JPH0885238A - Image forming system - Google Patents

Abstract

PURPOSE: To correct misregistrations without deteriorating efficiency in use of devices by detecting annular state of a plurality of image forming devices, deciding a timing for optional simultaneous correction of registrations based on the detection, and instructing remaining devices to start processing. CONSTITUTION: When a plurality of image forming devices (ST1-ST4) are being operated simultaneously, a registration correction mark is detected by a read means 10 and a correction means 51. An optional simultaneous correction timing for correcting registrations simultaneously at a time based on an annular state of a detected device body is decided by a CPU of an image processing station 52. In each image forming device which remains based on the decision, an instruction means for start of registration correction processing is provided so as to decide an optional simultaneous correction timing. When each image forming device is being operated simultaneously, a misregistration of each image forming device can be automatically corrected at a proper timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a plurality of image bearing members, in which a plurality of image forming apparatuses capable of forming multiple images formed on the image bearing members on a recording medium are communicable. It is about the system.

[0002]

2. Description of the Related Art Conventionally, recording is performed by irradiating a photosensitive drum with laser beam light which is modulated according to recording information, developing an electrostatic latent image on a photosensitive member by an electrophotographic process, and transferring the image onto a transfer paper. There has been proposed an image forming apparatus that has a plurality of apparatuses and is capable of forming a color image by superimposing and transferring each color image while sequentially transferring a transfer paper to each recording apparatus by a transfer belt.

When a plurality of image forming apparatuses of this type are used, an electrostatic latent image is formed on each photosensitive drum due to mechanical attachment error of each photosensitive drum, optical path length error of each laser beam, optical path change, etc. When developing and transferring to the recording paper on the transfer belt, there was a phenomenon in which the registration of each color image did not match properly in each device.

Therefore, conventionally, for each device, a registration correction pattern image formed on each transfer belt from each photosensitive drum is read by a CCD sensor or the like,
The registration deviation on the photosensitive drum corresponding to each color is detected, the image signal to be recorded is electrically corrected, and / or the reflection mirror provided in the optical path of the laser beam is driven to detect the optical path. The correction of the length change or the optical path change was performed independently.

[0005]

However, in the above-mentioned conventional example, each image forming apparatus independently forms a pattern image for registration correction on the photosensitive drum of each color, and the electrostatic latent image is developed by the developing device to form a visible image. Is transferred to a transfer belt, the registration correction pattern images that are sequentially conveyed are read by a CCD sensor, and registration deviations of each color are corrected according to the read pattern image data. When deviation occurs, it is necessary for the operator or the apparatus itself to perform registration correction at each arbitrary timing, which not only increases the labor of the operator but also causes a problem that the efficiency of use of the apparatus deteriorates. there were.

The present invention has been made to solve the above-mentioned problems, and an object of the first to seventh inventions of the present invention is to set the timing of registration deviation correction of a plurality of image forming apparatuses. Since any one of the image forming apparatuses automatically performs the registration correction at the same time as the determination timing, it is possible to simultaneously perform the registration deviation correction that occurs randomly in each image forming apparatus at an appropriate timing. An object of the present invention is to provide an image forming apparatus capable of performing registration deviation correction without reducing the use efficiency of each image forming apparatus.

[0007]

According to a first aspect of the present invention, a plurality of images in which an image forming unit is arranged around an image carrier which moves unsupported via a plurality of image carrier drive systems. A station, a transport body that sequentially transports a transfer material in a predetermined direction via a plurality of transport body drive systems, and image forming means provided in each image station to form a registration correction mark on the transport body at a predetermined timing. Pattern forming means, reading means for reading the registration correction marks transferred onto the carrier by the pattern forming means, and read data of the registration correction marks output from the reading means to analyze the registration of each image station. In an image forming system in which a plurality of image forming apparatuses having a correction unit that mechanically or electrically corrects are configured to be communicable, Note that when a plurality of image forming apparatuses are operating simultaneously, a detecting unit that detects an annular state of the image forming apparatus main body and a registration of the plurality of image forming apparatuses based on the environmental state detected by the detecting unit are performed. Each image includes a determination unit that determines an arbitrary synchronization correction timing for performing simultaneous correction at the same time, and an instruction unit that instructs the remaining image forming apparatus to start registration correction processing based on the arbitrary synchronization correction timing determined by the determination unit. It is provided in each of the forming devices.

According to a second aspect of the present invention, the determining means is
It is configured such that a plurality of interval times for simultaneously correcting the registrations of a plurality of image forming apparatuses are simultaneously determined on the basis of the registration deviation amount characteristic data to determine an arbitrary synchronization correction timing.

According to a third aspect of the present invention, any one of the image forming apparatuses is used as a master apparatus, and an instruction means of the master apparatus is used to perform registration correction on another image forming apparatus based on an arbitrary synchronization correction timing. It is configured to instruct the start of processing.

According to a fourth aspect of the present invention, the image forming apparatus having the shortest initial interval time determined by each determining means of each image forming apparatus is used as a master apparatus.

