JP7415378B2 - Image forming system and program - Google Patents

Description

The present disclosure relates to an image forming system in which a plurality of image forming apparatuses are arranged in series.

Conventionally, various techniques have been proposed regarding image forming systems in which a plurality of image forming apparatuses such as MFPs (Multi-Functional Peripherals) are arranged in series. For example, Japanese Patent Application Laid-Open No. 2018-45032 (Patent Document 1) discloses that in addition to an upstream image forming apparatus and a downstream image forming apparatus, an image forming apparatus that is connected to the downstream image forming apparatus is further connected to the downstream side of the downstream image forming apparatus. An image forming system including a post-processing device is disclosed. The image forming system has a paper transport interval from an upstream image forming apparatus to a downstream machine (a second paper interval) than a paper transport interval from a downstream image forming apparatus to a post-processing apparatus (a first paper interval). It has a setting to shorten the paper interval).

JP 2018-45032 Publication

However, Patent Document 1 does not provide a technique for responding to a change in the conveyance interval of paper from an upstream image forming apparatus to a downstream image forming apparatus. Therefore, if the transport interval changes in either of the two image forming apparatuses, the transport interval in the other image forming apparatus will also change in accordance with the change. If the conveyance interval in one image forming apparatus is simply changed in accordance with the change in the conveyance interval in the other image forming apparatus, the period in which elements such as photoreceptor drums operate in vain in the other image forming apparatus becomes longer. As a result, a situation may arise in which the element reaches the end of its lifespan before the number of images it is nominally capable of printing on the other image forming apparatus.

The present disclosure has been devised in view of the actual situation, and its purpose is to solve the problem in an image forming system in which a plurality of image forming apparatuses are arranged in series, in which the paper conveyance interval in one image forming apparatus changes. An object of the present invention is to provide a technique for shortening the period during which elements in the other image forming apparatus operate in vain.

According to an aspect of the present disclosure, a first image forming apparatus, a second image forming apparatus connected to the downstream side of the first image forming apparatus with respect to the first image forming apparatus; a control section that controls the operation of at least one of the image forming apparatus and the second image forming apparatus, the control section controlling the paper conveyance speed in one of the first image forming apparatus and the second image forming apparatus; An image forming system is provided that performs control based on a paper transport interval on the one hand and a paper transport interval on the other hand.

Preferably, the control unit reduces the conveyance speed of one sheet when the interval between sheets being output from the other sheet becomes longer.

Preferably, the control unit increases the interval at which sheets are output from the other side when the coverage of the image formed on the other side increases.

Preferably, the control unit causes one of the first image forming device and the second image forming device to form images on both sides of the sheet, and causes the other to pass the sheet through the sheet without forming an image on the sheet.

Preferably, the control section causes one side to form images on both sides of the paper, and causes the other side to pass through the paper without forming an image on the recording paper, on the condition that a defect occurs in the image formed by the other side.

Preferably, the control section causes the second image forming apparatus to further form an image on the surface of the paper on which the image has been formed by the first image forming apparatus.

Preferably, the image forming system further includes a notification unit that notifies information, and the control unit causes the notification unit to notify the user when an error occurs in at least one of the first image forming device and the second image forming device. do.

Preferably, the control unit controls one of the first image forming device and the second image forming device, and the other of the first image forming device and the second image forming device controls the paper in the other one. When the output interval is changed, the control unit is notified of the change.

According to another aspect of the present disclosure, there is provided a program executable by a computer, the program providing information on paper conveyance intervals in each of a first image forming apparatus and a second image forming apparatus constituting an image forming system. A program is provided that executes the steps of: acquiring the information; and controlling the paper conveyance speed in one of the first image forming apparatus and the second image forming apparatus based on the acquired information.

According to the present disclosure, in an image forming system including a first image forming apparatus and a second image forming apparatus, based on the paper conveyance interval in each of the first image forming apparatus and the second image forming apparatus, , the paper conveyance speed of one image forming apparatus is controlled. As a result, the period during which elements in the other image forming apparatus operate unnecessarily can be shortened.

1 is a diagram showing the overall configuration of an image forming system 10. FIG. 1 is a diagram showing control blocks of an image forming system 10. FIG. 1 is a diagram schematically showing a conveyance path in an image forming system 10. FIG. 2 is a flowchart of a process for controlling the conveyance speed and paper conveyance interval of each of the upstream machine 100 and the downstream machine 200. 2 is a flowchart of a process for controlling the conveyance speed and paper conveyance interval of each of the upstream machine 100 and the downstream machine 200. 2 is a flowchart of a process for controlling the conveyance speed and paper conveyance interval of each of the upstream machine 100 and the downstream machine 200. 2 is a flowchart of a process for controlling the conveyance speed and paper conveyance interval of each of the upstream machine 100 and the downstream machine 200. 2 is a flowchart of a process for controlling the conveyance speed and paper conveyance interval of each of the upstream machine 100 and the downstream machine 200. 2 is a flowchart of processing for controlling the conveyance speed and paper conveyance interval of the upstream machine 100 and the downstream machine 200. 9 is a diagram showing the linear speed and paper spacing settings in each of the upstream machine 100 and the downstream machine 200 according to the processes shown in FIGS. 4 to 9. FIG. FIG. 9 is a diagram for comparing the control shown in FIGS. 4 to 9 with that according to the prior art.

An embodiment of an image forming system will be described below with reference to the drawings. In the following description, the same parts and components are given the same reference numerals. Their names and functions are also the same. Therefore, these descriptions will not be repeated.

[1. Configuration of image forming system]
FIG. 1 is a diagram showing the overall configuration of an image forming system 10. As shown in FIG. FIG. 2 is a diagram showing control blocks of the image forming system 10. The configuration of the image forming system 10 will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the image forming system 10 is configured by sequentially connecting a large-capacity paper feeding unit 300, an upstream machine 100, a reversing unit 400, a downstream machine 200, and a paper discharge unit 500. Each of the upstream machine 100 and the downstream machine 200 is an image forming apparatus such as an MFP.

