JP2005321709A - Image forming apparatus using specific developing unit for management operation - Google Patents

Abstract

To prevent the user from paying for the toner consumed in the initialization operation of a photosensitive drum.
An image forming apparatus includes a photosensitive drum (20) on which a latent image is formed, a developing device (50) in which a plurality of developing units storing developers of the same color are detachably mounted, and a photosensitive member. And a control unit (100) for controlling a printing operation in which the developer of the developing unit adheres to the latent image of the drum and performs development. Then, the control unit of the image forming apparatus performs a management operation including an initialization operation of the photosensitive drum using a developer of a specific developing unit among the plurality of mounted developing units, and performs a normal operation according to a user instruction. The printing operation is executed using a developer of a developing unit other than the specific developing unit. Then, by excluding the specific development unit from the user expense burden, the cost of the developer consumed in the management operation can be excluded from the user burden.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus that forms an image using an electronic printing technique, and in particular, has a plurality of developing units that store developers of the same color, and performs management operations other than normal printing such as initialization operation of a photosensitive drum. The present invention relates to an image forming apparatus that performs developer consumption in a specific developing unit.

  An image forming apparatus that forms an image using electrophotographic technology is provided in a printer, a facsimile machine, a copying machine, etc., and an image carrier (photosensitive drum) on which an electrostatic latent image is formed according to image data, and an image A charging unit that charges the outer peripheral surface of the carrier, an exposure unit that exposes the outer peripheral surface of the charged image carrier according to image data to form an electrostatic latent image, and a toner that is a developer on the image carrier And a developing device that develops the electrostatic latent image on the image carrier into a toner image, and a transfer unit that transfers the toner image to a transfer target medium. The developing device detachably holds a developing unit containing a plurality of color toners, and brings an appropriate developing unit close to the image carrier corresponding to the development timing. For this purpose, the developing device has a developing rotary whose rotation is controlled. When performing color printing, development units of a plurality of color toners, for example, four colors (yellow Y, magenta M, cyan C, black K) are mounted on the development rotary, and these development units are sequentially connected to the image carrier. Each color is developed.

  On the other hand, it has been proposed that a plurality of developing units of the same color, for example, black, be simultaneously mounted on the developing rotary of the developing device to provide an image forming apparatus dedicated to monochrome printing. For example, as shown in Patent Documents 1 and 2. Since this monochrome-dedicated image forming apparatus can be equipped with a plurality of black development units, even when a large amount of monochrome printing is performed, the development units can be replaced less frequently by sequentially using the plurality of development units. be able to.

In an image forming apparatus using electrophotographic technology, a photosensitive drum, which is an image carrier, transfers a developed toner image and then cleans the developer remaining on the surface of the photosensitive drum. A cleaning blade is provided in contact with the drum. The cleaning blade is an elastic body such as rubber, and is always in contact with the photosensitive drum, and the photosensitive drum rotates in a state of being in contact with the printing operation. Therefore, some lubricant needs to be supplied between the photosensitive drum and the cleaning blade. As the lubricant, toner that is a developer is usually used. In other words, a predetermined amount of developer is supplied from the developing unit to the entire surface of the photosensitive drum during initialization processing by the user after shipment of the image forming apparatus or during initialization operation after the photosensitive drum is replaced. The developer as a lubricant is supplied to the cleaning blade by rotating the body drum.
JP 2002-351190 A (released on December 4, 2002) JP 2003-316106 A (published on November 6, 2003)

  In an image forming apparatus that operates in a monochrome printing mode with a plurality of black developing units mounted, a relatively large amount of developer must be consumed in the initialization operation of the photosensitive drum. The consumption of the developer in the management operation that is not directly related to the normal print request of the user increases the burden on the user or shortens the life of the developing unit that the user is burdened with. Have. In addition to the photosensitive drum initialization operation, the management operation includes a status sheet printing operation for confirming the finally set status when various settings are made by the user or maintenance personnel. There is also test printing by maintenance personnel. In various management operations that consume such developer, it is not preferable in terms of customer service to use the developer borne by the user.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus that excludes the developer consumed in the management operation from the user expense burden target.

  Another object of the present invention is to provide an image forming apparatus in which the developer consumed in the initialization operation of the photosensitive drum is not targeted for user cost.

