EP2037328B1 - Bilderzeugungsvorrichtung - Google Patents

Bilderzeugungsvorrichtung Download PDF

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Publication number
EP2037328B1
EP2037328B1 EP08252838.1A EP08252838A EP2037328B1 EP 2037328 B1 EP2037328 B1 EP 2037328B1 EP 08252838 A EP08252838 A EP 08252838A EP 2037328 B1 EP2037328 B1 EP 2037328B1
Authority
EP
European Patent Office
Prior art keywords
color
gears
photosensitive drums
black
photosensitive drum
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
EP08252838.1A
Other languages
English (en)
French (fr)
Other versions
EP2037328A2 (de
EP2037328A3 (de
Inventor
Tetsuji Nishikawa
Makoto Kikura
Kazuki Suzuki
Yasuhiro Maehata
Masahiro Ishida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Publication of EP2037328A2 publication Critical patent/EP2037328A2/de
Publication of EP2037328A3 publication Critical patent/EP2037328A3/de
Application granted granted Critical
Publication of EP2037328B1 publication Critical patent/EP2037328B1/de
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/75—Details relating to xerographic drum, band or plate, e.g. replacing, testing
    • G03G15/757—Drive mechanisms for photosensitive medium, e.g. gears
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
    • G03G15/0142—Structure of complete machines
    • G03G15/0178—Structure of complete machines using more than one reusable electrographic recording member, e.g. one for every monocolour image
    • G03G15/0194—Structure of complete machines using more than one reusable electrographic recording member, e.g. one for every monocolour image primary transfer to the final recording medium
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/01—Apparatus for electrophotographic processes for producing multicoloured copies
    • G03G2215/0103—Plural electrographic recording members
    • G03G2215/0119—Linear arrangement adjacent plural transfer points
    • G03G2215/0122—Linear arrangement adjacent plural transfer points primary transfer to an intermediate transfer belt
    • G03G2215/0125—Linear arrangement adjacent plural transfer points primary transfer to an intermediate transfer belt the linear arrangement being horizontal or slanted
    • G03G2215/0132—Linear arrangement adjacent plural transfer points primary transfer to an intermediate transfer belt the linear arrangement being horizontal or slanted vertical medium transport path at the secondary transfer
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/01—Apparatus for electrophotographic processes for producing multicoloured copies
    • G03G2215/0151—Apparatus for electrophotographic processes for producing multicoloured copies characterised by the technical problem
    • G03G2215/0154—Vibrations and positional disturbances when one member abuts or contacts another member
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/01—Apparatus for electrophotographic processes for producing multicoloured copies
    • G03G2215/0151—Apparatus for electrophotographic processes for producing multicoloured copies characterised by the technical problem
    • G03G2215/0158—Colour registration
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/01—Apparatus for electrophotographic processes for producing multicoloured copies
    • G03G2215/0151—Apparatus for electrophotographic processes for producing multicoloured copies characterised by the technical problem
    • G03G2215/0158—Colour registration
    • G03G2215/0161—Generation of registration marks
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/01—Apparatus for electrophotographic processes for producing multicoloured copies
    • G03G2215/019—Structural features of the multicolour image forming apparatus
    • G03G2215/0193—Structural features of the multicolour image forming apparatus transfer member separable from recording member
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2221/00—Processes not provided for by group G03G2215/00, e.g. cleaning or residual charge elimination
    • G03G2221/16—Mechanical means for facilitating the maintenance of the apparatus, e.g. modular arrangements and complete machine concepts
    • G03G2221/1651—Mechanical means for facilitating the maintenance of the apparatus, e.g. modular arrangements and complete machine concepts for connecting the different parts
    • G03G2221/1657—Mechanical means for facilitating the maintenance of the apparatus, e.g. modular arrangements and complete machine concepts for connecting the different parts transmitting mechanical drive power

Definitions

  • the present invention relates to an image forming apparatus.
  • tandem type color image forming apparatuses in which plural photosensitive drums are arranged side by side.
  • Such a color image forming apparatus is configured to be capable of selecting not only a color mode in which different colors of toner images are formed on the front cylindrical surfaces of the plural photosensitive drums for color and then transferred to a transfer member in a superposed manner, but also a monochrome mode in which a black toner image is formed only on a photosensitive drum for black and then transferred to a transfer member.
  • EP-A1-1429201 and JP-A-11084799 disclose examples of such machines.
  • gears for color and a gear for black are concentrically coupled with the color photosensitive drums and the black photosensitive drum, respectively.
  • the respective photosensitive drums are rotated.
  • rotational irregularities occur in the color photosensitive drums and the black photosensitive drum, which may cause color shifts in the superposed toner images transferred to the transfer member. Therefore, in order to prevent the occurrence of the color shifts in the superposed toner images transferred to the transfer member, the color gears and the black gear are configured to be rotated with their predetermined phase relationships maintained.
  • the color gears and the color photosensitive drums remain stopped.
  • the above predetermined phase relationships are disrupted, which may cause the color shifts at the time of forming images in a subsequent color mode.
