JPH10305943A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To feed a sheet of special paper in rigid force without using any manual feeding tray as well as to prevent any paper jam from occurring. SOLUTION: This paper feeder is provided with a device body 2, where a feeding route is set up so as to make a sheet of special paper S2 in rigid force so as not to be curved as far as less than a constant radius of curvature, and being made up of a paper conveyor route 8 to guide a sheet of paper S1 inclusive of the special paper S2 to an image forming part 3 and a discharged paper receiver 13 at the downstream side, and in this constitution, two paper feed cassettes 28a and 28b inclusive of this multi-paper feed cassette 28b permitting the storage of the paper S1 including the special paper S2 are installed in a projected surface of the device body 2, and then a guide part 36 with a radius of curvature of more than the constant one is formed in a flexure of a paper feeding path 34 connecting the multi-paper feed cassette 28b and an inlet of the paper conveyor route 8 to each other, Accordingly, in the case where the special paper S2 stored in the multi-paper feed cassette 28b is fed to the image forming part 3, this special paper S2 is fed without curving it perforce, so that any paper jam is thus prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device for feeding sheets to an image forming apparatus such as a copying machine and a printer.

[0002]

2. Description of the Related Art Recently, OA equipment has been required to be downsized to save space. Therefore, in an image forming apparatus having a plurality of paper feed cassettes for handling plain papers of different sizes, in order to reduce the installation space, a plurality of paper feed cassettes are stacked below the apparatus main body, and any selected paper feed cassette is selected. Paper is being fed from the cassette. In this case, since the individual paper feed cassettes are arranged horizontally, the paper drawn from the paper feed cassette is curved by the paper feed path and guided to the upper image forming unit.

Some paper feed cassettes used in such an image forming apparatus can selectively store sheets of different sizes. In this case, for example, Japanese Unexamined Utility Model Publication No. 58-7742 discloses a paper feed cassette. As described, a display window is formed in the paper feed cassette, and a size indicator indicating the size of the paper is arranged in the display window. The size of the display has been done.

When feeding paper from a paper feed cassette arranged below the apparatus main body, the paper is curved by a paper feed path and guided to an upper image forming apparatus. When the sheet is fed, the sheet cannot be flexibly curved due to the small radius of curvature of the sheet feeding path, and stagnates, thereby causing a jam. Therefore, in a model handling special paper, a manual tray is provided on a side surface of the apparatus main body so as to feed the special paper without curving as much as possible.

Some image forming apparatuses have a double-sided printing function and a sorter function. In such an image forming apparatus, in a normal print mode, printed paper is discharged to a standard paper discharge tray. When the duplex printing mode is set or the sorter mode is set, the switching claw provided to selectively change the paper direction in the paper transport path is automatically controlled. The printed paper is guided to a double-sided printing unit or a sorter in accordance with the above.

In this case, the radius of curvature of the paper discharge path from the image forming section to the standard paper discharge receiver is not so small. On the other hand, in the case of double-sided printing, it is necessary to turn over the paper in a narrow space and re-feed the paper to the image forming unit in order to save space. Similarly, when a sorter is used, since a sheet is inverted and discharged in a narrow space, a portion where the sheet is curved with a small radius of curvature is formed in the sheet conveying path.

[0007]

When special paper is fed from the manual feed tray provided on the side of the apparatus main body, the special paper does not have a curl, but the manual feed tray can be fed from the side of the apparatus main body. The projecting space increases the installation space, which defeats the purpose of saving space.

Further, in an image forming apparatus having a double-sided printing function and a sorter function, when performing double-sided printing or using a sorter, the sheet is inverted and conveyed in a narrow space. When such special paper such as thick paper is used, the paper cannot be flexed flexibly in the paper transport path and stagnates, causing a jam.

