JP2003276884A - Paper feeding controller and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding controller and an image forming device capable of executing paper feeding wherein productivity takes priority. <P>SOLUTION: In the case of a paper end of a paper feeding side tray 21a in copy print wherein a tandem tray 21 is specified, a sheet of the same size and in the same direction is retrieved from the trays 22-24 to execute the paper feeding without waiting sheet transfer from a reserve side tray 21b. In tray retrieval order of limitless paper feeding, retrieval order of the tandem tray 21 in the case of the paper end of the paper feeding side tray 21a is set to lowest order. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile and the like and a paper feed control apparatus for the image forming apparatus.

[0002]

2. Description of the Related Art In recent years, image forming apparatuses have tended to be faster and have a larger memory capacity, and have been configured as a multi-function peripheral that executes a plurality of applications such as FAX, copy, printer, and scanner. This makes it possible to execute complicated arithmetic processing in the image forming apparatus,
This is because many printing processes can be performed. Actually, recording media (hereinafter,
The productivity (printing speed) when printing on paper is also very important.

In order to improve productivity, a function for automatically selecting a paper feed unit and performing a printing operation is added to a portion related to paper feed so that the shortest transport path from paper feed to paper discharge is provided, and trays are also added. There is also a growing need for a structure that reduces the frequency of paper ends by increasing the number of paper sheets stored in. As a means for increasing the number of sheets of paper stored in the tray, there are a large-volume paper feeding tray, a tandem tray, and the like.

[0004]

However, in order to stock a large amount of paper in the paper feed unit, the tray / cassette inevitably becomes large in size. The enlargement of the tray / cassette has the opposite direction from the trend toward downsizing of the image forming apparatus in order to reduce the installation area. Further, when one paper feed tray becomes large, it becomes difficult to install another paper feed tray, and it becomes impossible to set various paper sizes and paper types.

Although the tandem tray effectively utilizes the apparatus space to increase the number of sheets of paper (especially small size) to be accommodated, the tandem tray is fed from the reserve tray side when the paper end of the paper feed side tray is reached. Productivity decreases as the paper is transferred to the paper tray side.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet feeding control device and an image forming apparatus capable of solving the above-mentioned problems in a conventional image forming apparatus and performing sheet feeding with priority on productivity.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the above-mentioned problem is solved by providing a plurality of sheet feeding units, and each of the sheet feeding units has a means for detecting the presence or absence of sheets stored in the sheet feeding unit and a sheet feeding unit. It has a means to detect the size and setting direction of the stored paper,
When the paper of the selected paper feed unit is finished, another paper feed unit that stores paper of the same size and direction as the paper of the selected paper feed unit is searched, and the searched paper feed unit is searched. In a paper feeding control device having a paper feeding function, at least one paper feeding portion of the plurality of paper feeding portions is configured as a tandem tray, and when the paper out of the paper feeding side tray of the tandem tray, the other This can be solved by setting the search order of the tandem tray in the paper feed unit search of the lowest order.

In order to solve the above problems, the present invention is provided with a plurality of paper feed units, each of the paper feed units is provided with means for detecting the presence or absence of paper stored in the paper feed unit, and the paper feed unit. A means for detecting the size and setting direction of the selected sheet, and when the sheet of the selected sheet feeding unit is finished, the sheet of the same size and the same direction as the sheet of the selected sheet feeding unit is stored. In the paper feed control device having a function of searching for a paper feed unit of the plurality of paper feed units and feeding paper from the searched paper feed unit, at least one paper feed unit of the plurality of paper feed units is configured as a large-volume tray, The tray has a cover that can be opened and closed, and a cover open / close detection unit that detects opening / closing of the cover. When the cover of the large-volume tray is open, the search order of the large-volume tray in the search of the other sheet feeding unit. Suggest setting the lowest

In order to solve the above problems, the present invention is provided with a plurality of paper feed units, each of the paper feed units is provided with a means for detecting the presence / absence of paper stored in the paper feed units, and a paper feed unit. A means for detecting the size and setting direction of the selected sheet, and when the sheet of the selected sheet feeding unit is finished, the sheet of the same size and the same direction as the sheet of the selected sheet feeding unit is stored. In a paper feed control device having a function of searching for a paper feed unit of the above and feeding paper from the searched paper feed unit, at least one paper feed unit of the plurality of paper feed units feeds paper in the paper feed unit. Configured as a paper feed tray having a bottom plate for raising to a position,
A push-up mechanism for pushing up the bottom plate and a means for detecting whether or not the push-up mechanism is in operation. When the push-up mechanism for pushing up the bottom plate of the paper feed tray is in operation, the other sheet feeding unit. It is proposed to set the search order of the paper feed tray in the search to the lowest order.

