JP2005292790A - Image forming apparatus, computer program, image forming system, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an image forming system or the like very convenient for a user or the like. <P>SOLUTION: In the image forming apparatus which can be used as a color image forming apparatus to form a color image and used as a monochrome image forming apparatus to form a monochrome image, one of attached development units is moved to an attaching/detaching position, whereby the development unit can be exchanged. In the apparatus, timing to move the predetermined development unit to the attaching/detaching position when a phenomenon that an image cannot be developed by the predetermined development unit occurs is made to differ between the case when it is used as the color image forming apparatus and the case when it is used as the monochrome image forming apparatus. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, a computer program, an image forming system, and an image forming method for forming an image using a plurality of developing units that develop a latent image carried on an image carrier with a developer stored therein. About.

As this type of image forming apparatus, for example, there is known an image forming apparatus capable of forming a color image by having a plurality of detachable portions to which a plurality of developing units for developing a latent image with a stored developer can be attached and detached. It has been. The image forming apparatus can be used as a single-color image forming apparatus that forms a single-color image in a state where at least two developing units containing the same color developer are attached to a plurality of attachment / detachment portions. When used as a single-color image forming apparatus, development is performed by replacing a mounted developing unit containing the same color developer (hereinafter referred to as the same color developing unit). Then, when there is no developer stored in all the same color developing units mounted, this is displayed on the display unit or the like, and the image forming operation is stopped (for example, see Patent Document 1).
JP 2002-351190 A

However, in the above image forming apparatus, when it is displayed that there is no developer when used as a single color image forming apparatus, there is no developer in all the installed developing units. An image cannot be formed until a new developing unit is installed. That is, if a message indicating that there is no developer is displayed during execution of a print job for printing a plurality of sheets, the print job being executed is interrupted. In order to finish the print job, the developing unit must be replaced, which causes a problem that throughput is reduced.
On the other hand, when it is used as a color image forming apparatus, a normal color image cannot be formed if development becomes impossible due to the lack of developer even for one color. At this time, if the image forming operation is continued to finish the print job, the user may waste the developer and the printing paper. That is, there is a problem in that it is not convenient for the user or the like whether it is used as a monochromatic image forming apparatus or a color image forming apparatus.

  SUMMARY An advantage of some aspects of the invention is that it realizes an image forming apparatus, a computer program, an image forming system, and an image forming method that are highly convenient for users and the like. is there.

  A main invention has an image carrier for carrying a latent image, and a plurality of attachment / detachment portions that store a developer and to which a development unit for developing the latent image with the developer can be attached / detached. Each of the plurality of developing units containing the different colors of developer is mounted on the image carrier by the developer stored in the mounted developing unit in a state where each of the developing units is mounted on the plurality of attaching / detaching portions. The development can be used as a color image forming apparatus for developing a carried latent image to form a color image, and the developer of the same color is accommodated in at least two of the plurality of attaching / detaching portions. With the unit mounted, it can be used as a monochrome image forming apparatus that forms a monochrome image by developing a latent image carried on the image carrier with a developer contained in the developing unit. Attachable part In the image forming apparatus in which one of the developed development units is moved to a predetermined attachment / detachment position so that the developed development unit can be replaced with another development unit that is not attached. When an event that cannot be developed by the predetermined developing unit occurs, the timing for moving the predetermined developing unit to the attachment / detachment position is the same as when the color image forming apparatus is used, and when the monochrome image forming apparatus is used. The image forming apparatus is characterized in that it is different from the case where it is used as an image forming apparatus.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

  An image carrier for carrying a latent image, and a plurality of attachment / detachment portions in which a developer is accommodated and a development unit for developing the latent image with the developer can be attached / detached. Each of the plurality of developing units containing the developer is attached to the plurality of attaching / detaching portions, and the latent image carried on the image carrier by the developer contained in the attached developing unit. It can be used as a color image forming apparatus that develops an image to form a color image, and the developing unit containing the developer of the same color is attached to at least two attaching / detaching portions of the plurality of attaching / detaching portions. In this state, it can be used as a monochromatic image forming apparatus that develops a latent image carried on the image carrier with a developer contained in the developing unit to form a monochromatic image, and is attached to the plurality of detachable portions. Said current In the image forming apparatus in which one of the units is moved to a predetermined attaching / detaching position so that the moved developing unit can be replaced with another developing unit that is not mounted. When an event that cannot be developed by the developing unit occurs, the timing for moving the predetermined developing unit to the attach / detach position is used when the color image forming apparatus is used or when the monochrome image forming apparatus is used. The image forming apparatus is characterized in that the image forming apparatus is different from the case where it is present.

  When such an image forming apparatus is used as a color image forming apparatus, when an event that cannot be developed by the predetermined developing unit occurs, the predetermined developing unit is used at a timing suitable for the color image forming apparatus. Can be moved to the attachment / detachment position. Further, when an event that cannot be developed by the predetermined developing unit occurs when the image forming apparatus is used as a single color image forming apparatus, the predetermined developing unit is moved to the attachment / detachment position at a timing suitable for the single color image forming apparatus. It is possible to move. Since the development unit that cannot be developed is moved to the attachment / detachment position, the user can easily replace the development unit without performing a complicated operation of confirming or moving the development unit that cannot be developed. Therefore, it is possible to realize an image forming apparatus that is highly convenient for the user regardless of whether it is used as a color image forming apparatus or a single color image forming apparatus.

  In this image forming apparatus, the image forming apparatus includes an image forming unit for developing the latent image to form an image on a medium, and a controller for causing the image forming unit to form an image, and the controller includes the image forming unit. The controller appropriately outputs a request request for requesting image formation on one of the media, and when the image forming unit is capable of image formation, the controller displays a reception response indicating that the request request has been received. When the medium forming job in which the image forming unit forms an image on one medium is generated and used as the color image forming apparatus, the predetermined developing unit is moved to the attachment / detachment position. The timing to move the medium unit job that has already occurred when an event that cannot be developed by the predetermined development unit occurs. It is preferable that after forming an image Zui.

  According to such an image forming apparatus, after an image is formed based on a medium-unit job that has already occurred when an event that cannot be developed by the predetermined developing unit occurs, the predetermined developing unit is moved to the attach / detach position. Therefore, the image forming operation is not interrupted. In other words, since the image forming operation is not stopped in a state where the image is formed halfway based on the generated medium unit job, the image is formed without wasting the developer and the medium used in the image forming operation executed halfway. Is possible. In addition, since the image forming operation based on the generated medium unit job is terminated, the image is formed based on the newly generated medium unit job after the development unit moved to the attachment / detachment position is replaced. It is.

  In such an image forming apparatus, the predetermined developing unit when the controller receives an image forming job for generating at least one medium unit job and the image formation is started and used as the monochromatic image forming apparatus. Is moved to the attachment / detachment position when a phenomenon in which development cannot be performed in the predetermined development unit occurs, development is possible in which the same color developer as that stored in the predetermined development unit is stored. When the other developing unit is mounted on any of the plurality of attaching / detaching portions, the other developing unit that can be developed is moved to the position of the developing position, and the moved developing unit is used. And after forming an image based on all the medium unit jobs generated in the image forming job. There.

  According to such an image forming apparatus, when another developing unit that is used as a single-color image forming apparatus and contains a developer of the same color is mounted, a predetermined developing unit is used. Even if an event that cannot be developed occurs, it is possible to develop using the other development unit. Therefore, after an image is formed based on several medium unit jobs of an image forming job, even if an event that cannot be developed by a predetermined developing unit occurs, an image is generated based on all the medium unit jobs of the image forming job. Can be formed.

  In such an image forming apparatus, when it is used as the monochromatic image forming apparatus, and an event that cannot be developed in all of the mounted development units occurs, it is based on the medium unit job that has already occurred. It is desirable that after the image is formed, the developing unit in which the phenomenon that cannot be developed occurs is moved to the attachment / detachment position.

  In such an image forming apparatus, when an event in which development cannot be performed in all of the mounted development units occurs, an event in which development cannot be performed after an image is formed based on the medium unit job that has already occurred. Since the generated developing unit is moved to the attachment / detachment position, an image based on the already generated medium unit job is formed. For this reason, since the image forming operation is not interrupted during the formation of an image based on the medium unit job, it is possible to suppress the waste of the developer and the medium. In addition, after an image is formed based on a medium unit job that has already occurred, the developing unit in which an event that cannot be developed occurs is moved to the attach / detach position, so that the developing operation is continued using the developing unit that cannot be developed. There is no. Therefore, it is possible to prevent waste of the developer and the medium due to continued development.

  In such an image forming apparatus, an event that cannot be developed by the predetermined developing unit is that the remaining amount of developer stored in the predetermined developing unit is less than a predetermined amount, and the controller is installed. The remaining amount information indicating the remaining amount of the developer stored in the developing unit is acquired from the image forming unit, and the remaining amount of the developer stored in the developing unit based on the acquired remaining amount information When the color image forming apparatus is used, it is possible to determine whether or not the remaining amount of developer in any one of the mounted development units is the predetermined amount when the controller is used as the color image forming apparatus. It is desirable that the controller does not output the request request to the image forming unit when it is determined that the amount is below the fixed amount.

  Such an image forming apparatus does not output a request request when the controller determines that the remaining amount of developer in any of the mounted development units is equal to or less than a predetermined amount. That is, the controller does not output a request request when development cannot be performed because the remaining amount of the developer in any of the development units is equal to or less than a predetermined amount. For this reason, if development cannot be performed in any one of the development units, a new medium unit job does not occur, so that the development operation is not continued using a development unit that cannot be developed. If the remaining amount of the color image is less than a predetermined amount for any color developer, for example, an image with a different color tone may be formed. For this reason, when used as a color image forming apparatus, the controller determines that the remaining amount of developer in any of the developing units has become a predetermined amount or less, and thereafter By not generating a medium unit job, it is possible to suppress the formation of a defective image. Therefore, it is possible to prevent the waste of the developer and the medium due to the continued development in a state where any of the development units cannot develop.

  In such an image forming apparatus, when used as the monochrome image forming apparatus, the developer remaining in the predetermined developing unit is equal to or less than the predetermined amount, and the developer stored in the predetermined developing unit Preferably, the controller outputs the request request to the image forming unit when another developing unit that can store and develop a developer of the same color as that is attached to any of the plurality of attaching / detaching units. .

  When used as a single color image forming apparatus, only one color developer is used. For this reason, even if the remaining amount of developer in the predetermined developing unit becomes a predetermined amount or less and development becomes impossible, if another developing unit that contains the same color developer and can be developed is mounted, It is possible to develop using this development unit. Therefore, even if the remaining amount of developer in the predetermined developing unit becomes equal to or less than the predetermined amount, a new medium unit job is generated when the controller outputs a request request, and the developing operation is performed using the other developing unit. Can be continued. In other words, even if the remaining amount of developer in the predetermined developing unit becomes equal to or less than the predetermined amount, the image forming operation is not stopped in the middle of the image forming job, so that the throughput can be improved.

  In such an image forming apparatus, each of the developing units includes a developer carrying roller that is rotatably supported and carries the developer, and an event that cannot be developed by the predetermined developing unit is the predetermined developing unit. The rotation time of the developer-carrying roller included in the controller is equal to or longer than a predetermined time, and the controller acquires and acquires rotation information indicating the rotation time of the developer-carrying roller of the installed development unit Based on the rotation information, it can be determined whether or not the rotation time of the developer carrying roller of the developing unit is equal to or longer than the predetermined time, and the controller is mounted when the color image forming apparatus is used. When it is determined that the rotation time of the developer carrying roller of any of the developing units is equal to or longer than the predetermined time, Controller, it is preferable not to output the request request to the image forming unit.

  Such an image forming apparatus does not output a request request when the controller determines that the rotation time of the developer carrying roller of any of the installed development units is equal to or longer than the predetermined time. That is, the controller does not output a request request when development cannot be performed because the rotation time of the developer carrying roller of any of the development units exceeds a predetermined time. For this reason, if development cannot be performed in any one of the development units, a new medium unit job does not occur, so that the development operation is not continued using a development unit that cannot be developed. For a color image, an image having density unevenness may be formed when the rotation time is equal to or longer than the predetermined time regardless of the developer carrying roller of any developing unit. For this reason, when used as a color image forming apparatus, the controller determines that the rotation time of the developer carrying roller of any of the developing units has reached the predetermined time or more as in the case of the image forming apparatus. Since no medium unit job is generated thereafter, it is possible to suppress the formation of a defective image. Therefore, it is possible to prevent the waste of the developer and the medium due to the continued development in a state where any of the development units cannot develop.

  In such an image forming apparatus, when used as the monochromatic image forming apparatus, the rotation time of the developer carrying roller of the predetermined developing unit is equal to or longer than the predetermined time and is stored in the predetermined developing unit. The controller outputs the request request to the image forming unit when another developing unit that can store and develop a developer of the same color as the developer is attached to any of the plurality of attaching / detaching units. Is desirable.

  When used as a single color image forming apparatus, only one color developer is used. For this reason, even if the rotation time of the developer carrying roller of the predetermined developing unit is longer than the predetermined time and the development cannot be performed, if another developing unit that can store and develop the same color developer is mounted. It is possible to perform development using the other development unit. Therefore, even if the rotation time of the developer carrying roller of the predetermined developing unit becomes equal to or longer than the predetermined time, a new medium unit job is generated when the controller outputs a request request, and the other developing unit is used. Thus, the developing operation can be continued. That is, even when the rotation time of the developer carrying roller of the predetermined developing unit becomes equal to or longer than the predetermined time, the image forming operation is not stopped in the middle of the image forming job, so that the throughput can be improved.

An image carrier for carrying a latent image; and a plurality of attachment / detachment portions in which a developer is accommodated and a development unit for developing the latent image with the developer can be attached / detached. An image forming unit for developing a latent image to form an image on a medium, and a controller for causing the image forming unit to form an image, each of the developing units being rotatably supported and A developer carrying roller for carrying a developer, wherein the controller obtains rotation information indicating a rotation time of the developer carrying roller of the installed development unit, and based on the obtained rotation information, the controller The remaining amount information indicating whether the rotation time of the developer carrying roller of the developing unit is a predetermined time or more and the remaining amount of the developer stored in the mounted developing unit is acquired from the image forming unit. ,Acquired Based on the remaining amount information, it is possible to determine whether or not the remaining amount of developer stored in the developing unit is equal to or less than a predetermined amount, and the controller controls the image forming unit on one medium. When the image forming unit outputs an acceptance response indicating that the request is accepted when the image can be formed, the image forming unit is appropriately output. A medium unit job for forming an image on one medium is generated, and an image forming job for generating at least one medium unit job is received by the controller, and image formation is started. Each of the plurality of development units in which the developer is accommodated is accommodated in the attached development unit in a state of being attached to the plurality of attachment / detachment portions. It can be used as a color image forming apparatus that forms a color image by developing a latent image carried on the image carrier with a developer, and at least two of the plurality of attachment / detachment portions have the same color. A monochromatic image forming apparatus that forms a monochromatic image by developing a latent image carried on the image carrier with the developer contained in the developing unit in a state in which the developing unit containing the developer is mounted. The developed developing unit is not attached by moving one of the developing units attached to the plurality of attaching / detaching portions to a predetermined attaching / detaching position. An image forming apparatus that can be replaced with another developing unit, and cannot be developed with a predetermined developing unit when used as the color image forming apparatus. As an event, when the controller determines that the remaining amount of the developer in any of the attached development units is equal to or less than the predetermined amount, and the developer in any of the attached development units When it is determined that the rotation time of the carrying roller is equal to or longer than the predetermined time, the controller does not output the request request to the image forming unit, and when an event that cannot be developed in the predetermined developing unit occurs, The timing for moving the predetermined developing unit to the attachment / detachment position is after the image is formed based on the medium unit job that has already occurred when the event occurs, and is used as the monochromatic image forming apparatus. In the case where the controller cannot be developed by a predetermined developing unit, the controller is attached to any of the attached ones. When it is determined that the remaining amount of developer in the image unit is equal to or less than the predetermined amount, and it is determined that the rotation time of the developer carrying roller of any of the mounted development units is equal to or greater than the predetermined time. Sometimes, when the other developing unit capable of developing, in which the developer of the same color as the developer stored in the predetermined developing unit is stored, is attached to any of the plurality of attaching / detaching portions. The controller outputs the request request to the image forming unit, and when an event that cannot be developed by the predetermined developing unit occurs, the other developing unit that can be developed is positioned at the predetermined developing unit. And using the moved development unit, an image is formed based on all the medium unit jobs generated in the image forming job, and the predetermined development is performed. The timing of moving the knit to the attachment / detachment position is after the image is formed based on the medium unit job that has already occurred when an event that cannot be developed occurs in all of the attached development units. An image forming apparatus characterized by the above.
According to such an image forming apparatus, the effects of the present invention can be most effectively achieved since the above-described effects can be achieved.

