JP7446909B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile machine, and a multifunction device.

Printed matter produced by commercial printing machines requires stable printing position accuracy on the front and back sides of the sheet. Patent Document 1 discloses an image forming apparatus in which printing position accuracy is stabilized. In order to stabilize printing position accuracy, this image forming apparatus prints an adjustment image that serves as a mark of a printing position (image forming position) on a sheet to create an adjustment chart. In the adjustment chart, an image for adjustment is read by an image reading sensor provided on the conveyance path of the sheet. The image forming apparatus feeds back the reading result of the adjustment image to the image forming conditions and adjusts the printing position.

Japanese Patent Application Publication No. 2006-11285

In order to stabilize the print position accuracy on the front and back sides, a series of processes from creating the adjustment chart to adjusting the print position as described above can be set to be performed automatically. A series of image forming condition adjustment processing that is automatically performed is called automatic adjustment. In particular, the automatic adjustment that adjusts the printing position on the front and back sides is called front and back auto adjustment. A user can, for example, register values for adjusting image forming conditions (for example, values for front and back printing positions) for each paper feed deck that accommodates sheets. When printing according to a print job, the image writing position is adjusted based on the values of the front and back printing positions registered in the paper feed deck that feeds the paper. In addition, the front and back automatic adjustment is performed every time a predetermined number of sheets are printed, and the values of the printing positions on the front and back sides of the paper feed deck are updated based on the reading result of the adjustment chart.

The user can select whether to enable or disable the front and back automatic adjustment. If the front and back automatic adjustment is disabled, the front and back automatic adjustment will not be performed during printing by the print job, so the values of the print positions on the front and back sides of the paper feed deck will not be updated. For this purpose, the writing start position of the image being printed is adjusted by a constant value. When the front and back automatic adjustment is enabled, the front and back automatic adjustment is performed during printing by a print job, so the values of the printing positions on the front and back sides of the paper feed deck are updated. For this purpose, the writing position of the image being printed is adjusted to be optimal.

Enabling/disabling of front and back automatic adjustment can be performed for each job. For this reason, for example, if you perform an interrupt print job with front and back auto adjustment enabled while printing with front and back auto adjustment disabled, the front and back auto adjustment will be performed during processing by the interrupt print job. There is a possibility that the value of the printing position on the front and back sides of the paper feed deck will be updated. In other words, if the interrupt print job and the interrupted print job feed paper from the same paper feed deck, the values of the front and back print positions used by the interrupted print job will be updated. As a result, even though front and back automatic adjustment is disabled for the interrupted print job, the image writing position is adjusted using different print position values for the front and back sides before and after the interrupted print job.

In this way, by performing an interrupt print job with automatic adjustment enabled during execution of a print job with automatic adjustment disabled, image forming conditions such as the image writing position are adjusted. In this case, the image quality (image density, color shift, print position) of an image printed by a print job in which automatic adjustment is disabled may change before and after the interrupt print job is performed. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an image forming apparatus that suppresses changes in image quality due to interruption print jobs.

The image forming apparatus of the present invention includes: an image forming means for forming an image on a sheet based on image forming conditions; a reading means for reading an image for adjusting the image forming conditions formed on the sheet; an adjustment unit that adjusts the image forming conditions based on a reading result of the adjustment image, and when forming an image on a sheet according to a print job, the image forming unit adjusts the adjustment image together with the image. is formed on a sheet , and the image forming apparatus is capable of automatically adjusting the image forming conditions by the adjustment means based on the reading result of the adjustment image by the reading means , the image forming apparatus comprising: If an interrupt command for a second print job for which automatic adjustment is enabled is received during a period in which an image is formed on a sheet in accordance with a first print job for which adjustment is disabled, the second print job for which automatic adjustment is enabled is The present invention is characterized by comprising a control means for prohibiting execution of interrupt processing.

According to the present invention, it is possible to suppress changes in image quality due to interrupt print jobs.

A configuration diagram of an image processing system. system configuration diagram. FIG. 1 is a configuration diagram of an image forming apparatus. An explanatory diagram of CIS. (a) to (f) are exemplary diagrams of setting screens. FIG. 3 is an exemplary diagram of job information. FIG. 4 is an exemplary diagram of automatic adjustment information. An illustrative diagram of an adjustment chart. Flowchart showing print processing. Flowchart showing print processing.

Hereinafter, embodiments will be described in detail with reference to the drawings.

(Image processing system)
FIG. 1 is a configuration diagram of an image processing system including an image forming apparatus of this embodiment. The image processing system includes an image forming apparatus 101 and an external controller 102. The image forming apparatus 101 is, for example, a multifunction device, a multifunction peripheral (MFP), or the like. The external controller 102 is, for example, an image processing controller, a digital front end (DFE), a print server, or the like.

