Touch Electrode Sensing Circuit Using Intensity-to-Phase Conversion
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Solution Overview
Problem
Conventional touch control sensing systems face challenges with low signal-to-noise ratio (SNR) and slow operating speed, particularly with medium or large touch panels, due to thermal noise, flicker noise, and parasitic resistances, which increase manufacturing costs and limit the accuracy of detecting touch areas.
Innovation Solution
A control circuit for a sensing electrode array comprising a signal intensity analyzer, an intensity-to-phase frequency converter, and a phase frequency analyzing unit, which converts DC intensity signals into phase frequency signals to enhance SNR and operating speed without the need for an integrator or analog-to-digital converter, allowing for medium or large touch panels without increasing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional control circuits with integrators and ADCs are used, then signal processing capability is maintained, but operating speed becomes slow and manufacturing cost increases
Solution Approach 1:
The patent extracts and removes the integrator and ADC components from the conventional control circuit. By taking out these complex components, the circuit complexity is reduced while maintaining signal processing capability through alternative means (direct sampling and digital signal processing), thereby improving operating speed without sacrificing functionality.
Solution Approach 2:
The patent substitutes the analog signal processing mechanism (integrator + ADC) with a digital signal processing approach. Instead of using analog integration followed by analog-to-digital conversion, the system directly samples the sensing signal and processes it digitally, replacing the mechanical/analog system with a digital one to achieve faster operation.
2Area of stationary object
If conventional control circuits are used for medium or large touch panels, then coverage area is increased, but signal-to-noise ratio deteriorates due to thermal noise and parasitic resistances
Solution Approach 1:
The patent replaces the analog signal processing chain (which is susceptible to thermal noise and parasitic resistances in integrators) with direct digital sampling and processing. This substitution eliminates the analog integration stage that generates thermal noise and is affected by parasitic resistances, thereby maintaining signal-to-noise ratio even in medium or large touch panels.
Solution Approach 2:
By removing the integrator component, the patent eliminates the source of thermal noise and parasitic resistance effects that degrade signal-to-noise ratio. The extraction of this component allows the system to maintain measurement precision across larger touch panel areas without the noise penalties inherent in conventional analog integration circuits.
3Ease of manufacture
If integrators and ADCs are used in control circuits, then signal processing is achieved, but manufacturing cost increases
Solution Approach 1:
The patent extracts and removes the expensive integrator and ADC components from the control circuit. By eliminating these complex and costly components, the manufacturing cost is reduced while the essential signal processing functionality is maintained through direct digital sampling and processing methods, making the system easier and more economical to manufacture.
Solution Approach 2:
The patent replaces expensive, complex analog components (integrators and ADCs) with simpler, more economical digital sampling and processing circuitry. This substitution uses cheaper components that can be easily manufactured, reducing overall manufacturing cost while maintaining adequate signal processing capability for the application.
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 proposed solution achieves a higher SNR and faster operating speed compared to conventional systems, enabling accurate detection of touch areas on medium or large touch panels without the need for expensive high-performance ADCs or additional hardware, thus reducing manufacturing costs.
Implementation Method 1
Due to field coupling, the driving signals of the driving lines induce the sensing lines to generate sensing signals
Implementation Method 2
When a human finger touches the touch panel 14, an electric field formed by some drive pulses Drive_Pulses would be coupled to the human finger due to field coupling
Data Source
AI summary
A control circuit for a sensing electrode array is described. The control circuit for the sensing electrode array includes a signal intensity analyzer, an intensity-to-phase frequency converter, and a phase frequency analyzing unit. The signal intensity analyzer obtains an intensity signal corresponding to a sensing signal of each sensing line of the sensing electrode array, wherein each intensity signal is a direct-current signal. The intensity-to-phase frequency converter generates a phase frequency signal based on the intensity signal. At least the phase or the frequency of the phase frequency signal is related to the level of the corresponding intensity signal. The phase frequency analyzing unit obtains a signal magnitude of the corresponding sensing line according to each phase frequency signal. The control circuit for the sensing electrode array enhances the operating speed and the signal-to-noise ratio of the touch control sensing system without increasing the manufacturing cost.