  And an image carrier for carrying a latent image, and a plurality of attachment / detachment portions in which a developer is accommodated and a development unit for developing the latent image with the developer can be attached and detached. Each of the plurality of developing units containing the developer of different colors is carried on the image carrier by the developer contained in the attached developing unit in a state of being attached to the plurality of attaching / detaching portions. The developing unit can be used as a color image forming apparatus that develops a latent image to form a color image, and the developer of the same color is accommodated in at least two of the plurality of attaching / detaching portions. In the mounted state, it can be used as a monochrome image forming apparatus that forms a monochrome image by developing a latent image carried on the image carrier with a developer contained in the developing unit, and the plurality of attachment / detachment portions Attached to By moving one of the developing units to a predetermined mounting / demounting position, the moved developing unit is transferred to an image forming apparatus that can be replaced with another developing unit that is not mounted. When the development unit is unable to develop the image, the predetermined color image forming apparatus and the monochrome image forming apparatus are used at different timings depending on whether the color image forming apparatus is used or not. A computer program that realizes a function of moving the developing unit to the attachment / detachment position can also be realized.

  Also, a computer main body, an image carrier for carrying a latent image, and a developing unit for accommodating the developer and developing the latent image with the developer are detachable. Each of the plurality of development units each having a plurality of attachment / detachment portions and containing the developer of different colors is accommodated in the attached development unit in a state of being attached to the plurality of attachment / detachment portions. It can be used as a color image forming apparatus that forms a color image by developing a latent image carried on the image carrier with a developer, and at least two of the plurality of attachment / detachment portions have the same color. A monochromatic image forming apparatus for developing a latent image carried on the image carrier with the developer contained in the developing unit in a state where the developing unit containing the developer is attached to form a monochromatic image. The developed developing unit is not mounted by moving one of the developing units mounted on the plurality of mounting / demounting portions to a predetermined mounting / demounting position. In an image forming system having an image forming apparatus that can be replaced with another developing unit, when an event that cannot be developed by the predetermined developing unit occurs, the timing for moving the predetermined developing unit to the attachment / detachment position is It is also possible to realize an image forming system that is different when used as the color image forming apparatus and when used as the monochrome image forming apparatus.

  In addition, a plurality of detachable portions in which developers of different colors are accommodated, and each of the plurality of developing units for developing the latent image carried on the image carrier by the developer can be detachably attached to the developing unit. In a state where the image forming apparatus is used as a color image forming apparatus that forms a color image by developing the latent image with the developer contained in the mounted developing unit. When an event that cannot be developed occurs, one development unit of the development units attached to the plurality of attachment / detachment units can be replaced with another development unit that is not attached at a predetermined timing. And a step of moving to a predetermined attaching / detaching position, and at least two attaching / detaching portions of the plurality of attaching / detaching portions mounted with the developing unit containing the developer of the same color. In the case of being used as a monochrome image forming apparatus that forms a monochrome image by developing the latent image carried on the image carrier by the developer contained in the developing unit, When an event that cannot be developed occurs, one of the developing units attached to the plurality of attaching / detaching units is attached to the attaching / detaching unit at a timing different from that when the color image forming apparatus is used. It is also possible to realize an image forming method characterized by including the step of moving to a position.

=== Example of Overall Configuration of Image Forming Apparatus ===
Next, the outline of the printer 10 as an example of the image forming apparatus will be described with reference to FIGS. 1 and 2 are diagrams showing main components constituting the printer 10, FIG. 1 is a diagram showing main components when the printer 10 is used as a color printer, and FIG. FIG. 10 is a diagram illustrating main components when 10 is used as a monochrome printer. The use of the printer 10 as a color printer or a monochrome printer will be described in detail later. 1 and 2, the vertical direction is indicated by arrows. For example, the paper feed tray 92 is disposed at the lower part of the printer 10, and the fixing unit 90 is disposed at the upper part of the printer 10. ing.

  As shown in FIGS. 1 and 2, the printer 10 includes a charging unit 30, an exposure unit 40, a developing device holding unit 50, along the rotation direction of the photoconductor 20 as an image carrier for carrying a latent image. The image forming apparatus includes a primary transfer unit 60, an intermediate transfer body 70, and a cleaning unit 75, and further includes a secondary transfer unit 80, a fixing unit 90, a liquid crystal panel, and a display unit 95 as a display unit for a user or the like. It has the control unit 100 for controlling.

The photoreceptor 20 has a cylindrical conductive substrate and a photosensitive layer formed on the outer peripheral surface thereof, and can rotate around a central axis. In the present embodiment, the photoreceptor 20 in FIGS. Rotate clockwise as indicated by the arrow.
The charging unit 30 is a device for charging the photoconductor 20, and the exposure unit 40 is a device for forming a latent image on the photoconductor 20 charged by irradiating a laser. The exposure unit 40 includes a semiconductor laser, a polygon mirror, an F-θ lens, and the like. Based on image information input from an external computer (not shown), a photosensitive laser charged with a modulated laser is provided. Irradiate toward the body 20.
The developing device holding unit 50 has a plurality of detachable portions 50 a, 50 b, 50 c, and 50 d, in which a developing device as a developing unit for containing the developer and developing the latent image formed on the photoreceptor 20 can be attached and detached. doing. The latent image formed on the photoconductor 20 is developed using the toner T as an example of the developer accommodated in the developing device attached to the detachable portion.

By the way, in the printer 10 according to the present embodiment, the photoconductor 20 is provided by the toner T accommodated in each developing device in a state where the developing device is attached to each of the plurality of attaching / detaching portions 50a, 50b, 50c, 50d. It can be used as a color printer (color image forming apparatus) that develops a latent image carried on the printer and forms a color image. Further, the printer 10 is accommodated in the developing device in a state in which a developing device containing the developer of the same color is attached to at least two of the attaching / detaching portions 50a, 50b, 50c, 50d. It can be used as a monochromatic printer (monochromatic image forming apparatus) that develops a latent image carried on the photoconductor 20 with a developer to form a monochromatic image.
When the printer 10 is used as a color printer, as shown in FIG. 1, four developing units, that is, a black developing unit 51 are provided in the four attaching / detaching portions 50a, 50b, 50c, and 50d of the developing unit holding unit 50. A magenta developing unit 53, a cyan developing unit 52, and a yellow developing unit 54 are mounted. The latent image formed on the photoconductor 20 is developed with the toner T accommodated in each developing device 51, 52, 53, 54.

  In addition, the developing device holding unit 50 can move the four developing devices 51, 52, 53, and 54 by rotating. That is, the developing device holding unit 50 is provided so as to be rotatable about the rotation shaft 50e, and four attachment / detachment portions are provided so as to surround the rotation shaft 50e. For this reason, when the developing device holding unit 50 is rotated around the rotation shaft 50e in a state where the four developing devices 51, 52, 53, and 54 are attached to the detachable portions, the four developing devices 51 that are attached are rotated. , 52, 53, and 54 are moved while maintaining their relative positions. The developing devices 51, 52, 53, and 54 sensitize the latent image formed on the photoconductor 20 when developing with the toner T contained in the developing devices 51, 52, 53, and 54. It is moved to a position facing the body 20. When a latent image for one page is developed by a certain developing device, the developing device holding unit 50 rotates 90 °, and adjacent developing devices are sequentially moved to a position facing the photoconductor 20.

  On the other hand, when the printer 10 is used as a monochrome printer, as shown in FIG. 2, the developer of the same color is stored in at least two of the plurality of attachment / detachment portions of the developing device holding unit 50. A developing device is installed. Then, the latent image formed on the photoconductor 20 is developed by the toner T accommodated in the developing device in which the mounted developer of the same color is accommodated. In the present embodiment, the black developing device 51 is attached to two of the four attachment / detachment portions 50a, 50b, 50c, and 50d. Then, by rotating the developing device holding unit 50, one of the two mounted black developing devices 51 is moved to a position facing the photoconductor 20. Then, the latent image formed on the photoconductor 20 appropriately moves the positions of the two mounted black developing devices 51, and the black toner T accommodated in the developing device moved to a position facing the photoconductor 20. Developed with Details of the developing device will be described later.

The primary transfer unit 60 is a device for transferring the toner image formed on the photoconductor 20 to the intermediate transfer body 70.
The intermediate transfer body 70 is an endless belt in which an aluminum vapor deposition layer is provided on the surface of a PET film and a semiconductive paint is formed on the surface layer and laminated. The intermediate transfer body 70 is driven to rotate at substantially the same peripheral speed as the photoconductor 20.
The secondary transfer unit 80 is a device for transferring the toner image formed on the intermediate transfer body 70 to a medium such as paper, film, or cloth.
The fixing unit 90 is a device for fusing the toner image transferred onto the medium to a permanent image.
The cleaning unit 75 includes a rubber cleaning blade 76 that is provided between the primary transfer unit 60 and the charging unit 30 and is in contact with the surface of the photoreceptor 20. The cleaning unit 75 is a unit for scraping and removing the toner T remaining on the photosensitive member 20 by the cleaning blade 76 after the toner image is transferred onto the intermediate transfer member 70 by the primary transfer unit 60.

  The control unit 100 includes a controller unit 101 and a unit control unit 102 (FIG. 7). The controller unit 101 communicates with an external computer, and the unit control unit 102 controls each unit and forms an image. The controller unit 101 and the unit control unit 102 are connected via an interface. The controller unit 101 corresponds to the “controller” according to the claims, and each unit, the unit control unit 102, and the like described above correspond to the “image forming unit” 103 according to the claims.

=== Configuration Example of Developer ===
Next, a configuration example of the developing device will be described with reference to FIGS. 3 and 4. FIG. 3 is a conceptual diagram of the developing device, and FIG. 4 is a cross-sectional view showing main components of the developing device. Note that the cross-sectional view shown in FIG. 4 represents a cross-section obtained by cutting the developing device along a plane perpendicular to the longitudinal direction shown in FIG. In FIG. 4, as in FIG. 1, the up and down directions are indicated by arrows, and the black developing device 51 is in a developing position facing the photoconductor 20.

The developing device holding unit 50 includes a black developing device 51 containing black (K) toner, a magenta developing device 53 containing magenta (M) toner, a cyan developing device 52 containing cyan (C) toner, and yellow. (Y) Although the yellow developing unit 54 containing toner can be mounted, the configuration of each developing unit is the same, so the black developing unit 51 will be described below.
The black developing device 51 includes a developing roller 510 as a developer carrying roller, a seal member 520, a toner accommodating portion 530, a housing 540, a toner supply roller 550, a regulating blade 560, and the like.

  The developing roller 510 carries the toner T and conveys it to a developing position facing the photoconductor 20. Further, as shown in FIG. 3, the developing roller 510 is supported at both ends in the longitudinal direction, and is rotatable about the central axis. As shown in FIG. 4, the developing roller 510 rotates in a direction (counterclockwise in FIG. 4) opposite to the rotation direction of the photoconductor 20 (clockwise in FIG. 4). Further, as shown in FIG. 4, the developing roller 510 of the black developing device 51 and the photosensitive member 20 are opposed to each other with a space therebetween. That is, the black developing device 51 develops the latent image formed on the photoconductor 20 in a non-contact state. When developing the latent image formed on the photoconductor 20, an alternating electric field is formed between the developing roller 510 and the photoconductor 20.

  The seal member 520 prevents the toner T in the black developing device 51 from leaking out of the device, and collects the toner T on the developing roller 510 that has passed the developing position into the developing device without being scraped off. The seal member 520 is a seal made of a polyethylene film or the like, and is pressed against the developing roller 510 by the elastic force of a seal urging member 524 made of a malt plane or the like provided on the opposite side to the developing roller 510 side.

The housing 540 is formed by welding a plurality of integrally molded housing portions. As shown in FIG. 4, the housing 540 has an opening 572 that communicates with the outside of the housing 540, the peripheral surface of the housing 540 faces the opening 572 from the outside of the housing 540, and the developing roller 510 described above is one of them. It is arranged with the part exposed. Further, a regulation blade 560 described later is also arranged in a state of facing the opening 572 from the outside of the housing 540.
The housing 540 forms a toner storage portion 530 that can store the toner T.

  The toner supply roller 550 is provided in the toner storage unit 530 described above, and supplies the toner T stored in the toner storage unit 530 to the developing roller 510. The toner supply roller 550 is made of polyurethane foam or the like, and is in contact with the developing roller 510 in an elastically deformed state. The toner supply roller 550 is disposed below the toner storage unit 530, and the toner T stored in the toner storage unit 530 is supplied to the developing roller 510 by the toner supply roller 550 below the toner storage unit 530. The The toner supply roller 550 rotates around the central axis in a direction (clockwise in FIG. 4) opposite to the rotation direction of the developing roller 510 (counterclockwise in FIG. 4). The toner supply roller 550 has a function of supplying the toner T accommodated in the toner accommodating portion 530 to the developing roller 510, and peels off the toner T remaining on the developing roller 510 after the development from the developing roller 510. It also has a function.

  The regulating blade 560 applies a charge to the toner T carried on the developing roller 510 and regulates the layer thickness of the toner T carried on the developing roller 510. The regulation blade 560 has a rubber part 560a and a rubber support part 560b. The rubber part 560a is made of silicon rubber, urethane rubber or the like, and the rubber support part 560b is a thin plate having spring properties such as phosphor bronze or stainless steel. The rubber part 560a is supported by a rubber support part 560b, and the rubber support part 560b is supported by being sandwiched between a pair of blade support metal plates 562 via the blade support metal plate 562. Is attached. Further, a blade back member 570 made of malt plane or the like is provided on the side opposite to the developing roller 510 side of the regulating blade 560.

