Pixel Circuit With Shared TFT Selection for Higher Aperture Ratio
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Solution Overview
Problem
The low aperture ratio in liquid crystal display devices results in low display brightness.
Innovation Solution
A pixel circuit utilizing a first thin film transistor and a selection circuit to sequentially charge two pixels through a single scan line, reducing the number of scan lines and thin film transistors required in the effective display area, thereby increasing the aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional pixel circuits are used with separate scan lines for each pixel, then each pixel can be controlled independently, but the number of scan lines and thin film transistors increases, reducing the aperture ratio
Solution Approach 1:
The patent merges the control of two pixels (first pixel and second pixel) into a single scan line by using a shared thin film transistor. The selection circuit selectively connects the thin film transistor output to either the first pixel electrode or the second pixel electrode, allowing one scan line to control two pixels that were traditionally required to have separate scan lines.
Solution Approach 2:
The thin film transistor connected to the scan line serves multiple functions: it controls both the first pixel and the second pixel sequentially through the selection circuit. This multi-functional approach allows a single transistor to replace what would traditionally require two separate transistors, reducing the overall device complexity.
2Measurement precision
If more scan lines and thin film transistors are provided to control more pixels, then pixel control precision is improved, but the aperture ratio decreases
Solution Approach 1:
By combining the control pathways of two pixels into a single scan line through the selection circuit, the patent reduces the total number of scan lines required. This merging allows more area to be allocated to the aperture while maintaining the same level of pixel control precision.
3Illumination intensity
If the number of scan lines is reduced to increase aperture ratio, then display brightness is improved, but pixel control complexity increases
Solution Approach 1:
The patent segments the pixel control into two distinct sub-stages: a first sub-stage for controlling the first pixel with positive-polarity data signals, and a second sub-stage for controlling the second pixel with negative-polarity data signals. This temporal segmentation allows a single scan line to control multiple pixels without signal interference, managing complexity through time-division multiplexing.
Solution Approach 2:
The control method uses periodic alternating polarities in successive sub-stages to drive different pixels. The first sub-stage uses positive-polarity signals while the second sub-stage uses negative-polarity signals, creating a periodic control pattern that enables efficient use of shared scan lines while maintaining clear signal differentiation.
Data Source
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AI summary
Disclosed are a pixel circuit, a method for controlling a pixel and a display panel. The pixel circuit includes a first thin film transistor (T1), a controlled end of the first thin film transistor (T1) is connected to the scan line (L1), and an input end of the first thin film transistor (T1) is connected to the data line (L2); and a first selection circuit (10), an input end of the first selection circuit (10) is connected to an output end of the first thin film transistor (T1), the first output end of the first selection circuit (10) is connected to the first pixel electrode (S1), and a second output end of the first selection circuit (10) is connected to the second pixel electrode (S2); the first thin film transistor (T1) is configured to sequentially write a data signal transmitted on the data line (L2) into the first pixel (PXL1) and the second pixel (PXL2) through the first selection circuit (10) to charge the first pixel (PXL1) and the second pixel (PXL2) sequentially, so that the first pixel (PXL1) and the second pixel (PXL2) are sequentially charged to a corresponding pixel electric potential of a current frame.