  In order to achieve the above object, according to the first aspect of the present invention, in the image forming apparatus, a photosensitive drum on which a latent image is formed and a plurality of developing units that store the same color developer are detachable. And a control unit that controls a printing operation in which the developer of the developing unit adheres to the latent image on the photosensitive drum and performs development. Then, the control unit of the image forming apparatus performs a management operation including an initialization operation of the photosensitive drum using a developer of a specific developing unit among the plurality of mounted developing units, and performs a normal operation according to a user instruction. The printing operation is executed using a developer of a developing unit other than the specific developing unit.

  Then, by excluding the specific development unit from the user expense burden, the cost of the developer consumed in the management operation can be excluded from the user burden.

In order to achieve the above object, according to a second aspect of the present invention, there is provided a photosensitive drum on which a latent image is formed, and a developing device in which a plurality of developing units containing the same color developer are detachably mounted. And a control means for controlling a printing operation for performing development by attaching the developer of the developing unit to the latent image of the photosensitive drum,
The control means executes a management operation other than a normal printing operation using a developer of a specific developing unit among the plurality of mounted developing units, and performs the normal printing operation other than the specific developing unit. The image forming apparatus is characterized in that the image forming apparatus is executed using the developer of the normal developing unit.

  In the second aspect, in a preferred embodiment, the management operation includes an initialization operation of the photosensitive drum, and a predetermined amount of developer is supplied from the specific development unit to the photosensitive drum in the initialization operation. Is done. In another preferred embodiment, the management operation includes a management printing operation, and in the management printing operation, the latent image on the photosensitive drum is developed using the developer of the specific development unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the matters described in the claims and equivalents thereof.

  FIG. 1 is a main configuration diagram of an image forming apparatus according to the present embodiment. In the present embodiment, a laser beam printer 10 will be described as an example of the image forming apparatus. The printer 10 in FIG. 1 shows a configuration in the monochrome printing mode.

  The printer 10 includes a charging unit 30, an exposure unit 40, a developing device 50, a primary transfer unit 60, and an intermediate transfer body 70 along the rotation direction of the photosensitive drum 20 that is an image carrier that carries a latent image. And a cleaning unit 75. Further, the printer 10 includes a secondary transfer unit 80, a fixing unit 90, a display unit 95 that outputs various information to a user, and a control unit 100 that controls these units.

  The photosensitive drum 20 has a cylindrical conductive substrate and a photosensitive layer formed on the outer peripheral surface thereof, is rotatable about a central axis, and rotates clockwise as indicated by an arrow. The charging unit 30 uniformly charges the outer peripheral surface of the photosensitive drum 20, and the exposure unit 40 irradiates the charged photosensitive drum 20 with a beam of a light source such as a built-in laser or an LED array, thereby causing latent electrostatic charges. Form an image. Beam irradiation of the exposure unit 40 is controlled by a drive signal modulated based on image information input from a host computer.

  The developing device 50 is a developing rotary that has mounting portions 50a to 50d to which developing units 51 to 54 that store toner as a developer are detachably mounted, and is rotatable with respect to a central shaft 50e. The developing device 50 is rotated to bring the necessary developing units 51 to 54 close to the photosensitive drum 20, and the charged developer is supplied to the photosensitive drum 20 by a bias voltage between the developing unit and the photosensitive drum, thereby causing latent potential. The image is developed into an image with a developer.

  In the example of FIG. 1, the developing units 51 to 54 that contain the black K developer are all attached to the mounting portions 50 a to 50 d of the developing device 50, and the monochrome printing mode is set. In the monochrome printing process, development is performed using the developer of any of the development units. In addition, when the developing units that respectively store black K, cyan C, magenta M, and yellow Y developers are mounted on the mounting portions 50a to 50d of the developing device 50, the color printing mode is set. In the color printing process, formation of latent images on the photosensitive drum 20 and development with respective developers are performed in the order of CMYK. Therefore, the developing device 50 rotates counterclockwise for each color latent image formation and development process to bring a developing unit of an appropriate color close to the photosensitive drum 20, and sequentially performs development.

  The primary transfer unit 60 transfers the toner image formed on the photoconductor 20 to the intermediate transfer body 70. The intermediate transfer member 70 is, for example, an endless belt in which an aluminum vapor deposition layer is formed on the surface of a PET film and a semiconductive paint is formed on the surface thereof, and is driven to rotate at the same peripheral speed as the photosensitive drum 20. In the color printing mode, the CMYK images are transferred to the intermediate transfer body 70 in an overlapping manner, and in the monochrome printing mode, a monochrome image is transferred to the intermediate transfer body 70. Then, the secondary transfer unit 80 transfers the toner image formed on the intermediate transfer body 70 to a printing medium such as paper, and the fixing unit 90 welds the toner image transferred onto the printing medium to the medium and becomes permanent. The print medium is discharged out of the printer.

