# US 7,845,572 B2 · Solid-color embedded security feature

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- Number: US 7,845,572 B2
- Document ID: US7845572B2
- Status: Granted
- Kind: B2
- Application number: 11/740,696
- Filed: 2007-04-26
- Published: 2007-10-25
- Granted: 2010-12-07
- Earliest claimed: 2005-08-01
- Assignees: Document Security Systems, Inc.
- Inventors: David Michael Wicker; Michael Scott Caton
- Web page: https://patentgrep.com/patent/US7845572B2

## CPC

- B42D 25/30: Identification or security features, e.g. for preventing forgery
- B41M 3/14: Security printing {(securities B42D25/29)}
- B42D 25/29: Securities; Bank notes
- G03G 21/04: Preventing copies being made of an original
- G07D 7/207: Matching patterns that are created by the interaction of two or more layers, e.g. moiré patterns
- H04N 1/32203: {Spatial or amplitude domain methods (H04N1/32309 takes precedence)}
- H04N 1/4493: {Subsequently rendering the image intelligible using a co-operating image, mask or the like}
- B41M 3/146: {using a non human-readable pattern which becomes visible on reproduction, e.g. a void mark}
- B42D 2035/16
- B42D 2035/24
- B42D 2035/34
- G03G 2215/00299: Confidential, e.g. secret documents
- G03G 2215/00932: Security copies
- B42D: BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- B41M: PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING, (correction of typographical errors B41J; processes for applying transfer pictures or the like B44C1/16; fluid media for correction of typographical errors by coating C09D10/00; printing textiles D06P)
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G07D: HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A latent image is incorporated into an apparent solid-color background for representing a desired solid-color background having a target color. An underlying solid-color background is printed on a print medium using a first color composition that differs from the target color. Line-screen patterns embedding a latent image in a visually integrated setting are printed over the solid-color background using a second color composition that differs from both the first color composition and the target color. The visual characteristics of the line-screen patterns forming the latent image and the visually integrated setting are matched for rendering the latent image practically indistinguishable from the visually integrated setting without a visual aid. The print densities of the line-screen patterns and the first and second color compositions are interrelated so that the line-screen patterns in combination with the underlying solid-color background produce the apparent solid-color background in the target color.

## Claims

### Claim 1

A method of incorporating a latent image in an apparent solid-color background for representing a desired solid-color background having a target color comprising steps of
printing an underlying solid-color background on a print medium using a first color composition that differs from the target color,
printing line-screen patterns on the print medium over an area in common with the solid-color background embedding the latent image in a visually integrated setting using a second color composition that differs from both the first color composition and the target color,
matching visual characteristics of the line-screen patterns forming the latent image and the visually integrated setting for rendering the latent image practically indistinguishable from the visually integrated setting without a visual aid, and
interrelating print densities of the line-screen patterns and the first and second color compositions so that the line-screen patterns in combination with the underlying solid-color background produce the apparent solid-color background in the target color.

### Claim 2 (depends on 1)

The method of claim 1 in which the target color is represented by a target combination of color components, and the first and second color compositions are drawn from the target combination of color components.

### Claim 3 (depends on 2)

The method of claim 2 in which the target combination of color components includes the color components having predetermined percentages within the target combination of color components and the first and second color compositions are exposed in the apparent solid-color background in similar percentages as the predetermined percentages of the color components within the target combination of color components.

### Claim 4 (depends on 2)

The method of claim 2 in which the first color composition of the underlying solid-color background contributes to the target combination of color components in the apparent solid-color background in accordance with a percent departure of the print density from 100 percent, and the second color composition of the line-screen patterns contributes to the target combination of color components in the apparent solid-color background in accordance with the print density.

### Claim 5 (depends on 2)

The method of claim 2 in which a percent “TBC1” of one of the color components of the target combination of color components is matched by a percent “UBC1” of the same color component in the first color composition of the underlying solid-color background and a percent “LSC1” of the same color component in the second color composition of the line-screen patterns in accordance with the print density “PD” of the line-screen patterns as follows:
TB
C
⁢
⁢
1
=
(
100
-
PD
)
100
*
UB
C
⁢
⁢
1
+
PD
100
*
LS
C
⁢
⁢
1
.