  Here, the rubber portion 560 a is pressed against the developing roller 510 by the elastic force caused by the bending of the rubber support portion 560 b. Further, the blade back member 570 prevents the toner T from entering between the rubber support portion 560b and the housing 540, stabilizes the elastic force due to the bending of the rubber support portion 560b, and provides rubber from the back of the rubber portion 560a. The rubber portion 560 a is pressed against the developing roller 510 by urging the portion 560 a toward the developing roller 510. Therefore, the blade back member 570 improves the uniform contact property of the rubber portion 560a to the developing roller 510.

  In the black developing device 51 configured as described above, the toner supply roller 550 supplies the toner T accommodated in the toner accommodating portion 530 to the developing roller 510. The toner T supplied to the developing roller 510 reaches the abutting position of the regulating blade 560 as the developing roller 510 rotates, and when the toner T passes through the corresponding contacting position, an electric charge is applied and the layer thickness is regulated. Is done. The toner T on the developing roller 510 whose layer thickness is regulated reaches the developing position facing the photoconductor 20 by further rotation of the developing roller 510, and is formed on the photoconductor 20 under an alternating electric field at the developing position. Used for developing the latent image. The toner T on the developing roller 510 that has passed the developing position due to further rotation of the developing roller 510 passes through the seal member 520 and is collected in the developing unit without being scraped off by the seal member 520.

  Each of the developing units 51, 52, 53, and 54 stores various information related to the developing unit such as the color information of the toner accommodated in each developing unit, the remaining amount of toner, and the rotation time of the developing roller 510. Storage elements, for example, non-volatile storage memory (hereinafter also referred to as developing device side memory) 51a, 52a, 53a, 54a such as serial EEPROM.

  The developing device side memories 51a, 52a, 53a, 54a include developing device side connectors 51b, 52b, 53b, 54b provided on one side surface of the developing device, and an apparatus main body provided on the apparatus main body side (printer side). The side connector 34 is in contact with each other when necessary, and is electrically connected to the unit control unit 102 of the main body control unit 100.

=== Overview of Developer Holding Unit ===
Next, an outline of the developing device holding unit 50 will be described with reference to FIGS. 5A to 5C. In this section, for the sake of convenience, the case where the developing devices 51, 52, 53, and 54 are attached to the four attachment / detachment portions 50a, 50b, 50c, and 50d will be described as an example. The present invention can also be applied to a case where a developing device containing the same color developer is attached to at least two attachment / detachment portions among 50a, 50b, 50c, and 50d.
The developing device holding unit 50 has a rotation shaft 50e located at the center thereof, and a support frame 55 for holding the developing device is fixed to the rotation shaft 50e. The rotation shaft 50e serves as a housing of the printer 10. It spans between two frame side plates (not shown) formed, and both ends thereof are supported. In addition, the axial direction of the rotating shaft 50e intersects the vertical direction.
The support frame 55 includes four attaching / detaching portions 50a, 50b, 50c, and 50d in which the four color developing devices 51, 52, 53, and 54 are detachably attached around the rotating shaft 50e in the circumferential direction. It is provided at 90 ° intervals.
A pulse motor (not shown) is connected to the rotary shaft 50e. By driving the pulse motor, the support frame 55 can be rotated to position the four phenomenon devices 51, 52, 53, 54 at predetermined positions. It is like that.

  5A to 5C show three stop positions of the rotating developing device holding unit 50, and FIG. 5A shows the standby position when the image forming execution is on standby, and the developing device holding unit 50. FIG. 5B shows a developer position side connector 51b of the black developing device 51 mounted on the developing device holding unit 50. FIG. 5C shows the attachment / detachment position of the black developing device 51, and the connector attachment / detachment position facing the apparatus body side connector 34 provided on the apparatus body side.

  5B and 5C, the connector attaching / detaching position and the developing device attaching / detaching position are shown with respect to the black developing device 51, but the position where the developing device holding unit 50 is rotated by 90 ° is the position of each developing device. A connector attach / detach position and a developer attach / detach position.

  First, the HP position shown in FIG. 5A will be described. On one end side of the rotation shaft 50e of the developing device holding unit 50, an HP detection unit 31 (FIG. 7) for detecting the HP position is provided. The HP detection unit 31 includes a signal generation disk fixed to one end of the rotating shaft 50e, and an HP sensor including a photo interrupter and the like provided with a light emitting unit and a light receiving unit. The peripheral part of the disk is arranged so as to be positioned between the light emitting part and the light receiving part of the HP sensor, and when the slit part formed in the disk moves to the detection position of the HP sensor, the output from the HP sensor The signal changes from “L” to “H”. The HP position of the developing device holding unit 50 is detected based on the change in the signal level and the number of pulses of the pulse motor, and the developing device can be positioned at the developing position of each developing device on the basis of the HP position. Has been.

  FIG. 5B shows a connector attaching / detaching position of the black developing device 51 in which the pulse motor is rotated by a predetermined number of pulses from the HP position. At this connector attaching / detaching position, the developing device side connector 51b of the black developing device 51 attached to the developing device holding unit 50 and the device main body side connector 34 provided on the device main body side face each other, and these connectors are mutually abutted. It is possible to make contact or separation.

  Further explanation will be given with reference to FIGS. 6A and 6B. FIG. 6A is a diagram related to the separation position, and FIG. 6B is a diagram related to the contact position.

  FIG. 6A shows a state where the apparatus main body side connector 34 and the developing device side connector 51b of the black developing device 51 are separated from each other. The apparatus main body side connector 34 is configured to be movable toward and away from the black developing device 51 and moves in a direction approaching the black developing device 51 (the direction of the arrow shown in FIG. 6B) as necessary. As a result, as shown in FIG. 6B, the apparatus main body side connector 34 abuts on the developing device side connector 51 b of the black developing device 51, and the developing device side memory 51 a attached to the black developing device 51 is connected to the control unit 100. The unit controller 102 is electrically connected, and communication is performed between the developing device side memory 51a and the apparatus main body.

  6B, the apparatus main body side connector 34 moves away from the black developing device 51 from the state in which the apparatus main body side connector 34 and the developing device side connector 51b of the black developing device 51 are in contact with each other (see FIG. 6B). Move in the direction opposite to the direction of the arrow shown in 6B. As a result, as shown in FIG. 6A, the apparatus main body side connector 34 is separated from the developing device side connector 51 b of the black developing device 51.

  The movement of the apparatus main body side connector 34 is realized by, for example, a mechanism (not shown) including a pulse motor, a plurality of gears connected to the pulse motor, and an eccentric cam connected to the gear. That is, when the pulse motor is rotated by a predetermined number of pulses, the mechanism moves the apparatus main body side connector 34 by a distance corresponding to the pulse number from a predetermined separation position, and the apparatus main body side connector 34 is moved. It is positioned at a predetermined contact position. Conversely, when the pulse motor is reversely rotated by a predetermined number of pulses, the mechanism moves the device body side connector 34 by a distance corresponding to the number of pulses from a predetermined contact position, and the device body side The connector 34 is positioned at a predetermined separation position.

  Further, the connector attaching / detaching position with respect to the black developing device 51 is the developing position of the cyan developing device 52 with the developing roller 510 of the cyan developing device 52 and the photosensitive member 20 facing each other. That is, the connector attaching / detaching position of the developing device holding unit 50 related to the black developing device 51 is the developing position of the developing device holding unit 50 related to the cyan developing device 52. Further, when the pulse motor rotates the developing device holding unit 50 by 90 ° counterclockwise, the connector attaching / detaching position of the yellow developing device 54 and the developing position of the black developing device 51 are set, and the developing device holding unit 50 is rotated by 90 °. Each time it is done, it becomes the connector attaching / detaching position and developing position of each developing device.

One of the two frame side plates that support the developing device holding unit 50 and form the housing of the printer 10 covers the detachable opening 37 through which one developing device can pass and the detachable opening 37 that can be opened and closed. An inner cover (not shown) is provided. When the developing device holding unit 50 is rotated and each developing device is stopped at the set developing device attaching / detaching position, the attaching / detaching dedicated port 37, as shown in FIG. Only the developing device 51) is formed at a position where it can be pulled out and removed in the direction along the rotation shaft 50e. In addition, the attachment / detachment port 37 is formed to be slightly larger than the outer shape of the developing device. At the developing device attaching / detaching position, not only the developing device is removed, but also a new developing device is installed in the direction along the rotation shaft 50e through the attaching / detaching port 37. The developing device can also be attached to the support frame 55 by making it enter. While the developing device holding unit 50 is located at a position other than the developing device attaching / detaching position, the attaching / detaching of the developing device is restricted by the frame side plate.
A locking mechanism (not shown) is provided in order to securely position and fix the developing device holding unit 50 at the above-described position.

=== Overview of Control Unit ===
Next, the configuration of the control unit 100 will be described with reference to FIG. FIG. 7 is a block diagram showing the control unit 100 of the printer 10.

  The controller unit 101 includes a CPU 111, an interface 112 for connecting to a computer (not shown), an image memory 113 for storing an image signal input from the computer, an electrically rewritable EEPROM 114a, a RAM 114b, various types And a controller unit side memory 114 composed of a program ROM or the like having a control program. Various information such as an image signal is sent to the controller unit 101 from a computer connected to the printer 10.

  The controller unit 101 converts RGB data of red, green, and blue as image signals transmitted from a computer or the like into YMCK image data of yellow, magenta, cyan, and black, and the converted YMCK image data is stored in the image memory 113. It has a function to memorize. When the printer 10 is used as a single color printer, the RGB data is converted into black image data, and the converted black image data is stored in the image memory 113. Further, the controller unit 101 has a function of sending various information to a connected computer.

  Further, the controller unit 101 counts the number of pixels to be developed when forming the toner image of each color based on the converted YMCK image data, and predicts that it will be consumed when the image is formed based on the YMCK image data. A function of calculating the amount of toner consumed and outputting this information to the unit controller 102. At this time, if the printer is used as a single-color printer, the toner consumption estimated by counting the number of pixels to be developed when forming a black toner image based on the converted black image data And outputs this information to the unit controller 102.

  The EEPROM 114a stores model information as device information indicating whether the printer 10 is used as a color printer or a monochrome printer. Although the details will be described later, the CPU 111 displays the developing device mounting information indicating where the developing device is mounted in the above-described four attaching / detaching units and information on each developing device at a predetermined timing. Receive from. Based on the mounting information, the model information in the EEPROM 114a is rewritten as necessary. The model information is written as 1-bit information in the EEPROM 114a. When the value is 0, the printer 10 is used as a color printer. When the value is 1, the printer 10 is monochrome. It shows that it is being used as a printer. This model information is rewritten in the RAM 114b based on the EEPROM 114a when the printer 10 is turned on.

  The information on each developing device is, for example, the remaining amount of developer stored in each developing device, the rotation time of the developing roller included in the developing device, and the like. The remaining amount of developer is stored in a predetermined area of the EEPROM 114a when the amount of developer accommodated in an unused developing device is 100%. The rotation speed of the developing roller is stored in a predetermined area of the EEPROM 114a from the time when the developing device is started to be used. The information on each developing device is rewritten when the information stored in the memory from the unit control unit 102 is output to the controller unit 101 as a response to the request request output from the controller unit 101.

  The unit control unit 102 includes a CPU 120, an electrically rewritable EEPROM 116a, a RAM, a unit control unit side memory 116 including a program ROM having various control programs, and each unit (charging unit 30, The exposure unit 40, the primary transfer unit 60, the cleaning unit 75, the secondary transfer unit 80, the fixing unit 90, the display unit 95), and drive control circuits for driving and controlling the developing device holding unit 50 are included.

  The CPU 120 is connected to a non-volatile storage element (hereinafter referred to as a main body side memory) 122 such as a serial EEPROM via a serial interface (I / F) 121. The main body side memory 122 stores data necessary for device control. The CPU 120 is connected not only to the main body side memory 122 but also to the developing device side memories 51 a, 52 a, 53 a, 54 a provided in the developing devices 51, 52, 53, 54 via the serial interface 121. In addition, data can be transferred between the main body side memory 122 and the developing device side memories 51a, 52a, 53a, 54a, and chip select can be made to each developing device side memory 51a, 52a, 53a, 54a via the input / output port 123. The signal CS can be input. The CPU 120 is also connected to the HP detection unit 31 via the input / output port 123.

  The CPU 120 of the unit control unit 102 is electrically connected to each drive control circuit, and controls each drive control circuit based on a control signal from the CPU 111 of the controller unit 101. That is, the unit control unit 102 receives a signal from a sensor or the like included in each unit, detects the state of each unit and the developing device holding unit 50, and based on a signal input from the controller unit 101, Each unit and the developer holding unit 50 are controlled.

  The CPU 120 controls each drive control circuit based on the above-described model information. That is, when the model information value is 0, each unit of the printer 10 and the developing device holding unit 50 are controlled as a color printer. When the device information value is 1, the printer 10 is a monochrome printer. Control each unit.

  When the connector of any of the developing devices arranged at the connector attaching / detaching position and the apparatus main body side connector 34 among the developing devices are connected to the apparatus main body side connector 34, the CPU 120 Communication is possible. Then, various information on the developing device is acquired from the developing device side memories 51a, 52a, 53a, 54a of the developing device connected to the apparatus main body side connector 34. The information on the developing device includes, for example, mounting information of the developing device indicating where the developing device is mounted on the four attaching / detaching portions of the developing device holding unit 50, and the color of the toner stored in the mounted developing device. Information, remaining toner remaining amount information, developing roller rotation time information, and the like, and the acquired various information is associated with each developing device in a predetermined area of the main body side memory 122 of the unit control unit 102. Remembered.

  For example, four developing units (black developing unit 51, magenta developing unit 53, cyan developing unit 52, and yellow developing unit 54) each containing developer of different colors are mounted on four attachment / detachment portions, respectively, and a color printer. In this case, the CPU 120 accesses the developing unit side memory of each developing unit to detect that the developing units are respectively attached to the four attaching / detaching units. Then, “1” indicating that the developing device is mounted in a predetermined area in the main body side memory 122 is stored. At this time, the CPU 120 also acquires information on each developing device, and information indicating the color, remaining amount of toner stored in the mounted developing device, and the rotation time of the developing roller is represented by binary information for each attaching / detaching unit. Is stored in the area of the main body side memory 122 corresponding to. Further, of the four attachment / detachment sections, for example, when a developing device containing black toner is attached to the two attachment / detachment portions 50a and 50c and used as a single color printer, the CPU 120 includes two development devices. By accessing the developing device side memory, it is detected that the developing devices are respectively attached to the two attachment / detachment portions. Then, “1” indicating that the developing device is mounted in a predetermined area in the main body side memory 122 is stored, and it is confirmed that the developing device is not mounted in the corresponding area in the other attaching / detaching portions 50b and 50d. The indicated “0” is stored. At this time, the CPU 120 also acquires information on each developing device, and information indicating the color (black) of the toner contained in the mounted developing device, the remaining amount, and the rotation time of the developing roller as binary information. The data is stored in an area of the main body memory 122 corresponding to each detachable part.

  Further, when the CPU 120 detects the information indicating the toner consumption amount output from the controller unit 101, the CPU 120 subtracts the toner consumption amount from the remaining toner amount stored in the main body side memory 122, and calculates the calculated remaining toner amount on the main body side. Store in the memory 122. The CPU 120 has a function of outputting information indicating the remaining toner amount stored in the main body side memory 122 to the controller unit 101 in response to a request for remaining toner information from the controller unit 101.

