Retroreflective Indication Member for Optical Position Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing optical position detection devices face low detection accuracy due to low received light intensity caused by scattered or diffusely reflected detection light, and existing solutions with retroreflective members are limited in improving accuracy as they are prone to errors when inclined.

Innovation Solution

An indication member with a round bar shaft and a spherical body at its end, featuring a retroreflective surface on both the spherical body and shaft end, which ensures high light intensity detection regardless of posture or position, and a light source configuration that adjusts emission intensity to maintain accuracy at varying distances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a round bar portion serves as a retroreflective portion, then the received light intensity is high, but position detection accuracy deteriorates when the indication member is inclined

Engineering Contradiction:

Improvereceived light intensityVSAvoidposition detection accuracy

Core Design Contradiction:

Illumination intensityVSMeasurement precision

Solution Approach 1:

The invention replaces the round bar retroreflective portion with a spherical body portion. The spherical shape maintains high received light intensity through retroreflection while eliminating the inclination detection error problem. The sphere's geometry ensures that the distal end position can be accurately detected regardless of the indication member's orientation, as the sphere presents a consistent reflective surface from all angles.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention creates a composite structure with different functional portions: a spherical body portion for accurate position detection and a shaft portion for structural support. The spherical body's outer peripheral surface serves as the retroreflective portion, concentrating the detection function in a specific geometric form that optimizes both light reception and positional accuracy.

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If the spherical body portion is enlarged to increase light incident amount, then the received light intensity is high, but the indication position becomes unclear

Engineering Contradiction:

Improvelight incident amountVSAvoidindication position clarity

Core Design Contradiction:

Illumination intensityVSMeasurement precision

Solution Approach 1:

The invention applies retroreflective properties specifically to the outer peripheral surface of the spherical body portion and shaft end portion, rather than enlarging the entire spherical body. This localized application of retroreflection maintains a compact overall size while ensuring sufficient light incident amount on the light receiving section, thereby preserving indication position clarity.

Inventive Principle:

Principle #3Local quality

3Measurement precision

If detection light is emitted only to the spherical body portion, then the indication position is clear, but the received light intensity is insufficient when the indication member is far from the light source

Engineering Contradiction:

Improveindication position clarityVSAvoidreceived light intensity

Core Design Contradiction:

Measurement precisionVSIllumination intensity

Solution Approach 1:

The invention makes both the spherical body portion and shaft end portion serve as retroreflective portions. This multi-functional design ensures that detection light can be effectively reflected to the light receiving section whether the indication member is close to or far from the light source, maintaining both position clarity and sufficient light intensity across varying distances.

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

The solution provides high detection accuracy by increasing light intensity and reducing errors even when the indication member is inclined, maintaining consistent detection precision near or far from the light source.

Implementation Method 1

an outer peripheral surface of the spherical body portion and an outer peripheral surface of a shaft end portion of the shaft portion connected to the spherical body portion are a retroreflective portion

Methodology Applied

Scientific EffectRetroreflection: Retroreflector

Data Source

PatentUS9122355B2Indication member, optical position detection device, and display system with input function

Publication Date: 2015.09.01 COLUMBIA PEAK VENTURES LLC

AI summary

A detectable indication member for an optical position detection device includes a round bar shaped shaft and a spherical body provided at the distal end of the shaft. The outer peripheral surface of the spherical body and the outer peripheral surface of an end portion of the shaft portion connected to the spherical body form a retroreflective portion. A portion of the shaft adjacent the base end of the end portion absorbs infrared light.