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US-12623470-B2 - Printing apparatus, control method for printing apparatus, and conveyance apparatus

US12623470B2US 12623470 B2US12623470 B2US 12623470B2US-12623470-B2

Abstract

A printing apparatus includes a printing unit configured to perform printing on a sheet, a conveying unit configured to convey a sheet to a print position of the printing unit, a motor configured to drive the conveying unit, and a control unit configured to control rotation of the motor. The control unit is capable of executing holding control of holding the motor at a stop position. The control unit is configured to determine a second output value, which is an output value of the motor in the holding control, in accordance with a first output value, which is an output value of the motor before stopping at the stop position.

Inventors

  • Keisei Hakamata
  • Yuki Shindo

Assignees

  • CANON KABUSHIKI KAISHA

Dates

Publication Date
20260512
Application Date
20231024
Priority Date
20221025

Claims (19)

  1. 1 . A printing apparatus comprising: a printing unit configured to perform printing on a sheet; a conveying unit configured to convey a sheet to a print position of the printing unit; a motor configured to drive the conveying unit; and a control unit configured to control rotation of the motor, wherein the control unit is capable of executing holding control of holding the motor at a stop position, and the control unit is configured to determine a first output value, which is an output value of the motor before stopping at the stop position, and determine a second output value, which is an output value of the motor in the holding control, in accordance with the first output value.
  2. 2 . The printing apparatus according to claim 1 , wherein the conveying unit is configured to convey a sheet to a conveying-direction downstream side by rotating the motor in a first rotational direction, and the second output value is an output value which is less than the first output value and makes the motor rotate in the first rotational direction.
  3. 3 . The printing apparatus according to claim 1 , wherein the second output value is a value obtained by subtracting a first predetermined value from the first output value.
  4. 4 . The printing apparatus according to claim 1 , wherein the second output value is a value obtained by dividing the first output value by a predetermined value.
  5. 5 . The printing apparatus according to claim 1 , wherein the control unit is configured to update a target position for stopping the motor to a current position based on a rotational speed of the motor during execution of the holding control.
  6. 6 . The printing apparatus according to claim 1 , wherein the control unit is capable of executing feeding control of controlling rotation of the motor such that the conveying unit conveys a sheet by a predetermined distance, and the first output value is an output value of the motor at an end of the feeding control.
  7. 7 . The printing apparatus according to claim 6 , wherein the control unit executes the holding control in a period from the end of the feeding control to a start of next feeding control.
  8. 8 . The printing apparatus according to claim 1 , wherein the conveying unit includes: a first roller provided in a conveyance path, and configured to convey a sheet to the print position of the printing unit, and a second roller provided upstream of the first roller in the conveyance path, and configured to convey a sheet, and the motor is configured to drive the first roller and the second roller.
  9. 9 . The printing apparatus according to claim 8 , further comprising: a switching unit capable of switching between a transmission state in which a drive force is transmitted from the motor to the second roller and a non-transmission state in which a drive force is not transmitted from the motor to the second roller, wherein, when the switching unit is in the transmission state, the control unit determines the second output value in accordance with the first output value.
  10. 10 . The printing apparatus according to claim 8 , wherein the control unit is capable of executing feeding control of controlling rotation of the motor such that the conveying unit conveys a sheet by a predetermined distance, and the control unit is capable of executing a conveying operation of conveying a first sheet by the first roller as the feeding control and concurrently conveying a second sheet succeeding the first sheet by the second roller.
  11. 11 . The printing apparatus according to claim 10 , wherein when a difference between a target rotational speed of the motor and an actual rotational speed becomes greater than a predetermined value in a deceleration section of the motor in the feeding control during execution of the conveying operation, the control unit makes an output value of the motor less than that in a case of the difference not more than the predetermined value.
  12. 12 . The printing apparatus according to claim 10 , further comprising: a path forming member configured to form a curved section between the second roller and the first roller in the conveyance path.
  13. 13 . The printing apparatus according to claim 12 , wherein the curved section is a section forming a reverse path for reversing a traveling direction of a sheet.
  14. 14 . The printing apparatus according to claim 12 , further comprising: a stacking portion on which sheets are stacked, wherein the second roller is a pickup roller that conveys the sheet stacked on the stacking portion to the conveyance path, the path forming member includes a separation unit configured to separate an uppermost sheet of the sheets stacked on the stacking portion from remaining sheets, and the separation unit includes an inclined surface member that forms an inclined surface in the conveyance path, and a protrusion that can catch a leading end of the sheet conveyed along the inclined surface.
  15. 15 . The printing apparatus according to claim 1 , further comprising: a first stacking portion on which sheets are stacked; and a second stacking portion on which sheets are stacked, wherein the control unit is configured to change a method of determining the second output value in accordance with the first output value between a case of conveying the sheet from the first stacking portion to the conveyance path and a case of conveying the sheet from the second stacking portion to the conveyance path.
