Photoelectric Sensor Sensitivity Control Using LED Feedback

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Solution Overview

Problem

Existing non-contact optical-sensing switching devices for field devices face challenges in automatically adjusting sensitivity without exposing the internal components to external air and relying on operator intervention, which complicates sensitivity adjustments and can lead to malfunctions.

Innovation Solution

A photoelectric sensing sensitivity adjusting device that uses a CPU-controlled digital potentiometer to adjust the energy supplied to an LED light emitter, allowing for automatic sensitivity adjustment without exposing the internal components, ensuring stable and precise sensitivity settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual sensitivity adjustment is performed by exposing internal components to external air, then sensitivity can be adjusted, but the device complexity increases and reliability decreases

Engineering Contradiction:
Improvesensitivity adjustment precisionVSAvoiddevice reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the manual mechanical adjustment method with an automatic electronic control system. A CPU-controlled variable resistor automatically adjusts the light emitter's output based on detected light intensity, eliminating the need for manual exposure of internal components and achieving both precision and reliability.

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

Solution Approach 2:

The system performs self-adjustment through automatic sensitivity calibration. The light receiver detects the light intensity from the light emitter, and the CPU automatically adjusts the variable resistor to achieve the desired sensitivity level without requiring external manual intervention or exposure of internal components.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If operator intervention is required for sensitivity adjustment, then sensitivity can be tuned, but ease of operation decreases and productivity reduces

Engineering Contradiction:
Improvesensitivity tuning capabilityVSAvoidoperation simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system automatically performs sensitivity adjustment without requiring operator intervention. The CPU controls the variable resistor based on feedback from the light receiver, enabling the device to self-tune its sensitivity and eliminating manual adjustment steps for users.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements a feedback mechanism where the light receiver continuously monitors the light intensity from the light emitter, and this information is fed back to the CPU. The CPU then adjusts the variable resistor accordingly to maintain optimal sensitivity, creating a closed-loop automatic adjustment system.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If internal components are exposed to external air for adjustment, then sensitivity adjustment is possible, but manufacturing precision requirements increase

Engineering Contradiction:
Improvesensitivity adjustabilityVSAvoidcomponent positioning precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent replaces mechanical exposure and manual adjustment with an electronic control system. The CPU-controlled variable resistor adjusts sensitivity electronically without requiring physical exposure of internal components, thereby reducing manufacturing precision requirements for component positioning and assembly.

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

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 stable and automatic sensitivity adjustment of the optical switch, preventing malfunctions and allowing for precise control of the light emission, thereby improving the reliability and ease of operation of field devices.

Implementation Method 1

a light emitter (31) configured by an LED, for emitting light by being supplied with energy

Methodology Applied
Scientific EffectLight emission from LED: Light Emitting Diode

Implementation Method 2

a photodetection portion for detecting an optical signal emitted from the LED, converting the optical signal to an electrical signal

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Implementation Method 3

a light receiving device for receiving the light which is emitted from the light emitter and reflected by bringing the light reflector closer to the front surface

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2424113B1Field equipment photoelectric sensing sensitivity adjustment
Publication Date: 2014.06.18 OVAL CORP
  • EP2424113B1 patent drawingFigure 1
  • EP2424113B1 patent drawingFigure 2
  • EP2424113B1 patent drawingFigure 3

AI summary

Provided is a photoelectric sensing sensitivity adjusting device including: an LED for emitting light by being supplied with energy (current or voltage); a regulator for LED driving for supplying the energy to the LED; a light receiving device for receiving the light emitted from the LED; a digital potentiometer for controlling increase or decrease of the energy to be supplied to the LED; a CPU for digitally controlling, according to a control program, the increase or decrease of the energy to be supplied to the LED; and a photodetection portion for detecting an optical signal, converting the optical signal to an electrical signal, and outputting the electrical signal.