JP2000010372A - Image forming device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the installation area by reducing the size and simplification of the entire image forming apparatus, and to improve various functions of the apparatus. An image forming apparatus performs post-processing on an image forming apparatus main unit having an image forming unit for forming an image on a supplied recording sheet, and a recording sheet on which an image is formed by the image forming unit. A sheet processing unit 500 having a sheet processing unit and detachably provided below the image forming apparatus main unit, and a recording sheet stacking unit 401 for stacking recording sheets to be supplied to the image forming apparatus main unit; A sheet supply unit 400 detachably provided below the processing unit 500
The sheet processing unit has a sheet supply path for guiding a recording sheet from the sheet supply unit to the image forming apparatus main unit.

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 such as a copying machine or a laser beam printer (LBP), and more particularly, to an image forming apparatus main unit having an image forming section for forming an image on a sheet surface of a recording sheet. The present invention also relates to an image forming apparatus including a sheet processing unit that sorts and post-processes recording sheets after image formation, and the image forming apparatus main unit.

[0002]

2. Description of the Related Art Conventionally, as this type of image forming apparatus,
Generally, a sheet processing apparatus is arranged on one of the left and right sides of an image forming apparatus, and a plurality of sheet supply units are arranged on the other side or below the image forming apparatus. .

In this conventional configuration, a recording sheet separated from a sheet supply unit one by one and supplied to an image forming apparatus is subjected to image transfer and fixing of the transferred image by the image forming apparatus. Thereafter, the sheet bundle is conveyed into a sheet processing apparatus to be a recording sheet bundle, and the sheet bundle is aligned and bound. Next, the processed recording sheet bundle is stored in the sheet storage unit.

Further, in order to respond to diversification requests from the user side, this image forming apparatus has expanded functions, for example, increases the number and types of sheet supply units, and arbitrarily determines the presence / absence and type of sheet processing apparatuses. In many cases, the configuration is such that it can be selected.

[0005]

However, with the conventional image forming apparatus having the above-described structure, the demand for multi-type and multi-function sheet processing apparatuses is increasing, and as the entire image forming apparatus becomes larger, it is difficult to install the image forming apparatus. The area occupied by the office is relatively large and has become incompatible with recent office situations.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem. It is an object of the present invention to reduce the installation area by simplifying the size of the entire image forming apparatus. It is another object of the present invention to provide an image forming apparatus capable of improving various functions.

[0007]

The above object is achieved by the following image forming apparatus.

An image forming apparatus main unit having an image forming unit for forming an image on a supplied recording sheet, and a sheet processing unit for performing post-processing on the recording sheet on which an image has been formed by the image forming unit. A sheet processing unit detachably provided below the image forming apparatus main unit, and a recording sheet stacking unit for stacking the recording sheets to be supplied to the image forming apparatus main unit; A sheet supply unit detachably provided below, wherein the sheet processing unit includes a sheet supply path for guiding the recording sheet from the sheet supply unit to the image forming apparatus main unit. I do.

A new sheet supply unit having recording sheet stacking means for stacking the recording sheets to be supplied to the image forming apparatus main unit is detachably provided between the image forming apparatus main unit and the sheet processing unit. Provided.

The second sheet supply unit has a sheet transport path for guiding the recording sheet on which an image is formed from the image forming apparatus main unit to the sheet processing unit.

The image forming apparatus main body unit has an external discharge tray for receiving the recording sheet on which an image is formed.

The recording sheet stacking means is provided in a plurality of stages.

The image forming apparatus main body unit includes a double-sided conveying path for conveying the recording sheet so as to form images on both sides of the recording sheet. The sheet also serves as a sheet conveyance path for guiding a recording sheet on which an image is formed to the sheet processing unit.

The image forming apparatus main body unit includes the sheet supply path and a sheet conveyance path for conveying the recording sheet on which an image is formed on the other side.

The processing section of the sheet processing unit is provided below the image forming apparatus main unit.

The processing section of the sheet processing unit is an aligning means for aligning the recording sheet on which an image is formed.

The processing section of the sheet processing unit is sheet binding means for binding the recording sheet on which an image is formed.

The sheet binding means is provided on the sheet supply path side.

The sheet processing unit includes a bundle sheet discharge tray for receiving the bound recording sheets.

The bundle sheet discharge tray is provided below the image forming apparatus main unit.

The processing section of the sheet processing unit and the bundle sheet discharge tray are provided below the image forming apparatus main unit.

The bundle sheet discharge tray is provided in the sheet processing unit.

The bundle sheet discharge tray is provided outside the sheet processing unit on the side of the sheet binding means.

(Operation) In the image forming apparatus, a sheet processing unit and a sheet supply unit are provided below the main unit of the image forming apparatus so as to be separable in order. As a result, the overall configuration of the image forming apparatus can be relatively reduced in size as compared with the conventional configuration, and the occupied area at the time of installation can be reduced. As a result, in the image forming apparatus, productivity, maintainability, and the like of the image forming apparatus are further improved.

The recording sheet in the sheet supply unit is guided from the sheet supply unit to a sheet supply path provided in the sheet processing unit, and is supplied to the image forming apparatus main unit. For this reason, the above operation of the image forming apparatus is further promoted.

