JP5397317B2 - Image forming apparatus and image stabilization method thereof - Google Patents

Description

  The present invention relates to an image forming apparatus and an image stabilization method thereof.

  Conventionally, in an image forming apparatus that includes an image forming unit and a post-processing unit that performs post-processing on an image-formed recording sheet, in order to stabilize the image quality for each predetermined reference processing number A technique for adjusting image quality is known (for example, see Patent Document 1).

  In Patent Document 1, image quality adjustment is performed regardless of the arrival of a preset reference processing number so that the time when the post-processing unit operates and the time when image quality adjustment is performed are synchronized.

JP 2007-33829 A

  However, in Patent Document 1, control is performed independently from when maintenance of the post-processing unit is performed and when image adjustment is performed. Since the post-processing unit cannot operate during maintenance of the post-processing unit, the image forming unit may not be able to form an image. In this case, in Patent Document 1, it is impossible to perform image quality adjustment in the image forming unit using the time for maintenance of the post-processing unit. Therefore, the time during which image formation cannot be performed occurs twice during the maintenance of the post-processing unit and the image quality adjustment, resulting in a reduction in productivity.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an image forming apparatus and an image stabilization method thereof that can improve productivity by reducing time during which image formation cannot be performed. is there.

  A first feature of the present invention is an image forming apparatus including an image forming unit that forms an image on a sheet and a post-processing unit that performs post-processing on the sheet on which the image is formed. The image forming apparatus performs an image stabilization process for stabilizing the image quality of an image formed by the image forming unit every time a preset parameter reaches a preset stabilization reference value. If the post-processing unit cannot operate and the image forming unit detects the occurrence of an inoperable time during which an image cannot be formed on the paper, the inoperable time is extracted, and the time required for the image stabilization process is extracted. It is determined whether or not to perform the image stabilization process by comparing with the unavailable time. Then, when it is determined that the image stabilization process is to be performed, the image stabilization process is performed in the unavailable time regardless of whether or not the parameter has reached the stabilization reference value.

  In the first feature of the present invention, it is determined whether or not the parameter has reached a stabilization possible range from a value lower than the stabilization reference value to the stabilization reference value, and the parameter falls within the stabilization possible range. Only when it is determined that the image has arrived, the image stabilization process may be performed in the unavailable time. Thereby, the increase in the number of times of image stabilization can be suppressed and productivity can be maintained.

  Further, in the first feature of the present invention, when the occurrence of the unavailable time is detected in a state where the parameter has not reached the stabilizing range, the parameter when the image forming job being executed at the time of detection is ended However, it may be determined whether or not the stabilization reference value is reached. Then, only when it is determined that the parameter at the end reaches the stabilization reference value, the image stabilization process may be performed in the unavailable time. By considering the job being executed, the downtime can be used more effectively.

  In addition, in the first feature of the present invention, when the occurrence of the unavailable time is detected in a state where the parameter does not reach the stabilization possible range, the image forming job being executed at the time of the previous detection and subsequent to this It may be determined whether or not the parameters when all other image forming jobs to be executed reach the stabilization reference value. Then, only when it is determined that the parameter at the end reaches the stabilization reference value, the image stabilization process may be performed in the unavailable time. The downtime can be used more effectively by considering not only the job being executed but also other jobs that are executed subsequently.

  In this case, the unavailable time set in advance for each user of the image forming apparatus and recorded in the image forming apparatus may be extracted. Accordingly, since the user can set in advance an incapable time during which the image forming unit cannot form an image on the paper, convenience for the user is improved.

  When receiving an emergency output instruction from the user, even if it is determined that the parameter reaches the stabilization possible range, it is not necessary to perform the image stabilization processing in the unavailable time. When an emergency output instruction is received from the user, the image forming process can be prioritized over the image stabilization process, and the convenience for the user is improved.

