JP3679701B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine or a printer, and more particularly to an image forming apparatus having a sheet discharge space between an image reading unit and an image forming unit or above an image forming unit.
[0002]
[Prior art]
Recently, digitization of the copying machine, as shown in FIG. 6 (a), between the image reading unit 100 and the image forming section 101, a discharge space portion 102 for discharging the sheet was placed, the so-called flight-emptying A copier has been invented. Conventionally, by disposing a discharge tray or the like that protrudes to the side of the apparatus between the image reading unit 100 and the image forming unit 101, the occupation area of the copying machine can be drastically reduced.
[0003]
Further, when images are formed on both sides of a sheet, it is possible to reverse the direction of the sheet using the discharge space portion 102. Specifically, as shown in FIG. 6 (b), the image forming unit 103 a sheet having an image formed on one surface, once begins to discharge into the discharge space portion 102 by a discharge roller 104. Subsequently, the discharge roller 104 is reversed at a predetermined position, and the sheet is drawn into the apparatus again. Then, the sheet is conveyed again to the image forming unit 103 via the refeed path 105 to form an image on the opposite side, and is discharged again by the discharge roller 104 so as to be stacked on the discharge space portion 102. That is why.
[0004]
By adopting the above-described configuration, it is possible to omit the configuration of the reversing unit and the like that have been conventionally required, and further downsizing and cost reduction can be realized.
[0005]
[Problems to be solved by the invention]
Recently, however, in order to achieve both space saving and high productivity, as shown in FIG. 7, it has been devised to place the processor 106 to the discharge space portion 102 performs staple processing and sort processing. When the processing device 106 is provided in the in-machine discharge space 102 of the reversible copying machine described in the prior art, a transport roller that receives the sheet discharged from the discharge roller 104 on the main body side and transports the sheet to the processing unit 106a such as a staple. 106b, guide 106c, and the like are required.
[0006]
In a copying machine equipped with the processing device 106, when the sheet is reversed by reversing the discharge roller 104 as before, the conventional image forming apparatus was recorded on one side during reversal during duplex recording, as described above. To operate so that the trailing edge of the sheet protrudes from the discharge port and is transported again into the image forming apparatus, the sheet full-height height regulation value is pushed out by pushing the sheet that has already been stacked on both sides. The load guarantee height must be set low with a margin so as not to be trapped. In addition, there is a drawback in that a user feels uncomfortable when the sheet once comes out into the main body again.
[0007]
Further, in the conventional example, the reversal operation during double-sided recording with the processing device 106 installed is such that the end of the long sheet enters the receiving portion of the processing device 106 and eventually the nip of the conveying roller 106b of the processing device. Go through and turn over.
[0008]
Therefore, when a stepping motor is used to control the conveyance roller 106b, proper synchronization cannot be achieved because the discharge roller 104 and the controller of the image forming apparatus main body are different, which may cause buckling, step-out, and the like. There is. In order to prevent this, it is necessary to newly add a mechanism for releasing the nip of the conveying roller 106b of the processing apparatus 106.
[0009]
In order to prevent these, it is necessary to increase the distance between the discharge roller 104 on the main body side and the conveying roller 106b of the processing apparatus. In other words, it is necessary to increase the distance between the discharge roller 104 and the processing apparatus 106 in the discharge space portion 102. Occurs. However, if the processing device 106 is moved away from the discharge roller 104, the processing device 106 protrudes from the copying machine body, and the object of space saving cannot be achieved.
[0010]
In addition, the addition of a mechanism for releasing the nip of the conveying roller 106b causes problems such as an increase in size and cost of the apparatus.
[0011]
The present invention has been made in view of the above problems, and an object of the present invention is to solve the problems in the case where a processing apparatus is installed in the discharge space portion in the in-machine discharge type image forming apparatus, thereby saving space and improving usability. An image forming apparatus that achieves the above is provided.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a typical configuration according to the present invention performs predetermined processing on a sheet in an image forming apparatus in which a space for discharging the sheet is provided between the image reading unit and the image forming unit. A post-processing unit, a sheet receiving unit that receives a sheet and conveys the sheet to the post-processing unit, and a reversing path that is different from the sheet receiving unit and does not have a conveying unit for reversing the sheet by entering the sheet Are provided in the space portion .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
An image forming apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 are cross-sectional explanatory views of the main part of the image forming apparatus, FIG. 3 is a state explanatory view of the sheet processing apparatus, FIG. 4 is a configuration explanatory view of the sheet processing apparatus, and FIG. It is state explanatory drawing which opened the cover.
