KR100669855B1 - Screen for rear projection - Google Patents

Abstract

The present invention relates to a rear projection screen, and an object of the present invention is to provide a rear projection screen capable of sharply forming an image / image by minimizing spherical aberration.

Accordingly, in the present invention, a plurality of cylindrical convex lens portions 20a are sequentially formed on one surface thereof, and a plurality of long triangular prisms 20b are formed at positions spaced apart at equal intervals from each other. The black stripe layer 42 is stacked between the plurality of long triangular prisms 20b, the diffusion layer 30 is laminated on the black stripe layer 42, and the microlens array 50 is disposed on the diffusion layer 30. ) Is constructed of a lenticular lens 40 having a stacked structure.

Therefore, the present invention can secure a wider horizontal viewing angle and a vertical viewing angle, improve contrast, and have a useful effect of achieving clear imaging due to improvement of hardness and wear resistance and minimization of spherical aberration.

Projection, screen, fresnel, lens, lenticular, diffuser, micro

Description

Rear projection screen {screen for rear projection}

1 is a schematic diagram showing an image signal projection structure of a general rear projection;

Figure 2 is a schematic perspective view of the rear projection screen composite according to the prior art,

3 is a schematic cross-sectional view of a rear projection screen composite according to the prior art,

Figure 4 is a schematic perspective view of the "projector screen" of the Republic of Korea Patent Publication No. 10-0238300,

FIG. 5 is a schematic perspective view showing in detail the lenticular lens structure of the “projector screen” shown in FIG. 4;

6 is a schematic cross-sectional view of the "projection screen of the rear projection television set" of the Republic of Korea Patent Office registered Patent No. 0178734,

FIG. 7 is an enlarged cross-sectional view showing a microlens array cross-sectional structure of an application number 10-2003-440 filed by the present applicant to the Korean Intellectual Property Office of "Optical Screen for Rear Projection of a Microsphere Lens Array Structure"

Figure 8 is an enlarged perspective view showing the surface structure of the micro lens array of the application No. 10-2003-440 "back projection optical screen of the micro-spherical lens array structure" filed by the applicant

FIG. 9 is a conceptual diagram illustrating a light projection structure through a micro lens array of “No. 10-2003-440,“ Rear projection optical screen of a micro-spherical lens array structure ”filed by the Korean Patent Office.

10 is a schematic perspective view for showing a structure of an embodiment of a "rear projection screen" according to the present invention;

11A and 11B are schematic cross-sectional views of a coupling state for showing the structure of an embodiment of a “rear projection screen” according to the present invention;

12A and 12B are schematic structural diagrams of a separated state of a “rear projection screen” to which a micro lens array of another embodiment according to the present invention is applied;

12C and 12D are schematic configuration diagrams of a separated state of a “rear projection screen” to which a lenticular lens of another embodiment according to the present invention is applied;

13A and 13B are conceptual views for comparing and showing spherical aberration characteristics according to each of the spherical and aspherical states of the cylindrical convex lens portion applied to the rear projection screen of the present invention.

<Description of Symbols for Main Parts of Drawings>

2 projection engine 20 Fresnel lens

40 lenticular lens 20a cylindrical cylindrical convex lens portion

20b: long triangular prism 42: black stripe layer

30: diffusing agent layer 50: micro lens array

70: acrylic resin layer 51: micro lens

52a, 52b: convex surface 52c: concave surface

52c ': Gorge 60: Cured coating layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear projection screen, and more particularly, to a rear projection screen in which images and image rays are enlarged and imaged on the rear surface thereof.

Projection is a type of magnification projection apparatus that enlarges an image (image) from a projection engine and projects it on a screen of a large screen. The projection has an advantage that a large screen can be obtained, and its demand is increasing day by day.

On the other hand, projection is projection using CRT, LCD or DMD depending on the image projection method.Front projection method in which the projection engine is placed in front of the screen, and the projection engine is placed behind the screen, and the image from the projection engine is reflected on the mirror screen It may also be classified as a rear projection method to be projected onto.