  Further, the CPU 120 calculates the rotation time of the developing roller from information indicating the print size and the number of prints included in the print request from the controller unit 101, and stores it in the main body side memory 122. The CPU 120 has a function of outputting information indicating the rotation time of the developing roller stored in the main body memory 122 to the controller unit 101 in response to a request for the rotation time of the developing roller from the controller unit 101.

  Then, the CPU 120 rotates the developing device holding unit 50 based on the information of each developing device. For example, when printing is continuously performed for a plurality of sheets using only a black developing device, the developing device is used each time printing for the set number of sheets is completed in order to stir the contained toner. The holding unit 50 is rotated once. Further, when two or more black developing devices are mounted, for example, when the remaining amount of toner in a certain developing device is below a predetermined remaining amount, the developing device holding unit 50 is rotated. To move the other developing device mounted to the developing position. Further, among the mounted developing devices, when the rotation time of the developing roller becomes equal to or longer than a predetermined rotation time that is set, the other developing devices mounted by rotating the developing device holding unit 50 Is moved to the developing position, or the developing device that has reached a predetermined time is moved to the attaching / detaching position. Such control for rotating the developing device holding unit 50 is executed by the control of the unit control unit 102 based on the acquired various information.

=== Printer Operation ===
Next, the operation of the printer 10 will be described separately for a case where it is used as a color printer for forming a color image and for a case where it is used as a monochrome printer for forming a monochrome image as a monochrome image. In the present embodiment, an example in which an event that cannot be developed by a predetermined developing device during a printing operation based on a printing command input from an external computer has occurred and an example that has not occurred are described separately. To do. By the way, an event in which development cannot be performed by a predetermined developing device is, for example, when the remaining amount of toner stored in the developing device becomes a predetermined amount or less, or the rotation time of the developing roller of the developing device is a predetermined time or more There are some cases. Here, the processing and operation of the printer when the remaining amount of toner becomes equal to or less than a predetermined amount and when the rotation time of the developing roller becomes equal to or longer than a predetermined time will be described.

  The remaining amount of toner is obtained by subtracting the amount of toner consumed by the printing operation, and indicates the expected remaining amount. As described above, the amount (initial amount) of developer accommodated in an unused developing device is 100%, and the remaining amount of toner is shown as a percentage of the initial amount and stored in the main body side memory 122. In this embodiment, when it is determined that the remaining amount is 10% or less, the controller unit 101 designates the target developing device and the display unit 95 warns that the toner is low. Is set to display. Further, when the toner remaining amount becomes 5% or less, the developing unit becomes in a state where development cannot be performed, and settings such as “no toner” and “replace developing unit” are displayed.

  Further, the rotation time of the developing roller is stored by adding a predetermined rotation time every time an image is formed on one medium. That is, the rotation time of the developing roller indicates the accumulated rotation time from the rotation time “0” of the developing roller in the unused developing device. The predetermined rotation time is set corresponding to the size of the medium on which the image is formed. For example, when the developing roller rotates for 5 seconds when developing an A4 size image, “5” is displayed in the information of the corresponding developing device stored in the main body side memory 122 every time development is performed on one medium. It is set to be added. If the rotation time is 1000 seconds or more as a result of the addition, the unit controller 102 determines that the target developing device cannot be developed. When the controller unit 101 detects this event, the display unit 95 is set to display “Please replace the developing device”.

<Initial operation of the printer>
First, an initial operation from when the printer 10 is turned on until it enters a standby state where it waits for a print command will be described. During this initial operation, the controller unit 101 of the printer 10 communicates with the unit control unit 102 and acquires information on the installed developing devices. Based on the acquired information, the printer 10 starts to operate as a color printer or a single color printer.

  FIG. 8 is a diagram for explaining the initial operation of the printer. When the printer 10 is turned on (S101), the display unit 95 displays "Memory Checking" (S102), and the controller unit 101 initializes the image memory 113, the EEPROM 114a, etc. (S104). The control unit 102 initializes the main body memory 122 and the like (S105). In addition, the controller unit 101 sends a request for confirming whether or not predetermined communication is possible to the unit control unit 102 (S106). The unit control unit 102 that has received this request outputs a response indicating that communication is possible to the controller unit 101 (S107), and communication between the controller unit 101 and the unit control unit 102 is started.

  When the power is turned on (S101), the unit controller 102 rotates the developing device holding unit 50 to sequentially move the four attachment / detachment portions to the connector attachment / detachment position (S108). Then, the apparatus main body side connector 34 is moved, and when the developing device is attached to the attaching / detaching portion disposed at the connector attaching / detaching position, the information stored in the developing device side memory of the developing device is acquired. (S109). At this time, as the information of each developing device, the color information of the stored toner, the remaining amount information of the stored toner, the information indicating the rotation time of the developing roller, and the like are read and stored in a predetermined area of the main body side memory 122. Store for each developing device. When the information is acquired from each developing device side memory, the unit control unit 102 moves the developing device holding unit 50 to the home position based on the output of the HP detection unit 31 (S110). At this time, the unit controller 102 executes a predetermined warm-up operation in parallel (S103). The warm-up operation is, for example, to execute printing such as causing the light source of the exposure unit 40 to emit light, turning on the heater of the fixing unit 90, rotating the photosensitive member 20 and the intermediate transfer member 70, and cleaning. The necessary operations are shown.

  Further, the controller unit 101 acquires information of each developing device stored in the main body side memory 122 during the warm-up operation of the image forming unit 103, and stores it in the EEPROM 114a of the controller unit 101 (S111). At this time, the controller unit 101 outputs an information request for requesting information indicating the remaining amount of each toner color and the rotation time of the developing roller to the unit control unit 102 (S111a). The unit control unit 102 outputs an information response response indicating the remaining amount of toner of each color and the rotation time of the developing roller to the controller unit 101 (S111b). Based on the information response response, for example, the controller unit 101 detects that Y, M, C, and K developing devices are respectively attached to the four attachment / detachment units based on the information in the main body side memory 122. In this case, the printer operates as a color printer. When it is detected that two or more developing devices of the same color, for example, a K developing device are mounted, the printer operates as a single color printer (S112).

  While the unit control unit 102 is performing the initial operation, the controller unit 101 sends out status request requests for requesting status information indicating the state of the image forming unit 103 at appropriate intervals (S113). ). Upon receiving this request, the unit control unit 102 detects the output of the sensor or the like provided in each unit. If the warm-up operation is completed, the unit control unit 102 outputs a response indicating that printing is possible to the controller unit 101. If the operation is not completed, a response indicating that printing is not possible is output to the controller unit 101 (S114). If the response from the unit control unit 102 indicates “cannot print”, the controller unit 101 displays “warming up” or the like on the display unit 95 (S115).

  When information indicating “printable” is acquired as the status information of the image forming unit 103, “printable” or the like is displayed on the display unit 95, and the printer 10 is set in a standby state (S116).

<One-page color printing process and operation when used as a color printer>
First, basic processing and operation at the time of color printing in the case of being used as a color printer will be described by taking as an example the case of executing color printing for one page. In this example, information that yellow, magenta, cyan, and black developing devices are attached to each attachment / detachment unit is acquired during the initial operation, and the remaining amount of toner in each developing device is 10 % Is stored in the EEPROM 114 a, and information that the rotation time of the developing roller of each developing device is “30” is stored in the main body side memory 122.

  FIG. 9 is a diagram for explaining processing and operation when color printing of one page is executed when the printer is used as a color printer. As shown in the figure, an image signal and a control signal from a computer (not shown) connected so as to be capable of bidirectional communication, that is, for performing color printing of one sheet (one page) on a sheet as an A4 size medium. When the print command and the image data are input to the printer 10 in the standby state via the interface (I / F) 112, the printing process is started (S210). In this way, the number of sheets to be printed (number of pages) is designated, and the print process to be executed generated by the print command and image data for executing the print input to the printer is the “image forming job” according to the claims. It corresponds to. Based on this image forming job, a medium unit job, which is a printing process to be executed for one medium, is generated for the designated number of sheets. In other words, the medium unit job is generated for the designated number of sheets, and printing of one page is executed based on the generated medium unit job, thereby completing the image forming job.

  Based on the image forming job, the controller unit 101 outputs a one-page print request request for requesting one page of color printing processing, that is, execution of a medium unit job, to the unit control unit 102 at an appropriate timing (S221). ). Upon receiving this one-page print request request, the unit control unit 102 detects the status of each unit of the image forming unit 103, and if it is in a printable state, the unit control unit 102 sends an acceptance response allowing the one-page print request to the controller unit 101. Output (S222). As a result, one medium unit job is generated and the printing process is started. The process for generating one medium unit job in this way is hereinafter referred to as a medium unit job generation process (S220). Since the controller unit 101 and the unit control unit 102 communicate with each other while the unit control unit 102 controls each unit, the one-page print request request does not generate a medium unit job at a constant interval.

  The unit controller 102 rotates the developing device holding unit 50 from the home position, and moves the yellow developing device (Y developing device) 54 to the developing position (S230). When the Y developing device 54 is moved to the developing position, the unit control unit 102 outputs a request for requesting Y image data to the controller unit 101 (S241a). Upon receiving this request, the controller unit 101 outputs the Y image data to the unit control unit 102 (S241b), calculates the toner consumption consumed when developing based on the Y image data, and the unit control unit 102 (S241c). The unit control unit 102 executes the developing operation (S241d), and subtracts the received consumption amount from the remaining toner amount of the Y developing unit 54 stored in the main body side memory 122, and the remaining toner amount after development. And the information in the main body memory 122 is rewritten (S241e). Further, the unit controller 102 adds “5” to the rotation time of the developing roller of the Y developing device 54 stored in the main body side memory 122, and sets the rotation time (cumulative rotation time) of the developing roller after development. Calculate and rewrite the information in the main body side memory 122 (S241f). At this time, the unit controller 102 detects that the rotation time of the developing roller of the Y developing device 54 is less than 1000 seconds. The controller unit 101 outputs an information request request for requesting information indicating the remaining amount of toner after development by the medium unit job and information indicating the rotation time of the developing roller to the unit control unit 102 at an appropriate timing (S241g). . The unit control unit 102 outputs information indicating the remaining amount of Y toner stored in the main body side memory 122 and information indicating the rotation time of the developing roller to the controller unit 101 (S241h). The controller unit 101 rewrites the information in the EEPROM 114a based on the acquired information indicating the remaining amount of Y toner and the information indicating the rotation time of the developing roller (S241i). At this time, the controller unit 101 determines whether the acquired information indicating the remaining amount of Y toner is information indicating 10% or less, or 5% or less, and the rotation time of the developing roller of the Y developing unit is 1000. It is determined whether or not the information indicates seconds or more. Here, it is assumed that the information indicating the remaining amount of Y toner is more than 10%, and the information indicating the rotation time of the developing roller of the Y developing device 54 is less than 1000 seconds. The controller unit 101 determines that development is possible and continues the printing process.

  When the development of the Y image is completed, the unit controller 102 rotates the developing device holding unit 50 and moves the magenta developing device (M developing device) 53 to the developing position (S241j). The processing and operation from when the unit control unit 102 requests Y image data to the controller unit 101 until the M developing unit 53 is moved to the development position is hereinafter referred to as Y development processing / operation (S241). .

  When the Y development processing / operation is completed, the unit control unit 102 outputs a request for requesting magenta image (M image) data to the controller unit 101 (S242a). Upon receiving this request, the controller unit 101 outputs the M image data to the unit control unit 102 (S242b), calculates the amount of toner consumed when developing based on the M image data, and calculates the unit control unit 102. (S242c). The unit control unit 102 executes the developing operation (S242d), and subtracts the received consumption amount from the remaining toner amount of the M developing unit 53 stored in the main body side memory 122, and the remaining toner amount after development. And information in the main body memory 122 is rewritten (S242e). Further, the unit controller 102 adds “5” to the rotation time of the developing roller of the M developing device 53 stored in the main body side memory 122, and sets the rotation time (cumulative rotation time) of the developing roller after development. The information is calculated and the information in the main body side memory 122 is rewritten (S242f). At this time, the unit controller 102 detects that the rotation time of the developing roller of the M developing device 53 is less than 1000 seconds. The controller unit 101 outputs an information request request for requesting information indicating the remaining toner amount after development by the medium unit job and information indicating the rotation time of the developing roller to the unit control unit 102 at an appropriate timing (S242g). . The unit control unit 102 outputs information indicating the remaining amount of M toner stored in the main body side memory 122 and information indicating the rotation time of the developing roller to the controller unit 101 (S242h). The controller unit 101 rewrites the information in the EEPROM 114a based on the acquired information indicating the remaining amount of M toner and the information indicating the rotation time of the developing roller (S242i). At this time, the controller unit 101 determines whether or not the acquired information indicating the remaining amount of M toner is information indicating 10% or less, or 5% or less, and the rotation time of the developing roller of the M developing unit 53. It is determined whether the information indicates 1000 seconds or more. Here, the information indicating the remaining amount of M toner is more than 10%, the information indicating the rotation time of the developing roller of the M developing device 53 is less than 1000 seconds, and the controller unit 101 determines that development is possible. Continue the printing process.

  When the development of the M image is completed, the unit controller 102 rotates the developing device holding unit 50 and moves the cyan developing device (C developing device) 52 to the developing position (S242j). Processing and operation from when the unit control unit 102 requests M image data to the controller unit 101 until the C developing device 52 is moved to the development position will be referred to as M development processing / operation (S242). .

  When the development of the M image is completed, the unit control unit 102 outputs a request for requesting cyan image (C image) data to the controller unit 101 (S243a). Upon receiving this request, the controller unit 101 outputs the C image data to the unit control unit 102 (S243b), calculates the amount of toner consumed when developing based on the C image data, and calculates the unit control unit 102. (S243c). The unit control unit 102 executes the developing operation (S243d), and subtracts the received consumption amount from the remaining toner amount of the C developing device 52 stored in the main body side memory 122 to obtain the remaining toner amount after development. And the information in the main body memory 122 is rewritten (S243e). Further, the unit controller 102 adds “5” to the rotation time of the developing roller of the C developing device 52 stored in the main body side memory 122, and calculates the rotation time (cumulative rotation time) of the developing roller after development. The information is calculated and the information in the main body memory 122 is rewritten (S243f). At this time, the unit controller 102 detects that the rotation time of the developing roller of the C developing device 52 is less than 1000 seconds. The controller unit 101 outputs an information request request for requesting information indicating the remaining amount of C toner after development by the medium unit job and information indicating the rotation time of the developing roller to the unit control unit 102 at an appropriate timing ( S243g). The unit control unit 102 outputs information indicating the remaining amount of C toner stored in the main body side memory 122 and information indicating the rotation time of the developing roller to the controller unit 101 (S243h). The controller unit 101 rewrites the information in the EEPROM 114a based on the acquired information indicating the remaining amount of C toner and the information indicating the rotation time of the developing roller of the C developing device 52 (S243i). At this time, the controller unit 101 determines whether the acquired information indicating the remaining amount of C toner is information indicating 10% or less, or 5% or less, and the rotation time of the developing roller of the C developing device 52. It is determined whether the indicated information is 1000 seconds or longer. Here, the information indicating the remaining amount of C toner is more than 10%, the information indicating the rotation time of the developing roller of the C developing device 52 is less than 1000 seconds, and the controller unit 101 determines that development is possible. To continue printing.

