Touch Display Driver Pin Sharing for More Sensing Electrodes
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Solution Overview
Problem
The increasing size of touch displays requires more touch sensors, which exceeds the capacity of single touch and display driver chips, leading to high bill-of-materials costs and the need for innovative solutions to increase the number of touch sensors at a lower cost.
Innovation Solution
The electronic device incorporates a substrate with data lines, data switches, sensing electrodes, and touch switches, where the touch switches connect to both data lines and sensing electrodes, allowing for shared transmission pins, reducing the number of pins required in the driving integrated circuit and lowering overall costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the size of touch display is increased, then the number of touch sensors is increased, but the number of pins in touch and display driver becomes insufficient
Solution Approach 1:
The patent merges the touch sensing function and display driving function into a single integrated driver chip. The touch switches are directly integrated with the display driver, allowing both touch sensors and display pixels to share the same driver circuitry and transmission pins. This integration resolves the pin shortage problem by eliminating the need for separate touch controller pins.
Solution Approach 2:
The driver chip is designed to perform multiple functions: it drives both display pixels and touch switches simultaneously. The same transmission pins are used for both display data transmission and touch signal transmission at different time periods. This multi-functionality allows the driver to support a larger number of touch sensors without proportionally increasing the number of pins.
2Quantity of substance
If multiple touch and display chips are used, then the number of touch sensors is increased, but the bill-of-materials cost becomes too high
Solution Approach 1:
By combining touch sensing and display driving into a single chip, the patent eliminates the need for multiple separate chips (touch controller + display driver). This single-chip solution reduces the bill-of-materials cost while supporting a large number of touch sensors through the integrated architecture.
Solution Approach 2:
The patent employs time-division multiplexing where the driver alternates between driving display pixels and sensing touch switches in different time periods. During display period, display data is transmitted; during touch sensing period, touch signals are sensed. This periodic operation allows the same hardware resources to serve both functions, reducing component count and cost.
Data Source
AI summary
An electronic device includes a substrate, a plurality of data lines, a plurality of data switches, a plurality of sensing electrodes, and a plurality of touch switches. The data lines and the sensing electrodes are arranged on the substrate. The plurality of data switches respectively have a first connection end and a second connection end, and the plurality of touch switches respectively have a third connection end and a fourth connection end. The first connection end of the plurality of data switches respectively couple to one of the plurality of the data lines. The third connection end of the plurality of touch switches respectively couple to one of the plurality of the sensing electrodes, and the fourth connection end of the plurality of touch switches respectively couple to the second connection end of one of the plurality of data switches.