JPH0455232A - Image forming device - Google Patents

Abstract

PURPOSE:To exchange a sheet feeding means efficiently by providing a moving means to move a sheet feeding means so that it may correspond to a housing means selected by a selecting means and an image forming means to form an image information on a medium subjected to image formation taken out from the corresponding housing means by the sheet feeding means which is moved by the moving means. CONSTITUTION:There is provided a plurality of housing means 31-33 to house a medium subjected to image form and a sheet feeding means 18 movably provided to correspond to each of plural housing means 31-33. A selecting means selects one of the housing means 31-33 and a moving means moves the sheet feeding means so that it can correspond to the selected housing means. An image forming means 10 forms image information on the medium subjected to image formation taken out from the corresponding housing means by the sheet feeding means 18 which is moved by the moving means.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an image forming apparatus such as an electronic copying machine.

(Prior Art) For example, an electronic copying machine has a plurality of paper feed cassettes (accommodating means) and is capable of forming images on paper (image forming medium) of various sizes.

However, in conventional electronic copying machines, a paper feeding means is provided for each paper feeding cassette, which increases costs and makes maintenance extremely troublesome.

That is, the paper feeding means is worn out by repeated paper feeding operations, and the degree of wear differs depending on the frequency of use. Therefore, it is rare that all the paper feeding means are replaced at once, and it is necessary to go to replace them at intervals, resulting in a disadvantage that the replacement work is inefficient.

(Problems to be Solved by the Invention) As mentioned above, in the past, each paper feeding cassette is provided with a paper feeding means, which has the drawbacks of increasing costs and inefficient replacement work. was there.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus that can reduce costs and improve work efficiency in replacing paper feeding means.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the image forming apparatus of the present invention includes a plurality of storage means for storing image forming media, and a plurality of storage means for storing image forming media. a paper feeding means movably provided to correspond to each of the storage means; a selection means for selecting one of the plurality of storage means; and a paper feed means for selecting one of the storage means selected by the selection means; It is composed of a moving means for moving a paper feeding means, and an image forming means for forming image information on an image forming medium taken out from a corresponding storage means by the paper feeding means moved by the moving means.

(Function) According to the above-described means, the image forming medium can be fed from each storing means by a smaller number of paper feeding means than the number of storing means, so that the image forming medium can be fed from each storing means. The media can be fed by the same feeding means.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of, for example, an electronic copying machine as an image forming apparatus of the present invention.

This electronic copying machine includes a copying machine main body 1 and a copying machine main body 1.
A document feeder (auto document feeder/AD
F) 2, and a paper feeding device 3 which also serves as a mounting table on which the copying machine main body is placed and conveys and supplies paper as an image forming medium into the copying machine main body.

The copying machine main body 1 is constructed as follows.

That is, a document table (transparent glass) 5 is provided on the top surface of the housing 4, and the document transport device 2 is provided on the document table 5 so as to be able to open and close freely so as to cover the top surface of the document table 5. The document is automatically conveyed by the conveyance device 2 to the exposure position on the document table 5.

A drum-shaped photoreceptor 10 is disposed approximately in the center of the housing 4 as an image carrier. Around this photoreceptor 10, a charging charger 11, an LED erasing array 51, an exposure optical system 12, a developing device 13, a transfer charger 14, a stripping charger 15, a cleaner 6, and a static elimination lamp 17 are installed in order. It is arranged.

A photoreceptor 10 and a transfer charger 14 are located in the center of the housing 4.
A paper conveyance path 20 is formed to guide the paper conveyed through the image transfer section between the casing 4 to one paper discharge tray provided on the left side of the housing 4. Further, on the downstream side of the paper transport path 20, a fixing device (heat roller) 22 and a pair of paper ejection rollers 23a are provided.

23b1 and the fixing device 22, then the paper ejection roller pair 23
A sorting gate 25 is provided for guiding the paper conveyed by a to the direction changing conveyance device 24.

