CN116339061A - Large-viewing angle projection film and preparation method thereof - Google Patents

Abstract

The invention provides a large-viewing angle projection film and a preparation method thereof, wherein the preparation method comprises the following steps: (1) Electroplating a copper layer on the surface of a base roller, and carrying out patterning treatment on the copper layer on any side of the base roller to obtain a micro-concave structure; (2) Atomizing the surface of the micro-concave structure in the step (1) to form irregular concave-convex pits; (3) And (3) transferring the concave-convex pits in the step (2) to the surface of a base material, performing photo-curing, and then coating a reflecting material on the outer surface of the concave-convex pits to prepare the large-visual-angle projection film. According to the invention, the micro-concave structure is engraved on the surface of the base roller, then atomization treatment is carried out on the inner surface of the micro-concave structure, and the back surface of the concave-convex pit is coated with the reflective material, so that projection light is diffusely reflected by the irregular concave-convex pit, the visual angle of the projection film is increased, and meanwhile, the central brightness is not lost.

Description

Large-viewing angle projection film and preparation method thereof

Technical Field

The invention belongs to the technical field of projection display, and particularly relates to a large-viewing angle projection film and a preparation method thereof.

Background

With the increasing development of electronic audio-visual technology, under the background that a liquid crystal television falls into price war and an OLED television is good and does not call a seat, a laser television accidentally detonates a high-end large-screen market, and the liquid crystal television becomes the first choice for upgrading and upgrading of a plurality of consumers. The data of 1-10 months in 2019 of Zhongyi kang show that the sales of the laser television in the large-screen television market of 80 inches and more in China reaches 48.05 percent, and a large-screen consumption age dominated by the laser television has been of course.

The future attribute range of the laser television is precisely aimed at the whole large-screen potential circle of the color television, and the market space is a large market of millions of levels. The laser television can enjoy the bonus of the market burst in the field of large-size color television, and has monopoly independent market segment. This is why industry is very high looking at this product line.

The projection curtain is one of the necessary accessories for displaying the laser television, and no matter the projection curtain is used for traditional projection, intelligent projection and the laser television, the picture is shot onto the curtain or the wall surface by using light, and then is reflected into eyes by the curtain or the wall surface, so that the picture is seen by people.

CN111999978A discloses a method for manufacturing a laser projection screen and a laser projection screen, the method for manufacturing the laser projection screen comprises the following steps: (1) Processing the surface of the optical mould core into an optical mould core with a microstructure; (2) performing ultrasonic cleaning on the optical mold core; (3) coating a release agent to obtain a release layer; (4) coating optical adhesive on the release layer; (5) attaching an optical plate on the optical adhesive; (6) Performing UV curing to obtain a semi-finished product of the laser projection screen coated with the release layer, the optical cement and the optical plate; (7) Demolding the semi-finished product of the laser projection screen and the optical mold core; (8) Spraying the semi-finished product of the laser projection screen to form a reflecting surface; (9) Baking the laser projection screen semi-finished product sprayed with the reflecting surface, and cutting the baked laser projection screen semi-finished product; (10) And setting a color-changing layer on the baked semi-finished product of the laser projection screen, thereby preparing the laser projection screen. But the steps are complicated and the cost is high, thereby restricting the popularization and application of the screen in the laser television.

At present, laser projection has various problems, such as small viewing angle, because the laser projection is reflective light, the direction of the reflective light is relatively fixed, and the overall viewing angle is small, and the brightness loss is large if the angle is large.

Therefore, in order to solve the above-mentioned problems, it is desirable to design a projection film that is low in cost and simple in process, and can improve the viewing angle while ensuring brightness.

Disclosure of Invention

The invention aims to provide a large-view angle projection film and a preparation method thereof, wherein the preparation method combines a specific processing mode through reasonable microstructure arrangement, and the prepared projection film has excellent brightness and viewing angle, so that the problem that the brightness and viewing angle cannot be simultaneously achieved in the prior art is solved.

