Patterned optical structures with enhanced security feature
View Patent ↗A security image and method for forming said image is disclosed wherein an image having a layer with a hologram therein has an additional layer of magnetically aligned flakes together forming an image that is difficult to counterfeit and is highly attractive. Preferably windows of an opaque layer provide additional means of encoding or forming the image.
1. A security device having a first region coated with magnetically aligned pigment particles; and, a second marked region different from the first region; wherein the magnetically aligned pigment particles form an image that appears to move with a change in viewing angle or incident light, and wherein the second marked region serves as a frame of reference against which the image appears to move.
2. A security device as defined in claim 1 wherein the second marked region is marked with indicia formed thereon by embossing or etching the second region to form a grating.
3. A security device as defined in claim 2 , wherein the first region forms a layer of the security device and wherein the second region forms another layer of the security device.
4. A security device as defined in claim 3 wherein said another layer is a substrate layer.
5. A security device as defined in claim 1 wherein the second marked region has printed indicia thereon formed of material other than magnetically alignable pigment particles.
6. A security device as defined in claim 5 , wherein the printed indicia is printed with ink or paint.
7. A security device as defined in claim 1 , wherein the second marked region has a patterned segmented reflector layer.
8. A security device as defined in claim 1 wherein the magnetically aligned pigment particles form a color-shifting ink or paint.
9. A security device as defined in claim 1 , wherein the first region is on one side of the substrate, and wherein the second marked region is on an opposite side of the substrate.
10. A security device comprising: a substrate; a first region coated with a magnetically aligned pigment and a second different region having a diffraction grating thereon, wherein the magnetically aligned pigment forms an image that appears to move with a change in viewing angle or angle of incident light, and wherein the diffraction grating serves as a frame of reference against which the image appears to move.
11. A security device as defined in claim 10 , wherein the second region having the diffraction grating is segmented so that some sub regions are absent a the diffraction grating and other sub-regions include the diffraction grating.
12. A security device as defined in claim 10 , wherein the first region is on one side of the substrate, and wherein the second different region is on an opposite side of the substrate.
13. A security device as defined in claim 10 wherein the diffraction grating has a high refractive index layer having a index of refraction of 1.65 or greater, adjacent to the diffraction grating.
14. A security device as defined in claim 10 where a reflective layer is coated upon portions of the diffraction grating.
15. A security device as defined in claim 10 , further comprising a patterned segmented reflector layer, wherein at least some of the magnetically aligned pigment can be seen simultaneously with at least some of the patterned reflective layer.
16. A security device as defined in claim 10 , wherein the diffraction grating serves as a frame of reference against which the image appears to move, and wherein the first region is contained within boundaries of the second region, or, wherein the second region is contained within boundaries of the first region, and wherein both the diffraction grating and the magnetically aligned pigment can be seen from one side of the device.
17. A security device as defined in claim 16 wherein one of the diffraction grating and the color-shifting coating have discontinuities therein defining windows wherein a portion of the grating or color-shifting coating is absent forming a diffraction grating pattern or a color-shifting coating pattern.
18. A security device as defined in claim 16 including a reflective layer or a high refractive index layer having an index of refraction of 1.61 or greater.
19. A security device as defined in claim 18 , wherein the reflective layer or high index layer is patterned having windows therein where some of said layer is absent.
20. A security device as defined in claim 10 , wherein the first region is on a first layer and wherein the second region is on a different layer.
21. A device as defined in claim 20 wherein the magnetically aligned pigment is a color switching pigment which changes color with angle of incident light.
22. A security device as defined in claim 10 , wherein the first region is on one side of the substrate, and wherein the second different region is on a same side of the substrate.