JP2007112632A - Printing system and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the deterioration by drying of paper while preventing reduction in throughput of a job by eliminating a loss in switching paper feeding stages by an ACC in an image forming device having a plurality of paper feeding stages for feeding paper by air. <P>SOLUTION: The image forming device has a plurality of paper storage parts requiring a paper feeding preprocessing process in a paper feeding process, and the respective paper storage parts are provided with a paper residual quantity detecting means for detecting a residual quantity of the paper. A control means controls to perform the paper feeding preprocessing process to a candidate for the paper storage parts when the paper storage parts capable of carrying on feeding paper except for the paper storage part in the paper feeding exist when a paper residual quantity of the paper storage part during the paper feeding is reduced less than a predetermined value by the paper residual quantity detecting means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing system and a control method thereof.

  Image forming apparatuses such as copiers, printers, and facsimile machines have a paper storage unit (paper feed stage) for storing recording paper, and the recording paper is transported from the paper storage unit to the image forming unit by the paper supply device. An image is formed on the top and discharged outside the image forming apparatus. A sheet feeding device in such an image forming apparatus is generally a roller sheet feeding device that conveys sheets stacked on a sheet tray to the downstream side by rotation of a sheet feeding roller. In this roller feeder, the roller surface is made of an elastic body such as rubber, and its performance greatly depends on the friction coefficient of the roller surface. Therefore, the paper feeding performance is not stable due to changes in the outer shape of the roller due to wear, changes in the roller material over time, changes in the friction coefficient of the roller surface due to adhesion of paper dust, etc., and it is possible to handle various sheets with different surface conditions. There was no problem.

  In order to solve these problems, there has been proposed an air sheet feeder that employs an air separation system as disclosed in Japanese Patent Laid-Open No. 6-199437 (Patent Document 1). The air feeding device includes a sheet stacking unit, a sheet handling unit that blows air onto the end of the sheet stacked on the sheet stacking unit to handle the upper sheet, a transport belt, and the uppermost sheet on the transport belt. It is comprised with the adsorption | suction conveyance means to adsorb | suck and convey a sheet | seat.

  In addition, there are some conventional image forming apparatuses that can store sheets of various sheet sizes in each sheet storage section by providing a plurality of sheet storage sections to form an image on various sheets. To do. In addition, image forming apparatuses that store a large amount of paper in the image forming apparatus by storing paper of the same paper size in a plurality of paper feed stages and perform a large amount of image formation by supplying paper once are also currently available. Then it has become common.

  In the image forming apparatus constituted by a plurality of paper feed stages as described above, there are the following problems when the air paper feed device is used.

  As described above, the air feeding device provided in each paper feed stage has means for blowing the air to the end portion of the sheet to separate the upper sheet, and means for sucking the uppermost sheet to the conveyance belt. However, these means use air pressure. Here, in practice, even if air extraction / intake is performed to perform the sheet feeding operation, a time delay occurs until the air pressure acts on the sheet in the sheet feeding stage. Possible causes for this include the length of the duct, the switching time of the on-off valve in the duct for switching the air for each sheet feed stage, and the delay in the handling time due to the weight of the sheet.

  An image forming apparatus that stores paper of the same paper size in a plurality of paper feed stages has an ACC (Auto Cassette Change) function as disclosed in JP-A-2002-40881 (Patent Document 2). Things are known. This function is to continue feeding from other sheet storage units without stopping the sheet feeding operation if there are sheets of the same sheet size other than the sheet storage unit where no paper has occurred. . As a result, the operation stop time due to the absence of paper is shortened and the efficiency is increased. However, in the above-described air sheet feeding device, there is a time delay until the air pressure acts on the sheet even if the sheet feeding operation is started, so that the sheet feeding operation is delayed and the job throughput is reduced. There's a problem.

  In order to solve such a problem, Japanese Patent Application Laid-Open No. 5-286590 (Patent Document 3) discloses an air sheet feeder that eliminates a delay in sheet feed stage switching by always applying air to two sheet feeders. Has proposed. In this document, in an air sheet feeder that performs extraction and distribution of air supply to a plurality of copy trays by one bleeder and an air supply device, the pressure is such that paper can be fed when the opening and closing valves of the two trays are opened. The valve control is performed so that the two on-off valves are always opened. Since the two on-off valves are always open, the characteristics that the air pressure does not fluctuate or are negligible even when two trays are simultaneously fed are obtained. Using this characteristic, the air pressure on the tray side can be quickly changed to the value required for operation when switching the paper feed stage, eliminating the loss of paper feed stage switching and suppressing the reduction in job throughput. it can.

  Further, when the fan for causing air to act on the sheet feeding device is rotated after the copy start switch is pressed, it takes time until the air pressure is stabilized after reaching a predetermined rotational speed. In this regard, in Japanese Patent Application Laid-Open No. 5-262437 (Patent Document 4), when the main power is turned on, the fan is rotated at a low speed, and immediately after the copy start switch is pressed, the fan is immediately increased to a predetermined rotational speed. The time to stability is shortened.

JP-A-6-199437 JP 2002-40881 A JP-A-5-286590 Japanese Patent Laid-Open No. 5-262437

  Although various proposals as described above have been made, however, the printing process using the sheet of the first stacking unit can be executed by the printing apparatus, and the printing process using the sheet of the second stacking unit is performed by the printing. In the printing system that can be executed by the apparatus, the remaining amount of sheets of the first stacking unit is in the middle of the printing process of the job in which the printing process is started by the printing apparatus using the sheets of the first stacking unit. No proposal is made to continue the printing process of the job by the printing apparatus using the sheets of the second stacking unit without using up the sheets of the first stacking unit when the predetermined amount greater than 0 is reached. Not done.

  Also, a printing system that allows a printing apparatus to execute printing processing using either the sheet of the first stacking unit or the sheet of the second stacking unit that requires execution of air supply by the feeding device prior to sheet conveyance. In the middle of print processing of a job for which printing processing has been started by the printing apparatus using the sheets of the first stacking unit, the remaining amount of sheets of the first stacking unit is set to a first predetermined amount greater than zero. If it has reached, the sheet supply of the first stacking means is continued to be used, and the print processing of the job is continued by the printing apparatus, while the air supply to be executed prior to the conveyance of the sheets of the second stacking means Is further executed by the feeding device, and the remaining amount of sheets in the first stacking unit is zero while the print processing of the job is continued using the sheets in the first stacking unit. When the second predetermined amount that is larger and smaller than the first predetermined amount is reached, the sheet of the first stacking unit is not used up, and the sheet of the second stacking unit that has been supplied with air is used. No proposal has been made to continue the printing process of the job by the printing apparatus.

  According to the first aspect of the present invention, the printing process using the sheet of the first stacking unit can be executed by the printing apparatus, and the printing process using the sheet of the second stacking unit can be executed by the printing apparatus. In the printing system, the remaining amount of sheets in the first stacking unit is greater than 0 during the printing process of the job in which the printing process is started by the printing apparatus using the sheets in the first stacking unit. When the predetermined amount is reached, it is possible to provide a printing system in which the printing apparatus continues the print processing of the job using the sheets of the second stacking unit without using up the sheets of the first stacking unit.

  According to the second aspect of the present invention, the printing process using either the sheet of the first stacking unit or the sheet of the second stacking unit that requires the air supply to be performed by the feeding device prior to the conveyance of the sheet. In the printing system in which the printing apparatus is capable of executing the printing process, the sheet of the first stacking unit is left in the middle of the printing process of the job in which the printing process is started by the printing apparatus using the sheet of the first stacking unit. When the amount reaches a first predetermined amount greater than 0, the printing device continues to use the sheet of the first stacking unit and the printing apparatus continues to print the sheet of the second stacking unit. The air supply to be executed prior to the conveyance of the first sheet is executed by the feeding device, and further, while the print processing of the job is continued using the sheets of the first stacking unit, When the remaining amount of sheets in the stacking unit reaches a second predetermined amount that is greater than 0 and smaller than the first predetermined amount, the air supply is executed without using up the sheets of the first stacking unit. It is possible to provide a printing system in which the printing process of the job is continued by the printing apparatus using the sheet of the second stacking unit.

  According to the first aspect of the present invention, the printing process using the sheet of the first stacking unit can be executed by the printing apparatus, and the printing process using the sheet of the second stacking unit can be executed by the printing apparatus. In the printing system, the remaining amount of sheets in the first stacking unit is greater than 0 during the printing process of the job in which the printing process is started by the printing apparatus using the sheets in the first stacking unit. When the predetermined amount is reached, it is possible to provide a printing system in which the printing apparatus continues the print processing of the job using the sheets of the second stacking unit without using up the sheets of the first stacking unit. According to the second aspect of the present invention, the printing process using either the sheet of the first stacking unit or the sheet of the second stacking unit that requires the air supply to be performed by the feeding device prior to the conveyance of the sheet. In the printing system in which the printing apparatus is capable of executing the printing process, the sheet of the first stacking unit is left in the middle of the printing process of the job in which the printing process is started by the printing apparatus using the sheet of the first stacking unit. When the amount reaches a first predetermined amount greater than 0, the printing device continues to use the sheet of the first stacking unit and the printing apparatus continues to print the sheet of the second stacking unit. The air supply to be executed prior to the conveyance of the sheet is executed by the feeding device, and further, while the print processing of the job is continued using the sheets of the first stacking unit, When the remaining amount of sheets in the stacking unit reaches a second predetermined amount that is greater than 0 and smaller than the first predetermined amount, the air supply is executed without using up the sheets of the first stacking unit. It is possible to provide a printing system in which the printing process of the job is continued by the printing apparatus using the sheet of the second stacking unit. As a result, for example, in the case of using a sheet in another sheet feed stage after using up all sheets in one sheet feed stage, such as the conventional ACC function, “Detecting paper out in sheet feed stage → Paper feed fails due to the absence of paper → An error indicating that the paper feed has failed is notified → After receiving this error notification, an available paper feed stage other than the paper-free paper feed stage is specified. A series of processing flows such as “continue print processing using the specified paper feed stage” can be simplified, and the loss of the paper feed stage switching by the conventional ACC is eliminated. It is possible to improve the job throughput rather than the job throughput obtained by a simple configuration.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
(Outline of image input / output system)
FIG. 1 is a diagram showing an overall configuration of an image input / output system (printing system) 100 according to the present embodiment of the present invention.

  A reader unit (image input device) 200 optically reads a document image and converts it into image data. Specifically, the reader unit 200 includes a scanner unit 210 that controls a function for reading a document, and a document feed unit 250 that controls a function for transporting a document sheet.

  A printer unit (image output device) 300 conveys recording paper, prints image data as a visible image thereon, and discharges the recording paper out of the device. The printer unit 300 includes a paper feeding unit 310 that controls a plurality of types of recording paper cassettes, a marking unit 320 that controls a function of transferring and fixing image data onto the recording paper, and outputting printed recording paper to the outside. And a paper discharge unit 330 for controlling the function to be performed.