Further, according to the present invention, the above-mentioned problems can be solved by an image forming apparatus provided with the sheet feeding control device according to any one of claims 1 to 3.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a schematic configuration of a copying machine which is an example of an image forming apparatus according to the present invention.

In the copying machine shown in this figure, a paper feeding device 20 is arranged below the print engine unit 10. An image reading unit 30 is arranged above the print engine unit 10, and a paper discharge space 31 is provided between them. An automatic document feeder (ADF) 40 is arranged on the upper surface of the apparatus.

Although the copying machine of this embodiment is a conventionally well-known copying machine using an electrophotographic system, it may have a printer or facsimile function. Here, a copying operation in the copying machine of this example will be briefly described.

The surface of the photosensitive drum 1 which is rotationally driven by a driving unit (not shown) is uniformly charged by the charging unit 2. An image of the original document conveyed on the contact glass (not shown) by the ADF 40 is read by the image reading unit 30, and a laser beam corresponding to the image information is irradiated onto the photosensitive drum 1 by the optical writing device 6 to form an electrostatic latent image. To be done. The latent image on the photosensitive drum 1 is visualized by the developing device 3 to form a toner image.

On the other hand, the tandem tray 2 of the paper feeding device 20
1, the paper in the selected tray among the paper feed tray 22, the large quantity paper feed tray 23, and the manual feed tray 24 is called, separated into one sheet, and conveyed to the registration rollers 7 via the conveyance rollers. Then, the toner image on the photosensitive drum 1 is transferred to the transfer position at a transfer timing.

By the action of the transfer device 5, the toner image on the photosensitive drum 1 is transferred onto the sheet sent to the transfer position, the sheet is separated from the photosensitive drum 1 by the action of the separating means, and the conveying belt 8 is provided. Is sent to the fixing device 9.
Then, after the unfixed toner image on the paper is fixed by the fixing device 9, the paper is discharged onto the paper discharge tray 32 of the paper discharge unit 31. After the transfer of the toner image, the photosensitive drum 1 is cleaned by the cleaning device 4 to prepare for the next copying.

In the copying machine of this example, the registration roller 7 is
The sheet is configured to be conveyed at a conveyance speed higher than the sheet conveyance speed from each of the trays 21 to 24 to the registration roller 7, and reaches the transfer position (a region where the photosensitive drum 1 and the transfer device 9 face each other). At that time, the sheet interval between the trailing edge of the preceding sheet and the leading edge of the succeeding sheet becomes an extremely small interval that is almost zero. Of course, the image forming control is performed according to the sheet interval.

In the copying machine of this embodiment, each of the trays 21 to 24 of the paper feeding section is provided with a known paper size detecting means (not shown), and the size of the paper set in each tray. And the set direction can be detected.

The tandem tray 21 is a paper feed side tray 21.
a and the reserve side tray 21b are arranged side by side, and when the sheets stacked on the sheet feeding side tray 21a are consumed, the sheets stacked on the reserve side tray 21b are transferred to the sheet feeding side tray 21a. It is configured to feed paper. By supplying new paper to the reserve tray 21b after transferring the stacked paper to the paper feed tray 21a, it is possible to prevent a decrease in productivity due to paper shortage. The trays 21a and 21b of the tandem tray have, for example, A
It can be loaded with up to 4 horizontal sheets, and can also be loaded with B5 horizontal sheets.

The paper feed tray 22 can store large size paper, for example, A3 portrait size paper. A paper sensor 25 is provided on the paper conveyance path from the tandem tray 21 and the paper feed tray 22 so that the size of the conveyed paper can be detected.

The manual feed tray 24 is convenient for feeding a paper which is rarely used. The large-volume tray 23 can stack, for example, 2000 sheets of A4 horizontal size paper,
This tray is suitable for users who consume a large amount of paper of the same size. An opening / closing detection sensor 27 for detecting opening / closing of the cover 26 is provided on the large-volume tray.

By the way, as described above, the tandem tray 21 transfers the paper loaded on the reserve tray 21b to the paper feed tray 21a when the paper loaded on the paper feed tray 21a is consumed. You can do it. In the conventional paper feed control, if the paper in the paper feed tray runs out during copying or printing with the tandem tray specified, wait until the paper is transferred from the reserve tray before feeding paper from the tandem tray. Was configured to continue. For this reason, the productivity of the apparatus is reduced as the paper is transferred.

