WO2006054284A1

WO2006054284A1 - Lenticular display panels with interchangeable print sheets

Info

Publication number: WO2006054284A1
Application number: PCT/IL2005/001186
Authority: WO
Inventors: Itzhak Bar Yona
Original assignee: Itzhak Bar Yona
Priority date: 2004-11-21
Filing date: 2005-11-10
Publication date: 2006-05-26
Also published as: IL165313A0

Abstract

The invention is a large format, commercial lenticular display sheet or panel for displaying at least two consecutive changing images to be viewed by a viewer. The display panel of the invention comprises a lenticular sheet or panel comprising an array of linear lenses and a complementary interchangeable print sheet that is bonded to the lens panel by a peelable adhesive layer. This arrangement allows the lenticular sheet to be removed from the lenticular sheet or panel and replaced with a different interchangeable print sheet. Methods of preparing the display sheet or panel are described. In another aspect the invention is a print sheet comprising a lightweight indicia carrier on which is printed an interlaced image comprising an array of parallel information strips having a given pitch and a pressure-sensitive adhesive layer spread over the printed side of the indicia carrier. The print sheet can be aligned and attached by means of the pressure-sensitive adhesive layer to the rear flat side of a lenticular lens sheet or panel having the same pitch, in order to display through the sheet or panel, multi-image messages, and then be periodically removed and replaced by another print sheet of the same type, without damaging the lens sheet or panel.

Description

LENTICULAR DISPLAY PANELS WITH INTERCHANGEABLE

PRINT SHEETS

Field of the Invention

The present invention relates to lenticular displays, which are capable of presenting changing images, animations, 3D presentations and the like. Specifically the invention relates to large format, commercial lenticular displays for advertising or information purposes.

Background of the Invention

Lenticular displays have been known for many years. They are used for displaying changing images as a function of the viewing angle. Such displays are produced in one of two ways: either printing an interlaced image directly on the rear side of a transparent lenticular lens sheet or printing an interlaced image on a separate substrate and then laminating the substrate to the rear face of the lens sheet. Lenticular technology, in general, requires the fulfillment of the following three basic conditions that must be satisfied between the interlaced printed image and the linear lenses of the sheet:

1. Complete alignment between the printed lines and the linear lenses must exist. 2. Constant spacing, essentially equal to the focal length of the lenses, between the plane of the printed information and the plane of lenses is required. 3. The "cumulative pitch distance" for the array of the linear lenses and of the printed lines on the print must be equal at all times.

The definitions of some of the terms used in this application are: - A "lenticular lens sheet" is a transparent substrate having two planar faces one of which is smooth and on the other one of which is created an array of lenticular lenses. For large format lenticular displays the thickness of the substrate is such that it more correctly should be called a "panel" however the terms are sometimes used interchangeably herein.

- A "print sheet" is a thin film or sheet of material sometimes referred to as an "indicia carrier" or "substrate" on which an interlaced image has been printed. - A print sheet is "peelable" if it is designed to be peeled or removed from a lenticular lens sheet without damage to at least the lens sheet.

- The term "lenticular display panel" is used to designate a lenticular lens panel or sheet with a print sheet attached to it. The lenticular display sheet or panel can be used alone as a display. However it is more commonly the principal component of a lenticular display, which also typically comprises other components, e.g. a sealed cabinet with access door and backlighting the terms "lenticular display sheet" and "lenticular display" are used interchangeably herein.

- "Pitch distance" refers to the distance between the centers of two adjacent lenses or two adjacent lines of print on a print sheet.

- "Cumulative pitch distance" is the sum of the pitch distances for all of the lenses or lines of print, i.e. the distance between the centers of the first and last lenses on a given lens sheet or lines of print lines on a given print. - "Large format" lenticular displays are those that are larger than the standard "one sheet" size (70cmxl00cm)h generally use a 10-20 lpi lens sheet, and are typically at least "city format size" (120cmxl80cm). The printing for large format displays must be done on commercial large format printing machines. - "Small format" lenticular displays are smaller than the standard A4 printing sheets (~20cmx30cm) and generally use a 50-75 lpi lenticular lens sheet. The printing for small format displays can be done on home or office printing machines using appropriate software. - "Commercial displays" are those that are used, for example, for large advertising campaigns such as the city format displays that are featured at bus stops and on street corners.

