The principle of touch LCD is actually very simple. Simply put, a touch screen is installed on the display to become a display with touch function. The more popular on the market is the liquid crystal touch display (CRT has gradually withdrawn from the arena). According to the difference of the installed touch screen, it is generally divided into four types: resistive type, capacitive type, acoustic wave type and infrared type.
1. What is a LCD touch screen
LCD touch screen is an active matrix LCD driven by thin film transistors (TFTs). It mainly uses current to stimulate liquid crystal molecules to generate dots, lines, and surfaces with the back light tube to form a picture. IPS, TFT, and SLCD are all subclasses of LCD.
The working principle of the liquid crystal display is: under the action of the electric field, the arrangement direction of the liquid crystal molecules is changed, so that the light transmittance of the external light source is changed (modulated), the electro-optical conversion is completed, and then the three primary color signals of R, G, and B are used. Different excitation, through red, green, blue three primary color filter, complete the color reproduction in time domain and space domain.
2. Principle of LCD touch screen
LCD is a display that uses liquid crystal as material. Liquid crystal is a kind of organic compound between solid state and liquid state. Under normal temperature conditions, it exhibits both the fluidity of liquid and the optical anisotropy of crystal. It will become a transparent liquid when heated, and will become crystalline after cooling. turbid solid.
Under the action of the electric field, the liquid crystal molecules will change in arrangement, which will affect the change in the intensity of the incident light beam passing through the liquid crystal. Accordingly, through the control of the liquid crystal electric field, the light and dark changes of light can be realized, so as to achieve the purpose of information display. Therefore, the liquid crystal material acts like a small “light valve”.
Because there are control circuits and driving circuits around the liquid crystal material. When the electrodes in the LCD generate an electric field, the liquid crystal molecules will be twisted, so that the light passing through it will be refracted regularly (the optical rotation of the liquid crystal material), and then filtered by the second layer of polarizers and displayed on the screen.
3. LCD touch screen function
1. Telecommunications departments, banks and other institutions (business inquiries and service business promotion in business locations)
2. Government agencies (public information release, government disclosure, teaching application)
3. Catering industry, entertainment KTV, industry, logistics, (ordering machine, POS cash register, business inquiry, office automation)
4. Shopping center (shopping guide, merchant and product inquiry, advertising promotion, POS cash register)
5. Flagship store, specialty store, 4S store, chain store, retail store (POS cash register, new product recommendation, product display)
6. Company reception room or conference room (company introduction, exhibit display, advertising promotion, office automation)
7. Exhibition hall and venue design company (event venue layout)
8. Cinema (movie trailers and movie trailers)