Optical Reflective Control Panel for Tolerance-Robust Force Input

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Solution Overview

Problem

Existing operating devices with force-actuated pushbuttons require high manufacturing and assembly accuracy and often necessitate additional insulation or transparent materials, making them complex and prone to errors.

Innovation Solution

An operating device with a cover plate featuring elastically deformable control sections, a common transmitter, and separate receivers or transmitters, allowing for spatially resolved detection of minimal deformations or movements, which reduces manufacturing tolerances and eliminates the need for absolute calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If capacitive, inductive or piezoelectric pushbuttons are used, then force actuation is enabled, but manufacturing and assembly accuracy requirements increase significantly

Engineering Contradiction:
Improveforce actuation capabilityVSAvoidmanufacturing and assembly accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent replaces complex mechanical pushbutton structures (capacitive, inductive, or piezoelectric elements) with a simple optical reflection system. The control section acts as a mirror that reflects light from a common transmitter to a common receiver, eliminating the need for precision mechanical components while maintaining force actuation capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent makes the control sections serve multiple functions: they act as both the actuated interface for the user and as optical reflectors for detection. This multi-functionality eliminates the need for separate sensing components, thereby reducing manufacturing precision requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If touch or proximity-sensitive pushbuttons with sensor systems are used, then actuation detection is enabled, but additional electrical insulation measures or transparent materials are required

Engineering Contradiction:
Improveactuation detection capabilityVSAvoidadditional insulation measures or transparent materials
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces electronic sensor systems (capacitive, inductive, or optical sensors requiring insulation) with a purely optical reflection mechanism. The control sections themselves reflect light, eliminating the need for separate sensors and their associated insulation or transparent material requirements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detection parameter from electrical or electromagnetic field changes (requiring insulation) to optical reflection properties. This allows the use of opaque, non-conductive materials for the control sections without compromising detection capability.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple separate transmitters and receivers are provided for each operating section, then detection accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetection accuracyVSAvoidnumber of transmitters and receivers
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple separate transmitters into a single common transmitter and multiple separate receivers into a single common receiver. The control sections act as individual mirrors that direct light from the common transmitter to the common receiver, enabling detection of multiple buttons with minimal components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the optical path at the control section level, where each control section independently reflects light to a specific region on the receiver. This allows a single receiver to spatially resolve multiple actuation points, achieving multi-button detection with one receiver.

Inventive Principle:
Principle #1Segmentation

4Reliability

If high manufacturing accuracy is required, then detection reliability is improved, but tolerance ranges decrease and error susceptibility increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidtolerance ranges
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces precision mechanical systems with an optical system where the control sections function as reflectors. This substitution allows for larger tolerance ranges in manufacturing and assembly while maintaining reliable detection, as the optical reflection principle is less sensitive to dimensional variations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 provides a reliable, simple, and adaptable operating device that can be made from various materials, with increased tolerance ranges and reduced susceptibility to errors, enabling efficient actuation detection and integration with diverse electronic household appliances.

Implementation Method 1

at least one transmitter for emitting electromagnetic radiation

Methodology Applied
Scientific EffectElectromagnetic radiation emission: Light

Implementation Method 2

the operating sections each being designed in such a way that they at least partially reflect the radiation emitted by the at least one transmitter

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

at least one receiver for detecting electromagnetic radiation, the at least one receiver being arranged and/or is designed such that it enables a spatially resolved detection of the radiation reflected by the operating sections

Methodology Applied
Scientific EffectElectromagnetic radiation detection: Photoelectric Effect

Implementation Method 4

the cover plate having a plurality of control sections for defining a plurality of control elements, which are each configured in such a way that they can be at least partially elastically deformed and/or moved by the action of a force

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3143696B1Operating device, in particular for an electronic household appliance
Publication Date: 2023.03.29 DIEHL AKO STIFTUNG & CO KG
  • EP3143696B1 patent drawingFigure 1A~2
  • EP3143696B1 patent drawingFigure 3~4
  • EP3143696B1 patent drawingFigure 5~6

AI summary

An operating device, for example for electronic household appliances, has a cover plate (10) comprising an operating section (12), at least one transmitter (16) for emitting electromagnetic radiation, at least one receiver (18) for detecting electromagnetic radiation, and a control electronics (20) for evaluating measurement signals generated by the at least one receiver (18). The operating section (12) is equipped such that it is at least partially elastically deformable and/or moveable by an application of force (F) on the user side (10a) of the cover plate (10), and such that it at least partially reflects radiation emitted by the at least one transmitter (16). The at least one receiver (18) is arranged and/or configured such that it enables locally resolved detection of radiation reflected from the operating section (12) so that the control electronics (20) can detect an actuation of the operating section (12) as a function of a detection location of the reflected radiation.