JP6488926B2 - Image forming apparatus and image forming control method - Google Patents

Description

  The present invention relates to an image forming apparatus and an image forming control method, and more particularly to an image forming apparatus including an output material reading unit that reads an image of a sheet on which an image is formed by an image forming unit, and a control method therefor.

  There is an image forming apparatus that connects an output reading unit configured with an inline sensor or the like downstream of an image forming unit that forms an image on a sheet and reads an image on the sheet on which an image has been formed. In addition, there is an image forming system in which a reading device (output material reading device) is connected to a subsequent stage of an image forming device that forms an image on a sheet, and an image on the sheet on which an image is formed is read by the reading device.

Such an image forming apparatus or image forming system has a function of referring to a reading result after image formation and adjusting an image forming position and image quality (color, density, line width, etc.).
Note that an in-line sensor used in the output reading unit uses a CCD or CIS as an image sensor. These image sensors require calibration such as gain correction for adjusting the sensitivity of the element with the white reference plane and shading correction for correcting the light amount unevenness of the lamp before reading the image. In addition, since the light amount of the lamp may decrease and the color may change due to the temperature rise due to the heat generated by the lamp, periodic calibration with the white reference surface is required even during continuous reading of paper.

  However, since the white reference surface is a calibration reference, it is essential to prevent contamination. For this reason, it is necessary to place the white reference surface at the reading position only during calibration, and to evacuate the white reference surface and place another paper passing surface at the reading position during the other periods (when reading an image and passing paper). is there.

  As this type of technology, various related proposals have been made in the following patent documents.

JP 2002-305633 A

Patent Document 1 described above describes that shading correction is executed when a predetermined time has elapsed since the previous shading correction.
By the way, in order to perform the shading correction, it is necessary to move the retracted white reference plane to the reading position.

  For example, a white reference surface and a paper passing surface are formed on a prism whose longitudinal direction is the reading direction of the inline sensor, and the white reference surface is arranged at the reading position at the time of shading correction by rotating this prism so that shading is performed. A sheet passing surface is arranged at the reading position except during correction.

Here, in order to move the retracted white reference plane to the reading position, a movement time for mechanically moving the white reference plane is required. In the above specific example, it takes time to rotate the prism.
In recent high-productivity image forming apparatuses, it is difficult to execute calibration of an output object reading unit such as shading correction and gain correction by setting the above white reference plane during the inter-paper period during execution of a print job. .

For this reason, it is necessary to widen the sheet interval (inter-paper period), but it is not desirable to temporarily stop image formation during continuous reading and widen the inter-paper interval every time calibration is performed, because this leads to a decrease in productivity.
An object of the present invention is to realize an image forming apparatus and an image forming control method capable of suppressing a decrease in productivity by executing calibration of an output object reading unit at an appropriate timing.

That is, the present invention for solving the above-described problems is as follows.
(1) An image forming apparatus or an image forming control method reflecting one aspect of the present invention includes an image forming unit that forms an image on a sheet, and an output that reads the image formed on the sheet by the image forming unit. Controls reading unit and image formation by image forming unit, reading by output object reading unit, multiple types of adjustment in image forming unit based on reading result by output object reading unit, and calibration in output object reading unit A control unit that performs the calibration in the output object reading unit that is performed between sheets during a job execution, and the type of adjustment that is performed in the image forming unit. Whether or not the calibration is necessary is determined according to the control, and whether or not the calibration is executed is controlled according to the determination result.

(2) In the above (1), the control unit sets the necessity of the calibration in a table in each of a plurality of types of adjustments, and refers to the setting of the table to determine the necessity of the calibration. It is characterized by determining.
(3) In the above (1) to (2), the control unit previously determines an adjustment interval from the execution of the calibration until the next execution becomes necessary in each of a plurality of types of adjustments. In each of a plurality of types of adjustments, an elapsed time from the previous execution of the calibration is calculated, and when the elapsed time exceeds the adjustment interval, the calibration is executed. Features.

(4) In the above (3), the control unit determines whether or not the calibration is necessary when starting the adjustment.
(5) In the above (3) to (4), the output reading unit includes a light source that illuminates the reading position of the paper and an inline sensor that reads an image at the reading position illuminated by the light source. The control unit changes the adjustment interval until a predetermined time elapses from the start of lighting of the light source.

  (6) In the above (3) to (5), whether or not there is any of the adjustments scheduled to be executed until the next time the calibration is executed, at the time of executing the calibration. If there is any of the adjustments scheduled to be performed until the next time the calibration is performed, control is performed so as to advance the execution timing of the adjustment scheduled to be performed. And

(7) In the above (6), when the difference between the timing of executing the calibration next and the timing of executing the adjustment is within a certain range, the control unit Control is performed so that the execution timing is advanced.
(8) In the above (1) to (7), the control unit determines the number of read lines from the start of execution of calibration to the end of execution according to the type of adjustment performed in the image forming unit. It is characterized by that.

  (9) In the above (1) to (8), the output object reading unit is configured to be able to read the images formed on both sides of the paper, and the control unit is configured to be on one side of the paper. The single-sided calibration control for executing the calibration of the output object reading unit for the reading of the sheet and the double-sided calibration control for performing the calibration of the output object reading unit for the reading of both sides of the paper are possible. If the timing for executing the double-sided calibration is within a predetermined range, the control is performed so that the double-sided calibration is executed instead of the single-sided calibration.

According to the present invention, the following effects can be obtained.
(1) In the image forming apparatus or the image forming control method in which one aspect of the present invention is reflected, an adjustment performed in the image forming unit for calibration such as shading correction in the output object reading unit performed between sheets during job execution. The output reading unit can be calibrated at an appropriate timing to determine whether or not calibration is necessary according to the type of output and control whether or not to perform the calibration according to the determination result. It becomes possible to suppress the deterioration of the property.

  (2) In the above (1), for each of a plurality of types of adjustments, the necessity of calibration is set in a table, and the necessity of calibration is determined based on the table settings. Therefore, it is possible to calibrate the output reading unit at an appropriate timing, and it is possible to suppress a decrease in productivity.