Lines connecting points X1, X2, X3, X5, X6, X7, X9, and X10 in FIG. 1 indicate the paper transport path. The image forming system 10 is an example of a tandem image forming system configured by connecting two or more image forming apparatuses in series.

When performing double-sided printing, the image forming system 10 may feed paper from the large-capacity paper feed unit 300 and print the front side of the paper using the upstream machine 100. Thereafter, the image forming system 10 may invert the paper using the reversing unit 400 and convey the paper to the downstream machine 200. Then, the image forming system 10 may print the back side of the paper using the downstream machine 200. The image forming system 10 may eject the paper to the paper ejection unit 500 after printing the back side of the paper.

Inversion unit 400 includes pre-registration rollers 410 . The image forming system 10 can retain the paper output from the upstream machine 100 using the pre-registration roller 410. Then, the image forming system 10 can send the paper to the downstream machine 200 by restarting the rotation of the pre-registration roller 410. That is, the image forming system 10 can use the pre-registration roller 410 to adjust the timing at which the paper output from the upstream machine 100 is introduced into the downstream machine 200.

In the case of single-sided printing, the image forming system 10 may feed paper from the large-capacity paper feeding unit 300, perform single-sided printing on the upstream machine 100, and perform only conveyance on the downstream machine 200. Alternatively, the image forming system 10 may feed paper from the large-capacity paper feed unit 300, the upstream machine 100 may only transport the paper without printing, and the downstream machine 200 may perform single-sided printing. To explain in detail the flow of the printing process representing the former case, first, the image forming system 10 feeds paper from the large-capacity paper feed unit 300, and prints the front surface of the paper using the upstream machine 100. Thereafter, the image forming system 10 transports the paper to the downstream machine 200. Then, in the image forming system 10, the downstream machine 200 passes the paper with one-sided printing completed. Finally, the image forming system 10 discharges the sheet with one-sided printing to the paper discharge unit 500.

Next, the configuration of each function of the image forming system 10 will be explained.
The large-capacity paper feed unit 300 includes a paper feed tray that stores a plurality of different types of paper by type, and feeds the paper stored in the paper feed tray to the upstream machine 100 (point X1 → point X2) . In one implementation example, the paper feeding operation of the large capacity paper feeding unit 300 is controlled by the control unit 105 included in the upstream machine 100.

The upstream machine 100 can form an image on at least one side of the paper fed from the large-capacity paper feeding unit 300. As shown in FIGS. 1 and 2, the upstream machine 100 includes a first conveyance path 101, a second conveyance path 102, an image forming section 103, a fixing section 104, a control section 105, a communication section 106, a storage section 107, a document It includes a reading section 108, an operation display section 109, an image processing section 110, a first conveyance control section 111, and a switching gate 112.

The control unit 105 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU reads a program according to the processing content from the ROM, expands it into the RAM, and centrally controls the operation of each block of the upstream machine 100 in cooperation with the expanded program. At this time, various data stored in the storage unit 107 are referred to. The storage unit 107 includes, for example, a nonvolatile semiconductor memory (so-called flash memory) or a hard disk drive.

The control unit 105 exchanges various data with an external device (for example, a personal computer) connected to a communication network such as a LAN (Local Area Network) or a WAN (Wide Area Network) via the communication unit 106. Send and receive. For example, the control unit 105 receives image data transmitted from an external device, and outputs this image data (input image data) to the image forming unit 103. The communication unit 106 is composed of a communication control card such as a LAN card, for example.

The control unit 105 transmits and receives various data to and from the downstream device 200 via the communication unit 106. Further, the control unit 105 also controls the operation of the downstream machine 200 in cooperation with the control unit 205 of the downstream machine 200 via the communication unit 106.

The document reading unit 108 optically scans the document conveyed onto the contact glass, forms an image of reflected light from the document on the light receiving surface of a CCD (Charge Coupled Device) sensor, and reads the document. Note that although the document is conveyed onto the contact glass using an automatic document feeder (ADF), the document may be placed on the contact glass manually.

The operation display unit 109 has a touch panel type screen. The user inputs various instructions and settings such as printing conditions (for example, single-sided/double-sided printing type, image density and magnification, number of copies, paper size and basis weight) through the touch panel screen. It can be done by

Image processing section 110 includes a circuit that performs analog-to-digital (A/D) conversion processing and a circuit that performs digital image processing. The image processing section 110 generates digital image data by A/D conversion processing from the analog image signal acquired by the CCD sensor of the document reading section 108 and outputs it to the image forming section 103 .

An image forming section 103 and a fixing section 104, which will be described below, are provided on the first conveyance path 101.

The image forming unit 103 emits laser light based on the digital image data generated by the image processing unit 110 or the digital image data acquired from the control unit 105, and irradiates the photosensitive drum with the emitted laser light. , forming an electrostatic latent image on the photoreceptor drum (exposure step);

In addition to the above-mentioned exposure process, the image forming unit 103 has a configuration for performing a charging process performed before the exposure process, a developing process performed after the exposure process, a transfer process after the development process, and a cleaning process after the transfer process. It is equipped with

In the charging process, the image forming unit 103 uniformly charges the surface of the photoreceptor drum by corona discharge from the charging device. In the developing process, the image forming unit 103 forms a toner image on the photoreceptor drum by attaching toner contained in a developer in the developing device to the electrostatic latent image on the photoreceptor drum.

In the transfer process, the image forming unit 103 transfers the toner image on the photoreceptor drum to a sheet of paper that is transported on the first transport path 101 . In the cleaning process, the image forming unit 103 removes toner remaining on the photoreceptor drum after the transfer process.

