Dummy Pixel Circuit Repair for OLED Display Defects
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Solution Overview
Problem
In organic light emitting display apparatuses, defects in pixel circuits can lead to bright or dark defects, which are difficult to repair due to the complex circuitry, causing image quality issues.
Innovation Solution
The integration of dummy pixels with modified circuit structures and repair lines allows for the repair of defective pixels by providing a driving current to the light emitting device, enabling normal operation and improved image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pixel circuit is repaired by modifying the dummy pixel connection, then the defective pixel can be restored to normal operation, but the device complexity increases due to additional dummy pixels and repair lines
Solution Approach 1:
The dummy pixel circuit is designed to serve multiple functions: it acts as a regular pixel during normal operation and simultaneously serves as a repair mechanism for defective pixels. By configuring the dummy pixel with a compensation capacitive element and controllable connection portions, it can provide driving current to defective pixels through repair lines, eliminating the need for separate repair circuitry.
Solution Approach 2:
The dummy pixel functions as an intermediary between the control circuitry and defective pixels. It receives control signals and data signals, processes them through its driving transistor and compensation capacitive element, and delivers the appropriate driving current to defective pixels via the repair lines, mediating the repair process without requiring direct modification of the defective pixel circuit.
2Ease of repair
If the connection portion electrically connects the compensation capacitive element and driving transistor, then the pixel can be repaired, but the image quality may deteriorate due to residual defects
Solution Approach 1:
The connection portion between the compensation capacitive element and driving transistor is designed to be dynamically controllable rather than fixed. It can be electrically connected during repair operations and electrically separated during normal operation or when repair is not needed. This dynamic control allows the system to adapt its configuration based on operational requirements, ensuring both effective repair and maintained image quality.
Solution Approach 2:
The electrical state of the connection portion can be changed between connected and separated states based on repair needs. This parameter change allows the dummy pixel to selectively engage with defective pixels only when necessary, preventing any potential image quality degradation from continuous connection while enabling effective repair when defects are present.
3Adaptability or versatility
If repair lines are added to connect dummy pixels with defective pixels, then defective pixels can be restored, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The repair functionality is segmented into distinct components: dummy pixels positioned in non-display areas, separate repair lines for each dummy pixel, and controllable connection portions. This segmentation allows for modular manufacturing where each component can be fabricated and tested independently before integration, simplifying the overall manufacturing process despite the increased system complexity.
Data Source
AI summary
An organic light emitting display apparatus includes: a plurality of pixels at a display area; a plurality of dummy pixels at a dummy area; and a plurality of repair lines that are connected to the plurality of dummy pixels and connectable to the plurality of pixels, wherein each of the plurality of dummy pixels includes: a compensation capacitive element; a driving transistor configured to output a driving current corresponding to a data signal applied to a gate electrode of the driving transistor; and a connection portion between a first electrode of the compensation capacitive element and the gate electrode of the driving transistor, and that is configured to electrically connect or separate the first electrode of the compensation capacitive element and the gate electrode of the driving transistor to or from each other based on a physical quantity applied to the connection portion.