As opposed to small format displays, for which the lenticular sheets cost on the order of a few American cents, the main drawback of the existing large format lenticular lens panels is their cost to the user. For example the cost of 10 lpi lens sheet is about $80 per square meter. The price of the lens sheet is to be compared with the price of a substrate with an interlaced image printed on it, which typically costs about $6 per square meter. An average advertising campaign lasts for about two to four weeks, after which, the lenticular lens sheet and attached printed substrate are thrown away and replaced with a new display. There exists, therefore, a need to reduce the overall cost of lenticular displays if they are to become a commercially viable option for clients of the advertising agencies that own and rent commercial display units. One way to reduce the cost of large format lenticular displays would be to only replace the relatively very much less expensive rear interlaced print with a new one for each new advertising campaign while reusing the lenticular lens sheet repeatedly.

Achieving such a goal is very difficult for the following reasons:

1. According to the second basic condition mentioned above, a separate interchangeable print sheet should be located exactly in the focal lines (the locus) of the lenses. This requires, for example, a rear resilient support pressing the independent print against the front lenticular panel such as described in published International Patent Application WOO2/2351O ("Means for Maintaining Spatial Relationship in Lenticular Display Units") by the inventor of the present application, the description of which, including reference cited therein, is incorporated herein by reference in its entirety. Such a support element is rather expensive and tends to obscure the transparency of the print, when backlighting is required. 2 According to the third requirement, the cumulative pitch distance of the print should be exactly equal to the cumulative pitch distance of the lenticular sheet. In the existing lenticular display sheets the print and the panel are bonded together, therefore they are uninfluenced by thermal deformations; i.e. they expand or contract as a single unit. This is not the situation when an independent interchangeable print sheet has to be adapted to an existing permanent panel. Normally produced from different substances they react differently to thermal deformations, sometimes resulting in a "ghosting effect" displayed to the viewer.

In US 2003/0035135 is described a method of producing small format lenticular displays using home or office computers and printers. The method includes a step of attaching the print to the lenticular sheet initially having a self-adhesive layer. By proper choice of adhesive the print can be removed and repositioned or replaced with another one. Since the method described in this patent application is limited to small format displays it does not address and is not capable of being "scaled-up" to meet the requirements of large format displays. For example, as will be discussed hereinbelow, the teaching in US 2003/0035135 to apply the adhesive to the back of the lenticular sheet has been found by the inventor of the present invention to be detrimental if used for large format commercial displays.

It is therefore the object of the present invention to provide a simple inexpensive large format, commercial lenticular display, for advertising or information purposes, comprising a front lenticular sheet and a complementary interlaced interchangeable print sheet, wherein said interchangeable print sheet can be periodically replaced, keeping the basic expensive lenticular sheet intact. It is another object of the present invention to provide large format, commercial lenticular displays that can be used in outdoor conditions of changing weather without deviating from the quality requirements of the images.

It is yet another purpose of the present invention to provide a method of preparing and replacing the interchangeable print sheet of a large format, commercial lenticular display, either in a central facility or preferably in situ at the location where the display unit is located.

It is a further object of the present invention to provide a method for creating a large format, commercial lenticular display unit comprising several modular lenticular display sheets, creating together a unified large animated image.

Further purposes and advantages of this invention will appear as the description proceeds.

Summary of the Invention In a first aspect the invention is a large format, commercial lenticular display sheet or panel for displaying at least two consecutive changing images to be viewed by a viewer. The display panel comprising:

- a lenticular sheet or panel comprising an array of linear lenses of about 10- 20 lpi size; - a complementary interchangeable print sheet; and

- a peelable adhesive layer bonding the interchangeable print sheet to the lenticular sheet or panel.

The peelable adhesive layer allows the lenticular sheet to be removed from the lenticular sheet or panel and replaced with a different interchangeable print sheet. In preferred embodiments, the peelable adhesive layer is applied to the front of the complementary interchangeable print sheet and the interchangeable print sheet comprises a resilient stretchable substrate on which an interlaced image has been printed. In other embodiments the peelable adhesive layer can be applied to the back of the lenticular lens panel or sheet.

In preferred embodiments, the lenticular sheet or panel comprises an array of alignment means and the interchangeable print sheet comprises complementary alignment means. The alignment means and the complementary alignment means serve to align the printed information on the print sheet with the linear lenses of the lenticular sheet or panel. The alignment means can be an array of pins and the complementary alignment means a matching array of punctures.

