Common Optical Axis Distance Measurement for Hemispherical Fields

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing distance measuring apparatuses take a considerable time to obtain distance information for a wide field of view due to the need to obtain information for each deflection angle of the optical scanning mechanism, making it inefficient for hemispherical areas.

Innovation Solution

The use of a phototransmitter optical system and a photoreceiver optical system with a common optical axis and shared components, including a wide-angle lens, allows for simultaneous measurement of distances across a hemisphere without a movable scanning mechanism, reducing system size and complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an optical scanning mechanism is used to obtain distance information for each deflection angle, then measurement precision is improved, but measurement time increases considerably

Engineering Contradiction:

Improvedistance information accuracyVSAvoidmeasurement time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical optical scanning mechanism with a stationary optical system that uses multiple light sources and a beam splitter to simultaneously illuminate and detect reflected light from multiple directions. This eliminates the need for mechanical rotation or scanning, achieving parallel measurement of distance information across the entire field of view without time sequential acquisition.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Area of stationary object

If a scanning mechanism is used to cover a wide field of view, then area coverage is improved, but device complexity increases

Engineering Contradiction:

Improvefield of view coverageVSAvoidsystem complexity

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent merges multiple optical paths into a single detection system using a beam splitter. Multiple light sources illuminate different angular regions, and their reflected lights are combined by the beam splitter to form images on a single image sensor. This integration eliminates the need for separate scanning mechanisms for each direction, reducing system complexity while maintaining wide field of view coverage.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If separate optical systems are used for light emission and reception, then functional independence is improved, but system size increases

Engineering Contradiction:

Improvefunctional independenceVSAvoidsystem size

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent implements a common optical system where the same optical path serves both as the illumination path and the detection path. The beam splitter enables the system to function as both a light emitter (through multiple light sources) and a light receiver (through the image sensor), allowing the optical system to perform multiple functions simultaneously without requiring separate independent systems, thereby reducing overall system size.

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

This approach enables rapid acquisition of distance information for all measurement targets within a hemispherical area, reducing system size, cost, and assembly complexity while ensuring high stability and accuracy without the need for a scanning mechanism.

Implementation Method 1

a light source to emit reference light

Methodology Applied

Scientific EffectLight emission: Light

Implementation Method 2

reflected light resulting from the reference light reflected at a measurement target

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 3

the distance measuring apparatus detects the distance to the measurement target on the basis of the time taken by the reference light to be reflected at the measurement target and received by the light receiving element

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Data Source

PatentUS11215445B2Optical apparatus and distance measuring system

Publication Date: 2022.01.04 RICOH CO LTD

AI summary

An optical apparatus includes: a light source to emit reference light; a phototransmitter optical system to project the reference light emitted from the light source onto a measurement area extending 90 degrees or more; an image sensor having an imaging surface on which an optical image is formed; and a photoreceiver optical system to form an image of reflected light on the imaging surface, the reflected light being resulting from the reference light reflected at a measurement target present in the measurement area extending 90 degrees or more. The phototransmitter optical system and the photoreceiver optical system are disposed such that at least an optical axis of the phototransmitter optical system and an optical axis of the photoreceiver optical system partially coincide with each other, and at least a portion of the phototransmitter optical system and a portion of the photoreceiver optical system constitute a common optical system unit.