  • JP-B2-3496566 proposes an image forming apparatus that has a driving motor for rotating and driving the black gear and a driving motor for rotating and driving the color gears.
  • the image forming apparatus causes the black gear to stop at a position where the above predetermined phase relationships are obtained when the monochrome mode is terminated.
  • the turning path of an endless transfer belt is changed in accordance with the color mode and the monochrome mode.
  • the monochrome mode the transfer belt is separated from the color photosensitive drums so as to come into sliding contact only with the black photosensitive drum.
  • the color mode on the other hand, it comes into sliding contact not only with the black photosensitive drum but also with the color photosensitive drums. Therefore, it is necessary to change the turning path of the transfer belt in accordance with the change of the modes, which may cause fluctuations in the transfer speed of the transfer belt with ease and the color shifts.
  • JP-A-179372 discloses an image forming apparatus on which the precharacterising portion of claim 1 is based.
  • the present invention has been made in view of the above circumstances and may provide an image forming apparatus capable of reliably reducing the occurrence of phase shifts in a short period of time and with a simple configuration even if a printing mode is switched between a color mode and a monochrome mode.
  • the present invention provides an image forming apparatus as defined in the appended claims.
  • the driving source may be a driving motor by which the gears for color and the gear for black are driven and rotated.
  • the driving gears corresponding to the gears for color and the driving source may be driven and coupled by plural other coupling gears.
  • the photosensitive drums for color and the photosensitive drum for black may be linearly arranged in parallel, and the chromatic toner images and the black toner image formed on the photosensitive drums for color and the photosensitive drum for black, respectively, may be transferred to an endless belt that is arranged parallel to the arrangement direction of the photosensitive drums and endlessly moved in the arrangement direction.
  • the contact/separation means may be arranged so that the corresponding photosensitive drums for color are separated from the endless belt simultaneously with the separation of the gears for color of the photosensitive drums for color from the corresponding driving gears, making the separation direction of the gears for color from the driving gears match the separation direction of the photosensitive drums for color from the endless belt.
  • the gears for color may be molded by the same mold.
  • the photosensitive drums for color may have rotational position detection means that detects rotational positions of the photosensitive drums for color.
  • the photosensitive drums for color may be integrally coupled with corresponding development units, and the development units may be moved together with the photosensitive drums for color that are moved as the gears for color are separated from the driving gears.
  • the photosensitive drums for color may be removably attached to an image forming apparatus main body.
  • the removing direction of the photosensitive drums for color from the image forming apparatus main body and the separation direction of the gears for color from the driving gears for color may be matched with each other.
  • the photosensitive drums for color may have detection means that detects the removals of the photosensitive drums for color.
  • the gears for color of the photosensitive drums for color are meshed with corresponding driving gears coupled with and driven by a driving source and rotated and are arranged to correspond to the driving gears so as to stop rotations of the photosensitive drums for color when the gears for color are in a non-meshed state after being separated from the driving gears.
  • the image forming apparatus has contact/separation means that moves the gears for color so as to be in a meshed state or in the non-meshed state with respect to the corresponding driving gears, rotational position detection means that is provided in the photosensitive drum for black and detects a rotational position of the photosensitive drum for black, the rotational position detection means detecting and storing the rotation stop position of the photosensitive drum for black in the color mode, and a control unit that controls, in the monochrome mode, the photosensitive drum for black to be stopped at the same position as the stored rotation stop position of the photosensitive drum for black in the color mode. Accordingly, it is possible to provide the image forming apparatus capable of reliably reducing the occurrence of phase shifts in a short period of time and with a simple configuration even if a printing mode is switched between a color mode and a monochrome mode.
  • FIG. 1 is a cross-sectional view showing a schematic configuration of an electrophotographic printer as an image forming apparatus according to the embodiment of the present invention.
  • the printer according to this embodiment has process cartridges 1Y, 1C, 1M, and 1K and development units 20Y, 20C, 20M, and 20K corresponding to the colors of yellow (Y), cyan (C), magenta (M), and black (K) (hereinafter referred to as Y, C, M, and K), respectively.
  • the process cartridges 1Y, 1C, 1M, and 1K have photosensitive drums 2Y, 2C, 2M, and 2K, respectively.
  • Charging units 21 and cleaning units 22 are integrally attached to the peripheries of the photosensitive drums 2Y, 2C, 2M, and 2K.
  • the charging units 21 and the cleaning units 22 attached to the photosensitive drums 2Y, 2C, 2M, and 2K are also removed together with the photosensitive drums 2Y, 2C, 2M, and 2K.
  • the photosensitive drums 2Y, 2C, 2M, and 2K of the process cartridges 1Y, 1C, 1M, and 1K are linearly arranged in parallel on an endless intermediate transfer belt 4 stretched between a driving roller 29 and a driven roller 30 along the moving direction (as indicated by arrow A) of the endless intermediate transfer belt 4.
  • the respective colors of toner images formed on the photosensitive drums 2Y, 2C, 2M, and 2K are transferred to the intermediate transfer belt 4 by primary transfer rollers 23.
