Resistive touch screen is a kind of sensor, which is basically a structure of film and glass. The adjacent side of the film and glass is coated with ITO (nano-indium tin metal oxide) coating. ITO has good conductivity and transparency. When the touch operation is performed, the ITO on the lower layer of the film will contact the ITO on the upper layer of the glass, and the corresponding electrical signal will be transmitted through the sensor, sent to the processor through the conversion circuit, and converted into the X and Y values on the screen through operation, and complete the single point of touch and rendered on the screen.
The working principle of the resistive touch screen is mainly to realize the operation and control of the screen content through the principle of pressure sensing. The main part of touch screen is a multi-layer composite film that is very compatible with the display surface. The first layer is glass or plexiglass, the second layer is the partition layer, the third layer is the multi-component resin surface layer, and the surface is also coated with a transparent conductive layer, which is covered with a hardened, smooth and scratch-resistant plastic layer on the outer surface. The conductive layer and glass layer sensors on the surface of the polyester surface layer are separated by many tiny spacers. The current passes through the surface layer. When the surface layer is touched lightly, it touches the bottom layer, and the controller reads the corresponding current and Calculate the distance of the finger position. This touch screen uses two highly transparent conductive layers to form a touch screen, and the distance between the two layers is only 2.5 microns. When a finger touches the screen, the two conductive layers that are usually insulated from each other have a contact at the touch point. Because one of the conductive layers is connected to a 5V uniform voltage field in the Y-axis direction, the voltage of the detection layer changes from zero to If it is not zero, after the controller detects this connection, it performs A/D conversion, and compares the obtained voltage value with 5V to obtain the Y-axis coordinate of the touch point, and similarly obtains the X-axis coordinate. It is the most basic principle common to all resistive technology touch screens.
The advantage of resistive touch screen is that its screen and control system are relatively cheap, and has high sensitivity touch, and whether it is a four-wire resistive touch screen or a five-wire resistive touch screen, their working environment that are completely isolated from the outside world, not afraid of dust and water, can adapt to various harsh environments. It can be touched with any object and has better stability.High accurate, which can reach the level of pixel points, and the applicable maximum resolution can reach 4096x4096.
The disadvantage is that the outer film of the resistive touch screen is easily scratched, which makes the touch screen unusable. The multi-layer structure will cause a large loss of light. For handheld devices, it is usually necessary to increase the backlight to make up for the problem of poor light transmittance and will increase battery consumption.
The touch screen technology facilitates human machine interaction to a large extent, and it is very durable. Using the touch screen technology, the user only needs to click the corresponding touch pattern with his finger to solve the complicated operation problems in the past, which greatly facilitates the user.