Thorough introduction of rear projection technology

reality

Member
The rear projection is relative to the rear Projector. The market is common, people often mentioned multimedia projector is mainly pointing projector. In principle, rear projection and forward projection are the same.

Definition of rear projection

Simply put, forward projection means that the observer and the projector are on the same side of the reflecting screen. The light from the projector shines onto the screen, and the observer sees the light reflected back from the screen. Rear projection means that the viewer and the projector are located on both sides of the rear projection screen, and the projector is installed at the bottom of the fuselage. When the light projected from the projector shines on the translucent rear projection screen, part of the light will pass through, while the viewer will see the light transmitted.

For users using rear projection, since the projector and screen are integrated, there is no need to optically adjust the system and it is as easy to use as a normal TV. In rear projection, the projector is placed in the box, and the image projected onto the screen will not be affected by the ambient light, so the image can be perfectly displayed in a brighter environment. There is a large space in the rear projection box, which allows easy access to TV signals and high quality sound. Rear projection is a product of this principle. Rear projection television can be divided into CRT(cathode ray tube), LCD(liquid crystal), DLP(digital optical processor), LCOS(reflecting liquid crystal) and other types according to the type of projector used.

1. The CRT rear projection

The rear projection has the advantages of high brightness and long continuous use. Due to the mature CRT technology, large production scale and high cost performance, the rear projection is in a dominant position in the current rear projection market. The disadvantage of CRTrear projection is that it is difficult to increase the brightness, since it is based on phosphor, and it is easy to age the picture tube. If it takes a long time, the picture will become dark and the definition will be reduced.

2. LCD rear projection

LCD rear projection adopts very mature liquid crystal projection technology, which has good color reduction, brightness and contrast are better than CRT rear projection. LCD rear projection since it relies on light bulb, it is very easy to increase the brightness, as long as the power of the bulb is increased, with the continuous improvement of technology, the life of the bulb has been greatly improved, which is close to the life of ordinary TV. The main reason why LCD rear projection has not become mainstream in the rear projection market is the high cost; In addition, compared with the CRT rear projection, although the display effect is good, due to its working principle, it cannot be turned on and off as the CRT rear projection, so it takes time to warm up the machine and dissipate the heat after the machine is turned off.

3. The DLP rear projection

DLP rear projection has high brightness, long continuous use and complete function. Due to the use of digital processing technology, it has great advantages in the reproduction of digital signals. DLP technology can achieve miniaturization more easily than CRT and LCD, and the cost is lower, the development prospect is optimistic by the industry. In the past, the DLP rear projection, which is 42/52 inches, has been widely praised for its clear and bright image.

4. LCOS rear projection

LCOS rear projection has the advantages of high brightness, high resolution and low power consumption. At present, products based on LCOS technology have not been mass-produced on a large scale, and only a few manufacturers (such as LG, skyworth, etc.) have launched several products. As the LCOS display chip mass production has the potential to significantly reduce the cost, it is regarded as a popular product technology by the industry. As the technology matures, once the mass production is realized, it will have a very good market prospect.
 
Top