Projection engines usually use small CRT or liquid crystal methods, and the liquid crystal projection engine combines red, green, and blue pixels into one to realize color, and reduce the size and weight of the projection engine itself. There is an advantage that can easily overcome the limitation of the large size of the screen of the direct display type display, while the price is less competitive than the CRT type projection engine.

In the transmissive screen used in the rear projection television, a fresnel lens sheet is arranged on the light source side to collect the image light from the cathode ray tube (CRT) or the image light transmitted through the liquid crystal within a predetermined angle range. A lenticular lens sheet having a function of widening the image light transmitted through the Fresnel lens sheet to an appropriate angle range is arranged on the observer's side.

That is, the rear projection as shown in Fig. 1 employs a high brightness CRT type image receiving tube as a projection engine 2, and a mirror 4 and a rear projection screen composite. 6, the rear-projection screen composite 6 overlaps the Fresnel lens 8 and the lenticular lens 10 so as to be spaced apart at very small intervals as shown in FIGS. 2 and 3. It is a structure closely attached to the inside.

As described above, the Fresnel lens 8 is a lens formed to have a flat surface while converging like a convex lens. There are a number of concentric grooves on the surface, and the surface between the grooves and the grooves is inclined toward the portion away from the center. It is largely formed, and thus, the convex angle of the center and the outer side is different, so that the light converging effect can be emitted like a convex lens.

The lenticular lens 10 is a lens having a structure in which a plurality of micro lenses having a semicircular cross section is assembled on one surface thereof, and has a function of making a planar image appear perspective and three-dimensional.

In addition, the other surface of the lenticular lens 12 has a structure in which a plurality of convex lens portions 10a and a stripe lens portion 10b are alternately continuous, and the protective screen is in contact with the other surface of the lenticular lens 10. 12 may be formed of acrylic or tempered glass.

That is, light rays for an image that is enlarged from the projection engine 2 with a substantially uniform brightness over a wide viewing angle are deflected into parallel light while passing through the Fresnel lens 8, and from such a Fresnel lens 8 Of light is diffused by the lenticular lens 10.

Light rays for the image passing through the lenticular lens 10 are partially absorbed by the stripe lens portion 10b on the other side thereof, and this action is possible by painting black ink on the stripe lens portion 10b surface. This increases the contrast of the image or the image.

However, since the rear projection screen composite body 6 protrudes more than the convex lens portion 10a of the stripe lens portion 10b of the lenticular lens 10, the light diffusion angle is limited and thus an image or an image can be observed. There is a problem that the horizontal viewing angle is limited.

The problem of the conventional general projection rear projection screen composite 6 can be solved by the "projector screen" of the registration number 10-0238300 (registration date: October 13, 1999) disclosed in the Republic of Korea Patent Publication have.

That is, the "projector screen" is to improve the viewing angle and brightness characteristics by distributing light rays for an image or an image in a large horizontal angle, as shown in Figures 4 and 5 Fresnel to make the light beams parallel This relates to a combination of a lens 21, a lenticular lens 22 for diffusing parallel light emitted from the Fresnel lens 21, and a protective panel 23 made of acrylic material.

The lenticular lens 22 includes a plurality of lens groups 22G configured to vertically connect a plurality of unit lenses 22L to form a pillar, and a plurality of the lens groups 22G include the protective panel 23. ) And a light diffusing surface 22D formed by application of a hologram technique using a laser is formed on the surface of the unit lens 22L, and a light diffusing agent D is formed therein. Contains.

Another example of the prior art of the rear projection screen composite 6 for a projection as described above is the "rear projection" of the registered patent No. 0178734 (registration date: November 24, 1998) disclosed in the Patent Publication of the Republic of Korea Projection screen of a television set.

That is, in the “projection screen” including the Fresnel lens 30, the lenticular lens 31, and the tempered glass 205 as shown in FIG. 6, the tempered glass 205 has its inner surface portion. (27) is formed by the corroded light diffusing member 20.

