DOCUMENT READING DEVICE, IMAGE FORMING APPARATUS, DOCUMENT READING METHOD, AND COMPUTER-READABLE STORAGE MEDIUM

• US 20140078532A1
• Filed: 08/20/2013
• Published: 03/20/2014
• Est. Priority Date: 09/14/2012
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: NIKAKU, Daisuke
• Granted Patent: US 8,970,861 B2
• Time in Patent Office: Days
• US Class Current: 358/1.13
• CPC Class Codes: G03G 15/00 Apparatus for electrographic processes using a charge pattern G03G16/00, G03G17/00 take precedence ; xerographic printers for data processors per se G06K15/14
• CPC Class Codes: G03G 15/60 Apparatus which relate to the handling of originals for photographic purposes in general G03B
• CPC Class Codes: G03G 2215/00189 original moving
• CPC Class Codes: G03G 2215/0129 horizontal medium transport path at the secondary transfer
• CPC Class Codes: H04N 1/00 Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
• CPC Class Codes: H04N 1/00814 according to a detected condition or state of the reading apparatus, e.g. temperature
• CPC Class Codes: H04N 1/1061 Details relating to flat picture-bearing surfaces, e.g. transparent platen
• CPC Class Codes: H04N 1/401 Compensating positionally unequal response of the pick-up or reproducing head H04N1/403 takes precedence

Abstract

An image reading device includes a document reading unit configured to guide light emitted from a light source to a photoelectric conversion unit to read an image on the document; a driving unit configured to drive the document reading unit so that the document reading unit reciprocates along the document; a reading position obtaining unit configured to obtain a home position at which the document reading unit is in a stopped state when starting a read operation; a dark time data obtaining unit configured to obtain dark time output data of the photoelectric conversion unit while the light source is turned off; and a read control unit configured to perform control for causing the driving unit to return the document reading unit to the home position and entering a document read operation to read a document image after the dark time data obtaining unit obtains the dark time output data.

Claims

1. An image reading device comprising:

a light source configured to emit light to a document to be read;

a document reading unit configured to guide the light emitted from the light source to a photoelectric conversion unit to read an image on the document;

a driving unit configured to drive the document reading unit so that the document reading unit reciprocates along the document;

a document reading position obtaining unit configured to obtain a home position at which the document reading unit is in a stopped state when starting a read operation;

a dark time data obtaining unit configured to obtain dark time output data of the photoelectric conversion unit while the light source is turned off; and

a read control unit configured to perform control for causing the driving unit to return the document reading unit to the home position and entering a document read operation to read a document image after the dark time data obtaining unit obtains the dark time output data.

2. The document reading device according to claim 1, further comprising a white reference plate for obtaining white reference data for image data correction,

wherein an optical axis of the document reading unit is located directly under the white reference plate.

3. The document reading device according to claim 1, further comprising an open/closed state obtaining unit configured to obtain an open/closed state of a document pressing unit for holding a document,

wherein, when starting a read operation in a state where the open/closed state obtaining unit detects that the document pressing unit is in a closed state, the read control unit causes the document reading unit to stop at the home position, and enters the document read operation after obtaining dark time output data from the photoelectric conversion unit in a state where the light source is in a turned-off state.

4. The document reading device according to claim 3, wherein, when the open/closed state obtaining unit detects that the document pressing unit is in an open state, the read control unit causes the image reading unit to move to a position at which the dark time output data is obtained and be put on standby.

5. The document reading device according to claim 4, wherein, after finishing an operation for obtaining the dark time output data, the read control unit performs control for starting turning on the light source of the image reading unit during a period when the image reading unit is moved to the stop position as the home position.

6. The document reading device according to claim 1, wherein

the document pressing unit is an automatic document feeder having a document feeding function, and

the document pressing unit includes

a second document reading unit different from the document reading unit inside the automatic document feeder, and

a simultaneous double-sided reading unit configured to read both sides of a double-sided document by feeding the double-sided document through the second document reading unit only once.

7. The document reading device according to claim 6, wherein the second document reading unit is formed from same components as the document reading unit.

8. An image forming apparatus comprising:

the image reading device according to claim 1; and

an image forming unit configured to perform image forming based on an image signal of the document, the image signal being output from the image reading device.

9. A document reading method performed in an image reading device that includes a light source configured to emit light to a document to be read, a document reading unit configured to guide the light emitted from the light source to a photoelectric conversion unit to read an image on the document, and a driving unit configured to drive the document reading unit so that the document reading unit reciprocates along the document, the document reading method comprising:

obtaining a home position at which the document reading unit is in a stopped state when starting a read operation;

obtaining dark time output data of the photoelectric conversion unit while the light source is turned off; and

performing control for causing the driving unit to return the document reading unit to the home position and entering a document read operation to read a document image after the dark time output data is obtained.

10. A non-transitory computer-readable storage medium with an executable program stored thereon and executed by a computer that includes a light source configured to emit light to a document to be read, a document reading unit configured to guide the light emitted from the light source to a photoelectric conversion unit to read an image on the document, and a driving unit configured to drive the document reading unit so that the document reading unit reciprocates along the document, wherein the program instructs the computer to perform:

obtaining a home position at which the document reading unit is in a stopped state when starting a read operation;

obtaining dark time output data of the photoelectric conversion unit while the light source is turned off; and

performing control for causing the driving unit to return the document reading unit to the home position and entering a document read operation to read a document image after the dark time output data is obtained.