JP2024110617A - Image forming device - Google Patents

Abstract

[Problem] To improve the overall productivity of a job in which a plurality of jobs in which recording media are fed from different storage units are linked. [Solution] The apparatus includes an image forming unit, a feeding unit that feeds recording media from a plurality of storage units capable of storing recording media, an image reading unit that is provided downstream of the image forming unit in the recording medium transport direction and reads an image formed on the recording media by the image forming unit, and a control unit that executes an adjustment mode that adjusts image formation conditions based on information read from an adjustment pattern formed on the recording media, and when a linked job is executed in which a first job in which a first recording medium is fed from a first storage unit and a second job in which a second recording medium is fed from a second storage unit, the control unit executes the adjustment mode by interrupting the feeding of the first recording medium from the first storage unit during the execution of the first job, feeding the second recording medium from the second storage unit, and resuming the feeding of the first recording medium from the first storage unit before reading of the adjustment pattern formed on the second recording medium is started. [Selected Figure] Figure 9

Description

The present invention relates to an image forming device that forms an image on a recording medium.

Conventionally, in image forming devices, a specific pattern such as a gradation adjustment pattern is printed on a recording medium such as paper in the image forming unit, the specific pattern is read by the image reading unit, and the read information is fed back to image forming conditions such as gamma correction. In this way, a method of improving the stability of image quality is known.

In conventional image forming devices, tone correction corrects the tone characteristics of image data so that the tone characteristics of the image forming device match the target tone characteristics. In Patent Document 1, a band pattern of a specific tone of a predetermined length extending in the main scanning direction is formed on a recording medium, and density measurements are taken at multiple positions and fed back to the image formation conditions, thereby suppressing density unevenness in the main scanning direction.

JP 2011-191414 A

It is known that the resistance value and surface properties of recording media vary depending on the type. Therefore, even if the amount of toner on the image carrier is the same, the density that appears on the recording media may differ depending on the type of recording media. Furthermore, even if the recording media is the same type, if the conditions inside the image forming device change (for example, changes in development characteristics due to toner replenishment, or changes in transfer characteristics due to changes in temperature and humidity), the density that appears on the recording media may change due to this influence. Therefore, it is necessary to adjust the image formation conditions using adjustment values that take into account the type of recording media and changes in conditions inside the image forming device.

For example, when multiple jobs that feed recording media from different storage units are linked together and the image formation conditions of the later job are to be adjusted, the specific pattern described above must be read by the image reading unit before the later job is executed. However, in this case, the start of the later job must wait for the time it takes for the recording medium to be used for the later job to travel from the storage unit through the image forming unit to the image reading unit. This poses the problem of reduced productivity for the entire job in which multiple jobs that feed recording media from different storage units are linked together.

The object of the present invention is to improve the overall productivity of multiple linked jobs that feed recording media from different storage units when performing such a job.

A typical configuration of the present invention for achieving the above object includes an image forming unit that forms an image on a recording medium, a feeding unit that feeds the recording medium from a plurality of storage units capable of accommodating the recording medium, an image reading unit that is provided downstream in the recording medium transport direction from the image forming unit and reads the image formed on the recording medium by the image forming unit, and a control unit that controls the image forming unit, the feeding unit, and the image reading unit to implement an adjustment mode that adjusts image formation conditions based on information read from an adjustment pattern formed on the recording medium, and the control unit controls a first job of feeding a first recording medium from a first storage unit to form an image, and a second job of feeding the first recording medium from a first storage unit to form an image. When a linked job is performed in which a second job is performed in which a second recording medium is fed from a second storage unit different from the storage unit to form an image, the feeding of the first recording medium from the first storage unit is interrupted during the execution of the first job, the second recording medium is fed from the second storage unit, and the feeding of the first recording medium from the first storage unit is resumed before reading of the adjustment pattern formed on the second recording medium is started, and the adjustment mode is performed to adjust the image formation conditions of the second job based on information obtained by reading the adjustment pattern formed on the second recording medium.

According to the present invention, when performing a job that links multiple jobs that feed recording media from different storage units, it is possible to improve the productivity of the entire linked job.

Overall diagram showing the hardware configuration of the image processing system Block diagram showing the system configuration of the image processing system FIG. 1 is a cross-sectional view showing a configuration of a main part of an image forming apparatus. Schematic diagram of the CIS unit A diagram explaining adjustment patterns Four-limit chart showing density correction overview A table showing an example of a job list for linked jobs. FIG. 13 is a table showing an example of a job list in which an interrupt adjustment is made to a previous job in a linked job. Flowchart showing the operation of a print job

The following describes in detail the preferred embodiments of the present invention by way of example, with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments should be appropriately changed depending on the configuration and various conditions of the device to which the present invention is applied, and are not intended to limit the scope of the present invention to these alone.