On the other hand, on the upstream side of the image transfer section in the casing 4, that is, on the paper feeding section side, there are sheets taken out by the paper feeding system 9a from the manual paper feeding table 9 provided on the right side of the casing 4, and the paper that is direction-changed. Images are transferred between the photoreceptor 10 and the transfer charger 1 - 4 of the paper that is guided from the transport device 24 or the paper feed device 3 and fed through the paper feed unit (paper feed means)] 8. A pair of registration rollers 21 are provided for supplying the image to the parts.

The exposure optical system 12 includes an exposure lamp [2a1] that irradiates light onto the document on the document table 5; Second. Third mirrors 12b, 12c.

12d, the first of these. Second. Third mirror 12b.

12c and '12d, a variable magnification lens unit 12e for varying the magnification of the light guided by the lenses 12c and 12d according to the copying magnification; Fifth mirror 12f.

12g1 and these 4th. Fifth mirror 12f.

12g to reflect the light guided toward the photoreceptor 10.
The configuration includes a mirror 12h.

No. 2 above. The third mirrors 12c and 12d are the exposure pumps 1
2a and the first mirror 12b in the same direction.
It is designed to move at a speed of /2. Further, a variable power lens unit 12e and a fourth lens unit 12e are provided. Fifth mirror 12
The positions of f and 12g are moved according to the copying magnification.

The direction conversion conveyance device 24 receives the fixed paper as needed, and guides the paper as it is to the paper feed section of the copying machine main body 1 again in order to perform multiple (same side) copying on the paper. In order to perform first conveyance path 24a1 or double-sided copying,
A second conveyance path 24b for guiding the paper to the sheet feeding section of the copying machine main body 1 again in a reversed state; A sorting gate 24c for sorting into the second conveyance paths 24a, 24b, a storage section 24d1 in which sheets guided through the first and second conveyance paths 24a, 24b are temporarily stored, and a storage section 24d1 that can freely rotate in the vertical direction. The storage section 24d is provided with a paper feeding system 24e that appropriately takes out the paper stored in the storage section 24d and guides it to the paper feeding unit 18.

On the other hand, the document conveying device 2 includes a supply section 41 that sequentially separates and feeds documents set on a paper feed tray 44 one by one, and a supply section 41 that feeds and conveys documents set on a paper feed tray 44, and a document feed section 41 that feeds and conveys the documents set on a paper feed tray 44 onto a document table 5. A transport unit 4 that transports the original to the exposure position and discharges the original after exposure from the original table 5 onto the output tray 72.
It is composed of 3.

Note that a document detection switch 44a for detecting the presence or absence of a document on the paper feed tray 44 is provided at the document setting position of the paper feed tray 44.

The paper feeding device 3 has, for example, a first . 2nd, 3rd
The paper feed cassette (accommodating means) 31, 32, and 33 are provided. And each paper feed cassette 31, 32
．． 33 includes paper size detection switches 31a, 32a, 3 for detecting the size of paper stored therein.
3a are provided respectively.

Also, inside the paper feeding device 3, each paper feeding cassette 31.3
In order to correspond to the paper feeding position of 2.33, a limit switch 34 is arranged to detect the lower limit position (lower limit position) of the paper feeding unit 18 which is movable up and down.

Furthermore, a guide belt 35 extends from inside the copying machine main body 1 and guides the paper guided from each paper feed cassette 31, 32, 33 and fed through the paper feed unit 18 to the paper feed section. , are provided along the vertical path of the paper feeding unit 18.

In such a configuration, one sheet of the original set on the paper feed tray 44 of the document transport device 2 is separated and sent from the supply section 41 to the transport section 43, and the transport section 43 transfers the original onto the document table 5. is transported to the exposure position.

On the other hand, the photoreceptor 10 rotates in the direction of the arrow shown in the figure, and the surface thereof is first uniformly charged by the charger 11 for charging. After this,
The non-image area is exposed to light and static electricity is removed by the LED erasing array 51.