According to a fifth aspect of the present invention, the interval time for the simultaneous correction determined by the determining means is arbitrarily long after the first time according to the registration deviation amount characteristic.

According to a sixth aspect of the present invention, a plurality of image stations in which image forming means is arranged around an image carrier which moves unbearably via a plurality of image carrier drive systems, and a plurality of transport stations. A carrier for sequentially transferring the transfer material in a predetermined direction via a body drive system, and a pattern forming unit for forming a registration correction mark on the carrier at a predetermined timing by each image forming unit provided in each image station, Reading means for reading the resist correction marks transferred onto the carrier by the pattern forming means, and read data of the resist correction marks output from the reading means are analyzed to mechanically or electrically register the image stations. In an image forming system configured so that a plurality of image forming apparatuses having a correcting unit for correcting can communicate with each other,
Before starting a plurality of image forming apparatuses at the same time, each image forming apparatus is provided with an instructing means for instructing all image forming apparatuses to start registration correction processing at the same time. .

According to a seventh aspect of the present invention, any one of the image forming apparatuses is used as a master apparatus, and the instruction means of the master apparatus instructs another image forming apparatus to start registration correction processing. It was done.

[0014]

According to the first aspect of the present invention, when a plurality of image forming apparatuses are operating simultaneously, a plurality of determining means are provided on the basis of the environmental state detected by the detecting means for detecting the annular state of the image forming apparatus main body. An arbitrary synchronization correction timing for simultaneously correcting the registrations of the image forming apparatus is determined, and the instruction means instructs the image forming apparatus to remain to perform registration correction processing start based on the determined arbitrary synchronization correction timing, Under a use environment in which each image forming operation is operating at the same time, it is possible to automatically correct the registration deviation of each image forming apparatus at an appropriate timing.

In the second aspect of the invention, the determining means calculates a plurality of interval times for simultaneously correcting the registrations of a plurality of image forming apparatuses simultaneously on the basis of the registration deviation amount characteristic data, and determines an arbitrary synchronization correction timing. Then, it is possible to instruct the registration correction by grasping an appropriate timing when the registration deviation amount changes with the use of each image forming apparatus.

According to the third aspect of the invention, one of the image forming apparatuses is used as a master apparatus, and an instruction means of the master apparatus starts registration correction processing with respect to another image forming apparatus based on a predetermined synchronization correction timing. Direct,
By any one of the master devices in the image forming system, it is possible to surely determine the timing for simultaneously correcting the registration deviation of the other image forming devices.

In the fourth aspect of the invention, the image forming apparatus having the shortest initial interval time determined by each determining means of each image forming apparatus is set as the master apparatus, and the registration deviation amount that requires the registration correction most is determined. The registration correction timing of another image forming apparatus is determined with the image forming apparatus having a fast changing speed as the reference timing.

In the fifth aspect of the invention, the interval time for simultaneous correction determined by the determining means is arbitrarily lengthened from the first time onward in accordance with the registration deviation amount characteristic so that the registration deviation amount characteristic of the image forming apparatus can be adjusted. Therefore, the registration deviation amount can be surely corrected at an appropriate interval.

In the sixth aspect of the present invention, before simultaneously starting a plurality of image forming apparatuses, the instructing means issues an instruction from one of the image forming apparatuses to another image forming apparatus to start registration correction processing all at once. It is possible to simultaneously start the initial correction of the registration deviation amount before starting the image formation of the plurality of image forming apparatuses.

In the seventh invention, one of the image forming apparatuses is used as a master apparatus, and the instruction means of the master apparatus instructs the other image forming apparatuses to start the registration correction process, so that the image forming system is started. With any of the above master devices, it is possible to reliably determine the timing for simultaneously correcting the registration deviation of the other image forming apparatuses.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram for explaining the configuration of an image forming apparatus showing an embodiment of the present invention.

In the figure, reference numeral 1 is a transfer belt, which is moved in the direction of the central arrow in the figure when the drive of the pulse motor 15 is transmitted to the drive roller 42. 2 to 5 are photosensitive drums, which are laser beams LM corresponding to magenta (M), cyan (C), yellow (Y), and black (BK) in order.
(L1), LC (L2), LY (L3), LBK (L
The electrostatic latent image formed by the scanning of 4) is visualized by the toner contained in the developing device (not shown), and the transfer belt 1
The color image formed on is transferred. Drum motors 11 to 14 rotate the photosensitive drums 2 to 5 at a predetermined speed.

The pattern forming means of the present invention reads predetermined registration correction pattern data stored in a ROM (not shown) or the like, and modulates the laser beams LM, LC, L based on the pattern data.
By scanning Y and LBK, a pair of pattern latent images are formed at two predetermined positions which are different from each other in the axial direction of the photosensitive drums 2 to 5, and these latent images are magenta (M), cyan (C) and yellow (Y). Corresponding to a means of developing with black (BK) color toner and transferring this to the transfer belt 1. In the present embodiment, 1 is set so as to face a predetermined position in the width direction orthogonal to the transport direction of the transfer belt 1. Paired.