In the following description, the external controller may also be called an image processing controller, digital front end, print server, DFE, etc. The image forming device may also be called a printer, multifunction device, multifunction peripheral, or MFP.

(Schematic configuration of image processing system)
The configuration of the image processing system will be described with reference to Figures 1 and 2. Figure 1 is an overall diagram of the hardware configuration of the image processing system according to this embodiment. The image processing system includes an image forming apparatus 101 and an external controller 102. The image forming apparatus 101 and the external controller 102 are communicatively connected via an internal LAN 105 and a video cable 106. The external controller 102 is communicatively connected to a client PC 103 via an external LAN 104, and a print instruction is sent from the client PC 103 to the external controller 102.

A printer driver is installed in the client PC 103 that has the function of converting print data into a print description language that can be processed by the external controller 102. A user who performs printing can issue a print instruction from the client PC 103 (various applications) via the printer driver. The printer driver sends print data to the external controller 102 based on the print instruction from the user. When the external controller 102 receives a print instruction from the client PC 103, it performs data analysis and rasterization processing, and sends the print data to the image forming device 101 to issue a print instruction.

Next, the image forming apparatus 101 will be described. The image forming apparatus 101 includes a printing device 107 and a finisher 109 connected to the printing device 107, and is configured to be capable of processing such as printing and bookbinding.

The printing device 107 forms an image using toner on a recording medium conveyed from a feed unit 230 (see FIG. 3) at the bottom of the printing device 107. The configuration and operating principle of this printing device 107 are as follows. A light beam such as a laser beam modulated according to image data is reflected by a rotating polygon mirror such as a polygon mirror and irradiated as a scanning light onto a photosensitive drum, forming an electrostatic latent image on the photosensitive drum. The electrostatic latent image formed on the photosensitive drum by this laser beam is developed by toner. The toner image formed on the photosensitive drum is transferred to the recording medium via an intermediate transfer belt. This series of image formation processes is performed on the photosensitive drums for each color of yellow (Y), magenta (M), cyan (C), and black (K), and the toner images formed on each photosensitive drum are superimposed on the intermediate transfer belt to form a full-color image on the recording medium. The recording medium on which the full-color image has been formed is conveyed to the fixing unit 229 (see FIG. 3). The fixing unit includes a rotating body such as a roller or belt, and the roller has a heat source such as a halogen heater built in. The toner on the recording medium to which the toner image has been transferred is melted by heat and pressure, and fixed to the recording medium.

The finisher 109 is connected to the printing device 107 and can perform processes such as bookbinding and load recording media.

Note that, although the image processing system described in FIG. 1 has a configuration in which the external controller 102 is connected to the image forming device 101, the present invention is not limited to a configuration in which the external controller 102 is connected. For example, the image forming device 101 may be connected to an external LAN 104, and processable print data may be sent from a client PC 103 to the image forming device 101. In this case, data analysis and rasterization processing are performed in the image forming device 101, and print processing is executed.

(Block diagram of image processing system)
FIG. 2 is a block diagram showing a system configuration of the image forming apparatus 101, the external controller 102, and the client PC 103. As shown in FIG.

First, the configuration of the printing device 107 of the image forming apparatus 101 will be described. The printing device 107 is composed of a communication I/F 217, a LAN I/F 218, a video I/F 220, a HDD 221, a CPU 222, a memory 223, an operation unit 224, a display 225, and a job analysis unit 226. The printing device 107 further includes a laser exposure unit 227, an image creation unit 228, a fixing unit 229, a feeding unit 230, and an image reading unit 241. Each of the components is connected via a system bus 231.

The communication I/F 217 is connected to the finisher 109 via a communication cable 279, and communication for controlling each device is performed. The LAN I/F 218 is connected to the external controller 102 via the internal LAN 105, and communication of print data and the like is performed. The video I/F 220 is connected to the external controller 102 via the video cable 106, and communication of image data and the like is performed.

The HDD 221 is a storage device in which programs and data are stored. The CPU 222 is a control unit that comprehensively controls image processing and printing based on the programs and the like stored in the HDD 221. The memory 223 stores programs and image data required when the CPU 222 performs various processes, and operates as a work area. The operation unit 224 accepts various setting inputs and operation instructions from the user. The display 225 displays setting information of the image forming device, the processing status of a print job, and the like. The job analysis unit 226 analyzes setting information of the image forming device and print data received from the external controller 102.

The laser exposure unit 227 is a device that performs primary charging and laser exposure to irradiate the photosensitive drum with laser light in order to transfer a toner image. In the laser exposure unit 227, primary charging is first performed to charge the surface of the photosensitive drum to a uniform negative potential. The laser exposure unit 227 converts the light into laser light using a laser driver, and irradiates the photosensitive drum with the laser light while adjusting the reflection angle using a polygon mirror. This neutralizes the negative charge on the part of the photosensitive drum surface that is irradiated with the laser light, and an electrostatic latent image is formed on the photosensitive drum.

