JP2015191020A - Image formation device, image formation device and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that forms an image with an image formation setting corresponding to an environment as suppressing waste of a formation of a mark in image formation devices forming the image by use of toner.SOLUTION: A printer 100 is configured to have a plurality of environmental sections set and further have an image formation setting corresponding to each of the environmental sections. Then, the printer 100 is configured to form a mark using a first image formation setting corresponding to the environmental section when forming the mark according to satisfaction of a formation condition serving as a condition separate from a change of the environmental section and for forming a correction mark, and read the mark to determine a second image formation setting different from the first image formation setting. Then, an image formation device is configured to form an image to be output to a sheet on the basis of the first image formation setting obtained by a previous correction and second image formation setting during a period of time until a next mark formation.

Description

  The present invention relates to an image forming apparatus that forms an image using toner, an image forming method, and a storage medium. More specifically, it is a technique for forming an image using image formation settings according to the environment.

  Conventionally, in an image forming apparatus that forms an image using toner, it is known that a suitable setting value differs in image forming settings such as charging setting, exposure setting, and developing setting depending on the environment such as temperature and humidity. ing.

  As a technique for changing the image formation setting according to the environment, there is, for example, Patent Document 1. In the image forming apparatus disclosed in Patent Document 1, development settings corresponding to each of the three environmental classifications are stored, and a density correction mark is formed on condition that a change in the environmental classification is detected by the sensor. The image formation settings have been changed.

JP 2001-331004 A

  However, the conventional technique described above has the following problems. That is, in the technique of Patent Document 1, since the image formation setting suitable for each environmental classification is used every time the environmental classification changes, marks are frequently formed in an environment near the boundary of the environmental classification. there is a possibility. Even if the mark is formed when the change in the environment is small, the preferred image formation setting hardly changes, so there is room for improvement.

  The present invention has been made to solve the above-described problems of the prior art. That is, an object of the present invention is to provide a technology for forming an image with an image forming setting according to the environment while suppressing wasteful mark formation for an image forming apparatus that forms an image using toner. is there.

  An image forming apparatus designed to solve this problem includes an image forming unit that forms an image using toner, a sensor, and a control unit. The control unit is a condition for forming a correction mark. In response to satisfying a formation condition that is satisfied at a timing different from the change of a plurality of environmental classifications, among the image formation settings corresponding to each of the environmental classifications, the environmental classification when the correction mark is formed Obtained from the sensor by using the first image formation setting corresponding to the mark forming process to cause the image forming unit to form the mark and causing the sensor to read the mark formed by the mark forming process. A determination process for determining a second image formation setting having an attribute different from the first image formation setting when the image forming unit forms an image based on the signal; After the processing, until the next mark formation, on the basis of the first image formation setting used in the mark formation processing and the second image formation setting determined in the determination processing And an image forming process for causing the image forming unit to form an image to be output to the image forming unit.

  In the image forming apparatus disclosed in this specification, a plurality of environment divisions are set, and there are image formation settings corresponding to each of the environment divisions. The environmental classification is classified by at least one of temperature and humidity. The image formation settings include, for example, charging settings, exposure settings, and development settings. Then, in response to satisfying the formation condition for forming the correction mark for adjusting the image formation setting, the image forming apparatus performs the first according to the environmental classification when forming the correction mark. The correction mark is formed using the image formation setting, and the mark is read to determine a second image formation setting having an attribute different from that of the first image formation setting. As the correction, for example, density correction for adjusting development settings is applicable. The formation condition is a condition different from the change of the environmental classification, and corresponds to, for example, that the change amount of the environmental parameter from the previous mark formation is larger than the threshold value. Then, the image forming apparatus outputs to the sheet based on the first image formation setting and the second image formation setting obtained by forming the correction mark in the previous period until the next mark formation. Form an image.

  That is, in the image forming apparatus disclosed in the present specification, the second image forming setting is determined by reading the mark formed based on the first image forming setting corresponding to the environment classification when the forming condition is satisfied. After that, until the next mark formation, even if the current environment classification is different from the environment classification at the time of the previous mark formation, the first image formation setting and the second image formation setting are continuously used. . As a result, the chance of forming a mark can be reduced in a situation where there is almost no change in the environment from the previous mark formation.

  The correction mark may be a density correction mark. Examples of density correction include development bias correction and gamma correction. Since the density correction is more influenced by the environmental change than the position shift correction, the configuration of the image forming apparatus disclosed in this specification works favorably.