  The control device (controller unit) 110 is electrically connected to the reader unit 200 and the printer unit 300, and further connected to host computers 4001 and 4002 via the LAN 4000. The control device 110 controls the reader unit 200 to read image data of a document, and controls the printer unit 300 to output the image data to a recording sheet to provide a copy function. Also, a scanner function that converts image data read from the reader unit 200 into code data and transmits the code data to the host computer via the LAN 4000. Code data received from the host computer via the LAN 4000 is converted into image data, and the printer unit. A printer function for outputting to 300 is also provided.

  The operation unit 150 is connected to the control device 110 and is configured by a liquid crystal touch panel, for example, and provides a user interface for operating the image input / output system.

  FIG. 3 is a diagram illustrating an example of the operation unit 150.

  Reference numeral 600 denotes an LCD touch panel, and main mode setting and status display are performed here. Reference numeral 601 includes a numeric keypad for inputting a numerical value from 0 to 9. Reference numeral 602 denotes an ID key which is used when a department number, a recitation mode, or the like is input when the apparatus is department-managed.

  603 is a reset key for resetting the set mode, 604 is a guide key for displaying an explanation screen for each mode, 605 is a user mode key for entering the user mode screen, and 606 is for performing interrupt copying. It is an interrupt key.

  Reference numeral 607 denotes a start key for starting a copy operation, and reference numeral 608 denotes a stop key for stopping a copy job being executed.

  Reference numeral 609 denotes a soft power switch. When this switch is pressed, the backlight of the LCD 600 is turned off, and the apparatus falls into a low power state. Reference numeral 610 denotes a power saving key, which is pressed to enter a power saving state and is pressed again to return from the power saving state.

  Reference numerals 611 and 612 denote function keys for transferring to copy and box, respectively. In FIG. 3, a standard screen for copying is displayed, and the standard screen for each function is displayed when another function key 612 is pressed.

  Reference numeral 614 denotes an adjustment key for adjusting the contrast of the LCD touch panel 600.

  Reference numeral 615 denotes a counter confirmation key. When this key is pressed, a count screen for displaying the total number of copies used so far is displayed on the LCD 600.

  616 is an LED indicating that the job is being executed and the image is being stored in the image memory, 617 is an error LED indicating that the device is in an error state such as a jam or door open, and 618 is that the main power supply of the device is ON. The power LED indicates

(Description of control device 110)
FIG. 4 is a block diagram illustrating a configuration of the control device 110.

  The main controller 111 mainly includes a CPU 112, a bus controller 113, and various I / F controller circuits.

  The CPU 112 and the bus controller 113 control the overall operation of the control device 110. The CPU 112 operates based on a program read from the ROM 114 via the ROM I / F 115. The operation of interpreting PDL (page description language) code data received from the host computer and decompressing it into raster image data is also described in this program and processed by software. The bus controller 113 controls data transfer input / output from each I / F, and performs arbitration at the time of bus contention and control of DMA data transfer.

  The DRAM 116 is connected to the main controller 111 by a DRAM I / F 117, and is used as a work area for operating the CPU 112 and an area for storing image data.

  A network controller 121 is connected to the main controller 111 via an I / F 123 and is connected to an external network via a connector 122. The network is generally Ethernet (registered trademark).

  An expansion connector 124 for connecting an expansion board and an I / O control unit 126 are connected to the general-purpose high-speed bus 125. A general-purpose high-speed bus is a PCI bus.

  The I / O control unit 126 is equipped with two channels of an asynchronous serial communication controller 127 for transmitting / receiving control commands to / from the CPUs of the reader unit 200 and the printer unit 300. F circuits 140 and 145 are connected.

  The panel I / F 132 is connected to the LCD controller 131 and includes an I / F for displaying on the liquid crystal screen on the operation unit 150 and a key input I / F 130 for inputting hard keys and touch panel keys. Is done.

  The operation unit 150 includes a liquid crystal display unit, a touch panel input device attached to the liquid crystal display unit, and a plurality of hard keys. A signal input from the touch panel or hard key is transmitted to the CPU 112 via the panel I / F 132 described above, and the liquid crystal display unit displays image data sent from the panel I / F 520. The liquid crystal display unit displays function display, image data, and the like in the operation of the image forming apparatus.

  The real time clock module 133 is for updating / saving the date and time managed in the device, and is backed up by a backup battery 134.

  The E-IDE interface 161 is for connecting an external storage device. A hard disk or a CD-ROM drive can be connected via this I / F, and programs and image data can be written and read.

  The connectors 142 and 147 are connected to the reader unit 200 and the printer unit 300, respectively, and are composed of a synchronized step-synchronized serial I / F (143, 148) and a video I / F (144, 149).

  The scanner I / F 140 is connected to the reader unit 200 via the connector 142, and is also connected to the main controller 111 via the scanner bus 141, and an image received from the reader unit 200 is processed according to the contents of processing in the subsequent process. , Have the function of performing the optimal binarization and the scaling process of the main scanning and the sub scanning, and further, the control signal generated based on the video control signal sent from the reader unit 200, It also has a function of outputting to the scanner bus 141.

  Data transfer from the scanner bus 141 to the DRAM 116 is controlled by the bus controller 113.

  The printer I / F 145 is connected to the printer unit 300 via the connector 147, and is connected to the main controller 111 via the printer bus 146. The printer I / F 145 performs smoothing processing on the image data output from the main controller 111, and And a function of outputting a control signal generated based on the video control signal sent from the printer unit 300 to the printer bus 146.

  The transfer of the raster image data expanded on the DRAM 116 to the printer unit is controlled by the bus controller 113 and is DMA-transferred to the printer unit 300 via the printer bus 146 and the video I / F 149.

(Description of main controller 111)
FIG. 5 is a block diagram showing a configuration of the main controller 111.

  The CPU 112 that is a processor core is connected to a system bus bridge (SBB) 402 via a 64-bit processor bus (SC bus). The SBB 402 is a 4 × 4 64-bit crossbar switch, and is connected to a memory controller 403 for controlling an SDRAM and a ROM having a cache memory in addition to the CPU 112 by a dedicated local bus (MC bus), and further to a graphic. It is connected to the G bus 404 that is a bus and the B bus 405 that is an IO bus, and is connected to all four buses. The SBB 402 is designed to ensure simultaneous parallel connection between these four modules as much as possible. The data compression / decompression unit (codec) 418 is also connected via a codec I / F.

  The G bus 404 is cooperatively controlled by a G bus arbiter (GBA) 406 and is connected to a scanner / printer controller (SPC) 408 for connecting to a scanner or a printer. The B bus 405 is cooperatively controlled by a B bus arbiter (BBA) 407. In addition to the SPC 408, a power management unit (PMU) 409, an interrupt controller (IC) 410, and a serial interface controller (SIC) 411 using a UART. , USB controller 412, parallel interface controller (PIC) 413 using IEEE1284, LAN controller (LANC) 414 using Ethernet (registered trademark), LCD panel, key, general purpose input / output controller (PC) 415, PCI bus interface ( (PCIC) 416 is also connected.

  An operation panel 417 including a display panel and a keyboard is connected to the PC 415.

(Description of interrupt controller 410)
The interrupt controller 410 is connected to the B bus 405, integrates each functional block in the main controller chip and interrupts from the outside of the chip, and supports six levels of external interrupts and non-maskable interrupts (NMI) supported by the CPU core 401. Redistribute to Each functional block includes a power management unit 409, a serial interface controller 411, a USB controller 412, a parallel interface controller 413, an Ethernet (registered trademark) controller 414, a general-purpose IO controller 415, a PCI interface controller 416, a scanner / printer controller 408, and the like. is there.

(Description of the memory controller 403)
The memory controller 403 is connected to an MC bus, which is a local bus dedicated to the memory controller, and controls a synchronous DRAM (SDRAM), a flash ROM, and a ROM.

(Description of system bus bridge 402)
FIG. 6 is a block diagram showing the configuration of the system bus bridge (SBB) 402.

  The SBB 402 is a multi-channel bi-directional bus bridge that provides interconnection between the B bus (input / output bus), G bus (graphic bus), SC bus (processor local bus), and MC bus using a crossbar switch. With the cross bus switch, two systems of connections can be established simultaneously, and high-speed data transfer with high parallelism can be realized.

  The SBB 402 includes a B bus interface 2009 for connection to the B bus 405, a G bus interface 2006 for connection to the G bus 404, a CPU interface slave port 2002 for connection to the processor core 401, a memory controller 403, In addition to a memory interface master port 2001 for connection and a CODEC bus interface 2014 for connection to the compression / decompression unit 418, an address switch 2003 for connecting an address bus and a data switch 2004 for connecting a data bus are included. Further, a cache invalidation unit 2005 for invalidating the cache memory of the processor core is provided.

(Description of PCI bus interface 416)
The PCI bus interface 416 is a block that interfaces between the B bus, which is a general-purpose IO bus inside the main controller, and the PCI bus, which is a chip external IO bus.

(Description of G bus arbiter 406 and B bus arbiter 407)
The arbitration of the G bus is a central arbitration method, and has a dedicated request signal and a grant signal for each bus master. This arbiter can program the control method. In addition, as a method of giving priority to the bus master, all bus masters have the same priority, the fair arbitration mode in which the bus right is given fairly, and the priority of any one bus master is raised, and the bus is used preferentially. You can specify either the priority arbitration mode.

  The B bus arbiter 407 receives a bus use request of the B bus 405 that is an IO general-purpose bus, and after arbitration, gives a use permission to the selected master, and two or more masters simultaneously access the bus. Is prohibited. The arbitration method has three levels of priority, and a plurality of masters can be assigned to each priority in a programmable manner.

(Description of Scanner / Printer Controller 408)
FIG. 7 is a block diagram showing the configuration of the scanner / printer controller 408.

  The scanner / printer controller 408 is a block that is connected to the scanner and the printer by the Video I / F and interfaces with the internal bus G bus and B bus. Broadly divided into the following three blocks.

  The first is a scanner controller 4302. It is connected to a scanner via a video I / F and performs operation control and data transfer control. The G bus / B bus I / F unit (GBI) 4301A is connected by an IF bus to perform data transfer and register read / write.

  The second is a printer controller 4303. It is connected to a printer via a video I / F and performs operation control and data transfer control. The GBI 4301B is connected by an IF bus to perform data transfer and register read / write.

  The third is a G bus / B bus I / F unit (GBI) 4301.

This is a unit for connecting the scanner controller 4302 and printer controller 4303 to the G bus or B bus. The scanner controller 4302 and the printer controller 4303 are independently connected, and are connected to both the G bus and the B bus.
In addition, it has a CP bus for directly connecting image data of the scanner and the printer and a synchronizing signal for horizontal and vertical synchronization, and the scanner controller 4302 and the printer controller 4303 are connected by this CP bus.

(Description of power management unit 409)
The main controller 111 is a large-scale ASIC with a built-in CPU. For this reason, if all the internal logics operate simultaneously, a large amount of heat is generated and the chip itself may be destroyed. In order to prevent this, the main controller performs power management for each block, that is, power management, and further monitors the power consumption of the entire chip.