The image forming unit 228 is an image forming unit that forms an image (toner image) on a recording medium, and is composed of a photosensitive drum, a developing unit, a transfer unit, a toner supply unit, etc. In the developing unit, negatively charged toner from a developing sleeve is attached to the electrostatic latent image on the surface of the photosensitive drum, creating a visible image. In the transfer unit, a positive potential is applied to the primary transfer roller to perform primary transfer, transferring the toner on the surface of the photosensitive drum to the intermediate transfer belt. In the transfer unit, a positive potential is applied to the secondary transfer outer roller to perform secondary transfer, transferring the toner on the intermediate transfer belt to the recording medium.

The fixing unit 229 is a device for fixing the toner on the recording medium to the recording medium using heat and pressure, and is composed of a heater, a fixing roller, a pressure roller, etc.

The feed unit 230 is a feed unit for feeding recording media from multiple storage units, such as cassettes, that can store recording media, and is composed of multiple storage units, rollers, various sensors, etc.

The image reading unit 241 is composed of CIS (Contact Image Sensor) units 321 and 322 (see Figure 4), and reads the image on the transported recording medium based on instructions from the CPU 222.

Next, the configuration of the finisher 109 of the image forming apparatus 101 will be described. The finisher 109 is composed of a communication I/F 271, a CPU 272, a memory 273, and a paper discharge control unit 274, and each component is connected via a system bus 275. The communication I/F 271 is connected to the printing apparatus 107 via a communication cable 279, and communication required for control is performed. The CPU 272 performs various controls required for paper discharge according to a control program stored in the memory 273. The memory 273 is a storage device in which the control program is saved. The paper discharge control unit 274 controls the transport of the transported recording medium to the stack tray 332 based on instructions from the CPU 272.

Next, the configuration of the external controller 102 will be described. The external controller 102 is composed of a CPU 208, a memory 209, a HDD 210, a keyboard 211, a display 212, a LAN I/F 213, a LAN I/F 214, and a video I/F 215, and is connected through a system bus 216. The CPU 208 comprehensively executes processes such as receiving print data from the client PC 103, RIP processing, and sending print data to the image forming device 101 based on the programs and data stored in the HDD 210. The memory 209 stores programs and data required for the CPU 208 to perform various processes, and operates as a work area. The HDD 210 stores programs and data required for operations such as printing processing. The keyboard 211 is a device for inputting operation instructions for the external controller 102. The display 212 displays information such as the execution application of the external controller 102 by video signals of still images and moving images. The LAN I/F 213 is connected to the client PC 103 via the external LAN 104, and performs communication such as print instructions. The LAN I/F 214 is connected to the image forming apparatus 101 via the internal LAN 105, and performs communication such as print instructions. The video I/F 215 is connected to the image forming apparatus 101 via the video cable 106, and performs communication such as print data.

Next, the configuration of the client PC 103 will be described. The client PC 103 is composed of a CPU 201, a memory 202, a HDD 203, a keyboard 204, a display 205, and a LAN I/F 206, which are connected via a system bus 207. The CPU 201 creates print data and executes print instructions based on a document processing program stored in the HDD 203. The CPU 201 also comprehensively controls each device connected to the system bus 207. The memory 202 stores programs and data required for the CPU 201 to perform various processes, and operates as a work area. The HDD 203 stores programs and data required for operations such as print processing. The keyboard 204 is a device for inputting operation instructions for the client PC 103. The display 205 displays information such as the application executed by the client PC 103 using video signals of still images and moving images. The LAN I/F 206 is connected to the external controller 102 via the external LAN 104, and communication such as print instructions is performed.

In the above description, the external controller 102 and the image forming device 101 are connected by the internal LAN 105 and the video cable 106, but any other configuration is acceptable as long as it allows transmission and reception of data necessary for printing, and for example, a connection configuration of only a video cable is also acceptable. Also, the memory 202, memory 209, and memory 223 may each be a storage device for holding data and programs. For example, they may be replaced by volatile RAM, non-volatile ROM, an internal HDD, an external HDD, a USB memory, etc.

(Basic Image Forming Operation of Image Forming Apparatus)
The operation of the image forming apparatus 101 will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view showing the main components of the image forming apparatus 101 in this embodiment. The printing device 107 is a device that forms an image to be printed on a recording medium. As described above, the printing device 107 of the image forming apparatus 101 includes a laser exposure unit 227, an image creating unit 228, a fixing unit 229, a feeding unit 230, and an image reading unit 241. Note that the laser exposure unit is not shown in Fig. 3.