The recording sheet on which an image has been formed by the image forming section is discharged onto a discharge tray or sent to a double-sided conveyance path where both sides are subjected to image processing and then discharged onto a discharge tray. . That is, when the post-processing is not performed on the recording sheet on which the image is formed by the image forming unit, the recording sheet is discharged to the discharge tray. When performing post-processing, the recording sheet is sent to a sheet processing unit via a sheet transport path, aligned, bound in a bundle, and discharged onto a bundle sheet discharge tray.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an image forming apparatus according to the present invention will be described below in detail with reference to the drawings.

<< First Embodiment >> FIG. 1 is an overall sectional view showing a schematic configuration of an image forming apparatus according to the first embodiment.

The image forming apparatus includes an image forming apparatus main body unit 100 having an image forming unit 111 therein, a document conveying device 200 disposed above the image forming unit 111, and a detachable unit which can be attached to and detached from the lower part of the image forming apparatus main unit 100. , A sheet processing unit 500 detachably provided below the sheet supply unit 300, and a sheet supply unit 400 detachably mounted below the sheet processing unit 500. Have.

The image forming apparatus main unit 100 includes:
A photoconductor drum 110a, an image transfer unit 110, and the like, which are image forming units 111, are provided in the first machine housing unit 11, and the first sheet supply unit 300 or the second sheet is provided by the image transfer unit 110. An image is transferred to a sheet surface of a recording sheet as a transfer material selectively fed from the feeding unit 400, as is well known.

The document feeder 200 separates one sheet at a time from a plurality of document bundles corresponding to formed images stacked on a document tray, and
The separated document is conveyed to the image reading unit 101 provided on the top surface of No. 0.

On the other hand, the second and third machine housing parts 12, 13
In the first and second paper feeding units 300 and 400, one by one is separated from a plurality of recording sheet bundles on each of the sheet cassettes 301 and 401 which are sheet stacking means set therein. A pair of conveying rollers 516 (see FIG. 3 described later) constituting the sheet supply path 557 passes through the right side portion of the main body unit 100 of the image forming apparatus in the drawing, and then the photosensitive drum 110a of the main body unit 100 of the image forming apparatus.
And transport the separated recording sheet.

Then, the recording sheet on which the image has been transferred by the image transfer unit 110 is subjected to a fixing process of the transferred image by an image fixing unit 120 on the downstream side, and thereafter, is discharged to a main body discharging unit, here, a first discharging unit.
The paper is discharged from the main body discharge unit 130 to a discharge tray 140 which is a discharge tray provided outside the apparatus, and is stacked.

When images are formed on both sides of the recording sheet, a switchback path 150 branched by a sheet deflecting unit 160 formed downstream of the image fixing unit 120 is used.
The recording sheet on which one side of the image is formed is switch-back-reversed by the transfer roller pair 151 in the switch-back path 150, and again from the right side of the apparatus via the reversing path 170 which is a two-sided conveyance path. By feeding the image to the image transfer unit 110 and repeating the same processing, an image is formed on the other surface, and then discharged onto the discharge tray 140 and stacked.

Here, the downstream portion of the switchback path 150 also serves as a connection portion with the sheet processing unit 500, which is one of the features of the present invention, and constitutes a second main body discharge portion outside the machine. In this case, the sheet processing unit 500 includes a processing tray 500a and a stacking tray 50.
0b, and the processing tray unit 5
00a is a first sheet supply unit 300 and a second sheet supply unit 400 below the image forming unit 111.
It is arranged between. The sheet processing unit 500 includes:
It is housed in the fourth machine housing unit 14.

Each of the above components, in particular, each of the machine body structure 1
1, 12, 14, 13 can be divided by dividing surfaces 15, 16, 17, and then each unit 100, 300,
500 and 400 are overlaid.

With this configuration, the size of the image forming apparatus according to the present invention can be reduced, and the installation area can be reduced.

Next, the sheet processing unit 500 will be specifically described with reference to FIGS.

First, the configuration of each main part will be described.

FIG. 2 shows a second embodiment of the present invention applied to the first embodiment.
FIG. 3 is an overall cross-sectional view schematically showing a configuration of a sheet processing unit disposed on the side of the machine housing. FIG. 3 is an enlarged cross-sectional view showing a main part configuration of the sheet processing unit.
FIG. 2 is a detailed partial plan view of a main part of the sheet processing unit.

FIGS. 5 to 10 are explanatory views respectively showing the detailed configuration of each required part in the sheet processing unit.

<< Configuration of Processing Tray Unit 500a >> In the configuration of the processing tray unit 500a, the transport path of the image-formed recording sheet is such that the recording sheet transported via the switchback path 150 is discharged to the first sheet. Part I
From the sheet stacking guide 517 to the discharge section side (the left side in FIG. 3), and the sheets are stacked once. After the processing in the first sheet discharge section I is completed, the stacking tray section 500b is renewed.
A first path for bundle conveyance to the first path, and a first path
In order to temporarily stock the conveyed recording sheets between the discharge stacking of the recording sheets at the sheet discharge section I and the discharge of the recording sheet bundle to the stacking tray section 500b after the processing, The incoming recording sheet is temporarily discharged from the buffer path section III to the non-discharge section side (right side in FIG. 3) on the sheet stacking guide 517 via the second sheet discharge section II and is stacked. After the processing in the sheet discharge section I is completed, the first sheet discharge section I includes a second path for carrying a bundle along the sheet stacking guide 517.

