PAPER SHEET IDENTIFICATION DEVICE AND PAPER SHEET IDENTIFICATION METHOD

• US 20090263020A1
• Filed: 08/31/2006
• Published: 10/22/2009
• Est. Priority Date: 08/31/2006
• Status: Active Grant

• Current Assignee: Glory Limited
• Original Assignee: Glory Limited
• Inventors: Ohmatsu, Kazuhiro, Hamasaki, Hiroki, Kasuya, Tomohiko
• Granted Patent: US 8,606,013 B2
• Time in Patent Office: Days
• US Class Current: 382/181
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G07D 7/187 Detecting defacement or contamination, e.g. dirt
• CPC Class Codes: G07D 7/2041 Matching statistical distributions, e.g. of particle sizes orientations

Abstract

A paper sheet identification device that detects a stain on a paper sheet and identifies the stained condition of the paper sheet includes an area memory (12) that stores therein in advance an area where a stain is to be detected on the paper sheet as a target detection area, a pixel number memory (11) that stores therein in advance the number of pixels of an image printed on the target detection area as the reference number of pixels used as a reference value when being compared, an image reading unit (13) that, based on the target detection area stored in the area memory, reads an image on the target detection area from the paper sheet, a pixel-number detection unit (14) that detects the number of pixels in the image read by the image reading unit as the number of read pixels, and a calculation unit (15) that calculates a stain value that indicates a stained condition on the target detection area of the paper sheet, by comparing the number of read pixels detected by the pixel-number detection unit with the reference number of pixels stored in the pixel number memory.

Claims

1. A paper sheet identification device for identifying a stained condition of a paper sheet by detecting a stain on the paper sheet, the paper sheet identification device comprising:

an area memory that stores therein in advance information about an area where a stain is to be detected on the paper sheet as information about a target detection area;

a pixel number memory that stores therein in advance a number of pixels in an image printed on the target detection area as a reference number of pixels used as a reference value when being compared;

an image reading unit that, based on the information about the target detection area stored in the area memory, reads an image on the target detection area from the paper sheet;

a pixel-number detection unit that detects a number of pixels in the image read by the image reading unit as number of read pixels; and

a calculation unit that calculates a stain value indicating a stained condition on the target detection area of the paper sheet, by comparing the number of read pixels detected by the pixel-number detection unit and the reference number of pixels stored in the pixel number memory.

2. The paper sheet identification device according to claim 1, further comprising:

a reference-stain-value memory that stores therein in advance a reference stain value used as a reference to determine whether a stain is present, when it is determined whether a stain is present on the target detection area; and

a determination unit that, based on the stain value calculated by the calculation unit and the reference stain value stored in the reference-stain-value memory, determines whether a stain is present on the target detection area.

3. The paper sheet identification device according to claim 1, further comprising:

a paper-sheet-type discrimination unit that discriminates a type of the paper sheet, wherein

the image reading unit reads an image on the target detection area corresponding to a type of the paper sheet discriminated by the paper-sheet-type discrimination unit from the paper sheet, and

the calculation unit calculates the stain value by comparing the reference number of pixels corresponding to the type of the paper sheet discriminated by the paper-sheet-type discrimination unit and the number of read pixels.

4. The paper sheet identification device according to claim 3, wherein the determination unit, based on the stain value calculated by the calculation unit and a reference stain value corresponding to the type of the paper sheet discriminated by the paper-sheet-type discrimination unit, determines whether a stain is present on the target detection area.

5. The paper sheet identification device according to claim 1, wherein the target detection area is an area on the paper sheet where a portrait is drawn.

6. The paper sheet identification device according to claim 2, wherein, when the image reading unit reads an image corresponding to each target detection area from a plurality of target detection areas, the determination unit determines whether a stain is present on each of the target detection areas depending on importance of each of the target detection areas.

7. The paper sheet identification device according to claim 1, further comprising:

a display unit that displays an identification result of the stained condition of the paper sheet, wherein

the display unit displays a determination result of whether a stain is present on the target detection area as the identification result of the stained condition of the paper sheet.

8. The paper sheet identification device according to claim 7, wherein the display unit displays the stain value calculated by the calculation unit.

9. The paper sheet identification device according to claim 1, wherein the target detection area is an area set by referring to a print original point on the paper sheet.

10. A paper sheet identification method for identifying a stained condition of the paper sheet by detecting a stain on a paper sheet, the paper sheet identification method comprising:

setting in advance an area where a stain is to be detected on the paper sheet as a target detection area and setting in advance a number of pixels in an image printed on the target detection area as a reference number of pixels used as a reference value when being compared;

reading an image on the target detection area from the paper sheet, based on the target detection area set in advance;

detecting a number of pixels in the read image, as a number of read pixels; and

calculating a stain value indicating a stained condition on the target detection area of the paper sheet, by comparing the number of read pixels detected and the reference number of pixels set in advance.