In preferred embodiments, the lenticular display sheet or panel comprises an array of anchoring means and the interchangeable print sheet comprises complementary anchoring means. The anchoring means and the complementary anchoring means serve to maintain the fixed relationship between the cumulative pitch distance of the print sheet with the cumulative pitch distance of the linear lenses of the lenticular sheet or panel. The anchoring means can be an array of pins and the complementary anchoring means a matching array of punctures.

In another aspect, the invention is a billboard comprised of two or more of the large format, commercial lenticular display sheets or panels of the invention that are attached side-by-side to a frame.

In another aspect the invention is a method for preparing a lenticular display sheet or panel having an interchangeable print sheet. The method comprises the steps: a. preparing a lenticular lens sheet or panel comprising an array of alignment means projecting from its rear face; b. processing a digital interlaced image according to the rules of lenticular technology; c. printing the digital interlaced image on an indicia carrier, thereby creating a print sheet; d. puncturing the print sheet according to the array of alignment means; e. layering the print sheet with a peelable adhesive compound; f. pressing the print sheet against the back surface of the lenticular sheet or panel, thereby adhering the print sheet to the lenticular lens sheet or panel.

In a preferred embodiment of the method of the invention, the indicia carrier comprises a resilient stretchable substrate, the lenticular lens film or sheet comprises an array of anchoring pins attached to its rear surface, and the print sheet is stretched to fit over the anchoring pins, thereby assuring that the cumulative pitch distance of the print sheet equals that of the lenticular lens film or sheet.

According to the method of the invention, the peelable adhesive layer can be applied to the front of the complementary interchangeable print sheet or to the back of the lenticular lens film or sheet.

In another aspect the invention is a print sheet comprising a lightweight indicia carrier on which is printed an interlaced image comprising an array of parallel information strips having a given pitch and a pressure-sensitive adhesive layer spread over the printed side of the indicia carrier. The print sheet can be aligned and attached by means of the pressure-sensitive adhesive layer to the rear flat side of a lenticular lens sheet or panel having the same pitch, in order to display through the sheet or panel, multi-image messages, and then be periodically removed and replaced by another print sheet of the same type, without damaging the lens sheet or panel.

The print sheet may comprise aligning means in the form of marks or punctures for aligning the strips of print on the print sheet with the lenses on the lenticular lens sheet or panel.

Preferably the indicia carrier of the print sheet of the invention is made of a plastic resilient compound having a pitch slightly smaller then the pitch of the lenticular lens sheet or panel. This allows the print sheet to be slightly stretched when attached to the lenticular lens sheet or panel in order to equal the pitch of the print sheet to the pitch of the lenticular lens sheet or panel. In some embodiments the indicia carrier of the print sheet is made of a transparent material.

All the above and other characteristics and advantages of the invention will be further understood through the following illustrative and non-limitative description of preferred embodiments thereof, with reference to the appended drawings.

Brief Description of the Drawings

— Fig. IA is in a frontal view of a prior art lenticular large format display unit 1;

— Fig. IB is a cross sectional view of the display unit shown in Fig IA; — Fig. 2 shows a large format, commercial lenticular display panel comprising an interchangeable print sheet, according to the invention;

— Fig. 3, Fig. 4, and Fig. 5 are enlarged views of area A at the upper corner of the corner of the lenticular display panel 100 shown in Fig. 2; and

— Fig. 6 shows a method of creating a large format display unit comprising a given number of lenticular display panels. Detailed Description of Preferred Embodiments

A prior art lenticular large format display unit 1 is shown in a cross sectional view in Fig IB and in a frontal view in Fig. IA. Display unit 1 consists of a supporting frame 2 accommodating lenticular sheet 3, embossed with an array of linear cylindrical lenses 4. A rear-interlaced print 5 is bonded to lenticular sheet 3 in a way that its constituent images, A and B in this example, can be projected by lenses 4 of lenticular panel 3. The images are illuminated either by artificial back lighting shining through print 5, or by ambient light reflected back from the front of print 5.

According to the above-mentioned third condition of lenticular technology, printed lines of information should be accurately positioned in the focal lines of cylindrical lenses 4. Fig IB illustrates what can occur to the display when misalignment occurs, for example as a result of thermal deformation caused by unequal expansion of lenticular panel 3 relative to print 5. Image A will be seen by a viewer standing directly in front of display 1 if interlaced print 5 is positioned relative to lenses 4, as shown in the upper part of Fig. IB. In the lower part of the figure, the situation changes and image B will be seen. Midway, around the center of the lenticular sheet 3, a "ghosting effect" will be created from a mixture of images A and B.