In addition, one side of the lenticular lens constituting the screen is formed by a meniscus negative lens, and the other part is formed by a black stripe layer. In this case, a large horizontal viewing angle can be secured and contrast can be increased. It becomes possible.

However, such conventional screens can secure a wide horizontal viewing angle by diffusing an image or a video signal in a horizontal direction by a fine band-shaped convex lens and stripe on the surface of the lenticular lens, but a vertical viewing angle cannot be secured. Occurred.

In addition, since irregular reflection occurs due to the band-shaped convex lens portion and the stripe lens portion, clear image expression cannot be realized.

In addition, in the conventional screen, foreign matters such as dust easily accumulate between the convex lens portion and the stripe lens portion, and scratches are generated in the process of cleaning such foreign matters, which may damage the surface of the lenticular lens.

In addition, by providing a separate protective screen, the risk of damage due to scratches or external shocks is reduced, but it is difficult to achieve a clearer picture quality.

In addition, the conventional screens are an assembly structure of the Fresnel lens, the lenticular lens and the protective screen, so the assembling work is essential and thus there is no room for improvement in workability, and there is a disadvantage in that the productivity is greatly reduced.

In order to solve all the problems and disadvantages of the prior art as described above, the applicant has already filed a "rear projection optical screen of the microsphere lens array structure" of the Republic of Korea Patent No. 10-2003-0000440.

As described above, the "back-projection optical screen of the microspherical lens array structure", which is filed by the present applicant, uses the Fresnel lens 20 as shown in FIGS. 7 to 9 to transmit light rays for images and images from the projection engine. In the projection optical screen which enlarges the viewing angle and projects through the lenticular lens and the lenticular lens, etc., it is formed of a silicon-containing high-hardness acrylic resin, is formed with a thickness of 12 ~ 25㎛, the curvature radius of the micron unit It is configured to further include a micro lens array 50 having a plurality of micro lenses 51 having.

In addition, the microlens array 50, the Fresnel lens 20, and the 0.2 μm thick diffusing agent 30 are integrally formed with a thickness of about 5 mm, and the microlens surface is convex surface 52 and concave curved surface ( 53) to allow a wider spread of light rays for the image / image passed through the diffusing agent 30.

The diffusion agent 30 serves to disperse the image signal passing through the Fresnel lens 20, and distributes and diffuses a light source constituting the image signal, and also dark tints The contrast ratio is controlled by adjusting the ratio.

The distribution of the image signal and the adjustment of the contrast ratio are made by adjusting the concentration of the diffusion agent 30 and the thickness of the layer, and by forming a cured coating layer 60 by ultraviolet curing treatment on the surface of the micro lens 51 Surface wear resistance and hardness and contrast ratio can be improved.

Thus, the image / image beams projected by the projection engine are reflected on the mirror surface and then projected onto the Fresnel lens 20 to deflect the beams in parallel. In addition, the deflected light beams are simultaneously diffused in the horizontal and vertical directions through the plurality of micro lenses 51 in a state in which diffusion is limited by the diffusion agent 30, thereby providing a wider horizontal viewing angle and a vertical viewing angle. .

That is, the light beams are simultaneously diffused in the horizontal and vertical directions by the convex curved surface 52 and the concave curved surface 53. Since the microlens 51 is formed in a constant pattern and a radius of curvature, diffuse reflection due to light rays from the outside is generated. In addition, it is possible to greatly reduce, thereby not only the uniform brightness of the central portion and the edge of the entire screen, it is also possible to eliminate the cumulative problems such as foreign matter on the surface of the micro lens array 50.

However, the “back-projection optical screen of the microspherical lens array structure” filed by the applicant has not obtained a clear image because no means for minimizing spherical aberration has been devised.

In addition, in order to obtain high image contrast in the presence of external light, it is not sufficient to form an external light absorbing layer on the lenticular lens or to form the microlens 51 in a constant pattern and radius of curvature. In general, steel balls as a means for further reducing the reflection of external light remained a problem.

