Optical Image Measurement Device Feedback Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Optical coherence tomography (OCT) devices face challenges in maintaining optimal received-light amounts for interference light, leading to saturation or inadequate detection of information due to variations in light amounts, particularly affected by environmental changes and displacement of optical components.

Innovation Solution

An optical image measurement apparatus that automatically adjusts the relative position between the emission end and the light-receiving surface, and the light amount of signal or reference light, to maintain a target received-light amount, facilitating easy and quick adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the light amount of reference light is increased to improve signal strength, then the interference light intensity increases, but the received-light amount may become too great causing saturation of the light-receiving part

Engineering Contradiction:
Improveinterference light intensityVSAvoidsaturation of light-receiving part
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The control unit continuously monitors the received-light amount from the light-receiving part and automatically adjusts the light amount of reference light through the reference light control unit. This closed-loop feedback system ensures the received-light amount remains within the optimal range, preventing saturation while maximizing signal strength.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the light amount parameter of reference light based on real-time detection of received-light amount. By adjusting this parameter within a predetermined range, the system optimizes interference light intensity without causing saturation of the light-receiving part.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If manual adjustment of relative position between emission end and light-receiving surface is performed to optimize received-light amount, then detection accuracy improves, but the operation becomes cumbersome and time-consuming

Engineering Contradiction:
Improvereceived-light amount detection accuracyVSAvoidadjustment operation complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The control unit automatically adjusts the relative position between the emission end of the light guiding part and the light-receiving surface based on detection of received-light amount. This self-adjusting mechanism eliminates the need for cumbersome manual operations while maintaining optimal detection accuracy.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses feedback from the light-receiving part to automatically control the relative position adjustment. This automated feedback loop replaces manual adjustment operations, making the system easier to operate while maintaining precise received-light amount detection.

Inventive Principle:
Principle #23Feedback

3Loss of information

If the received-light amount is increased to improve signal detection, then the interference light intensity increases, but information may be lost due to saturation or inadequate detection

Engineering Contradiction:
Improveinformation detection completenessVSAvoidsaturation or inadequate detection
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The control unit continuously monitors the received-light amount and automatically adjusts reference light amount to keep it within the optimal range. This feedback control prevents both saturation and inadequate detection, ensuring complete and reliable information detection without loss.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the light amount parameter of reference light based on real-time conditions to optimize the received-light amount. This parameter adjustment ensures the system operates within the optimal range, preventing information loss from saturation or inadequate detection.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If automatic control of reference light amount is implemented to maintain optimal received-light amount, then adjustment speed improves, but the device complexity increases

Engineering Contradiction:
Improveadjustment speedVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The control unit implements automatic feedback control by monitoring received-light amount and adjusting reference light amount accordingly. This automated feedback mechanism speeds up adjustments significantly compared to manual methods, despite adding control system components.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control unit performs multiple functions including detecting received-light amount, determining optimal reference light amount, and controlling the reference light. This multi-functionality consolidates control operations into a single unit, reducing overall system complexity while maintaining fast adjustment capability.

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

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 precise and efficient adjustment of received-light amounts, improving the detection of interference light and maintaining optimal imaging conditions, reducing the need for cumbersome adjustments.

Implementation Method 1

superposes the reflected light and the reference light to generate an interference light

Methodology Applied
Scientific EffectInterference: Interference

Implementation Method 2

an interferometer is mounted at the outlet to analyze, by a spectrometer, the intensity of an interference light

Methodology Applied
Scientific EffectSpectral detection:

Data Source

PatentEP2518472B1Optical image measurement device
Publication Date: 2021.10.20 TOPCON CORPORATION
  • EP2518472B1 patent drawingFigure 1
  • EP2518472B1 patent drawingFigure 2
  • EP2518472B1 patent drawingFigure 3

AI summary

A main controller 211 controls a fiber-end drive mechanism 140 and an attenuator 121 with reference to the received-light amount of interference light LC to cause the following operations (1) and (2) to be executed alternately: (1) moving an emission end 116 to increase the received-light amount to at least an upper limit; and (2) changing the light amount of reference light LR to decrease the received-light amount to at least a lower limit. When the received-light amount specified by an received-light-amount specifying part 212 decreases in response to the movement of the emission end 116 in (1), the main controller 211 controls the fiber-end drive mechanism 140 to return the relative position to the immediately preceding status of this change. The main controller 211 leads the received-light amount of interference light LC by a CCD image sensor 120 to a target value by controlling the attenuator 121 to change the light amount of interference light LC.