JP3730132B2 - Paper feed unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper feeding unit used in an image forming apparatus represented by a copying machine or a printer.
[0002]
[Prior art]
In an image forming apparatus such as a copying machine or a printer, usually, by providing a large number or a large capacity of sheet feeding trays, the number of sheets supplied to the sheet feeding tray can be reduced and the operation rate can be increased.
[0003]
Here, in Japanese Patent Laid-Open No. 7-219401, when feeding paper from two paper trays accommodated on the same support and containing the same size paper, at least the first paper is fed. An image forming apparatus is disclosed that adopts a paper feeding method that is performed from the side closer to the paper tray with respect to the image forming unit and uses a paper tray on the side farther from the image forming unit during the remaining feeding. The first copy time can be shortened, and the overall processing time can be shortened.
[0004]
[Problems to be solved by the invention]
However, as described in Japanese Patent Application Laid-Open No. 7-219401, a plurality of paper storage units supported by the same support body and capable of being pulled out integrally are supplied with the same size paper or different supports. After the same size paper is replenished to a plurality of paper storage units supported by the body and separately drawable, several sheets including the first sheet are short on the side of the paper storage unit to the image forming unit. If the sheet storage unit on the side having the long transport distance to the other image forming unit is already in a state where paper can be fed, the sheet storage unit having a short transport distance to the image forming unit is provided. It is necessary to wait until the paper can be fed, and the first copy time becomes longer.
[0005]
This is remarkable when there is a placement unit that accommodates a large volume of paper. Here, the paper storage unit A having a short transport distance to the image forming unit is used as the paper storage unit A, and the transport distance is long. The side paper storage section will be specifically described as a paper storage section B.
[0006]
For example, when dealing with a paper shortage in a situation where the user is urgent, assuming that the paper storage unit A is not replenished with paper up to the storage upper limit and the paper storage unit B is supplied with paper up to the storage upper limit, After the paper is replenished, the time for the paper storage unit A and the paper storage unit B to rise and be ready to feed is shorter in the paper storage unit B than in the paper storage unit A. That is, the difference in time caused by the storage state of the paper is the time required to transport the paper from the paper storage unit A to the image forming unit and the time required to transport the paper from the paper storage unit B to the image forming unit. The difference, that is, the time difference caused by the transport distance may be longer, and in this case, not only the advantage of always feeding paper from the paper storage unit A is lost, but also the time is lost. .
[0007]
In other words, in the technique described in Japanese Patent Laid-Open No. 7-219401, since several sheets including the first sheet are always transported from the side of the sheet storage section with a short transport distance to the image forming section, The first copy time is increased by waiting for the paper storage unit having a short conveyance distance to the forming unit to be ready for paper feeding.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to provide a paper processing apparatus such as an image forming apparatus having a plurality of paper storage units that store a large amount of paper of the same size, and to select and feed the optimum paper storage unit each time. Is to provide a unit.
[0009]
[Means for Solving the Problems]
The present invention has the following configuration.
[0010]
(1) It is supported on the same support body and can be pulled out integrally, A plurality of paper storage units each storing the same size paper to be fed to the paper processing unit;
A paper mounting table disposed in the paper storage unit and movable between a paper feeding position where paper can be fed and a paper feeding position where paper can be replenished;
A first sensor that detects whether or not a paper placement table is positioned at a feeding position for each of the plurality of paper storage units;
A second sensor for detecting the presence or absence of paper for each of the plurality of paper storage units,
When the second sensor detects that there is no paper in the paper storage unit being fed, paper is fed from another paper storage unit in which the same size paper is stored,
When the second sensor detects that there is no paper of the same size in any of the paper storage portions, the paper placement table in each of the plurality of paper storage portions is moved to the replenishment position; and ,
After the paper of the same size is replenished, the paper mounting table has reached the feeding position First sensor Is preferentially fed from the paper storage unit detected earliest.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a diagram showing a configuration of an image forming apparatus 1 as a paper processing apparatus to which a paper feeding unit 2 of the present invention is applied. The image forming apparatus 1 feeds an image reading unit 2 that reads an image such as a document, an image forming unit 3 that forms an image based on image data from the image reading unit 2, and a sheet to be supplied to the image forming unit 3. The sheet feeding unit 4 and a post-processing device 5 that performs processing such as stapling processing and punching processing on paper are configured.
