Roll sheet conveying apparatus and sheet conveying control method

Patent metadata

Field	Value
Publication number	US-2016207333-A1
Application number	US-201615082390-A
Country	US
Kind code	A1
Filing date	Mar 28, 2016
Priority date	Feb 22, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

A print apparatus has a supporting section for supporting a roll of a continuous sheet, a driving mechanism having a motor for rotating the roll supported by the supporting section, a detection unit configured to detect a rotation state of the roll supported by the supporting section, a conveyance roller for conveying the continuous sheet drawn out from the roll and a print unit configured to form an image on the continuous sheet conveyed by the conveyance roller. A control unit is configured to obtain information indicating a moment of inertia of the roll supported by the supporting section based on detected values of the detection unit and to adjust a driving torque of the motor based on the obtained information, intermittently during printing.

First claim

What is claimed is:

1 . A print apparatus comprising:
a supporting section for supporting a roll of a continuous sheet; a driving mechanism having a motor for rotating the roll supported by the supporting section; a detection unit configured to detect a rotation state of the roll supported by the supporting section; a conveyance roller for conveying the continuous sheet drawn out from the roll; a print unit configured to form an image on the continuous sheet conveyed by the conveyance roller; and a control unit configured to obtain information indicating a moment of inertia of the roll supported by the supporting section based on detected values of the detection unit and to adjust a driving torque of the motor based on the obtained information, intermittently during printing.

2 . The apparatus according to claim 1 , wherein the control unit performs adjustment of the driving torque of the motor in a case where a sheet conveying amount reaches a predetermined amount from previous adjustment.

3 . The apparatus according to claim 1 , wherein the detection unit comprises a first encoder configured to detect a rotation state of the roll, and the apparatus further comprises a second encoder configured to detect a rotation state of the conveyance roller, and
wherein the control unit controls driving of the motor of the driving mechanism and a motor to drive the conveyance roller based on detected values of the first and the second encoders.

4 . The apparatus according to claim 3 , wherein the control unit obtains the information by calculation using a mass and the radius of the roll supported by the supporting section, wherein the radius of the roll is calculated based on detected values of the first and the second encoders.

5 . The apparatus according to claim 4 , wherein the control unit estimates a torque T for rotating the roll by calculation using a driving current of each of the motors and detected values of the first and the second encoders, and obtains the mass of the roll by the estimated torque T.

6 . The apparatus according to claim 1 , wherein the print unit comprises a carriage and a print head mounted on the carriage to perform serial printing, and wherein the control unit sets the driving torque of the motor for each of a zero-speed period, an acceleration period, a constant-speed period and a deceleration period of the sheet conveyance in the serial printing.

7 . The apparatus according to claim 6 , wherein the control unit sets the driving torque of plus value at the acceleration period and sets the driving torque of minus value at the zero-speed period, a constant-speed period and a deceleration period.

8 . The apparatus according to claim 7 , wherein each of the driving torque for the acceleration period and the deceleration period is adjusted to be varied in accordance with consumption of the continuous sheet by printing, whereby a tension of the continuous sheet between the roll and the conveyance roller is appropriately maintained regardless of the sheet consumption.

Assignees

• Canon Kk

Inventors

• Igarashi Yuki
• Shinjo Ryoya
• Tanami Haruhiko
• Maruyama Ryohei
• Genta Shin
• Wakayama Naoki

Classifications

• B65H23/1888

  and controlling web tension · CPC title

• B65H2801/12

  Single-function printing machines, typically table-top machines · CPC title

• B41J13/0009 Primary

  control of the transport of the copy material · CPC title

• B65H2553/51

  Encoders, e.g. linear · CPC title

• B65H2601/272

  Skewing of handled material during handling · CPC title