[0014]
{overall structure}
First, the overall configuration of the image forming apparatus will be described. As shown in FIG. 1, in this image forming apparatus, a sheet discharge space C is formed between an image reading unit A and an image forming unit B.
[0015]
The image reading unit A has a document feeding unit 2 attached above the document reading unit 1. The document reading unit 1 optically reads the documents supplied one by one from the document feeding unit 2 and photoelectrically reads them. This is converted and sent to the image forming unit B as a digital signal.
[0016]
The image forming unit B is loaded with a sheet cassette 3 in which a sheet bundle for image formation is set at the lower part of the apparatus. The uppermost sheet in the sheet cassette 3 is fed by a pickup roller 4 and a separation roller. The sheets are separated and fed one by one by the pair 5 and conveyed to the image forming means 7 by the conveying roller 6.
[0017]
In this embodiment, an electrophotographic recording system is used as the image forming means 7 in which a toner image is formed on the photosensitive drum 7a by a developing unit (not shown), and this toner image is transferred and recorded on the conveyed sheet. The image transferred to the sheet at this time is determined by the laser beam emission timing based on the image signal digitally processed after being read by the image reading unit A or the image signal sent from an external personal computer or the like. A latent image formed by irradiating a laser beam from a laser scanner unit (not shown) on the surface of the body drum is reversely developed by a developing device.
[0018]
The sheet on which the image has been formed is conveyed to the fixing unit 8, and heat and pressure are applied to fix the image. Then, the sheet is guided upward by the switching flapper 9 and discharged from the discharge port 12 to the discharge tray portion 13 formed in the space portion C by the conveying roller 10 and the discharge roller 11. The discharge tray unit 13 also serves as an upper cover of the image forming unit B.
[0019]
The image forming apparatus according to the present embodiment is capable of recording on both sides of a sheet. When performing double-sided recording, the sheet recorded on one side as described above is switchback-conveyed in the middle of discharge, and a duplex conveying unit. is conveyed to 14, it is conveyed to the image forming unit 7 again in the same manner as in the case of single-sided printing. Then, is discharged to the second surface is an image recorded on the (side recorded surface of the unrecorded side of sheets) with a discharge tray portion 13. Therefore, the transport roller 10 is in a switchable positive reverse rotation.
[0020]
{Sheet processing device}
In the image forming apparatus of the present embodiment, a processing device D for performing a stapling process or the like on the discharged sheet bundle is provided in the space C. As shown in FIG. 3, the processing device D is installed in the direction of the arrow from the front of the device (side operated by the user).
[0021]
As shown in FIG. 1, the processing apparatus D is provided with a front cover 15 at the front of the processing apparatus, and covers a staple replacement port (not shown). In the post-processing, the sheet discharged from the discharge unit 16 including the discharge roller 11 of the image forming unit B is received by the sheet receiving unit 17 including the conveying roller 31, and the post-processing unit 18 performs post-processing such as stapling processing. after, it discharged to the stacking tray 19 of the processing unit D.
[0022]
The configuration of the processing apparatus D will be described more specifically. As shown in FIG. 4, the sheet receiving unit 17 is provided with a sheet conveyance guide 20 for guiding the sheet discharged to the conveyance roller 31, The lower surface of the sheet conveying guide 20 is an upper guide portion 20a that guides the upper surface side of the discharged sheet. A support member 21 that forms a lower guide portion 21a that guides the lower surface side of the discharged sheet is provided below the sheet conveyance guide 20, and a discharge path is formed by the upper guide portion 20a and the lower guide portion 21a. ing. Incidentally, the sheet conveying guide 20 is pivoted available-in the direction of the arrow a in FIG. 4 for a jam (sheet clogging) process, is provided grip portion 20b for this when a user lifts the sheet conveying guide 20 ing.
