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

Patent metadata

Field	Value
Publication number	US-2016101956-A1
Application number	US-201514969470-A
Country	US
Kind code	A1
Filing date	Dec 15, 2015
Priority date	Feb 8, 2012
Publication date	Apr 14, 2016
Grant date	—

Abstract

A sheet detecting apparatus including: a detection unit including a lever member having an abutment surface abutting a conveying sheet and a holding member configured to hold the lever member, the detection unit moved by the lever member pushed by the sheet; a first urging portion configured to urge the holding member to a waiting position after the sheet is separated from the abutment surface; a support portion configured to support the lever member movable with respect to the holding member to move the lever member to a retracted position for allowing the sheet to pass the lever member contacting a surface of the sheet when the holding member is in the waiting position; and a second urging portion configured to urge the lever member so that the lever member is moved from the retracted position to a position in which the abutment surface abuts a succeeding sheet.

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:
a detection unit including a lever member having an abutment surface against which a leading edge of the sheet being conveyed on the sheet conveying path abuts, and a holding member configured to hold the lever member, the lever member and the holding member being configured to move integrally with each other when the lever member is pushed by the leading edge of the sheet being conveyed; a detection sensor configured to output a signal corresponding to a position of the detection unit; a first urging portion configured to urge the holding member so as to move the holding member to a waiting position after the lever member and the holding member integrally move with each other by the sheet being conveyed; a movable support portion configured to support the lever member in a manner that the lever member is movable with respect to the holding member so that the lever member is located in a retracted position in which the lever member allows the sheet to pass the lever member in contact with a surface of the sheet being conveyed in a state in which the holding member is located in the waiting position; and a second urging portion configured to urge the lever member in a manner that the lever member is moved from the retracted position to a position in which the abutment surface of the lever member abuts against a leading edge of a succeeding sheet as a trailing edge of the sheet passes the lever member.

2 . A sheet detecting apparatus according to claim 1 ,
wherein the movable support portion rotatably supports the lever member.

3 . A sheet detecting apparatus according to claim 1 ,
wherein, after the leading edge of the sheet, which has moved the lever member and the holding member integrally with each other, is separated from the abutment surface, the holding member is located in the waiting position and the lever member is rotated relative to the holding member when the lever member moves to the retracted position.

4 . A sheet detecting apparatus according to claim 1 ,
further comprising a pressing member configured to press the lever member so as to move the lever member relative to the holding member when the holding member is rotated by being pushed by the sheet.

5 . A sheet detecting apparatus according to claim 1 ,
wherein the holding member comprises a regulating portion configured to regulate movement of the lever member by the regulating member abutting against the lever member urged by the second urging portion.

6 . A sheet detecting apparatus according to claim 5 ,
wherein the holding member and the lever member are rotated integrally with each other by being pushed by the leading edge of the sheet, with the movement of the lever member being regulated by the regulating portion.

7 . A sheet detecting apparatus according to claim 1 ,
wherein the detection sensor comprises a photo interrupter, and wherein the lever member comprises a light blocking portion configured to block an optical path of the photo interrupter.

8 . A sheet detecting apparatus according to claim 1 ,
further comprising a conveying portion configured to nip and convey the sheet, the conveying portion being provided downstream of the detection unit in a sheet conveying direction.

9 . A sheet detecting apparatus according to claim 1 ,
wherein a reactive force that is applied from the lever member to the sheet is generated by the first urging portion when the lever member is pushed by the leading edge of the sheet being conveyed.

10 . A sheet detecting apparatus according to claim 1 ,
wherein the holding member is rotatably supported on a side opposite to a nip of a roller pair with respect to a rotation center of one roller of the roller pair.

11 . An image forming apparatus, comprising:
detecting apparatus according to claim 1 ; and an image forming portion configured to form an image on a sheet which is detected by the sheet detecting apparatus.

12 . An image forming apparatus according to claim 11 ,
wherein the image forming portion starts an operation of forming the image on the sheet based on the signal from the detection sensor.

13 . 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:
a rotatable holding member; a lever member held by the holding member, the lever member having an abutment surface against which a leading edge of the sheet abuts; and a detection sensor configured to detect movement of the lever member, wherein, when the lever member is pushed by the sheet of which the leading edge abuts against the abutment surface, the holding member rotates together with the lever member, wherein, the lever member moves relative to the holding member so that the lever member moves between a protruding position where the abutment surface abuts against the leading edge of the sheet and a passage position where the lever member allows the sheet to pass, and wherein, as the trailing edge of the sheet passes the lever member, the lever member is moved from the sheet passage position to the protruding position.

14 . A sheet detecting apparatus according to claim 13 ,
further comprising a pressing member configured to press the lever member toward the retracted position when the holding member is rotated to the second position.

15 . A sheet detecting apparatus according to claim 13 ,
wherein the holding member is moved from a first position to the second position by the sheet pushing the lever member, the sheet detecting apparatus further comprising a first urging portion configured to urge the holding member to the first position; and a second urging portion configured to urge the lever member to the protruding position.

16 . A sheet conveying apparatus, comprising:
a roller configured to convey a sheet; a lever member provided downstream of the roller in a sheet conveying direction and having an abutment surface against which a leading edge of the sheet being conveyed by the roller abuts; a detection sensor configured to produce a signal corresponding to a position of the lever member; a holding member configured to rotatably hold the lever member; a spring configured to urge the lever member in a rotational direction in which the abutment surface is moved in the sheet conveying direction, the spring being provided between the holding member and the lever member; a pivot shaft configured to pivotably support the holding member, wherein the holding member and the lever member pivot integrally with each other about the pivot shaft by the lever member being pushed by the leading edge of the sheet; and an urging portion configured to urge the holding member so as to generate a reactive force applied from the lever member to the sheet when the holding member and the lever member pivot integrally with each other by the lever member being pushed by the leading edge of the sheet.

17 . A sheet conveying apparatus according to claim 16 ,
a regulating portion provided on the holding member and configured to abut against the lever member to stop rotation of the lever member urged by the spring; and a stopper configured to regulate the holding member urged by the urging portion from pivoting about the pivot shaft.

Assignees

• Canon Kk

Inventors

• Iizuka Yoichiro

Classifications

• B65H7/14 Primary

  by photoelectric feelers or detectors · CPC title

• B65H2511/20

  Location in space · CPC title

• B65H5/062

  between rollers or balls · CPC title

• B65H2553/61

  Mechanical means, e.g. contact arms · CPC title

• B65H2513/52

  Age; Duration; Life time or chronology of event · CPC title