Capacitive Sensor Dual-Side Input Detection Using Dielectric Thickness
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Solution Overview
Problem
Conventional input devices with capacitive sensors face challenges in operability due to reduced size, making it difficult to perform double-sided inputs on smaller electronic devices, leading to potential erroneous operations on minute input keys.
Innovation Solution
An input device with a capacitive sensor system that includes protective sheets of different thicknesses on the front and rear surfaces, a clock signal generator, delay unit, logical product unit, and controller to differentiate and control inputs from both surfaces, allowing for accurate detection and switching between front and rear surface inputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the electronic apparatus is made smaller, then the size of the electronic apparatus is reduced, but the input surface area becomes smaller causing deteriorated operability
Solution Approach 1:
The patent extends the input surface from a single plane to three-dimensional space by adding a rear surface input area behind the main display. This allows users to input data from both the front and back of the device, effectively doubling the available input area without increasing the device's footprint, thus resolving the contradiction between small size and operability.
Solution Approach 2:
The rear input surface is positioned within the spatial envelope of the device, utilizing the space behind the main display. This nested arrangement allows the input surface to extend into the device's depth dimension rather than requiring additional external space, maintaining compact form factor while increasing functional area.
2Ease of operation
If input units are formed on both front and rear surfaces to increase total input area, then operability is improved, but the device complexity increases requiring separate capacitive sensors
Solution Approach 1:
A single capacitive sensor serves dual functions by detecting inputs from both the front and rear surfaces of the device. The sensor is positioned to sense capacitance changes through the display structure from either side, eliminating the need for separate sensors and reducing device complexity while maintaining enhanced operability.
Solution Approach 2:
The patent combines the front and rear input detection capabilities into a single integrated capacitive sensing system. By merging the detection function for both surfaces into one sensor, the design reduces component count and simplifies the overall device architecture while still providing dual-sided input functionality.
3Volume of moving object
If the input surface area is reduced, then the device size is decreased, but the risk of erroneous operations increases
Solution Approach 1:
By utilizing the rear surface as an additional input dimension, the patent provides more spatial separation between input targets. This increased spacing reduces the likelihood of accidental touches and improves input accuracy, while the compact front surface maintains small device size.
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
Enhances operability by enabling accurate detection and differentiation of inputs from both surfaces of a single capacitive sensor, improving the usability and reducing the size of electronic devices without increasing the risk of erroneous operations.
Implementation Method 1
when a finger of an operator operating the corresponding electronic apparatus moves closely to or comes into contact with the input surface opposite to the electrode, a capacitance of the electrode varies
Implementation Method 2
protective sheets each of which is formed of a dielectric and which are disposed on front and rear surfaces of the capacitive sensor
Data Source
AI summary
A input device is provided which includes a clock signal generator that generates a clock signal; a delay unit that has a capacitive sensor where an electrode is formed on a substrate; protective sheets each of which is formed of a dielectric and which are disposed on front and rear surfaces of the capacitive sensor; a logical product unit that transmits an output signal on the basis of a clock signal obtained from the clock signal generator and a delay signal obtained from the delay unit; and a controller that makes a predetermined program executed in accordance with an output signal obtained on the basis of the logical product unit.