Mini-LED Keyboard Backlight With Light Guide for Uniform Illumination

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Solution Overview

Problem

Conventional keyboard backlights with side-directed LEDs consume high power and cause light leakage as bright spots, affecting user visibility and battery life in portable information handling systems.

Innovation Solution

A mini-LED system providing both direct and indirect illumination to keyboard keys through a light guide material, such as acrylic, around the perimeter of each mini-LED, reducing power consumption and hot spots.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional side-directed LEDs are used to illuminate the keyboard, then the keyboard receives adequate illumination, but power consumption increases and light leakage occurs as bright spots

Engineering Contradiction:

Improvekeyboard illuminationVSAvoidbacklight power consumption

Core Design Contradiction:

Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent segments the illumination function by using individual mini-LEDs positioned under each key rather than a single side-directed LED array. Each mini-LED illuminates only its corresponding key, eliminating unnecessary illumination of other keys and reducing overall power consumption while maintaining adequate key visibility

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by directing light precisely where needed - each mini-LED is positioned and oriented to illuminate only its specific key from below. This localized illumination approach eliminates the light leakage problem of conventional side-directed LEDs that illuminate entire rows or sections, reducing power consumption by avoiding wasted light on non-active keys

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If multiple mini-LEDs are placed under each key for direct illumination, then key brightness is improved, but power consumption and cost increase

Engineering Contradiction:

Improvekey brightnessVSAvoidbacklight power consumption

Core Design Contradiction:

Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent uses partial action by employing a single mini-LED per key positioned at an angle to provide both direct and indirect illumination. This single LED delivers sufficient brightness through its dual illumination paths without the excessive power consumption that would result from using multiple LEDs per key

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent adds a dimensional aspect to illumination by positioning mini-LEDs at angles beneath keys to provide both direct upward illumination and indirect side illumination through light guide material. This angular positioning creates two illumination dimensions from a single LED source, achieving full key coverage without needing multiple LEDs per key

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Use of energy by moving object

If mini-LEDs directly illuminate keys from below, then power consumption is reduced, but light leakage occurs at key sides as bright spots

Engineering Contradiction:

Improvebacklight power consumptionVSAvoidlight leakage as bright spots

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by using light guide material with specific optical properties positioned around each mini-LED. This material locally captures and redirects light that would otherwise leak sideways, converting harmful lateral light leakage into useful indirect illumination at the key periphery while maintaining low power consumption

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces light guide material as an intermediary between the mini-LED and the key structure. This intermediary material captures light from the angled mini-LED and redirects it to illuminate the key periphery, preventing direct light leakage while providing beneficial indirect illumination that enhances overall key visibility without creating bright spots

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances keyboard illumination with reduced power consumption and minimized hot spots, improving user experience and battery life while maintaining brightness.

Implementation Method 1

A mini-LED disposed under a keyboard key provides direct illumination at the key bottom surface and indirect illumination at the key periphery

Methodology Applied

Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

indirect illumination directed from the mini-LED through a light guide material, such as acrylic having a reflector and mask, and towards a periphery of the key

Methodology Applied

Scientific EffectLight transmission and direction: Refraction

Data Source

PatentUS11823850B1Information handling system keyboard backlight having mini-LED integrated light guide arrangement

Publication Date: 2023.11.21 DELL PROD LP

AI summary

An information handling system keyboard backlight illuminates with a single mini-LED disposed under each of plural keyboard keys and having a penta directional illumination that illuminates directly at the key and coplanar a light guide material around the perimeter of the mini-LED. The light guide material in cooperation with a reflector below and a mask above provides indirect illumination at the periphery of the key for a more uniform key illumination. A substrate carried with circuits below the mini-LED powers the mini-LED so that a more bulky flexible printed circuit is not needed.