JPH0527510A - Image forming device - Google Patents

Abstract

PURPOSE:To provide a device for housing a paper supply cassette and a paper ejecting cassette in a copying machine main body with simple structure. CONSTITUTION:This device is provided with the copying machine main body 1, an image forming part consisting of a photosensitive drum 8, etc., an aperture 1c functioning as a cassette housing part, a supplied paper carrying means consisting of a paper feeding device 15, etc., and an ejected paper carrying means consisting of an ejected paper carrying device 25, etc. The cassette housing part is provided in the copying machine main body 1, and both of the paper supply cassette and the paper ejecting unit are selectively housed in the cassette housing part. The supplied paper carrying means is a means for carrying the paper in the paper supply cassette which is housed in the cassette housing part to the image forming part. The ejected paper carrying means is a means for carrying the paper where the image is formed to the paper ejecting unit which is housed in the cassette housing part.

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 image forming apparatus having a sheet feeding cassette and a sheet discharging cassette which are detachably attached to a main body of the image forming apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a paper feeding cassette is detachably attached to one side of a copying machine main body, and an ejected sheet containing an image-formed sheet on the opposite side. The paper tray is loaded. In such a conventional copying machine, there is a problem that the installation space becomes large because cassettes and trays are provided on both sides of the copying machine body.

Therefore, for example, Japanese Patent Laid-Open No. 63-10626.
As shown in Japanese Patent Publication No. 9 and the like, there is provided a device in which a paper discharge tray is arranged inside the copying machine main body. Further, there is provided a copying machine in which a paper feeding cassette is removable from the front side of the copying machine main body, and the paper feeding cassette and a paper discharging cassette as a paper discharging tray are arranged vertically below the image forming unit. ing.

[0004]

In the above-mentioned conventional image forming apparatus such as a copying machine, particularly, when the paper feed cassette and the paper discharge cassette are arranged vertically below the image forming unit, the size of the apparatus in the left-right direction. And the installation space of the entire device is reduced.

However, in order to attach / detach the paper feed cassette and the paper discharge cassette to the inside of the main body of the copying machine, an independent guide rail or the like is required, which causes a problem that the number of parts is increased and the structure is complicated. is there. In addition, since the accommodation portion for the paper discharge cassette is necessary, the number of paper feed cassettes that can be simultaneously installed in the copying machine main body is reduced, and the paper feed cassette replacement work may be required frequently.

An object of the present invention is to provide an image forming apparatus capable of accommodating a paper feed cassette and a paper discharge cassette within the main body of the image forming apparatus with a simple structure.

Another object of the present invention is to provide an image forming apparatus capable of increasing the number of paper feed cassettes that can be simultaneously installed in the main body of the image forming apparatus as needed.

[0008]

(1) An image forming apparatus according to a first aspect of the present invention includes an image forming apparatus main body, an image forming unit disposed inside the image forming apparatus main body and performing image formation on a surface of a sheet, The cassette storage unit, the sheet feeding / conveying unit, and the sheet discharging / conveying unit are provided.

The cassette accommodating portion is provided in the main body of the image forming apparatus, and selectively selects both a paper feeding cassette for accommodating sheets to be supplied to the image forming portion and a discharge cassette for receiving sheets image-formed by the image forming portion. It can be accommodated in. The sheet feeding / conveying unit is a unit that conveys the sheets in the sheet feeding cassette accommodated in the cassette accommodating unit to the image forming unit. The paper discharge conveyance means is a means for conveying the image-formed sheet to a paper discharge cassette housed in the cassette housing portion.

(2) An image forming apparatus according to a second aspect of the present invention includes an image forming apparatus main body, an image forming section disposed inside the image forming apparatus main body for forming an image on the surface of a sheet, a cassette accommodating section, and a detection section. And means.

The cassette accommodating section is provided in the main body of the image forming apparatus and selectively selects both a sheet feeding cassette for accommodating sheets to be supplied to the image forming section and a sheet ejection cassette for receiving the sheet on which the image is formed in the image forming section. Can be accommodated in. The detecting means is means for detecting whether the cassette accommodated in the cassette accommodating portion is a paper discharge cassette or a paper feed cassette.

[0012]

(1) In the image forming apparatus according to the first aspect, the main body of the image forming apparatus is provided with the cassette accommodation portion, and both the paper feeding cassette and the paper ejection cassette are selectively mounted in the cassette accommodation portion. can do. Further, when a paper feed cassette is mounted in the cassette housing portion, a paper feed / conveying unit that conveys the sheets in the paper feed cassette to the image forming portion is provided, and a paper ejection cassette is mounted in the cassette housing portion. When the sheet is discharged, a sheet discharge conveying unit that conveys the image-formed sheet to the sheet discharge cassette is provided.

As described above, since the cassette accommodating portion into which both the paper feeding cassette and the paper ejecting cassette can be mounted is provided, the structure of the cassette accommodating portion can be simplified by making the external shape of each cassette the same. . Also, if the size of the sheets to be used is small, you can install a paper discharge cassette in the cassette housing and a paper feed cassette in the other cassette housing to place cassettes on both sides of the main body of the image forming apparatus. Does not protrude, and the space of the entire device can be reduced.

