阅读说明：本技术 投影屏幕及投影系统
(Projection screen and projection system
) 是由 张益民
王祖熊
胡世加
吴庆富 于 2019-12-21 设计创作，主要内容包括：本发明提供的投影屏幕及投影系统,涉及中长焦光学投影技术领域。所述投影屏幕包括沿厚度方向依次设置的菲涅尔透镜层、成像元件层、光学结构层和反射层；所述菲涅尔透镜层由一排排相互排列的线性菲涅尔透镜构成,所述线性菲涅尔透镜为三棱柱透镜；所述光学结构层在厚度方向的横截面为若干一排排相互排布的三角形,所述光学结构层由若干所述三角形分别沿着若干弧线扫略形成的光学结构组成,所述三角形的一边设置在所述成像元件层表面,所述三角形远离所述成像元件层的角为70°～110°。所述投影系统由上述投影屏幕和投影装置构成。本发明投影屏幕及投影系统亮度高、光能利用率高、图像清晰度高、抗环境光性能好、对比度高,具有极好的投影显示效果。(The invention provides a projection screen and a projection system, and relates to the technical field of medium and long focus optical projection. The projection screen comprises a Fresnel lens layer, an imaging element layer, an optical structure layer and a reflecting layer which are sequentially arranged along the thickness direction; the Fresnel lens layer is composed of a row of linear Fresnel lenses which are mutually arranged, and the linear Fresnel lenses are triangular prism lenses; the cross section of the optical structure layer in the thickness direction is a plurality of triangles which are arranged in a row, the optical structure layer is composed of optical structures which are formed by sweeping a plurality of triangles along a plurality of arc lines, one side of each triangle is arranged on the surface of the imaging element layer, and the angle of each triangle far away from the imaging element layer is 70-110 degrees. The projection system is composed of the projection screen and the projection device. The projection screen and the projection system have the advantages of high brightness, high light energy utilization rate, high image definition, good ambient light resistance, high contrast and excellent projection display effect.)
1. A projection screen is characterized by comprising a Fresnel lens layer, an imaging element layer, an optical structure layer and a reflecting layer which are sequentially arranged along the thickness direction; the Fresnel lens layer is composed of a row of linear Fresnel lenses which are mutually arranged, and the linear Fresnel lenses are triangular prism lenses; the cross section of the optical structure layer in the thickness direction is a plurality of triangles which are arranged in a row, the optical structure layer is composed of optical structures which are formed by sweeping a plurality of triangles along a plurality of arc lines, one side of each triangle is arranged on the surface of the imaging element layer, and the angle of each triangle far away from the imaging element layer is 70-110 degrees.
2. The projection screen of claim 1, wherein the fresnel lens structure layer is asymmetric.
3. The projection screen of claim 1 wherein the imaging element layer comprises at least one of a diffusing particle layer, a spot lens layer, a diffusing surface layer, and a lenticular layer.
4. The projection screen of claim 3 wherein the diffusing particle layer comprises a transparent substrate layer and a transparent resin layer with diffusing particles mixed therein.
5. The projection screen of claim 4 wherein the diffusing particles are spheres or polyhedrons, the diffusing particles having a different index of refraction than the transparent resin layer.
6. The projection screen of claim 3 wherein the spot lens layers are not less than one layer, each layer of the spot lens layers having a spot lens disposed on at least one side perpendicular to the thickness direction.
7. The projection screen of claim 3 wherein the diffusion surface layer is not less than one layer, each of the diffusion surface layers having at least one non-smooth surface perpendicular to the thickness direction.
8. The projection screen of claim 3 wherein the lenticular layers are not less than one layer, each layer of lenticular layers comprises a plurality of rows of linear lenticular lenticules, and the cross-section of each layer of lenticular lenticules in the thickness direction is a plurality of circular, elliptical, parabolic, arcuate or polygonal shapes.
9. The projection screen of claim 1 wherein the arcs are circular arcs, and wherein the circular arcs are arranged in concentric circles.
10. A projection system is characterized by comprising a projection device and a projection screen for performing imaging display based on a projection light beam output by the projection device, wherein the projection screen comprises a Fresnel lens layer, an imaging element layer, an optical structure layer and a reflecting layer which are sequentially arranged along the thickness direction; the Fresnel lens layer is composed of a row of linear Fresnel lenses which are mutually arranged, and the linear Fresnel lenses are triangular prism lenses; the cross section of the optical structure layer in the thickness direction is a plurality of triangles which are arranged in a row, the optical structure layer is formed by sweeping a plurality of triangles along a plurality of arc lines, one side of each triangle is arranged on the surface of the imaging element layer, and the angle of each triangle far away from the imaging element layer is 70-110 degrees.