  (3) In the above (1) to (3), for each of a plurality of types of adjustments, an adjustment interval from the execution of calibration until the next execution becomes necessary is determined in advance. To calculate the elapsed time from the previous calibration, and to control the calibration when the elapsed time exceeds the adjustment interval, each type of adjustment is adjusted based on the adjustment interval. Calibration of the output reading unit can be executed reliably at an appropriate timing, and it becomes possible to suppress a decrease in productivity.

(4) In the above (3), in order to determine whether or not calibration is necessary when starting the adjustment, it is possible to calibrate the output reading unit at an appropriate timing without waste for each of the plurality of types of adjustment. It is possible to suppress a decrease in productivity.
(5) In the above (3) to (4), since the adjustment interval is changed until a predetermined time has elapsed since the start of lighting of the light source of the output object reading unit, the output is surely performed at an appropriate timing based on the adjustment interval. The object reading unit can be calibrated, and the output material reading unit can be reliably calibrated at an appropriate timing according to the lighting state of the light source, so that a reduction in productivity can be suppressed.

  (6) In the above (3) to (5), at the time of executing calibration, it is checked whether there is any adjustment to be executed until the next time of executing calibration, and then the calibration is performed. If there is any adjustment that is scheduled to be executed by the time it is executed, a single calibration is required for a plurality of adjustments in order to control the execution timing of the adjustment that is scheduled to be executed earlier. Therefore, calibration of the output object reading unit can be suppressed to a small number of times, and a decrease in productivity can be suppressed.

  (7) In the above (6), when the difference between the timing for executing the next calibration and the timing for executing the adjustment is within a certain range, control is performed so as to advance the execution timing of the adjustment to be executed. Therefore, it is possible to properly associate a plurality of adjustments and complete the calibration with a single calibration for the plurality of adjustments. Therefore, it is possible to suppress the calibration of the output object reading unit to a small number of times, thereby suppressing a decrease in productivity. Become.

(8) In the above (1) to (7), in order to determine the number of reading lines from the start of execution of calibration to the end of execution according to the type of adjustment performed in the image forming unit, the output product reading unit is calibrated. It can be suppressed in a short time, and it becomes possible to suppress a decrease in productivity.
(9) In the above (1) to (8), if the timing for executing double-sided calibration is within a predetermined range at the timing for executing single-sided calibration, control is performed so that double-sided calibration is executed instead of single-sided calibration. Therefore, single-sided calibration and double-sided calibration can be completed by one-sided double-sided calibration. Therefore, calibration of the output object reading unit can be suppressed to a small number of times, and a decrease in productivity can be suppressed.

It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of embodiment of this invention. It is a block diagram which shows the structure of the principal part of embodiment of this invention. It is a block diagram which shows the structure of the principal part of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a block diagram which shows an example of the table used by embodiment of this invention. It is a block diagram which shows an example of the table used by embodiment of this invention. It is a block diagram which shows an example of the table used by embodiment of this invention. It is explanatory drawing which shows an example of the patch of embodiment of this invention. It is explanatory drawing which shows an example of the patch of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a block diagram which shows an example of the table used by embodiment of this invention. It is a block diagram which shows an example of the table used by embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a block diagram which shows an example of the table used by embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention. It is a block diagram which shows an example of the table used by embodiment of this invention. It is a block diagram which shows an example of the table used by embodiment of this invention.

In the following, an embodiment of reading an image formed on an image forming apparatus and an image formed and output in the image forming apparatus with necessary image quality without waste will be described in detail with reference to the drawings.
[Configuration of image forming apparatus]
Here, a first configuration example of the image forming apparatus will be described in detail with reference to FIGS. 1 and 2. 1 and 2, an image forming apparatus 100 capable of reading an image-formed sheet (output product) will be described.

  Here, the image forming apparatus 100 includes a control unit 101 that controls each unit in the image forming apparatus 100, a communication unit 102 for communicating with other connected apparatuses, an operation input by a user, and an image forming apparatus. An operation display unit 103 for displaying a status of 100, a storage unit 104 for storing various settings, a paper feed unit 105 capable of feeding paper stored in a paper feed tray, and transport for transporting paper in the apparatus Unit 107, document reading unit 110 that reads a document, image data storage unit 130 that stores image data and various types of data when forming an image, image processing unit 140 that executes various types of image processing necessary for image formation, An image forming unit 150 that forms an image on a sheet based on an image formation command and image data, a fixing unit 160 that stabilizes an image formed by toner formed on the sheet with heat and pressure, and a shape formed on the sheet. And is configured to include an output object reading unit 190 for reading an image, a.

  As shown in FIG. 2, the image forming unit 150 develops the electrostatic latent image formed on the charged image carrier to become a toner image, and the toner images of the respective colors are superimposed on the intermediate transfer member. This is a so-called electrophotographic image forming unit that is transferred to a sheet afterwards. However, the specific configuration of the image forming unit 150 is not limited to that shown in FIG.

  The output product reading unit 190 reads an image formed on a sheet, and is arranged on the downstream side of the image forming unit 150 and the fixing unit 160, and is configured to read an image during sheet conveyance. Yes. Note that the output product reading unit 190 may be disposed in an intermediate processing device or a post-processing device at the subsequent stage of the image forming apparatus 100.

The output object reading unit 190 includes an output object reading unit 190a that reads an image on one side of a sheet and an output object reading unit 190b that reads an image on the other side of the sheet.
Such an image forming apparatus 100 has a function of adjusting an image forming position and image quality (color, density, line width, etc.) with reference to a reading result after image formation, and an output product reading unit 190. Is read to the control unit 101.

Here, with reference to FIG. 3 and FIG. 4, a schematic configuration of the output material reading unit 190 will be described. Here, the configuration of the output product reading unit 190a will be described, but the basic configuration of the output product reading unit 190b is the same except that the reading surface is different.
FIG. 3 shows the output object reading unit 190a other than during calibration, that is, in a state such as normal image formation, standby, and stop. A line sensor 1910 is arranged on the surface to read the paper, and a counter plate 1920 is arranged on the back side of the paper, with a conveyance path 1930 for conveying the paper.