[0018]
The image reading unit 2 includes a contact glass 20 as a document table made of transparent glass, a double-sided automatic document feeder (hereinafter referred to as RADF) 21 for automatically feeding and conveying a document onto the contact glass 20, and the like. A mirror base 22 that scans and reads an image of a document placed on the contact glass 20, a photoelectric conversion element (hereinafter referred to as CCD) 23 that converts reflected light from the document into an electrical image signal, and a document. And an optical lens 24 that forms an image of the reflected light on the CCD 23.
[0019]
Among these, the mirror base 22 includes a first reflector base 22 a provided with a lamp reflector assembly 25 as scanning means for irradiating the original surface and a first reflection mirror 26 a for reflecting the reflected light from the original to guide the CCD 23. And a second mirror base 22b including a second reflection mirror 26b and a third reflection mirror 26c for guiding the reflected light from the first reflection mirror 26a to the CCD 23.
[0020]
Therefore, the image reading unit 2 scans the mirror base 22 along the lower surface of the contact glass 20 while sequentially placing the document to be read on the contact glass 20 by the operation related to the RADF 21 and the mirror base 22. It is configured to read an image.
[0021]
In particular, the first mirror base 22 a travels at a constant speed V in the sub-scanning direction along the contact glass 20. The second mirror base 22b scans in the same direction at a speed of V / 2 with respect to the speed V of the first mirror base 22a. As a result, the image of the document placed on the contact glass 20 is sequentially imaged on the CCD 23 line by line and the image of the document is read.
[0022]
The image data of the document read by the image reading unit 2 is sent to an image processing unit 52, which will be described later, and is temporarily stored in a memory in the image processing unit 52 after various processing. This image data is read in response to the output instruction and transferred to a laser writing device 31 of the image forming unit 3 described later.
[0023]
Next, the image forming unit 3 of the present embodiment is of an electrophotographic type, and the image data from the image bearing unit 2 and the photoconductor 32 that carries the image, the charging device 33 that uniformly charges the surface of the photoconductor, and the image reading unit 2 are used. A laser writing device 31 for exposing the photosensitive member to form an electrostatic latent image on the basis thereof, a developing device 34 for supplying a developer to the electrostatic latent image formed by the laser writing device 31 to visualize the surface, and the surface of the photosensitive member 32 Are provided with a transfer device 35 for transferring the developer image onto the paper and a cleaning device 36 for cleaning the surface of the photoreceptor 32.
[0024]
In addition, on the downstream side of the image forming unit 3 on the sheet conveyance path, a conveyance belt 37 that conveys the sheet on which the developer image is transferred, and a fixing device 38 that fixes the developer image on the sheet surface are provided. Yes.
[0025]
As a result, charging, exposure, development, transfer, and cleaning processes are sequentially performed on the photosensitive member 32, and an image forming process is performed on a sheet guided from a sheet feeding unit 4 described later. After the image forming process, the sheet is guided to the fixing device 38 by the conveyance belt 37, and heated and pressurized by the fixing apparatus 38, and the developer image is fixed on the surface of the sheet. After that, the sheet is sent to the switchback conveyance path 39b if image processing is further performed on the back surface, and is post-processed via the discharge conveyance path 39a if image processing is performed only on the front surface. It is sent out to the device 5.
[0026]
In addition to the above-described two transport paths 39a and 39b, the image forming apparatus 1 has a main transport path 39c that guides paper from each paper feed unit to the image forming unit 3, and a main transport from the first paper storage unit 41. A first paper feed transport path 39d to the path 39c, a second paper feed transport path 39e from the second paper storage section 42 to the main transport path 39c, and a third feed from the large capacity paper storage section 43 to the main transport path 39c. A paper transport path 39f is provided.
