Keyboard Magnetic Shield Layout for Parallel Key Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional keyboard devices face limitations in design flexibility due to the need for vertical displacement of magnets relative to magnetic detection circuits and the requirement for space to accommodate shield frames, which restricts the structure and arrangement of components.
Innovation Solution
A keyboard device with a substrate containing coils and magnetic shields formed by conductive patterns, allowing for parallel displacement of displacement members and reducing interference between magnetic fields, thereby enhancing design flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a shield frame is formed like a wall rising from the magnetic detection circuit to suppress interference between magnetic fields, then magnetic field interference is reduced, but the flexibility in designing the keyboard device is restricted due to vertical displacement requirements and space constraints
Solution Approach 1:
The patent transitions from a vertical shield structure (rising from the substrate) to a planar shield structure (formed by conductive patterns on the substrate surface). This dimensional change allows the shield to suppress magnetic field interference while enabling parallel displacement of displacement members and improving design flexibility.
Solution Approach 2:
The patent replaces the mechanical shield frame structure with an electromagnetic shield formed by conductive patterns. This substitution eliminates the need for vertical walls and space-consuming mechanical structures, allowing for more flexible keyboard device design while maintaining magnetic field interference suppression.
2Object-affected harmful factors
If a shield frame is formed like a wall rising from the magnetic detection circuit, then magnetic field interference is suppressed, but the space required for arranging the shield frame restricts the keyboard device structure
Solution Approach 1:
The patent extracts the shielding function from the vertical wall structure and implements it through conductive patterns formed on the substrate surface. This eliminates the need for additional vertical space and allows the shield to be integrated into the substrate itself, reducing the overall volume required for the shield frame.
Solution Approach 2:
The patent merges the shield function with the substrate structure by forming conductive patterns directly on the substrate. This integration eliminates the need for separate vertical shield walls and reduces the space required for accommodating the shield frame, while still providing effective magnetic field interference suppression.
3Measurement precision
If the magnet is displaced vertically with respect to the magnetic detection circuit, then key depression information can be detected, but the structure of the keyboard device is restricted
Solution Approach 1:
The patent changes the displacement direction from vertical to parallel (horizontal) by using a planar shield structure. This allows the magnet to be displaced in the horizontal direction while still enabling accurate detection of key depression information, thereby improving structural flexibility.
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 enables accurate detection of key depression information with improved design freedom by allowing parallel displacement of displacement members and reducing magnetic field interference, thus enhancing the structural arrangement of the keyboard device.
Implementation Method 1
a coil which generates a magnetic field for detecting displacement of the plurality of displacement members
Implementation Method 2
a magnetic shield partitioning the plurality of coils and formed by a conductive pattern of the substrate
Data Source
Figure 1
Figure 2~2(b)
Figure 3~3(b)
AI summary
Magnetic shields 82a, 82b are formed from conductor patterns of a substrate 8. Hence, the magnetic shields 82a, 82b can be formed thin. Thus, even when a displacement member 7 (detection part 75) is displaced substantially in parallel with the substrate 8, key pressing information based on the increase/decrease of inductance of a coil 80 can be detected while suppressing interference of the magnetic shields 82a, 82b with the displacement of the displacement member 7. Also, even when the displacement member 7 (detection part 75) is displaced perpendicularly to the substrate 8, the key pressing information based on the increase/decrease of the inductance of the coil 80 can be detected. Thus, the degree of design freedom of a keyboard instrument 1 is increased. Further, constraints can be suppressed from being imposed on the arrangement of the substrate 8 by forming the magnetic shields 82a, 82b to be thin from the conductor patterns. This also increases the degree of design freedom of the keyboard instrument 1.