On the other hand, when there are many kinds of sheet sizes to be used, a paper feed cassette is mounted in the cassette housing portion in which the paper ejection cassette was housed, instead of the paper ejection cassette, and this is fed by the paper feeding and conveying means. Can be transported by. In this case, the sheet discharge path may be switched, and a sheet discharge tray may be attached to the side of the apparatus to discharge the image-formed sheet.

(2) In the image forming apparatus according to the second aspect, both the paper feed cassette and the paper discharge cassette can be selectively mounted in the cassette housing portion as described above. Therefore, if a paper discharge cassette is installed in this cassette housing part and a paper feed cassette is installed in another cassette housing part,
The installation space for the entire device is reduced. Further, if a paper feed cassette is attached to the cassette housing instead of the paper ejection cassette, the types of paper feed cassettes that can be attached to the image forming apparatus main body at the same time can be increased.

Further, since it is detected by the detecting means whether the cassette accommodated in the cassette accommodating portion is the paper discharge cassette or the paper feed cassette, the paper discharge path is controlled according to the type of the cassette. In addition, it becomes easy to control the sheet conveying means.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Overall Structure FIG. 1 shows a copying machine according to an embodiment of the present invention.
In the figure, the copying machine body 1 includes a lower portion 1a and a lower portion 1a.
It is composed of an upper portion 1b mounted on a by a hinge 2 so as to be freely opened and closed. The hinge 2 is provided at the right end of the copying machine body 1 in the figure, and the hinge 2 is provided at the opposite left end.
A cylinder 3 that connects a and 1b is attached.
Two openings 1 are formed on the front surface of the lower portion 1a of the copying machine body 1.
c and 1d are formed vertically side by side. Upper opening 1
A sheet discharge unit (sheet discharge cassette) can be detachably attached to c, and a sheet cassette can be detachably attached to the lower opening 1d. As described above, in the present device, the paper discharge unit and the paper feed cassette are attachable / detachable in the front-rear direction of the device.

A document table 4 is fixed on the upper surface of the copying machine body 1, and a document retainer 5 is provided on the document table 4 so as to be openable and closable. Further, inside the copying machine main body 1, an exposure device 7 for reading a document is provided above the main body. The exposure device 7 is composed of a light source, a mirror, a lens unit, and the like. In addition, in the center of the copying machine body 1,
A photoconductor drum 8 on which an electrostatic latent image is formed is arranged. Around the photosensitive drum 8, a charging device 9, a developing device 10, a transfer device 11, a paper separating device 12 and a cleaning device 13 are arranged.

A sheet feeding device 15 is provided on the upper right side of the opening 1d for the sheet feeding cassette in the figure. The sheet feeding device 15 contacts the uppermost sheet in the sheet cassette and picks up the pickup roller 16 for taking out the sheet.
And a paper feed roller 18 for sending out the taken-out paper to the paper feed / transport path 17, and a belt 19 spanned between the pickup roller 16 and the paper feed roller 18. The sheet feeding / conveying path 17 extends upward from the right side of the opening 1d, and is curved to the inside of the apparatus on the right side of the developing device 10. Conveying rollers 20 and 21 are provided at the middle and upper ends of the paper feeding and conveying path 17, respectively. Further, a paper feeding device 15 having the same configuration is provided on the upper right side of the opening 1c for the paper discharging unit, and the paper feeding device 15 and the paper feeding and conveying path 17 are provided.
A sheet feeding / conveying path 22 is provided between and. The paper feed / transport path 22 merges with the upper part of the paper feed / transport path 17. A paper feeding / transporting path 23 is provided between the paper feeding / transporting path 17 and an image forming section constituted by the photoconductor drum 8 and the like, and the paper feeding / transporting path 23 has an end portion on the image forming section side. Is provided with a registration roller 24 for controlling the paper supply timing. It should be noted that each paper feed transport path 17,
22 and 23 are each configured by a guide plate or the like.

On the downstream side of the image forming section in the sheet conveying direction, there is provided a sheet discharge conveying device 25 for conveying the sheet to the left side of the apparatus. The sheet discharging and conveying device 25 is mainly composed of a circulation belt 26 that circulates in the left-right direction of the device, a drive roller 27 for driving the circulation belt 26, and a driven roller 28. On the downstream side of the sheet discharging and conveying device 25,
The fixing device 30 and a lateral discharge conveyance path 31 and a discharge roller (not shown) for discharging the sheet as it is to the left side of the device.
Is provided. A paper discharge tray 32 for receiving paper can be attached to the discharge side end of the horizontal discharge conveyance path 31. A return transport device 33 is provided below the fixing device 30 and branched from the lateral discharge transport path 31 to guide the paper while reversing the paper. The return transport device 33 includes a guide plate 34 curved downward from the lateral discharge transport path 31, and a plurality of transport rollers 35 for transporting the paper guided by the guide plate 34.
At this time, the guide plate 34 is attached to the paper discharge unit 40 described later.
Make sure that the leading edge of the paper does not hit the circulation belt 62 of
That is, it is provided so as to be inclined with respect to the circulation belt 62 so that the belt can be slipped and discharged smoothly. Further, the discharge end of the sheet is extended so that the discharge end of the guide plate 34 is located on the left end of the circulation belt 62 in the figure so that the sheet can be completely discharged onto the circulation belt 62. Note that the fixing device 3 is provided downstream of the fixing device 30.
A transport switch 37 for detecting that the paper has been transported from 0 is arranged.

