JP2012068463A - Image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize downtime in an image forming system of series tandem system and prevent image quality change in separate image forming apparatuses.SOLUTION: The image forming system includes: a first image forming apparatus 100 that has a control section configured such that in a case where a correction start notification is received, a determination is made whether the correction is possible; and a second image forming apparatus 300 that has a control section configured such that in a case where the timing of correction execution is perfect, the correction start notification is sent to the first image forming apparatus. In a case where the correction start notification is received from the control section of the second image forming apparatus and the correction is possible, the control section of the first image forming apparatus exerts control to send correction permission notification to the second image forming apparatus and to correct by the first image forming apparatus as well. In a case where a correction permission notification is received from the control section of the first image forming apparatus, the control section of the second image forming apparatus exerts control to correct by the second image forming apparatus.

Description

  The present invention relates to an image forming system in which a plurality of image forming apparatuses are connected in series so that an image can be formed by sharing either the front or back side of a recording sheet or a page.

  A plurality of image forming apparatuses are connected in tandem in series, and recording paper on which an image is formed in one area by one image forming apparatus is continuously input to the other image forming apparatus, and the other image forming apparatus There is an image forming system that forms an image on another area of a recording sheet.

  According to such an image forming system, there is an advantage that high speed output is possible by forming images on the front and back of the recording paper with two image forming apparatuses. In addition, two image forming apparatuses can form images using different color toners, or two image forming apparatuses can perform image formation suitable for each of a character area and an image area. A fine image can be formed.

  This type of image forming system is disclosed in Patent Document 1 below.

  Further, in an image forming system using a plurality of image forming apparatuses, the following Patent Document 2 describes that correction of each image forming apparatus is executed at a timing determined by an administrator.

Japanese Patent Laid-Open No. 11-348384 JP-A-8-85238

  In the image forming systems described in Patent Documents 1 and 2 described above, correction in each image forming apparatus is efficiently performed for a plurality of serial tandem image forming apparatuses, and the entire system downtime (does not contribute to image formation). The idea of minimizing downtime is not suggested or described. In the image forming system of the cited document 2, since the image forming apparatuses are connected in parallel, it is not necessary to consider downtime unlike the case of the serial tandem system.

  The present invention has been made in view of such a problem, and a plurality of image forming apparatuses are connected in series so that an image can be formed by sharing either the front or back side of a recording sheet or a page. An object of the present invention is to realize an image forming system that minimizes downtime and does not cause a change in image quality with respect to the sharing of each image forming apparatus.

  That is, the present invention for solving the above-described problems is as follows.

  (1) The invention described in claim 1 is a tandem type image forming system in which a plurality of image forming apparatuses are connected in series so as to be able to form an image by sharing any region of the recording paper. When a correction start notification requesting the start of correction is received, the first image forming apparatus including a control unit that determines whether the correction can be executed, and correction start when the correction execution timing for adjusting each unit is met A second image forming apparatus including a control unit that notifies the first image forming apparatus of a notification, and the control unit of the first image forming apparatus corrects from the control unit of the second image forming apparatus. In response to the start notification, if the correction can be executed, the correction permission notification is notified to the second image forming apparatus, and the first image forming apparatus is also controlled to execute the correction. Second image forming apparatus The control unit receives the correction permission notification from the control unit of the first image forming apparatus, and controls to execute the correction as the second image forming apparatus. .

  (2) The invention according to claim 2 is characterized in that when only one image forming apparatus is in charge of image formation on the recording paper, the second image forming apparatus forms an image. An image forming system. In this case, the sheet is fed from the sheet feeding unit in the second image forming apparatus to form an image.

  (3) The invention according to claim 3 forms an image by sharing both sides of the recording paper between the first image forming apparatus and the second image forming apparatus. The image forming system according to claim 1, wherein the second image forming apparatus forms an image. In this case, the sheet is fed from the sheet feeding unit in the second image forming apparatus to form an image.

