JPH10194522A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically discharge the paper sheet left in a carrying passage or the like outside an image forming device without generating any inconveniences such as paper jamming by detecting the paper sheet in the carrying passage when the power supply is turned on, and discharging the paper sheet outside the image forming device when it is judged possible to discharge the paper sheet. SOLUTION: When any of paper sheet sensors 16, 17, 18, and 19 detects a paper sheet left in a carrying passage 12, it is judged whether or not the automatic discharge of the left paper sheet is possible. The data to indicate the condition of a device which is stored in an non-volatile RAM immediately before the power supply is turned off is used for judgment. When it is judged that the data is stored that the left paper sheet can be automatically discharged, carrying rollers 22, 23, 24, 25 arranged in each part of the carrying passage 12 are turned for the prescribed time required for discharging the left paper sheet. The left paper sheet can be automatically discharged without further promotion of the paper sheet jamming to make it difficult to remove, or without damaging the device by the discharging operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus. In particular, the present invention relates to an image forming apparatus having a function of automatically discharging paper remaining in a conveyance path when the power is turned on to the outside of the apparatus.

[0002]

2. Description of the Related Art Japanese Utility Model Publication No. 59-26365 discloses an apparatus for discharging a residual sheet by operating a transport mechanism for a predetermined time when the power is turned on. Japanese Patent Application Laid-Open No. Hei 5-278899 discloses an apparatus for discharging a residual sheet outside the apparatus by driving a transport system for a predetermined time in response to opening and closing of a predetermined door or unit when a jam occurs. ing.

[0003] JP-A-53-45244 (USP4)
No. 123155) discloses a two-sided copying machine having an intermediate tray, which automatically selects a copy mode according to the state of the intermediate tray when the power is turned on / off. Japanese Patent Publication No. 6-57575 (USP
No. 4,497,569) discloses a method of detecting a jam by monitoring a sheet in a conveyance path, and a technique of conveying a sheet to a position where processing is easy when a jam occurs. US Pat. No. 4,985,729 states that if a jam is detected, the time until the machine stops is extended,
An apparatus for completing a copy cycle is disclosed.

[0004]

In a device for discharging the residual paper in the transport path by operating the transport mechanism for a certain period of time when the power is turned on, when the residual paper in the transport path cannot be discharged, For example, even when a trouble such as a paper jam occurs, the transport mechanism is automatically operated. As a result, there is a problem that the paper jam is further promoted and the removal becomes difficult, or the apparatus is easily damaged.

An object of the present invention is to make it possible to automatically discharge remaining paper to the outside of the apparatus without causing a problem such as a paper jam when paper remains in the conveyance path when the power is turned on. Aim.

[0006]

According to a first aspect of the present invention, there is provided an image forming apparatus for forming an image on a sheet conveyed in a conveying path by a conveying unit and discharging the image from the conveying path to the outside of the apparatus.
Detecting means for detecting the presence or absence of a sheet in the transport path, monitoring means for monitoring the state of the image forming apparatus during power-on, and storing the data in a storage means capable of holding data even when the power is off; If a sheet is detected by the detection unit when the power is turned on, it is determined whether the sheet can be discharged out of the apparatus based on the latest state of the image forming apparatus stored in the storage unit. An image forming apparatus comprising: a determination unit; and a discharge unit configured to discharge a sheet in the transport path to the outside of the apparatus by the transport unit when the determination unit determines that the paper can be discharged.

According to a second aspect of the present invention, in the first aspect of the present invention, the monitoring means monitors a paper transport state in the transport path, and the determining means determines that the latest state is in the transport path. The image forming apparatus determines that the sheet can be discharged when the sheet is being conveyed by the printer.

According to a third aspect of the present invention, in the first aspect of the present invention, the monitoring means monitors the presence or absence of a paper jam in the transport path, and the determination means determines that the latest state is the transport status. The image forming apparatus determines that paper cannot be discharged when a paper jam occurs in a road.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the monitoring means monitors whether or not a trouble related to the transport means has occurred, and the determination means determines that the latest state is the transport means. The image forming apparatus determines that it is impossible to discharge the sheet when the trouble related to the image is generated.