  Each block performs power management individually. Information on the power consumption of each block is collected in a power management unit (PMU) 409 as a power management level. In the PMU 409, the power consumption of each block is summed, and the power consumption of each block of the main controller is collectively monitored so that the value does not exceed the limit power consumption.

(Description of reader unit 200 and printer unit 300)
FIG. 2 is a cross-sectional view of the reader unit 200 and the printer unit 300. The document feeding unit 250 in the reader unit 200 feeds the documents one by one to the platen glass 211 in order from the top, and discharges the documents on the platen glass 211 to the discharge tray 219 after the document reading operation is completed. When the document is conveyed onto the platen glass 211, the lamp 212 is turned on, and the movement of the optical unit 213 is started to expose and scan the document. Reflected light from the original at this time is guided to a CCD image sensor (hereinafter referred to as CCD) 218 by mirrors 214, 215, and 216 and a lens 217. Thus, the scanned image of the original is read by the CCD 218. Image data output from the CCD 218 is transferred to the control device 110 after being subjected to predetermined processing. The reader unit includes a document detection sensor 251, and the document detection sensor 251 detects the presence or absence of a document. The document detection sensor is configured by a lever sensor or an optical sensor.

  The control device 110 and the reader unit 200 exchange commands as shown in FIG. First, the control device 110 issues a “document feed execution request” (8001) to the reader unit 200 in order to feed the document on the feeder. On the other hand, the reader unit 200 issues a “document feed end status notification” (8002) to the control device 110 when the document on the feeder is fed. At this time, the reader unit 200 detects whether or not a document exists on the document detection sensor 251, and notifies that “there is a next document” if there is paper on the document detection sensor 251, and “next” if there is no document. “No original” is notified. In other words, the presence / absence of a document is determined at the time of “document feeding execution request” (8001), and the presence / absence of the next document is determined at the time of “document feeding end status notification” (8002).

  Then, the control device 110 issues a “scan execution request” (8003) to the reader unit 200 to request image reading of the document. Thereafter, the reader 200 notifies the control device 110 of “scan execution preparation end notification” (8004) when actually starting image reading and “scan end status notification” (8005) after image reading ends.

  Returning to FIG. A laser driver 321 of the printer unit 300 drives the laser light emitting unit 322, and causes the laser light emitting unit 322 to emit laser light corresponding to the image data output from the control device 110. The laser beam is irradiated onto the photosensitive drum 323, and a latent image corresponding to the laser beam is formed on the photosensitive drum 323. A developer is attached to the latent image portion of the photosensitive drum 323 by a developing device 324.

  The printer unit 300 includes a cassette 350a, a cassette 350b, a cassette 350c, and a cassette 350d each having a shape on the drawer as a paper storage unit, and a manual paper feed stage 360 on a tray exposed outside the apparatus. With the exception of the manual paper feed stage 360, paper is normally supplied by pulling out the cassette, supplying paper to the cassette, and closing the cassette.

  This paper storage unit employs a so-called air separation system, and is a type that separates and feeds sheets sequentially from the uppermost sheet. As shown in FIG. 2, the sheet storage unit includes a sheet storage unit 350 (350a, 350b, 350c, 350d) on which sheets are stacked, and a sheet suction conveyance unit 352 (352a, 352b, 352c, 352d), separation sections 353 (353a, 353b, 353c, 353d) for separating sheets, conveyance rollers 382 (382a, 382b, 382c, 382d), and the like.

  The sheet storage unit 350 (350a, 350b, 350c, 350d) includes a paper feed tray 351 (351a, 351b, 351c, 351d), a height detection sensor 365 (365a, 365b, 365c, 366d), and a height detection sensor lever 364. (364a, 364b, 364c, 364d) and the like.

  The paper feed tray 351 (351a, 351b, 351c, 351d) is for stacking sheets. The sheet feeding tray 351 is configured such that its vertical position is adjusted so that the upper surface of the stacked sheets S is maintained at a predetermined height position. This position adjustment is performed by the sheet feeding unit 310 according to the detection results of a height detection sensor 365 (365a, 365b, 365c, 365d) and a height detection sensor lever 364 (364a, 364b, 364c, 364d), which will be described later. This is done by controlling the rotation of a tray motor (not shown) that raises and lowers the paper feed tray 351.

  The height detection sensor 365 (365a, 365b, 365c, 365d) and the height detection sensor lever 364 (364a, 364b, 364c, 364d) detect the height of the upper surface of the sheet S placed on the tray. belongs to. The height detection sensor lever 365 is operated according to the height position of the upper surface of the sheet S, and the height detection sensor 365 detects the operation state (position of the height detection sensor lever 364), whereby the upper surface of the sheet S is changed. Whether or not a predetermined height position has been reached is detected. The detection result (ON / OFF) of the height detection sensor 365 is output to the paper feed unit 310 to control the rotation of a tray motor (not shown) that raises and lowers the paper feed tray 351 described above. It is used for adjustment. At the same time, the remaining position of the sheet S in the paper feed tray 351 can be detected at the same time as the height of the paper feed tray 351 is detected by the rotational position of the tray motor. The detection result of the remaining amount of paper is notified to the control device 110 through the paper feeding unit 310 as needed.

  The sheet suction conveyance unit 352 (352a, 352b, 352c, 352d) is for feeding the sheets stacked on the paper feed tray 351. Details of the sheet suction conveyance unit 352a are shown in FIG. 22, FIG. 23, and FIG. The sheet suction conveyance units 352b, 352c, and 352d have the same configuration. The sheet suction conveyance unit 352 (352a, 352b, 352c, 352d) includes a conveyance belt 356 (356a, 356b, 356c, 356d), a drive unit 382, a suction duct 371 (371a, 371b, 371c, 371d), and an ejection duct 370 ( 370a, 370b, 370c, 370d) and the like.

  The conveyor belt 356 (356a, 356b, 356c, 356d) is disposed above the paper feed tray 351 with the paper feed direction side slightly upward. The conveyor belt 356 (356a, 356b, 356c, 356d) is wound around a driving roller 390 and a driven roller 391, and moves in the direction of arrow B along with the rotation of the driving roller 390 (390a, 390b, 390c, 390d). It is rotated (see FIG. 22). Further, a suction hole 355 for sucking and adsorbing the sheet is formed on the surface.

  Further, in the suction duct 371 (371a, 371b, 371c, 371d), an adsorption sensor lever 367 (367a, 367b) that rotates upward by being pressed by a sheet adsorbed by the conveyance belt 356 (356a, 356b, 356c, 356d). 367c, 367d), and an adsorption sensor 368 that detects that the sheet is adsorbed to the conveyance belt 356 based on the upward rotation of the adsorption sensor lever 367 and outputs an adsorption signal to the sheet feeding unit 310.

  The drive unit 12 illustrated in FIG. 23 operates the transport belt 356 by rotating the drive roller 390. As shown in FIG. 23, the drive unit 12 includes a motor 395, a gear pulley 381, a clutch 394, and the like. The driving force of the motor 395 is transmitted to the input shaft of the clutch via the gear pulley 381 and the belt 396. The clutch 394 has its output shaft connected to the drive shaft 392 of the drive roller 390. Accordingly, the clutch 394 is connected by the paper feeding unit 310, whereby the driving force of the motor 395 is transmitted to the driving roller 390 via the driving shaft 392, and the conveying belt 356 is rotated.

  The suction duct 371 (371 a, 371 b, 371 c, 371 d) is for sucking air through the suction hole 355 of the transport belt 356 and is disposed in the track of the transport belt 356. By operating the fan 357 (see FIG. 23) and sucking air through the suction duct 371, negative pressure is generated in the vicinity of the suction hole 355. Further, suction valves 375 (375a, 375b, 375c, 375d) for adjusting the amount of air sucked are arranged in the suction duct 371 (see FIG. 23). Note that the air sucked by the action of the fan 357 flows into the separation unit 353 and is ejected.

  The separation unit 353 (353a, 353b, 353c, 353d) assists the suction conveyance of the sheet by blowing air to the sheet end portion to lift and separate the sheet. The separation unit 353 (353a, 353b, 353c, 353d) includes an ejection duct 370 (370a, 370b, 370c, 370d), a valve 374 (374a, 374b, 374c, 374d), a relay duct 372, a fan 357, and the like. .

  The ejection duct 370 (370a, 370b, 370c, 370d) is disposed on the downstream side in the sheet feeding direction of the sheet feeding tray 351 and below the driving roller 390. In the ejection duct 370 (370a, 370b, 370c, 370d), a separating nozzle 358 for ejecting air in the direction of arrow C (horizontal direction) in FIG. 22 and a separation nozzle 359 for ejecting air in the direction of arrow D are formed. Has been. Air ejected from the separation nozzle 358 and the separation nozzle 359 is supplied from the fan 357 through the relay duct 372. Valves 374 (374a, 374b, 374c, 374d) for adjusting the amount of air ejection are arranged at the connection between the ejection duct 370 and the relay duct 372 (see FIG. 23). The opening degree of the valve 374 can be adjusted in accordance with an instruction from the paper supply unit 310.

  The fan 357 shown in FIGS. 23 and 24 is driven by a motor (not shown) that operates in accordance with an instruction from the paper feed unit 310. The fan 357 is also connected to the above-described suction duct 371 as shown in FIG. That is, the fan 357 is configured to serve both for suction in the suction conveyance unit 352 and for blowing in the separation unit 353. The flow of air between the suction duct 371 and the ejection duct 370 is shown in FIG.

  When such a configuration is employed, there may be a case where there is not enough air to be ejected from the ejection duct 370 only by performing suction suitable for sheet adsorption. Further, there is a case where it is desired to perform only the ejection of air in the ejection duct 370 without performing suction in the duct 371. Therefore, the suction duct 371 is opened upstream from the suction opening 354 and is released to the atmosphere. A relief valve 376 (376a, 376b, 376c, 376d) is provided on the downstream side of the opening. The relief valve 376 normally closes this opening of the suction duct 371 by its own weight. However, when the negative pressure in the suction duct 371 exceeds a predetermined value, it is pushed by the atmospheric pressure to open, and the atmosphere is introduced into the suction duct 371. That is, the relief valve 376 plays a role as a constant pressure valve.

  The conveyance rollers 382 (382 a, 382 b, 382 c, 382 d) are for conveying the sheet conveyed by the suction conveyance unit 352 to the transfer unit 325, and downstream of the sheet adsorption conveyance unit 352 in the sheet feeding direction. is set up.

  The paper feed unit 310 controls and controls the entire paper storage unit. The paper feeding unit 310 has a function of performing a paper feeding operation by operating each unit in accordance with an instruction from the control device 110.

(Description of paper feeding operation)
Next, the paper feeding operation will be described.

  The paper feed unit 310 raises the paper feed tray 351 in accordance with the detection results of the height detection sensor lever 364 and the height detection sensor 365, so that the interval between the sheet suction conveyance unit 352 and the top sheet S1 of the sheet S is increased. Is kept constant (see FIG. 22).