[0027]
Here, FIG. 2 is a diagram illustrating a configuration of a control unit of the image forming apparatus 1.
[0028]
The control unit of the image forming apparatus 1 mainly includes an image data input unit 51, an image processing unit 52, a hard disk 53, an image data output unit 54, an image data communication unit 55, a central processing unit 56, and an operation board unit 57. ing.
[0029]
The image data input unit 51 performs shading correction and the like on the image data read by the CCD 23. Further, the image processing unit 52 performs correction such as region separation unit and under color removal processing on the image signal input from the image data input unit 51, and magnification conversion of the image information input based on the set magnification. The zoom processing is performed, and the processed image data is stored in the main memory inside the hard disk 53 or the image processing unit 52.
[0030]
The image data output unit 54 sends the image data read from the main memory to the laser writing unit 31. Further, the image data communication unit 55 is a communication interface means provided separately from the image forming apparatus 1 for receiving image data from an external image input device such as a communication portable terminal, a digital camera, or a digital video camera.
[0031]
The image data input from the image data communication unit 55 is also input to the image processing unit 52 and subjected to color space correction or the like, so that the image data can be handled by the image forming unit 3 of the image forming apparatus 1. The data is converted and stored and managed in the hard disk 53 or the like.
[0032]
The central processing unit 56 includes mechanisms relating to image data such as the image data input unit 51, the image processing unit 52, the image data output unit 54, and the image data communication unit 55, the ADF control unit 58, the image reading unit 2, and the like. Each drive mechanism unit constituting the image forming apparatus 1 is managed by sequence control, and a control signal is output to each unit.
[0033]
Further, an operation board unit 57 composed of operation keys or the like is connected to the central processing unit 56 in a state where mutual communication is possible. As a result, a control signal indicating the copy mode contents set and input by the user in response to the operation of the operation key is transferred to the central processing unit 56, and the entire image forming apparatus 1 operates according to the set mode. ing.
[0034]
Further, control signals indicating various operation states of the image forming apparatus 1 are transferred from the central processing unit 56 to the operation board unit 57. At this time, on the operation board unit 57 side, the operation state is displayed on a liquid crystal display (hereinafter referred to as LCD) or the like so that the user can indicate the current state of the apparatus by this control signal. ing.
[0035]
Further, the sheet feeding unit 4 of the present invention includes a sheet storage unit loading / unloading sensor 10 for detecting insertion / removal of each storage unit described later at each of the three sheet storage units 41, 42, and 43 shown in FIG. A sheet presence / absence sensor 12 for detecting the presence / absence of a sheet on the sheet; a sheet feeding position sensor 13 for detecting whether or not the sheet on each storage section has reached a sheet feeding position; 1 is provided with a sheet loading / unloading position sensor 14 and a conveying unit 15 for conveying the sheet on each storage unit to the main conveying path 39c in FIG. These are also controlled.
[0036]
Here, shortening of the so-called first copy time using the optimum sheet storage unit selection unit of the present invention will be described.
[0037]
In the paper transport system in FIG. 1, each paper storage unit 41, 42, and 43 for feeding paper to the transport unit is distinguished by the size of recording paper, ordinary paper and OHP sheet, or high-quality paper. The large-capacity paper tray 43 is a paper storage section that can store a large amount of prints at a time or a type of paper that is frequently used. It is.
[0038]
Further, the large-capacity paper storage section 43 includes a large-capacity paper storage section first storage section (hereinafter referred to as a first storage section) 43a and a large-capacity paper storage section second storage section (hereinafter referred to as a second storage section). .) 43b is provided with a plurality of paper placement areas.
[0039]
When the user makes a print request by feeding paper from the large-capacity paper storage unit 43, the optimum paper feed unit selection unit provided in the paper feed unit 4 determines which storage unit is used. It is supposed to be.
