Now you may find in many public places, a computer input device that everyone will use, which is a computer that allows users to manipulate the screen directly with their fingers. This computer is actually a touch screen that people often talk about. Touch screen not only for China’s multimedia information query the situation, and the touch screen with a durable, fast response, save space, easy to communicate and many other advantages. The use of touch screen, our users simply use your fingers gently touch the computer screen icon or text can be achieved on the host operation, so that human-computer interaction more straightforward, this technology greatly facilitates those who do not understand the computer operation of the user The Now a lot of banks, hospitals, hotels, shopping malls, sales hall, schools, libraries, museums, theaters, exhibitions, stations, large bookstores, tourist attractions, community and other large public places are using touch screen technology. So how do you know how the touch screen works? Are you familiar with the operation of the touch screen?
In general, when we operate on the touch screen, you must first touch the touch screen installed on the front of the monitor with your fingers or other objects, and then the system selects the information input according to the icon or menu position of the finger touch. The touch screen is composed of a touch detection part and a touch screen controller; the touch detection part is installed in front of the display screen for detecting the user touch position and receiving the rear touch screen controller; and the main function of the touch screen controller is to receive the touch from the touch point detection device Information, and convert it into contact coordinates, and then sent to the CPU, it can also receive commands issued by the CPU and be executed. In order to operate the touch screen efficiently, we still need to first understand the various types of touch screen works:
1, the working principle of resistive touch screen
Resistive touch screen works mainly through the principle of pressure sensing to achieve the operation of the screen content and control, this touch screen screen part is a very consistent with the display surface of the multi-layer composite film, which is the first layer of glass or plexiglass The bottom layer, the second layer for the compartment, the third layer for the multi-resin surface, the surface is also coated with a layer of transparent conductive layer, and then covered with a layer of the outer surface of the hardened, smooth scratch plastic layer. The conductive layer and the glass layer sensor on the surface of the multi-fat surface are separated by a number of small separators. The current flows through the surface layer and touches the bottom layer when the touch surface is pressed, and the controller simultaneously reads the commensurate current from the four corners And calculate the distance of the finger position. This touch screen uses two layers of highly transparent conductive layer to form the touch screen, the distance between the two layers is only 2.5 microns. When the finger touches the screen, the two layers of conductive layers, which are usually insulated from each other, have a contact at the touch point where one of the conductive layers turns on the 5V uniform voltage field in the Y-axis direction so that the voltage of the detection layer changes from zero to Non-zero, the controller detects the connection, the A / D conversion, and the resulting voltage and 5V compared to the touch point can be Y-axis coordinates, the same reason to get the X-axis coordinates, which That is, all resistance technology touch screen common basic principle.
2, the surface acoustic wave touch screen
The working principle of the surface acoustic wave touch screen is mainly based on the principle that the mechanical wave propagates on the surface of a kind of medium. The touch screen carries out the sound wave transmission through the acoustic generator which is attached to the three corners of the screen surface and receives it through the acoustic receiver Sound waves, and then through the acoustic reflector is responsible for transmitting signals to the touch screen, in which the sound wave generator can send a high-frequency sound waves across the screen surface, when the fingers touch the screen, the contact sound is blocked, the received signal is converted to coordinates Value, which determines the specific touch point of the coordinate position, which the controller through the amount of sound waves absorbed by the amount of touch screen can be measured the size of the pressure, while returning to the reaction touch pressure size of the coordinates. On the surface of the surface acoustic wave touch screen, the X-direction and the Y-direction acoustic transmitter and the acoustic wave receiver are attached, and around the glass screen is engraved with 45 degrees of reflected sound. The controller produces a 5.53MHZ signal, which is transmitted to the transmitter by cable, which converts it into ultrasonic energy. Through the reflective reflection of the two reflections, spread to the receiving transducer, and converted to electrical signals to the controller. As the surface acoustic wave touch screen is composed of touch screen, sound wave generator, reflector and acoustic receiver, especially the acoustic sensor from temperature and humidity and other environmental factors, high resolution, excellent scratch resistance, long life; High transmittance, can maintain a clear and transparent image quality; no drift, just install a correction; a third axis (ie pressure axis) response, the most suitable for public places.
3, capacitive touch screen
Capacitive touch screen is in the glass surface affixed to a layer of transparent special metal conductive material, this touch screen has a total of five layers. The first layer is the bottom of the glass, the second layer is the conductive layer, the third layer is the glass sensing layer, the fourth layer is anti-reflective matte or bright surface, and the fifth layer is the anti-noise protection layer. When the finger touches the surface of the capacitive touch screen, the sensing mode is the voltage connected to the four corners of the glass layer, the voltage is spread through the electrode in the glass layer and the establishment of a non-changing voltage electric field, while the contact capacitance will change, So that the frequency of the oscillator connected to it changes, by measuring the frequency change can determine the touch location to obtain information. As the capacitance with temperature, humidity or ground conditions vary, so the stability is poor, often produce drift phenomenon. In addition, when the surface is touched, the current is collected from the four corners of the glass layer, and the controller calculates the distance of the current to the position of the finger to determine the exact position of the touch.
