Automatic document feeding device and image forming apparatus incorporating same

Patent metadata

Field	Value
Publication number	US-2016360073-A1
Application number	US-201615171009-A
Country	US
Kind code	A1
Filing date	Jun 2, 2016
Priority date	Jun 2, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

An automatic document feeding device includes a conveyance unit, an image reading unit, a color reference member, a moving assembly, and a drive source. The conveyance unit conveys a document to an image reading position. The image reading unit reads an image of the document. The color reference member faces the image reading unit and includes a white reference face to correct shading. The moving assembly relatively moves the image reading unit and the color reference member. The movement regulator regulates a relative movement of the image reading unit and the color reference member by the moving assembly. The drive source includes a common rotation output shaft to drive the conveyance unit and the moving assembly. The drive source changes the rotation output shaft from a forward rotation direction to a reverse rotation direction to reversely rotate the rotation output shaft to a set reverse rotation angle set in advance, according to a condition of conveyance of the document by the conveyance unit. In a rotation transmission route from the rotation output shaft to the moving assembly, the movement regulator is disposed in a first reverse rotation drive region from when a rotation direction of the rotation output shaft is changed to the reverse rotation direction to when a rotation angle of the rotation output shaft after the change in the reverse rotation direction reaches the set revere rotation angle. The moving assembly relatively moves the image reading unit and the color reference member in a second reverse rotation drive region where the rotation output shaft is rotated in the reverse rotation direction beyond the set reverse rotation angle.

First claim

What is claimed is:

1 . An automatic document feeding device comprising:
a conveyance unit to convey a document to an image reading position; an image reading unit to read an image of the document; a color reference member facing the image reading unit and including a white reference face to correct shading; a moving assembly to relatively move the image reading unit and the color reference member; a movement regulator to regulate a relative movement of the image reading unit and the color reference member by the moving assembly; and a drive source including a common rotation output shaft to drive the conveyance unit and the moving assembly, wherein the drive source changes the rotation output shaft from a forward rotation direction to a reverse rotation direction to reversely rotate the rotation output shaft to a set reverse rotation angle set in advance, according to a condition of conveyance of the document by the conveyance unit, wherein, in a rotation transmission route from the rotation output shaft to the moving assembly, the movement regulator is disposed in a first reverse rotation drive region from when a rotation direction of the rotation output shaft is changed to the reverse rotation direction to when a rotation angle of the rotation output shaft after the change in the reverse rotation direction reaches the set revere rotation angle, and wherein the moving assembly relatively moves the image reading unit and the color reference member in a second reverse rotation drive region where the rotation output shaft is rotated in the reverse rotation direction beyond the set reverse rotation angle.

2 . The automatic document feeding device according to claim 1 ,
wherein the movement regulator includes a pair of rotation transmitters relatively rotatable within a delay angle set in advance in the rotation transmission route from the rotation output shaft to the moving assembly, and wherein the moving assembly delays an operation to relatively move the image reading unit and the color reference member to positions where the image reading unit and the color reference member are used to correct shading, by relative rotation of the pair of rotation transmitters, from when the rotation direction of the rotation output shaft is changed to the reverse rotation direction to when the rotation output shaft reaches the second reverse rotation drive region.

3 . The automatic document feeding device according to claim 2 ,
wherein the movement regulator includes a collar member relatively rotatable within the delay angle with respect to one rotation transmitter of the pair of rotation transmitters disposed at a side of the rotation output shaft, wherein the collar member engages the other rotation transmitter of the pair of rotation transmitters disposed at a side of the moving assembly, to allow rotation transmission only in the reverse rotation direction.

4 . The automatic document feeding device according to claim 3 ,
wherein the collar member includes a first engagement portion engageable with and detachable from the one rotation transmitter in a direction of rotation, a second engagement portion to engage the other rotation transmitter to allow rotation transmission only in the reverse rotation direction, and a ringed protection wall that surrounds the first engagement portion and the second engagement portion.

5 . The automatic document feeding device according to claim 2 ,
wherein the movement regulator includes a deceleration gear assembly in a rotation transmission route from the rotation output shaft to the one rotation transmitter, to decelerate rotation from the rotation output shaft.

