Security document and method of manufacturing
Disclosed is a security document including an image area, a repeating image pattern in the image area of mutually spaced image elements at a mutual distance D and a layer of a plastics material overlying the image area and an array of lenses in the plastics material. The lenses are spaced at a mutual distance L which may be equal to D or which may differ from D, the array of lenses overlying only a part of the image area surface and are formed in the plastics material within an image contour. Within the contour an image may be observed such as a Moiré magnification or a Moiré effect of light and dark stripes. The lenses may be formed for instance by laser ablation or by imprinting.
1. A security document ( 1 ), comprising:
a portrait image ( 2 ) of a holder; and
an image area ( 3 ),
the image area having therein
an image pattern of mutually spaced image elements ( 5 , 6 ) at a mutual first distance D,
a layer ( 8 ) of plastic material overlying the image area, and
an array of lenses ( 11 , 12 ; 17 , 18 ) in said plastic material layer ( 8 ),
wherein the lenses ( 11 , 12 ) are spaced at a mutual second distance L which differs from the first distance D,
wherein the array of lenses overlies only a part of the image pattern ( 4 ), and is formed in the plastic material layer ( 8 ) within an image contour ( 10 , 19 ) in such a way that a part of the image pattern below the plastic material layer ( 8 )
is situated outside the image contour,
is not covered by any lenses, and
has a uniform appearance when viewed by a user,
and wherein said image contour forms holder-specific indicia that displays information pertaining to the holder and/or an issuing authority of the document ( 1 ).
2. The security document ( 1 ) according to claim 1 , wherein the lenses ( 11 , 12 ; 17 , 18 ) are formed by laser ablation of the plastic material layer ( 8 ).
3. The security document ( 1 ) according to claim 1 , wherein the lenses ( 11 , 12 ; 17 , 18 ) are formed by imprinting.
4. The security document ( 1 ) according to claim 1 , wherein the image elements ( 4 , 6 ) are formed by an array of microstructures.
5. The security document ( 1 ) according to claim 1 , wherein the array of lenses is an array of elongated cylindrical lenses ( 17 , 18 ), and the image elements comprise parallel image lines ( 15 , 16 ) having a length direction ( 1 ) extending at an angle (a) to the elongated cylindrical lenses ( 17 , 18 ).
6. The security document ( 1 ) according to claim 1 , wherein the image elements ( 5 , 6 ) are written into either of the plastic material layer or a layer below the plastic material layer, by means of a laser.
7. The security document ( 1 ) according to claim 1 , in which the image elements ( 5 , 6 ) are printed.
8. The security document ( 1 ) according to claim 2 , wherein the image elements ( 4 , 6 ) are formed by an array of microstructures.
9. The security document ( 1 ) according to claim 3 , wherein the image elements ( 4 , 6 ) are formed by an array of microstructures.
10. The security document ( 1 ) according to claim 2 , wherein the array of lenses is an array of elongated cylindrical lenses ( 17 , 18 ), and the image elements comprise parallel image lines ( 15 , 16 ) having a length direction ( 1 ) extending at an angle (a) to the elongated cylindrical lenses ( 17 , 18 ).
11. The security document ( 1 ) according to claim 3 , wherein the array of lenses is an array of elongated cylindrical lenses ( 17 , 18 ), and the image elements comprise parallel image lines ( 15 , 16 ) having a length direction ( 1 ) extending at an angle (a) to the elongated cylindrical lenses ( 17 , 18 ).
12. The security document ( 1 ) according to claim 4 , wherein the array of lenses is an array of elongated cylindrical lenses ( 17 , 18 ), and the image elements comprise parallel image lines ( 15 , 16 ) having a length direction ( 1 ) extending at an angle (α) to the elongated cylindrical lenses ( 17 , 18 ).
13. The security document ( 1 ) according to claim 2 , wherein the image elements ( 5 , 6 ) are written into either of the plastic material layer or a layer below the plastic material layer, by means of a laser.
14. The security document ( 1 ) according to claim 3 , wherein the image elements ( 5 , 6 ) are written into either of the plastic material layer or a layer below the plastic material layer, by means of a laser.
15. A security document ( 1 ), comprising:
a portrait image ( 2 ) of a holder: and
an image area ( 3 ),
the image area having therein
an image pattern of mutually spaced image elements ( 5 , 6 ) at a mutual first distance D,
a layer ( 8 ) of plastic material overlying the image area,
and an array of lenses ( 11 , 12 ; 17 , 18 ) in the plastic material layer ( 8 ),
wherein the array of lenses overlies only a part of the image pattern ( 4 ), and is formed in the plastic material layer ( 8 ) within an image contour ( 10 , 19 ) by laser ablation of the plastic material layer in such a way that a part of the image pattern below the plastic material layer ( 8 )
is situated outside the image contour,
is not covered by any lenses, and
has a uniform appearance when viewed by a user,
and wherein said image contour forms holder-specific indicia that displays information pertaining to the holder and/or an issuing authority of the document.
16. A method of forming a security document ( 1 ), comprising the steps of:
providing a first layer ( 9 ) comprising an image area ( 3 ), the image area having an image pattern therein, and a second layer ( 8 ) of a plastic material overlying the image area ( 3 );
providing a portrait image of a holder in or on said first layer ( 9 );
forming an array of lenses ( 11 , 12 ; 17 , 18 ) in the second layer within an image contour, wherein said array of lenses overlies only a first part of the image pattern such that a second part of the image pattern below the second layer ( 8 ) and outside the image contour is not covered by any lenses and has a uniform appearance when viewed by a user, and said image contour forms holder-specific indicia that displays information pertaining to the holder and/or an issuing authority of the document.
17. The method according to claim 16 , wherein the array of lenses ( 11 , 12 ; 17 , 18 ) is formed by laser ablation of the second layer ( 8 ).
18. The method according to claim 16 wherein the array of lenses( 11 , 12 ; 17 , 18 ) is formed by imprinting of the second layer ( 8 ).
19. The method according to claim 16 , wherein the image pattern comprises a matrix of images spaced at a first mutual distance D, and the array of lenses ( 11 , 12 ; 17 , 18 ) is comprised of lens elements that are spaced apart from each other at a second mutual distance L which differs from the first mutual distance D.
20. The method according to claim 16 , wherein the image pattern is comprised of groups of image lines ( 15 , 16 ), the array of lenses comprising elongate cylindrical lenses ( 17 , 18 ) that are formed at an angle (a) to the image lines ( 15 , 16 ).