  • the development units 20Y, 20C, 20M, and 20K accommodate the toner of yellow, cyan, magenta, and black, respectively, and supply the respective colors of toner to the front cylindrical surfaces of the photosensitive drums 2Y, 2C, 2M, and 2K through development rollers 20aY, 20aC, 20aM, and 20aK arranged separated from the peripheries of the photosensitive drums 2Y, 2C, 2M, and 2K with a predetermined interval.
  • the development rollers 20aY, 20aC, 20aM, and 20aK are moved up and down with the predetermined interval as the photosensitive drums 2Y, 2C, 2M, and 2K are moved up and down.
  • An optical scanning unit 3 optically scans the front surfaces of the photosensitive drums 2Y, 2C, 2M, and 2K of the process cartridges 1Y, 1C, 1M, and 1K with laser beams LB1, LB2, LB3, and LB4 emitted based on the control signal of an optical writing circuit. With this optical scanning, electrostatic latent images for Y, C, M, and K are formed on the photosensitive drums 2Y, 2C, 2M, and 2K uniformly charged with the charging units 21. Note that, in the optical scanning unit 3, the laser beams emitted from a laser oscillator are applied to photosensitive bodies through plural optical lenses and mirrors while being deflected with a polygon mirror rotated and driven by a motor.
  • a transfer unit 5 that moves the intermediate transfer belt 4 as a transfer body while stretching the same.
  • the transfer unit 5 as transfer means has, for example, a cleaning unit (not shown) that cleans the toner remaining after toner images transferred to the intermediate transfer belt 4 are transferred to a transfer member P by a secondary transfer roller 26.
  • a cleaning unit (not shown) that cleans the toner remaining after toner images transferred to the intermediate transfer belt 4 are transferred to a transfer member P by a secondary transfer roller 26.
  • a superposed toner image with four colors of toner (hereinafter referred to as a four-color toner image) is formed on the intermediate transfer belt 4.
  • pattern detection means 15 is arranged that detects a speed fluctuation detection pattern of the toner image on the intermediate transfer belt 4 after the toner image of Y is transferred from the photosensitive drum 2Y by the primary transfer roller 23.
  • the four-color toner image formed on the intermediate transfer belt 4 is transferred to the transfer member P such as a transfer sheet, which is separately ejected from a sheet accommodation cassette 31 by a feed roller 24 and fed in accordance with adjusted timing by a resist roller 25, by the secondary transfer roller 26.
  • the toner image transferred onto the transfer member P is heated and pressed by a fixing unit 27 so as to be fixed and then ejected onto a sheet receiving tray 32 by a sheet ejection roller 28.
  • the printer of this embodiment it is possible to select either a color mode in which the four-color toner image of Y, C, M, and K is formed on the transfer member P or a monochrome mode in which the toner image of black is formed on the transfer member P.
  • a color mode in which the four-color toner image of Y, C, M, and K is formed on the transfer member P
  • a monochrome mode in which the toner image of black is formed on the transfer member P.
  • FIG. 2 shows an example of a driving mechanism consisting of gears from a motor gear 6 attached to a driving motor as a driving source to photosensitive drum gears 10Y, 10C, 10M, and 10K attached to the photosensitive drums 2Y, 2C, 2M, and 2K, respectively.
  • the motor gear 6 is meshed with coupling gears 7a and 7c and coupled therewith.
  • the coupling gear 7a is meshed with a coupling gear 7b and coupled therewith
  • the coupling gear 7c is meshed with a coupling gear 7d and coupled therewith.
  • the coupling gear 7b is meshed with large diameter gears 8a3 and 8a4 of two-stage driving gears 8K and 8M
  • the coupling gear 7d is meshed with large diameter gears 8a2 and 8a1 of two-stage driving gears 8C and 8Y.
  • the torque of the motor gear 6 is transmitted to the two-stage driving gears 8Y, 8C, 8M, and 8K, so that small diameter gears 8b1, 8b2, 8b3, and 8b4 concentrically coupled with the large diameter gears 8a1, 8a2, 8a3, and 8a4 of the two-stage driving gears 8Y, 8C, 8M, and 8K are rotated and driven.
  • the photosensitive drum gears 10Y, 10C, 10M, and 10K are meshed with the small diameter gears 8b1, 8b2, 8b3, 8b4 of the two-stage driving gears 8Y, 8C, 8M, 8K, respectively, so as to be rotated and driven.
  • the photosensitive drum gears 10Y, 10C, 10M, and 10K are concentrically attached to the photosensitive drums 2Y, 2C, 2M, and 2K, respectively.
  • the photosensitive drum gears 10Y, 10C, and 10M of the photosensitive drums 2Y, 2C, and 2M are arranged so as to be movable up and down in the direction as indicated by arrow B when they are meshed with or separated from the small diameter gears 8b1, 8b2, and 8b3 of the two-stage driving gears 8Y, 8C, and 8M by a contact/separation member 12 (contact/separation means) (see FIG. 4B ).
