Infrared touch screen and its multi-point touch positioning method

Abstract

The invention discloses an infrared touch screen and a multi-touch positioning method thereof, that is, in at least one detection direction of the touch screen, one set of infrared emitting scanning circuits corresponds to two sets of infrared receiving scanning circuits; one infrared emitting scanning circuit in one set of infrared emitting scanning circuits While the light emitted by the transmitting element is received and detected by an infrared receiving element in one set of infrared receiving scanning circuit, it is also received and detected by an infrared receiving element in another set of infrared receiving scanning circuit within the receiving range; the algorithm of the infrared touch screen The program has a touch point pre-detection algorithm module that can be used to determine the touch point range in advance. After the present invention obtains the position coordinates of a touch point with a common touch position detection algorithm, it uses a touch point pre-detection algorithm to determine the area where another touch point is located, and then combines the common detection algorithm to obtain the touch point position coordinates. The present invention can identify two or more touch operations, and can also effectively identify touch positions when multiple points are touched simultaneously.

Description

【Technical field】 [0001] The invention relates to an infrared touch screen, in particular to an infrared touch screen capable of distinguishing multiple touch points and operating simultaneously and a multi-touch positioning method thereof. 【Background technique】 [0002] As an interactive device with simple production process and low production cost, infrared touch screen has been developed rapidly, and has been widely used in many fields. The basic structure of the infrared touch screen is to install several pairs of infrared emitting and infrared receiving elements in a certain order around the edge of a display surface suitable for installation. These transmitting and infrared receiving elements form a transmitting and receiving pair in a one-to-one correspondence, forming a mutually perpendicular transmitting and receiving array along the edge of the display surface, and each pair of transmitting and receiving elements is connected in a certain order under the control o...

AI Technical Summary

Problems solved by technology

This touch detection mode makes the existing infrared touch screen only receive a unique set of position coordinate data within a given period of time, so when there is only one touch point, the touch screen can work normally, for two or more touch points When operating at the same time, the system will calculate the wrong position coordinates, resulting in the reported touch location is not the actual touch location

[0004] Due to the above reasons, the existing infrared touch screen technology will fail in some occasions that need to use multi-touch, such as multiple people playing games at the same time, multiple people writing and drawing at the same time, etc., which greatly limits the application field of infrared touch screen

At present, there are some solutions, such as identifying multiple touch points by detecting the sequence of touch events, but it is easy to occur when there is no relative movement between multiple touch points, and there is no shape and size value of the touch point to refer to. Misjudgment

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