阅读说明：本技术 一种光学成像薄膜及其制备方法 (Optical imaging film and preparation method thereof ) 是由 蔡福鑫 姚明亮 鲁金超 于 2021-09-28 设计创作，主要内容包括：本发明提供了一种光学成像薄膜及其制备方法,所述成像薄膜包括微聚焦层、图案层、以及位于微聚焦层和图案层之间的基体层,所述微聚焦层包括复数周期排列的柱透镜,所述图案层包括复数周期排列的微图案,所述基体层为聚合物薄膜；沿所述基体层厚度方向,所述图案层配置于基体层的一侧,所述微聚焦层配置于基体层的另一侧；所述微聚焦层与所述图案层相匹配,以使在视角范围内所述光学成像薄膜呈现上浮和/或下沉的所述微图案的放大影像；所述微图案通过计算软件切割成具有周期排列的线光栅。光栅化的微图案可使莫尔像呈彩色,解决了采用油墨颜色单一化及污染等问题。(The invention provides an optical imaging film and a preparation method thereof, wherein the imaging film comprises a micro-focusing layer, a pattern layer and a substrate layer positioned between the micro-focusing layer and the pattern layer, the micro-focusing layer comprises a plurality of cylindrical lenses which are arranged periodically, the pattern layer comprises a plurality of micro-patterns which are arranged periodically, and the substrate layer is a polymer film; the pattern layer is arranged on one side of the substrate layer along the thickness direction of the substrate layer, and the micro-focusing layer is arranged on the other side of the substrate layer; the micro focusing layer is matched with the pattern layer so that the optical imaging film presents a magnified image of the raised and/or sunk micro pattern in a visual angle range; the micro-pattern is cut into line gratings with periodic arrangement by calculation software. The raster micro pattern can make the Moire image be colored, and solves the problems of simplification of ink color and pollution.)

1. An optical imaging film comprises a micro-focusing layer, a pattern layer and a substrate layer positioned between the micro-focusing layer and the pattern layer, wherein the micro-focusing layer comprises a plurality of cylindrical lenses which are arranged periodically, the pattern layer comprises a plurality of micro-patterns which are arranged periodically, and the substrate layer is a polymer film; the pattern layer is arranged on one side of the substrate layer along the thickness direction of the substrate layer, and the micro-focusing layer is arranged on the other side of the substrate layer; the micro focusing layer is matched with the pattern layer so that the optical imaging film presents a magnified image of the raised and/or sunk micro pattern in a visual angle range;

the micro-pattern was cut by MATLAB programming into line gratings with periodic arrangement.

2. The optical imaging film according to claim 1, wherein the cylindrical lenses are periodically arranged in a width direction thereof, and a ratio of the width of the cylindrical lenses to the period thereof is 70% to 90%.

3. The optical imaging film according to claim 1, wherein the cylindrical lens has an aperture of 40 μm to 130 μm.

4. The optical imaging film of claim 1, wherein the micro-pattern has a duty cycle of 70% to 90%.

5. The optical imaging film according to claim 1, wherein the periodic direction of the line grating is perpendicular to the periodic direction of the cylindrical lens.

6. The optical imaging film according to claim 1, wherein the focal length of said cylindrical lens is equal to the thickness of said base layer.

7. The optical imaging film according to claim 1, wherein the periodic width of the cylindrical lens is different from the periodic width of the micro pattern.

8. The optical imaging film of claim 1 wherein said polymer film is a biaxially oriented polypropylene film.

9. A method of making the optical imaging film of any of claims 1-8, comprising the steps of:

(1) preparing a micro-focusing layer mold: firstly, drawing an AutoCAD drawing of a cylindrical lens array; according to a drawing, utilizing laser direct writing combined with hot melting and developing processes to manufacture a photoresist plate mould of the cylindrical lens array; and finally, manufacturing a cylindrical lens array nickel plate mould through an electroplating process.

(2) Preparing a micro-pattern layer mold: drawing an AutoCAD drawing of the micro-pattern array; rasterizing a graph in a drawing by using MATLAB programming; according to the rasterized drawing, a photoresist plate mould of the micro-pattern array is manufactured by utilizing a laser direct writing and developing process; and finally, manufacturing a micro-pattern array nickel plate mould by an electroplating process.