  The second image formation setting may include a setting of development bias. The image formation setting includes charging, exposure, and development settings. In the development located downstream in the image formation process, the first image formation setting is newly set by upstream charging and exposure. In this case, it is preferable to newly set the second image formation setting according to the image formation setting.

  The control unit may form a gamma correction mark in response to changing the first image formation setting. When the first image formation setting that is the basis of the second image formation setting that is the image formation setting of the image output to the sheet is changed, the influence on the image quality is large. Therefore, it is preferable to form a gamma correction mark.

  The first image formation setting may include a charging bias setting. In the image forming process, the charging corresponding to the previous step is set as the first image forming setting, and the exposure and developing corresponding to the subsequent step is adjusted to the first image by adjusting the exposure and developing image forming setting corresponding to the subsequent step. Compared to the case of forming settings, adjustment is easier.

  The formation condition may include that the current environmental parameter does not belong to a range within a predetermined amount from the environmental parameter at the previous mark formation. Furthermore, the environmental classification is classified according to environmental parameters including at least one of temperature and humidity, and the environmental classification is preferably smaller than the range. Since the environmental classification is small, a more suitable image formation setting can be obtained. In addition, if the environmental classification is small, the environmental classification changes frequently. However, in this configuration, the current environmental parameters may not be included within a predetermined amount from the previous mark formation environmental parameters. Even if the current environmental classification is different from the environmental classification at the time of the previous mark formation, the mark is not necessarily formed. For this reason, even with the above-described configuration, it is possible to reduce the chance of mark formation.

  A control method for realizing the functions of the image forming apparatus, a computer program, and a computer-readable storage medium storing the computer program are also novel and useful.

  According to the present invention, for an image forming apparatus that forms an image using toner, a technique for forming an image with an image forming setting according to the environment while suppressing waste of mark formation is realized.

1 is a block diagram illustrating an electrical configuration of a printer according to an embodiment. FIG. 2 is a cross-sectional view illustrating an internal configuration of the printer illustrated in FIG. 1. It is a figure which shows arrangement | positioning of a mark sensor. 4 is a flowchart illustrating a procedure of print processing executed by a printer. It is a figure which shows an example of the setting value of the surface potential of the photoreceptor according to an environmental division. It is a figure which shows the relationship between an environmental division and the surface potential of a photoreceptor. It is a figure which shows an example of the setting value of the surface potential of the photoreceptor according to a temperature division.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an image forming apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a printer that forms an image by electrophotography.

  As shown in FIG. 1, the printer 100 of this embodiment includes a controller 30 having a CPU 31, a ROM 32, a RAM 33, an NVRAM (Non Volatile RAM) 34, and an ASIC 35. The printer 100 also measures an image forming unit 10 that forms an image by an electrophotographic method, an operation unit 40 that receives an input operation from a user, a temperature sensor 45 that measures the temperature in the device, and humidity in the device. And a communication interface 37 for connecting to an external device, which are controlled by the CPU 31. Note that the controller 30 in FIG. 1 is a collective term for hardware used for controlling the printer 100 such as the CPU 31, and does not necessarily represent a single piece of hardware that actually exists in the printer 100.

  The ROM 32 stores firmware, which is a control program for controlling the printer 100, various settings, initial values, and the like. The RAM 33 is used as a work area from which various control programs are read or as a storage area for temporarily storing image data.

  The CPU 31 controls each component of the printer 100 while storing the processing result in the RAM 33 or the NVRAM 34 in accordance with a control program read from the ROM 32 and signals sent from various sensors. The CPU 31 is an example of a control unit. The controller 30 may be a control unit, and the ASIC 35 may be a control unit.

  The communication interface 37 is hardware that enables communication with other devices. Specific examples of the communication interface 37 include a wired LAN interface, a wireless LAN interface, a serial communication interface, a parallel communication interface, and a facsimile interface. The printer 100 can receive a job for causing the image forming unit 10 to form an image from an external device via the communication interface 37.

  The operation unit 40 is provided on the exterior of the printer 100 and has various buttons for receiving input operations from the user, and a touch panel for displaying messages and setting contents. Examples of the various buttons include an execution button for causing the image forming unit 10 to form an image and a cancel button for inputting an instruction for canceling image formation. The operation unit 40 also accepts various inputs when the user touches the touch panel with a finger.