4, infrared touch screen
This infrared touch screen works is relatively simple, just add a light on the monitor from the frame, without the need to add the screen surface coating or access controller, and then in the light from the frame on the four sides arranged in the infrared emission And receive the sensing element on the screen surface, the formation of infrared detection network, any touch the object touch the screen a certain point, it will block the location of the vertical and horizontal two infrared, the computer can immediately calculate the touch point position. Infrared touch screen from current, voltage and electrostatic interference, suitable for some harsh environmental conditions. As the infrared touch screen in the work of no capacitor charge and discharge process, the response speed faster than the capacitor, but the resolution is low.
Know the working principle of the touch screen, we come to talk about how to operate the touch screen! In order to better help you operate the touch screen, I especially summed up the following some of the operating methods and techniques:
1, if you are using a capacitive touch screen, it is recommended that you first use, first in accordance with the requirements of the instructions to install the necessary capacitive touch screen driver, and then click on the screen with the “start” / “Program” / “Microtouch Touchware” to run the screen calibration program, calibration is complete, the system automatically after the calibration of the data stored in the controller register, after the re-start the system no longer need to re-calibrate the screen.
2, if you operate the capacitive touch screen halfway, re-change the touch screen display resolution or display mode, or adjust the touch screen controller refresh rate, feel the cursor and touch point can not correspond, you must re-touch the screen The system performs a calibration operation.
3, in order to ensure the normal operation of the touch screen system, in addition to ensuring the correct installation of the system software, we must also remember in a host do not install two or more than two or more touch screen driver, this will easily lead to system operation Conflict, so that the touch screen system can not be used normally.
4, in the use of resistive touch screen, if you find the cursor does not move or can only move in the local area, you can check the touch screen touch area is always the other touch objects always pressure, for example, once the touch screen is the display shell or cabinet shell pressure Live, it is equivalent to a point has been touched, then feedback to the controller coordinates of the location is not accurate, of course, the cursor can not be properly positioned. If the cabinet case is pressed against the touch area, you can adjust the distance between the cabinet and the monitor screen. If the display housing is pressed against the touch area, you can try to loosen the screws of the monitor housing.
5, in front of the author once mentioned that once the system in the replacement display resolution, adjust the screen size and the first installation will appear when the click is not allowed or drift, need to start the application comes with the positioning program repositioning, but Everyone in the positioning, it is best to use a relatively thin pen or fingertip positioning, so more accurate.
6, the surface acoustic wave touch screen work environment requires a higher, it must be required to work in a clean, no dust pollution in the environment, but also regularly clean the touch screen surface dust, otherwise, the dust in the air cover the touch screen around Reflect the stripes or transducers, it will affect the correct positioning of the system.
7, do not let the touch screen surface with water droplets or other soft things stick to the surface, otherwise the touch screen is easy to mistakenly believe that the touch of the surface caused by sound waves are not allowed. Also, remove the dirt from the touch screen surface with a soft, dry cloth or detergent carefully wipe it out from the center of the screen or clean the touchscreen surface with a dry cloth dampened with industrial alcohol or glass cleaning solution.
8, if the hand or other touch to touch the surface acoustic wave touch screen, the touch screen reaction is very slow, which shows that the touch screen system is already outdated, the internal clock frequency is too low, or because the touch screen surface water droplets in the move, to For quick response to the touch screen, you must replace or upgrade the system, or wipe the surface of the touch screen with a rag.
9, the touch screen is usually used for serial signal transmission, from the PS / 2 port to take the signal, and TPS screen is directly from the host power supply. If the indicator does not light, indicating that no signal is taken, the PS / 2 line on the control box may be broken. If the light is on, but still not flash, indicating that the control box is broken, so we must replace the control box. If you change the control box or not, it is possible that the screen is pressed too tightly, need to be slightly around the screws loose, because the touch screen is composed of special materials, it is not easy to damage. If the serial port is bad or disabled, will lead to the driver can not be installed, because the installation driver will automatically find the serial port. Even if you can install, will appear the mouse does not move or can not locate. It is best not to use the serial mouse to determine the serial port is good or bad, the serial port 9 for their own use in different ways. If the screen is crimped, or if the ground is not connected, it can not be positioned. If there are some areas can not click or slow response, there may be dust, need to open the shell to remove the dust.
10, when the touch screen with a finger touch the screen of a certain position, the touch screen without any reaction, it is likely that the location of the ITO coating should be damaged or scratched, the only way is to re-purchase the new touch screen.
11, when the finger touch the surface of the sound wave touch screen of a certain position, the touch screen without any reaction, it is likely that the corresponding position should be reflected in the touch strip is partially covered or scraped by a hard object, for the former case As long as the soft cloth to touch the location can be wiped clean, for the latter case, we can only re-purchase a new touch screen.
12, if the user in the operation of the touch screen, touch the direction of the move is to the left, but the system’s cursor is moving to the right, the failure may be due to the control box and the touch screen connected to the connector or reverse touch screen position, The user as long as the direction of the re-swap just fine.
13, in the confirmation of the connection to the host keyboard port connection is correct, and the driver installation process selected serial port number and the touch screen is actually connected to the correct serial number, the surface acoustic wave touch screen still can not work, you can re-format Hard drive, and install the latest drivers required by the system.
14, in the surface acoustic wave touch screen calibration, to ensure that the system pre-installed MOUSEWARE software and touch screen drive can not conflict, or will not be correct calibration operation.
15, the user in the operation of the capacitive touch screen, if the system does not respond, you can check the touch screen connection is connected, check the power part of the first through a keyboard converter head will be connected to the host keyboard port, and then the other head Connect the computer keyboard, and will take a 5V power supply connector into the host serial port.

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