[0010]

FIG. 1 shows an outline of a sheet conveying mechanism of an image forming apparatus 11 according to an embodiment of the present invention, and FIG. 2 shows an outline of a control circuit of the apparatus of FIG. .

Paper is stored in the paper feed tray 13. CP that executes the procedure according to the program in ROM 32
When the paper feed unit motor is driven via the gate array 34 by a command from U31, the paper feed roller 21 is rotated in a certain direction, and one sheet of the uppermost layer in the paper feed tray 13 is unwound. . The fact that the paper has been separated from the paper feed tray 13 is detected by the paper sensor 16 of the paper feed unit, and information to that effect is provided.
The data is input from the gate array 34 to the CPU 31.

The paper released from the paper feed tray 13 is C
The sheet is conveyed by conveyance rollers 22, 23, and 24 rotated in a certain direction by a conveyance motor driven in response to a command from the PU 31, and is sent to a transfer position between the photosensitive drum 26 and the transfer unit. A toner image is formed on the surface of the photoreceptor drum 26 by a known electrophotographic method, and the toner image is transferred onto a sheet fed to the transfer position as described above by the operation of the known transfer unit 14. Is done. The sheet sensor 17 detects that the sheet has passed the position immediately before the conveying roller 23 provided downstream of the conveying roller 22,
Input to PU31. Further, the fact that the sheet has passed the position immediately before the conveying roller 24 provided downstream of the conveying roller 23 is detected by the sheet sensor 18 and input to the CPU 31.

The sheet on which the toner image has been transferred at the transfer position is further conveyed to the fixing device 15 where a known image fixing process is performed, and a fixing unit motor driven in accordance with a command from the CPU 31 in a fixed direction. The sheet is conveyed by a fixing roller 25 that rotates, and is discharged onto a sheet discharge tray 20 outside the apparatus.
The fact that the sheet has been discharged out of the apparatus is detected by a sheet sensor 19 provided immediately after the fixing device 15 and is input to the CPU 31.

The conveyance path 12 is a path through which the paper separated from the paper supply tray 13 by the paper supply roller 21 is conveyed as described above and discharged to the paper discharge tray 20 outside the apparatus. The mechanism in FIG. 1 is an example. That is, the present invention
An apparatus of an image forming system other than the electrophotographic system, an apparatus having a plurality of paper feed trays and paper discharge trays, or a different number of conveying rollers from FIG. The present invention is also applicable to a device having the same.

Next, in order to automatically discharge the paper remaining in the conveyance path 12 without any trouble when the image forming apparatus of FIG. 1 is turned on, the processing is executed by the CPU 31 of FIG. The procedure will be described with reference to FIGS.

FIG. 3A shows a discrimination / discharge procedure executed when the power of the image forming apparatus is turned on, and FIG.
Shows an example of a monitoring and storing procedure that is repeatedly executed while the power of the image forming apparatus is turned on. FIG.
Shows the procedure of FIGS. 3A and 3B collectively.

Discrimination / discharge procedure (FIG. 3A). When the power of the image forming apparatus is turned on, it is determined whether there is any remaining sheet in the conveyance path 12 (S31). For this determination, detection signals from the paper sensors 16 to 19 are used. If any of the paper sensors 16 to 19 detects that the paper remains in the transport path 12 (S31; YES), it is determined whether the automatic discharge of the remaining paper is possible (S32). For this determination, data (“possible” or “impossible” data) stored in the nonvolatile RAM 33 is used. This data is data indicating the state of the image forming apparatus immediately before the power of the image forming apparatus is turned off. A detailed example thereof will be described later with reference to FIG. 3B and FIGS.

If it is determined in step S32 that "possible" data indicating that the residual paper can be automatically discharged is stored (S32; YES), the residual paper in the transport path 12 is discharged. (S33). That is, the transport rollers 22 to 25 disposed at various positions on the transport path 12 are rotated for a predetermined time necessary for discharging the remaining paper. Details of an example of the procedure for discharging the residual sheet will be described later with reference to FIGS. Note that the above steps
S31 to S33 correspond to steps S101 to S103 in FIG.

Monitoring and storage procedure (FIG. 3B). If data indicating that "paper is being conveyed" is stored in the non-volatile RAM 33 by the processing of FIG. 4 described below (S41; Y
ES), "possible" data indicating that the residual paper can be automatically discharged is stored in the nonvolatile RAM 33 (S44).
Details of an example of a procedure for determining whether or not the sheet is being conveyed will be described later with reference to FIG.

