When working, the resistive touch screen can only judge one touch point at a time, and if there are more than two touch points, it can not make a correct judgment, so the resistive touch screen is only suitable for the judgment of some simple actions such as clicking and dragging. There are four different types of resistive screens.
1. Four-wire resistance screen:
When the two transparent metal layers of the four-wire resistance analog technology work, the constant voltage of each layer is increased by 5V: one vertical direction and one horizontal direction. A total of four cables are required.
Four-wire resistive screen features: high resolution, high-speed transmission response. Surface hardness treatment, reduce scratches, scratches and anti-chemical treatment. With smooth surface and fog surface treatment. Once correction, high stability, never drift.
2. Five-wire resistance screen:
The base of the five-wire resistance technology touch screen adds the voltage fields of both directions to the conductive working face of the glass through the precision resistance network, we can simply understand that the voltage fields of the two directions are time-sharing work on the same working face, while the outer nickel-gold conductive layer is only used as a pure conductor. The position of the touch point is measured by time-sharing detection of the X-axis and Y-axis voltage of the inner ITO contact point after touch. The inner ITO of the five-wire resistance touch screen needs four leads, the outer layer only acts as a conductor, and there are five leads for the touch screen.
The characteristics of five-wire resistance screen: high resolution, high-speed transmission response. High surface hardness, reduce scratches, scratches and anti-chemical treatment. It can still be used for 30 million times of contact with the same point. A medium in which conductive glass is used as a substrate. Once correction, high stability, never drift.
3. Seven-wire touch screen.
The implementation method of the seven-wire touch screen is the same as that of the five-wire touch screen, except that a line is added in the upper left corner and the lower right corner. When performing a screen measurement, connect one line in the upper left corner to the VREF and the other to the positive reference end of the SAR ADC. At the same time, one line in the lower right corner is connected to 0V, and the other is connected to the negative reference end of SAR ADC. The conductive layer is still used to measure the voltage of the voltage divider.
4. Eight-wire touch screen.
Except for adding a wire to each bus, the implementation method of the eight-wire touch screen is the same as that of the four-wire touch screen. For the VREF bus, one line is used to connect the VREF, and the other is used as the positive reference input of the digital-to-analog converter of the SAR ADC. For the 0V bus, one line is used to connect the 0V, and the other is used as the negative reference input of the SAR ADC digital-to-analog converter. Any of the four wires on the unbiased layer can be used to measure the voltage of the voltage divider.