  If at least the unavailable time is longer than the time required for the image stabilization process, it may be determined that the image stabilization process is performed. Since the image stabilization process is completed when the post-processing unit becomes operable, it is possible to suppress a decrease in productivity.

  Furthermore, it may be determined that the image stabilization process is performed even when the time required for the image stabilization process is shorter than the time obtained by adding the predetermined time to the unavailable time. If the predetermined time elapses from when the post-processing unit can operate, the image stabilization process is completed, so that it is possible to suppress a decrease in productivity.

  A second feature of the present invention includes an image forming unit that forms an image on a sheet, and a post-processing unit that performs post-processing on the sheet on which the image is formed, and a stable parameter in which preset parameters are set in advance. This is an image stabilization method for an image forming apparatus that performs an image stabilization process for stabilizing the image quality of an image formed by an image forming unit every time the image formation reference value is reached. In this image stabilization method, when the post-processing device cannot be operated, the occurrence of an incapacity time in which the image forming unit cannot form an image on a sheet is detected, and the incapacity time is extracted. Then, the time required for the image stabilization process is compared with the extracted unavailable time to determine whether or not to perform the image stabilization process. If it is determined to perform the image stabilization process, the parameter is stable. Regardless of whether or not the image stabilization reference value has been reached, image stabilization processing is performed during the unavailable time.

  According to the image forming apparatus and the image stabilization method of the present invention, the image stabilization processing is performed to stabilize the image quality by using the incapacitated time during which the image forming unit cannot form the image on the paper. be able to. For this reason, it is possible to improve the productivity of the image forming apparatus by effectively using the unavailable time to reduce the time during which image formation cannot be performed.

1 is a front view illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention. It is a front view which shows the detailed internal structure of the post-processing part 300 of FIG. 3 is a flowchart illustrating an example of a procedure of image stabilization processing by a control unit included in the copier of FIG. 1. FIG. 4A to FIG. 4D are time charts for explaining the operational effects according to the embodiment of the present invention. It is a table which shows an example of the stabilization reference value, the range which can be stabilized, and time required for an image stabilization process preset for every image stabilization process. It is a table which shows an example of the occurrence of a downtime, and the downtime preset for every user. It is a table which shows an example of the down time preset for every paste temperature. Flowchart showing an example of a processing procedure when the occurrence of downtime is detected (YES in step S01 of FIG. 3) and the parameter does not reach the stabilizing range in step S05 of FIG. 3 (NO in step S05). It is.

  Embodiments of the present invention will be described below with reference to the drawings. In the description of the drawings, the same portions are denoted by the same reference numerals, and description thereof is omitted.

(First embodiment)
With reference to FIG. 1, the configuration of the image forming apparatus according to the first embodiment of the present invention will be described. An image forming apparatus according to an embodiment of the present invention reads an image formed on a document and acquires image information, and after forming an image on the photosensitive drum 1 based on the image information, The copier includes an image forming unit 100 that forms an image on a sheet S and a post-processing unit 300 that performs post-processing such as alignment and binding processing of the image-formed sheet S.

  The image forming unit 100 includes a rotating photosensitive drum 1, a charging unit 2 that uniformly charges the surface of the photosensitive drum 1, and an image exposure unit 3 that forms a latent image on the surface of the uniformly charged photosensitive drum 1. The developing unit 4 that forms a toner image on the surface of the photosensitive drum 1 on which the latent image is formed, the transfer unit 5A that transfers the toner image onto the paper S, and the paper S on which the toner image is formed are transferred from the photosensitive drum 1. A separation unit 5B for separating, a fixing unit 8 for performing a heat fixing process on the paper S, and a cleaning unit 6 for removing the developer remaining on the surface of the photosensitive drum 1 are provided.

  The image exposure unit 3 performs exposure scanning based on image data read from an original by irradiating the surface of the photosensitive drum 1 with a laser beam. As a result, a latent image is formed on the surface of the photosensitive drum 1. The developing unit 4 reversely develops this latent image. As a result, a toner image is formed on the surface of the photosensitive drum 1.

