What is the difference between led TV and LCD TV

led LCD TV

In principle, liquid crystal display devices are somewhat like the advertising light boxes on the street. After a certain diffusion, the light source behind is evenly irradiated on the transparent film painted with the picture, thereby transmitting a bright picture. The LCD panel is like that layer of film, but the picture in it will change.
Traditional liquid crystal display devices use CCFLS (cold cathode fluorescent lamps) as the light source. Although the name is very professional, we understand it as a fluorescent lamp for home use, but the tube is very thin. Many objects have strange colors under fluorescent lamps, because the light they emit is not really sunlight. The sunlight light we have already adapted is composed of red orange yellow green blue blue purple and other colors in a certain proportion. However, the light of the fluorescent lamp is overemphasized in some colors, and some colors are lacking.
So the problem arises, the color of the light source behind the light box is not accurate enough, and the image generated after passing through the liquid crystal panel cannot naturally overcome the congenital deficiencies, resulting in color reproduction deviation. This is one of the reasons why LCD monitors have been difficult to satisfy professional users in image display.
QUALIA005 extends the color gamut of LCD TVs to 105% of the NTSC standard, which can basically reproduce all the natural scenes we have observed. Its core is the LED backlight system that replaces CCFL.

Advantages of LED backlight technology:
Wider color gamut (more than NTSC and EBU color gamut) to achieve more colorful colors;
High brightness, and can achieve stable brightness and color performance within the life span;
Adjustable backlight white balance, while ensuring overall contrast. When the user's video source is switched between the computer and the DVD player, the white balance can be easily adjusted between 9600K and 6500K without sacrificing brightness and contrast;
Can provide continuous area array light source for large screen;
Real-time color management. Because the three colors of red, green and blue independently emit light, it is easy to accurately control the current display color characteristics;
Reduce artificial traces in dynamic scenes without sacrificing brightness and longevity. Because the flickering frequency of traditional CCFL lamps is low, the dynamic scene may produce picture jumps. LED backlight can flexibly adjust the light emitting frequency, and the frequency is much higher than CCFL, so it can perfectly present the moving picture;
The brightness adjustment range is large. It is easy to achieve LED power control, unlike CCFL, there is a threshold for minimum brightness. Therefore, the user can easily adjust the brightness of the display device to the most pleasing state no matter it is in a bright outdoor or a completely dark indoor
Low electromagnetic radiation. The LED light source does not produce any rays, and there are no toxic substances such as mercury, which can be described as a green environmental light source;
Wide use temperature range, low voltage, impact resistance. Because the solid-state light-emitting device is adopted, the LED backlight has no delicate components, and has a strong adaptability to the environment.


Liquid crystal display, referred to as LCD (Liquid Crystal Display). The world's first liquid crystal display device appeared in the early 1970s and is called a TN-LCD (twisted nematic) liquid crystal display. Although it is a monochrome display, it is still popularized in the fields of electronic watches and calculators. In the 1980s, STN-LCD (Super Twisted Nematic) liquid crystal displays appeared, and TFT-LCD (thin film transistor) liquid crystal display technology was developed, but the liquid crystal technology is still immature and difficult to popularize. In the late 1980s and early 1990s, Japan mastered the production technology of STN-LCD and TFT-LCD, and the LCD industry began to develop rapidly.
Liquid crystal is a substance between solid and liquid. It is an organic compound with regular molecular arrangement. If it is heated, it will show a transparent liquid state, and if it is cooled, it will appear as a turbid solid state of crystalline particles. Because of its characteristics, it is called liquid crystal (Liquid Crystal). The arrangement of liquid crystal molecules used in liquid crystal displays is similar to that of thin matchsticks, called NemaTIc liquid crystals, and the liquid crystal displays manufactured using such liquid crystals are also called LCD (Liquid Crystal Display). In LCD TVs, a voltage is added to the liquid crystal between the two glasses, and the screen is reproduced through molecular arrangement changes and zigzag changes. The screen is made by the collision of electron groups to create the screen and form the screen through the perspective reflection of external light.

The advantages of LCD TVs are large resolution and high definition. Liquid crystal displays use purely flat glass plates from the beginning, and the display effect at a right angle to the plane looks much better than traditional monitors. However, in terms of resolution, the LCD monitor can theoretically provide higher resolution, but the actual display effect is much worse (there is a problem with an optimal resolution). Although the LCD TV can overcome the jitter and flicker of the scanning line, but Because the gap of the liquid crystal itself is relatively thick, it will cause the viewing effect of the image like a grid. Therefore, the best resolution of the LCD screen is generally up to 1024X768 (enough). The traditional display achieves a perfect display effect with the support of a better display card.
Low power consumption is converted according to the industry standard, the annual power consumption of 4.5 hours per day. Using a 30-inch LCD TV instead of a 32-inch CRT TV can save 71 kilowatts per year.
Due to the use of a CRT, a thin and portable traditional display must emit an electron beam to the screen through an electron gun. Therefore, the neck of the picture tube cannot be made very short. When the screen is increased, the volume of the entire display is bound to increase. The liquid crystal display controls the state of the liquid crystal molecules through the electrodes on the display screen to achieve the display purpose. Even if the screen is enlarged, its volume will not increase proportionally (only the size is increased and the thickness is not increased, so many products provide a wall-mounted function that allows The user saves more space), and the weight is much lighter than the traditional display with the same display area. The weight of the LCD TV is about 1/3 of the traditional TV.
The green environmental protection liquid crystal display has no radiation at all, and only a small amount of electromagnetic waves from the drive circuit, as long as the casing is strictly sealed, the electromagnetic waves can be excluded. Therefore, liquid crystal displays are called cold displays or environmentally friendly displays. There is no screen flicker in LCD TVs, which is not easy to cause visual fatigue.