Image forming apparatus 101 and external controller 102 are communicably connected via internal LAN (Local Area Network) 105 and video cable 106 . The external controller 102 is connected to a client PC (Personal Computer) 103 via an external LAN 104. The external controller 102 obtains a print instruction (print job) from the client PC 103.

A printer driver having a function of converting print data into a print description language that can be processed by the external controller 102 is installed in the client PC 103 . A user can instruct printing via a printer driver using various applications. The printer driver transmits print data to the external controller 102 based on a print job from a user. The external controller 102 receives a print job including print data from the client PC 103, performs data analysis and rasterization processing, and instructs the image forming apparatus 101 to perform printing (image formation) based on the print data.

The image forming apparatus 101 is configured by connecting a plurality of apparatuses having different functions including a printing apparatus 107, and is capable of performing complex printing processes such as bookbinding. The image forming apparatus 101 of this embodiment includes a printing device 107 and a finisher 109. The printing device 107 uses developer (for example, toner) to form an image on a sheet fed from a paper feeding unit provided at the bottom of the main body. The printing device 107 forms yellow (Y), magenta (M), cyan (C), and black (K) images. A full-color image in which images of each color are superimposed is formed on the sheet. The sheet on which the image has been formed is conveyed from the printing device 107 to the finisher 109. A finisher 109 stacks sheets on which images are formed.

This image processing system has a configuration in which an external controller 102 is connected to an image forming apparatus 101, but the external controller 102 is not necessarily required. For example, the image forming apparatus 101 may directly obtain a print job including print data from the client PC 103 via the external LAN 104. In this case, the image forming apparatus 101 performs data analysis and rasterization processing performed by the external controller 102. In other words, the image forming apparatus 101 and the external controller 102 may be integrated.

(System configuration)
FIG. 2 is a system configuration diagram that controls the operation of the image processing system. Here, the system configurations of the image forming apparatus 101, external controller 102, and client PC 103 will be described.

- Printing device The printing device 107 includes a communication interface (I/F) 217, a LAN I/F 218, and a video I/F 220 in order to communicate with other devices. The printing apparatus 107 includes a CPU (Central Processing Unit) 222, a memory 223, a storage 221, an image reading section 231, and an image processing section 232 to control the operation of the printing apparatus 107. The printing device 107 includes an exposure section 227, an image forming section 228, a fixing section 229, and a paper feeding section 230 to form an image. The printing device 107 includes an operation unit 224 and a display 225 as a user interface. These components are communicably connected to each other via a system bus 233.

Communication I/F 217 is connected to finisher 109 via communication cable 249 and controls communication with finisher 109. When the printing apparatus 107 and the finisher 109 operate together, information and data are transmitted and received via the communication I/F 217. LAN I/F 218 is connected to external controller 102 via internal LAN 105 and controls communication with external controller 102 . The printing apparatus 107 receives print data representing printing settings and the like from the external controller 102 via the LAN I/F 218 . Video I/F 220 is connected to external controller 102 via video cable 106 and controls communication with external controller 102. The printing device 107 receives image data representing an image to be formed from the external controller 102 via the video I/F 220 .

The CPU 222 comprehensively controls image processing and printing by executing a computer program stored in the storage 221. The memory 223 provides a work area when the CPU 222 executes various processes. When performing image forming processing, the CPU 222 controls the exposure section 227, the image forming section 228, the fixing section 229, and the paper feeding section 230.

The exposure unit 227 uniformly charges the surface of the photoreceptor and irradiates the charged surface of the photoreceptor with laser light based on image data. The exposure section 227 charges the surface of the photoreceptor to a uniform negative potential. The exposure unit 227 outputs a laser beam using a laser driver, and scans the uniformly charged surface of the photoreceptor with the laser beam while adjusting the reflection angle of the laser beam using a rotating polygon mirror. The potential of the photoconductor changes at a position irradiated with laser light, and an electrostatic latent image is formed on the surface of the photoconductor. Four photoreceptors are provided corresponding to four colors: yellow (Y), magenta (M), cyan (C), and black (K). Electrostatic latent images corresponding to images of different colors are formed on the four photoreceptors.

The image forming unit 228 transfers the toner image formed on the photoreceptor onto a sheet. The image forming section 228 includes a developing device, a transfer unit, a toner supply section, and the like. The developing device forms a toner image by attaching negatively charged toner from a developing cylinder to an electrostatic latent image formed on the surface of a photoreceptor. Four developing units are provided corresponding to four colors: yellow (Y), magenta (M), cyan (C), and black (K). The developer visualizes the electrostatic latent image on the photoreceptor using toner of a corresponding color.

