OLED Display Compensation Circuit for Brightness Uniformity
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Solution Overview
Problem
In OLED display apparatuses, variations in threshold voltages and mobility of driving transistors lead to uneven brightness, affecting display quality due to manufacturing limitations.
Innovation Solution
A display compensation circuit comprising a pixel circuit and a power supply selection circuit, which includes compensation sub-circuits to detect and compensate for threshold voltage and mobility of driving transistors, ensuring uniform brightness by controlling the driving transistor to emit light based on obtained compensation voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If driving transistors are manufactured with standard process limitations, then manufacturing cost and ease of manufacture are improved, but threshold voltage and mobility variations cause brightness unevenness deteriorating display quality
Solution Approach 1:
The patent performs preliminary measurement of threshold voltage and mobility parameters during the manufacturing process, before the display device is completed. Compensation values are calculated and stored in advance, so that when the device operates, the compensation is already in place, eliminating the need for post-manufacturing adjustment and maintaining manufacturing simplicity while achieving precision.
Solution Approach 2:
The patent changes the electrical parameters (threshold voltage and mobility) of the driving transistor through compensation mechanisms. By measuring actual parameters and adjusting compensation values, the system effectively modifies the transistor's electrical characteristics to achieve uniform brightness across all pixels despite manufacturing variations.
2Ease of manufacture
If driving transistors are manufactured with standard process limitations, then manufacturing cost and ease of manufacture are improved, but mobility variations cause current inconsistency deteriorating display quality
Solution Approach 1:
The patent performs preliminary measurement of mobility parameters during the manufacturing process, before the display device is completed. Compensation values are calculated and stored in advance, so that when the device operates, the compensation is already in place, eliminating the need for post-manufacturing adjustment and maintaining manufacturing simplicity while achieving precision.
Solution Approach 2:
The patent changes the electrical parameters (mobility) of the driving transistor through compensation mechanisms. By measuring actual mobility values and adjusting compensation values accordingly, the system effectively modifies the transistor's electrical characteristics to achieve consistent current output across all pixels despite manufacturing variations.
3Manufacturing precision
If compensation circuits are added to measure and compensate threshold voltage and mobility, then display quality and brightness uniformity are improved, but circuit complexity increases
Solution Approach 1:
The patent designs the compensation circuit to perform multiple functions: it measures threshold voltage, measures mobility, stores compensation values, and applies compensation during operation. By making this single circuit multi-functional, the patent achieves brightness uniformity without proportionally increasing circuit complexity, as one circuit structure serves multiple compensation purposes.
Data Source
AI summary
The present disclosure discloses a display compensation circuit and a method for controlling the same, and a display apparatus. The display compensation circuit comprises a pixel circuit and a power supply selection circuit. The pixel circuit comprises: a light-emitting control sub-circuit; a driving transistor; a first compensation sub-circuit; a second compensation sub-circuit; and a light-emitting element. The power supply selection circuit is coupled to the first power supply terminal, the second power supply terminal, a first switch control terminal, a second switch control terminal and the third node respectively, and is configured to selectively transmit a first power supply signal at the first power supply terminal and a second power supply signal at the second power supply terminal to the third node under control of the first switch control terminal and the second switch control terminal.