The feeding unit 230 has paper feed stages 301 and 302, which are multiple storage sections capable of storing recording media. Paper feed stages 301 and 302 can store different types of recording media. The feeding unit 230 can separate only the topmost recording medium from the recording media stored in paper feed stages 301 and 302, and transport it to the transport path 303.

Here, the first recording medium accommodated in the first feed stage 301, which is the first storage unit, and the second recording medium accommodated in the second feed stage 302, which is a second storage unit different from the first storage unit, are of different types. More specifically, the first recording medium accommodated in the first feed stage 301 and the second recording medium accommodated in the second feed stage 302 are of different thicknesses. Here, the first feed stage 301 accommodates plain paper (first recording medium), and the second feed stage 302 accommodates cardboard (second recording medium) that is thicker than the plain paper. In this case, the feeding unit 230 can separate only the topmost plain paper sheet of the plain paper accommodated in the first feed stage 301 and transport it to the transport path 303. In addition, the feeding unit 230 can separate only the topmost sheet of cardboard stored in the second paper feed tray 302 and transport it to the transport path 303.

The types of recording media that can be stored in the multiple storage sections are not limited to the above, and recording media with different resistance values and surface properties, such as coated paper and glossy paper, are also possible.

The image forming unit 228 is an image forming unit that forms an image on a recording medium, and has developing stations 304 to 307. To form a color image, the developing stations 304 to 307 form toner images on each photosensitive drum using yellow (Y), magenta (M), cyan (C), and black (K) color toners, respectively. The toner images formed on each photosensitive drum are primarily transferred so as to be superimposed on the intermediate transfer belt 308 that rotates in the clockwise direction in FIG. 3. The toner images transferred to the intermediate transfer belt 308 are then transferred by the secondary transfer unit 309 to the recording medium transported from the transport path 303.

The display 225 displays information about the printing status and settings of the image forming device 101.

The fixing section 229 is provided downstream of the image forming section 228 in the conveying direction of the recording medium and upstream of the image reading section 241 in the conveying direction of the recording medium. The fixing section 229 has a fixing unit 311 for fixing the toner image to the recording medium and a second fixing unit 313. The fixing unit 311 has a pressure roller and a heating roller, and the toner is melted and pressed by heat and pressure as the recording medium passes between the rollers, thereby fixing the toner image to the recording medium. The recording medium that has passed through the fixing unit 311 is conveyed to the conveying path 315 through the conveying path 312. If further melting and pressing are required for fixing depending on the type of recording medium, after passing through the fixing unit 311, it is conveyed to the second fixing unit 313 using the upper conveying path, and after additional melting and pressing are performed, it is conveyed to the conveying path 315 through the conveying path 314.

When the image formation mode is double-sided, the recording medium with the image fixed on one side is transported from transport path 312 or transport path 314 to reversing path 316, which constitutes an inversion section. After the recording medium is inverted in reversing path 316, it is transported to double-sided transport path 317, where the image is transferred to the other side in secondary transfer section 309. The inversion section (reversing path 316), which inverts the recording medium, is provided downstream in the transport direction of the recording medium from image creation section 228 (image formation section).

CIS units 321 and 322 constituting the image reading unit 241 are arranged downstream of the imaging unit 228 in the transport direction of the recording medium. The CIS units 321 and 322 are arranged facing each other across a transport path 323 that is downstream of the transport path 315 in the transport direction of the recording medium. As shown in FIG. 4, the CIS unit 321 is a first image reading unit for reading an image on the top surface, which is one side of the recording medium, and the CIS unit 322 is a second image reading unit for reading an image on the bottom surface, which is the other side opposite the one side of the recording medium.

When the recording medium conveyed to the conveying path 323 reaches a predetermined position, if real-time adjustment is specified, the adjustment pattern on the recording medium is read using the CIS units 321 and 322. If the recording medium conveyed to the conveying path 323 is an adjustment chart paper on which an adjustment pattern is formed, the adjustment pattern on the adjustment chart paper is read using the CIS units 321 and 322. The CIS units 321 and 322 each have an LED 350 or 352 and a reading sensor 351 or 353. The CPU 222 causes the LED 350 or 352 to emit light, and the reading sensor 351 or 353 reads the reflected light from the adjustment pattern. The adjustment pattern formed on the recording medium will be described later with reference to FIG. 5. The CIS unit may also be another optical system sensor such as a CCD image sensor or a CMOS image sensor.

The CPU 222 feeds back the information read by the image reading unit 241 to the image formation conditions, and stores and manages the information in the memory 223 as new image formation conditions. The CPU 222 controls the image forming device 101, which includes the image creating unit 228, the feed unit 230, and the image reading unit 241, and selectively implements an adjustment mode that adjusts the image formation conditions based on information read from an adjustment pattern formed on a recording medium.

