Integrated Mechanical Touch Key Structure for Portable Devices
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Solution Overview
Problem
Portable electronic devices face a challenge in balancing mechanical key functionality with touch key functionality, as both occupy significant space on the panel, limiting the screen size and utility of these devices.
Innovation Solution
A key structure that combines mechanical and touch key functionality by using a pressing portion with projections and conductive elements, allowing for reduced key area while maintaining sensitivity and accuracy, enabling both mechanical and touch key functions through a single interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If both mechanical keys and touch keys are applied to the portable electronic product, then both mechanical key functionality and touch key functionality are achieved, but the area occupied on the panel increases and the screen area is reduced
Solution Approach 1:
The patent combines mechanical key functionality and touch key functionality into a single integrated key structure. The key cap serves as both a mechanical pressing element and a touch-sensitive surface, merging two separate functional elements into one unified component that provides both mechanical and capacitive touch capabilities.
Solution Approach 2:
The key structure is designed to perform multiple functions simultaneously: it provides mechanical key pressing capability through the key cap and spring mechanism, while also serving as a capacitive touch sensor surface. This multi-functional design allows a single key element to replace what would traditionally require separate mechanical and touch key areas.
2Area of stationary object
If the area of keys on the panel is reduced to enlarge the screen, then the screen area is increased, but the key functionality may be compromised
Solution Approach 1:
By merging mechanical and touch key functions into a single structure, the patent enables reduced key area while preserving full key functionality. The integrated design maintains mechanical pressing capability through the key cap and spring assembly while adding capacitive touch sensitivity to the same surface, allowing compact layout without sacrificing operational capability.
Solution Approach 2:
The patent adds capacitive touch sensitivity as an additional functional dimension to the mechanical key structure. By incorporating capacitive sensors beneath or within the key cap, the design utilizes a different sensing dimension (electrical field detection) alongside the mechanical pressing dimension, enabling dual functionality within the same physical footprint.
3Area of stationary object
If a single key structure provides both mechanical and touch functionality, then the panel area is reduced and screen area is enlarged, but the structural complexity increases
Solution Approach 1:
The patent integrates multiple functional components into a unified key assembly where the key cap serves as both mechanical element and touch sensor surface. The spring mechanism provides mechanical return while capacitive traces are embedded within or beneath the key cap structure, creating a compact multi-functional unit that reduces overall panel area despite increased internal complexity.
Solution Approach 2:
The key structure employs a nested arrangement where capacitive sensor traces are embedded within or beneath the key cap layers, and the spring mechanism is positioned within the key assembly cavity. This nesting approach allows multiple functional elements to occupy overlapping or adjacent spatial volumes, reducing the overall footprint while maintaining all required functionalities.
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 solution allows for a compact design that enlarges the screen area in portable devices, enhancing user experience by integrating both mechanical and touch key functions without increasing the panel's physical size.
Implementation Method 1
the sensor receives a signal of change of capacitance transmitted by the conductive cover
Implementation Method 2
a metal spring located between a key and a pressing portion
Data Source
AI summary
A key structure in an electronic product includes a housing. The key structure includes a pressing portion, a printed circuit board (PCB), a key, and a sensor. The key and the sensor are both located on the PCB and electronically connected with each other. When the pressing portion is pressed, the key structure acts as a mechanical key. When the pressing portion is simply touched, the key structure acts as a touch key.