In this case, the recording sheet conveying means is the first sheet.
For discharging the recording sheet to the sheet discharge unit I side of
A main discharge roller 510 serving as a pair of discharge rollers, and a movable discharge roller 550 that can be selectively switched and brought into contact with the main discharge roller 510 as described in detail later.
And the discharged recording sheet is transferred to the sheet stacking guide 51.
7, a first sweeping paddle 514 for securely loading on the discharge side, a pair of alignment plates (alignment means) 531 and 532 for aligning the recording sheets to be discharged, and a third pair which is also a transport path. 1. Sheet discharge section I and buffer path section III
Switching flapper 511 for switching between
And a second discharge roller pair 513 for discharging the recording sheet from the buffer path section III to the second sheet discharge section II.

The recording sheet conveying means includes a second sweeping paddle 515 for surely loading the recording sheet discharged to the second sheet discharge section II on the non-discharge section side on the sheet stacking guide 517. A fixed stopper 524 for temporarily restricting the edge of the recording sheet discharged from the second sheet discharging portion II, and restricting the sheet edge at the first sheet discharging portion I, and for stacking the completed bundle later. A pusher 521 that bundles and conveys the sheet bundle to the processing position and bundles and conveys the recording sheet bundle of the second sheet discharge unit II, and holds and holds the sheet bundle at the binding processing position; A bundle discharge roller 556 that constitutes a bundle discharge roller pair for discharging onto the stacking tray 500b, which is a bundle sheet discharge tray, and can be selectively switched to the bundle discharge roller 556 in the same manner as described above. Be done And a movable paper discharge roller 550 of the output.

In the vicinity of the first sheet discharge section I, a sheet processing section for post-processing the recording sheet bundle on the sheet stacking guide 517 is arranged. In case, stapler (sheet binding means)
540 and one set of matching plate pairs (matching means) 531, 53
And 2.

Here, the operating position of the stapler 540 is within the stacking area of the recording sheets discharged from the first sheet discharging section I and the stacking area of the recording sheets discharged from the second sheet discharging section II. Outside. Stapler 540
Is disposed between the sheet stacking area from the second sheet discharge section II and the stacking tray section 500b. The pair of alignment plates 531 and 532 act on the recording sheets in the sheet stacking area from the first sheet ejection section I, and in the sheet stacking area from the second sheet ejection section II. The recording sheet ejected from the second sheet ejection unit II during sheet alignment because it is necessary to prevent the stack of sheets from being disturbed during the stapling operation. Is considered so as not to cause unnecessary trouble due to unnecessary restraint.

<< Detailed Configuration of Attached Main Parts >> As described above, the movable discharge roller 550 is interposed between the main discharge roller 510 and the bundle discharge roller 556, and both of these rollers 510 556 to form a pair of rollers by selectively switching and contacting the roller 556 with a switching mechanism shown in FIGS.

That is, in the configuration shown in FIGS. 5 and 6, the switching mechanism includes the movable discharge roller 550.
And a pair of left and right swing side plates 553 and 554 for holding the first and second grooves 553a and 554a in the radial direction on the distal end side, and a peripheral portion in the middle. The second long grooves 553b and 554b in the directions are respectively formed, and the first drive motor M1 is swingably pivotally supported on a fulcrum about a swing shaft 555 having a drive source as a drive source.

The former first long grooves 553a, 554
a, the shaft pins 552a and 552a of a pair of swing cams 552 and 552 on the intermediate shaft 551 driven to rotate by the first drive motor M1 are engaged.
The movable discharge rollers 550 are provided for the long grooves 553b and 554b.
, A one-way clutch is appropriately incorporated and interposed in the drive transmission portion of the first drive motor M1, so that the drive is released when the sheet is conveyed, and the drive to the cam portion is performed only when rotating in the reverse direction. To be transmitted.

In this case, regarding the cam stop positions of the swing cams 552 and 552, when the sheet is discharged, the position where the movable discharge roller 550 contacts the main discharge roller 510 (the solid line position in FIG. 6) and the bundle discharge roller 556 (see FIG. 6).
Dashed line position). Here, the movable discharge roller 550 is provided at the time of discharge of the recording sheet bundle, and an elastic member or the like is directed to the bundle discharge roller 556 side so that the nip portion is automatically adjusted according to the bundle thickness. Being energized.

As shown in FIGS. 3 and 7, a second drive motor M2 for transmitting drive to the relay roller pair 512 and the second paper discharge roller pair 513 includes a second drive motor M2, as shown in FIGS. A first drive solenoid SL1 for driving a switching flapper 511 for selectively switching between the sheet discharge unit I side and the buffer pass unit III side is provided for each. In addition, the first and second discharge sections I and II
, Each sweeping paddle 514 disposed in the vicinity of
515 is driven one rotation by second and third drive solenoids SL2 and SL3 (not shown).

As shown in FIGS. 3 and 4, the pusher 521 moves on a transport belt 520 stretched around a drive shaft 522 and a driven shaft 523 using a third drive motor M3 as a drive source. When the transport belt 520 travels counterclockwise (when transporting a bundle of recording sheets to the left), it is fixed to the belt and travels clockwise. At the time of moving (when moving to the leading end of the temporarily stocked recording sheet bundle), a mechanism configuration (not shown) is provided so that the sheet can be appropriately retracted from the sheet stacking surface.

