WO2004070437A1

WO2004070437A1 - Lenticular imaging laminate

Info

Publication number: WO2004070437A1
Application number: PCT/IL2004/000102
Authority: WO
Inventors: Benzion Landa
Original assignee: Benzion Landa
Priority date: 2003-02-04
Filing date: 2004-02-03
Publication date: 2004-08-19

Abstract

A lenticular object comprising: an image-bearing substrate (12); a lenticular cover sheet (14) juxtaposed with the image-bearing substrate (12) to form a sandwich; and a layer of cling material (16) or a weak adhesive located at the interface between the image-bearing substrate (12) and the lenticular cover sheet (14).

Description

LENTICULAR IMAGING RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. 119(e) of US Provisional Application 60/444,683 filed February 4, 2003, the disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION The present invention is concerned with lenticular imaging and in particular with attachment of a lenticular cover element to an image-bearing substrate.

Lenticular imaging, i.e., imaging in which an image-bearing substrate is covered with a substantially transparent lenticular cover sheet is well known. Depending on the image-bearing matter and on the structure of the lenticular cover sheet, a viewer can perceive a variety of imaging effects as the angle of view changes, including multiple images that "flip" or "morph" from one to the next and images that appear to have kinematic motion: In a common implementation of lenticular imaging, stereoscopic or "3D" viewing is possible. In each case, the image-bearing matter must be carefully aligned with the orientation of the lenticular cover sheet to achieve the desired effect.

In lenticular imaging, the image-bearing matter is either printed directly onto the flat side of the lenticular cover sheet, or is created - photographically or by printing - on a substrate and then attached to the lenticular cover sheet. In general such attachment is permanent, i.e., an adhesive is used to make the attachment. While, in principle, the image-bearing substrate could be removed from the lenticular cover sheet, so that the sheet is used again, this is generally difficult and the cover sheet may not be reusable. For posters or billboards, the lenticular cover sheet is the most expensive component of the system, by far. It is therefore desirable to enable the re-use of the lenticular cover sheet. Another problem with use of adhesives is that it is difficult to accurately align the image-bearing sheet and the lenticular cover sheet. Once the sheet is in place and the adhesive has set, no correction is possible. Also, since all bubbles should be removed, the adhesive must set relatively slowly and remain tacky over an extended period.

SUMMARY OF THE INVENTION

One aspect of some embodiments of the present invention is concerned with use of a non-permanent adhesive system to attach a lenticular cover sheet to an image-bearing surface. One aspect of some embodiments of the invention is concerned with a lenticular object having a lenticular cover sheet attached to an image bearing surface with a non- permanent adhesive system.

In some embodiments of the invention, the non-permanent adhesive system comprises a weak adhesive.

In some embodiments of the invention, the non-permanent adhesive system comprises a cling material.

There is thus provided, in accordance with an embodiment of the invention, a method of producing a lenticular object, comprising: providing an image-bearing substrate; providing a lenticular cover sheet, having a lenticular front face and a substantially smooth back face, at least one of said image-bearing substrate and said back face being made of or coated with a cling material or a weak adhesive material; and bringing the substrate and the cover sheet into contact so that they removably adhere to each other, such that the substrate and the cover sheet can be separated and at least the lenticular sheet reused.

In an embodiment of the invention, the cling material or weak adhesive material is a weak adhesive material. Optionally, the back face is coated with the weak adhesive material. Optionally, the image bearing substrate is coated with the weak adhesive material.

In an embodiment of the invention, the cling material or weak adhesive material is a cling material. Optionally, the back face is coated with the cling material. Optionally, the image bearing substrate is coated with the cling material.

There is further provided, in accordance with an embodiment of the invention, a lenticular object comprising: an image-bearing substrate; a lenticular cover sheet juxtaposed with the image-bearing substrate to form a sandwich; and a layer of cling material or a weak adhesive located at the interface between the image-bearing substrate and the lenticular cover sheet.

In an embodiment of the invention, the layer of cling material or weak adhesive is coated onto one or both of the image bearing substrate and the back of the cover sheet.

In an embodiment of the invention, the cling material or weak adhesive material is a weak adhesive material. Optionally, both the back face and the image bearing substrate are coated with the weak adhesive material.