If data indicating "paper jam" has been stored in the non-volatile RAM 33 by the processing of FIG. 5 described later (S42; YES), it indicates that automatic ejection of residual paper is impossible. "Impossible" data is stored in the nonvolatile RAM 33 (S45). Details of an example of a procedure for determining whether or not the paper is jammed will be described later with reference to FIG.

If data indicating that "trouble has occurred due to the drive of the transport path 12 and the transport section motor" is stored in the nonvolatile RAM 33 by the processing of FIG.
43; YES), “impossible” data indicating that the automatic ejection of the remaining paper is impossible is stored in the nonvolatile RAM 33 (S4).
6). Details of an example of a procedure for determining whether or not there is a transporter motor trouble will be described later with reference to FIG.

Although data indicating that "paper is not being conveyed" is stored (S41; NO), data indicating that "paper is jammed" is also stored (S42; NO). Is not stored (S43; NO), the "possible" data indicating that the residual paper can be automatically discharged is stored in the nonvolatile RAM 33 ( S47).

The above-described monitoring and storing procedure is repeatedly executed while the power of the image forming apparatus is turned on. As a result, data (“enabled” data or “impossible” data) indicating the latest state of the image forming apparatus is stored in the nonvolatile RAM 33. Therefore, when the power of the image forming apparatus is turned off, data indicating a state immediately before the power is stored. Note that the above steps S41, S42, S43, S44, S45,
S46 and S47 are steps S105, S107, S109, S111 and S11 in FIG.
2, S113 and S110.

Procedure for determining whether "paper is being conveyed" (FIG. 4). FIG. 4 corresponds to step S104 in FIG. 9, and shows a procedure for detecting whether or not the state of the image forming apparatus is carrying a sheet.

If a paper jam has occurred (S51; YES), the state of the image forming apparatus is stored in the nonvolatile RAM 33 to the effect that "paper is not being conveyed" (S56). Similarly, when a trouble occurs (S52; YES), the state of the image forming apparatus is stored in the nonvolatile RAM 33 to the effect that "paper is not being conveyed" (S52).
56).

When the paper supply from the paper supply tray 13 is started (S53; YES), the state of the image forming apparatus is stored in the nonvolatile RAM 33 to the effect that "paper is being conveyed" (S54). Until the paper is discharged to the paper discharge tray 20, the data indicating that "paper is being conveyed" is held (S53; NO, and, S57; YES,
and, S55; NO). Thereafter, when the paper is discharged to the paper discharge tray 20 (S55; YES), the data stored in the RAM 33 is rewritten to data indicating that "paper is not being conveyed" (S56). The start of sheet feeding from the sheet feeding tray 13 can be known by detecting the leading edge of the sheet by the sheet sensor 16. Further, the fact that the sheet has been discharged to the sheet discharge tray 20 can be known by detecting the trailing edge of the sheet with the sheet sensor 19.

Procedure for determining "paper jam" (FIG. 5). FIG. 5 corresponds to step S106 in FIG. 9 and shows a procedure for detecting whether or not the state of the image forming apparatus is a paper jam between the paper sensors 17 and 18. This procedure is executed substantially when an operation for conveying a sheet in the conveyance path 12 is instructed (S61; YES).

If the leading edge of the sheet is detected while passing the position of the sheet sensor 17 (S68; YES) while instructing the operation for conveying the sheet (S61; YES), the sheet jam detection timer is activated. This is set in the RAM 33 (S69). This paper jam detection timer is activated every time this procedure is substantially executed (S61; YES, and, S
62; YES), and is counted (S65).

Before the count of the paper jam detection timer reaches a predetermined number, that is, before the count-up, the paper sensor
When the leading edge of the sheet passes through 18 and is detected (S63; YES),
The setting of the paper jam detection timer is canceled (S64). In other words, when the leading edge of the paper reaches the paper sensor 18 within a normal time after passing through the paper sensor 17, the paper jam detection timer is canceled. Here, the normal time is a time that is estimated to be required for the leading end of the sheet passing through the sheet sensor 17 to reach the sheet sensor 18 when the sheet is normally conveyed. This is the time to allow the error.

