[Projection screen purchase and use knowledge] Projection screen purchase common sense

1. Classification of projection screens: 　　 Projection screens can usually be divided into front projection screens and rear projection screens. Front projection screens are divided into soft screens and hard screens. Soft screens include white screens, pearlescent screens and metal screens; hard screens include flat screens and curved screens; rear projection screens can also be divided into soft screens and hard screens. The rear projection hard screen is more used.　　White screen: When a considerable number of people want to watch the projected image in a large area, the image needs to be able to obtain the same brightness in all parts of the room, and then a white screen is required. But be warned, you cannot get a clear enough picture, and the room must be dark.　　Pearl screen: It is made by bonding fine glass beads on a strong base cloth such as glass fiber. This type of screen can reflect the brightest brightness to the incident position.　　Metal screen: It is made by bonding aluminum coating on the base cloth. With this screen, you can get 2 to 4 times the brightness and picture, bearing the characteristics of the mirror surface, and the exit angle is equal to the incident angle.　　Metal curved screen: When installing the projector in a small room, whether it is ground or ceiling installation, the aluminum curved screen can get a very bright picture. But it should be noted that the curved screen has a narrow directionality, resulting in a limited viewing area.　　 Rear projection hard screen is mainly composed of three parts: diffuser, Fresnel lens, biconvex lens.　　Diffuser plate: It is made by adding a diffusing agent to the acrylic plate, which has the effect of making the eyes see the light.　　 Fresnel lens: It has the function of concentrating the light in the direction of the person and reducing the brightness difference between the center of the picture and the surrounding area.　　 Double convex lens: It has the effect of improving the angle of view.　　 The screen made of double-layer lens (Fresnel lens and double-convex lens) can fill the entire screen with brightness and clarity. This screen has black stripes that can prevent light from scattering outward and produce high-quality, high-contrast images. 2. Precautions for the use of projection screens: 　　 1. The glass bead screen cannot be folded, and the screen surface cannot be touched with fingers or sharp objects to avoid contamination.　　2. The dust on the screen area should be wiped with a feather broom. If the stain is heavier, you can use a cotton ball dipped in clean water to gently scrub.　　 3. If the bucky white plastic curtain is stained, wipe it gently with a damp cloth.　　4. The spring roll screen should be handled with care to avoid collision and deformation, which will affect the service life.　　 5. If an abnormal phenomenon occurs during use, it must be shut down immediately to eliminate the fault.　　 6. Please do not disassemble or assemble the audio-visual screen by yourself to avoid unnecessary losses.