  The cleaning unit 75 is provided between the primary transfer unit 60 and the charging unit 30 and has a cleaning blade 76 that is always in contact with the surface of the photosensitive drum 20. After the primary transfer, the cleaning unit 75 is placed on the photosensitive drum 20. The remaining developer (toner) is removed by the cleaning blade 76. The removed developer is accumulated in the cleaning unit 75 having the cleaning blade 76.

  Each of the developing units 51 to 54 is detachable from the developing device 50, and the developing unit stores color information and remaining amount information of the developer so that the printer can recognize the state of the mounted developing unit. A storage medium, for example, a non-contact type nonvolatile memory is provided. Then, after the power is turned on or after the developing unit is mounted on the developing device, information in the nonvolatile memory of the developing unit is read out. Further, the developer remaining amount information is updated in the nonvolatile memory of the developing unit after development.

  As shown in FIG. 1, when the black development units 51 to 54 are attached to all the attachment positions of the development device 50, the color information is read from the nonvolatile memories of the four development units, and the control unit 100. Thus, the monochrome printing mode is determined. When a CMYK development unit is installed at the installation position of the development device 50, color information is similarly read from the non-volatile memories of the four development units, and the control unit 100 determines the color printing mode. In any printing mode, when printing is performed, the amount of developer used at that time is obtained, and based on the amount of developer used, the remaining toner amount information of each developing unit is updated and each non-volatile Maintained in memory.

  FIG. 2 is a cross-sectional view showing a detailed structure of the developing device 50. The developing device 50 detachably mounts the plurality of developing units 51 to 54 in a space between the housing 50f and the mounting portion 50a that rotates about the central shaft 50e. The plurality of developing units all have the same structure. For example, the developing unit 51 includes a container 51a, a developing roller 51b, a supply roller 51c, and a partition plate 51d. The developing roller 51b and the supply roller 51c are rotatably attached to the container 51a, and are rotated by motors (not shown) when the developing unit comes close to the photosensitive drum 20, respectively. The supply roller 51c rotates in pressure contact with the developing roller b to wear-charge the surrounding toner, and the charged toner is supplied to the photosensitive drum 20 via the developing roller b. The partition plate 51d is provided so as to surround the supply roller 51c, and partitions the toner storage space in the container 51c to the left and right. By providing the partition plate 51d, the toner in the space on the supply roller 51c side is supplied to the developing roller 51b side by the press-contact rotation between the supply roller 51c and the developing roller 51b. Further, when the developing device 50 is rotated 90 degrees counterclockwise by 180 degrees as indicated by an arrow and rotated 180 degrees, the developing unit 53 is positioned, and the toner in the storage space on the supply roller 51 c side is separated from the partition plate 51 c. Is mixed with the toner in the storage space opposite to the supply roller 51c, and further rotated by 90 degrees, the mixed toner is stirred and refreshed. When rotated 90 degrees, a part of the agitated and refreshed toner is stored in the storage space on the supply roller 51c side. As described above, the partition 51 is provided to divide the toner storage space, and the supply roller is provided in one of the toner storage spaces, so that the frictionally charged toner is stirred and refreshed by the rotation of the developing device 50. The Therefore, since it is not necessary to provide a stirring means in the developing unit, the developing unit can be reduced in size.

  FIG. 3 is a configuration diagram of the control unit 100 in the present embodiment. A control unit 100 serving as a control unit is supplied with print job data from a host computer, performs predetermined image processing, generates a control signal and an image signal for the engine, and performs display control for the display panel 95. And an engine controller 102 for controlling each unit of the print engine. The main controller 101 includes an interface 112 that receives print job data from the host computer, an image memory 113 that stores image data in the print job data, image processing such as halftone processing, setting of display modes, automatic determination, It includes a CPU 111 that performs display control of the display panel, and a memory unit 114 that includes a nonvolatile memory 114a, a RAM, and a ROM 114b. The non-volatile memory 114a stores print mode information indicating whether the printer is in a color print mode or a monochrome print mode. The print mode is determined by the main controller 101 according to the information from the memory of the developing unit attached to the developing device when the power is turned on, and the determined print mode information is written in the nonvolatile memory 114a.