[0040]
Here, FIG. 3 is a cross-sectional view showing the paper feed raising / lowering mechanism of each storage unit in the large capacity paper storage unit 43 of FIG.
[0041]
The large-capacity paper storage portion first storage portion 43a and the large-capacity paper storage portion second storage portion 43b of FIG. 1 are disposed in a paper feeding device frame 63 integrally formed on the drawer rail 60, and are independent of each other. A paper feed lifting mechanism is provided.
[0042]
These sheet feeding / lifting mechanisms have respective mounting tables 61 and 62 on which sheets are placed, lifting motors 64 and 65 serving as driving units for the sheet feeding lifting mechanism, and driving forces of the lifting motors 64 and 65. Wires 68 and 69 for transmission and pulleys 66 and 67 for controlling the raising and lowering direction of the wires 68 and 69 are provided. The wires 68 and 69 are mounted on the mounting tables 61 and 62, the pulleys 66 and 67, and the lifting motor. 64 and 65 are stretched. Further, a paper feed position sensor 13 for detecting the contact / non-contact state of the paper on the mounting tables 61 and 62 is provided.
[0043]
In this configuration, when the non-contact of the paper is detected by the paper feed position sensor 13, the lifting motors 64 and 65 are driven, and the wires 68 and 69 raise the mounting table via the pulleys 66 and 67, respectively. The first elevating motor 64 stops when the paper feed position sensor 13 detects the contact of the paper.
[0044]
Note that the basic mechanisms of the first storage portion 43a and the second storage portion 43b have the same structure, and the above-described paper feed lifting mechanisms operate independently of each other.
[0045]
Next, FIG. 4 is a diagram showing details of each sheet storage portion in the sheet feeding unit 4 of the present invention and a sheet conveyance path communicating with them. FIGS. 5 and 6 are flowcharts relating to a series of operations of the paper feeding unit 4.
[0046]
Hereinafter, the operation of the paper feeding unit of the present invention will be described with reference to these drawings. Here, the size detection by the paper size sensor 11 is performed in advance, and it is assumed that the first mounting table 61 and the second mounting table 62 described below are provided with the same type of paper.
[0047]
First, printing is performed from a state in which both the first mounting table 61 and the second mounting table 62 of the large capacity paper storage unit 43 are located at a feeding position where the paper placed on the paper storage unit can be fed. When there is an instruction to start processing (S5), the supply of paper from the first mounting table 61 or the second mounting table 62 is started and the printing operation is started (S10). In the initial setting in consideration of the sheet conveyance distance between the first mounting table 61 or the second mounting table 62 and the image forming unit 3, paper is fed from the first mounting table 61.
[0048]
Next, while the printing operation is being performed, it is determined whether or not there is paper on the mounting table being fed (S15). Here, if there is a sheet on the feeding table being fed, it is determined whether or not all printing has been completed for each printing operation on each sheet (S25). At this time, when it is determined that printing is completed, the printing operation is terminated. On the other hand, if it is determined that the printing is not yet completed, it is necessary to continue the printing operation. Therefore, the determination as to whether or not there is a sheet on the mounting table being fed again is continued (S15), and the sheet during the printing operation is continued. The determination of the presence / absence of the sheet is repeated until the detection of cutting or the completion of printing is reached.
[0049]
In addition, when it is determined that there is no paper in the loading table during feeding, it is not possible to continue feeding from this loading table, so it is different from the loading table currently in use. It is determined whether or not there is a sheet in the other sheet storage unit (S16). If there is paper in the other paper storage unit, the paper storage unit for paper feed is switched to feed paper from the other paper storage unit (S17).