  When the development of the C image is completed, the unit controller 102 rotates the developing device holding unit 50 and moves the black developing device (K developing device) 51 to the developing position (S243j). The processing and operation from when the unit control unit 102 requests C image data to the controller unit 101 until the K developing device 51 is moved to the development position will be referred to as C development processing / operation (S243). .

  When the development of the C image is completed, the unit control unit 102 outputs a request for requesting black image (K image) data to the controller unit 101 (S244a). Receiving this request, the controller unit 101 outputs the K image data to the unit control unit 102 (S244b), calculates the amount of toner consumed when developing based on the K image data, and the unit control unit 102 (S244c). The unit controller 102 executes the developing operation (S244d), and subtracts the received consumption amount from the remaining toner amount of the K developing device 51 stored in the main body side memory 122 to obtain the remaining toner amount after development. And the information in the main body memory 122 is rewritten (S244e). Further, the unit controller 102 adds “5” to the rotation time of the developing roller of the K developing device 51 stored in the main body side memory 122, and sets the rotation time (cumulative rotation time) of the developing roller after development. The information is calculated and the information in the main body side memory 122 is rewritten (S244f). At this time, the unit controller 102 detects that the rotation time of the developing roller of the K developing device 51 is less than 1000 seconds. The controller unit 101 outputs an information request request for requesting information indicating the remaining amount of K toner after development by the medium unit job and information indicating the rotation time of the developing roller to the unit control unit 102 at an appropriate timing ( S244g). The unit control unit 102 outputs information indicating the remaining amount of K toner stored in the main body side memory 122 and information indicating the rotation time of the developing roller to the controller unit 101 (S244h). The controller unit 101 rewrites the information in the EEPROM 114a based on the acquired information indicating the remaining amount of K toner and the information indicating the rotation time of the developing roller of the K developing device 51 (S244i). At this time, the controller unit 101 determines whether the acquired information indicating the remaining amount of K toner is information indicating 10% or less, or 5% or less, and the rotation time of the developing roller of the K developing device 51. It is determined whether or not the indicated information is 1000 seconds or longer. Here, the information indicating the remaining amount of K toner is more than 10%, the information indicating the rotation time of the developing roller of the K developing device 51 is less than 1000 seconds, and the controller unit 101 determines that development is possible. To continue printing.

  When the development of the K image is completed, the unit controller 102 rotates the developing device holding unit 50 and moves the developing device holding unit 50 to the home position (244j). The processing and operation from when the unit control unit 102 requests K image data to the controller unit 101 until the developing device holding unit 50 is moved to the home position will be described below as K development processing / operation (S244). That's it. In the example described here, since the image forming job is a print command for executing printing of one page, the developing device holding unit 50 is moved to the home position after developing the K image. If there is, the Y developing unit 54 is moved to the developing position after the K image is developed. In this case, the processing and operation from when the unit control unit 102 requests K image data to the controller unit 101 until the Y developing unit 54 is moved to the development position is referred to as K development processing / operation.

  When the development with each of the four color toners is completed, the four color toner images are superimposed on the intermediate transfer member 70 to form a color toner image. This color toner image is transferred by the secondary transfer unit 80 onto the paper fed from the paper feed tray, and is made into a permanent image by the fixing unit 90 and discharged (S245). Thus, in the printing process for one page by one medium unit job, the Y development process / operation (S241), the M development process / operation (S242), the C development process / operation (S243), the K development process / operation ( S244), primary transfer, secondary transfer, fixing, and paper discharge (S245) are executed. This processing and operation from the Y development processing / operation (S241) to the paper discharge (S245) is hereinafter referred to as one-page printing processing / operation (S240).

Then, a request for acquiring the print end page number is output from the controller unit 101 to the unit control unit 102 at an appropriate timing (S251). When the printing operation for one page is completed, a response indicating the completion of the printing operation for one page is output from the unit control unit 102 to the controller unit 101 (S252). At this time, when the number of printed pages specified in the image forming job is output as a response, the controller unit 101 detects that the image forming job has ended (S253). The process of confirming the number of pages for which printing has been completed every time printing of one page is referred to as print page number confirmation processing (S250).
Then, the printer 10 enters a standby state, and the controller unit 101 displays “printable” or the like on the display unit 95 (S260).

<Multi-page color printing process and operation when used as a color printer>
Next, processing and operation during continuous color printing of a plurality of pages will be described. FIG. 10 is a diagram for explaining processing and operation when color printing of five pages is performed when the printer is used as a color printer. In the following description, detailed description of the same processing and operation as the one-page printing processing and operation described above will be omitted.

As in the case of printing one page, an image signal and control signal from a computer (not shown), that is, a command for executing an image forming job for color printing on five sheets of A4 size paper (5 pages) is input to the interface (I / F) When input to the printer 10 in the standby state via 112, the printing process is started (S301).
Between the controller unit 101 and the unit control unit 102, two medium unit job generation processes are executed, and before the development of the Y image in the printing operation for the first page is started, two medium unit jobs are executed. It is assumed that it has occurred (S302, S303).
The unit controller 102 rotates the developing device holding unit 50 from the home position, and executes the one-page printing process / operation for the first page (S304). It is assumed that the toner remaining amount of each developing device calculated during this one-page printing process / operation is more than 10%, and the developing roller rotation time of each developing device is less than 1000 seconds.

When the one-page printing process / operation for the first page is completed, a printed page number obtaining process is executed (S305). In this process, a response indicating the end of the printing operation for one page is output from the unit control unit 102 to the controller unit 101.
In addition, a medium unit job generation process for generating a medium unit job for the third page is executed between the controller unit 101 and the unit control unit 102, and a third medium unit job is generated (S306). .
When the developing operation for one page by the first medium unit job is completed, the unit controller 102 moves the Y developing unit 54 to the developing position and executes the one-page printing process / operation for the second page (S307). It is assumed that the toner remaining amount of each developing device calculated during the one-page printing process / operation is more than 10%, and the developing roller rotation time of each developing device is less than 1000 seconds.

When the one-page printing process / operation for the second page is completed, a printed page number obtaining process is executed (S308). In this process, a response indicating the end of the printing operation for page 2 is output from the unit control unit 102 to the controller unit 101.
Further, a medium unit job generation process for generating a medium unit job for the fourth page is executed between the controller unit 101 and the unit control unit 102, and a fourth medium unit job is generated (S309). .
When the developing operation for one page by the second medium unit job is completed, the unit controller 102 moves the Y developing unit 54 to the developing position and executes the one-page printing process / operation for the third page (S310). ). It is assumed that the toner remaining amount of each developing device calculated during the one-page printing process / operation is more than 10%, and the developing roller rotation time of each developing device is less than 1000 seconds.

When the one-page printing process / operation for the third page is completed, a printed page number obtaining process is executed (S311). In this process, a response indicating the end of the printing operation for the third page is output from the unit control unit 102 to the controller unit 101.
Further, a medium unit job generation process for generating the medium unit job of the fifth page is executed between the controller unit 101 and the unit control unit 102, and a fifth medium unit job is generated (S312). .
When the developing operation for one page by the third medium unit job is completed, the unit controller 102 moves the Y developing unit 54 to the developing position and executes the one-page printing process / operation for the fourth page (S313). ). It is assumed that the toner remaining amount of each developing device calculated during the one-page printing process / operation is more than 10%, and the developing roller rotation time of each developing device is less than 1000 seconds.

When the one-page printing process / operation for the fourth page is completed, a printed page number obtaining process is executed (S314). In this process, a response indicating the end of the printing operation for page 4 is output from the unit control unit 102 to the controller unit 101.
When the development operation for one page by the fourth medium unit job is completed, the unit control unit 102 moves the Y developing unit 54 to the development position and executes the one-page printing process / operation for the fifth page (S315). ). It is assumed that the toner remaining amount of each developing device calculated during the one-page printing process / operation is more than 10%, and the developing roller rotation time of each developing device is less than 1000 seconds.

  When the one-page printing process / operation for the fifth page is completed, a printed page number obtaining process is executed (S316). In this process, a response indicating the end of the printing operation for page 5 is output from the unit control unit 102 to the controller unit 101. Based on this response, the controller unit 101 detects the end of the image forming job, the printer 10 enters a standby state, and the controller unit 101 displays “printable” or the like on the display unit 95 (S317).

<Operation of the color printer when the remaining amount of toner in the developing device is below a predetermined amount>
Next, processing and operation of the printer 10 when the remaining amount of toner in the M developing unit becomes 5% or less when used as a color printer will be described. In this example, paying attention to the remaining amount of toner, description of processing for calculating the rotation time of the developing roller and determination of whether or not the rotation time has become 1000 seconds or more are omitted. It is assumed that the information indicating the remaining amount of toner of the M developing device is 8% when the information of each developing device stored in the main body side memory 122 is acquired in the initial operation.

  FIG. 11 is a diagram for explaining the processing and operation of the printer 10 when the remaining amount of toner in the M developer becomes 5% or less when used as a color printer.

The controller unit 101 detects that the remaining amount of M toner in the initial operation is 10% or less, displays “M toner is low” or the like on the display unit 95, and puts the printer 10 in a standby state ( S400). As in the case of executing the 5-page color printing, when an image forming job for executing the 5-page color printing is input from the computer (not shown) to the printer 10, the printing process is started (S401). Also at this time, the medium unit job generation process is executed twice between the controller unit 101 and the unit control unit 102, and before the development of the Y image in the first medium unit job is started, It is assumed that a medium unit job has occurred (S410, 420).
The unit controller 102 rotates the developing device holding unit 50 from the home position, and executes the one-page printing process / operation for the first page (S430). It is assumed that the remaining amount of M toner calculated during the one-page printing process / operation is 6%, and the remaining amounts of other toners are all greater than 10%.

When the one-page printing process / operation for the first page is completed, a printed page number obtaining process is executed (S440). In this process, a response indicating the end of the printing operation for one page is output from the unit control unit 102 to the controller unit 101.
At this time, a medium unit job generation process for generating a medium unit job for the third page is executed between the controller unit 101 and the unit control unit 102, and a third medium unit job is generated. (S450).
The controller unit 101 continues the developing operation because the remaining amount of toner in any of the developing units is more than 5%.

  Similar to the one-page printing process / operation for the first page, the unit control unit 102 moves the Y developing unit 54 to the development position based on the second medium unit job, and the one-page printing process for the second page. The Y developing process / operation in the operation (S460) is executed (S461). It is assumed that the remaining amount of Y toner calculated during this Y development processing / operation is greater than 10%, and the controller unit 101 determines that development is possible and continues the printing process.

  When the development of the Y image is completed, the unit controller 102 executes the M development process / operation (S462). That is, the unit control unit 102 outputs a request for requesting M image data to the controller unit 101 (S462a). Receiving this request, the controller unit 101 outputs the M image data to the unit control unit 102 (S462b), calculates the toner consumption consumed when developing based on the M image data, and the unit control unit 102 (S462c). The unit control unit 102 executes the developing operation (S462d), and subtracts the received consumption amount from the remaining toner amount of the M developing device 53 stored in the main body side memory 122, and the remaining toner amount after development. And the information in the main body memory 122 is rewritten (S462e). At this time, the unit controller 102 detects that the remaining amount of toner in the M developing device 53 is 5% or less, and determines that the M developing device 53 cannot be developed.

  The controller unit 101 outputs an information request request for requesting information indicating the remaining amount of M toner after development by the medium unit job to the unit control unit 102 at an appropriate timing (S462f). Information indicating the remaining amount of M toner stored in the main body memory 122 is output from the unit control unit 102 to the controller unit 101 (S462g). The controller unit 101 rewrites the information in the EEPROM 114a based on the acquired information indicating the remaining amount of M toner (S462h). At this time, the acquired remaining amount of M toner is 4%, and the controller unit 101 detects that the remaining amount of toner in the M developing unit 53 is 5% or less, and the M developing unit 53 cannot be developed. Judge that there is. Subsequently, the controller unit 101 stops the process of outputting the one-page print request request. On the other hand, the unit controller 102 continues the developing operation for the M image, moves the C developing device to the developing position, and ends it (S462i).

  Thereafter, as in the printing process for the first page, C development processing / operation (S463), K development processing / operation (S464), primary transfer, secondary transfer, fixing, and paper discharge (S465) are executed. The one-page printing process / operation by the medium unit job of the eye is ended. At this time, in the C development processing / operation (S463) and the K development processing / operation (S464), it is assumed that the calculated toner remaining amounts of the C development unit and the K development unit are both greater than 10%.

  When the one-page printing process / operation for the second page is completed, a printed page number obtaining process is executed (S470). In this process, a response indicating the end of the printing operation for the second page is output from the unit control unit 102 to the controller unit 101. That is, at this point, three medium unit jobs are generated, and the development operation based on the two medium unit jobs is completed. The printer 10 executes the one-page printing process / operation for the third page based on the remaining medium unit job (S475).

  When the one-page printing process / operation for the third page is completed, a printed page number obtaining process is executed (S480). With this print page number acquisition process, the controller unit 101 detects that printing based on the three medium unit jobs that have already occurred has been completed.

Then, the unit controller 102 sequentially moves the developing devices mounted by rotating the developing device holding unit 50 to the connector attaching / detaching position (S485a). Then, the apparatus main body side connector 34 is moved, and information such as the toner remaining amount information stored in the main body side memory 122 is stored in the developing device side memory of each developing device (S485b). The processing for acquiring information stored in the main body side memory 122 and storing it in the developing device side memory of each developing device is hereinafter referred to as memory information acquisition processing (S485).
Then, by further rotating the developing device holding unit 50, the M developing device 53, which has become unable to develop, is moved to the developing device attaching / detaching position (S490). Then, the controller unit 101 displays “Replace the M developing device” or the like on the display unit 95, and the printer 10 is in an operation stop state (S495).

<Operation of color printer when developing roller rotation time exceeds specified time>
When the rotation time of the developing roller is equal to or longer than the predetermined time, detailed description of the same processing and operation as when the remaining amount of toner in the developing device is equal to or less than the predetermined amount is omitted. Further, in this example, paying attention to the rotation time of the developing roller, description of processing for calculating the remaining amount of toner and determination of whether or not the remaining amount of toner has become 5% or less are omitted. Also, the information of each developing device stored in the main body side memory 122 acquired in the initial operation is that the developing roller rotation time of the Y developing device, the C developing device, and the K developing device is already 900 seconds. Suppose that the information indicates that the rotation time of the developing roller of the M developing device has already reached 990 seconds.

  FIG. 12 is a diagram for explaining processing and operation of the printer 10 when the rotation time of the developing roller of the M developing device becomes 1000 seconds or more when used as a color printer.

  As in the case of executing the 5-page color printing, when an image forming job for executing the 5-page color printing is input from the computer (not shown) to the printer 10, the printing process is started (S500). Also at this time, the medium unit job generation process is executed twice between the controller unit 101 and the unit control unit 102, and before the development of the Y image in the first medium unit job is started, It is assumed that a medium unit job has occurred (S505, S510).

  The unit controller 102 rotates the developing device holding unit 50 from the home position, and executes the one-page printing process / operation for the first page (S515). The rotation time of the developing roller of the M developing device calculated during the one-page printing process / operation is 995 seconds, and the rotation time of the developing roller of the other developing devices is 905 seconds.