Technical Field
The invention relates to the technical field of medium and long focus optical projection, in particular to a projection screen and a projection system.
Background
With the continuous development of screen display technology, projection is widely used as a simple and convenient display mode, for example, for family entertainment life or office needs. Among them, when displaying by projection, one indispensable device is a projection screen. Thus, the level of projection screen performance directly determines how well the projection display is acceptable to the viewer.
The conventional projection screen such as a white plastic screen can only perform diffuse reflection on a light beam output by a projection device, cannot effectively control the transmission direction of the light beam, and cannot effectively control the transmission of ambient light, so that the brightness of the projection screen is uneven, the overall brightness coefficient is low, and the light energy utilization rate is low; because the traditional projection screen has no light resistance, the displayed image has poor definition and poor controllability of viewing angle; projection systems formed from commonly used projection screens require the projection device to be relatively powerful in order to meet the image display requirements, resulting in higher energy consumption losses.
In the projection system shown in fig. 1, the projection screen adopts a linear micro-optical structure 106 arranged perpendicular to the horizontal direction, the projection device T emits a projection beam E to the projection screen, and when the projection beam E is incident perpendicular to the linear micro-optical structure 106, the projection beam E is totally reflected to the viewing area to obtain a light beam E in the viewing area1(ii) a When the projection beam is not incident perpendicular to the linear micro-optical structure 106, the projection beam E is reflected to the outside of the viewing area from the surface of the projection screen deviating from the incident direction to obtain a light E outside the viewing area2. Similarly, in the projection system shown in fig. 2, the projection screen adopts the linear micro-optical structure 106 arranged along the horizontal direction, the projection device T emits the projection light beam E to the projection screen, and when the projection light beam E is incident perpendicularly to the linear micro-optical structure 106, the projection light beam E is totally reflected to the viewing area to obtain the light beam E in the viewing area1(ii) a When the projection beam is not incident perpendicular to the linear micro-optical structure 106, the projection beam E is reflected to the outside of the viewing area from the surface of the projection screen deviating from the incident direction to obtain a light E outside the viewing area2. Both of these two projection systems can cause the projection beam E not to be fully utilized effectively, increasing the energy consumption of the projection device. The concrete expression is as follows: the projection screen has high display brightness at the position facing the projection device T and low display brightness at the position deviated from the projection device TThe display brightness is lower at the position, which is far away from the incident projection beam E, on the projection screen, so that the brightness uniformity, the viewing angle and the image contrast of the projection screen are greatly limited, and the energy consumption of the projection system is increased.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a projection screen and a projection system, so as to solve the problems of low brightness uniformity, low image contrast, low light energy utilization rate and high energy consumption of the projection system of the conventional projection screen and system.
In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:
a projection screen comprises a Fresnel lens layer, an imaging element layer, an optical structure layer and a reflecting layer which are sequentially arranged along the thickness direction; the Fresnel lens layer is composed of a row of linear Fresnel lenses which are mutually arranged, and the linear Fresnel lenses are triangular prism lenses; the cross section of the optical structure layer in the thickness direction is a plurality of triangles which are arranged in a row, the optical structure layer is composed of optical structures which are formed by sweeping a plurality of triangles along a plurality of arc lines, one side of each triangle is arranged on the surface of the imaging element layer, and the angle of each triangle far away from the imaging element layer is 70-110 degrees.
In a preferred option of the embodiment of the present invention, in the projection screen, the fresnel lens structure layer is an asymmetric structure.
In a preferred option of the embodiment of the present invention, in the projection screen, the imaging element layer includes at least one of a diffusion particle layer, a dot lens layer, a diffusion surface layer, and a cylindrical microlens layer.
In a preferred option of the embodiment of the present invention, in the projection screen, the diffusion particle layer includes a transparent substrate layer and a transparent resin layer, and the diffusion particles are mixed in the transparent resin layer.
In a preferred option of the embodiment of the present invention, in the projection screen, the diffusion particles are spheres or polyhedrons, and the refractive index of the diffusion particles is different from that of the transparent resin layer.
In a preferred option of the embodiment of the present invention, in the projection screen, at least one of the dot lens layers is provided, and at least one surface of each of the dot lens layers perpendicular to the thickness direction is provided with a dot lens.