In an embodiment of the invention, the cling material or weak adhesive material is a cling material. Optionally, both the back face and the image bearing substrate are coated with the cling material.

There is further provided, in accordance with an embodiment of the invention, a lenticular object comprising: an image-bearing substrate comprised of a cling material; and a lenticular cover sheet juxtaposed with the image-bearing substrate to form a sandwich.

There is further provided, in accordance with an embodiment of the invention, a lenticular object comprising a lenticular cover sheet coated or laminated with a cling material or a weak adhesive material.

There is further provided, in accordance with an embodiment of the invention, a lenticular object comprising: a lenticular cover sheet; a layer of cling material or weak adhesive spread on the sheet; and a removable protective backing sheet, mounted on said layer.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is now illustrated using a number of non-limiting exemplary embodiments thereof. The description should be read in conjunction with the attached figures which are not to scale:

Fig. 1 shows a schematic cross-section of a lenticular image, in accordance with an embodiment of the invention; and Fig. 2 shows a schematic cross-section of a lenticular image in accordance with an alternate embodiment of the invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Fig. 1 shows a lenticular image 10 in which a sheet (substrate) 12, bearing an image is adhered to a lenticular cover sheet 14 utilizing a low strength adhesive layer 16.

The image and the structure of the cover sheet are not shown for simplicity of illustration.

The layout of the image and the lens or light guiding structure of the lenticular sheet are completely conventional.

In an embodiment of the invention, either the image-bearing sheet or the lenticular cover sheet is coated with a low strength adhesive, such as for example used in Post-It^® memo sheets or in other such products in which a non-permanent adhesive is used to temporarily attach a substrate to another surface. As used herein and in the claims, the term "weak adhesive" is used for an adhesive material whose adhesion is weak enough so that a sheet is easily removed therefrom without leaving portions of either the sheet or the adhesive behind.

In another embodiment of the invention, a "cling" layer is coated on one or both of the lenticular cover sheet and the substrate. This cling layer constitutes a weakly adhesive layer. Many soft, transparent and smooth materials can be used for such a layer, for example, soft silicone elastomer, for example having a Shore A hardness of 30 or less, and preferably 20 or less, or soft polyurethane having a similar softness is used for the layer.

In some embodiments of the invention, it may be necessary to provide an intermediate layer of material to enhance adhesion when a cling layer is used. Thus, when using a soft silicone elastomer as the cling layer, an underlayer of polyurethane may be coated on the back surface of the lenticular cover sheet and a primer coated on the cured polyurethane. Optionally, the primer underlayer is a thin underlayer (5-10 micrometer is sufficient). A silicone layer will then adhere well to the 'underlayer.

The image-bearing substrate can be a plastic substrate (especially useful for back- lit posters), a smooth paper substrate or a plastic coated paper substrate.

Without being tied to any theory, the present inventor believes that a pre-condition for "cling" adhesion is conformabihty to the substrate surface. In order to conform, the material must either be soft enough or thin enough (or both) to follow the surface topography of the substrate. In general, for cling between two rigid (or non-conforming) objects, especially if one of them is not flat (such as paper), the cling material is desirably soft and relatively thick. The optimal thickness of the cling material can vary widely, depending of the properties of the cling material and the smoothness and porosity of the substrate.

In general, cling layers of between 100 and 500 micrometers thickness are used, although thinner and certainly thicker layers can be used. For smooth surfaces, 100 micrometers or less of cling material may be sufficient. For somewhat less smooth papers a thickness of 300 or more may be used. In general, thicknesses of 300 micrometers work well, although this is not believed to be critical. One limitation on the thickness is a loss of transparency with some materials. In order to prevent the cling or adhesive surface from being contaminated by dust or dirt prior to use, it is desirable that the cling or adhesive coating be covered with a removable protective sheet, preferably of smooth plastic or suitably-coated paper.

