From the composition of projector products, it includes three main parts: core projection imaging module, optical engine, electrical control and interface. Among them, the core projection imaging component is the core of the projector product, which occupies a very important part in the cost composition of the whole projector product, and its position is quite similar to that of the processor in the computer. ? Up to now, the development of projectors has mainly gone through three stages, which are realized by three typical display technologies, namely CRT projection technology, LCD projection technology and DLP projection technology developed in recent years.

1 and CRT (cathode ray tube) as imaging devices, CRT is the earliest and most widely used display technology. CRT projector can be said to be the originator of projectors. CRT projector is also called three-gun projector, and its working principle is no different from CRT display. Its light source and imaging are CRT. The working characteristics of CRT projectors are essentially different from those of LCD and DLP projectors. It decomposes the input signal source into the fluorescent screens of R (red), G (green) and B (blue) CRT tubes, and the phosphor emits light, amplifies and converges under the action of high voltage, and displays color images on the big screen. CRT projector has high resolution, good contrast, good color saturation, strong signal compatibility and very mature technology. In terms of brightness, CRT projectors are much lower. So far, its brightness value has been hovering below 300 lumens. At the same time, the operation of CRT projector is complicated, especially the convergence adjustment is cumbersome, and the body volume is large. It is only suitable for installation in a relatively fixed place with weak ambient light, and is not suitable for moving. Therefore, although the projector market once flourished in the early stage of development, CRT projectors are rarely used at present and basically quit the projector market.

2.LCD projector LCD display technology is one of the leading technologies in the projector market at present. Liquid crystals include active liquid crystals and inactive liquid crystals. Inactive liquid crystals reflect light and are generally used in notebook computers and movie projectors. Active liquid crystal has light transmittance, and it is made into LCD panel for projector. LCD projectors are divided into LCD panels and LCD light valves. Most of our common projectors are LCD flat panel projectors. A. LCD projector LCD projector uses the electro-optical effect of liquid crystal to control the transmittance and reflectivity of liquid crystal cells through circuits, thus producing beautiful images with different gray levels and as many as 654.38+067 million colors.