In a preferred option of the embodiment of the present invention, in the projection screen, at least one diffusion surface layer is provided, and at least one surface of each diffusion surface layer in a direction perpendicular to the thickness direction is a non-smooth surface.
In a preferred option of the embodiment of the present invention, in the projection screen, the number of the lenticular layers is not less than one, each of the lenticular layers includes a plurality of linear lenticular microlenses arranged in a row, and a cross section of each of the lenticular layers in the thickness direction is a plurality of circles, ellipses, parabolas, arches, or polygons arranged in a row.
In a preferred option of the embodiment of the present invention, in the projection screen, the arc lines are circular arcs, and a plurality of the circular arcs are arranged in concentric circles.
A projection system comprises a projection device and a projection screen for imaging display based on projection light beams output by the projection device, wherein the projection screen comprises a Fresnel lens layer, an imaging element layer, an optical structure layer and a reflecting layer which are sequentially arranged along the thickness direction; the Fresnel lens layer is composed of a row of linear Fresnel lenses which are mutually arranged, and the linear Fresnel lenses are triangular prism lenses; the cross section of the optical structure layer in the thickness direction is a plurality of triangles which are arranged in a row, the optical structure layer is formed by sweeping a plurality of triangles along a plurality of arc lines, one side of each triangle is arranged on the surface of the imaging element layer, and the angle of each triangle far away from the imaging element layer is 70-110 degrees.
The projection screen provided by the embodiment of the invention has the advantages that by arranging the optical structure layer, the imaging element layer and the Fresnel lens layer, projection beams can be uniformly diffused and imaged on the imaging element layer, and the brightness uniformity and the image definition of the projection screen are effectively improved; the arrangement of the optical structure layer can effectively control the transmission direction of the projection light beam, effectively control the viewing angle and improve the optical utilization rate of the projection screen; the Fresnel lens layer, the optical structure layer and the reflection layer are arranged, so that the reflection of the surface of the projection screen is weakened. The projection system formed by the projection screen and the projection device effectively improves the utilization rate of light energy, reduces the power required by the projection device, further reduces the energy consumption of the whole projection system, and has the advantages of high brightness, high utilization rate of light energy, high image definition, good ambient light resistance, high contrast and excellent projection display effect.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
FIG. 1 is a schematic diagram of an optical path of a first prior art projection system;
FIG. 2 is a schematic diagram of an optical path of a second prior art projection system;
FIG. 3 is a schematic structural diagram of a projection screen according to an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of an imaging element layer provided in accordance with an embodiment of the present invention;
fig. 5 is a schematic structural diagram of a diffusion particle layer provided in an embodiment of the present invention;
fig. 6 is a schematic view of a first structure of a dot lens layer according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of a second dot lens layer according to an embodiment of the invention;
FIG. 8 is a schematic view of a first structure of a diffusion surface layer according to an embodiment of the present invention;
FIG. 9 is a schematic diagram of a second structure of a diffusion surface layer according to an embodiment of the present invention;
FIG. 10 is a schematic view of a first structure of a lenticular microlens layer according to an embodiment of the present invention;
FIG. 11 is a schematic diagram illustrating a second structure of a lenticular microlens layer according to an embodiment of the present invention;
FIG. 12 is a schematic diagram illustrating a third structure of a lenticular microlens layer according to an embodiment of the present invention;
FIG. 13 is a schematic cross-sectional view of an optical structure layer provided in accordance with an embodiment of the present invention;
FIG. 14 is a first schematic plan view of an optical structure layer according to an embodiment of the present invention;
FIG. 15 is a second schematic plan view of an optical structure layer according to an embodiment of the present invention;
FIG. 16 is a third schematic plan view of an optical structure layer according to an embodiment of the present invention;
FIG. 17 is a schematic plan view of a fourth optical structure layer according to an embodiment of the present invention;
FIG. 18 is a schematic cross-sectional view of a linear Fresnel lens layer provided by an embodiment of the present invention;
FIG. 19 is an exploded view of the path of a projection beam through a projection screen according to an embodiment of the present invention;
FIG. 20 is a schematic diagram illustrating reflection of ambient light by a projection screen according to an embodiment of the present invention;
FIG. 21 is a schematic view of a projection system according to an embodiment of the present invention;
icon: 10-a projection system; 20-a projection screen; 100-an imaging element layer; 101-a diffusion particle layer; 102-a diffusion surface layer; 103-a lenticular layer; 104-optical structure layer; 105-a reflective layer; 106-linear micro-optical structure; 107-spot lens layer; 108-a fresnel lens layer; 111-diffusion particles; 112-non-smooth face; 113-linear cylindrical microlenses; 114-an optical structure; 115-point lens; 116-a linear fresnel lens; 120-a transparent substrate layer; 140-a transparent resin layer; 150-rough surface; c-circle center; c1-a geometric center; e-projecting the light beam; e1-light within the viewing area; e2-light outside the viewing area, F-ambient light, G-viewer, T-projector, β -tooth apex angle, P-tooth intercept, H-tooth height.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. In the description of the present invention, the terms "remote", "one side", and the like are used for distinguishing descriptions only and are not to be construed as limiting or implying relative importance.