Therefore, in the copying machine of the present embodiment, when the paper-feed side tray 21a of the tandem tray runs out of paper (paper end), the transfer of paper from the reserve-side tray 21b is awaited. Instead of continuing the paper, control is performed so that the paper having the same size as the paper stored in the tandem tray 21 is searched / fed from another tray to continue copying / printing. At this time, if there is no paper of the same size and in the same direction (orientation of the paper set), paper of the same size but in a different direction may be retrieved and fed from another tray. By such control, it is possible to prevent a decrease in productivity without waiting for the sheet transfer from the reserve side tray 21b.

The above control can be set in combination with the limitless paper feeding function. In other words, limitless paper feed is a function to continue copying and printing by searching for paper of the same size from other trays and feeding it when the paper of the specified tray reaches the paper end. If limitless paper feed is set and paper runs out (paper end) in the paper feed tray 21a of the tandem tray, do not wait for the paper to be transferred from the reserve tray 21b (paper in the tandem tray). Even if it exists), the same size of paper is searched and fed from another tray to control copying and printing to continue. At this time, in this example, the search order of the tandem tray 21 when searching for the same size paper in the limitless paper feeding at the time of copying / printing with the tandem tray 21 specified is set to the lowest (paper feeding side). (Search order when the tray 21a is out of paper). Due to the setting of the search order, when the paper feed tray 21a of the tandem tray runs out of paper, the other trays are automatically fed in priority, and the paper feed from the reserve tray 21b is automatically performed. Productivity can be prevented from decreasing without waiting for transfer.

The paper feed control in the tandem tray 21 is shown in the flow chart of FIG. In the flowchart of FIG. 2, first, it is determined whether or not to continue feeding from the tandem tray 21 (S1).
It is determined whether or not there is a sheet in a (S2). If there is a sheet, the process proceeds to S3 to see if the sheet set in the tray 21a matches the search information. If the tray search is successful in S4, paper feeding is executed (S5), and the process returns to S1. That is,
If the paper feed tray 21a is not the paper end, S1
The processing is up to S5.

If the paper feed tray 21a is out of paper (paper end) in S2, the flow advances to S6 to determine whether the limitless paper feed function is set. Here, if the limitless paper feed function is not set, the process proceeds to S12 and print end processing is performed. In addition, in S1, the tandem tray 2
When the paper feeding from No. 1 is not continued (for example, when the copy of the set number of sheets is completed), the print ending process is executed (S12).

If the limitless paper feed function is set in S6, the paper of the same size and the same direction (the same size is not shown in the flowchart) of other paper feed trays is searched (S7), and the paper is searched. The information is matched (S8). S9
If the tray search is successful in, paper feed is executed (S1
0), it is determined whether or not to continue printing (S11). To continue printing, the process returns to S1. When the printing is not continued, the process proceeds to S12, and the print end process is executed (S12).
Even if the tray search fails in S4, the process proceeds to S7 to search for another tray.

If the tray search is unsuccessful in S9, that is, if there is no paper of the same size and in the same direction in another tray, the process proceeds to S13, and the reserve side tray 2 of the tandem tray is used.
It is determined whether there is a sheet on 1b. That is, the tandem tray 21 is set to the lowest search order in the tray search order (paper of the same size and in the same direction) in limitless paper feeding when the paper is exhausted in the paper feed side tray 21a of the tandem tray.

If there is paper in the reserve tray 21b,
Looking at the coincidence between the paper and the search information (S14), if the tray search is successful in S15, the process returns to S1 and waits for the completion of transfer. If the tray search is unsuccessful, the process proceeds to S12 to execute print end processing.

If there is no paper in the reserve tray 21b, the process proceeds to S16, and it is determined whether or not the paper is being transferred. If the paper is being transferred, the process proceeds to S14. If the tray search is successful in S15, the process returns to S1 to wait for the completion of the transfer. If the paper is not being transferred in S16, the paper of the same size and in the different direction is searched from another tray (S17). Then, if the paper and the search information match (S18), and if the tray search is successful in S19, paper feeding is executed (S20),
Return to S1. If the tray search fails, search failure processing is executed (S21).

As described above, when the paper feed side of the tandem tray becomes the paper end, the productivity is lowered if the paper is waited for transfer even if there is paper in the reserve side tray.
By controlling the sheets to be fed from another tray without waiting for the sheet transfer (by setting the search order of the tandem tray in the limitless sheet feeding to the lowest), it is possible to promptly feed the sheets.