  Next, the configuration of the image forming unit 10 of the printer 100 will be described with reference to FIG. The image forming unit 10 forms a toner image by an electrophotographic method, transfers the toner image to a sheet, an exposure device 53 that irradiates the process unit 50 with light, and unfixed toner on the sheet. A fixing device 8 for fixing, a paper feed tray 91 for placing a sheet before image transfer, a paper discharge tray 92 for placing a sheet after image transfer, and a transport belt for transporting the sheet to a transfer position of the process unit 50 7.

  Further, in the printer 100, the sheet stored in the paper feed tray 91 located at the bottom passes through the paper feed roller 21, the registration roller 22, the process unit 50, and the fixing device 8, and passes through the paper discharge roller 26. A substantially S-shaped transport path 11 (a chain line in FIG. 2) is provided so as to be guided to the paper discharge tray 92.

  The process unit 50 can form a color image, and process units corresponding to each color of cyan (C), magenta (M), yellow (Y), and black (K) are arranged in parallel. Specifically, a process unit 50C that forms an image of C color, a process unit 50M that forms an image of M color, a process unit 50Y that forms an image of Y color, and a process unit that forms an image of K color 50K. In the sheet conveyance direction, the process units 50C, 50M, 50Y, and 50K are arranged at equal intervals in this order from the downstream side. Note that the order of the process parts is not limited to this.

  The process unit 50K includes a drum-shaped photosensitive member 1, a charging device 2 that uniformly charges the surface of the photosensitive member 1, and a developing device 4 that develops the electrostatic latent image on the photosensitive member 1 with toner. , And a transfer device 5 that transfers the toner image on the photosensitive member 1 to a sheet or a conveyance belt 7. The photoreceptor 1 and the transfer device 5 are disposed in contact with the transport belt 7. The photosensitive member 1 is opposed to the transfer device 5 with the conveyance belt 7 interposed therebetween. The other process units 50C, 50M, and 50Y have the same configuration as the process unit 50K.

  In each of the process units 50C, 50M, 50Y, and 50K, the surface of the photoreceptor 1 is uniformly charged by the charging device 2. Thereafter, exposure is performed with light from the exposure device 53, and an electrostatic latent image of an image to be formed is formed on the photoreceptor 1. Next, toner is supplied to the photoreceptor 1 via the developing device 4. Thereby, the electrostatic latent image on the photoreceptor 1 is visualized as a toner image.

  The image forming unit 10 takes out the sheets placed on the paper feed tray 91 one by one and conveys the sheets onto the conveyance belt 7. The toner image formed by the process unit 50 is transferred to the sheet. At this time, in color printing, toner images are formed by the process units 50C, 50M, 50Y, and 50K, and the toner images are superimposed on the sheet. On the other hand, in monochrome printing, a toner image is formed only by the process unit 50K and transferred to a sheet. Thereafter, the sheet on which the toner image is transferred is conveyed to the fixing device 8 and the toner image is thermally fixed to the sheet. Then, the sheet after fixing is discharged to a discharge tray 92.

  Further, the printer 100 performs correction processing so that density unevenness and positional deviation do not occur in images formed by the process units 50C, 50M, 50Y, and 50K. As a procedure for the correction process, correction marks are formed on the process units 50C, 50M, 50Y, and 50K, the marks are transferred onto the conveyance belt 7, and correction values are determined based on the detection results of the marks. To do.

  Therefore, the printer 100 arranges the mark sensor 25 at a position downstream of the process units 50Y, 50M, 50C, and 50K and upstream of the fixing device 8 in the sheet conveyance direction. Then, the mark sensor 25 detects a correction mark formed on the conveyor belt 7.

  Specifically, as shown in FIG. 3, the mark sensor 25 includes two sensors, a sensor 25R disposed on the right side in the width direction of the transport belt 7 and a sensor 25L disposed on the left side. Each of the sensors 25R and 25L is a reflective optical sensor in which a light emitting element 23 such as an LED and a light receiving element 24 such as a phototransistor are paired. The mark sensor 25 is configured to irradiate light from the oblique direction to the dotted frame E in FIG. 3 on the surface of the conveyor belt 7 by the light emitting element 23, and the light receiving element 24 receives the light. . Then, the correction mark is detected based on the difference between the amount of light received when the correction mark 27 (mark 27 in FIG. 3 is an example of a gamma correction mark) and the amount of light received directly from the conveying belt 7. it can. The mark sensor 25 is an example of a sensor.