Of the pair of alignment plates 531 and 532, as for the alignment plate 531 on one side, as shown in FIG. 8, the recording sheet discharged on the basis of the center is determined according to the binding mode and the sheet size. In order to be able to move linearly, a fourth drive motor M4 is used to be driven, and the matching plate 532 on the other side is moved to three values according to the binding mode and the sheet size. The fourth and fifth drive solenoids SL4 and SL5 can be selectively switched to drive via the link plates 533 and 534.

More specifically, when the respective binding modes are corner binding in all sheet sizes and two bindings of A4 size and A3 size, the fourth and fifth driving modes are used. Solenoid SL4, SL5
Are both set to “OFF”, so that the one matching plate 531 and the other matching plate 532 are held at the positions indicated by the solid lines in FIG. 8, and the two bindings of the LTR and LDR sizes are performed. In this case, the fourth drive solenoid SL4 is turned “ON” and the fifth drive solenoid SL5 is turned “OFF”, so that one of the matching plates 531 follows the movement of one of the matching plates 531 and the other matching plate 532 in FIG. It is moved to and held at the position indicated by the dashed line, and in the case of binding at two places of B4 and B5 sizes, the fourth drive solenoid SL4 is set to “O”.
N "and the fifth drive solenoid SL5 being turned" ON ", the other alignment plate 532 is similarly moved to and held at the position of the one-point perforated line in FIG.

Next, as shown in FIGS. 9 and 10, the stapler 540 is fixed to a first bracket 541, and the first bracket 541 is horizontally supported by a second bracket 543. With the support shaft 542 in the direction as a fulcrum, it is rotatable in a reverse direction to a vertical position (a dashed line position in FIG. 10). Then, the second bracket 543
Is a set of each guide rail section in a direction perpendicular to the sheet conveying direction with respect to a main body frame (not shown) (a front-rear direction, a direction corresponding to a vertical direction in FIG. 9 and a direction perpendicular to the paper in FIG. 10). Between the third bracket 544 that is movable along 548 and 548, it is rotatable to a horizontal position (a dashed line position corresponding to the d portion in FIG. 9) via a vertical support shaft 547. It is kept. Further, a fifth drive motor M5 is disposed on the third bracket 544, and the fifth drive motor M5 is engaged with a rack gear 546 fixed to the main body frame by rotating the final gear 545 of the fifth drive motor M5. It is possible to move it to a fixed amount.

Here, in the case of the stapler 540, the set position (a) in FIG. 9 is a home position position, and each set position (b) and (c) is two places with respect to the set position (a). The front position and the back position at the time of binding are occupied. Similarly, the setting position (d) occupies the position at the time of corner binding,
Here, when moving from the (c) setting position to the (d) setting position, the second bracket 543 is moved by the cam means (not shown).
Is rotated in the horizontal direction by a predetermined angle, thereby changing the posture of the stapler 540 on the second bracket 543 to an oblique position (corresponding to a corner binding position) with respect to the recording sheet bundle. When replacing or refilling the needle cartridge in the stapler 540, the home position (a)
At the set position, when the user manually turns the first bracket 541 and, consequently, the stapler 540 to reverse (the dashed line in FIG. 10), the cartridge supply port of the stapler 540 is configured to face upward.

Further, the anvil 549 for performing the binding operation in cooperation with the stapler 540 is provided at each stop setting position of the stapler, that is, at two stapling positions 549 (1).
And 549 (2), and the corner binding position 54
9 (3), each of which is provided at a total of three locations, and can be individually adjusted with respect to the relative displacement, and the two binding positions 549 (1) and 549
(2) For each corresponding anvil position, corner binding position 549 (3) Fix each of the anvils 549 by setting the distance from stapler 540 shorter than the corresponding anvil position in design. The stay (not shown) corrects the amount of deflection generated during stapling.

<< Structure of Stacking Tray Section 500b >> In the stacking tray section 500b, the sheet is discharged by performing a lifting / lowering operation (a vertical drive by a sixth drive motor M6 (not shown)) following the recording sheet bundle to be discharged. In order to keep the stacking surface of the stack constant and to enable identification of each stack of stacks,
An offset operation (driven by a sixth drive solenoid SL6, not shown) is performed alternately orthogonally to the transport direction.

<< Each Sensor for Operation Control >> The sensors for this operation control include a first sensor S1 disposed downstream of the first sheet ejection section I and a second sensor S1 provided in the second sheet ejection section. A second sensor S2 disposed downstream of the sheet bundle II, and a third sensor S3 disposed downstream of the sheet bundle discharge unit. And each of the rotation amount detection sensors for detecting the rotation amount.

Next, the operation of each part in the above-described apparatus configuration will be described with reference to FIGS.

Here, FIGS. 11 to 16 are operation flow charts for explaining the outline of the operation in the image forming apparatus in this embodiment.