The reading means 10 is composed of illumination lamps 6 and 7, a condenser lens 8, a reflecting mirror 9, sensors 10a and 10b composed of CCDs, etc., and is placed on the transfer belt 1 which moves according to the drive of the pulse motor 15. Pattern reading is performed by forming an image of reflected light obtained by illuminating the formed pattern (for example, a cross mark having a predetermined width) on the sensors 10a and 10b. A controller unit 51 is a control program stored in a ROM or the like by a CPU 52-c in an image processing station 52 for performing normal image formation, pattern formation for predetermined registration correction, and pattern reading for predetermined registration correction. Based on.

Correspondence between this embodiment and each means of the first to seventh inventions and their functions will be described below with reference to FIG.

According to a first aspect of the present invention, a plurality of image stations ST1 to ST4 in which an image forming unit is arranged around an image carrier which is unsupported via a plurality of image carrier driving systems, and a plurality of carriers. A transfer body (transfer belt 1) that sequentially transfers a transfer material in a predetermined direction via a drive system, and a pattern for forming registration correction marks on the transfer body at a predetermined timing by each image forming unit provided in each image station. Forming means (in this embodiment, the patch forming part of the controller 51) and reading means 1 for reading the registration correction marks transferred onto the conveyance body by the pattern forming means.
0 and an image correction unit that analyzes the read data of the registration correction mark output from the reading unit 10 to mechanically or electrically correct the registration of each image station (the controller unit 51 in this embodiment). In an image forming system configured such that a plurality of image forming apparatuses can communicate with each other, when a plurality of the image forming apparatuses are operating simultaneously, a detection unit (environment sensor SEN detects temperature, A humidity determining means for detecting humidity, vibration, etc.) and a determining means (image processing station 52) for determining an arbitrary synchronous correction timing for simultaneously correcting the registrations of a plurality of image forming apparatuses based on the environmental condition detected by the detecting means. CPU) and the image remaining based on the arbitrary synchronization correction timing determined by this determining means. Instruction means for instructing the registration correction process starts forming apparatus (the communication interface 53)
Is provided in each image forming apparatus, and when a plurality of image forming apparatuses are operating simultaneously, based on the environmental state detected by the detection unit (environment sensor SEN) that detects the annular state of the image forming apparatus main body. The determining unit (the image processing station 52) determines an arbitrary synchronous correction timing for simultaneously correcting the registrations of a plurality of image forming apparatuses at the same time according to the procedure of the flowcharts shown in FIGS. Based on the synchronization correction timing, the registration unit instructs the remaining image forming apparatus to start the registration correction process, and appropriately adjusts the registration deviation of each image forming apparatus under the use environment in which each image forming operation is operating simultaneously. It is possible to automatically correct at the same time.

According to a second aspect of the invention, the determining means (the CPU of the image processing station 52) calculates a plurality of interval times for simultaneously correcting the registrations of a plurality of image forming apparatuses on the basis of the registration deviation amount characteristic data. Then, it is possible to determine an arbitrary synchronization correction timing and to instruct the registration correction by grasping an appropriate timing when the registration deviation amount changes with the use of each image forming apparatus.

In a third aspect of the invention, one of the image forming apparatuses is a master apparatus (determined as shown in FIG. 12 described later).
Then, the instruction means of the master apparatus instructs another image forming apparatus to start the registration correction process based on a predetermined synchronization correction timing, and one of the master apparatuses in the image forming system forms another image. It is possible to surely determine the timing for simultaneously correcting the registration deviation of the device.

According to a fourth aspect of the present invention, the image forming apparatus having the shortest initial interval time determined by each determining means of each image forming apparatus is used as a master apparatus, and the registration deviation amount that most requires registration correction varies. The registration correction timing of another image forming apparatus is determined using the image forming apparatus having a high speed as a reference timing.

According to a fifth aspect of the invention, the interval time for simultaneous correction determined by the determining means (CPU of the image processing station 52) is arbitrarily lengthened from the first time onward in accordance with the registration deviation amount characteristic, and the image forming apparatus is provided. It is possible to surely correct the registration deviation amount at appropriate intervals depending on the registration deviation amount characteristic of.

In a sixth aspect of the invention, a plurality of image stations ST1 to ST4 in which an image forming means is arranged around an image carrier which moves unbearably via a plurality of image carrier drive systems, and a plurality of carriers. A transfer body (transfer belt 1) that sequentially transfers a transfer material in a predetermined direction via a drive system, and a pattern for forming registration correction marks on the transfer body at a predetermined timing by each image forming unit provided in each image station. Forming means (in this embodiment, the patch forming part of the controller 51) and reading means 1 for reading the registration correction marks transferred onto the conveyance body by the pattern forming means.
0 and an image correction unit that analyzes the read data of the registration correction mark output from the reading unit 10 to mechanically or electrically correct the registration of each image station (the controller unit 51 in this embodiment). In an image forming system configured so that a plurality of image forming apparatuses can communicate with each other, before starting a plurality of image forming apparatuses at the same time, one image forming apparatus simultaneously instructs other image forming apparatuses to start registration correction processing. Instructing means (CPU of the image processing station 52) is provided in each image forming apparatus, and the instruction means registers from one image forming apparatus to another image forming apparatus before simultaneously starting a plurality of image forming apparatuses. Registration correction start at a time and register the registration It makes it possible to start all at once Deployment shift amount of initial correction.

