Method for identifying multiple true touch point by infrared touch screen

Abstract

The invention discloses a method for identifying a plurality of authentic touch points by using an infrared touch screen. Firstly, the infrared scanning is carried out in the directions of X, Y and Z axes; a scanning unit carries out the touch analysis for touch signals to generate the touch position information of the X, Y and Z axes; a controller is adopted to judge whether the touch position information belongs to the effective information; when the effective touch position information exists, the controller collects the information and arranges and combines the collected data to generate combination points; the controller respectively judges all of the combination points according to that X plus Y*tg(90 minus Alpha) equals Z, to see whether the combination point meeting the condition exists, wherein, Alpha is an included angle between the Z axis scanning unit and the X axis scanning unit; the obtained position information of each authentic touch point is transmitted to a computer system. The invention can fully cover the whole touch zone and the multi-point identification blind zone can be avoided in the whole touch zone so as to completely exclude false points and authentically realize the correct identification of a plurality of touch points.

Description

technical field [0001] The invention relates to an infrared touch screen, in particular to a method for identifying multiple real touch points on the infrared touch screen. Background technique [0002] As a branch of computer touch screen, infrared touch screen is gradually widely used in various fields due to its advantages of convenient installation, maintenance-free, high explosion resistance, and high reliability. 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. The angular displacement β of the infrared emitting tube and the receiving tube is generally less than or equal to ± ± when the relative radiation intensity is 0.5 times 15 degrees, these transmitting and infrared receiving elements form a transmitting and receiving pair in a one-to-one correspondence, forming a mutually perpendicular transmitting and...

AI Technical Summary

Problems solved by technology

[0007] Although the above two methods can achieve multi-touch to a certain extent, and the first one also solves the problem of slow response speed of the infrared multi-touch screen from the hardware circuit and algorithm to a certain extent, but there are the following two aspects: Disadvantages: 1. There are multi-point recognition blind spots in some areas

In some areas of the 4 corners, the Y=X[sinα*sin(α+β)] / sinβ described above cannot be formed, and multi-touch in this area cannot be effectively recognized.

2. Lower resolution

Since the emission tube is limited by the emission power, its emission angle is generally small (<20°), and the resolution of the oblique direction is 0.36 times that of the horizontal direction (tg20°=0.36), so the resolution of the oblique direction is greatly reduced, which is not conducive to Correct identification of nearby multiple points

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