<< Description of Sheet Discharge Operation (corresponding to Operation Flow of FIG. 11) >> In this sheet discharge operation (S11), the first
The switching flapper 511 by the drive solenoid SL1 is selectively switched to the first sheet discharge unit I side, and the movable discharge roller 550 is selectively contacted with the main discharge roller 510. In this state, the first drive motor M1 To “ON”
(S11-1), the discharged recording sheet on which the image has been formed is transferred from the first sheet discharging unit I to the sheet stacking guide 51.
The sheet is guided to the discharge unit side on the sheet 7 and stacked, and the rear end of the recording sheet is detected by the first sensor S1 (S11-2).
Thus, the second drive solenoid SL2 is turned “ON” to operate the first sweeping paddle 514 (S11-
3) At the same time, by turning on the fourth drive motor M4, the alignment plate pair 531 and 532 are driven to perform sheet alignment (S11-4, 5), and then the fourth drive motor M4 is turned on.
4 is reversed (S11-6) to prepare for the discharge of the recording sheet.

<< Description of Buffer Sheet Discharge Operation (corresponding to the Operation Flow of FIG. 12) >> This buffer sheet discharge operation (S
In 12), the switching flapper 511 by the first drive solenoid SL1 is selectively switched to the buffer path section III side, and the movable discharge roller 550 is selectively in contact with the main discharge roller 510. Drive motor M2
Is turned ON (S12-1), and the discharged image-formed recording sheet is guided from the buffer path section III side to the non-discharge section side on the sheet stacking guide 517 via the second sheet discharge section II. By stacking and detecting the rear end of the recording sheet with the second sensor S2 (S12-2),
The third drive solenoid SL3 is turned "ON" to operate the second sweeping paddle 515 (S12-3), and the leading end of the recording sheet abuts against the fixed stopper 524 to be received. In this case, if it is a recording sheet before switching (S12-
4) The sweeping paddle is not operated, and the switching time is shortened. Then, the second sensor S2 and the second drive motor M2 are sequentially turned "OFF" (S12).
-5, 6).

At this time, the rotation speed of the pair of relay rollers 512 and the pair of second discharge rollers 513 of the buffer path section III, that is, the sheet conveyance speed is determined by the rotation of the transfer roller pair 151 in the switchback path 150. The speed is set slightly higher than the speed, and consideration is taken so that the interval between the sequentially conveyed recording sheets is widened.
The drive transmitting portion of the transfer roller pair 151 has a built-in one-way clutch. When a recording sheet being conveyed is sandwiched between the transfer roller pair 151 and the relay roller pair 512, the one-way clutch is connected to the transfer roller. It can be easily pulled out in pairs 512.

<< Description of Buffer Switching Operation (corresponding to the Operation Flow of FIG. 13) >> Switching Operation to This Buffer (S1
At the time of 3), in accordance with the << sheet discharging operation (S11) >>, if this is a recording sheet corresponding to the last document (S13-1), the first drive solenoid SL1 and the second drive motor M2 are respectively set. “ON” (S13-
2) After that, the above << buffer sheet discharging operation (S1
2)], and at the same time, the post-processing operation in the first sheet discharge unit I is executed as follows.

That is, when the stapling mode is selected, the stapler 540 is set to the fifth drive motor M5 in advance.
Then, the pusher 521 holding the recording sheet bundle at the alignment position is driven by the third drive motor M3 (S13-3), whereby
The sheet bundle is moved to a predetermined binding position.

Here, the alignment position of the pusher 521 is varied depending on the sheet size so that the trailing edge of the recording sheet at the time of discharge is constant, but the binding position is constant regardless of the sheet size. It changes according to the binding mode. Specifically, since the distance between the staple end face and the sheet end face is different between the case of corner binding and the case of two-point binding, the amount of the recording sheet bundle entering the stapler 540 is made different in order to make this uniform. To do.

Subsequently, after the movement of the pusher 521, the first drive motor M1 is rotated in the reverse direction (S13-4), whereby the movable paper discharge roller 550 is swung toward the bundle discharge position and brought into contact with the bundle discharge roller 556. To hold the bundle of recording sheets.

Here, the processing time is shortened by transferring the recording sheet bundle between the pusher 521 and the bundle discharge unit before binding the recording sheet bundle.

After the delivery of the recording sheet bundle, the pusher 521 moves the third driving motor M3 to move the recording sheet bundle stacked in the second sheet discharging section II.
(S13-5), after retracting to the position of the fixed stopper 524, instead of the fixed stopper 524, the leading end of the recording sheet is regulated at the second sheet discharge unit II, and the next << stapling operation (S14) ) >>.

On the other hand, after the fifth drive motor M5 is driven (S13-6), << Stapling operation (S14) >> is performed on the recording sheet bundle discharged from the first sheet discharge unit I. (Skip if not in binding mode)
The process shifts to << bundle discharge operation (S16) >>, and together with << stacking tray elevating operation (S15) >>, the first drive motor M1 is rotated forward to perform the bundle discharge operation (S13-7, 8), and the discharge is performed. After the operation is completed, the movable paper discharge roller 55
After the first drive solenoid SL1 is turned OFF, the switching flapper 511 is returned to the first sheet discharge section I side, and the first sheet discharge is performed. The sheet discharge operation to the section I is enabled (S13
-9) Then, after the discharge in the second sheet discharge unit II is completed, the pusher 521 transfers the recording sheet bundle in the second sheet discharge unit II to the sheet stacking in the first sheet discharge unit I. The bundle is moved to the position, and a preparation is made for a sheet bundle discharging operation from the next first sheet discharging unit I (S13-10).