  On the other hand, the paper S stored in the paper storage unit 7A is fed to the transfer unit 5A. The transfer unit 5A transfers the toner image on the surface of the photosensitive drum 1 onto the paper S. Thereafter, the separation unit 5B separates the sheet S from the photosensitive drum 1, and the intermediate conveyance unit 7B conveys the separated sheet S to the fixing unit 8. The fixing unit 8 performs a heat fixing process on the paper S. Thereafter, the paper discharge unit 7C discharges the paper S to the post-processing unit 300. The cleaning unit 6 removes the developer remaining on the surface of the photosensitive drum 1 after the toner image is transferred onto the paper S by the transfer unit 5A.

  When image formation is performed on both sides of the paper S, the transport path switching plate 7 switches the transport direction of the paper S heat-fixed by the fixing unit 8 to the reverse transport unit 7E side different from the paper discharge unit 7C side. The reverse conveyance unit 7E reverses the front and back by switching back the paper S and conveys it again to the transfer unit 5A. The transfer unit 5A forms an image on the back surface of the paper S, and is discharged from the paper discharge unit 7C to the post-processing unit 300 via the fixing unit 8.

  The image reading unit 200 is arranged on the upper part of the image forming unit 100 and reads images formed on a set of originals to acquire image information. The image reading unit 200 includes an automatic document feeder that reads an image while moving the document.

  Although not shown in FIG. 1, the copying machine is provided with a control unit including a microcomputer for controlling the entire copying machine and an operation unit such as a touch panel for realizing a user interface.

  A detailed internal configuration of the post-processing unit 300 in FIG. 1 will be described with reference to FIG. The post-processing unit 300 includes an introduction unit 10 into which the image-formed paper S is introduced, a transport path 20 and a transport path 30 that transport the paper S, and an intermediate that stacks the paper S transported through the transport path 30. The stacker 40, a stapler 50 that performs binding processing on a plurality of sheets S stacked on the intermediate stacker 40, and a paper discharge unit 60 that discharges the sheets S stacked on the intermediate stacker 40 out of the post-processing unit 300. .

  The paper S discharged from the image forming unit 100 is introduced into the introduction unit 10. The switching gate 19 switches the transport destination of the introduced paper S between the transport path 20 and the transport path 30. Each of the conveyance path 20 and the conveyance path 30 includes a plurality of conveyance rollers R and guide members.

  A paper discharge roller 21 is disposed in the paper discharge portion of the conveyance path 20. The paper discharge roller 21 discharges the paper S transported through the transport path 20 onto the fixed paper discharge tray 22. A paper discharge roller 31 is disposed in the paper discharge portion of the conveyance path 30. The paper discharge roller 31 discharges the paper S transported through the transport path 20 onto the intermediate stacker 40. The intermediate stacker 40 includes a stacker discharge roller 41 as a discharge unit, a paper support base 42, a stopper 46, and a stacker alignment member 47.

  A plurality of sheets S can be stacked on the sheet support 42. The stacker aligning member 47 is made of, for example, a brush roller, and rotates to press the lower end of the sheet S against the stopper 46 to align a plurality of sheets S. A stapler 50 is provided at the lower right portion of the intermediate stacker 40. The stapler 50 performs a binding process on a plurality of sheets S stacked on the sheet support base 42. A paper discharge unit 60 is provided at the upper left of the intermediate stacker 40. The stacker discharge roller 41 discharges a plurality of sheets S collected on the sheet support base 42 to the sheet discharge unit 60.

  The paper discharge unit 60 includes a paper discharge roller pair 61 that discharges the paper S to the outside of the post-processing unit 300 and a paper discharge tray 63 on which the discharged paper S is stacked. The paper discharge tray 63 can be moved in the stacking direction to enable mass paper discharge. The paper discharge tray 63 can be translated in a range from an upper limit position indicated by a solid line in FIG. 2 to a lower limit position indicated by a dotted line in FIG.