[0050]
If there is no paper in the other paper storage unit, and there is no paper of the same size as the paper currently in use in any paper storage unit, all the papers are used to simplify the paper supply operation. The printing operation is temporarily interrupted in order to collectively supply sheets to the storage unit (S20). Here, in order to replenish the paper, the mounting table in each paper storage unit 43 is moved to a replenishment position where the paper can be replenished. The motor 65 is reversely rotated to start the lowering of the first mounting table 61 and the second mounting table 62 to the replenishment position (S30).
[0051]
Thereafter, it is determined by the paper loading / unloading position sensor 14 whether or not both the first mounting table 61 and the second mounting table 62 have been moved to the replenishment position (S35). At this time, if it is determined that both the first mounting table 61 and the second mounting table 62 are not arranged at the replenishment position, each of the mounting tables continues until reaching the replenishment position. It is determined whether or not the mounting table has reached the replenishment position and waits for them to reach the replenishment position (S50, S55, S60, and S65).
[0052]
Then, the reverse rotation of the lifting motor is stopped in order from the mounting table that has reached the replenishment position, and when both mounting tables reach the replenishment position, the driving of the lifting motor is completely stopped (S40). Stop at the replenishment position.
[0053]
Next, a message prompting the user to replenish paper on the mounting table of the paper storage unit 43 used until immediately before is displayed on the operation board unit 57 or the like (S45), and the user recognizes that the paper is out.
[0054]
At this time, the user pulls out the paper storage unit from the image forming apparatus 1 and replenishes the paper on the mounting tables 61 and 62. In the state where the paper storage unit 43 is extracted from the image forming apparatus 1 as described above, the paper storage unit loading / unloading sensor 10 is in an off state. When the user finishes the paper replenishment operation and attaches the paper storage unit 43 to the image forming apparatus 1, the paper storage unit loading / unloading sensor 10 is turned on.
[0055]
At this time, when it is not confirmed that the paper storage unit loading / unloading sensor 10 is turned on, it is determined that the replenishment work by the user has not been completed, so that the mounting tables 61 and 62 are placed on standby at the replenishment position. When it is confirmed that the paper storage unit loading / unloading sensor 10 is turned on (S75), the first lifting motor 64 and the second lifting motor 65 are driven to rotate in the forward direction, and the first mounting table 61 and the second mounting table 62 are driven. Is moved upward toward a feeding position where paper can be fed to the image forming unit (S80).
When the mounting tables 61 and 62 are raised, it is determined whether or not the movement of each mounting table 61 and 62 to the feeding position is completed (S85, S100). This determination is made based on whether or not the paper feed position sensor 13 has come into contact with the uppermost paper on each of the mounting tables 61 and 62 and has recognized that these are placed at the paper feed position.
[0056]
When the paper feed position sensor 13 is in contact with the uppermost paper, that is, when it is determined that the paper feed position has been reached, the respective lift motors 64 and 65 are stopped, and the lift motors 64 and 65 The mounted mounting table is automatically stopped at the feeding position.
[0057]
Thereafter, the presence / absence of a sheet on the mounting table previously arranged at the feeding position is confirmed by the sheet presence / absence sensor 12 (S90, S105). Here, when the presence of the sheet is detected, this mounting table is selected as a mounting table suitable for feeding paper, and the sheet is fed to the image forming unit 3 from here. Start printing.
[0058]
On the other hand, if the presence of the sheet is not detected, the paper cannot be fed by the mounting table. Therefore, the other mounting table is placed at the feeding position in order to feed paper from the other mounting table. If it is not arranged, it waits for the other mounting table to be arranged at the feeding position (S125, S115).
[0059]
Here, when it is detected that the other mounting table is in the feeding position, after determining whether or not there is a sheet to be fed (S130, S120), if there is a sheet, the sheet is removed from this mounting table. The paper is fed and printing is started (S95, S110).
[0060]
In addition, when there is no sheet on this mounting table, there is no sheet to be fed on any mounting table. The second lifting / lowering motor 65 is reversely rotated to lower the first mounting table 61 and the second mounting table 62 to the replenishment position (S35).
