Paper feed device, and document transport device and image forming apparatus including the same

Patent metadata

Field	Value
Publication number	US-9670019-B2
Application number	US-201514738964-A
Country	US
Kind code	B2
Filing date	Jun 15, 2015
Priority date	Jun 20, 2014
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A paper feed device includes a paper tray, a set-state sensor, a paper feed unit, and a control unit. The control unit checks an output from the set-state sensor each time before the start of the intermittent paper feed. In the case where no paper feed is detected even after the prescribed number of times of the intermittent paper feed, the control unit determines that a non-feed jam has occurred. In the case where it is detected that there is no paper on the paper tray before the number of repetition of the intermittent paper feed reaches the prescribed number of times, the control unit causes the paper feed unit to terminate the retry processing and determines that, with no paper on the paper tray, it is not the non-feed jam.

First claim

What is claimed is:

1. A paper feed device comprising:
a paper tray on which one or more sheets of paper are set;
a set-state sensor including an actuator which rotates a predetermined rotational angle and returns to a reference position by an urging force of an urging member when no document is set and arranged at a position where any set paper can be detected, the actuator being configured to move when paper is set, the set-state sensor outputting different values depending on the position of the actuator;
a paper feed unit configured to feed the paper set on the paper tray by rotating a feeding rotary body;
a transport unit configured to transport the paper fed from the paper feed unit;
a paper feed sensor configured to detect that the paper has been sent out of the paper tray by the paper feed operation of the paper feed unit; and
a control unit configured to detect the presence or absence of paper on the paper tray on the basis of the magnitude of an output value from the set-state sensor, detect whether the paper has been fed by the paper feed operation on the basis of an output from the paper feed sensor, check the output value from the set-state sensor when the paper feed sensor has detected passing of a tail end of the paper, and cause the paper feed unit to perform the paper feed operation for a next page when determining that there is the paper, wherein
when the control unit detects on the basis of the output from the paper feed sensor that no paper has been fed, the control unit causes the paper feed unit to perform retry processing of repeating intermittent paper feed of stopping and then resuming the paper feed operation a prescribed number of times until the paper feed sensor detects paper, the control unit checks an output from the set-state sensor each time before the start of the intermittent paper feed and, in the case where no paper feed is detected even after the intermittent paper feed was performed the prescribed number of times, the control unit determines that a non-feed jam has occurred, and in the case where it is detected that there is no paper on the paper tray before the number of repetition of the intermittent paper feed reaches the prescribed number of times, the control unit causes the paper feed unit to terminate the retry processing and determines that, with no paper on the paper tray, it is not the non-feed jam.

2. The paper feed device according to claim 1 , further comprising a longitudinal sensor arranged upstream of the set-state sensor, wherein
the control unit detects whether the paper set has a prescribed length or longer, on the basis of an output from the longitudinal sensor, and
in the case where one or more sheets of paper set on the tray all have the prescribed length or longer, the control unit checks an output value, not from the set-state sensor, but from the longitudinal sensor each time before the start of the intermittent paper feed, and in the case where it is detected that no paper with the prescribed length or longer has been set, the control unit causes the paper feed unit to terminate the retry processing.

3. The paper feed device according to claim 1 , further comprising a longitudinal sensor arranged upstream of the set-state sensor, wherein
the control unit detects whether the paper set has a prescribed length or longer, on the basis of an output from the longitudinal sensor, and
in the case where one or more sheets of paper set on the tray include the sheet(s) having the prescribed length or longer, the control unit checks output values from the set-state sensor and the longitudinal sensor each time before the start of the intermittent paper feed, and in the case where one of a condition that it is detected on the basis of the output value from the set-state sensor that there is no paper on the paper tray and a condition that it is detected on the basis of the output value from the longitudinal sensor that no paper with the prescribed length or longer has been set is satisfied, the control unit causes the paper feed unit to terminate the retry processing.

4. The paper feed device according to claim 2 , wherein in the case where one or more sheets of paper set on the tray are all shorter than the prescribed length, the control unit checks an output value, not from the longitudinal sensor, but from the set-state sensor each time before the start of the intermittent paper feed, and in the case where it is detected that there is no paper on the paper tray, the control unit causes the paper feed unit to terminate the retry processing.

5. The paper feed device according to claim 1 , further comprising:
a longitudinal sensor arranged upstream of the set-state sensor; and
an operation unit configured to accept setting for a mixed-size document mode in which sheets of paper of different sizes are loaded together on the paper tray; wherein
in the case where setting of performing reading in the mixed-size document mode has been accepted in the operation unit, the control unit checks an output value, not from the longitudinal sensor, but from the set-state sensor each time before the start of the intermittent paper feed, and in the case where it is determined on the basis of the output value from the set-state sensor that there is no paper on the paper tray, the control unit causes the paper feed unit to terminate the retry processing.

6. A document transport device comprising the paper feed device according to claim 1 .

7. An image forming apparatus comprising the paper feed device according to claim 1 .

8. The paper feed device according to claim 1 , wherein the set-state sensor is arranged at the paper tray.

Assignees

• Kyocera Document Solutions Inc

Inventors

• Murata Takuro

Classifications

• G03G15/55

  Self-diagnostics; Malfunction or lifetime display · CPC title

• B65H1/04

  adapted to support articles substantially horizontally, e.g. for separation from top of pile · CPC title

• B65H2701/1313

  trailing edge · CPC title

• G03G15/70

  Detecting malfunctions relating to paper handling, e.g. jams · CPC title

• B65H1/14

  comprising positively-acting mechanical devices {(B65H1/025 takes precedence)} · CPC title