  Next, image stabilization processing performed by the control unit provided in the copier of FIG. 1 will be described. The control unit has a function as a processing execution unit that performs an image stabilization process every time a preset parameter reaches a preset stabilization reference value.

  Here, examples of the “parameter” include the number of sheets on which image formation has been performed and the amount of change in the temperature of the image forming unit 100 since the image stabilization process performed last time. The “image stabilization process” is a process for stabilizing the image quality of the image formed by the image forming unit 100. For example, gamma performed on the image information acquired by the image reading unit 200 is used. Examples include correction adjustment, dmax correction adjustment, and registration correction adjustment.

  For example, as shown in FIG. 5, the processing execution unit performs gamma correction adjustment and dmax correction adjustment every time the number of sheets on which image formation has reached 5000 sheets. In addition, the process execution unit adjusts the registration correction every time the temperature of the image forming unit 100 has changed by ± 2 ° C. from the time of the previously performed image stabilization process.

  Furthermore, the control unit has functions as an impossible time occurrence detection unit, an impossible time extraction unit, a processing determination unit, and a range determination unit. The unavailable time occurrence detection unit detects the occurrence of an unavailable time (hereinafter referred to as “down time”) in which the image forming unit 100 cannot form an image on a sheet because the post-processing unit 300 cannot operate. The unavailable time extraction unit extracts this downtime. The process determination unit determines whether or not to perform the image stabilization process by comparing the time required for the image stabilization process with the downtime extracted by the unavailable time extraction unit. The range determination unit determines whether or not the parameter has reached a stabilization possible range from a value lower than the stabilization reference value to the stabilization reference value.

  Here, the “down time” includes a down time that occurs during execution of the image forming job, but does not include a down time that occurs simultaneously with the start-up of the copier.

  The process execution unit determines that the parameter has reached the stabilization reference value when it is determined by the range determination unit that the parameter has reached the stabilizing range and when the process determination unit has determined to perform the image stabilization process. Regardless of whether or not, image stabilization processing is performed in downtime.

  Specifically, the unavailable time occurrence detection unit detects an occurrence event of the downtime simultaneously with the occurrence of the downtime. As an occurrence event of downtime, for example, as shown in FIG. 6, temperature adjustment of the glue tank, replacement of staples of the stapler 50, replacement of punch waste, filling of the discharge tray 63, cover open, and replacement of the punch unit Etc. The glue tank is a tank that stores glue used when gluing the spine in the bookbinding process. The exchanging of punch scraps refers to exchanging scraps generated in the punching process for making holes in the paper. The full tank of the paper discharge tray 63 indicates a state where the paper discharge tray 63 has moved to the lower limit position indicated by the dotted line in FIG. The cover open indicates a state where a door attached to the front surface of the post-processing apparatus is opened. The replacement of the punch unit refers to replacement of a unit that performs punch processing.

  The downtime in the replacement of the staples of the stapler 50, the replacement of the punch waste, the full discharge tray 63, the cover open, and the replacement of the punch unit is related to the work time by the user, so a different time is set for each user. The That is, for each occurrence of downtime, a different downtime is preset for each user and recorded in the control unit. Further, different downtime can be set for each user (user A and user B in FIG. 6) according to the experience value of the user who performs the exchange work. Further, when waiting for the temperature rise of the glue tank, the downtime generated according to the temperature of the glue tank also changes. In this case, as shown in FIG. 7, a different down time may be set for each paste temperature.

  Based on the detected downtime occurrence event, the unavailable time extraction unit extracts a preset downtime with reference to, for example, the setting table shown in FIG. 6 or FIG.

  The process determining unit determines to perform the image stabilization process at least when the extracted downtime is longer than the time required for the image stabilization process. The process determination unit further determines that the image stabilization process is to be performed when the time required for the image stabilization process is shorter than a time obtained by adding a predetermined time (for example, 1 minute) to the extracted downtime. When the time required for the image stabilization process is equal to or longer than a time obtained by adding a predetermined time (for example, 1 minute) to the extracted downtime, it is determined that the image stabilization process is not performed.

