Product Overview: LCD liquid crystal display is the abbreviation of Liquid Crystal Display. The structure of LCD is to place liquid crystals in two parallel glasses. There are many vertical and horizontal small wires in the middle of two glass plates, and the rod crystal molecules are controlled through energization or not. Change direction and refract light to create a picture. It is much better than CRT, but the price is more expensive. product structure: Each pixel of the liquid crystal display consists of the following: a column of liquid crystal molecules suspended between two transparent electrodes (indium tin oxide), and two polarization filters perpendicular to each other on the outside. If there is no liquid crystal between the electrodes, the polarization direction of the light passing through one of the polarization filters will be completely perpendicular to the second polarization plate, and thus be completely blocked. However, if the direction of polarization of light passing through a polarizing filter is rotated by the liquid crystal, it can pass through another polarizing filter. The rotation of the liquid crystal in the polarization direction of the light can be controlled by the electrostatic field, so that the control of light can be achieved. Liquid crystal molecules are extremely susceptible to induced electric charges due to the influence of an applied electric field. A small amount of charge is applied to the transparent electrode of each pixel or sub-pixel to generate an electrostatic field, and the molecules of the liquid crystal will be induced by this electrostatic field to generate an induced charge and generate an electrostatic torsion, which causes the original rotational arrangement of the liquid crystal molecules to change and thus also change. The amount of rotation through the light. Change the angle so that it can pass through the polarizing filter. Some liquid crystal displays turn black under the influence of alternating current, alternating current destroys the spiral effect of the liquid crystal, and after shutting off the electric current, the liquid crystal display screen will become bright or transparent, this kind of liquid crystal display screen is common in the notebook computer and the low-price liquid crystal display screen. Another type of liquid crystal display commonly used in high-definition liquid crystal displays or large LCD televisions is when the power is turned off, the liquid crystal display is opaque. In order to save power, the liquid crystal display uses a multiplexing method. In the multiplexing mode, one end of the electrodes is grouped together, each set of electrodes is connected to one power supply, and the other end of the electrodes are also connected in groups. Each set is connected to a power supply. At the other end, the packet design ensures that each pixel is controlled by an independent power source. The electronic device or the software that drives the electronic device controls the pixel display by controlling the on/off serial of the power supply. The indicators for testing the LCD include the following important aspects: display size, response time (synchronization rate), array type (active and passive), viewing angle, supported colors, brightness and contrast, resolution and screen aspect ratio, And input interfaces (such as visual interfaces and video display arrays). Product principle: The LCD liquid crystal projector is a combination of liquid crystal display technology and projection technology. It utilizes the electro-optical effect of liquid crystals to control the transmittance and reflectivity of liquid crystal cells through circuits, thereby generating different gray levels and up to 16.7 million colors. Beautiful image. The main imaging device of the LCD projector is a liquid crystal panel. The size of the LCD projector depends on the size of the LCD panel. The smaller the LCD panel, the smaller the projector's size. According to the electro-optic effect, liquid crystal materials can be classified into two types of active liquid crystals and inactive liquid crystals, in which the active liquid crystal has high light transmittance and controllability. The liquid crystal panel uses active liquid crystal, and people can control the brightness and color of the liquid crystal panel through the relevant control system. Like liquid crystal displays, LCD projectors use twisted nematic liquid crystals. The light source of the LCD projector is a dedicated high-power light bulb, and the light emitting energy is much higher than that of a CRT projector using fluorescent light, so the brightness and color saturation of the LCD projector are higher than those of a CRT projector. The pixels of the LCD projector are the liquid crystal cells on the liquid crystal panel. Once the liquid crystal panel is selected, the resolution is basically determined. Therefore, the function of the LCD projector to adjust the resolution is worse than that of the CRT projector. According to the number of internal LCD panels, LCD projectors can be divided into single-chip and three-chip LCDs. Most modern LCD projectors use 3-chip LCD panels (Figure 1). The three-chip LCD projector uses red, green, and blue three liquid crystal panels as control layers for red, green, and blue light, respectively. The white light emitted by the light source is condensed into the dichroic mirror group after passing through the lens group. The red light is firstly separated and projected onto the red liquid crystal panel. The image information represented by the transparency under the “record†of the liquid crystal panel is projected into an image. Red light information. The green light is projected onto the green liquid crystal panel to form the green light information in the image. The same blue light passes through the blue liquid crystal panel to generate the blue light information in the image. The three colors of light converge in the prism and are projected by the projection lens. A full-color image is formed on the projection screen. Three-chip LCD projectors have higher image quality and higher brightness than monolithic LCD projectors. LCD projectors are smaller, lighter in weight, simpler in manufacturing process, higher in brightness and contrast, and moderate in resolution. Nowadays LCD projectors occupy a market share of about 70% of the total market share, which is the current market share. The highest and most widely used projector. Features: 1, low voltage micro power 2, small and exquisite appearance, thickness is only 6,5-8mm 3, passive display type (no glare, does not stimulate the human eye, will not cause eye fatigue) 4, shows a large amount of information (because the pixels can be done very small) 5, easy to color (can be very accurate reproduction on the chromatogram) 6, no electromagnetic radiation (safety to humans, conducive to the confidentiality of information) 7, long life (this device has almost no deterioration problem, so the life is extremely long, but the backlight life of the LCD is limited, but the backlight can be replaced) Product Categories: The liquid crystal display can be divided into passive matrix LCD and active matrix LCD according to different control modes. Segmented display and dot matrix display. Segment codes are the earliest and most common display methods, such as calculators and electronic watches. Since MP3 has been developed, dot-matrix formats such as MP3, mobile phone screens, and digital photo frames have been developed. 