The fixing unit 104 applies heat and pressure to the toner image on the paper introduced into the fixing nip (heat fixing) to fix the toner image on the paper (fixing step). As a result, a fixed toner image is formed on the paper.

The first conveyance path 101 is provided with a guide plate for guiding the paper in the paper conveyance direction, a plurality of pairs of conveyance rollers that are rotationally driven under the control of the control unit 105, and the like. The control unit 105 forms an image on one side (front surface) of the paper fed from the large-capacity paper feeding unit 300 and transports the paper to the reversing unit 400 through points X2, X3, and X5. Take control.

In this embodiment, when a service call occurs in upstream device 100, control unit 105 detects the service call and causes operation display unit 109 to display the content of the service call. A service call refers to calling a service person to perform maintenance because an abnormality has occurred in the upstream machine 100, such as a failure of the printed control board (not shown) that controls the image forming process in the upstream machine 100. . A paper jam or a service call occurring in the upstream machine 100 is also detected by the control unit 205 included in the downstream machine 200 via the communication unit 106.

Further, when a paper jam occurs in the upstream machine 100, the control unit 105 detects the paper jam and causes the operation display unit 109 to display the details of the paper jam. Specifically, a jam detection unit (not shown) provided in the upstream machine 100 detects passage of each part of the paper using optical sensors arranged at each part of the first conveyance path 101, and calculates the passage time between each part. If a predetermined time has elapsed, the occurrence of a paper jam is detected. The jam detection unit then outputs a jam code corresponding to the detected paper jam to the control unit 105. The jam code is a jam identification number for uniquely identifying the occurrence status of a paper jam (for example, location, cause of occurrence, date and time of occurrence, etc.). The control unit 105 can grasp the specific situation of paper jam occurrence by referring to the jam code output from the jam detection unit. Note that the jam detection section is not limited to an optical sensor, and may be configured by other mechanisms such as a mechanical switch.

The control unit 105 causes the storage unit 107 to store service call information indicating the details of the service call that occurred in the upstream machine 100 and paper jam information indicating the details of the paper jam that occurred in the upstream machine 100.

Note that the second conveyance path 102, first conveyance control section 111, and switching gate 112 will be described later.

The reversing unit 400 is provided between the upstream machine 100 and the downstream machine 200. When double-sided printing is performed in the image forming system 10 , the reversing unit 400 reverses a sheet of paper on which an image has been formed on one side in the upstream machine 100 and conveys the reversed sheet to the downstream machine 200 . The reversing operation of the reversing unit 400 is controlled by the control section 105 included in the upstream machine 100.

The downstream machine 200 can form an image on at least one side of the sheet conveyed from the reversing unit 400. As shown in FIGS. 1 and 2, the downstream machine 200 includes a third conveyance path 201, a fourth conveyance path 202, an image forming section 203, a fixing section 204, a control section 205, a communication section 206, a storage section 207, an operation It includes a display section 209 (corresponding to the "first notification section" of the present invention), a second conveyance control section 211, and a switching gate 212. The processing of the image forming unit 203, fixing unit 204, control unit 205, communication unit 206, storage unit 207, and operation display unit 209 in the downstream machine 200 is similar to that described in the upstream machine 100. Since the processing is the same as that of the section 105, the communication section 106, the storage section 107, and the operation display section 109, a description thereof will be omitted here.

The third conveyance path 201 is provided with a guide plate for guiding the paper in the paper conveyance direction, a plurality of pairs of conveyance rollers that are rotationally driven under the control of the control unit 205, and the like. The control unit 205 forms an image on one side (back side) of the sheet conveyed from the reversing unit 400 while controlling the sheet to pass through points X6, X7, and X9 and to be conveyed to the sheet discharge unit 500. The image forming section 203 and the fixing section 204 are provided on the third transport path 201.

Note that the fourth conveyance path 202, the second conveyance control section 211, and the switching gate 212 will be described later.

The paper discharge unit 500 includes a paper discharge tray that discharges the paper conveyed from the downstream machine 200 to the paper discharge tray. The paper discharge unit 500 stacks the paper sheets, on which images are formed on both sides by the upstream machine 100 and the downstream machine 200, and which are conveyed from the downstream machine 200, on a paper discharge tray. The paper discharging operation of the paper discharging unit 500 is controlled by a control unit 205 included in the downstream machine 200.

With the above-described configuration, in the image forming system 10, the upstream machine 100 at the front stage forms an image on the front side of the paper, and the downstream machine 200 at the latter stage forms an image on the back side of the paper, so that one image forming apparatus can form the image. Productivity can be improved compared to double-sided printing. However, in either the upstream machine 100 or the downstream machine 200, there is a problem in performing image formation, such as a failure of the print control board that controls the image forming process in the image forming apparatus, or a paper jam. When this occurs, there is a problem in that double-sided printing cannot be performed. Therefore, in the present embodiment, the image forming system 10 has a configuration that allows double-sided printing even if a problem occurs in forming an image in either the upstream machine 100 or the downstream machine 200. have

Specifically, as described above, the upstream machine 100 and the downstream machine 200 each have the second conveyance path 102 and the fourth conveyance path 202. Each of the upstream machine 100 and the downstream machine 200 also includes a first transport control section 111 that performs first transport control to transport the paper supplied from the upstream machine 100 to the downstream machine 200 using a fourth transport path 202; , a second transport control unit 211 that performs second transport control to transport the paper using the second transport path 102.

The second conveyance path 102 is provided with a guide plate for guiding the paper in the paper conveyance direction, a plurality of rotationally driveable pairs of conveyance rollers, and the like. If a problem occurs with image formation in the upstream machine 100, the second conveyance control unit 211 included in the downstream machine 200 rotates and drives the plurality of conveyance roller pairs provided on the second conveyance path 102. , second conveyance control is performed in which the sheet fed from the large-capacity sheet feeding unit 300 is conveyed to the reversing unit 400 by passing through points X2, X4, and X5 without forming an image on the sheet. In other words, the second conveyance path 102 is a bypass path for detouring the paper so that it does not pass through the image forming section 103 and the fixing section 104 when a problem occurs in performing image formation in the upstream machine 100.