The lateral discharge transport path 31 and the return transport device 38
A switching claw 36 is arranged at the branching portion of. As shown in FIG. 2, the switching claw 36 has a lateral ejection posture in which the fed sheet is ejected to the side of the apparatus through the lateral ejection conveyance path 31, and the conveyed sheet is conveyed as shown in FIG. And a front ejection posture for guiding the sheet to the return transport device 33 side.

Paper Discharging Unit (Paper Discharging Cassette) Next, the paper discharging unit mounted in the upper opening 1c of the copying machine main body 1 will be described with reference to FIGS. In the figure, as shown in FIG. 9, the paper discharge unit 40 includes a main body frame 41, a drive unit 42 that can be opened and closed around the rear end of the main body frame 41, a front end of the main body frame 41. It is mainly composed of a paper discharge tray 43 capable of appearing and disappearing with respect to 41.

A front cover 4 is provided on the front side of the body frame 41.
4 are provided. An opening 44a (see FIG. 7) is formed in almost the lower half of the front cover 44.
The stopper portion 43a on the front end face of the paper discharge tray 43 can be housed in a. Further, a recess 44b is formed substantially in the center of the front cover 44.
4b is a handle for pulling out the entire paper discharge unit 40. Further, when pulling out the paper discharge tray 43, it is possible to pull out the paper by using the concave portion 44b. A front guide plate 45 for guiding the sheet conveyed to the front side of the apparatus by the drive unit 42 is provided at the front end portion of the main body frame 41. Further, as shown in FIGS. 4 and 6, a rear guide plate 46 having a predetermined length that is inclined upward toward the front is formed over the entire width direction at the rear end portion that supports the drive unit 42 so as to be openable and closable. Has been done. The rear guide plate 46 is for guiding the sheet conveyed by the drive unit 42 to the inner side of the apparatus to the lower side of the drive unit 42. A plurality of notches 46a are formed in the rear guide plate 46, and a coil spring 47 as a bearing is locked in the notches 46a. This coil spring 47
A guide roller 48 is rotatably supported by the.

The front guide plate 45 and the rear guide plate 4
A guide member 45a (see FIG. 6) corresponding to No. 6 is provided so that the paper is guided downward on the front side.

Further, as shown in FIG. 9, the main body frame 4
A plurality of concave portions 41 a are provided in the sheet 1 at predetermined intervals in the sheet conveying direction and continuously in the width direction. Each recess 41
As shown in an enlarged view in FIG. 5, a guide roller 48 rotatably supported by a coil spring 47 as a bearing is provided in a. In addition, in the main body frame 41,
As shown by being broken in FIG. 4, a plurality of guide ribs 41b are formed along the sheet conveying direction. Further, on the lower surface of the front guide plate 45, a reflection type optical switch (paper discharge switch) 49 for detecting that the paper is discharged to the paper discharge tray 43 side is arranged.

Side walls 50 and 51 are formed on both left and right sides of the main body frame 41. The outer surfaces of the side walls 50 and 51 are shown in FIG. 7 and FIG. 8 which is a rear view of the paper discharge unit 40. As shown, the vertical reinforcing ribs 51a, 52
a is formed at a predetermined interval. Each rib 51a, 52
As is clear from FIG. 8, a is formed in an inverted triangular shape whose width becomes narrower as it goes downward.
Of the ribs 51a and 52a, the ribs 51b and 52 formed near the open / close support portion of the drive unit 42.
b has a rectangular shape in which the upper part and the lower part thereof project laterally by substantially the same amount. These ribs 51b, 52b
However, as will be described later, it serves as a stopper when the paper discharge unit 40 is pulled out.

The paper discharge tray 43 is slidably mounted between the front end portion 41c of the main body frame 41 and the drawer guide portion 41d provided below the front end portion 41c. A stopper projection 43b is formed at the rear end of the paper discharge tray 43 so as to project downward. When the paper discharge tray 43 is pulled out forward, this projection 43b is locked to the front end of the guide portion 41d. Therefore, the pull-out amount of the paper discharge tray 43 is regulated.

The drive unit 42 is a body frame 4
1 has a sub-frame 55 whose rear end is openably and closably mounted. As shown in FIG. 4, the sub-frame 55 includes side walls 56 and 57 arranged in parallel with the side walls 51 and 52 of the main body frame 41, a connecting plate (not shown) connecting the side walls 56 and 57, and a rear plate. It has a support plate 58 arranged substantially at the center of the end portion in the width direction. A drive roller 60 is rotatably attached to the rear end portion of the sub-frame 55, and a driven roller 61 is rotatably attached to the front end portion. A circulation belt 62 is stretched between the drive roller 60 and the driven roller 61. Note that pressing plates 59a and 59b are fixed to the left and right ends of the front guide plate 45, and the front ends of the drive unit 42 are held down by the tips of the pressing plates 59a and 59b.

