KR101167709B1 - Stereoscopic lens sheet comprising printed pattern layer formed at bottom of injection resin and method for fabricating the same lens sheet - Google Patents

Abstract

The present invention solves the problem of conventional lens implementation of a very small size, and provides a three-dimensional sheet and a three-dimensional sheet manufacturing method that can be easily manufactured using an insert in-mold injection process. The three-dimensional sheet includes a lens layer in which a plurality of large-area lenses having a diameter larger than the center thickness is formed; A transparent injection resin formed under the lens layer and having a thickness corresponding to a focal length of the lenses; And a printing pattern layer formed under the injection resin. In addition, the manufacturing method comprises the steps of: bonding a lens layer formed with a plurality of large-area lenses having a diameter larger than the center thickness in the upper mold; Forming an intermediate three-dimensional sheet having a transparent injection resin bonded to the lower part of the lens layer through an insert in-mold injection process; And forming a printed pattern layer on the lower surface of the injection resin to complete a three-dimensional sheet.

Description

Stereoscopic sheet including printed pattern layer formed at bottom of injection resin and method for fabricating the same lens sheet

The present invention relates to a three-dimensional sheet capable of realizing a 3D image, and more particularly, to a three-dimensional sheet in which a printing pattern layer is formed under a thick injection resin, and a method of manufacturing the three-dimensional sheet.

In general, two-dimensional patterns or images formed on a two-dimensional plane are recognized as two-dimensional because they are incident on the human eye in two-dimensional form through the reflection of light. However, when an optical lens sheet called a lenticular sheet is used, a two-dimensional image may be recognized as a three-dimensional (3D), that is, a three-dimensional image.

The principle of recognizing a two-dimensional image as a three-dimensional image using a lenticular sheet is due to the binocular disparity that appears because the human eye exists about 64 mm apart in the horizontal direction. Here, binocular parallax is a phenomenon in which the left and right eyes of a person are separated by a predetermined distance, so even if the image of the same position is different from the light paths coming into the left and right eyes, a slightly different image is formed on the left and right retinas. Say.

Such a lenticular sheet generally has a structure in which transparent hemispherical lenses are formed in an upper surface and a fine pattern is formed in a lower surface, and has a very thin thickness, for example, a thickness of about 0.2 mm. The thin lenticular sheet is attached to a thick exterior case formed of an injection resin, and the like, thereby causing a visual effect to the eyes of people.

However, in order to fabricate a lenticular sheet having a very thin thickness, the lens formed at the top should have a very small size. That is, in general, the thickness of the lenticular sheet is determined by the focal length of the lens. In the case of the lenticular sheet of about 0.2 mm, the size of the lens, that is, the diameter of the lens should be about 0.02 mm. It is very difficult to manufacture a mold for molding such a small size lens, and also the process of printing a pattern that fits such a small lens to the bottom surface is very difficult, and there are many problems in producing a realistically.

The problem to be solved by the present invention is to solve the problem of the conventional implementation of a very small size of the lens, and to provide a three-dimensional sheet and a method for manufacturing the three-dimensional sheet that can be easily manufactured using the insert in-mold injection process .

In order to solve the above problems, the present invention is a lens layer formed of a plurality of large area lenses having a diameter larger than the center thickness; A transparent injection resin formed under the lens layer and having a thickness corresponding to a focal length of the lenses; It provides a three-dimensional sheet comprising a three-dimensional sheet comprising a; and a printed pattern layer formed under the injection resin.

In one embodiment of the present invention, the lens layer may include a low refractive thin film layer formed in the convex direction of the lenses. The three-dimensional sheet may further include a protective film layer formed on the lens layer, and an adhesive layer formed between the lens layer and the injection resin.

In order to solve the above problems, the present invention also comprises the steps of: bonding a lens layer formed with a plurality of large area lenses having a diameter larger than the center thickness in the upper mold; Forming an intermediate three-dimensional sheet having a transparent injection resin bonded to the lower part of the lens layer through an insert in-mold injection process; And forming a printed pattern layer on the lower surface of the injection resin to complete a three-dimensional sheet.

In one embodiment of the present invention, before forming the intermediate three-dimensional sheet, in order to bond the lens layer to the injection resin, it may include the step of forming an adhesive layer under the lens layer. Before adhering the lens layer, the method may include forming the lens layer including lenses having a diameter of 0.2 mm or more.