In order to achieve the aim of the invention, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for preparing a large viewing angle projection film, the method comprising the steps of:

(1) Electroplating a copper layer on the surface of a base roller, and carrying out patterning treatment on the copper layer on any side of the base roller to obtain a micro-concave structure;

(2) Atomizing the surface of the micro-concave structure in the step (1) to form irregular concave-convex pits;

(3) And (3) transferring the concave-convex pits in the step (2) to the surface of a base material, performing photo-curing, and then coating a reflecting material on the outer surface of the concave-convex pits to prepare the large-visual-angle projection film.

In the invention, the irregular concave-convex pits in the step (2) are formed by spraying glass beads on the surface of a micro-concave structure to form pits with random sizes; the outer surface of the concave-convex pit in the step (3) is the back surface of the concave-convex pit at the side far away from the base material.

The invention designs the micro-concave structure, combines atomization treatment on the inner surface of the micro-concave structure and coating the reflective material on the back surface of the concave-convex pit, diffusely reflects projection light through the irregular concave-convex pit, increases the visual angle of the projection film, and does not lose central brightness.

As a preferable technical scheme of the invention, the base roller in the step (1) is of a columnar structure.

Preferably, the thickness of the copper layer in step (1) is 1.8-2.2mm, for example, 1.8mm, 1.9mm, 2mm, 2.1mm or 2.2mm, etc., but not limited to the recited values, and other values not recited in the numerical range are equally applicable.

In the invention, an ultra-precision electroplated copper layer is formed on the surface of a base roller by electroplating the copper layer and is used as a base for engraving.

Preferably, the copper layer is electroplated in the step (1) and then further comprises cooling, turning and polishing which are sequentially carried out.

Preferably, the cooling time is more than or equal to 24 hours, for example, 24 hours, 25 hours, 26 hours, 28 hours or 30 hours, etc., but the cooling time is not limited to the recited values, and other non-recited values in the range of values are equally applicable.

As a preferred technical solution of the present invention, the patterning process in step (1) is: and engraving the copper layer on any surface of the base roller by adopting a cutter.

Preferably, the R angle of the tool is 75 ° -85 °, for example, 75 °, 76 °, 77 °, 79 °, 80 °, 81 °, 83 °, 85 °, etc., but not limited to the recited values, other non-recited values within the range of values are equally applicable.

Preferably, the arc radius of the cutter is 0.08-0.12mm, for example, 0.08mm, 0.09mm, 0.1mm, 0.11mm or 0.12mm, etc., but the present invention is not limited to the recited values, and other values not recited in the numerical range are equally applicable.

The invention uses the diamond cutter with R angle to engrave the surface of the base roller, so that the copper layer surface forms a continuously extending micro-concave structure, and the diamond cutter is used for engraving.

As a preferred embodiment of the present invention, the diameter of the dimple structure in the step (1) is 0.22-0.26mm, for example, 0.22mm, 0.225mm, 0.23mm, 0.235mm, 0.24mm, 0.245mm, 0.25mm, 0.255mm or 0.26mm, etc., but not limited to the values listed, and other values not listed in the numerical range are equally applicable.

Preferably, the depth of the dimple structure in the step (1) is 0.11-0.13mm, for example, 0.11mm, 0.114mm, 0.118mm, 0.12mm, 0.124mm, 0.128mm or 0.13mm, etc., but not limited to the recited values, and other non-recited values in the range of values are equally applicable.

The dimple structure is a semicircular arc structure.

It is worth to say that, the distance between adjacent micro-concave structures is not reserved, and the micro-concave structures can ensure the reflecting area according to the arrangement of the diameter range, so that the view angle of the projection film is enlarged.

As a preferable technical scheme of the present invention, the atomization treatment in the step (2) is: spraying glass beads on the surface of the micro-concave structure in the step (1) by using a high-pressure air gun to form irregular concave-convex pits.