  When the paper feed execution request 9003 (details will be described later) shown in FIG. 9 is input from the control device 110, the paper feed unit 310 operates the fan 357 and the motor 395 corresponding to the paper feed tray 351 selected at that time. . Then, the valve 374 is opened, and air is supplied to the ejection duct 370. As a result, air is ejected from the separation nozzle 358 and the separation nozzle 359 in a predetermined direction. Here, it is assumed that the sheet S stored in the paper feed tray 351a is fed.

  At this time, the air ejected from the separation nozzle 358a enters between the sheets S, so that several upper sheets of the sheet S are floated while being separated (see FIG. 22).

  Next, the paper feed unit 310 opens the suction valve 375a. Then, a negative pressure is generated in the suction duct 371a, and the sheet S1 positioned at the top of the sheets S floating by the air from the separation nozzle 358a is adsorbed on the surface of the transport belt 356a. At this time, the sheet S2 located below the sheet S1 may be attracted together. However, the air ejected from the separation nozzle 359a flows between the sheet S1 and the sheet S2, whereby the sheet S2 is pushed back.

  The sheet feeding unit 310 detects that the sheet S1 is adsorbed on the surface of the transport belt 356a according to the detection results of the adsorption sensor lever 367a and the adsorption sensor 368a provided in the sheet suction duct 371a.

  Here, when the sheet feeding unit 310 cannot detect the adsorption of the sheet S1 to the conveying belt 356a by the adsorption sensor lever 367a and the adsorption sensor 368a within a predetermined time after the suction valve 375a is opened, It is detected that there is no sheet S in the paper feed tray 351 and notifies the control device 110 that there is no paper.

  Next, the paper feed unit 310 connects the clutch 394 and starts the rotation of the transport belt 356a. As a result, the sheet S1 adsorbed on the conveyance belt 356a is conveyed in the paper feeding direction. A paper feed sensor 366 (366a, 366b, 366c, 366d) is attached to the transport path between the transport belt 356a and the transport roller 382a. The paper feed sensor 366 detects whether the leading edge of the sheet S1 has reached the transport roller 382a, and notifies the paper feed unit 310 of it.

  When the leading edge of the sheet S1 reaches the conveying roller pair 382a, the paper feeding unit 310 stops the conveying belt 356a by turning off the clutch 394.

  Then, the conveyance roller pair 382a sends the sheet S1 to the transfer unit 325 through the conveyance path 331.

  Thereafter, the developer attached to the photosensitive drum 323 is transferred to the sheet S1, and the sheet on which the developer is placed is conveyed to the fixing unit 327 by the conveyance belt 326, and the developer is removed by the heat and pressure of the fixing unit 327. It is fixed on the image paper. Thereafter, the recording paper that has passed through the fixing unit 327 passes through the conveyance path 335 and is discharged. Alternatively, when the printing surface is reversed and discharged, the paper is guided to the conveyance path 336 and the conveyance path 338, from which the recording paper is conveyed in the reverse direction and passes through the conveyance path 337.

  If double-sided recording is set, after passing through the fixing unit 327, the recording paper is guided from the conveyance path 336 to the conveyance path 333 by the flapper 329, and then the recording paper is conveyed in the reverse direction. Thus, the sheet is guided to the conveyance path 338 and the refeed conveyance path 332. The recording sheet guided to the refeed conveyance path 332 passes through the conveyance path 331 and is fed to the transfer unit 325. The recording paper discharged from the transport path 335 is transported to the discharge bin 328 and stacked.

  Next, paper feed control in single-sided image formation and double-sided image formation will be described.

  First, the recording paper conveyance path in single-sided image formation and double-sided image formation will be described. FIG. 10 is a diagram schematically illustrating a recording paper conveyance path in the printer unit 300, FIG. 11A is a schematic diagram illustrating a recording paper conveyance path on one side in the front sheet ejection mode, and FIG. FIG. 4 is a diagram schematically illustrating a conveyance path of a recording sheet for single-sided image formation according to a mode. 12A and 12B are diagrams schematically illustrating a conveyance path for conveying a recording sheet for double-sided image formation. Here, the description is limited to the case where paper is fed from the manual paper feed stage 315.

  In the printer unit 300, as shown in FIG. 10, the recording paper conveyance path extends from the manual feed stage 360 or each cassette 350 (350a, 350b, 350c, 350d) to between the photosensitive drum 323 and the transfer unit 325. A conveyance path 331, a conveyance path 335 for obtaining a fixing unit (not shown) and conveying the recording paper onto which the toner image on the photosensitive drum 323 is transferred, to the outside (sheet discharge bin), and the photosensitive drum 323. The recording paper on which the toner image is transferred is obtained as a fixing unit (not shown), and the recording paper guided to the conveyance path 338 and the conveyance path 338 for guiding the recording paper to the conveyance path 338 or the conveyance path 333 are externally provided. A transport path 337 for discharging the paper to the transport path 333, and a paper refeed transport path 332 for guiding the paper guided to the transport path 333 to the transport path 331 and refeeding between the photosensitive drum 323 and the transfer unit 325. From It is made.

  In the case of single-sided image formation, as shown in FIG. 11A, first, the recording paper S fed from the manual paper feed stage 315 is transported between the photosensitive drum 323 and the transfer unit 325 through the transport path 331. Then, after the toner image on the photosensitive drum 323 is transferred to the surface of the recording paper S, the recording paper S is sent to the fixing unit, and the toner image is fixed on the recording paper S by the fixing unit. The recording sheet S on which the image has been fixed is discharged to the outside (a discharge bin or a discharge processing unit) through the conveyance path 335.

  Further, in the case of performing the rear discharge, as shown in FIG. 11B, the fixed recording paper S is once guided to the transport path 338 through the transport path 336 and then discharged through the transport path 337. Is done. As a result, the recording paper S is discharged to the outside from the back. In the drawing, the surface of the recording paper S that is marked with Δ is the image forming surface.

  In the case of double-sided image formation, as shown in FIG. 12A, the recording paper S fed from the manual paper feed stage 315 is transported between the photosensitive drum 323 and the transfer unit 325 through the transport path 331, and the recording paper S After the toner image on the photosensitive drum 323 is transferred to the surface, the toner image is sent to the fixing unit. The recording sheet S on which the image is fixed by the fixing unit is once guided to the transport path 333 through the transport path 336 and then guided to the refeed transport path 332. Here, when double-sided image formation is performed on a plurality of recording sheets, a predetermined number of recording sheets S are sequentially fed. When a predetermined number of recording sheets S are fed, the recording sheet on the refeed conveyance path 323 is refeeded to the photosensitive drum 323 via the conveyance path 331 as shown in FIG. 12B. Then, the toner image is transferred to the back surface of the re-fed recording paper, and the recording paper on which images are formed on both sides is discharged to the outside through the fixing unit. Next, the next recording sheet S on the refeed conveyance path 323 is refeeded. In the drawing, the surface marked with Δ in the recording paper S indicates the surface on which the image was first formed, and the surface marked with a semi-circular mark was formed by re-feeding. Show the surface.

(Description of paper settings for each paper source)
Hereinafter, a user interface for setting whether or not a paper feed stage can be changed for each paper feed stage and a user interface for setting a paper type for each paper feed stage will be described with reference to FIGS. To do.

  FIG. 13 is a diagram illustrating an example of a screen (user mode screen) displayed on the LCD panel 600 when the user mode selection button 605 of the operation unit 150 is pressed.

  On the user mode screen, there are several selection buttons for performing various settings. For example, for an item that needs to be set in common for the devices, the common specification setting button 1301 is selected. In addition, there are timer setting buttons for transitioning to a set screen for setting items such as transition to power saving mode, setting items for adjusting the position such as stapling position, etc. Adjustment / Cleaning button, Report output button for transitioning to a set of settings items for printing out the device status, System management setting button for transitioning to a set of settings screens for network settings, Copy-specific A copy use setting button for transitioning to a setting screen for setting items related to functions, and a transmission / reception specification setting button for shifting to a setting screen for setting items such as FAX and Internet FAX. Box specification setting buttons for transitioning to a setting screen for setting items related to the BOX function for storing images such as scanners and PDLs in the HDD in the device, and transmission destinations (destinations) such as FAX and Internet FAX described above in advance There is a destination cover setting button for registration. In addition, there is a close button 1302 for closing the screen of FIG. 13 and transitioning to the previous screen.

  FIG. 14 is a diagram showing an example of a screen (common specification setting screen) displayed on the LCD panel 600 when the common specification setting button 1301 in FIG. 13 is pressed.

  In the common specification setting screen, buttons for selecting setting items related to the entire device that are not specified as copy, PDL, BOX, FAX, or the like are displayed. In addition, since there are many setting items, it is difficult to display buttons corresponding to setting items that can be displayed on one screen. Therefore, buttons corresponding to five setting items (here, “initial function "Setting button", "Function button after auto clear", "Buzzer ON / OFF button", "Inch input button", "Cassette auto selection ON / OFF button 1402"), and settings other than the currently displayed five items When selecting an item button, the next screen selection button 1401 is selected. The display of “¼” on the right of the next screen selection button 1401 indicates that there are four screens in the common specification setting, and the first screen is currently displayed. Similar to the description of FIG. 13, there is a close button 1403 for closing the screen and transitioning to the previous screen of the common specification setting screen.

  FIG. 15 is a diagram showing an example of a screen displayed on the LCD panel 600 when the next screen selection button 1401 in FIG. 14 is pressed.

  As described with reference to FIG. 14, the common specification setting screen in FIG. 15 displays buttons for selecting setting items related to the entire device that are not specified as copy, PDL, BOX, FAX, or the like. For example, a paper type registration button 1503 for registering paper types (plain paper, recycled paper, colored paper, OHP, index paper, etc.) stored in each paper feed stage, and a power saving mode change button for changing the power saving mode . A sleep power consumption button that sets the sleep power consumption. There is a dedicated tray setting button for setting a paper discharge tray to be discharged for each job type (COPY, BOX, PDL, etc.). Similarly to the next screen setting button shown in FIG. 14, a button for displaying a screen for displaying buttons related to common specification setting items on the next screen, a next screen selection button 1501, and a previous screen (FIG. 13). ) To display a previous screen selection button 1502 and the like. The display of “2/4” to the right of the next screen selection button 1501 indicates that there are four screens in the common specification setting, and the second screen is currently displayed. Similarly to the description of FIG. 14, there is a close button 1504 for closing the screen and transitioning to the previous screen of the common specification setting screen.

  FIG. 16 is a diagram showing an example of a screen displayed on the LCD panel 600 when the cassette auto selection ON / OFF button 1402 is pressed in the common specification setting screen (1/4) shown in FIG.