For example, when the temperature inside the printing device 107 rises, the density of the image formed on the recording medium fluctuates compared to when the temperature inside the printing device 107 is low. The CPU 222 reads the adjustment pattern formed on the recording medium using the CIS unit, and based on the read information, obtains the amount of variation from the previously read information (information before the temperature inside the machine changed). The CPU 222 then determines an adjustment value for adjusting the image formation conditions based on the obtained amount of variation, and reflects this adjustment value in the image formation conditions, thereby adjusting so that the image on the recording medium is always formed with the same density. This aims to stabilize the image density precision.

If the recording medium transported to the transport path 352 is an adjustment chart paper, the flapper 324 is switched to a direction to transport the recording medium to the discharge path 326. The recording medium transported to the discharge path 326 is discharged to the discharge tray 328. If the recording medium transported to the transport path 323 is not an adjustment chart paper, the flapper 324 is switched to a direction to transport the recording medium to the downstream transport path 325. The recording medium transported to the downstream transport path 325 is transported to the finisher 109. If the finisher 109 notifies the user that a transport jam has occurred, the flapper 324 is switched to a direction to transport the recording medium to the discharge path 326 and discharged to the discharge tray 328 even if the recording medium is not an adjustment chart paper. Then, by discharging all remaining paper to the discharge tray 328, the user's jam processing burden can be reduced.

The finisher 109 is a device capable of stacking a large volume of recording media. The finisher 109 has a stack tray 332 as a tray for stacking recording media. Recording media transported from the printing device 107 are loaded onto the stack tray 332 via a transport path 331. The finisher 109 detects the passage of the recording media with transport sensors 334, 335, and 336. If the leading or trailing end of the recording media does not reach the transport sensors 334, 335, and 336 even after a predetermined time has elapsed, the CPU 272 of the finisher 109 determines that a transport jam has occurred within the finisher 109, and notifies the CPU 222 of the printing device 107 that a transport jam has occurred.

(Adjustment Pattern on Recording Medium)
The adjustment pattern 501 formed on the recording medium 500 will be described with reference to Fig. 5. Fig. 5 is a diagram showing the recording medium 500 on which the adjustment pattern 501 is formed. The recording medium 500 shown in Fig. 5 is passed along the longitudinal direction of the recording medium 500. The arrow in Fig. 5 indicates the transport direction of the recording medium 500.

The adjustment patterns 501 are formed on one side of the recording medium 500 for each of the colors C (cyan), M (magenta), Y (yellow), and K (black). The adjustment patterns 501 are made up of multiple gradation patches with gradually differing gradation values for C, M, Y, and K. In other words, the adjustment patterns 501 are patterns in which multiple gradation patches with different image densities are formed.

In the example shown in FIG. 5, the adjustment pattern 501 for each color has 11 gradation patches formed in the transport direction. The multiple gradation patches of each adjustment pattern 501 are each a square with sides of 8 mm, and are arranged in a line for each color in the transport direction of the recording medium 500. Furthermore, the adjustment pattern 501 for each color, which is formed with 11 gradation patches, has patches that read the background of the recording medium 500 (i.e., patches with a density gradation value of 0) arranged at both ends in the transport direction, and the other nine gradation patches are evenly arranged between the patches at both ends by density gradation value. In other words, when the density gradation value of each color is expressed as 0 to 255, the density gradation values of the 11 gradation patches of each adjustment pattern 501 are 0, 16, 32, 64, 86, 104, 128, 176, 224, 255, and 0 in the transport direction of the recording medium 500.

The tone patches of the adjustment pattern 501 are not limited to the colors C, M, Y, and K, but may be formed for each color of RGB or process Bk, etc. Furthermore, the size, number of tones, tone order, and patch arrangement of the tone patches of the adjustment pattern 501 are not limited to the example shown in FIG. 5.

(Overview of density correction)
Density correction will be described with reference to Fig. 6. Fig. 6 is a quartile chart showing how gradation is reproduced. Here, image density correction (adjustment) is illustrated as an example of adjustment of image forming conditions.