The method may further include forming a protective film layer on the lens layer. In the forming of the intermediate three-dimensional sheet, a predetermined pattern formed on the lower mold is transferred to reverse the pattern onto the lower surface of the injection resin. A pattern is formed, and in the step of completing the three-dimensional sheet, the pattern layer may be formed by back printing on the reverse pattern.

The three-dimensional sheet including the printing pattern layer formed on the lower portion of the injection resin and the method of manufacturing the three-dimensional sheet according to the present invention has a large size of the lens, and accordingly, by using a structure to form a printing pattern layer on the lower portion of the thick injection resin, It solves the difficulty of producing a thin three-dimensional sheet, and can also easily implement the external case of the desired shape through the IML process.

1 is a perspective view showing a three-dimensional sheet according to an embodiment of the present invention applied to a mobile phone exterior case.
FIG. 2 is an enlarged cross-sectional view of portion A of the three-dimensional sheet of FIG. 1.
3a to 3e is a flow chart showing a manufacturing method of a three-dimensional sheet according to another embodiment of the present invention.
4A to 4D are flowcharts illustrating a method of manufacturing a three-dimensional sheet according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, when an element is described as being present on top of another element, it may be directly on top of the other element, and a third element may be interposed therebetween. In the drawings, the thickness and size of each constituent element are exaggerated for convenience and clarity of description, and a portion not related to the description is omitted. Wherein like reference numerals refer to like elements throughout. It is to be understood that the terminology used is for the purpose of describing the present invention only and is not used to limit the scope of the present invention.

1 is a perspective view showing a three-dimensional sheet according to an embodiment of the present invention applied to a mobile phone exterior case.

Figure 1 shows a three-dimensional sheet 100 according to an embodiment of the present invention is applied to a mobile phone exterior case, the three-dimensional sheet 100 according to the present embodiment is not attached to the external case surface unlike the conventional exterior case It will construct itself. That is, in the prior art, a three-dimensional sheet was manufactured separately and used in a manner of adhering to an outer case formed of a thick injection resin. However, in the present embodiment, a lens layer is formed on the upper part of the injection resin and a printing pattern layer is formed on the lower part of the injection resin. The entire exterior case itself, including the three-dimensional sheet to function.

Accordingly, the three-dimensional sheet 100 of the present embodiment can solve the difficulty of manufacturing the existing thin three-dimensional sheet, and also, in the production of the three-dimensional sheet, the desired shape through the insert in-mold injection, that is, IML (In-Mold Labeling) process The three-dimensional sheet can be produced immediately. In other words, the outer case itself can be implemented as a three-dimensional sheet through the IML process.

In more detail, the IML process is a process of adhering a film to be coated on the upper mold and simultaneously molding the adhesive film and the injection resin. However, since the film thickness generally used for an IML process is about 0.125 mm, there exists a problem in using the three-dimensional sheet corresponding to about 0.2 mm as an adhesive film in injection molding. In addition, forming the thickness of the three-dimensional sheet thinner, as mentioned above, it is difficult to apply the IML process to the three-dimensional sheet due to the difficulty of manufacturing the mold and the lower print pattern work due to the reduction of the lens size.

However, in the present embodiment, by using a large-area lens layer as an adhesive film layer and introducing the concept of forming a printed pattern layer under the injection resin, it solves the difficulty of manufacturing a thin three-dimensional sheet, and also, only a large-area lens layer. By using as a contact film, the IML process can be easily performed. Hereinafter, the three-dimensional sheet structure of the present embodiment will be described in more detail.

FIG. 2 is an enlarged cross-sectional view of portion A of the three-dimensional sheet of FIG. 1.

Referring to FIG. 2, the three-dimensional sheet 100 of the present embodiment includes a lens layer 110, an injection resin 120, a printing pattern layer 130, an adhesive layer 140, and a protective film layer 150.

The lens layer 110 includes a plurality of lenses 112 at the upper side and a low refractive thin film layer 114 at the bottom.

The lenses 112 are formed convexly downward, and these lenses 112 are formed of a transparent resin, for example, polycarbonate (PC), and are formed by a thermoforming process using a mold having opposite curvature with the lens. Can be.

The lenses 112 are not limited to a PC, and as long as they are transparent, a transparent thermoplastic resin having a refractive index of about 1.45 to 1.58, such as polymethyl methacrylate, polyester, polyvinyl chloride, polystyrene, urethane acrylate, epoxy acryl, etc. It may be formed through a curable resin having a refractive index of about 1.45 to 1.60, such as a rate and an ester acrylate, or various resins such as polyethylene terephtalate (PET) and acrylonitrile butadiene styrene copolymer (ABS). However, it is a matter of course that an appropriate material should be selected in consideration of the refractive index of the lens, the thickness of the lens, and the thickness of the entire three-dimensional sheet.