  (4) According to the invention of claim 4, when the second image forming apparatus notifies the first image forming apparatus of a correction start notification corresponding to the execution timing of correction, the first image forming apparatus The image forming system according to any one of claims 1 to 3, wherein the correction is executed for a type that is in a predetermined correction executable range.

  According to the present invention, the following effects can be obtained.

  (1) According to the first aspect of the present invention, in the tandem type image forming system in which a plurality of image forming apparatuses are connected in series so that an image can be formed by sharing any area of the recording paper, Upon receiving the correction start notification from the image forming apparatus, the first image forming apparatus determines whether the correction can be executed, and if correction can be executed, notifies the second image forming apparatus of a correction permission notification. At the same time, the first image forming apparatus also performs correction.

  As a result, in a state where a plurality of image forming apparatuses are connected in series, downtime can be minimized by executing correction simultaneously, and sharing of each image forming apparatus can be performed by executing correction simultaneously. Does not cause a change in image quality. That is, it is possible to match the image quality and color on the front and back of the recording paper.

  (2) In the second aspect of the present invention, when only one image forming apparatus is in charge of image formation with respect to the recording paper, the second image forming apparatus forms an image. The correction execution timing comes, and a correction start notification can be generated from the second image forming apparatus.

  Then, the first image forming apparatus that has received the correction start notification from the second image forming apparatus determines whether the correction can be executed. If the correction can be executed, the correction permission notification is sent to the second image forming apparatus. Since the first image forming apparatus performs correction as well as notifying the forming apparatus, downtime can be minimized by executing correction simultaneously, and each image can be executed by executing correction simultaneously. There is no change in image quality regarding the sharing of the forming apparatus.

  (3) In the invention described in claim 3, each of both sides of the recording paper is formed by the first image forming apparatus and the second image forming apparatus, and the second image is formed when only one side of the recording paper is used. When the image forming apparatus forms an image, the correction execution timing comes first on the second image forming apparatus side, and a correction start notification can be generated from the second image forming apparatus. Then, the first image forming apparatus that has received the correction start notification from the second image forming apparatus determines whether the correction can be executed. If the correction can be executed, the correction permission notification is sent to the second image forming apparatus. Since the first image forming apparatus performs correction as well as notifying the forming apparatus, downtime can be minimized by executing correction simultaneously, and each image can be executed by executing correction simultaneously. There is no change in image quality regarding the sharing of the forming apparatus.

  (4) In the invention according to claim 4, when the correction start notification is received from the second image forming apparatus, the first image forming apparatus performs the correction for the types within a predetermined correction executable range. By executing the correction at the same time in a lean state, the downtime can be minimized, and the image quality does not change with respect to the type for which the correction is performed at the same time.

1 is a block diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment of the present invention. 1 is a configuration diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment of the present invention. 1 is a configuration diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment of the present invention. It is explanatory drawing which shows operation | movement of the image forming apparatus of embodiment of this invention. 3 is a flowchart illustrating an operation of the image forming apparatus according to the embodiment of the present invention. 3 is a flowchart illustrating an operation of the image forming apparatus according to the embodiment of the present invention. 3 is a flowchart illustrating an operation of the image forming apparatus according to the embodiment of the present invention. It is explanatory drawing which shows operation | movement of the image forming apparatus of embodiment of this invention. It is explanatory drawing which shows operation | movement of the image forming apparatus of embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.

  Here, an image forming system in which a plurality of image forming apparatuses are connected in tandem so that an image can be formed by sharing either the front or back side of a recording sheet or a page, and used in this image forming system. An image forming apparatus will be described.

<Configuration of image forming apparatus and image forming system>
1-4, as an embodiment of the present invention, a plurality of image forming apparatuses 100 and 300 are connected in series so that an image can be formed by sharing either the front or back side of a recording sheet or an area in a page. A serial tandem image forming system will be described. Here, a state in which two image forming apparatuses, the image forming apparatus 100 and the image forming apparatus 300, are connected in series is shown as a specific example, but three or more image forming apparatuses may be connected.

