Optical Pushbutton Panel Layout for Close-Spaced Actuation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing pushbuttons that require force actuation, such as capacitive, inductive, and piezoelectric types, face challenges in manufacturing and assembly due to high accuracy requirements and tolerance constraints, making it difficult to position them closely and simplify design and logistics.

Innovation Solution

An operating device with a cover plate, a carrier plate, and a partition plate, where sensors detect changes in distance between the cover plate's operating sections, and a detachable structural unit simplifies assembly and allows closer positioning of pushbuttons while maintaining reliable actuation detection, using a combination of elastic deformability and electromagnetic radiation for detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If capacitive, inductive, or piezoelectric pushbuttons are used for force actuation, then reliable actuation detection is achieved, but manufacturing and assembly accuracy requirements become excessively high with small tolerance ranges

Engineering Contradiction:
Improveactuation detection reliabilityVSAvoidmanufacturing and assembly accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces complex mechanical pushbutton structures (capacitive, inductive, or piezoelectric elements) with a simple elastic cover plate and optical sensor system. The cover plate's elastic deformation under force actuation changes the optical path distance, which is detected by sensors without requiring high manufacturing precision. This substitution resolves the contradiction by maintaining reliable detection while dramatically reducing tolerance requirements.

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

Solution Approach 2:

The patent changes the detection parameter from electrical properties (capacitance, inductance, piezoelectric effect) to optical distance measurement. By measuring the change in distance between the cover plate and sensor through optical means, the system achieves reliable actuation detection with much more relaxed manufacturing tolerances compared to electrical sensing methods.

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If pushbuttons are positioned closely together, then space efficiency is improved, but separation and independent actuation detection become difficult

Engineering Contradiction:
Improvecontrol panel areaVSAvoidindependent actuation detection
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent introduces a reflector plate as an intermediary element between the cover plate and sensors. This reflector plate, with its reflective surface, enables each sensor to detect only the optical path from its corresponding cover plate section, preventing cross-interference even when pushbuttons are closely positioned. This intermediary allows close spacing while maintaining independent detection reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent adds the optical dimension (light reflection paths) as a new layer of separation. By using optical paths at different angles and the reflector plate to guide these paths, the system creates virtual separation between closely positioned pushbuttons, allowing them to be physically close while maintaining independent detection through spatially resolved optical measurement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If design components and technical components are integrated, then structural simplicity is achieved, but manufacturing, assembly, and logistics complexity increase

Engineering Contradiction:
Improvestructural complexityVSAvoidmanufacturing and assembly ease
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The patent divides the operating device into separate functional modules: a design component (cover plate with operating sections) and a technical component (support plate with sensors and reflector plate). This segmentation allows each module to be manufactured, tested, and assembled independently, reducing overall manufacturing and assembly complexity despite the device's functional integration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the technical sensing components (sensors, reflector plate, support plate) from the design component (cover plate). This extraction allows the technical subsystem to be pre-assembled and tested separately, then integrated with the design component, thereby reducing manufacturing and assembly complexity while maintaining functional integration in the final product.

Inventive Principle:
Principle #2Taking out (Extraction)

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 design simplifies manufacturing and assembly, allows for closer positioning of pushbuttons, reduces crosstalk, and tolerates larger component tolerances, enabling easier logistics and independent design of the control panel from technical components.

Implementation Method 1

the cover plate defines a number of separate operating sections and is designed to be elastically deformable and/or movable in these operating sections

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a number of sensors which are arranged on the support plate and are designed and arranged such that they can each detect a change in distance to the cover plate

Methodology Applied
Scientific EffectElectromagnetic radiation detection: Electromagnetic Induction

Data Source

PatentEP3205022B1Operating device, in particular for an electronic household appliance
Publication Date: 2020.12.30 DIEHL AKO STIFTUNG & CO KG
  • EP3205022B1 patent drawingFigure 1~2B
  • EP3205022B1 patent drawingFigure 3A~3B
  • EP3205022B1 patent drawingFigure 4~5

AI summary

An operating device for electronic household appliances includes a cover plate (10) with a user side (10a) facing a user, wherein the cover plate (10) defines a number of operating sections (12) separated from one another and is configured to be elastically deformable and/or moveable in said operating sections (12); a support plate (14) which is arranged on the side of the cover plate (10) facing away from the user side (10a) and spaced apart from same; a number of sensors (16, 18) which are arranged on the support plate (14) and are arranged and configured in such a way that they can each detect a change of distance to the cover plate (10) in the area of one of the number of operating sections (12) of the cover plate (10); and a separating plate (26) which is arranged on the side of the cover plate (10) facing away from the user side (10a) and has support walls (28) contacting the cover plate in the areas between the number of operating sections (12) of the cover plate (10).