Quadrant I shows the reading characteristics of the sensor that converts the density of the original image into a density signal. Quadrant II shows the conversion characteristics (data characteristics) of the γLUT for converting the density signal into a laser output signal. Quadrant III shows the recording characteristics (printer characteristics) of the printer unit that converts the laser output signal into the density of the output image. Quadrant IV shows the relationship between the density of the original image and the density of the output image. That is, the quadrant chart in FIG. 6 shows the total gradation reproduction characteristics of the image forming apparatus 101 shown in FIG. 1. Note that the figure shows the case where the number of gradations is 256 gradations, assuming that processing is performed with an 8-bit digital signal. Here, the sensor in quadrant I includes the reading sensors 351 and 353 (see FIG. 4) that read the adjustment pattern 501 on the recording medium 500. In order to make the total gradation characteristics of the image forming apparatus 101, that is, the gradation characteristics in quadrant IV, linear, the non-linear portion of the printer characteristics in quadrant III is corrected by the γLUT in quadrant II. The image signal, whose gradation characteristics have been converted by the γLUT, is converted into a pulse signal corresponding to the dot width by the pulse width modulation (PWM) circuit of the laser driver, and is sent to the LD driver that controls the on/off of the laser exposure unit 227. In this embodiment, a gradation reproduction method using pulse width modulation is used for all colors of Y, M, C, and K.

Then, an electrostatic latent image having a predetermined gradation characteristic is formed on the photosensitive drum by scanning the laser light output from the laser exposure unit 227, and the gradation is controlled by changing the dot area, and the gradation image is reproduced through the above-mentioned processes of development, transfer, and fixing.

(Job Execution Flow)
Next, the print processing in this embodiment will be described with reference to Figs. 7, 8, and 9. Fig. 7 is a table showing an example of a job list of linked jobs. Fig. 8 is a table showing an example of a job list in which an interrupt adjustment is made in a previous job in a linked job. Fig. 9 is a flow chart showing the execution flow of the print processing in this embodiment.

In this embodiment, the control unit, CPU 222, performs print processing according to the job execution flow shown in FIG. 9.

The CPU 222, which is the control unit, receives data for job 1 (first job) from the external controller 102, which involves feeding and printing N sheets of the first recording medium (plain paper in this case) from the first paper feed tray 301. The CPU 222 then starts job 1 by feeding the first recording medium one sheet at a time from the first paper feed tray 301 (S901, S902).

The CPU 222 receives data for job 2 (second job) from the external controller 102, which involves feeding and printing M sheets of a second recording medium (here, cardboard) from a second paper feed tray 302 different from the first paper feed tray 301 (S903). The CPU 222 then updates the job list (FIGS. 7 and 8) so that jobs 1 and 2 are combined and printed consecutively (S904).

Here, FIG. 7 shows a job list of linked jobs that link job 1, which feeds N sheets of a first recording medium from the first paper feed tray 301 to form an image, and job 2, which feeds M sheets of a second recording medium from the second paper feed tray 302 to form an image.

Figure 8 shows a job list in which a page of an adjustment job for the next job that is executed consecutively to job 1 has been added to job 1, out of the linked jobs that link job 1 and job 2.

That is, in S904, the CPU 222 updates the job list by adding an adjustment job page for adjusting the image formation conditions of the next job 2 while job 1 is being performed. The CPU 222 compares the time required to feed the second recording medium from the second paper feed stage 302 and read the adjustment pattern by the image reading unit 241 with the time required to complete job 1, calculates the appropriate adjustment timing for adding an adjustment job page for the next job during job 1, and updates the job list.

The appropriate adjustment timing for adding a page of the adjustment job (the second recording medium in the second paper feed tray 302) is the timing during the execution of job 1, near the end of job 1. The adjustment timing for adding a page of the adjustment job may be shorter than the time taken to feed the second recording medium from the second paper feed tray 302 and read the adjustment pattern by the image reading unit 241, going back from the time when job 1 ends. Specifically, as shown in FIG. 8, the timing for adding a page of the adjustment job (page ID: N-1 shown in FIG. 8) is illustrated just before the feeding of the first recording medium (page ID: N shown in FIG. 8) starts near the end of job 1. The reason for performing the adjustment near the end of job 1 is to adjust the image forming conditions in the same environment (temperature) inside the image forming apparatus as when job 2 starts.

Then, the CPU 222 continues job 1 until the determined adjustment timing arrives (S905).

When the adjustment timing occurs during job 1, the CPU 222 determines whether the internal environment of the image forming device has changed compared to the previous time printing was performed from the second paper feed tray 302 (S906).

Here, the change in temperature inside the image forming device 101 is shown as an example of the internal environment of the image forming device. The image forming device 101 has a temperature detection means (not shown) such as a temperature sensor that detects the internal temperature. The CPU 222 monitors the internal temperature of the image forming device 101 using information from the temperature sensor.

That is, the CPU 222 determines whether the internal temperature of the image forming device 101 when the linking job is executed has changed compared to the internal temperature of the image forming device 101 when the previous job 2 was executed before the linking job was executed (S906).

If the CPU 222 determines in S906 that the internal temperature of the image forming device 101 has changed compared to the internal temperature of the image forming device 101 during the previous job 2, it uses the job list shown in FIG. 8 to implement the adjustment mode shown in S907 to S911 during the execution of job 1.

