Optoelectronic Sensor Hand Detection via Protective Pane Contamination
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Solution Overview
Problem
Conventional optoelectronic sensors require space-consuming switches or keyboards for operation, increasing size, manufacturing, and maintenance costs, while also being less compact and more expensive.
Innovation Solution
The optoelectronic sensor uses contamination detection to recognize a hand or finger approaching the protective pane, allowing for manual operation without physical switches or keyboards, by emitting a monitoring light signal and detecting changes in transmission or reflection to generate action signals, enabling control unit actions such as changing sampling rate or range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If switches or keyboards are added for manual operation, then ease of operation is improved, but device complexity and size increase
Solution Approach 1:
The contamination detection function is made multi-functional by enabling it to serve both its original purpose (detecting screen contamination) and a new function (detecting hand approach for manual operation). The control unit responds to hand detection by triggering manual operation modes, eliminating the need for separate switches or keyboards while maintaining ease of operation.
2Ease of operation
If switches or keyboards are added for manual operation, then ease of operation is improved, but manufacturing cost increases
Solution Approach 1:
The existing contamination detection hardware is made to serve dual purposes: detecting both screen contamination and hand approach. This eliminates the need for additional switches or keyboards, thereby reducing manufacturing costs while still providing manual operation capability.
3Ease of operation
If switches or keyboards are added for manual operation, then ease of operation is improved, but device size increases
Solution Approach 1:
The contamination detection system is repurposed to also detect hand approach, allowing manual operation without adding physical switches or keyboards. This maintains the compact sensor design while enabling ease of operation through the existing optical detection pathway.
4Device complexity
If contamination detection is used to detect hand approach, then device complexity is reduced, but measurement precision may be affected
Solution Approach 1:
The system applies different evaluation criteria to different detection scenarios: contamination detection uses one set of thresholds while hand approach detection uses another. The control unit is configured to distinguish between the two by analyzing the pattern and magnitude of light blockage, ensuring precise detection despite using a shared sensor.
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 approach allows for a compact, cost-effective design by eliminating the need for physical input devices, enabling reliable detection of hands or fingers to trigger actions, and providing a compact and affordable optoelectronic sensor with enhanced operational simplicity.
Implementation Method 1
a main light transmitter for emitting scanning light signals which pass through a protective screen into the monitoring area, a main light receiver for receiving light emanating from the monitoring area
Implementation Method 2
the sensor is configured to measure transmission through the protective screen and/or reflection from the protective screen
Implementation Method 3
the sensor is configured to measure transmission through the protective screen and/or reflection from the protective screen
Implementation Method 4
When a hand or finger is placed on or near the protective screen, the transmission can decrease significantly and, in particular, be completely blocked
Data Source
Figure 1
AI summary
The invention relates to an optoelectronic sensor for monitoring a monitoring area. The sensor comprises a main light emitter for emitting scanning light signals which reach the surveillance area through a protective pane, a main light receiver for receiving light coming from the surveillance area, and a control unit for controlling the sensor. In this case, the sensor is designed to carry out a contamination detection, in which the degree of contamination of the protective pane is determined by means of a contamination measured value. The sensor according to the invention is characterized in that the control unit is set up to recognize the approach of a hand and/or a finger to the protective pane based on the contamination detection and to output an action signal when the hand and/or finger is recognized.