As shown enlarged in FIG. 5, a drive motor 65 is fixed to the central support plate 58 of the sub-frame 55. A pinion 66 is fixed to the tip of the motor shaft of the drive motor 65. A first shaft 67, a second shaft 68, and a third shaft 69 are rotatably mounted on the central support frame 58. The first shaft 67 has a first gear 70
The second gear 71 is fixed, and the first gear 71 meshes with the pinion 66. Further, the second shaft 68 has
A third gear 72 meshing with the second gear 71 and a fourth gear 73
And are fixed. Further, a fifth gear 74 is fixed to the third shaft 69. The fifth gear 74 meshes with the fourth gear 73 and also meshes with the drive roller gear 75 formed at the axial center of the drive roller 60.
In this way, the rotation of the drive motor 65 is controlled by each gear 70.
Is transmitted to the gear 75 of the drive roller 60 via
The drive roller 60 is adapted to rotate.

As described above, the drive unit such as the drive motor 65 is arranged substantially at the center of the circulation belt 62 in the width direction.
Therefore, when the circulation belt 62 is circulated, the tensions on the left and right become substantially the same, and it is possible to prevent meandering or the like. Further, since the drive motor 65 and the gear train are covered by the circulation belt 62, the soundproof effect is great and the sound leaking to the outside can be reduced.

As enlargedly shown in FIG. 10, a regulation plate 80 for regulating the opening / closing angle of the drive unit 42 is provided at the rear end portion of the sub-frame 55. An arcuate long hole 80a is formed in the regulation plate 80,
The pin 81 fixed to the side wall of the main body frame 41 is inserted into the elongated hole 80a. Further, as shown in an enlarged view in FIG. 11, the bearing 82 that supports the driven roller 61 is provided with the notches 56 provided in the side walls 56 and 57 of the main body frame 55.
It is slidable in a, and a tension setting spring 83 for biasing the driven roller 61 in the direction in which the circulation belt 62 is stretched is provided between the end of the notch 56a and the bearing 82. It is arranged.

As described above, the paper discharge unit 40 has a unit structure and can be easily attached to and detached from the copying machine main body 1. Further, as will be described later, it is easy to replace the paper cassette.

The paper discharge unit 40 having the above structure
Is guided by guide rails 85 and 86 on the copying machine main body 1 side as shown in FIG. 12, and can be slid in the front-back direction with respect to the copying machine main body 1. The guide rails 85 and 86 are arranged in the front-rear direction on the frame of the copying machine main body 1. Further, the cross-section is formed into a substantially L shape, and the standing wall portions 85a and 86a and the paper discharge unit 4 are provided.
Support wall portion 85 for supporting the bottom surface of the main body frame 41 of 0
b and 86b. Each support wall portion 85b, 86b
Projections 85c and 86c projecting upward are formed at the front end portion of the. The projections 85c and 86c are engaged with the lower portions of the stopper ribs 51b and 52b formed on the main body frame 41 of the paper discharge unit 40 described above, and when the paper discharge unit 41 is pulled out to some extent, the pullout is temporarily stopped. It is supposed to be done. In addition, at the end of the support wall portion 85b of the guide rail 85, the paper discharge unit 4 is provided.
A guide protrusion 85d that engages with a guide groove 41e (see FIG. 8) formed in the main body frame 41 of No. 0 is formed. By these engagements, the lateral movement of the paper discharge unit 40 is restricted.

Sheet Feeding Cassette FIGS. 13 and 14 show a sheet feeding cassette 90 which can be mounted in the openings 1c and 1d of the copying machine main body 1. As shown in FIG. 13 is a plan view of the paper feed cassette 90, and FIG. 14 is a front view thereof. The paper feeding cassette 90 is formed such that the external dimensions, that is, the dimension L in the front-rear direction, the width W in the left-right direction, and the height H are substantially the same as those of the paper discharge unit 40. Guide rails 85 and 86 shown in FIG. 12 are fixed in the opening 1d of the copying machine body 1 in the front-rear direction.
Therefore, the paper feed cassette 90 is also formed with stopper projections 91 and 92 for engaging with the projections 85c and 86c of the guide rails 85 and 86, and is also engaged with the guide groove projection 85d of the guide rail 85. Guide groove 9
3 is formed. Further, on the wall surface at the rear end of the paper feed cassette 90, a size detection unit 94 indicating the paper size is provided. Then, on the copying machine main body 1 side, at a position corresponding to the size detecting section 94 of the attached paper feeding cassette 90,
A size reading sensor is provided. This size reading sensor is provided corresponding to both openings 1c and 1d.

In this way, the external dimensions of the paper discharge unit 40 and the paper feed cassette 90 are made the same, and the guide rails 85 and 86 on the main body side are made common, so that both openings 1c of the main body of the apparatus are fed. It is possible to mount the paper cassette 90. Moreover, the number of parts is reduced and the structure is simplified.