Here, the line sensor 1910 and the counter plate 1920 are configured to have a length that covers the maximum width of the paper in the direction perpendicular to the paper surface.
The line sensor 1910 includes a lamp 1911 that illuminates the vicinity of the reading surface of the paper, a dust-proof glass 1912 that prevents paper dust from adhering to the image sensor, a mirror 1913 that guides read light to the image sensor, and photoelectric conversion of the read light The imaging element 1914 is configured to be provided.

The counter plate 1920 is disposed on the back side of the sheet reading surface, and is calibrated so as to be rotatable about the longitudinal direction as a central axis while the vertical direction is the longitudinal direction.
The counter plate 1920 includes a sheet passing surface 1922 that supports a sheet from the back during sheet conveyance, and a white reference surface 19210 that is read as a white reference when the output reading unit 190a is calibrated. 3 shows states other than during calibration, that is, during normal image formation, standby, and stoppage, the opposing plate 1920 has the sheet passing surface 1922 facing the conveyance path 1930 side.

  FIG. 4 shows the output reading unit 190a in a state at the time of calibration. Here, since FIG. 4 shows a state at the time of calibration, the counter plate 1920 has the white reference surface 1921 facing the conveyance path 1930 side. That is, at the time of calibration, the line sensor 1910 reads the white reference surface 1921 instead of the paper. The white reference surface 1921 is configured to have uniform whiteness at a level that can be used for gain correction of each photoelectric conversion element included in the imaging element 1914.

  Here, the configuration is such that the sheet passing surface 1922 and the white reference surface 1921 are switched by the rotation of the counter plate 1920, but the present invention is not limited to this. For example, the sheet passing surface 1922 and the white reference surface 1921 may be provided on the same plane, and one of them may be arranged on the back surface of the sheet (reading position at the time of calibration) by sliding.

[Operation of Image Forming Apparatus (1)]
Hereinafter, the operation (1) of the image forming apparatus 100 in the present embodiment will be described. Here, “adjustment” in this embodiment means image formation position adjustment and image quality adjustment using the reading result of the output object reading unit 190. It is assumed that there are a plurality of types of adjustments.

Further, in the present embodiment, “calibration” means image sensor gain correction and lamp light amount unevenness correction (shading correction) using the reading result of the white reference surface 1921 by the output object reading unit 190.
Note that the control unit 101 includes various tables (operation state management table (FIG. 6), adjustment management table (FIG. 7), calibration setting table (FIG. 8), calibration interval setting table (FIG. 13) shown in FIG. Various modes and states in the operating state are managed using the calibration line number setting table (FIG. 14). Note that these various tables are stored in the storage unit 104.

[Operation (1-1)]
First, the operation of the image forming apparatus 100 in the normal mode instead of the adjustment mode will be described first.
In this image forming apparatus 100, the control unit 101 sets the initial value N = 1 and the operation mode = normal printing mode as the page counter value N as the job processing start processing, and instructs the image forming unit 150 to start the job. Then, preparation for image formation is made (step S101 in FIG. 5).

In addition, the control unit 101 instructs preparation for reading by the output material reading unit 190 as part of the start processing. That is, the control unit 101 turns on the lamp 1911 and rotates the counter plate 1920 so that the sheet passing surface 1922 is on the conveyance path 1930 side.
Then, the control unit 101 sets the current time as the previous calibration time in the operation state management table (see FIG. 6) as part of the job process start process. Further, in order to make sure that calibration is performed in the next adjustment, the initial calibration of the operation state management table is set to YES.

  Further, the control unit 101 confirms whether or not adjustment is necessary for each of the plurality of adjustments (step S102 in FIG. 5). The detailed processing of the adjustment condition confirmation (step S102 in FIG. 5) will be described in detail later with reference to another flowchart.

The control unit 101 determines whether it is necessary to execute any of a plurality of adjustments (step S103 in FIG. 5). Here, the control unit 101 refers to the adjustment management table (FIG. 7), and determines that adjustment is necessary if there is even one adjustment that is set to need adjustment = YES.
In the specific example of FIG. 7, the adjustment necessary for front / back position correction and color registration correction = YES is set, so the control unit 101 determines that adjustment is necessary (YES in step S103 in FIG. 5). If adjustment is necessary for all adjustments in this adjustment management table = NO, the control unit 101 determines that adjustment is not necessary (NO in step S103 in FIG. 5).

Note that the adjustment mode selection (step S104 in FIG. 5) and subsequent steps will be described in detail later, and normal image formation will be described first.
When adjustment is necessary for all adjustments in the adjustment management table = NO and the control unit 101 determines that adjustment is not necessary (NO in step S103 in FIG. 5), the control unit 101 forms an image of the Nth page. The sheet feeding unit 105 and the image forming unit 150 are controlled to do so (step S109 in FIG. 5). Then, the control unit 101 advances the page counter N in the operation state management table by one page as preparation for the next page (step S110 in FIG. 5).

The control unit 101 determines whether or not the operation mode currently being executed by the image forming apparatus 100 is the adjustment mode (step S111 in FIG. 5). Note that the control unit 101 determines the current operation mode using the operation state management table (see FIG. 6).
If it is determined by the operation mode determination that the mode is not the adjustment mode but the normal mode (NO in step S111 in FIG. 5), the image forming unit 150 is executing the normal mode image formation. Is updated in the adjustment management table (FIG. 7) as the number of elapsed sheets after the previous adjustment = the number of elapsed sheets after the previous adjustment + 1 (step S114 in FIG. 5).

  The control unit 101 determines whether there is a page corresponding to the page counter N in the job, that is, whether there is a next page (step S115 in FIG. 5). If it is determined that there is a next page (YES in step S115 in FIG. 5), the control unit 101 returns to the adjustment condition confirmation (step S102 in FIG. 5) for processing the next page. If it is determined that there is no next page (NO in step S115 in FIG. 5), the control unit 101 instructs the paper feeding unit 105 and the image forming unit 150 to end the job, and ends the image forming process. In addition, the control unit 101 instructs the output product reading unit 190 to end reading, and turns off the lamp 1911.