  Here, on the ON / OFF screen of the cassette auto selection, setting items for selecting a paper feed stage that can be automatically selected by the image forming apparatus for each job type (COPY, PDL, BOX, FAX, and others) are displayed. is doing. First, in FIG. 16, each job type is displayed. For example, a copy button 1601 for setting a paper feed stage that can be automatically selected by copying, a printer button 1602 for setting a paper feed stage that can be automatically selected by PDL (printing), and a BOX function can be automatically selected. A box button 1603 for setting a paper feed stage, a reception button 1604 for setting a paper feed stage that can be automatically selected by FAX or Internet fax, and a job that is not included in the job types described so far are automatically selected. There is an other button 1605 for setting a paper feed stage that can be used. There is a close button 1606 for closing the current cassette auto selection ON / OFF screen and transitioning to the common specification setting screen.

  FIG. 17 is a diagram showing an example of a screen displayed on the LCD panel 600 when the copy button 1601 in FIG. 16 is pressed.

  Reference numerals 1701 to 1706 are set for the paper storage unit present in the printer unit 300, the cassette 350 (350a, 350b, 350c, 350d) shaped on the drawer, and the manual paper feed stage 360 on the tray exposed outside the apparatus. The size of the paper being used and the type of paper are shown. Reference numeral 1701 denotes a paper size and paper type set in the manual paper feed stage 360, and here, nothing is registered. Reference numeral 1702 denotes the paper size and paper type set in the cassette 350a. In this example, the A4 size plain paper type is registered. Reference numeral 1703 denotes the paper size and paper type set in the cassette 350b. In this case, the A4 size indicates that recycled paper is registered. Reference numeral 1704 denotes the paper size and paper type set in the cassette 350c. Here, A4 indicates that colored paper is registered. Reference numeral 1705 denotes a paper size and a paper type set in the cassette 350d. Here, A3 indicates that plain paper is registered.

  On the right of the display (1701 to 1705) indicating the paper size and paper type set for each paper feed stage, ON / OFF indicating whether each paper feed stage is shown as a candidate for cassette auto selection is shown. . For example, an OFF button 1701 corresponding to the manual paper feed stage 360 is selected as indicated by 1711. Here, the OFF button and the ON button are opposite to each other. When the OFF button is selected, the ON button is not selected, and when the ON button is selected, the OFF button is not selected. On the other hand, 1712, 1713, 1714, and 1715 have the ON button selected opposite to 1711, and the cassette auto selection is turned ON in a copy job for these paper feed stages (cassette 350a, cassette 350b, cassette 350c, and cassette 350d). It shows that it has become.

  The “Consider paper type button (1709)” is a button for setting whether or not to consider the paper type when selecting cassette auto. When considering the type of paper when selecting cassette auto, the control device 110 determines that paper is fed in a certain job, the paper feed stage is out of paper, and paper is fed from another paper feed stage. Even if there is a paper feed stage that contains paper of the same size that has no paper in another paper feed stage, if the paper type that exists in that paper feed stage is not plain paper, the paper feed stage This is a button for indicating that the sheet feeding operation is not performed.

  Further, FIG. 17 includes a cancel button 1707 for returning to the previous screen without registering these settings, and an OK button 1708 for registering these settings and returning to the previous screen.

  FIG. 18 is a view showing an example of a screen displayed on the LCD panel 600 when the paper type registration button 1503 in FIG. 15 is pressed.

  On the paper type registration screen (FIG. 18), a paper storage unit existing in the printer unit 300 (that is, a cassette 350a, a cassette 350b, a cassette 350c, a cassette 350d having a shape on the drawer, and a tray exposed outside the apparatus. Buttons corresponding to the upper manual paper feed stage 360 or an optional paper feed stage (not shown) are displayed. For example, when the button 1801 is pressed, the screen changes to a screen for setting the paper type of the paper existing in the paper feed stage corresponding to the cassette 350a, and when the button 1802 is pressed, the paper feed stage corresponding to the cassette 350b is entered. When the screen changes to the screen for setting the paper type of the existing paper and the button 1803 is pressed, the screen changes to the screen for setting the paper type of the paper existing in the paper feed stage corresponding to the cassette 350c, and the button 1804 is pressed. In this case, the screen changes to a screen for setting the paper type of the paper existing in the paper feed stage corresponding to the cassette 350d.

  Each button displays the paper size and paper type existing in each paper feed stage. In the illustrated example, the button 1801 indicates that the A350 size plain paper type exists in the cassette 350a, and the button 1802 indicates that the A4 size recycled paper exists in the cassette 350b. Yes. Further, the button 1803 displays that colored paper is present at A4 in the cassette 350c, and the button 1804 displays that plain paper is present at A3 in the cassette 350d. In addition, FIG. 18 also includes a button 1805 for closing the current paper type registration screen in order to return to the common specification setting screen which is the previous screen.

  FIG. 19 shows an example of a screen displayed on LCD panel 600 when button 1801 in FIG. 18 is pressed.

  In FIG. 19, in order to register the paper type of the paper feed stage selected in FIG. 18, buttons corresponding to the types of paper that can be registered are arranged. For example, there are plain paper (1901), recycled paper (1902), and colored paper (1903). These plain paper, recycled paper, and colored paper are recognized as plain paper, and even if the button 1715 considering the paper type shown in FIG. 17 is OFF, the paper type such as from plain paper to recycled paper and from recycled paper to colored paper. This is a type of paper on which the control device 110 can change the paper feed stage (ACC) when there is no paper.

  Also, paper types such as thick paper 1904, second original drawing 1905, and index paper 1906 can be registered as special types of paper. For these special types of paper, the paper feed stage change (ACC) when there is no paper between different paper types is not performed. However, ACC between the same types of paper is performed, such as thick paper to thick paper, second original drawing to second original drawing, and index paper to index paper.

  The user registers the paper type existing in the paper feed stage selected in FIG. 18 by selecting the buttons 1901 to 1906 indicating the paper type. When registering these, the user selects the OK button 1908, When returning to the previous screen without registering, a cancel button 1907 of 1907 is selected.

  As described above, with reference to FIGS. 13 to 19, the user interface for setting whether or not the paper feed stage can be changed for each paper feed stage and the user interface for setting the paper type for each paper feed stage. explained.

(Description of print control processing)
FIG. 9 is a diagram schematically illustrating communication between the control device 110 and the printer unit 300 illustrated in FIG. 1.

  First, when printing one page, the control device 110 issues a print preparation request 9001 to the printer unit 300. Upon receiving the print preparation request, the printer unit 300 starts pre-print processing such as fixing device temperature control and pre-rotation. After the pre-printing process is completed, the printer unit 300 issues a print preparation status 9002 to the control device 110.

  The control device 110 that has received the print preparation status 9002 issues a paper feed execution request 9003 to the printer unit 300 in order to request paper feed. This request includes designation of which one of the cassettes 350a, 350b, 350c, 350d, and the manual paper feed stage 360 is the paper feed source.

  The printer unit 300 that has received the print execution request 9003 starts paper feeding. When the fan 357 and the motor 395 corresponding to the currently selected paper feed tray 350 are not operating, the paper supply unit 310 operates the fan 357 and the motor 395 in the printer unit 300. The valve 374 is opened and air is supplied to the ejection duct 370. As a result, air is ejected from the separation nozzle 358 and the separation nozzle 359 in a predetermined direction, and the separation processing is started. At this time, the air ejected from the separation nozzle 358 enters between the sheets S, so that several upper sheets of the sheet S are floated while being separated (see FIG. 22).

  These processes take some time until the air pressure stabilizes due to the rotational speed of the fan 357 of the target paper feed tray 350 and the opening / closing operation of the valve 374. The paper feeding operation can be smoothly performed in the paper feeding after the first. In addition, the paper feed unit 310 detects a paper feed tray 350 that has been subjected to the separation process and has not performed a paper feed operation within a predetermined time, and the fan 357 and the motor 395 corresponding to the paper feed tray 350 are provided. It also stops the operation and performs a timeout operation.

  Next, the paper feed unit 310 opens the suction valve 375 corresponding to the cassette designated as the paper feed source. Here, it is assumed that the cassette designated as the paper supply source is 350a. In this case, the suction valve 375a is opened. Then, a negative pressure is generated in the suction duct 371a, and the sheet S1 positioned at the top of the sheets S floating by the air from the separation nozzle 358a is adsorbed on the surface of the transport belt 356a. At this time, the sheet S2 located below the sheet S1 may be attracted together. However, the air ejected from the separation nozzle 359a flows between the sheet S1 and the sheet S2, whereby the sheet S2 is pushed back.

  The sheet feeding unit 310 detects that the sheet S1 is adsorbed on the surface of the conveyance belt 356a according to the detection results of the adsorption sensor lever 367a and the adsorption sensor 368a provided in the sheet suction duct 371a.

  Next, the paper feed unit 310 connects the clutch 394 and starts the rotation of the transport belt 356a. As a result, the sheet S1 adsorbed on the conveyance belt 356a is conveyed in the paper feeding direction. A paper feed sensor 366 (366a, 366b, 366c, 366d) is attached to the transport path between the transport belt 356a and the transport roller 382a. The paper feed sensor 366 detects whether the leading edge of the sheet S1 has reached the transport roller 382a, and notifies the paper feed unit 310 of it.

  After detecting the fed paper to each of the sensors 366a, 366b, 366c, 366d, and 366e mounted in each paper storage unit, a paper feed result status 9004 is issued to the control device 110. . Further, as described above, the suction sensor lever 367 and the suction sensor 368 cannot detect the suction of the sheet S1 on the transport belt 356 within a predetermined time after the sheet feeding unit 310 opens the suction valve 375. In this case, it is detected that there is no sheet S in the sheet feed tray 351. When an error such as the absence of paper occurs, the printer unit 300 notifies the controller 110 of the error with a paper feed result status.

  Next, when the sheet reaches the predetermined position, the printer unit 300 that has fed the sheet issues a print start permission (print start preparation completion 9005). The control device 110 that has received the print start permission (print start preparation completion 9005) from the printer unit 300 issues a print execution request 9006 to the printer unit 300 when the image formation is actually possible. Requires the formation and fixing of Thereafter, image hardware signal synchronization is performed between the control device 110 and the printer unit 300, and image formation and further fixing are performed.

  The paper on which the image has been formed is discharged out of the machine when it is one-sided, and when it is stacked on the paper discharge bin 328 supported at the time of paper feed execution request 9003, or when one-sided, single-sided completion (intermediate tray discharge) ), The printer unit 300 issues a print result status 9007 to the control device 110.

  When the sheets are discharged onto the paper discharge bin 328 and there is no subsequent output image, the control device 110 issues a print end notification 9008 to the printer unit 300, and the post-print post-processing is executed. Request to 300.

  FIG. 25 is a diagram illustrating another communication sequence performed between the control device 110 and the printer unit 300. As illustrated, the control device 110 issues a judgment processing request 30001 to the printer unit 300. Information for determining which paper feed tray 351 is to be subjected to the paper feed unit 310 in the printer unit 300 is added to the paper handling request. The paper feeding unit 310 in the printer unit 300 that has received the separation processing request 30001 determines that the fan 357 and the motor 395 corresponding to the paper feeding tray 350 selected by the separation processing request 30001 are not operating. 310 operates the fan 357 and the motor 395, opens the valve 374, and supplies air to the ejection duct 370. As a result, air is ejected from the separation nozzle 358 and the separation nozzle 359 in a predetermined direction, and the separation processing is started. At this time, the air ejected from the separation nozzle 358a enters between the sheets S, so that several upper sheets of the sheet S float while being separated.

