Method and image forming apparatus, and printing system for recording invisible information recording
First Claim
Patent Images
1. An invisible information recording method comprising:
- extracting a location of at least one blank area of a page image of a sheet of paper, wherein said location of said at least one blank area is different from a location of an image, which is visible to the naked eye, of said page image of said sheet of paper; and
recording a digital image on said location of said at least one blank area on said sheet of paper;
wherein said digital image comprises information in the form of pixels so sized as to be invisible to a naked eye and at a print density invisible to the naked eye,wherein said extracting comprises extracting a plurality of locations of blank areas from said page image of said sheet of paper,wherein said plurality of locations of blank areas extracted from said page image of said sheet of paper include at least one blank area which is located in a position on said page image of said sheet of paper other than a location of a margin of said sheet of paper,wherein no part of said digital image is recorded in said location of said image of said page image of the sheet of paper, andwherein a print density invisible to the naked eye is such that the pixels each so sized as to be invisible to the naked eye are coarsely distributed and an image density is 0.1 or less.
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Abstract
Invisible information are recorded in the form of pixels invisible to the naked eye and at a print density invisible to the naked eye.
28 Citations
23 Claims
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1. An invisible information recording method comprising:
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extracting a location of at least one blank area of a page image of a sheet of paper, wherein said location of said at least one blank area is different from a location of an image, which is visible to the naked eye, of said page image of said sheet of paper; and recording a digital image on said location of said at least one blank area on said sheet of paper; wherein said digital image comprises information in the form of pixels so sized as to be invisible to a naked eye and at a print density invisible to the naked eye, wherein said extracting comprises extracting a plurality of locations of blank areas from said page image of said sheet of paper, wherein said plurality of locations of blank areas extracted from said page image of said sheet of paper include at least one blank area which is located in a position on said page image of said sheet of paper other than a location of a margin of said sheet of paper, wherein no part of said digital image is recorded in said location of said image of said page image of the sheet of paper, and wherein a print density invisible to the naked eye is such that the pixels each so sized as to be invisible to the naked eye are coarsely distributed and an image density is 0.1 or less. - View Dependent Claims (2, 3, 4, 5, 6, 7, 13, 14, 18, 19, 20, 21)
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8. An invisible information recording method comprising:
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extracting a location of at least one blank area of a page image of a sheet of paper, wherein said location of said at least one blank area is different from a location of an image, which is visible to the naked eve, of said page image of said sheet of paper; and recording a digital image on said location of said at least one blank area on said sheet of paper; wherein said digital image comprises information in the form of pixels so sized as to be invisible to a naked eye and at a print density invisible to the naked eye, wherein said extracting comprises extracting a plurality of locations of blank areas from said page image of said sheet of paper, wherein each of the pixels so sized as to be invisible to the naked eve is 75 μ
m or less in diameter, andwherein a print density invisible to the naked eye is such that the pixels each so sized as to be invisible to the naked eye are coarsely distributed and an image density is 0.1 or less.
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9. An invisible information recording method comprising:
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extracting a location of at least one blank area of a page image of a sheet of paper, wherein said location of said at least one blank area is different from a location of an image. which is visible to the naked eye, of said page image of said sheet of paper; and recording a digital image on said location of said at least one blank area on said sheet of paper; wherein said digital image comprises information in the form of pixels so sized as to be invisible to a naked eye and at a print density invisible to the naked eye, wherein said extracting comprises extracting a plurality of locations of blank areas from said page image of said sheet of paper, and wherein each print density invisible to the naked eye is such that such a block that one or a plurality of image forming elements of a digital image forming apparatus is a representative point in a unit consisting of 16 image forming elements is a recording unit. - View Dependent Claims (10, 11, 12)
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15. A printing system including an archiving printer which prints a document upon receipt of a request of printing the document, and at the same time stores the document as document data into an archive, and upon receipt of a request of reprinting the document stored, reprints the document by using the document data stored in the archive, the archiving printer comprising:
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a blank area extracting section that extracts locations of a plurality of blank areas in a page image of a document, wherein'"'"' said locations of each of said plurality of blank areas is different from a location of an image, which is visible to the naked eye, in said page image of said document; and a recording section for recording archive management information on storage locations of documents in the archiving printer in to at least one of said plurality of blank areas of said document when the document is printed, in a state that the information is invisible to the human eye or needs a careful watching to see the information; a reading section for reading out the information being recorded in the printed document in a state that the information is invisible to the human eye or needs a careful watching to see the information, by reproducing the document printed by the archiving printer by means of reproducing means; and a knowing section for knowing the archive management information of the printed document from the read out information, wherein said plurality of locations of blank areas extracted from said page image of said sheet of paper include at least one blank area which is located in a position on said page image of said sheet of paper other than a location of a margin of said sheet of paper, wherein no part of said digital image is recorded in said location of said image of said page image of the sheet of paper, and wherein the state of the information which is invisible to the human eye is such that pixels of the information each so sized as to be invisible to the human eye are coarsely distributed and an image density is 0.1 or less. - View Dependent Claims (16, 17, 23)
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22. An invisible information recording method comprising:
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extracting locations of a plurality of blank areas of a page image of a sheet of paper, wherein each of said locations of said blank areas are different from locations of images, which are visible to the naked eye, of said page image of said sheet of paper; and recording a plurality of image forming elements used for a device for forming a digital image in said locations of said blank areas on said sheet of paper; wherein said digital image comprises information in the form of pixels so sized as to be invisible to a naked eye and at a print density invisible to the naked eye, wherein a print density invisible to the naked eye is such that the pixels each so sized as to be invisible to the naked eye are coarsely distributed and an image density is 0.1 or less, wherein said recorded information comprises at least one of a horizontal arrangement and a vertical arrangement in said blank areas of said page image of said sheet of paper, and wherein said recording the digital image comprises recording a copy of at least a portion of said information into at least one other location of said plurality of locations of said blank areas.
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Specification