[0009]

According to the first aspect of the present invention,
A sheet that guides a sheet containing the special paper to an image forming unit and a discharge receiving tray on the downstream side thereof, with a route determined so as not to forcibly curve a special paper having a strong rigidity such as an envelope or cardboard to a certain radius of curvature or less. An apparatus main body having a transport path formed therein is provided, and a plurality of paper feed cassettes including a multi-sheet feed cassette that allows storage of the paper including the special paper are spaced at predetermined intervals in a vertical direction within a projection plane of the apparatus main body. A plurality of paper feed paths for guiding the paper from each end of the paper feed cassette toward the entrance of the paper feed path, and providing a plurality of paper feed paths; A guide portion having a radius of curvature equal to or greater than a predetermined value is formed at the bent portion of the paper feed path connecting the entrance of the paper sheet so as not to forcibly bend the special paper. Therefore, when the special paper stored in the multi-feed cassette is fed to the image forming unit of the apparatus main body, the paper is fed without forcibly curving, thereby preventing the occurrence of a jam.

According to a second aspect of the present invention, in the first aspect of the invention, there is provided an input means for electrically inputting selection of a sheet to be fed, and a special paper feeding mode is selected by the input means. Is provided with a paper discharge path specifying means for specifying a paper discharge destination from the image forming unit as a paper discharge receiver. Therefore, when the special paper is used, the paper discharge path of the paper discharged from the image forming unit is automatically set to the paper discharge tray. This allows
When the special paper is selected, it is possible to prevent the occurrence of a jam due to the careless conveyance of the special paper to the duplex printing unit or the sorter.

According to a third aspect of the present invention, in the second aspect, a multi-sheet feeding cassette capable of selectively storing special paper and plain paper is used. Therefore, since the multi-sheet feeding cassette can be used as a sheet feeding cassette for storing sheets other than special sheets, it is possible to widen a selection range of sizes handled when using plain paper.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a default means for setting an input state of the input means to a selected state of the special paper when the multi-sheet cassette supported so as to be able to be pulled out is pulled out. It has. Therefore,
Plain paper is selectively stored in addition to the special paper in the multi paper cassette, but every time the multi paper cassette is pulled out to replenish paper, the special paper is selected regardless of the previous setting. State can be set. Thus, when special paper is used, it is possible to prevent the occurrence of a jam due to double-sided printing of the special paper or discharge of the special paper to a sorter due to an input error in the paper selection operation.

According to a fifth aspect of the present invention, in the second, third or fourth aspect of the present invention, an operation panel having a display unit for displaying a state inputted by the input means is provided. Accordingly, it is possible for the user to visually recognize the type of paper stored in the multi-sheet cassette.

The invention according to claim 6 is the first, second, second or third aspect of the present invention.
In the invention described in 3, 4, or 5, the multi-sheet feeding cassette includes identification means capable of visually distinguishing from the other sheet feeding cassettes. Therefore, it is possible to prevent the occurrence of a jam caused by storing and feeding the special paper in a paper feed cassette other than the multi paper feed cassette leading to the paper feed path having a large curvature radius.

[0015]

FIG. 1 shows a first embodiment of the present invention.
It will be described based on. Reference numeral 1 denotes an image forming apparatus. An image forming unit 3 is disposed inside the apparatus main body 2 of the image forming apparatus 1 so as to be close to one side. Since the image forming section 3 is of a known electrophotographic type, only its outline will be described.
A latent image is formed on the surface of the photoconductor 4 and developed, the image is transferred to a sheet by a transfer unit 5, and the transferred image is fixed by a fixing unit 6. The device body 2
Is provided with a paper transport path 8 extending from the bottom surface to the paper discharge port 7 through the image forming section 3, and registration rollers 9 and transport rollers 10 are arranged in the paper transport path 8. A rotatable switching claw 11 which is driven by a solenoid (not shown) and switches the paper discharge direction is provided above the paper transport path 8.
And a paper discharge roller 12 for discharging the paper guided by the switching claw 11 from the paper discharge port 7 are arranged. A discharge tray 13 is formed on the side of the discharge port 7. In addition,
The paper transport path from the lower end of the paper transport path 8 to the paper discharge port 7 has a large curvature even at a bent portion so that strong special paper such as an envelope or thick paper can be transported without forcibly curving. The radius is determined. Further, a scanner 14 is provided on an upper portion of the apparatus main body 2, and an operation panel 15 is provided on a front surface of the scanner 14.