  These processes take some time until the air pressure stabilizes due to the rotational speed of the fan 357 of the target paper feed tray 350 and the opening / closing operation of the valve 374. In addition, the paper feed unit 310 detects a paper feed tray 350 that has been subjected to the separation process and has not performed a paper feed operation within a predetermined time, and the fan 357 and the motor 395 corresponding to the paper feed tray 350 are provided. It also stops the operation and performs a timeout operation.

  FIG. 26 is a diagram illustrating still another communication sequence performed between the control device 110 and the printer unit 300. The paper feed unit 310 inside the printer unit 300 issues a remaining paper amount notice 31001 to the control device 110. This notification of the remaining amount of paper is sent to a height detection sensor 365 (365a, 365b, 365c, 365d) and a height detection sensor lever 364 (364a, 364b, 364c, 364d) provided on each paper feed tray 351, and not shown. Based on information from the tray motor, the paper feed unit 310 detects the remaining amount of paper stacked in each paper feed tray 351. The height detection sensor lever 365 is operated according to the height position of the upper surface of the sheet S, and the height detection sensor 365 detects the operation state (position of the height detection sensor lever 364), whereby the upper surface of the sheet S is changed. Whether or not a predetermined height position has been reached is detected. The detection result (ON / OFF) of the height detection sensor 365 is output to the paper feed unit 310 to control the rotation of a tray motor (not shown) that raises and lowers the paper feed tray 351 described above. It is used for adjustment. At the same time, the remaining position of the sheet S in the paper feed tray 351 can be detected at the same time as the height of the paper feed tray 351 is detected by the rotational position of the tray motor. The detection result of the remaining amount of paper is notified to the control device 110 through the paper feeding unit 310 as needed.

  FIG. 27 is a diagram illustrating a communication sequence between the control device 110 and the printer unit 300 during a conventional Auto Cassette Change (ACC). As shown in FIG. 9, the control device 110 and the printer unit 300 process a paper feed execution request 9003, a paper feed result status 9004, a print start preparation completion 9005, a print execution request 9006, and a print result status 9007 in units of pages. . When a plurality of pages are continuously fed, the control unit 110 feeds the next page after the printer unit 300 notifies the control unit 110 of the feed result status 9004 of the previous page. A request 9003 is issued to the printer unit 300.

  In FIG. 27, when performing image formation of a document including three pages of n-2, n-1, and n pages (n ≧ 3), no paper has occurred on the nth page, and ACC has occurred. It shows the exchange of time. First, a normal sequence is performed for n-2 and n-1, since paper is present. For both the n-2th and n-1th pages, the control unit 110 issues a paper feed execution request (32001, 32011) to the printer unit 300, and the printer unit 300 receives the paper feed source by the paper feed execution request (32001, 32011). The paper is fed from the cassette 350 or the manual paper feed stage 360 designated as, and the paper feed result status (32002, 32012) is notified to the control device 110 when the paper is fed. Upon receiving the paper feed result status (32002, 32012), the control device 110 issues a paper feed execution request for the next page. That is, when the paper supply result status 32002 for the (n-2) th page is received, a paper feed execution request 32011 for the (n-1) th page is issued, and when the paper supply result status 32012 for the (n-1) th page is received, n-- A paper feed execution request 32021 for the first page is issued. When the fed paper reaches a predetermined position on the conveyance path, the printer unit 300 that has fed the paper in the paper feed result status notifies the control device 110 of completion of print start preparation (32003, 32013). Receiving the print start preparation completion (32003, 32013), the control device 110 issues a print execution request (32004, 32014) to the printer unit 300, and then performs image transfer. When the paper passes through the conveyance path and is discharged out of the apparatus, the printer unit 300 notifies the control device 110 of the print result status (32005, 32015).

  Next, a description will be given of the case where no paper is generated on the nth page and ACC is performed.

  Receiving the (n−1) th page paper feed result status 32012, the control device 110 notifies the printer unit 300 of a n th page paper feed execution request 32021. Then, the printer unit 300 notifies the control device 110 of a paper out error indicating that the paper supply failed due to no paper as the paper supply result status 32022. The control device 110 notified of this error as the paper feed result status 32022 makes an ACC determination in 32023 as to whether or not there is another paper feed stage that can continue paper feed. The ACC determination at this time is specifically performed according to the flowchart shown in FIG.

  First, in step S101, it is determined whether or not the current (paper-free) paper feed stage is an ACC target paper feed stage. Here, if the current paper feed stage is not the target paper feed stage of ACC, the process proceeds to step S120, an error display indicating no paper is displayed on the operation unit, and the paper feed operation is stopped. On the other hand, if the current paper feed stage is the target paper feed stage of ACC, the process proceeds to step S102.

  In step S102 and subsequent steps, as shown in the drawing, the search is performed in order from the paper feed tray having the highest priority. Normally, the priority order of the paper feed stage of the printer unit 300, the cassettes 350a, 350b, 350c, 350d, and the manual paper feed stage 360 is selected from those having a short transport path to the transfer unit 325 from the viewpoint of output speed. That is, the priority order of the paper feed stages in the printer unit 300 shown in FIG. 2 is the order of the cassettes 350a, 350b, 350c, 350d, and the manual paper feed stage 360. In step S103, it is determined whether all the paper feed stages have been searched. If all the paper feed stages have been searched here, the process proceeds to step S120, an error display indicating no paper is displayed on the operation unit, and the paper feed operation is stopped. On the other hand, if not all the paper feed stages have been searched, the process proceeds to step S104.

  Steps S104 to S106 are conditions determination steps for the paper feed stage to be searched. If all of the conditions of S104 to S106 are satisfied, the process proceeds to step S107. Otherwise, the process returns to step S102 to supply the next search target. The processing for the paper tray is repeated. In step S104, a determination is made as to whether the search target paper feed stage is an ACC target paper feed stage. In step S105, a determination is made as to whether there is a paper in the search target paper feed stage. The paper sizes of the paper feed tray (that is, the paper feed tray that has been fed so far but is currently being processed and is now referred to as “current paper feed tray”) and the paper size of the paper feed tray to be searched are Judge whether they match.

  In step S107, it is determined whether the paper type of the current paper feed stage matches the paper type of the paper feed stage to be searched. The paper type here is based on the paper type of each paper feed stage registered on the paper type registration screen shown in FIGS. If the paper type of the current paper feed stage matches the paper type of the paper feed stage to be searched, the process proceeds to step S121, the paper feed stage to be searched is selected, and the paper feed operation from that paper feed stage is performed. (This corresponds to the issue of a paper feed execution request 32024 described later). On the other hand, when the paper type of the current paper feed stage does not match the paper type of the paper feed stage to be searched, the process proceeds to step S108.

  Steps S108 to S110 are steps for determining whether or not each set condition is satisfied. When the conditions of S108 to S110 are satisfied, the process proceeds to step S121, and when any of the conditions is not satisfied, step S102 is performed. Returning to, the next paper feed stage is searched. In step S108, it is determined whether a flag that considers the type of paper is set. The flag considering the paper type here is operated by the “Consider paper type button 1715” shown in FIG. In step S109, it is determined whether the paper type of the current paper feed stage is a paper type that can be selected because of the paper type mismatch. The paper types that can be selected even if the paper types do not match are plain paper, recycled paper, colored paper, and the like described above with reference to FIG. In step S110, it is determined whether the paper type of the paper feed stage to be searched is a paper type that can be selected because of the paper type mismatch. The paper types that can be selected even if the paper types do not match are the plain paper, recycled paper, colored paper, etc. described above with reference to FIG.

  As described above, when the conditions of S108 to S110 are satisfied, the process proceeds to step S121, the paper feed stage to be searched is selected, and the paper feed operation is continued from that paper feed stage.

  The ACC determination process performed when the paper feed result status indicates an error (no paper) is as described above.

  Returning to FIG. After the ACC determination, if there is an ACC destination paper feed stage, the control device 110 issues a new paper feed execution request 32024 to the printer unit 300 so as to feed paper from that paper feed stage ( As described above, this corresponds to step S121 in FIG. When the fan 357 and the motor 395 corresponding to the selected paper feed tray 350 are not operating, the paper feeding unit 310 operates the fan 357 and the motor 395 in the printer unit 300. The valve 374 is opened and air is supplied to the ejection duct 370. As a result, air is ejected from the separation nozzle 358 and the separation nozzle 359 in a predetermined direction, and the separation process is started. At this time, the air ejected from the separation nozzle 358a enters between the sheets S, so that several upper parts of the sheet S float while being separated (see FIG. 22). These processes take some time until the air pressure stabilizes due to the rotational speed of the fan 357 of the target paper feed tray 350 and the opening / closing operation of the valve 374. Then, after the air pressure becomes stable, the sheet suction conveyance unit 352 is operated, and the sheet feeding operation is started. After that, as with other pages, commands such as a paper feed result status 32025, a print start preparation completion 32026, a print execution request 32027, and a print result status 32028 are exchanged between the control device 110 and the printer unit 300 to form an image. Do.

  As described above, according to the communication processing between the control device and the printer unit in the conventional ACC shown in FIG. 27, after the control device issues the paper feed execution request 32024 to the printer unit, Since the pre-processing of operating 357 and the motor 395 and waiting until it stabilizes occurs, the actual paper feed is delayed, and the notification of the paper feed result status 32025 is delayed (32040). For this reason, a paper gap occurs, and the throughput decreases every time ACC occurs.

  FIG. 28 is a diagram schematically illustrating communication between the control device 110 and the printer unit 300 during Auto Cassette Change (ACC) in the present embodiment. As shown in FIG. 9, the control device 110 and the printer unit 300 process a paper feed execution request 9003, a paper feed result status 9004, a print start preparation completion 9005, a print execution request 9006, and a print result status 9007 in units of pages. . When a plurality of pages are continuously fed, the control unit 110 feeds the next page after the printer unit 300 notifies the control unit 110 of the feed result status 9004 of the previous page. A request 9003 is issued to the printer unit 300.

  FIG. 28 is a scene in which three pages of n-2, n-1, and n pages (where n ≧ 3) are continuously fed and image formation is performed as in the case shown in FIG. This shows an exchange when there is no paper on the nth page of the third page and an ACC occurs. First, since there is paper on the (n-2) th and (n-1) th pages, a normal sequence is performed. The sequence at this time is the same as that shown in FIG.

  Apart from the sequence in units of pages, a remaining sheet notification 33001 is notified as the status of the entire printer. For example, after the paper supply result status 33012 of the (n−2) th page, the printer unit 300 notifies the control device 110 of a remaining paper amount notification 33001. This notification of the remaining amount of paper is detected by the height detection sensor 365 and the height detection sensor lever 364, and therefore generally cannot be detected for each sheet. For this reason, every time paper is fed, that is, every time a paper feed result status is notified from the printer unit 300 to the control device 110, the paper remaining amount notification is not made, but a unit of several sheets or several tens of sheets. Thus, the printer remaining amount notification is notified from the printer unit 300.

