Display Driver Offset Compensation for AMOLED Mura
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Solution Overview
Problem
Display panels, particularly AMOLED displays, suffer from non-uniformity and Mura effect due to fabrication processes, leading to display defects like spots or clouding, which reduce display quality and user satisfaction.
Innovation Solution
A display driver with a power circuit that supplies multiple voltages to sense currents and determine offsets, which are stored in an external memory, is used to compensate for non-uniformity and Mura effect by adjusting drive data in a display apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple voltages are supplied to sense currents and determine offsets, then display quality is improved, but device complexity increases
Solution Approach 1:
The power circuit is designed to perform multiple functions: it supplies different voltages (first voltage and second voltage) to the display panel for sensing currents, determines offsets based on sensed currents, and stores these offsets in external memory. This multi-functional approach enables display quality compensation without adding separate dedicated circuits for each function.
Solution Approach 2:
The display driver system performs self-diagnosis and self-compensation by sensing its own operating currents and automatically determining offsets to compensate for Mura effects and non-uniformity. The system uses its existing power circuit to measure sensing currents and generate compensation data, eliminating the need for external testing equipment or additional compensation circuits.
2Manufacturing precision
If offsets are determined and stored in external memory, then non-uniformity is compensated, but manufacturing complexity increases
Solution Approach 1:
The system performs preliminary sensing and offset determination during the manufacturing or initialization phase. Multiple voltages are supplied to sense currents, offsets are calculated from these sensed currents, and the offset data is stored in external memory before the display enters normal operation. This preliminary compensation setup eliminates the need for complex real-time adjustment mechanisms during manufacturing.
Solution Approach 2:
External memory serves as an intermediary component that stores the determined offset data. The power circuit determines offsets based on sensed currents, stores them in external memory, and the display panel uses these stored offsets for compensation. This intermediary storage solution simplifies the manufacturing process by decoupling the offset determination from the display operation.
3Measurement precision
If sensing currents are measured with multiple voltages, then measurement precision is improved, but energy consumption increases
Solution Approach 1:
The power circuit supplies multiple voltages (first voltage and second voltage) periodically or in sequence to sense currents at different voltage levels, rather than continuously maintaining multiple voltage states. This periodic sensing approach achieves precise current measurement for offset determination while minimizing energy consumption during normal display operation.
Data Source
AI summary
A display apparatus including a display panel, a display driver, a controller and an external circuit is introduced. The display drive includes a power circuit that supplies a first voltage and a second voltage to the display panel to sense a plurality of sensing currents flowing through the display panel according to the first voltage and the second voltage in a first operating mode. The display driver receives the plurality of sensing currents and a target current from the display panel in the first operating mode. The controller is coupled to the display driver and configured to determine a plurality of offsets according to the plurality of sensing currents and the target current in the first operating mode. The external memory is coupled to the controller and the display driver to store the offsets in the first operating mode. The display driver and a method adapted to a display apparatus are also introduced.