JP2001042749A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily remove a sheet and to smoothly restart image forming operation by temporarily interrupting the image forming operation when the stacked amount of the sheets reaches the maximum amount on both upper and lower trays, removing all the sheets, then deciding and moving the tray set after restarting the operation thereby restarting the operation. SOLUTION: Transfer paper P where an image has been already formed is ejected from a device body 200, stacked on a processing tray 270 and then ejected to the upper and lower paper ejection trays 292 and 293. When both trays 292 and 293 attain the maximum stack amount, the image forming operation for the new transfer paper P is temporarily interrupted and the ejection of the paper P is stopped. Continuously, from which tray the operation started at the time of restarting the operation is selected by a stack tray selection part. Furthermore, the tray is raised so that a user may easily remove the paper P on the tray or the position of the tray selected as the ejection tray after restarting is adjusted to the position of the tray 270. When all the paper P is removed, the image forming operation is restarted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus using, for example, an electrophotographic system and an image forming apparatus with improved control of a sheet processing apparatus connected thereto. .

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a digital copying machine having a memory for storing a plurality of image data, such as a hard disk, a document image of an entire copy job is stored in a memory, and the copy job is stored in the memory. 2. Description of the Related Art There is known an image forming apparatus having an electronic sort function for reading out image data in order from the first output image to form an image and performing image forming processing for a desired number of copies.

If this electronic sort function is used, the sheets are sorted one by one at the time when the sheets are discharged from the image forming apparatus main body. Therefore, after the discharge, the sheet is processed using a sheet processing apparatus having a plurality of trays. This eliminates the need to sort the documents one by one on the tray. Therefore, a desired number of copies can be directly stacked on the same tray.

Further, since the amount of sheets loaded on the same tray is limited, there has been proposed a sheet processing apparatus having two vertically movable trays.

[0005]

However, in the conventional image forming apparatus, when the sheets stacked on both the upper and lower trays reach the maximum stacking amount, the image forming operation by the image forming means is stopped. After stopping, even if only a part of the sheet was removed, the image forming operation could be resumed.Therefore, it was necessary to determine again the tray on which the resumed sheet is to be stacked, and it took time to move the tray. The resumption of the image forming operation was not smooth.

According to the present invention, there is provided an image forming apparatus capable of smoothly restarting the image forming operation when the upper and lower trays of the sheet processing apparatus reach the maximum stacking amount and the image forming operation by the image forming means is stopped. It is intended to provide.

[0007]

The invention according to claim 1 is
Image forming means for forming an image on a sheet, and upper and lower two sheets on which a sheet on which an image is formed by the image forming means are stacked.
A tray composed of steps, a tray driving means for driving the upper and lower trays respectively up and down, a sheet conveying means for conveying sheets to the tray, and a stacking amount of sheets stacked on the upper and lower trays, respectively. A stacking amount detecting means for detecting, a tray selecting means for selecting which of the upper and lower trays to stack sheets on, and a stacking amount detecting means for maximizing a stacking amount of sheets on both upper and lower trays. When it is determined that the stacking amount has been reached, the image forming operation by the image forming unit is temporarily suspended, and after all the sheets stacked on the upper and lower trays are all removed, the image forming operation of the image forming unit is stopped. And control means for controlling to restart.

According to a second aspect of the invention, there is provided a priority setting means for setting a priority of stacking the sheets on the upper and lower trays, and the control means controls the remaining image forming operation after the temporary interruption. When restarting, the selection means selects a tray with a higher priority set by the priority setting means.

According to a third aspect of the present invention, the control means includes:
After the suspension, when resuming the remaining image forming operation,
The selection unit may continuously select a tray selected before the image forming operation is temporarily stopped.

According to a fourth aspect of the present invention, when the control means temporarily suspends the image forming operation, the tray driving means
The upper and lower trays are raised to a predetermined position.

According to a fifth aspect of the present invention, the predetermined position is:
When the image forming unit restarts the image forming operation, the start position is the sheet stacking start position of the tray selected by the selecting unit.

