Anti-counterfeiting pattern having optically variable structure and preparation method thereof

Abstract

An anti-counterfeiting pattern having an optically variable structure, comprising lithographic lines and gravure blind embossed relief lines printed on a carrier. The lithographic lines are a set of lithographic curve lines having a curvature, the widths of the lithographic curve lines changing from thick to thin, or thin to thick. The gravure blind embossed relief lines are a set of curve lines corresponding to the lithographic lines, and having the same curvature. The relief lines are overprinted on the lithographic lines with a width variation identical to that of said lithographic lines. Accurate overprinting of the two printing types forms a curved relief structure wherein the width of the lines changes continuously. When a printed product is rotated and observed, a continuously variable optical effect will be seen, which is visual, readily to identify, anti-copying and difficult to forgery.

Claims

1. An anti-counterfeiting pattern having the optically variable structure, comprising lithographic lines and gravure blind embossed relief lines printed on a carrier; the lithographic lines are a set of lithographic curve lines, the widths of each of the lithographic curve lines changes from thick to thin or thin to thick from one end to other end; the gravure blind embossed relief lines are a set of curve lines corresponding to the lithographic lines; the relief lines are superimposed on the lithographic lines, the widths of the gravure blind embossed relief lines changes from thick to thin or thin to thick from one end to other end; the widths of each of the lithographic curve lines are gradually decreased from 200-500 m to 20-50 m from one end to other end, or gradually increased from 20-50 m to 200-500 m from one end to other end; curvatures of the lithographic curve lines are incrementally changed from 0.01-0.02 mm.sup.1 to 1-2 mm.sup.1 from one end to other end; widths of the relief lines are slightly 2-5 m larger than that of the lithographic lines at the same point.

2. The anti-counterfeiting pattern having the optically variable structure according to claim 1, characterized in that, the width of the gravure blind embossed relief lines is 3-4 m larger that of the lithographic lines.

3. The anti-counterfeiting pattern having the optically variable structure according to claim 2, characterized in that, the ratio between the width of the gravure blind embossed relief lines and an interval of the gravure blind embossed relief lines is continuously decreased from 10:1 to 1:10, or continuously increased from 1:10 to 10:1.

4. The anti-counterfeiting pattern having the optically variable structure according to claim 1, characterized in that, the ratio between the width of the gravure blind embossed relief lines and an interval of the gravure blind embossed relief lines is continuously decreased from 10:1 to 1:10, or continuously increased from 1:10 to 10:1.

5. A preparation method of the anti-counterfeiting pattern having an optically variable structure, comprises the following steps: performing a lithography, wherein the lithographic lines are a set of lithographic curve lines, the widths of the lithographic curve lines changes from thick to thin or thin to thick from one end to other end; adopting gravure with a inkless or transparent printing ink, wherein the gravure blind embossed relief lines are a set of curve lines, corresponding to the lithographic lines; the relief lines are superimposed on the lithographic lines, the width of each of the gravure blind embossed relief lines is changed from thick to thin or thin to thick from one end to other end; wherein the widths of the lithographic curve lines are gradually decreased from 200-500 82 m to 20-50 m, or gradually increased from 20-50 m to 200-500 m; wherein curvatures of the lithographic curve lines are incrementally changed from 0.01-0.02 mm.sup.1 to 1-2mm.sup.1 from one end to other end; wherein widths of the relief lines is slightly 2-5 m larger than that of the lithographic lines at the same point.

6. The preparation method of the anti-counterfeiting pattern having an optically variable structure according to claim 5, wherein the lithography is an offset printing or a pad printing.

7. The preparation method of the anti-counterfeiting pattern having an optically variable structure according to claim 5, wherein the accuracy error of the overprinting between the gravure blind embossed relief lines and the lithographic lines is no more than 10 m.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a structural diagram of an anti-counterfeiting pattern having the optically variable structure.

(2) FIG. 2 is an enlarged view showing a lithographic line and a relief line of the anti-counterfeiting pattern.

(3) FIG. 3 is an enlarged cross section view along the D-D direction in the FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) Please refer to FIG. 1, the anti-counterfeiting pattern having the optically variable structure of the present invention comprises lithographic lines 1 and gravure blind embossed relief lines 2 printed on a carrier.

