Optical Touch Detection Using Invisible Light Reflection

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Solution Overview

Problem

Conventional large-size touch displays are expensive and fragile, and existing touch systems can adversely affect user experience and are costly.

Innovation Solution

A touch system comprising a window glass with a touch area and a display apparatus spaced apart, using a planar invisible light source and a camera device to detect invisible light reflected from subareas, with a processor determining touch positions based on optical information, allowing for low-cost and user-friendly touch input detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a touch film is provided on the front side of the computer terminal for implementing touch detection ability, then touch detection function is achieved, but the system becomes expensive and fragile

Engineering Contradiction:

Improvetouch detection reliabilityVSAvoidstructural strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent extracts the touch detection function from the traditional touch film structure and relocates it to a separate camera-based detection system. The touch detection is achieved by detecting reflected invisible light from the display surface, eliminating the need for a physical touch film layer that causes fragility and cost issues.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical touch film structure with an optical detection system using invisible light emission and reflection detection. Instead of relying on physical contact through a film layer, the system uses optical principles to detect touch positions, thereby eliminating the mechanical fragility associated with touch films.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If conventional touch display structures are used for large size displays, then touch functionality is achieved, but the cost increases and fragility occurs

Engineering Contradiction:

Improvetouch display adaptabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent makes the display system multi-functional by integrating both display and touch detection capabilities into a unified structure. The display apparatus serves dual purposes: visual output and touch input detection, eliminating the need for separate touch film components and reducing overall system cost while maintaining adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent replaces expensive, fragile touch films with a more cost-effective optical detection system using invisible light sources and camera sensors. This substitution significantly reduces manufacturing costs while maintaining touch detection functionality across large display areas.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If the touch area is spaced apart from the display apparatus, then installation is simplified and cost is reduced, but the structural integration is decreased

Engineering Contradiction:

Improveinstallation easeVSAvoidsystem integration

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent segments the touch detection system into separate functional modules: the display apparatus, the invisible light source, and the camera-based detection system. This segmentation allows for simplified installation and maintenance while maintaining effective touch detection functionality through optical coupling between the spaced components.

Inventive Principle:

Principle #1Segmentation

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 system provides a cost-effective and robust touch input detection method that does not compromise user interface quality, as the touch area is spaced apart from the display, simplifying installation and reducing costs compared to traditional touch films or proximity sensors.

Implementation Method 1

A plurality of subareas are defined on the touch area. The display apparatus includes a planar invisible light source configured to emit a first invisible light toward the touch area of the window glass. The touch system further includes a camera device configured to detect a second invisible light reflected from a subarea of the plurality of subareas.

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS11379081B2Touch system and method of operating the same

Publication Date: 2022.07.05 DYNASCAN TECH

AI summary

The present disclosure provides a touch system. The touch system includes a window glass having a touch area and a display apparatus spaced apart from the window glass and having a display area corresponding to the touch area of the window glass. A plurality of subareas are defined on the touch area. The display apparatus includes a planar invisible light source configured to emit a first invisible light toward the touch area of the window glass. The touch system further includes a camera device configured to detect a second invisible light reflected from a subarea of the plurality of subareas. The touch system further includes a processor electrically connected to the camera device and configured to retrieve an electrical information of the detected second invisible light. If the electrical information of the detected second invisible light exceeds a threshold, the processor determines that a position on the display area corresponding to the subarea of the plurality of subareas is touched. A method of operating a touch system is also provided.