[Operation] Based on the above configuration, the conveyed sheets are stacked on one of the upper and lower trays which can move up and down, and when the sheets on both trays reach the maximum stacking amount, image formation is performed. The image forming operation of the unit is temporarily suspended,
After all the sheets on the lower tray are removed, the remaining image forming operation is restarted. Further, the tray on which the sheets at the time of resumption are stacked is selected by the selection means,
The image forming operation is smoothly restarted by promptly moving to the start position where the corresponding tray can be stacked.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a digital copying machine will be described as an example of an image forming apparatus according to the present invention.

FIG. 1 is a block diagram showing a configuration of a digital copying machine according to an embodiment of the present invention.

The reader section 1 reads an image of a document and outputs image data corresponding to the document image to the image memory section 3.

The printer unit 2 records an image corresponding to the image data from the image memory unit 3 on a recording sheet. The image memory unit 3 compresses the image data transferred from the reader unit 1, stores the compressed image data, expands the stored compressed image data, and stores the expanded image data. Transfer to the printer unit 2.

In this block diagram, a CPU (control means) 171 which will be described later controls the reader section 1, the printer section 2 and the image memory section 3 and also controls the stacking tray selecting section (tray selecting means) 280. ing.

The CPU 171 includes a loading tray selection unit 280
To load sheets on the tray selected by
Via the I / F 281, information is notified to the sheet processing apparatus 290 which is a sheet discharging apparatus.

Further, the priority setting means 289 connected to the CPU 171 allows the operator to set the tray on which sheets are to be stacked with priority. When the setting by the priority setting unit 289 is performed, this setting operation has a higher priority than the tray selection by the loading tray selection unit 280.

The CPU 282 controls the sheet processing apparatus 290, and includes a load detection unit (load detection means).
A tray driving unit (tray driving unit) 283 is provided based on the amount of sheets loaded on the tray detected by the trays 284a and 284b.
a and 283b are instructed to drive the tray. In addition, information such as the amount of stacked sheets is notified via the I / F 285.

FIG. 2 is a sectional view showing a digital copying machine according to the present invention.

In the figure, reference numeral 200 denotes a digital copying machine main body, and reference numeral 6 denotes an automatic document feeder (DF). Reference numeral 201 denotes a platen glass as a document placing table, and 202 denotes a scanner, which includes a document illumination lamp 203, a scanning mirror 204, and the like. The scanner 202 is reciprocally scanned in a predetermined direction by a motor (not shown), and the reflected light of the original is
The light is transmitted through the lens 207 through to 206 and forms an image on the CCD sensor in the image sensor unit 208. Reference numeral 209 denotes an exposure control unit including a laser, a polygon scanner, and the like.
The photosensitive drum 211 is irradiated with a laser beam 219 that is converted into an electric signal by the image sensor unit 208 and modulated based on an image signal on which predetermined image processing described below has been performed.

Around the photosensitive drum 211, a primary band dragon device 212, a developing device 213, a transfer charger 216, a pre-exposure lamp 214, and a cleaning device 215 are provided. In the image forming section (image forming means) 210, the photosensitive drum 211 is rotated by a motor (not shown) in the direction of the arrow shown in the figure, and after being charged to a desired potential by the primary charger 212, exposure control is performed. Laser light 2 from unit 209
Irradiation is performed to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 211 is developed by the developing device 213 and is visualized as a toner image.

On the other hand, pick-up rollers 225, 226, and 2 from the right cassette deck 221, the left cassette deck 222, the upper cassette 223, or the lower cassette 224.
Sheets P fed by the printers 27 and 228 are sent to the main body by feed rollers 229, 230, 231, and 232,
The toner image fed to the transfer unit by the registration roller 233 and visualized is transferred to a sheet by the transfer charger 216. After the transfer, the photosensitive drum 211 is cleaned of residual toner by a cleaner device 215 and the pre-exposure lamp 2
14 erases the residual charge. The sheet after transfer is
Separated from the photosensitive drum by a separation charger 217,
The sheet is sent to the fixing device 235 by the conveyor belt 234. In the fixing device 235, the sheet is fixed by pressure and heat.
The sheet is discharged out of the main body 200 by the discharge roller 244.

