Optical Receiving Unit with Dual Sensors for Overload Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional optical receiver units have a limited operating range for radiant power evaluation, which can lead to overloading or damage, especially in applications where the transmitter and receiver are close or far apart, and require expensive and error-prone mechanical actuators to expand this range.

Innovation Solution

The optical receiving unit employs at least two separate radiation sensors with distinct zones in the collecting optics, each focusing optical radiation to a specific sensor, allowing adaptation to different power ranges without mechanical actuators, and an electronic control unit to manage sensor activation based on radiation intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a highly sensitive detector unit is used to detect weak optical radiation, then the sensitivity is improved, but the detector unit is overdriven or destroyed when exposed to strong optical radiation

Engineering Contradiction:
ImprovesensitivityVSAvoidoverloading
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The detector unit is divided into multiple radiation sensors with different sensitivities (e.g., first radiation sensor with higher sensitivity, second radiation sensor with lower sensitivity). Each sensor is assigned to handle specific radiation intensity ranges, allowing the system to detect both weak and strong optical radiation without overloading any single sensor.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different zones of the entrance surface are assigned to different radiation sensors based on their sensitivity characteristics. The first zone is assigned to the first radiation sensor for weak radiation detection, while the second zone is assigned to the second radiation sensor for strong radiation detection, optimizing the local quality of each detection region.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If attenuating elements are moved into the beam path to prevent overloading, then the protection is improved, but the device complexity and cost increase due to required actuators

Engineering Contradiction:
ImproveprotectionVSAvoidactuator system
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical actuator system with an electronic control system. The control and evaluation unit electronically selects and activates the appropriate radiation sensor based on the detected radiation intensity, eliminating the need for mechanical movement of attenuating elements and their associated actuators.

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

Solution Approach 2:

The system dynamically adapts to varying radiation intensities by electronically switching between different radiation sensors. The control unit monitors the radiation intensity and activates the appropriate sensor (first or second) in real-time, providing dynamic protection without mechanical components.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If multiple radiation sensors with different sensitivities are used, then the operating range is expanded, but the device complexity increases

Engineering Contradiction:
Improveoperating rangeVSAvoidsensor array
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The collecting optics with its divided entrance surface serves multiple functions: it simultaneously directs weak radiation to the first radiation sensor and strong radiation to the second radiation sensor. The single optical component handles multiple detection scenarios, reducing the need for separate optical paths and reducing overall system complexity despite having multiple sensors.

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

Solution Approach 2:

The system uses the inherent properties of the different radiation sensors (their different sensitivities) to automatically determine which sensor should be activated. The control unit simply monitors the radiation intensity and selects the appropriate sensor based on the sensors' own characteristics, without requiring complex external control mechanisms.

Inventive Principle:
Principle #25Self-service

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 expands the operating range of the optical receiving unit virtually indefinitely, protects sensors from overload, and prevents damage by selectively activating or deactivating sensors based on radiation intensity, using avalanche and PIN photodiodes for high and low light sensitivity.

Implementation Method 1

a collecting optic which defines an entry surface and is designed and arranged to focus optical radiation incident on the entry surface in the direction of the detector unit

Methodology Applied
Scientific EffectOptical focusing: Lens

Implementation Method 2

The detector unit comprises at least two separate radiation sensors (33, 34)... generate at least one received signal based on the radiation detected by the detector unit

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4432582B1Optical receiving unit
Publication Date: 2025.08.27 SICK AG
  • EP4432582B1 patent drawingFigure 1
  • EP4432582B1 patent drawingFigure 2

AI summary

An optical receiving unit comprises a detector unit for detecting optical radiation, an electronic control and evaluation unit connected to the detector unit and configured to generate a received signal based on the radiation detected by the detector unit, and a focusing optic that defines an entrance area and is configured to focus optical radiation incident on the entrance area towards the detector unit. The detector unit includes two separate radiation sensors. The entrance area of ​​the focusing optic has two separate zones, each zone configured to focus the incident optical radiation only towards one of the separate radiation sensors.