The present invention is to supplement the "back-projection optical screen of the micro-spherical lens array structure" filed by the applicant with the Korean Patent Application No. 10-2003-0000440, the object of the present invention is to combine the horizontal and vertical viewing angle It is possible to secure and improve the uniformity of brightness as well as to improve surface hardness and productivity, and to prevent deterioration of image quality due to diffuse reflection. Application No. 10-2003-0000440 “Micro-spherical lens array structure Is the same as the purpose of the “Rear Projection Optical Screen”.

It is an object of the present invention, in particular, to provide a rear projection screen in which an image / image can be clearly formed by minimizing spherical aberration.                         

It is also an object of the present invention to further reduce the reflection of external light by combining a number of requirements such as forming an external light absorbing layer on the lenticular lens, or forming a microlens in a predetermined pattern and a radius of curvature, thereby providing a high environment in the presence of external light. It is to provide a rear projection screen that solves the problem of obtaining image contrast.

In order to achieve the above object, the present invention provides a rear projection screen in which a Fresnel lens and a lenticular lens which project an image light incident from a projection engine to a viewer side under an enlarged viewing angle are combined in a close state. A plurality of cylindrical convex lens portions are sequentially formed on one surface thereof, and a plurality of long triangular prisms are formed at positions spaced apart at equal intervals from each other, and a black stripe layer is laminated between the plurality of long triangular prisms. And a diffuser layer is laminated on the black stripe layer, and a micro lens array is laminated on the diffuser layer.

The flat cross-sectional shape of each of the plurality of cylindrical convex lens parts is characterized in that the aspherical shape.

The curvature C _L of each of the plurality of cylindrical convex lens parts is characterized by satisfying the following formula 1).

0.006 <C _L <0.023 ........... 1 equation)

The pitch p of each of the plurality of cylindrical convex lens portions is 50 to 120 µm, and the thickness t ₁ is 0.1 to 0.4 mm.

The black stripe layer and the diffusing agent layer are each laminated on both sides of the acrylic resin layer, characterized in that laminated on one surface of the lenticular lens between a plurality of long triangular prism.

The planar cross-sectional shape of each of the plurality of long triangular prisms has a triangular structure with a partial section of the lenticular lens surface as the base.

The black stripe layer corresponds to the height (h) from the bottom side of the long triangular prism to the position where the bottom side is reduced to 1/2 so that 70% of the non-transmissive area is secured to the entire light transmissible area of the lenticular lens. It is formed to a thickness (t ₂ ), and when the specific transmittance of the light beam by the black stripe layer 'B / S', the following two expressions) is characterized.

B / S ratio = 1-a / p ... 2)

(A: gap between two neighboring black stripe layers, p: pitch of cylindrical convex lens portion)

One surface of the micro lens array is composed of a concave-convex surface in which a plurality of micro lenses are arranged in an alignment form, and a plurality of micro lenses of the concave-convex surface have a concave curved surface formed between adjacent convex curved surfaces. The cured coating layer by ultraviolet rays is laminated on the uneven surface of the micro lens array.

The plurality of micro lenses of one surface of the micro lens array is characterized in that formed in the form of a convex portion formed between the adjacent convex surface in series.

Each of the convex curved surfaces constituting the plurality of micro lenses of one surface of the micro lens array is formed to have a radius of curvature satisfying the following three expressions).

f · tanθ = h ........ 3 equation)

(However, f: focal length of the micro lens 51, h: pitch, θ: see Figs. 11A and 11B)

The micro lens array is characterized in that the acrylic resin is formed integrally with the micro lens.

On the other hand, the plurality of long triangular prism of the lenticular lens may be formed in the form of a form in which both of the hypotenuse is connected in series at the lower end.

As described above, the rear projection screen according to the present invention matches the degree of refraction according to the height of parallel light rays passing through the Fresnel lens according to the cylindrical aspherical convex lens portion, so that the spherical aberration is collected by collecting light at one point. It does not occur, which results in a clear image.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 is a schematic diagram showing the structure of the image signal projection of the general rear projection, Figure 10 is a schematic perspective view for showing the structure of the "rear projection screen" according to the present invention, Figure 11a, b is a micro lens of each embodiment according to the present invention 12A to 12D are schematic cross-sectional views of the coupling state for showing the structure of the “rear projection screen” to which the array is applied. FIGS. 12A to 12D are views for showing the structure of the “rear projection screen” to which the lenticular lens of each embodiment according to the present invention is applied. It is a schematic sectional drawing of a coupling state.

