Multi-channel Touch Screen Sampling Rate Optimization

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Solution Overview

Problem

Current touch screens face challenges in increasing resolution without increasing the number of infrared diodes, which affects response rate and costs, and off-axis scanning methods compromise response time due to interference light processing requirements.

Innovation Solution

A touch screen design that includes at least two infrared-receiving diodes receiving light from the same emitting diode, with first-stage processing circuits filtering out interfering signals and outputting them via a multiplexer to a second-stage processing circuit, optimizing circuit structure to enhance multi-channel sampling rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of infrared-receiving diodes is increased to improve resolution, then the resolution is improved, but the response rate deteriorates and the cost increases

Engineering Contradiction:
ImproveresolutionVSAvoidresponse rate
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

Multiple infrared-receiving diodes share a single first-stage processing circuit through a multiplexer, combining processing resources to reduce the total number of processing circuits while maintaining the capability to handle signals from multiple receiving diodes simultaneously

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multiplexer performs periodic switching to sequentially connect different infrared-receiving diodes to the shared first-stage processing circuit, enabling time-multiplexed signal processing that maintains response rate while supporting multiple channels

Inventive Principle:
Principle #19Periodic action

2Measurement precision

If off-axis scanning is used to improve resolution without increasing the number of infrared diodes, then the resolution is improved, but the response time deteriorates due to interference light processing

Engineering Contradiction:
ImproveresolutionVSAvoidresponse time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The first-stage processing circuit extracts and removes interference light signals from the received signals before further processing, separating the harmful interference component from the useful touch detection signals to enable faster processing

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Interference light filtering is performed as a preliminary action in the first-stage processing circuit before signals are passed to the second-stage processing circuit, eliminating the need for time-consuming interference removal later in the processing chain

Inventive Principle:
Principle #10Preliminary action

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 approach increases the multi-channel sampling rate by reducing processing time and maintaining effective signal filtering, thereby improving touch screen performance without the need for additional infrared diodes.

Implementation Method 1

at least two infrared-receiving diodes receive infrared light emitted from the same infrared light-emitting diode simultaneously

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP2597552B1Touch screen and multi-channel sampling method thereof
Publication Date: 2019.11.13 BEIJING IRTOUCH SYST CO LTD
  • EP2597552B1 patent drawingFigure 1
  • EP2597552B1 patent drawingFigure 2
  • EP2597552B1 patent drawingFigure 3

AI summary

A touch screen and a multi-channel sampling method thereof are disclosed. The touch screen comprises infrared-emitting diodes, infrared-receiving diodes (102), a touch detection region, first-stage processing circuits, and a second-stage processing circuit (203). At least two infrared-receiving diodes receive infrared light emitted from the same infrared light-emitting diode simultaneously, and the at least two infrared-receiving diodes output the received signals to the second-stage processing circuit for processing after the first-stage processing circuits filter out interfering light signals. The touch screen and the multi-channel sampling method thereof according to the present invention can be used to increase the multi-channel sampling rate of the touch screen.