JPH04324458A - Image forming device - Google Patents

Abstract

PURPOSE:To execute appropriate jamming management by controlling a means for preventing a carrying unit from being pulled out in the case that a jammed paper exists extending over a boundary area between the carrying unit and a carrying part. CONSTITUTION:This device is provided with a detection means S for detecting the presence or absence of the jammed transfer paper on the boundary area between the carrying units 23 and 26 and the carrying part B, and the prevention means for preventing the action of pulling out the carrying units 23 and 26 under the control of a control means 60 based on the detected result by the detection means S. Since the action of pulling out the both-side paper resupply unit 26 is temporarily prevented just after jamming, pulling out the unit 26 is prevented even though a user executes the jamming processing action before finishing a jammed paper feeding sequence. Therefore, the jammed paper extending over the unit 26 and a main body is prevented from being torn and the jamming management is executed by the action of feeding the transfer paper to the main body by rotating the knob of a 2nd resist roller 27 by hand.

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 using an electrostatic transfer process, such as an electrostatic copying machine or an electrostatic printer.

0002

[Background Art] In recent years, as image forming apparatuses such as electrostatic copying machines have become smaller, the space for handling jams within the apparatus body has become smaller, and various measures have been taken to maintain and improve jam handling performance. being done. For example, a device is known in which a fixing device or a duplex unit constituting a transfer paper conveyance system can be pulled out toward the front of the main device.

0003

However, in the conventional example of the above structure, the transfer paper is present across the boundary between the unit configured to be drawn out and the main body of the device.
To remove it, the transfer paper is torn between the boundary between the unit and the main body by pulling out the unit.
There is a risk that the fragments may remain in the main body and cause another jam, or the mechanical parts of the product may not be conveyed accurately if the transfer paper is forcibly pulled out while straddling it. Ta.

The present invention has been made to solve the above-mentioned problems, and its object is to provide an image forming apparatus that can properly handle paper jams.

[0005]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a transfer paper conveyance system includes a conveyance unit that can be pulled out in front of the apparatus main body, and a conveyance section that is assembled to the apparatus main body. an image forming apparatus comprising: a detection means for detecting the presence or absence of jammed transfer paper in a boundary area between the conveyance unit and the conveyance section; and a control means controlled by a control means based on the detection result of the detection means. Accordingly, the present invention is characterized in that a blocking means for blocking the pulling out operation of the transport unit is provided.

[0006]

[Operation] In the present invention having the above structure, when the transfer paper is jammed, the detection means detects whether or not the transfer paper is jammed in the boundary area between the conveyance unit and the conveyance section; Based on the detection result of the detection means, the control means controls the prevention means for preventing the withdrawal operation of the transport unit.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is an overall detailed view of the image forming apparatus in this embodiment, in which a document is placed on a document table 20C by an automatic document feeder 10, and an image of the document illuminated by a document exposure light 20a is captured by a lens. , optical system 20b such as a mirror
A latent image is formed on the photosensitive drum 21d through the photosensitive drum 21d. Toner in the toner hopper 21a of the developing device 21b is supplied onto the latent image to form a toner image, and 29a, 29
From above each paper feed tray such as b, 29c, etc., press the registration roller 2.
The toner image is transferred onto the transfer paper fed at the same timing by 8, and transferred to the fixing unit 2 via the conveyor belt 22.
3, the toner is fixed by heat and pressure on the transfer paper, and is discharged to the outside of the apparatus main body 50 via the paper discharge unit 24b, and is stacked on a paper discharge tray 24c equipped with a sorter. Here, from each paper feed tray 29a, 29b, 29c to the paper output tray 24c
A series of members for conveying the transfer paper up to
Configure.

On the other hand, transfer paper for double-sided copying is fixed in a fixing unit 23 as a transport unit, then reversed in a reversing section 24a, and then discharged according to the size of the transfer paper from a double-sided transport section 25 for each size. , after being loaded on the double-sided refeeding unit 26 as a transport unit, the second registration roller 2
7. The toner image is transferred again from the photosensitive drum 21d via the registration roller 28, passes through the conveyance section 22, is fixed in the fixing unit 23, is ejected from the main body via the paper ejection unit 24b, and is stacked on the paper ejection tray 24c. be done. here,
The transport system A other than the fixing unit 23 and the duplex paper refeeding unit 26 forms a transport section B.

The fixing unit 23 and the double-sided sheet refeeding unit 26 are constructed so that they can be pulled out toward the front of the main body of the apparatus (in the direction toward the front in the figure) by a guide member such as a rail (not shown). The detailed structure for pulling out these units 23 and 26 will not be omitted since it will not impede understanding of this embodiment. These units 23 and 26 that can be pulled out and their surroundings are provided with a paper detection sensor S1 as a detection means S for detecting the presence or absence of transfer paper at the position indicated by the black triangle mark in the figure.
to S6 are provided. However, although other paper detection sensors are provided at various locations, only those necessary for explaining this embodiment are shown in the drawing.

Furthermore, a jam display panel 30 (not shown) as shown in FIG. 2 displays the jam disposal position at a position visible to the user when the front door of the main body of the apparatus is opened.
is provided, and indicator sections 1 to 7 display the areas where jam clearing operations are required when the transfer paper jams.When a jam actually occurs, the circle marks on indicator sections 1 to 7 The lighting parts 1a to 7a are turned on to display the jam position. The lighting units 1a to 7a are transparent and are configured to be lit by LEDs on the back side thereof. In the figure, the instruction units 1 and 4 indicate that the double-sided paper refeeding unit 26 and the fixing unit 23 should be pulled out to the front to clear the jam. Also,
The instruction section 2 indicates that the jam should be cleared by turning a hand-cranked knob fixed to the second registration roller 27.
The instruction section 5 also indicates that the jam should be cleared by turning the knob for rotating the fixing roller of the fixing unit 23. The instruction section 6 also indicates that the paper discharge unit 24b should be opened to the left in the figure to clear the jam. Further, the image forming apparatus in this embodiment has a structure for preventing the pulling out operation of the fixing unit 23 and the double-sided sheet refeeding unit 26, depending on the state of a jam, as will be described in detail later.