As shown, the present invention is a screen in which the Fresnel lens 20 and the lenticular lens 40 which reflect the image light incident from the projection engine 2 to the mirror 4 and project to the viewer side under the enlarged viewing angle state It relates to a rear projection screen consisting of the composite (6).

In particular, a plurality of cylindrical convex lens portions 20a are sequentially formed on one surface of the lenticular lens 40, and on the other surface, a plurality of long triangular prisms 20b are spaced at equal intervals from each other. Formed on.

In addition, a black stripe layer 42 is laminated between the plurality of long triangular prisms 20b, and a diffusion layer 30 is laminated on the black stripe layer 42, and a micro lens array is disposed on the diffusion layer 30. 50 is laminated to form the rear projection screen of the present invention.

On the other hand, by forming a flat cross-sectional shape of each of the plurality of cylindrical convex lens portion 20a in an aspherical shape, as shown in FIG. 13B, light is collected at a point to prevent spherical aberration.

That is, FIGS. 13A and 13B are diagrams for showing spherical aberration characteristics according to spherical and aspherical states of the cylindrical convex lens unit 20a, respectively, as shown in FIG. 13A and 13B. When passing through the cylindrical aspherical convex lens portion 20a, the degree of refraction according to the height is matched, so that light is collected at one point so that spherical aberration does not occur, thereby obtaining a clear image. .

In addition, when the curvature C _L of each of the plurality of cylindrical convex lens parts 20a satisfies the following expression 1, each of the plurality of cylindrical convex lens parts 20a is formed as an aspherical surface having a parabolic or elliptic shape. You can do it.

0.006 <C _L <0.023 ........... 1 equation)

In addition, each of the plurality of cylindrical convex lenses 20a has a pitch p of 50 to 120 µm and a thickness t ₁ of 0.1 to 0.4 mm when viewed with reference to FIGS. 11A to 12D. It is formed in a shape having a substantially aspherical surface.

12A is a schematic cross-sectional view of a separated state to show another structure of the "rear projection screen" according to the present invention. As illustrated, the black stripe layer 42 and the diffusion agent layer 30 are acrylic resin layers 70. Each of the plurality of long triangular prisms 20b may be stacked on one surface of the lenticular lens 40 between the plurality of long triangular prisms 20b, respectively. It may be formed in a triangular shape with some section as the base.

11A to 12D, the black stripe layer 42 has a thickness corresponding to a height h _t from the bottom side of the long triangular prism 20b to a position where the bottom side is reduced to 1/2. (t ₂ ), and when the specific transmittance of the light beam by the black stripe layer 42 is 'B / S', the following two expressions are satisfied, whereby the entire light transmissible area of the lenticular lens 40 is satisfied. The non-transmissive area of 70% can be ensured.

B / S ratio = 1-a / p ... 2)

(A: the distance between two neighboring black stripe layers, p: the pitch of the cylindrical convex lens portion 20a)

In addition, referring to FIGS. 10 to 12A, one surface of the micro lens array 50 is formed of a concave-convex surface in which a plurality of micro lenses 51 are aligned, and such a micro lens array 50 is provided. The uneven surface of may be laminated with a cured coating layer 60 by ultraviolet light to enhance the surface.

In addition, the plurality of micro lenses 51 on one surface of the micro lens array 50 are formed by successively concave curved surfaces 52c formed between adjacent convex curved surfaces 52a and 52b. Each of the convex curved surfaces 52a and 52b constituting the plurality of micro lenses 51 on one surface of the micro lens array 50 may have a radius of curvature satisfying the following three expressions.

f · tanθ = h ........ 3 equation)

(However, f: focal length of the micro lens 51, h: pitch, θ: see Figs. 11A and 11B)

In addition, the micro lens array 50 may be formed integrally with the micro lens 51 as an acrylic resin material.