  Here, the image forming apparatus for forming an image by sharing the recording paper from the paper feeding device 50 that supplies a large amount of recording paper to the image forming apparatus, the front or back of the recording paper from the paper feeding device 50, or a page area. The intermediate processing apparatus 200 that performs intermediate processing such as reversal on the recording paper on which the image is formed by the apparatus 100 and the image forming apparatus 100 and then supplies the recording paper from the intermediate processing apparatus 200 to the subsequent image forming apparatus 300. Alternatively, the image forming apparatus 300 for forming an image by sharing any area in the page, and various post-processing (punch processing, stapling processing, binding processing, inversion processing, etc.) on the recording paper on which the image is formed by the image forming apparatuses 100 and 300 The post-processing device 400 that performs the above is connected in series along the flow of the recording paper.

  Note that “serial” means a state in which the image forming apparatuses are connected so that the recording paper on which the image forming apparatus 100 forms an image is continuously formed by the image forming apparatus 300.

  That is, as shown in FIGS. 2 and 3, the image forming apparatuses 100 and 300 are connected in series with the flow of the recording paper, and the image forming apparatus 100 in the previous stage forms an image in a partial area. In the image forming system, the recording sheet is continuously input to the subsequent image forming apparatus 300, and the subsequent image forming apparatus 300 forms an image on another area of the recording sheet.

  Here, the partial area and the other area may be different areas on the same side of the recording paper, but in the following description, one side and the other side of the recording paper are taken as specific examples.

  According to such an image forming system, the recording paper is reversed by the intermediate processing device 200 arranged in the middle, and the two image forming devices 100 and 300 perform image formation on the front and back of the recording paper, respectively. There is an advantage that a stable output is possible.

  In this case, as shown in FIG. 3A, the front-side image forming apparatus 100 forms the front image on the recording paper first, the recording paper is reversed by the intermediate processing device 200, and the subsequent-stage image is formed. By forming an image on the back side of the recording paper with the forming apparatus 300, the recording paper is output as a face-down in which the image on the front side faces downward. Although not shown in the drawing, the back side image is first formed on the recording paper by the preceding image forming apparatus 100, the recording paper is reversed by the intermediate processing apparatus 200, and further, the recording paper is recorded by the subsequent image forming apparatus 300. On the other hand, by forming a surface image, the recording paper can be output as a face-up with the surface image facing upward.

  In this embodiment, an image on the first side that precedes in the page order on the recording paper is referred to as a front side, and an image on the second side that follows in the page order on the recording paper is referred to as a back side.

  When forming an image only on one side of the recording paper, as shown in FIG. 3B, the recording paper is fed from the paper feeding unit in the subsequent image forming apparatus 300 to form an image. The shortest path is the entire path from paper feed to image formation to paper discharge. In addition, when the single-sided image formation is performed by the subsequent image forming apparatus 300 as described above, if there is any single-sided image formation in the double-sided image formation, the number of prints of the image forming apparatus 300 is the image forming system. More than device 100.

  In addition to the division between the front and back surfaces of the recording paper as described above, the image forming apparatuses 100 and 300 can share other areas such as upper and lower or left and right within the same page of the recording paper. The image forming apparatuses 100 and 300 can share the image formation of different colors such as the normal color and the spot color within the same page of the paper, and further, characters (monochrome) within the same page of the recording paper. It is also possible for the image forming apparatuses 100 and 300 to share image formation with different gradations such as the image (gradation image). Also in this case, by causing the image forming apparatus 300 to take charge of image formation using only one of the shared image forming apparatuses, the shortest path for all of the paper feeding, image forming, and paper discharging paths is achieved. The number of prints is larger than that of the image forming apparatus 100.

  Hereinafter, the detailed configuration of each apparatus in the image forming system will be described.

