GUANGZHOU VICPAS TOUCH TECHNOLOGY CO.,LTD
This touch screen uses pressure sensing to control the touch screen. The main part of the resistive touch screen is a resistive film screen that is very compatible with the surface of the display. It is a multi-layer composite film with a layer of glass or hard plastic as the base layer and a transparent oxide metal on the surface (transparent conductive). Resistor) Conductive layer, covered with a layer of outer surface hardened, smooth anti-scratch plastic layer, coated with a coating on its inner surface, with many fine (less than 1/1000 inch) transparency between them The isolation point separates the two conductive layers from each other. When the finger touches the screen, the two conductive layers have contact at the touch point position, the resistance changes, and signals are generated in both the X and Y directions, and then sent to the touch screen controller. The controller detects this contact and calculates the position of (X, Y), which then operates according to the way the mouse is simulated. This is the most basic principle of the resistive touch screen. Therefore, the resistive touch screen can be operated with a hard object. The key to resistive touch screens lies in material technology. Commonly used transparent conductive coating materials are:
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ITO, indium oxide, weakly conductive, the characteristic is that when the thickness drops below 1800 angstroms (A = 10-10 meters), it will suddenly become transparent, the light transmittance is 80%, and then the light transmittance will decrease. It rises to 80% at a thickness of 300 angstroms. ITO is the main material used in all resistance technology touch screens and capacitive technology touch screens. In fact, the working surface of the resistive and capacitive technology touch screen is ITO coating.
Nickel-gold coating, the outer conductive layer of the five-wire resistive touch screen uses a highly ductile nickel-gold coating material, mobile phone touch screen
Due to the frequent contact of the outer conductive layer, the purpose of using the ductile nickel gold material is to extend the service life, but the process cost is relatively high. Although the nickel-gold conductive layer has good ductility, it can only be used as a transparent conductor. It is not suitable as a working surface of a resistive touch screen because it has high conductivity and the metal is not easy to be very uniform in thickness. It is not suitable for voltage distribution layer. Floor.
1. Four-wire resistive screen Four-wire resistive analog technology works by adding two layers of transparent metal to each layer with a constant voltage of 5V: one vertical direction and one horizontal direction. A total of four cables are required. Features: High resolution, high speed transmission response. Surface hardness treatment to reduce scratches, scratches and chemical treatment. With smooth and matte finish. One calibration, high stability, never drift.
2, five-wire resistive screen five-wire resistance technology The basic layer of the touch screen puts the voltage field in both directions through the precision resistor network on the conductive working surface of the glass. We can simply understand the voltage field time-sharing operation in both directions. On the same working surface, the outer layer of nickel-gold conductive layer is only used as a pure conductor, and the position of the touch point is measured by a method of detecting the X-axis and Y-axis voltage values of the inner ITO contact point after touch. The inner layer of ITO of the five-wire resistive touch screen requires four leads, the outer layer is only used as one conductor, and the touch screen has five lead wires. Features: high resolution, high speed transmission response. High surface hardness reduces scratches, scratches and chemical resistance. 30 million contact points at the same point are still available. The conductive glass is the medium of the substrate. One calibration, high stability, never drift. The five-wire resistive touch screen has the disadvantages of high price and high environmental requirements.
3, the limitations of the resistance screen Whether it is a four-wire resistive touch screen or a five-wire resistive touch screen, they are a completely isolated working environment, 15-inch industrial touch display (touch screen application) is not afraid of dust and water vapor, it can use any object Touch to use, can be used for writing and drawing, more suitable for industrial control and the use of limited people in the office. The common disadvantage of resistive touch screens is that because the outer layer of the composite film is made of plastic material, an unknown person who is too hard or uses a sharp touch may scratch the entire touch screen and cause scrapping. However, within the limits, scratching only hurts the outer conductive layer. The scratch of the outer conductive layer is irrelevant for a five-wire resistive touch screen and fatal for a four-wire resistive touch screen.