Principle of liquid crystal display
Tags: OLED TFT This article refers to the address: http:// Principle of liquid crystal display Liquid crystal is a substance between a solid state and a liquid state. It is an organic compound having a regular molecular arrangement. If it is heated, it will exhibit a transparent liquid state, and if it is cooled, a turbid solid state of the crystal particles will occur. Because of this characteristic, it is called Liquid Crystal. The structure of the liquid crystal molecules used in the liquid crystal display is similar to that of a fine match stick, which is called a Nematic liquid crystal. A liquid crystal display manufactured by using such a liquid crystal is also called an LCD (Liquid Crystal Display). In the liquid crystal television, a voltage is applied to the liquid crystal between the two glasses, and the screen is reproduced by molecular arrangement change and zigzag change. The screen is created by the collision of the electron group, and the screen is formed by the perspective reflection of the external light. Classification of liquid crystal displays There are four common types of liquid crystal displays; TN-LCD (Twisted Nematic-LCD, Twisted Nematic LCD); STN-LCD (Super TN-LCD, Super Twisted Nematic LCD); DSTN-LCD (Double layer STN- LCD, double-layer super twisted nematic LCD); TFT-LCD (Thin Film Transistor-LCD). The three basic display principles of TN-LCD, STN-LCD and DSTN-LCD are the same, except that the twist angle of the liquid crystal molecules is different. The liquid crystal molecules of the STN-LCD have a twist angle of 180 degrees or even 270 degrees. The TFT-LCD uses a different display method than the TN series LCD. TN is usually applied to electronic watches and calculators because it cannot display delicate characters. As the display TN series of liquid crystal displays have been basically eliminated, STN due to the large twist angle, the character display is more delicate than TN, but also supports basic color display, mostly used for LCD TVs, LCD monitors, handheld game consoles and so on. The subsequent DSTN and TFT were widely used as liquid crystal display devices. The DSTN liquid crystal display is mostly used in early notebook computers. It is also called pseudo color display because of the limited number of colors supported. TFT is a kind of LCD, also called true color screen. In brightness, but the angle is stronger than the other. TFT can be applied to notebook computers and gradually enter the flat-panel TV market and become mainstream. LCD liquid crystal display LCD is the full name of liquid crystal display: it includes TFT, OLED, UFB, TFD, STN and other types of liquid crystal display. LCD principle Liquid crystal displays (LCDs) are now very common displays. It has the advantages of small size, light weight, low power consumption, low radiation, and easy to carry. The principle of a liquid crystal display (LCD) is quite different from that of a cathode ray tube display (CRT). The LCD is a display device based on the electro-optical effect of liquid crystal. The character segment display device including the segment display mode; the character display, the graphic, the image display device in the matrix display mode, the large-screen liquid crystal projection television LCD screen in the matrix display mode, and the like. The working principle of the liquid crystal display is to utilize the physical properties of the liquid crystal, and conduct electricity when energized, so that the liquid crystal alignment becomes orderly, and the light is easily passed; when not energized, the arrangement becomes chaotic and blocks the light from passing. The following describes the working principle of the three liquid crystal displays. T FT thin film transistor A TFT (ThinFilm Transistor) thin film transistor is one of the active matrix type liquid crystal displays AM-LCD. The TFT is provided with a special light pipe on the back of the liquid crystal to control the individual pixels on the screen "actively". It is the origin of the so-called active matrix TFT (activematrix TFT), which can greatly improve the reaction time. The reaction time of the TFT is relatively fast, about 80ms, and the STN is 200ms. If it is to be improved, there will be flickering. TFT panel principle Moreover, since the TFT is an active matrix LCD, the arrangement of the liquid crystals is memorable, and does not return to the original state immediately after the current disappears. TFT also improves the STN flicker (water ripple)-blurring phenomenon, effectively improving the ability to play dynamic pictures. Compared with STN, TFT has excellent color saturation, reducing power and higher contrast, but the disadvantage is that it consumes more power and costs. TFT-LCD technology is a technology that combines microelectronics technology with liquid crystal display technology. People use the technology of microelectronics fine processing on Si to transplant TFT arrays on large-area glass, and then use the mature LCD technology with the array substrate and another substrate with color filter. Forming a liquid crystal cell in combination, and then going through a post-process such as polarizing film coating, etc., and finally forming a liquid crystal display (screen). In a TFT-LCD, the function of the TFT is equivalent to a switching transistor. A commonly used TFT is a three-terminal device. A semiconductor layer is generally formed on a glass substrate, and has a source and a drain connected thereto at both ends thereof. And a gate insulating film is opposed to the semiconductor and a gate electrode is provided. The current applied between the source and drain electrodes is controlled by the voltage applied to the gate. In summary, TFT-LCD is different from the simple matrix of passive TN-LCD and STN-LCD. It has a thin film transistor (TFT) on each pixel of the liquid crystal display, which can effectively overcome the non-gating time. Crosstalk makes the static characteristics of the