[0012] Depending on the state of the jam, each unit 23
, 26 is shown in FIG. 3(a), for example.
), a locking pawl 30 having a rotation fulcrum 30a fixed to the main body is provided at the rear of each unit 23, 26, and this is turned ON/OFF using a solenoid 31 to prevent jamming. This is made to engage with a portion P1 of the side plate or the like at the rear of each unit 23, 26 to prevent the pull-out operation. Here, the rotation fulcrum 30a, the locking pawl 30, the solenoid 31, a portion P1 of the side plate, etc. constitute a blocking means C.

[0013] Also, depending on the state of jam, each unit 2
3 and 26 as another configuration for preventing the pull-out operation of FIG.
As shown in (b), a blocking piece 35 having a rotation fulcrum 35a fixed to the main body is provided on the front of each unit 23, 26, and this is turned ON/OFF using a solenoid 36 etc. to prevent jamming. This is engaged with a portion P2 of the side plate or the like at the front of each unit 23, 26 to prevent the pull-out operation. Here, the rotation fulcrum 35a, the blocking piece 35, the solenoid 36, a portion P2 of the side plate, etc. constitute a blocking means C.

[0014] In the apparatus having the above configuration, the operation when actually executing jam processing will be described below with reference to FIG.

First, regarding the fixing unit 23, if the transfer paper jams between the paper ejection unit 24b and the paper ejection unit 24b, the paper detection sensor S2 installed near the entrance of the fusing unit 23 and the paper ejection unit 24b The presence of paper is determined by detecting the presence of paper both with the paper detection sensor S3 provided near the entrance. Paper presence signals from both paper detection sensors S2 and S3 are sent to a microprocessor (MPU) 60 as a control means controlled by the main body of the apparatus. An ON signal for the solenoid 31 or 36 in FIG. 3 is issued from the MPU 60 to the drive circuit, and the solenoid 31 or 3
6 is turned ON, and the pulling out operation of the fixing unit 23 is first blocked. Next, in order to feed the transfer paper across the boundary area between the duplex paper refeeding unit 26 and the main body side, the second
The clutch of the registration roller 27 is turned on to drive the main body, and the jammed paper is fed into the conveyance space in front of the registration roller 28. At this time, the fixing unit 23 and the paper ejection unit 24b
Also, considering the case where the transfer paper is jammed, a clutch is provided in the drive section of the fixing unit 23 and paper ejection unit 24b, and this clutch is turned off to remove the jammed paper that has occurred at the exit of the duplex paper refeeding unit 26. send the
This is intended to prevent damage to the rollers in the fixing unit 23 due to jammed paper.

When the paper detection sensor S5 detects that the transfer paper is out of paper due to the jammed paper feeding operation described above, an OFF signal is sent to the solenoid 31 or 36 of the duplex paper refeeding unit 26, and the duplex refeeding unit 26 is fed with an OFF signal. It becomes possible to pull out the paper feed unit 26. In this way, by temporarily preventing the pull-out operation of the duplex paper refeeding unit 26 immediately after a jam, even if the user attempts to remove the jam before the above-mentioned jammed paper feeding sequence is completed, the duplex paper refeeding operation is prevented. Since the unit 26 is prevented from being pulled out, the paper jammed between the duplex paper refeeding unit 26 and the main body is not torn, and in this case, the knob of the second registration roller 27 is turned by hand to feed the transfer paper into the main body. Due to the action,
Jam processing will be performed. Then, when it becomes possible to pull out the double-sided sheet refeeding unit 26 again as described above, a lighting signal is issued from the MPU to the instruction sections 1 and 2 on the jam display panel 30, and the lighting sections 1a,
2a lights up. Then, the user pulls out the duplex paper refeed unit 26 according to this display, removes the transfer paper remaining on the duplex paper refeed unit 26, and turns the knob of the second registration roller 27 to remove the jammed paper fed into the main body. It becomes possible to remove it.

That is, in the case of a jam in the fixing unit, the state of the jam can be determined by a sensor and the jam can be removed by pulling out the fixing unit. It is no longer necessary to move the paper, which is effective in improving jam handling performance.

[0018]

As explained above, in the present invention, when there is jammed transfer paper across the boundary area between the transport unit and the transport section, the blocking means for preventing the unit from being pulled out is controlled. By doing so, it is possible to avoid the problem of paper fragments remaining when jammed paper is torn off by pulling out the conveyance unit.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a display panel of the device.

FIG. 3 is a diagram showing blocking means of the device.

FIG. 4 is a block diagram of the device.

[Explanation of symbols]

23 Fixing unit (conveyance unit) 26 Double-sided paper refeed unit (conveyance unit) 60 Microprocessor (control means) A Conveyance system B Conveyance section C Blocking means S Paper detection sensor (detection means)

Claims (1)

[Claims] 1. An image forming apparatus in which a transfer paper conveyance system includes a conveyance unit that can be pulled out to the front of the apparatus main body, and a conveyance section assembled to the apparatus main body,
a detection means for detecting the presence or absence of jammed transfer paper in a boundary area between the conveyance unit and the conveyance section; and a control means that prevents a pull-out operation of the conveyance unit by being controlled by a control means based on the detection result of the detection means. An image forming apparatus characterized in that it is provided with a blocking means.