  The paper feeding device 50 includes a control unit 51 that controls each unit in the paper feeding device 50, a communication unit 52 for communicating with the image forming apparatus 100 that is a paper feeding destination, and an image of a large amount of accumulated transfer paper. And a sheet feeding unit 55 that feeds the forming apparatus 100 at a predetermined timing. Note that when the sheet feeding unit 55 is directly operated by control from the image forming apparatus 100 described later, the control unit 51 can be omitted. In addition, a paper feeding unit can be provided in the image forming apparatus 100 or the image forming apparatus 300, and the paper feeding device 50 can be omitted depending on the amount of recording paper used.

  The image forming apparatus 100 is a first image forming apparatus disposed in the preceding stage when connected in series tandem, and is used for communication with a control unit 101 that controls each unit in the image forming apparatus 100 and other connected devices. A communication unit 102, an operation display unit 103 for performing an operation input by a user and a state of the image forming apparatus 100, a paper feeding unit 105 for feeding the accumulated transfer paper at a predetermined timing, and an image forming unit A storage unit 130 that stores page data and various data, an image processing unit 140 that executes various image processes necessary for image formation, and an image forming unit 150 that executes image formation based on an image formation command and page data , And is configured.

  In the image forming system, a case where the preceding image forming apparatus 100 is a master (master unit) and has initiative, and the image forming apparatus 300 is a slave (slave unit) and has a subordinate role. For example, this relationship may be reversed.

  Further, as illustrated in FIG. 4, the control unit 101 notifies the image forming apparatus 300 of a correction permission notification when the correction can be executed in response to the correction start notification from the subsequent image forming apparatus 300. When the correction can be executed in response to the correction start notification from the correction permission notification unit 1011 and the subsequent image forming apparatus 300, the image forming apparatus 100 also generates an instruction for executing the correction. A correction execution unit 1012 and a correction information storage unit 1013 that stores correction information (correction type and correction content) accompanying a correction start notification from the image forming apparatus 300 are provided.

  Here, “correction” refers to adjustment or correction of each part of the image forming apparatus every time the number of prints reaches a predetermined number for types such as color registration correction, toner density correction, and gradation correction. This operation is performed to keep the color resist, toner density, gradation, etc. at a certain level. Regarding the correction, the type, details of correction, the number of prints for each type, and the like are stored in the correction information storage unit 1013, the storage unit 130, and the like.

  The “correction start notification” is a notification requesting the start of correction at the timing of executing the above-described correction.

  Further, the “correction permission notification” is a notification for permitting execution of correction when correction can be executed in response to the correction start notification described above.

  The intermediate processing apparatus 200 includes a control unit 201 that controls each unit in the intermediate processing apparatus 200, a communication unit 202 that communicates with the image forming apparatuses 100 and 300 that are processing partners, and an image forming apparatus 100 in the previous stage. An intermediate processing unit 205 that performs intermediate processing such as reversing the recording paper so that the formed recording paper is in a state suitable for image formation on the opposite surface of the recording paper in the subsequent image forming apparatus 300. Has been. When the middle processing unit 205 is directly operated by control from the image forming apparatus 100, the control unit 201 can be omitted.

  The image forming apparatus 300 is a second image forming apparatus that is arranged in a subsequent stage when connected in series tandem, and is used for communicating with a control unit 301 that controls each unit in the image forming apparatus 300 and other connected devices. A communication unit 302, an operation display unit 303 for performing an operation input by a user and a state of the image forming apparatus 300, a paper feeding unit 305 for feeding accumulated transfer paper at a predetermined timing, and an image forming unit A storage unit 330 that stores page data and various data, an image processing unit 340 that executes various image processes necessary for image formation, and an image forming unit 350 that executes image formation based on an image formation command and page data , And is configured.

  As shown in FIG. 4, the control unit 301 generates a correction start notification when the number of prints reaches a predetermined number, and a correction start notification unit 3011 that notifies the previous image forming apparatus 100 of the correction start notification. The image forming apparatus 300 includes a correction execution unit 3012 that generates an instruction for executing correction in response to a correction permission notification from the preceding image forming apparatus 100.