  Next, density correction executed by the printer 100 will be described. The printer 100 according to the present embodiment executes development bias correction and gamma correction as density correction. The development bias correction is a process for acquiring a correction value for adjusting a deviation between the ideal density defined by the printer 100 and the density of the actually formed mark. In developing bias correction, the printer 100 forms a mark with a predetermined density (for example, 100%) for each color. These marks are read by the mark sensor 25, the actual density is calculated based on the amount of received light, and a development bias correction value for obtaining an ideal density is obtained.

  The gamma correction is a process for correcting a deviation between an indicated density (indicated gradation) by an external computer and an output density of the printer 100 itself. In gamma correction, the printer 100 forms a plurality of marks having different densities at predetermined density intervals (for example, 20%, 40%, 60%, 80%, and 100%) for each color. These marks are read by the mark sensor 25, the actual density is calculated based on the amount of received light, and the density change characteristic of each color is specified from the relative density relation between the marks. Then, a relative relationship table between the change characteristic and the gradation indicated by the external computer is created.

  As described above, density correction for suppressing density unevenness includes development bias correction and gamma correction. Among them, the development bias correction corrects density shifts in all gradations that are insufficient or excessive in density over all gradations. On the other hand, the gamma correction is a correction for correcting the density deviation for each gradation that is insufficient or excessive in density for each gradation and appropriately changing the density when the gradation is changed.

  When executing a print job, the printer 100 determines whether or not the formation conditions for forming a density correction mark are satisfied. The formation conditions include, for example, user instruction input, new article detection, printing of a predetermined number or more, continuous operation time exceeding a threshold, environmental change such as humidity and temperature exceeding a specified amount, or a combination thereof. If the formation conditions are satisfied, for example, a density correction mark is formed prior to execution of the print job. In other words, the density correction mark formation is not executed immediately when the density correction mark formation condition is satisfied, but the density correction mark formation condition is satisfied. Before the subsequent print job is executed, the print job is continuously performed.

  Next, print control of the printer 100 including the above-described density correction will be described. FIG. 4 shows a print processing procedure executed by the printer 100. The print processing is executed by the CPU 31 when the print execution condition is satisfied, such as when a print job is received.

  In the printing process, the printer 100 first determines whether or not the formation conditions for forming the density correction mark are satisfied (S101). In the printer 100 according to this embodiment, the density correction mark forming condition includes the time when a new member containing toner, such as a toner cartridge, is detected or the first printing after the main body is unpacked. That is, in the state where various correction values are not stored in the printer 100, the conditions for forming the density correction mark are satisfied. In addition, when the current environmental parameter does not belong to a range within a predetermined amount from the environmental parameter in which the previous density correction mark was formed, the density correction mark formation condition is satisfied. On the other hand, the printer 100 according to the present embodiment does not include the change in the environmental classification in the density correction mark formation conditions.

  When the density correction mark formation condition is satisfied, the printer 100 turns the correction flag for density correction from OFF to ON, and turns the correction flag from ON to OFF after the density correction mark is formed. Alternatively, the correction flag is turned off from on when the density correction mark formation condition is not satisfied after the correction flag is turned on until the print execution condition is satisfied. In S101, this correction flag is read out, and if the correction flag is on, it is determined that the conditions for forming the density correction mark are satisfied.

  When the density correction mark formation conditions are satisfied (S101: YES), the density correction mark is formed. Therefore, first, the current environmental classification is acquired based on the output signals of the temperature sensor 45 and the humidity sensor 46 (S121). Specifically, the printer 100 has a high temperature state higher than the first temperature, a low temperature state lower than the second temperature lower than the first temperature, and from the second temperature to the first temperature. It is divided into three categories with the standard state between, and the temperature category is acquired according to the temperature in the current device. In addition, the humidity in the apparatus is also between the high humidity state above the first humidity, the low humidity state below the second humidity lower than the first humidity, and from the second humidity to the first humidity. The standard condition is divided into three categories, and the humidity category is acquired according to the humidity in the current device.