Disadvantages of LCD
The viewing angle of the LCD is relatively small compared to the CRT display;
Liquid crystal is an organic compound with regular molecular arrangement between solid and liquid. Under the action of different current electric fields, the liquid crystal molecules will be arranged at a regular rotation of 90 degrees, resulting in a difference in light transmittance, so that the difference between light and dark under the power ON / OFF, each pixel is controlled according to this principle to form the desired image . LCD TVs are made using this principle. However, it is precisely because of this principle that all LCD TVs are difficult to make large in technology and expensive;
In terms of display response speed, traditional displays have very good response speed due to their technical advantages. TFT LCDs are less optimistic due to their display characteristics (low temperature does not work properly and there is a reaction time). The response time of the LCD is relatively long, so the performance in terms of dynamic images is not ideal;
The current manufacturing process determines that the LCD has point defects, and its manufacturing yield is relatively low, which also increases the manufacturing cost of the LCD to a certain extent. Therefore, the price is the biggest obstacle to the promotion of LCD. Sometimes a good 17 "LCD will cost more than 20,000 yuan, which is the price of a superb 21" flat display for CRT;
Display quality: The display screen of traditional monitors uses phosphors, which are displayed by hitting the phosphors with electron beams, so the brightness of the display is brighter than that of the liquid crystal transmissive display (using fluorescent lamps as the light source). LCD can only display 18-bit color (about 262144 colors) in theory, but the color depth of CRT is almost infinite;
The LCD display is fragile and easily damaged. This increases the difficulty of using and maintaining the LCD TV;
Most domestic and foreign TV manufacturers believe that in the next few years, the more popular high-definition TVs and rear projection TVs will be gradually replaced by LCD TVs. In terms of technical content, LCD TVs basically use progressive scanning, 4H digital comb filter, DVD component terminals, and more than 16.7 million color phenomena. At present, there is no complete set of specifications for LCD products at home and even in the world. This has caused the problem of inconsistent standards for LCD products on the market, which makes users easily confused and even misled when choosing LCD products. .

The difference between LCD monitor and LCD TV

The monitor is simpler in function than the TV but in terms of performance, the requirements are higher than the TV, reflecting the following three points:

One is the image definition: because the traditional TV set receives the radio frequency signal emitted by the TV station, the video image bandwidth corresponding to this signal is usually less than 6M, so the TV set resolution is usually greater than 400 lines, which requires the monitor to have a high Compared with traditional TV sets, professional monitors should have bandwidth compensation and boost circuits on the channel circuit to make the passband wider and the image sharper.

The second is the color reproduction degree. If the definition is mainly determined by the amplitude and frequency characteristics of the video channel, the reduction degree is mainly determined by the chromaticity of the three primary colors of red (R), green (G), and blue (B) in the monitor. Determined by the phase of the signal and the brightness signal. Since the monitor usually observes static images, the requirements for the color reproduction of the monitor are higher than that of the TV. Therefore, the viewing channel of professional monitors should have the brightness, chroma processing and R, G, B processing. Accurate compensation circuit and delay circuit to ensure the phase synchronization of the bright / color signal and the R, G, and B signals.

The third is the stability of the whole machine: when the monitor constitutes a closed-circuit monitoring system, it usually needs 24 hours a day, 365 days a year of continuous uninterrupted power supply (and the TV usually only works for a few hours a day), and some monitor applications The environment may be harsh, which requires higher reliability and stability of the monitor. Compared with a TV, in terms of design, the monitor's current, power consumption, temperature and resistance to electrical interference, electrical shock capability and margin, and the average trouble-free use time are much longer than the TV, and the monitor must also Use a fully shielded metal shell to ensure electromagnetic compatibility and interference performance; in the selection of components, the characteristics of the components used in the monitor, such as withstand voltage, current, temperature, humidity, etc., are higher than those used in TV sets; In terms of installation and commissioning, especially the technological requirements of the aging of components and the whole machine, the requirements of the monitor are also higher. When the TV is manufactured, the aging of the whole machine is usually about 8 hours at normal temperature on the assembly line, and the whole machine of the monitor Aging needs to be energized on an aging pipeline in a high-temperature and high-humidity closed environment for more than 24 hours to ensure the stability of the whole machine.

The difference between plasma TV and LCD TV

The full name of Plasma TV is Plasma Display Panel, which is called Plasma TV in Chinese. It is a device that injects a mixed gas between two ultra-thin glass plates and applies voltage to use fluorescent powder for imaging. Compared with CRT display, it has the characteristics of high resolution, large screen, ultra-thin, rich and bright colors. Compared with LCD, it has the characteristics of high brightness, high contrast, large viewing angle, bright colors and rich interfaces.

The difference between led TV and LCD TV LCD TV has LCD, LED, and this means that the LCD TV uses the backlight as the type, as far as the current situation is based on the LCD TV using LED, its clarity, contrast, picture quality are obtained In order to improve, while using the power saving and TV body can be made thinner. Now the most reflected is the flagship product of Toshiba TV SC650. It has a great appearance, good audio-visual effects (including color and picture quality), good screen (Samsung screen), good after-sales. What can be said.

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