Illuminated Keyswitch Spacer Structure for Uniform Keycap Lighting

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Solution Overview

Problem

Existing illuminated keyswitch structures face issues with uneven structures due to convex insulation sheets, leading to interference with keycap movement and uneven illumination, and difficulty in achieving uniform luminance across keycap characters and outlines.

Innovation Solution

The use of a flat spacer to separate the base plate and light-emitting part, combined with a light-permeable covering structure and reflective layers, ensures even illumination and protects the light-emitting part from structural interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a convex insulation sheet is attached onto the light source and circuit board, then electrostatic discharge protection is improved, but the structure becomes uneven and assembly difficulty increases

Engineering Contradiction:

Improveelectrostatic discharge protectionVSAvoidstructural uniformity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the insulation function into two separate components: a flat insulation sheet attached to the circuit board and a separate convex insulation structure integrated with the light source housing. This segmentation allows each component to perform its function without compromising the overall structural flatness, resolving the contradiction between ESD protection and structural uniformity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a flat spacer as an intermediary component between the circuit board assembly and the base plate. This spacer provides a flat mounting surface that prevents the convex insulation structure from protruding upward, thereby maintaining structural uniformity while still allowing the insulation function to be performed by the integrated convex insulation at the light source level.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the light source protrudes from the circuit board, then electrostatic discharge protection is improved, but structural interference with keycap movement occurs

Engineering Contradiction:

Improveelectrostatic discharge protectionVSAvoidkeycap movement smoothness

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent relocates the convex insulation structure from the vertical dimension (protruding upward from the circuit board) to the horizontal dimension (integrated with the light source housing at the same level as the circuit board surface). This dimensional change eliminates interference with keycap movement while preserving the insulation function through proper positioning and integration with the light source assembly.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Illumination intensity

If the light source is located below the keycap, then illumination is provided, but luminance uniformity across keycap characters becomes difficult to achieve

Engineering Contradiction:

Improvekeycap illuminationVSAvoidluminance uniformity

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent applies different optical properties to different regions of the covering structure: the first covering layer is made light-permeable to allow light transmission for character illumination, while the second covering layer is made light-blocking to control and uniformize the light distribution. This local differentiation of material properties enables uniform luminance across the keycap surface while maintaining effective illumination.

Inventive Principle:

Principle #3Local quality

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 illumination uniformity across the keycap and reduces structural interference, maintaining a flat design while protecting the light-emitting components.

Implementation Method 1

the first covering layer covers above the light-emitting part and overlaps with vertical projection of said one of the openings of the base plate; wherein the second covering layer vertically corresponds to the light-emitting part and said corresponding one opening of the base plate, the second covering layer blocks at least partial light of the light-emitting part toward said corresponding one opening to reduce illuminating intensity provided there through

Methodology Applied

Scientific EffectLight absorption and transmission: Absorption (EM radiation)

Data Source

PatentUS12525414B2Illuminated keyswitch structure and illuminating module

Publication Date: 2026.01.13 DARFON ELECTRONICS CORP

AI summary

An illuminated keyswitch structure and an illuminating module thereof are provided. The illuminating module includes a drive circuit board having a reflector layer disposed thereon, a light-emitting part disposed on the drive circuit board and proximate to the reflector layer, a covering structure having an island-shaped covering portion, and a spacer adhered between the covering structure and the drive circuit board and having a through hole and an adhesive-less clearance fringe at least partially surrounding the through hole, wherein the island-shaped covering portion covers above the light-emitting part and the through hole.