  Here, the time required for the image stabilization process varies depending on the image stabilization process. For example, as shown in FIG. 5, in the case of gamma correction adjustment and dmax correction adjustment, the time required for image stabilization processing is 3 minutes, and in the case of registration correction adjustment, time required for image stabilization processing. Is 30 seconds. Similar to the downtime, the time required for the image stabilization process differs for each image stabilization process, and is preset by the user and recorded in the control unit.

  For example, as illustrated in FIG. 5, the range determination unit may stabilize the number of sheets on which image formation has been performed (an example of a parameter) from 4500 sheets to 5000 sheets, which is lower than 5000 sheets (stabilization reference value). It is determined whether or not the reachable range has been reached. In addition, the stabilization possible range from ± 1.5 ° C. to ± 2 ° C., in which the temperature change of the image forming unit 100 from the previous image stabilization processing is lower than ± 2 ° C. (stabilization reference value). It is determined whether or not.

  For example, let us consider a case in which a downtime occurs due to replacement of the staples of the stapler 50 in the state where the number of sheets on which image formation has been performed is 4600 while the user B is in use. According to FIG. 6, the downtime due to the replacement of the staple of the stapler 50 during use of the user B is 5 minutes. According to FIG. 5, 4600 sheets are within the stabilizing range for the gamma correction adjustment and the dmax correction adjustment. The downtime (5 minutes) due to the replacement of the staple of the stapler 50 is longer than the time (3 minutes) required for the gamma correction adjustment and the dmax correction adjustment. Therefore, in this case, the process execution unit performs the image stabilization process during downtime.

  In addition, a case where a downtime due to replacement of punch waste occurs in the state where the temperature change of the image forming unit 100 from the time of the previously performed image stabilization processing is + 1.7 ° C. during use of the user A will be considered. . According to FIG. 6, the downtime due to the exchange of punch scraps during use by user A is 30 seconds. According to FIG. 5, + 1.7 ° C. is within the stabilization possible range for the adjustment of the resist correction. The time required for exchanging punch scraps (30 seconds) is shorter than the time (1 minute 30 seconds) obtained by adding a predetermined time (for example, 1 minute) to the downtime (30 seconds) due to the adjustment of the resist correction. Therefore, in this case, the process execution unit performs the image stabilization process during downtime.

  Note that, for example, when an emergency output instruction is received from the user, such as when outputting a facsimile, the process determination unit may determine whether the parameter reaches the stabilizing range even if the range determination unit determines that the parameter It is determined that the stabilization process is not performed.

  With reference to FIG. 3, an image stabilization process will be described in a case where a non-operation time (down time) in which the image forming unit 100 cannot form an image on a sheet occurs due to the inability of the post-processing unit 300 to operate.

  (A) In step S01, it is monitored whether or not the post-processing unit 300 cannot operate, so that a downtime in which the image forming unit 100 cannot form an image on a sheet occurs. When the occurrence of the downtime and the occurrence event are detected (YES in S01), the process proceeds to step S03, and the downtime is extracted with reference to FIG. At this time, the user of the copying machine is specified at the time when the downtime occurs, and the downtime is extracted based on the specified user.

  (B) Proceeding to step S05, the number of sheets on which image formation has been performed and the image from the previous image stabilization process within the stabilizing range such as 4500 to 5000 sheets and ± 2 ° C. shown in FIG. It is determined whether a parameter such as a temperature change of the forming unit 100 has been reached. If it has reached (YES in step S05), the process proceeds to step S07. On the other hand, if it has not reached (NO in step S05), it is determined that the image stabilization process is not performed in the downtime detected in step S01, and the flow in FIG. 3 ends.