Preferably, the pressure of the high-pressure air gun is 30-35kg, for example, 30kg, 31kg, 32kg, 33kg, 34kg or 35kg, etc., but the pressure is not limited to the values listed, and other values not listed in the numerical range are equally applicable.

Preferably, the glass beads have a diameter of 50-60 μm, for example, 50 μm, 52 μm, 54 μm, 56 μm, 58 μm or 60 μm, etc., but are not limited to the recited values, and other non-recited values within the range of values are equally applicable.

According to the invention, atomization treatment is carried out on the surface of the micro-concave structure, glass beads are adopted to strike the copper surface, so that concave-convex pits with random sizes are formed, and the diffuse reflection effect is formed on the surface of the concave-convex pits, which is equivalent to the effect of forming an atomization surface.

Preferably, the haze after atomization treatment in the step (2) is 75% -80%, for example, 75%, 76%, 77%, 78%, 79% or 80%, etc., but not limited to the recited values, and other values not recited in the numerical range are equally applicable.

It is worth to say that, the haze is controlled in the above range, so that the projection light is diffused when passing through the projection film, and the brightness of the projection film is improved after the reflected light is emitted; if the haze is too large, the roughness increases, so that the viewing angle of the projection film becomes large, but the gain decreases significantly, and the cost benefit becomes poor.

As a preferred embodiment of the present invention, the photo-curing in step (3) includes ultraviolet lamp curing.

Preferably, the ultraviolet light in the ultraviolet light curing is 320-400nm, for example, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm, 390nm or 400nm, etc., but not limited to the recited values, and other values not recited in the numerical range are equally applicable.

Preferably, the energy of the ultraviolet light curing is 150-300mj, for example, 150mj, 170mj, 200mj, 220mj, 240mj, 260mj, 280mj or 300mj, etc., but the energy is not limited to the recited values, and other non-recited values in the range of values are equally applicable.

Preferably, the substrate of step (3) comprises a PET base film.

Preferably, the reflective material of step (3) comprises aluminium.

Preferably, the thickness of the coating in step (3) is 350-400nm, which may be, for example, 350nm, 360nm, 370nm, 380nm, 390nm or 400nm, etc., but is not limited to the values recited, and other non-recited values within the range of values are equally applicable.

The invention is beneficial to improving the reflectivity of projection light after passing through the projection film by plating mirror aluminum on the back surface of the irregular concave-convex pit structure.

In a preferred embodiment of the present invention, the transmittance of the projection film is 3% to 5%, for example, 3%, 3.4%, 3.8%, 4%, 4.4%, 4.8% or 5%, but the present invention is not limited to the above-mentioned values, and other values not mentioned in the numerical range are applicable.

Preferably, the viewing angle of the projection film is equal to or greater than 90 °, for example, 90 °, 91 °, 92 °, 93 °, 94 °, 95 °, 97 °, etc., but the present invention is not limited to the recited values, and other non-recited values in the numerical range are equally applicable.

As a preferable technical scheme of the invention, the preparation method comprises the following steps:

(1) Electroplating a copper layer with the thickness of 1.8-2.2mm on the surface of a base roller with a columnar structure, then cooling for more than or equal to 24 hours, leveling and polishing, and then carrying out patterning treatment on the copper layer on any side of the base roller to obtain a micro-concave structure; the method comprises the steps of carrying out a first treatment on the surface of the

The patterning process in the step (1) is as follows: engraving the copper layer on any surface of the base roller by adopting a cutter with an R angle of 75-85 degrees and an arc radius of 0.08-0.12 mm; the diameter of the micro-concave structure in the step (1) is 0.22-0.26mm, and the depth is 0.11-0.13mm;

(2) Atomizing the surface of the micro-concave structure in the step (1) to form irregular concave-convex pits, so that the haze of the micro-concave pits is 75% -80%;

the atomization treatment in the step (2) is as follows: spraying glass beads with the diameter of 50-60 mu m on the surface of the micro-concave structure in the step (1) by using a high-pressure air gun with the pressure of 30-35kg to form irregular concave-convex pits;

(3) Transferring the concave-convex pits in the step (2) to the surface of a substrate, performing photo-curing, and then coating aluminum on the outer surface of the concave-convex pits to prepare a projection film with 3-5% of transmittance and a visual angle of more than or equal to 90 degrees;

the thickness of the coating in the step (3) is 350-400nm.