  The post-processing device 400 includes a control unit 401 that controls each unit in the post-processing device 400, a communication unit 402 that communicates with each device, and a control unit 401 on a recording sheet on which an image is formed by the image forming apparatuses 100 and 300. And a post-processing unit 405 that performs various post-processing (punch processing, stapling processing, binding processing, reversal processing, etc.) according to the above control. Note that when the post-processing unit 405 is directly operated by control from the image forming apparatus 100 or the image forming apparatus 300, the control unit 401 can be omitted.

<Operation of Image Forming Apparatus and Image Forming System (1)>
The operation of the first embodiment of the image forming system will be described below with reference to the flowchart of FIG. Here, a control flowchart of the image forming apparatus 100 by the control unit 101 and a control flowchart of the image forming apparatus 300 by the control unit 301 are shown side by side.

  First, the control unit 101 confirms whether there is page data to be image-formed (step S101 in FIG. 5). If page data does not exist (NO in step S101 in FIG. 5), the process ends. (End in FIG. 5).

  Similarly, the control unit 301 confirms the presence / absence of the correction permission notification (FIG. 5C) (step S201 in FIG. 5). If there is no correction permission notification (NO in step S201 in FIG. 5), the control unit 301 It is confirmed whether there is an image formation instruction (FIG. 5A) from the control unit 101 (step S202 in FIG. 5), and if there is no image formation instruction (NO in step S202 in FIG. 5), The process ends (end in FIG. 5).

  When there is page data to be image-formed (YES in step S101 in FIG. 5), the control unit 101 has a correction start notification (FIG. 5B) from the control unit 301 at the subsequent stage. (Step S102 in FIG. 5).

  If there is no correction start notification (NO in step S102 in FIG. 5), the control unit 101 confirms whether double-sided image formation or single-sided image formation (step S104 in FIG. 5).

  If double-sided image formation is performed (YES in step S104 in FIG. 5), the control unit 101 instructs each unit to execute image formation with the image forming apparatus 100 with respect to the front page data and also instructs the intermediate processing apparatus 200. 5 is given (step S105 in FIG. 5), and for the back page data, an image formation instruction is given to the control unit 301 so that the subsequent image forming apparatus 300 forms an image (step S106 in FIG. 5). FIG. 5 (a)).

  If it is single-sided image formation (NO in step S104 in FIG. 5), the control unit 101 does not form an image in the image forming apparatus 100, and the single-sided page data is as shown in FIG. An image forming instruction is given to the control unit 301 so that the subsequent image forming apparatus 300 forms an image (step S106 in FIG. 5, FIG. 5A).

  Then, the control unit 101 returns to the confirmation of the existence of page data to be image-formed (step S101 in FIG. 5) and repeats the above operation.

  The control unit 301 confirms whether an image formation instruction (FIG. 5A) exists from the control unit 101 in the preceding stage (step S202 in FIG. 5), and if an image formation instruction exists (FIG. 5). In step S202, YES, the control unit 301 instructs each unit to execute image formation with the image forming apparatus 300 for page data on the back side of double-sided image formation or on the front side of single-sided image formation (step in FIG. 5). S204). When executing single-sided image formation, the control unit 301 controls each unit of the image forming apparatus 300 so as to form an image by feeding paper from the paper feeding unit 305.

  At this time, the control unit 301 counts up the correction counter according to the number of prints (step S205 in FIG. 5). Since the correction counter is reset when correction is performed for each correction type (color registration correction, toner density correction, gradation correction, etc.), it is desirable to count up for each correction type.

  Here, the control unit 301 checks the number of prints counted by the correction counter, and determines whether each correction type has reached a predetermined number of sheets that is determined in advance, that is, whether the correction execution condition is satisfied (see FIG. 5 in step S206). If the correction execution condition is not met (NO in step S206 in FIG. 5), the control unit 301 returns to the confirmation of the presence or absence of the correction permission notification (FIG. 5C) (step S201 in FIG. 5). Repeat the operation.

