According to the projection method, the screen is mainly divided into: front projection screen and rear projection screen; according to the material of the screen, the screen is divided into hard screen and soft screen; according to the different application methods, the screen is divided into: electric, manual, frame, bracket; The screens are divided into regression type, diffuse reflection type and reflective type according to the light reflection; the screens are divided into flat, curved, cylindrical, and trapezoidal screens according to the shape of the screen surface. 1. Soft screen technology and type Regardless of the application method, the main technology of the front projection soft screen is the spraying technology of various materials on the upper surface of an opaque cloth, and the surface material is applied Different optical materials, the number and quality of optical factors in the optical materials, determine the viewing angle and surface gain of the screen, as well as other important parameters. The stability and uniformity of the surface spraying optical factors affect the quality of the screen picture. The optical factor of the screen surface optimizes the projection optics to improve the image quality. The number and distribution of the optical factor determines the gain, viewing angle and resolution of the screen. The optical factors and other pigments on the screen surface can optimize the color saturation of the projected image and the image. Wisdom lights up life, and all displays become possible. Whether it is front projection (the projector is placed in front of the screen, that is, the projection method of the projector and the audience in the same direction of the screen) or the rear projection soft screen, TIMAX can meet the different requirements of users , And customized, gain from 0.83 to 3.0 or even higher, can be achieved, curved screen, spherical screen, etc., used in stadiums, conference rooms, simulation rooms, home theaters, control centers and different occasions, making all displays possible ... 2. Types and technology of hard screens Hard screens are mainly diffuse reflection optical hard screens and Fresnel lens optical screens. (1) The technology of diffuse reflection rear projection hard screen diffuse reflection screen originated relatively early, but the early development was relatively slow. In recent years, with the expansion of the application range, it has developed rapidly. The main characteristics are: large viewing angle, low gain, and environmental protection. The light photography ability is relatively strong, and the application range is wide. One of the technologies of the diffuse reflection screen is to directly process the acrylic surface. The second technology of the diffuse reflection screen is to use transparent materials such as resin as the substrate and add some optical materials to its material. This technology has been maturely applied in various industries. The vertical and horizontal viewing angles are 180 degrees, and there is no solar effect. The size of the screen is relatively large. (2) Fresnel lens optical screen The Fresnel optical lens screen has textures on the front and rear surfaces of the screen, the surface facing the projector has concentric Fresnel lens textures, and the surface facing the audience has double convex ( The vertical stripes of the (cylindrical) lens, and the different lines on both sides optimize the projector’s optics, thereby greatly increasing the gain of the screen, but the vertical viewing angle of the screen is seriously affected. At present, famous international manufacturers mainly include: American STEWART screen company (manufacturing place: USA), DNP manufacturing place: Denmark), and Danish SVS screen company (manufacturing place: Denmark). According to the angle of the Fresnel lens groove, each screen has a different focal length to meet the needs of different lens projectors. The principle of the Fresnel optical lens screen, as shown in the figure: (3) Other rear-projection screens and some rear-projection screens are processed by different technologies because they are used in different occasions, such as: Holo screens, etc., used in window displays . In addition, some short-focal-length double-layer screens are specially used in rear projection cabinets. In principle, the screen with short-focus wide-angle lens must completely overcome the sun effect. The better way is to align the Fresnel screens. , Its effect is best. At the same time, some companies produce ultra-short-throw projection screens that add some black glass beads (pigments) in the middle of the double-layer screen to improve the ability to resist ambient light, and are used in some ultra-short-throw wide-angle lens projectors.