The transfer unit includes an intermediate transfer belt, and transfers the toner image from the photoreceptor to the intermediate transfer belt. A primary transfer roller is provided at a position facing the photoreceptor with the intermediate transfer belt in between. By applying a positive potential to the primary transfer roller, toner images from each of the four photoreceptors are transferred onto the intermediate transfer belt in a superimposed manner. As a result, a full-color toner image is formed on the intermediate transfer belt. The toner image formed on the intermediate transfer belt is transferred onto a sheet by a secondary transfer roller, which will be described later. The secondary transfer roller transfers a full-color toner image from the intermediate transfer belt to the sheet by applying a positive potential.

The fixing unit 229 fixes the transferred toner image on the sheet. The fixing unit 229 melts and fixes the toner image on the sheet by heating and pressurizing the toner image on the sheet. This forms an image on the sheet. The paper feeding unit 230 includes rollers such as a transport roller and various sensors on a transport path, and controls the sheet feeding operation.

The image reading unit 231 reads an image formed on a sheet being conveyed based on instructions from the CPU 222. For example, when adjusting the image forming conditions, the CPU 222 uses the image reading unit 231 to read an image for adjusting the image forming conditions formed on the sheet. The image processing unit 232 sets a gain adjustment value for the image reading unit 231, etc. based on the reading result by the image reading unit 231. Such processing by the image processing unit 232 is reflected in the image reading result by the image reading unit 231. The operation unit 224 is an input device that accepts various setting inputs and operation instructions from the user. The operation unit 224 is, for example, various input keys, a touch panel, or the like. The display 225 is an output device that displays setting information of the image forming apparatus 101, print job processing status, and the like.

-Finisher The finisher 109 is, for example, a large-capacity stacker. The finisher 109 includes a communication I/F 241, a CPU 242, a memory 243, and a paper discharge control section 244. These components are communicatively connected to each other via system bus 245. The communication I/F 241 is connected to the printing device 107 via a communication cable 249, and controls communication with the printing device 107. When the finisher 109 and the printing device 107 operate cooperatively, information and data are transmitted and received via the communication I/F 241. The CPU 242 executes a control program stored in the memory 243 and performs various controls necessary for paper ejection. Memory 243 stores control programs. Further, the memory 243 provides a work area when the CPU 242 executes various processes. The paper discharge control unit 244 discharges the conveyed sheets to the stack tray based on instructions from the CPU 242.

- External Controller The external controller 102 includes a LAN I/F 213, a LAN I/F 214, and a video I/F 215 in order to communicate with other devices. The external controller 102 includes a CPU 208, a memory 209, and a storage 210 to control the operation of the external controller 102. The external controller 102 includes a keyboard 211 and a display 212 as a user interface. These components are communicatively connected to each other via system bus 216.

The LAN I/F 213 is connected to the client PC 103 via the external LAN 104 and controls communication with the client PC 103. The external controller 102 obtains print jobs and the like from the client PC 103 via the LAN I/F 213 . The LAN I/F 214 is connected to the printing device 107 via the internal LAN 105 and controls communication with the printing device 107. The external controller 102 transmits print data representing printing settings and the like to the printing apparatus 107 via the LAN I/F 214 . The video I/F 215 is connected to the printing device 107 via the video cable 106 and controls communication with the printing device 107. The external controller 102 transmits image data and the like to the printing device 107 via the video I/F 215.

The CPU 208 comprehensively performs processing such as receiving print data transmitted from the client PC 103, RIP processing, and transmitting print data to the image forming apparatus 101 by executing a computer program stored in the storage 210. The memory 209 provides a work area when the CPU 208 executes various processes. The keyboard 211 is an input device that accepts various setting inputs and operation instructions from the user. The display 212 is an output device that displays information such as applications executed by the external controller 102 as still images or moving images.

・Client PC
The client PC 103 includes a CPU 201, a memory 202, a storage 203, a keyboard 204, a display 205, and a LAN I/F 206. These components are communicably connected to each other via a system bus 207.

The CPU 201 controls the operation of the client PC 103 by executing a computer program stored in the storage 203. In this embodiment, the CPU 201 performs print data creation and print job transmission processing. The memory 202 provides a work area when the CPU 201 executes various processes. Keyboard 204 and display 205 are a user interface. The keyboard 204 is an input device that accepts instructions from the user. The display 205 is an output device that displays information such as applications executed by the client PC 103 as still images or moving images. LAN I/F 206 is connected to external controller 102 via external LAN 104 and controls communication with external controller 102 . The client PC 103 transmits a print job and the like to the external controller 102 via the LAN I/F 206.