Here, the configuration of the optional double-sided printing unit 16 selectively mounted on the apparatus main body 2 will be described. The double-sided printing unit 16 has a unit case 17 detachably mounted on the apparatus main body 2 of the image forming apparatus 1.
Reversing path 18 that guides the sheet guided by the right by curving it in the right direction, and connects the sheet U
A switchback passage 19 which is bent and guided in the shape of a letter,
The sheet sent out from the switchback path 19 is
A sheet re-feeding path 20 that is bent in a letter shape and guided below the sheet conveying path 8 of the apparatus main body 2 is provided. Reversing passage 18
A conveyance roller 21 driven clockwise to convey the sheet from the reversing path 18 to the switchback path 19 in the vicinity of a confluence where the switchback path 19 and the refeed path 20 converge; When transport roller 21
And a switchback roller 22 that conveys the sheet delivered to the switchback path 19 and switches back the sheet when driven in a counterclockwise direction, and a driven roller 23 pressed against each of the rollers 21 and 22. , 24 are provided. Also, the re-feeding path 20
Is provided with a transport roller 25 for transporting a sheet.
The switchback roller 22 is configured such that when the leading end of the sheet conveyed to the switchback path 19 is detected by a sheet sensor (not shown), the rotation direction is reversed by the reversing operation of the motor. I have.

Next, the configuration of the sheet feeding device 26 will be described. A plurality of paper feed cassettes 28a and 28b are attached to the outer casing 27 supporting the apparatus main body 2 of the image forming apparatus 1 in a mounted state so as to be able to be pulled out toward the front (in a direction perpendicular to the plane of FIG. 1). . These sheet cassettes 28a and 28b support the sheets S1 and S2 in a stacked state, and have a sheet pressing plate 29 that is urged upward and is undulating. At the right end of these sheet cassettes 28a, 28b, the uppermost sheet S1,
Paper feed roller 30 for feeding S2;
And a separation roller 31 that separates and conveys the sheets S1 and S2 delivered one by one. Further, a vertical path 32 having an upper end connected to the lower end of the paper transport path 8 of the apparatus main body 2 is formed in the outer casing 27. And
A plurality of paper feed paths 33 and 34 are provided to guide the papers S1 and S2 by bending them toward the entrance (lower end) of the paper transport path 8 from the right ends of the paper feed cassettes 28a and 28b. These paper feed paths 33 and 34 are connected to the entrance of the paper transport path 8 via a vertical path 32. further,
In the path 32, a plurality of transport rollers 35 are arranged.

Here, S1 is plain paper used as a cut sheet, and S2 is special paper having strong stiffness such as an envelope or cardboard. The second-stage paper cassette 28b is a special paper S having a strong stiffness.
2 is set as a multi-sheet cassette, and the other sheet cassettes 28a are set for plain paper S1. Then, the multi-sheet feeding cassette 28b and the sheet conveying path 8
The special paper S2 is provided at the bent portion of the paper feed path 34 connecting the entrance of the special paper S2 so as not to forcibly bend the special paper S2.
A guide portion 36 having a radius of curvature equal to or greater than a predetermined value is formed so as not to forcibly bend 2.

The operation panel 15 described above is used to set a mode,
It has a function of selecting the paper feed cassettes 28a and 28b, inputting the setting of the number of copies, and displaying the operation state.
Since various settings are input as electric signals, the image forming apparatus 1 includes a control unit (not shown) having a microcomputer configuration that controls the operation of each unit according to the input. This control unit operates the special paper S2
When the paper feed of the image forming unit 3 is selected, the paper discharge unit has a function as a paper discharge path specifying unit that specifies the paper discharge destination from the image forming unit 3 to the paper discharge receiver 13. The function will be described later.