In a second aspect, the present invention also provides a projection film, which is manufactured by the manufacturing method in the first aspect;

the projection film comprises a substrate layer and a reflecting layer arranged on the substrate layer;

the reflecting layer comprises a concave-convex pit structure which is arranged continuously;

the outer surface of the reflecting layer, which is far away from the substrate layer, is coated with a reflecting material.

As a preferable technical scheme of the invention, the transmittance of the projection film is 3% -5%.

Preferably, the viewing angle of the projection film is equal to or greater than 90 °.

The numerical ranges recited herein include not only the recited point values, but also any point values between the recited numerical ranges that are not recited, and are limited to, and for the sake of brevity, the invention is not intended to be exhaustive of the specific point values that the recited range includes.

Compared with the prior art, the invention has the following beneficial effects:

(1) According to the preparation method, the micro-concave structure is engraved on the surface of the base roller, then atomization treatment is carried out on the inner surface of the micro-concave structure, and the back surface of the concave-convex pit is coated with a reflecting material, so that projection light is diffusely reflected by the irregular concave-convex pit, the visual angle of the projection film is increased, and meanwhile, the central brightness is not lost;

(2) The invention designs the size, the interval distribution and the like of the micro-concave structure, limits the haze range after atomization treatment, and improves the diffuse reflection of the projection film to the maximum extent on the premise of not losing the central brightness and ensuring the gain;

(3) The preparation method provided by the invention is simple to operate, has high universality and is suitable for large-scale production.

Drawings

FIG. 1 is a schematic cross-sectional view of a base roll according to the present invention;

FIG. 2 is a schematic cross-sectional view of a base roll surface dimple structure provided by the present invention;

fig. 3 is a schematic cross-sectional view of the irregular pits on the surface of the base roller according to the present invention.

Detailed Description

The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.

The invention provides a large-viewing angle projection film and a preparation method thereof, wherein the preparation method comprises the following steps:

(1) Electroplating a copper layer with the thickness of 1.8-2.2mm on the surface of a base roller (the structural schematic diagram of which is shown in figure 1) with a columnar structure, then cooling for more than or equal to 24 hours, turning and polishing, and then carrying out patterning treatment on the copper layer on any side of the base roller to obtain a micro-concave structure; (the schematic structure is shown in FIG. 2);

the patterning process in the step (1) is as follows: engraving the copper layer on any surface of the base roller by adopting a cutter with an R angle of 75-85 degrees and an arc radius of 0.08-0.12 mm; the diameter of the micro-concave structure in the step (1) is 0.22-0.26mm, and the depth is 0.11-0.13mm;

(2) Atomizing the surface of the micro-concave structure in the step (1) to form irregular concave-convex pits (the structure schematic diagram of which is shown in figure 3) so that the haze of the micro-concave pits is 75-80%;

the atomization treatment in the step (2) is as follows: spraying glass beads with the diameter of 50-60 mu m on the surface of the micro-concave structure in the step (1) by using a high-pressure air gun with the pressure of 30-35kg to form irregular concave-convex pits;

(3) Transferring the concave-convex pits in the step (2) to the surface of a substrate, performing photo-curing, and plating mirror aluminum on the outer surface of the concave-convex pits to prepare a projection film with 3-5% of transmittance and a visual angle of more than or equal to 90 degrees;

the thickness of the mirror aluminum plated in the step (3) is 350-400nm.