Note that the external controller 102 and the image forming apparatus 101 are connected by an internal LAN 105 and a video cable 106, but any configuration is sufficient as long as the data necessary for printing can be sent and received; for example, the external controller 102 and the image forming apparatus 101 may be connected only by a video cable. You can leave it there. The memory 202, the memory 209, the memory 223, and the memory 243 may each be a storage device for holding data or programs. For example, volatile RAM (Random Access Memory), non-volatile ROM (Read Only Memory), storage, USB (Universal Serial Bus) memory, etc. can be used as these memories.

(Configuration of image forming apparatus)
FIG. 3 is a configuration diagram of the image forming apparatus 101. A display 225 is provided on the top of the printing device 107. The display 225 displays information for the printing status and settings of the image forming apparatus 101. The sheet on which an image has been formed by the printing device 107 is conveyed to a finisher 109 provided at a subsequent stage.

The printing device 107 includes a plurality of paper feed decks 301 and 302 and a transport path 303 as a paper feed unit 230. Each paper feed deck 301, 302 can accommodate different types of sheets. The sheets stored in each of the paper feed decks 301 and 302 are separated and fed to a conveyance path 303, with the top sheet being separated. The printing device 107 includes image forming units 304 , 305 , 306 , and 307 as an exposure unit 227 for forming images. Printing device 107 forms a color image. For this purpose, the image forming unit 304 forms a black (K) image (toner image). The image forming unit 305 forms a cyan (C) image (toner image). The image forming unit 306 forms a magenta (M) image (toner image). The image forming unit 307 forms a yellow (Y) image (toner image).

The printing device 107 includes, as an image forming section 228, an intermediate transfer belt 308 and a secondary transfer roller 309 to which toner images are transferred from each image forming section 304, 305, 306, and 307. Intermediate transfer belt 308 rotates clockwise in the figure, and toner images are transferred in the order of image forming section 307, image forming section 306, image forming section 305, and image forming section 304 in a superimposed manner. As a result, a full-color toner image is formed on the intermediate transfer belt 308. Intermediate transfer belt 308 conveys the toner image to secondary transfer roller 309 by rotating. The sheet is conveyed to the conveyance path 303 in synchronization with the timing at which the toner image is conveyed to the secondary transfer roller 309 . The secondary transfer roller 309 transfers the toner image on the intermediate transfer belt 308 onto the conveyed sheet.

The printing apparatus 107 includes a first fixing device 311 and a second fixing device 318 as the fixing unit 229. The first fixing device 311 and the second fixing device 318 have the same configuration and fix the toner image on the sheet. For this purpose, the first fixing device 311 and the second fixing device 318 each include a pressure roller and a heating roller. The sheet is heated and pressurized by passing between a pressure roller and a heating roller, and the toner image is melted and pressed onto the sheet. The sheet that has passed through the second fixing device 318 is conveyed to a conveyance path 314. Note that the second fixing device 318 is disposed downstream of the first fixing device 311 in the sheet conveyance direction, and adds gloss to the image on the sheet that has been fixed by the first fixing device 311 and improves fixability. Used for securing. Therefore, the second fixing device 318 may not be used depending on the type of sheet or the content of the image forming process. A conveying path 312 is provided to convey the sheet that has been subjected to the fixing process in the first fixing device 311 without passing through the second fixing device 318 .

After the conveyance path 314 and the conveyance path 312 merge, a conveyance path 315 and a reversal path 316 are provided. If double-sided printing is instructed, the sheet is conveyed to the reversing path 316. The sheet conveyed to the reversing path 316 has its conveying direction reversed at the reversing path 316 and is conveyed to the double-sided conveying path 317 . By the reversing path 316 and the double-sided transport path 317, the surface (first surface) on which the image is formed on the sheet is reversed. The sheet is conveyed to the conveyance path 303 by the double-sided conveyance path 317, and an image is formed on the second side by passing through the secondary transfer roller 309 and the fixing section 229.

In the case of single-sided printing or in the case of double-sided printing in which images are formed on both sides, the sheet is conveyed to the conveyance path 315. A conveyance path 323 is arranged downstream of the conveyance path 315 in the sheet conveyance direction.

On the transport path 323, CIS (Contact Image Sensors) 321 and 322 are arranged as image reading units 231, facing each other with the transport path 323 in between. FIG. 4 is an explanatory diagram of the CIS 321 and 322. The CIS 321 is an optical sensor that reads an image on the top surface of a sheet conveyed through the conveyance path 323. The CIS 322 is an optical sensor that reads an image on the bottom surface of the sheet conveyed through the conveyance path 323.

