[Analysis of the quality of commonly used scroll projection screens in home theater] Home projection screen technology introduction

Nowadays, it is widely used with projectors. The representative screens in home theater mainly include (1) white matte (WHITE MATT), (2) glass bead surface (GLASS BENDED), (3) pearl surface (PEARL), (4) ) Silver noodles SILVER and other 4 kinds. The quality of the screen is the most important consideration. Among them, the white rough surface and glass bead surface are more suitable for general home theaters. At present, a polarizing screen that can be used in a brighter environment is also on sale, but this kind of screen is more expensive and is generally seldom used in home theaters, so I won't introduce it here.

　　Due to the different material of the screen, the reflection method of receiving light from the projector will be different. Therefore, in view of this characteristic of the screen, the screen has a new classification: glass beaded screen, because it has the characteristic of reflecting the incoming light from the angle of incidence, so this kind of screen is retroreflective; and pearlescent The light reflected by the silver screen is reflected diagonally to the incident angle, so it is called the reflection type; the reflection of the white rough screen is completely independent of the angle of incidence, and the light is diffused and emitted, so this screen Known as the diffuse type, the white matte screen is the most capable of emitting natural light among the three types of screens. The following is a detailed introduction to several roll-type projection screens that are available on the market.

　　1, white matte screen 

　　 The white matt rough diffused wide-angle screen has a gain of about 1 (usually 'gain' is used to indicate the enhancement of light by the screen). The characteristic of this screen is that the reflection is non-directional when light is irradiated, and the field of view The angle is the largest among several screens, and it can show the same brightness from different angles. The picture quality is also mainly natural, and there is nothing to fault. If you want to enjoy movies in a darker room, then it is best to choose this screen. 

　　 White Matt Projection Screen (White Matt Projection Screen) is composed of polyvinyl chloride (Polyvinyl Chloride/PVC). Because PVC has the characteristics of waterproof, mildew and flame resistance, PVC is a popular type. The screen is indispensable. 

　　2, glass bead spherical screen (bead screen)

　　 The so-called beaded spherical screen is sprayed with a layer of very small glass balls on the screen. Because the surface of the screen is scattered with micro-shaped glass balls, it has strong reflectivity, especially for flat light. . The viewing angle of this retroreflective screen is narrower than other types of screens, but the gain of this screen is as high as 2.8, so even if it is combined with a liquid crystal projector with insufficient brightness, it will get better results, but due to the reflection of the screen The light will be refracted back to the point of the light source (retroreflectivity), so it is not suitable for combination with a projector suspended on a flowering board. 

　　The main material of the Glass Beads Projection Screen, in addition to the PVC and glass fiber cloth mentioned above, a layer of glass beads is sprayed on the surface of the screen. Bead projection screens can be divided into ordinary bead spherical projection screens and advanced bead projection screens. The first introduction is the ordinary bead spherical projection screen. This type of screen uses glass fiber cloth as the basic material of the screen. Since the glass beads cannot be closely attached to the glass fiber cloth, it is added between the glass fiber cloth and the glass beads. A layer of PVC is used as the medium (Medium).

　　 Another higher-level bead projection screen uses Ultra Beads, which are buried in PVC. On the other hand, a layer of PVC is added to the back of the glass fiber cloth for the purpose of The whole screen is completely waterproof, mildew-proof and flame-resistant, and it is more durable than ordinary beaded spherical screens. These two screens are more suitable for low-light single-gun liquid projectors. 

　　3, pearlescent screen 

　　 The pearl screen is a reflective screen. Most of the screen’s viewing angle is set at about 60 degrees, and the gain is slightly higher than that of the white rough screen. The image quality is white with a strong sense of expansion, while the black is compact. , The dynamic tone performance is interesting. Because of its reflective characteristic that still emits the incident light in the positive and negative directions, this type of screen is more suitable for use with projectors hung from the ceiling. 

　　4, silver screen 

　　Silver screen is a screen made into a small curved shape, and then coated with silver aluminum powder on its surface. It is characterized by strong directionality and high reflectivity of the screen to light, up to 12.8. But the disadvantage is that there are certain requirements for the viewing angle, and the image will be distorted if viewed from the side. This kind of aluminum-plated screen, which can also be used in brighter places, is usually used in 3D (stereoscopic film) or image fax services.