In addition, as shown in FIG. 12B, the plurality of micro lenses 51 of the concave-convex surface of the micro lens array 50 have a valley portion 52c 'formed between adjacent convex curved surfaces 52a and 52b. It may be of the form.

In addition, as shown in FIGS. 12C and 12D, the plurality of long triangular prisms 20b of the lenticular lens 40 may have a shape in which both hypotenuses are connected in series at the lower end thereof.

Hereinafter will be described the operation and effect of the present invention according to an embodiment.

The black stripe layer 42 is laminated by applying black ink to the output side of the lenticular lens 40 that has been extruded or UV (ultra violet rays) molded into a shape as shown in FIGS. 10 and 11A by screen printing. The diffuser layer 30 is further laminated on the black stripe layer 42.

The plurality of micro lenses 51 on one surface of the micro lens array 50 may have a form in which a valley portion 52c ′ is formed between adjacent convex curved surfaces 52a and 52b as shown in FIG. 11B.

In FIG. 12A, the black stripe layer 42 and the diffuser layer 30 are laminated on both sides of the acrylic resin layer 70, and then the black stripe layer 42 is disposed on one surface of the lenticular lens 40 between the plurality of long triangular prisms 20b. ) Are stacked in close contact.

The plurality of micro lenses 51 on one surface of the micro lens array 50 may have a form in which a valley portion 52c ′ is formed between adjacent convex curved surfaces 52a and 52b as shown in FIG. 12B.

The lenticular lens 40 and the micro lens array 50 are combined, and one surface of the micro lens array 50 is disposed between a plurality of convex curved surfaces 52a and 52b adjacent to the plurality of micro lenses 51. By providing the concave curved surface 52c or the one in which the valley part 52c 'was formed, the diffuse reflection can be greatly reduced.

On the other hand, since the cured coating layer 60 by ultraviolet rays is formed on the surface of the micro lens array 50, it is possible to greatly improve the wear resistance and hardness, and distribute the light rays for the image / image passing through the diffusion agent 30 ( Light Distribution) and diffusion, and also it is possible to dramatically improve the contrast (Contrast) according to the control of the Dark Tint ratio.

First, referring to FIG. 1, the image / image beam projected by the projection engine 2 is reflected on the mirror surface 4 and then projected by the Fresnel lens 20 to be deflected in parallel. Is diffused simultaneously in a horizontal direction and a vertical direction through a plurality of micro lenses 51 in a state in which diffusion is limited by the diffusion agent 30 as shown in FIGS. 10 to 12D to provide a wider horizontal viewing angle and a vertical viewing angle. It becomes possible.

In particular, by forming the flat cross-sectional shape of each of the plurality of cylindrical convex lens parts 20a in an aspherical shape, the spherical surface as shown in FIG. 13A which appears when the flat cross-sectional shape of each of the convex lens parts 20a is formed in an aspherical shape. Aberration characteristics do not occur.

That is, by forming the cylindrical convex lens portion 20a into an aspherical surface, the degree of refraction according to the height of parallel light rays passing through the Fresnel lens 20 through the cylindrical aspherical convex lens portion 20a is measured. As shown in 13b, the light is collected at one point so that spherical aberration is not generated, which results in a clear image and minimizes the loss of light.

The contents described as described above are merely illustrative of preferred embodiments of the present invention, and the scope of application of the present invention is not limited to such embodiments, and may be appropriately changed within the scope of the same idea.

For example, the technical idea of the present invention can be widely changed within the scope in addition to the many cylindrical convex lens portion 20a described in the detailed description.

As described above, the rear projection screen of the present invention diffuses the image light beam simultaneously in the horizontal direction and the vertical direction due to the micro lens array, thereby providing an effect of securing a wider horizontal viewing angle and a vertical viewing angle.

In addition, it is possible to greatly improve the uniformity of the brightness, greatly reduce the diffuse reflection, and has the effect of significantly improving the contrast (Contrast).

