1、附录 英文原文 Touch-screen technology overview and comparison of performance The basic principles of touch-screen The current touch screen technology has been a growing number of manufacturers used in various fields, in the future and even now have a broader space for development, which is human intellige
2、nce into the high technology is the best embodiment of the era. I believe we are not unfamiliar to the touch screen, touch screen system generally consists of two parts: the touch-detection devices and touch screen controller. Touch detection devices installed in front of the display screen for dete
3、cting user touch position, touch screen controller to receive evacuation； touch screen controller is a major role in the detection device touch touch receive information and coordinate it into contact, send to the CPU, it can receive commands sent CPU and implemented. Touch screen technology has als
4、o gone through step by step from low-to high-grade promotion and development. In accordance with its working principle, which is generally divided into four categories: resistive touch screen, capacitive touch screen, infrared touch screen and the surface acoustic wave touch screen. Resistive Touch
5、Screen Resistance touch screen part of the screen body is a multilayer film, by a layer of glass or plexiglass as a grass-roots level, the surface coated with a layer of transparent conductive layer (ITO film), and then covered with a layer above the outer surface after hardening, smooth scratch res
6、istant plastic layer. Its inner surface is also coated with a layer of ITO, the conductive layer between two layers there are many small (less than one-thousandth inch) transparent isolation points separated them.When the fingers touch-screen, the two-tier ITO contact, resistance to change, the cont
7、roller based on the resistance change is detected to calculate the coordinates of contact point, and then carried out in accordance with the coordinates of the corresponding operation. Lead a number of resistors in accordance with the number of screens, divided into four-lane, five types of lines. F
8、ive-wire resistive touch screen is the outer surface of conductive glass instead of conductive coating layer, the conductive glass of longer life expectancy, and higher transmittance. Resistive Touch Screen, if the ITO coating is too thin brittle fracture easily, thick coating will reduce the transp
9、arency and clarity to reduce the formation of internal reflection. As a result has often been touched, the use of ITO surface after a certain period of time there will be a small crack, or even change, so its not a long life. Resistive touch screens are cheap and easy production, and thus remains a
10、more common choice. Four-wire, five-and seven-wire line, eight-wire touch screen to the emergence of more reliable performance, but also to improve its optical properties. Capacitive touch screen Capacitive touch screens are plated on the four sides of the strip electrode, the internal exchange of a
11、 low-voltage electric field. Stickers have a touch screen thin-film transparent layer, which is a special kind of metal conductive material. When the user capacitive touch screen, the user fingers and face to form a coupling capacitor, as the work surface then there are high-frequency signals, so th
12、e fingers will siphon off a small current, the current from the four corners of the screen electrode in the outflow； and theory of current flow through the four electrode fingers to the corners and in proportion to the distance, the controller of the four current proportion of precision, the locatio
13、n of contact points can be derived. Capacitance of the double-glass touch screen is not only to protect the conductor and the sensors are more effective in the prevention of external environmental factors on the impact of touch-screen, even if the piles of dirty screen, dust or grease, capacitive to
14、uch screen is still able to accurately calculate the touch location. However, as capacitance with temperature, humidity, or ground conditions vary, the stability of poor, often drift phenomenon. Although not so widely applied resistive, capacitive touch screen is also popular for the type of electio
15、n. Accuracy of such equipment, the reaction speed, size, slightly larger when a higher resolution, more durable (scratch resistant), and thus suitable for use as touch-screen console. Moreover, the new near-field imaging technique to improve the capacitive touch-screen performance, weakened it and r
16、esistive touch screen that may occur in the phenomenon of drift. Infrared Touch Screen Infrared touch screen arrangement of the four sides of the infrared emission infrared receiver tubes and pipes, they form a one-to-one cross infrared matrix. Users touch the screen, the fingers will be blocked aft
17、er the location of two infrared, the controller can be determined by calculating the location of touch points. Infrared touch screens are also not subject to current, voltage and electrostatic interference, and suitable for some of the poor environment. Its main advantage is low cost, easy installat
18、ion, can be used in the grade of the computer. In addition, the absence of capacitor charge-discharge process, response speed faster than the capacitor, but with lower resolution. Surface Acoustic Wave Touch Screen Surface acoustic wave is an ultrasound, it is in the medium (such as glass or metal,
19、such as rigid material) shallow surface-wave transmission of mechanical energy. Through the triangular wedge-shaped base (according to the strict design of the wavelength of SAW), can be targeted, small-angle firing of the surface acoustic wave energy. Surface Acoustic Wave Properties of a stable, e
20、asy analysis and S-wave transmission in the course of a very sharp frequency characteristics, in recent years, nondestructive testing, imaging and back-wave applications such as rapid development. This touch-screen display of the four were fired with ultrasound transducer and receiving transducer, a
21、n ultrasound can be issued and covers the surface of the screen. When the finger touch screen, as part of acoustic energy absorption, so that changes in the receiving waveform, that is, a waveform of a time gap attenuation, based on the attenuation of the signal controller can calculate the location
22、 of touch points. Surface Acoustic Wave touch screen from temperature, humidity and other environmental factors, high resolution, has an excellent scratch resistant, and long life (50 million times without failure), high transmittance (92%), clear and transparent to maintain the image； not drift, ju
23、st installed a correction； a third axis (that is, the pressure axis) in response to the most suitable for use in public places. Surface Acoustic Wave touch screen vulnerable to water droplets, dust, the impact of improved methods to increase the dust, the dirt or to increase the monitoring, operation and identify the difference between dirt. In addition, because screen can feel the pressure of sound waves virtually means increased control of the screen is very beneficial to the expansion of
