Optical Input Actuator with Internal Reflection to Reduce Dirt Impact

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Solution Overview

Problem

Existing input devices for electronic devices, such as cooking appliances, face challenges in being simple, easy to clean, and tolerant of contamination while providing user feedback for input operations.

Innovation Solution

An input device with a base and a movable actuator featuring a light source and sensor system with reflection bodies that guide the measurement beam within the material, reducing dirt's influence on reflection quality, combined with magnetic feedback for haptic input detection and a design that minimizes protrusions for easy cleaning and aesthetics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional optical encoders with external reflection surfaces are used, then the device structure is simple, but dirt on the reflection surface significantly degrades reflection quality and measurement reliability

Engineering Contradiction:
Improvereflection qualityVSAvoiddirt influence
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Instead of having the light beam reflect off an external surface, the patent inverts the approach by guiding the light beam to reflect internally within the actuator material itself. The actuator serves as both the moving component and the reflection medium, eliminating the separate reflection surface that accumulates dirt.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The actuator material itself acts as an intermediary medium that guides and reflects the light beam internally. This intermediary function is built into the actuator's material properties and structure, providing stable reflection without requiring external reflective surfaces that are susceptible to contamination.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If multiple protruding components are used for input detection, then the detection functionality is comprehensive, but the device is difficult to clean and aesthetics are compromised

Engineering Contradiction:
ImprovecleanabilityVSAvoidnumber of protrusions
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into the actuator: it serves as the input interface for rotation detection, contains the internal reflection structures for optical encoding, and provides the outer aesthetic surface. This merging eliminates the need for separate protruding components for each function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The actuator is designed as a universal component that performs multiple functions: it is the user interface for input, the structural element containing optical reflection paths, and the aesthetic outer surface. This multi-functionality reduces the overall number of components and simplifies cleaning.

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

3Ease of manufacture

If external reflection surfaces are used in the optical path, then the manufacturing is simple, but contamination easily accumulates on exposed surfaces

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcontamination accumulation
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent transitions from two-dimensional external reflection surfaces to three-dimensional internal light guidance within the actuator volume. The light path is embedded within the actuator's thickness, moving the reflection function from an exposed surface to an internal volume, which is not accessible to contaminants.

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

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 reliable input detection with reduced dirt impact and haptic feedback, enhancing user experience and device cleanliness, while maintaining a sleek design.

Implementation Method 1

The base comprises at least one light source for generating a measurement beam and at least one sensor for detecting the reflected measurement beam, and the input actuator comprises a large number of reflection bodies for reflecting the measurement beam onto the sensor

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

the base has at least one magnet and the input actuator has a plurality of metal sections. In this case, for an input with the input device, a movement path of the metallic sections is defined relative to the magnet and a haptic feedback similar to latching is effected

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Data Source

PatentEP2901554B1Input device for an electrical device
Publication Date: 2020.11.11 BSH HAUSGERATE GMBH
  • EP2901554B1 patent drawingFigure 1~3
  • EP2901554B1 patent drawingFigure 4~5

AI summary

The invention relates to an input device (10) for an electrical device (1) having at least one light source (55) on a base for producing a measurement beam and at least one sensor (58) for detecting the reflected measurement beam. An input actuator (20) comprises a plurality of reflection bodies (42) each having at least one reflection surface (45, 45) for reflecting the measurement beam onto the sensor (58). The measurement beam is reflected within the reflection body.