1, passive matrix Passive-matrix LCDs are greatly limited in brightness and viewing angle, and their response speed is slow. Due to the problem of picture quality, such a display device is not conducive to the development of a desktop display. However, due to a low cost factor, some displays on the market still employ a passive matrix LCD. The passive matrix LCD can be divided into TN-LCD (Twisted Nematic-LCD, Twisted Nematic LCD), HTN-LCD (High Twisted Netamic-LCD, High Twisted Nematic LCD), and STN-LCD (Super TN-LCD). Twisted nematic (LCD) and DSTN-LCD (Double layer STN-LCD, double layer supertwisted nematic LCD). 2, active matrix Currently widely used active matrix LCD, also known as TFT-LCD (Thin Film Transistor-LCD, thin film transistor LCD). The TFT liquid crystal display has built-in transistors in each pixel of the picture, which can make the brightness brighter, the colors more abundant, and the wider viewing area. Compared with CRT displays, the flat display technology of LCD displays is characterized by fewer parts, fewer desktops, and less power consumption, but CRT technology is relatively stable and mature. Product Specifications: 1, visible area The size of the LCD display is the same as the actual screen area that can be used. For example, a 15-inch LCD display is approximately equal to the viewing range of a 17-inch CRT screen. 2, visual angle The viewing angle of the liquid crystal display is symmetric, but the top and bottom are not necessarily symmetrical. For example, when the incident light of the backlight passes through the polarizer, the liquid crystal, and the alignment film, the output light has a specific directional characteristic, that is, most of the light emitted from the screen has a vertical direction. If we look at a completely white picture from a very oblique angle, we may see black or distorted colors. In general, the upper and lower angles are less than or equal to the left and right angles. If the viewing angle is 80 degrees left and right, it means that the screen image can be clearly seen when the screen is at a position of 80 degrees from the normal of the screen. However, due to the different scope of human vision, if you do not stand in the best viewing angle, you will see errors in the color and brightness. Currently, some vendors have developed various wide viewing angle technologies to try to improve the viewing angle characteristics of LCDs, such as IPS (In Plane Switching), MVA (Multidomain Vertical Alignment), and TN FILM. These technologies can increase the viewing angle of the liquid crystal display to 160 degrees or even more. 3, pitch We often ask how big is the dot pitch of the liquid crystal display, but most people do not know how this value is obtained, let us now understand how it is obtained. For example, a typical 14-inch LCD has a viewing area of ​​285, 7mm x 214, and 3mm. Its maximum resolution is 1024 x 768, so the dot pitch is equal to: visible width/horizontal pixels (or visible height/vertical pixels ), ie 285, 7mm/1024=0, 279mm (or 214, 3mm/768=0,279mm). 4, color degree The important color of LCD is of course the degree of color expression. We know that any color in nature is composed of three basic colors: red, green, and blue. The LCD panel is composed of 1024×768 pixels. Each independent pixel color is controlled by three basic colors of red, green, and blue (R, G, and B). The liquid crystal display produced by most manufacturers, each basic color (R, G, B) reaches 6 bits, that is 64 degrees of expression, then each individual pixel has 64×64×64=262144 colors. Many manufacturers also use the so-called frame rate control (FRC) technology to display full-color images in an emulated manner. That is, each basic color (R, G, B) can reach 8 bits, that is, 256 performance degrees. , then each individual pixel has up to 256×256×256=16,777,216 colors. 5, the contrast value The contrast value is the ratio that defines the maximum brightness value (all white) divided by the minimum brightness value (all black). CRT displays typically have contrast ratios as high as 500:1, so that rendering a true black screen on a CRT monitor is easy. However, it is not easy for the LCD. The backlight formed by the cold cathode ray tube is difficult to perform fast switching operations. Therefore, the backlight is always on. In order to get a full black picture, the liquid crystal module must completely block the light coming from the backlight, but in terms of physical characteristics, these components cannot fully meet this requirement, and there will always be some light leakage. In general, the acceptable value for human eyes is about 250:1. 6, brightness value The maximum brightness of the liquid crystal display is usually determined by a cold cathode ray tube (backlight), and the brightness value is generally between 200 and 250 cd/m2. The brightness of the liquid crystal display is slightly lower and the screen will feel dark. Although technically higher brightness can be achieved, this does not mean that the higher the brightness value, the better, because too high brightness of the display may cause the viewer's eyes to be injured. 7, response time The response time refers to the speed at which each pixel of the liquid crystal display reacts to the input signal. Of course, the smaller the value, the better. If the response time is too long, it may cause the liquid crystal display to have the feeling of tail dragging when displaying a dynamic image. The response time of a typical liquid crystal display is between 20-30ms. Hair Scissors Set,6.0 Inch Barber Scissors,440C 440C Hair Scissors,Professional Hair Scissors Heb Zhangjiagang Mister Tools Co., Ltd , https://www.msscissors.com