### Claim 6 (depends on 2)

The method of claim 2 in which the first color composition of the underlying solid-color background is defined by a percent reduction of the color components of the target combination of color components and the print density of the line-screen patterns matches this percent reduction.

### Claim 7 (depends on 2)

The method of claim 2 including a step of defining the target color as a combination of color components of the Pantone Matching System, and each of the first and second color compositions include one or more of the Pantone Matching System color components of the target combination of color components.

### Claim 8 (depends on 1)

The method of claim 1 in which the step of matching visual characteristics of the line-screen patterns includes matching the line-screen patterns of the latent image and the visually integrated setting in both color and print density.

### Claim 9 (depends on 1)

The method of claim 1 including a step of differentiating other characteristics of the line-screen patterns so that the latent image can be distinguished from the visually integrated setting with the visual aid.

### Claim 10 (depends on 9)

The method of claim 9 in which the line-screen patterns of the latent image and the visually integrated setting differ by at least one of line frequency and relative angular orientation.

### Claim 11 (depends on 10)

The method of claim 10 in which the visual aid includes a line-screen pattern having a line frequency matching a line frequency of at least one of the line-screen patterns.

### Claim 12

A print medium having an apparent solid-color background in a target color containing a latent image comprising
an underlying solid-color background printed with a first color composition that differs from the target color,
a latent image and a visually integrated setting printed over an area in common with the underlying solid-color background as line-screen patterns having a second color composition that differs from both the target color and the first color composition,
the latent image being practically indistinguishable from the visually integrated setting without a viewing aid,
the line-screen patterns of the latent image and the visually integrated setting having a limited print density so that at least some of the underlying solid-color background is visible through the line-screen patterns, and
a combination of the first color composition of the underlying solid-color background that is visible through the line-screen patterns and the second color composition of the line-screen patterns producing the apparent solid-color background in the target color.

### Claim 13 (depends on 12)

The print medium of claim 12 in which the line-screen patterns of the latent image and the visually integrated setting have a matching print density.

### Claim 14 (depends on 13)

The print medium of claim 13 in which the line-screen patterns of the latent image and the visually integrated setting have a matching color composition.

### Claim 15 (depends on 12)

The print medium of claim 12 in which the target color is defined by a combination of color components and each of the first and second color compositions include one or more color components of the target combination of color components.

### Claim 16 (depends on 15)

The print medium of claim 15 in which each of the color components of the target combination of color components is exposed in the apparent solid-color background in a similar percentage as in the target combination of color components.

### Claim 17 (depends on 15)

The print medium of claim 15 in which the first color composition of the underlying solid-color background contributes to the target combination of color components in the apparent solid-color background in accordance with the percent departure of the print density from 100 percent, and the second color composition of the line-screen patterns contributes to the target combination of color components in the apparent solid-color background in accordance with the print density.

### Claim 18 (depends on 15)

The print medium of claim 15 in which a percent “TBC1” of one of the color components of the target combination of color components is matched by a percent “UBC1” of the same color component in the first color composition of the underlying solid-color background and a percent “LSC1” of the same color component in the second color composition of the overlying line-screen patterns in accordance with the print density “PD” of the line-screen patterns as follows:
TB
C
⁢
⁢
1
=
(
100
-
PD
)
100
*
UB
C
⁢
⁢
1
+
PD
100
*
LS
C
⁢
⁢
1
.

### Claim 19 (depends on 15)

The print medium of claim 15 in which the first color composition of the underlying solid-color background is defined by a percent reduction of the color components of the target combination of color components and the print density of the line-screen patterns matches this percent reduction.

### Claim 20 (depends on 15)

The print medium of claim 15 in which the color components of the target combination of color components are color components of the Pantone Matching System, and each of the first and second color compositions include one or more of the Pantone Matching System color components of the target combination of color components.

### Claim 21 (depends on 12)

The print medium of claim 12 in which the apparent solid-color background formed by the combination of the line-screen patterns and the underlying solid-color background has a luminosity of no more than 50 percent.

### Claim 22

A targeted solid-color printing system with covert imaging comprising
a targeted color,
a substrate printed with line-screen patterns having a first color over a solid-color background printed with a second color,
a first of the line-screen patterns embedding a latent image within a visually integrated setting formed by a second of the line-screen patterns, and
the line-screen patterns being arranged with a limited print density to form together with the solid-color background an uninterrupted tint in the targeted color.