The main body 200 is equipped with a deck 250 capable of storing, for example, 4000 sheets. The lifter 251 of the deck 250 rises according to the amount of the sheet so that the sheet always contacts the pickup roller 252, and the sheet is sent to the main body by the sheet feeding roller 253. In addition, a multi-bypass tray 254 capable of storing 100 sheets is provided.

Further, in FIG. 2, reference numeral 237 denotes a paper discharge flapper, which switches the path between the transport path 238 and the discharge path 243. Reference numeral 240 denotes a lower conveyance path, which guides the sheet sent from the sheet discharge roller 236 to a re-feeding path 241 by turning over the sheet through a reversing path 239. Sheets fed from the left cassette deck 222 by the feed rollers 230 are also guided to the refeed path 241. Reference numeral 242 denotes a re-feed roller that re-feeds the sheet to the image forming unit 210. 244 is disposed near the discharge flapper 237,
A discharge roller for discharging the sheet switched to the discharge path 243 side by the discharge flapper 237 to the outside of the apparatus.

At the time of double-sided recording (double-sided copying), the discharge flapper 237 is raised upward, and the copied sheet is guided to the re-feeding path 241 via the transport path 238, the reversing path 239, and the lower transport path 240. At this time, the rear end of the sheet is completely pulled out of the conveyance path 238 by the reversing roller 245, and the sheet is pulled into the reversing path 239 to a position where the sheet is bitten by the reversing roller 245. To send out. When the sheet is inverted and discharged from the main body, the discharge flapper 237 is raised upward, and the sheet is pulled into the reversing path 239 by the reversing roller 245 to a position where the rear end of the sheet remains in the conveyance path 238, and the reversing roller 245 is rotated in reverse. Then, the sheet is turned over and sent out to the discharge roller 244 side.

Reference numeral 290 denotes a sheet processing apparatus for closing and aligning the sheets discharged from the image forming apparatus 200, and stacks and discharges the sheets discharged one by one on a processing tray 270. When the discharge of one copy of image formation is completed, the sheet bundle is stapled by the stapler 294 as necessary, and the upper tray 292 or the lower tray 2 serving as a discharge tray.
The bundle is discharged to 93.

The sheet P carried into the sheet processing apparatus 290 is conveyed to the upper tray 292 via the sheet conveying path 271 to perform the sheet processing when sheet processing such as alignment, stapling, and sorting is not performed. In some cases, the sheet may be conveyed to the processing tray 270 via the sheet conveying path 272.

The discharge trays 292 and 293 are controlled to move up and down by the motors of the tray driving units 283a and 283b shown in FIG. Then, when the discharged sheets are stacked, the sheet moves so that the height of the sheet becomes the position of the processing tray 270. Further, the discharge trays 292 and 293 can load up to about 2000 sheets, and when one of the trays reaches the maximum amount, the height of the sheet surface is processed so as to load the other tray. It is moved to the position of the tray 270. 291
Denotes a paper tray on which separator sheets to be inserted between the discharged sheets are stacked, and 295 denotes a Z-folding machine that Z-folds the discharged sheets. Reference numeral 296 denotes a bookbinding machine that performs bookbinding by folding the center of one set of discharged sheets and performing stapling. The bound sheet bundle is discharged to a discharge tray 297.

FIG. 3 is a control block diagram of the digital copying machine 200.

Reference numeral 171 denotes a CPU for performing basic control of the digital copying machine 200.
The OM 174, a work RAM 175 for performing processing, and an input / output port 173 are connected by an address bus and a data bus. The input / output port 173 is connected to various loads (not shown) such as a motor and a clutch, which control the digital copying machine 200, and inputs (not shown) such as sensors for detecting the position of the sheet. The CPU 171 executes the RO
In accordance with the contents of M174, input / output control is sequentially performed via the input / output port 173 to execute an image forming operation.
An operation unit 172 is connected to the CPU 171, and controls a display unit and a key input unit of the operation unit 172. The operator instructs the CPU 171 to switch the display between the image forming operation mode, the scanner reading mode, and the print output mode through the key input unit.
Reference numeral 71 indicates the state of the digital copying machine 200 and the operation mode setting by key input. The CPU 171 is connected to an image processing unit 170 that processes a signal converted into an electric signal by the image sensor unit 208 and an image memory unit 3 that stores a processed image.