(5) The lithographic lines 1 are a set of lithographic curve lines having a curvature, the width m of the lithographic curve line changes from thick to thin, or thin to thick, i.e., gradually and continuously changes from 200-500 m to 20-50 m, or gradually and continuously changes from 20-50 m to 200-500 m, while curvature of the lithographic curve line continuously changes from 0.01-0.02 mm.sup.1 to 1-2 mm.sup.1.

(6) The gravure blind embossed relief lines 2 are a set of curve lines corresponding to the lithographic lines, and having the same curvature.

(7) The relief lines 2 are overprinted on the lithographic lines 1 with a width variation identical to that of said lithographic lines 1, and the width at the same point is slightly 2-5 m larger than that of the lithographic lines.

(8) The accuracy error of the overprinting between the engraving gravure blind embossed relief lines 2 and the lithographic lines 1 is no more than 10 m.

(9) Preferably, the width of the engraving gravure blind embossed relief lines 2 is slightly 3-4 m larger than that of the lithographic lines 1. The ratio between the width of the engraving gravure blind embossed relief lines 2 and the interval of the engraving gravure blind embossed relief lines 2 continuously changes from 10:1 to 1:10, or continuously changes from 1:10 to 10:1.

Embodiment 1

(10) Please refer to FIGS. 1 to 3.

(11) As shown in figures, in the upper part (i.e., part A in FIG. 1):

(12) It firstly adopts ordinary black ink to perform a lithography 1 on a paper 3 by offset printing, wherein the whole graphic pattern is concentric circles, and the widths m of the lithographic lines 1 continuously changes from 200 m to 20 m, that is, from thick to thin. Then, the relief lines 2 are overprinted by using inkless air compressor technology, the lines 2 are accurately overprinted on the lines 1, and the widths M of the relief lines 2 continuously changes from 210 m to 25 m, that is, from thick to thin.

(13) In the lower part (i.e., part B in FIG. 1): The widths m of the lithographic lines 1 continuously changes from 20 m to 200 m, that is, from thin to thick, and an ordinary black ink print is adopted herein.

(14) Then, the relief lines 2 are overprinted by using inkless air compressor technology, the lines are accurately overprinted on the lines 1, and the widths M of the relief lines 2 continuously changes from 25 m to 210 m.

(15) Preferably, the width M of the engraving gravure blind embossed relief lines 2 is slightly 3-4 m larger than that m of the lithographic lines 1. The ratio between the width M of the engraving gravure blind embossed relief lines 2 and the interval P of the engraving gravure blind embossed relief lines 2 continuously changes from 10:1 to 1:10, or continuously changes from 1:10 to 10:1.

Embodiment 2

(16) A preparation method of the anti-counterfeiting pattern having an optically variable structure, comprises the following steps:

(17) performing a lithography, wherein the lithographic lines are a set of lithographic curve lines 1, the widths m of the lithographic curve lines changes from thick to thin, or thin to thick;

(18) adopting gravure with a inkless or transparent printing ink, wherein the gravure blind embossed relief lines 2 are a set of curve lines corresponding to the lithographic lines 1; the relief lines 2 are overprinted on the lithographic lines 1, the widths M of the gravure blind embossed relief lines 2 changes from thick to thin, or thin to thick;

(19) wherein the widths m of the lithographic curve lines 1 gradually and continuously changes from 200-500 m to 20-50 m, or gradually and continuously changes from 20-50 m to 200-500 m;

(20) wherein curvatures r of the lithographic curve lines 1 continuously changes from 0.01-0.02 mm.sup.1 to 1-2 mm.sup.1;

(21) wherein widths M of the relief lines is slightly 2-5 m larger than that of the lithographic lines 1 at the same point.

(22) wherein the lithography is an offset printing or a pad printing.

(23) wherein the accuracy error of the overprinting between the gravure blind embossed relief lines and the lithographic lines is no more than 10 m.

(24) In such way, the anti-counterfeiting pattern having an optically variable structure is obtained. The obtained graphic pattern may generate a continuously variable optical effect along with the rotation of the printed product.