ANTI-COUNTERFEITING MEDIUM AND METHOD FOR FABRICATING ANTI-COUNTERFEITING MEDIUM

• US 20190135021A1
• Filed: 01/05/2019
• Published: 05/09/2019
• Est. Priority Date: 03/26/2014
• Status: Active Grant

• Current Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Original Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Inventors: OKAWA, Mihoko, OCHIAI, Hideki, ICHIKAWA, Koji, KOTEGAWA, Yuki
• Granted Patent: US 10,647,148 B2
• Time in Patent Office: Days
• CPC Class Codes: B41M 3/14 Security printing securities B42D25/29
• CPC Class Codes: B42D 25/21 for multiple purposes
• CPC Class Codes: B42D 25/23 Identity cards
• CPC Class Codes: B42D 25/24 Passports
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: B42D 25/36 comprising special materials
• CPC Class Codes: B42D 25/364 Liquid crystals
• CPC Class Codes: B42D 25/378 Special inks
• CPC Class Codes: B42D 25/382 absorbing or reflecting infrared light
• CPC Class Codes: B42D 25/387 absorbing or reflecting ultraviolet light
• CPC Class Codes: B42D 25/391 absorbing or reflecting polarised light
• CPC Class Codes: B42D 25/41 using electromagnetic radiation B42D25/435 takes precedence
• CPC Class Codes: B42D 25/435 using electromagnetic radiation, e.g. laser
• CPC Class Codes: B42D 25/47 using adhesives
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid

Abstract

An anti-counterfeiting medium includes a recording medium, a polarizer layer arranged on a part of the recording medium. The polarizer layer is formed thereon with a low extinction-ratio area that forms an image portion where a polarizer exhibits an extinction ratio lower than in a portion other than the low extinction-ratio area of the polarizer layer. The recording medium is formed thereon with an image portion that is a part of the recording medium and has a nature different from that of a portion other than the part of the recording medium.

Claims

1. A method for fabricating an anti-counterfeiting medium, comprising:

preparing a recording medium;

arranging a polarizer layer that contains a dichroic dye on a part of the recording medium; and

continuously forming an image across the polarizer layer and the recording medium by laser irradiation, wherein in a first portion of the polarizer layer, which was not exposed to the laser irradiation, the dichroic dye is oriented and wherein in a second portion of the polarizer layer, which was exposed to the laser radiation and which contains a portion of the image, an orientation of the dichroic dye is disturbed by the laser irradiation so that the second portion of the polarizer layer has a lower extinction ratio that the first portion of the polarizer layer.

2. The method of claim 1, further comprising:

preparing a transfer foil including a support base, the polarizer layer on the support base, and an adhesive layer arranged on the polarizer layer;

arranging the transfer foil on the recording medium such that the adhesive layer is adhered to the recording medium; and

separating the support base from the polarizer layer to thereby transfer the adhesive layer and the polarizer layer to the recording medium.

3. The method of claim 2, wherein the support base comprises a uniaxially stretched film and the polarizer layer is a uniaxially oriented polarizer layer.

4. The method of claim 2, wherein the support base comprises a biaxially stretched film and the polarizer layer is a biaxially oriented polarizer layer.

5. The method of claim 2, wherein preparing the transfer foil comprises rubbing a surface of the support base and applying on the rubbed surface of the support base the dichroic dye, wherein a direction of the rubbing determines an orientation direction of the dichroic dye.

6. The method of claim 5, wherein the support base comprises a non-stretched film.

7. The method of claim 2, further comprising photo-aligning the dichroic dye on a surface of the support base.

8. The method of claim 2, wherein the adhesive layer comprises a heat-sensitive adhesive.

9. The method of claim 8, further comprising pressing the transfer foil with a hot stamp to soften a portion of the adhesive layer facing the hot stamp.

10. The method of claim 1, further comprising providing a shielding layer over the first portion of the polarizer layer prior to the forming the image.

11. The method of claim 10, wherein the shielding layer comprises a metal vapor-deposited film or a dielectric vapor-deposited film.