[0023]
Here, FIG. 5 shows the state of the jam processing. It can be seen that the user can easily access the handle portion 20b for opening the sheet conveyance guide 20 of the sheet receiving portion 17 of the processing apparatus D by opening the side door 27 (see FIG. 3) provided on the left side surface of the apparatus. .
[0024]
The sheet discharged onto the bundle pressing belt portion 25 by the conveying roller 31 is pressed against a stopper portion (not shown) by a return member 23 that rotates as shown by a one-dot chain line in FIG. Be aligned. On the other hand, alignment in the width direction of the sheet bundle (direction perpendicular to the conveyance direction) is performed by the side guide 24. That is, a pair of side guides 24 are disposed on both sides in the sheet width direction so as to sandwich the discharge sheet. One of the side guides 24 is moved in the sheet width direction by a drive mechanism (not shown), and the discharged sheet is sandwiched between the other side guides, thereby aligning the sheet bundle in the width direction.
[0025]
The aligned sheet bundle is subjected to post-processing such as shifting and stapling in the post-processing unit 18 and sequentially fed to the stacking tray 19 by the bundle pressing belt unit 25. The bundle pushing belt unit 25 is provided with an extrusion claw 26 for pushing out the sheet bundle to the stacking tray 19.
[0026]
Here, the drive control of the sheet processing apparatus D is performed by incorporating a unique controller CPU in view of the degree of design freedom, cost, versatility, and the like. Therefore, the relationship is such that only a signal output for taking timing is received from the apparatus main body side.
[0027]
{Reverse path}
Next, with reference to FIG. 1, FIG. 2 and FIG. 4, a reversal pass when performing duplex recording on a sheet will be described.
[0028]
A sheet guide member 22 that guides the sheet to be conveyed is provided upstream of the sheet conveyance guide 20 of the processing apparatus D in the sheet conveyance direction. The sheet guide member 22 also functions as a flapper that switches the sheet conveyance direction between sheet discharge and reverse conveyance, and is rotatable about a shaft 28 by a drive mechanism such as a solenoid (not shown).
[0029]
In the case of single-sided recording, as shown in FIG. 4, the lower surface of the sheet guide member 22 becomes an upper guide portion 22a that guides the upper surface side of the discharged sheet, and is discharged by a support member 21 that guides the lower surface side of the sheet. A path is formed. The sheet that has passed through the discharge path is guided by the sheet conveyance guide 20 and the support member 21 and conveyed by the conveyance roller 31.
[0030]
On the other hand, when performing duplex recording, as shown in FIG. 2, the sheet guide member 22 is rotated counterclockwise by a predetermined amount. At this time, the upper surface of the sheet guide member 22 becomes the lower guide portion 22b for guiding the lower surface side of the sheet, and the sheet guide member 22 and the upper guide member 29 form a reverse path. When thus conveying the sheet on one side recording is performed to the transport roller 10 in this state, the sheet together with the sheet bottom side is guided by the lower guide portion 22b of the sheet guide member 22, is a sheet upper surface side by the upper guide member 29 guides The reversing path is entered, and the lower surface of the sheet is guided by the handle portion 20b of the sheet conveyance guide 20 and guided upward of the processing apparatus D. Therefore, the handle portion 20b also serves as a lower guide portion of the sheet in the reverse path.
[0031]
The reversing path is formed above the processing apparatus D by the rotation of the sheet guide member 22, and this part is covered by the front cover 15. Therefore, even if the sheet protrudes from the discharge roller 11 by a predetermined amount, it is exposed to the outside of the apparatus. There is no.
[0032]
Then, the sheet conveyed through a reversing path by a predetermined amount (until the trailing edge of the sheet passes through the switching flapper 9) is reversed and conveyed to the double-side conveying unit 14.
[0033]
As described above, it is necessary to provide a mechanism that reversely drives the conveyance roller 31 or releases the sheet nip by the conveyance roller 31 by forming the reverse path above the processing device D, specifically, the conveyance roller 31. There is no need to increase the distance between the discharge roller 11 and the transport roller 31 of the processing apparatus. For this reason, space saving and usability of the apparatus are achieved.