6 . The automatic document feeding device according to claim 1 , further comprising:
a document mount table disposed upstream from the conveyance unit in a direction of conveyance of the document; a call roller to call the document on the document mount table to the conveyance unit; and an elevation assembly to lower the call roller to approach a document mount surface of the document mount table according to a forward rotation of the rotation output shaft in the forward rotation direction, and to raise the call roller to be separated from the document mount surface of the document mount table according to a reverse rotation of the rotation output shaft in the reverse rotation direction, wherein the elevation assembly raises the call roller to a stand-by position above the document mount table from when the drive source changes the rotation direction of the rotation output shaft to the reverse rotation direction to when the rotation angle of the rotation output shaft in the reverse rotation direction reaches the set reverse rotation angle.

7 . The automatic document feeding device according to claim 1 ,
wherein the movement regulator includes a pair of rotation transmitters in the rotation transmission route from the rotation output shaft to the moving assembly, and a switching operation member to be able to switch the pair of rotation transmitters to a rotation transmittable connection state and an interruption state of interrupting the rotation transmission, wherein a spring clutch is interposed between the pair of rotation transmitters, wherein, according to a twist direction due to the relative rotation of the pair of rotation transmitters, the spring clutch is switchable to a fastened state where the spring clutch regulates the relative rotation in a first twist direction and a loosened state where the spring clutch allows the relative rotation in a second twist direction opposite to the first twist direction, wherein the switching operation member includes a base end coupled via a bidirectional torque limiter to any one of the plurality of rotation transmitters disposed in the rotation transmission route from the rotation output shaft to the elevation assembly, and a rotation stopper to engage a driven-side rotation transmitter of the pair of rotation transmitters disposed at the side of the moving assembly to allow rotation regulation when the rotation output shaft is rotated in the reverse rotation direction, and wherein, when rotation of the driven-side rotation transmitter is regulated by the rotation stopper of the switching operation member, the spring clutch is switched to the loosened state where the relative rotation of the pair of rotation transmitters in the second twist direction is allowed.

8 . The automatic document feeding device according to claim 7 , further comprising a sheet feeding clutch disposed in the rotation transmission route from the rotation output shaft to the elevation assembly, the sheet feeding clutch configured to connect and interrupt the rotation transmission route according to operations of the conveyance unit and the moving assembly,
wherein the switching operation member switches engagement and detachment of the rotation stopper with respect to the driven-side rotation transmitter when the sheet feeding clutch is in a connection state of connecting the rotation transmission route.

9 . An image forming apparatus comprising:
the automatic document feeding device according to claim 1 ; an image forming unit configured to form an external output image based on a read image in the image reading unit of the automatic document feeding device; and a controller configured to rotate the rotation output shaft in the reverse rotation direction beyond the set reverse rotation angle and relatively move the image reading unit and the color reference member, when a number of times of image formation in the image forming unit reaches a period corresponding to a number of times of shading correction requests set in advance, and to execute the shading correction of the image formed i

Assignees

• Hatayama Koji
• Andoh Takayuki
• Nagano Tatsuaki
• Tada Kaoru
• Hirata Munekazu
• Kawamura Kazushige
• Horikawa Toshiyuki
• Kawai Takuji
• Osanai Yohei
• Youda Yasunobu
• Ricoh Co Ltd

Inventors

• Hatayama Koji
• Andoh Takayuki
• Nagano Tatsuaki
• Tada Kaoru
• Hirata Munekazu
• Kawamura Kazushige
• Horikawa Toshiyuki
• Kawai Takuji
• Osanai Yohei
• Youda Yasunobu

Classifications

• B65H3/0669

  Driving devices therefor · CPC title

• B65H2513/50

  Timing · CPC title

• H04N2201/0094

  Multifunctional device, i.e. a device capable of all of reading, reproducing, copying, facsimile transception, file transception · CPC title

• H04N1/0032

  with a medium handling apparatus, e.g. a sheet sorter (handling thin or filamentary material, e.g. sheets B65H) · CPC title

• B65H2403/00

  Power transmission; Driving means · CPC title