In addition, the cured coating layer can greatly improve the hardness and wear resistance of the microlens array, thus providing an effect of eliminating the risk of scratching and damage due to external impact force.

The present invention in particular provides a useful effect of minimizing spherical aberration so that images / images can be imaged vividly.

Claims (10)

In the rear projection screen in which the Fresnel lens 20 and the lenticular lens 40 which project the image light incident from the projection engine 2 to the viewer side under a viewing angle enlargement state are combined in an intimate state, In the lenticular lens 40, a plurality of cylindrical convex lenses 20a are sequentially formed on one surface thereof. A plurality of long triangular prisms 20b are formed at the other surface at positions spaced at equal intervals from each other, The black stripe layer 42 is laminated between the plurality of long triangular prisms 20b, The diffusion agent layer 30 is laminated on the black stripe layer 42, The rear projection screen, characterized in that the microlens array 50 is laminated to the diffusion layer (30). The rear projection screen according to claim 1, wherein the flat cross-sectional shape of each of the plurality of cylindrical convex lens portions (20a) is aspheric. The rear projection screen according to claim 1 or 2, wherein the curvature C _L of each of the plurality of cylindrical convex lenses 20a satisfies the following expression. 0.006 <C _L <0.023 ........... 1 equation) 3. The back surface according to claim 1 or 2, wherein the pitch p of each of the plurality of cylindrical convex lens portions 20a is 50 to 120 mu m, and the thickness t ₁ is 0.1 to 0.4 mm. Projection screen. The method of claim 1, wherein the black stripe layer 42 and the diffusing agent layer 30 is laminated on both sides of the acrylic resin layer 70, respectively, on one surface of the lenticular lens 40 between the plurality of long triangular prism 20b. Rear projection screen, characterized in that laminated. 2. The black stripe layer 42 has a bottom side of the long triangular prism 20b so as to secure a 70% non-transmissive area with respect to the entire light transmissive area of the lenticular lens 40. Is formed to a thickness (t ₂ ) corresponding to the height (h _t ) to the position reduced to 1/2, The back projection screen characterized in that the following formula 2 is satisfied when the transmittance of the light beam by the black stripe layer 42 is set to 'B / S'. B / S ratio = 1-a / p ... 2) (A: the distance between two neighboring black stripe layers, p: the pitch of the cylindrical convex lens portion 20a) According to claim 1, wherein one surface of the micro lens array 50 is composed of a concave-convex surface formed with a plurality of micro lenses 51 in alignment, The plurality of microlenses 51 of the uneven surface are formed by successively concave curved surface 52c having a concave curved surface 52c formed between adjacent convex curved surfaces 52a and 52b. The projection screen, characterized in that the cured coating layer 60 is laminated by the uneven surface of the micro lens array (50). 8. The method of claim 7, wherein the plurality of micro lenses 51 on one surface of the micro lens array 50 has a form in which a valley portion 52c 'is formed between adjacent convex curved surfaces 52a and 52b. Rear projection screen, characterized in that formed after. The method of claim 7, wherein each of the convex surfaces 52a, 52b constituting the plurality of micro lenses 51 on one surface of the micro lens array 50 is formed to have a radius of curvature that satisfies the following three expressions. Rear projection screen. f · tanθ = h ........ 3 equation) (Where f is the focal length of the micro lens 51 and h is the pitch) In the rear projection screen in which the Fresnel lens 20 and the lenticular lens 40 which project the image light incident from the projection engine 2 to the viewer side under a viewing angle enlargement state are combined in an intimate state, In the lenticular lens 40, a plurality of cylindrical convex lenses 20a are sequentially formed on one surface thereof. The long triangular prism 20b on the other side is formed in a form in which both oblique lines are connected in series at the lower end, The black stripe layer 42 is laminated between the plurality of long triangular prisms 20b, The diffusion agent layer 30 is laminated on the black stripe layer 42, The rear projection screen, characterized in that the microlens array 50 is laminated to the diffusion layer (30).

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