In such a configuration, at the time of copying or printing, the paper feed cassettes 28a, 28
Select 8b. If the first-stage paper feed cassette 28a is selected, the plain paper S1 stored in the paper feed cassette 28a can be easily curved with a small radius of curvature. No, but accepts settings from the user, such as the sorter mode using the sorter. In the control unit, according to the set mode,
The operation of each unit is controlled according to a preset program to set the discharge destination of the plain paper S1, and the image forming unit 3
Control the operation of. Since the control itself is the same as that of the conventional method, the general operation will be described by taking the double-sided printing mode as an example.

When the start button on the operation panel 15 is pressed, the transport roller 10 is driven, and at the same time, the paper feed roller 30 and the separation roller 31 corresponding to the first-stage paper feed cassette 28a are driven. The plain paper S1 in the second paper feed cassette 28a is fed to the paper transport path 8, and comes into contact with the nip portion of the registration roller 9 which stops, and stops. On the other hand, in the image forming unit 3, an image is formed on the photoconductor 4, and the registration roller 9 rotates in synchronization with the image forming process to convey the plain paper S <b> 1 toward the outer periphery of the photoconductor 4. 4 is transferred to the plain paper S1 by the transfer unit 5. When the plain paper S1 passes through the fixing unit 6, the transfer image is fixed. In the process of front-side printing of double-sided printing, the switching claw 11 is oriented so as to connect between the fixing unit 6 and the reversing passage 18, so that the fixed plain paper S 1 is transferred to the reversing passage 18 by the switching claw 11. You will be guided.

The plain paper S1 guided to the reversing path 18 is
The sheet is guided to the switchback passage 19 by the transport roller 21 and the switchback roller 22 that rotate clockwise. Until the rear end of the plain paper S1 passes through the nip portion between the switchback roller 22 and the driven roller 24, the paper S
Is detected by the paper sensor, the rotation direction of the motor driving the switchback roller 22 is reversed by using the detection signal as a trigger, so that the paper S conveyed to the switchback passage 19 moves in the reverse direction. Conveyed.
At this time, the leading end of the plain paper S1 conveyed in the reverse direction comes into contact with the conveying roller 21 rotating clockwise, so that the plain paper S1 is guided to the re-feeding path 20 without the switching claw, and the conveying roller 25 and the conveying roller 10 Is fed again to the sheet transport path 8.
In this state, the plain paper S1 comes into contact with the nip portion of the registration roller 9 which is stationary with the printing surface printed last time on the back side, and stops.

In the meantime, the next image is formed on the photoconductor 4, and the registration roller 9 rotates in synchronization with the image forming process to convey the plain paper S1 toward the outer periphery of the photoconductor 4. The image on the body 4 is transferred to the plain paper S1 by the transfer unit 5. When the plain paper S1 passes through the fixing unit 6, the transfer image is fixed. By this time, since the direction of the switching claw 11 is reversed, the fixed plain paper S
1 is guided to the paper discharge port 7 side by the switching claw 11, and is discharged to the paper discharge receiver 13 by the paper discharge roller 12.

Next, assuming that the second multi-sheet feeding cassette 28b is selected by the operation panel 15, the special sheet S2 stored in the multi-sheet feeding cassette 28b cannot be easily curved with a small radius of curvature. The control unit prohibits the user from setting the duplex printing mode, the sorter mode using the sorter, and the like.
Control to be set.