<< Explanation of the stapling operation (corresponding to the operation flow of FIG. 14) >> At the time of this stapling operation (S14), the operation of the alignment plate pairs 531 and 532 (S14-1) prevents the disturbance of the recording sheet bundle due to the binding impact. I am trying to
During the operation of the clinch motor in the stapler 540, that is, during the stapling operation (S14-2), the alignment plate pair 53
The alignment plate pair 531 and 532 are returned to the alignment position, and thereafter, the alignment plate pair 531 and 532 are returned (S14-3).

<< Description of Stacking Tray Elevating Operation (corresponding to the Operation Flow of FIG. 15) >> At the time of this stacking tray elevating operation (S15), in order to make the ejection surface of the recording sheet bundle constant, it is not shown after the bundle ejection is completed. The tray surface of the stacking tray 500b is lowered by a predetermined amount by the sixth drive motor M6, and is raised again to a position where the paper surface detection sensor S4 (not shown) is turned ON (S15-1 to S15-1). The position of the stacking tray 500b is switched between the offset position (S15-7) and the home position (S15-8) depending on whether or not the next recording sheet bundle is an even bundle (S15-6).

<< Description of Bundle Discharge Operation (corresponding to the Operation Flow of FIG. 16) >> As described above, the main bundle discharge operation (corresponding to the operation flow of FIG. 16) is to discharge the bundle by turning the first drive motor M1 ON. S16-1) and “OF” of the first drive motor M1 based on the detection result (S16-2) of the third sensor S3.
F "is performed (S16-
3).

<< Each Operation Flow According to Sheet Size >> [Case of Half-Size Recording Sheet such as A4 and LTR] In the first embodiment, the <buffer switching operation is performed only for half-size recording sheet. (S1
3)], and the operation flow is as shown in FIG.
As shown in FIG. 5, after the discharge and stacking of the recording sheets to the first sheet discharging unit I are completed, the post-processing operation such as stapling is performed on the recording sheet bundle, while the image forming unit 1
The recording sheets from 11 are temporarily discharged and stacked on the second sheet discharge section II. Next, after the post-processing operation and the completion of the bundle discharge to the stacking tray 500b, the second sheet discharging unit
II, the bundle of recording sheets is conveyed to the first sheet discharging portion I,
The remaining recording sheets are discharged and stacked at the first sheet discharge unit I. The above operation is repeated until the last recording sheet is discharged, and the job is completed.

[Case of Large Size Recording Sheets such as A3 and LDR] After the above-mentioned “Sheet Ejection Operation (S11)” is completed, the control unit (not shown) of the sheet processing unit 500 sends the unillustrated image of the main unit 100 of the image forming apparatus. By outputting an "image formation pause signal" to the control unit, the conveyance of the recording sheet from the image forming apparatus main unit 100 is temporarily stopped, and, on the other hand, the << staple operation (S14) is performed on the recording sheet bundle. >> and << bundle discharge operation (S1
6) >> is executed.

Then, the post-processing operation and the loading tray 50
After completion of the bundle discharge operation to 0b, the "image formation restart signal"
And the above-mentioned << sheet discharging operation (S11) >> for discharging and stacking the recording sheets to the first discharging unit I again.
Execute

<< Each Operation Flow According to Copy Mode >> [In the Case of Single-Sided Copy Mode] The operation flow is the same as the above << Each Operation Flow According to Sheet Size >>, and the description thereof is omitted.

[Case of Duplex Copy Mode] As described above, in the image formation on both sides of the recording sheet in the image forming apparatus main unit 100, the image is formed on one side, and then as described above. , Switchback path 15
0, and the image is formed on the other side via the reversing path 180. Thereafter, the recording sheets on which the images are formed on both sides are conveyed to the processing tray section 500a. The interval becomes longer. Therefore, it is not necessary to perform the << buffer switching operation (S13) >> again (a post-processing operation can be performed between recording sheets).
For this reason, the sheet is not related to the sheet size, and the sheet is ejected according to the same operation flow as in the above [for a large-size recording sheet such as A3 and LDR].

Incidentally, as for a series of timings in each of the above-mentioned operations, here, an example of a timing chart in the case of [sheet size: A4, binding mode: two places, number of originals: 5, and number of placed: 3] is shown. As shown in FIG.

<< Second Embodiment >> Next, a second embodiment of the present invention will be described in comparison with the first embodiment.

FIG. 18 is an explanatory view schematically showing an outline of a main part of an image forming apparatus according to the first aspect. FIG. 19 is an explanatory diagram schematically showing an outline of a main part configuration according to the second embodiment. Although the image forming apparatus of the first embodiment is shown in FIG. 1, this image forming apparatus corresponds to claim 2.

In each of FIGS. 18 and 19,
a represents an image forming unit (corresponding to the image forming unit 111), b represents a first sheet discharging unit (corresponding to the first sheet discharging unit I), and c represents a second sheet discharging unit (corresponding to the second sheet discharging unit). (Corresponding to the discharge unit II), and these main components are respectively provided in the first machine housing unit 11;
d is a sheet post-processing unit, e is a bundle sheet discharge tray, f is a sheet supply path, g is a sheet stacking unit, h is a two-sided conveyance path, i
Indicates a sheet conveyance path, and these main components are housed in the image forming apparatus main unit 100, the sheet processing unit 500, and the sheet supply unit 400 which are connected to be separable.

