JP2007316195A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus improving throughput in image formation by only minimally adjusting control parameter as necessary when an adjusting action is restarted after being interrupted during adjusting of a control parameter regarding image formation. <P>SOLUTION: The image forming apparatus is provided with; the image forming part 1 forming an image based on a plurality of control parameters, a plurality of image adjusting means 12a adjusting the control parameter so that the image formed by the image forming part 1 fulfills specified image characteristics, and an image adjustment control means 12b adjusting the image by activating a plurality of the image adjusting means 12a in a specified order during a specified period. The image adjustment control means 12b carries out control so that an unfinished image adjusting means 12a is activated without activating already finished image adjusting means 12a again when restarting the image adjustment which was interrupted by an external factor in the image forming apparatus. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes an image forming unit that forms an image based on a plurality of control parameters, and a plurality of image adjusting units that adjust the control parameters so that an image formed by the image forming unit satisfies predetermined image characteristics. The present invention also relates to an image forming apparatus including an image adjustment control unit configured to operate the plurality of image adjustment units in a predetermined order at a predetermined time.

Patent Document 1 discloses either a full calibration mode for executing all types of calibration or a simple calibration mode for executing only a part of calibration among a plurality of calibrations for adjusting image forming characteristics. There has been proposed an image forming apparatus that includes a selection unit for selecting the image and that can execute the minimum necessary calibration based on a request from a user or the like, or an environmental condition or a use condition.
JP 2002-296851 A

  The above-described calibration adjusts a plurality of control parameters related to image formation such as a look-up table including a gamma table of output data with respect to input data and a development bias. Depending on the situation and the conditions of the image forming apparatus at that time, calibration for the minimum necessary control parameters is executed to suppress a decrease in image formation throughput due to calibration that requires time and operation. However, it was not taken into account until the calibration was interrupted and restarted due to some external factor such as the exterior cover being opened during the calibration. .

  In other words, in the above-described prior art, when the calibration is interrupted and restarted during calibration, all the scheduled calibrations are executed again even if the calibration is the minimum necessary. Further, there is room for further improvement in suppressing a decrease in image formation throughput.

  In view of the above-described conventional disadvantages, the present invention adjusts only the minimum necessary control parameters when the adjustment operation is interrupted and resumed after adjustment of the control parameters for image formation, thereby reducing the image formation throughput. An object of the present invention is to provide an improved image forming apparatus.

  In order to achieve the above-mentioned object, the first characteristic configuration of the image forming apparatus of the developing device according to the present invention is to form an image based on a plurality of control parameters as described in claim 1 of the claims. A plurality of image adjusting units that adjust the control parameters so that an image formed by the image forming unit satisfies predetermined image characteristics, and the plurality of image adjusting units at a predetermined time in a predetermined order. An image forming apparatus comprising: an image adjustment control unit that operates and adjusts an image, wherein the image adjustment control unit reopens the already-adjusted image adjustment unit when the image adjustment suspended due to an external factor is resumed. The point is that control is performed so that the unfinished image adjusting means is actuated without being actuated.

  According to the above-described configuration, in the interrupted and resumed image adjustment operation, only the image adjustment unit that has not been adjusted is operated and the control parameter is adjusted. Throughput can be improved. In addition, when the image adjusting unit that has already been completed includes an image adjusting unit that adjusts control parameters such as toner density and toner conveyance amount, the amount of toner consumption required for image adjustment can be suppressed.

  According to the second characteristic configuration, as described in claim 2, in addition to the first characteristic configuration described above, the image adjustment control means is configured to change the temperature or humidity when the image adjustment is interrupted and restarted. When it is within the predetermined range, it is controlled to operate the image adjustment means that has not been completed without operating the image adjustment means that has already been completed.

  In maintaining predetermined image forming characteristics, one of the main factors that must change the control parameters relating to image formation is a change in temperature or humidity. That is, the image forming characteristics change due to fluctuations in temperature or humidity. However, when the variation in temperature or humidity is within a predetermined range, the influence on the image forming characteristics is small, so that it is not necessary to vary the control parameter. Therefore, when the variation in temperature or humidity is within the predetermined range, it is not necessary to adjust the adjusted control parameter again.