[Operation (1-2)]
Hereinafter, the operation of the image forming apparatus 100 in the adjustment mode will be described. That is, when the control unit 101 refers to the adjustment management table (FIG. 7) and determines that adjustment is necessary (YES in step S103 in FIG. 5), it will be described below.

  The control unit 101 sets, in the operation state management table (FIG. 6), the adjustment mode determined to be necessary for adjustment with reference to the adjustment management table (FIG. 7). If it is determined that a plurality of adjustments are necessary, an adjustment having a high priority in the adjustment management table (FIG. 7) is selected and set as an adjustment mode (step S104 in FIG. 5).

Then, the control unit 101 determines whether calibration is necessary when executing the adjustment mode. Then, if necessary, calibration is executed (step S105 in FIG. 5). Details of this portion will be described in detail with reference to a separate flowchart.
The control unit 101 determines whether the selected adjustment mode is dedicated chart adjustment or dual-purpose chart adjustment with reference to the calibration setting table (FIG. 8) (step S106 in FIG. 5). In this calibration setting table, if dedicated chart adjustment = YES, dedicated chart adjustment is performed, and if dedicated chart adjustment = NO, dual chart adjustment is performed.

In the dual-purpose chart adjustment, adjustment patches and registration marks are printed outside the image to be printed as a job. The example of FIG. 9 shows a state in which a density correction or color correction chart is formed outside the image to be printed as a job.
In this case, the control unit 101 prepares the image data of the combined chart so that printing of the combined chart corresponding to the selected adjustment mode can be performed simultaneously with the printing of the image in the normal mode (step S109 in FIG. 5). (Step S108 in FIG. 5). Then, the control unit 101 controls the paper feeding unit 105 and the image forming unit 150 to form an image of the Nth page together with the surrounding dual-purpose chart (step S109 in FIG. 5).

  On the other hand, in dedicated chart adjustment, as shown in FIG. 10, only adjustment patches, registration marks, and the like are printed in the image forming unit 150 (step S107 in FIG. 5). FIG. 10 shows a specific example of a density correction chart. That is, the control unit 101 prepares dedicated chart adjustment data, controls the sheet feeding unit 105 and the image forming unit 150, and causes the dedicated chart to be printed.

  The control unit 101 refers to the operation state management table (see FIG. 6) to determine whether or not the operation mode currently being executed by the image forming apparatus 100 is the adjustment mode (step S111 in FIG. 5). If it is determined by the operation mode determination that the adjustment mode is selected (YES in step S111 in FIG. 5), the control unit 101 controls the output material reading unit 190 to read the chart printed on the paper (FIG. 5). Middle step S112).

  Note that the control unit 101 instructs one or both of the output material reading unit 190a and the output material reading unit 190b to read the chart depending on which side of the sheet the chart is printed. In addition, it is desirable that the control unit 101 detects a sheet conveyed on the conveyance path 1930 with a sheet detection sensor and instructs to start reading the chart.

  Then, the control unit 101 refers to the reading result in the output product reading unit 190 and adjusts each unit of the image forming unit 150 (step S113 in FIG. 5). More specifically, the control unit 101 calculates an adjustment value by performing an analysis corresponding to the adjustment mode based on the chart read by the output material reading unit 190. Then, when the calculated adjustment value is a normal value (within a normal range), the control unit 101 instructs the image forming unit 150 to set the calculated adjustment value. In addition, the control unit 101 sets the elapsed number of sheets after the previous adjustment in the adjustment management table (FIG. 7) = 0 for the adjustment item that has been implemented. For the adjustment that has not been performed, the number of elapsed sheets after the previous adjustment is updated to the number of elapsed sheets after the previous adjustment + 1.

[Operation (1-2-1)]
Hereinafter, detailed processing of the adjustment condition confirmation (step S102 in FIG. 5) of the basic flowchart will be described in detail with reference to the flowchart of FIG.
The control unit 101 confirms whether or not adjustment is necessary for each of the plurality of adjustments (step S102 in FIG. 5).

  At this time, the control unit 101 reads the adjustment management table (FIG. 7) (step S1021 in FIG. 11). In this adjustment management table, whether or not each adjustment of the image forming unit 150 preset by the user via the operation display unit 103 is stored for each adjustment type (“adjustment type” “adjustment” in FIG. 7). Presence or absence "). In addition, the number of sheets printed since each adjustment was last performed is counted and stored as the number of sheets that have elapsed since the last time adjustment ("elapsed sheets (sheets) after last adjustment" in FIG. 7).

  The control unit 101 determines whether or not the adjustment is effective (step S1022 in FIG. 11). Here, the control unit 101 refers to the adjustment management table (FIG. 7) and the calibration setting table (FIG. 8), and determines that the adjustment is valid when the presence / absence of adjustment = valid (YES in step S <b> 1022 in FIG. 11). ). On the other hand, if the presence / absence of adjustment = invalid, the control unit 101 determines that the adjustment is invalid (NO in step S1022 in FIG. 11), and sets no adjustment as described later (step S1028 in FIG. 11). .

When it is determined that the adjustment is valid (YES in step S1022 in FIG. 11), the control unit 101 refers to the adjustment management table (FIG. 7) and acquires the number of elapsed sheets after the previous adjustment (step S1023 in FIG. 11). ).
Then, the control unit 101 determines whether or not the number of elapsed sheets after the previous adjustment is equal to or greater than the adjustment interval (step S1026 in FIG. 11). Here, if the number of elapsed sheets after the previous execution ≧ the adjustment interval (YES in step S1026 in FIG. 11), the control unit 101 determines that adjustment of the image forming unit 150 is necessary, and an adjustment necessary flag in the adjustment management table = YES (adjustment is required) is set (step S1027 in FIG. 11). On the other hand, if the number of sheets elapsed since the previous implementation <the adjustment interval (NO in step S1026 in FIG. 11), the control unit 101 determines that adjustment of the image forming unit 150 is unnecessary, and an adjustment necessary flag in the adjustment management table = NO. (Adjustment unnecessary) is set (step S1028 in FIG. 11).