In the case of the image forming apparatus according to the second embodiment shown in FIG. 19, the difference between the image forming apparatus corresponding to claim 1 in FIG. 18 and the image forming apparatus according to the first embodiment in FIG. Is that a sheet bundle accommodating section e is provided in the fourth casing body section 14. In the image forming apparatus of the second embodiment, as in the image forming apparatus of the first embodiment, The overall configuration of the apparatus is relatively small, and the area occupied when the apparatus is installed can be reduced, and the productivity and maintenance of the apparatus can be improved.

<< Third Embodiment >> Next, an image forming apparatus according to a third embodiment of the present invention will be described in comparison with the first and second embodiments.

FIG. 20 is an explanatory diagram schematically showing the outline of the configuration of the main part according to the third embodiment. The respective reference numerals are the same as those in the first and second embodiments. The same is true.

The image forming apparatus according to the third embodiment is different from the image forming apparatuses according to the first and second embodiments in that a sheet bundle accommodating section e is provided in a fourth machine housing section 14. Are provided, and each of the machine body structures 11, 14, 13
Is that the sheet post-processing unit d is arranged vertically below the first sheet discharging unit b on the outside side of the image forming apparatus. Also in the image forming apparatus of the third embodiment, The same effects as those of the image forming apparatus according to the second embodiment can be obtained.

[0088]

According to the image forming apparatus of the present invention, the main unit of the image forming apparatus, the sheet processing unit, and the sheet supply unit are configured to be separable, and various functions of each unit are provided in each machine housing of these units. Since the main components of the apparatus are provided in consideration of the performance, the overall configuration of the image forming apparatus can be relatively reduced in size as compared with the conventional configuration, and the occupied area at the time of installation can be reduced. Productivity, maintainability, etc. can be improved in each stage.

Further, according to the image forming apparatus of the present invention, since the sheet processing unit is provided with the sheet supply path for guiding the recording sheet from the sheet supply unit to the main unit of the image forming apparatus, the above-described effect of the image forming apparatus is provided. Can be further promoted.

Further, according to the image forming apparatus of the present invention,
Since a discharge tray is provided in the image forming apparatus main unit,
In the case where only image formation is performed on the recording sheet, that is, in other words, when the user does not perform post-processing that is most frequently accessed, the recording sheet on which the image has been formed is discharged to the outside without passing through each part corresponding to the post-processing. In this case, in this case, the overall size of the image forming apparatus can be relatively reduced while maintaining the convenience in using the apparatus.
The effect of the image forming apparatus system can be further promoted.

Therefore, according to the present invention, the expandability of the image forming apparatus for responding to the diversification of users is ensured in accordance with the respective effects of the above-described configurations. There is an excellent feature that it is possible to easily provide a product that can arbitrarily select the presence or absence and type of the processing unit.

[Brief description of the drawings]

FIG. 1 is an overall sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is an overall sectional view illustrating a schematic configuration of a sheet processing unit according to the first embodiment.

FIG. 3 is an enlarged cross-sectional view showing a main part configuration of the sheet processing unit of FIG. 2 in an enlarged manner.

FIG. 4 is a plan view showing a main part of FIG. 3;

FIG. 5 is an explanatory plan view showing a switching mechanism of a movable discharge roller in the sheet post-processing apparatus in FIG. 3;

FIG. 6 is an enlarged side view showing a main part of FIG. 5;

FIG. 7 is an explanatory plan view showing a buffer path unit including a switching flapper in the sheet post-processing apparatus of the sheet processing unit.

FIG. 8 is an explanatory plan view showing an operation mode of a pair of alignment plates in the sheet post-processing apparatus of the sheet processing unit.

FIG. 9 is an explanatory plan view showing an operation mode of a stapler in the sheet post-processing device of the sheet processing unit.

FIG. 10 is an enlarged side view showing a main part of FIG. 9;

FIG. 11 is an operation flowchart of a sheet discharging operation.

FIG. 12 is an operation flowchart of a buffer sheet discharging operation.

FIG. 13 is an operation flowchart of a buffer switching operation.

FIG. 14 is an operation flowchart of a stapling operation.

FIG. 15 is an operation flowchart of a loading tray elevating operation.

FIG. 16 is an operation flowchart of a bundle discharging operation.

FIG. 17 is a timing chart illustrating the operation timing of the entire sheet processing system.

FIG. 18 is an explanatory diagram schematically showing an arrangement of a main part configuration according to the first embodiment of the present invention.

FIG. 19 is an explanatory view schematically showing an arrangement of a main part configuration according to a second embodiment of the present invention.