  According to the configuration described above, adjustment of control parameters that do not require adjustment is not performed, and only control parameters that require adjustment can be adjusted.

  In the third feature configuration, as described in claim 3, in addition to the first or second feature configuration described above, the image forming unit is configured by a single unit or a plurality of units that are detachable from the main body. The image adjustment control means operates the unfinished image adjustment means without re-activating the already-finished image adjustment means when the unit is not detached from the time when the image adjustment is interrupted until the time of resumption. It is in the point to control.

  If a unit is removed from the time when image adjustment is interrupted until it is restarted, the unit may have been subjected to some external adjustment, and the reliability of control parameters that have already been adjusted may be lost. .

  According to the above-described configuration, the reliability of the control parameter that has already been adjusted is not lost with respect to the unit that is not detached, and it is not necessary to readjust the control parameter. It is possible to adjust only control parameters that need to be adjusted.

  In the fourth feature configuration, as described in claim 4, in addition to the first or second feature configuration described above, the image adjustment control means may be configured such that the specific unit has a specific unit between the time when the image adjustment is suspended and the time when the image adjustment is resumed. Among the image adjusting means that have already been completed, the image adjusting means corresponding to the specific unit is controlled to be operated again when it is detached.

  According to the configuration described above, among the control parameters that have already been adjusted, the readjustment is performed only for the control parameters corresponding to the specific unit that may have changed in image formation characteristics due to the attachment / detachment of the specific unit. The image adjustment is appropriately executed and the time required for the image adjustment can be shortened.

  As described above, according to the present invention, when the adjustment operation is interrupted during the adjustment of the control parameters relating to image formation and then resumed, only the minimum necessary control parameters are adjusted to reduce the image formation throughput. An improved image forming apparatus can be provided.

  The image forming apparatus according to the present invention will be described below.

  A printer as an example of an electrophotographic image forming apparatus including a developing device according to the present invention forms a toner image of each color component of MCYK based on a print job input from an external device as shown in FIG. An image forming unit 1; a paper feeding unit 2 including a paper tray for supplying, transporting, and discharging paper as a recording medium; a transporting roller; a fixing unit 4 for fixing a toner image transferred to the recording medium; The system includes an interface unit 5 that transmits and receives data to and from the external device, and a system control unit 6 that includes a microcomputer that performs overall control of the printer.

  The image forming unit 1 includes an endless transfer member 31 supported by three rollers 30 and a plurality of transfer rollers 32 and 33 arranged in contact with the transfer member 31. Four photoconductor units 100 corresponding to the respective colors M (magenta), C (cyan), Y (yellow), and K (black) arranged along the circumferential direction of the transfer body 31, and the image formation The control unit 12 is configured to control the unit 1.

  The image forming unit 1 detects the density of each color based on the amount of light reflected from the toner pattern of each color carried on the transfer body 31 so that the toner density of the toner image to be formed is maintained at a predetermined toner density. A toner density sensor 11 is provided on the downstream side of the photoreceptor unit 100 along the circumferential direction of the transfer body 31. Further, in order to detect the in-machine temperature and the in-machine humidity in the image forming unit 1, the image forming unit 1 includes an in-machine temperature sensor 16 composed of a thermistor utilizing the temperature characteristics of the semiconductor, and a lithium chloride ceramic as a hygroscopic substance. An in-machine humidity sensor 17 that uses a polymer or the like and measures a change in the amount of water vapor as an electrical change such as an electric resistance or an electric capacity is provided.

  As shown in FIG. 3, each photoconductor unit 100 includes an image carrier 110 and a charging charger 120, an exposure head 130, a developing device 140, a cleaner 150, a static elimination lamp 160 and the like along the circumferential direction of the image carrier 110. Is arranged and is detachable from the printer body. Here, in order to attach and detach the photosensitive unit 100 to and from the printer main body, it is necessary to open a cover (not shown) of the printer.