Next, the details of the image processing section 170 will be described with reference to FIG. FIG. 4 is a block diagram of the image processing unit.

The original image formed on the CCD sensor via the lens 207 is input as black luminance data, and is converted into an analog electric signal by the CCD sensor. The converted image information is input to an analog signal processing unit (not shown), and after sample and hold, dark level correction, and the like are performed, the A / D conversion unit 501 performs analog-to-digital conversion (A / D conversion). Then, the digitized signal is subjected to shading correction (correction of variations in a sensor for reading a document and light distribution characteristics of a document illumination lamp). After that, it is sent to the log converter 502.

The log conversion unit 502 stores an LUT for converting the input luminance data into density data, and outputs a table value corresponding to the input data to convert the luminance data into density data. Convert. After that, the image is scaled to a desired magnification by the scaling unit 503 and input to the γ correction unit 504. γ correction unit 5
In step 04, when outputting the density data, conversion is performed by an LUT in consideration of the characteristics of the printer, and the output is adjusted according to the density value set by the operation unit. After that, the binarization unit 5
05. The binarization unit 505 binarizes the multi-value density data, and the density value becomes “0” or “255”. The 8-bit image data is binarized and converted into 1-bit image data of “0” or “1”, and the amount of image data stored in the memory is reduced.

However, when an image is binarized, the number of gradations of the image is changed from 256 gradations to two gradations. Therefore, binarization of image data having a large number of halftones such as a photographic image generally deteriorates the image. Remarkable. Therefore, it is necessary to perform pseudo halftone expression using binary data. Here, an error diffusion method is used as a method for pseudo-halftone expression using binary data. According to this method, when the density of a certain image is larger than a certain threshold value, it is determined that the density data is “255”. When the density is less than a certain threshold value, it is determined that the density data is “0”. In this method, the difference between the data and the binarized data is distributed to surrounding pixels as an error signal.
The distribution of the error is performed by multiplying the weighting coefficient on the matrix prepared in advance by the error generated by the binarization, and adding the result to surrounding pixels. As a result, the density average value of the entire image is stored, and the halftone can be represented in a pseudo binary manner. The binarized image data is sent to the image memory unit 3, where the image is stored.

The image data from the computer input from the external I / F processing unit 4 is processed as binary image data by the external I / F processing unit, and is thus sent to the image memory unit 3 as it is. . The image memory unit 3
It has a high-speed page memory and a large-capacity memory (hard disk) capable of storing a plurality of page image data. The plurality of image data stored in the hard disk are output in an order according to the editing mode specified by the operation unit of the digital copying machine 200. For example, in the case of sorting, the images of the document bundle read from the DF 6 are sequentially output. The image data of the document once stored is read from the hard disk, and this is repeated a plurality of times and output. Thereby, it can play the same role as a sorter having a plurality of bins.

The image data output from the image memory unit 3 is sent to a smoothing unit 506 in the printer unit 2. The smoothing unit 506 performs data interpolation so that the line ends of the binarized image are smoothed, and outputs image data to the exposure control unit 209. Exposure control unit 209
Then, the image data is formed on the sheet by the above-described processing.

Next, details of the image memory unit 3 will be described with reference to FIG.

The image memory unit 3 writes a binary image from the external I / F processing unit 4 and the image processing unit 170 via a memory controller unit 302 to a page memory unit 301 formed by a memory such as a DRAM. External I / F
The processing unit 4 reads out an image to the printer unit 2 and accesses the hard disk 304 as a large-capacity storage device for inputting and outputting an image. The memory controller 302
A DRAM refresh signal for the page memory 301 is generated, and the external I / F processing unit 4, the image processing unit 17
0, page memory 301 from hard disk 304
Arbitrate access to.

Further, in accordance with an instruction from the CPU 171, a write address to the page memory unit 301, a read address from the page memory unit 301, a read direction, and the like are controlled. Accordingly, the CPU 171 arranges a plurality of document images in the page memory unit 301 to perform layout, and controls a function of outputting to the printer unit, a function of cutting out and outputting only a part of the image, and an image rotation function.

