the area occupied by the pixel drive circuit. This area reduction is then allocated to increase the number of light-emitting elements that can be arranged per unit area, thereby improving display resolution and productivity.
3Reliability
If separate reset circuits are used for energy-storage capacitor, then the reset function is reliable, but the device complexity increases
Solution Approach 1:
The switch tube T7 is designed with multi-functionality, serving both as a capacitor reset switch and a light-emitting element reset switch. By controlling T7 through the scan signal SCAN(n-1), the circuit achieves reliable reset functionality for both energy-storage capacitor C and light-emitting element OLED without requiring separate dedicated reset circuits, thus reducing device complexity while maintaining reliability.
Data Source
AI summary
A display panel and a drive circuit of the same are provided. The drive circuit includes multiple drive circuit rows. Each of the drive circuit rows includes multiple pixel drive circuits and a signal processing circuit. According to the drive circuit, a signal processing circuit can obtain a drive signal by processing a scan signal and a light-emitting control signal of a drive circuit row to which the signal processing circuit belongs, and can output the drive signal to each pixel drive circuit in the drive circuit row to which the signal processing circuit belongs; a pixel drive circuit can form a capacitor-reset loop by multiplexing a first switch tube in a light-emitting element reset loop of the pixel drive circuit, a second switch tube in a data-writing loop of the pixel drive circuit, and a third switch tube in a light-emitting loop of the pixel drive circuit.