In Fig. 2 there is illustrated an embodiment of the invention showing a method of producing a large format, commercial lenticular display panel. The display panel 100 shown in Fig. 2 comprises a lenticular sheet and a replaceable print sheet and means of attaching them to each other in a manner which satisfies all three of the fundamental conditions of lenticular technology mentioned hereinabove.

A lenticular panel 10 is prepared comprising a cylindrical array of lenticular lenses on its front side and a first array of alignment pins 12 and a second array of anchoring pins 14 on its back side. A lightweight frame 18 is also prepared; comprising a first array of sleeves 22 corresponding to the array of alignment pins 12 and a second array of punctures 24 corresponding to the array of anchoring pins 14.

An interlaced print 20 is prepared according to methods known in the art, for example such as described in US 6,542,646 by the inventor of the present application, the description of which, including reference cited therein, is incorporated herein by reference in its entirety. Interlaced print 20 is printed on a special indicia carrier (substrate), which is capable of minor elongation (about 0.2%) when stretched. The reason for using a streatchable indicia carrier will be discussed hereinbelow. The substrate chosen for the indicia carrier has to retain its elastic properties, being able to repeatedly return to its original dimensions when stretched to about 100.2% of its original size. Suitable materials are commercially available from, for example, PPG Industries (Teslin synthetic sheet) and Neschen Company (Printex WP, synthetic paper).

The print sheet is punctured at spaced apart locations, which correspond to the array of pins 12 and 14, and then sprayed with a peelable adhesive, over its printed area. Chemical formulas of the peelable adhesive are specifically prepared taking into account such factors as the properties of the chosen printed substrate, the method and pigments related to the printing process, the type of resin of the lenticular substrate, and environmental factors at the site the display will be positioned such as ambient temperature and level of UV radiation. In general, such adhesive compounds can be prepared using a liquid dispersion of acrylic polymer or organic solutions of synthetic rubber. Other methods of preparing suitable peelable adhesives are also known, nevertheless, these two categories have proven to be the most useful and easy to adapt to each of the particular cases tried to date. Stretchable print sheet 20 can now be inserted on sleeves 22, creating a kind of membrane, spread over lightweight frame 18. Attaching stretchable print sheet 20 to lenticular panel 10 is the final step of preparing the lenticular display sheet. This is done by sliding sleeves 22 on lightweight frame 18 over alignment pins 12 on the back of lenticular lens panel 10. As the frame 18 and attached print sheet 20 approach the back of lenticular lens panel 10, anchoring pins 14 slide through the matching punctures in the print sheet 20 and into the punctures 24 in the frame. When contact between print 20 and lenticular lens panel 10 is achieved frame 18 is drawn backwards; thereby leaving print sheet 20 held in its stretched position by anchoring pins 12, to assure that the cumulative pitch distance of the print matches that of the lenses, and uniformly attached to the back side of panel 10 by the adhesive layer, thereby assuring that the print is always located at the focal point of the lenses.

The lenticular display panel 100 now acts as an integral unit and the cumulative pitch distance of the printed information relatively to the cumulative pitch of the lenses as well as distance from the lenses is perfectly maintained regardless of changing temperatures or any other cause of deformation of the lens sheet 10.

The method described above also serves to overcome another limitation of lenticular technology, i.e. the inconsistency of the extrusion process as well as inconsistency of the printing process, which has the practical result that lens panels or print sheets with the same nominal pitch distance do not always have the same exact cumulative pitch distance. The dimension of lightweight frame 18 in a direction, perpendicular to the axis of the lenses can be slightly changed by use of two stretching means 26 located on the horizontal bars of frame 18. In practice, when interlacing the images to be printed on stretchable substrate 20, a minor shrinking of the image is required. As a result the final printed information does not have the same pitch distance as that of the lenses, but rather about 0.2% less. Being attached to lightweight frame 18 by means of sleeves 22, it is possible to stretch print 20, thereby making the cumulative pitch distance of the print equal to that of the lenticular panel. In other words, the print can be customized to various lenticular sheets, which have pitch distances that vary over a reasonable range.

