ANC Earphone
ANC earphone means Active Noise Cancellation (ANC) .The noise cancelling earbuds uses noise-cancelling speakers to reduce unwanted background noise.This allows the user to more clearly hear the nature of the sound.
ANC Earphone,Htc True Wireless Earbuds,Anc Wireless Earbuds,Best Anc Earbuds 2021 Pogo Technology International Ltd , https://www.wisesir.net When using the projector, the projection screen is often used. Today, we will introduce you to the basic classification and application characteristics of the projection screen. There are four types of projection screens: the first is a soft curtain, the second is a glass curtain, the third is a woven white plastic screen, and the fourth is a bead curtain. The following is a separate introduction.
First, the soft screen
The curtain is superior to the original US. It is divided into a soft screen for front projection and a soft screen for rear projection. Most of the soft screens for the front projection are white, while the soft screen for the rear projection is gray. The reason is that the current projection device does not need to increase the contrast by gray, and the gray has a negative effect on the display of the color. The gray of the rear projection soft screen is because the reflection of the direct light source is reduced, so that the viewer watching the front sees a more natural picture quality, so the rear projection is gray, and it has its meaning.
In general, the effect of a positive cast is better than a rear projection. Regardless of the front projection or the rear projection soft screen, this PVC material specially used for projection has the best image quality, the brightness of the glass curtain and the softness of performance, both of which are available. There is also the biggest feature: the soft screen is not a surface coating, but a special imaged PVC with a thickness. The three-dimensional effect is very rich, and the picture quality is transparent. It is praised by the industry as the DLP in the screen, which is the first choice for the most advanced screen. Since there is no support for the base fabric at all, the material is softer. Therefore, it is necessary to make a drawstring screen with expansion and flattening effect, so that the screen surface is more straight, or it can be made into a frame frame, and the spring of the frame frame will be used. The curtain is straight. Soft screen features: bright and soft, three-dimensional transparent, "DLP in the screen."
Second, the glass curtain
The curtain is superior to the original US. Divided into white glass fiber and gray glass fiber. The base fabric is woven from glass thread, and the surface layer is coated with PVC material with special projection effect. Thanks to the support of the fiberglass backing, there is no need to level and the natural stretch will be straight. Its greatest advantage is that it can remain flat even in the case of temperature differences and large climate changes. The gain and contrast are increased due to the effect of the fiberglass backing. The white screen is brightly colored, and the gray screen increases the contrast. In the past, the projection equipment was bright enough, and the gray screen was used when the contrast was insufficient. At present, most HD projection equipments are faithful to real colors, and the new generation HD projection equipment itself has sufficient contrast, so most people will choose the white screen. Glass fiber curtains are widely used in high-end screens. Glass fiber screen features: bright and realistic, high contrast.
Third, woven white plastic screen
Divided into white screen (also known as white plastic) and gray screen. A base fabric woven from a textile thread, the surface layer is coated with a PVC material with a special projection effect. Widely used in business and teaching.
Fourth, the glass bead curtain
Woven into a cloth bottom by a textile thread, the surface is coated with glass beads, which are mainly used to increase the brightness, but the contrast and viewing angle are not good, and the picture quality is worse than other screens. Used in bright places. Since the business education projection equipment has enough lumen light, the glass bead curtain has been used less and less, even if the teaching is generally changed to a woven white plastic screen.
May 17, 2024