  Next, a charging bias to be applied to the charging device 2 is determined based on the acquired environmental classification (S122). In the printer 100, the appropriate surface potential of the photoreceptor 1 varies depending on the environment. Therefore, as shown in FIG. 5, the printer 100 is set with a surface potential V0 corresponding to the environmental classification. For example, in a low-temperature and low-humidity environment, the surface potential V0 is set to be higher than that in the standard environment because the amount of water in the toner is small and the toner is easily charged. On the other hand, in a high-temperature and high-humidity environment, since the toner has a large amount of water and the toner is difficult to be charged, the surface potential V0 is set lower than the standard environment. Then, the charging bias is determined so that the surface potential V0 suitable for the current environmental classification acquired in S121 is obtained.

  After S122, the determined charging bias is stored in the NVRAM 34 (S123). The charging bias is an example of a first image formation setting. If there is an exposure potential setting suitable for the environmental classification, the amount of light of the exposure device 53 that will be the exposure potential may also be determined and stored in S123. In this case, the light quantity of the exposure device 53 is also an example of the first image formation setting.

  After S123, the surface of the photoreceptor 1 is charged using the stored charging bias, and density correction is performed. Specifically, development bias correction is performed (S131), and then gamma correction is performed (S132). That is, a developing bias to be applied to the developing device 4 is determined based on an adjustment amount obtained by forming each correction mark on the image forming unit 10 and reading the mark with the mark sensor 25. Note that S131 and S132 may be reversed. However, in gamma correction, if the printer 100 itself has the above-described density deviation of all gradations, a mark having a predetermined density cannot be formed correctly, and each color is not properly formed. It becomes difficult to accurately detect the characteristic change for each gradation of density. Therefore, when performing gamma correction, it is preferable to execute development bias correction first.

  In S131 and S132, the process of forming a mark using the charging bias determined in S122 is an example of the mark formation process. In S131 and S132, the process of reading the mark and acquiring the adjustment amount of the developing bias is an example of the determination process. Thereafter, the development bias determined by the density correction is stored in the NVRAM 34 (S133). The development bias is an example of a second image formation setting.

  After S133, the image forming unit 10 is caused to form an image to be printed on the sheet using each image forming setting stored in S123 and S133 (S112). Thus, the printer 100 performs image formation using image formation settings suitable for the current environment classification acquired in S121.

  On the other hand, if the density correction mark formation conditions are not satisfied (S101: YES), image formation is performed using the image formation settings obtained by the previous density correction mark formation. . Therefore, first, the image formation settings stored in S123 and S133 are read from the NVRAM 34 (S111).

  After S111, an image to be printed on the sheet is formed on the image forming unit 10 using each read image formation setting (S112). The image formation in S112 is not limited to the case where the read image formation setting itself is used, and the image may be formed using a setting finely adjusted based on the read image formation setting. Thus, in the printer 100, until the next density correction mark formation condition is satisfied, image formation is performed using image formation settings suitable for the environment classification at the time of the previous density correction mark formation. S112 is an example of an image forming process. After S112, the printing process is terminated.

  According to this printing process, after the density correction mark is formed, the printer 100 performs image formation using the image formation setting based on the density correction until the next density correction mark formation condition is satisfied. Do. In the printer 100 of this embodiment, the density correction mark formation condition includes that the current environmental parameter does not belong to a range within a predetermined amount from the previous mark formation environmental parameter. For this reason, if the other density correction mark forming conditions are not satisfied, the image stored at the time of the previous density correction mark formation is maintained while the change from the environment at the time of the previous density correction mark formation is small. The configuration settings are used continuously.

  FIG. 6 shows the relationship between the environmental classification and the surface potential V0 of the photoreceptor 1. FIG. 6A shows a case where a mark for density correction is formed in a standard environment, and the surface potential V0 is 700V. Further, it is shown that a range within a predetermined amount from the environment when the density correction mark is formed is also within the standard environment. FIG. 6B shows a case where a density correction mark is formed in a high temperature and high humidity environment, and the surface potential V0 is 650V. Further, it is indicated that the range within a predetermined amount from the environment when the density correction mark is formed is also in the high temperature and high humidity environment. FIG. 6C shows a case where a mark for density correction is formed in a low-temperature and low-humidity environment, and the surface potential V0 is 750V. Further, the range within a predetermined amount from the environment when the density correction mark is formed also indicates that it is in the low temperature and low humidity environment.

  In these cases, while the density correction mark formation conditions are not satisfied, that is, in a range where the difference from the environment at the time of the previous density correction mark formation is smaller than a predetermined amount, the previous density correction mark Is in the same environmental category as when For this reason, high-quality printing can be expected by using the image formation setting stored at the time of the previous density correction mark formation.