At this time, if a sheet of the same size as the sheet set in the tandem tray and set in the same direction exists in another tray, the tray search is successful and the sheet is fed from that tray.

However, if the search fails in the same direction and the same size, if there is paper in the reserve side tray of the tandem tray, or if it is being transferred from the reserve side to the paper feed side,
When the transfer is performed (when the transfer is completed), it is determined that the sheet can be fed, and after the transfer is completed, the sheet is fed from the tandem tray (S13, S16 → S14 → S1).

If there is no paper in the reserve side tray of the tandem tray and it is not being transferred (S9 → S17), it is judged that there is no paper tray and another paper feed tray is searched. However, in this example, since the paper search in the same direction has been completed in the previous stage, the tray search is started under the condition of the same size and different direction (S17). If the search in the same size and different direction fails, there is no tray that can be fed, and the process proceeds to tray search failure processing (S21).

Next, the handling of the large-volume tray 23 will be described. Since a large number of sheets can be set in the large-volume tray 23, the frequency of paper end is low, and it is advantageous in terms of productivity if paper is fed from the large-volume tray 23 during copying / printing. However, the cover 2 of the large quantity tray 23
6 is open (the open / closed state of the cover 26 is the sensor 2
7), the copying / printing is interrupted and the productivity of the apparatus is lowered. Therefore, large quantity tray 2
For copy / print with 3 specified, 2 large trays
When the cover 26 of No. 3 is opened, the same size paper is retrieved from another paper feed tray and the paper feed is controlled to prevent the productivity from decreasing. At this time, if there is no paper of the same size and in the same direction, paper of the same size and in the different direction may be searched and fed from another tray.

The paper feed control for the large-volume tray 23 can be set in combination with the limitless paper feed function. That is, in this example, the cover 26 is used for limitless paper feeding at the time of copying / printing with the large-volume tray 23 specified.
When is open, the search order of the large-volume tray 23 when searching for the same size paper is set to the lowest. By setting the search order, when the cover 26 of the large number of trays 23 is open, the sheets are preferentially fed from the other trays, and it is possible to prevent the productivity from decreasing.

However, normally, when the user specifies a large number of trays, it is considered that the user expects to feed paper from the large number of trays as much as possible. Therefore, when the large number tray has paper and the cover 26 is open. , Since it is in a state where the paper feed can be restarted immediately by closing the cover 26, a warning display prompting the user to close the cover 26 of the large-volume tray 23 after the search for the paper of the same size and the same direction in the other paper feed tray is completed The information is displayed on the operation unit (not shown) of the copying machine.

Paper feed control in the large-volume tray 23 will be described with reference to the flowchart of FIG. In addition, here
Limitless paper feed is specified. In the flowchart of FIG. 3, first, it is determined whether or not the printing operation is continued (S31), and if it is not continued, the processing of this flowchart is ended. In the case of continuing, the tray search for the sheets of the same size and the same direction (the same size is not shown in the flowchart) is started (S32), and the coincidence between the sheet and the search information is checked (S33). If the tray search is successful in S34, paper is fed from the tray that has been successfully searched (S3
5) and returns to S31. That is, when the large-volume tray 23 has paper and the cover 26 is also closed, the search is performed under the same conditions as the other trays.

If the tray search fails in S34, S3
In step 6, it is determined whether or not there is paper in the large-volume tray 23. If there is paper, it is determined whether the cover 26 of the large number of trays is open (S37). Cover here 26
If is open or if there is no paper in the large-volume tray 23 in S36, the process proceeds to S40 to search for paper of the same size and different direction (the same size is not shown in the flowchart).

If the cover 26 is closed in S37, the matching of the paper and the search information is checked (S38), and if the tray search is successful in S39, a "warning display urging to close the cover 26 of the large number of trays 23" is displayed. Yes (S44).

If the tray search is unsuccessful in S39, the cover 26 is open, or the large number of trays 23 are out of paper, the process proceeds to S40 and the search for the same size different direction paper is started (S40). In S41, if the paper matches the search information, and if the tray search is successful in S42, the paper is fed from the tray that has been successfully searched (S45), that is, the same size different direction paper is fed, and S31 Return to. On the other hand, S4
If the tray search is unsuccessful in step 2, that is, if the search is unsuccessful even under the condition of the same size and different direction paper, it is determined that there is no tray that can be fed, and the process proceeds to tray search failure processing (S4
3).

