Choice of ruggedized tablet touch screen
The high temperature resistant industrial tablet computer is a touch panel, which is generally matched with a liquid crystal display to form a touch display device. The high temperature resistant industrial panel computer is an industrial control device with a touch display device. Commonly used high temperature industrial panel computers include resistive screens, capacitive screens, infrared screens, and surface acoustic wave screens.
1. Resistive screen
The screen body of the resistive screen is a multi-layer composite film, with a layer of glass or plexiglass as the base layer, the surface is coated with a layer of transparent conductive layer (ITO film), and covered with a layer of hardened, smooth and scratch-resistant outer surface. plastic layer.
Its inner surface is also coated with a layer of ITO, separated by many tiny transparent spacers between the two conductive layers. When the high temperature resistant industrial panel computer screen is used, the two layers of ITO come into contact and the resistance changes. The controller calculates the coordinates of the contact point according to the detected resistance change.
Then according to this coordinate to carry out the corresponding operation. Therefore, the high-temperature-resistant industrial tablet computer using the resistive screen must apply force to the screen to obtain the touch effect during operation.
The resistive screen has low requirements on the working environment, is not afraid of dust, moisture and oil, and can be touched by any object. It does not have much requirements on temperature and humidity, and is suitable for use in the field of industrial control. In addition, the resistive screen is a soft screen,
The high temperature resistant industrial panel computer with resistive screen will have a soft feeling when operating the screen, and too much force or touching with a sharp object may cause scratches on the high temperature resistant industrial panel computer.
Four-wire resistance high temperature industrial panel computer: It is not afraid of dust, oil and photoelectric interference, and it is the main defect that it is afraid of scratches. It is suitable for public places with fixed users, such as industrial control sites, self-service terminals, etc.
Five-wire resistance high temperature industrial panel computer: good sensitivity and light transmittance, long service life, not afraid of dust, oil pollution and photoelectric interference, suitable for all kinds of public places, especially for industrial control sites that require precision.
2. Capacitive screen
The capacitive screen is a four-layer composite glass screen. The inner surface of the glass screen and the interlayer are each coated with a layer of ITO, the outer layer is a thin layer of silica glass protective layer, and the interlayer ITO coating is used as the working surface.
Four electrodes are drawn from the four corners, and the inner layer of ITO is a shielding layer to ensure a good working environment.
When touching the screen of the high temperature-resistant industrial tablet computer, the human body acts as one pole of the coupling capacitor, and the current is collected from the four corners of the screen to form the other pole of the coupling capacitor. The controller calculates the relative distance from the current to the touch position to obtain the coordinates of the touch.
High-temperature-resistant industrial tablet computers using capacitive screens can perform multi-touch. The main disadvantage is that when the ambient temperature, humidity, electric field, etc. change, it may cause the capacitive screen to drift, resulting in inaccuracy, requiring frequent calibration and positioning. Therefore, the capacitive screen is not easy to be used in industrial control places and places with interference