(3) Respectively imprinting a micro-focusing layer and a micro-pattern layer on two sides of a substrate layer by adopting a nano-imprinting process, and plating a high-reflectivity material on the surface of the micro-pattern layer to obtain the optical imaging film.

Technical Field

The invention relates to the technical field of optical films, in particular to an optical imaging film and a preparation method thereof.

Background

The moire imaging system is to use a micro focusing element array as a sampling tool to sample a micro pattern array, and the design principle is as follows: the micro-lens array layer Tr and the micro-pattern array layer Tb are arranged periodically, and the periods of the micro-lens array layer Tr and the micro-pattern array layer Tb have small deviation, so that the position of each micro-lens continuously deviates relative to each micro-pattern, the sampling of the whole micro-pattern is completed, and finally all sampling points are amplified and spliced to present a Moire image. In order to increase the contrast of the moire image, the grooves on the surface of the micro pattern are filled with colored ink by using a scraper through a nano printing technology, but only one color of ink is filled. However, in addition to being limited to a single color, the use of inks has several disadvantages: firstly, volatile polymer organic compounds (VOC) remained in printing ink printing pollute and damage the environment and harm human health; second, ink residue in the non-patterned groove structure areas will lead to film contamination and image-wise fouling.

Disclosure of Invention

In view of the above, the present invention provides an optical imaging film and a method for manufacturing the same, which colorizes a moire image by rasterizing a micro pattern.

In order to achieve the above object, the present invention provides an optical imaging film, comprising a micro-focusing layer, a pattern layer, and a substrate layer located between the micro-focusing layer and the pattern layer, wherein the micro-focusing layer comprises a plurality of periodically arranged cylindrical lenses, the pattern layer comprises a plurality of periodically arranged micro-patterns, and the substrate layer is a polymer film; the pattern layer is arranged on one side of the substrate layer along the thickness direction of the substrate layer, and the micro-focusing layer is arranged on the other side of the substrate layer; the micro focusing layer is matched with the pattern layer so that the optical imaging film presents a magnified image of the raised and/or sunk micro pattern in a visual angle range;

the micro-pattern was cut by MATLAB programming into line gratings with periodic arrangement.

Furthermore, the cylindrical lenses are periodically arranged along the width direction, and the ratio of the width of the cylindrical lenses to the period of the cylindrical lenses is 70% -90%.

Furthermore, the aperture of the cylindrical lens is 40-130 μm.

Further, the duty cycle of the micro-pattern is 70% -90%.

Further, the periodic direction of the line grating is perpendicular to the periodic direction of the cylindrical lens.

Further, the focal length of the cylindrical lens is equal to the thickness of the base layer.

Further, the periodic width of the cylindrical lens is different from the periodic width of the micro-pattern.

Further, the polymer film is a biaxially oriented polypropylene film.

The invention also provides a preparation method of the optical imaging film, which comprises the following steps:

(1) preparing a micro-focusing layer mold: firstly, drawing an AutoCAD drawing of a cylindrical lens array; according to a drawing, utilizing laser direct writing combined with hot melting and developing processes to manufacture a photoresist plate mould of the cylindrical lens array; and finally, manufacturing a cylindrical lens array nickel plate mould through an electroplating process.

(2) Preparing a micro-pattern layer mold: drawing an AutoCAD drawing of the micro-pattern array; rasterizing a graph in a drawing by using MATLAB programming; according to the rasterized drawing, a photoresist plate mould of the micro-pattern array is manufactured by utilizing a laser direct writing and developing process; and finally, manufacturing a micro-pattern array nickel plate mould by an electroplating process.

(3) Respectively imprinting a micro-focusing layer and a micro-pattern layer on two sides of a substrate layer by adopting a nano-imprinting process, and plating a high-reflectivity material on the surface of the micro-pattern layer to obtain the optical imaging film.

