Sheet conveying apparatus, image reading apparatus, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-11820618-B2
Application number	US-202117166864-A
Country	US
Kind code	B2
Filing date	Feb 3, 2021
Priority date	Feb 7, 2020
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

A sheet conveying apparatus includes a transmitting mechanism-, a movable member, and a control portion to input a signal having first and second levels. The transmitting mechanism transmits driving force and includes a spring clutch and an electromagnetic clutch. The driving force pivotally moves the movable member. The spring clutch idles by a slackness of a spring when the rotation in a second direction is inputted to the transmitting mechanism and the movable member is regulated from pivoting at a predetermined position. The control portion inputs the signal to the transmitting mechanism such that the state electromagnetic clutch state changes the engagement state to the disengagement state through an intermediary state gradually varying a length of time where the signal of the first level is inputted into the electromagnetic clutch after the movable member reaches the predetermined position by inputting the rotation in the second direction to the transmitting mechanism.

First claim

What is claimed is:

1. A sheet conveying apparatus comprising:
a transmitting mechanism configured to transmit driving force input from a driving source, wherein the transmitting mechanism includes a spring clutch and an electromagnetic clutch, wherein the electromagnetic clutch is capable of taking an engagement state transmitting the driving force and a disengagement state disconnecting the driving force;
a pivotally movable member configured to be pivotally moved by the driving force transmitted through the transmitting mechanism;
a supporting portion configured to support a sheet;
a feeding, member supported by the pivotally movable, member and configured to feed the sheet supported by the supporting portion;
a regulating portion configured to regulate the pivotally movable from pivoting upward a predetermined position; and
a control portion configured to control to input a signal, having a first level and a second level, varying the state of the electromagnetic clutch to the electromagnetic clutch,
wherein, in a case in which rotation in a first direction is inputted to the transmitting mechanism, the transmitting mechanism transmits the driving force to the pivotally movable so as to rotate the pivotally movable member in a direction in which the feeding member comes into contact with the sheet supported by the supporting portion,
wherein, in a case in which rotation in a second direction is inputted to the transmitting mechanism, the transmitting mechanism transmits the driving force to the pivotally movable so as to rotate the pivotally movable member in a direction in direction which the feeding member moves away from the sheet supported by the supporting portion and moves toward the predetermined position,
wherein, in a case in which the rotation in the second direction is inputted to the transmitting mechanism and the pivotally movable is regulated from pivoting by the regulating portion at the predetermined position, a spring clutch idles by a slackness of a spring, and
wherein, after the pivotally movable reaches the predetermined position by inputting the rotation in the second direction to the transmitting mechanism, the control portion controls to input the signal to the transmitting mechanism such that the state of the electromagnetic clutch changes the engagement state to the disengagement state through an intermediary state having a length of time gradually varying the length of time where the signal of the first level is inputted into the electromagnetic clutch.

2. The sheet conveying apparatus according to claim 1 , wherein the length of time in the intermediary state is longer than a time constant of a coil of the electromagnetic clutch when input of the signal to the coil is stopped.

3. The sheet conveying apparatus according to claim 1 , wherein the electromagnetic clutch is provided on a transmission route transmitting the driving force of the driving source through the spring clutch.

4. The sheet conveying apparatus according to claim 3 , wherein the electromagnetic clutch is provided coaxially with the spring clutch.

5. The sheet conveying apparatus according to claim 1 , wherein the transmitting mechanism includes a first transmission route which transmits the driving force of the driving source to the pivotally movable through the spring clutch, and a second transmission route which transmits the driving force of the driving source to a driven portion, different from the pivotally movable, without passing through the spring clutch.

6. The sheet conveying apparatus according to claim 1 , wherein, in a case in which the rotation in the second direction is inputted to the transmitting mechanism until the spring clutch idles, the slackness of the spring of the spring clutch remains while the electromagnetic clutch is in the engagement state, and the slackness of the spring restores when the electromagnetic clutch changes in the disengagement state.

7. The sheet conveying apparatus according to claim 1 , wherein the feeding member includes a feed roller, wherein the feed roller is supported by the pivotally movable, member and is configured to feed the sheet by being rotated by the driving force transmitted through the spring clutch.

8. The sheet conveying apparatus according to claim 1 ,
wherein the signal of the first level is transmitted to the electromagnetic clutch, and
wherein the control portion is configured to alternately input the signal of the first level and the signal of the second level to the electromagnetic clutch in the intermediary state, and is configured to gradually reduce the length of time where the signal of the first level is inputted.

9. The sheet conveying apparatus according to claim 1 wherein the control portion is configured to vary a width of the signal by pulse width modulation (PWM) so that the electromagnetic clutch is in the intermediary state.

10. An image reading apparatus comprising:
a sheet conveying apparatus having:
a transmitting mechanism configured to transmit driving force input from a driving source, wherein the transmitting mechanism includes a spring clutch and an electromagnetic clutch, wherein the electromagnetic clutch is capable of taking an engagement state transmitting the driving force and a disengagement state disconnecting the driving force,
a pivotally movable configured to be pivotally moved by the driving force transmitted through the transmitting mechanism,
a supporting portion configured to support a first sheet,
a feeding member supported by the pivotally movable and configured to feed the first sheet supported by the supporting portion,
a regulating portion configured to regulate the pivotally movable from pivoting upward a predetermined position, and
a control portion configured to control to input a signal, having a first level and a second level, varying the state of the electromagnetic clutch to the electromagnetic clutch,
wherein, in a case in which rotation in a first direction is inputted to the transmitting mechanism, the transmitting mechanism transmits the driving force to the pivotally movable so as to rotate the pivotally movable in a direction in which the feeding member comes into contact with the first sheet supported by the supporting portion,
wherein, in a case in which rotation in a second direction is inputted to the transmitting mechanism, the transmitting mechanism transmits the driving force to the pivotally movable so as to rotate the pivotally movable in a direction in which the feeding member moves away from the first sheet supported by the supporting portion and moves toward the predetermined position,
wherein, in a case in which the rotation in the second direction is inputted to the transmitting mechanism and the pivotally movable is regulated from pivoting by the regulating portion at the predetermined position, a spring clutch idles by a slackness of a spring, and
wherein, after the pivotally movable reaches the predetermined position by inputting the rotation in the second direction to the transmitting mechanism, the control portion controls to input the signal to the transmitting mechanism such that the state of the electromagnetic clutch changes the engagement state to the disengagement state through an intermediary state having a length of time gradually varying the length of time where the signal of the first level is inputted into the electromagnetic clutch; and
an image reading portion configured to read an information of an image from the first sheet fed by the feeding member.

11. An image forming apparatus comprising:
the image reading apparatus according to claim 10 ; and
an image forming, portion configured to form an image on a second sheet based o

Assignees

• Canon Kk

Inventors

• AIHARA Ryo

Classifications

• B65H3/0669 Primary

  Driving devices therefor · CPC title

• B65H3/0676

  with two or more separator rollers in the feeding direction · CPC title

• B65H3/0684

  on moving support, e.g. pivoting, for bringing the roller or like rotary separator into contact with the pile · CPC title

• B65H5/062

  between rollers or balls · CPC title

• G03G15/50

  Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode copiers, microprocessor control (sequencing control G03G21/14) · CPC title