Infrared touch screen triggered by body capacitance

Abstract

The present invention provides an infrared touch screen touched by human capacitance, a transparent conductive coating is covered on the protecting glass plate of the touch screen, and the circuit system of the touch screen includes a set human parasitic capacitance signal detection treatment system, the output end of the system is connected with the I / O end of the microcontroller in the touch screen. The parasitic capacitance signal detection treatment system triggers screen to check touching operation after checking the capacitance between fingers and conductive coating. The invention utilizes the inductive stray electromagnetic signal, the attenuation of parasitic capacitance to the vibrator, the dromotropic action of AC signal between two finger shaped cross semimembranes of the parasitic capacitance to achieve the detection of the parasitic capacitance. The invention has mature technology, lower cost, effectively filters the false triggering interference caused by bug and flotage etc, at the same time can greatly prolong the worlding life of the touching screen.

Description

technical field [0001] The invention relates to the technical field of sensing measurement and signal processing, in particular to a detection device for improving the accuracy of identifying touch operations on an infrared touch screen. technical background [0002] Infrared touch screen is already a very mature technology, widely used. U.S. Patents 3,764,813, 3,775,560, 3,860,754, and 6,439,857 and patent numbers 00121462.4, 00250806.0, 00200147.6, 00262072.3, 01202252.7, 200420093591.3, and 200420117952.3 have provided various technology improvements for touch screens, including infrared touch screens. However, in practical applications, the existing infrared touch screens all have a shortcoming: that is, they cannot distinguish the interference of environmental objects. For example, a flying insect falling on the screen, or a large floating object, and other occasional obstructions, etc., may be considered by the touch screen as being touched by a human finger, causing ...

AI Technical Summary

Problems solved by technology

However, in practical applications, the existing infrared touch screens have a shortcoming: that is, they cannot distinguish the interference of environmental objects.

First of all, if you use strain gauges, generally speaking, you need to use multiple semiconductor strain gauges to obtain sufficient sensitivity, which increases the component cost of the product; secondly, if you use a pickup to detect vibration, because the pickup has a wide frequency band, it is easy to It is interfered by the environmental noise around the touch screen; if you want to eliminate this interference, you need to invest more in circuit design and signal processing, which will also increase the cost of production

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