Capacitive Touch Panel Signal Processing Circuit with Shared Microcomputer Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrostatic capacity type touch panels incur increased component costs due to duplication of microcomputers in multiple sensor circuits, leading to higher overall costs.
Innovation Solution
A signal processing circuit design for an electrostatic capacity type touch panel that includes first and second sensor circuits to detect capacitance changes between sense lines and drive lines, with a bus for data communication, eliminating the need for multiple microcomputers by using a master device to process signals from these sensor circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensor circuits each incorporate a microcomputer, then touch position detection capability is improved, but component cost increases due to duplication
Solution Approach 1:
Multiple sensor circuits are merged under a single microcomputer control. The microcomputer serves as a shared resource that processes signals from all sensor circuits, eliminating the need for duplicate microcomputers in each sensor circuit while maintaining full touch position detection functionality across the panel.
Solution Approach 2:
A single microcomputer is designed to perform multiple functions by controlling and processing signals from multiple sensor circuits. This universal controller handles detection tasks for all sensor circuits, replacing the need for dedicated microcomputers in each circuit and reducing overall component count.
2Quantity of substance
If a single microcomputer controls multiple sensor circuits, then component cost is reduced, but signal processing complexity increases
Solution Approach 1:
The signal processing function is segmented between hardware and software components. Simple analog-to-digital conversion and signal conditioning are performed in dedicated circuits, while the microcomputer handles higher-level processing tasks. This segmentation reduces the processing burden on the single microcomputer while maintaining cost efficiency.
Solution Approach 2:
Preliminary signal processing and conditioning are performed in dedicated circuits before signals reach the microcomputer. This preliminary action prepares signals in advance, reducing the complexity of processing required by the single microcomputer and enabling efficient multi-circuit control.
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
This design reduces component duplication and costs while maintaining effective touch position detection capabilities, improving noise immunity and allowing for arbitrary patterning of touch pads without parasitic capacitance restrictions.
Implementation Method 1
a first sensor circuit to detect a change in a capacitance between the first sense line and the first drive line
Data Source
AI summary
There is offered a signal processing circuit of the electrostatic capacity type touch panel which can eliminate duplication of components to reduce a cost of the components. A touch panel 51 is formed on a glass substrate 200. Sensor circuits 50A and 50B are arrayed in a Y direction, and sensor circuits 50C and 50D are arrayed in an X direction on the periphery of the touch pane 51. Serial clock terminals SCL of the sensor circuits 50A-50D are connected to a serial clock line 53 all together, while serial data terminals SDA are connected to a serial data line 54 all together. A microcomputer 52 is disposed on a PCB substrate outside the glass substrate 200. Data communication can be performed between the microcomputer 52 and the sensor circuits 50A-50D through the serial clock line 53 and the serial data line 54.