According to a seventh aspect of the present invention, any one of the image forming apparatuses is used as a master apparatus, and an instruction means of the master apparatus instructs another image forming apparatus to start registration correction processing, and an image forming system in the image forming system. By any one of the master apparatuses, it is possible to reliably determine the timing for simultaneously correcting the registration deviation of the other image forming apparatuses.

In each image forming apparatus, when the image forming means forms the registration correction mark on the conveyance body by the pattern forming means (in this embodiment, the patch forming portion of the controller portion 51) at a predetermined timing, the reading is performed. The means 10 starts reading the registration correction mark transferred onto the carrier (transfer belt 1), and the read processing data is subjected to a predetermined calculation processing by the calculation processing means (the controller unit 51 in this embodiment) to obtain the result. Each color is stored in the storage means (RAMs 603 and 604 described later), and the correction means (the controller unit 51 in this embodiment) analyzes the stored calculation result to mechanically or electrically register the registration of each image station. Even if the memory capacity is corrected, even if the memory capacity is small, the registration resister with each image carrier is not affected by the uneven rotation of the image carrier. The ® down shift information to accurately calculate the registration deviation of each image bearing member is accurately corrected.

The correction means in this embodiment is the reflection mirror 100 of the scanning optical system (provided for each drum).
By driving pulse motors M1 to M4, which will be described later, to mechanically correct the registration deviation at the positions of 0 Ma, 1000 Cy, 1000 Ye, and 1000 Bk, and electrically correct the scanning timing of the light beam,
The resists on each drum are matched.

First, the image forming operation will be described. The photosensitive drums 2 to 5 corresponding to magenta (M), cyan (C), yellow (Y), and black (BK) are rotationally driven by drum motors 11 to 14, respectively, and uniformly charged by a charging unit (not shown). . Magenta (M),
The photosensitive drums 2 to 5 corresponding to cyan (C), yellow (Y), and black (BK) are exposed by the laser beams L1 to L4 optically modulated by the video signal, and the respective electrostatic latent images are exposed on the photosensitive drums 2 to 2. 5 and is developed by a developing unit (not shown) to form a visible image. next,
The visible images formed on the photosensitive drums 2 to 5 are fed from a sheet feeding unit (not shown), transferred onto the transfer sheet electrostatically adsorbed on the transfer belt 1 at a predetermined timing, and driven by the pulse motor 15. The sheet is conveyed in the direction of the arrow in the figure, and is fixed and discharged through the fixing unit.

Next, reading of the registration correction pattern image will be described. The pattern images visualized on the photosensitive drums 2 to 5 by the registration correction pattern image forming circuit are transferred onto the transfer belt 1 at the timing of the timing chart shown in FIG.
It is conveyed in the direction of the arrow in the figure. The transferred pattern image is illuminated by the illumination lamps 6, 7, the condenser lens 8, and the reflection mirror 9.
The CCD sensor 10 (sensor 1
0a, 10b).

FIG. 3 shows the controller section 51 shown in FIG.
3 is a block diagram illustrating a detailed configuration of FIG. The configuration and operation will be described below.

The pattern images of the respective colors formed as shown in FIG. 4 on the front side and the back side with respect to the conveying direction of the transfer belt 1 shown in FIG. 1 are read by the CCD sensors 10a and 10b. The original oscillation clocks β507 and β508 from the registration controller 20 are the CCD driver 1
8 and 19, clocks (transfer pulse, reset pulse, shift pulse, etc.) β501 and β502 necessary for driving the CCD sensors 10a and 10b are generated, and CCDs are generated.
It is supplied to the sensors 10a and 10b. CCD sensor 10
pattern image signal β50 read by a and 10b
The CCD drivers 18 and 19 perform processing such as amplification, DC reproduction, and A / D conversion on the signals β3 and β504, and the signals are sent to the registration controller 20 as digital signals β505 and β506.

Each color pattern image signal received by the registration controller 20 is subjected to registration correction pattern recognition processing, and then a plurality of recognition processing data are stored in the memory, and the color pattern image controlled by the CPU is used as a reference. The amount of registration deviation is calculated, the electrical image writing timing setting data β509 for each color main scan and sub scan is sent to the system controller 21, and the optical path length change and optical path change of the recording laser beam are corrected in the optical path. Reflection mirror 1 installed in
The pulse data β511 of the pulse motors 23, 24, 25 and 26 for driving and controlling 000Ma, Cy, Ye and Bk are supplied to the mirror motor driver 22. In the mirror motor driver 22, the current signals β512 to β515 are supplied to the pulse motors 23 to 26 for driving the reflection mirrors of the respective colors according to the pulse data β511, and the pulse motors 23 to 2 are supplied.
6 is driven to cause reflection mirrors 1000Ma, Cy, Ye,
The positioning of Bk is controlled. These registration corrections are performed by the activation signal β from the system controller 21.
It is supplied to the registration controller 20 by 510 and executed.

