Touch Screen

For operational convenience, people use the touch screen to replace the mouse or keyboard work, we must first use your fingers or other objects touch installed in front of the monitor touch screen, then the system according to the finger touching the icon or menu location to locate selected information into the touch screen by the touch detection component parts and touch screen controller; touch detection unit installed in the front of the monitor screen for detecting user touch position, touch screen controller to accept evacuation; and touch screen controller's main role is from the touch point touch detection device to receive information, and transform it into contact coordinates, and then sent to CPU, it also can receive commands sent to the CPU and run it.Functional classificationInfrared touch screenInfrared touch screen, very simple principle, but on the display rack with light pitch box, the screen surface with no coating or optical connection controller pitch frames, arranged in four sides of the infrared emission tube and receiver tube, the surface of the screen the formation of an infrared network users to a certain point a finger touch screen, it will block if they had been the location of two infrared touch computer can immediately calculate the position from current and voltage infrared touch screen and electrostatic interference, some of the harsh environmental conditions suitable for its The main advantage is low cost easy to install no card or any other controller can be used in all grades on the computer, however, because only an increase in the general framework of the screen, in the course of infrared frames, around the launch tube and receiver tube is easily damaged, and the lower resolutionCapacitive touch screenCapacitive touch screen of the structure mainly in the glass screen coated with a transparent film layer, the longer the conductor layer, plus a protective glass, double glass design can completely protect the conductor layer and the sensor capacitive touch screen on the touch screen edges are coated with narrow electrode, the conductive body to form a low voltage AC field when the user touches the screen, because the body electric, fingers and the conductor layer to form a coupling capacitor, four sides of the electrode current will flow to the contact issue, but the current strength of the finger to proportional to the distance between electrodes in the touch screen controller will calculate the current ratio and strength, accurately calculate the location of the touch points of the dual-glass capacitive touch screen can not only protect the conductors and sensors, to more effectively prevent external environmental factors on Touch-screen impact, even if the screen of dust or grease stained with dirt, capacitive touch screen is still able to accurately calculate the location of the touchResistive touch screenTouch screen panel is a body part with the display surface of the well in line with the multi-layer composite film by a layer of glass or plexiglass as a grass-roots, the surface coated with a layer of transparent conductive layer (OTI, indium oxide), and then covered with a layer above the outer surface smooth and scratch-resistant hardened plastic layer, and its inner surface is also coated with a layer of OTI, the two conductive layers there are many small (less than one thousandth inch) separation point of transparency when they are separated by a finger contact with insulation screen, two conductive layers OTI A point of contact, because one side of the conductive layer connected to the Y-axis voltage of 5V uniform field, making the detection level of the voltage from zero to zero, after the controller detects the connected , the A / D conversion, and will be compared to the voltage to 5V, you can get the touch point Y axis X axis coordinates obtained empathy, which is a common resistive touch screen technology screen according to the most basic principles of resistance Lead-out of how many, is divided into four-five-wire resistive touch screen and other multi-line five-wire resistive touch screen A-conductive glass surface is not conductive coating, conductive glass technology to greatly increase the life span, and can improve transmittance OTI resistive touch screen coating is thin and easy to brittle fracture, the thick coating will reduce the formation of internal reflection to reduce light transmission and clarity, OTI, although more a thin outer protective layer of plastic, but still easily damaged by sharp objects; and because often touched the surface after a certain time to use OTI hairline cracks will appear, and even variants, such as the outer one of which damaged and broken OTI, will lose the role as a conductor, not the life of the touch screen Resistive touch screen long but water contamination from dust impactSurface acoustic wave touch screenSurface acoustic wave touch screen touch screen can be a part of spherical or cylindrical surface of the glass plate, mounted on CRTLEDLCD or plasma display screen in front of the glass plate is a piece of pure glass, apart from other touch-screen technology is no film and cover the upper left and lower right corner of the glass screen of the fixed vertical and horizontal direction of the ultrasonic transmitter transducer, the upper right corner is fixed two corresponding ultrasonic receiver transducer around the glass screen is engraved with four 45 ° angle intervals from sparse to dense reflective stripes very sophisticated transmitter transducer to the controller via the touch screen cable into electrical signals sent to the left side surface of the acoustic energy to pass, and then by a group of precision glass below the reflective stripes the acoustic energy reflected into a uniform surface upward transmission of acoustic energy through the screen surface, and then gather by the reflective stripes on top of the line spread to the right into the X-axis receiving transducer, receiving transducer will return to the surface of the acoustic energy into electrical signals and transmit the received signal waveform in the absence of touch when the received signal waveform and the reference waveform the same as when a finger or other acoustic energy to absorb or block the object touching the screen, X-axis position to go up through your fingers The acoustic energy is partly absorbed, reflected in the received waveform on the waveform location that is a time gap there is a received waveform corresponding to the decay part of a finger to block the signal attenuation of a gap, the gap calculated coordinates of the location that was touched, the controller analyzes the received signal attenuation determined by the location of the gap after the X-coordinate Y axis the same process to determine the Y coordinate of the touch points in addition to general touch screen can respond to the XY coordinates, the surface acoustic wave touch panel also responded to the third axis Z-axis coordinates, the user is able to perceive the size of the value of three-axis touch-pressure, once established, they put the controller to the host surface acoustic wave touch screen from temperature, humidity and other environmental factors, high resolution, has an excellent scratch resistance, long life (50 million times without failure ); high transmittance (92%), to maintain a clear bright image quality; no drift, the most suitable for use in public places but the surface of the sensor system in the long induction converter operation, the acoustic energy generated due to the pressure damage generally wool or leather gloves will receive part of the sound waves, the accuracy of the sensor is also affected by some surface or screen finger touch screen, such as dirt or dust contaminated with grease stains, will also affect its performance, even so the system stops operation.