Optical Touch Panel Retroreflective Plate Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical touch panels in automatic vending machines are prone to detection accuracy deterioration due to dust or snow accumulation on the retroreflective plates, leading to reduced reflection and impaired touch detection performance.
Innovation Solution
The optical touch panel design includes a pair of retroreflective plates inside a rectangular frame with detectors at four corners that irradiate infrared rays and generate detection images, allowing for touch position detection even when the reflection amount from the retroreflective plates decreases, by using additional detectors to cover the entire detection area and employing triangulation for accurate position identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single retroreflective plate is used in the optical touch panel, then the device structure is simple, but detection accuracy deteriorates when dust or snow accumulates on the plate
Solution Approach 1:
The single retroreflective plate is divided into multiple segments (first retroreflective plate and second retroreflective plate) arranged at different positions. This segmentation allows the system to maintain detection capability even when one segment is obscured by dust or snow, as other segments remain functional for touch detection.
Solution Approach 2:
Different retroreflective plates are positioned at specific locations (e.g., upper and lower portions) with detectors arranged correspondingly. Each local region has specialized detection capability, and the system can selectively use detectors associated with cleaner regions when dust or snow accumulates on specific plates, maintaining overall detection accuracy through local quality differentiation.
2Area of stationary object
If detectors are arranged only at two corners of the frame, then the device complexity is reduced, but the detection area coverage is insufficient
Solution Approach 1:
The detection area is segmented into multiple zones corresponding to different retroreflective plates and detector positions. By placing detectors at all four corners rather than just two, each corner detector is responsible for a specific zone, ensuring complete coverage of the entire touch panel area without gaps in detection capability.
Solution Approach 2:
The detector arrangement extends from a minimal two-corner configuration to a comprehensive four-corner configuration, utilizing the full dimensional space of the rectangular frame. This dimensional expansion ensures that detection rays can cover the entire area including edge regions, preventing blind spots while maintaining geometric symmetry.
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 configuration ensures highly accurate touch position detection across the entire area, even when the retroreflective plates are affected by dust or snow, maintaining detection accuracy and preventing deterioration.
Implementation Method 1
a pair of retroreflective plates that are arranged inside at least a left and right pair of frame portions facing each other in a rectangular frame; a plurality of detectors that are arranged at four corners of the rectangular frame, the detectors being configured to irradiate infrared rays to, at least, the retroreflective plates, and to generate detection images based on reflection light from the retroreflective plates
Data Source
AI summary
An optical touch panel includes: a pair of retroreflective plates that are arranged inside at least a left and right pair of frame portions facing each other in a rectangular frame; a plurality of detectors that are arranged at four corners of the rectangular frame, the detectors being configured to irradiate infrared rays to, at least, the retroreflective plates, and to generate detection images based on reflection light from the retroreflective plates; and an operation determining unit configured to detect a touch position based on the detection images generated by the detectors.