  The cover of the printer protects the devices inside the printer, suppresses the entry of dust and dirt that hinders image formation, and plays a role of keeping the in-machine temperature and in-machine humidity in the image forming unit 1 constant. When in the closed state, it is fixed to the printer main body by a magnet, and the user can pull the handle portion disposed on the cover and pivot it to open the cover.

  Further, an open / close detection sensor comprising a hard switch for detecting an open / closed state is installed on the cover, and the open / close detection sensor outputs a high signal when the cover is in the open state and a low signal when the cover is in the closed state. Is output to the control unit 12. However, the open / close detection sensor is not limited to this, and may be configured to output a Low signal when the cover is in an open state and a High signal when the cover is in a closed state. It may be configured by a sensor or the like, and may detect the open / closed state of the cover in a non-contact manner, as long as it detects the open / closed state of the cover and outputs it to the control unit 12.

  The toner density sensor 11 is disposed on the downstream side of the photoreceptor unit 100 disposed along the circumferential direction of the transfer body 31. More specifically, as shown in FIG. 4, the toner density sensor 11 includes a light projecting unit 13 that projects a single polarized light at a predetermined inclination angle with respect to the normal direction of the transfer body 31, and The first polarized light that is disposed on the opposite side of the light projecting unit 13 with respect to the normal direction and that reflects light from the transfer body 31 is the same as the projected light and the second polarized light that is different from the projected light. A polarization separation unit 14 that separates the light into light; and first and second light reception units 15 that receive the first and second polarized light, the first and second polarized light. The toner density is detected from the difference in the amount of light.

  The image carrier 110 includes a photosensitive drum having a photosensitive member in which an amorphous silicon layer, which is a positively chargeable photoconductor, is deposited on the surface of an aluminum cylinder, and is positively charged by the charging charger 120. By the exposure from 130, the charge in the exposed portion is grounded through the cylinder.

  As shown in FIG. 3, the developing devices 140 provided in the photoreceptor units 100 of M (magenta), C (cyan), Y (yellow), and K (black) colors correspond to the corresponding colors. A toner cartridge 141 filled with the toner, a developer tank 142 that stirs the toner and carrier supplied from the toner cartridge 141, and a two-component developer 145 composed of the carrier and toner filled in the developer tank 142. A magnetic roll 143 for holding the magnetic brush 143l, and a developing roll for developing the electrostatic latent image formed on the image carrier 110 by holding the toner conveyed from the magnetic roll 143 as a toner thin layer 144l. 144.

  The magnetic roll 143 is composed of a rotating sleeve including a fixed magnet roller in which N poles and S poles are alternately magnetized, and a DC bias voltage (hereinafter referred to as “bias voltage”) Vdc3 is applied to the rotating shaft thereof. A high voltage circuit 143v is connected, and the high voltage circuit 143v can be controlled by the control unit 12. Further, the rotary shaft is connected to a drive mechanism 146m including a motor and a speed reduction mechanism so that the magnetic roll 143 rotates in one direction at a predetermined rotational speed.

  The developing roll 144 is made of uniformly charged aluminum, and a high voltage circuit 144v for applying an AC bias voltage Vac4 and a bias voltage Vdc4 is connected to the rotation axis thereof. The control unit 12 can control the high voltage circuit 144v. It is configured. Further, the rotation shaft is connected to a drive mechanism 146s composed of a motor and a speed reduction mechanism so that the developing roll 144 rotates in one direction at a predetermined rotation speed.

  The control unit 12 includes a CPU, a ROM storing an operation program for the CPU, a RAM serving as a work area, and the like, and operates as the image adjustment control unit 12b of the present invention illustrated in FIG. Image adjustment is performed by operating a plurality of image adjusting units 12a for adjusting a plurality of control parameters in a predetermined order so that an image formed by the image forming unit 1 satisfies predetermined image characteristics.

