METHODS FOR FORMING SHEETING WITH A COMPOSITE IMAGE THAT FLOATS AND A MASTER TOOLING

• US 20100316959A1
• Filed: 11/10/2008
• Published: 12/16/2010
• Est. Priority Date: 11/27/2007
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Gates, Brian J., Krasa, Robert T., Wetzels, Serge, Potts, Travis L.
• Granted Patent: US 8,586,285 B2
• Time in Patent Office: Days
• US Class Current: 430/321
• CPC Class Codes: B29D 11/00365 Production of microlenses lenticular sheets B29D11/00278
• CPC Class Codes: G02B 3/0031 Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 30/56 by projecting aerial or floating images

Abstract

A sheeting and a method of forming a sheeting from a master tool are described where the sheeting has a composite image that floats above or below the sheeting. The method includes providing a first sheeting comprising a first array of microlenses and a photopolymerizable first material layer adjacent to the first array of microlenses. Another step is exposing the first sheeting to a radiation source to form a master tool comprising a plurality of polymerized first structured areas in the first material layer, wherein at least some of the first structured areas include a portion shape in common with at least some of the first structured areas and wherein each first structured area is associated with one of the first array of microlenses. Yet another step is replicating the plurality of first structured areas using a substance that conforms to the plurality of structured areas to form a second material layer having a plurality of replicated structured areas.

Claims

1. A method of forming a sheeting from a master tool, comprising:

providing a first sheeting comprising a first array of microlenses and a photopolymerizable first material layer adjacent to the first array of microlenses;

exposing the first sheeting to a radiation source to form a master tool comprising a plurality of polymerized first structured areas in the first material layer, wherein at least some of the first structured areas comprise a portion shape in common with at least some of the other first structured areas, and wherein each first structured area is associated with one of the first array of microlenses;

replicating the plurality of first structured areas using a substance that conforms to the plurality of structured areas to form a second material layer having a plurality of replicated structured areas.

2. The method of claim 1 further comprising:

associating the second material layer with a second array of microlenses to form a second sheeting, wherein individual replicated structured areas are associated with individual microlenses in the second array of microlenses;

wherein each of the second array of microlenses has a refractive surface that transmits light to a position of the second material layer to produce, under reflected or transmitted light, a composite image from the replicated structured areas formed within the second material layer, where the composite image appears to float above or below the second sheeting.

3. The method of claim 2 wherein a part of the composite image appears to float above the second sheeting and a different part of the composite image appears to float below the second sheeting.

4. The method of claim 1 wherein the first array of microlenses is formed as a layer separate from the first material layer.

5. The method of claim 1 wherein at least one of the structured areas has a dimension that protrudes above a plane of the master tool or is recessed below the plane of the master tool by at least 1 micrometer.

6. The method of claim 1 wherein at least one of the structured areas has a dimension that protrudes above a plane of the master tool or is recessed below the plane of the master tool by at least 4 micrometers.

7. The method of claim 1 wherein the photopolymerizable material is polymerized upon exposure to conditions resulting in simultaneous absorption of two or more photons.

8. The method of claim 1 wherein the replicated structured areas include at least two partially complete structures, wherein the partially complete structures each include at least one portion in common with the composite image.

9. The method of claim 1, wherein the substance that conforms to the plurality of structured areas is a curable composition.

10. The method of claim 1, wherein the substance that conforms to the plurality of structured areas is an electroplated metal.

11. A master tool for forming a sheeting that has a composite image that floats above or below the sheeting, comprising:

a first sheeting have a first array of microlenses and a photopolymerized first material layer adjacent to the first array of microlenses, wherein the photopolymerized material is polymerized upon exposure to conditions resulting in simultaneous absorption of two or more photons;

wherein the first sheeting comprises a plurality of polymerized structured areas in the first material layer, wherein at least some of the structured areas comprise a portion shape in common with some of the other structured areas, and wherein each structured area is associated with one of the first array of microlenses.