Next, according to FIG. 6, the external I / F processing unit 4
Is described.

The external I / F processing unit 4 fetches the binary image data of the reader unit into the external I / F processing unit via the image memory unit 3 as described above, and The binary image data from the external I / F to the printer unit 2
To form an image. The external I / F processing unit 4 includes:
It has a core unit 406 and a facsimile unit 401, a hard disk 402 for storing communication image data of the facsimile unit, a computer interface unit 403 connected to the external computer 11, a formatter unit 404, and an image memory unit 405.

The facsimile unit 401 is connected to a public line via a modem (not shown), and receives facsimile communication data from the public line and transmits facsimile communication data to the public line. Facsimile unit 401
Then, the facsimile function, such as sending a fax at a designated time or sending image data by inquiring of a designated password from the other party, such as the hard disk 4
02, a fax image is stored and processed. Thereby, once from the reader unit 1 via the image memory unit 3,
After the image is transferred to the facsimile unit 401 and the facsimile hard disk 402, fax transmission can be performed without using the reader unit 1 and the image memory unit 3 for the facsimile function.

Computer interface unit 403
Is an interface unit for performing data communication with an external computer, and has a local area network (hereinafter, LAN), a serial I / F, an SCSII / F, a centro I / F for inputting data to a printer, and the like. Via this I / F, the statuses of the printer unit and the reader unit are notified to an external computer, and the image read by the reader unit 1 is transferred to the external computer according to instructions from the computer. Also, it receives print image data from an external computer. Since the print data notified from the external computer via the computer interface unit 403 is described in a dedicated printer code, the formatter unit 404 forms the image in the printer unit 2 via the image memory unit 3. Convert to raster image data.

The formatter unit 404 develops raster image data in the image memory unit 405. The image memory unit thus has the formatter unit 404
Is used as a memory for developing raster image data, or when the image of the reader unit is sent to an external computer via the computer interface unit 403 (image scanner function), the image data sent from the image memory unit 3 is used. It is also used in a case where the data is once expanded in the image memory unit, converted into a format of data to be sent to an external computer, and transmitted from the computer interface unit 403.

The core unit 406 includes a facsimile unit 401,
It controls and manages data transfer among the computer interface unit 403, the formatter unit 404, the image memory unit 405, and the image memory unit 3. Thereby, even if the external I / F processing unit 4 has a plurality of image output units or the image memory unit 3 has only one image transfer path,
Under the management of the core unit 406, exclusive control and priority control are performed, and image output is performed.

Next, the operation of the automatic document feeder (DF) 6 in the present invention will be described with reference to FIGS. 7 (a) to 10 (m) which are schematic sectional views of the automatic document feeder 6.

First, each part of the DF 6 will be described with reference to FIG. Reference numeral 601 denotes a paper feed roller, which drops a document bundle 621 placed on a document tray 620 for placing a document bundle 621 made up of at least one sheet material, and rotates the document bundle 621 to rotate the document bundle. Feed the top document in the stack. Reference numeral 611 denotes a stopper, which protrudes as shown in FIG. 7A before the start of document feeding. The document bundle 621 is restricted by the stopper 611 so that it cannot advance downstream. The document fed by the paper feed roller 601 is separated into one sheet by the operation of the separation roller 602 and the separation belt 603. Separation is achieved by the well-known retard separation technique. A transport roller 604 transports the document separated by the separation roller 602 and the separation belt 603 to the registration roller 605. By hitting the document against the registration roller 605 and forming a loop, skew in the conveyance of the document is eliminated.