Further, the control unit 101 checks whether there is an adjustment item for which the adjustment condition has not been confirmed. If there is an adjustment item, the control unit 101 returns to step S1021, and if there is no adjustment item, the process ends (see the adjustment in FIG. 11). Section check end).
[Operation (1-2-2)]
Hereinafter, detailed processing of the calibration execution of the basic flowchart (step S105 in FIG. 5) will be described in detail with reference to the flowchart of FIG.

The control unit 101 refers to the operation state management table (FIG. 6) and confirms the initial calibration flag (step S1050 in FIG. 12).
Here, when the initial calibration = YES, the control unit 101 determines that the calibration is necessary (YES in step S1050 in FIG. 12), and proceeds to the following processing.

  The control unit 101 instructs the output object reading unit 190 to perform calibration, and also transmits a calibration start to the image forming unit 150, and executes calibration as follows (step S1057 in FIG. 12). Here, the image forming unit 150 that has received the start of calibration interrupts sheet feeding and image formation so that the sheet is not conveyed on the conveyance path 1930 during calibration.

  The control unit 101 rotates the counter plate 1920 so that the white reference surface 1921 is on the conveyance path 1930 side. The control unit 101 receives the output data of the output object reading unit 190 that has read the white reference surface 1921, performs gain correction and shading correction of the output object reading unit 190, and sets a calibration result. The control unit 101 performs the above calibration on the output product reading unit 190a and the output product reading unit 190b included in the output product reading unit 190.

  After the calibration is completed, the control unit 101 rotates the counter plate 1920 so that the sheet passing surface 1922 is on the conveyance path 1930 side. When the calibration is completed, the control unit 101 transmits calibration completion to the image forming unit 150. When receiving the completion of calibration, the image forming unit 150 resumes paper feeding and image formation.

Further, the control unit 101 updates the previous calibration time in the operation state management table (FIG. 6) to the current time (step S1058 in FIG. 12). Further, if the calibration executed this time is the first calibration, the control unit 101 sets the first calibration flag = NO.
If the initial calibration = NO in step S1050, the control unit 101 determines that the calibration is unnecessary by determining that the calibration has been performed at least once after the start of the job (NO in step S1050 in FIG. 12). Proceed to the following processing.

Here, the control unit 101 refers to the calibration setting table (FIG. 8), refers to the column of calibration necessity during job (“necessity of calibration during job” in FIG. 8) of the selected adjustment mode, and determines the job. It is determined whether intermediate calibration is necessary (step S1051 in FIG. 12).
If it is determined that calibration is required during the job (YES in step S1051 in FIG. 12), the process proceeds to the following process. On the other hand, if it is determined that calibration is not necessary during the job (NO in step S1051 in FIG. 12), the calibration is not performed, and the process is terminated (END in FIG. 12).

  When the adjustment type is front / back position correction or line width correction, the output object reading unit 190 only needs to detect the registration mark position. For this reason, the color accuracy may be low. Therefore, it can be considered that calibration during a job due to fluctuations in lamp light quantity is unnecessary. On the other hand, when the type of adjustment is color correction, the demand for color accuracy is stricter than density correction or the like. For this reason, it is necessary to frequently calibrate the output reading unit 190 to maintain high color accuracy. As described above, in this embodiment, whether or not calibration during a job is necessary or not is determined by the adjustment type.

Here, the control unit 101 calculates the elapsed time (calibration elapsed time) from the previous calibration from the difference between the previous calibration time and the current time in the operation state management table (FIG. 6) (step S1052 in FIG. 12).
Further, the control unit 101 refers to the calibration setting table (FIG. 8) and determines whether to apply the calibration interval coefficient to the current adjustment mode (step S1053 in FIG. 12). Although the calibration interval coefficient will be described later, it is a coefficient for temporarily changing the calibration interval when the lamp is not in a stable state immediately after lighting, etc. and is susceptible to the unstable state. is there.

  If calibration interval coefficient is applied in the calibration setting table of FIG. 8 (YES in step S1053 in FIG. 12), the control unit 101 proceeds to the processing from step S1054 onward in order to select and apply the calibration interval coefficient. . On the other hand, when the calibration interval coefficient is not applied in the calibration setting table of FIG. 8 (NO in step S1053 in FIG. 12), the control unit 101 assumes that the calibration interval coefficient is 1.0 and performs the processing after step S1056. move on.

  If the calibration interval coefficient is applied in the calibration setting table of FIG. 8 (YES in step S1053 in FIG. 12), the control unit 101 calculates the difference between the previous calibration time and the current time in the operation state management table (FIG. 6). Then, an elapsed time from the start of lamp lighting is calculated (step S1054 in FIG. 12).

  The control unit 101 selects a calibration interval coefficient corresponding to the elapsed time since the lamp is lit with reference to the calibration interval coefficient table (FIG. 13) (step S1055 in FIG. 12). This is because the time from when the lamp is lit until the lamp temperature is stabilized varies greatly in color, so it is necessary to reduce the calibration interval and increase the execution frequency. Here, although the calibration interval is selected based on the lamp lighting time, it is desirable to select the calibration interval coefficient in the same manner if there is another part that requires time to reach a stable state.

  Then, the control unit 101 refers to the calibration setting table (FIG. 8), and determines whether or not “elapsed time from previous calibration ≧ calibration interval in current adjustment mode” (step S1056 in FIG. 12). The calibration interval in the current adjustment mode is multiplied by the calibration interval coefficient selected as described above.

  Then, the control unit 101 refers to the calibration setting table (FIG. 8), and if “elapsed time from previous calibration ≧ calibration interval in current adjustment mode” (YES in step S1056 in FIG. 12), the calibration is performed. It is determined that it is necessary, and the process proceeds to the following calibration (step S1057 in FIG. 12). Note that after the calibration is performed, the control unit 101 updates the previous calibration time in the operation state management table (FIG. 6) to the current time (step S1058 in FIG. 12).