  Here, in the present embodiment, the control parameters include a gamma table used for gamma correction of output image data with respect to input image data, a bias voltage Vdc4 to the developing roll 144, and a bias voltage to the magnetic roll 143. Vdc3 corresponds to this. The predetermined timing is the time when the printer is turned on and a predetermined interval set in advance. In this embodiment, the cumulative operating time of the developing device 140 reaches a predetermined time, or the cumulative number of prints is This is the time when the predetermined number of prints has been reached.

  The image adjusting unit 12a includes a gamma correction adjusting unit 12a1 that corrects the gamma table, which is a lookup table used for gamma correction of output image data with respect to input image data, and a bias to the magnetic roll 143 and the developing roll 144. By adjusting the voltages Vdc3 and Vdc4, the toner conveyance amount from the magnetic roll 143 to the developing roll 144, in other words, the layer thickness of the toner thin layer 144l formed on the developing roll 144 is adjusted, and the developing roll The control unit 12 includes a bias voltage adjusting unit that adjusts a developing bias between the image carrier 144 and the image carrier 110.

  As described above, the control unit 12 serves as the plurality of image adjustment units 12a and the image adjustment control unit 12b in the present invention, and at the predetermined timing, the image adjustment control unit 12b includes a plurality of the image adjustment units 12b in a predetermined order. The image adjustment means 12a is operated to adjust the image.

  In this embodiment, the predetermined order is set in the order of the bias voltage adjusting means and the gamma correction adjusting means 12a1, which will be described in detail below.

  At the predetermined timing, the image adjustment control unit 12b operates the bias voltage adjustment unit according to the predetermined order. The bias voltage adjusting means is a solid pattern formed on the image carrier 110 with at least a predetermined low-voltage bias voltage Vdc4 (L) applied to the developing roll 144 or a solid pattern after transfer to the transfer body 31. Is formed on the image carrier 110 after the execution of the solid pattern adjusting unit 12a2 for adjusting the bias voltage Vdc3 applied to the magnetic roll 143 so that the density of the toner becomes the target solid density, and the solid pattern adjusting unit 12a2. A difference voltage between bias voltages applied to the magnetic roll 143 and the developing roll 144 so that a predetermined halftone pattern or a density of a predetermined halftone pattern after transfer to the transfer body 31 becomes a target halftone density. Both bias voltages are maintained while keeping the carrier bias voltage ΔVc constant. Composed of the halftone pattern adjustment unit 12a3 for integer. As shown in FIG. 5, the solid pattern and the halftone pattern in this embodiment are obtained by transferring four continuous patterns onto the transfer body 31 with one continuous toner image of each color as one pattern.

  The solid pattern adjusting unit 12a2 adjusts so that the toner conveyed from the magnetic roll 143 to the developing roll 144 is not supplied excessively, and the halftone pattern adjusting unit 12a3 Is used to adjust the gradation.

  The bias voltage adjusting means is not limited to the above-described adjusting method. In order to detect the toner layer thickness on the developing roller 144 on the image carrier 110, the developing bias of the developing roller 144 is set. A toner layer thickness detection pattern in which a solid pattern using the toner layer formed in the second round after the start of application and a halftone pattern using the toner layer formed during the next one rotation is revealed. The toner density in the toner layer thickness detection pattern on the transfer body 31 on which the image is formed and the toner layer thickness detection pattern on the image carrier 110 or the toner layer thickness detection pattern on the image carrier 110 is transferred. Other adjustments such as an adjustment means for detecting the toner density sensor 11 by the toner density sensor 11 and controlling the toner layer on the developing roller 144 to a predetermined layer thickness based on the detected toner density Or it may be using the stage.

  The image adjustment control means 12b operates the gamma correction adjustment means 12a1 when the halftone pattern adjustment means 12a3 cannot secure a predetermined gradation. The gamma correction adjusting unit 12a1 keeps the transport bias voltage ΔVc constant and maintains a constant developing bias between the image carrier 110 and the developing roll 144 while maintaining a predetermined voltage. The gamma table used for gamma correction is corrected to an optimum state.

