IMAGE READING DEVICE, IMAGE READING METHOD, AND NON-TRANSITORY COMPUTER-READABLE MEDIUM

• US 20170208208A1
• Filed: 01/04/2017
• Published: 07/20/2017
• Est. Priority Date: 01/19/2016
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: FUJII, Yuki, YOUDA, Yasunobu, NARAI, Satoshi, KAWAI, Takuji, MIYAZAKI, Susumu, INUI, Tetsuo, ONO, Koichi, SHIKAMA, Takeshi, SHIRAMURA, Shingo, TANAKA, Hideo, OSANAI, Yohei, NAGANO, Tatsuaki, HORIKAWA, Toshiyuki, ANDOH, Takayuki, IMAKI, Daisuke
• Granted Patent: US 10,200,564 B2
• Time in Patent Office: Days
• CPC Class Codes: H04N 1/00718 Skew
• CPC Class Codes: H04N 1/00745 Detecting the leading or trailing ends of a moving sheet
• CPC Class Codes: H04N 1/00769 Comparing, e.g. with threshold
• CPC Class Codes: H04N 1/04 Scanning arrangements , i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versaH04N1/387 takes precedence
• CPC Class Codes: H04N 1/0473 in subscanning direction, e.g. picture start or line-to-line synchronisation
• CPC Class Codes: H04N 1/3878 Skew detection or correction
• CPC Class Codes: H04N 2201/0081 Image reader H04N2201/0091 - H04N2201/0094 take precedence

Abstract

An image reading device includes: a reading unit; a first detecting unit that detects a position of the reading unit in the sub-scanning direction; a second detecting unit that detects a position of the reading unit in the sub-scanning direction; and a calculating unit that calculates a skew quantity and a skew direction of the reading unit, based on a difference, introduced by the skew, between a travel distance by which the reading unit has travelled from a measurement reference position located on an upstream side of the first detecting unit and the second detecting unit in a moving direction to a point where the reading unit is detected by the first detecting unit, and a travel distance by which the reading unit has travelled from the measurement reference position to a point where the reading unit is detected by the second detecting unit.

Claims

1. An image reading device comprising:

a reading unit configured to include a scanning section extending in a main scanning direction, and configured to optically read an image of an original;

a driving unit configured to move the reading unit in a sub-scanning direction;

a first detecting unit configured to detect a position of the reading unit in the sub-scanning direction;

a second detecting unit configured to be disposed at a position different from that of the first detecting unit in the main scanning direction, and configured to detect a position of the reading unit in the sub-scanning direction; and

a calculating unit configured to calculate a skew quantity and a skew direction of the reading unit, based on a difference, introduced by the skew, between a travel distance by which the reading unit has travelled from a measurement reference position located on an upstream side of the first detecting unit and the second detecting unit in a moving direction to a point where the reading unit is detected by the first detecting unit, and a travel distance by which the reading unit has travelled from the measurement reference position to a point where the reading unit is detected by the second detecting unit.

2. The image reading device according to claim 1, wherein the second detecting unit and the first detecting unit are disposed interspaced with respect to each other in the sub-scanning direction.

3. The image reading device according to claim 1, further comprising a non-volatile storage unit configured to store therein an interspace distance in the main scanning direction, and an interspace distance in the sub-scanning direction, between the first detecting unit and the second detecting unit.

4. The image reading device according to claim 1, wherein the first detecting unit is configured to detect one end of the reading unit in the main scanning direction, and the second detecting unit is configured to detect the other end of the reading unit in the main scanning direction.

5. The image reading device according to claim 1, further comprising a skew correcting unit configured to correct skew in the image of the original read by the reading unit, based on the skew direction and the skew quantity of the reading unit, calculated by the calculating unit.

6. The image reading device according to claim 1, wherein when the skew quantity of the reading unit calculated by the calculating unit is equal to or greater than a threshold, the driving unit is configured to move the reading unit in the sub-scanning direction in such a manner that the skew of the reading unit is corrected.

7. The image reading device according to claim 1, further comprising a notifying unit configured to, when the skew quantity of the reading unit calculated by the calculating unit is equal to or greater than a threshold, notify outside that the skew quantity has exceeded the threshold.

8. The image reading device according to claim 6, further comprising an input unit configured to receive an input of the threshold of the skew quantity from the outside.

9. The image reading device according to claim 7, further comprising an input unit configured to receive an input of the threshold of the skew quantity from the outside.

10. An image reading method performed by an image reading device, the image reading device including:

a reading unit configured to include a scanning section extending in a main scanning direction, and configured to optically read an image of an original;

a driving unit configured to move the reading unit in a sub-scanning direction;

a first detecting unit configured to detect a position of the reading unit in the sub-scanning direction; and

a second detecting unit configured to be disposed at a position different from that of the first detecting unit in the main scanning direction, and configured to detect a position of the reading unit in the sub-scanning direction, the image reading method comprising

calculating a skew quantity and a skew direction of the reading unit based on a difference, introduced by the skew, between a travel distance by which the reading unit has travelled from a measurement reference position located on an upstream side of the first detecting unit and the second detecting unit in a moving direction to a point where the reading unit is detected by the first detecting unit, and a travel distance by which the reading unit has travelled from the measurement reference position to a point where the reading unit is detected by the second detecting unit.

11. A non-transitory computer-readable medium comprising computer readable program codes, performed by a processor configured to control an image reading device, the image reading device including:

a reading unit configured to include a scanning section extending in a main scanning direction, and configured to optically read an image of an original;

a driving unit configured to move the reading unit in a sub-scanning direction;

a first detecting unit configured to detect a position of the reading unit in the sub-scanning direction; and

a second detecting unit configured to be disposed at a position different from that of the first detecting unit in the main scanning direction, and configured to detect a position of the reading unit in the sub-scanning direction, the program codes when executed causing the processor to execute;

calculating a skew quantity and a skew direction of the reading unit based on a difference, introduced by the skew, between a travel distance by which the reading unit has travelled from a measurement reference position located on an upstream side of the first detecting unit and the second detecting unit in a moving direction to a point where the reading unit is detected by the first detecting unit, and a travel distance by which the reading unit has travelled from the measurement reference position to a point where the reading unit is detected by the second detecting unit.