Light Scanning Device Charge Reduction Control

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Solution Overview

Problem

In light scanning devices where emission light and external reflection light share the same optical system, internal reflection light can saturate the light receiving element at unintended times, making it difficult to accurately measure the light reception timing of external reflection light.

Innovation Solution

The control unit executes a process to reduce the electric charges accumulated in the light receiving element during specific periods determined based on the emission timing of the light source, preventing saturation by internal reflection light and allowing accurate measurement of external reflection light timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If light emitted from the light source and light reflected by external objects pass through the same optical system, then device complexity is reduced, but the light receiving element may be saturated by internal reflection light at unintended timing

Engineering Contradiction:
Improveoptical system structureVSAvoidlight reception timing accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The control unit executes a charge reduction process in advance during a first period determined based on light emission timing, before the light receiving element would be saturated by internal reflection light. This preliminary action clears accumulated electric charges that would otherwise cause saturation, ensuring the element is ready to accurately detect external reflection light when it arrives.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the operational state of the light receiving element by controlling the accumulation and reduction of electric charges. By dynamically adjusting the charge level through timed reduction processes, the system adapts the element's sensitivity to prevent saturation while maintaining detection capability for external reflection light.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the light receiving element continuously accumulates electric charges for high sensitivity detection, then detection sensitivity is improved, but the element becomes saturated by internal reflection light

Engineering Contradiction:
Improvelight detection sensitivityVSAvoidinternal reflection light saturation
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The control unit periodically executes charge reduction processes at specific timings determined by the light emission schedule. This periodic maintenance of charge levels allows the light receiving element to maintain high sensitivity between reduction cycles while preventing saturation from internal reflection light, creating a rhythm of accumulation and reduction that balances both requirements.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The charge reduction process is executed in advance during a first period determined based on light emission timing, before internal reflection light causes saturation. This preliminary clearing of charges ensures the element can subsequently accumulate charges for high-sensitivity detection of external reflection light without being compromised by earlier saturation.

Inventive Principle:
Principle #10Preliminary action

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 configuration prevents the light receiving element from being saturated by internal reflection light, enabling accurate detection of external reflection light and enhancing the measurement accuracy of distances to external objects.

Implementation Method 1

light emitted from a light source 110 and light reflected by an external object pass through different optical systems

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3584602B1Light scanning device and control method
Publication Date: 2025.04.02 PIONEER IP
  • EP3584602B1 patent drawingFigure 1
  • EP3584602B1 patent drawingFigure 2
  • EP3584602B1 patent drawingFigure 3

AI summary

A light scanning device (10) includes a light source (110), a light receiving circuit (120), an optical system (130), and a control unit (140). The optical system (130) directs emission light emitted from the light source (110) to the outside. The optical system (130) directs reflection light of an emission light from an object positioned outside the light scanning device (10) to a light receiving element provided in the light receiving circuit (120). The control unit (140) executes a process of reducing electric charges accumulated in the light receiving element provided in the light receiving circuit (120) in a period determined based on an emission timing of the emission light of the light scanning device (10).