  When the number of prints counted by the correction counter is confirmed and one of the correction types has reached a predetermined number of sheets and satisfies the correction execution condition (YES in step S206 in FIG. 5), the control unit 301 If no correction permission notification has already been generated for the correction type (NO in step S207 in FIG. 5), a correction permission notification is generated and notified to the control unit 101 in the previous stage (step in FIG. 5). S208, FIG. 5 (b)). The correction start notification includes, as correction start information, information such as a declaration that the correction is requested and a correction type to be executed. Then, the control unit 301 returns to the confirmation of presence / absence of the correction permission notification (step S201 in FIG. 5) and the image formation instruction confirmation (step S202 in FIG. 5), and repeats the above operations.

  While the control unit 101 returns to the subsequent image formation instruction (step S106 in FIG. 5) and returns to the page data existence confirmation (step S101 in FIG. 5) to repeat the above operation, When a correction start notification (FIG. 5B) is received from the control unit 301 at the subsequent stage (YES in step S102 in FIG. 5), it is determined whether correction can be started (step S103 in FIG. 5). ).

  Here, the case where correction can be started corresponds to the timing of a division such as a division of a copy unit or a division of a job unit in order to maintain image quality uniformity without causing a sudden change in image quality during image formation. Say to do.

  If it is the timing at which correction can be started (YES in step S103 in FIG. 5), the control unit 101 does not proceed to image formation and sends a correction permission notification (FIG. 5C) to the subsequent control unit 301. This is performed (step S107 in FIG. 5).

  If it is the timing when correction can be started (YES in step S103 in FIG. 5), the control unit 101 instructs each unit to perform the same correction as the correction type included in the correction start notification also in the image forming apparatus 100. (Step S108 in FIG. 5).

  The control unit 101 waits for reception of a correction completion notification from the subsequent control unit 301 (NO in step S109 in the figure), and after receiving the correction completion notification (YES in step S109 in FIG. 5), image formation is performed. The processing is resumed (step S101 in FIG. 5), and the above image forming processing operation is repeated.

  The control unit 301 notifies the correction start notification to the control unit 101 (step S208 in FIG. 5), returns to the correction permission notification confirmation (step S201 in FIG. 5), and repeats the above image forming processing operation. If a correction permission notification (FIG. 5C) is received from the previous control unit 101 (YES in step S201 in FIG. 5), an image formation instruction (FIG. 5) is received from the previous control unit 101. It is confirmed whether (a)) exists (step S203 in FIG. 5).

  The control unit 101 in the previous stage generates a correction permission notification as a case where correction of the timing of the division such as the division of the copy unit or the division of the job unit can be started (YES in step S103 in FIG. 5, S107). There are cases where image formation is performed on the recording paper from the image forming apparatus 100 at the preceding stage on the side of the image forming apparatus 300 at the subsequent stage or single-sided image formation is performed on the side of the image forming apparatus 300 (step in FIG. When YES in S203, the control unit 301 gives priority to image formation with an image formation instruction without interruption (step S204 in FIG. 5).

  In this case, if the correction start notification has already been notified, the control unit 301 does not need to notify again (YES in step S207 in FIG. 5). However, by executing image formation, if the predetermined number of corrections for another type of correction has been reached and the correction execution condition is satisfied (YES in step S206 in FIG. 5), a correction permission notification is generated. This is notified to the control unit 101 in the previous stage (step S208 in FIG. 5, FIG. 5B).

  Then, when a correction permission notification (FIG. 5C) is received from the control unit 101 at the preceding stage (YES in step S201 in FIG. 5), an image formation instruction (FIG. 5 (FIG. 5) is received). a)) does not exist (NO in step S203 in FIG. 5), the control unit 301 performs the type of correction corresponding to the correction execution condition (YES in step S206 in FIG. 5). Each unit is instructed to be executed at 300 (step S209 in the figure). Here, when the correction in the image forming apparatus 300 is completed, the control unit 301 notifies the control unit 101 of a correction completion notification (FIG. 5D) (step S210 in the figure). Then, the control unit 301 returns to the confirmation of presence / absence of the correction permission notification (step S201 in FIG. 5) and the image formation instruction confirmation (step S202 in FIG. 5), and repeats the above operations.

