CN217846882U - Rear projection type projection screen - Google Patents

Abstract

A rear projection type projection screen is characterized by sequentially comprising a substrate layer, a transmission type imaging layer, a speckle suppression layer, a filter layer and an anti-glare layer, wherein the substrate layer is light-permeable; the transmissive imaging layer is used for transmissive imaging; the speckle suppression layer is transparent and is mixed with scattering particles; the filter layer is used for filtering ambient light; the anti-glare layer is used for anti-glare. The utility model discloses a rear-projection type projection screen not only can weaken the speckle effect greatly, can improve the picture contrast moreover, and it has simple structure, the effectual characteristics of projection, and it has very strong practicality.

Description

Rear projection type projection screen

[ technical field ] A method for producing a semiconductor device

The present invention relates to projection screens, and more particularly to a rear projection screen.

[ background ] A method for producing a semiconductor device

Laser light is a light source which has high brightness and strong directivity and emits a monochromatic coherent light beam, and is gradually applied to the technical field of projection display as a light source in recent years due to various advantages of laser light. The high coherence of laser light brings speckle effect when laser projection display. Speckle refers to light scattered when a coherent light source irradiates an object surface, because the wavelength of the light is the same and the phase is constant, interference occurs in a space, some parts of the space have constructive interference and some parts have destructive interference, and finally, granular light and dark spots appear on a screen.

In the laser light source used in practical applications, the speckle effect is more serious as the laser light source is more various. In the prior art, a vibrating display screen is adopted, which can be essentially understood as a continuous variable focus point, and because of the continuous variable focus of vibration, only one-nth second of vibration frequency is actually really focused for imaging, and the method utilizes the visual delay of human eyes, which weakens the visual speckles but still has certain limitation: in the case of playing a pure video image, the imaging blur is not perceived by the visual delay, but if a text image is played, the text is not clear due to the visual delay; therefore, this method is mainly applied to a cinema. Therefore, the laser projection screen in the prior art still needs to be improved to eliminate speckle.

[ Utility model ] content

The present invention is directed to solve the above problems and to provide a rear projection screen.

In order to solve the above problems, the present invention provides a rear projection type projection screen, which is characterized in that it comprises a substrate layer, a transmissive imaging layer, a speckle suppression layer, a filter layer and an anti-glare layer in sequence, wherein the substrate layer is light permeable; the transmissive imaging layer is used for transmissive imaging; the speckle inhibiting layer is transparent and is mixed with scattering particles; the filter layer is used for filtering ambient light; the anti-glare layer is used for anti-glare.

Further, the filter layer is a gray mirror.

Furthermore, the transmission type imaging layer is provided with a plurality of micro lenses distributed in an array.

Further, the micro lens is a convex lens.

Further, an imaging layer is integrally formed with the microlens at a focal plane of the microlens.

Further, the particle size of the scattering particles in the speckle suppression layer is 10-100nm.

The beneficial contributions of the utility model reside in that, it has effectively solved above-mentioned problem. The utility model discloses a rear-projection type projection screen compares in prior art and has following advantage:

1. the micro lens in the transmission type imaging layer can homogenize and shape the projection light beam to reduce the coherence of a light source, thereby reducing the speckle effect or avoiding the generation of speckles;

2. the speckle effect can be further reduced by arranging the speckle inhibiting layer;

3. the filter layer is arranged and can filter ambient light to improve the contrast of the picture.

The utility model discloses a rear-projection type projection screen not only can weaken the speckle effect greatly, can improve the picture contrast moreover, and it has simple structure, the effectual characteristics of projection, and it has very strong practicality.

[ description of the drawings ]

Fig. 1 is a schematic view of the overall structure of the present invention.

The attached drawings are as follows: substrate layer 10, transmissive imaging layer 20, speckle suppression layer 30, filter layer 40, antiglare layer 50.

[ detailed description ] A

The following examples are further to explain and supplement the present invention, and do not constitute any limitation to the present invention.

As shown in fig. 1, the rear projection screen of the present invention sequentially includes a substrate layer 10, a transmissive imaging layer 20, a speckle suppression layer 30, a filter layer 40, and an antiglare layer 50.

The side of the substrate layer 10 is the side facing the projection device, i.e. the back side. The side of the anti-glare layer 50 is a side facing the viewer, i.e., a front side. Projection light emitted by the projection device sequentially passes through the substrate layer 10, the transmissive imaging layer 20, the speckle suppression layer 30, the filter layer 40, and the antiglare layer 50 and enters the field of view of a viewer in front of the substrate layer.

The substrate layer 10 is used for supporting other structural layers, is made of a transparent material, and is light-permeable. The material for making the substrate layer 10 includes but is not limited to PP, PC, PET, glass, etc. In this embodiment, the substrate layer 10 is preferably made of PET material.

