Printing method

Patent metadata

Field	Value
Publication number	US-9667828-B2
Application number	US-201615067872-A
Country	US
Kind code	B2
Filing date	Mar 11, 2016
Priority date	Mar 13, 2015
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A printing method detects a density of a first black image to be printed in a first black color; determines, when the detected density is equal to a first density, a size of a first character to be embedded in the first black image to a first size, and prints the first character at the first size in a second black color with a transmissivity at a near infrared ray band that is different from that of the first black color; determines, when the detected density is lower than the first density, a size of the first character to a second size larger than the first size, and prints the first character at the second size in the second black color; and prints a region except a region in which the first character is to be printed in the first black image, in the first black color.

First claim

What is claimed is:

1. A printing method, comprising:
detecting a density of a first black image to be printed in a first black color;
determining, when the detected density is equal to a first density, a size of a first character to be embedded in the first black image to a first size, and printing the first character at the first size in a second black color with a transmissivity at a near infrared ray band that is different from that of the first black color;
determining, when the detected density is lower than the first density, a size of the first character to a second size larger than the first size, and printing the first character at the second size in the second black color; and
printing a region except a region in which the first character is to be printed in the first black image, in the first black color.

2. The printing method according to claim 1 , wherein:
the first black color is a color of a black (K) ink; and
the second black color is a color in which respective inks of cyan (C), magenta (M) and yellow (Y) are superposed;
further comprising:
detecting a first ratio of a black image in a first image of a print target;
dividing the first image of the print target into a second image to be printed with the CMY inks and the first black image to be printed with the K ink, at a prescribed ratio;
printing the second image with the CMY inks; and
printing the first image by synthesizing the second image and the first black image.

3. The printing method according to claim 2 , wherein:
when the first ratio is not more than a prescribed ratio, a ratio of the first black image in the division ratio is increased.

4. The printing method according to claim 2 , wherein:
the size of the first character is determined with reference to a table in which the density of the first black image and a size of a character to be embedded in the first image are associated with each other.

5. The printing method according to claim 1 , wherein:
in the first black image, the density varies depending on an area of dots per unit area.

6. The printing method according to claim 5 , wherein:
the size of the first character is determined so that a line width of the first character is longer than a distance between the dots.

7. The printing method according to claim 1 , wherein:
the first black color is a black color printed by laser engraving.

8. The printing method according to claim 1 , wherein:
to detect the density of the first black image to be printed in the first black color is to detect a density of a prescribed region in which a character is to be embedded in the first black image.

9. A printing method, comprising:
printing a first region that is at least a part of a first black image, using a first black color with a transmissivity of a light at a near infrared band that is a first transmissivity, at a second density which is not more than a first density that is previously set to the first region and corresponds to forgery preventing information; and
printing, when the second density is lower than the first density, the first region using a second black color with a transmissivity of a light at the near infrared band that is a second transmissivity different from the first transmissivity, so that a density of the first region becomes equal to the first density.

10. The printing method according to claim 9 , wherein:
the first region is a region of shape of a character code in the first black image.

11. The printing method according to claim 9 , further comprising:
printing a second region which is different from the first region in the first black image, using the first black color, at a density that is a reference of the first density.

12. The printing method according to claim 11 , wherein:
the second region has two regions in the first black image;
further comprising:
printing one region using the first black color, at an upper limit density of a density set for the first region; and
printing another region using the first black color, at a lower limit density of the density set to the first region.

13. The printing method according to claim 12 , wherein:
a density of the first region of the first black image is the first density.

14. The printing method according to claim 9 , wherein:
in the first black image, the density varies depending on an area of dots per unit area.

15. The printing method according to claim 9 , wherein:
the first black color is a color of a black (K) ink; and
the second black color is a color in which respective inks of cyan (C), magenta (M) and yellow (Y) are superposed;
further comprising:
detecting a first ratio of a black image in a first image of a print target;
dividing the first image of the print target into a second image to be printed with the CMY inks and the first black image to be printed with the K ink, at a prescribed ratio;
printing the second image with the CMY inks;
printing a region except the first region in the first black image, with the K ink; and
printing the first image by synthesizing the second image and the first black image.

Assignees

• Toshiba Kk

Inventors

• Nakano Takahisa
• Morimoto Fumitoshi
• Kure Shota
• Nemoto Nobuki

Classifications

• H04N1/6008

  with primary colour signals, e.g. RGB or CMY(K) · CPC title

• H04N1/6027

  Correction or control of colour gradation or colour contrast (H04N1/6058 takes precedence) · CPC title

• B41M5/26

  Thermography (B41M5/20, B41M5/24 take precedence); {Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used (B23K takes precedence; thermographic or photothermographic systems using noble metal compounds G03C1/494)} · CPC title

• B41M3/14

  Security printing {(securities B42D25/29)} · CPC title

• H04N1/0087

  with hidden additional data, e.g. data invisible to the human eye · CPC title