In addition, when the downstream machine 200 does not print on the paper and the upstream machine 100 performs double-sided printing on the paper, the second conveyance path 102 passes through the points X2, X3, and After image formation is performed on the paper, the paper is reversed while passing through points X5, X4, and X2, and the paper is introduced into the first transport path 101 for forming an image on the other side (back side).Double-sided conveyance Also used as a route. The structure of the second conveyance path 102 for reversing the paper will be described later with reference to FIG. 3 and the like.

In the vicinity of point X2, a switching gate 112 is provided that switches the conveyance path for conveying paper in the upstream machine 100 between the first conveyance path 101 and the second conveyance path 102. The switching operation of the transport route by the switching gate 112 is controlled by the second transport control unit 211 included in the downstream machine 200.

On the other hand, when double-sided printing is performed on a sheet in the downstream machine 200, the third conveyance path 201 causes the sheet to pass through points X6, X7, and X9. As a result, an image is formed on one side (front surface) of the paper. Thereafter, the fourth conveyance path 202 reverses the paper while passing the paper through points X9, X8, and X6. Thereafter, the third transport path 201 causes the paper to pass through points X6, X7, and X9 again. As a result, an image is formed on the other side (back side) of the paper. The structure of the fourth conveyance path 202 for reversing the paper is shown in FIG.

[2. Differences in transport speed or print mode between image forming devices]
FIG. 3 is a diagram schematically showing a conveyance path in the image forming system 10. FIG. 3 shows two states ST11 and ST12. State ST11 represents a state in which the upstream machine 100 and the downstream machine 200 have the same print mode and transport speed. State ST12 represents a state in which the print mode and transport speed are different between the upstream machine 100 and the downstream machine 200. Each state will be explained in detail below.

In FIG. 3, each sheet of paper is indicated by a solid line, and the broken line attached to the solid line of each sheet of paper represents an image formed on each sheet of paper. The fact that a broken line is added to only one side of the solid line representing the paper indicates that the paper has an image formed only on one side. A broken line attached to both sides of a solid line representing a sheet of paper indicates that images are formed on both sides of the sheet of paper. The fact that a broken line is not added to the solid line representing the paper indicates that the paper has no image formed on it.

(State ST11)
In state ST11, ten sheets of paper that are continuously transported are shown as sheets P10, P11, P12, P13, P14, P15, P16, P17, P18, and P19.

In state ST11, the upstream machine 100 forms an image on the front side of the paper, and the downstream machine 200 forms an image on the back side of the paper. More specifically, the paper introduced into the upstream machine 100 is introduced into the image forming section 103, as shown as paper P10. As a result, an image is formed on the surface of the paper as shown as paper P11.

Thereafter, as shown as paper P12, the paper is introduced into the fixing section 104, and the image formed on the surface is fixed. The paper output from the fixing unit 104 as shown as paper P13 is introduced into the reversing unit 400 as shown as paper P14.

After being reversed in the reversing unit 400, the image forming system 10 fixes the sheet output from the upstream machine 100 with the pre-registration roller 410, as shown as a sheet P15. Thereafter, the image forming system 10 restarts the rotation of the pre-registration roller 410 at an appropriate timing, and introduces the paper output from the upstream machine 100 into the downstream machine 200, as shown as paper P16.

In the downstream machine 200, the paper is introduced into the image forming section 203, as shown as paper P17. An image is formed on the back side of the paper by the image forming unit 203, as shown as paper P18, and then the paper is introduced into the fixing unit 204.

After the image on the back side is fixed in the fixing unit 204, the paper is discharged from the fixing unit 204 as shown as paper P19, and then introduced into the paper discharge unit 500 (see FIG. 1).

In state ST11, an image is formed on one side of the sheet in each of the upstream machine 100 and the downstream machine 200. In state ST11, it is assumed that the time required for image formation in each of the upstream machine 100 and the downstream machine 200 is approximately equal. In this case, the upstream machine 100 and the downstream machine 200 may use the same transport speed and paper interval.

(State ST12)
In state ST12, nine sheets of paper that are continuously transported are shown as sheets P20, P21, P22, P23, P24, P25, P26, P27, and P28. In state ST12, the upstream machine 100 forms images on both sides of the sheet, and the downstream machine 200 forms an image only on one side of the sheet.

More specifically, in state ST12, the upstream machine 100 forms an image in the image forming unit 103 on the surface of the paper introduced into the upstream machine 100, as shown as paper P20. As a result, an image is formed on the surface of the paper, as shown as paper P21, and then the paper is discharged from the image forming unit 103. Thereafter, the image on the surface of the paper is fixed by the fixing unit 104, as shown as paper P22, and then the paper is introduced into the second transport path 102. In the second conveyance path 102, the sheets are reversed as shown as a sheet P23 and a sheet P24, and then introduced into the first conveyance path 101 again.

Thereafter, an image is formed on the back side of the paper by the image forming unit 103, and the paper is introduced into the fixing unit 104 as shown as paper P25. After the image on the back side is fixed by the fixing unit 104, the paper is introduced from the upstream machine 100 to the reversing unit 400, as shown as paper P26.

Thereafter, an image is formed on the surface of the paper by the image forming unit 203, as shown as paper P27. Thereafter, the image is fixed on the paper by the fixing unit 204, as shown as paper P28, and then the paper is introduced into the paper discharge unit 500.

Note that when the downstream machine 200 forms an image on the back side of the paper, the image forming system 10 reverses the paper output from the upstream machine 100 using the reversing unit 400, and then introduces the paper into the downstream machine 200.