In the description of the present invention, the terms "disposed" and the like are to be understood broadly unless otherwise explicitly specified and defined. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
As shown in fig. 3, a projection screen 20 includes a fresnel lens layer 108, an imaging element layer 100, an optical structure layer 104, and a reflective layer 105, which are arranged in this order in the thickness direction; the fresnel lens layer 108 is composed of a row of linear fresnel lenses 116 arranged mutually, and the linear fresnel lenses 116 are triangular prism lenses; the cross section of the optical structure layer 104 in the thickness direction is a plurality of triangles arranged in a row, the optical structure layer 104 is composed of a plurality of optical structures 114 formed by sweeping the triangles along a plurality of arcs, one side of each triangle is arranged on the surface of the imaging element layer 100, and the angle of each triangle far away from the imaging element layer 100 is 70-110 degrees.
Alternatively, the imaging element layer 100 of the imaging element layer projection screen 20 includes at least one of a diffusion particle layer 101, a dot lens layer 107, a diffusion surface layer 102, and a pillar microlens layer 103. That is, the imaging element layer 100 may be any one of the diffusing particle layer 101, the dot lens layer 107, the diffusing surface layer 102, and the lenticular lens layer 103; any two of the diffusion particles 101, the dot lens layers 107, the diffusion surface layer 102, and the columnar microlens layer 103 may be stacked; any three of the diffusion particle layer 101, the point-like lens layer 107, the diffusion surface layer 102, and the columnar microlens layer 103 may be laminated without limiting the positional relationship; the diffusion particle layer 101, the dot lens layer 107, the diffusion surface layer 102, and the pillar microlens layer 103 may be laminated, and the positional relationship between the layers is not limited.
Specifically, the imaging element layer 100 may also be uniformly filled with pigment or toner, or a colored layer may be separately provided in the imaging element layer 100, and the position of the colored layer may be adjusted as needed, and the colored layer may be located between the structures of the imaging element layer 100 or outside the structures of the imaging element layer 100; the light with corresponding wavelength can be selectively absorbed, and the effect of improving the contrast of the projection screen is further realized.
Particularly, a speckle suppression layer is arranged on the surface of the imaging element layer 100 close to the fresnel lens layer 108, the speckle suppression layer is a microstructure manufactured by adopting an optical micromachining technology, and the positions of the speckle suppression layer are different from each other in phase of the projection beam, so that alternate bright and dark irregular spots generated by interference during imaging of the projection screen can be eliminated, and the image display definition of the projection screen 20 is improved.
As shown in fig. 4, the imaging element layer 100 is formed by laminating a diffusion surface layer 102, a diffusion particle layer 101, and a columnar microlens layer 103, which are sequentially arranged in the thickness direction; the diffusion surface layer 102, the diffusion particle layer 101, and the lenticular layer 103 may be of a single-layer structure or a multi-layer structure; that is, the diffusion surface layer 102, the diffusion particle layer 101, and the lenticular lens layer 103 may all have a single-layer structure, may all have a multilayer structure, or may partially have a single-layer structure or may partially have a multilayer structure.