  (C) Proceeding to step S07, referring to FIG. 5 and FIG. 6, the time required for the image stabilization processing is compared with the downtime extracted in step S03. In step S09, it is determined whether or not to perform image stabilization processing. Specifically, when the downtime is longer than the time required for the image stabilization process, and when the time required for the image stabilization process is shorter than the time obtained by adding the predetermined time to the downtime, the image is displayed in the downtime. It is determined that the stabilization process is to be performed (YES in S09). On the other hand, when the time required for the image stabilization process is equal to or longer than the time obtained by adding the predetermined time to the downtime, it is determined that the image stabilization process is not performed in the downtime (NO in S09), and the flow of FIG. Ends. When an emergency output instruction is received from the user, it is determined that the image stabilization process is not performed in the downtime regardless of the comparison result between the downtime and the time required for the image stabilization process.

  (D) In step S11, image stabilization processing is executed during the downtime detected in step S01. Then, parameters such as the number of sheets on which image formation has been performed and the temperature change of the image forming unit 100 since the last image stabilization process are reset. Specifically, the temperature change of the image forming unit 100 is monitored again based on the temperature of the image forming unit 100 in step S11. In addition, the number of sheets on which image formation has been performed is set to zero and starts counting again.

  FIG. 4A shows image stabilization processing in the comparative example. In the comparative example, the downtime on the post-processing unit side and the image stabilization process are controlled independently. Therefore, even if a downtime on the post-processing unit side occurs in the stabilization possible range RS, the image stabilization process is not performed in this downtime, and the image stabilization process is performed when the stabilization reference value PT is reached. carry out. For this reason, the time during which image formation cannot be performed occurs twice during the downtime on the post-processing unit side and the image stabilization process, and productivity is reduced.

  FIG. 4B shows an image stabilization process in the first embodiment of the present invention. In the stabilization possible range RS, when the downtime on the post-processing unit side occurs, the downtime and the time required for the image stabilization process are compared, and the image stabilization process is performed during this downtime. Reset the parameters. Therefore, after that, when the image stabilization process is not performed, the image stabilization process is not performed when the stabilization reference value is reached. Therefore, the downtime can be effectively used to reduce the time during which image formation cannot be performed (FF in FIG. 4) and to improve the productivity of the copying machine.

  The control unit has a function as a range determination unit that determines whether or not the parameter has reached the stabilizing range RS, and the range determination unit determines that the parameter has reached the stabilization range Only in some cases, image stabilization processing is performed during downtime. Thereby, compared with the case where the range determination unit is not provided, an increase in the number of times of image stabilization can be suppressed, so that productivity can be maintained. Further, the toner consumption and power consumption can be reduced, and the life of the photoreceptor and the motor can be extended.

  As shown in FIG. 6, the user can set in advance a downtime during which the image forming unit 100 cannot form an image on a sheet, so that convenience for the user is improved.

  When receiving an emergency output instruction from the user, the control unit (processing determination unit) does not perform the image stabilization process in the downtime even when it is determined that the parameter reaches the stabilization possible range. As a result, when an emergency output instruction is received from the user, the image forming process can be prioritized over the image stabilization process, and the convenience for the user is improved.

  The control unit (processing determination unit) determines to perform the image stabilization process at least when the downtime is longer than the time required for the image stabilization process (S09). As a result, when the post-processing unit can operate, the image stabilization process is completed, so that it is possible to suppress a decrease in productivity.

  The control unit (process determination unit) further determines that the image stabilization process is to be performed when the time required for the image stabilization process is shorter than the time obtained by adding a predetermined time (1 minute) to the downtime (S09). ). As a result, if a predetermined time has elapsed since the post-processing unit can operate, the image stabilization processing has been completed, so that it is possible to suppress a decrease in productivity.

(Second Embodiment)
When the occurrence of downtime is detected, the image stabilization process may be performed based on the image forming job being executed even if the parameter does not reach the stabilizing range.