On the other hand, if the CPU 222 determines in S906 that the internal temperature of the image forming device 101 has not changed compared to the internal temperature of the image forming device 101 during the previous job 2, the CPU 222 does not execute the adjustment mode using the job list shown in FIG. 7 and proceeds to S912.

When the CPU 222 executes the adjustment mode in S906, it first interrupts job 1 (feeding of the first recording medium from the first paper feed tray 301) and switches the paper feed tray to feeding from the second paper feed tray 302 (S907).

In this case, out of job 1 which feeds N sheets of the first recording medium, job 1 is interrupted after the feeding of the first recording medium (page ID: N-2 shown in FIG. 8) from the first paper feed tray 301 immediately before feeding the first recording medium (page ID: N shown in FIG. 8) near the end of job 1. Then, the paper feed tray to be fed is switched to feeding from the second paper feed tray 302.

After switching the paper feed tray to the second paper feed tray 302, the CPU 222 feeds the second recording medium (page ID: N-1 shown in FIG. 8) from the second paper feed tray 302 as the adjustment recording medium (S908). When the fed adjustment recording medium reaches the image creation unit 228, the image creation unit 228 prints the adjustment pattern 501 on the adjustment recording medium (S909).

After the CPU 222 has fed the adjustment recording medium from the second feed tray 302, it switches the feed tray to the first feed tray 301 and resumes job 1 (feeding the first recording medium from the first feed tray 301) (S910).

Here, out of job 1 which feeds N sheets of the first recording medium, feeding of the (N-1)th first recording medium (page ID: N shown in FIG. 8), which is the page immediately before the final page, is resumed. In addition, feeding of the first recording medium from the first paper feed stage 301 is resumed before reading of the adjustment pattern 501 formed on the adjustment recording medium (second recording medium) begins.

Then, the CPU 222 reads the adjustment pattern 501 when the adjustment recording medium reaches the image reading unit 241 (S911). The CPU 222 then obtains an adjustment value for adjusting the image formation conditions from the variable value obtained based on the read information, and sets the obtained adjustment value as the adjustment value for the image formation conditions of job 2, which feeds and prints the second recording medium from the second paper feed stage 302.

The amount of variation obtained based on the read information here refers to the amount by which the relationship between the internal temperature of the image forming device and the image density has changed compared to when the previous job was performed. The adjustment value is a correction value for the image density calculated from the amount of variation so that the image density is the same as when the previous job was performed. This information is stored in memory 223 for each type of recording medium.

In this way, the CPU 222 executes an adjustment mode to obtain adjustment values for adjusting the image formation conditions of the next job 2 while the previous job 1 of the linked jobs is being performed.

Then, when all pages of job 1 are output, the CPU 222 ends job 1. When job 1 ends, the CPU 222 reflects the adjustment values in the image formation conditions of the next job 2, switches the paper feed tray to the second paper feed tray 302, and starts job 2 by feeding the second recording medium one sheet at a time from the second paper feed tray 302 (S912).

Here, if there is a change in the temperature of the image forming device in S906, the CPU 222 corrects the image forming conditions for job 2 using the new adjustment values acquired in the above-mentioned adjustment mode (S907 to S911) and starts job 2. On the other hand, if there is no change in the temperature of the image forming device in S906, the CPU 222 corrects the image forming conditions using the adjustment values from the previous job 2 as is and starts job 2.

When all pages of job 2 have been output, the CPU 222 ends the linked job (FIGS. 7 and 8) linked in S904 (S913, S914).

As described above, according to this embodiment, when performing a linked job that links jobs 1 and 2, if it is necessary to adjust the image formation conditions of job 2, the adjustment mode described above can be performed while job 1 is being performed to obtain the adjustment values. Therefore, after the end of job 1, it is no longer necessary to wait for the start of the next job 2 until the second recording medium to be used in the next job 2 travels from the second paper feed stage through the imaging unit to the image reading unit. This makes it possible to improve the productivity of the entire linked job when performing a job that links multiple jobs in which recording media are fed from different paper feed stages. Furthermore, it is possible to suppress density fluctuations from the beginning of the job.

In the above-described embodiment, the job information received by the CPU 222 indicates which of a plurality of paper feed stages paper is to be fed from, but this is not limited to this, and the job information may also include the type of recording medium. The same effect can be obtained by applying the present invention even when implementing a linked job that links separate jobs that use different types of recording media.

In the above-described embodiment, a configuration was exemplified in which, when a linked job is being performed and adjustment of the image forming conditions of the subsequent job 2 is required, the adjustment mode is performed while the previous job 1 is being performed, but this is not limited to this. For example, when performing a linked job, if a predetermined time has passed since the previous job 2, which was performed before the linked job was performed, the CPU 222 performs the adjustment mode while job 1 is being performed. On the other hand, if the predetermined time has not passed since the previous job 2, the adjustment mode is not performed. A configuration like this is also acceptable. With this configuration, the same effect as the above-described configuration can be obtained.