When the one-page printing process / operation for the first page is completed, a printed page number obtaining process is executed (S520). In this process, a response indicating the end of the printing operation for one page is output from the unit control unit 102 to the controller unit 101.
At this time, a medium unit job generation process for generating a medium unit job for the third page is executed between the controller unit 101 and the unit control unit 102 (S525). At this time, since the unit control unit 102 detects that the rotation time of the developing rollers of all the developing devices is less than 1000 seconds, a one-page print request for requesting a medium unit job for the third page from the controller unit 101 Output acceptance response to the request. Therefore, a third medium unit job is generated.

  Similar to the one-page printing process / operation for the first page, the unit control unit 102 moves the Y developing unit 54 to the development position based on the second medium unit job, and the one-page printing process for the second page. The Y developing process / operation in the operation (S530) is executed (S531). It is detected that the rotation time of the developing roller of the Y developing unit 54 calculated during the Y developing process / operation is less than 1000 seconds.

  When the development of the Y image is completed, the unit controller 102 executes the M development processing / operation (S532). That is, the unit control unit 102 outputs a request for requesting M image data to the controller unit 101 (S532a). Receiving this request, the controller unit 101 outputs the M image data to the unit control unit 102 (S532b). The unit controller 102 executes a developing operation (S532c). The unit controller 102 adds “5” to the rotation time of the developing roller of the M developing device 53 stored in the main body side memory 122 and calculates the rotation time (cumulative rotation time) of the developing roller after development. Then, the information in the main body side memory 122 is rewritten (S532d). At this time, the calculated rotation time of the developing roller of the M developing device 53 is 1000 seconds, and the unit controller 102 detects that the rotating time of the developing roller of the M developing device 53 is 1000 seconds or more.

  The controller unit 101 outputs an information request request for requesting the rotation time of the developing roller of the M developing unit 53 after development by the medium unit job to the unit control unit 102 at an appropriate timing (S532e). Information indicating the rotation time of the developing roller of the M developing device 53 stored in the main body side memory 122 is output from the unit control unit 102 to the controller unit 101 (S532f). The controller unit 101 rewrites the information in the EEPROM 114a based on the acquired information indicating the rotation time of the developing roller of the M developing device 53 (S532g). At this time, the acquired rotation time of the developing roller of the M developing device 53 is 1000 seconds, and the controller unit 101 detects that the rotating time of the developing roller of the M developing device 53 is 1000 seconds or more, and M developing It is determined that the device 53 cannot be developed. Subsequently, the controller unit 101 stops the process of outputting the one-page print request request. On the other hand, the unit controller 102 continues the developing operation for the M image, moves the C developing device 52 to the developing position, and ends it (S532h).

Thereafter, as in the printing process for the first page, C development processing / operation (S533), K development processing / operation (S534), primary transfer, secondary transfer, fixing, and paper discharge (S535) are executed. The one-page printing process / operation by the medium unit job of the eye is terminated. At this time, the rotation times of the developing rollers of the C developing device and the K developing device are both less than 1000 seconds.
When the one-page printing process / operation for the second page is completed, a printed page number obtaining process is executed (S540).
At this point, three medium unit jobs have occurred, and the development operation based on the two medium unit jobs has been completed. The printer 10 executes the one-page printing process / operation for the third page based on the remaining medium unit job (S555).

When the one-page printing process / operation for the third page is completed, a printed page number obtaining process is executed (S560). With this print page number acquisition process, the controller unit 101 detects that printing based on the three medium unit jobs that have already occurred has been completed.
The unit control unit 102 executes a memory information acquisition process (S565), and stores information such as information indicating the rotation time of the developing roller stored in the main body side memory 122 in the developing unit side memory of each developing unit. Remember. Then, by further rotating the developing device holding unit 50, the M developing device 53, which has become unable to develop, is moved to the developing device attaching / detaching position (S570). Then, the controller unit 101 displays “Replace the M developing device” or the like on the display unit 95, and the printer 10 is stopped (S575).

<Operation when used as a monochrome printer>
In the present embodiment, when the developing device holding unit 50 has the four attaching / detaching portions 50a, 50b, 50c, 50d, the two attaching / detaching portions 50a, 50c are mounted with the K developing device 51 and used as a monochromatic printer. Will be described. In the following description, the K developing device 51 attached to the attaching / detaching portion 50a is referred to as a first K developing device, and the K developing device 51 attached to the attaching / detaching portion 50c is referred to as a second K developing device.

  The processing and operation for printing one page when used as a monochrome printer is different from the one-page printing processing / operation (S240) of the processing and operation of the color printer shown in FIG. That is, when the printer is used as a single color printer, Y image development processing / operation (S241), M image development processing / operation (S242), C image development processing / operation in one-page printing processing / operation (S240). The difference is that (S243) is not executed and the developing device is not moved for each developing operation by each developing device. The processing and operation for printing a plurality of pages when used as a single color printer is the same as the one-page printing processing / operation (S304, S307, S310, S313, S315) are different. That is, when used as a single color printer, each one-page printing process / operation for printing a plurality of pages is different. For this reason, when the printer is used as a single-color printer, the description of the processing and operation when printing one page and the processing and operation when printing a plurality of pages are omitted. In order to distinguish one-page printing processing / operation when used as a color printer from one-page printing processing / operation when used as a single-color printer, the following is a single-page printing processing / operation for a single-color printer. -The operation is referred to as monochrome one-page printing processing / operation.

<Operation of single-color printer when the amount of toner remaining in the developing device falls below a predetermined amount>
Next, the processing and operation of the printer 10 when the remaining amount of toner in the K developing device becomes 5% or less when used as a monochrome printer will be described. In this example, paying attention to the remaining amount of toner, description of processing for calculating the rotation time of the developing roller and determination of whether or not the rotation time has become 1000 seconds or more are omitted. Here, the controller unit 101 acquires the information of the two developing devices stored in the main body side memory 122 in the initial operation. It is assumed that the acquired information is information indicating that the remaining amount of toner in the first K developing unit 51 is 8% and that the remaining amount of toner in the second K developing unit 51 is 50%. At this time, the controller unit 101 is equipped with the first and second K developing devices, detects that the remaining amount of toner in the second K developing device is more than 10%, and determines which of the first and second K developing devices is Is also determined to be developable.

FIG. 13 is a diagram for explaining the processing and operation of the printer 10 when the remaining amount of toner in one of the K developing devices becomes 5% or less when used as a single color printer.
The controller unit 101 detects that the remaining amount of K toner in the first K developing device is 10% or less, and displays “the toner in the first K developing device is low” or the like on the display unit 95. The printer 10 is set in a standby state (S600).

  When an image forming job for executing monochrome printing of five pages is input to the printer 10 from a computer (not shown) connected so as to be capable of bidirectional communication, the printing process is started (S601). Also at this time, the medium unit job generation process is executed twice between the controller unit 101 and the unit control unit 102, and before the development of the K image in the first medium unit job is started, It is assumed that a medium unit job has occurred (S605, S610).

  The unit controller 102 rotates the developing device holding unit 50 from the home position to move the first K developing device 51 to the developing position (S615), and based on the first medium unit job, the monochrome one page of the first page Print processing / operation is executed (S620). The remaining amount of toner in the first K developing device calculated during the monochrome one-page printing process / operation is 6%.

When the monochrome one-page printing process / operation for the first page is completed, a printed page number obtaining process is executed (S625). In this process, a response indicating the end of the printing operation for one page is output from the unit control unit 102 to the controller unit 101.
At this time, a medium unit job generation process for generating a medium unit job for the third page is executed between the controller unit 101 and the unit control unit 102, and a third medium unit job is generated. (S630).
Since the remaining amount of toner in the first K developing device is more than 5%, the controller unit 101 continues the developing operation.

  Similar to the monochrome one-page printing process / operation for the first page, the unit control unit 102 executes the monochrome one-page printing process / operation for the second page based on the second medium unit job (S635). That is, the unit control unit 102 outputs a request for requesting K image data to the controller unit 101 (S635a). Upon receiving this request, the controller unit 101 outputs the K image data to the unit control unit 102 (S635b), calculates the amount of toner consumed when developing based on the K image data, and the unit control unit 102. (S635c). The unit control unit 102 executes the developing operation (S635d), and subtracts the received consumption amount from the remaining toner amount of the first K developing device 51 stored in the main body side memory 122 to obtain the remaining toner amount after development. The amount is calculated and the information in the main body memory 122 is rewritten (S635e). At this time, the calculated remaining amount of K toner in the first K developing device 51 is 4%, and the unit controller 102 detects that the remaining amount of toner in the first K developing device 51 is 5% or less. It is determined that the developing device 51 cannot be developed.

  The controller unit 101 outputs an information request request for requesting information indicating the remaining amount of K toner of the first K developing device 51 after development by the medium unit job to the unit control unit 102 at an appropriate timing (S635f). Information indicating the remaining amount of K toner of the first K developing device 51 stored in the main body memory 122 is output from the unit control unit 102 to the controller unit 101 (S635g). The controller unit 101 rewrites the information in the EEPROM 114a based on the acquired information indicating the remaining amount of K toner in the first K developing device 51 (S635h). At this time, the acquired remaining amount of K toner in the first K developing device 51 is 4%, and the controller unit 101 detects that the remaining amount of toner in the first K developing device 51 is 5% or less and detects the first K It is determined that the developing device 51 cannot be developed.

  On the other hand, the unit control unit 102 continuously ends the monochrome one-page printing process / operation for the second page. At this time, the unit control unit 102 has already detected that the second K developing device containing toner of the same color as the toner of the first K developing device is attached to the attaching / detaching unit 50c. For this reason, the unit controller 102 rotates the developing device holding unit 50 to move the second K developing device 51 to the developing position (S650).

When the monochrome one-page printing process / operation for the second page is completed, a printed page number obtaining process is executed (S655). In this process, a response indicating the end of the printing operation for page 2 is output from the unit control unit 102 to the controller unit 101.
At this time, a medium unit job generation process for generating a medium unit job for the fourth page is executed between the controller unit 101 and the unit control unit 102, and a fourth medium unit job is generated. (S660).

  Based on the third medium unit job, the unit control unit 102 executes the monochrome one-page printing process / operation for the third page (S665). In the monochrome one-page printing process / operation for the third page, the EEPROM 114a stores information indicating that the remaining toner amount of the second K developing device is, for example, 48%. The controller unit 101 continues the developing operation because the remaining amount of toner in the second K developing device is more than 5%.

When the monochrome one-page printing process / operation for the third page is finished, a printed page number obtaining process is executed (S670). In this process, a response indicating the end of the printing operation for the third page is output from the unit control unit 102 to the controller unit 101.
At this time, a medium unit job generation process for generating a medium unit job for the fifth page is executed between the controller unit 101 and the unit control unit 102, and a fifth medium unit job is generated. (S675).

  The unit control unit 102 executes the monochrome one-page printing process / operation for the fourth page based on the fourth medium-unit job (S680). In the monochrome one-page printing process / operation for the fourth page, information that the remaining toner amount of the second K developing device is 46%, for example, is stored in the EEPROM 114a. The controller unit 101 continues the developing operation because the remaining amount of toner in the second K developing device is more than 5%.

  When the monochrome one-page printing process / operation for the fourth page is completed, a printed page number obtaining process is executed (S685). In this process, a response indicating the end of the printing operation for page 4 is output from the unit control unit 102 to the controller unit 101.

  The unit control unit 102 executes the monochrome one-page printing process / operation for the fifth page based on the fifth medium-unit job (S690). In the monochrome one-page printing process / operation for the fifth page, information that the remaining toner amount of the second K developing device is, for example, 44% is stored in the EEPROM 114a. The controller unit 101 continues the developing operation because the remaining amount of toner in the second K developing device is more than 5%.

  When the monochrome one-page printing process / operation for the fifth page is completed, a printed page number obtaining process is executed (S691). In this process, a response indicating the end of the printing operation for page 5 is output from the unit control unit 102 to the controller unit 101. With this print page number acquisition process, the controller unit 101 detects that printing based on the image forming job has been completed.

  Then, the unit control unit 102 executes a memory information acquisition process (S692), and stores information such as toner remaining amount information of the two developing units stored in the main unit side memory 122 in the two developing unit side memories. Remember. Then, by further rotating the developing device holding unit 50, the first K developing device 51, which has become unable to develop, is moved to the developing device attaching / detaching position (S693). Then, the controller unit 101 displays “Please replace the first K developing device” or the like on the display unit 95, and the printer 10 is stopped (S695). At this time, the controller unit 101 may display “no toner in the first K developer” or “printable” on the display unit 95, and the printer 10 may enter a standby state.

  In the present embodiment, the case where the remaining toner amount of the mounted second K developer is 50% has been described. For example, when the remaining toner amount of the second K developer is 8%, an image forming job is performed. Before the process is completed, the remaining amount of toner in the two developing units becomes 5% or less. In this case, first, when printing is performed using the first K developer unit based on the first two medium unit jobs, the remaining amount of toner in the first K developer unit is 5% or less, and the second K developer unit is moved to the development position. To do. When printing is performed using the second K developing device based on the third and fourth medium unit jobs, the remaining amount of toner in the second K developing device is 5% or less, and neither of the two developing devices can be developed. It becomes a state. Since the controller unit 101 that has detected that the remaining amount of toner in each of the two developing devices has become 5% or less does not output a one-page print request request thereafter, a medium unit job does not occur. At this time, for example, if the fifth medium unit job has already occurred, the unit controller 102 executes the printing operation based on the fifth medium unit job using the second K developing device, Then, any K developing device is moved to the developing device attaching / detaching position. The controller unit 101 detects the developing device moved to the developing device attaching / detaching position, and displays on the display unit 95 a message prompting replacement of the corresponding K developing device.

<Operation of single-color printer when developing roller rotation time exceeds specified time>
Next, processing and operation of the printer 10 when the rotation time of the developing roller of the K developing device becomes 1000 seconds or more when used as a single color printer will be described. In this example, paying attention to the rotation time of the developing roller, description of processing for calculating the remaining amount of toner and determination of whether or not the remaining amount of toner has become 5% or less are omitted. Here, the controller unit 101 acquires the information of the two developing devices stored in the main body side memory 122 in the initial operation. The acquired information is information indicating that the rotation time of the developing roller of the first K developing device 51 is 990 seconds, and is information indicating that the rotation time of the developing roller of the second K developing device 51 is 500 seconds. At this time, the unit controller 102 determines that both of the rotation times of the developing rollers of the first and second developing units are less than 1000 seconds, and both can be developed.

  FIG. 14 is a diagram for explaining the processing and operation of the printer when the rotation time of the developing roller of one of the K developing devices becomes 1000 seconds or longer when used as a single color printer.

  When an image forming job for executing monochrome printing of A4 size 5 pages is input to the printer 10 from a computer (not shown) connected so as to be capable of bidirectional communication, the printing process is started (S700). Also at this time, the medium unit job generation process is executed twice between the controller unit 101 and the unit control unit 102, and before the development of the K image in the first medium unit job is started, It is assumed that a medium unit job has occurred (S705, S710).