In state ST12, the upstream machine 100 forms images on both sides of the sheet, but the downstream machine 200 forms an image on one side of the sheet. Therefore, when the upstream machine 100 transports paper at the same transport speed as the downstream machine 200, the downstream machine 200 needs to transport the paper at longer intervals than the paper transport interval in the upstream machine 100.

Therefore, the image forming system 10 lowers the conveyance speed of the downstream machine 200 in state ST12 than in state ST11. As a result, the interval between paper conveyances in the downstream machine 200 can be shortened, and the period during which the image forming elements of the downstream machine 200 are not performing an image forming operation can be shortened.

Note that the situation shown in FIG. 3 is just one example of the control in the image forming system 10, and the situation in which the control in the image forming system 10 is provided is not limited to that shown in FIG. For example, in the situation shown in FIG. 3, upstream machine 100 and downstream machine 200 may be interchanged. In other words, when the upstream machine 100 forms an image on only one side of the paper, and the downstream machine 200 forms images on both sides of the paper, the image forming system 10 changes the paper conveyance speed in the upstream machine 100 to that of the upstream machine 100. It may be lower than when both downstream machines 200 form an image on only one side of the paper.

[3. Process flow]
4 to 9 are flowcharts of processes for controlling the conveyance speed and paper conveyance interval of the upstream machine 100 and the downstream machine 200, respectively. The image forming system 10 includes a control unit 105 on the upstream machine 100 side, a control unit 205 on the downstream machine 200 side, a control device installed in a device other than the upstream machine 100 and the downstream machine 200, or a combination thereof. The processes shown in FIGS. 4 to 9 may be executed by executing a given program.

4 to 9, the upstream machine 100 and the downstream machine 200 each set the print mode (single-sided printing or double-sided printing) and paper conveyance speed (also called "linear speed") for each print job, for example. is set. Each of the upstream machine 100 and the downstream machine 200 basically operates according to the settings.

Further, ON/OFF of high coverage control can be set for each of the upstream device 100 and the downstream device 200. The value of the high coverage control is OFF in the initial state. When the coverage (print rate) of the image formed on the paper in each device is relatively high (for example, exceeds a given threshold), the value of the high coverage control is changed to ON. By turning on the high coverage control, the paper conveyance speed is reduced and/or the paper conveyance interval is widened.

Furthermore, in the following description, "high speed" and "low speed" may be referred to as paper conveyance speeds in upstream machine 100 and downstream machine 200. If two types of values are registered for the paper transport speed of each of the upstream machine 100 and the downstream machine 200, the larger value of the two types of values is set as the transport speed for "high speed", and the transport speed for "low speed" is set as the transport speed. The smaller value of the two types of values is set as the conveyance speed. In each of the upstream machine 100 and the downstream machine 200, motors that rotate various motors are driven so that the paper is conveyed at a speed according to a set value.

In addition, in the following explanation, "control for high productivity" (described as "high productivity" in FIG. 5 etc.) means control to relatively shorten the paper conveyance interval, and "control for low productivity" (Described as "low productivity" in FIG. 5 and the like) means control to make the paper conveyance interval relatively long. For example, if two types of values regarding the paper conveyance interval are registered in each of the upstream machine 100 and the downstream machine 200, in high productivity control, the smaller of the two values is the conveyance interval. In the low productivity control, the larger value of the two types of values is set as the value of the conveyance interval. In each of the upstream machine 100 and the downstream machine 200, motors that rotate various motors are driven so that the paper is conveyed at intervals according to set values.

Referring to FIG. 4, in step S10, image forming system 10 reads the print mode of upstream machine 100. If the print mode of the upstream device 100 is "single-sided" (single-sided printing), the image forming system 10 advances the control to step S12, and if the print mode of the upstream device 100 is "double-sided" (double-sided printing), it advances the control to step S12. Control proceeds to S14.

In step S12, the image forming system 10 reads the print mode of the downstream machine 200. If the print mode of the downstream device 200 is "single-sided" (single-sided printing), the image forming system 10 advances the control to step S100 (FIG. 5), and determines that the printing mode of the downstream device 200 is "double-sided" (double-sided printing). If there is, control proceeds to step S200 (FIG. 6).

In step S14, the image forming system 10 reads the print mode of the downstream machine 200. If the print mode of the downstream device 200 is "single-sided" (single-sided printing), the image forming system 10 advances the control to step S300 (FIG. 7), and determines that the printing mode of the downstream device 200 is "double-sided" (double-sided printing). If there is, control proceeds to step S400 (FIG. 8).

Referring to FIG. 5, in step S100, image forming system 10 sets "high speed" as the transport speed and "high productivity" as the transport interval for upstream machine 100. The upstream machine 100 operates according to these settings.

In step S102, the image forming system 10 sets the conveyance speed to "high speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S104, the image forming system 10 determines whether the upstream device 100 is executing "high coverage control". If the image forming system 10 determines that the upstream device 100 is executing the "high coverage control" (YES in step S104), the image forming system 10 advances the control to step S106, otherwise (NO in step S104). , control proceeds to step S110.

In step S106, the image forming system 10 sets the transport speed to "low speed" and the transport interval to "high productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S108, the image forming system 10 sets the conveyance speed to "low speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S110, the image forming system 10 determines whether the downstream device 200 is executing "high coverage control". If the image forming system 10 determines that the downstream device 200 is executing the "high coverage control" (YES in step S110), the image forming system 10 advances the control to step S112, otherwise (NO in step S110). , control proceeds to step S110.

