Photo Sensor Amplifying Element for Touch Accuracy and Aperture Ratio
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Solution Overview
Problem
Touch screen display devices face challenges in accurately determining touch information due to small sensing signals from photo sensors, which can lead to incorrect presence or position detection, and complex sensing circuits that reduce the aperture ratio of the display.
Innovation Solution
A photo sensor design incorporating an amplifying element, a sensing capacitor, a photosensitive sensing element, and a reset element, with specific voltage pulses and control signals to enhance touch information accuracy and aperture ratio, including a scan signal line, sensing signal line, and a sensing signal processor to generate touch information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a complex sensing circuit is used to improve touch information accuracy, then measurement precision improves, but device complexity increases and aperture ratio decreases
Solution Approach 1:
The patent extracts the amplification function from a complex sensing circuit and implements it using a simple operational amplifier connected to a photo sensor. This separates the core function (signal amplification) from unnecessary circuit complexity, achieving accurate touch detection with minimal components and maintaining high aperture ratio
Solution Approach 2:
The operational amplifier serves as an intermediary element between the photo sensor and the control unit. It amplifies the weak photo current signal generated by the photo sensor, making the signal strong enough for accurate touch detection without requiring a complex sensing circuit
2Measurement precision
If a complex sensing circuit is used to improve touch information accuracy, then measurement precision improves, but aperture ratio decreases
Solution Approach 1:
The patent removes unnecessary circuit components that would occupy space on the display panel. By using only the essential elements (photo sensor, operational amplifier, capacitor), the design minimizes the area occupied by sensing circuits, thereby maintaining a high aperture ratio while achieving accurate touch detection
Solution Approach 2:
The patent changes the approach from using multiple components to achieve accuracy to using signal processing (amplification) to enhance the signal from minimal components. This parameter change in the sensing approach allows for both high accuracy and high aperture ratio
3Device complexity
If the sensing signal from photo current is small, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The operational amplifier acts as an intermediary that takes the weak photo current signal and amplifies it to a sufficient level for accurate detection. This allows the system to maintain simple circuitry while achieving high measurement precision through signal enhancement
Solution Approach 2:
The patent changes the signal parameter by introducing amplification. The operational amplifier multiplies the small photo current signal, transforming it into a stronger signal that can be reliably detected and processed, thus improving precision without increasing complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution increases the accuracy of touch information and aperture ratio of touch screen display devices by amplifying sensing signals and simplifying the circuit structure, thereby improving sensitivity and preventing aperture ratio reduction.
Implementation Method 1
sensing a photo current produced by light irradiated upon a channel unit of the transistor
Data Source
AI summary
Provided are a photo sensor, a display device including the same, and a driving method thereof. The photo sensor includes: an amplifying element including an input terminal coupled to a scan line for receiving a scan signal, an output terminal configured to output a sensing signal, and a control terminal connected to a first node; a sensing capacitor connected with the first node; a photosensitive sensing element including a control terminal connected with a terminal of a first control signal, an output terminal connected with the first node, and an input terminal; and a reset element connected with the output terminal of the amplifying element and resetting the output terminal of the amplifying element to second voltage according to a reset control signal.