In this embodiment, the size of the lenses 112 is formed in a large area. Accordingly, the focal length of the lenses 112 is greater than or equal to the thickness of the injection resin 120 formed below. Conventionally, the lenses 112 are formed in a very small size in order to form the entire three-dimensional sheet while forming a printed pattern layer directly under the lens. For example, in the case of the three-dimensional sheet of about 0.2 mm, the diameter of the lens was formed very small, about 0.02 mm.

However, in the present embodiment, lenses of a large area having a focal length corresponding to the thickness of the injection resin, for example, the thickness of the cellular phone exterior case are formed, and the printing pattern layer 130 is formed under the injection resin. Thereby, the lens layer 110 can be used as an adhesive film of an IML process. For example, since there is no restriction on the position of the printed pattern layer, the lens layer 110 including the low refractive thin film layer 114 can be manufactured to about 0.125 mm or less. In addition, when manufacturing the thickness of the injection resin to about 1 mm or more, the lens itself can be formed very easily by forming the diameter of the lens to about 0.2 mm or more. That is, manufacture of the metal mold | die for shaping a lens is easy.

Meanwhile, in the drawing, the lenses 112 are formed in a convex downward structure, but in some cases, the lenses 112 may be formed in a convex upward structure.

The low refractive thin film layer 114 should be formed of a material that is transparent and increases the refractive index change of the upper lenses 112. That is, the difference between the refractive index of the lenses 112 and the refractive index of the low refractive thin film layer should be within a predetermined range, for example, 0.2 to 0.3 or more. If it is less than 0.2 ~ 0.3, when the light is incident, the refractive index does not change so much that the focal length is not short enough. Therefore, the distance of vision that can feel a three-dimensional effect is also farther away. Because you can't. Here, the low refractive index in the low refractive thin film layer 114 means that it has a relatively low refractive index in relation to the lenses. On the other hand, if the lenses have a convex structure upwards, a low refractive thin film layer is formed on top of the lenses. That is, the low refractive thin film layer is formed with convex surfaces of the lenses.

Injection resin 120 is a resin that can be used in the IML process, it is preferable to form an amorphous resin because the injection resin 120 in this embodiment should have a transparent characteristic. This is because the printing pattern layer 130 is formed under the injection resin, so that light may be transmitted to the printing pattern layer 130 to realize three-dimensional characteristics. For example, the injection resin 120 may be formed using transparent ABS, GPPS, SAN (AS), PMMA, PC, and the like, which are amorphous resins.

In addition, since the main body of the injection resin 120 or the like is formed, there should be no deformation and robustness, and it is preferable that the wear resistance and the chemical resistance are excellent. On the other hand, it is preferable to select a material with good printability in order to form a print pattern layer below.

The print pattern layer 130 may be formed under the injection resin 120, and may include a pattern 132 and a concealed resin 134. The pattern 132 is formed at the focal length of the plurality of lenses 112 formed above the injection resin 120 and is formed with a predetermined rule so that an appropriate three-dimensional shape can be seen.

The pattern 132 may generally be formed through an offset-printing method. That is, a pattern is designed according to the shape to be implemented and the focal position of the lenses 112, and a plate for printing, that is, a plate is made based on the pattern, and a pattern is formed on the bottom surface of the injection resin 120 through the plate. Will print. On the other hand, the pattern 132 may also be formed by etching. Although the offset printing and etching methods are illustrated for the method of forming the pattern 132, a pattern may be formed through other methods without being limited thereto.

The concealed resin 134 may be formed to have a structure filling the patterns 132 or covering the entire patterns 132. This concealment resin 134 functions to distinguish the patterns 132 from each other. The concealed resin 134 may be formed in a silk-screen manner, and the concealed resin 134 fills in between the patterns 132 already formed. This concealment resin 134 is also not limited to the silkscreen method can be formed in other ways, of course.

On the other hand, when the predetermined pattern is formed at the bottom, such as the injection resin (120a) of Figures 4a to 4d, the print pattern layer 130a only needs to perform the back printing with the concealed resin 134, without the need to form separate patterns again do. In addition, since the pattern formed on the injection resin 120a is transparent, a high-gloss thin film layer may be further formed before the back printing is performed to prevent blur or distortion of the image.