  More specifically, the gamma table is a look-up table that performs numerical conversion on the input image data so that the output image data can ensure a desired gradation, and has gradation characteristics as shown in FIG. It is The gamma correction adjusting means 12a1 corrects the table data so that the gradient of the gradation characteristic is increased when the detected density by the toner density sensor 11 is low, that is, when the detected toner density is high. The table data is corrected so that the gradient of the gradation characteristic is small, that is, the toner density is low.

  When an external factor that interrupts the adjustment operation works when the image adjustment control unit 12b adjusts the control parameters related to each of the plurality of image adjustment units 12a operated in a predetermined order, the image adjustment control unit 12b The control unit 12b instructs the operating image adjustment unit 12a to interrupt the adjustment operation, and stores which image adjustment unit 12a was operating in the state storage unit 12c including a non-volatile RAM included in the control unit 12b. Further, the in-machine temperature Ts and the in-machine humidity Hs at the time of interruption are acquired from the in-machine temperature sensor 16 and the in-machine humidity sensor 17, and stored in the state storage means 12c.

  Here, as the external factor, the cover of the printer is opened or the power of the printer is turned off. The image adjustment control means 12b opens and closes the cover of the printer. The state is detected by an output from the open / close detection sensor, and whether the printer is turned off or off is detected by an output from the system control unit 6 of the printer.

  When the external factor is eliminated, that is, when the cover of the printer is closed and the printer is turned on, the image adjustment control means 12b is connected to the in-machine temperature sensor 16 and the in-machine temperature. The in-machine temperature Tr and the in-machine humidity Hr at the time of resumption are acquired from the humidity sensor 17, and each is compared with the in-machine temperature Ts and the in-machine humidity Hs at the time of interruption.

  Further, when the photoconductor unit 100 is released from the interruption to the restart of the image adjustment operation due to the external factor, the image adjustment control means 12b determines which photoconductor of each color toner. Whether or not the unit 100 is in the detached state is stored in the state storage means 12c.

  More specifically, when the toner unit 141 is removed from the state where it is mounted on the printer, for example, when the toner cartridge 141 is replaced for toner replenishment or when the photosensitive unit 100 itself is replaced. A unit attachment / detachment confirmation sensor (not shown) installed in the printer detects this and outputs it to the image adjustment control means 12b.

  Specifically, the unit attachment / detachment confirmation sensor 12c is configured by a hard switch, and is disposed at an attachment position of the photosensitive unit 100 for each color, and the photosensitive unit 100 is in a detached state with respect to the printer. The High signal is output when the printer is in the state, and the Low signal is output when the printer is in the wearing state. However, the unit attachment / detachment confirmation sensor is not limited to this, and is configured to output a Low signal when the printer is detached and a High signal when the printer is worn. The image adjustment control unit may be configured by an optical sensor or the like, and may detect the attachment / detachment state of the photoreceptor unit 100 in a non-contact manner. The image adjustment control unit may detect the attachment / detachment state of the photoreceptor unit 100. What is necessary is just to output to 12b.

  The image adjustment control unit 12b is in operation stored in the state storage unit 12c without operating the image adjustment unit that has already ended when the fluctuation of the in-machine temperature or the in-machine humidity is within a predetermined range. The state storage means 12c indicates that the toner unit 100 of any toner color has been removed from the time of interruption to the time of resumption. When stored, prior to the operation of the unfinished image adjusting unit 12a, the image adjusting unit 12a corresponding to the detached photosensitive unit 100 among the already completed image adjusting units 12a is operated again. To control. At this time, when the bias voltage adjusting unit is operated, only the toner image corresponding to the detached photosensitive unit 100 is transferred to the transfer body 31 and detected by the toner density sensor 11.

  When the variation in the in-machine temperature or the in-machine humidity is outside the predetermined range, the image adjustment control unit 12b controls all the image adjustment units 12a to operate again in the predetermined order.

