JPH0725477B2 - Image forming device - Google Patents

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, and more particularly to an improvement in the structure of a paper discharge section thereof.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine, a discharge tray is usually attached to the main body of the apparatus,
After the image formation, the transfer paper discharged from the apparatus main body is stacked on the paper discharge tray. However, if more than the specified amount of transfer paper is loaded on the paper output tray and the paper is further discharged, the paper will not be discharged smoothly and will cause paper jams. It is known to provide a sensor that detects when the paper has reached a specified amount.

FIG. 2 is a block diagram showing an example of a conventional paper discharge tray provided with a transfer paper detection sensor. The transfer papers 3 sent out from the apparatus main body 1 by the fixing roll 2 through a predetermined image forming process are sequentially stacked on the paper discharge tray 4. Further, a detection lever 5 connected to the micro switch 6 is provided on the paper ejection tray 4, and when a predetermined amount or more of the transfer paper 3 is stacked on the paper ejection tray 4, and a certain weight or more is applied to the upper portion of the detection lever 5. The micro switch 6 is turned on (FIG. 3), and it is detected that the transfer paper 3 on the paper discharge tray 4 has reached a predetermined amount.

However, according to the above-mentioned structure, the detection lever 5 does not operate unless the weight of the stacked sheets reaches a predetermined value.
It is necessary to accurately set the operation limit of the, and for that reason, a design with high component accuracy is required. Further, when the precision of the parts is not pursued, the operation timing of the detection lever 5 is varied, and the micro switch 6 is turned on with a fixed amount of stacked paper in each product, and the transfer paper 3 reaches a predetermined amount. It becomes difficult to detect accurately.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the prior art, once the discharged sheets are stacked on the discharged sheet stacking table, the amount of discharged sheets to be stacked thereafter is counted and the counted value is stored in the stacking table. When a value corresponding to the stacking paper amount limit is reached, a warning is issued or control is performed so as to stop the image forming operation thereafter, and paper jams at the discharge port or discharge paper from the stacking table may occur. An object of the present invention is to provide a highly reliable image forming apparatus that does not occur.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a discharge port for discharging the discharged paper after the image forming process to the outside of the apparatus, and the apparatus for stacking the discharged paper discharged from the discharge port.
Discharged paper stacking table formed on the main body and the tip of the discharged paper stacking table
In the image forming apparatus having a detachable paper discharge tray configured to be connectable to the
The detection lever that is displaced by contacting the discharged paper and the device book
It is arranged inside the body and operates according to the displacement of the detection lever.
Switch means, counting means for counting the number of image forming operations performed after the operation of the switch means, and control means for issuing a warning or stopping the image forming operation when the count value of the counting means reaches a predetermined number It is characterized by having and.

[0007]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view of an image forming apparatus showing an embodiment of the present invention, and FIG. 4 is a perspective view thereof.

The photoconductor 8 in the apparatus main body 7 has a photoconductive layer formed on a conductive substrate, and is supported rotatably in the direction of the arrow shown in the figure. Around the photoconductor 8, a charging device, an exposure device, a developing device (not shown above), a transfer device 12, a cleaning device (not shown), a device for removing electrophotographic means and the like are sequentially arranged. ing. The cassette 9 for accommodating the transfer paper 15 is attached to the lower part of the apparatus body 7 from the front side of the apparatus body 7 in the axial direction of the photoconductor 8, and a part of the cassette 9 is set without protruding from the apparatus body 7.

Further, a concave portion formed by cutting out a part of the side surface of the apparatus body 7 on the paper discharge side forms a discharged paper stacking portion 21, and the discharged transfer paper 15 can be stacked on the surface indicated by an arrow A. Has become. A detection lever 16 and a micro switch 17 are provided on the surface A of the discharged paper stacking unit 21.
6 is rotatable about a shaft 16a, and the micro switch 17 is normally in contact with the detection lever 16 by the reaction force of the actuator, but is in the off state (FIG. 6). Further, as shown in FIG. 7, instead of the detection lever 16 and the micro switch 17, a combination of a detection lever 19 and a photo switch 20 can be used.

Further, a discharge tray 18 which is continuously removable from the discharge sheet stacking section 21 is mounted so that a large size transfer sheet 15 can be stacked. Next, the operation of the image forming apparatus having the above configuration will be described.

