Image scanning device and image forming apparatus

• US 20090244649A1
• Filed: 03/25/2009
• Published: 10/01/2009
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Shinkawa, Shohei
• Granted Patent: US 8,248,670 B2
• Time in Patent Office: Days
• US Class Current: 358/474
• CPC Class Codes: H04N 1/0071 Width
• CPC Class Codes: H04N 1/00713 Length
• CPC Class Codes: H04N 1/00737 using the scanning elements as detectors
• CPC Class Codes: H04N 1/00748 Detecting edges, e.g. of a stationary sheet
• CPC Class Codes: H04N 1/00758 using a prescan
• CPC Class Codes: H04N 1/00795 Reading arrangements details of scanning heads H04N1/024; scanning arrangements therefor H04N1/04
• CPC Class Codes: H04N 1/00811 according to user specified instructions, e.g. user selection of reading mode
• CPC Class Codes: H04N 1/00814 according to a detected condition or state of the reading apparatus, e.g. temperature
• CPC Class Codes: H04N 1/0097 Storage of instructions or parameters, e.g. customised instructions or different parameters for different user IDs
• CPC Class Codes: H04N 1/1013 with sub-scanning by translatory movement of at least a part of the main-scanning components H04N1/107 takes precedence
• CPC Class Codes: H04N 1/193 using electrically scanned linear arrays , e.g. linear CCD arrays
• CPC Class Codes: H04N 2201/0081 Image reader H04N2201/0091 - H04N2201/0094 take precedence

Abstract

An image scanning device includes a document table; a document pressing unit configured to press a document placed on the document table; a scanning unit including a light source for illuminating the document and configured to optically scan the document; an open/close detection unit configured to detect opening and closing of the document pressing unit; and a control unit configured to cause the scanning unit to move parallel to the document and thereby to detect a size of the document when the closing of the document pressing unit is detected by the open/close detection unit or when a scanning start signal is detected. The control unit detects the size of the document within a document size detection period that is changeable according to a speed of closing the document pressing unit, and turns on and off the light source based on the document size detection period.

Claims

1. An image scanning device, comprising:

a document table;

a document pressing unit configured to press a document placed on the document table;

a scanning unit including a light source for illuminating the document and configured to optically scan the document;

an open/close detection unit configured to detect opening and closing of the document pressing unit; and

a control unit configured to cause the scanning unit to move parallel to the document and thereby to detect a size of the document when the closing of the document pressing unit is detected by the open/close detection unit or when a scanning start signal is detected;

wherein the control unit is configured to detect the size of the document within a document size detection period that is changeable according to a speed of closing the document pressing unit, and to turn on and off the light source based on the document size detection period.

2. The image scanning device as claimed in claim 1, wherein the document size detection period is fixed and an effective detection period for detecting the size of the document in the document size detection period is changeable according to the speed of closing the document pressing unit.

3. The image scanning device as claimed in claim 1, wherein the control unit is configured to turn on the light source after a predetermined period of time from a time when the closing of the document pressing unit is detected by the open/close detection unit.

4. The image scanning device as claimed in claim 1, wherein the document size detection period is changeable according to a type of the document pressing unit.

5. The image scanning device as claimed in claim 2, wherein the effective detection period is changeable according to a type of the document pressing unit.

6. The image scanning device as claimed in claim 4, wherein the control unit is configured to automatically detect the type of the document pressing unit and to change the document size detection period based on the detected type of the document pressing unit.

7. The image scanning device as claimed in claim 5, wherein the control unit is configured to automatically detect the type of the document pressing unit and to change the effective detection period based on the detected type of the document pressing unit.

8. The image scanning device as claimed in claim 1, wherein the control unit is configured to select different document size detection periods for a case where the closing of the document pressing unit is detected by the open/close detection unit and a case where the scanning start signal is detected while the document pressing unit is open.

9. The image scanning device as claimed in claim 2, wherein the control unit is configured to select different effective detection periods for a case where the closing of the document pressing unit is detected by the open/close detection unit and a case where the scanning start signal is detected while the document pressing unit is open.

10. An image forming apparatus including the image scanning device as claimed in claim 1.