As shown in fig. 5, the diffusing particle layer 101 includes a transparent base material layer 120 and a transparent resin layer 140, and the diffusing particles 111 are mixed in the transparent resin layer 140. The specific type of the transparent substrate layer 120 is not limited, and may be set according to the actual application requirements, for example, the transparent substrate layer may be a flexible structure, or may be a structure with certain rigidity; the flexible structure may include, but is not limited to, flexible transparent plastic or rubber film such as polyethylene, polyvinyl chloride, chlorinated polypropylene, biaxial polypropylene, polycarbonate, polyethylene, polymethyl methacrylate, polycarbonate, polyamide (nylon), thermoplastic polyurethane resin, etc., and the structure having a certain rigidity may include, but is not limited to, a transparent substrate such as glass, acryl, ceramic, etc. In addition, the transmittance of the transparent substrate layer 120 to visible light is not limited, and may be set according to the actual application requirements. In this embodiment, in order to ensure the best imaging display, the light transmittance of the transparent substrate layer 120 is selected to be not less than 75%. The transparent resin layer 140 may be a thermosetting resin, a radiation-curable resin, or a reaction-curable resin, and the transparent resin layer 140 may be selected according to actual production requirements.
As an optional way, the material, the number, and the proportion of the diffusion particles 111 are not limited, and a specific material may be selected and a specific number proportion may be set according to the requirements of the actual viewing field and the uniformity of the screen display brightness. Specifically, the material of the diffusion particles 111 is not limited, and may be a metal material or a non-metal material, and in actual production, the refractive index of the diffusion particles 111 may be as different as possible from the refractive index of the transparent resin layer 140 so as to diffuse the projection light beam entering the transparent resin layer 140.
As an alternative, the manner of mixing the diffusion particles 111 in the transparent resin layer 140 is not limited, and may be specifically set according to the requirements of the actual viewing field and the brightness uniformity of the screen display. The setting mode includes but is not limited to: the diffusion particles 111 are mixed with a liquid resin, and then the mixture is coated on the diffusion particle layer 101.
In this embodiment, the distribution manner of the diffusion particles 111 in the transparent resin layer 140 is not limited, and for example, the diffusion particles 111 may be distributed in the transparent resin layer 140 in an ordered manner, or may be arranged in the transparent resin layer 140 in a disordered and disordered manner. In order to have better imaging display effect and enable the projection light beam to be better diffused, the diffusion particles 111 are orderly arranged in the transparent resin layer 140 according to a multilayer array.
It is understood that the diffusion particles 111 may be in any shape, for example, spheres or polyhedrons, and specifically, the diffusion particles 111 may be elliptical spheres, spheres or polyhedrons with certain edges.
As shown in fig. 6, a first structure diagram of the dot lens layer 107 is provided. The point-shaped lens layer 107 is a single layer, the point-shaped lens layer 107 is provided with point-shaped lenses 115 on at least one plane perpendicular to the thickness direction, and the point-shaped lenses 115 are uniformly distributed on the plane of the point-shaped lens layer 107 perpendicular to the thickness direction, so that the projection light beams are uniformly diffused and better images are formed.
As shown in fig. 7, a second structure diagram of the dot lens layer 107 is provided. The point-shaped lens layers 107 are arranged in a multilayer structure, each point-shaped lens layer 107 is provided with point-shaped lenses 115 on the plane perpendicular to the thickness direction, the point-shaped lenses 115 are uniformly distributed on the plane perpendicular to the thickness direction of the point-shaped lens layers 107, and the multilayer structure of the point-shaped lens layers 107 plays a role in more uniformly diffusing incident light.
As shown in fig. 8, a first structural diagram of the diffusion surface layer 102 is provided, the diffusion surface layer 102 is provided as a single layer, one surface of the diffusion surface layer 102 perpendicular to the thickness direction is a non-smooth surface 112, and the projection light beam can diffuse on the non-smooth surface 112 when entering the diffusion surface layer 102.
As shown in fig. 9, a second structural diagram of the diffusion surface layer 102 is provided, the diffusion surface layer 102 is provided as a multi-layer structure, and one surface of each diffusion surface layer 102 in the direction perpendicular to the thickness direction is a non-smooth surface 112, so that the projection light beam entering the diffusion surface layer 102 is diffused more sufficiently, and a more uniform luminance display is obtained.
It is understood that the diffusion surface layer 102 can be directly used as the imaging element layer 100, directly coated or transferred on the surface of the fresnel lens layer 108, and sequentially stacked with the optical structure layer 104 and the reflective layer 105 to form the projection screen 20; the diffusion surface layer 102 may be bonded to at least one of the diffusion particle layer 101, the dot lens layer 107, and the lenticular lens layer 103, which are formed of the transparent substrate layer 120 and the transparent resin layer 140, to form the image forming element layer 100, and the diffusion surface layer 102 may be applied or transferred to the transparent substrate layer 120 and then bonded to the fresnel lens layer 108.