A toner image corresponding to the original is formed on the photosensitive member 8 by a well-known electrophotographic method by a charging device, an exposing device, and a developing device (not shown). On the other hand, the transfer papers 15 stored in the cassette 9 are sent out one by one by the paper feed roller 10 and temporarily stand by by the standby roll 11. Here, the transfer paper 15 is re-fed toward the transfer portion by the standby roll 11 so as to match the timing with the toner image on the photoconductor 8. In the transfer section, the toner image on the photoconductor 8 is transferred to the transfer paper 15 by the transfer device 12. The transfer paper 15 that has been transferred is separated from the photoconductor 8 and then conveyed to the conveyor belt 13.
The sheet is conveyed above, fixed by the fixing roll 14, and discharged. The discharged transfer papers 15 are sequentially stacked on the discharged paper stacking unit 21. When the number of stacked transfer papers 15 exceeds a predetermined number, the detection lever 16 is rotated downward by its own weight to turn on the micro switch 17 (FIG. 5), and the number of stacked transfer papers 15 reaches the predetermined number. This is output as an electric signal, and an alarm is issued by this output signal or the apparatus itself is stopped to prevent the transfer paper 15 from overflowing the discharged paper stacking unit 21.
In this embodiment, the micro switch 17 is initially maintained in the off state only by the reaction force, but the detection lever 16 is biased upward by a spring or the like to adjust the number of transfer sheets 15 to be stacked arbitrarily. be able to.

The switch is turned on when one or several sheets of the transfer paper 15 are stacked, the number of image formations after the switch is turned on is counted, and a warning is issued when the counted number exceeds a predetermined number. It is also possible to stop the device itself.

Further, according to the present invention, a side surface of the apparatus main body on which the paper is discharged is partially cut away to form a concave portion, so that, for example, the cassette 9 and the optical system member and the optical path thereof which interfere with the operation when protruding outside the apparatus main body. There is a limit to the compactness of the optical system that can be accommodated in the bottom and top of the main body of the device, respectively, and the transfer paper conveyance path inside the device can be shortened, reducing the possibility of paper jams. . Further, since the discharge paper stacking portion 21 is formed in the concave portion, the discharge tray 18 is not necessary for a small size transfer paper, and the small discharge tray 18 is used even when a large size transfer paper is used.
Just attach the. That is, by configuring a part of the apparatus main body 7 as the discharged paper stacking unit 21, the structure of the paper discharge unit is made more compact than the conventional one.

Further, in the structure of the present invention, since the detection switches for detecting the transfer paper are provided on the apparatus main body side rather than the discharge tray side, there is no inconvenience at the time of attaching / detaching the discharge tray as in the prior art, and the design is improved. Is also good.

[0015]

As described above in detail, in the image forming apparatus of the present invention, once the transfer paper is discharged onto the discharge paper stacking table, the number of image forming operations performed thereafter is counted to discharge the transfer paper. The amount of discharged paper that accumulates on the paper stack is monitored, and if the image forming operation is repeated without removing the discharged paper on the stack for the number of times the stack limit is reached, a warning is generated and the user is notified. Prompts the user to remove the discharged paper from the stack, or automatically stops the image forming operation.
It becomes possible to remove the discharged paper within the limit of the exact amount of paper to be stacked and to stop the subsequent paper discharge, which may cause a paper jam at the paper discharge port or drop of the discharged paper from the stacking table. Thus, it is possible to provide a highly reliable image forming apparatus. Further, the detection mechanism for detecting the placement of the discharged paper does not need to be designed with high component accuracy, and the inexpensive and simple mechanism can configure the detection mechanism for the stacked paper amount.

[Brief description of drawings]

FIG. 1 is a sectional view of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional paper discharge unit.

FIG. 3 is a cross-sectional view of a conventional paper discharge unit.

FIG. 4 is a perspective view showing an embodiment of the present invention.

FIG. 5 is a cross-sectional view of a paper discharge unit showing an embodiment of the present invention.

FIG. 6 is a perspective view showing configurations of a detection lever and a micro switch.

FIG. 7 is a perspective view showing configurations of a detection lever and a photo switch.

[Explanation of symbols]

 7 Device Main Body 8 Photoreceptor 15 Transfer Paper 16 Detection Lever 17 Micro Switch 18 Paper Ejection Tray 21 Ejected Paper Loading Platform

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Etsuro Kawakami 1-2 Minami, Minami, Musashimurayama City, Tokyo Inside AI Day Co., Ltd. (72) Kiyotsugu Asami 1, 1-2 Minami, Musashimurayama City, Tokyo Address within AI Day Co., Ltd. (56) Reference JP-A-59-194971 (JP, A) Real-open Sho-57-33643 (JP, U) Real-open Sho-58-94064 (JP, U) Real-open Sho 55 -155759 (JP, U) Actual public Sho 52-4779 (JP, Y2)

Claims (1)

[Claims] 1. A discharge port for discharging the discharged paper after the image forming process to the outside of the apparatus, a discharge paper stacking base formed on the apparatus main body for stacking the discharged paper discharged from the discharge port ,
Detachable paper ejection tray that can be connected to the tip of the paper ejection tray
In an image forming apparatus including a ray, a detection lever that is displaced in contact with the discharged paper stacked on the discharged paper stacking table.
And the displacement of the detection lever, which is arranged in the main body of the device.
A switch means which operates in response to, action of said switch means
And wherein the counting means for counting the image forming operation times to be performed after the dynamic, that count value of said counting means and a control means for stopping or image forming operation for generating an alarm upon reaching a predetermined number of times Image forming apparatus.