In the above-described embodiment, the image forming unit has four development stations, but the number of stations is not limited to four and can be set as needed.

In the above-mentioned embodiment, a printer (printing device) including a finisher is exemplified as an image forming device, but the present invention is not limited to this, and may be other image forming devices such as a copier or facsimile machine. Or it may be other image forming devices such as a multifunction machine that combines these functions. In addition, an image forming device that uses an intermediate transfer body, transfers toner images of each color to the intermediate transfer body in a sequentially overlapping manner, and transfers the toner images carried on the intermediate transfer body to a recording medium all at once is exemplified, but is not limited to this. It may be an image forming device that uses a recording medium carrier, and transfers toner images of each color to the recording medium carried on the recording medium carrier in a sequentially overlapping manner. Similar effects can be obtained by applying the present invention to these image forming devices.

In the above-described embodiment, the recording method is an electrophotographic method, but the recording method is not limited to this, and other recording methods such as an inkjet method may also be used.

101: Image forming apparatus 107: Printing apparatus 109: Finisher 222: CPU (control unit)
223 ... memory (storage unit)
227 ... laser exposure unit 228 ... imaging unit (image forming unit)
229: fixing unit 230: feeding unit 241: image reading unit 301: first paper feed stage (first storage unit)
302 ... second paper feed tray (second storage section)
311 ... fixing unit 313 ... second fixing unit 316 ... reversing path (reversing section)
321 ... CIS unit (first image reading unit)
322 ... CIS unit (second image reading unit)
500: Recording medium 501: Adjustment pattern

Claims (8)

an image forming unit that forms an image on a recording medium;
a feeding unit that feeds the recording medium from a plurality of storage units that can store the recording medium;
an image reading unit provided downstream of the image forming unit in a recording medium transport direction and configured to read an image formed on the recording medium by the image forming unit;
a control unit that controls the image forming unit, the feeding unit, and the image reading unit to implement an adjustment mode in which image forming conditions are adjusted based on information obtained by reading an adjustment pattern formed on a recording medium;
Equipped with
When the control unit executes a linked job in which a first job for forming an image by feeding a first recording medium from a first storage unit and a second job for forming an image by feeding a second recording medium from a second storage unit different from the first storage unit are linked,
an image forming apparatus comprising: an image forming unit that, during execution of the first job, interrupts feeding of the first recording medium from the first storage unit, feeds the second recording medium from the second storage unit, and resumes feeding of the first recording medium from the first storage unit before reading of the adjustment pattern formed on the second recording medium begins; and implements the adjustment mode in which the image forming conditions of the second job are adjusted based on information obtained by reading the adjustment pattern formed on the second recording medium. A temperature detection unit detects the temperature inside the image forming apparatus,
The image forming apparatus according to claim 1, wherein the control unit implements the adjustment mode during the execution of the first job if the internal temperature of the image forming apparatus when the linking job is executed has changed compared to the internal temperature of the image forming apparatus at the time of the previous second job executed before the linking job is executed, and does not implement the adjustment mode if the internal temperature of the image forming apparatus has not changed compared to the internal temperature of the image forming apparatus at the time of the previous second job. The plurality of storage sections are capable of storing different types of recording media,
2. The image forming apparatus according to claim 1, wherein the feeding section feeds the first recording medium from the first storage section that houses the first recording medium, or feeds the second recording medium from the second storage section that houses the second recording medium of a different type than the first recording medium. The image forming device according to claim 3, characterized in that the first recording medium accommodated in the first storage section and the second recording medium accommodated in the second storage section have different recording medium thicknesses. The image forming device according to claim 1, characterized in that the adjustment pattern is a pattern in which multiple patches with different image densities are formed, and the control unit corrects the image density as the image forming condition based on information read from the adjustment pattern. The image forming apparatus according to claim 1, characterized in that the control unit interrupts the feeding of the recording medium from the first storage unit near the end of the first job and executes the adjustment mode. a reversing unit that is provided downstream of the image forming unit in a conveying direction of the recording medium and that reverses the recording medium;
2. The image forming apparatus according to claim 1, wherein the image reading unit has a first image reading unit that reads an adjustment pattern on one side of the recording medium, and a second image reading unit that reads an adjustment pattern on the other side opposite to the one side of the recording medium, and is disposed downstream of the inversion unit in the conveying direction of the recording medium. The image forming apparatus according to claim 1, characterized in that, when the control unit executes the linked job, if a predetermined time has elapsed since the previous second job executed before the linked job is executed, the control unit executes the adjustment mode during the execution of the first job, and does not execute the adjustment mode if the predetermined time has not elapsed since the previous second job.

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