As described above, when the large-volume tray 23 has paper and the cover 26 is open, the paper feed can be promptly continued by controlling the paper feed from another tray. In addition, by displaying the "warning display", the user is urged to close the cover of the large number of trays, which enables highly productive copy / print using the large number of trays with a large number of sheets loaded.

By the way, the paper feed tray 22 is provided with a tray bottom plate 22a for pushing up the paper to the paper feed position, and a bottom plate pushing up mechanism (not shown) is provided on the copying machine main body side. Whether or not the bottom plate lifting mechanism is operating can be detected by the control means of the copying machine (for example, by instructing the operation of the motor of the lifting mechanism from the control means of the copying machine). Therefore, when the tray bottom plate 22a of the paper feed tray 22 is being lifted, it is possible to feed paper from the paper feed tray 22 after waiting for the bottom plate to be lifted.

Therefore, the tray bottom plate 22 of the paper feed tray 22
When a is rising (the bottom plate lifting mechanism is in operation), it is handled in the same manner as during the tray transfer in the tandem tray 21 described above, and the bottom plate 22 is used at the time of copying / printing with the tray 22 specified.
When a is rising (even if there is paper), it is possible to prevent lowering of productivity by controlling paper feeding from another tray. This control can be set in combination with the limitless paper feeding function. That is, the search order in limitless paper feeding is set to the lowest, and the same size of paper is searched and fed from another tray so that copying and printing are continued.

This control will be described with reference to the flowchart of FIG. Here, it is assumed that limitless sheet feeding is designated. In the flowchart of FIG. 4, first, it is determined whether or not to continue the printing operation (S51), and when it is not continued, the processing of this flowchart is ended.
In the case of continuing, the tray search for the sheets of the same size and the same direction (the same size is not shown in the flowchart) is started (S52), and the coincidence between the sheet and the search information is checked (S53).
If the tray search is successful in S54, paper is fed from the tray that has been successfully searched (S55), and the process returns to S51.

If the tray search fails in S54, S5
In step 6, it is determined whether the target tray (here, the paper feed tray 22) has paper. If there is paper, it is determined whether the bottom plate is rising (S37). Here, when the bottom plate is not rising and when the target tray is out of paper in S56, the process proceeds to S60, and paper of the same size and different direction (the same size is omitted in the flowchart) is searched.

If the bottom plate is rising in S57, the matching of the paper and the search information is checked (S58), and if the tray search is successful in S59, the process returns to S51. If the tray search is unsuccessful in S59, the bottom plate is not being raised, or the target tray is out of paper, the process proceeds to S60, and the search for the same size different direction paper is started. In S61, see if the paper and the search information match, S62
If the tray search is successful, paper feed is executed from the tray for which the search is successful (S64), that is, paper of the same size and different direction is fed, and the process returns to S51. On the other hand, if the tray search is unsuccessful in S62, that is, the search is unsuccessful even under the condition of the same size and different direction paper, it is determined that there is no tray that can be fed, and the process proceeds to the tray search failure process (S63).

In this way, if there is paper in the paper feed tray 22 and the bottom plate is not moving, a search is performed under the same conditions as other trays (S51 to S54). When the paper feed tray 22 has paper and the bottom plate is moving, when there is no paper of the same size and the same size in the other tray (S54 → S56), the paper feed tray 22 is successfully searched, and the completion of the bottom plate rise is waited ( S59 → S51). If there is no paper in the paper feed tray 22, the tray search for the same size and the same direction is performed, and then the tray search is performed for the same size and different direction by proceeding from S56 to S60.

In the present embodiment, the above-mentioned paper feed control is controlled by the control unit of the copying machine main body. Also, the paper size and paper direction in each tray are determined by inputting signals from each sensor to the control unit of the copying machine main body. It is also possible to provide a detection means for detecting the type of the paper stored in each tray (paper type, for example, the density of the paper, etc.) so that the paper can be fed by checking the matching of the paper types. .

The present invention has been described above with reference to the illustrated examples.
The present invention is not limited to this. For example, the image forming method, the developing method, the presence or absence of the image reading unit, and the like are arbitrary.

Further, the structure of the tray in the paper feeding unit, the number of trays, etc. are arbitrary. The size and number of sheets stored in each tray are also examples, and can be set as appropriate. Of course, the image forming apparatus is not limited to the copying machine,
It may be a printer or a facsimile.

