Backlit Keyboard Light Guide Microstructures for Uniform Key Luminance

Solution Overview

Problem

Conventional illuminated keyboards exhibit uneven luminance due to microstructures on the light guide plate being uniformly concave, resulting in brighter light closer to the light source and dimmer light farther away, leading to an inconsistent visual experience.

Innovation Solution

The design of the illuminated keyboard incorporates microstructures on the light guide plate with varying depths and heights, and alternative convex and concave arrangements, along with surface roughness, to adjust the light transmission path and ensure uniform luminance across all keycaps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If microstructures are uniformly concave to the light guide plate, then the manufacturing process is simple, but the luminance distribution becomes uneven

Engineering Contradiction:

Improvemicrostructure uniformityVSAvoidluminance uniformity

Core Design Contradiction:

Ease of manufactureVSIllumination intensity

Solution Approach 1:

The patent applies local quality by varying the depth of microstructures at different locations on the light guide plate. Specifically, microstructures closer to the light source have different depths compared to those farther away, creating localized variations in light refraction and reflection properties. This ensures that each region of the keyboard receives appropriate light intensity, achieving uniform overall luminance while maintaining manufacturing simplicity through a systematic depth variation pattern.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements parameter changes by modifying the depth parameter of microstructures based on their position relative to the light source. The depth of microstructures is adjusted as a function of distance from the light source, with closer microstructures having different depths than farther ones. This parameter variation compensates for the natural light intensity gradient, transforming the uniform microstructure design into a position-dependent design that achieves luminance uniformity.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If microstructures are positioned at fixed depths, then the manufacturing precision is easy to control, but the light transmission path cannot be optimized

Engineering Contradiction:

Improvemicrostructure depth consistencyVSAvoidlight transmission uniformity

Core Design Contradiction:

Manufacturing precisionVSIllumination intensity

Solution Approach 1:

The patent applies local quality by varying the depth of microstructures at different locations on the light guide plate. Specifically, microstructures closer to the light source have different depths compared to those farther away, creating localized variations in light refraction and reflection properties. This ensures that each region of the keyboard receives appropriate light intensity, achieving uniform overall luminance while maintaining manufacturing simplicity through a systematic depth variation pattern.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements parameter changes by modifying the depth parameter of microstructures based on their position relative to the light source. The depth of microstructures is adjusted as a function of distance from the light source, with closer microstructures having different depths than farther ones. This parameter variation compensates for the natural light intensity gradient, transforming the uniform microstructure design into a position-dependent design that achieves luminance uniformity.

Inventive Principle:

Principle #35Parameter changes

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 configuration provides consistent and uniform luminance across all keycaps, eliminating the issue of uneven lighting and enhancing the visual experience by ensuring equal brightness regardless of the keycap's distance from the light source.

Implementation Method 1

The microstructures 22 are used for changing the transmission path of light emitted by a light source 5

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

a surface 21 of the light guide plate 2 facing a reflector 3

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 3

The light guide plate 2 is disposed on the reflector 3, and a surface of the light guide plate facing the reflector has multiple microstructures

Methodology Applied

Scientific EffectLight guidance: Waveguide (optics)

Data Source

PatentUS11755123B2Illuminated keyboard

Publication Date: 2023.09.12 LITE ON TECH CORP

AI summary

An illuminated keyboard including a backlight module and a key structure is provided. The backlight module includes a reflector, a light guide plate, a light source, and a light shielding plate. The light guide plate is disposed on the reflector, and a surface of the light guide plate facing the reflector has multiple microstructures. The light source is located on a light incident surface side of the light guide plate. The light shielding plate is disposed on the light guide plate. The light shielding plate has a shielding area and a light transmissive area, and the microstructures are correspondingly disposed in the light transmissive area. The key structure has multiple keycaps. In the microstructures correspondingly disposed under one single keycap, peaks of any two microstructures adjacent to each other keep different distances from the surface of the light guide plate facing the reflector.