  FIG. 8 shows the processing procedure when the occurrence of downtime is detected (YES in step S01 of FIG. 3) and the parameter does not reach the stabilizing range in step S05 of FIG. 3 (NO in step S05). It is a flowchart which shows an example.

  (Ii) If the parameter does not reach the stabilizing range in step S05 of FIG. 3, the processing procedure of FIG. 8 is started. First, in step S21, parameters when an image forming job being executed when downtime is detected are calculated.

  (B) Proceeding to step S23, it is determined whether or not the parameter calculated in step S21 reaches the stabilization reference value. When the parameter calculated in S21 reaches the stabilization reference value (YES in S23), the process proceeds to S25. On the other hand, if the parameter calculated in S21 does not reach the stabilization reference value (NO in step S23), it is determined that the image stabilization process is not performed in the downtime detected in step S01, and the parameters shown in FIGS. The flow ends.

  (Ha) In step S25, image stabilization processing is executed during the downtime detected in step S01. Then, parameters such as the number of sheets on which image formation has been performed and the temperature change of the image forming unit 100 since the last image stabilization process are reset.

  As shown in FIG. 4C, when the occurrence of downtime is detected in a state where the parameters have not reached the stabilization possible range, the parameters when the image forming job JOB1 being executed at the time of the completion ends. Determines whether the stabilization reference value PT is reached or not. Only when the parameter at the end of the job reaches the stabilization reference value PT, the image stabilization process is performed in the downtime. By considering the job JOB1 being executed, the downtime can be used more effectively.

(Third embodiment)
Even when the occurrence of downtime is detected, even if the parameter does not reach the stabilizing range, based on the image forming job being executed and other image forming jobs executed subsequently, Image stabilization processing may be performed.

  The second embodiment is that, in step S21 in FIG. 8, parameters are calculated when the image forming job being executed at the time of downtime detection and all other image forming jobs subsequently executed are completed. The form is different. Other processing procedures are the same as those in the second embodiment, and a description thereof will be omitted.

  As shown in FIG. 4D, the parameters when the image forming job JOB1 being executed and the other image forming jobs JOB2 executed subsequently are finished reach the stabilization reference value PT. Determine whether or not. Then, only when the parameters when all jobs (JOB1, JOB2) have reached the stabilization reference value PT, the image stabilization process is performed in the downtime. By considering not only the job JOB1 being executed but also another job JOB2 executed subsequently, the downtime can be used more effectively.

(Other embodiments)
As described above, the present invention has been described in terms of three embodiments. However, it should not be understood that the description and drawings that form part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  The control unit may not have a function as a range determination unit that determines whether or not the parameter has reached the stabilizing range from a value lower than the stabilization reference value to the stabilization reference value. In other words, the step S05 may be omitted in FIG. In this case, when it is determined that the image stabilization processing is performed, the control unit (processing execution unit) reaches the stabilization range regardless of whether the parameter has reached the stabilization reference value. Regardless of whether or not, image stabilization processing is performed during downtime. Even in this case, an image stabilization process that stabilizes the image quality of the image is performed by using a down time in which the image forming unit 100 cannot form an image on a sheet because the post-processing unit 300 cannot operate. Can do. For this reason, it is possible to improve the productivity of the image forming apparatus by effectively using the unavailable time to reduce the time during which image formation cannot be performed.

  As an example of the post-processing unit 300, the case of performing alignment and binding processing of the sheet S on which the image is formed has been described. In addition to this, the second fixing processing, curl correction processing, and humidification performed to increase the gloss of the image. A post-processing unit that performs processing, punching processing, wrapping bookbinding processing, and spine pasting processing is included.

  In the table of FIG. 6, an example of downtime set for each user is shown, but other than this, a default value of downtime may be set in advance when the copying machine is manufactured. This saves the user from having to set downtime after manufacturing.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters according to the scope of claims reasonable from this disclosure.

