As we all known, Laser TV need a professional anti-light screen.So which kind projection screen is the best option? There are two kinds selection; Black Grid Screen and Fresnel Screen, which one is the best one? Now let’s discuss the details.
First of all, those two kinds of screens have different structures, they can be used with UST projectors, and both rely on special optical structures to achieve directional reflection and anti-light. Today I will talk about the principles of the two structures.
Principles of the two Structures Laser TV Screen
First of all, the black grid structure, the principle is to use special technology to make the cross- section of the zigzag screen. As shown in the picture:
The black grid screen uses black and white prisms to absorb interference light while reflecting projection light. The white slant is a reflecting layer. The light from the projector is projected from bottom to top on the white reflecting layer and then reflected into our eyes. The interference light from above will be absorbed by the black parallel layer, but this only block the ceiling light（please notice）
While Fresnel structure. Using Fresnel Lens technology principle,Fscreen Optical Screen will form an arc protective cover to resist the interference of ambient light from above (lamplight) and from left& right (window light) on the projected image.
The Fresnel structure actually uses the convergence principle of the concave mirror. It divides the concave mirror into a circle of circular structure and puts it on a plane. This can save a lot of useless space and explain it more abstractly. We have found some pictures on the Internet to help you understand.
The front of this lens looks like a dart board, but each ring is tilted at a different angle, Each ring is an independent lens, which together is a lens group,through different structural design, the direction of light can be adjusted to produce different optical effects.
In this way, the concave surface becomes a plane structure, but its function is the same as the concave mirror, because the screen can not be made into a large concave mirror, so there is the screen of Fresnel technology.
Fresnel anti-light structure, the screen surface is full of semi-circular lines from large to small,Using Fresnel Lens technology principle,Fscreen Optical Screen will form an arc protective cover to resist the interference of ambient light from above (lamplight) and from left& right (window light) on the projected image.so using Fscreen Optical Screen no matter turn on the light at night and watch during the day can achieve the ideal display effect!
Contrast of Projection Effect
Different structures will naturally bring different effects, and even a phenomenon appears: “Fresnel” and “Black Grid” have their own “advocates”. What are the projection differences between them?
Brightness of Screen
Generally, the gain of screen with black-grid structure is 0.4-0.5.while Fresnel’s unique semi-circle structure can effectively focus the reflected light, thus enhancing the brightness of the picture, making the gain of the best angle of view increase to 1.0, even some excellent manufacturer can improve a lot based on this data, for example, Fscreen’s screen gain can reach to 1.6 and the positive brightness effect is excellent.
Compared with the positive brightness, the brightness of the black grid screen is inferior to that of Fresnel. Many people who like Fresnel screen pursue its high brightness.
The structure of black grid screen is a parallel prism structure.The advantage of this black grid structure is that it has no visual angle (180 degree visual angle)
While Fresnel’s visual angle around 160 degree, this as its semi-circular structure, because the concave mirror principle, can let the brightness focus in a certain range, that is, the front position of the screen.
Screen Structure and Reflection
The saw-tooth structure of the black grid screen is located on the surface of the screen. This way can achieve imaging and anti-light. The overall picture effect is clean and no reflection. The existence of the saw-tooth structure can be felt by touching the screen surface gently with hands. But the disadvantage is that the screen can not be scratched, once damaged can not be repaired, so installation and use need to be carefully maintained, which is hard to clean.
The Fresnel structure is located behind the resin layer on the screen, which can effectively protect the structure from damage and is closer to the surface appearance of LCD TV. This is an additional advantage, it is more easier to clean and maintenance.
About the Black-grid and Fresnel form, now both of them with hard screen and flexible soft screen, but the black grid hard screen was made by dense spring devices on the back of the black grid screen. The stretching force of the spring forces the screen to be spread flat on the frame. The screen is easy to be deformed as the spring has the risk of collapse.
Beside the difference mentioned as above,Fresnel screen with anti-glare scratch Layer which will protect the Fresnel lens layer, and it is difficult for object scratch the surface.it has made the aging test.while the Black-grid screen structure exposed on the air, the dust will enter into the structure, It yellows over time.
The Fresnel screen factory will installed well, and user just fixed on the wall is OK, while the black-grid screen installation is very trouble, the user need DIY by themselves, normally more than 2 hours.
At present,the maximum size of the Fresnel structure and black-grid structure both can be 120 inches, Fscreen is still R&D more larger Fresnel screen, its UST screen was ended the global monopoly of Japanese corporations, and LT screen is the first optical screen developed in the world.