  • a gear ratio is only required to be set so that the cycle per rotation of the gears arranged upstream of the photosensitive drum gears 10Y, 10C, 10M, and 10K is 1/m times (where m is an integer) the cycle between the exposure and the transfer of the photosensitive drum. For example, it is set as follows.
  • Za2 Za x ( ⁇ /360)
  • Za3 Zb1/N
  • the contact/separation member 12 is used so that the photosensitive drum gears 10Y, 10C, and 10M are meshed with or separated from the corresponding two-stage driving gears 8Y, 8C, and 8M.
  • FIGS. 4A through 4D a description is made of operations in which the photosensitive drum gears 10Y, 10C, and 10M are meshed with or separated from the corresponding two-stage driving gears 8Y, 8C, and 8M by the contact/separation member 12.
  • the contact/separation member 12 includes a rectangular guiding member 12a having a guiding surface 12b that comes into contact with rotational shafts 13Y, 13C, 13M, and 13K of the photosensitive drums 2Y, 2C, 2M, and 2K and includes a driving gear 11 that moves the guiding member 12a along the arrangement direction (as indicated by arrow C) of the photosensitive drums 2Y, 2C, 2M, and 2K.
  • the guiding surface 12b of the guiding member 12a alternates between having concave surfaces 12b1 that allow movement of the rotational shafts 13Y, 13C, 13M, and 13K of the photosensitive drums 2Y, 2C, 2M, and 2K elastically pressed downward by a pressing member (not shown) such as a spring in the downward direction (as indicated by arrow E1 and having convex surfaces 12b2 that allow movement of the rotational shafts 13Y, 13C, and 13M in the upward direction (as indicated by arrow E2 in FIG. 4B ) against the pressing force generated by the pressing member.
  • a pressing member such as a spring in the downward direction (as indicated by arrow E1 and having convex surfaces 12b2 that allow movement of the rotational shafts 13Y, 13C, and 13M in the upward direction (as indicated by arrow E2 in FIG. 4B ) against the pressing force generated by the pressing member.
  • the photosensitive drum gears 10Y, 10C, 10M, and 10K are meshed with the small diameter gears 8b1, 8b2, 8b3, and 8b4 of the two-stage driving gears 8Y, 8C, 8M, and 8K.
  • the photosensitive drum gears 10Y, 10C, 10M, and 10K are rotated to thereby rotate the photosensitive drums 2Y, 2C, 2M, and 2K.
  • the lower surface of the guiding member 12a is provided with a rack 12c meshed with the driving gear 11. With the rotation of the driving gear 11, the guiding member 12a is moved in the right and left horizontal directions (as indicated by arrow C). Accordingly, as shown in FIG.
  • FIG. 4A when the driving gear 11 is rotated to make the rotational shafts 13Y, 13C, 13M, and 13K of the photosensitive drums 2Y, 2C, 2M, and 2K come into contact with the concave surfaces 12b1 of the guiding surface 12b, the photosensitive drum gears 10Y, 10C, 10M, and 10K are meshed with the small diameter gears 8b1, 8b2, 8b3, and 8b4 to rotate the photosensitive drums 2Y, 2C, 2M, and 2K.
  • this makes it possible to transfer toner images to the intermediate transfer belt 4 in full color, i.e., it is possible to perform color mode printing (separation state 1).
  • reference numeral 42 denotes a guiding groove formed in the guiding member 12a and serves as a guiding mechanism that reliably guides the guiding member 12a in the right and left horizontal directions together with a guiding projection 43 formed in the apparatus main body.
  • the black photosensitive drum 2K to transfer a black toner image to the intermediate transfer belt 4, i.e., it is possible to perform monochrome mode printing (separation state 4).
  • the driving gear 11 is rotated to move the guiding member 12a in the horizontal direction, thereby making it possible to perform the color mode printing and the monochrome mode printing.
  • the image forming apparatus of this embodiment it is possible to align the rotational positions of the photosensitive drums 2Y, 2C, 2M, and 2K using the contact/separation member 12 so that the transfer positions of the toner images of the photosensitive drums 2Y, 2C, 2M, and 2K are matched with each other when the photosensitive drums 2Y, 2C, 2M, and 2K are assembled or replaced.
  • the alignment of the rotational positions of the photosensitive drums 2Y, 2C, 2M, and 2K is performed in accordance with the separation states 1 through 4 after the phases of the photosensitive drums 2Y, 2C, 2M, and 2K are adjusted using phase detection patterns (see FIG. 10 ).
  • FIGS. 4A through 4D the separation states 1 through 4 are described.
  • FIG. 4B shows a state in which the rotation of the photosensitive drum 2Y is stopped so that the phase of the photosensitive drum 2Y is matched with the phases of the photosensitive drums 2C, 2M, and 2K whose phases are matched with each other (separation state 2).
  • the driving gear 11 is rotated to move the guiding member 12a from the position shown in FIG. 4C in the right direction.
  • the rotational shaft 13Y of the photosensitive drum 2Y is pushed up by the convex surface 12b2, and the small diameter gear 8b1 is separated from the photosensitive drum gear 10Y to stop the rotation of the photosensitive drum 2Y.