Next, with the exposure lamp 12a turned on, the exposure lamp 12a and the first mirror 12b move along the document table 5, and in synchronization with this movement, the second mirror 1
2c and the third mirror 13d move in the same direction at half the speed, the original set on the original platen 5 is optically scanned. In this manner, the image of the document is formed on the photoreceptor 10 by the exposure optical system 12, thereby forming an electrostatic latent image on the surface thereof.

The electrostatic latent image formed on the photoreceptor 10 is developed with toner from the developing device 13, and then transferred to the transfer charging device 14.
The image is sent to the image transfer section opposite to the image transfer section.

Also, at this timing, paper manually fed from the manual paper feed table 9, paper taken out from the first paper feed cassette 31 in the paper feed device 3 and guided by the paper feed unit 18, 3 in the second paper feed 'paper taken out from the cassette 32 and guided by the paper feed unit 18,
Alternatively, the paper taken out from the third paper feeding cassette 33 in the paper feeding device 3 and guided by the paper feeding unit 18 is supplied to the image transfer section via the registration roller pair 21.

As a result, the transfer charger 14 causes the photoreceptor 1 to
The toner image on 0 is transferred onto the paper. Then, the paper onto which the toner image has been transferred is peeled off from the surface of the photoreceptor 10 by a peeling charger 5, and guided through a paper transport path 20 to a fixing device 22, where the toner image is fixed. After that, the paper is delivered to the paper ejection tray 19 via the paper ejection roller pair 23a, 23b.
is discharged to.

After the toner image has been transferred to the paper, the surface of the photoconductor 0 is cleaned of residual toner by facing a cleaner 16, and is further neutralized by a static elimination lamp 17 in preparation for the next copying operation.

Further, the original after exposure is discharged from the original platen 5 onto the paper ejection tray 72 by the operation of the transport unit 43, and the next original is transported to the exposure position on the original platen 5.

In addition, when performing same-sided or double-sided copying, the distribution gate 2 provided between the pair of paper ejection rollers 23a and 23b
5, the paper after fixing can be transferred to paper output tray 1.
Instead of being ejected to the paper 9, the paper is first guided to the direction changing conveyance device 24, and then fed via the paper feeding unit 18 to the pair of registration rollers 21 again either in that state or in the reversed state.

2 and 3 show the structure of the paper feeding unit 18 and its moving mechanism.

That is, the paper feeding unit] 8 stores therein the paper guided from the storage section 24d of the direction changing conveyance device 24 or the first paper in the paper feeding device 3. Second. third paper cassette 31,
32. A pair of feed rollers that receive the paper taken out from 33] 8a1 A guide path 18b that guides the paper received by the pair of feed rollers 18a; A pair of transport rollers 18c that conveys the paper guided to the guide path 18b. The configuration includes the following.

On the other hand, one end of a guide belt 180 is fixed to the upper surface of the paper feed unit 18 on the ejection section side. This guide belt 180 is bent in a 90 degree direction with a shaft 81 interposed in the middle thereof, and then the other end is wound around a drive shaft 182. Then, a guide bell l-180 between the upper surface of the paper feed unit 18 on the ejection section side and the shaft 181 is used to guide the paper conveyance 1.
83 is formed. Furthermore, the belt surface of the guide belt 80 that forms the conveyance guide 183 is coated with a low friction coefficient material, for example, to improve sheet feeding.
has been done.

A moving motor (for example, a pulse motor)] 84 is attached to the shaft of the drive shaft 182, and the motor 184 is driven to rotate the drive shaft 182 in the direction of the arrow shown in the figure.

On the other hand, one end of a belt] 85 is fixed to the lower surface of the paper feed unit 18 facing the discharge section, and the other end is wound around a driven shaft 186.

Additionally, this driven shaft 186 and the driving shirt l
A timing belt 187 is attached to -182.

Thus, when the moving motor 184 is driven, the drive shaft 182 and the driven shaft 186 are rotated in the same direction and at the same timing. Then, either the guide belt 80 is wound around the driving shirt 82 or the belt 185 is wound around the driven shirt 86. As a result, the paper feeding unit 18 is guided on both sides by the guide rails 188, 188, and is moved (elevated and lowered) along the guide belt 35 in the direction of the arrow in the figure.