FIG. 20 is an explanatory diagram schematically showing an arrangement of a main part configuration according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 1st housing | casing structure part 12 2nd housing | casing structure part 13 3rd housing | casing structure part 14 4th housing | casing structure part 100 Image forming apparatus main body unit 101 Image reading part 110 Image transfer part 110a Photoconductor drum Reference Signs List 111 Image forming unit 120 Image fixing unit 130 Main body discharging unit 140 Paper discharge tray (discharge tray) 150 Switchback path 151 Transfer roller pair 160 Sheet deflecting unit 170 Reverse path (double-sided conveying path) 200 Document conveying device 300 (second) Sheet supply unit 301 Sheet cassette (sheet loading means) 400 (third) sheet supply unit 401 Sheet cassette (sheet loading means) 500 Finisher unit (sheet processing unit) 500a Processing tray unit I First sheet discharge unit II Second Sheet discharge section III Buffer pass section 500b Loading tray Section A (bundle sheet discharge tray) 510 Main discharge roller (first discharge roller pair) 511 Switching flapper 512 Relay roller pair 513 Second discharge roller pair 514 First sweep paddle 515 Second sweep paddle 516 Transport roller Pair (relay transport section) 517 Sheet loading guide 520 Transport belt 521 Pusher 522 Drive shaft 523 Follower shaft 524 Fixed stopper 531, 532 One set of matching plate pair (sheet processing unit, matching means) 533, 534 Link plate 540 Stapler (sheet) 541 First bracket 542 Support shaft 543 Second bracket 544 Third bracket 545 Last gear 546 Rack gear 547 Support shaft 548 Guide rail unit 549 Anvil 550 Movable paper discharge roller (first paper discharge roller pair, Bundle discharge roller pair) 551 Intershaft 552 Swing cam 552a Shaft pin 553, 554 Swing side plates 553a, 554a First long groove 553b, 554b Second long groove 555 Swing shaft 556 Bundle discharge roller (bundle discharge roller pair) 557 Sheet supply path a Image forming part b 1st sheet discharge section c 2nd sheet discharge section d sheet post-processing section e sheet bundle storage section f sheet supply path g sheet stacking means h double-sided conveyance path i sheet conveyance path

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/00 108 H04N 1/00 108K 5C062 F term (Reference) 2C059 AA16 DD02 2H071 BA03 BA13 BA36 DA23 2H072 BA12 CB06 FB01 FB09 GA08 HB07 3F108 GA02 GA04 GB01 HA02 HA39 3F343 FA02 FB02 FC12 GA02 GB01 GC01 HC03 KB03 KB14 5C062 AA05 AB30 AB32 AB35 AC10 AD05 AD06 BA01

Claims (16)

[Claims] 1. An image forming apparatus main unit having an image forming unit for forming an image on a supplied recording sheet, and a sheet processing unit for performing post-processing on the recording sheet on which an image has been formed by the image forming unit. A sheet processing unit detachably provided below the image forming apparatus main unit; and a recording sheet stacking unit for stacking the recording sheets to be supplied to the image forming apparatus main unit. A sheet supply unit detachably provided below the unit, wherein the sheet processing unit includes a sheet supply path for guiding the recording sheet from the sheet supply unit to the image forming apparatus main unit. Characteristic image forming apparatus. 2. A new sheet feeding unit having a recording sheet stacking unit for stacking the recording sheets to be supplied to the image forming apparatus main body unit between the image forming apparatus main body unit and the sheet processing unit is attached and detached. The image forming apparatus according to claim 1 provided as possible. 3. The image forming apparatus according to claim 2, wherein the second sheet supply unit includes a sheet conveying path for guiding the recording sheet on which an image is formed from the image forming apparatus main unit to the sheet processing unit. Image forming device. 4. The image forming apparatus according to claim 1, wherein the image forming apparatus main unit is provided with a discharge tray for receiving the recording sheet on which an image is formed. 5. The image forming apparatus according to claim 1, wherein the recording sheet stacking unit is provided in a plurality of stages. 6. The image forming apparatus main body unit includes a double-sided conveyance path for conveying the recording sheet to form images on both sides of the recording sheet, and a part of the double-sided conveyance path. The image forming apparatus according to claim 1, wherein the image forming apparatus also serves as a sheet conveyance path for guiding a recording sheet on which an image is formed from a sheet to the sheet processing unit. 7. The image according to claim 1, wherein the image forming apparatus main unit includes the sheet supply path and a sheet conveyance path for conveying the recording sheet on which an image is formed on the other side. Forming equipment. 8. The image forming apparatus according to claim 1, wherein the processing unit of the sheet processing unit is provided below the image forming apparatus main unit. 9. The image forming apparatus according to claim 1, wherein the processing unit of the sheet processing unit is an aligning unit that aligns the recording sheet on which an image is formed. 10. The processing unit of the sheet processing unit,
The image forming apparatus according to claim 1, wherein the image forming apparatus is a sheet binding unit that binds the recording sheet on which an image is formed. 11. The image forming apparatus according to claim 10, wherein the sheet binding unit is provided on the sheet supply path side. 12. The image forming apparatus according to claim 10, wherein the sheet processing unit includes a bundle sheet discharge tray that receives the bound recording sheets. 13. The image forming apparatus according to claim 1, wherein the bundle sheet discharge tray is provided below the image forming apparatus main unit.
3. The image forming apparatus according to 2. 14. A processing unit of the sheet processing unit,
14. The image forming apparatus according to claim 8, wherein the bundle sheet discharge tray is provided below the image forming apparatus main unit. 15. The sheet processing unit according to claim 12, wherein said bundle sheet discharge tray is provided in said sheet processing unit.
5. The image forming apparatus according to 4. 16. The image forming apparatus according to claim 11, wherein the bundle sheet discharge tray is provided outside the sheet processing unit on the sheet binding unit side.