Operation Panel An operation panel 95 as shown in FIG. 15 is arranged at the front end of the upper surface of the copying machine main body 1. On the operation panel 95,
Liquid crystal display 96, numeric keypad 97, print key 98
A density adjustment key 99, a zoom key 100, and a paper discharge mode selection key 101 are provided. A key 101 for selecting a paper discharge mode is a front paper discharge face-up mode instruction key 102 for discharging the paper to the front side of the apparatus main body in a face-up state with the image forming surface facing upward.
And a front paper discharge face-down mode instruction key 103 for discharging the paper to the front side of the apparatus with the image forming surface facing downward.
And a lateral paper ejection mode instruction key 104 for ejecting the paper laterally of the copying machine body 1.

Control Unit Further , this copying machine has a control unit 110 as shown in FIG. The control unit 110 includes a CPU, a RAM and an RO.
A microcomputer including M and the like is provided. The control unit 110 includes an operation panel 95 shown in FIG. 15, a transport switch 37 for detecting the transport of paper, and the paper discharge unit 4
0, the paper discharge switch 49, and the copying machine main body 1
The size detecting sensor 111 for detecting the paper size of the paper feeding cassette 90 mounted in the openings 1c and 1d of the above is connected. When the size reading sensor 111 cannot read the paper size, it is determined that the paper discharge unit 40 is attached to the openings 1c and 1d. Further, the control unit 110 includes a conveyance roller drive unit 112 that drives the conveyance rollers 35 of the return conveyance device 33, a drive motor 65 that drives the circulation belt 62, and the like.
13, a switching claw driving unit 114 for driving a solenoid for controlling the attitude of the switching claw 36, and other input / output units are connected.

Usage Method and General Operation Next, the usage method and the general operation of the copying machine of this embodiment will be described. In this apparatus, in the initial state, that is, when the main switch is turned on, the front paper ejection face-up mode is automatically selected as the paper ejection mode. Therefore, normally, the paper discharge unit 40 is mounted in the upper opening 1c, and the paper feed cassette 90 is mounted in the lower opening 1d. Further, when performing the copy process in the front paper discharge mode, the paper discharge tray 43 is pulled out from the paper discharge unit 40 to the front side. When the copying process is not performed, the paper discharge tray 43 can be stored inside the apparatus, so that a wide working space, passage, etc. in front of the apparatus can be secured.

When the print key is pressed, the paper is fed from the paper feeding cassette 90 by the paper feeding device 15 to the paper feeding and conveying path 1.
7 and is sent to the image forming unit via the registration roller 24. The copy-processed paper is sent to the fixing device 30 by the paper discharge / conveyance device 25. The sheet for which the fixing process has been completed is returned to the return transport device 3 by the switching claw 36.
The sheet is guided to the third side and once placed on the circulation belt 62 of the sheet discharge unit 40 in the inverted state. Next, the circulation belt 6
2 circulates so that its upper part moves from the front to the rear. Therefore, the sheet on the circulation belt 62 is once conveyed to the rear side, wraps downward at the rear end portion, is inverted, and is conveyed to the front side. In this way, the sheet is discharged face-up onto the sheet discharge tray 43 on the front side of the apparatus.

When the sheet is discharged face down on the front side of the apparatus, the D key 103 on the operation panel 95 is pressed,
Set the paper ejection mode to the front paper ejection face-down mode. In this case, after the paper is placed on the circulation belt 62 in the same manner as described above, the circulation belt 6 is moved in the opposite direction to the above.
2 rotates. As a result, the paper is ejected onto the paper ejection tray 43 with the face-down posture placed on the circulation belt 62.

When performing horizontal sheet discharge, the S key 104 on the operation panel 95 is pressed and the sheet discharge tray 32 is mounted on the side of the apparatus. Further, since the paper discharge tray 43 of the paper discharge unit 40 is unnecessary, it is stored inside the apparatus. In this case, the sheet subjected to the fixing process is directly discharged onto the discharge tray 32 via the horizontal discharge conveyance path 31.

In this apparatus, instead of the paper discharge unit 40, another paper feed cassette can be attached to the upper opening 1c. In this case, the paper discharge mode is automatically set to the horizontal paper discharge mode. When the upper sheet feeding cassette is selected, the sheet is supplied to the image forming unit via the sheet feeding and conveying paths 22 and 23.

As described above, in the apparatus of this embodiment, various paper discharge modes can be selected according to the usage status. Further, when the paper discharge unit 40 is not attached, the horizontal paper discharge mode can be automatically selected, so that it is possible to prevent a paper jam inside the apparatus due to a mistake in setting the paper discharge mode. Further, since the paper discharge unit 40 is installed above the paper feed cassette and the paper is discharged to the position (uppermost position) closest to the operator, the copy state and the like can be easily confirmed.

Control Operation The control operation will be described with reference to the flowchart shown in FIG. When a main switch (not shown) is turned on, initialization is performed in step S1. In this initial setting, processing such as setting the number of copies to one is performed. Next, in step S2, it is determined whether or not the print key is pressed. Also, step S3 and step S4
Then, it is determined whether or not the key for selecting the paper discharge mode is pressed, and whether or not another key is pressed. If another key is pressed, the program goes to step S4.
Then, the process proceeds to step S5, and the process corresponding to the pressed key is executed. In step S6, other processing is executed and the process returns to step S2.