In step S112, the image forming system 10 sets the transport speed to "low speed" and the transport interval to "high productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S114, the image forming system 10 sets the conveyance speed to "low speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S116, the image forming system 10 determines whether both the upstream machine 100 and the downstream machine 200 are executing "high coverage control". If the image forming system 10 determines that both the upstream device 100 and the downstream device 200 are executing the "high coverage control" (YES in step S116), the image forming system 10 advances the control to step S118; otherwise, ( If NO in step S116), control proceeds to step S116.

In step S118, the image forming system 10 sets the transport speed to "high speed" and the transport interval to "high productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S120, the image forming system 10 sets the conveyance speed to "high speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings. After that, the image forming system 10 advances the control to step S16 (FIG. 9).

Referring to FIG. 6, in step S200, image forming system 10 sets "low speed" as the transport speed and "high productivity" as the transport interval for upstream machine 100. The upstream machine 100 operates according to these settings.

In step S202, the image forming system 10 sets the conveyance speed to "high speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S204, the image forming system 10 determines whether the upstream device 100 is executing "high coverage control". If the image forming system 10 determines that the upstream device 100 is executing the "high coverage control" (YES in step S204), the image forming system 10 advances the control to step S206; otherwise (NO in step S204). , control proceeds to step S210.

In step S206, the image forming system 10 sets the transport speed to "low speed" and the transport interval to "low productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S208, the image forming system 10 sets the conveyance speed to "low speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S210, the image forming system 10 determines whether the downstream device 200 is executing "high coverage control". If the image forming system 10 determines that the downstream device 200 is executing the "high coverage control" (YES in step S210), the image forming system 10 advances the control to step S212, otherwise (NO in step S210). , control proceeds to step S210.

In step S212, the image forming system 10 sets the transport speed to "low speed" and the transport interval to "high productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S214, the image forming system 10 sets "low speed" as the transport speed and "low productivity" as the transport interval for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S216, the image forming system 10 determines whether both the upstream machine 100 and the downstream machine 200 are executing "high coverage control". If the image forming system 10 determines that both the upstream device 100 and the downstream device 200 are executing the "high coverage control" (YES in step S216), the image forming system 10 advances the control to step S218; otherwise, ( If NO in step S216), control proceeds to step S216.

In step S218, the image forming system 10 sets the transport speed to "low speed" and the transport interval to "high productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S220, the image forming system 10 sets the conveyance speed to "high speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings. After that, the image forming system 10 advances the control to step S16 (FIG. 9).

Referring to FIG. 7, in step S300, image forming system 10 sets "high speed" as the transport speed and "high productivity" as the transport interval for upstream machine 100. The upstream machine 100 operates according to these settings.

In step S302, the image forming system 10 sets the conveyance speed to "low speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S304, the image forming system 10 determines whether the upstream device 100 is executing "high coverage control". If the image forming system 10 determines that the upstream device 100 is executing the "high coverage control" (YES in step S304), the image forming system 10 advances the control to step S306, otherwise (NO in step S304). , control proceeds to step S310.

In step S306, the image forming system 10 sets the transport speed to "low speed" and the transport interval to "high productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S308, the image forming system 10 sets "low speed" as the transport speed and "low productivity" as the transport interval for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S310, the image forming system 10 determines whether the downstream device 200 is executing "high coverage control". If the image forming system 10 determines that the downstream device 200 is executing the "high coverage control" (YES in step S310), the image forming system 10 advances the control to step S312, otherwise (NO in step S310). , control proceeds to step S310.

In step S312, the image forming system 10 sets the transport speed to "low speed" and the transport interval to "low productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S314, the image forming system 10 sets "low speed" as the transport speed and "high productivity" as the transport interval for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S316, the image forming system 10 determines whether both the upstream machine 100 and the downstream machine 200 are executing "high coverage control". If the image forming system 10 determines that both the upstream device 100 and the downstream device 200 are executing the "high coverage control" (YES in step S316), the image forming system 10 advances the control to step S318; otherwise, ( If NO in step S316), control proceeds to step S316.

In step S318, the image forming system 10 sets "high speed" as the transport speed and "high productivity" as the transport interval for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S320, the image forming system 10 sets the conveyance speed to "low speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings. After that, the image forming system 10 advances the control to step S16 (FIG. 9).

Referring to FIG. 8, in step S400, image forming system 10 sets "high speed" as the transport speed and "high productivity" as transport interval for upstream machine 100. The upstream machine 100 operates according to these settings.

In step S402, the image forming system 10 sets the conveyance speed to "high speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S404, the image forming system 10 determines whether the upstream device 100 is executing "high coverage control". If the image forming system 10 determines that the upstream device 100 is executing "high coverage control" (YES in step S404), the image forming system 10 advances the control to step S406; otherwise (NO in step S404). , control proceeds to step S410.

In step S406, the image forming system 10 sets the transport speed to "low speed" and the transport interval to "high productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S408, the image forming system 10 sets the conveyance speed to "low speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S410, the image forming system 10 determines whether the downstream device 200 is executing "high coverage control". If the image forming system 10 determines that the downstream device 200 is executing the "high coverage control" (YES in step S410), the image forming system 10 advances the control to step S412; otherwise (NO in step S410). , control proceeds to step S410.

In step S412, the image forming system 10 sets the transport speed to "low speed" and the transport interval to "high productivity" for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S414, the image forming system 10 sets the conveyance speed to "low speed" and the conveyance interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings.

In step S416, the image forming system 10 determines whether both the upstream machine 100 and the downstream machine 200 are executing "high coverage control". If the image forming system 10 determines that both the upstream device 100 and the downstream device 200 are executing the "high coverage control" (YES in step S416), the image forming system 10 advances the control to step S418; otherwise, ( If NO in step S416), control proceeds to step S416.

In step S418, the image forming system 10 sets "high speed" as the transport speed and "high productivity" as the transport interval for the upstream machine 100. The upstream machine 100 operates according to these settings.

