Multipoint infrared touch screen receiving circuit and multipoint infrared touch screen receiving method

Abstract

The invention discloses a multipoint infrared touch screen receiving circuit and a multipoint infrared touch screen receiving method. The circuit comprises N corresponding infrared emission lamp tubes and infrared receiving lamp tubes, wherein the infrared receiving circuit further comprises serial-in parallel-out shifting registers which are cascaded, a decoder, a gating circuit, a phototriode and a sunlight interference resistant circuit; the decoder, the gating circuit and the phototriode are connected in parallel; the gating circuit comprises a combined switch, a logic chip and a signal gating circuit; the signal receiving unit comprises a power supply control pin, a signal receiving end circuit and a signal output controller. The multipoint infrared touch screen receiving circuit is capable of realizing single transmitting and multiple receiving, can resist sunlight interference, and is also capable of reducing the use amount of analogue switches and amplification circuits in an infrared touch screen and greatly lowering the cost of the touch screen.

Description

technical field [0001] The invention belongs to the technical field of computers, and in particular relates to a touch circuit and a control method. Background technique [0002] Existing infrared touch screens, no matter multi-point or single-point infrared touch screens, are formed by infrared emitting tubes and infrared receiving tubes that are evenly arranged in X and Y directions along the touch area, forming infrared rays that cross vertically and horizontally in X and Y directions. The matrix, control and drive circuit drives the infrared emitting tube and the infrared receiving tube under the control of the CPU. The infrared emitting tube and the infrared receiving tube together form a positioning plane. When there is a touch, fingers or other objects will block the horizontal and vertical infrared rays passing through this point, and scan all the corresponding infrared emitting tubes and infrared receiving tubes in the horizontal and vertical directions sequentially...

AI Technical Summary

Problems solved by technology

However, this application has high requirements for hardware. Although a certain number of transceiver components can be reduced, the cost of hardware is still greatly increased, and the reduced transceiver components affect the effect of the accepted judgment, and are easily interfered by sunlight, which is not conducive to accurate Judging the touch point

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