  In addition to the CPU 120, the engine controller 102 includes drive control circuits 124, 125, driving a memory unit 116, a serial interface 121, an input / output port 123, a charging unit 30, an exposure unit 40, and a developing device 50, respectively. 126, and a drive control circuit group 128 that drives the primary transfer unit 60, the secondary transfer unit 80, the fixing unit 90, the display unit 95, and the cleaning unit 75, respectively. Further, a detection unit 31 that detects the home position of the developing device 50 is provided. The engine controller 102 is supplied with a control signal for controlling the printing process and an image signal for controlling exposure beam irradiation from the main controller 101, and controls each unit.

  The developing units 51 to 54 attached to the developing device 50 have developing unit side memories 51a to 54a, respectively. These memories are composed of nonvolatile memories such as FeRAM and EEPROM, for example, and store information such as developer color information, developer remaining amount information, and development unit ID (identification information). When these memories are composed of FeRAM, they can be accessed without contact via the serial interface 121. When they are composed of EEPROM, they can be accessed by physically connecting the serial interface 121. . When the power is turned on or when the development unit is replaced or additionally installed, the engine controller 102 accesses these development unit side memories 51a to 54a to check whether or not the development unit is installed, color information, identification information, specific development unit or normal development. Read unit attribute information. In addition, during the development process, the developer remaining amount information is updated in the memory of the development unit that has completed the development process.

  In the nonvolatile memory 116a in the memory unit 116, information on whether or not the developing unit is mounted at four mounting positions of the developing device, and color information, ID information, attribute information, and remaining amount of the mounted developing unit. Information is stored. Further, the non-volatile memory 116a stores control parameters for engine control, control parameters corresponding to each developing unit, color or monochrome print mode information, and the like. The memory unit 116 includes a program ROM and a RAM. The program ROM includes a management operation program including a photosensitive drum initialization operation, a status setting operation, a status printing operation, a development unit calibration control, and the like. The printing operation control program is stored. The CPU 120 executes a normal printing process by executing a normal printing operation control program with reference to the control parameter of the nonvolatile memory 116a. Further, the CPU 120 executes the management operation program to perform the initialization operation when the photosensitive drum is replaced or at the first operation after shipment, and the setting operation and the status printing operation when the status setting is requested. Are respectively controlled at a predetermined calibration timing.

  FIG. 4 is a diagram for explaining the initialization operation of the photosensitive drum. As described above, the developing device 50 is equipped with a plurality of developing units 51 to 54. In FIG. 4, the developing unit 51 is in a developing position close to the photosensitive drum 20. In a normal printing operation, while the photosensitive drum 20 rotates in the direction of the arrow, an exposure beam from a photosensitive unit (not shown) is irradiated on the charged surface of the photosensitive drum 20 to form an electrostatic latent image, The developer (toner) in the developing unit 51 is supplied to the photosensitive drum 20 by the charging bias voltage, adheres to the latent image, and is developed. The developed toner image is transferred to a transfer belt (not shown). After the transfer, the toner remaining on the surface of the photosensitive drum 20 is removed by the cleaning blade 76 that is always in contact with the photosensitive drum 20. As described above, since the photosensitive drum 20 is rotationally controlled with the cleaning blade 76 in contact with the toner, the toner is applied as a lubricant between the cleaning blade 76 and the surface of the photosensitive drum 20. Maintained.

  On the other hand, when the image forming apparatus is shipped or when a new photoconductor drum is replaced, printing control is not yet performed, so that toner as a lubricant is not supplied to the surface of the photoconductor drum 20. Therefore, as an initialization operation, toner is supplied from the developing unit 51 while rotating the photosensitive drum 20. As shown in the figure, the toner supply area 51K has a predetermined circumferential length between both ends of the photosensitive drum 20, and the toner supply develops a black solid pattern having a large area. Requires an equivalent amount of toner. By this initialization operation, toner as a lubricant is sufficiently supplied between the cleaning blade 76 and the photosensitive drum 20, and the cleaning blade 76 is turned up in the rotation direction even when the photosensitive drum 20 rotates. The trouble can be avoided.

  FIG. 5 is a flowchart of control of the image forming apparatus in the present embodiment. First, as initialization processing, the nonvolatile memory of the mounted development unit is accessed, and attribute information, color information, and remaining toner amount information indicating whether the development unit is a specific development unit or a normal development unit corresponding to the mounting position. Are stored in the nonvolatile memory 116a in the engine controller (S10). The attribute information indicating whether the specific development unit or the normal development unit is not necessarily stored in the non-volatile memory of the development unit. In this case, the user may have information on which development unit is the specific development unit. Input from the operation panel 95. Alternatively, the specific mounting position of the developing device may be fixedly set with the mounting position of the specific developing unit.