The CIS 321 includes an LED (Light Emitting Diode) 350 that serves as a light source, a reading sensor 351 that serves as a light receiving section, and a white reference plate 352. The LED 350 irradiates the top surface of the sheet with light at the timing when the sheet conveyed through the conveyance path 323 reaches the reading position. The reading sensor 351 receives reflected light from the sheet. The reading sensor 351 performs photoelectric conversion of the received reflected light and transmits the reading result, which is an electrical signal, to the CPU 222 . The image formed on the sheet in this way is read. The reading sensor 351 includes a plurality of light receiving elements (photoelectric conversion elements) in a direction perpendicular to the sheet conveyance direction. Therefore, the direction perpendicular to the sheet conveyance direction is the main scanning direction of the CIS 321. The direction perpendicular to the main scanning direction (sheet conveyance direction) is the sub-scanning direction. The white reference plate 352 is used during shading correction of the CIS 321. During shading correction, the LED 350 and the reading sensor 351 move to a position where the white reference plate 352 is read. Shading correction of the CIS 321 is performed based on the reading result of the white reference plate 352.

Like the CIS 321, the CIS 322 includes an LED 353, a reading sensor 354, and a white reference plate 355. The CIS 322 operates in the same manner as the CIS 321, and reads the image formed on the bottom surface of the sheet at the timing when the sheet conveyed through the conveyance path 323 reaches the reading position. Note that in addition to the CIS 321 and 322, the image reading unit 231 can also be realized by a CCD sensor or a CMOS sensor.

In this embodiment, adjustment images for adjusting image forming conditions can be formed on both sides of the sheet. The sheet on which the adjustment image is formed is called an adjustment chart. The printing device 107 prints the adjustment image on a sheet to create an adjustment chart, and the CIS 321 and CIS 322 read the adjustment image. The results of reading the adjustment chart by the CIS 321 and CIS 322 are stored in the memory 223. The CPU 222 refers to the memory 223, feeds back the results of reading by the CIS 321 and the CIS 322 to the image forming conditions, and adjusts the image forming conditions.

For example, when the internal temperature of the printing apparatus 107 rises, the position of the image formed on the sheet changes compared to when the internal temperature of the printing apparatus 107 is low. In this case, the printing device 107 creates an adjustment chart, acquires the amount of variation based on the reading results of the CIS 321 and 322, and adjusts the printing position based on the amount of variation so that it is at the same position as when the internal temperature is low. adjust. Thereby, the printing device 107 attempts to stabilize the printing position accuracy.

The adjustment image formed on the adjustment chart is not only an image for adjusting the printing position on the front and back sides of the sheet, but also an image for adjusting image forming conditions such as image density and color shift. good. Image quality is maintained constant by adjusting image forming conditions. The adjustment image may be printed as an adjustment chart or printed on the same sheet in addition to the image corresponding to the print job specified by the user. In this embodiment, a case will be described in which the adjustment chart is printed.

The adjustment chart is excluded so as not to be mixed in with printed matter according to the print job. For this purpose, the printing device 107 includes a flapper 324, a discharge path 326, a conveyance sensor 327, and a discharge tray 328. The adjustment chart whose image (adjustment image) has been read by the CIS 321 and 322 is conveyed to the discharge path 326 by the flapper 324 . The sheet conveyed to the ejection path 326 is ejected to the ejection tray 328.

If the sheet is not an adjustment chart, the sheet is conveyed from the conveyance path 323 to the downstream conveyance path 325 by the flapper 324. The sheet conveyed to the downstream conveyance path 325 is delivered to the finisher 109. Note that when the printing device 107 receives a notification from the finisher 109 that a conveyance jam has occurred, it switches the flapper 324 to the ejection path 326 side and removes all sheets in the machine, regardless of whether or not it is an adjustment chart. (residual paper) is discharged to the discharge tray 328. By discharging the remaining paper to the discharging tray 328, the burden of jam handling on the user is reduced.

The finisher 109 can stack a large number of sheets received from the printing device 107. The finisher 109 includes a conveyance path 331 and a stack tray 332 on which sheets are stacked. The conveyance path 331 is provided with conveyance sensors 333 , 334 , 335 , and 336 . Sheets conveyed from the printing device 107 are stacked on a stack tray 332 via a conveyance path 331. Conveyance sensors 333 , 334 , 335 , and 336 detect passage of sheets conveyed through conveyance path 331 . If the leading edge or trailing edge of the sheet in the conveying direction is not detected by the conveyance sensors 333, 334, 335, and 336 even after a predetermined period of time has elapsed since the start of sheet conveyance, the CPU 242 detects a conveyance jam (conveyance abnormality) in the finisher 109. ) has occurred. In this case, the CPU 242 notifies the printing device 107 that a conveyance jam has occurred.