Note that a paper feed unit position sensor 189 is used to detect the current position of the paper feed unit 18.

FIG. 4 shows an operation panel 111 provided on the copying machine main body 1 described above.

This operation panel 111 has a copy button (
Start) key 112, numeric keypad 113 for setting the number of copies, etc., all clear key 114 for clearing all conditions such as the number of copies, displaying the operating status of each part, copy magnification, number of copies, etc., as well as operating procedures, etc. A liquid crystal display section 116 for displaying a message, this display section 1
Operation unit 1 that performs various operations by interacting with the message displayed in 16] 7, Magnification setting unit 1 that sets the copy magnification
18. Edit key 119 for superimposing (same-sided copying), trimming, or masking, mode key 120 for setting various operation modes such as double-sided copying, color pictograms for instructions for paper and toner replenishment, paper jam locations, etc. Color display panel] 21, Density setting section 122 that automatically or manually sets the copy density, Preheat key 123, Interrupt key 124, Page continuous copy key] 25, Wake key 126, Gutter key 127, Original size A designation section 128, a paper size selection section 129, and the like are provided.

FIG. 5 schematically shows the main parts of the control system in the above-described copying machine.

That is, 100 is a CPU that controls the entire copying machine, and this CPU 100 includes the operation panel 111, input port 101, motor driver 102, and memory 103.
etc. are connected.

The paper size detection switch 3 is connected to the input port 101.
1a, 32a, 33a, the paper feed unit position sensor 1
89, various outputs from the limit switch 34, the document detection switch 44a1, the all clear key 114 of the operation panel 111, the paper size selection section 129, etc. are supplied.

A moving motor 184 for moving the position of the paper feeding unit 18, a paper feeding motor 04 for driving the registration roller pair 21, a direct current (DC) power source 105, etc. are connected to the motor driver 102. ing.

The memory 103 stores programs and control data necessary for operation, and also stores the paper feed unit position sensor 18.
It is used to store current position data, which is one output, and to store priority position data. This priority position data determines the position of the paper feeding unit 18 during standby, and the setting can be changed.

Next, the operation in the above configuration will be explained.

Figure 6 shows paper feed unit 1 depending on the paper size selection.
8 shows the flow of processing when moving 8.

That is, suppose that the paper size selection section 129 on the operation panel 5 is operated while the copying machine is in the ready state. Then, each paper size detection switch 31a is supplied via the input port 101.

By determining the outputs from 32a and 33a, the paper feed cassette containing the paper of the size selected by the above operation is specified.

Next, it is determined whether or not there is paper in the paper feed cassette based on the output from a paper detection sensor (not shown). If it is determined that there is no paper, a message such as "There is no paper" is displayed on the liquid crystal display section 116 of the operation panel 111.

On the other hand, when it is determined that there is paper, whether or not the paper feed unit 18 corresponds to the predetermined position of the paper feed cassette is determined by the paper feed unit position sensor 189 supplied via the input port 101. Determined by output. If it is determined that they are not compatible, the amount of movement (the number of steps of the moving motor -17 184) from the current position to the paper feeding position of the paper feeding cassette is calculated.

Once the amount of movement is calculated, the motor driver 102 is controlled accordingly. As a result, the moving motor 184
is driven, and the paper feeding unit 18 is moved up and down. That is, when the paper feed unit 18 corresponds to the paper feed position for the second paper feed cassette 32, for example, the third paper feed cassette 3
3 is specified, the third paper feed cassette 3 is selected from this position.
The amount of movement to the paper feeding position with respect to 3 is calculated, and the paper feeding unit 18 is lowered accordingly.

For example, if the first paper feed cassette 31 is specified in a case where the paper feed position corresponds to the third paper feed cassette 33, then from here to the paper feed position for the first paper feed cassette 31. The amount of movement is calculated, and the paper feeding unit 18 is raised accordingly.