  • the guiding member 12a is moved in the right direction to guide the rotational shaft 13Y of the photosensitive drum 2Y to the concave surface 12b1.
  • the above the separation state 1 is activated. Under this separation state 1, it is possible to rotate the photosensitive drum 2Y together with the other photosensitive drums 2C, 2M, and 2K with their phases matched with each other.
  • FIG. 4C shows a state in which the rotations of the photosensitive drums 2C and 2Y are stopped so that the phase of the photosensitive drum 2C is matched with the phases of the photosensitive drums 2M and 2K whose phases are matched with each other (separation state 3).
  • the driving gear 11 is rotated to further move the guiding member 12a in the left direction to make the rotational shafts 13Y and 13C come into contact with the convex surfaces 12b with the rotation of the photosensitive drum 2Y stopped.
  • the small diameter gears 8b1 and 8b2 are separated from the photosensitive drum gears 10Y and 10C to stop the rotations of the photosensitive drums 2Y and 2C.
  • the guiding member 12a is moved in the right direction to guide the rotational shaft 13C of the photosensitive drum 2C to the concave surface 12b1.
  • the above separation state 2 is activated. Under this separation state 2, it is possible to rotate the photosensitive drum 2C together with the other photosensitive drums 2M and 2K with their phases matched with each other.
  • FIG. 4D shows a state in which the rotations of the photosensitive drums 2Y, 2C, and 2M are stopped so that the phase of the photosensitive drum 2K is matched with the phase of the photosensitive drum 2M (separation state 4). Under this state, it is possible to match the phase of the photosensitive drum 2K with the phase of any of the photosensitive drums 2Y, 2C, and 2M when stopped. In this case, however, the phase of the photosensitive drum 2M is matched with the phase of the photosensitive drum 2K.
  • the driving gear 11 is rotated to further move the guiding member 12a in the left direction to also push up the rotational shaft 13M of the photosensitive drum 2M so as to separate the small diameter gears 8b1, 8b2, and 8b3 from the photosensitive drums 10Y, 10C, and 10M. Accordingly, the photosensitive drums 2Y, 2C, and 2M are stopped at their predetermined reference rotational positions. Then, when the black photosensitive drum 2K reaches its predetermined reference rotational position and matches the reference rotational position of the photosensitive drum 2M, the driving gear 11 is rotated to activate the separation state 3 shown in FIG. 4C . As a result, the reference rotational positions and the phases of the photosensitive drums 2K and 2M are matched with each other. Note that the separation state 4 is applied not only to the matching of the phases of the photosensitive drums 2M and 2K, but also to black printing in the monochrome mode.
  • the black photosensitive drum 2K is configured to be rotated at all times.
  • each of the photosensitive drums 2Y, 2C, 2M, and 2K is provided with a rotational position detection mechanism for detecting its reference rotational position.
  • FIGS. 5A through 5C are views showing the detection mechanisms for detecting the rotational positions of the photosensitive drums 2Y, 2C, 2M, and 2K used in the image forming apparatus of this embodiment.
  • each of the photosensitive drums 2Y, 2C, 2M, and 2K uses the same mechanism. Therefore, FIGS. 5A through 5C exemplify the case of the photosensitive drum 2Y.
  • the detection mechanisms for detecting the rotational positions of the photosensitive drums 2Y, 2C, 2M, and 2K used in the image forming apparatus of this embodiment there are a disk-shaped member 16 that is attached to the rotational shaft 13Y of the photosensitive drum 2Y and is rotated in synchronization with the photosensitive drum 2Y, and a detection sensor 17 such as an optical sensor that detects the rotational position of the member 16 are used, as shown in FIG. 5A . Furthermore, as shown in FIG. 5B , the member 16 has a concave notched part 16a at its periphery. As shown in FIG. 5A , the detection sensor 17 provided at the photosensitive drum 2Y that transfers a toner image to the intermediate transfer belt 4 detects the notched part 16 to detect the rotational position of the photosensitive drum 2Y.
  • the photosensitive drum 2Y has attached at its end the photosensitive drum gear 10Y meshed with the small diameter gear 8b1 of the two-stage driving gear 8Y, and is rotated while being in sliding contact with the intermediate transfer belt 4 by the rotation of the large diameter gear 8a1 rotated and driven by the motor gear 6. Accordingly, a yellow toner image formed on the front surface of the photosensitive drum 2Y is transferred to the intermediate transfer belt 4.
  • the notched part 16a of the member 16Y is detected as it passes the immediate front of the detection sensor 17.
  • the guiding member 12a of the contact/separation member 12 is moved and rotated, for example, by one revolution to activate the state shown in FIG. 4B . Accordingly, as shown in FIG. 5C , the photosensitive drum gear 10Y is separated from the small diameter gear 8b1 of the two-stage driving gear 8Y, while the intermediate transfer belt 4 is separated from the photosensitive drum 2Y. As a result, the photosensitive drum 2Y can be stopped at the reference rotational position.