  During this printing operation, for example, the fan (357a, for example) for the paper feed stage currently used as the paper feed source is driven, while the other fans (357b-d) are stopped.

  The control device 110 that is notified of the remaining sheet notification 33001 performs an ACC determination 33002 at this time. The ACC determination at this time is performed according to the flowchart of FIG. As can be seen from the flowchart of FIG. 21, the processing of the portion indicated by the broken line is the same as the paper feed stage selection processing in the broken line portion of the flowchart of FIG. However, here, before the paper feed stage selection process in the broken line portion is performed, in step S100, it is determined whether or not the remaining amount of paper in the current paper feed stage is less than a predetermined value N1. As a result, it is predicted whether or not paper will soon be generated. Here, when the remaining amount of paper in the current paper feed stage is less than the predetermined value N1, the paper feed stage selection process in the broken line portion in FIG. 21 is performed. On the other hand, when the remaining amount of paper in the current paper feed stage is equal to or greater than the predetermined value N1, the flow is directly exited. In the flow of FIG. 21, when a paper feed stage is selected by the paper feed stage selection process indicated by the broken line portion, the process proceeds to step S130, and the separation process is executed for the selected paper feed stage.

  The description returns to FIG. When the remaining amount of paper becomes less than N1, and it is determined that the control device 110 will soon be out of paper in the paper feed stage being fed, the control device 110 issues a judgment processing request 33003 to the printer unit 300. To do. This judgment processing request 33003 corresponds to the judgment processing request 30001 shown in FIG. Then, step S130 of FIG. 21 is executed by this judgment processing request 33003. The paper feed unit 310 in the printer unit 300 that has received the separation processing request 33003 supplies a fan (357b) corresponding to the paper feed tray (for example, 350b) selected by the separation processing request 33003 (preferably simultaneously with its motor (395b). ) Also work. Then, the corresponding valve (374b) is opened, and air is supplied to the ejection duct (370b). As a result, air is ejected in a predetermined direction from the separating nozzle (358b) and the separating nozzle (359b) in the ejection duct (370b), and the separating process for the selected paper feed stage is started.

  Next, a description will be given of a case where no paper has occurred on the nth page and ACC is performed.

  The control device 110 that has received the (n−1) th page paper feed result status 33022 notifies the printer unit 300 of an nth page paper feed execution request 32031. Then, the printer unit 300 notifies the control device 110 of a paper out error indicating that paper feeding has failed because there is no paper, as a paper feeding result status 33032. Thereafter, the control device 110 issues a new paper feed execution request 33034 to the printer unit 300 so as to feed paper from the paper feed stage selected by the ACC determination performed in advance in 33002. Conventionally, since the ACC determination is performed at this time point and the separation process is started thereafter, it takes time to switch the paper feed stage by the ACC (see 32040 in FIG. 27). The apparatus 110 makes an ACC determination each time a paper remaining amount notification of 33001 is received (33002), and when the paper remaining amount is less than the predetermined value N1, the separation processing is already started at this point (33003). The supply of air is started in the switching destination paper feed stage. For this reason, the printer unit 300 notifies a paper out error as the paper feed result status 33032, and after receiving a paper feed execution request 33034 accordingly, performs a paper feed operation of the switching destination paper feed stage, and feeds the paper feed result. The status 33035 can be notified to the control device 110.

  Thereafter, like the other pages, commands such as a paper feed result status 32025, a print start preparation completion 32026, a print execution request 32027, and a print result status 32028 are exchanged between the control device 110 and the printer unit 300 to form an image. I do.

  As described above, according to the communication processing between the control device and the printer unit at the time of ACC in the present embodiment as shown in FIG. 28, the remaining amount of paper in the currently used paper feed stage is less than the predetermined value N1. At that time, the fan 357 (preferably the motor 395 at the same time) in the switching destination paper feed stage is operated to start the air supply, so that a new out-of-paper error occurs. It is possible to minimize the delay until the paper is fed from the paper feed stage.

  Therefore, according to the present embodiment, it is possible to eliminate a loss of paper feed stage switching due to ACC, thereby preventing a reduction in job throughput. Furthermore, deterioration due to drying of the paper can also be prevented.

  In the above-described embodiment, the aspect in which the paper feed stage is switched after a paper out error has occurred has been described. Here, the paper out error generally refers to an error that occurs when the remaining amount of paper in the currently used paper feed stage becomes zero. However, the present invention is not limited to a mode in which the paper feed stage is switched after the remaining amount of paper in the currently used paper feed stage becomes zero. The remaining amount of paper “0” is an example, and depending on the image forming apparatus, a mode in which the paper feed stage is switched when the remaining amount of paper becomes less than a predetermined value greater than 0 may be considered. That is, when the remaining amount of paper in the currently used paper feed stage becomes less than the predetermined value N1, the fan in the paper feed stage at the switching destination is operated, and then the remaining amount of paper in the paper feed stage is the predetermined value N2 ( However, a mode in which the paper feed tray is switched when 0 ≦ N2 <N1) is also included in the scope of the present invention.

<Second Embodiment>
As described above, according to Japanese Patent Laid-Open No. 5-262437 (Patent Document 4), when the fan for causing air to act on the sheet feeding device is rotated after the copy start switch is pressed, a predetermined number of rotations is reached. Since it takes time for the air pressure to stabilize, always turn the fan at a low speed when the main power is turned on, and after pressing the copy start switch, immediately increase the fan to the specified number of rotations, so that the time until the air pressure stabilizes It has been proposed to shorten.

  However, it is not preferable in terms of noise and power consumption to rotate the fan at low rotation and apply air pressure to the air feeding device. Also in this case, there remains a problem that the sheet is significantly deteriorated by drying.

  Therefore, in the present embodiment, in an image forming apparatus including a plurality of paper feed stages that perform air paper feed, a delay in paper feed operation with time until the air pressure stabilizes due to air paper feed is prevented, thereby reducing noise and power consumption. This paper proposes a paper feed control technology that can reduce the amount of paper and prevent deterioration due to paper drying.

  Since the configuration of the image input / output device according to this embodiment is the same as that of the first embodiment, the following description uses the configuration diagram used in the first embodiment and refers to other drawings as necessary. While explaining.

  FIG. 29 is a diagram illustrating an example of a screen (copy standard screen) displayed on the LCD panel 600 on the operation unit 150 illustrated in FIG. 3 immediately after the image input / output system is powered on.

  The copy standard screen has several buttons for performing various settings related to copying. For example, a magnification button (13002) for setting the magnification of the original to be read, an equality button (13001) for returning the magnification changed by the magnification button to the same magnification, and various types of paper feed stages (350a) shown in FIG. , 350b, 350c, 350d, 360), a paper selection button (13007) for selecting which paper is to be printed, a sort setting button (13003) for setting the type of sorting such as stapling or shifting, and the original on one side or both sides A duplex setting button (13005) for setting whether to read or perform single-sided printing or double-sided printing with the printer unit 300, an interrupt button (13004) for interrupting another copy during a copying operation, and a density setting Density setting buttons (13009, 13010, 13011), and an image quality setting button (130 for selecting image quality) 2) application mode button (13013 to open a dialog for performing various application specific settings) and there.

  In particular, which paper feed stage (350a, 350b, 350c) is selected by a paper selection button (13007) for selecting which paper of each paper feed stage (350a, 350b, 350c, 350d, 360) is to be printed. , 350d, 360) indicates the current setting to indicate whether it is the paper source. Display unit 13006 in the illustrated example are displayed as "Auto Paper", the user rather than to indicate whether to feed paper from a previously which paper feed stage (350, 360), the paper size of the read document, This is a mode in which the control device 110 determines from which paper feed stage paper is automatically fed.

  There is also a number display portion 13008 indicating how many copies of the read document are to be copied. This numeric value setting is input by the numeric keypad 601 in FIG.

  FIG. 30 is a diagram showing an example of a screen displayed on the LCD panel 600 when the paper selection button (13007) on the copy standard screen shown in FIG. 29 is pressed.

  Here, a dialog is displayed that indicates what paper is stored in each paper feed stage (350a, 350b, 350c, 350d, 360) and from which paper feed stage the paper is fed. . In order to indicate from which paper feed stage paper is fed, an automatic paper selection button 14001, a button 14002 showing a paper feed stage corresponding to the cassette 350a, a button 14003 showing a paper feed stage corresponding to the cassette 350b, and a cassette 350c There are a button 14004 indicating a paper feed stage corresponding to, and a button 14005 indicating a paper feed stage corresponding to the cassette 350d. 14001 to 14005 are exclusive, and only one of the buttons is highlighted. Here, 14001 is highlighted, indicating that the automatic paper selection button is selected.

  Further, on the buttons, what size paper is currently stored can be displayed on the buttons 14002 to 14005 (functioning as the first instruction unit) corresponding to each paper feed stage. In the illustrated example, A4 indicates a paper feed stage corresponding to the cassette 350a, and A4 indicates a paper feed stage corresponding to the cassette 350c. The button 14004 indicates that B4 exists, and the button 14005 indicating the paper feed stage corresponding to the cassette 350d indicates that A3 exists.

  FIG. 31 shows a state when a paper selection button (14002) corresponding to the cassette 350a is pressed on the paper selection screen shown in FIG. When the paper selection button (14002) is pressed, the paper selection button (14002) corresponding to the cassette 350a is highlighted as shown in FIG. 31 from the automatic paper selection button (14001) highlighted in FIG. , The user has selected to feed the recording paper from the cassette 350a. In this embodiment, at this point, the control device 110 notifies the printer unit 300 of a judgment processing request 30001 shown in FIG. The paper feeding unit 310 in the printer apparatus 300 that has received this judgment processing request 30001 operates the fan 357 and the motor 395 corresponding to the paper feeding tray 350 selected by the judgment processing request 30001, and operates the valve 374. Open and supply air to the ejection duct 370. As a result, air is ejected in a predetermined direction from the separation nozzle 358 and the separation nozzle 359, and the separation processing is started.

  In FIG. 31, when the “close” button (14006) is pressed after designating the paper feed source as the paper feed source, it is possible to return to the copy standard screen.

  FIG. 32 shows a copy standard screen that is displayed when the “close” button (14006) is pressed after the paper feed source serving as the paper feed source is designated on the screen of FIG. In the copy standard screen shown in FIG. 29 described above, the display unit 13006 showing the current setting in order to indicate which paper feed stage (350a, 350b, 350c, 350d, 360) is currently fed is displayed as “automatic”. are displayed as sheet ", the user rather than to indicate whether to feed paper from a previously which paper feed stage (350, 360), the paper size of the read document, fed from automatically any feeding stage In FIG. 31, the sheet selection button (14002) has been pressed. In FIG. 32, the sheet feeding stage 1 corresponding to the cassette 350a is accordingly displayed. It is displayed that A4 is selected (16001).