  In this embodiment, as the predetermined range, the temperature difference between the interruption and the restart is within ± 5 ° C. at the internal temperature, and the humidity difference between the interruption and the restart is within ± 5% at the internal humidity. However, the present invention is not limited to this, and an optimal range that does not affect the image forming characteristics may be set according to the unique conditions and environmental conditions of each image forming apparatus.

  The image adjustment operation in the printer will be described below with reference to the flowchart shown in FIG.

  When a predetermined timing is reached during use of the printer (S1), the image adjustment control unit 12b operates the plurality of image adjustment units 12a in the predetermined order to start an image adjustment operation (S2). When there is no factor (S3) and all the image adjusting units 12a finish the adjustment, the image adjustment operation is finished (S17).

  If there is an external factor during the image adjustment operation (S3), the image adjustment control unit 12b instructs the image adjustment unit 12a that is operating to interrupt the image adjustment operation being performed (S4). Then, the state storage unit 12c stores which image adjustment unit 12a is the interrupted image adjustment unit 12a (S5).

  Further, the in-machine temperature Ts and the in-machine humidity Hs are acquired from the in-machine temperature sensor 16 and the in-machine humidity sensor 17 (S6), and stored in the state storage means 12c (S7).

  When any of the photoconductor units 100 of the respective color toners is detached from the interruption to the resumption of the image adjustment operation (S8), the image adjustment control means 12b stores the state memory for the detached photoconductor unit 100. It memorize | stores in the means 12c (S9).

  When the external factor disappears (S10), the image adjustment control means 12b acquires the internal temperature Tr and the internal humidity Hr from the internal temperature sensor 16 and the internal humidity sensor 17 (S11), and the state storage means The in-machine temperature Ts stored in 12c is compared with the in-machine humidity Hs, and when the fluctuation of the in-machine temperature or the in-machine humidity is outside a predetermined range (S12), the image adjustment control unit 12b The plurality of image adjusting means 12a are operated in order, and image adjustment is performed again from the beginning (S15).

  When the variation in the in-machine temperature or the in-machine humidity is within a predetermined range (S12) and there is no memory for the detached photoconductor unit 100 in the state storage means 12c (S13), the image adjustment control means 12b When the interrupted image adjustment unit 12a stored in the state storage unit 12c is operated again to resume image adjustment (S14), and there is a storage for the photoconductor unit 100 attached to and detached from the state storage unit 12c. (S13) Prior to the operation of the unfinished image adjustment means 12a, image adjustment corresponding to the detached photoreceptor unit 100 stored in the state storage means 12c among the already completed image adjustment means 12a. The means 12a is actuated again (S16).

  Hereinafter, another embodiment will be described. In the above-described embodiment, the image bearing member 110 is a photoreceptor drum having a photoreceptor in which an amorphous silicon layer as a positively chargeable photoconductor is deposited on the surface of an aluminum cylinder. An OPC drum that is an organic photoconductor, or other types of photoconductive semiconductor drums in which the photoconductor is selenium or the like may be employed, and in this case, depending on the charging characteristics of the photoconductor, What is necessary is just to change suitably the two-component developer to employ | adopt.

  In the above-described embodiment, four patterns of toner images are formed in toner density detection. However, the present invention is not limited to this, and an optimal pattern of toner images is formed according to various conditions such as device characteristics, use conditions, and costs. The toner density of each pattern of the toner image may be detected, and the bias voltages Vdc3 and Vdc4 applied to the magnetic roll 143 and the developing roll 144 may be adjusted.

  In the above-described embodiment, a configuration in which the present invention is applied to a tandem type printer in which four photoconductor units 100 corresponding to M, Y, C, and K toner colors are installed in parallel with the transfer body 31 will be described. However, the present invention may be applied to a printer in which four developing units corresponding to M, Y, C, and K toner colors are arranged in the circumferential direction of one image carrier. The present invention may be applied to a single color printer in which one toner color developing unit is arranged. In this case, instead of the photoconductor unit in the above-described embodiment, it may be configured that the attachment / detachment of the developing unit is detected by the unit attachment / detachment confirmation sensor.

