Keyswitch Assembly with Magnetic Sensing and Light Blocking
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Solution Overview
Problem
Conventional keyswitches, including membrane and mechanical types, face issues such as damage from frequent use, poor tactile feedback, wear and rust leading to reduced lifespan, and complexity making them unsuitable for portable devices, along with inadequate backlight illumination.
Innovation Solution
A keyswitch assembly with a switch module, support mechanism, blocking mechanism, and dual light sources is designed to optimize light source placement and reduce interference, enhancing backlight illumination and signal sensing within a compact form factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If membrane circuit is used to generate triggering signal, then the keyswitch can be activated, but the membrane circuit is easily damaged and difficult to repair when frequently used
Solution Approach 1:
The patent replaces the membrane circuit with a magnetic field-based sensing system. A magnet is positioned on the movable support mechanism, and a Hall sensor detects changes in the magnetic field as the support mechanism moves, generating the triggering signal without mechanical contact or membrane deformation. This eliminates the wear and damage issues associated with membrane circuits.
2Reliability
If metal piece and metal contact are used for triggering, then the keyswitch can be activated, but they are easily worn out and prone to rusty due to operation impact
Solution Approach 1:
The patent eliminates metal-to-metal contact by using a magnetic field-based sensing mechanism. The magnet moves with the support mechanism and interacts with the Hall sensor through magnetic field changes, eliminating wear, rust, and contact degradation issues associated with traditional metal piece and metal contact systems.
3Reliability
If conventional mechanical keyswitch structure is used, then the triggering function is achieved, but the structure is more complicated and bigger in volume not suitable for portable electronic devices
Solution Approach 1:
The patent replaces complex mechanical triggering structures with a compact magnetic sensing system. The Hall sensor detects magnetic field changes from a small magnet on the support mechanism, eliminating the need for complex metal contacts, springs, and housing structures, thereby significantly reducing the overall volume while maintaining reliable triggering function.
Solution Approach 2:
The support mechanism serves multiple functions: it provides the pressing motion for key activation, carries the magnet for signal generation, and acts as the movable element for the blocking mechanism. This multi-functionality reduces the number of separate components needed, simplifying the overall structure and reducing volume.
4Illumination intensity
If duo light sources are added to enhance backlight illumination, then the illumination effect is improved, but the interference to the sensing switch from light sources increases
Solution Approach 1:
The patent positions the enhancing light source specifically within the vertical projection of the blocking mechanism's light-permeable portion, directing illumination locally to where it is needed on the keycap while avoiding the Hall sensor area. The blocking mechanism selectively blocks light in the sensor direction while allowing light transmission in the keycap illumination direction, resolving the contradiction between illumination intensity and sensor interference.
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 effectively improves backlight illumination and reduces interference, extending keyswitch lifespan and usability in portable devices without compromising signal integrity.
Implementation Method 1
the signal generator and the signal sensor are a combination of a light emitter and a light receiver
Implementation Method 2
a portion of the blocking mechanism driven by movement of the top portion to insert into or escape from a gap between the signal generator and the signal sensor
Implementation Method 3
an enhancing light source disposed on the top surface and located within the vertical projection of the blocking mechanism on the top surface and corresponding to the light-permeable portion
Data Source
AI summary
A keyswitch assembly includes a switch module, a support mechanism, a blocking mechanism, an enhancing light source, and a backlight source. The switch module includes a substrate, a signal generator, and a signal sensor. The signal generator generates a sensing signal. The signal sensor receives the sensing signal to obtain a sensing strength. The support mechanism is disposed on the substrate. The blocking mechanism is disposed on the substrate and has a light-permeable portion. A portion of the blocking mechanism inserts into or escapes from a gap between the signal generator and the signal sensor. The backlight source is disposed on the substrate and located outside the vertical projection of the blocking mechanism on the substrate. The enhancing light source is disposed on the substrate and located within the vertical projection of the blocking mechanism on the substrate and corresponds to the light-permeable portion.