Optical Pushbutton Control Through Opaque Appliance Cover Plates
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Solution Overview
Problem
Existing force-actuated pushbuttons require high manufacturing and assembly accuracy and struggle to provide differentiated functionality, especially when used with optically impermeable cover plates.
Innovation Solution
An operating device with a partially elastically deformable or movable cover plate and an optical sensor system that emits and detects electromagnetic radiation, allowing for qualitative and quantitative detection of actuation forces, enabling multiple operating functions regardless of cover plate transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical sensors are used to detect pushbutton actuation, then detection sensitivity is improved, but the cover plate material is restricted to optically transparent materials
Solution Approach 1:
A reflective layer is introduced as an intermediary between the optical sensor and the cover plate. This reflective layer enables the optical sensor to detect actuation forces by reflecting light back to the sensor, even when the cover plate is made of optically impermeable materials like metal. The reflective layer acts as a mediator that makes the actuation detectable without requiring the cover plate itself to be transparent.
2Reliability
If high manufacturing accuracy is required for force-actuated pushbuttons, then detection reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The system uses the dynamic response of the reflective layer to actuation forces. When the control panel is pressed, the reflective layer moves dynamically, changing the position and intensity of reflected light. This dynamic optical response provides reliable detection of actuation forces without requiring extremely tight manufacturing tolerances, as the system detects changes in light reflection rather than relying on precise mechanical positioning.
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 reliable and sensitive detection of pushbutton actuation, allowing for convenient operation of electronic household appliances with multiple functions, even with metal cover plates, and provides user feedback.
Implementation Method 1
an optical sensor with a transmitter for emitting electromagnetic radiation and a receiver for spatially resolved detection of reflected electromagnetic radiation
Implementation Method 2
the cover plate defining a control panel and being at least partially elastically deformable and/or movable in this control panel by the action of a force from the user side
Data Source
Figure 1A~1C
AI summary
An operator control apparatus for an electronic domestic appliance has a covering plate (10) with a user side which faces a user and a rear side which is averted from the user, wherein the covering plate (10) defines an operator control area (12) and, in this operator control area (12), can be at least partially elastically deformed and/or moved by an action of force (F1, F2) from the user side, and an optical sensor with a transmitter (16) for emitting electromagnetic radiation (E) and with a receiver (18) for spatially resolved detection of reflected electromagnetic radiation (R0, R1, R2). The operator control apparatus further has a control electronics system (22) for evaluating measurement signals which are generated by the receiver (18) and which are designed in such a way that they can differentiate between non-operation of the operator control area (12), operation of the operator control area (12) with a first action of force (F1) and operation of the operator control area (12) with a second action of force (F2), which is different from the first action of force, depending on a detection location (x0, x1, x2) of the reflected electromagnetic radiation (R0, R1, R2).