### Claim 23 (depends on 22)

The printing system of claim 22 in which the first and second line-screen patterns are sufficiently similar so that the latent image is not readily distinguishable from the visually integrated setting without use of a visual aid.

### Claim 24 (depends on 23)

The printing system of claim 23 in which the visual aid is an at least partially transmissive viewing device incorporating a pattern matching one of the line-screen patterns.

### Claim 25 (depends on 23)

The printing system of claim 23 in which the line-screen patterns are arranged with line frequencies that cause the line-screen patterns to drop out as indistinguishable from the solid-color background upon conventional digital reproduction.

### Claim 26 (depends on 25)

The printing system of claim 25 in which the line frequencies of the first and second line-screen patterns are both around 180 lines per inch.

### Claim 27 (depends on 23)

The printing system of claim 23 in which the screen patterns are arranged with differing line frequencies that cause the latent image to become visible apart from both its visually integrated setting and the solid-color background upon conventional digital reproduction.

### Claim 28 (depends on 23)

The printing system of claim 23 in which a combination of the line-screen patterns and the solid-color background has a luminosity of no more than 50 percent so that upon conventional digital reproduction, the line-screen patterns are not reproduced in a color different from the solid-color background.

### Claim 29 (depends on 22)

The printing system of claim 22 in which the targeted color differs from of both the first color of the solid-color background and the second color of the line-screen patterns.

### Claim 30 (depends on 22)

The printing system of claim 22 in which the targeted color matches both the first color of the solid-color background and the second color of the line-screen patterns and the line-screen patterns vary in height on the substrate with respect to the solid-color background.

### Claim 31 (depends on 22)

The printing system of claim 22 in which the target color is defined by a combination of color components and each of the first and second colors includes one or more color components of the target combination of color components.

### Claim 32 (depends on 22)

The printing system of claim 22 in which a percent “TBC1” of one of the color components of the target combination of color components is matched by a percent “UBC1” of the same color component in the first color of solid-color background and a percent “LSC1” of the same color component in the second color of the line-screen patterns in accordance with the print density “PD” of the line-screen patterns as follows:
TB
C
⁢
⁢
1
=
(
100
-
PD
)
100
*
UB
C
⁢
⁢
1
+
PD
100
*
LS
C
⁢
⁢
1
.

### Claim 33

A targeted solid-color print medium comprising
a targeted color having a luminosity no greater than 50 percent,
a substrate printed with at least one line-screen pattern having a first color over a solid-color background printed with a second color, and
the at least one line-screen pattern having a line frequency of approximately 180 lines per inch and a limited print density to form together with the solid-color background an uninterrupted tint in the targeted color at the target color luminosity of no more than 50 percent so that the at least one line-screen pattern is not reproduced as line structures distinct from the solid-color background upon conventional digital reproduction.

### Claim 34 (depends on 33)

The print medium of claim 33 including visible graphic information printed over the solid-color background.

### Claim 35 (depends on 33)

The print medium of claim 33 in which the visible graphic information is printed over both the solid-color background and the line-screen pattern.

### Claim 36 (depends on 33)

The print medium of claim 33 in which the line-screen pattern is a first of two or more line-screen patterns, and a first of the line-screen patterns embeds a latent image within a visually integrated setting formed by a second of the line-screen patterns.

### Claim 37 (depends on 36)

The print medium of claim 36 in which the first and second line-screen patterns are sufficiently similar so that the latent image is not readily distinguishable from the visually integrated setting without use of a visual aid.

### Claim 38 (depends on 37)

The print medium of claim 37 in which the line-screen patterns are arranged with line frequencies that cause the line-screen patterns to drop out as indistinguishable from the solid-color background upon conventional digital reproduction.

### Claim 39 (depends on 38)

The print medium of claim 38 in which the line frequencies of the first and second line-screen patterns are both around 180 lines per inch.

### Claim 40 (depends on 36)

The print medium of claim 36 in which the target color is defined by a combination of color components and each of the first and second colors includes one or more color components of the target combination of color components.

### Claim 41 (depends on 40)

The print medium of claim 40 in which each of the color components of the target combination of color components is exposed in the uninterrupted tint in the target color in a similar percentage as in the target combination of color components.