  The unit control unit 102 rotates the developing device holding unit 50 from the home position to move the first K developing device 51 to the developing position (S715), and based on the first medium unit job, the monochrome one page of the first page Print processing / operation is executed (S720). The rotation time of the developing roller of the first K developing device calculated by the monochrome one-page printing process / operation is 995 seconds. The unit controller 102 detects that the rotation time of the developing roller of the first K developing device is less than 1000 seconds.

When the monochrome one-page printing process / operation for the first page is completed, a printed page number obtaining process is executed (S725). In this process, a response indicating the end of the printing operation for one page is output from the unit control unit 102 to the controller unit 101.
At this time, a medium unit job generation process for generating a medium unit job for the third page is executed between the controller unit 101 and the unit control unit 102, and a third medium unit job is generated. (S730).

  Similar to the monochrome one-page printing process / operation for the first page, the unit control unit 102 executes the monochrome one-page printing process / operation for the second page based on the second medium unit job (S735). That is, the unit control unit 102 outputs a request for requesting K image data to the controller unit 101 (S735a). Receiving this request, the controller unit 101 outputs the K image data to the unit control unit 102 (S735b). The unit controller 102 executes the developing operation (S735c). The unit control unit 102 adds “5” to the rotation time of the developing roller of the first K developing device 51 stored in the main body side memory 122 and calculates the rotation time (cumulative rotation time) of the developing roller after development. Then, the information in the main body memory 122 is rewritten (S735d). At this time, the calculated rotation time of the developing roller of the K developing device 51 is 1000 seconds, and the unit controller 102 detects that the rotation time of the developing roller of the K developing device 51 is 1000 seconds or more (S735e).

  The controller unit 101 outputs an information request request for requesting the rotation time of the developing roller of the first K developing device 51 after development by the medium unit job to the unit control unit 102 at an appropriate timing (S735f). Information indicating the rotation time of the developing roller of the first K developing device 51 stored in the main body side memory 122 is output from the unit control unit 102 to the controller unit 101 (S735g). The controller unit 101 rewrites information in the EEPROM 114a based on the acquired information indicating the rotation time of the developing roller of the first K developing device 51 (S735h). At this time, the acquired rotation time of the developing roller of the first K developing device 51 is 1000 seconds, and the controller unit 101 detects that the rotating time of the developing roller of the first K developing device 51 is 1000 seconds or more, It is determined that the first K developing device 51 is in a state where development cannot be performed.

  The unit control unit 102 continues the K image developing operation and ends the monochrome one-page printing process / operation by the second medium unit job. At this time, the unit control unit 102 has already detected that the second K developing device containing toner of the same color as the toner of the first K developing device is attached to the attaching / detaching unit 50c. Therefore, the unit controller 102 rotates the developing device holding unit 50 to move the second K developing device 51 to the position of the first K developing device, that is, the developing position (S740).

When the monochrome one-page printing process / operation for the second page is completed, a printed page number obtaining process is executed (S750). In this process, a response indicating the end of the printing operation for page 2 is output from the unit control unit 102 to the controller unit 101.
At this time, a medium unit job generation process for generating a medium unit job for the fourth page is executed between the controller unit 101 and the unit control unit 102, and a fourth medium unit job is generated. (S755).

  Based on the third medium unit job, the unit control unit 102 executes the monochrome one-page printing process / operation for the third page (S760). In the monochrome one-page printing process / operation for the third page, the main body side memory 122 stores information indicating that the rotation time of the developing roller of the second K developing device is 505 seconds. The unit controller 102 detects that the rotation time of the developing roller of the second K developing device is less than 1000 seconds.

When the monochrome one-page printing process / operation for the third page is completed, a printed page number obtaining process is executed (S765). In this process, a response indicating the end of the printing operation for the third page is output from the unit control unit 102 to the controller unit 101.
At this time, a medium unit job generation process for generating a medium unit job for the fifth page is executed between the controller unit 101 and the unit control unit 102, and a fifth medium unit job is generated. (S770).

  Based on the fourth medium unit job, the unit control unit 102 executes the monochrome one-page printing process / operation for the fourth page (S775). In the monochrome one-page printing process / operation for the fourth page, the main body side memory 122 stores information indicating that the rotation time of the developing roller of the second K developing device is 510 seconds. The unit controller 102 detects that the rotation time of the developing roller of the second K developing device is less than 1000 seconds.

When the monochrome one-page printing process / operation for the fourth page is completed, a printed page number obtaining process is executed (S780). In this process, a response indicating the end of the printing operation for page 4 is output from the unit control unit 102 to the controller unit 101.
The unit control unit 102 executes the monochrome one-page printing process / operation for the fifth page based on the fifth medium-unit job (S785). In the monochrome one-page printing process / operation for the fifth page, the main body memory 122 stores information indicating that the rotation time of the developing roller of the second K developing device is 515 seconds. The unit controller 102 detects that the rotation time of the developing roller of the second K developing device is less than 1000 seconds.

  When the monochrome one-page printing process / operation for the fifth page is completed, a printed page number obtaining process is executed (S790). In this process, a response indicating the end of the printing operation for page 5 is output from the unit control unit 102 to the controller unit 101. With this print page number acquisition process, the controller unit 101 detects that printing based on the image forming job has been completed.

  The unit control unit 102 executes a memory information acquisition process (S791), and stores information such as the rotation times of the developing rollers of the two developing units stored in the main unit side memory 122 in the two developing unit side memories. Remember. Then, by further rotating the developing device holding unit 50, the first K developing device 51, which has become incapable of developing, is moved to the developing device attaching / detaching position (S792). Then, the controller unit 101 displays “Replace the first K developing device” or the like on the display unit 95, and the printer 10 is stopped (S795). At this time, the controller unit 101 may display “please replace the first K developing device”, “printable”, etc. on the display unit 95, and the printer 10 may enter a standby state.

In this embodiment, the case where the rotation time of the developing roller of the second K developing device is 500 seconds before executing the image forming job has been described. For example, the rotation time of the developing roller of the second K developing device is 995 seconds. In such a case, the rotation time of the developing rollers of the two developing units becomes 1000 seconds or longer before the image forming job is completed.
In this case, the case where the rotation time of the developing roller of one of the K developing devices is 1000 seconds or longer is the same as the case where the fourth medium unit job generation process is executed, but thereafter The processing of is different. That is, the same applies to the medium unit job generation process (S755) for the fourth page in FIG. Therefore, the monochromatic one-page printing process / operation (S760) after the third page will be described.

  FIG. 15 is a diagram for explaining the processing and operation of the printer when the rotation time of the developing rollers of all the K developing devices mounted when used as a single color printer is also 1000 seconds or more. .

  The unit control unit 102 executes the monochrome one-page printing process / operation for the third page based on the third medium-unit job (S800). That is, the unit control unit 102 outputs a request for requesting K image data to the controller unit 101 (S800a). Receiving this request, the controller unit 101 outputs the K image data to the unit control unit 102 (S800b). The unit controller 102 executes a developing operation (S800c). The unit controller 102 adds “5” to the rotation time of the developing roller of the second K developing device 51 stored in the main body side memory 122, and calculates the rotation time (cumulative rotation time) of the developing roller after development. Then, the information in the main body side memory 122 is rewritten (S800d). At this time, the calculated rotation time of the developing roller of the second K developing device 51 is 1000 seconds, and the unit controller 102 detects that the rotation time of the developing roller of the second K developing device 51 is 1000 seconds or more.

  The controller unit 101 outputs an information request request for requesting the rotation time of the developing roller of the second K developing device 51 after development by the medium unit job to the unit control unit 102 at an appropriate timing (S800e). Information indicating the rotation time of the developing roller of the second K developing device 51 stored in the main body side memory 122 is output from the unit control unit 102 to the controller unit 101 (S800f). The controller unit 101 rewrites the information in the EEPROM 114a based on the acquired information indicating the rotation time of the developing roller of the second K developing device 51 (S800g). At this time, the acquired rotation time of the developing roller of the second K developing device 51 is 1000 seconds, and the controller unit 101 detects that the rotating time of the developing roller of the second K developing device 51 is 1000 seconds or more, It is determined that the second K developing device 51 is in a state where it cannot be developed. Subsequently, the controller unit 101 stops the process of outputting the one-page print request request. The unit controller 102 continues the K image developing operation and ends the monochrome one-page printing process / operation by the third medium unit job.

When the monochrome one-page printing process / operation for the third page is completed, a printed page number obtaining process is executed (S810). At this point, four medium unit jobs have occurred, and the development operation based on the three medium unit jobs has been completed. Based on the remaining medium unit job, the printer 10 executes the monochrome one-page printing process / operation for the fourth page (S830).
When the monochrome one-page printing process / operation for the fourth page is completed, a printed page number obtaining process is executed (S840). With this print page number acquisition process, the controller unit 101 detects that printing based on the four medium-unit jobs that have already occurred has been completed.

  Then, the unit control unit 102 executes a memory information acquisition process (S850), and stores information such as the rotation times of the developing rollers of the two developing units stored in the main unit side memory 122 in the two developing unit side memories. Remember. Then, by further rotating the developing device holding unit 50, the first K developing device 51, which has become unable to develop, is moved to the developing device attaching / detaching position (S860). Then, the controller unit 101 displays a message such as “Please replace the second developer after replacing the first developer” on the display unit 95, and the printer 10 is in an operation stop state (S870).

  According to the printer 10 of the present embodiment, when it is used as a color printer, if any of the installed developing devices cannot be developed, the medium already generated at that time When the one-page printing process / operation based on the unit job is completed, the developing device which has become undeveloped is moved to the developing device attaching / detaching position. On the other hand, when it is used as a monochrome printer, even if one of the installed developing devices is in a state where it cannot be developed, printing processing / operation is continued using another developing device, When the image forming job is completed, or when any of the mounted developing devices cannot be developed, the developing device that has not been developed is moved to the developing device attaching / detaching position.

  That is, when used as a color printer, since different color toners are stored in the installed developing devices, a good image cannot be printed even if any of the developing devices cannot be developed. There is drowning. For this reason, when being used as a color printer, if one of them cannot be developed, it cannot be developed after the one-page printing process / operation based on the generated medium unit job is terminated. The developed developer is moved to the developer attachment / detachment position. As described above, when any of the developing devices cannot be developed, the printing process / operation is not continued until the image forming job is completed, and therefore, a defective image is not printed. It is possible to prevent. Therefore, when used as a color printer, if one of them is in a state where development is not possible, the state where development cannot be performed after one-page printing processing / operation based on the generated medium unit job is completed This timing is suitable for moving the developed developer to the developer attachment / detachment position.

  On the other hand, when the printer is used as a single-color printer, since a plurality of developing devices containing the same color toner are installed, any of the installed developing devices cannot be developed. However, it is possible to continue the printing process / operation using another developing device. For this reason, when a certain developing device cannot be developed like the single color printer of the above embodiment, the other developing device is moved to the developing position, and the printing process / operation is continued. Can be terminated. In other words, even if one attached developing device is in a state where development cannot be performed, the image forming job is not interrupted, so that the throughput can be improved. In addition, if any of the installed developing devices cannot be developed, the printing process / operation is not continued until the image forming job is completed, and a defective image is not printed. It is possible to prevent waste. Therefore, when used as a single-color printer, the image forming job is completed by moving the other developing device, which is different from the developing device that has become unable to develop, to the developing position and continuing the printing process / operation. After that, or after any of the attached developing devices is in a state where development cannot be performed, it is a suitable timing for moving the developing device in a state where development cannot be performed to the developing device attaching / detaching position.

  As described above, when the developing device becomes in a state where it cannot be developed when used as a color printer or when used as a single color printer, the developing device which has become unable to develop is removed from the developing device. By changing the timing of moving to a position, it is possible to realize a printer that is highly convenient for the user, whether it is used as a color printer or a monochrome printer. .

  In either case of using as a color printer or as a single color printer, it can be used for a medium unit job that has already occurred at the time when any of the developing devices cannot be developed. Since the one-page printing process / operation is executed, the printing process and the operation are not interrupted in the middle of the medium unit job. For this reason, after replacing the developing device, a new medium unit job is generated and printing is resumed, so that it is possible to prevent the generation of unprinted pages and the duplicate printing of the same page. Yes, printer control is easy.

  In this embodiment, as an example of a state where development cannot be performed by the developing device, the case where the remaining amount of toner is equal to or less than a predetermined amount and the case where the rotation time of the developing roller is equal to or longer than a predetermined time have been described. When one of these two cases occurs, after developing an image based on a medium-unit job that has already occurred, the developer that can no longer be developed is moved to the developer attachment / detachment position, and the event is reported. May be.

  In the present embodiment, the rotation time of the developing roller is calculated based on the time for which the developing roller is rotating. However, the number of rotations of the developing roller and the number of printed sheets may be counted and converted into the rotation time of the developing roller. .

  Further, in the present embodiment, an example in which two developing devices are mounted on the developing device holding unit 50 when used as a single color printer has been described. However, at least two attaching / detaching portions have the same color toner. A housed developer may be attached. For example, when three or four developing devices are mounted, printing can be performed without replacing the developing devices for a longer period of time.

  In addition, when using as a color printer or when using as a single color printer, the developer that can no longer be developed is moved to the attach / detach position, so the user can check or move the developer that cannot be developed. It is possible to easily replace the developing device without performing complicated operations.

=== Other Embodiments ===
The image forming apparatus and the like according to the present invention have been described above based on the above embodiment. However, the above embodiment of the present invention is for facilitating understanding of the present invention and limits the present invention. is not. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  In the above embodiment, the intermediate transfer type laser beam printer has been described as an example of the image forming apparatus. Applicable.

  In the above embodiment, the image forming apparatus provided with the rotary developing device has been described as an example. However, the present invention is not limited to this. For example, the image forming apparatus includes a tandem developing device. Also, the present invention can be applied.

  In the above embodiment, the apparatus main body side connector is brought into contact with the developing device side connector to perform communication between the developing device side memory and the apparatus main body. However, the present invention is not limited to this. Instead, for example, the communication may be performed without contacting a member on the developing device side and a member on the apparatus main body side.

  Also, the photosensitive member is not limited to a so-called photosensitive roller, which is configured by providing a photosensitive layer on the outer peripheral surface of a cylindrical conductive substrate, and is configured by providing a photosensitive layer on the surface of a belt-shaped conductive substrate. A so-called photosensitive belt may be used.

  Further, in the above-described embodiment, an example in which the K developing device is mounted when used as a single color printer has been described. However, if the developing device to be mounted is a developing device containing toner of the same color, the K developing device is used. It is not limited to.

=== Configuration of Image Forming System ===
An embodiment of an image forming system which is an example of an embodiment according to the present invention will be described with reference to the drawings.

  FIG. 16 is an explanatory diagram showing an external configuration of the image forming system. The image forming system 700 is configured by connecting a computer 701 and a laser beam printer (hereinafter also referred to as a printer) 10 as an image forming apparatus so that bidirectional communication is possible.

  The computer 701 includes a computer main body 702, a display device 704 as a display unit, an input device 708, and a reading device 710. In this embodiment, the computer main body 702 is housed in a mini-tower type housing, but is not limited thereto. The display device 704 is generally a CRT (Cathode Ray Tube), a plasma display, a liquid crystal display device, or the like, but is not limited thereto. In this embodiment, the input device 708 uses a keyboard 708A and a mouse 708B, but is not limited thereto. In this embodiment, the reading device 710 uses a flexible disk drive device 710A and a CD-ROM drive device 710B. However, the reading device 710 is not limited to this. For example, an MO (Magneto Optical) disk drive device or a DVD (Digital Versatile) is used. Disk) etc. may be used.

