The four main categories of touch screen, small make up take you to meet together

According to the working principle of touch screen and transmission of information media, we put the touch screen is divided into four kinds, respectively is resistive, capacitive sensing type, infrared and surface acoustic wave. Has its own advantages and disadvantages of each kind of touch screen, and to understand the touch screen is suitable for the occasion, the key is to understand the working principle and characteristics of every kind of touch screen technology. A brief description of the various types of touch screen to introduce: 1, resistive touch screens use pressure sensor for the touch screen control. Resistive touch screen is a main part of the surface is very match the resistance of the film and display screen, it is a kind of multilayer composite films, it with a piece of glass or hard plastic flat as grassroots, surface coated with a layer of transparent metal oxide ( Transparent conductive resistance) Conductive layer, the top with a layer of surface hardening treatment, smooth and rubbing the plastic layer, its inner surface is coated with a layer of coating, among them there are many small ( Less than 1/1000 of an inch) Transparent isolation point separates two conductive layer insulation. When fingers touching the screen, two conductive layers in touch point location had contact, resistance to change, produced in the X and Y directions signal, and then send a touch screen controller. Controller to detect the contact and calculate the ( X，Y) Position, according to simulation the mouse operate. This is the most basic principle of resistance technology of touch screen. 2, capacitive touch screen capacitive touch screen is to use the working current of induction of human body. Capacitive touch screen is a four layer composite glass screen, the inner surface of the glass and laminated coated with a layer of ITO, the outermost layer is a thin layer of silica glass coating, laminated ITO coating as the working face, four corners raises four electrodes, inner ITO for shield to ensure good working environment. When the fingers on the metal layer, the electric field due to the human body, the user and the touch screen surface formed by a coupling capacitance, for high frequency current, capacitance is directly conductor, so the fingers from the point of contact suck a small current. The current points out from the touch screen on the four corners of the electrode, the four electrodes and the current is proportional to the finger to the four corners, the controller based on the four current ratio of precise calculation, it is concluded that the location of the touch point. 3, infrared touch screen is the use of infrared touch screen with infrared ray matrix X, Y direction to detect and locate the user's touch. Infrared touch screen in front of the display to install a circuit board frame, circuit boards and around the screen configuration of infrared transmitting tube and infrared receiving tube, one to one correspondence form somehow cross infrared matrix. Users in the touch screen, the finger will block after the location of the relation of two infrared, which can determine the location of the touch point on the screen. Any touch objects can change the infrared on the contact and touch screen operation. 4, surface acoustic wave touch screen surface acoustic wave, a kind of ultrasonic, the medium ( For example, rigid material such as glass or metal) The spread of the surface and shallow mechanical energy wave. Through the wedge triangle base ( According to the wavelength of surface wave strict design) Can be done, directional, small Angle of surface acoustic wave energy emission. Surface acoustic wave, stable performance, easy to analysis and in the process of shear wave transmission has a very sharp frequency characteristic, in recent years in nondestructive flaw detection, imaging and annealing wave direction on application development soon, surface acoustic wave related theory research, semiconductor materials, acoustic materials, testing technology and technology already quite mature. Touch screen part of the surface acoustic wave touch screen can be a piece of plane and spherical or cylindrical glass plate, mounted on a CRT, LED, LCD or plasma display in the front of the screen. Glass screen for fixed on the upper left and lower right of the vertical and horizontal direction of ultrasonic transmitting transducer, the top right corner is fixed for two corresponding ultrasonic receiving transducer. Four around the glass screen is engraved with 45 ° Angle from sparse to dense spacing is very sophisticated reflection stripe. Above is the characteristics of the four kinds of touch screen, users can choose according to their own needs more suitable type of touch screen.