Basic principles and characteristics of smart phones with touch screen TFT Display Module

The touch screen is a computer input device, the type of keyboard input can be realized, and to be able to click on the mouse, it allows the user to be selected by touching the screen. Not having a touch screen computer storage space required, the movable portion small, and be able to package. The touch screen is more intuitive to use than a keyboard and mouse, and training costs low.
All touch screen has three main components. Processing the user's selection of the sensor unit; touch perception and positioning controller, and the touch signal transmitted by a device driver to the computer's operating system software. The touch screen sensor has five technologies: resistive technology, capacitive technology, infrared technology, acoustic technology or near-field imaging technology.Lcd display modules 
Resistive touch screen usually includes a flexible top layer, and a layer of glass as a grass-roots level, by the point of the insulation isolation. The inner surface of each layer are transparent metal oxide coating. Voltage on each diaphragm has a difference. Pressing the top film is formed in each of the resistance layer between the electrical contact signal
Capacitive touch screen is made of a transparent metal oxide as a coating bonded to the glass surface of the monolayer. Unlike resistive touch screen, any touch will form a signal capacitive touch screen directly with your fingers touch or stylus contact and conduction. Finger capacitance, or the ability to store charge, can absorb the touch screen one at each corner of the current, and current flows through four electrodes with a finger to proportional to the square of the distance, to arrive at the touch point.
Infrared touch screen interrupt light-based technology. It is not in front of the display surface by placing a thin film layer, but set a frame around the display. The frame light source or a light emitting diode (LED) located in the side of the frame on the other side, and the light detectors or photoelectric sensors, infrared grid is formed in one-to-one correspondence, vertical cross. When the objects touch screen, invisible light interrupt, photoelectric sensors can not accept the signal in order to determine the touch signal.
An acoustic wave sensor, the sensor is mounted is at the edge of the glass screen for transmitting an ultrasonic signal. Ultrasound through the reflection of the screen, and accepted by the sensor, and the received signal is weakened. (Surface acoustic wave, SAW) surface acoustic wave signal, the light passes through the surface of the glass; oriented sound waves (guided acoustic wave, GAW) technology, sound waves through the glass.lcd modules
Near field imaging touch screen (NFI), by two thin glass layers, the intermediate is a transparent metal oxide coating. The coating is applied to the guide point an AC signal, generating an electric field in the surface of the screen. When the finger, wearing gloves can be, or other conductive stylus contact sensor, the electric field disturbance, in order to get the signal.