55 inch touch screen 4k.All touch screens can detect whether a touch occurs. The method is to pull up one layer with a weak pull-up resistor and pull down the other layer with a strong pull-down resistor. If the measured voltage of the pull-up layer is greater than a certain logic threshold, there is no touch, otherwise there is a touch. The problem with this method is that the touch screen is a huge capacitor. In addition, the capacitance of the touch screen leads may need to be increased in order to filter out the noise introduced by the LCD . Connecting a weak pull-up resistor to a large capacitor will increase the rise time and may cause a false touch to be detected.

55 inch touch screen 4k.All touch screens can detect whether a touch occurs. The method is to pull up one layer with a weak pull-up resistor and pull down the other layer with a strong pull-down resistor. If the measured voltage of the pull-up layer is greater than a certain logic threshold, there is no touch, otherwise there is a touch. The problem with this method is that the touch screen is a huge capacitor. In addition, the capacitance of the touch screen leads may need to be increased in order to filter out the noise introduced by the LCD . Connecting a weak pull-up resistor to a large capacitor will increase the rise time and may cause a false touch to be detected. IQTouch K interactive touch screen feature 20-point touch and dual system -- Android 8.0 system and optional OPS Windows 10Pro system. Its 4K UHD resolution facilitates presentations and collaboration. With optional multi-screen casting software, IQClass 6.0 and installation-free IQClass Plus software, IQTouch K Series can help create an interactive and collaborative teaching atmosphere in class.