Object Detector With Segmented Light Emission For Distance Measurement

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Solution Overview

Problem

Existing object detection systems face challenges in accurately determining the distance to objects due to limitations in light emission timing and scanning efficiency, leading to suboptimal detection performance and increased system size.

Innovation Solution

The implementation of a laser radar system with multiple light emitting areas arranged along the Z-axis, utilizing a light-source drive circuit to synchronize light emission and detection, allowing for precise distance calculation and improved scanning efficiency by dividing the scanning range into multiple fields and adjusting the timing of light emission across these fields.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple light emitting areas are used to improve detection accuracy, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedistance measurement accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The light source is divided into multiple light emitting areas (first, second, third light emitting areas) arranged along the Z-axis direction. Each area independently emits light toward different detection fields, enabling simultaneous multi-field detection and improving distance measurement accuracy without requiring a single complex emitting structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The light emitting areas are arranged in the Z-axis direction (depth dimension), creating a three-dimensional light emission configuration. This spatial arrangement allows light to be emitted toward multiple detection fields simultaneously, transforming a two-dimensional scanning problem into a three-dimensional solution that improves detection efficiency and accuracy.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If light emission timing is synchronized across multiple areas to improve detection accuracy, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidtiming control complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The light emitting areas emit light in a periodic sequence rather than simultaneously. The first light emitting area emits light during a first period, the second area emits during a second period, and the third area emits during a third period. This periodic emission pattern simplifies timing control while maintaining detection accuracy through sequential multi-field coverage.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The light emitting areas operate in continuous succession without idle gaps between emissions. Each area emits light during its designated period, ensuring that the detection process continues uninterrupted across all fields. This continuous action maintains high detection efficiency while simplifying control logic compared to complex simultaneous coordination.

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If scanning range is divided into multiple fields with sequential light emission, then productivity is improved, but loss of time increases

Engineering Contradiction:
Improvescanning efficiencyVSAvoiddetection time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The scanning range is segmented into multiple detection fields (first, second, third detection fields), each associated with a dedicated light emitting area. This segmentation allows parallel processing of different spatial regions, improving overall scanning efficiency by eliminating the need for sequential scanning of entire fields with a single emitter.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The light emitting areas operate in periodic cycles, with each area emitting light during its designated time period. This periodic operation ensures systematic coverage of all detection fields while maintaining efficient time utilization, as each field receives dedicated illumination without waiting for other fields to be scanned.

Inventive Principle:
Principle #19Periodic 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 approach enhances the accuracy of object detection by allowing for more precise distance measurement and reduces system size through optimized light emission and detection timing, improving overall detection performance.

Implementation Method 1

a first light emitting area A1, a second light emitting area A2, and a third light emitting area A3 sequentially emit lights

Methodology Applied
Scientific EffectLight emission and reflection: Reflection

Implementation Method 2

calculate a first distance to the object in the first detection field G1, based on a time of flight of the light emitted from the first light emitting area A1

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP3165946B1Object detector, sensor, and movable device
Publication Date: 2023.03.08 RICOH CO LTD
  • EP3165946B1 patent drawingFigure 1~2
  • EP3165946B1 patent drawingFigure 3~4
  • EP3165946B1 patent drawingFigure 5~6

AI summary

An object detector (20) includes an optical scanning system (201) and a light-receiving system (202). When the scanning range to be scanned by the optical scanning system (201) is divided into M (M ≥ 2) fields, the optical scanning system (201) scans m (m ≥ 1) fields out of the M fields in T that is a time period for scanning the scanning range in one scan. The n (n ≥ 1) light emitting areas (A) out of the N light emitting areas (A) sequentially emit light to each of the m fields at an interval of T / (m × n) in a time period of T / m.