On the other hand, the control unit 101 refers to the calibration setting table (FIG. 8), and if “elapsed time from previous calibration ≧ calibration interval in current adjustment mode” is not satisfied (NO in step S1056 in FIG. 12), calibration is not necessary. And the process ends (END in FIG. 12).
In the above calibration execution (step S1057 in FIG. 12), it is desirable to change the number of reading lines on the calibration surface according to the type of adjustment, instead of making the number of reading lines on the calibration surface constant.

  That is, as shown in FIG. 14, the number of lines read by the output material reading unit 190 may be determined according to the accuracy of calibration required according to the type of adjustment. If high-precision calibration is required, the number of read lines is increased, and if high-precision calibration is not required, the number of read lines is reduced. As a result, the calibration of the output object reading unit 190 can be suppressed in a short time, and a reduction in productivity can be suppressed.

[Operation (1-3)]
In the above description of the present embodiment, when a plurality of adjustments are necessary at the same time, one adjustment item is selected based on the priority in the adjustment mode selection (step S104 in FIG. 5). On the other hand, in the adjustment mode selection (step S104 in FIG. 5) when a plurality of adjustments are necessary at the same time, a plurality of adjustments are collected together (a dedicated chart in which a plurality of adjustment charts are collected), or Alternatively, the selection may be made so as to be executed in order (printing the chart in order on successive pages).

In this case, when the control unit 101 determines whether or not calibration is necessary (step S1056 in FIG. 12), the control unit 101 can determine the calibration in the shortest time among the “calibration intervals” of the adjustment to be performed. It is desirable to carry out.
[Operation of Image Forming Apparatus (2)]
Hereinafter, the operation (2) of the image forming apparatus 100 in the present embodiment will be described. Here, a description of the same part as the operation (1) already described is omitted, and a description will be given focusing on a different part.

  In this image forming apparatus 100, the control unit 101 sets the initial value N = 1 and the operation mode = normal printing mode as the page counter value N as the job processing start processing, and instructs the image forming unit 150 to start the job. Then, preparation for image formation is made (step S101a in FIG. 15).

  Further, in this image forming apparatus 100, the control unit 101 initializes parameters relating to the advance processing, such as advance reservation = NO, advance reservation number = 0, as an initial setting of the advance processing described later (step in FIG. 15). S101b). These parameters will be described later.

  Further, the control unit 101 confirms whether or not the adjustment is necessary for each of the plurality of adjustments including the forward moving process (step S102A in FIG. 15). The detailed processing of the adjustment condition confirmation (step S102A in FIG. 15) will be described in detail with reference to another flowchart.

[Operation (2-1)]
Hereinafter, detailed processing of adjustment condition confirmation (step S102 in FIG. 15) of the basic flowchart will be described in detail with reference to the flowchart of FIG.
In this case as well, the description of the same part as the operation (1) already described is omitted, and the description will focus on the different part.

After acquiring the adjustment condition, determining whether the adjustment is valid, and acquiring the elapsed number, the control unit 101 refers to the “advance reservation (YES / NO)” column of the adjustment management table (FIG. 17) to determine whether there is an advance reservation. Judgment is made (step S1024 in FIG. 16).
If the advance reservation = YES in the adjustment management table (FIG. 17), the control unit 101 determines that there is an advance reservation (YES in step S1024 in FIG. 16), and the current adjustment item from the adjustment management table (FIG. 17). Is read out (step S1025 in FIG. 16). On the other hand, if the advance reservation = NO in the adjustment management table (FIG. 17), the control unit 101 determines that there is no advance reservation (NO in step S1024 in FIG. 16), and sets the initially advanced number of advance = 0. .

  Then, the control unit 101 determines whether or not the total of the elapsed number of sheets after the previous adjustment and the number of forwards is equal to or greater than the adjustment interval (step S1026A in FIG. 16). If (elapsed number of sheets after previous execution + number of sheets advanced) ≧ adjustment interval (YES in step S1026A in FIG. 16), the control unit 101 determines that adjustment of the image forming unit 150 is necessary, and an adjustment management table. Adjustment necessary flag = YES (adjustment required) is set (step S1027 in FIG. 16). On the other hand, if (elapsed number of sheets after previous execution + number of sheets advanced) <adjustment interval (NO in step S1026A in FIG. 16), the control unit 101 determines that adjustment of the image forming unit 150 is not necessary, and Adjustment necessary flag = NO (adjustment unnecessary) is set (step S1028 in FIG. 16).

The advance reservation and the advance number (steps S1024 and S1025 in FIG. 16) referred to by the control unit 101 in the flowchart of FIG. 16 are registered and the advance number is recorded in the flowchart of FIG. And is made.
[Operation (2-2)]
Hereinafter, detailed processing of the calibration execution of the basic flowchart (step S105 in FIG. 15) will be described in detail with reference to the flowchart of FIG.

In this case as well, the description of the same part as the operation (1) already described is omitted, and the description will focus on the different part.
The control unit 101 refers to the calibration interval of each adjustment, determines whether there is an adjustment that can be moved forward, and if it can be moved forward, sets the advance adjustment reservation (step S1059 in FIG. 18).

[Operation (2-3)]
Hereinafter, detailed processing of the advance adjustment reservation setting (step S1059 in FIG. 18) will be described in detail with reference to the flowchart of FIG.
The control unit 101 refers to the adjustment management table (FIG. 17) and the calibration setting table (FIG. 8), calculates the number of sheets until the next adjustment from the number of adjustment intervals and the number of sheets elapsed since the previous adjustment, and until this next adjustment. Next adjustment scheduled time is calculated from the number of images (step S10591 in FIG. 18).

Further, the control unit 101 refers to the adjustment management table (FIG. 17) and determines whether or not calibration is required before the next adjustment (step S10592 in FIG. 19).
That is, if the time until the next adjustment is scheduled> the calibration interval, the control unit 101 determines that calibration is necessary before the next adjustment (YES in step S10592 in FIG. 19), and proceeds to the following processing.

On the other hand, if the time until the next adjustment schedule is equal to or less than the calibration interval, the control unit 101 determines that calibration is not necessary until the next adjustment (NO in step S10592 in FIG. 19), and the same determination is made for the next adjustment. Is performed (step S10595 in FIG. 19).
If it is determined that calibration is necessary before the next adjustment (YES in step S10592 in FIG. 19), control unit 101 determines whether or not the adjustment can be advanced (step S10593 in FIG. 19).

