Optical large screen projection technology analysis

 Rear-projection big-screen projection technology has the greatest feature is the ultra-high-resolution, large display screen, ultra-high resolution, this advantage makes large-screen projection edge blending occasions at conferences have an unprecedented advantage. 1, projection screen choice is unifocal screen? Or multifocal screen? Rear-projection big-screen projection screen is an important part. Although simple projection screen, but the screen focal length and there is a direct link. Especially in the projection system, it is a rather special and major parameters. In the manufacturing process of the optical screen, the Fresnel lens back surface concentric to the cutting direction, in order to control the angle of incidence of light. In order to form a good image on the projection screen to focus on the distance of the light source will have certain limits, the projector in this range, in order to make an image to get a good degree of focus and resolution to avoid image blur or ghosting. If the screen does not match the focal length of the projection distance, the lens is easier to cut traces on the screen as a spiral striped background is displayed, the four corners of the screen's outstanding performance. Projection screen with a single focal length range is called monofocal screen; projection screen can have a variety of different focal length range, try to limit the focal length from the screen, said multifocal screen, such as the United States 3M and Denmark DNP rear-projection screen. To customers in the design, the engineer must take into account this aspect, otherwise, not professional! 2, how to design the best video screen focal length and the point? The presence of the screen and the projector lens focal length optics close relationship, under normal circumstances, the focal length of the screen in any case not recommend more than the lens focal length. If it is affected by the environment, the lens focal length to allow controlled within 1.4 times larger than the screen of the focal length. Within this range, select a different focal length lens of the projector will directly affect the position of the best video viewing point. 3, when the projection screen behind the space is small, how to choose the refractor? Rear-projection big-screen projection problem often encountered in the project is the use of space-saving issue refractor. Ordinary people do not understand the mirror, which is very poor, because of the interaction between the back most of the use mercury mirror coating, mercury coated glass surface and will form multiple refraction and reflection light path, resulting in blurred image ghosting. Professionals using vacuum coating mirror once or several times of refraction. Currently a good vacuum coating mirror reflection rate up to 94%, so the birefringence projection does not cause significant loss of brightness. 4, how to calculate the distance refractor, projector and projection screen between? Many engineers use some probability to estimate one or more refraction can shorten the projection distance, but the lack of scientific and rigorous manner, because the data and screen installation height, projection mode (off-axis or off-axis), the volume of the projector, mirror area and so closely related. When we have all relevant environmental data projector, the use of AutoCad software to simulate mapping is a very effective, efficient and accurate method. This article comes from true color DLP big screen, http: //www.bjrealcolor.com/