  FIG. 17 is a block diagram showing a configuration of the image forming system shown in FIG. An internal memory 802 such as a RAM and an external memory such as a hard disk drive unit 804 are further provided in a housing in which the computer main body 702 is housed.

  In the above description, the example in which the computer 701 includes the computer main body 702, the display device 704, the input device 708, and the reading device 710 has been described. However, the present invention is not limited to this. For example, the computer 701 may include a computer main body 702 and a display device 704 provided with a touch panel on the screen, and may not include any of the input device 708 and the reading device 710.

FIG. 3 is a diagram illustrating main components constituting a printer when the printer is used as a color printer. It is the figure which showed the main components which comprise a printer when a printer is used as a monochrome printer. It is a conceptual diagram of a developing device. It is sectional drawing which showed the main components of the developing device. FIG. 5A is a diagram illustrating a home position that is a standby position when the printer is in a standby state and is a stop position that is a reference position in the rotation direction of the developing device holding unit 50. FIG. 5B is a diagram showing a connector attaching / detaching position where the developing device side connector of the black developing device mounted on the developing device holding unit and the device main body side connector provided on the device main body side face each other. FIG. 5C is a diagram illustrating a mounting position of the black developing device. FIG. 6A is a diagram illustrating a separation position between the developing device side connector of the black developing device 51 and the apparatus main body side connector. FIG. 6B is a diagram illustrating a contact position between the developing device side connector and the apparatus main body side connector of the black developing device. It is a block diagram which shows the control unit of a printer. It is a figure for demonstrating the initial operation | movement of a printer. It is a figure for demonstrating the process and operation | movement at the time of performing color printing of 1 page in the case of being used as a color printer. It is a figure for demonstrating the process and operation | movement at the time of performing color printing of 5 pages when it is used as a color printer. FIG. 6 is a diagram for explaining the processing and operation of a printer when the remaining amount of toner in an M developing device becomes 5% or less when used as a color printer. It is a figure for demonstrating the process and operation | movement of a printer when the rotation time of the developing roller of M developing device becomes 1000 second or more when it is used as a color printer. FIG. 5 is a diagram for explaining processing and operation of a printer when the remaining amount of toner in one K developing device becomes 5% or less when used as a single color printer. It is a figure for demonstrating the process and operation | movement of a printer when the rotation time of the developing roller of one K developing device becomes 1000 seconds or more when it is used as a monochrome printer. It is a figure for demonstrating the process and operation | movement of a printer when the rotation time of the developing roller of all the K developing devices mounted when it is used as a monochrome printer also becomes 1000 seconds or more. 1 is an explanatory diagram showing an external configuration of an image forming system. It is a block diagram which shows the structure of the image forming system shown in FIG.

Explanation of symbols

10 printer, 20 photoconductor, 30 charging unit, 31 HP detector,
34 Main unit side connector, 37 Detachable port, 40 Exposure unit,
50 developer holding unit, 50a, 50b, 50c, 50d detachable part,
50e rotation axis, 51 black developer, 52 cyan developer,
53 Magenta developer, 54 Yellow developer,
51a, 52a, 53a, 54a Developer side memory,
51b, 52b, 53b 54b Developer side connector, 55 Support frame,
60 primary transfer unit, 70 intermediate transfer member, 75 cleaning unit,
76 Cleaning blade, 80 Secondary transfer unit, 90 Fixing unit,
92 paper feed tray, 95 display unit,
100 control unit, 101 controller unit, 102 unit control unit,
103 image forming unit, 111 CPU, 112 interface,
113 image memory,
114 controller side memory, 114a EEPROM, 114b RAM,
116 unit control side memory, 116a EEPROM, 120 CPU,
121 serial interface (I / F), 122 main unit side memory,
123 input / output port, 510 developing roller, 520 seal member,
524 seal urging member, 530 toner accommodating portion,
540 housing, 550 toner supply roller,
560 regulating blade, 560a rubber part, 560b rubber support part,
562 Blade support sheet metal, 570 Blade back member 572 Opening, 700 Image forming system, 701 Computer,
702 computer main body, 704 display device,
708 input device, 708A keyboard, 708B mouse,
710 reader,
710A flexible disk drive device,
710B CD-ROM drive, 802 internal memory,
804 Hard disk drive unit, T toner

Claims (12)

An image carrier for carrying a latent image;
A plurality of attaching and detaching portions that contain a developer, and a detachable developing unit for developing the latent image with the developer,
Each of the plurality of developing units containing the developer of different colors is carried on the image carrier by the developer contained in the attached developing unit while being attached to the plurality of attaching / detaching portions. The developed latent image can be used as a color image forming apparatus for forming a color image,
With the developing unit containing the developer of the same color attached to at least two of the plurality of attaching / detaching portions, the image carrier carries the developer with the developer contained in the developing unit. Can be used as a monochrome image forming apparatus for developing a latent image formed to form a monochrome image,
By moving one of the developing units attached to the plurality of attaching / detaching portions to a predetermined attaching / detaching position, the moved developing unit is replaced with another developing unit that is not attached. In an image forming apparatus that can be used,
When an event that cannot be developed by the predetermined developing unit occurs, the timing at which the predetermined developing unit is moved to the attachment / detachment position is determined when the color image forming apparatus is used and when the monochrome image forming apparatus is used. An image forming apparatus, wherein the image forming apparatus is different from that in use. The image forming apparatus according to claim 1.
An image forming unit for developing the latent image to form an image on a medium; and a controller for causing the image forming unit to form an image;
The controller appropriately outputs a request request for requesting the image forming unit to form an image on one medium, and the image forming unit has accepted the request when the image can be formed. Output an acceptance response to the controller to generate a medium unit job in which the image forming unit forms an image on one medium,
In the case of being used as the color image forming apparatus, the timing at which the predetermined developing unit is moved to the attachment / detachment position is already generated when an event that cannot be developed by the predetermined developing unit occurs. An image forming apparatus after an image is formed based on a unit job. The image forming apparatus according to claim 1, wherein:
The controller accepts an image forming job for generating at least one medium unit job, and image formation is started.
The timing when the predetermined developing unit is moved to the attach / detach position when used as the monochrome image forming apparatus is accommodated in the predetermined developing unit when an event in which the predetermined developing unit cannot be developed occurs. In the case where the other developing unit capable of developing containing a developer of the same color as the developer being mounted is attached to any of the plurality of detachable portions,
The other development unit that can be developed is moved to a development position, and the developed development unit is used to form an image based on all the medium unit jobs generated in the image formation job. An image forming apparatus. The image forming apparatus according to claim 1, wherein:
When an event that cannot be developed in all of the mounted development units occurs when the monochrome image forming apparatus is used, after forming an image based on the medium unit job that has already occurred, An image forming apparatus, wherein the developing unit in which the phenomenon that cannot be developed occurs is moved to the attachment / detachment position. 5. The image forming apparatus according to claim 2, wherein:
An event that cannot be developed by the predetermined developing unit is that the remaining amount of developer stored in the predetermined developing unit is equal to or less than a predetermined amount,
The controller acquires remaining amount information indicating the remaining amount of developer stored in the mounted developing unit from the image forming unit, and is stored in the developing unit based on the acquired remaining amount information. It is possible to determine whether or not the remaining amount of the developer is below the predetermined amount,
When the controller is used as the color image forming apparatus, when the controller determines that the remaining amount of developer in any of the mounted developing units is equal to or less than the predetermined amount, the controller An image forming apparatus that does not output a request request to the image forming unit. The image forming apparatus according to claim 5.
When used as the monochromatic image forming apparatus, the remaining amount of developer in the predetermined developing unit is equal to or less than the predetermined amount, and a developer having the same color as the developer stored in the predetermined developing unit is present. When another developing unit that is housed and can be developed is attached to any of the plurality of attaching / detaching portions,
The image forming apparatus, wherein the controller outputs the request request to the image forming unit. The image forming apparatus according to any one of claims 2 to 6,
Each of the developing units includes a developer carrying roller that is rotatably supported and carries the developer,
The event that the predetermined developing unit cannot be developed is that the rotation time of the developer carrying roller of the predetermined developing unit is a predetermined time or more,
The controller acquires rotation information indicating a rotation time of the developer carrying roller of the developing unit mounted, and the rotation time of the developer carrying roller of the developing unit is based on the acquired rotation information. It can be determined whether or not it is over time,
When the controller is used as the color image forming apparatus, when the controller determines that the rotation time of the developer carrying roller of any of the mounted development units is equal to or longer than the predetermined time, the controller The image forming apparatus does not output the request request to the image forming unit. The image forming apparatus according to claim 7.
When used as the monochromatic image forming apparatus, the rotation time of the developer carrying roller of the predetermined developing unit is equal to or longer than the predetermined time, and development with the same color as the developer stored in the predetermined developing unit is performed. When another developing unit that contains the agent and can be developed is attached to any of the plurality of attaching / detaching portions,
The image forming apparatus, wherein the controller outputs the request request to the image forming unit. An image carrier for carrying a latent image;
A plurality of detachable portions that contain a developer and that are detachable with a developing unit for developing the latent image with the developer, and for developing the latent image to form an image on a medium An image forming unit, and a controller for causing the image forming unit to form an image,
Each of the developing units includes a developer carrying roller that is rotatably supported and carries the developer,
The controller acquires rotation information indicating a rotation time of the developer carrying roller of the mounted developing unit, and the rotation time of the developer carrying roller of the developing unit is a predetermined time based on the acquired rotation information. Whether or not and the remaining amount information indicating the remaining amount of developer accommodated in the mounted developing unit is acquired from the image forming unit, and the developing unit is based on the acquired remaining amount information It is possible to determine whether or not the remaining amount of developer stored in the
The controller appropriately outputs a request request for requesting the image forming unit to form an image on one medium, and the image forming unit has accepted the request when the image can be formed. Output an acceptance response to the controller to generate a medium unit job in which the image forming unit forms an image on one medium,
The controller accepts an image forming job for generating at least one medium unit job, and image formation is started.
Each of the plurality of developing units containing the developer of different colors is carried on the image carrier by the developer contained in the attached developing unit while being attached to the plurality of attaching / detaching portions. The developed latent image can be used as a color image forming apparatus for forming a color image,
With the developing unit containing the developer of the same color attached to at least two of the plurality of attaching / detaching portions, the image carrier carries the developer with the developer contained in the developing unit. Can be used as a monochrome image forming apparatus for developing a latent image formed to form a monochrome image,
By moving one of the developing units attached to the plurality of attaching / detaching portions to a predetermined attaching / detaching position, the moved developing unit is replaced with another developing unit that is not attached. An image forming apparatus capable of
When used as the color image forming apparatus,
As an event in which development cannot be performed in a predetermined development unit, when the controller determines that the remaining amount of developer in any of the installed development units is equal to or less than the predetermined amount, and any of the installed development units When the rotation time of the developer carrying roller of the developing unit is determined to be equal to or longer than the predetermined time, the controller does not output the request request to the image forming unit,
When an event that cannot be developed by the predetermined developing unit occurs, the timing for moving the predetermined developing unit to the attach / detach position is based on the medium unit job that has already occurred when the event occurs. After the image is formed,
In the case of being used as the monochrome image forming apparatus,
As an event in which development cannot be performed in a predetermined development unit, when the controller determines that the remaining amount of developer in any of the installed development units is equal to or less than the predetermined amount, and any of the installed development units When the developer carrying roller of the developing unit determines that the rotation time of the developing unit is equal to or longer than the predetermined time, development is possible in which the same color developer as that stored in the predetermined developing unit is stored. When the other developing unit is attached to any of the plurality of attaching / detaching units, the controller outputs the request request to the image forming unit,
When an event that cannot be developed by the predetermined developing unit occurs, the other developing unit that can be developed is moved to the position of the predetermined developing unit, and the image forming job is moved using the moved developing unit. Forming an image based on all the media unit jobs generated in
The timing at which the predetermined developing unit is moved to the attachment / detachment position is that an image is formed based on the medium unit job that has already occurred when an event that cannot be developed occurs in all of the mounted developing units. An image forming apparatus characterized by being later. An image carrier for carrying a latent image;
A plurality of attaching and detaching portions that contain a developer, and a detachable developing unit for developing the latent image with the developer,
Each of the plurality of developing units containing the developer of different colors is carried on the image carrier by the developer contained in the attached developing unit while being attached to the plurality of attaching / detaching portions. The developed latent image can be used as a color image forming apparatus for forming a color image,
With the developing unit containing the developer of the same color attached to at least two of the plurality of attaching / detaching portions, the image carrier carries the developer with the developer contained in the developing unit. Can be used as a monochrome image forming apparatus for developing a latent image formed to form a monochrome image,
By moving one of the developing units attached to the plurality of attaching / detaching portions to a predetermined attaching / detaching position, the moved developing unit is replaced with another developing unit that is not attached. In the image forming apparatus that can be
When an event that cannot be developed by the predetermined developing unit occurs, the predetermined time is different depending on whether the color image forming apparatus is used as the color image forming apparatus or the monochrome image forming apparatus. A computer program for realizing a function of moving the developing unit to the attachment / detachment position. A computer body, and
An image carrier for carrying the latent image connected to the computer;
A plurality of attaching and detaching portions that contain a developer, and a detachable developing unit for developing the latent image with the developer,
Each of the plurality of developing units containing the developer of different colors is carried on the image carrier by the developer contained in the attached developing unit while being attached to the plurality of attaching / detaching portions. The developed latent image can be used as a color image forming apparatus for forming a color image,
With the developing unit containing the developer of the same color attached to at least two of the plurality of attaching / detaching portions, the image carrier carries the developer with the developer contained in the developing unit. Can be used as a monochrome image forming apparatus for developing a latent image formed to form a monochrome image,
By moving one of the developing units attached to the plurality of attaching / detaching portions to a predetermined attaching / detaching position, the moved developing unit is replaced with another developing unit that is not attached. In an image forming system having an image forming apparatus capable of
When an event that cannot be developed by the predetermined developing unit occurs, the timing at which the predetermined developing unit is moved to the attachment / detachment position is determined when the color image forming apparatus is used and when the monochrome image forming apparatus is used. An image forming system, wherein the image forming system is different from that in use. Developers of different colors are stored, and a plurality of development units for developing a latent image carried on the image carrier by the developers are mounted on a plurality of detachable portions to which the development units can be attached and detached. In this state, when used as a color image forming apparatus that develops the latent image with a developer contained in the mounted developing unit to form a color image,
When an event that cannot be developed by the predetermined developing unit occurs, at a predetermined timing, one of the developing units attached to the plurality of attaching / detaching portions is not attached to another developing unit that is not attached. Moving to a predetermined attachment / detachment position that is replaceable with the development unit;
With the developing unit containing the developer of the same color attached to at least two of the plurality of attaching / detaching portions, the image carrier carries the developer with the developer contained in the developing unit. In the case of being used as a monochromatic image forming apparatus for developing a latent image formed to form a monochromatic image,
One of the developing units attached to the plurality of attaching / detaching portions at a timing different from that used when the color image forming apparatus is used when an event that cannot be developed by the predetermined developing unit occurs. And a step of moving the developing unit to the attachment / detachment position.

Images