  • the photosensitive drum 2Y is automatically separated from the intermediate transfer belt 4 as the photosensitive drum gear 10Y is separated from the small diameter gear 8b1 of the two-stage driving gear 8Y by the convex surfaces 12b2 of the guiding member 12a. Accordingly, it is possible to prevent damage on the front surface caused when the photosensitive drum 2Y comes into sliding contact with the intermediate transfer belt 4.
  • phase detection patterns 14 are transferred from the photosensitive drums 2Y, 2C, 2M, and 2K to the intermediate transfer belt 4 as shown in FIG. 6 .
  • An interval D between the phase detection patterns 14 is detected by the pattern detection means 15, thereby making it possible to detect phase shifts.
  • the reference positions of the photosensitive drums 2Y, 2C, 2M, and 2K in this manner it is possible to correct the reference positions of the photosensitive drums 2Y, 2C, 2M, and 2K in this manner.
  • the reference position of the black photosensitive drum 2K i.e., the stop position of the black photosensitive drum 2K in the color mode is caused to be shifted when the mode is switched between the color mode and the monochrome mode.
  • color shifts occur between color toner images and a black toner image.
  • the present invention makes it possible to reduce the downtime as much as possible so as to correct the color shifts in a short period of time.
  • the notched part 16a of the member 16 that is attached to the black photosensitive drum 2K is detected by the detection sensor 17, and the rotation stop position of the black photosensitive drum 2K in the color mode is stored in advance.
  • the black photosensitive drum 2K in the monochrome mode is controlled to be stopped at the same position as the rotation stop position of the black photosensitive drum 2K in the color mode. Accordingly, the rotation stop position of the black photosensitive drum 2K in the monochrome mode becomes the same as that in the color mode.
  • the reference positions of the photosensitive drums 2Y, 2C, 2M, and 2K in the color mode are matched with each other, thereby making it possible to prevent the color shifts between the color toner images and the black toner image.
  • FIG. 7A shows the reference position 16a1 of a member 16K to be detected that is attached to the rotational shaft 13K of the black photosensitive drum 2K and the position of the notched part 16a2 when the rotation of the black photosensitive drum 2K is stopped in the color mode.
  • FIG. 7B shows an arrangement relationship between the member 16K to be detected and the detection sensor 17.
  • time Ti since the immediately preceding rotational reference position 16a1 is calculated by a timer in accordance with a detection signal at the rotational reference position 16a1, and then it is stored.
  • the phase of the black photosensitive drum 2K is matched with the phases of the photosensitive drums 2Y, 2C, and 2M whose rotations are stopped in the color mode, thereby making it possible to prevent the positional shifts between the color toner images and the black toner image.
  • FIG. 8 is a diagram showing a schematic configuration of a control unit that controls the rotation stop position of the black photosensitive drum 2K when the printing mode is switched.
  • Reference numeral 33 denotes detection means including the member 16 that is attached to the black photosensitive drum 2K and the detection sensor 17.
  • Reference numeral 34 denotes the timer that calculates the time Ti from the immediately preceding rotational reference position 16a1 of the black photosensitive drum 2K to the rotation stop position 16a2.
  • Reference numeral 35 denotes storage means that stores the time Ti.
  • Reference numeral 36 denotes the control unit that controls photosensitive drum stopping means 37 that stops the rotation of the photosensitive drum 2K, photosensitive drum driving means 38 that starts and drives the rotation of the photosensitive drum 2K, and contact/separation member driving means 39 that operates the contact/separation member 12 to activate the states shown in FIGS. 4A through 4D .
  • Reference numeral 40 denotes mode switching means that switches the printing modes between the color mode and the monochrome mode.
  • Reference numeral 41 denotes photosensitive drum operations inputting means through which the rotation and stopping operations of the photosensitive drum 2K are input. Referring here to FIG. 9 , a description is made of the controlling of the rotation stop position of the black photosensitive drum 2K using the control unit 36.
  • FIG. 9 is a flowchart showing a method of controlling the rotation stop position of the black photosensitive drum 2K.
  • the driving motor (not shown) is rotated to drive and rotate the motor gear 6.
  • the two-stage driving gears 8K, 8M, 8C, and 8Y are rotated and driven through the coupling gears 7a, 7b, 7c, and 7d (step S1).
  • the control unit 36 determines whether the printing mode has been set to be the color mode based on a signal from the mode switching means 40 (step S2).
  • the control unit 36 determines and confirms that the contact/separation member 12 has been in the separation state 1 based on a signal from the contact/separation member driving means 39 and then performs the printing operation (step S3). Based on a stop operation signal from the photosensitive drum operations inputting means 41, the control unit 36 operates the photosensitive drum stopping means 37 to stop the rotation of the motor gear 6. At the same time, the timer 34 is operated based on a signal that the detection means 33 detects immediately before the rotation of the black photosensitive drum 2K is stopped so as to calculate the time Ti until the rotation is stopped, and then the time Ti stored in the storage means 35 is rewritten (overwritten with the new time Ti) (step S4). After this, the printing operation is terminated (step S5).