[0061]
When printing is started by paper feeding from the first mounting table 61 or the second mounting table 62 (S95, S110), each sheet is printed while feeding from the mounting table to the image forming unit. The paper presence / absence sensor 12 determines whether or not there is paper on the mounting table being fed (S135), so that it is possible to detect out of paper during the printing operation.
[0062]
During this time, it is determined whether or not the other mounting table other than the mounting table being fed has completed the movement to the feeding position (S136), and the feeding position of the other mounting table is determined. When the arrival at is confirmed, the driving of the lifting motor is stopped (S138).
[0063]
If it is determined in step S135 that there is no paper on the mounting table, it is determined that there is no paper on the mounting table being fed, that is, the topmost paper on the mounting table other than the mounting table being fed is fed. If there is no more paper on the loading table before reaching the position, the sheet feeding means of the loading table is stopped to stop the sheet feeding (S140), and the sheet feeding is performed immediately before. The process waits for the uppermost sheet placed on a placement table other than the placed table to reach the feeding position (S145).
[0064]
Next, after reaching the feeding position of the other mounting table, it is determined whether or not there is a sheet on the mounting table (S150). If it is determined that there is a sheet on the mounting table, the sheet is fed from the mounting table and the printing operation is resumed (S155). Thereafter, the process returns to the above-described determination of the presence / absence of the paper on the mounting table (S15), and the printing operation is performed while constantly checking the presence / absence of the paper.
[0065]
In step S150, it is determined whether or not there is a sheet on the other mounting table. If it is determined that there is no sheet on the mounting table, the sheet to be fed to both the first and second mounting tables 61 and 62. Therefore, in order to supply the paper again, the first elevating motor and the second elevating motor are reversely rotated to lower the first mounting table 61 and the second mounting table 62 to the supply position (S35). ).
[0066]
If it is determined in step S137 whether or not printing is completed, the process ends. If it is determined that the printing has not been completed, the paper feeding from the mounting table is continued, so the determination of the paper being fed is continued (S135), and a paper out detection is performed.
[0067]
According to the above control, when the paper is placed on the first placement table 61 and the second placement table 62, the upper end of the paper reaches the feeding position first, and printing starts immediately. Control is performed so that the sheet is fed to the image forming unit 3 from the accommodating portion that can be performed.
[0068]
By controlling in this way, even when the paper is fed from a mounting table having a long transport distance to the image forming unit as in the prior art, the transport distance to the image forming unit is short even if the time to first copy is short. Compared with the case where it is controlled to feed the paper from the paper transport table, the time until the first copy can be shortened.
[0069]
In addition, when there is no more paper on the loading table, whether to wait for the topmost sheet on the loading table other than the loading table to reach the feeding position and notify the paper supply Since it is determined whether or not the printing operation is to be continued, the placement unit is not moved to the replenishment position every time the paper out of each storage unit occurs, and the time required for completing the print formation is shortened. it can.
[0070]
Further, since sheets of the same size are present on any one of the mounting tables, the sheets are not replenished, so that it is possible to prevent the user's number of operations from increasing and the user from being confused. Further, only when both the first mounting table 61 and the second mounting table 62 run out of paper, both the mounting tables are moved to the replenishment position to replenish the paper. Reduced compared to the conventional case.
[0071]
In the present embodiment, the paper feed position sensor 13 that detects that the mounting table has reached the feeding position where paper can be fed and the paper presence sensor 12 that can detect the presence or absence of paper are separately provided. However, as described below, both the presence / absence of the paper and the feeding position may be detected by one sensor.
[0072]
For example, a part of the mounting table constituting the paper storage unit is cut out so that a detection lever of the sensor is inserted, and further, a time required for the mounting table to move from the supply position to the feeding position is measured. A combination of means can also be used.
[0073]
Specifically, when the paper is on the mounting table, the detection lever of the sensor does not fall into the notch, and it is possible to detect both the presence / absence of the paper and the feeding position from the state of the detection lever. In addition, the time measuring means measures the time required for the mounting table to move from the replenishment position to the feeding position, and it takes advantage of the fact that the completion time for moving the mounting table to the paper feeding position differs depending on the amount of paper. Thus, the presence / absence of a sheet on the mounting table may be determined.