FIG. 5 is a circuit block diagram for explaining the structure of the pattern forming section in the image forming apparatus of the video controller 52-a in the image processing station 52 shown in FIG. The configuration and operation will be described below.

A beam detect signal (BD) β528, which is obtained by scanning the laser beam outside the recording area and serves as a synchronizing signal in the main scanning direction, is applied to an enable signal generating circuit (H enable signal generating circuit) 27 in the main scanning direction. ,
The H direction enable signal β516 of the image pattern signal for registration correction is formed.

Further, a registration correction image pattern formation start signal (ITOP) β529 is added to the sub-scanning direction enable signal generation circuit (V enable signal generation circuit) 28, and the V direction enable signal β517 of each color image pattern signal is added. Is formed. The H direction enable signal β516 and the V direction enable signal β517 are supplied to the address counter 29, and the address signal β531 of the pattern RAM 30 for the next registration correction image.
Generate An image pattern signal β518 is output from the pattern RAM 30 in accordance with the address signal β531 (“cross pattern” in this embodiment).

The patch register 31 stores patch data formed under the registration correction image pattern via the CPU bus β530 from the system controller 21. The patch data signal β519 and the image pattern signal β518 are input to the selector 32, and the selection signal β526 is input so that the image pattern signal β518 is always output for magenta (M) and cyan (C). For yellow (Y) and black (BK), the signal β520 in which the image pattern data and the patch data are switched at a predetermined timing is output to the register 35 via the CPU bus β530 according to the timing chart shown in FIG. To selector 33
Is input to The video signal β521 is input to the selector 33. Here, when the selector 32 is switched, when a carbon black type toner is used as the black toner, carbon black absorbs light in the reflective optical system, so that the pattern image cannot be read.

Therefore, a solid pattern (patch) of any one of the other color (magenta, cyan, and yellow) toners that reflect light (yellow toner in this embodiment) is used when the registration correction image pattern for yellow is formed. It is formed on the transfer belt 1 after a predetermined time, and a black registration correction image pattern is formed on the patch formed by the yellow toner.

Therefore, in the mode for forming the image pattern and patch, the image pattern and patch are selected by the selection signal β527, the selected image information β522 is output to the γRAM 34, and the γ-converted image information β523 is gated. Video signal β5 via circuit 37
25 is output to the laser driver 38. The image signal β is sent to the laser driver 38 via the NAND gate 36.
524 is input. The semiconductor laser 39 is ON / OFF-modulated based on the image signal β524 or the video signal β525 input to the laser driver 38, and a latent image is formed on the photosensitive drums 2 to 5 via an optical scanning system (not shown). To be done.

In this embodiment, the pattern generating circuit is provided for each color, but the pattern R is used.
The AM 30 and the like can also be configured to be commonly used for each color.

Hereinafter, each color pattern position and pattern shape calculation process will be described with reference to FIGS. 6 and 7. FIG. 6 is a detailed block diagram for explaining a main configuration of the registration controller 20 shown in FIG.

In the figure, DF1 to DF4 are D-type flip-flops, 601 and 602 are adders, and inputs A and B
Is added. A RAM 603 stores the density histogram in the sub-scanning direction of each color pattern at the timing according to the timing chart shown in FIG. 604 is a RAM
Then, the density histogram of the pattern of each color in the main scanning direction is stored at the timing according to the timing chart shown in FIG. A bus controller 607 outputs various timing signals and a bank selection signal BANKSEL.

In the present embodiment, pattern data read for calculating each color pattern position and pattern shape, integrated data is created for each pixel for each line for main scanning and sub-scanning, and based on the created integrated data. Shape recognition is performed.

First, the integrated data in the main scanning direction is created by first clearing the pattern data of one main scanning line output from the CCD sensor 10a by the reset signal RES1 and then adding the data for one line by the adder 602. The address counter 606 is obtained based on the main scanning enable signal LEN output at the timing shown in FIG.
Write signal RAMWR according to the address determined by
The data is written in the RAM 604 in synchronization with 2. The memory is enabled while the sub-scanning direction enable signal is being sent.

On the other hand, the integrated data in the main scanning direction is created by
After the pattern data for one main scanning line is cleared by the reset signal RES2, the pattern data is stored in the RAM 603, and then the read-modify-write operation is repeated for each pixel by the write signal RAMWR1 and the data direction switching signal RAMDIR and added to the adder 601 The integrated data of each sub-scanning line is stored in the RAM 603 for each pixel.

As a result, the main scanning / sub scanning integrated data for the pattern image as shown in FIG. 8 is stored in the RAM for each color.
It will be stored in 603 and 604.

The memory space is selectively used by sending the bank of each color and the bank of each set to the higher order of the RAM by the bank selection signal BANKSEL.

The registration correction process in the image forming apparatus according to the present invention will be sequentially described below with reference to FIGS. 9 and 10.

The present invention has an image processing station 52 and an interface 53 shown in FIG. 1 in order to enable registration correction and image formation of a plurality of second image apparatus devices.

FIG. 9 is a block diagram for explaining the image processing station 52 and I / F 53 shown in FIG.