(How to set automatic adjustment)
The image forming apparatus 101 of this embodiment can set automatic adjustment in which image forming conditions are automatically adjusted during printing. FIG. 5 is an exemplary diagram of a setting screen for setting automatic adjustment. The setting screen is displayed on the display 225 by the CPU 222. The user can set automatic adjustment from the setting screen using the operation unit 224. The user sets automatic adjustment before instructing execution of printing.

FIG. 5(a) is an initial screen. When the user selects the “applied mode” soft key from the initial screen, the CPU 222 displays the applied mode selection screen of FIG. 5(b) on the display 225. When the user selects the soft key "adjust" from the application mode selection screen, the CPU 222 displays the automatic adjustment setting screen of FIG. 5(c) on the display 225. When the user selects the soft key "Set" from the automatic adjustment setting screen, the CPU 222 displays the adjustment frequency selection screen shown in FIG. 5(d) on the display 225.

When the user selects the soft key "predetermined interval" from the adjustment frequency selection screen, the CPU 222 displays the adjustment interval setting screen of FIG. 5(e) on the display 225. Automatic adjustment is enabled when the user inputs the number of sheets using the numeric keys on the adjustment interval setting screen and presses the soft key "OK." In the example of FIG. 5E, the number of sheets at the adjustment interval is set to 10. An adjustment chart is created for each number of sheets set at the adjustment interval. That is, automatic adjustment is performed for each number of sheets set at the adjustment interval, and the image forming conditions are adjusted. Note that when the user selects the soft key "Cancel" from the automatic adjustment setting screen, the automatic adjustment is disabled.

When automatic adjustment is set, the CPU 222 displays an initial screen on the display 225. FIG. 5F shows the display 225 on which the initial screen is displayed, and includes a print button 601 and an interrupt button 602. When the user presses the print button 601, the CPU 222 executes printing. When automatic adjustment is enabled, the CPU 222 creates an adjustment chart for each number of sheets set in the adjustment interval. If automatic adjustment is disabled, no adjustment chart will be created.

Automatic adjustment can also be set for interrupt print jobs that are interrupt processing. When the user presses the interrupt button 602 during printing, settings for an interrupt print job are performed. After pressing the interrupt button 602, the user enables automatic adjustment, sets the adjustment interval to a predetermined number of sheets (for example, 5 sheets), and presses the print button 601. As a result, an adjustment chart is created for every five sheets during printing by the interrupt print job.

(Information when executing print job)
FIG. 6 is an exemplary diagram of job information stored in the memory 223 when a print job is executed. Job information is stored in the memory 223 by the CPU 222 in response to input of a print job or an interrupt print job.

Job information is managed by job ID. The job information includes a paper feed deck ID, the number of sheets at an adjustment interval, an automatic adjustment flag, an interrupt print flag, and a previous job ID. The paper feed deck ID indicates the paper feed deck that feeds sheets in the print job. The number of sheets at the adjustment interval is the number set on the adjustment interval setting screen. The automatic adjustment flag indicates the setting state of automatic adjustment. For example, if automatic adjustment is valid, the automatic adjustment flag is set to "1", and if automatic adjustment is invalid, the automatic adjustment flag is set to "0". The interrupt print flag indicates whether the job is an interrupt print job. For example, if it is an interrupt print job, the interrupt print flag is set to "1", and if it is not an interrupt print job, the interrupt print flag is set to "0". If the job is an interrupt print job, the previous job ID is the job ID of the print job that was being executed before the interrupt.

The image forming conditions adjusted by automatic adjustment are set for each paper feeding deck. The image forming conditions for each paper feeding deck are stored in the memory 223 as automatic adjustment information, for example. FIG. 7 is an exemplary diagram of automatic adjustment information. In this embodiment, a case will be described in which front and back registration adjustment is performed by automatic adjustment.

The automatic adjustment information is identified for each paper feed deck by the paper feed deck ID. The automatic adjustment information includes front and back registration adjustment values for each paper feeding deck. The front and back side registration adjustment values are values for adjusting (offsetting) the writing start position of each image on the front and back sides. The CPU 222 reads the automatic adjustment information at the timing of starting the print process. For example, in the case of a job that feeds sheets from the paper feeding deck 301 (first paper feeding deck), the CPU 222 reads the front and back registration main scanning offset value 802 and the front and back registration sub-scanning offset value 803 of the first paper feeding deck ID 801. to offset the image export position. The front and back registration main scanning offset value 802 and the front and back registration sub-scanning offset value 803 are updated based on the reading result of the adjustment chart.