Example 1

The embodiment provides a preparation method of a large-viewing angle projection film, which comprises the following steps:

(1) Electroplating a copper layer with the thickness of 2mm on the surface of a base roller with a columnar structure, cooling for 24 hours, turning and polishing, and engraving the copper layer on any side of the base roller by adopting a diamond cutter with the R angle of 80 degrees and the arc radius of 0.1mm to obtain a continuously arranged micro-concave structure;

the diameter of the micro-concave structure in the step (1) is 0.24mm, and the depth is 0.11mm;

(2) Atomizing the surface of the micro-concave structure in the step (1) to form irregular concave-convex pits, so that the haze of the micro-concave pits is 77%;

the atomization treatment in the step (2) is as follows: spraying glass beads with the diameter of 55 mu m on the surface of the micro-concave structure by using a high-pressure air gun with the pressure of 32kg to form irregular concave-convex pits;

(3) Transferring the concave-convex pits in the step (2) to the surface of a PET base film, performing light curing under the conditions of 365nm ultraviolet wavelength and 250mj energy, and plating mirror aluminum with the thickness of 360nm on the outer surface of the concave-convex pits to prepare the projection film.

Example 2

The embodiment provides a preparation method of a large-viewing angle projection film, which comprises the following steps:

(1) Electroplating a copper layer with the thickness of 2.2mm on the surface of a base roller with a columnar structure, cooling for 30, turning and polishing, and engraving the copper layer on any side of the base roller by adopting a diamond cutter with the R angle of 75 degrees and the arc radius of 0.08mm to obtain a continuously arranged micro-concave structure;

the diameter of the micro-concave structure in the step (1) is 0.23mm, and the depth is 0.12mm;

(2) Atomizing the surface of the micro-concave structure in the step (1) to form irregular concave-convex pits, so that the haze of the micro-concave pits is 80%;

the atomization treatment in the step (2) is as follows: spraying glass beads with the diameter of 50 mu m on the surface of the micro-concave structure by using a high-pressure air gun with the pressure of 35kg to form irregular concave-convex pits;

(3) Transferring the concave-convex pits in the step (2) to the surface of a PET base film, performing light curing under the conditions of 375nm ultraviolet wavelength and 400mj energy, and plating mirror aluminum with 380nm thickness on the outer surface of the concave-convex pits to prepare the projection film.

Example 3

The embodiment provides a preparation method of a large-viewing angle projection film, which comprises the following steps:

(1) Electroplating a copper layer with the thickness of 1.8mm on the surface of a base roller with a columnar structure, cooling for 30 hours, turning and polishing, and engraving the copper layer on any side of the base roller by adopting a diamond cutter with the R angle of 85 degrees and the arc radius of 0.12mm to obtain a continuously arranged micro-concave structure;

the diameter of the micro-concave structure in the step (1) is 0.25mm, and the depth is 0.13mm;

(2) Atomizing the surface of the micro-concave structure in the step (1) to form irregular concave-convex pits, so that the haze of the micro-concave pits is 75%;

the atomization treatment in the step (2) is as follows: spraying glass beads with the diameter of 55 mu m on the surface of the micro-concave structure by using a high-pressure air gun with the pressure of 30kg to form irregular concave-convex pits;

(3) Transferring the concave-convex pits in the step (2) to the surface of a PET base film, performing light curing under the conditions of 365nm ultraviolet wavelength and 150mj energy, and plating mirror aluminum with the thickness of 350nm on the outer surface of the concave-convex pits to prepare the projection film.

Example 4

This example provides a method for producing a projection film, which is the same as example 1 except that the "dimple structure of 0.24mm diameter and 0.11mm depth" in step (1) is replaced with "dimple structure of 0.18mm diameter and 0.1mm depth".

Example 5

This example provides a method for producing a projection film, which is the same as example 1 except that the "dimple structure of 0.24mm diameter and 0.11mm depth" in step (1) is replaced with "dimple structure of 0.3mm diameter and 0.16mm depth".

Example 6

This example provides a method for producing a projection film, which is the same as example 1 except that the continuously arranged dimple structures in step (1) are replaced with "the distance between adjacent dimple structures is 0.05 mm".

Example 7

This example provides a method for producing a projection film, which is the same as example 1 except that the "glass beads" are replaced with "alumina fine sand".