[0074]
Further, in the present embodiment, the feeding units are provided corresponding to the number of the mounting tables, respectively. However, the feeding unit can move to a position facing the mounting tables so that the feeding units can move. It is also possible to reduce the number of sending means and simplify the configuration. In this case, when there is no more paper on the mounting table that has started feeding, the feeding unit is moved toward the other mounting table in order to use it when feeding paper from the other mounting table. What should I do?
[0075]
【The invention's effect】
As described above, according to the present invention,
(1) Optimum for a paper feed unit having a plurality of paper storage units that store paper of the same size to feed paper at that time from the paper storage state in each paper storage unit and the paper transport distance to the paper processing unit Even when there is no more paper in the paper storage unit in use, the position of the paper storage unit other than this paper storage unit and the number of stored papers are provided. Based on the above, it is possible to select the optimum paper storage unit for paper supply and continue paper supply, and the paper supply time is always longer than when the first paper supply is performed from the same paper storage unit. Can be shortened.
[0076]
In addition, even though the same size of paper remains in any of the paper storage units, it is not necessary to replenish this size of paper without using the remaining paper. The burden on the person can be reduced.
[0077]
(2) The position of the mounting table that is movable between the feeding position and the replenishment position in each paper storage unit and the presence or absence of the loaded paper are detected, and this mounting table is suitable for paper feeding. When the paper processing starts, the paper supply from the mounting table where the paper processing operation is started is selected immediately. When the paper runs out during the paper processing printing operation, Since it is determined whether or not it is possible to select a placement table to be fed, an optimum process is selected each time, and therefore the processing time in the sheet processing operation can be shortened.
[0078]
Therefore, in a sheet processing apparatus such as an image forming apparatus that includes a plurality of sheet storage units that store a large amount of sheets of the same size, a sheet supply unit that selects and feeds an optimum sheet storage unit each time is provided. be able to.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of an image forming apparatus to which a paper feeding unit of the present invention is applied.
FIG. 2 is a diagram illustrating a configuration of a control unit of the image forming apparatus of the present invention.
FIG. 3 is a diagram showing a configuration of a paper feed lifting mechanism according to the present invention.
FIG. 4 is a diagram illustrating a configuration of a paper feeding unit according to the present invention.
FIG. 5 is a flowchart showing a series of operations of the paper feeding unit of the present invention.
FIG. 6 is a flowchart showing a series of operations of the paper feeding unit of the present invention.
[Explanation of symbols]
1-Image forming apparatus
2-Image reading unit
3-Image forming unit
4-feed unit
5-Post-processing device
41-first sheet storage unit
42-second paper storage section
43-Large capacity paper storage
61-First mounting table
62-second mounting table
63-Feeder frame
64-first lifting motor
65-second lifting motor

Claims (1)

A plurality of paper storage portions that are supported by the same support body and can be integrally pulled out, and each store paper of the same size to be fed to the paper processing unit;
A paper mounting table disposed in the paper storage unit and movable between a paper feeding position where paper can be fed and a paper feeding position where paper can be replenished;
A first sensor that detects whether or not a paper placement table is positioned at a feeding position for each of the plurality of paper storage units;
A second sensor for detecting the presence or absence of paper for each of the plurality of paper storage units,
When the second sensor detects that there is no paper in the paper storage unit being fed, paper is fed from another paper storage unit in which the same size paper is stored,
When the second sensor detects that there is no paper of the same size in any of the paper storage portions, the paper placement table in each of the plurality of paper storage portions is moved to the replenishment position; and ,
The first paper is preferentially fed from the paper storage unit detected by the first sensor that the paper placement table has reached the feeding position after the paper of the same size is replenished. Paper feeding unit to be used.

Images