Systems and methods for creating optical effects on media

• US 8,840,983 B2
• Filed: 12/15/2011
• Issued: 09/23/2014
• Est. Priority Date: 07/02/2004
• Status: Active Grant

• Current Assignee: 3DTL, Inc.
• Original Assignee: 3DTL, Inc.
• Inventors: Downing, Elizabeth A.
• Primary Examiner(s): HIGGINS, GERARD T
• Application Number:
  US13/327,744
• Publication Number:
  US 20120080877A1
• Time in Patent Office: 1,013 Days
• Field of Search: 428/195.1, 428/913, 428/916, 283/87, 283/92, 283/94
• US Class Current: 428/195.1
• CPC Class Codes: B42D 2035/24 Colours
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: B42D 25/30 Identification or security features, e.g. for preventing forgery
• CPC Class Codes: B42D 25/387 absorbing or reflecting ultraviolet light
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C09B 67/0004 Coated particulate pigments or dyes
• CPC Class Codes: C09C 1/00 Treatment of specific inorganic materials other than fibrous fillers tenebrescent materials C09K9/00; luminescent materials C09K11/00; Preparation of carbon black
• CPC Class Codes: C09C 1/3063 Treatment with low-molecular organic compounds
• CPC Class Codes: C09C 3/08 Treatment with low-molecular-weight non-polymer organic compounds C09C3/006, C09C3/048 take precedence
• CPC Class Codes: C09D 11/037 characterised by the pigment
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: G07D 7/005 Testing security markings invisible to the naked eye, e.g. verifying thickened lines or unobtrusive markings or alterations
• CPC Class Codes: G07D 7/1205 Testing spectral properties
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10S 428/916 Fraud or tamper detecting
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24893 including particulate material
• CPC Class Codes: Y10T 428/24901 including coloring matter
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/2991 : Coated

Abstract

Methods and systems for optical effects in pigments, inks, and on media. One aspect of this disclosure involves a pigment particle which includes a core, having a fluorescent material and having a spherical shape, and a shell surrounding the core; the shell includes a photochromic material which has a first optical property in a first light source and a second optical property in a second light source which includes a set of wavelengths not sufficiently present in the first light source. The second optical property attenuates an emitted radiation from the fluorescent material. Other aspects are also described.

Claims

1. An object comprising:

a substrate having an indicia thereon, wherein

the indicia comprises a first layer having a first fluorescent chromophore which emits fluorescent radiation in response to ultraviolet (UV) illumination,

a second layer comprising a photochromic material, wherein the photochromic material has a first optical appearance without UV excitation and a second optical appearance after receiving UV excitation,

a third layer comprising a second fluorescent chromophore which emits fluorescent radiation in response to UV illumination, wherein the first, second, and third layers are present in this order on the substrate, wherein the indicia appears to radiate a first color that is based on the mixed fluorescence radiation from the first fluorescent chromophore and the second fluorescent chromophore, the indicia appears to radiate a second color upon continued UV excitation as the second layer has changed to the second optical appearance, the photochromic material attenuates the fluorescent radiation from the first fluorescent chromophore in the second optical appearance, the photochromic material changes from the first optical appearance to the second optical appearance while under UV excitation over a period of more than one-third second to less than 20 seconds such that the first color is visible for at least one-third second to as long as 20 seconds, and the second color is based on fluorescent radiation from the second fluorescent chromophore.

2. An object as in claim 1 wherein the object is currency.

3. The object of claim 1, wherein the photochromic material is organic.

4. The object of claim 1, wherein the first optical appearance is transparent.

5. A method to authenticate an object, the method comprising:

exposing an object to ultraviolet (UV) illumination;

observing radiation of a first color in response to the exposing;

observing radiation of a second color in response to the exposing and after the observing of radiation of the first color, wherein the observing radiation of the first and the second colors is used to determine an authenticity of the object, wherein the object includes a substrate having an indicia thereon, the indicia including;

a first layer having a first fluorescent chromophore which emits fluorescent radiation in response to the ultraviolet (UV) illumination,

a second layer comprising a photochromic material, wherein the photochromic material has a first optical appearance without UV excitation and a second optical appearance after receiving UV excitation,

a third layer comprising a second fluorescent chromophore which emits fluorescent radiation in response to UV illumination, wherein the first, second, and third layers are present in this order on the substrate, wherein the indicia appears to radiate the first color that is based on the mixed fluorescence radiation from the first fluorescent chromophore and the second fluorescent chromophore, the indicia appears to radiate the second color upon continued UV excitation as the second layer has changed to the second optical appearance, the photochromic material attenuates the fluorescent radiation from the first fluorescent chromophore in the second optical appearance, the photochromic material changes from the first optical appearance to the second optical appearance while under UV excitation over a period of more than one-third second to less than 20 seconds such that the first color is visible for at least one-third second to as long as 20 seconds, and the second color is based on fluorescent radiation from the second fluorescent chromophore.

6. A method as in claim 5 wherein the material has an initial color prior to the exposing and wherein the material appears to change from the initial color then to the first color and then to the second color in response to the exposing and, after the exposing is stopped, the material reversibly returns to the initial color.