In this way, the position of the paper feed unit 18 has been moved and it has reached the predetermined paper feed position corresponding to the paper feed cassette.
As determined by the output from the paper feed unit position sensor 189, the copying machine is placed in a standby state. That is,
In this state, the copy key 112 of the operation panel 1]
As described above, the copying operation for the paper taken out from the paper feed cassette and fed through the paper feed unit 18 is started.

Note that if it is determined in advance that the paper feeding unit 18 corresponds to the paper feeding position of the paper feeding cassette, the copying machine is immediately put into a standby state.

Furthermore, if the paper size is not selected, the copying machine is immediately put into a standby state, assuming that a copy operation is to be performed on the paper in the paper feed cassette that the paper feed unit 18 corresponds to.

Further, during same-sided (multiple) copying or double-sided copying, the paper feeding unit 18 is moved to correspond to the paper feeding position (home position) with respect to the direction changing conveyance device 24. That is, when same-sided or double-sided copying is specified, when performing a copying operation on the same side or different sides of a sheet, one direction change conveyance device 24 is moved from the paper feeding position of the paper feeding cassette.
The amount of movement to the paper feeding position is calculated, and the paper feeding unit 18 is raised accordingly.

Then, this paper feeding unit 18 is connected to the direction changing conveyance device 2.
It is designed to function as a paper refeeding device for paper guided from 4.

FIG. 7 shows the operation during same-sided or double-sided copying.

For example, suppose that the copy key 112 on the operation panel 1]1 is operated in the standby state described above. Then, the copy operation starts. That is, one sheet of the document set on the paper feed tray 44 of the document conveyance device 2 is taken in and automatically conveyed to the exposure position on the document table 5. Then, an image of the document is formed on the photoreceptor 10 by optical scanning by the exposure optical system 12, and this is converted into a toner image by the developing device 13. Next, this toner image is taken out from the paper feed cassette and transferred onto a sheet of paper that is fed via the paper feed unit 18 and the pair of registration rollers 2. Then, after being fixed by the fixing device 22, it is guided to the direction changing conveyance device 24 by the distribution gate 25.

Here, if same-sided copying is specified, the paper guided to the direction changing conveyance device 24 is guided to the first conveyance path 24a by the distribution gate 24c, and is returned to the copying machine main body 1 in that state. It is stored in the storage section 24d to be guided to the paper feed section. If double-sided copying is specified, the distribution gate 24c guides the user to the second conveyance path 24b;
The sheet is stored in the storage section 24d with its front and back sides reversed so that it can be led to the paper feed section of the main body 1 of the copying machine again.

In this way, after the above copying operation is repeated for the specified number of copies, the original on the original table 5 is transferred to the paper output tray 7.
2, the series of copying operations for the original document is completed.

When the copying operation for this document is completed, that is, when all the sheets for the number of copies are stored in the storage section 24d in the direction changing conveyance device 24, the direction from the paper feeding position of the paper feeding cassette is changed as described above. The amount of movement to the paper feeding position with respect to the conversion conveyance device 24 is calculated, and the paper feeding unit 18 is raised accordingly. And paper feed unit] -
When it is determined by the output from the paper feed unit position sensor 189 that the sheet 8 has reached the paper feeding position relative to the direction changing conveyance device 24, it is guided by the direction changing conveyance device 24 and re-feeded via this sheet feeding unit 18. A copying operation similar to that described above is performed on paper.

In other words, in the case of same-side copying, the copying operation is performed to overlay the image of the next original on the same side of the paper on which the toner image has been fixed, and in the case of double-sided copying, the image of the next original is superimposed on the same side of the paper on which the toner image has been fixed. A copying operation is performed to form an image of the next original on the other side of the paper. After the toner image has been fixed on the same side or the other side, the paper is discharged to the paper discharge tray 19 by a pair of paper discharge rollers 23a and 23b.