100 Image forming unit 200 Image reading unit 300 Post-processing unit PT Stabilization reference value RS Stabilizable range

Claims (9)

An image forming apparatus including an image forming unit that forms an image on a sheet and a post-processing unit that performs post-processing on the sheet on which the image is formed.
A process execution unit that performs an image stabilization process for stabilizing the image quality of an image formed by the image forming unit each time a preset parameter reaches a preset stabilization reference value;
An impossible time occurrence detection unit that detects the occurrence of an unavailable time in which the image forming unit cannot form an image on a sheet because the post-processing unit cannot operate;
An unavailable time extracting unit for extracting the unavailable time;
A process determination unit that determines whether to perform the image stabilization process by comparing the time required for the image stabilization process and the impossible time extracted by the impossible time extraction unit;
When the process determination unit determines that the image stabilization process is performed, the process execution unit performs the image stabilization process in the unavailable time regardless of whether the parameter has reached the stabilization reference value. An image forming apparatus comprising: A range determination unit for determining whether or not the parameter has reached a stabilization possible range from a value lower than the stabilization reference value to the stabilization reference value;
2. The image processing unit according to claim 1, wherein the processing execution unit performs an image stabilization process in the impossible time only when the range determination unit determines that the parameter has reached the stabilizing range. The image forming apparatus described.   A range determination unit for determining whether or not the parameter has reached a stabilization possible range from a value lower than the stabilization reference value to the stabilization reference value;
  In the state where the parameter has not reached the stabilization possible range, when the impossible time occurrence detection unit detects the occurrence of the impossible time, the range determination unit ends the image forming job being executed at the time of the detection. Determining whether the parameter at the time of reaching the stabilization reference value,
  The process execution unit performs the image stabilization process in the unavailable time only when the range determination unit determines that the parameter reaches the stabilization reference value.
  The image forming apparatus according to claim 1.   A range determination unit for determining whether or not the parameter has reached a stabilization possible range from a value lower than the stabilization reference value to the stabilization reference value;
  In a state where the parameter has not reached the stabilizing range, when the impossible time occurrence detection unit detects the occurrence of an impossible time, the range determination unit is configured to execute an image forming job being executed at the time of the detection and the image forming job. Determining whether or not the parameters when all other image forming jobs to be executed subsequently reach the stabilization reference value;
  The process execution unit performs the image stabilization process in the unavailable time only when the range determination unit determines that the parameter reaches the stabilization reference value.
  The image forming apparatus according to claim 1.   5. The image according to claim 1, wherein the unavailable time extracting unit extracts the unavailable time set in advance for each user of the image forming apparatus and recorded in the image forming apparatus. 6. Forming equipment.   When receiving an emergency output instruction from the user, the process execution unit performs image stabilization processing in the unavailable time even when the range determination unit determines that the parameter reaches the stabilization range. The image forming apparatus according to claim 2, wherein the image forming apparatus is not performed.   The said process determination part determines that the said image stabilization process is performed at least when the said impossibility time is longer than the time required for the said image stabilization process. The image forming apparatus described in the item.   The process determination unit further determines that the image stabilization process is to be performed when a time required for the image stabilization process is shorter than a time obtained by adding a predetermined time to the unavailable time. Item 8. The image forming apparatus according to Item 7. An image forming unit that forms an image on a sheet and a post-processing unit that performs post-processing on the sheet on which the image has been formed, each time a preset parameter reaches a preset stabilization reference value, An image stabilization method for an image forming apparatus that performs an image stabilization process for stabilizing an image quality of an image formed by the image forming unit,
When the post-processing device cannot operate, the occurrence of an incapacitating time in which the image forming unit cannot form an image on paper is detected,
Extracting the impossibility time;
Compare the time required for the image stabilization process with the extracted unavailable time to determine whether to perform the image stabilization process,
When it is determined that the image stabilization process is to be performed, the image stabilization process is performed in the unavailable time regardless of whether the parameter has reached the stabilization reference value or not. Stabilization method.

Images