A reversing sheet flapper 613 is provided below the registration roller 605 to guide the original that has passed through the registration roller 605 to a sheet supply path 652 or a reverse entrance path 653, which is a conveyance path in the direction of the platen 201. Have been. Reference numeral 614 denotes a first reversing roller, and 615 denotes a second reversing roller, both of which rotate when the document is reversed. A reversing flapper 612 guides a document arriving from the direction of the second reversing roller 615 to the reversing path 650 or the re-feeding path 651. A belt driving roller 606 drives a feeding belt 607 for arranging a document on a platen. The feeding belt 607 is a platen 2
It is in contact with 01. Reference numeral 617 denotes a paper feed / discharge roller for feeding / discharging a document fed from the manual paper feed port 622 and feeding the document fed by the feed belt 607 to the document discharge port 62.
The paper is discharged to 3. Reference numeral 616 denotes a paper discharge flapper, which guides a document to a manual feed / discharge path 654 or a document discharge path 655. The paper discharge flapper 616 acts to prevent the document from being discharged toward the manual paper discharge port 622 when the document is discharged.
Reference numeral 619 denotes a manual feeding / discharging roller for feeding / discharging a manually fed document. Reference numeral 618 denotes a paper discharge roller for discharging a document.

In the lower part of the document tray 620, three sensors (608 to 610) are arranged. 610
Reference numeral denotes a document set detection sensor which is a transmission type optical sensor for detecting that the document bundle 621 is set. An original trailing edge detection sensor 608 is a reflection-type optical sensor for determining whether the original is a half-size original. 6 between the original set detection sensor 610 and the original trailing edge detection sensor
A final document detection sensor 09 is a reflection type optical sensor for determining whether the document being transported is the final document.

Reference numerals 624, 625, and 626 denote original size detecting sensors for detecting the size of the original being conveyed. Three original size detection sensors are arranged in the width direction of the original. The width is detected in three stages, and the widths of the originals A and B or A4 and A5 are determined. Also, the original length is detected based on the passage time of the original. This makes it possible to detect individual document sizes even in a document bundle in which documents of different sizes are mixed. However, in this case,
It is assumed that the document bundle is placed with the rear side in the document width direction aligned.

Next, the operation of the automatic document feeder 6 when reading both sides of a document printed on both sides (double-sided document) will be described.

When the automatic document feeder 6 is instructed to start feeding a double-sided document, the stopper 611 is lowered, and the paper feed roller is further dropped on the upper surface of the document (FIG. 7B).

By the operation of the paper feed roller 601, the separation roller 602, the separation belt 603, and the conveyance roller 604, the original is separated from the uppermost surface of the original bundle 621 by one sheet and fed to the registration roller 605 (FIG. c)). At this time, the reversing paper feed flapper 613 is set in a direction for transporting the document to the reversing path.

When the registration roller 605 rotates, the original is conveyed to the position shown in FIG. 8E via the path shown in FIG. 7D. From here, the driving directions of the first reversing roller 614 and the second reversing roller 615 are reversed, the document is fed onto the platen, and stops at the position shown in FIG.

When the reading of the original is completed, FIG.
As shown in FIG. 8, the original is turned over via a re-feed path 651, and as shown in FIG.
01.

When the reading of the document is completed, the document is fed rightward, and is discharged from the document discharge port 623 to the outside of the automatic document feeder 6. By repeating the above operation,
The two-sided document can be separated one by one from the top surface, read on both sides, and discharged with the top surface facing down (face down).

Next, the scanner 202 is fixed at a predetermined position, and the operation of the original reading method (flow reading) for reading an image by moving the original is described in the case where the original is only a small size and the case where a large size is included. I will explain separately. In the present embodiment, the small size is a size at which the document trailing end detection sensor 608 does not detect a document when the document bundle 621 is placed on the document tray 620, and the large size is a size at which the document bundle is placed on the document tray 620. When the document 621 is placed, the size of the document is detected by the document trailing edge detection sensor 608.

First, the flow-reading of a small-size original will be described. The operation until the document reaches the registration rollers 605 is as described with reference to FIGS. 7A to 7C. In the case of the flow reading, as shown in FIG. 9I, the reversing sheet feeding flapper 613 guides the document onto the platen 201. The original is conveyed at a predetermined speed on point A in the figure,
The image of the original is scanned by the scanner 202 below the point A.
(FIG. 9 (j)). Point A is defined as the position where the trailing edge of the small size document has passed the registration roller 605. The original is conveyed to the right in the figure as it is, and is discharged out of the automatic document feeder 6 from the original discharge port 623 (FIG. 9 (k)).