  In the above-described embodiment, the image adjustment control unit 12b has already finished the image adjustment unit 12a when the photosensitive unit 100 of any toner color is detached from the time when the image adjustment is interrupted to the time when the image adjustment is resumed. Among them, the image adjusting means 12a corresponding to the photoconductor unit 100 is controlled so as to be operated again. However, the photoconductor unit 100 of any toner color from the time when the image adjustment is suspended to the time when the image adjustment is resumed. A configuration may be adopted in which image adjustment is performed from the beginning by controlling all of the image adjustment means 12a to operate again regardless of whether the image is detached or not.

  In the above-described embodiment, the image adjustment control unit 12b does not operate the already-finished image adjustment unit 12a again when the variation in temperature or humidity at the time of interruption and resumption of image adjustment is within a predetermined range. Although the configuration is such that the unfinished image adjustment means 12a is controlled to operate, if there is any change in the temperature or humidity at the time of interruption and resumption of image adjustment, all adjustments are made regardless of whether the adjustment is finished or not finished. The image adjustment unit 12a is controlled to operate again, and the image adjustment is performed from the beginning. When there is no change, the image adjustment unit 12a that has not been completed is activated without reactivating the image adjustment unit 12a that has already been completed. It is good also as a structure controlled in this way.

  In the above-described embodiment, the image adjustment control unit 12b does not operate the already-finished image adjustment unit 12a again when the variation in temperature or humidity at the time of interruption and resumption of image adjustment is within a predetermined range. Although the configuration is such that the unfinished image adjustment means 12a is controlled to operate, the temperature and humidity at the time of interruption and resumption of the image adjustment, or only the temperature, or the variation of only the humidity is within a predetermined range. The configuration may be such that the image adjustment means 12a that has not been completed is operated again without operating the image adjustment means 12a that has already been completed.

  The above-described embodiments are merely examples of the present invention, and the scope of the present invention is not limited by the description, and the specific configuration of each part is appropriately changed within the scope of the effects of the present invention. It goes without saying that it can be done.

Functional block diagram Illustration of printer Explanatory drawing of photoconductor unit Illustration of toner density sensor Explanatory drawing of the toner image of the pattern formed on the transfer body Illustration of gamma table Diagram used to explain image adjustment

Explanation of symbols

1: Image forming unit 12a: Image adjustment unit 12a1: Gamma correction unit 12a2: Solid pattern adjustment unit 12a3: Halftone pattern adjustment unit 12b: Image adjustment control unit 12c: Status storage unit 16: In-machine temperature sensor 17: In-machine humidity sensor 100 : Photosensitive unit (K, Y, C, M colors)

Claims (4)

An image forming unit that forms an image based on a plurality of control parameters; a plurality of image adjusting units that adjust the control parameter so that an image formed by the image forming unit satisfies a predetermined image characteristic; An image forming apparatus comprising: an image adjustment control unit that operates the plurality of image adjustment units in a predetermined order to adjust an image;
The image adjustment control unit controls an unfinished image adjustment unit to be operated without reactivating the already completed image adjustment unit when the image adjustment suspended due to an external factor is resumed.   The image adjustment control means operates the unfinished image adjustment means without reactivating the already-finished image adjustment means when the variation in temperature or humidity at the time of interruption and resumption of the image adjustment is within a predetermined range. The image forming apparatus according to claim 1, wherein the image forming apparatus is controlled so as to be controlled.   The image forming unit is composed of a single unit or a plurality of units that are detachably attached to the main body, and the image adjustment control means is already installed when the unit is not detached from the time when image adjustment is suspended until the time when it is resumed. 3. The image forming apparatus according to claim 1 or 2, wherein control is performed such that an unfinished image adjusting unit is operated without operating the completed image adjusting unit again.   The image adjustment control unit is configured to re-activate the image adjustment unit corresponding to the specific unit among the already-adjusted image adjustment units when the specific unit is detached from the time when the image adjustment is interrupted to the time when the image adjustment is resumed. The image forming apparatus according to claim 1, wherein the image forming apparatus is controlled as follows.