  16. 16 . The printing apparatus according to claim 15 , wherein at least one of the conveyance path from the first stacking portion to the print position of the printing unit and the conveyance path from the second stacking portion to the print position includes a reverse path for reversing a traveling direction of a sheet.
  17. 17 . The printing apparatus according to claim 1 , wherein the motor is controlled by servo control.
  18. 18 . A control method of a printing apparatus including a printing unit configured to perform printing on a sheet, a conveying unit configured to convey a sheet to a print position of the printing unit, and a motor configured to drive the conveying unit, the method comprising: executing holding control of holding the motor at a stop position; and determining a first output value, which is an output value of the motor before stopping at the stop position, and determining a second output value, which is an output value of the motor in the holding control, in accordance with the first output value.
  19. 19 . A conveyance apparatus comprising: a conveying unit configured to convey a sheet; a motor configured to drive the conveying unit; and a control unit configured to control rotation of the motor, wherein the control unit is capable of executing holding control of holding the motor at a stop position, and the control unit is configured to determine a first output value, which is an output value of the motor before stopping at the stop position, and determine a second output value, which is an output value of the motor in the holding control, in accordance with the first output value.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a printing apparatus, a control method for the printing apparatus, and a conveyance apparatus. Description of the Related Art In an inkjet printer as an example of a printing apparatus, printing is performed by repeating conveyance of a sheet by a predetermined distance and discharge of ink onto the sheet by a print head. In such a printing apparatus, when stopping the sheet being conveyed, an external force in a direction opposite to the conveying direction may be applied to a conveyance member such as a conveyance roller due to the torsion or resistance of a member of a conveyance mechanism. This force may return the temporarily stopped sheet in the direction opposite to the conveying direction. In order to reduce such a phenomenon, Japanese Patent Laid-Open No. 2006-273559 discloses that the value of current flowing to the motor is controlled so that the motor, which drives the conveyance mechanism, stops at a target stop position. The output of the motor required to hold the motor at the stop position can vary in accordance with the magnitude of the external force described above. Therefore, depending on the magnitude of the external force, the output of the motor may be insufficient, and the motor may not be held at the stop position and rotate in the reverse direction. Further, depending on the magnitude of the external force, the output of the motor may be excessive, and the motor may rotate further forward from the stop position. SUMMARY OF THE INVENTION The present invention provides a technique of more appropriately controlling the output of a motor in holding control of holding the motor at a stop position than a conventional technique. According to an aspect of the present invention, there is provided a printing apparatus comprising a printing unit configured to perform printing on a sheet; a conveying unit configured to convey a sheet to a print position of the printing unit; a motor configured to drive the conveying unit; and a control unit configured to control rotation of the motor, wherein the control unit is capable of executing holding control of holding the motor at a stop position, and the control unit is configured to determine a second output value, which is an output value of the motor in the holding control, in accordance with a first output value, which is an output value of the motor before stopping at the stop position. Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing the internal structure of a printing apparatus according to an embodiment; FIG. 2 is a sectional view of the feeding unit and the conveying unit of the printing apparatus in FIG. 1; FIG. 3 is a perspective view of the feeding unit; FIGS. 4A and 4B are views for explaining the structure of a separation unit; FIGS. 5A to 5C are views for explaining the structure of the separation unit; FIG. 6 is a perspective view of the conveying unit; FIG. 7 is a schematic view of the conveying unit and a conveyance path; FIG. 8 is a block diagram showing the control arrangement of the printing apparatus; FIG. 9 is a view showing the control arrangement of a conveyance motor; FIG. 10 is a flowchart showing an outline of a printing operation; FIG. 11 is a view for explaining a conveying operation for one pass in the printing operation; FIG. 12 is a flowchart showing an example of the process of a control unit; FIG. 13A is a view showing an example of the change in speed upon switching from feeding control to holding control; FIG. 13B is a view showing an example of the change of the PWM value upon switching from feeding control to holding control; FIG. 14 is a flowchart showing an example of the process of the control unit; FIGS. 15A and 15B are views showing the comparison between a case of executing the holding control of this embodiment and a case of not executing the holding control; FIGS. 16A and 16B are views showing the further comparison between the case of executing the holding control of this embodiment and the case of not executing the holding control; FIG. 17 is a flowchart showing a consecutive feeding operation in the printing apparatus; FIGS. 18A and 18B are graphs showing the change in speed and the change of the PWM value, respectively, of the conveyance motor; FIG. 19 is a flowchart showing an example of the process of the control unit; FIG. 20 is a block diagram showing the control arrangement of a printing apparatus; FIG. 21 is a flowchart showing an example of the process of a control unit; FIG. 22 is a perspective view showing an outline of a printing apparatus according to an embodiment; FIG. 23 is a perspective view of a feeding unit; FIG. 24 is a sectional view of the feeding unit in a widthwise direction; FIG. 25 is a sectional view of a pressur