Rotary Switch Light Guide for Vehicle Control

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Solution Overview

Problem

Current rotary switch control devices for motor vehicle air conditioning and ventilation systems have fixed diameters and haptic functions, limiting design flexibility, and existing backlighting solutions are inefficient due to the use of multiple LEDs, causing size and heating issues.

Innovation Solution

A rotary switch control device with a one-piece light guide that retro-illuminates both the rotary switch and peripheral display area, allowing for adjustable size and haptic function customization, using a light source and light guide to provide adaptable backlighting and force feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple LEDs are used for backlighting the rotary switch and peripheral display zone, then the illumination coverage is improved, but the device size and heat generation increase

Engineering Contradiction:

Improvebacklighting coverageVSAvoidnumber of light sources

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent combines multiple light sources and their respective light guides into a single integrated light guide structure. This one-piece light guide replaces what would otherwise require multiple separate LED assemblies, reducing device complexity while maintaining comprehensive backlighting coverage for both the rotary switch and peripheral display zone

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single light guide serves multiple functions simultaneously: it guides light to the rotary switch, illuminates the peripheral display zone, and provides structural support as a fixed mounting element. This multi-functionality eliminates the need for separate components for each lighting function

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If standard rotary encoders are used to provide both electrical switching and haptic functions, then the switching function is improved, but the adaptability of diameter and haptic function is reduced

Engineering Contradiction:

Improveelectrical switching functionVSAvoidcustomization of diameter and haptic function

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent separates the electrical switching function from the haptic function. The rotary encoder wheel provides electrical switching through contactless sensing, while the haptic feedback is generated independently by an actuator mechanism. This segmentation allows each function to be optimized and customized independently

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces traditional mechanical rotary encoders with a contactless sensing system that uses magnetic or capacitive fields to detect rotational position. This substitution eliminates mechanical constraints on diameter and haptic function design, allowing greater adaptability while maintaining reliable switching

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If the rotary switch diameter is fixed by the rotary encoder specification, then the manufacturing is simplified, but the design flexibility is reduced

Engineering Contradiction:

Improvestandardized encoder productionVSAvoidcontrol device size

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent uses contactless sensing technology that allows the rotary switch diameter to be varied as a design parameter rather than being fixed by encoder specifications. The sensing mechanism remains functional across different diameters, enabling designers to optimize the size for specific application requirements while maintaining manufacturing feasibility

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

Enables vehicle manufacturers to customize rotary switch size, haptic feedback, and backlighting, improving design flexibility and reducing the complexity and heat issues associated with traditional LED-based solutions.

Implementation Method 1

a light guide illuminating both the luminous index and the zone peripheral display

Methodology Applied

Scientific EffectLight guidance: Optical Fibre

Implementation Method 2

at least one light source which cooperates with a light guide illuminating

Methodology Applied

Scientific EffectLight propagation: Light

Data Source

PatentEP2548093B1Control device having a rotary switch back-lit by a light guide

Publication Date: 2016.04.27 DELPHI TECHNOLOGIES INC

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AI summary

The invention relates to a control device (12), in particular for a motor vehicle, comprising a rotary switch (16, 18) and a peripheral display area, which are arranged on a plate (19) and which are back-lit by a back-lighting device (24, 26), the rotary switch (16, 18) comprising a thumb wheel (38) which is rotatably mounted relative to the plate (19) about an axis, the thumb wheel (38) being provided with a luminous index (40) rotating with the thumb wheel (38), the peripheral display area comprising stationary luminous symbols (36) arranged around the rotary switch (16, 18), characterized in that the back-lighting device (24, 26) comprises at least one light source (60) which cooperates with a light guide (62, 64) illuminating both the luminous index (40) and the peripheral display area (30, 32).