Example 8

This example provides a method for producing a projection film, which is the same as example 1, except that the haze in step (2) is 70%.

Example 9

This example provides a method for producing a projection film, which is the same as example 1, except that the haze in step (2) is 85%.

Example 10

This example provides a method for producing a projection film under the same conditions as in example 1 except that the thickness of the mirror-coated aluminum in step (3) was 300 nm.

Example 11

This example provides a method for producing a projection film under the same conditions as in example 1 except that the thickness of the mirror-coated aluminum in step (3) is 450 nm.

Comparative example 1

This comparative example provides a method for producing a projection film, which is the same as example 1 except that the dimple structure in step (1) is replaced with a "triangle structure, and the length of the base is 0.24 mm".

Comparative example 2

This comparative example provides a method for producing a projection film, which is the same as example 1 except that the dimple structure in step (1) is replaced with a "trapezoid structure" having a length of the base of 0.24 mm.

Comparative example 3

This comparative example provides a method for producing a projection film, and the conditions are the same as in example 1 except that the atomization treatment in step (2) is not performed.

Comparative example 4

This comparative example provides a method for producing a projection film, which is the same as example 1 except that mirror aluminum is not plated on the outer surface of the pit.

Comparative example 5

This comparative example uses conventional projection films of the prior art.

The projection films prepared in the above examples and comparative examples were used to manufacture projection screens, and performance tests of viewing angle, transmittance and gain were performed on the projection screens, and the test results are shown in table 1.

TABLE 1

From table 1, the following points can be found:

(1) The projection film prepared by the preparation method provided by the embodiment 1-3 of the invention can improve the view angle of the projection film to 90 degrees or more on the premise of ensuring the brightness, and simultaneously ensures the gain to be 2.4 or more;

(2) As can be seen from comparison of examples 1 and examples 4 to 6, when the diameter of the obtained dimple structure is too small, the viewing angle of the projection film is small due to insufficient reflection area; when the diameter of the obtained micro-concave structure is too large, the view angle of the projection film becomes large due to the increase of the reflecting area, but the gain is reduced; if a distance exists between the adjacent micro-concave structures, the distance forms specular reflection, so that the view angle of the projection film becomes smaller;

(3) As is clear from comparison of examples 1 and examples 8 to 9 and comparative example 3, when the haze after the atomization treatment is too low, the viewing angle of the projection film becomes small due to insufficient roughness; when the haze is too high after atomization treatment, the visual angle of the projection film becomes large due to large roughness, but the gain is reduced; if the atomization treatment is not performed, the view angle of the projection film is reduced due to the strong mirror surface feel of the structure surface;

(4) As can be seen from comparison of examples 1, 10-11 and comparative example 4, when the thickness of the mirror-plated aluminum is too thin, the viewing angle of the projection film is reduced and the gain is obviously reduced because the aluminum layer cannot fully reflect light; when the thickness of the aluminum plated with the mirror surface is too thick, the reflection is enhanced, so that the view angle of the projection film is reduced; if the back surface of the concave-convex pit is not coated with the reflective material, the visual angle of the projection film is reduced and the gain is obviously reduced due to no aluminum surface reflection;

(5) As is clear from comparison of example 1 and comparative examples 1-2, when the dimple structure is replaced with a triangular or trapezoidal structure, the viewing angle of the projection film is reduced and the gain is increased due to the non-circular arc structure.

The applicant states that the detailed structural features of the present invention are described by the above embodiments, but the present invention is not limited to the above detailed structural features, i.e. it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be apparent to those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope of the present invention and the scope of the disclosure.

Claims (10)

1. A method for preparing a large viewing angle projection film, comprising the steps of:

(1) Electroplating a copper layer on the surface of a base roller, and carrying out patterning treatment on the copper layer on any side of the base roller to obtain a micro-concave structure;

(2) Atomizing the surface of the micro-concave structure in the step (1) to form irregular concave-convex pits;

(3) And (3) transferring the concave-convex pits in the step (2) to the surface of a base material, performing photo-curing, and then coating a reflecting material on the outer surface of the concave-convex pits to prepare the large-visual-angle projection film.