Compared with the prior art, the invention has the beneficial effects that: the micro-pattern is cut into the periodic line grating through programming software, the grating micro-pattern array enables the moire image to have colors under the diffraction effect of natural light, meanwhile, along with different diffraction angles, the colors seen by human eyes are different, the moire image is enabled to have multiple colors, and the problems that the color of used printing ink is single, the environment is polluted and the like are solved.

Drawings

FIG. 1 is a schematic view of the structure of an imaging film according to example 1 of the present invention;

FIG. 2 is a schematic diagram of the micro-pattern rasterization of example 1 of the present invention;

FIG. 3 is a top view of a micro-focus layer of an imaged film of example 1 of the present invention.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

Example 1

As shown in fig. 1, the optical imaging film structure provided by this embodiment includes a micro-focusing layer 101, a pattern layer 102, and a substrate layer 103 located between the micro-focusing layer and the pattern layer, where the micro-focusing layer 101 includes a plurality of periodically arranged cylindrical lenses 101a, the pattern layer 102 includes a plurality of periodically arranged micro-patterns 102a, and the substrate layer 103 is a polymer film; the pattern layer 102 is arranged on one side of the base layer 103, and the micro-focus layer 101 is arranged on the other side of the base layer 103 along the thickness direction of the base layer 103; the micro-focusing layer 101 is matched with the pattern layer 102, so that the optical imaging film presents a magnified image of the raised and/or sunk micro-pattern in a visual angle range;

as shown in fig. 2, the micro pattern 102a is cut into line gratings 102b having a periodic arrangement by MATLAB programming.

As shown in fig. 3, the lenticular lenses 101a are periodically arranged in the width direction thereof.

In some embodiments, the width of the cylindrical lens is 70% to 90% of its period ratio.

In some embodiments, the aperture of the cylindrical lens is 40 μm to 130 μm, and the cylindrical lens array with the aperture larger than 130 μm will be observed by human eyes, resulting in the defect of pixelation.

In some embodiments, the duty cycle of the micropattern is from 70% to 90%, and specifically can be 70%, 75%, 80%, 85%, 90%.

In some embodiments, the periodic direction of the linear grating is perpendicular to the periodic direction of the cylindrical lens, so that the diffraction light splitting effect of the grating cannot be damaged by the convergence effect of the cylindrical lens, and when a human eye observes the imaging film, the direction of the line connecting the two eyes should be parallel to the periodic direction of the grating, otherwise, the color effect cannot be seen.

In some embodiments, the focal length of the cylindrical lens is equal to the thickness of the base layer, and the micropattern layer is positioned at the focal point of the micropoocusing layer to enable clear imaging.

In some embodiments, the periodic width of the cylindrical lenses is different from the periodic width of the micro patterns to ensure that the position of each cylindrical lens is constantly shifted with respect to each micro pattern, thereby completing the sampling of the entire micro pattern.

In some embodiments, the polymer film is a biaxially oriented polypropylene film, which has better stretchability and better adhesion to photoresist, and facilitates the loading of the lenticular lens array and the micro-pattern array on the film through a nano-printing process.

Example 2

The specific embodiment discloses a preparation method of an optical imaging film, which comprises the following steps:

(1) preparing a micro-focusing layer mold: firstly, drawing an AutoCAD drawing of a cylindrical lens array; according to a drawing, utilizing laser direct writing combined with hot melting and developing processes to manufacture a photoresist plate mould of the cylindrical lens array; and finally, manufacturing a cylindrical lens array nickel plate mould through an electroplating process.

(2) Preparing a micro-pattern layer mold: drawing an AutoCAD drawing of the micro-pattern array; rasterizing a graph in a drawing by using MATLAB programming; according to the rasterized drawing, a photoresist plate mould of the micro-pattern array is manufactured by utilizing a laser direct writing and developing process; and finally, manufacturing a micro-pattern array nickel plate mould by an electroplating process.

(3) Respectively imprinting a micro-focusing layer and a micro-pattern layer on two sides of a substrate layer by using the nickel plate mould obtained in the step by adopting a nano-imprinting process, and then plating a high-reflectivity material on the surface of the micro-pattern layer to obtain the optical imaging film.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.