Multimode Light Guide Touch Scanner
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Solution Overview
Problem
There is a need for a multimode apparatus that can function both as a touch input device and a scanning device, capable of detecting touch locations and scanning content, with existing technologies lacking a unified solution for these dual functionalities.
Innovation Solution
The apparatus employs a light guide with a slanted facet and a diffractive element on its surface, using a camera or optical sensing module to detect the intensity and angle of a light beam, allowing it to determine touch locations in touch-input mode and scan content in scanning mode, by diffracting light and guiding it through the slanted facet for angular and intensity-based detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single apparatus is designed to perform both touch input and scanning functions, then device versatility is improved, but device complexity increases
Solution Approach 1:
The patent implements a single apparatus that performs both touch input and scanning functions using shared components. The light guide, light source, and camera module serve dual purposes: detecting touch locations through light interruption and capturing scanned images of documents. This multi-functional design eliminates the need for separate touch pad and scanner devices, directly resolving the technical contradiction by improving versatility while managing complexity through component sharing.
Solution Approach 2:
The patent merges the touch detection mechanism and document scanning mechanism into a single integrated system. The light guide structure combines light sources for illumination with light paths for both touch sensing and image capture. The camera module simultaneously serves as both the detection sensor for touch inputs and the imaging device for scanning, effectively combining multiple functions into unified hardware components.
2Measurement precision
If a light guide with diffractive element is used to enable angular-sensitive detection for touch location, then measurement precision is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs a diffractive element with concentric fringes that creates angular-sensitive light diffraction patterns. By changing the angular parameter of light detection, the system can precisely determine touch locations based on the angle at which light exits the light guide. The diffractive structure transforms spatial information into angular information, enabling precise touch location measurement while using relatively simple manufacturing techniques for creating the fringe patterns.
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
Enables effective detection of touch inputs and scanning of content, allowing for both precise location tracking and image acquisition, with the ability to differentiate between touch objects and document content based on intensity and angle variations, facilitating efficient operation in both modes.
Implementation Method 1
The light guide has a diffractive element located on the second surface. The diffractive element has one or more diffractive structures with a plurality of concentric fringes centered at that corner. The concentric fringes form an angular sensitive grating, such that when a light beam is directed from a location P on the first surface toward the second surface along a pre-defined direction or angle, the light beam is diffracted toward the first surface and guided in the light guide unit it exits through slanted facet at an exiting angle into the camera.
Implementation Method 2
The apparatus uses a light guide having a first surface and a second surface, and a camera or optical sensing module to look into the light guide for providing signals indicative of what the camera sees on the first surface on the light guide.
Data Source
AI summary
An apparatus operable in touch-input mode and scanning mode uses a light guide and a camera to look through a slanted facet at one corner of the light guide. The light guide has an upper surface for placing a touch object or an item for scanning. An angular sensitive grating is located on lower surface having fringes such that when a light beam directed from a location P on upper surface toward lower surface at a predefined direction, it is diffracted by the grating and guided toward the slanted facet. The diffracted beam exits the slanted facet at an exiting angle indicative of the location P. When an object or item is placed on upper surface, it causes changes in exit beam intensity. From exiting angles and intensity changes, a camera is able to locate touch objects or to acquire an image of the scanned item.