In this way, when the above-mentioned copying operation is completed for all the sheets corresponding to the number of copies, by checking the output from the document detection switch 44a supplied via the input port 101, the paper is placed on the paper feed tray 44. It is determined whether there is a next manuscript. Then, when the presence of the next document is detected, the paper feed unit 18 is again moved to the paper feed position of the paper feed cassette in which the paper of the size selected by the above operation is stored.

From this point on, the above-described operations are repeated until there are no more documents on the paper feed tray 44. That is, the paper feed unit 18 is alternately moved between the paper feed cassette and the direction changing conveyance device 24 in units of the number of copies until it is determined that there is no document based on the output from the document detection switch 44a. The above-described copying operation is repeated in sequence for each sheet of paper guided from the paper feed cassette or the direction changing conveyance device 24.

Note that if same-sided or double-sided copying is not specified, the paper feed unit 18 is fixed at the paper feeding position of the paper feed cassette, and after the toner image is fixed by being guided from the paper feed cassette. The paper is not guided to the direction changing conveyance device 24, but is ejected to the ejection tray 19 by the ejection roller pair 23a, 23b.

In this way, the paper feeding unit 18 is first set to correspond to the paper feeding position of the paper feeding cassette, and when the paper fed from this paper feeding cassette is stored in the direction changing conveyance device 24, the paper feeding unit 18 is then adapted to the paper feeding position of the paper feeding cassette. This corresponds to the paper feeding position of the transport device 24. Then, when the refeeding of paper from the direction changing conveyance device 24 is completed, the paper is again moved to the paper feeding position of the paper feeding cassette. By repeating the movement of the paper feed unit 18 in this manner, copying operations are performed for all documents on the same or both sides of the paper.

FIG. 8 shows an example of a case in which priority is given to the paper feed cassettes 31, 32, and 33, so that when the copying machine is on standby, the paper feed unit ]8 is on standby at the priority position.

That is, when the power of the copying machine is turned on, the paper feed unit 18 is lowered. Then, by checking the output from the limit switch 34 supplied via the input port 101, it is determined that the lower limit position has been moved by the lowering operation.

When it is determined that the lower limit position has been reached, paper feed unit 1
8 is stopped, and position data indicating the current position (for example, the amount of movement from the lower limit position) in the memory 103 is cleared to "0". Next, the priority position data is read from the memory 103, and the paper feeding unit 18 is raised based on this priority position data.

In this case, the priority position data is given as the amount of movement to a predetermined paper feed cassette. As a result, the paper feeding unit 18 is moved from the first to the second paper. It is moved to a paper feeding position for a predetermined paper feeding cassette among the third paper feeding cassettes 31, 32, and 33 that is associated with the above-mentioned priority position data, and is put on standby at that location. That is, if the amount of movement to the paper feed position for the first paper feed cassette 31 is set as the priority position data, for example,
The paper feeding unit 18 is moved from the lower limit position to the paper feeding position relative to the first paper feeding cassette 31, and is put on standby here.

In this way, the paper feeding unit 18 is always on standby at the same paper feeding position after the power is turned on (during standby).

FIG. 9 shows an example of a case in which the paper feeding unit 18 is returned to the priority position at the end of the copying operation.

For example, assume that the above-described copying operation has now been completed.

Then, all clear key 114 on operation panel 111 is pressed.
It is determined whether or not the has been operated.

Further, if it is determined that no operation has been performed, it is checked whether a certain period of time or more has elapsed by counting the time since the copy operation was completed.

Then, when it is determined that a certain period of time has elapsed, or when it is determined that the all clear key 114 has been operated, the above-mentioned priority position data is read out from the memory 103, and based on this priority position data, the paper feed unit 18 is moved. In this case, by comparing the position data indicating the current position with the priority position data, it is determined whether the paper feed unit 18 corresponds to the paper feed position of the paper feed cassette associated with the priority position data. Then, only when it is determined that it is not supported, the amount of movement to the prioritized paper feed cassette is calculated, and the paper feed unit 18 is moved accordingly.

In this way, the paper feeding unit 18 is automatically returned to the same paper feeding position when the copying operation is completed.

