Light Source Device for Electronic Blackboard Position Recognition

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Solution Overview

Problem

Infrared laser light emitted non-parallel to the screen surface in electronic blackboard systems can lead to incorrect recognition of indicated positions due to varying offset distances, and adjusting the recognizable region is challenging due to the invisibility of infrared light, which may result in direct application onto the screen or mistaken detection of projection light.

Innovation Solution

A light source device with both invisible and visible light emitters, controlled by a light source controller and propagation controller, allows for adjusting the propagation region of the light beam to be parallel to the screen, enabling accurate recognition of indicated positions by emitting either or both light beams based on operation modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If infrared laser light is emitted non-parallel to the screen surface, then the light can be emitted from the device, but the indicated position is incorrectly recognized due to varying offset distances

Engineering Contradiction:

Improvelight emissionVSAvoidindicated position recognition

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent adjusts the emission angle parameter of the infrared laser light to be parallel to the screen surface, eliminating the varying offset distance problem and enabling accurate position recognition

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If infrared laser light is emitted parallel to the screen surface, then accurate position recognition is achieved, but the recognizable region cannot be visually checked due to invisibility of infrared light

Engineering Contradiction:

Improveindicated position recognitionVSAvoidrecognizable region adjustment

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces a visible light source as an intermediary to mark the recognizable region, allowing visual adjustment while maintaining infrared light parallel emission for accurate detection

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses visible light to indicate the recognizable region boundaries, enabling visual feedback for adjustment while the infrared light remains invisible for accurate position recognition

Inventive Principle:

Principle #32Color changes

3Difficulty of detecting and measuring

If visible light is used instead of infrared laser light, then the recognizable region can be viewed, but the image sensor may mistakenly detect the projection light due to wavelength overlap

Engineering Contradiction:

Improverecognizable region visibilityVSAvoidindicated position recognition

Core Design Contradiction:

Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent segments the light sources into two distinct types: infrared light for detection and visible light for marking, allowing each to perform its specific function without interference

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The visible light acts as an intermediary marker that does not interfere with the infrared detection process, providing visual feedback without causing false detections

Inventive Principle:

Principle #24Intermediary (Mediator)

4Ease of operation

If infrared laser light is emitted in a direction approaching the screen surface, then light emission occurs, but the light is applied directly onto the screen making appropriate detection impossible

Engineering Contradiction:

Improvelight emissionVSAvoiddetection accuracy

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent changes the emission angle parameter to be parallel to the screen surface, preventing direct application of light onto the screen and ensuring reliable detection

Inventive Principle:

Principle #35Parameter changes

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 solution allows for precise adjustment of the recognizable region, preventing incorrect recognition of indicated positions and ensuring accurate detection by projecting an image based on the detection result.

Implementation Method 1

infrared laser light emitted from the device is propagated along a plane parallel to the screen

Methodology Applied

Scientific EffectLight propagation: Light

Implementation Method 2

a visible light emitter that emits a visible light beam

Methodology Applied

Scientific EffectLight propagation: Light

Implementation Method 3

the infrared laser light reflected by the shielding object is detected by an image sensor

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS10331274B2Light source device, electronic blackboard system, and method of controlling light source device

Publication Date: 2019.06.25 SHARP KK

AI summary

A light source includes an invisible light emitter that emits an invisible light beam and a visible light emitter that emits a visible light beam. A light source controller causes the light source to emit at least one light beam from among the invisible light beam and the visible light beam. A propagation controller causes an emission light beam emitted from the light source to propagate along a predetermined plane.