In the display technology is to high clear, low electromagnetic radiation, low consumption and small volume, etc.. Although the production technology of CRT (cathode ray tube) display is becoming more and more mature, the quality of the picture is also getting better, but its volume and radiation problem is still the inevitable. Therefore, LCD display with its small size, light weight, no radiation, and other features to speed up the pace of the replacement of the traditional CRT display, but also by many people as the terminator CRT. Let's talk about the working principle of the LCD display.
    Liquid crystal display is the most important material is liquid crystal, which is a regular arrangement of organic compounds, is a kind of material between solid and liquid, is generally used in the molecular arrangement is the most suitable for the manufacture of liquid crystal display nematic thin column type liquid crystal. The physical characteristics of the liquid crystal is: when the power is on the conduction, the molecular arrangement of the orderly, make the light easy to pass; when the electric power molecules arranged in disorder, to stop the light through. Let the liquid crystal molecules, such as gate - like barrier or let the light penetrate. Most liquid crystals are organic matter, which is composed of a long rod. In the natural state, the long axis of the rod molecules is roughly parallel. The liquid crystal into a well - processing of the slotted plane, the liquid crystal molecules will be arranged along the groove, so if the groove is very parallel, then the molecules will be completely parallel. Technically speaking, the liquid crystal panel contains two very fine sodium free glass material, called Substrates, which is sandwiched between a layer of liquid crystal. When the beam passes through the liquid crystal, the liquid crystal itself will stand or twist the shape of the irregular shape, and thus block or make the beam pass through.
    From the perspective of the structure of the liquid crystal display, whether it is a notebook computer or a desktop system, the use of LCD display is composed of different parts of the layered structure. LCD consists of two pieces of glass plate, the thickness of about 1mm, which consists of a liquid crystal material of 5 m uniform spaced. Because the liquid crystal material itself is not luminous, so on both sides of the display screen has as a light source of the lamp tube, and a backlight plate (or uniform plate) and a reflecting film on the back of the liquid crystal display, the backlight plate is composed of fluorescent substances can emit light, its role is mainly provided for the uniform background light. The light emitted by the backlight is entered into the liquid crystal layer containing thousands of liquid crystal droplets after passing through the first layer of polarization filter layer. Droplets in the liquid crystal layer are contained in a small cell structure, one or more cells constitute a pixel on the screen. Between the glass plate and the liquid crystal material is a transparent electrode, the electrode is divided into rows and columns, at the crossing point of the line and column, by changing the voltage and changing the optical rotation state, the role of the liquid crystal material is similar to a small light valve. The control circuit and the driving circuit of the liquid crystal material are peripheral. When an electric field is generated in the electrodes in the LCD, the liquid crystal molecules will be distorted, and the light rays passing through them have a rule of refraction, and then a second layer filter is displayed on the screen.
    Liquid crystal display technology also has weaknesses and technical bottlenecks, compared with the CRT display brightness, image uniformity, visual angle and reaction time are obvious gaps. The reaction time and visual angle depend on the quality of the LCD panel, and the uniformity of the image and the auxiliary optical module are very significant. The brightness of the LCD display mainly depends on the backlight.For liquid crystal displays, the brightness is often related to his back light source. The more light the back light source, the brightness of the LCD display will be improved. In the early LCD, because only use 2 cold light source tube, often caused by uneven brightness and other phenomena, at the same time, the brightness is not satisfactory. Until the end of the use of 4 cold light source tube products, the introduction of a small improvement in.
   The signal response time is the LCD cell response delay. Is actually refers to the liquid crystal cell from a molecular arrangement state into another molecular arrangement need time, response time is, the smaller the better. It reflects the speed of response to input signals of the liquid crystal display pixel, that pixel by the dark turn bright or dark by the light switch speed. The smaller the response time, the user will not have the feeling of the tail when watching the motion picture. Some manufacturers can achieve the rapid response of the signal through the conductive ion concentration in the liquid crystal, but the color saturation, brightness, contrast will have a corresponding reduction, and even the phenomenon of partial color. The signal response time went up, but at the expense of LCD display effect. Some manufacturers such as "pure" in the display circuit is used to add a IC image output control chip, specifically to display the signal processing method to achieve. IC chip can be based on the VGA output video frequency signal, adjust the signal response time. Since no change of the physical properties of liquid crystal, so the brightness, contrast, color saturation are not affected, the method of manufacturing cost is relatively high.
Can be seen from the above, the quality of the liquid crystal surface and can not completely represent the quality of the LCD monitor, no excellent display circuit with no good panel also can not.