Sheet discharge device and image forming apparatus

Patent metadata

Field	Value
Publication number	US-10077164-B2
Application number	US-201715489412-A
Country	US
Kind code	B2
Filing date	Apr 17, 2017
Priority date	Apr 25, 2016
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

When a discharge count has exceeded a specified number of sheets, a sheet discharge device executes a process of moving down a discharge tray by a specified quantity and thereafter moving up the discharge tray until a top-surface detection part outputs a top-surface detection signal, while clocking a move-up time lasting from a move-up start of the discharge tray until output of the top-surface detection signal by the top-surface detection part. When the move-up time is equal to or less than a reference time, the sheet discharge device makes a next sheet discharged while the top-surface detection part outputs the top-surface detection signal; on the other hand, when the move-up time is more than the reference time, the sheet discharge device executes a correction process of moving down the discharge tray before making the next sheet discharged.

First claim

What is claimed is:

1. A sheet discharge device comprising:
a sheet carry-in inlet for carrying in a sheet;
a carry-in detection part which is placed at the sheet carry-in inlet and which changes an output value thereof depending on a presence or absence of a sheet at the sheet carry-in inlet;
a sheet discharge outlet for discharging a sheet;
a discharge tray on which a sheet discharged from the sheet discharge outlet is to be stacked and which is inclined obliquely upward from an upstream side toward downstream side of a sheet discharge direction;
an up/down moving part for moving up and down the discharge tray in a vertical direction;
a sheet discharge part for discharging a sheet onto the discharge tray;
a top-surface detection part which has a detection position set at a position under the sheet discharge outlet and which outputs a top-surface detection signal when a top surface of the discharge tray moved up by the up/down moving part or a top surface of a sheet on the discharge tray has arrived at the detection position; and
a control section which, in order to make the sheet discharge part discharge a sheet onto the discharge tray, drives the up/down moving part to move up the discharge tray until the top-surface detection part outputs the top-surface detection signal, by which the top surface of the discharge tray or the top surface of the sheet on the discharge tray is made to arrive at the detection position, the control section further executing a state decision process of deciding a stacking state of sheets discharged on the discharge tray, wherein
while counting a discharge count of sheets discharged on the discharge tray based on the output of the carry-in detection part, the control section keeps the state decision process unexecuted until the discharge count exceeds a specified number of sheets; when the discharge count has exceeded the specified number of sheets, the control section executes, as the state decision process, a process of moving down the discharge tray by a specified quantity and thereafter moving up the discharge tray until the top-surface detection part outputs the top-surface detection signal, the control section further executing a process of clocking a move-up time lasting from a move-up start of the discharge tray until output of the top-surface detection signal by the top-surface detection part,
when the move-up time is equal to or less than a predetermined reference time, the control section decides that the stacking state is a normal state, where the control section makes a next sheet discharged while the top-surface detection part outputs the top-surface detection signal; on the other hand, when the move-up time is more than the reference time, the control section decides that the stacking state is an abnormal state, where the control section executes a correction process of moving down the discharge tray before making the next sheet discharged, and
the control section resets a count number of the discharge count upon execution of the state decision process, and after the execution of the state decision process, the control section executes the state decision process each time the discharge count exceeds the specified number of sheets.

2. The sheet discharge device according to claim 1 , further comprising
an information part for giving information to a user, wherein
when a number of consecutive execution times of the correction process has reached a predetermined threshold number of times, the control section makes the information part give information for prompting the user to check a sheet on the discharge tray.

3. The sheet discharge device according to claim 1 , wherein
the control section executes, as the correction process, a process of moving down the discharge tray by a quantity corresponding to a time period resulting from subtracting the reference time from the move-up time.

4. An image forming apparatus including the sheet discharge device according to claim 1 .

5. A sheet discharge device comprising:
a sheet carry-in inlet for carrying in a sheet;
a carry-in detection part which is placed at the sheet carry-in inlet and which changes an output value thereof depending on a presence or absence of a sheet at the sheet carry-in inlet;
a sheet discharge outlet for discharging the sheet;
a discharge tray on which a sheet discharged from the sheet discharge outlet is to be stacked and which is inclined obliquely upward from an upstream side toward downstream side of a sheet discharge direction;
an up/down moving part for moving up and down the discharge tray in a vertical direction;
a sheet discharge part for discharging a sheet onto the discharge tray;
a top-surface detection part which has a detection position set at a position under the sheet discharge outlet and which outputs a top-surface detection signal when a top surface of the discharge tray moved up by the up/down moving part or a top surface of a sheet on the discharge tray has arrived at the detection position; and
a control section which, in order to make the sheet discharge part discharge a sheet onto the discharge tray, drives the up/down moving part to move up the discharge tray until the top-surface detection part outputs the top-surface detection signal, by which the top surface of the discharge tray or the top surface of the sheet on the discharge tray is made to arrive at the detection position, the control section further executing a state decision process of deciding a stacking state of sheets discharged on the discharge tray, wherein
while counting a discharge count of sheets discharged on the discharge tray based on the output of the carry-in detection part, the control section keeps the state decision process unexecuted until the discharge count exceeds a specified number of sheets; when the discharge count has exceeded the specified number of sheets, the control section executes, as the state decision process, a process of moving down the discharge tray by a specified quantity and thereafter moving up the discharge tray until the top-surface detection part outputs the top-surface detection signal, the control section further executing a process of clocking a move-up time lasting from a move-up start of the discharge tray until output of the top-surface detection signal by the top-surface detection part,
when the move-up time is equal to or less than a predetermined reference time, the control section decides that the stacking state is a normal state, where the control section makes a next sheet discharged while the top-surface detection part outputs the top-surface detection signal; on the other hand, when the move-up time is more than the reference time, the control section decides that the stacking state is an abnormal state, where the control section executes a correction process of moving down the discharge tray before making the next sheet discharged,
the reference time is one half of a sum of a first time and a second time,
the first time is a time required for the discharge tray to move up by the specified quantity; and
the second time is a theoretical value of the move-up time for a case where a specified number of sheets have been stacked on the discharge tray.

6. A sheet discharge device comprising:
a sheet carry-in inlet for carrying in a sheet;
a carry-in detection part which is placed at the sheet carry-in inlet and which changes an output value thereof depending on a presence or absence of a sheet at the sheet carry-in inlet;
a sheet discharge outlet for discharging the sheet;
a discharge detection part which is placed at the sheet discharge outlet and which changes an output value thereof depending on presence or absence of a sheet at the sheet discharge outlet;
a discharge tray on which a sheet discharged from the sheet discharge

Assignees

• Kyocera Document Solutions Inc

Inventors

• Kotani Takashi
• Ueno Yasunori

Classifications

• B65H43/02

  detecting, or responding to, absence of articles (B65H43/08 takes precedence) · CPC title

• B65H43/04

  detecting, or responding to, presence of faulty articles (B65H43/08 takes precedence; diverting faulty articles from main streams B65H29/62) · CPC title

• B65H2511/24

  Irregularities, e.g. in orientation or skewness · CPC title

• B65H43/06

  detecting, or responding to, completion of pile (B65H43/08 takes precedence) · CPC title

• B65H43/08

  Photoelectric devices · CPC title