  As described above, in a state where a plurality of image forming apparatuses are connected in series, downtime can be minimized by executing correction simultaneously, and each image forming apparatus can be executed by executing correction simultaneously. There is no change in the image quality with respect to the sharing. That is, it is possible to match the image quality and color on the front and back of the recording paper.

  In addition, since the subsequent image forming apparatus 300 is in charge of single-sided image formation, the correction execution timing comes first on the image forming apparatus 300 side, and a correction start notification can be generated from the image forming apparatus 300. Become.

  Then, it is determined whether or not the correction can be executed by the preceding image forming apparatus 100 that has received the correction start notification from the subsequent image forming apparatus 300. In addition to notifying the forming apparatus 300 and executing the same correction as the image forming apparatus 100, downtime can be minimized by executing corrections simultaneously, and each correction can be performed simultaneously. There is no change in image quality regarding the sharing of the image forming apparatus.

<Operation of Image Forming Apparatus and Image Forming System (2)>
The operation of the second embodiment of the image forming system will be described below with reference to FIGS. In FIG. 6, similarly to FIG. 5, a control flowchart of the image forming apparatus 100 by the control unit 101 and a control flowchart of the image forming apparatus 300 by the control unit 301 are shown side by side.

  In FIG. 6, the same steps as those in FIG. 5 are denoted by the same step numbers, and redundant description is omitted.

  The control unit 101 sends a correction permission notification (FIG. 6C) to the subsequent control unit 301 at a timing when correction can be started with respect to the correction permission notification from the control unit 301 (YES in step S103 in FIG. 6). (Step S107 in FIG. 6), the image forming apparatus 100 does not execute all the corrections that are the same as the correction type included in the correction start notification, but performs correction of an appropriate type to be executed as the image forming apparatus 100. An instruction is given to each unit to be executed (step S108 ′ in FIG. 6).

  First, the control unit 101 acquires correction start information from the control unit 301 (step S1081 in FIG. 7). This correction start information may be notified from the control unit 301 together with the correction start notification, or may be requested by the control unit 101 from the control unit 301 after the correction start notification. Here, the correction start information is at least information about a correction type to be executed on the image forming apparatus 300 side as shown in FIG.

  Further, the control unit 101 acquires the remaining number of prints until the correction is executed for each correction type and the correction execution threshold (correction executable range) for each correction type (step S1082 in FIG. 7).

  The remaining number of prints until the correction is executed is a value from the current number of prints to the number of prints scheduled to be executed next time for each correction type. Here, since the number of remaining prints until the previous correction execution differs for each correction type, it is counted and managed for each correction type.

  The correction execution threshold is a threshold for determining that correction is performed if the number of remaining prints until the correction is executed does not completely reach 0, but is less than a predetermined range such as 100 sheets or 150 sheets. . The correction execution threshold value may be stored in advance in the storage unit 130 or may be set by an operator. This correction execution threshold value may be the same value for each correction type, or may be a different value.

  Then, for the correction type included in the correction start information, the control unit 101 compares the number of remaining prints until the correction is executed with the corresponding correction execution threshold (correction executable range) (step S1083 in FIG. 7). If the number of remaining prints until the correction is executed is equal to or less than the threshold (within the correction executable range) (YES in step S1084 in FIG. 7), the correction type is determined to be executed (step S1085 in FIG. 7). If the number of remaining prints until the correction is executed is not less than the threshold value (within the correction executable range) (NO in step S1084 in FIG. 7), it is determined that the correction type is not executed (in FIG. 7). End).

  In the case of FIG. 8, since the correction type included in the correction start information is color registration correction, for the color registration correction, the control unit 101 determines the remaining print number “90 sheets” until the correction is executed, and the correction executable range. Compare with “100 sheets or less”. In this case, since the remaining number of prints 90 before the color registration correction is performed is within the correction executable range 100, it is determined that “correction is executed”. Note that the toner density correction and the gradation correction are not included in the correction start information, and therefore are not judged and executed.