Specifically, the non-smooth surface 112 may be a surface with a rugged structure, where the specific shape, number and distribution of the rugged structure may be set according to the actual application requirement. For example: the non-smooth surface 112 may be formed of an irregular concave-convex shape, may be formed of a regular concave-convex shape, or may be formed of a combination of an irregular concave-convex shape and a regular concave-convex shape; the asperities in the non-smooth surface 112 can be tens, hundreds, or thousands; the non-smooth portions 112 may be arranged orderly according to a certain rule, may be arranged randomly according to a certain rule, may be arranged orderly according to a certain rule, and may be arranged randomly according to a certain rule. In order to improve the diffusion capability of the diffusion surface layer 102 to the projection light beam, the non-smooth surface 112 may be randomly arranged.
As shown in fig. 10, a first structural diagram of the lenticular lens layer 103 is provided, the lenticular lens layer 103 is a single-layer structure, the lenticular lens layer 103 is formed by a plurality of linear lenticular lenses 113 arranged in a row, and the cross section of the lenticular lens layer 103 in the thickness direction is a plurality of circular, elliptical, parabolic, arcuate, or polygonal shapes arranged in a row.
As shown in fig. 11, a second structural diagram of the lenticular lens layer 103 is provided, where the lenticular lens layer 103 is a multilayer structure, the lenticular lens layer 103 is formed by a plurality of linear lenticular lenses 113 arranged in a row, and a cross section of the lenticular lens layer 103 in a thickness direction is a plurality of circles, ellipses, parabolas, arches, or polygons arranged in a row; the shape and arrangement of each layer of the lenticular microlens layers 103 are the same, that is, the lenticular microlens layers 103 of each layer are the same, and the lenticular microlens layers 103 of each layer are stacked in the same direction.
As shown in fig. 12, a schematic diagram of a third structure of the lenticular microlens layer 103 is provided, which is different from the second structure of the lenticular microlens layer 103 in fig. 11 in that: the second layer of the lenticular microlens layer 103 is rotated 90 ° along the plane and then laminated with the first layer of the lenticular microlens layer 103; the third layer of the lenticular microlens layer 103 is arranged in the same direction as the first layer of the lenticular microlens layer 103, and is laminated with the second layer of the lenticular microlens layer 103; the fourth layer of the lenticular microlens layer 103 is arranged in the same direction as the second layer of the lenticular microlens layer 103, and is laminated with the second layer of the lenticular microlens layer 103 in sequence according to the above rule.
Specifically, the lenticular microlens layer 103 may be directly coated or transferred on the side of the optical structure layer 104 away from the reflective layer 105, or may be bonded to at least one of other structures such as the diffusion particle layer 101, the point lens layer 107, or the diffusion surface layer 102, and then the side of the optical structure layer 104 away from the reflective layer 105 is adhered.
As shown in fig. 13, a cross-sectional view of the optical structure layer 104 is provided, in a cross-section in a thickness direction, with a plurality of triangles arranged in a row and a row, the optical structure layer is formed by sweeping a plurality of triangles 114 along a plurality of arcs, respectively, one side of each triangle is disposed on a surface of the imaging element layer, and an angle α of each triangle away from the imaging element layer 100 is 70 ° to 110 °.
It is understood that the optical structures 114 may be the same or different, that is, the triangles of the cross section of the optical structure layer 104 in the thickness direction may be the same or different, the two sides forming the angle α may be equal or different in length, and the angle α of the triangle away from the imaging element layer 100 may be set between 70 ° and 110 ° according to practical requirements, so as to achieve the purpose of adjusting the reflection of the incident light to a specific viewing area.
In particular, the angle α is preferably 85 ° to 95 °, the setting angle α is preferably 90 °, and when the angle α is 90 °, all incident light to the optical structure layer 104 can be returned in a direction parallel to the incident light, so that the projection screen obtains the best brightness and contrast.