In FIG. 9, the video signal for image formation is external bus β502 (external bus interface is GP.
It is also stored in the video memory 52-b via the bus selector 53-a via a general-purpose interface such as IB). The bus selector 53-a stores the video data in the video memory 52-b and the CPU 52-c.
The transfer of commands (registration correction command, image formation start command, etc.) sent from the external bus β502 is switched.

The bus controller 53-b is the CPU 52-
The instruction from c controls the address counter control of the video memory 52-b and the command transfer to the CPU 52-c. The video memory 52-b sends the video data to the video controller according to the control signal of the video controller 52-a, forms the laser lights L1, L2, L3 and L4 which are PWM-modulated as described above, respectively, and exposes them respectively. A latent image is formed on the drum.

Further, the CPU 52-c is the CPU bus β50.
Is connected to the controller unit 51 via 0 to receive registration deviation data and receives electrical and mechanical registration correction target data from the controller unit 51.
And the registration correction of the present invention is comprehensively controlled.

FIG. 10 is a characteristic diagram for explaining the changing state of the registration deviation amount in the image forming apparatus according to the present invention, in which the vertical axis represents the registration deviation amount and the horizontal axis represents the time.

In the figure, a time interval having a large deviation amount with respect to time is TS2, and a time interval having a small deviation amount is TS4. Further, the time intervals for performing registration correction in TS2 and TS4 are TS1 and TS3, respectively, and TS1, TS2, TS3, which will be described below with reference to FIG.
TS4 corresponds to this numerical value.

FIG. 11 is a flowchart showing an example of a first registration correction processing procedure in the image forming apparatus according to the present invention. Note that (1) to (18) indicate each step. Further, the first registration correction process corresponds to a process for simultaneously performing registration correction before simultaneously starting a plurality of image forming apparatuses.

First, it is determined whether the operation mode is the plural simultaneous start mode (1). At this time, any one of the image forming apparatuses is used as a master apparatus, and the master apparatus transmits an operation mode designation command to another slave apparatus.

If it is determined that the operation mode is the normal mode, that is, if the respective devices are operating independently instead of the simultaneous start mode, the timing unique to each device (at the start of image formation, predetermined Registration correction is performed at time intervals (18).

On the other hand, when the simultaneous start mode is determined in step (1), the number of prints set by the master device is evenly allocated to the device to be used (2). Next, the environmental temperature of the master device is measured by an environmental sensor (not shown). The registration shift amount shows a change as shown in FIG. 10 with time as the image forming apparatus main body warms up.

Therefore, since the initial environmental temperature of the master device is measured, the time interval TS1 is set by the CPU 52-c.
The time interval TS4 is calculated from (3). Further, the video data transferred to the master device is transferred to another slave device, and the master device instructs all the devices to start printing (4).

At this time, the counters T and T0 secured in the RAM in the CPU 52-c of the master device are reset (5), and after a lapse of a predetermined time, the counter T is counted up (6). After that, when T = TS1, that is, when the first registration correction execution timing comes (7), the master device instructs each device to execute registration correction (8).

As a result, the counter T of the master device is reset and the counter T0 is incremented. In this way, during the time interval TS2, the registration correction is executed all the devices at the time interval TS1 (6) to (10).

Further, as shown in steps (11) to (17), during the time interval TS4, the registration correction is executed all the devices at the interval TS3.

As described above, the temperature at which printing is started can be measured, and the timing at which registration correction is executed can be determined from the relationship between the temperature at that time and the temperature until saturation.

Of course, if the measured temperature at the start of printing is high, the amount of registration deviation with respect to time change will be small, and therefore the execution interval of registration correction will be long. If the measured temperature is low, the execution interval will be short. Will be.

The printing is finished as soon as the designated number of sheets are printed (18), regardless of the timing of registration correction.

FIG. 12 is a flowchart showing an example of a second registration correction processing procedure in the image forming apparatus according to the present invention. Note that (1) to (19) indicate each step.

First, it is judged whether or not the operation mode is the plural simultaneous starting mode (1), and in the case of the normal mode, the registration correction and the image formation are performed individually for each apparatus (19).

On the other hand, when the simultaneous start mode is determined in step (1), the number of prints set by the master device is evenly allocated to the device to be used (2). Next, the environmental temperature of the master device is measured by an environmental sensor (not shown). Then, the environmental temperature of each device is measured and the TS of each device is measured.
1 to TS4 are calculated (3). Furthermore, after the master device instructs the other devices to start printing (4),
The counters Tn and T0n of each device are reset (5).
At that time, the counters Tn and T0n secured in the RAM in the CPU 52-c of each device are reset, and after a predetermined time has elapsed, the counter Tn is counted up (6). After that, when Tn = TS1n, that is, when the first registration correction execution timing comes (7), the device that reaches the time interval TS1 for the first time is referred to as the device F thereafter (8), and the time interval of this device F The execution timing of the registration correction is determined by comparing the counter values of the counter TF and the counter TF0 with TS1 to TS4 as a reference.