In an embodiment of the invention, the image-bearing surface and the lenticular cover sheet (with one or more cling layers between them) are aligned so that the desired effect is achieved. Then means, such as a blade or roller, is used to provide local pressure on one or both of the image-bearing surface and lenticular cover sheet to bring the two into intimate contact so that they stick together. It is believed that, in general, the forces that cause the sticking can be one or more of van der Waals forces or a partial vacuum between the cling layer and an opposing surface. Of course, the exact forces present will depend on the materials involved (and their smoothness) as well as whether the layers have some tackiness.

It will be understood that if misalignment is present, the cling bond or weak adhesive bond is easily broken, by peeling away the image-bearing substrate, and the substrate and cover sheet can be realigned. Also, when it is desired that the image being viewed is to be changed, the image-bearing sheet is removed from the lenticular cover sheet and a different image-bearing sheet is substituted for the one removed.

In a further embodiment of the invention, illustrated in Fig. 2, sheet 12 itself is a cling material. Such materials can be printed on and are generally used to wrap a product without need for adhesive. Such materials will cling sufficiently well to the back of a smooth plastic lenticular cover sheet so that no additional layer need be provided. Optionally, the cover sheet is also coated with a print cling material. In some embodiments of the invention, the printing is on the side of the substrate that does not contact the cover sheet and is printed in reverse. The invention has been described in the context of the best mode for carrying it out. It should be understood that not all features shown in the drawing or described in the associated text may be present in an actual device, in accordance with some embodiments of the invention. Furthermore, variations on the method and apparatus shown are included within the scope of the invention, which is limited only by the claims. Also, features of one embodiment may be provided in conjunction with features of a different embodiment of the invention. As used herein, the terms "have", "include" and "comprise" or their conjugates mean "including but not limited to."

Claims

1. A method of producing a lenticular obj ect, comprising: providing an image-bearing substrate; providing a lenticular cover sheet, having a lenticular front face and a substantially smooth back face, at least one of said image-bearing substrate and said back face being made of or coated with a cling material or a weak adhesive material; and bringing the substrate and the cover sheet into contact so that they removably adhere to each other, such that the substrate and the cover sheet can be separated and at least the lenticular sheet reused.

2. A method according to claim 1 wherein the cling material or weak adhesive material is a weak adhesive material.

3. A method according to claim 2 wherein the back face is coated with the weak adhesive material.

4. A method according to claim 2 wherein the image bearing substrate is coated with the weak adhesive material.

5. A method according to claim 1 wherein the cling material or weak adhesive material is a cling material.

6. A method according to claim 5 wherein the back face is coated with the cling material.

7. A method according to claim 5 or claim 6 wherein the image bearing substrate is coated with the cling material.

8. A lenticular object comprising: an image-bearing substrate; a lenticular cover sheet juxtaposed with the image-bearing substrate to form a sandwich; and a layer of cling material or a weak adhesive located at the interface between the image-bearing substrate and the lenticular cover sheet.

9. An object according to claim 8 wherein the cling material or weak adhesive material is a weak adhesive material.

10. An object according to claim 9 wherein the back face is coated with the weak adhesive material.

11. An object according to claim 9 wherein, the image bearing substrate is coated with the weak adhesive material.

12. An object according to claim 8 wherein the cling material or weak adhesive material is a cling material.

13. An object according to claim 12 wherein the back face is coated with the cling material.

14. An object according to claim 12 wherein the image bearing substrate is coated with the cling material.

15. A lenticular object according to claim 8 wherein the layer of cling material or weak adhesive is coated onto one or both of the image bearing substrate and the back of the cover sheet.

16. An object according to claim 15 wherein the cling material or weak adhesive material is a weak adhesive material.

17. An object according to claim 16 wherein both the back face and the image bearing substrate are coated with the weak adhesive material.

18. An object according to claim 15 wherein the cling material or weak adhesive material is a cling material.

19. An object according to claim 18 wherein both the back face and the image bearing substrate are coated with the cling material.

20. A lenticular object comprising: an image-bearing substrate comprised of a cling material; and a lenticular cover sheet juxtaposed with the image-bearing substrate to form a sandwich.

21. A lenticular object comprising a lenticular cover sheet coated or laminated with a cling material or a weak adhesive material.

22. A lenticular object comprising: a lenticular cover sheet; a layer of cling material or weak adhesive spread on the sheet; and a removable protective backing sheet, mounted on said layer.