  • step S2 when the printing mode has not been set to be the color mode (NO) in step S2, the control unit 36 controls and drives the contact/separation member driving means 39 so that the contact/separation member 12 is in the separation state 4 based on a switching signal from the mode switching means 40 to switch to the monochrome mode (step S6). After it is confirmed that the contact/separation member driving means 39 has been driven to set the monochrome mode, the printing operation for black is performed (step S7).
  • control unit 36 controls the photosensitive drum stopping means 37 so that the rotation of the black photosensitive drum 2K is stopped when the time Ti elapses since the reference position detection signal based on a reference position detection signal detected immediately before the rotation of the black photosensitive drum 2K is stopped and the time Ti stored in step S4 (step S8).
  • the contact/separation member driving means 39 is operated to set the contact/separation member 12 to be in the separation state 1 (step S9). The printing operation is then terminated.
  • the rotation of the black photosensitive drum 2K is stopped at the position matching the rotation stop position of the black photosensitive drum 2K when the printing operation is performed in the color mode. Therefore, when the printing mode is next switched to the color mode, the color printing is performed with the reference positions of the photosensitive drums 2Y, 2C, 2M, and 2K matched with each other, thereby making it possible to prevent the occurrence of the positional shifts between the color toner images and the black toner image.
  • FIG. 10 describes a method of matching the phases of the photosensitive drums 2Y, 2C, 2M, and 2K with each other.
  • phase matching control is started to set the contact/separation member 12 to be in the separation state 1 (step S11).
  • the photosensitive drum gears 10Y, 10C, 10M, and 10K set to be in the separation state 1 are meshed with the two-stage driving gears 8Y, 8C, 8M, and 8K to rotate the photosensitive drums 2Y, 2C, 2M, and 2K.
  • the respective colors of the phase detection patterns 14 are transferred to the intermediate transfer belt 4 (step S12).
  • the phase detection patterns 14 thus formed on the intermediate transfer belt 4 are detected by the pattern detection means 15 (step S13), and then an optimum phase difference is calculated based on a detected signal (step S14).
  • the contact/separation member 12 is set to be in the separation state 4 (step S15) to match the phase of the photosensitive drum 2K with the phase of the photosensitive drum 2M (step S16).
  • the contact/separation member 12 is set to be in the separation state 3 (step S17) to match the phase of the photosensitive drum 2K with the phase of the photosensitive drum 2C (step S18).
  • the contact/separation member 12 is set to be in the separation state 2 (step S19) to match the phase of the photosensitive drum 2K with the phase of the photosensitive drum 2Y (step S20).
  • the time Ti from the rotational reference position 16a1 to the rotation stop position is measured by the detection means 33 attached to the black photosensitive drum 2K, and then the time Ti stored in the storage means 35 is rewritten and stored again (step S21).
  • the phase matching control is performed when the photosensitive drums 2Y, 2C, 2M, and 2K are replaced in the image forming apparatus.
  • FIG. 11 shows a flowchart of the phase matching control.
  • the photosensitive drums 2Y, 2C, 2M, and 2K are provided with an IC tag (not shown) in which an identification number is embedded.
  • the apparatus main body 100 is provided with communication means (not shown) that reads the information items of the IC tags of the photosensitive drums 2Y, 2C, 2M, and 2K. Based on the information items of the IC tags of the photosensitive drums 2Y, 2C, 2M, and 2K, it is determined whether the photosensitive drums 2Y, 2C, 2M, and 2K have been replaced.
  • step S30 it is determined whether the door of the apparatus main body 100 has been opened.
  • step S31 it is determined whether a control open flag exists.
  • step S31 a flow after step S30 is repeated.
  • step S32 the control open flag is set (step S32) and the flow after step S30 is repeated.
  • step S33 it is determined whether the control open flag exists.
  • the open flag does not exist, it is determined that the photosensitive drums 2Y, 2C, 2M, and 2K (the process cartridges 1Y, 1C, 1M, and 1K) have not been removed and replaced. Then, the flow after step S30 is repeated.
  • step S34 communication with the IC tags of the photosensitive drums 2Y, 2C, 2M, and 2K is performed (step S34). Then, it is determined whether the identification numbers read from the IC tags match the identification numbers stored in the memory of the control section (not shown) of the image forming apparatus (step S35).
  • step S36 a solenoid (not shown) as moving means is operated based on the detection result of the pattern detection means 15 as phase difference detection means to adjust the phase differences of the driving speed fluctuations of the photosensitive drums 2Y, 2C, 2M, and 2K.
  • the control open flag is deleted (step S37). After this, the identification numbers in the memory of the apparatus main body are rewritten, and then the flow is terminated.
  • step S35 when these identification numbers match each other in step S35, it is determined that the photosensitive drums 2Y, 2C, 2M, and 2K (the process cartridges 1Y, 1C, 1M, and 1K) have not been replaced. Accordingly, the flow is terminated after steps S37 and S38 without performing the phase matching control.
  • the positional shifts of plural toner images formed on the intermediate transfer belt 4 in a superposed manner are corrected every time the photosensitive drums 2Y, 2C, 2M, and 2K (the process cartridges 1Y, 1C, 1M, and 1K) are replaced. Therefore, it is possible to provide a color image without causing color shifts at all times.