Next, the flow reading of a document including a large size will be described. The operation until the document reaches the registration rollers 605 is as described with reference to FIGS. 7A to 7C. In the case of the flow reading, as shown in FIG.
Lead up one. The document is conveyed at a predetermined speed above point B in the figure, and the image of the document is read by the scanner 202 waiting below point B. Point B is defined as the position where the trailing edge of the large-sized document has passed the registration roller 605. The original is conveyed to the right in the figure as it is, and is discharged out of the automatic document feeder 6 from the original discharge port 623 (FIG. 10 (m)).

Finally, in the case of original fixed reading in which the scanner 202 is moved to read an image, the original is placed at a position where the rear end of the original is aligned with the end of the platen 201 (the position shown in FIG. 8H).

Next, the document tray 6 of the automatic document feeder 6
FIG. 11 shows how the direction of the document bundle 621 set in the document tray 20 and the direction of the document bundle 621 conveyed and discharged to the document discharge port 622 correspond to each other. The original shown on the left side of FIG. 11 is the original bundle 6 set on the original tray 620.
21. Since the document is conveyed in order from the number 1 document on the uppermost surface of the document and is output with its front and back reversed, FIG.
As shown on the right side of FIG. 1, the uppermost document is turned upside down and discharged as the lowermost surface.

In the image forming apparatus having the above configuration, a control example in the case where the discharge tray of the sheet processing apparatus reaches the maximum stacking capacity in both the upper and lower stages will be described.

FIG. 12 is a flowchart showing a control method in the case where both trays have reached the maximum load capacity. The control is started when the printer starts the image forming operation.

First, in S1, an image forming operation is started on the first transfer sheet. Next, in S2, the transfer paper on which the image formation is completed is discharged from the main body, and is stacked on the processing tray. Next, the process proceeds to S3, where it is determined whether the transfer paper stacked in S2 is the last paper of the set. If it is not the last sheet, the process returns to S1, and the operations from S1 to S3 are repeated until the last sheet of the set is stacked on the processing tray. If it is the last sheet of the set in S3, S4
To discharge the set of transfer paper bundles stacked on the processing tray to the tray. Next, the process proceeds to S5, where it is determined whether or not all the images have been formed. If completed, the process ends.

If it is determined in S5 that the count has not been completed, the process proceeds to S6, and it is determined whether both the upper and lower trays have reached the maximum load capacity. If not reached, the process returns to S1, and the operations from S1 to S6 are continued. At this time,
If the operation is continuous, the following operations in S1 and S2 may be performed before the determination in S6 ends. In S6, if both trays have reached the maximum stacking amount, the process proceeds to S7, where the operation of forming an image on a new transfer sheet is temporarily stopped, and the discharge of sheets to the tray is also stopped.

Subsequently, the process proceeds to S8, where the loading tray selection unit 280 (FIG. 1) selects which of the upper and lower trays to start from when the operation is resumed. At this time, depending on the conditions set by the priority order setting means 289 (FIG. 1), when the selection is made based on the priority order of the tray designated by the user, or the tray loaded before the temporary suspension is selected as it is. There are cases.

Further, in order to make it easier for the user to remove the transfer paper from the tray, the position of the tray selected as the discharge stage after raising the tray or resuming the image forming operation is set to the height of the processing tray 270. To match.

Subsequently, the flow advances to S9, where it is determined whether or not all the stacked transfer papers have been removed from both trays. If the transfer paper has not been removed, the process returns to S9 and waits until all the transfer paper has been removed. In S9, if all the transfer paper has been removed, the process proceeds to S10, and the temporarily stopped image forming operation is restarted. Then, returning to S1, the operations from S1 to S10 are continued until the processing for the set number of copies is completed.

By controlling as described above, when the number of sheets stacked on both the upper and lower trays reaches the upper limit, the image forming operation is temporarily stopped, and the operation is resumed after the transfer paper on the tray is removed. Control. Also, when both trays reach the upper limit, the tray after resumption is determined, and the user moves the tray to a position where it is easy to remove the loaded transfer paper, or moves the tray to a predetermined position according to the operation after resumption. You can move.