Here, the control unit 101 determines that the adjustment can be advanced (YES in step S10593 in FIG. 19) when (calibration interval + proactive time)> time until the next execution schedule (YES in step S10593 in FIG. 19), and the following processing Proceed to
On the other hand, the control unit 101 determines that the adjustment cannot be advanced (NO in step S10593 in FIG. 19) when (calibration interval + possible advance time) ≦ time until the next execution schedule (NO in step S10593 in FIG. 19), and the next adjustment. A similar determination is made for (step S10595 in FIG. 19).

  For example, in the case of color registration correction, the calibration interval is 1200 seconds (see FIG. 8), the forward possible time is 150 seconds (see FIG. 17), and the time until the next execution schedule is 1275 seconds (see FIG. 17). Therefore, the above formula (Calibration interval: 1200 seconds + Possible to move forward: 150 seconds)> Time until next scheduled implementation: 1275 seconds is satisfied. For this reason, the control unit 101 determines that advance reservation is possible. Similarly, in the case of color correction, (Calibration interval: 60 seconds + Advance possible time: 400 seconds) <Time to next execution schedule: 1160 seconds, so the control unit 101 determines that advance reservation is not possible. .

  If it is determined as described above that it is possible to make an advance reservation (YES in step S10592 in FIG. 19; YES in S10593), the control unit 101 adjusts the adjustment management table (FIG. 17) to advance the adjustment. ) Is registered (advance reservation in FIG. 17 = YES, step S10594 in FIG. 19).

At this time, the number of sheets corresponding to (time until next execution-calibration interval) is calculated as the number of sheets advanced and recorded in the adjustment management table (FIG. 17).
Note that, as described above, the advance reservation registration and the advance number recording (step S10594 in FIG. 19) are referred to by the control unit 101 in the flowchart of FIG. 16 (in FIG. 16). Steps S1024 and S1025).

Further, the control unit 101 checks whether there is an adjustment item for which calibration is not necessary at the next adjustment (step S10595 in FIG. 19), and if there is an adjustment item, returns to step S10591 and repeats the same processing. If there is no adjustment item, the process ends.
In the above description, the advance adjustment is managed as the number of sheets. However, the present invention is not limited to this. For example, it is possible to manage the advancement of adjustment by time.

[Operation of Image Forming Apparatus (3)]
Hereinafter, the operation (3) of the image forming apparatus 100 in the present embodiment will be described. Here, the description of the parts overlapping with the operation (1) and the operation (2) already described is omitted, and the description will focus on the different parts.

[Operation (3-1)]
Hereinafter, the detailed processing as the operation (3) of the calibration execution of the basic flowchart (step S105 in FIG. 5 and step S105 in FIG. 15) will be described with reference to the flowchart in FIG. Will be described in detail. In addition, description about the part which overlaps already demonstrated operation | movement (1) and operation | movement (2) is abbreviate | omitted or simplified here, and it demonstrates centering on a different part.

The control unit 101 refers to the calibration setting table (FIG. 21), refers to the column of calibration necessity during job of the selected adjustment mode (“necessity of calibration during job” in FIG. 21), and performs calibration during job. It is determined whether it is necessary (step S1051 in FIG. 20).
If it is determined that calibration is necessary during the job (YES in step S1051 in FIG. 20), the control unit 101 determines whether the output product reading unit 190a and the output product reading unit 190b included in the output product reading unit 190 For each, the elapsed time (calibration elapsed time) from the previous calibration is calculated from the difference between the previous calibration time and the current time in the operation state management table (FIG. 22) (step S1052a in FIG. 20).

Further, the control unit 101 determines whether or not the current adjustment is double-sided reading (step S1052b in FIG. 20).
If the adjustment is for double-sided reading (YES in step S1052b in FIG. 20), the control unit 101 refers to the calibration setting table (FIG. 21) and either the output material reading unit 190a or the output material reading unit 190b. It is determined whether or not “elapsed time since previous calibration ≧ calibration interval in current adjustment mode” is satisfied (step S1056a in FIG. 20). In this case, if either one of the output material reading unit 190a and the output material reading unit 190b satisfies the condition, it is determined that the interval is equal to or longer than the calibration interval (YES in step S1056a in FIG. 20).

  If the control unit 101 determines that calibration is necessary for adjustment of double-sided reading (YES in step S1056a in FIG. 20), the control unit 101 proceeds to calibration for double-sided reading (step S1057a in FIG. 20). That is, calibration is performed on each of the output material reading unit 190a and the output material reading unit 190b included in the output material reading unit 190. After the calibration, the control unit 101 updates the previous calibration time of the operation state management table (FIG. 22) to the current time for each of the output material reading unit 190a and the output material reading unit 190b (in FIG. 20). Step S1058a).

Further, if neither of the output object reading unit 190a and the output object reading unit 190b satisfies the condition, it is determined that the interval is not equal to or longer than the calibration interval (NO in step S1056a in FIG. 20), and the process ends (end in FIG. 20). ).
If the adjustment is not for double-sided reading (NO in step S1052b in FIG. 20), the control unit 101 refers to the calibration setting table (FIG. 21) and outputs an output material reading unit 190 (for example, an output material) that reads the first surface of the sheet. The reading unit 190a) determines whether or not “elapsed time since previous calibration ≧ calibration interval in current adjustment mode” is satisfied (step S1056b in FIG. 20).

If the control unit 101 determines that calibration is necessary for the single-sided reading adjustment (YES in step S1056b in FIG. 20), the control unit 101 calculates a scheduled time for double-sided scanning adjustment (planned time for double-sided scanning adjustment) (FIG. Step S1056c in 20)
That is, the control unit 101 refers to the adjustment management table (FIG. 17) and the calibration setting table (FIG. 21), and extracts the adjustment for double-sided reading = YES other than the current adjustment mode as the next double-sided adjustment. Then, the control unit 101 calculates the number of adjustment intervals and the number of sheets from the previous adjustment to the next adjustment for each surface of the extracted next double-sided adjustment, and uses the next adjustment scheduled time as the scheduled double-sided scanning adjustment time. calculate.