  FIG. 6 is a diagram showing an example of information stored in the memory by the initialization process S10. In the nonvolatile memory 116a, development unit ID information, attribute information (specific or normal), color information, and remaining toner information are stored for the development unit mounting positions 50a to 50d. In the example of FIG. 6, the developing unit A mounted at the mounting position 50a is a specific developing unit, and the developing units B, C, and D mounted at the other mounting positions 50b to 50d are normally current units.

  Returning to FIG. 5, in the initialization process performed after shipment and after installation by the user, for example, a photosensitive drum initialization operation and calibration using a patch pattern by all the development units are performed (S12). The initialization operation of the photosensitive drum is as described with reference to FIG. 4, and the engine controller 102 refers to the information in the memory in FIG. 6 to bring the developing unit A, which is a specific developing unit, close to the photosensitive drum 20. Then, while rotating the photosensitive drum, a predetermined amount of toner as a lubricant is supplied to the surface of the photosensitive drum 20, and the toner is applied to the cleaning blade. In calibration, each development unit is used to form a predetermined patch pattern image on the surface of the photosensitive drum, the optical density of the toner image is detected, and control parameters such as exposure intensity and charging bias voltage are determined. Is done.

  When the above initialization process ends, normal control is performed. When the photosensitive drum is replaced (S14), the engine controller executes an initialization operation for the photosensitive drum (S16). Also in this photoreceptor initialization operation, the toner of the specific developing unit is supplied to the surface of the photoreceptor drum, and toner as a lubricant is supplied to the cleaning blade.

  Further, when the setting change mode by the user is entered from the operation panel or the host computer (S18), the status is changed and the information is stored in the nonvolatile memory 116a or the like. When a status print request for printing the set status information is issued in the setting change mode, the control unit 100 executes the status sheet printing using the specific development unit A (S22).

  Further, when a normal printing request is issued (S24), the control unit 100 executes a printing operation using any of the normal developing units B to D (S26). As a result, normal printing is performed using the toner of the normal development unit, which is borne by the user, but the management operation, for example, the initialization operation of the photosensitive drum or status printing, uses the toner of the specific development unit. Done. When this specific development unit is exempt from the user's cost burden, the user burden on the toner consumption due to the management operation can be avoided. As described above, in the monochrome printing mode in which a plurality of developing units are mounted, a specific developing unit is used for toner consumption in a management operation such as the initialization operation of the photosensitive drum, and the normal printing operation is a normal printing operation other than the specific developing unit. This can be done using a development unit.

  If none of the plurality of mounted development units is designated as a specific development unit, the management operation is executed using an arbitrary development unit. In that case, if a specific developing unit is attached later, the normal printing operation may be executed using the specific developing unit with the toner consumed in the management operation as the upper limit.

1 is a main configuration diagram of an image forming apparatus in the present embodiment. 3 is a cross-sectional view showing a detailed structure of the developing device 50. FIG. It is a block diagram of the control unit 100 in this Embodiment. It is a figure explaining the initialization operation | movement of a photoconductive drum. FIG. 5 is a flowchart of control of the image forming apparatus in the present embodiment. It is a figure which shows the example of information stored in memory by initialization process S10.

Explanation of symbols

10: Image forming apparatus (printer), 20: Image carrier (photosensitive drum), 40: Exposure unit 50: Developing device, 51 to 54: Developing unit, 100: Control unit

Claims (5)

A photosensitive drum on which a latent image is formed;
A developing device in which a plurality of developing units containing the same color developer are detachably mounted; and
Control means for controlling a printing operation for performing development by attaching the developer of the developing unit to the latent image of the photosensitive drum;
The control means executes a management operation other than a normal printing operation using a developer of a specific developing unit among the plurality of mounted developing units, and performs the normal printing operation other than the specific developing unit. An image forming apparatus, which is executed using a developer of a normal developing unit. In claim 1,
The management operation includes an initialization operation of the photosensitive drum, and in the initialization operation, a predetermined amount of developer is supplied from the specific development unit to the photosensitive drum. In claim 1,
The management operation includes a management printing operation, and in the management printing operation, a latent image on the photosensitive drum is developed using a developer of the specific development unit. In claim 1,
The image forming apparatus, wherein the specific developing unit and the normal developing unit are identified by attribute data stored in a memory provided in each of the developing units. In claim 1,
The image forming apparatus, wherein the specific developing unit and the normal developing unit are distinguished by a setting from a user, and the set attribute data is stored in a memory.

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