On the other hand, if the count of the paper jam detection timer has reached a predetermined number, that is, if the count has been increased (S66; YES), the leading edge of the paper passing through the paper sensor 17 is detected within the normal time. , The data indicating "paper jam" is stored in the RAM 33 (S67).

FIG. 5 shows a procedure for detecting whether or not the state of the image forming apparatus is a paper jam between the paper sensors 17 and 18. However, the procedure between the paper sensors 16 and 17 and between the paper sensors 18 and 19 is described. Is detected in the same manner as in FIG.

Procedure for determining whether or not "transport unit motor trouble" (FIG. 6). FIG. 6 corresponds to step S108 in FIG. 9 and shows a procedure for detecting whether or not the state of the image forming apparatus is a motor trouble of the transport unit. This procedure is executed while the instruction to drive the transport unit motor is issued (S71; YES).

If the instruction to drive the transport motor has not been issued (S71; NO), the transport motor trouble detection timer has been cleared (S76). An instruction to drive the transport unit motor has been issued (S71; YES), and the transport unit motor trouble detection timer is also cleared when the transport unit motor is rotating normally (S72; YES). (S76). In addition, the drive circuit of the transport unit motor includes a known circuit that determines whether or not the motor is rotating normally.
It has been sent to PU31.

Although the instruction to drive the transport unit motor has been issued (S71; YES), if the transport unit motor is not rotating normally (S72; NO), it is set in the RAM 33. The transport motor trouble detection timer is counted (S73)
. After that, when the rotation of the transport unit motor returns to normal (S72; YES), the trouble detection timer of the transport unit motor is cleared (S76).

On the other hand, if the count value of the transport unit motor trouble detection timer, which is counted each time this procedure is executed, reaches a predetermined number and the transport unit motor trouble detection timer counts up (S74; YES), the "transport" Is stored in the non-volatile RAM 33 (S
75).

FIG. 6 shows a procedure for detecting whether or not the state of the image forming apparatus is a trouble of the transport motor.
As for the fixing unit driving motor for driving the fixing roller 25 and the paper feeding unit motor for driving the paper feeding roller 21, whether or not there is a motor trouble is detected in the same manner as in FIG.

Automatic discharge procedure (FIGS. 7 and 8). FIGS. 7 and 8 correspond to step S103 in FIG. 9, and show a procedure for automatically discharging the remaining paper when the power of the image forming apparatus is turned on. If the paper is not detected by the paper sensor 16 of the paper supply unit (S81; NO), the fixing unit motor is driven to rotate the fixing roller 25, and the transport unit motor is driven to transport the transport rollers 22, 23. , 24 are rotated (S82). The rotation continuation time is determined from the paper sensor 16 of the paper feeding unit to the paper sensor of the fixing unit.
This corresponds to the time required for paper transport up to 19, and is managed by a timer counter set to a predetermined value (S83, S84).
When this time has elapsed (S84; YES), the fixing unit motor and the transport unit motor are stopped (S85).

When the sheet is detected by the sheet sensor 16 of the sheet feeding unit (S81; YES), the fixing unit motor is driven to rotate the fixing roller 25, and the conveyance unit motor is driven to rotate the conveyance roller. 22, 23 and 24 are rotated (S86). This rotation continuation time is determined when the leading edge of the maximum size paper is
When the sheet is in contact with 22, the rear end of the sheet corresponds to the time required for exiting the position of the sheet sensor 16 of the sheet feeding unit,
It is managed by a timer counter set to a predetermined value different from steps S83 and S84 (S87, S88).

When the above time has elapsed (S88; YES), again
It is determined whether or not a sheet is detected by the sheet sensor 16 of the sheet feeding unit (S89). As a result, the paper sensor 16
If the paper is no longer detected (S89; NO),
After a predetermined time from that time (S97, and, S98; YES), the fixing unit motor and the transport unit motor are stopped (S99). In this case, the predetermined time is a time required for paper transport from the position of the paper sensor 16 of the paper supply unit to the position of the paper sensor 19 of the fixing unit.