  Then, the control unit 101 determines whether there is one or more next double-side adjustments such that (double-sided read adjustment scheduled time-current time) <calibration interval (step S1056d in FIG. 20). If there is one or more of the following double-sided adjustments as described above, the control unit 101 determines that double-sided calibration is necessary for the current calibration (YES in step S1056d in FIG. 20), and performs double-sided scanning calibration (FIG. Proceed to step S1057a). That is, calibration is performed on each of the output material reading unit 190a and the output material reading unit 190b included in the output material reading unit 190. After the calibration, the control unit 101 updates the previous calibration time of the operation state management table (FIG. 22) to the current time for each of the output material reading unit 190a and the output material reading unit 190b (in FIG. 20). Step S1058a).

  On the other hand, if there is no next double-sided adjustment that satisfies (double-sided reading adjustment scheduled time−current time) <calibration interval, the control unit 101 determines that double-sided calibration is unnecessary as the current calibration (in FIG. 20). In step S1056d, the process proceeds to calibration (step S1057b in FIG. 20) for the output object reading unit 190 (for example, the output object reading unit 190a) that reads the first surface of the sheet. That is, calibration is performed on one side of the output object reading unit 190. After the calibration, the control unit 101 updates the previous calibration time of the operation state management table (FIG. 22) to the current time for the output material reading unit 190 (for example, the output material reading unit 190a) that reads the first surface of the sheet. (Step S1058b in FIG. 20).

  In the case of the third embodiment, since the timing for executing the double-sided calibration is within a predetermined range at the timing for executing the single-sided calibration, the double-sided calibration is executed instead of the single-sided calibration. As a result, single-sided calibration and double-sided calibration can be completed by one-sided double-sided calibration. Therefore, calibration of the output material reading unit can be suppressed to a small number of times, and a decrease in productivity can be suppressed.

<Other embodiments>
In the above embodiment, the part controlled by the control unit 101 may be divided into a plurality of control units for each function.
Similarly, parts for performing various types of processing, various types of management, various types of adjustments, various types of determinations, and the like may be configured separately, and may be shared and processed.

In addition, even in the configuration in which the output product reading apparatus exists outside the image forming apparatus 100, the same effect can be obtained by the same operation as the above embodiment, and the embodiment of the present invention. It is included in one aspect.
In the above embodiment, the case where the calibration interval coefficient is reduced in the initial lighting period of the lamp is shown, but the present invention is not limited to this. For example, when there is a device whose operation becomes unstable during continuous driving for a long time, it is possible to set the coefficient to be small during long-time driving.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 102 Communication part 103 Operation display part 104 Storage part 105 Paper feed part 107 Conveyance part 110 Document reading part 130 Image data storage part 140 Image processing part 150 Image forming part 160 Fixing part 190 Output matter reading part

Claims (10)

An image forming unit for forming an image on paper;
An output reading unit that reads the image formed on the sheet by the image forming unit;
A control unit for controlling image formation by the image forming unit, reading by the output product reading unit, a plurality of types of adjustments in the image forming unit based on a reading result by the output product reading unit, and calibration in the output product reading unit; An image forming apparatus comprising:
The control unit determines whether the calibration is necessary or not according to the type of adjustment performed in the image forming unit for the calibration in the output object reading unit performed between sheets of a job being executed. Control whether to perform the calibration according to the result,
An image forming apparatus. The controller is
In each of a plurality of types of adjustments, the necessity of the calibration is set in a table,
Determining the necessity of the calibration with reference to the setting of the table;
The image forming apparatus according to claim 1. The controller is
In each of a plurality of types of adjustments, an adjustment interval from the execution of the calibration until the next execution becomes necessary is determined in advance.
In each of a plurality of types of adjustments, an elapsed time from the previous execution of the calibration is calculated, and when the elapsed time exceeds the adjustment interval, the calibration is controlled to be executed.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The control unit determines whether or not the calibration is necessary when starting the adjustment.
The image forming apparatus according to claim 3. The output product reading unit includes a light source that illuminates the reading position of the paper, and an inline sensor that reads an image of the reading position illuminated by the light source,
The control unit changes the adjustment interval until a predetermined time has elapsed from the start of lighting of the light source.
The image forming apparatus according to claim 3, wherein the image forming apparatus is an image forming apparatus. The control unit examines whether or not any of the adjustments scheduled to be performed before the next calibration is performed at the time of performing the calibration, and until the next time the calibration is performed. If any of the adjustments scheduled to be performed in the meantime exists, control to advance the execution timing of the adjustments scheduled to be performed,
The image forming apparatus according to claim 3, wherein the image forming apparatus is an image forming apparatus. The controller is
Next, when the difference between the timing of executing the calibration and the timing of executing the adjustment next is within a certain range, control is performed so as to advance the execution timing of the adjustment scheduled to be performed.
The image forming apparatus according to claim 6. The control unit determines the number of read lines from the start of execution of calibration to the end of execution according to the type of adjustment performed by the image forming unit.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The output object reading unit is configured to be able to read the images formed on both sides of the paper,
The controller is
One-side calibration control for calibrating the output material reading unit for reading one side of the paper and double-sided calibration control for calibrating the output material reading unit for reading both sides of the paper are possible,
If the timing for executing double-sided calibration is within a predetermined range at the timing of executing single-sided calibration, control to execute double-sided calibration instead of single-sided calibration.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. An image forming unit that forms an image on a sheet, an output object reading unit that reads the image formed on the sheet by the image forming unit, image formation by the image forming unit, reading by the output object reading unit, and the output A control unit that controls a plurality of types of adjustments in the image forming unit based on a reading result by an object reading unit and a calibration in the output object reading unit, and an image forming control method for controlling an image forming apparatus,
The control unit determines whether the calibration is necessary or not according to the type of adjustment performed in the image forming unit for the calibration in the output object reading unit performed between sheets of a job being executed. Control whether to perform the calibration according to the result,
An image formation control method characterized by the above.