In the initial setting of step S1, the display and control processing of the paper discharge mode is executed. FIG. 18 shows the contents of the discharge mode display and control processing. That is, in step S10, it is determined whether the paper size reading sensor detects the paper size. When the paper discharge unit 40 is attached to the upper opening 1c of the copying machine main body 1, the paper size is not detected, and the program shifts from step S10 to step S11. Step S1
In 1, the solenoid for driving the switching claw 36 is turned on. As a result, the switching claw 36 is in the front sheet ejection posture as shown in FIG. 3, and guides the sheet sent from the fixing device 30 to the return conveyance device 33 side. Next, in step S12, the front paper ejection face-up key (U key) 102 on the operation panel 95 is turned on.

On the other hand, if the paper discharge unit 40 is not attached to the copying machine main body 1, for example, if the paper feed cassette is attached to the opening 1c, the program proceeds to step S.
The process proceeds from step 10 to step S13. In step S13, the solenoid for driving the switching claw 36 is turned off. As a result, the switching claw 36 is in the horizontal paper ejection posture as shown in FIG. Next, in step S14, the horizontal paper ejection mode key 104 on the operation panel 95 is turned on.

As described above, in the initial state, the sheet discharge path is automatically switched depending on the mounting state of the sheet discharge unit 40, and when the sheet discharge unit 40 is mounted, the front sheet discharge face-up sheet discharge mode is set. Automatically selected,
If the paper discharge unit 40 is not attached, the horizontal paper discharge mode is automatically selected.

It is also possible for the operator to arbitrarily select the paper discharge mode by pressing the select key on the operation panel 95. That is, when the paper discharge mode selection key is pressed, the process proceeds from step S3 to step S15 in FIG. In step S15, step S16, and step S17, it is determined whether the front paper ejection face-up mode key (U key) 102 has been pressed, the front paper ejection face-down mode key (D key) 103 has been pressed, or not. It is determined whether or not the discharge mode key (S key) 104 has been pressed. When the U key 102 is pressed, the process proceeds from step S15 to step S18, and the front paper ejection face-up mode is selected as the paper ejection mode. In this case, the solenoid for controlling the posture of the switching pawl 36 is turned on as in the above, and the switching pawl 36 is in the front paper ejection posture. If the D key 103 is pressed, steps S16 to S19 are performed.
Move to. In step S19, as the paper discharge mode,
Front paper ejection face down mode is selected. Also in this case, the switching claw 36 is controlled to the front paper ejection posture. If the S key 104 is pressed, the process proceeds from step S17 to step S20. Step S20
Then, the horizontal discharge mode is selected as the discharge mode. In this case, the switching claw 36 is controlled to the horizontal paper ejection posture.

If the print key is pressed, the program moves from step S2 to step S21. In step S21, copy processing including paper feeding processing, image forming processing, and paper discharge processing is performed. When the copy process ends, the process returns to step S2.

Next, the paper discharge process included in the copy process of step S21 will be described with reference to the flowchart of FIG. In step S30, it is determined whether or not the paper transport switch 37 provided on the downstream side of the fixing device 30 is turned on. After the conveyance switch 37 is turned on, the process proceeds from step S30 to step S31. In step S31, it is determined whether the paper discharge mode is the front paper discharge mode. If the front paper ejection mode is selected, the process proceeds from step S31 to step S32. In step S32, the transport roller 35 of the return transport device 33 is driven. As a result, the sheet that has passed through the fixing device 30 is guided to the transport path 34 of the return transport device 33 by the guide of the switching claw 36, and the transport roller 35.
Thus, the front and back of the sheet are reversed and guided onto the sheet discharge unit 40 below the fixing device 30. In step S33, it is determined whether or not time T1 has elapsed since the paper transport switch 37 was turned on. This time T1 is set according to the paper size, and the paper is discharged from the paper discharge unit 4
This is for determining whether or not it is placed on the circulation belt 62 of 0. When the time T1 has elapsed, it is determined that the paper is placed on the circulation belt 62 of the paper discharge unit 40, and the process proceeds from step S33 to step S34. In step S34, driving of the transport rollers 35 in the return transport path 33 is stopped.

In step S35, it is determined whether the face-up mode is selected from the front paper ejection modes as the paper ejection mode. When the face-up mode is selected, the program proceeds from step S35 to step S36. In step S36, the drive motor 65 is rotated in the forward direction. As a result, the rotation of the drive motor 65 is controlled by the pinion 66 and the first to fifth parts.
Is transmitted to the gear 75 of the drive roller 60 through the gears 70 to 74 of the drive roller 60, and the drive roller 60 rotates. By the rotation of the drive roller 60, the circulation belt 62 stretched over the drive roller 60.
Rotates in the direction A of FIG. As a result, the sheet placed on the circulation belt 62 is temporarily sent to the rear side of the copying machine main body 1 along the circulation belt 62. And the rear guide plate 4
6 is guided to the lower side of the circulation belt 62, and is guided to the front side of the apparatus by the circulation belt 62 and the conveyance roller 48. In this way, the sheet placed on the circulation belt 62 is reversed by feeding the sheet to the front side of the apparatus while the circulation belt 62 rotates in the direction A, and is discharged face-up to the sheet discharge tray 43. To be done.