(Image for adjustment)
FIG. 8 is an exemplary diagram of an adjustment chart. When automatic adjustment is enabled, an adjustment image is printed on a sheet every number of sheets set in the adjustment interval, and an adjustment chart is created. The adjustment image on the front side of the adjustment chart is read by the CIS 321, and the adjustment image on the back side is read by the CIS 322. The CPU 222 calculates the amount of deviation of the adjustment image from the reference position from the reading results of the adjustment charts by the CIS 321 and 322, and calculates each adjustment value in the main scanning direction and the sub-scanning direction (front and back registration main scanning offset value and front and back registration Determine the registration sub-scanning offset value). The CPU 222 updates the automatic adjustment information in the memory 223 using the determined adjustment value. For example, when feeding paper from the paper feeding deck 301, the CPU 222 updates the front/back registration main scanning offset value 802 and the front/back registration sub-scanning offset value 803 using the determined adjustment value.

(Print processing)
9 and 10 are flowcharts showing print processing. This print process shows how an interrupt print job is handled when automatic adjustment is enabled and when automatic adjustment is disabled.

When the CPU 222 starts printing processing, it acquires job information corresponding to the printing job (S501). Based on the paper feed deck ID included in the acquired job information, the CPU 222 refers to the automatic adjustment information of the paper feed deck and determines the front and back registration main scanning offset value and the front and back registration sub-scanning offset value (S502 ). Hereinafter, the front and back registration main scanning offset value and the front and back registration sub-scanning offset value are collectively referred to as the "front and back registration adjustment value." The CPU 222 determines whether automatic adjustment is effective based on the automatic adjustment flag in the job information (S503).

If automatic adjustment is valid (S503: Y), the CPU 222 determines whether the image to be printed is an adjustment image (S504). The CPU 222 determines whether the image to be printed is an adjustment image, for example, based on whether the number of sheets already printed is equal to the interval number.

If the image to be printed is an adjustment image (S504: Y), the CPU 222 performs automatic adjustment. The CPU 222 prints an adjustment image on a sheet to create an adjustment chart. In the adjustment chart, an adjustment image is read by the CIS 321 and 322. The CPU 222 acquires the reading results of the adjustment images from the CIS 321 and 322 (S505). The CPU 222 calculates adjustment values based on the reading results of the adjustment images, and updates the front and back registration adjustment values (S506).
If the image to be printed is not an adjustment image (S504:N), the CPU 222 prints the image corresponding to the print job on the sheet (S511).

When the front and back registration adjustment values have been updated or image printing has been completed, the CPU 222 determines whether printing of all pages according to the print job has been completed (S507). If all pages have been printed (S507: Y), the CPU 222 checks whether the interrupt print flag in the job information is on (S508). If the interrupt print flag is on (S508: Y), the current job is an interrupt print job. In this case, the CPU 222 refers to the job ID of the previous job using the job information and obtains the job information of the previous job (S509). The previous job is a job interrupted by an interrupt print job. Based on the paper feed deck ID included in the job information of the previous job, the CPU 222 refers to the automatic adjustment information of the paper feed deck and determines the front and back registration adjustment values (S510). The CPU 222 performs the remaining print processing of the previous job through the processing from S503 onwards. Note that if the interrupt printing flag is off (S508: N), the CPU 222 ends the printing process.

If all pages corresponding to the print job have not been printed (S507: N), the CPU 222 determines whether there is an interrupt print request for the next job (S513). If there is an interrupt print request (S513: Y), the CPU 222 acquires job information of the interrupt print job (S514). Based on the paper feed deck ID included in the acquired job information, the CPU 222 refers to the automatic adjustment information of the paper feed deck to determine front and back registration adjustment values (S515). The CPU 222 performs print processing using an interrupt print job through the processing from S503 onwards. If there is no interrupt printing request (S513:N), the CPU 222 performs subsequent printing processing by the processing from S504 onwards.

Next, processing when automatic adjustment is disabled will be explained (FIG. 10).
If automatic adjustment is disabled (S503:N), the CPU 222 prints an image corresponding to the print job on the sheet (S516). When image printing is completed, the CPU 222 determines whether printing of all pages according to the print job has been completed (S517). If all pages have been printed (S517: Y), the CPU 222 checks whether the interrupt print flag in the job information is on (S518). If the interrupt print flag is on (S518: Y), the current job is an interrupt print job. In this case, the CPU 222 refers to the job ID of the previous job using the job information and obtains the job information of the previous job (S519). The previous job is a job interrupted by an interrupt print job. Based on the paper feed deck ID included in the job information of the previous job, the CPU 222 refers to the automatic adjustment information of the paper feed deck to determine front and back registration adjustment values (S520). The CPU 222 performs the remaining print processing of the previous job through the processing from S503 onwards. Note that if the interrupt printing flag is off (S518:N), the CPU 222 ends the printing process.