Alternatively, the arc may be a curve, including a circular arc, an elliptical curve, an arc, a parabola, or other high-order curve. The particular arc settings may be made as required by the projected beam. Fig. 14 is a schematic plan view of a first optical structure layer according to an embodiment of the present invention; the arc is a circular arc, and the optical structures 114 of the optical structure layer 104 are arranged in concentric circles. The center C of the optical structure 114 on the projection screen 20 is at the geometric center C of the projection screen 201. Fig. 15 is a first schematic plan view of an optical structure layer according to an embodiment of the present invention; the arc line is a circular arc, the optical structures 114 of the optical structure layer 104 are arranged in a concentric circle, and a center C of the optical structure 114 on the projection device 20 is not located at a geometric center C of the projection screen 201. When the arc line is a circular arc, the circle center C of the optical structure 114 is arranged and can be adjusted according to actual conditions, so that the optical structure 114 is more matched with the projection light beam, and the projection light beams in different directions are enabled to be projectedThe beam can be adjusted in the direction of transmission. As shown in fig. 16, a third schematic plan view of an optical structure layer according to an embodiment of the present invention; the arc is an elliptical curve, the arc is an elliptical arc, and the centers of the plurality of optical structures 114 of the optical structure layer 104 are located at the same point. Fig. 17 is a schematic plan view of a fourth optical structure layer according to an embodiment of the present invention; the arc is arcuate, and the center points of the optical structures 114 of the optical structure layer 104 are the same point.
In this embodiment, as shown in fig. 18 (a) - (c), the fresnel lens layer 108 is composed of a row of linear fresnel lenses 116 arranged mutually, the linear fresnel lenses 116 are triangular prism lenses, the cross section of the fresnel lens layer 108 in the thickness direction is a plurality of mutually arranged triangles in a saw-tooth shape, the tooth vertex angles β of the triangles may be all the same, may be partially the same, or may be all different, the fresnel lens layer 108 has an asymmetric structure, and the boundary line of the asymmetric arrangement may be within the geometric dimension of the linear fresnel lenses 116 or outside the geometric dimension, and the angle of the tooth vertex angle β of the cross-sectional triangle of the fresnel lens layer may be adjusted according to the actual viewing field and the requirement of light energy utilization, so as to obtain a better image display effect.
In practical application, the tooth vertex angle β, the tooth intercept P and the tooth height H of the triangle of the fresnel lens layer 108 can be adjusted according to the position of the projection light beam and the requirement of the viewing field, and the trend of the incident light inside the projection screen is further controlled by adjusting the parameters of the triangle of the fresnel lens layer 108, so that the projection light beam is prevented from being reflected outside the viewing area, the ambient light is prevented from being emitted into the viewing area, and the brightness uniformity of the projection screen can be adjusted.
It can be understood that a rough surface can be manufactured on a plane formed by the tooth-shaped apex β of the fresnel lens layer 108 through a micro-structure processing technology, so as to perform appropriate diffuse reflection on the projection light beam, prevent the projection light beam from being directionally reflected, and form a bright interference fringe.
FIG. 19 is an exploded view of the path of a projection beam through a projection screen according to an embodiment of the present invention; the projection device T outputs a projection beam E, which sequentially passes through the fresnel lens layer 108, the imaging element layer 100 (not shown), and the optical structure layer 104, and finally is reflected by the reflection layer 105, and then is emitted to the viewing range through the optical structure layer 104, the imaging element layer 100 (not shown), and the fresnel lens layer 108, so as to obtain a light ray E in the viewing range1。
It can be understood that, in the whole optical path transmission process, when the angle α between the optical structure of the optical structure layer 104 and the imaging element layer is 90 °, the two projection beams E are parallel but the transmission directions are opposite, when the angle α > 90 °, the reflected projection beam is close to the incident direction of the projection beam E, according to this principle, the directions of the projection beams in different fields of view can be adjusted by changing the angle α, so as to achieve that the projection beam is projected to a specific viewing field, meanwhile, after the optical structure layer 104 is matched with the fresnel lens layer 108, the surface reflection of the projection screen can be effectively reduced, and the propagation waveform of the projection beam can be better matched, so that the components of the projection beam in each direction can be effectively reflected by the optical structure layer 104 into the viewing field of view, thereby greatly avoiding that part of the projection beam is reflected outside the viewing field of view, and effectively improving the display brightness and light energy utilization rate of the projection screen.
It is understood that the reflectivity of the reflective layer 105 to visible light can be set according to the requirements of practical application, that is, according to the requirements of imaging display effect. In particular, the reflectivity of the reflective layer 105 to visible light is greater than or equal to 60% to ensure the best imaging effect. In addition, no corresponding convention is made on the thickness of the reflecting layer 105, and the thickness of the reflecting layer 105 can be controlled to be 50 nm-50000 nm for the best effect. The reflective layer 105The reflective layer can be a metal reflective layer, an alloy reflective layer or a non-metal composite reflective layer as long as the reflective layer has certain visible light reflection capability; the metal reflective layer includes, but is not limited to: aluminum, silver, gold, chromium, nickel, copper; the alloy reflective layer includes, but is not limited to: nichrome, aluminum alloy, titanium alloy; the non-metallic composite reflective layer includes, but is not limited to: TiO 22/SiO2，Nb2O5/SiO2，Ta2O5/SiO2，Al2O3/SiO2，HfO2/SiO2，TiO2/MgF2，Nb2O5/MgF2，Ta2O5/MgF2，Al2O3/MgF2，HfO2/MgF2The film stack structure is formed by alternately combining materials with equal height and low refractive index.