When the start button on the operation panel 15 is pressed, the transport rollers 10 and 35 are driven, and
Since the paper feed roller 30 and the separation roller 31 corresponding to the multi-stage paper feed cassette 28b of the second stage are driven, the special paper S2 of the multi-stage paper feed cassette 28b of the second stage is fed to the paper conveyance path 8. An image is printed on the special paper S2 by the image forming unit 3 in the same manner as the operation described above. When the discharge destination is set to the discharge tray 13, the switching claw 11 is set so as to connect between the fixing unit 6 and the discharge port 7, so that the fixed plain paper S <b> 1 is switched. The paper is guided to the paper discharge port 7 by the claws 11 and discharged to the paper discharge receiver 13.

As described above, the multi-sheet feeding cassette 28b
When the special paper S2 stored in the image forming unit 3 is fed to the image forming unit 3 of the apparatus main body 2, the special paper S2 can be fed without forcibly curving, so that occurrence of a jam can be prevented. . Further, it is possible to prevent the special paper S2 from being curled.

Further, the selection of the plain paper S1 or the special paper S2 is performed by operating the operation panel 15 (corresponding to the input means). When the paper supply of the special paper S2 is selected by the operation panel 15, the image is displayed. When the special paper S2 is used, the paper discharge path of the special paper S2 discharged from the image forming unit 3 is automatically discharged because the paper discharge destination from the forming unit 3 is specified in the paper discharge receiver 13. The receiver 13 can be set.
Thereby, when the special paper S2 is selected, the special paper S
2 can be prevented beforehand from being transported to the duplex printing unit 16 or the sorter carelessly.

Next, a second embodiment of the present invention will be described. In this embodiment and other embodiments that follow it, the same parts as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIGS. 2 and 3, a lever 38 is provided on one side of the multi-sheet feeding cassette 28b which can selectively use the plain paper S1 and the special paper S2 so as to be rotatable up and down around a fulcrum shaft 37 as a fulcrum. Have been. Further, inside the outer casing 27 of the sheet feeding device 26 (see FIG. 1), a surface 27a facing the rear surface of the multi sheet feeding cassette 28b.
Is provided with input means 39 for electrically inputting selection of paper to be fed. The input means 39 is provided for the plain paper S
1 and a switch 41 for selecting the special paper S2. When the direction of the lever 38 is changed as shown by a solid line in FIG.
Reference numeral 1 denotes a switch that is turned on when the direction of the lever 38 is changed as indicated by a virtual line. In this case, the lever 38
Are biased in one direction by a spring 42 in a direction to turn on a switch 41 for selecting the special paper S2, and stoppers 43 and 44 for limiting the rotation range are provided on the multi-sheet cassette 28b.

Further, the multi-sheet cassette 28b includes
There is provided a default unit 45 for setting the input unit 39 to the selection state of the special paper S2 when the multi sheet cassette 28b is pulled out. The default means may electrically detect the pulling-out operation of the multi-sheet feeding cassette 28b and designate the selection of the special paper S2 by electrical processing. However, in this embodiment, the mechanical default means 45 is used. I have. That is, the default means 45 includes a link 48 having a pin 46 at its lower end for pressing the upper surface of the end of the lever 38 opposite to the switches 40 and 41 and rotating integrally with the fulcrum shaft 47; And a handle 49 for rotating. The fulcrum shaft 47 is connected to the multi-sheet feeding cassette 28b.
Are rotatably supported by a part of the.

In such a configuration, the multi-sheet feeding cassette 28a can selectively store the plain paper S1 in addition to the special sheet S2.
b can be used as a sheet cassette for storing plain paper S1 other than the special paper S2. Thereby, the plain paper S
1 can be used in a wider range of sizes to be handled.

When the plain paper S1 is stored, the lever 38 is turned as shown by a solid line against the urging force of the spring 42, the link 48 is turned clockwise, and the pin 46 is turned. 38 end. In this state, since the lever 38 is maintained in a state where the switch 40 is turned on by the pin 46, an electric signal for selecting the plain paper S1 is input. Thus, the control unit can accept the setting of the duplex printing mode or the sorter mode.