In step S37, it is determined whether or not time T2 has elapsed since the circulation belt 62 started rotating. After waiting the time T2, the process proceeds to step S38. In step S38, it is determined whether or not the switch 49 provided on the lower surface of the front guide plate 45 for detecting the paper discharge is turned on. If the discharge switch 49 is turned on, the process proceeds to step S39, and it is determined whether or not time T4 has elapsed since the discharge switch 49 was turned on. This time T4
Is set according to the paper size and is for detecting whether or not the paper is normally discharged from the paper discharge unit 40. When the time T4 has elapsed, the process proceeds to step S40. In step S40, it is determined whether the discharge switch 49 is turned off. When the paper is normally ejected from the paper ejection unit 40, the ejection switch 49 is turned off after the elapse of the time T4, and therefore the program proceeds from step S40 to step S41. In step S41, the rotation of the drive motor 65 is stopped,
The circulation belt 62 is stopped.

In step S38, if the discharge switch 49 does not turn on even after the time T2 has elapsed,
It is possible that the paper is jammed near the rear of the paper discharge unit 40. If the discharge switch 49 does not turn off even after the lapse of time T4 in step S40, it is considered that the paper is jammed at the front end portion of the paper discharge unit 40 and is not normally discharged. Therefore, in these cases, the process proceeds to step S42 and the apparatus is stopped. Next, in step S43, the jam display is lit on the operation panel 95, and the process ends.

When a paper jam occurs in the paper discharge unit 40, the entire paper discharge unit 40 is pulled out to the front side of the apparatus using the recess 44a of the front cover 44 of the paper discharge unit 40. At this time, the paper discharge unit 40 is smoothly pulled out along the guide rails 85 and 86 fixed to the apparatus main body side. Then, at the position where the rear end portion of the circulation belt 62 is exposed to the outside of the apparatus, the ribs 51b for stoppers,
When 52b is a guide rail, it is locked to 85c and 86c, and its withdrawal is temporarily stopped. In this state, by removing the holding plates 59a and 59b of the paper discharge unit 40, the front of the drive unit 42 can be lifted to the state shown in FIG. In this way, the paper discharge unit 4
It is possible to easily remove the paper jammed at the rear end portion or the front end portion of 0.

As described above, when the front paper discharge face-up mode is selected, the copy-processed paper is reversed by the return conveyance device 33 and is placed face down on the circulation belt 62. To be done. Then, the circulation belt 62 circulates in the direction A, and the paper is ejected onto the paper ejection tray 43 on the front side of the apparatus while face-up while further reversing the paper. Therefore, the operator can easily confirm the copy status during the copying process, and a large amount of miscopy can be prevented.

On the other hand, when the front paper discharge face down mode is selected as the paper discharge mode, NO is determined in step S35 of FIG. 19, and the program proceeds from step S35 to step S45. In step S45, the drive motor 65 is rotated in the opposite direction. As a result, the drive roller 60 is rotated in the opposite direction to the above through the pinion 66 and the first to fifth gears 70 to 74, and the circulation belt 62 is rotated in the B direction. Therefore, the sheet placed on the circulation belt 62 is discharged to the front side of the apparatus with the face down state. In step S46, it is determined whether or not time T3 has elapsed since the circulation belt 62 started circulating. This time T3
Is shorter than the time T2 and is set according to the paper size. If it is determined in step S46 that the time T3 has elapsed, the program proceeds to step S46.
To Step S38. The process after step S38 is exactly the same as that in the face-up mode.

When the horizontal sheet discharge mode is selected as the sheet discharge mode, NO is determined in step S31 of FIG. 19, and the program proceeds from step S31 to step S50. In step S50, a horizontal paper discharge process is performed. That is, the sheet that has passed through the fixing device 30 is guided by the lateral discharge conveyance path 31 and the switching claw 36, is guided to the left side of the device, and is discharged onto the discharge tray 32.

[Other Embodiments] FIG. 20 shows another embodiment. In this embodiment, a reversing device 120 for reversing the paper is provided in the middle of the path for guiding the paper that has passed through the fixing device 30 to the paper discharge unit 40. The reversing device 120 extends downward from the switching pawl 36 and extends in a substantially horizontal direction below the opening 1c for mounting the paper discharge unit 40, and branches from the middle of the first transport path 121. The second transport path 122 for guiding the sheet transported from below to the sheet discharge unit 40 side, and each transport path 12
Conveying rollers 123 for conveying the sheets in 1, 122
It consists of and. In addition, the first transport path 121 and the second
As shown in FIG. 21, a switching claw 124 is provided at a branch portion with respect to the transport path 122. This switching claw 124
Has a posture indicated by a chain line that guides the sheet in the first conveyance path 121 from the upper side to a lower side, and a posture indicated by a solid line that guides the sheet sent from the lower side to the upper side to the second conveyance path 122 side. I'm supposed to get it. The other structure is the same as that of the above embodiment.