If all pages corresponding to the print job have not been printed (S517: N), the CPU 222 determines whether there is an interrupt print request for the next job (S522). If there is an interrupt print request (S522: Y), the CPU 222 acquires job information of the interrupt print job (S523). The CPU 222 checks whether the same paper feeding deck is used for the interrupt print job and the interrupted job and whether automatic adjustment of the acquired job information is enabled (S524).

If the same paper feed deck is used and automatic adjustment is enabled (S524: Y), the CPU 222 does not execute the interrupt print job (S525), continues the print job in progress, and executes the print job from S516 onward. Perform processing. Note that in this case, the CPU 222 may display a warning screen on the display 225 to notify the user that the interrupt print job will not be executed. Further, the CPU 222 may display a selection screen on the display 225 for selecting whether or not to execute an interrupt print job after the job currently being executed is completed. Depending on the selection screen, the user can use the operation unit 224 to instruct the interrupt print job to be executed after the job being executed is finished.

If the same paper feeding deck is not used or automatic adjustment is not enabled (S524: N), the CPU 222 automatically adjusts the paper feeding deck based on the paper feeding deck ID included in the acquired job information. The front and back registration adjustment values are determined with reference to the information (S526). The CPU 222 performs print processing using an interrupt print job through the processing from S503 onwards. In other words, an interrupt print job is executed when the paper feed deck used is different from the paper feed deck of the job being executed, or when automatic adjustment is disabled even if the paper feed deck is the same.

In this way, in a print job where the automatic adjustment flag is 0 (invalid), the automatic adjustment information is not updated because the printing of the adjustment image is not inserted while the image is being printed. Therefore, the adjustment value for the writing start position of the image being printed remains constant. In addition, even if an interrupt print job is interrupted, if there is a possibility that the automatic adjustment information being used may be updated by the interrupt print job, the switch to the interrupt print job will not be performed and the The print job continues. Therefore, the automatic adjustment value is not updated and remains constant.

In this embodiment, the front and back registration adjustment values have been described as an example of automatic adjustment information, but even if image density adjustment values or color shift correction values are used as automatic adjustment information, the processing in FIGS. 9 and 10 may be applied. is valid. Further, although the inhibition of interrupt processing is determined based on the paper feed deck, the present invention is not limited to this, and other printing conditions may be used as conditions for determining inhibition of interrupt processing.

Claims (6)

an image forming means for forming an image on a sheet based on image forming conditions;
a reading means for reading an image for adjusting the image forming conditions formed on the sheet;
an adjustment unit that adjusts the image forming conditions based on a reading result of the adjustment image by the reading unit, and when forming an image on a sheet according to a print job, the image forming unit adjusts the image forming condition. and an image forming apparatus capable of automatically adjusting the image forming conditions by forming the adjustment image on a sheet and using the adjustment means to adjust the image forming conditions based on the reading result of the adjustment image by the reading means. There it is,
If an interrupt command for a second print job for which the automatic adjustment is enabled is received during a period in which an image is formed on a sheet in accordance with the first print job for which the automatic adjustment is set to be disabled, the second printing characterized by comprising a control means for prohibiting execution of job interrupt processing;
Image forming device. comprising a plurality of paper feed decks for accommodating the sheets;
The control means is characterized in that when sheets are fed from the same paper feed deck for the first print job and the second print job, execution of an interrupt process for the second print job is prohibited .
The image forming apparatus according to claim 1. characterized by comprising an input means for setting either enable or disable the automatic adjustment,
The image forming apparatus according to claim 1 or 2. The control means is characterized in that, when the automatic adjustment is enabled, the control means performs the automatic adjustment every time the number of sheets on which images are formed by the image forming means reaches a predetermined number.
The image forming apparatus according to any one of claims 1 to 3. The image forming means forms the adjustment images on both sides of the sheet to create an adjustment chart,
The reading means includes a first reading sensor that reads the adjustment image formed on the first side of the adjustment chart, and a second reading sensor that reads the adjustment image formed on the second side of the adjustment chart. including a sensor;
The adjustment means adjusts the image forming conditions based on the reading result by the first reading sensor and the reading result by the second reading sensor,
The image forming apparatus according to any one of claims 1 to 4. The first reading sensor and the second reading sensor are optical sensors,
The image forming apparatus according to claim 5.

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