Sheet conveyer

Patent metadata

Field	Value
Publication number	US-11623832-B2
Application number	US-202017130959-A
Country	US
Kind code	B2
Filing date	Dec 22, 2020
Priority date	Dec 25, 2019
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

A sheet conveyer, having a sheet tray, a tray-driving mechanism, a conveyance guide, a feed roller, a conveyer-driving mechanism, a first sensor, and a controller, is provided. The controller controls the tray-driving mechanism and the conveyer-driving mechanism, during a sequential conveying action, when the first sensor detects an upper-surface level being at a lower limit of a correct range, delay a lift-start timing, at which the tray-driving mechanism starts moving the sheet tray upward, to be later at least than a timing, at which the feed roller after feeding one of the sheets completely and pausing resumes rotating for feeding a next one of the sheets, and cause the sheet tray to complete moving to a higher position prior to completion of feeding of the next sheet.

First claim

What is claimed is:

1. A sheet conveyer, comprising:
a sheet tray configured to support sheets for being fed;
a tray-driving mechanism configured to move the sheet tray vertically;
a conveyance guide configured guide the sheets fed from the sheet tray;
a feed roller configured to feed the sheets supported by the sheet tray along the conveyance guide by rotating;
a conveyer-driving mechanism configured to drive the feed roller, the conveyer-driving mechanism being configured to, for a sequential conveying action to convey a plurality of ones of the sheets supported by the sheet tray sequentially, cause the feed roller to pause after feeding one of the sheets completely and before starting to feed a next one of the sheets;
a first sensor configured to detect whether a top-surface level being a height level of an uppermost one of the sheets supported by the sheet tray is at a lower limit of a correct range for feeding the sheets along the conveyance guide; and
a controller configured to control the tray-driving mechanism and the conveyer-driving mechanism, the controller being configured to, during the sequential conveying action for each of the sheets that is fed, when the first sensor detects the top-surface level being at the lower limit of the correct range, delay a lift-start timing, at which the tray-driving mechanism starts moving the sheet tray upward, to be later at least than a timing, at which the feed roller after feeding one of the sheets completely and pausing resumes rotating for feeding the next one of the sheets, and cause the sheet tray to complete moving to a higher position prior to completion of feeding of the next sheet.

2. The sheet conveyer according to claim 1 , further comprising:
a second sensor located along the conveyance guide, the second sensor being configured to output sheet-detection signals while detecting one of the sheets being conveyed from a leading edge to a trailing edge along the conveyance guide,
wherein the controller is configured to:
based on the sheet-detection signals from the second sensor, determine a sheet length being a length of the one of the sheets being conveyed along the conveyance guide;
based on the sheet length, calculate a first time between a timing, at which the second sensor stops outputting the sheet-detection signals, and a rotation-resume timing, at which the feed roller after pausing resumes rotating;
after detection of the top-surface level being at the lower limit of the correct range by the first sensor, calculate a second time between a first timing, at which the second sensor stopped outputting the sheet-detection signals immediately prior to the detection of the top-surface level being at the lower limit of the correct range, and a second timing, at which the top-surface level being at the lower limit of the correct range was detected by the first sensor; and
based on an absolute value of a difference between the first time and the second time, determine the lift-start timing.

3. The sheet conveyer according to claim 2 ,
wherein the controller is configured to:
based on the sheet length, calculate a third time between a rotation-stop timing, at which the feed roller pauses, and the rotation-resume timing; and
when the absolute value of the difference between the first time and the second time is smaller than the third time, delay the lift-start timing to be later than the second time for a length longer than or equal to the third time.

4. The sheet conveyer according to claim 3 ,
wherein the controller is configured to delay the lift-start timing to be later than the second time for a length at least twice as long as the third time.

5. The sheet conveyer according to claim 3 , further comprising:
a separator configured to be driven by the conveyer-driving mechanism, the separator being configured to separate the sheets fed by the feed roller from one another and convey the sheets separately along the conveyance guide; and
a conveyer configured to be driven by the conveyer-driving mechanism, the conveyer being configured to convey the sheets passed from the separator along the conveyance guide,
wherein the controller is configured to:
calculate a fourth time between the rotation-resume timing and a timing, at which one of the sheets reaches the conveyer; and
delay the lift-start timing to be later than the second time for a length longer than or equal to the third time and longer than or equal to the fourth time.

6. The sheet conveyer according to claim 1 , further comprising:
a separator configured to be driven by the conveyer-driving mechanism, the separator being configured to separate the sheets fed by the feed roller from one another and convey the sheets separately along the conveyance guide; and
a conveyer configured to be driven by the conveyer-driving mechanism, the conveyer being configured to convey the sheets passed from the separator along the conveyance guide,
wherein the conveyer-driving mechanism includes a transmission-active portion and a transmission-passive portion arranged in a path to transmit a driving force to the feed roller and the separator, the conveyer-driving mechanism being configured to drive the feed roller, the separator, and the conveyer in a setting such that a conveying velocity to convey the sheets by the conveyer is higher than a conveying velocity to convey the sheets by the feed roller and the separator;
wherein the transmission-active portion is configured to be driven to rotate about a transmission axis; and
wherein the transmission-passive portion is configured to be driven to rotate about the transmission axis, the transmission-passive portion being configured to contact the transmission-active portion along a circumferential direction of the transmission axis, the transmission-passive portion being configured to start rotating passively by being pushed by the transmission-active portion.

Assignees

• Brother Ind Ltd

Inventors

• Okamoto Yoshihiro
• Mizuno Tomoyuki

Classifications

• B65H2701/1311

  leading edge · CPC title

• B65H2513/50

  Timing · CPC title

• B65H5/062

  between rollers or balls · CPC title

• B65H7/02 Primary

  by feelers or detectors · CPC title

• B65H2511/11

  Length · CPC title