In this embodiment, in order to prevent the reflective layer 105 from being oxidized and deteriorated and falling off after long-term use, and to prolong the service life of the projection screen, the projection screen 20 may further include a protective layer, which is disposed on the surface of the reflective layer 105 away from the optical structure layer 104; the materials of the protective layer include, but are not limited to: SiO 22、Si3N4、Al2O3、SiCN、TiO2SiN, SiC, chromium, nickel, stainless steel, aluminum plates, glass plates, ceramic plates and iron plates, scratch-resistant resin, PET protective films, hot melt adhesives and the like.
As shown in fig. 20, a schematic view of the reflection of ambient light by the projection screen according to the embodiment of the present invention is provided. The ambient light F is incident from above the projection screen 20, and the projection screen 20 is composed of a fresnel lens layer 108, an imaging element layer 100, an optical structure layer 104, and a reflection layer 105, which are arranged in this order in the thickness direction. The ambient light F enters the fresnel lens layer 108, is refracted on the fresnel lens layer 108, enters the imaging element layer 100, the optical structure layer 104, and the reflection layer 105 after being refracted, is finally reflected by the reflection layer 105, and exits from the lower side of the projection screen 20 to the outside of the viewing area, so as to obtain a light E2 outside the viewing area. In the incident and reflection process, the ambient light F is lost or far away from the viewing area after being refracted and reflected for many times, and the image display of the projection screen 20 is hardly affected by the ambient light F through the matching of the fresnel lens layer 108 and the optical structure layer 104, so that the image display contrast of the projection screen is effectively improved.
As shown in fig. 21, an embodiment of the invention provides a schematic diagram of a projection system. The projection system 10 includes a projection device T and a projection screen 20 for performing imaging display based on a projection light beam E output by the projection device T, and includes a fresnel lens layer 108, an imaging element layer 100, an optical structure layer 104 and a reflection layer 105, which are sequentially arranged along a thickness direction; the fresnel lens layer 108 is composed of a row of linear fresnel lenses 116 arranged mutually, and the linear fresnel lenses 116 are triangular prism lenses; the cross section of the optical structure layer 104 in the thickness direction is a plurality of triangles arranged in a row, the optical structure layer 104 is composed of a plurality of optical structures 114 formed by sweeping the triangles along a plurality of arcs, one side of each triangle is arranged on the surface of the imaging element layer 100, and the angle of each triangle far away from the imaging element layer 100 is 70-110 degrees. The projection light beam E is refracted by the Fresnel lens layer 108, is diffused and imaged by the imaging element layer 100, and is jointly controlled in the transmission direction based on the optical structure layer 104 and the reflection layer 105, so that the projection light beam E is reduced from being reflected to the outside of a view field which can be watched by a viewer G, the display brightness and the light energy utilization rate of the projection screen are effectively improved, the viewing angle controllability of the projection screen can be enhanced, and the reflection of the projection light beam by the surface of the projection screen is effectively reduced; the optical structure layer 104 surrounds the whole projection screen in the upper, lower, left and right directions, so that ambient light projected by each party can be reflected and kept away from the viewing area, thereby reducing the interference of the ambient light to the projection light beam and realizing the improvement of the contrast and the light resistance of the projection screen.
After the projection light beam E emitted by the projection device T enters the fresnel lens layer 108, the projection light beam E is refracted to enter the imaging element layer 100 inside the projection screen, so that the projection light beam E incident on the projection screen 20 at various angles can be adjusted in transmission direction by the fresnel lens layer 108. The trend of light beam is controlled through the profile of tooth parameter cooperation optical structure layer of adjusting the fresnel lens layer, can prevent that projection beam from being reflected outside watching the region, makes more projection beam refract the inside demonstration that is used for of projection screen, promotes projection screen luminance and light energy utilization ratio to can also block within the ambient light penetrates watching the region, play the effect of the luminance homogeneity of adjusting each part of screen.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