2. The method of claim 1, wherein the base roll of step (1) is of a columnar structure;

preferably, the thickness of the copper layer in the step (1) is 1.8-2.2mm;

preferably, the copper layer is electroplated in the step (1) and then the copper layer is cooled, turned and polished sequentially;

preferably, the cooling time is more than or equal to 24 hours.

3. The method of claim 1 or 2, wherein the patterning process of step (1) is: engraving the copper layer on any surface of the base roller by using a cutter;

preferably, the R angle of the cutter is 75-85 degrees;

preferably, the arc radius of the cutter is 0.08-0.12mm.

4. A method of manufacture according to any one of claims 1 to 3, wherein the diameter of the dimple structure of step (1) is 0.22 to 0.26mm;

preferably, the depth of the micro-concave structure in the step (1) is 0.11-0.13mm.

5. The method according to any one of claims 1 to 4, wherein the atomizing treatment in the step (2) is: spraying glass beads on the surface of the micro-concave structure in the step (1) by using a high-pressure air gun to form irregular concave-convex pits;

preferably, the pressure of the high-pressure air gun is 30-35kg;

preferably, the glass beads have a diameter of 50-60 μm;

preferably, the haze of the atomized water obtained in the step (2) is 75% -80%.

6. The method of any one of claims 1-5, wherein the photocuring of step (3) comprises uv lamp curing;

preferably, the wavelength of ultraviolet light in the ultraviolet light curing is 320-400nm;

preferably, the energy of ultraviolet light curing is 150-300mj;

preferably, the substrate of step (3) comprises a PET base film;

preferably, the reflective material of step (3) comprises aluminium;

preferably, the thickness of the coating of step (3) is 350-400nm.

7. The method of any one of claims 1-6, wherein the projected film has a transmittance of 3% -5%;

preferably, the viewing angle of the projection film is equal to or greater than 90 °.

8. The preparation method according to any one of claims 1 to 7, characterized in that the preparation method comprises the steps of:

(1) Electroplating a copper layer with the thickness of 1.8-2.2mm on the surface of a base roller with a columnar structure, then cooling for more than or equal to 24 hours, leveling and polishing, and then carrying out patterning treatment on the copper layer on any side of the base roller to obtain a micro-concave structure;

the patterning process in the step (1) is as follows: engraving the copper layer on any surface of the base roller by adopting a cutter with an R angle of 75-85 degrees and an arc radius of 0.08-0.12 mm; the diameter of the micro-concave structure in the step (1) is 0.22-0.26mm, and the depth is 0.11-0.13mm;

(2) Atomizing the surface of the micro-concave structure in the step (1) to form irregular concave-convex pits, so that the haze of the micro-concave pits is 75% -80%;

the atomization treatment in the step (2) is as follows: spraying glass beads with the diameter of 50-60 mu m on the surface of the micro-concave structure in the step (1) by using a high-pressure air gun with the pressure of 30-35kg to form irregular concave-convex pits;

(3) Transferring the concave-convex pits in the step (2) to the surface of a substrate, performing photo-curing, and then coating aluminum on the outer surface of the concave-convex pits to prepare a projection film with 3-5% of transmittance and a visual angle of more than or equal to 90 degrees;

the coating thickness in the step (3) is 350-400nm.

9. A projection film produced by the production method according to any one of claims 1 to 8;

the projection film comprises a substrate layer and a reflecting layer arranged on the substrate layer;

the reflecting layer comprises a concave-convex pit structure which is arranged continuously;

the outer surface of the reflecting layer, which is far away from the substrate layer, is coated with a reflecting material.

10. The projection film of claim 9, wherein the projection film has a transmittance of 3% -5%;

preferably, the viewing angle of the projection film is equal to or greater than 90 °.

Images