In such an embodiment, when the front paper discharge mode is selected, the paper that has passed through the fixing device 30 is guided by the switching claw 36 and conveyed to the first conveyance path 121 side. At this time, the switching claw 124 is
The posture is controlled as shown by the alternate long and short dash line. Therefore,
The paper in the first transport path 121 is guided to the transport path 121 and sent to the lower side of the paper discharge unit. In this case, the paper is face down.

When the paper is transported to the horizontal portion of the first transport path 121, the transport rollers 123 start rotating in the opposite direction. As a result, the sheet is conveyed in the direction opposite to the above on the first conveying path 121 and is sent upward. At this time, the switching claw 124 is controlled to the posture shown by the solid line in FIG. Therefore, the sheet conveyed upward in the first conveying path 121 is guided to the second conveying path 122 side by being guided by the switching claw 124, and passes through the second conveying path 122, and the circulation belt of the paper discharge unit 40. It is conveyed onto 62. In this state, the sheet is placed face up on the circulation belt 62.

Therefore, in this apparatus, when the front paper discharge face-up mode is selected as the paper discharge mode, the circulation belt 62 is circulated in the direction B of FIG. 4 contrary to the above embodiment. As a result, the paper is discharged onto the paper discharge tray 43 on the front surface of the apparatus while keeping the face-up state. Conversely, when the front paper discharge face-down mode is selected, the circulation belt 62 is circulated in the direction A of FIG. As a result, the sheet is inverted and discharged face-down onto the sheet discharge tray 43 on the front side of the apparatus.

Although the present invention is applied to the copying machine in each of the above-described embodiments, the present invention can be similarly applied to other image forming apparatuses such as printing machines and sheet discharging apparatuses thereof.

[0063]

As described above, according to the present invention, since the cassette accommodating portion capable of selectively accommodating both the paper feed cassette and the paper discharge cassette is provided, if the outer dimensions of the cassettes are the same, The structure of the cassette housing can be simplified and the number of parts can be reduced. Further, when the paper discharge cassette is mounted in the cassette housing, the installation space of the entire apparatus can be reduced, and when the paper feeding cassette is mounted, the types of sheets that can be simultaneously mounted in the apparatus main body can be increased.

Further, in the present invention, since the detecting means for detecting the type of the cassette accommodated in the cassette accommodating portion is provided, the control of the paper discharge path and the drive control of the conveying means can be facilitated based on the detection result. It can be carried out.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional configuration diagram of a copying machine to which an embodiment of the present invention is applied.

FIG. 2 is an enlarged view of a switching claw of the device.

FIG. 3 is an enlarged view of a switching claw of the device.

FIG. 4 is a plan view of a paper discharge unit of the apparatus.

FIG. 5 is a partially enlarged view thereof.

FIG. 6 is a side view of the paper discharge unit.

FIG. 7 is a front view thereof.

FIG. 8 is a rear view thereof.

FIG. 9 is a sectional side view of the paper discharge unit.

FIG. 10 is a partially enlarged view of FIG.

FIG. 11 is a partially enlarged view of FIG. 9.

FIG. 12 is a front view of a guide rail of the copying machine.

FIG. 13 is a plan view of a paper feed cassette mounted in the copying machine.

FIG. 14 is a front view thereof.

FIG. 15 is a diagram showing an operation panel of the copying machine.

FIG. 16 is a control block diagram of the copying machine.

FIG. 17 is a control flowchart thereof.

FIG. 18 is a flowchart of display and control processing of a paper discharge mode.

FIG. 19 is a flowchart of paper discharge processing.

FIG. 20 is a schematic sectional configuration diagram of a copying machine according to another embodiment.

FIG. 21 is a partially enlarged view thereof.

[Explanation of symbols]

1 Copier body 8 photoconductor drum 9 Charging device 10 Development device 11 Transfer device 12 Paper separating device 15 Paper feeding device 17,21,22,23 Paper feed transport path 25 Paper discharge transport path 33 Return transport device 40 paper discharge unit 90 paper cassettes

Claims (2)

[Claims] 1. An image forming apparatus main body, an image forming unit disposed inside the image forming apparatus main body, for forming an image on a surface of a sheet, and provided in the image forming apparatus main body, and supplied to the image forming unit. A sheet cassette for storing sheets to be stored and a sheet discharge cassette for selectively receiving the sheet on which the image is formed by the image forming section; and a sheet cassette in the cassette storing section. An image forming apparatus including: a sheet feeding and conveying unit configured to convey the sheet to the image forming unit; and a sheet discharging and conveying unit configured to convey the image-formed sheet to a sheet discharging cassette housed in the cassette housing unit. 2. An image forming apparatus main body, an image forming section which is disposed inside the image forming apparatus main body and forms an image on a surface of a sheet, and which is provided in the image forming apparatus main body and is supplied to the image forming section. And a cassette accommodating section capable of selectively accommodating both a sheet feeding cassette accommodating a sheet to be accommodated and a sheet ejection cassette receiving a sheet on which an image has been formed in the image forming section, An image forming apparatus comprising: a detection unit that detects whether a cassette or a paper feed cassette.