For reference, by forming the patterns 132 at the focal position of the lenses 112 with a predetermined rule, the principle of making a three-dimensional feeling is as follows. That is, binocular parallax occurs because the left eye and the right eye of the person are separated by a predetermined distance, and the brain interprets the minute difference of the binocular parallax appropriately to feel a stereoscopic space. In order to maximize the stereoscopic recognition effect according to binocular parallax, the focal position of the lenses and the corresponding positions of the patterns should be accurately determined.

That is, based on the binocular parallax characteristic of the person, lenses corresponding to one left and right interval are bonded to the front of the patterns that can be displayed, and different left and right patterns on the left and right eyes are formed through the formed lenses. By making only visible, you can feel three-dimensional. For example, as in the present embodiment, a plurality of hemispherical lenses 112 are formed with the lens layer 110, and a regular pattern 132 is periodically formed below the injection resin 120 at the focal length of the lenses 112. ), But if the period interval of the pattern and the hemispherical lens are properly matched, the left eye and the right eye recognize different patterns, and accordingly, the brain properly combines the images recognized from the left eye and the right eye. It is recognized as a three-dimensional image.

The adhesive layer 140 is formed between the lens layer 110 and the injection resin 120. The adhesive layer 140 is used to more firmly adhere the lens layer 110 to the injection resin 120 in the IML process. Used. Therefore, if the lens layer 110 can be firmly adhered to the injection resin 120 through the adhesive force of the lens layer 110 itself or the injection resin itself, the adhesive layer 140 may be omitted. When the adhesive layer 140 is used, the lens layer 110 and the adhesive layer 140 together function as an adhesive film in the IML process, and thus, the overall thickness of the lens layer 110 and the adhesive layer 140. May be formed to about 0.125mm.

The protective film layer 150 is formed on the lens layer 110 to protect the three-dimensional sheet, it is preferably formed of a material having a high surface hardness for the three-dimensional sheet protection function. The protective film layer 150 may be formed through hard coating on the lens layer 110 after the IML process, before or after the printing pattern layer 130 is formed. However, the present invention is not limited thereto, and a method of forming the protective film layer 150 on the lens layer 110 first and using the protective film layer 150 as an adhesive film of the IML process may also be considered.

In the three-dimensional sheet according to the present embodiment, by forming the lenses of the lens layer in a large area, it is possible to eliminate the difficulty in forming the lens of the existing fine size. In addition, since the printing pattern layer can be formed under the injection resin based on the large area lens, the lens layer can be formed thin, and such a thin lens layer can be used as the adhesive film of the IML process. Therefore, the three-dimensional sheet of the present embodiment can be formed by applying the IML process, and since the injection resin itself constitutes the body portion of the three-dimensional sheet, the three-dimensional sheet can be used directly as the exterior case itself.

3a to 3e is a flow chart showing a manufacturing method of a three-dimensional sheet according to another embodiment of the present invention.

Referring to FIG. 3A, first, a lower mold 510 and an upper mold 520 are prepared. Although the lower surface of the lower mold 510 and the lower surface of the upper mold 520 are shown flat in the drawing, this is represented by considering only the three-dimensional sheet portion of FIG. 2, and the three-dimensional sheet is actually applied to a real object such as a mobile phone exterior case. In the case where the lower mold 510 and the upper mold 520 has an appropriate shape of the inside according to the appearance of the object to be formed, of course.

Referring to FIG. 3B, the lens layer 110 and the adhesive layer 140 are adhered to the lower surface of the upper mold 520. The lens layer 110 includes the lenses 112 and the low refractive thin film layer 114. As described above, if the film layer 110 can be firmly adhered to the injection resin 120, the adhesive layer 140 may be omitted. In addition, when the protective film layer 150 is also applied to the IML process, the protective film layer 150 may be further formed on the lens layer 110.

Referring to FIG. 3C, a liquid resin is injected between the lower mold 510 and the upper mold 520 to perform an IML process through thermoforming. When the IML process is completed, an intermediate stage three-dimensional sheet is formed by bonding the lens layer 110 and the adhesive layer 140 onto the injection resin 120. Here, since the injection resin 120 forms a main body of the three-dimensional sheet, it may be formed to a predetermined thickness, for example, about 1 mm. In addition, it should be formed of a transparent material that can transmit light as described above.

Referring to FIG. 3D, the protective film layer 150 is formed on the lens layer 110. If the protective film layer 150 is already formed through the IML process, this step may be omitted. On the other hand, the protective film layer 150 may be formed after the formation process of the lower print pattern layer 130, of course.

