Sheet detecting apparatus, sheet conveying apparatus, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-2017305697-A1
Application number	US-201715643632-A
Country	US
Kind code	A1
Filing date	Jul 7, 2017
Priority date	Feb 8, 2012
Publication date	Oct 26, 2017
Grant date	—

Abstract

A sheet detecting apparatus has an abutment member against which a leading edge of a conveyed sheet abuts, a holding member with positioning portion to hold the abutment member, and an indicator flag moving in association with movement of the abutment member. The abutment member moves between an abutment position and a retracted position, the holding member moves between a first position and a second position retracted from the first position, the abutment member is pushed by the leading edge of the sheet when the holding member is at the first position, the push moves the holding member the second position, the holding member is moves in a direction away from the first position so that the leading edge of the sheet is separated from the abutment surface, and the holding member moves from the second position to the first position when the abutment member is pushed by the sheet to the retracted position.

First claim

1 . A sheet detecting apparatus configured to detect a sheet on a sheet conveying path on which the sheet is conveyed, the sheet detecting apparatus comprising:
an abutment member having an abutment surface against which a leading edge of a sheet being conveyed abuts; a holding member having a positioning portion and configured to hold the abutment member; and a flag configured to move in association with movement of the abutment member in order to change indication of detection by a detecting portion, wherein the abutment member is movable between an abutment position in which the abutment member is positioned with respect to the holding member while contacting the positioning portion so that the leading edge of the sheet abuts against the abutment surface and a retracted position in which positioning of the abutment member with respect to the holding member is released and the leading edge of the sheet does not abut against the abutment surface, wherein the holding member is movable between a first position and a second position retracted from the first position, wherein the abutment surface is pushed by the leading edge of the sheet in a waiting state in which the abutment member is located at the abutment position and the holding member is located at the first position, and the holding member is moved from the first position toward the second position while the abutment member contacts the positioning portion, and wherein the holding member is moved in a direction away from the first position so that the leading edge of the sheet is separated from the abutment surface, and the holding member is moved from the second position to the first position in a state in which the abutment member is pushed by a surface of the sheet to be moved to the retracted position.

2 . A sheet detecting apparatus according to claim 1 , further comprising a first urging portion configured to urge the holding member.

3 . A sheet detecting apparatus according to claim 2 , further comprising a second urging portion configured to urge the holding member.

4 . A sheet detecting apparatus according to claim 1 , wherein the abutment member is rotatable about a first rotary shaft with respect to the holding member.

5 . A sheet detecting apparatus according to claim 4 , wherein the holding member is rotatable about a second rotary shaft different from the first rotary shaft.

6 . A sheet detecting apparatus according to claim 1 , further comprising a conveying portion configured to form a nip portion to nip and convey the sheet, wherein in a case where the holding member is located at the first position, the abutment surface of the abutment member is located upstream of the nip portion in a sheet conveying direction.

7 . A sheet detecting apparatus according to claim 6 , wherein the conveying portion comprises a roller pair including a first roller and a second roller, and
wherein the holding member is provided on a side of the second roller.

8 . A sheet detecting apparatus according to claim 2 , wherein in a case where the holding member is moved from the first position to the second position, the holding member is moved against an urging force of the first urging portion.

9 . A sheet detecting apparatus according to claim 7 , wherein in a state in which the sheet is nipped by the nip portion and the holding member is located at the second position, the abutment member is located closer to the side of the second roller than the first roller.

10 . A sheet detecting apparatus according to claim 1 , wherein the abutment member is provided in each position of a plurality of positions in a width direction intersecting with a sheet conveying direction.

11 . A sheet detecting apparatus according to claim 1 , further comprising a stopper configured to position the holding member in the first position.

12 . An image forming apparatus comprising:
a sheet detecting apparatus; and an image forming portion configured to form an image on a sheet, the sheet detecting apparatus comprising:
an abutment member having an abutment surface against which a leading edge of a sheet being conveyed abuts;
a holding member having a positioning portion and configured to hold the abutment member; and
a flag configured to move in association with movement of the abutment member in order to change an indication of detection by a detecting portion,
wherein the abutment member is movable between an abutment position in which the abutment member is positioned with respect to the holding member while contacting the positioning portion so that the leading edge of the sheet abuts against the abutment surface and a retracted position in which positioning of the abutment member with respect to the holding member is released and the leading edge of the sheet does not abut against the abutment surface, wherein the holding member is movable between a first position and a second position retracted from the first position, wherein the abutment surface is pushed by the leading edge of the sheet in a waiting state in which the abutment member is located at the abutment position and the holding member is located at the first position, and the holding member is moved from the first position toward the second position while the abutment member contacts the positioning portion, and wherein the holding member is moved in a direction away from the first position so that the leading edge of the sheet is separated from the abutment surface, and the holding member is moved from the second position to the first position in a state in which the abutment member is pushed by a surface of the sheet to be moved to the retracted position.

Assignees

• Canon Kk

Inventors

• Iizuka Yoichiro

Classifications

• B65H2403/531

  Planar mechanisms · CPC title

• B65H2513/53

  Operations & Transport · mapped topic

• B65H5/062

  between rollers or balls · CPC title

• B65H7/14 Primary

  by photoelectric feelers or detectors · CPC title

• B65H2511/20

  Location in space · CPC title