  On the other hand, FIG. 6D shows a case where the density correction mark is formed in the standard environment, and the environment in which the density correction mark is further formed is an environment close to a high temperature and high humidity environment. . In this case, since it is a standard environment, the surface potential V0 is 700V. However, the lower limit of the environmental parameter that satisfies the formation condition of the density correction mark is the standard environment, but the upper limit indicates a high temperature and high humidity environment.

  In this case, if the conditions for forming the density correction mark are not satisfied, that is, the previous density correction mark is formed even if it is within a predetermined amount from the environment at the time of the previous density correction mark formation. It may be in a different environmental category from the time. However, the printer 100 according to the present embodiment does not use a change in the environmental classification as a condition for forming a density correction mark. Therefore, even if the environmental classification is different, if the difference between the current environment and the environment at the time of the previous density correction mark formation is smaller than a predetermined amount, the image stored at the time of the previous density correction mark formation is stored. Use formation settings. In other words, since image formation settings were originally acquired in an environment close to a high-temperature and high-humidity environment, if the amount of change in the environment is small, image quality fluctuations may occur even if the image formation settings acquired at the time of previous mark formation are used. Is small. Therefore, new density correction is not performed, and the image formation setting stored at the time of the previous density correction mark formation is continuously used.

  Further, in this embodiment, a range in which the image formation setting at the time of forming the previous density correction mark is used, that is, a range in which the difference from the environment at the time of forming the previous density correction mark is not a predetermined amount or more (see FIG. 6). R1) is smaller than the environmental classification range (R2 in FIG. 6). By making the range in which the image formation setting at the time of the previous mark for density correction formation is smaller than the range of the environment classification, the possibility of using the image formation setting suitable for the environment classification is increased.

  As a configuration different from the present embodiment, the environment classification range R2 may be smaller than the range R1 using the image formation setting at the time of the previous density correction mark formation. For example, as shown in FIG. 7, the temperature classification (R2) is in units of 2 ° C., and the density correction mark formation condition is that the current temperature is not within the range of 3 ° C. from the previous temperature. The range (R1) that uses the image formation setting when forming the density correction mark may be set to 6 ° C.

  As described above, since the environmental classification is small, a more suitable surface potential V0 can be set. Further, if the environmental classification is small, the environmental classification changes frequently. However, the printer 100 does not include the environmental classification change in the density correction mark forming conditions. Therefore, even if the current environmental classification is different from the environmental classification at the time of the previous mark formation, the mark is not necessarily formed. Therefore, even if it is the above-mentioned structure, possibility that a mark will be formed frequently is low.

  As described above in detail, in the printer 100 according to this embodiment, the marks formed based on the charging bias corresponding to the environmental classification when the density correction mark formation conditions are satisfied are read to determine other image formation settings. After that, until the next mark formation, even if the current environment classification is different from the environment classification at the time of density correction mark formation, those image formation settings are continuously used. As a result, the chance of forming a mark can be reduced in a situation where there is almost no change in the environment from the previous mark formation.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the image forming apparatus is not limited to a printer, but can be applied to any apparatus having a printing function, such as a copier, a FAX apparatus, or a multifunction machine. Further, the printer 100 according to the embodiment is a color printer and includes the process units 50C, 50M, 50Y, and 50K corresponding to the respective colors, but may be a monochrome printer including one process unit.

  In the embodiment, both the development bias correction and the gamma correction are performed when the density correction mark formation conditions are satisfied, but it is not always necessary to perform both. For example, since gamma correction requires time, other formation conditions such as only when the first density correction mark formation condition is satisfied or when a predetermined time or more has elapsed since the last gamma correction are used. You may add to the formation conditions of the mark for gamma correction.

  In the embodiment, the new image formation setting is stored when the density correction mark formation conditions are satisfied. However, the correction processing is not limited to density correction. For example, since there is a possibility that the density of the mark may change due to environmental changes, the mark misalignment correction forming conditions for adjusting the misalignment of the images formed by the process units 50C, 50M, 50Y, and 50K are changed. When satisfied, the surface potential V0 suitable for the environmental classification is set, a mark for correcting misregistration is formed based on the image formation setting, and the exposure timing adjustment value obtained by the misregistration correction is set to the second value. You may memorize | store as image formation setting.