[0034]
In addition, since the sheet to be reversed is guided so as not to come out of the apparatus during reversal conveyance, problems such as a mistaken touch or pulling by the user can be avoided.
[0035]
In the image forming apparatus of the first embodiment form state described above, the top is an upper image reader is provided, the present invention is not limited thereto, the image forming of the printer type is not one corresponding to an image reading portion of the device Even in the case of the apparatus, it is obvious that the configuration in which the sheet is reversed above the processing apparatus has the same effect as the image forming apparatus in the above-described embodiment. At this time, the sheet to be reversed may be configured not to be exposed to the outside. Further, it is also effective in a printer provided with a table-like plate member (top plate) instead of the image reading unit.
[0036]
【The invention's effect】
Since the present invention is configured as described above, the sheet can be reversed and conveyed without increasing the size and complexity of the apparatus, and the leading edge of the sheet does not jump out of the apparatus during the reversal. Also give.
[Brief description of the drawings]
FIG. 1 is an explanatory cross-sectional view of a main part of an image forming apparatus.
FIG. 2 is an explanatory cross-sectional view of a main part of an image forming apparatus that is reversed and conveyed.
FIG. 3 is an explanatory diagram of a state in which the sheet processing apparatus is mounted.
FIG. 4 is a configuration explanatory diagram of a sheet processing apparatus.
FIG. 5 is an explanatory view showing a state in which a side cover is opened.
FIG. 6 is an explanatory diagram of an image forming apparatus according to a conventional technique.
FIG. 7 is an explanatory diagram of a conventional image forming apparatus provided with a sheet processing apparatus.
[Explanation of symbols]
A ... Image reading section B ... Image forming section C ... Space section D ... Processing device 1 ... Document reading means 2 ... Document feeding means 3 ... Sheet cassette 4 ... Pickup roller 5 ... Separation roller pair 6 ... Conveying roller 7 ... Image formation Means 7a ... photosensitive drum 8 ... fixing section 9 ... switching flapper
10… Conveying roller
11… discharge roller
12… discharge port
13… discharge tray
14… Double-sided conveyance section
15… Front cover
16… discharge section
17… Sheet receiving part
18 Post-processing section
19… Loading tray
20 ... Sheet conveyance guide
20a ... Upper guide part
20b ... handle part
21… Support member
21a ... Lower guide part
22… Sheet guide member
22a ... Upper guide part
22b ... Lower guide part
23… Return member
24… Side guide
25… Bundle push belt
26… extruded nails
27… Side door
28… axis
29… Upper guide member
31… Conveying roller

Claims (6)

In the image forming apparatus provided with a space for discharging the sheet between the image reading unit and the image forming unit,
A post-processing unit that performs a predetermined process on the sheet, a sheet receiving unit that receives the sheet and conveys the sheet to the post-processing unit, and conveyance for reversing the sheet by entering the sheet in a different path from the sheet receiving unit An image forming apparatus comprising: a processing device including a reversing path having no means provided in the space portion . The image forming apparatus according to claim 1 , wherein the sheet receiving unit includes a sheet conveyance guide, and the reverse path is provided on an upper surface of the sheet conveyance guide . The image forming apparatus according to claim 2 , wherein the sheet conveying guide is displaced so as to be opened . The image forming apparatus according to claim 2 , wherein the sheet conveyance guide includes a handle for displacing the sheet conveyance guide, and an upper surface of the handle also serves as the reverse path . In the image forming apparatus provided with a space part for discharging the sheet above the image forming part,
A post-processing unit that performs a predetermined process on the sheet, a sheet receiving unit that receives the sheet and conveys the sheet to the post-processing unit, and conveyance for reversing the sheet by entering the sheet in a different path from the sheet receiving unit An image forming apparatus comprising: a processing device including a reversing path having no means provided in the space portion . 6. The image forming apparatus according to claim 5 , wherein a plate-like member that covers the processing apparatus is provided above the reversing path.

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