Note that the settings of this priority position data can be changed arbitrarily by the operator.

FIG. 10 shows the operation when changing the settings of the priority position data described in "1".

For example, assume that predetermined code data is input using the numeric keypad 113 of the operation panel 111. Then, C.P.
U1. OO is set to adjustment mode.

In this state, when a key is pressed manually using the numeric keypad 113, the priority position data in the memory 103 is rewritten according to the input value.

That is, in a state where, for example, the amount of movement to the paper feeding position for the first paper feeding cassette 3 is set as the priority position data, the amount of movement to the paper feeding position for the third paper feeding cassette 33 is newly set. Suppose the key person was powered.

Then, the priority position data in the memory 103 is updated based on the amount of movement to the paper feeding position with respect to the third paper feeding cassette 33.

Thereafter, by inputting predetermined code data using the numeric keypad 113, the adjustment mode described above is ended.

In this way, the priority order of the paper feed cassettes can be arbitrarily changed by the operator's settings.

As described above, sheets can be fed from each paper feed cassette using paper feed units whose number is smaller than the number of paper feed cassettes.

That is, the paper feeding unit is provided movably along the paper feeding position of each paper feeding cassette.

This allows the same paper feeding unit to feed paper from each paper feeding cassette. Therefore, the cost required for the paper feeding means can be reduced, and the number of maintenance operations required for replacing the paper feeding means can also be reduced.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to feed the image forming medium from each storage means using a smaller number of paper feeding means than the number of storage means, thereby reducing costs. Accordingly, it is possible to provide an image forming apparatus that can improve the efficiency of replacing paper feeding means.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a configuration diagram of an image forming apparatus taking an electronic copying machine as an example, FIG. 2 is a side view showing the configuration of a paper feeding unit, and FIG. FIG. 4 is a perspective view showing the configuration of a paper unit moving mechanism, FIG. 4 is a plan view showing an example of the configuration of the operation panel, FIG. 5 is a block diagram schematically showing the main parts of the control system of the copying machine, and FIG. 6 is a flowchart shown to explain the raising and lowering operation of the paper feed unit according to paper size selection, FIG. 7 is a flowchart shown to explain the operation using same-sided or double-sided copying as an example, and FIG. 8 is a flowchart shown when the copying machine is on standby. 9 is a flow chart shown to explain the standby operation of the paper feed unit at the end of the copy operation, and FIG. 10 is a flow chart shown to explain the return operation of the paper feed unit at the end of the copy operation. It is a flowchart shown in order to explain the operation|movement when changing a setting. 1... Copying machine main body, 2... Original transport device, 3...
Paper feeder, 4... Original table, Co-0... Photoreceptor, 11
... Charger for charging, 12... Exposure optical system, 13 Developer, ]4... Charger for transfer, 18... Paper feeding unit, 21... Registration roller pair, 22...・Fuser,
23a. 23b...Paper discharge roller pair, 24...Direction conversion conveyance device, 25...Distribution gate, 31, 32.33...Paper feed cassette, 31a, 32a, 33a...Paper size detection switch , 34... limit switch, 35...
- Guide belt, 4]... Supply unit, 43... Conveyance unit, 44... Paper feed l/ray, 44a... Original detection switch, 100... CPU, 103... Memory, 11
1...Operation panel, 112...Copy key 113.
・・Numeric keypad 114・・All clear key 116・
...Liquid crystal display section,]19...Edit key 120...
Mode key 129...paper size selection section, 180...
・Guide belt, 182... Drive shaft, 183・
...Conveyance guide, 184...Movement motor, 186...
- Driven shaft, 187...Timing belt, 18
-Paper feed unit position sensor.

Claims (1)

[Scope of Claims] A plurality of storage means for storing image forming media, a paper feeding means movably provided to correspond to each of the plurality of storage means, and one of the plurality of storage means. a selection means for selecting one of the paper feeding means; a moving means for moving the paper feeding means to make it correspond to the storage means selected by the selection means; An image forming apparatus comprising an image forming means for forming image information on an image forming medium.