OLED Dead Pixel Repair Circuit with Grayscale Compensation
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Solution Overview
Problem
OLED displays face issues with dead pixels due to defects like broken lines or short-circuits, which cannot be effectively repaired without degrading display quality, as existing methods either make dead pixels brighter or transform them into dark pixels that do not contribute to image display.
Innovation Solution
An OLED display panel with a substrate having a display region and a peripheral region, where dead pixel circuits are disconnected and connected to a repair line, receiving grayscale and compensation repair currents to accurately represent image grayscales and compensate line loads, thereby preventing dead pixels from being recognized as dark or bright pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dead pixel circuits are left disconnected, then manufacturing productivity is improved by avoiding complex repair processes, but display quality deteriorates due to visible dead pixels
Solution Approach 1:
The patent implements repair pixel parts and repair lines in advance during manufacturing, so that when dead pixels occur, the repair can be performed by simply switching signals without complex physical repairs. This preliminary preparation resolves the contradiction by enabling quick repair (maintaining productivity) while ensuring display quality through the repair mechanism.
Solution Approach 2:
The patent introduces repair pixel parts as intermediary elements that mediate between the dead pixel circuits and the display output. These repair pixel parts receive signals from repair lines and generate compensation signals to mask or replace dead pixel defects, thus improving display quality without requiring complex repair processes that would reduce productivity.
2Reliability
If existing repair methods are used to make dead pixels brighter, then visibility of dead pixels is reduced, but display accuracy deteriorates due to incorrect luminance representation
Solution Approach 1:
The patent employs repair pixel parts that receive feedback signals from the display system and adjust their output accordingly. The repair pixel parts analyze the actual display requirements and generate appropriate compensation signals to restore correct luminance representation, thus maintaining both dead pixel invisibility and display accuracy through dynamic feedback control.
3Reliability
If repair pixel parts are added to the OLED panel, then display quality is improved by enabling dead pixel repair, but device complexity increases due to additional components
Solution Approach 1:
The patent merges the repair pixel parts with the existing pixel structure of the OLED panel. The repair pixel parts are integrated into the pixel array and share common elements such as scan lines, data lines, and signal processing circuits with the display pixels, thus reducing the overall device complexity while maintaining the dead pixel repair capability.
Solution Approach 2:
The repair pixel parts are designed to serve multiple functions: they can operate as normal display pixels during regular operation and switch to repair mode when dead pixels are detected. This multi-functionality reduces the need for separate dedicated repair components, thereby minimizing the increase in device complexity while providing comprehensive dead pixel repair capability.
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
The OLED display panel effectively repairs dead pixels by providing grayscale and compensation currents, ensuring accurate image representation and preventing luminance degradation, thus improving manufacturing productivity and display quality.
Implementation Method 1
OLEDs include an organic layer formed between two electrodes, namely, an anode and a cathode. Positive holes supplied from the anode are combined with electrons supplied from the cathode in the organic layer to emit light.
Data Source
AI summary
An organic light-emitting diode (OLED) display panel is disclosed. In one aspect, the OLED display panel includes a substrate including a display region and a peripheral region surrounding the display region. The panel further includes a plurality of OLEDs formed in the display region, a plurality of pixel circuits formed in the display region, and a pixel repair circuit formed in the peripheral region. When one of the pixel circuits is a dead pixel circuit, the dead pixel circuit is disconnected from a corresponding dead pixel OLED and the dead pixel OLED is connected to the pixel repair circuit via a corresponding repair line. The pixel repair circuit is configured to provide the dead pixel OLED with a grayscale repair current for representing a grayscale of the image and a compensation repair current for compensating a line load of the repair line.