display LCD independent of the number of scan lines, thus greatly improving the image quality. The characteristics of the switching unit (ie, TFT) are required to meet the requirements of low on-state resistance and very large closed-state resistance. Following the LCD and LED, the OLED era is coming to us. The OLED scientific name is organic light-emitting diode. This new generation display technology after CRT (negative ray tube) and LCD (liquid crystal display) has high resolution, fast response, ultra-thin, low temperature resistance, rich color and power consumption. The amount is small, flexible display can be realized, and behind many advantages, there is a huge industry. At present, the development focus of global OLED manufacturers has shifted to AMOLED (Active Matrix Organic Light Emitting Diode). Well-known home appliance companies such as Sony, Samsung and LG all have their own advantages in OLED technology, and OLED technology is gradually being sought after by high-definition enthusiasts. So, what is the OLED technology that people call "fantasy images"? Interested friends please continue to understand. OLED, or Organic Light-Emitting Diode, is also known as Organic Electroluminesence Display (OELD). Since 2003, this display device has been widely used in MP3 players since 2003. For DCs and mobile phones that are also digital products, they have only been used in some exhibitions. The engineering samples of the screen have not yet entered the stage of practical application. In terms of flat-panel TVs, OLED technology has been applied to color TVs, and manufacturers of OLED TVs have gradually increased. At this year's CES Consumer Electronics Show, Samsung and LG have exhibited their large-size OLED TV products, and plans to It will be sold soon. In general, OLED screens have many advantages that LCDs can't match. The difference between OLED and TFT Although OLEDs with better technology will replace LCDs such as TFTs in the future, organic light-emitting display technologies have shortcomings such as short lifetime and large screen size. The OLED is constructed such that each OLED unit can be imagewise compared to a hamburger, the luminescent material is the vegetables sandwiched in the middle, and the display unit of each OLED can controlly generate three different colors of light. Like LCDs, OLEDs are also active and passive. In the passive mode, the cell selected by the row and column address is illuminated; in the active mode, there is a thin film transistor (TFT) behind the OLED unit, and the light emitting unit is lit under the TFT driving. In the current situation, passive OLEDs are more energy efficient, but active OLEDs display better performance. For the time being, OLED technology is ahead of LCD TVs with many advantages. With the continuous discovery of TV technology, OLED technology will gradually become popular and become the mainstream in the flat-panel TV market. The so-called mini projector is also called pico projector, TRT-Lcos Portable Projector. Mainly through the 3M LCOS RGB three-color projector and 720P film decoding technology, the traditional huge projector is refined, portable, miniaturized, entertaining and practical, making the projection technology closer to life and entertainment. best mini projectors under £100,mini projector pvo portable projector,mini projector portable,mini projector amazon,mini projectors for movies Shenzhen Happybate Trading Co.,LTD , https://www.happybateprojectors.com
Usually the projector has certain regulations on 2 aspects:
a). Size: Usually the size is the size of a mobile phone.
b). Battery life: It is required to have at least 1-2 hours or more of battery life when it is not connected to power.
In addition, its general weight will not exceed 0.2Kg, and some do not even need fan cooling or ultra-small silent fan cooling. It can be carried with you (it can be put into your pocket), and the screen can be projected to 40-50 inches or more.
Advantage:
1. Completely replace the MP5 player, video, listening to songs, playing games, e-books, picture browsing, etc. MP5 video is affected by physical performance, the screen can not be bigger, and the screen of this thing is at least 20 inches.
2. Instead of the TV function, the machine can have a built-in CMMB function, or it can be directly connected to the set-top box to play the TV, and it can be used as a 21-inch TV during the day.
Look, it can be used as a 60-100-inch TV at night to achieve the effect of home theater; it is convenient to move and break through the traditional film and television space. Even if you are on the mountain, you can also share today's TV series, movies, and MTV with your lover.
3. Business office: instead of large projectors, it is used for company meetings; the price of large projectors is 4,000 to 14,000, and the lamp life is more than 1,000 hours, which is not convenient to carry. 30,000 hours, no need to change the bulb for 3 years, easy to carry, the salesman only needs to bring a micro projector to demonstrate the new product, which can achieve the demonstration effect.
4. Teaching: training meetings, classroom teaching; traditional projectors are not easy to carry. In school classrooms, due to the naughty students, projectors are not safe to place in the classroom and are easily damaged by students. The portability of micro projectors makes up for the teaching vacancies. In the future, teachers only need to store the materials in the projector and show them to students for teaching, saving the trouble of textbooks and handwriting with pens and chalks.
In addition, the micro-projection has no radiation, which can fully protect pregnant women and people with myopia. Its low power consumption function is 1/1,000,000 of the power consumption of color TVs. One day of electricity has completely impacted the indicators of safety, environmental protection, health, etc., and has made amazing contributions to future social development, standing at the peak of the green world as a leader.