Referring to FIG. 3E, the print pattern layer 130 is formed under the injection resin 120. The print pattern layer 130 may include a pattern and a printing resin, and may be formed through offset printing or silk screen printing.

4A to 4D are flowcharts illustrating a method of manufacturing a three-dimensional sheet according to another embodiment of the present invention.

Referring to FIG. 4A, first, a lower mold 510a and an upper mold 520 are prepared. Unlike FIG. 3A, predetermined patterns 512 are formed on an upper surface of the lower mold 510.

Referring to FIG. 4B, the lens layer 110 and the adhesive layer 140 are attached to the upper mold 520, and resin is injected to perform an IML process. When the IIML process is completed, an intermediate stage stereoscopic sheet formed by bonding the lens layer 110 and the adhesive layer 140 onto the injection resin 120a is formed. Meanwhile, as the patterns 512 formed on the upper surface of the lower mold 510a are transferred, a predetermined pattern 122 protruding is formed on the lower surface of the injection resin 120a. In the present embodiment, the transparent patterns 122 formed on the lower surface of the injection resin 120a function as patterns for stereoscopic images. Thus, of course, such patterns 122 should be formed with a predetermined rule in the focal position of the upper lenses 112.

Referring to FIG. 4C, the protective film layer 150 is formed on the upper surface of the lens layer 110 as in FIG. 3D. Of course, if the protective film layer 150 is already formed through the IML process, this step may be omitted.

Referring to FIG. 4D, back printing is performed under the injection resin 120a to form a print pattern layer 130a. That is, unlike FIG. 3E, only the concealed resin may be formed through offset printing or silk-sketch printing without forming patterns separately. On the other hand, when performing the back printing, the light may be absorbed by the concealed resin, so that the image of the patterns on the injection resin 120 may be blurred or distorted. The glossy thin film layer may be further formed as the lower surface of the injection resin.

While the present invention has been described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. will be. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: solid sheet 110: lens layer
112: lens 114: low refractive thin film layer
120, 120a: injection resin 130: printing pattern layer
132: Pattern 134: Printed Layer
130a: back printing layer 140: adhesive layer
150: protective film layer 510: lower mold
520: upper mold

Claims (13)

A lens layer in which a plurality of large-area lenses having a diameter larger than the center thickness are formed;
A transparent injection resin formed under the lens layer and having a thickness corresponding to a focal length of the lenses; And
And a printed pattern layer formed under the injection resin. The method according to claim 1,
And the lens layer comprises a transparent thin film layer formed in the convex direction of the lenses and having a lower refractive index than the lenses. The method according to claim 1,
The three-dimensional sheet,
And a protective film layer formed on the lens layer, and an adhesive layer formed between the lens layer and the injection resin. The method according to claim 1,
And a pattern for giving a three-dimensional effect in correspondence with the focus position of each of the lenses. delete Adhering to the upper mold a lens layer in which a plurality of large-area lenses having a diameter larger than the center thickness is formed;
Forming an intermediate three-dimensional sheet having a transparent injection resin bonded to the lower part of the lens layer through an insert in-mold injection process; And
And forming a printed pattern layer on the lower surface of the injection resin to complete a three-dimensional sheet. The method of claim 6,
The injection resin, the three-dimensional sheet manufacturing method characterized in that it has a thickness corresponding to the focal length of the lenses. The method of claim 6,
Before forming the intermediate three-dimensional sheet,
And forming an adhesive layer under the lens layer in order to couple the lens layer to the injection resin. The method of claim 6,
The lens layer comprises a transparent thin film layer formed in the convex direction of the lenses and having a lower refractive index than the lenses. The method of claim 6,
The printing pattern layer is a three-dimensional sheet manufacturing method characterized in that a pattern for giving a three-dimensional effect corresponding to the focus position of each of the lenses is formed. The method of claim 6,
Before the step of adhering the lens layer,
Forming a three-dimensional sheet comprising the step of forming the lens layer. The method of claim 6,
Before the step of completing the three-dimensional sheet,
Forming a protective film layer on the lens layer, characterized in that it comprises a three-dimensional sheet manufacturing method. The method of claim 6,
In the step of forming the intermediate three-dimensional sheet,
The predetermined pattern formed on the lower mold is transferred to form the reverse pattern of the pattern on the lower surface of the injection resin,
In the step of completing the three-dimensional sheet, the pattern layer is a three-dimensional sheet manufacturing method characterized in that the back printing is formed on the reverse pattern.

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