  Next, how the sheet feeding operation is accelerated by the sheet feeding control process according to the present embodiment will be described with reference to FIG.

  The left is a conventional sequence and the right is a sequence according to the present invention. First, in the conventional sequence, the job is executed by pressing the start button 607 at the timing of 31209 without transmitting the judgment execution request 30001 from the control device 110 to the printer unit 300 in advance. Only when the printer apparatus 300 receives the paper execution request 9003 (31001), the fan 357 and the motor 395 are operated, the valve 374 is opened, and air is supplied to the ejection duct 370. And it takes time for the air pressure to stabilize. Therefore, when the actual paper feed starts and the paper 366a is detected by the sensor 366a installed in the paper storage unit, the paper feed result status 9004 is issued to the control device 110 at the time of 31002. Thus, it can be seen that the time 31003 from the paper feed execution request 9003 until the paper feed result status 9004 returns is longer.

  On the other hand, in the sequence according to the present invention, at the point when the paper selection button is pressed (for example, when the paper selection button 14002 is pressed as shown in FIGS. In contrast, a judgment execution request 30001 is transmitted. Accordingly, at this time 31010 before the copy start button is pressed, the printer apparatus 300 drives the fan 357 and the motor 395, the valve 374 is opened, and the supply of air to the ejection duct 370 starts. At the time point 31004 when the control device 110 transmits the paper feed execution request 9003 to the printer device 300, since the air pressure is stable, the paper feed operation can be performed immediately. The paper result status can be notified to the control device 110 at 31005. It can be seen that the time from the paper feed execution request 9003 to the paper feed result status 9004 is 31003 in the conventional sequence, but is shortened to 31006 in the present invention.

  Further, when the print result status 9007 notified from the printer apparatus 300 to the control apparatus 110 when the paper is discharged outside the apparatus is compared, the print result status is conventionally notified at the time of 31008. Then, since the notification is made at the time of 31007, it can be seen that the paper feeding operation is accelerated by the time of 31010.

  As described above, according to the present embodiment, in an image forming apparatus including a plurality of paper feeding stages that perform air feeding, a delay in feeding operation with time until the air pressure due to air feeding is stabilized is prevented. Therefore, noise and power consumption can be reduced, and deterioration due to drying of the paper can be prevented.

<Third Embodiment>
In the first and second embodiments described above, as shown in FIGS. 23 and 24, one fan 357 is provided for each sheet suction conveyance unit, and the drive timing of each fan is set. Although controlled, the present invention can also be applied to a printer apparatus configured to supply and exhaust air to all the sheet suction conveyance units with a single fan. However, the control target in this case is not a fan driving timing as described above, but a valve or the like for adjusting the air ejection amount in each sheet suction portion.

  FIG. 34 is a diagram illustrating a configuration of the sheet suction conveyance unit in the present embodiment. Here, the same reference numerals are assigned to components common to the above-described embodiment, and descriptions thereof are omitted. As illustrated, each of the ejection ducts 370a to 370d and each of the suction ducts 371a to 371d in the sheet suction conveyance unit is connected to a single fan 357, and the ejection ducts 370a to 370d are supplied with air by the fan 357. Receive.

  A control sequence in the case of this configuration will be described with reference to FIG. 28 used in the first embodiment. While a printing operation is being performed using any one of the paper feed stages (for example, 350a) as a paper feed source, the valve (374a) corresponding to the paper feed stage (350a) is opened while the other paper feed stages are supported. The valves (374b-d) are closed. When the remaining amount of paper becomes less than N1, and it is determined that the control device 110 will soon be out of paper in the paper feed stage being fed, the control device 110 issues a judgment processing request 33003 to the printer unit 300. To do. The paper feeding unit 310 in the printer unit 300 that has received this judgment processing request 33003 opens the valve (374b) corresponding to the paper feeding stage (for example, 350b) selected by the judgment processing request 33003, and closes the other valves. Thus, air is supplied only to the ejection duct (370b). As a result, air is ejected from the separation nozzle and separation nozzle in the ejection duct (370b), and the separation process for the selected paper feed stage is started.

  Even with this configuration and control operation, the same effects as those of the first embodiment can be obtained.

  The second embodiment can be similarly realized by adopting the valve 374 as a control target when the configuration of FIG. 34 is adopted. For example, before starting the image forming process, the valves 374a to 374d are closed so that air to all the paper feed stages is shut off. When a paper selection button 14002 as shown in FIGS. 30 and 31 is pressed, when a paper feed stage as a paper source is selected, air is supplied to that paper feed stage. Open the valve in the paper feed stage. Thereafter, when the user presses a copy start button on the displayed copy standard screen, the image forming process is started. That is, when the image forming process is started, air is already supplied to the selected paper feed stage, and the air pressure is stable. Therefore, it is possible to execute the paper feeding operation quickly.

1 is a diagram illustrating an overall configuration of an image input / output system according to an embodiment of the present invention. It is sectional drawing of a leader part and a printer part. It is a figure which shows the example of an operation part. It is a block diagram which shows the structure of a control apparatus. It is a block diagram which shows the structure of a main controller. It is a block diagram which shows the structure of a system bus bridge. 2 is a block diagram illustrating a configuration of a scanner / printer controller. FIG. It is a figure which shows an example of the communication sequence between a control apparatus and a leader part. It is a figure which shows an example of the communication sequence between a control apparatus and a printer part. FIG. 3 is a diagram schematically illustrating a recording paper conveyance path in a printer unit. FIG. 6 is a diagram schematically illustrating a conveyance path of a recording paper having a single-sided formability in the front-surface discharge mode. FIG. 6 is a diagram schematically illustrating a conveyance path of a recording sheet for single-sided image formation in a back discharge mode. , FIG. 4 is a diagram schematically illustrating a conveyance path for conveying a recording sheet for double-sided image formation. It is a figure which shows an example of a user mode screen. It is a figure which shows an example of the menu screen for common specification setting. It is a figure which shows the example of the screen which shows the other menu for common specification setting. It is a figure which shows the example of a screen for designating the job type which concerns on auto cassette selection. It is a figure which shows the example of a screen for designating ON / OFF of auto cassette selection. FIG. 6 is a diagram illustrating an example of a screen for selecting a paper feed location for setting a paper type. 10 is a diagram illustrating an example of a screen for registering a paper type. FIG. 6 is a flowchart illustrating an example of an ACC determination process performed when a paper feed result status indicates an error. It is a flowchart which shows the ACC determination process performed after notification of remaining paper amount is notified. It is a figure which shows the structure of a sheet | seat adsorption | suction conveyance part. It is a figure which shows the structure of a sheet | seat adsorption | suction conveyance part. It is a figure which shows the structure of a sheet | seat adsorption | suction conveyance part. It is a figure which shows an example of the communication sequence between a control apparatus and a printer part. It is a figure which shows an example of the communication sequence between a control apparatus and a printer part. It is a figure which shows the communication sequence between the control apparatus at the time of the conventional Auto Cassette Change (ACC), and a printer part. It is a figure which shows the communication sequence between the control apparatus at the time of Auto Cassette Change (ACC) in this embodiment, and a printer part. It is a figure which shows the example of a copy standard screen. , FIG. 10 illustrates an example of a paper selection screen. FIG. 10 is a diagram illustrating an example of a copy standard screen that is returned after designating a paper feed source as a paper feed source on a paper selection screen. FIG. 10 is a diagram illustrating a paper feed control process according to a second embodiment. It is a figure which shows the structure of the sheet | seat adsorption | suction conveyance part in 3rd Embodiment.

Claims (6)

A printing system in which a printing process using a sheet of a first stacking unit can be executed by a printing apparatus, and a printing process using a sheet of a second stacking unit can be executed by the printing apparatus,
When the remaining amount of sheets in the first stacking unit reaches a predetermined amount greater than 0 in the middle of the printing process of a job whose printing process has been started by the printing apparatus using the sheets in the first stacking unit The printing system is characterized in that the printing process of the job is continued by the printing apparatus using the sheets of the second stacking unit without using up the sheets of the first stacking unit. A printing system in which a printing process using either the sheet of the first stacking unit or the sheet of the second stacking unit that requires execution of air supply by the feeding device prior to sheet conveyance can be executed by the printing apparatus. And
During the printing process of a job for which printing processing has been started by the printing apparatus using the sheets of the first stacking unit, the remaining amount of sheets of the first stacking unit has reached a first predetermined amount greater than zero. In this case, the print processing of the job is continued by the printing apparatus by continuously using the sheets of the first stacking unit, while the air supply to be executed prior to the conveyance of the sheets of the second stacking unit is performed. Executed by the feeding device, and
While the printing process of the job is continued using the sheets of the first stacking unit, the remaining amount of sheets of the first stacking unit is larger than 0 and smaller than the first predetermined amount. 2. When the predetermined amount is reached, the printing device continues printing processing of the job by using the sheet of the second stacking unit that has been supplied with air, without using up the sheets of the first stacking unit. A printing system characterized by that. The printing system according to claim 1 or 2,
On the condition that the sheet of the second stacking unit is the same size and the same type as the sheet of the first stacking unit, the printing process of the job is continued by the printing apparatus using the sheet of the second stacking unit. A printing system characterized by allowing A control method for a printing system, wherein a printing process using a sheet of a first stacking unit can be executed by a printing apparatus, and a printing process using a sheet of a second stacking unit can be executed by the printing apparatus. ,
When the remaining amount of sheets in the first stacking unit reaches a predetermined amount greater than 0 in the middle of the printing process of a job whose printing process has been started by the printing apparatus using the sheets in the first stacking unit A control method characterized in that printing of the job is continued by the printing apparatus using the sheets of the second stacking unit without using up the sheets of the first stacking unit. Control of a printing system that allows a printing apparatus to execute a printing process using either the sheet of the first stacking unit or the sheet of the second stacking unit that requires execution of air supply by the feeding device prior to the conveyance of the sheet. A method,
During the printing process of a job for which printing processing has been started by the printing apparatus using the sheets of the first stacking unit, the remaining amount of sheets of the first stacking unit has reached a first predetermined amount greater than zero. In this case, the print processing of the job is continued by the printing apparatus by continuously using the sheets of the first stacking unit, while the air supply to be executed prior to the conveyance of the sheets of the second stacking unit is performed. Executed by the feeding device, and
While the printing process of the job is continued using the sheets of the first stacking unit, the remaining amount of sheets of the first stacking unit is larger than 0 and smaller than the first predetermined amount. 2. When the predetermined amount is reached, the printing device continues printing processing of the job by using the sheet of the second stacking unit that has been supplied with air, without using up the sheets of the first stacking unit. A control method characterized by that. The control method according to claim 4 or 5, wherein
On the condition that the sheet of the second stacking unit is the same size and the same type as the sheet of the first stacking unit, the printing process of the job is continued by the printing apparatus using the sheet of the second stacking unit. A control method characterized by allowing the control to be performed.

Images