When the user grips the handle 49 and pulls out the multi-sheet cassette 28b to replenish the plain paper S1 or the special paper S2, the fulcrum shaft 47 rotates counterclockwise together with the link 48 in FIG. 46 comes off the end of the lever 38. As a result, the lever 38 is
The switch 41 is turned on by pivoting counterclockwise about the fulcrum shaft 37 by the urging force of. That is, each time the multi-sheet cassette 28b is pulled out, the special sheet S2 is set to the selected state regardless of the previous setting.

By doing so, the plain paper S1
When a user who does not know that has been selected has pulled out the multi-sheet feeding cassette 28b to replenish the special paper S2, a state in which the special paper S2 is automatically selected can be obtained. Since the control unit recognizes that the switch 41 is turned on, the setting of the double-sided printing mode or the sorter mode is prohibited as described above. Accordingly, occurrence of a jam due to double-sided printing of the special paper S2 or discharge of the special paper S2 to the sorter is prevented.

Next, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, the plain paper S1 and the special paper S2 can be selectively stored in the second-stage multi-sheet feeding cassette 28b. Paper cassette 2
This is an example in which input means 50 for selecting a sheet to be stored in 8b is provided. The input means 50 includes a switch 51 for selecting plain paper S1 and a switch 52 for selecting special paper S2.
In the center of the button 52, display units (LEDs) 53 and 54 for displaying the input state are embedded.

Therefore, the user can visually recognize the types of the sheets S1 and S2 stored in the multi-sheet cassette 28b.

Further, a fourth embodiment of the present invention will be described with reference to FIG. The multi-sheet feeding cassette 28b in this example is visually recognized as another sheet feeding cassette 28a.
And identification means 55 capable of identifying the user. The identification means 55 includes a display window 57 formed on the front surface 56 of the multi-sheet cassette 28b, and a display plate 58 inserted into the display window 57. On the front surface of the display plate 58, "Multi" indicating selection of the special paper S2 is displayed, and on the back surface, "Normal" indicating selection of the plain paper S1.
Is displayed.

Therefore, when the special paper S2 is used, an unspecified paper feeding cassette 2 other than the second-stage multi paper feeding cassette 28b corresponding to the paper feeding path 34 having a large radius of curvature is used.
It is possible to prevent the occurrence of a jam caused by storing and feeding the special paper S2 in 8a.

The identification means by which the multi-sheet cassette 28b can be visually distinguished from other sheet cassettes 28a is as follows.
The color and shape of the multi-sheet cassette 28b may be changed.

[0039]

According to the first aspect of the present invention, the paper including the special paper is routed so as not to bend the special paper having a strong rigidity to a predetermined radius of curvature or less. A main body with a paper transport path formed to guide the paper to the paper receiving tray is provided, and a plurality of paper feed cassettes including a multi-paper feed cassette that allows the storage of paper including special paper are vertically moved within the projection plane of the main body. Arranged at predetermined intervals,
A guide portion having a radius of curvature equal to or greater than a predetermined value is formed at a bent portion of the paper feed path connecting the multi paper feed cassette and the entrance of the paper transport path, so that the special paper is not forcibly bent. When the special paper stored in the printer is fed to the image forming unit of the apparatus main body, the paper is fed without forcibly curving, thereby preventing occurrence of a jam.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided an input means for inputting selection of a sheet to be fed by an electric signal, and a special sheet feeding is selected by the input means. Is provided with a paper discharge path specifying means for specifying a paper discharge destination from the image forming unit as a paper discharge receiver. Therefore, when special paper is used, the paper discharge path of the paper discharged from the image forming unit is changed. It can be automatically set as a paper discharge tray. Thus, when the special paper is selected, it is possible to prevent the occurrence of a jam due to the careless conveyance of the special paper to the duplex printing unit or the sorter.

