Double-Gate Pixel Circuit for OLED Brightness Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
OLED displays face non-uniform brightness due to varying threshold voltage in pixel circuits, making it difficult to adjust gamma voltage and increasing power consumption.
Innovation Solution
A pixel circuit with a driving transistor in a double-gate structure, along with specific switch transistors and capacitors, is designed to compensate for threshold voltage, ensuring driving current is dependent only on the data signal voltage, thereby maintaining uniform brightness across pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If threshold voltage compensation is implemented using existing circuit schemes with capacitors and reference voltages, then non-uniform brightness is improved, but device complexity increases and power consumption rises
Solution Approach 1:
The patent extracts and eliminates the reference voltage component from the light emission current path. By redesigning the pixel circuit to remove the capacitor-based reference voltage storage, the circuit complexity is reduced while maintaining threshold voltage compensation functionality through an alternative mechanism that does not require separate reference voltage management.
Solution Approach 2:
The patent implements a multi-functional transistor structure where the same transistor serves both as the driving transistor for light emission and as part of the threshold voltage compensation mechanism. This eliminates the need for separate dedicated compensation components, thereby reducing overall device complexity while achieving brightness uniformity.
2Illumination intensity
If threshold voltage compensation is implemented using existing circuit schemes with capacitors and reference voltages, then non-uniform brightness is improved, but power consumption increases
Solution Approach 1:
The patent removes the capacitor-based reference voltage storage from the circuit, eliminating the energy required to maintain and update reference voltage levels. This extraction of the reference voltage component directly reduces power consumption while preserving the essential function of compensating for threshold voltage variations to ensure brightness uniformity.
3Ease of manufacture
If existing pixel circuit design is used, then manufacturing is simpler, but gamma voltage adjustment becomes difficult and data signal voltage range must be wider
Solution Approach 1:
The patent creates a unified transistor structure that simultaneously handles driving functions and threshold compensation, eliminating the need for separate gamma voltage adjustment mechanisms. This multi-functional design maintains manufacturing simplicity while enabling more flexible and easier gamma voltage control through the integrated structure.
Data Source
AI summary
Disclosed are a pixel circuit, a method for driving the same, a display panel, a display device, and the pixel circuit which includes a driving transistor structured with double-gates, a first switch transistor, a second switch transistor, a third switch transistor, a fourth switch transistor, a first capacitor, a second capacitor, and a light-emitting element; and the respective transistors and capacitors above cooperate with each other to compensate for threshold voltage of the driving transistor, so that driving current to drive the light-emitting element to emit light is only dependent upon voltage of a data signal, the light-emitting element is avoided from being affected by the threshold voltage of the driver control module, and when the same data signal is applied to different pixel elements, an image at the same brightness can be displayed.