In step S420, the image forming system 10 sets the transport speed to "high speed" and the transport interval to "high productivity" for the downstream machine 200. The downstream machine 200 operates according to these settings. After that, the image forming system 10 advances the control to step S16 (FIG. 9).

Referring to FIG. 9, in step S16, image forming system 10 determines whether the job being executed has ended. If the image forming system 10 determines that the job being executed has not yet been completed (NO in step S16), control returns to step S10 (FIG. 4). On the other hand, if the image forming system 10 determines that the job being executed has ended (YES in step S16), it ends the processing in FIGS. 4 to 9.

According to the processes described above with reference to FIGS. 4 to 9, the paper transport speed (high speed/low speed) in one of the upstream machine 100 and the downstream machine 200 is different from the paper transport speed (high speed/low speed) in the upstream machine 100 and the downstream machine 200. It is set based on the information on the transport interval (ON/OFF of high coverage control).

When the processing described with reference to FIGS. 4 to 9 is executed by the control unit 105 or the control unit 205, the operating state of one device may be notified to the other device. For example, when the control unit 105 executes the above process, the control unit 205 may notify the control unit 105 of the operating state (paper spacing, coverage, print mode, etc.) of the downstream machine 200.

[4. Control summary]
FIG. 10 is a diagram showing the linear speed and sheet spacing settings in each of the upstream machine 100 and the downstream machine 200 according to the processes shown in FIGS. 4 to 9. "Linear speed" represents the paper conveyance speed, and "paper interval" represents the paper conveyance interval.

FIG. 10 shows the combinations of two types of print modes (single-sided or double-sided) of the upstream machine 100 and two types of print modes (single-sided or double-sided) of the downstream machine 200, in each of the upstream machine 100 and the downstream machine 200. Sixteen types of settings corresponding to four types of ON/OFF combinations of high coverage control are shown. Each of the 16 types of settings is assigned a number as a "setting number." For example, setting No. is "1", the print mode of the upstream machine 100 is "single-sided", the print mode of the downstream machine 200 is "single-sided", the high coverage control is OFF in the upstream machine 100, and the print mode of the downstream machine 100 is "single-sided". 2 shows the settings in the upstream device 100 and the downstream device 200 when the high coverage control is OFF in 200.

Setting No. According to the comparison between the setting where is "1" and the setting where is "5", the print mode of the downstream machine 200 is changed from "single-sided" (setting No. 1) to "duplex" (setting No. 5). Then, the linear speed in the upstream machine 100 is changed from "high speed" (setting No. 1) to "low speed" (setting No. 5).

Setting No. According to the comparison between the setting where is "1" and the setting where is "9", the print mode of the upstream machine 100 changes from "single-sided" (setting No. 1) to "duplex" (setting No. 9). Then, the linear speed in the downstream machine 200 is changed from "high speed" (setting No. 1) to "low speed" (setting No. 9).

Setting No. According to a comparison between the setting where is "5" and the setting where is "6" to "8", the paper spacing in the downstream machine 200 is about 70 mm (67 mm for setting No. 5, If the paper distance of the upstream machine 100 is changed from 73 mm (setting No. 5) to 356 mm (setting No. 6 to 8), the linear speed of the downstream machine 200 becomes "high speed". (setting No. 5) to "low speed" (setting No. 6 to 8). More specifically, when the paper distance of the upstream machine 100 becomes longer, the linear speed of the downstream machine 200 decreases.

Setting No. According to a comparison between the setting where is "9" and the setting where is "10" to "12", the paper spacing in the upstream machine 100 is about 70 mm (67 mm for setting No. 9, If the paper spacing of the downstream machine 200 is changed from 73 mm (setting No. 9) to 356 mm (setting No. 10 to 12), the linear speed of the upstream machine 100 becomes "high speed". (setting No. 9) to "low speed" (setting No. 10 to 12). More specifically, when the paper distance of the downstream machine 200 becomes longer, the linear speed of the upstream machine 100 decreases.

[5. Comparison with conventional technology]
FIG. 11 is a diagram for comparing the control shown in FIGS. 4 to 9 with that according to the prior art. FIG. 11 shows settings in the upstream machine 100 and the downstream machine 200 for each of conditions (1) to (7). Condition (1), condition (3) to condition (5), and condition (7) are based on the control according to the control shown in FIGS. 4 to 9. Condition (2) and condition (6) are based on control according to the prior art. In FIG. 11, PPM (Print Per Minute) represents the number of printing surfaces on which an image is formed per minute. 136 PPM means that 136 sheets of paper are printed on each side in one minute. Further, 136 PPM means that both sides (two sides) of each of 68 sheets of paper are printed in one minute.

(Regarding condition (2))
Condition (2) represents a case where the paper size is A4. As shown in condition (2), according to the control based on the conventional technology, when the linear speed of both the upstream machine 100 and the downstream machine 200 is "high speed", the print mode of the upstream machine 100 is "duplex". If there is, 344 m is set as the paper spacing in the downstream machine 200.

On the other hand, as shown in condition (3), according to the control shown in FIGS. 4 to 9, if the print mode of the upstream machine 100 is "duplex", "low speed" is set as the linear speed of the downstream machine 200. . As a result, the paper distance in the downstream machine 200 can be suppressed to 73 m. Compared to condition (2), under condition (3), the paper interval in the downstream machine 200 is shortened, thereby shortening the period during which elements such as photoreceptors operate in vain in the downstream machine 200. Furthermore, by reducing the conveyance speed, the value of the current that should be passed through the conveyance rollers can be reduced. This can reduce the rate of deterioration of the motor and contribute to extending the life of the motor.

(Regarding condition (6))
Condition (6) represents a case where the paper size is A3. As shown in condition (6), according to the control based on the conventional technology, when the linear velocity of both the upstream machine 100 and the downstream machine 200 is "high speed", the print mode of the upstream machine 100 is "duplex". If there is, 547 m is set as the paper spacing in the downstream machine 200.