According to a third aspect of the present invention, in the second aspect of the present invention, a multi-sheet feeding cassette capable of selectively storing special paper and plain paper is used. It can be used as a paper cassette for storing papers other than. As a result, it is possible to widen a selection range of sizes handled when using plain paper.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a default means for setting an input state of the input means to a selection state of special paper when the multi-sheet cassette supported so as to be able to be pulled out is pulled out. The multi-sheet feeder can store plain paper as well as special paper in the multi-sheet feeder, but every time the multi-sheet feeder is pulled out to replenish paper, Regardless, the special paper can be set to the selected state. Thus, when special paper is used, it is possible to prevent the occurrence of a jam due to double-sided printing of the special paper or discharge of the special paper to a sorter due to an input error in the paper selection operation.

According to a fifth aspect of the present invention, in accordance with the second, third or fourth aspect of the present invention, since an operation panel having a display unit for displaying a state input by the input means is provided, the operation panel is stored in a multi-sheet feeding cassette. The user can visually recognize the type of paper that has been used.

The invention according to claim 6 is the invention according to claims 1, 2, and
In the invention described in 3, 4, or 5, since the multi-sheet feeding cassette is provided with identification means capable of visually distinguishing the other sheet feeding cassette from other sheet feeding cassettes, the multi-sheet feeding cassette other than the multi-sheet feeding cassette having a large radius of curvature leads to the sheet feeding path. It is possible to prevent the occurrence of a jam caused by storing and feeding the special paper in the paper feed cassette.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and is a front view schematically showing an internal structure of an image forming apparatus main body and a sheet feeding device with a part cut away.

FIG. 2 is an explanatory diagram showing a side view of a multi-sheet feeding cassette according to a second embodiment of the present invention.

FIG. 3 is a plan view showing a part of the multi-sheet feeding cassette.

FIG. 4 is a front view of an operation panel according to a third embodiment of the present invention.

FIG. 5 is a perspective view showing a multi sheet feed cassette according to a fourth embodiment of the present invention.

[Explanation of symbols]

 2 Apparatus main body 3 Image forming unit 8 Paper transport path 13 Paper discharge receiver 15 Operation panel 28a Paper feed cassette 28b Multi paper feed cassette 33, 34 Paper feed path 36 Guide unit 39 Input means 45 Default means 50 Input means 53, 54 Display unit 55 Identification means

Claims (6)

[Claims] 1. A path is defined so that a special paper such as an envelope or a thick paper having a strong stiffness is not forcibly curved to a certain radius of curvature or less, and a paper including the special paper is discharged to an image forming unit and a downstream side thereof. An apparatus main body having a paper conveyance path formed therein for guiding the receiver is provided, and a plurality of paper feed cassettes including a multi-sheet feed cassette allowing storage of the paper including the special paper are vertically moved within the projection plane of the apparatus main body. Arranged at predetermined intervals, provided with a plurality of paper feed paths for guiding the paper from each end of the paper feed cassette toward the entrance of the paper transport path and guide the paper, the multi paper feed cassette and A sheet feeding device, wherein a guide portion having a radius of curvature equal to or greater than a predetermined value is formed at a bent portion of the sheet feeding path connecting to an entrance of the sheet conveying path so as not to forcibly bend the special sheet. . 2. An input means for electrically inputting selection of paper to be fed, and a discharge destination from the image forming unit to a discharge tray when feeding of special paper is selected by the input means. 2. The paper feeding apparatus according to claim 1, further comprising a paper ejection path specifying means for specifying. 3. The paper feeding device according to claim 2, wherein a multi paper feeding cassette capable of selectively storing special paper and plain paper is used. 4. The apparatus according to claim 3, further comprising default means for setting an input state of the input means to a selection state of the special paper when the multi-sheet cassette supported so as to be able to be pulled out is pulled out. Paper feeder. 5. The sheet feeding device according to claim 2, further comprising an operation panel having a display unit for displaying a state input by the input unit. 6. The sheet feeding device according to claim 1, wherein the multi sheet feeding cassette includes identification means for visually distinguishing the sheet feeding cassette from another sheet feeding cassette.