[0052]

According to the paper feed control device of the first aspect, when the paper end is reached on the paper feed side tray of the tandem tray, the tandem tray search order in the limitless paper feed is set to the lowest order. By setting, even if there is a sheet in the reserve tray, the sheet is fed from another tray without waiting for the sheet transfer, so that the sheet can be fed promptly and the productivity can be prevented from lowering.

According to the paper feeding control device of the second aspect,
If the cover of the large-volume tray is open, set the search order for the large-volume tray in limitless paper feeding to the lowest priority, so that when the cover of the large-volume tray is open, other trays are given priority. Since paper is used, it is possible to prevent a decrease in productivity.

According to the paper feed control device of the third aspect,
If the push-up mechanism that pushes up the bottom plate of the input tray is operating, set the search order of the input tray for limitless paper feeding to the lowest order, and if the bottom plate is rising, it will give priority to other trays. As a result, the productivity is prevented from decreasing.

In the image forming apparatus according to the fourth aspect, it is possible to perform sheet feeding while giving priority to productivity while preventing interruption of sheet feeding as much as possible.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a copying machine which is an example of an image forming apparatus according to the present invention.

FIG. 2 is a flowchart showing paper feed control of a tandem tray in the copying machine.

FIG. 3 is a flowchart showing sheet feeding control of a large number of trays in the copying machine.

FIG. 4 is a flowchart showing paper feed control of a paper feed tray having a bottom plate in the copying machine.

[Explanation of symbols]

1 photoconductor drum 6 Optical writing device 10 Print engine section 20 Paper feeder 21 tandem tray 21a Paper tray 21b Reserve side tray 22 Paper tray 22a tray bottom plate 23 Mass Paper Tray 26 cover 27 Open / close detection sensor 30 Image reading unit 40 Automatic Document Feeder (ADF)

Continued front page    F term (reference) 3F343 FA02 FB02 FB03 FB04 GA01                       GB01 GC01 GD01 HB03 HB04                       HC04 HC05 KB03 KB04 KB20                       LA04 LA16 MA02 MA10 MA12                       MA23 MA24 MA33 MB04 MB13                       MC21 MC23

Claims (4)

[Claims] 1. A means for detecting the presence / absence of a sheet stored in the sheet feeding section in each sheet feeding section, and a means for detecting the size and setting direction of the sheet stored in the sheet feeding section. And when the paper of the selected paper feed unit is finished, the other paper feed unit in which the paper of the same size and the same direction as the paper of the selected paper feed unit is stored is searched. In a paper feeding control device having a function of feeding paper from a paper feeding unit, at least one paper feeding unit of the plurality of paper feeding units is configured as a tandem tray, and the paper out of the paper feeding side tray of the tandem tray In this case, the paper feed control device is characterized in that the search order of the tandem tray in the other paper feed unit search is set to the lowest order. 2. A means for detecting the presence / absence of paper stored in each paper feed portion, and a means for detecting the size and setting direction of the paper stored in the paper feed portion, comprising a plurality of paper feed portions. And when the paper of the selected paper feed unit is finished, the other paper feed unit in which the paper of the same size and the same direction as the paper of the selected paper feed unit is stored is searched. In a paper feed control device having a function of feeding paper from a paper feed unit, at least one paper feed unit of the plurality of paper feed units is configured as a large-volume tray, and a cover capable of opening and closing the large-volume tray and opening and closing of the cover are provided. A cover opening / closing detection unit for detecting, and when the cover of the large-volume tray is opened, the search order of the large-volume tray in the search of the other sheet feeding unit is set to the lowest order. Paper feed control device. 3. A means for detecting the presence / absence of a sheet stored in the sheet feeding section, comprising a plurality of sheet feeding sections, and a means for detecting the size and the setting direction of the sheet stored in the sheet feeding section. And when the paper of the selected paper feed unit is finished, the other paper feed unit in which the paper of the same size and the same direction as the paper of the selected paper feed unit is stored is searched. In a paper feeding control device having a function of feeding paper from a paper feeding unit, at least one paper feeding unit of the plurality of paper feeding units has a bottom plate for raising a sheet in the paper feeding unit to a paper feeding position. And a push-up mechanism for pushing up the bottom plate, and means for detecting whether or not the push-up mechanism is in operation, and when the push-up mechanism for pushing up the bottom plate of the paper feed tray is in operation, The lowest search order for the paper tray in the paper feed section search A paper feed control device characterized by being set in order. 4. An image forming apparatus comprising the paper feed control device according to claim 1.