  In the case of FIG. 9, since the correction type included in the correction start information is toner density correction, the control unit 101 sets the remaining print number “180 sheets” until the correction execution and the correction executable range for toner density correction. Compare with "150 sheets or less". In this case, it is determined that “no correction is performed” because the remaining number of prints 180 until the correction for toner density correction is not less than the correction executable range 150. Note that the color registration correction and the gradation correction are not included in the correction start information, and therefore are not determined and are not executed.

  In this embodiment, the correction execution threshold (correction executable range) is wasteful when correction is executed with a large number of remaining prints until the correction is performed. If the correction is not executed even if the number of remaining prints until the execution is small, there is a difference in image quality between the image forming apparatus 300 that performs the correction and the image forming apparatus 100 that does not perform the correction. It is desirable to set the two meanings to be compatible with each other to prevent the difference in image quality.

  As described above, when a correction start notification is received from the subsequent image forming apparatus 300 in a state where a plurality of image forming apparatuses are connected in series, the preceding image forming apparatus 100 can execute a predetermined correction. By executing the correction for the types that are in the range, it is possible to minimize the downtime by simultaneously executing the corrections in a lean state, and the image quality for the types for which the corrections are performed at the same time. It does not cause change.

<Other embodiment (1)>
In the above description, the correction of the image forming apparatus 100 at the preceding stage is also performed at the same time as the correction timing of the image forming apparatus 300 at the subsequent stage. However, the present invention is not limited to this. For example, it is possible to perform the correction of the subsequent image forming apparatus 300 in accordance with the correction timing of the previous image forming apparatus 100. In this case, it is only necessary to determine whether the correction can be executed by counting the number of prints only on the image forming apparatus 100 side in the preceding stage.

<Other embodiment (2)>
In the above description, in FIGS. 8 and 9, only one correction type is included in the correction start information. However, the present invention is not limited to this. For example, when a plurality of corrections are to be executed simultaneously on the image forming apparatus 300 side, the correction start information may include a plurality of correction types.

DESCRIPTION OF SYMBOLS 50 Paper feeder 100 Image forming apparatus 101 Control part 102 Communication part 103 Operation display part 105 Paper feed part 130 Storage part 140 Image processing part 150 Image forming part 200 Middle processing apparatus 300 Image forming apparatus 301 Control part 302 Communication part 303 Operation display Section 305 sheet feeding section 330 storage section 340 image processing section 350 image forming section 400 post-processing apparatus

Claims (4)

A tandem type image forming system in which a plurality of image forming apparatuses are connected in series so as to be able to form an image by sharing any area of recording paper,
A first image forming apparatus including a control unit that determines whether the correction can be executed when a correction start notification requesting the start of correction is received;
A second image forming apparatus comprising a control unit for notifying the first image forming apparatus of a correction start notification when the correction execution timing for adjusting each part is met;
With
The control unit of the first image forming apparatus receives a correction start notification from the control unit of the second image forming apparatus and, when the correction can be executed, sends a correction permission notification to the second image forming apparatus. Notifying the image forming apparatus and controlling the first image forming apparatus to execute the correction,
The control unit of the second image forming apparatus receives the correction permission notification from the control unit of the first image forming apparatus, and controls to execute the correction as the second image forming apparatus.
An image forming system. When only one image forming apparatus is in charge of image formation for the recording paper, the second image forming apparatus forms an image.
The image forming system according to claim 1. The first image forming apparatus and the second image forming apparatus share images on both sides of the recording paper, and the second image forming apparatus forms an image when only one side of the recording paper is used.
The image forming system according to claim 1, wherein the image forming system is an image forming system. When the second image forming apparatus notifies the first image forming apparatus of a correction start notification corresponding to the correction execution timing,
In the first image forming apparatus, the correction is executed for a type that is in a predetermined correction executable range.
The image forming system according to claim 1, wherein the image forming system is an image forming system.

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