On the other hand, as shown in condition (7), according to the control shown in FIGS. 4 to 9, if the print mode of the upstream machine 100 is "duplex", "low speed" is set as the linear speed of the downstream machine 200. . As a result, the paper distance in the downstream machine 200 can be suppressed to 63 m. Compared with condition (6), under condition (7), the paper interval in the downstream machine 200 is shortened, thereby shortening the period during which elements such as photoreceptors operate in vain in the downstream machine 200.

[6. Other controls]
In the image forming system 10, control can be performed according to each mode, such as pass-through mode, reprint mode, and error mode. The image forming system 10 includes a control unit 105 on the upstream machine 100 side, a control unit 205 on the downstream machine 200 side, a control device installed in a device other than the upstream machine 100 and the downstream machine 200, or a combination thereof. Control according to each mode may be executed by executing a given program. Each mode will be explained below.

(pass-through mode)
The pass-through mode is a mode in which only one of the upstream machine 100 and the downstream machine 200 forms an image on a sheet, and the other only carries the sheet without forming an image. In one example, only the upstream machine 100 executes image formation on the paper, and the downstream machine 200 discharges the paper output from the upstream machine 100 to the paper discharge unit 500 without performing image formation. In another example, the upstream machine 100 outputs the paper to the downstream machine 200 without performing image formation on the paper, and the downstream machine 200 performs image formation on the paper.

In one implementation example, the image forming system 10 may execute the pass-through mode due to an abnormality occurring in an image formed by either the upstream device 100 or the downstream device 200.

The presence or absence of an abnormality in the image may be determined by the user or by a sensor. In the latter case, an image sensor may be installed at each end of the upstream machine 100 and the downstream machine 200 to read the image formed on the paper. In one example, the image forming system 10 compares an image detected by an image sensor installed at the end of the upstream machine 100 with an image of the document, and if a difference of more than a threshold value is detected, the image forming system 10 causes the upstream machine 100 to It is determined that an abnormality has occurred in the formed image. In another example, an image detected by an image sensor installed at the end of the downstream machine 200 and an image of the document are compared, and if a difference of more than a threshold is detected, the image formed by the downstream machine 200 is It is determined that an abnormality has occurred.

(Additional printing mode)
The additional printing mode is a mode in which the downstream machine 200 further forms an image on the surface of the paper on which the image was formed in the upstream machine 100.

(Error mode)
The error mode is implemented when an error occurs in at least one of the upstream machine 100 and the downstream machine 200. An example of the control content of the error mode is error notification. In one example, when an error such as a paper jam occurs in either the upstream machine 100 or the downstream machine 200, the image forming system 10 notifies the operation display unit 109 and/or the operation display unit 209 of the occurrence of the error (e.g. , display and/or audio output).

If the error that occurs in one of the upstream machine 100 and the downstream machine 200 is a defective image formation, the image forming system 10 may execute a pass-through mode as error mode control.

Each of the embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the scope and meanings equivalent to the claims are included. Further, the inventions described in the embodiments and each modification are intended to be implemented alone or in combination to the extent possible.

10 image forming system, 100 upstream machine, 101 first conveyance path, 102 second conveyance path, 103, 203 image forming section, 104, 204 fixing section, 105, 205 control section, 106, 206 communication section, 107, 207 memory section, 108 document reading section, 109, 209 operation display section, 110 image processing section, 111 first conveyance control section, 112, 212 switching gate, 200 downstream machine, 201 third conveyance path, 202 fourth conveyance path, 211 th 2 transport control unit, 300 large capacity paper feeding unit, 400 reversing unit, 410 pre-registration roller, 500 paper ejection unit.

Claims (8)

a first image forming device;
a second image forming apparatus connected to the downstream side of the first image forming apparatus with respect to the first image forming apparatus;
a control unit that controls the operation of at least one of the first image forming device and the second image forming device,
The control unit includes:
controlling a paper conveyance speed in one of the first image forming apparatus and the second image forming apparatus based on a paper conveyance interval in the one and a paper conveyance interval in the other ;
The image forming system reduces the conveyance speed of the one sheet when the interval between sheets being outputted from the other sheet becomes longer . The image forming system according to claim 1 , wherein the control unit lengthens the interval at which sheets are outputted from the other side when the coverage of the image formed on the other side increases. The control unit causes one of the first image forming device and the second image forming device to form an image on both sides of the paper, and causes the other to pass the paper through without forming an image on the paper. The image forming system according to claim 1 or claim 2 . The control unit causes the one side to form images on both sides of the paper, and causes the other side to pass through the paper without forming an image on the paper, on the condition that a defect occurs in the image formed by the other side. The image forming system according to claim 3 . 3. The image forming system according to claim 1 , wherein the control unit causes the second image forming apparatus to further form an image on the surface of the paper on which the image has been formed by the first image forming apparatus. . It is further equipped with a notification section that broadcasts information,
The controller according to any one of claims 1 to 5 , wherein the controller notifies the notifier when an error occurs in at least one of the first image forming device and the second image forming device. The image forming system described in . The control unit controls one of the first image forming device and the second image forming device,
Any one of the first image forming apparatus and the second image forming apparatus notifies the control unit of the change when the interval at which paper is output is changed in the other of the first image forming apparatus and the second image forming apparatus. The image forming system according to claim 6 . A program executable by a computer,
to the computer;
acquiring information about paper conveyance intervals in each of a first image forming apparatus and a second image forming apparatus constituting the image forming system;
controlling a paper conveyance speed in one of the first image forming apparatus and the second image forming apparatus based on the acquired information ;
Controlling the paper transport speed in one of the first image forming apparatus and the second image forming apparatus reduces the transport speed of the one paper as the interval between sheets being output from the other becomes longer. program , including .

Images