As a result, the counter TF of the device F is reset and the counter T0F is counted up. In this way, during the time interval TS2F, the registration correction is executed all the devices at the time interval TS1F (6) to (10).

Further, as shown in steps (11) to (17), during the time interval TS4F, the registration correction is executed all at once in the interval TS3F.

The printing is finished as soon as the designated number of sheets are printed (18), regardless of the registration correction timing.

This embodiment is effective when devices having different environments (device installation environment, power-on timing, etc.) are connected by communication means and are started simultaneously, and the device having the fastest registration deviation is used as a reference. In addition, all registration correction timings can be performed at the same time. [Second Embodiment] FIG. 13 is a flowchart showing an example of a third registration correction processing procedure in the image forming apparatus according to the present invention. It should be noted that (1) to (7) indicate the respective steps, and particularly correspond to the processing when the registration correction is simultaneously performed on a plurality of devices before simultaneous startup.

First, it is determined whether the operation mode is the multiple simultaneous start mode (1). At this time, any one of the devices is used as a master device, and the master device transmits an operation mode designation command to another slave device.

Here, when the operation mode is the normal mode,
That is, when the devices are operating independently of each other in the simultaneous start mode, the registration correction is performed at the timing unique to each device (at the start of image formation, a predetermined time interval, etc.) (8).

On the other hand, if the simultaneous start mode is determined in step (1), the number of prints set by the master device is evenly allocated to the device to be used (2). This can improve the use efficiency of the device. Further, the video data transferred to the master device is transferred to another slave device (3), and the master device issues an instruction to execute registration correction simultaneously to all devices (4).
Executes registration correction operation. In this state, all the devices are registered and adjusted to the same level of registration. After confirming the completion of all registration corrections (5), the master device sends a print start command command to each device (6) to start printing.

Then, after the master device confirms that the number of prints of each device is completed (7), the series of flow is ended.

FIG. 14 is a flow chart showing an example of a fourth registration correction processing procedure in the image forming apparatus according to the present invention. It should be noted that (1) to (9) indicate the respective steps, and particularly correspond to other processing in the case of simultaneously performing registration correction before simultaneously starting a plurality of devices.

First, it is judged whether or not the operation mode is the plural simultaneous start mode (1), and in the normal mode, each device independently performs registration correction and image formation (8).

On the other hand, if it is determined in step (1) that the mode is the simultaneous start mode, the master device sends a registration correction execution command command to the other devices, and each device performs registration correction (2).

After all the devices have completed the registration correction operation, the master device inspects the presence and the number of devices for which registration correction cannot be performed for some reason (3).

Here, if there is no device for which registration correction is impossible (when all registration correction is possible), the number of prints is evenly allocated to each device (9), but registration correction is impossible. If there are devices, the number of prints is equally shared by the number of usable devices (4).

Further, the video data is transferred to the video memory of each device (5), the print start instruction command of each device is transferred to each device by the master device (6), and each device printing is started.

Then, after the master device confirms that the number of printed sheets of each device is completed (7), the series of flows is ended.

[0091]

As described above, the first aspect of the present invention
According to the invention, when a plurality of image forming apparatuses are operating at the same time, the determining unit determines the number of the image forming apparatuses based on the environmental state detected by the detecting unit that detects the annular state of the image forming apparatus main body. Since an arbitrary synchronization correction timing for simultaneously correcting the registrations is determined and the instruction means instructs the remaining image forming apparatus to start the registration correction processing based on the determined arbitrary synchronization correction timing, each image forming operation is performed. It is possible to automatically correct the registration deviation of each image forming apparatus simultaneously at an appropriate timing under a use environment in which the two operate simultaneously.

According to the second aspect of the invention, the determining means determines a plurality of interval times for simultaneously correcting the registrations of the plurality of image forming apparatuses at the same time based on the registration deviation amount characteristic data, thereby performing arbitrary synchronization correction. Since the timing is determined, it is possible to instruct the registration correction by grasping an appropriate timing when the registration deviation amount changes with the use of each image forming apparatus.

According to the third invention, any one of the image forming apparatuses is used as a master apparatus, and the registration correction processing is started from the instruction means of the master apparatus to the other image forming apparatuses based on a predetermined synchronization correction timing. Since any one of the master devices in the image forming system can surely determine the timing for simultaneously correcting the registration deviation of the other image forming devices.

According to the fourth aspect of the invention, the image forming apparatus having the shortest initial interval time determined by each determining means of each image forming apparatus is set as the master apparatus, so that the registration requiring the registration correction most is required. The registration correction timing of another image forming apparatus can be determined by using the image forming apparatus having a high speed at which the deviation amount fluctuates as a reference timing.

According to the fifth aspect of the invention, the interval time for simultaneous correction determined by the determining means is arbitrarily lengthened from the first time onward in accordance with the registration deviation amount characteristic. Therefore, the registration deviation amount of the image forming apparatus is increased. The registration deviation amount can be surely corrected at proper intervals depending on the characteristics.

According to the sixth aspect of the present invention, before simultaneously starting a plurality of image forming apparatuses, the instructing means issues an instruction from one of the image forming apparatuses to another image forming apparatus to start the registration correction process all at once. Therefore, the initial correction of the registration deviation amount can be simultaneously started before the image formation of the plurality of image forming apparatuses is started.