12. The master tool of claim 11 wherein each of the first array of microlenses has a refractive surface that transmits light to a position of the first material layer to produce, under reflected or transmitted light, a composite image from the structured areas formed within the first material layer, where the composite image appears to float above or below the first sheeting.

13. The master tool of claim 12 wherein a part of the composite image appears to float above the second sheeting and a different part of the composite image appears to float below the first sheeting.

14. The master tool of claim 12 wherein the structured areas include at least two partially complete structures, wherein the partially complete structures each include at least one portion in common with the composite image.

15. The master tool of claim 11 wherein at least one of the structured areas has a dimension that protrudes above a plane of the master tool or is recessed below the plane of the master tool by at least 1 micrometer.

16. The master tool of claim 11 wherein at least one of the structured areas has a dimension that protrudes above a plane of the master tool or is recessed below the plane of the master tool by at least 4 micrometers.

17. A method of using a master tool to form a sheeting, comprising:

providing a first sheeting comprising a first array of microlenses and a photopolymerizable first material layer adjacent to the first array of microlenses, wherein the photopolymerizable material is polymerized upon exposure to conditions resulting in simultaneous absorption of two or more photons;

exposing the first sheeting to a radiation source to form a master tool comprising a plurality of polymerized first structured areas in the first material layer, wherein at least some of the first structured areas comprise a portion of some of the other first structured areas, and wherein each first structured area is associated with one of the first array of microlenses;

replicating the plurality of first structured areas using a substance that conforms to the plurality of structured areas to form a second material layer having a plurality of replicated structured areas.

18. The method of claim 17 further comprising:

associating the second material layer with a second array of microlenses to form a second sheeting, wherein individual replicated structured areas are associated with individual microlenses in the second array of microlenses;

wherein each of the second array of microlenses has a refractive surface that transmits light to a position of the second material layer to produce, under reflected or transmitted light, a composite image from the replicated structured areas formed within the second material layer, where the composite image appears to float above or below the second sheeting.

19. The method of claim 18 wherein a part of the composite image appears to float above the second material layer and a different part of the composite image appears to float below the second sheeting.

20. The method of claim 18 wherein the replicated structured areas have at least two partially complete structures formed therein, wherein the partially complete structures each include at least one portion in common with the composite image.

21. The method of claim 17 wherein each of the first array of microlenses has a refractive surface that transmits light to a position of the material layer to produce, under reflected or transmitted light, a composite image from the structured areas formed within the first material layer, where the composite image appears to float above or below the first sheeting.

22. A master tool comprising:

a first array of microlenses, and

a regular array of structures,

wherein each structure is associated with one of the microlenses,

wherein at least some of the structures comprise a portion shape in common with at least some of the other structures,

wherein substantially flat areas exist between the structures such that in the substantially flat areas there is no variation in feature height greater than 100 nanometers.

23. The master tool of claim 22 wherein the structures have a maximum structure height above a plane of the master tool, wherein there is no feature in the substantially flat areas that has a height of greater than or equal to 10% of the maximum structure height.

24. A photolithography process using visible or infrared radiation, comprising:

providing a first array of microlenses and a photopolymerizable first material layer adjacent to the microlenses;

exposing the first material layer to a radiation source including visible or infrared radiation;

developing the photopolymerizable first material layer to form a master tool comprising a plurality of polymerized first structured areas in the first material layer,

wherein at least some of the first structured areas comprise a portion shape in common with some of the other first structured areas,

wherein each first structured area is associated with one of the first array of microlenses,

wherein at least one feature dimension of a plurality of the first structured areas is less than or equal to 100 nanometers.

25. The process of claim 24, wherein the photopolymerized material is polymerized upon exposure to conditions resulting in simultaneous absorption of two or more photons;

and

wherein at least one feature dimension of a plurality of the first structured areas is less than or equal to 70 nanometers.