The transmissive imaging layer 20 is used for transmissive imaging and, in addition, it can be used to homogenize the light beam to reduce the coherence of the light source and eliminate the brightness non-uniformity and the step effect caused by the point light source. The transmissive imaging layer 20 includes a plurality of microlenses distributed in an array. The micro lens can be a convex lens, and the size of the micro lens can be set according to needs. The transmissive imaging layer 20 replaces a conventional fresnel lens with an infinite number of micro-convex lenses that are not required for the object distance of the incident light, and thus, it can be applied to a variety of short-focus lenses. The transmissive imaging layer 20 has been combined during processing to form a rear-projection transmissive imaging layer 20 that is located at the focal plane of the microlenses.

The microlenses in the transmissive imaging layer 20 are typically micron-sized. The shape of the microlens is not limited, and it may be a circle, a square, a hexagon, or other shapes. The array of the micro lenses is not limited, and the micro lenses may be arranged in a square grid, a hexagon or other shapes. The array-distributed micro-lenses can divide the incident laser beam into a series of sub-beams, the energy distribution of the series of sub-beams is nearly uniform, and therefore the series of sub-beams are superposed on the imaging layer at the focal plane to form a uniform light spot, so that the uniform shaping of the incident laser beam can be realized. In the same light source, the incident angles of the light beams are the same, and the phases or phase differences are constant, which is a main reason for strong spatial coherence of the laser. After the laser beam is homogenized and shaped by the transmission type imaging layer 20, the energy distribution of the beam changes, and the optical path difference and phase difference of different sub-beams in the transmission process are large, so that the probability of interference among the sub-beams is reduced to a certain extent, the coherence of the beam can be reduced, the speckle effect can be reduced, the required shape and uniformity can be maintained at any distance, and the quality of the homogenized and shaped light spots is improved.

The speckle reduction layer 30 is used to further reduce speckle, and is transparent and has scattering particles mixed therein. The scattering particles can change the transmission direction of light rays, so that the angles of the light rays are more diversified, the coherence of the light rays is reduced, and the speckle effect is reduced. The scattering particles have a particle size in the range of 10-100nm. In specific implementation, the speckle reduction layer 30 is a coating layer, and the speckle reduction layer 30 can be formed by doping organic particles in a transparent paint and then spraying the transparent paint on the transmissive imaging layer 20, and curing the coating layer.

As shown in fig. 1, filter layer 40 is used to filter ambient light and functions to selectively filter and merge light beams from a projection device in a particular direction. In this embodiment, the filter layer 40 is a gray mirror, which has uniform absorption characteristics in the visible light range, and has a light blocking effect by reducing the amount of light passing therethrough, and has no influence on the color while blocking light. When ambient light reaches filter layer 40, the ambient light may be blocked and most of the ambient light may be filtered out by filter layer 40, and projection light may be blocked and some of the light flux may be lost, but the light flux lost by the projection light is a very small part of the total projection light, and the light flux lost by the ambient light is a very large part of the total ambient light reaching filter layer 40, or even all of the total ambient light, so that the ambient light may be substantially filtered out after passing through filter layer 40, and only a very small part of the projection light is lost. After the ambient light is filtered out, the projection light can not be interfered, and the contrast of a projection picture can be greatly improved; and a part of the light flux loss of the projection light is very little, and only slight change of the brightness is influenced, so that the visual effect presented by the whole is that the contrast of the picture visible by naked eyes is improved.

The antiglare layer 50 is used for antiglare, has high surface roughness, can eliminate glare by improving a diffuse reflection effect of light, and enlarges a viewing angle of a projection screen. The antiglare layer 50 may be selected from known antiglare layers 50, such as the antiglare layer 50 obtained by roughening the surface of PET.

By this, has just formed the utility model discloses a rear-projection type projection screen, it is including compound substrate layer 10, transmission type formation of image layer 20, speckle suppression layer 30, filter layer 40 and anti-dazzle layer 50 in proper order, and it not only can weaken the speckle effect greatly, can improve the picture contrast moreover, and it has simple structure, the effectual characteristics of projection, and it has very strong practicality.

While the invention has been described with reference to the above embodiments, the scope of the invention is not limited thereto, and the above components may be replaced with similar or equivalent elements known to those skilled in the art without departing from the concept of the invention.

Claims (6)

1. A rear projection screen, comprising in order:

a substrate layer (10) that is light-permeable;

a transmissive imaging layer (20) for transmissive imaging;

a speckle suppression layer (30) which is transparent and in which scattering particles are mixed;

a filter layer (40) for filtering ambient light;

an antiglare layer (50) for antiglare purposes.

2. A rear projection screen as claimed in claim 1, characterized in that the filter layer (40) is a gray mirror.

3. A rear projection screen according to claim 1, characterized in that the transmissive imaging layer (20) is provided with a plurality of microlenses distributed in an array.

4. The rear projection screen of claim 3, wherein the microlenses are convex lenses.

5. A rear projection screen as recited in claim 4, wherein an imaging layer is integrally formed with the microlenses at the focal planes thereof.

6. A rear projection screen according to claim 1, characterized in that the scattering particles in the speckle reduction layer (30) have a particle size of 10 to 100nm.

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