[0072]

As described above, according to the present invention,
When the stacking amount of the sheets stacked on the upper, lower, and both trays of the sheet processing apparatus both reached the maximum amount, the image forming operation of the image forming unit was temporarily suspended, and all the sheets on both trays were removed. Since the image forming operation is resumed later, the job can be continued to the end without the sheet stacking amount on the tray exceeding the predetermined amount. Also,
When the image forming operation is temporarily stopped, the tray after the operation is resumed is determined and moved, so that the user can easily remove the stacked sheets, and the image forming operation can be smoothly resumed. The usability of the user can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital copying machine as an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a vertical sectional front view of the digital copying machine.

FIG. 3 is a control block diagram in the digital copying machine.

FIG. 4 is a block diagram of an image processing unit.

FIG. 5 is a detailed view of the image memory unit.

FIG. 6 is a configuration diagram of an external I / F processing unit.

7A is a vertical sectional front view of the automatic document feeder, and FIGS. 7B to 7D are operation diagrams.

FIG. 8 is an operation diagram of the automatic document feeder.

FIG. 9 is an operation diagram of the automatic document feeder.

FIG. 10 is an operation diagram of the automatic document feeder.

FIG. 11 is a diagram illustrating the direction of a document bundle discharged from a document discharge port.

FIG. 12 is a flowchart illustrating a control method when both trays of the sheet processing apparatus reach the maximum stacking amount.

[Explanation of symbols]

171 Control unit of image forming apparatus main body 200 Image processing apparatus main body 210 Image forming unit (image forming unit) 244 Discharge roller (discharge unit) 271 and 272 Sheet transport path (sheet transport unit) 280 Loading tray selecting unit (tray selecting unit) 289 Priority setting means 282 Sheet processing apparatus control means 283a, 283b Tray driving section (tray driving section) 284a, 284b Load amount detection section (load amount detection section) 290 Sheet processing apparatus 292 Upper tray 293 Lower tray 292, 293 Loading tray

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G03G 21/00376 G03G 21/00 376 386 386 (72) Inventor Hideyuki Ikegami 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Mitsuhiko Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term within Canon Inc. (reference) 2H027 DB01 DB09 DC12 EC10 ED16 ED19 ED22 ED30 EE02 EE10 EH01 EH04 EK04 EK06 FA11 FA21 FA22 FA23 FA33 FA35 FA37 FC02 FD08 ZA07 ZA09 2H072 FB01 3F050 BE01 CA05 CB02 LA01 LB03 3F054 AA01 AC04 BA02 BF07 BF22 CA12 CA21 CA33 CA36 DA14

Claims (5)

[Claims] 1. An image forming means for forming an image on a sheet, a tray including two upper and lower trays on which the image formed by the image forming means is stacked, and the upper and lower trays being vertically arranged respectively. A tray driving unit that drives, a sheet conveying unit that conveys a sheet to the tray, a loading amount detecting unit that detects a loading amount of the sheets loaded on the upper and lower trays, and a loading amount detecting unit that detects which one of the upper and lower trays. A tray selecting unit for selecting whether to load sheets, and a stacking amount detecting unit, when it is determined that the stacking amount of sheets on both the upper and lower trays has reached the maximum stacking amount, the image formed by the image forming unit Suspending the forming operation,
An image forming apparatus comprising: control means for controlling the image forming means to restart the image forming operation after all the sheets stacked on the lower tray are all removed. 2. The image forming apparatus according to claim 1, further comprising: a priority setting unit configured to set a priority order of stacking sheets on the upper and lower trays. 2. The image forming apparatus according to claim 1, wherein the unit selects a tray having a higher priority set by the priority setting unit. 3. When the control unit resumes the remaining image forming operation after the temporary stop, the selecting unit continuously selects a tray selected before the image forming operation is temporarily stopped. The image forming apparatus according to claim 1, wherein: 4. The image forming apparatus according to claim 1, wherein when the control unit temporarily suspends the image forming operation, the tray driving unit raises the upper and lower trays to a predetermined position. 5. The image according to claim 4, wherein the predetermined position is a start position of stacking sheets on a tray selected by the selecting unit when the image forming unit restarts an image forming operation. Forming equipment.