Fig. 3, Fig. 4, and Fig. 5 are enlarged views of area A at the upper corner of the corner of the lenticular display panel 100 shown in Fig. 2. These figures help to illustrate the stages in the process described above for attaching stretchable interchangeable print sheet 20 to lenticular panel 10. Fig. 3 shows stretchable print sheet 20 attached to frame 18 by means of the array of sleeves 22. After adjusting stretching means 26, the array of alignment pins 12 are inserted into sleeves 22 and the frame 18 is pressed against the back of lenticular lens panel 10 until pins 12 and 14 pass through the sleeves and the print respectively. If necessary, the back of the print sheet 20 is rubbed to cause the adhesive layer to stick uniformly to the lenticular panel. Finally, as seen in Fig. 5, the frame 18 is pulled back leaving print sheet 20 held to the back of lens sheet 10 by means of anchoring pins 14 and the adhesive.

The attachment process can be carried out in the print shop or some other facility, however in commercial applications, where it is required to frequently change the display, returning the lenticular display panel to a central location for replacement of the print would require either a large stock of lenticular lens panels of which only some were in use at any given time or a "down time" during which the display unit is empty while the display panel is returned to the central facility to be replaced. Neither of these situations is desirable and it is much more efficient and economical to replace the print in situ. When the advertising campaign is over, the representative of the advertising agency arrives at the site of the display unit, opens the case, strips the old print off the lenticular lens panel, throws the old print away, and cleans any remaining adhesive off the back of the lens panel. It has been the experience of the inventor, that a very large percentage of the adhesive approaching 100% adheres to the print, thereby resulting in a very fast and simplified procedure for preparing the lens panel to receive the new print sheet. For field conditions therefore it has been found essential to apply the adhesive to the print in order to simplify the procedure and save time. One of the problems being that if the adhesive layer is applied to the lens sheet, it is difficult to prevent dust and other wind borne material from sticking to the adhesive while the new print is being prepared. If this occurs, then it may be necessary to remove and replace all or part of the adhesive layer.

The new print is then slipped over sleeves 22 on the frame that the worker carries with him and the peelable cover sheet that was placed over the print sheet 20 to protect the adhesive layer that was placed on the print sheet after the interlaced print was printed on the indicia carrier is removed. Alternatively, but very much less preferred for reasons similar to those for not applying the adhesive layer to the lens panel, the adhesive layer need not be placed on the print sheet at the time of printing but can be sprayed or spread over the print sheet once it is attached to frame 18. Once the print sheet is stretched onto the frame it is attached to the back of the lenticular lens panel as described hereinabove.

Fig. 6 shows a method of preparing a very large lenticular display unit, such as a billboard 200 that comprises a plurality of modular lenticular display sheets of the invention. The main achievement of the method of the invention is that it provides the ability to position the interchangeable print sheets relative to the lenticular panel in such a way that a single continuous image is displayed on the entire billboard.

In Fig. 6 a basic frame 30 is shown comprising an array of pins 32, protruding from its front at a predetermined pattern. Lenticular display panels 100 comprising lens panels 10 and stretchable print sheets 20 are also shown. The lenticular lens panels 10 comprise punctures 38 and the print sheets 20 comprise punctures 40, which correspond to the locations of pins 32. A unified image for the billboard is created as follows: i. the entire interlaced image is processed on a computer; ϋ. the digital image is divided into modular portions; in this example four portions corresponding to each of the lenticular display panels 10O₁, 10O₂, 10O₃, and 10O₄; iii. the locations of the punctures 40 are digitally marked on the interlaced image; iv. four prints 36 are printed, punctured and sprayed with a peelable adhesive; v. as explained hereinabove with reference to Fig. 2, the print sheets 20 are attached to their respective lenticular panels 10 set of pins 32; vi. lenticular display panels 10Oi to 10O₄ are placed on pins 32 and pressed against a backstop 42 attached to a rear rigid wall like support 44.

The fact that a correct and uniform relationship exists between the printed information and the lenses in each lenticular display panel 10O₁ to IOO4, assures that the right image will be displayed in the entire billboard, depending on the given viewing angle.

In the above-mentioned embodiments the peelable adhesive layer is sprayed on the front side of the prints. Nevertheless it may be desirable, in special cases to spread the peelable adhesive layer on the rear side of the lenticular sheet. In such a case the process of spraying the prints is saved. On the other hand renewing of the peelable adhesive layer of the print in this case, especially under field conditions, may be more difficult as explained hereinabove.