According to the seventh invention, any one of the image forming apparatuses is used as the master apparatus, and the instruction means of the master apparatus instructs the other image forming apparatuses to start the registration correction process. Any one of the master devices can surely determine the timing for simultaneously correcting the registration deviation of the other image forming apparatuses.

Therefore, it is possible to correct the registration deviation without deteriorating the use efficiency of each image forming apparatus and to stably form an image without registration deviation in each image forming apparatus. Play.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment of the present invention.

2 is a timing chart showing pattern image writing timing in the image forming apparatus shown in FIG.

FIG. 3 is a block diagram illustrating a detailed configuration of a controller unit illustrated in FIG.

FIG. 4 is a plan view showing a written state of a pattern image transferred onto the transfer belt shown in FIG.

5 is a circuit block diagram illustrating a configuration of a pattern forming unit in the image forming apparatus shown in FIG.

FIG. 6 is a detailed block diagram illustrating a main part configuration of the registration controller illustrated in FIG.

FIG. 7 is a timing chart illustrating the operation of FIG.

8 is a diagram showing a histogram gram based on the pattern image transferred to the transfer belt shown in FIG.

FIG. 9 is a block diagram illustrating the image processing station and the like illustrated in FIG. 1.

FIG. 10 is a characteristic diagram illustrating a change state of the registration deviation amount in the image forming apparatus according to the present invention.

FIG. 11 is a flowchart showing an example of a first registration correction processing procedure in the image forming apparatus according to the present invention.

FIG. 12 is a flowchart showing an example of a second registration correction processing procedure in the image forming apparatus according to the present invention.

FIG. 13 is a flowchart showing an example of a third registration correction processing procedure in the image forming apparatus according to the present invention.

FIG. 14 is a flowchart showing an example of a fourth registration correction processing procedure in the image forming apparatus according to the present invention.

[Explanation of symbols]

 1 Transfer Belt 2 Photosensitive Drum 3 Photosensitive Drum 4 Photosensitive Drum 5 Photosensitive Drum 10 Reading Unit 51 Controller Section ST1 Image Station ST2 Image Station ST3 Image Station ST4 Image Station

Claims (7)

[Claims] 1. A transfer material through a plurality of image stations in which an image forming unit is arranged around an image carrier that moves unsupported through a plurality of image carrier drive systems and a plurality of carrier drive systems. And a pattern forming means for forming registration correction marks on the conveyor at a predetermined timing by each image forming means provided in each image station, and on the conveyor by the pattern forming means. An image having a reading unit for reading the registration correction mark transferred to the image reading unit and a correction unit for analyzing the read data of the registration correction mark output from the reading unit to mechanically or electrically correct the registration of each image station. In an image forming system configured so that a plurality of image forming apparatuses can communicate with each other, the plurality of image forming apparatuses operate simultaneously. At this time, a determination unit that detects an annular state of the image forming apparatus main body and a determination that determines an arbitrary synchronization correction timing for simultaneously correcting the registrations of a plurality of image forming apparatuses based on the environmental state detected by the detection unit Image forming means characterized in that each image forming apparatus is provided with a means and an instruction means for instructing the remaining image forming apparatus to start registration correction processing based on the arbitrary synchronization correction timing determined by the determining means. system. 2. The determining means determines a desired synchronization correction timing by calculating a plurality of interval times for simultaneously correcting the registrations of a plurality of image forming apparatuses simultaneously based on the registration deviation amount characteristic data. The image forming system according to claim 1, wherein 3. An image forming apparatus is set as a master apparatus, and an instruction means of the master apparatus instructs another image forming apparatus to start registration correction processing at an arbitrary synchronization correction timing. The image forming system according to claim 1. 4. The image forming system according to claim 3, wherein the image forming apparatus having the shortest initial interval time determined by each determining means of each image forming apparatus is the master device. 5. The image forming system according to claim 3, wherein the interval time for the simultaneous correction determined by the determining means is arbitrarily long after the first time according to the registration deviation amount characteristic. 6. A transfer material through a plurality of image stations in which an image forming unit is arranged around an image carrier that moves unsupported through a plurality of image carrier drive systems and a plurality of carrier drive systems. And a pattern forming means for forming registration correction marks on the conveyor at a predetermined timing by each image forming means provided in each image station, and on the conveyor by the pattern forming means. An image having a reading unit for reading the registration correction mark transferred to the image reading unit and a correction unit for analyzing the read data of the registration correction mark output from the reading unit to mechanically or electrically correct the registration of each image station. In an image forming system configured so that a plurality of image forming apparatuses can communicate with each other, before simultaneously starting a plurality of image forming apparatuses, An image forming system, wherein each image forming apparatus is provided with an instructing unit for instructing all image forming apparatuses to start registration correction processing all at once. 7. The image according to claim 6, wherein any one of the image forming apparatuses serves as a master apparatus, and the instruction means of the master apparatus instructs another image forming apparatus to start registration correction processing. Forming system.