  In the embodiment, the charging bias corresponding to the environmental classification when the formation conditions are satisfied is determined, and the developing bias is acquired based on the charging bias. However, the present invention is not limited to this. For example, a developing bias corresponding to the environmental classification when the formation conditions are satisfied may be acquired, and the charging bias may be acquired based on the developing bias. However, it is easier to adjust the exposure and development corresponding to the post-process based on the charge corresponding to the pre-process in the image forming process.

  In the embodiment, the density correction mark is formed continuously with the print job before the execution of the print job after satisfying the density correction mark formation condition. The timing at which marks are formed is not limited to this. For example, it may be executed when the power is turned on, or may be executed immediately when the density correction mark forming condition is satisfied.

  The processing disclosed in the embodiments may be executed by a single CPU, a plurality of CPUs, hardware such as an ASIC, or a combination thereof. Further, the processing disclosed in the embodiment can be realized in various modes such as a recording medium or a method recording a program for executing the processing.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging apparatus 4 Developing apparatus 10 Image forming part 25 Mark sensor 31 CPU
100 printer

Claims (9)

An image forming unit that forms an image using toner;
A sensor,
A control unit;
With
The controller is
Of the image formation settings corresponding to each of the environmental divisions, the correction mark formation conditions are satisfied in accordance with the formation conditions of the correction marks that are satisfied at a timing different from the change of the plurality of environmental divisions. A mark forming process for forming the mark on the image forming unit using the first image forming setting corresponding to the environmental classification when forming the mark;
Attributes different from the first image formation setting when the mark formed by the mark formation process is read by the sensor and an image is formed on the image forming unit based on a signal obtained from the sensor. A determination process for determining the second image formation setting,
After the mark formation process, until the next mark formation, based on the first image formation setting used in the mark formation process and the second image formation setting determined in the determination process An image forming process for causing the image forming unit to form an image output on the sheet;
An image forming apparatus characterized in that The image forming apparatus according to claim 1,
The image forming apparatus, wherein the correction mark is a density correction mark. The image forming apparatus according to claim 2,
The image forming apparatus, wherein the second image forming setting includes a setting of a developing bias. In the image forming apparatus according to claim 2 or 3,
The controller is
An image forming apparatus, wherein a mark for gamma correction is formed in response to changing the first image forming setting. In the image forming apparatus according to any one of claims 1 to 4,
The image forming apparatus according to claim 1, wherein the first image forming setting includes a setting of a charging bias. The image forming apparatus according to any one of claims 1 to 5,
The image forming apparatus according to claim 1, wherein the formation condition includes that the current environmental parameter does not belong to a range within a predetermined amount from the environmental parameter at the time of the previous mark formation. The image forming apparatus according to claim 6,
The environmental classification is classified by environmental parameters including at least one of temperature and humidity.
The image forming apparatus according to claim 1, wherein the environmental classification is smaller than the range. In an image forming method of an image forming apparatus that forms an image using toner,
Among the image formation settings corresponding to each of the environmental classifications according to the formation conditions of the correction marks that satisfy the formation conditions that are satisfied at different timings, which are different conditions from changes in a plurality of environmental classifications , A mark forming step for forming the mark using the first image forming condition corresponding to the environmental classification when forming the correction mark;
When the mark formed in the mark forming step is read by a sensor and an image is formed on the image forming unit based on a signal obtained from the sensor, the attribute differs from the first image forming setting. A determining step for determining a certain second image forming setting;
After the mark formation step, until the next mark formation, based on the first image formation setting used in the mark formation step and the second image formation setting determined in the determination step. An image forming step for forming an image to be output on the sheet;
An image forming method comprising: An image forming unit that forms an image using toner;
A sensor,
In an image forming apparatus comprising
Of the image formation settings corresponding to each of the environmental divisions, the correction mark formation conditions are satisfied in accordance with the formation conditions of the correction marks that are satisfied at a timing different from the change of the plurality of environmental divisions. A mark forming process for forming the mark on the image forming unit using the first image forming setting corresponding to the environmental classification when forming the mark;
Attributes different from the first image formation setting when the mark formed by the mark formation process is read by the sensor and an image is formed on the image forming unit based on a signal obtained from the sensor. A determination process for determining the second image formation setting,
After the mark formation process, until the next mark formation, based on the first image formation setting used in the mark formation process and the second image formation setting determined in the determination process An image forming process for causing the image forming unit to form an image output on the sheet;
A storage medium for storing a program for executing the program.

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