On the other hand, if it is determined in step S89 that the paper is detected by the paper sensor 16 of the paper supply unit (S89; YES), the paper supply unit motor is driven for a predetermined time (S91, S92). After that, the operation is stopped (S93). This allows the paper feed roller
The rotation of 21 causes the paper to reach the transport roller 22. The drive continuation time of the paper feed unit motor corresponds to the time required for paper transport from the position of the paper sensor 16 of the paper feed unit to the transport roller 22.

Thereafter, after a predetermined time period (S94, S95) in which the discharge of the sheet out of the apparatus is completed (S94, S95), the transport motor and the fixing motor are stopped (S96). The drive continuation time of the conveyance unit motor and the fixing unit motor is such that when the leading end of the maximum size sheet is in contact with the conveyance roller 22, the rear end of the sheet is detected by the sheet sensor.
This is the time required to get out of position 19.

In FIGS. 7 and 8, the drive continuation time of each motor is specified by the time of a predetermined timer counter. However, by monitoring the presence / absence of paper by each paper sensor,
It is also possible to discharge in a much shorter time.

[0043]

According to the present invention, if paper remains in the conveyance path when the power is turned on, it is determined whether or not the remaining paper can be discharged based on the state at the time of power-off immediately before the image forming apparatus. Discharge operation is performed only when possible.
The discharge operation has the effect that the remaining paper can be automatically discharged without further promoting the paper jam and making the removal difficult or without damaging the apparatus.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an outline of an image forming apparatus according to an embodiment.

FIG. 2 is a block diagram illustrating an outline of a control circuit of the image forming apparatus of FIG. 1;

FIG. 3 is a flowchart (a) showing a procedure of a discriminating means and a discharging means executed when the power of the image forming apparatus of FIG. 1 is turned on.
And a flowchart (b) showing an example of a procedure of the monitoring means executed during power-on of the image forming apparatus of FIG.

FIG. 4 is a flowchart showing an example of a procedure for determining whether or not “paper is being conveyed”;

FIG. 5 is a flowchart showing an example of a procedure for determining whether or not “paper is jammed”;

FIG. 6 is a flowchart showing an example of a procedure for determining whether or not “transport unit motor trouble”;

FIG. 7 is a part of a flowchart showing an example of an automatic discharge procedure.

FIG. 8 is a remaining part of a flowchart showing an example of an automatic discharge procedure.

FIG. 9 is a flowchart showing an example of a procedure of a discriminating unit and a discharging unit executed when the image forming apparatus of FIG. 1 is turned on, and an example of a procedure of a monitoring unit executed while the power is turned on.

[Explanation of symbols]

 REFERENCE SIGNS LIST 12 transport path 13 paper feed tray 16 paper sensor in paper feed section 17 paper sensor in transport section 18 paper sensor in transport section 19 paper sensor at discharge section 20 paper discharge tray 21 paper feed roller 22 transport roller 23 transport roller 24 transport roller 25 Fixing roller 26 Photoconductor drum 33 Non-volatile RAM memory

Claims (4)

[Claims] 1. An image forming apparatus for forming an image on a sheet conveyed in a conveyance path by a conveyance unit and discharging the image from the conveyance path to the outside of the apparatus, a detection for detecting the presence or absence of a sheet in the conveyance path. Means for monitoring the state of the image forming apparatus during power-on, storing the data in a storage means capable of holding data even when the power is off, and detecting the paper when the power is turned on. Is detected, based on the latest state of the image forming apparatus stored in the storage unit, a determination unit that determines whether or not the paper can be discharged out of the apparatus; And an ejecting unit for ejecting the paper in the conveying path to the outside of the apparatus by the conveying unit when it is determined that the sheet can be discharged. 2. The apparatus according to claim 1, wherein said monitoring means monitors a paper transport state in said transport path, and said discriminating means determines that said latest state is during paper transport in said transport path. An image forming apparatus that determines that paper can be discharged when the state is. 3. The apparatus according to claim 1, wherein the monitoring unit monitors whether or not a paper jam has occurred in the transport path, and the determining unit determines that the latest state of the paper sheet in the transport path. An image forming apparatus that determines that paper cannot be discharged when a jam occurs. 4. The apparatus according to claim 1, wherein the monitoring unit monitors whether or not a trouble related to the transport unit has occurred, and the determining unit determines whether the latest state is a trouble related to the transport unit. An image forming apparatus that determines that paper cannot be ejected when an occurrence state occurs.