The embodiments of the present invention above described are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A large format, commercial lenticular display sheet or panel for displaying at least two consecutive changing images to be viewed by a viewer, comprising:

- a lenticular sheet or panel comprising an array of linear lenses; a complementary interchangeable print sheet; and

- a peelable adhesive layer bonding said interchangeable print sheet to said lenticular sheet or panel; wherein said peelable adhesive layer allows said lenticular sheet to be removed from said lenticular sheet or panel without damaging said lenticular sheet or panel, and replaced with a different interchangeable print sheet.

2. A lenticular display sheet or panel according to claim 1, wherein the peelable adhesive layer is initially applied to the front of the complementary interchangeable print sheet.

3. A lenticular display sheet or panel according to claim 1, wherein the peelable adhesive layer is initially applied to the back of the lenticular sheet or panel.

4. A lenticular display sheet or panel according to claim 1, wherein said interchangeable print sheet comprises a resilient stretchable substrate on which an interlaced image has been printed.

5. A lenticular display sheet or panel, according to claim 1, wherein the lenticular sheet or panel comprises an array of alignment means and the interchangeable print sheet comprises complementary alignment means, wherein said alignment means and said complementary alignment means serve to align the printed information on said print sheet with the linear lenses of said lenticular sheet or panel.

6. A lenticular display sheet or panel, according to claim 5, wherein the alignment means are an array of pins and the complementary alignment means are a matching array of punctures.

7. A lenticular display sheet or panel, according to claim 1, wherein the lenticular sheet or panel comprises an array of anchoring means and the interchangeable print sheet comprises complementary anchoring means, wherein said anchoring means and said complementary anchoring means serve to maintain the fixed relationship between the cumulative pitch distance of said print sheet with the cumulative pitch distance of the linear lenses of said lenticular sheet or panel.

8. A lenticular display sheet or panel, according to claim 7, wherein the anchoring means are an array of pins and the complementary anchoring means are a matching array of punctures.

9. A billboard comprised of two or more large format, commercial lenticular display sheets or panels according to claim 1; wherein said two or more display sheets or panels are attached side-by-side to a frame.

10. A method for preparing a lenticular display sheet or panel having an interchangeable print sheet, comprising the steps: a. preparing a lenticular lens sheet or panel comprising an array of alignment means projecting from its rear face; b. processing a digital interlaced image according to the rules of lenticular technology; c. printing said digital interlaced image on an indicia carrier, thereby creating a print sheet; d. puncturing said print sheet according to said array of alignment means; e. layering said print sheet with a peelable adhesive compound; f. pressing said print sheet against the back surface of said lenticular sheet or panel, thereby adhering said print sheet to said lenticular lens sheet or panel.

11. The method described in claim 10, wherein the indicia carrier comprises a resilient stretchable substrate, the lenticular lens film or sheet comprises an array of anchoring pins attached to its rear surface, and the print sheet is stretched to fit over said anchoring pins, thereby assuring that the cumulative pitch distance of said print sheet equals that of said lenticular lens film or sheet.

12. A method according to claim 10, wherein the peelable adhesive layer is initially applied to the front of the complementary interchangeable print sheet.

13. A method according to claim 10, wherein the peelable adhesive layer is initially applied to the back of the lenticular lens film or sheet.

14. A print sheet comprising: - a lightweight indicia carrier on which is printed an interlaced image comprising an array of parallel information strips having a given pitch; and - a pressure-sensitive adhesive layer spread over the printed side of said indicia carrier; wherein said print sheet can be aligned and attached by means of said pressure-sensitive adhesive layer to the rear flat side of a lenticular lens sheet or panel having the same pitch, in order to display through said sheet or panel, multi-image messages, and then be periodically removed and replaced by another print sheet of the same type, without damaging said lens sheet or panel.

15. A print sheet according to claim 14, comprising aligning means in the form of marks or punctures, said aligning means used to align the strips of print on said print sheet with the lenses on the lenticular lens sheet or panel.

16. A print sheet according to claim 14, wherein the indicia carrier is made of a plastic resilient compound having a pitch slightly smaller then the pitch of the lenticular lens sheet or panel, thereby allowing said print sheet to be slightly stretched when attached to said lenticular lens sheet or panel in order to equal the pitch of said print sheet to the pitch of said lenticular lens sheet or panel.

17. A print sheet according to claim 14, wherein the indicia carrier is made of a transparent material.