  • the development units 20Y, 20C, 20M, and 20K are integrally attached to the photosensitive drums 2Y, 2C, 2M, and 2K, respectively.
  • the development units 20Y, 20C, 20M, and 20K are moved up and down while a positional relationship between the photosensitive drums 2Y, 2C, 2M, and 2K and the development units 20Y, 20C, 20M, and 20K, i.e., a separation distance between the peripheries of the photosensitive drums 2Y, 2C, 2M, and 2K and the development units 20Y, 20C, 20M, and 20K is maintained.
  • the positional relationship between the photosensitive drums 2Y, 2C, 2M, and 2K and the development units 20Y, 20C, 20M, and 20K is maintained to be constant even if the photosensitive drums 2Y, 2C, 2M, and 2K are separated from the intermediate transfer belt 4 at the time of the phase matching control.
  • the separation direction of the photosensitive drums 2Y, 2C, 2M, and 2K from the intermediate transfer belt 4 at the time of the phase matching control is matched with the removing direction (upward direction) of the photosensitive drums 2Y, 2C, 2M, and 2K or the process cartridges 1Y, 1M, 1C, and 1K from the apparatus main body 100. Therefore, it is possible to remove and assemble the photosensitive drums 2Y, 2C, 2M, and 2K or the process cartridges 1Y, 1M, 1C without changing the contact position between the contact/separation member 12 and the rotational shafts 13Y, 13C, 13M, and 13K of the photosensitive drums 2Y, 2C, 2M, and 2K. In this case, the process cartridges 1Y, 1C, 1M, and 1K are removed in the upward direction after the optical scanning unit 3 arranged above the process cartridges 1Y, 1C, 1M, and 1K is removed.
  • the detection means that detects the removals of the photosensitive drums 2Y, 2C, 2M, and 2K or the process cartridges 1Y, 1C, 1M, and 1K from the apparatus main body 100, it is possible to avoid the phase matching control when the photosensitive drums 2Y, 2C, 2M, and 2K or the process cartridges 1Y, 1C, 1M, and 1K are removed from the apparatus main body 100.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Color Electrophotography (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Electrophotography Configuration And Component (AREA)

Claims (12)

  1. Bilderzeugungsvorrichtung, umfassend
    mehrere lichtempfindliche Farbtrommeln (2Y, 2C, 2M), die linear parallel zueinander angeordnet sind und auf denen chromatische Tonerbilder gebildet werden sollen,
    eine lichtempfindliche Schwarztrommel (2K), auf der ein schwarzes Tonerbild gebildet werden soll,
    Zahnräder für Farbe (10Y, 10C, 10M), die konzentrisch zu den lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) angeordnet und mit den lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) gekoppelt sind, um zusammen mit diesen gedreht zu werden,
    ein Zahnrad für Schwarz (10K), das konzentrisch zur lichtempfindlichen Schwarztrommel (2K) angeordnet und mit der lichtempfindlichen Schwarztrommel (2K) gekoppelt ist, um zusammen mit dieser gedreht zu werden,
    Antriebszahnräder (6, 7a-d, 8Y, 8C, 8M, 8K) und eine Antriebsquelle;
    wobei die Bilderzeugungsvorrichtung dazu konfiguriert ist, Folgendes auswählen zu können:
    einen Farbmodus, in dem verschiedene Farben der chromatischen Tonerbilder auf den lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) gebildet werden, die zusammen mit den Zahnrädern für Farbe (10Y, 10M, 10M) gedreht und angetrieben werden, wobei das schwarze Tonerbild auf der lichtempfindlichen Schwarztrommel (2K) gebildet wird, die zusammen mit dem Zahnrad für Schwarz (10K) gedreht und angetrieben wird, und wobei die chromatischen Tonerbilder und das schwarze Tonerbild auf eine überlagerte Art und Weise an ein Übertragungselement (4) übertragen werden, so dass ein Farbbild erhalten wird, und
    einen monochromen Modus, in dem das schwarze Tonerbild auf der lichtempfindlichen Schwarztrommel (2K) gebildet wird, die zusammen mit dem Zahnrad für Schwarz (10K) gedreht und angetrieben wird, nachdem die Zahnräder für Farbe (10Y, 10C, 10M) und die lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) angehalten werden und nur das schwarze Tonerbild an das Übertragungselement (P) übertragen wird, um ein schwarzes Bild zu erhalten; wobei:
    die Zahnräder für Farbe (10Y, 10C, 10M) der lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) mit den entsprechenden Antriebszahnrädern (8Y, 8C, 8M), die mit der zu drehenden Antriebsquelle gekoppelt sind und davon angetrieben werden, in Eingriff gebracht werden können, und sie dazu eingerichtet sind, Drehungen der lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) anzuhalten, wenn die Zahnräder für Farbe (10Y, 10C, 10M) sich in einem nicht-eingreifenden Zustand befinden, nachdem sie von den Antriebszahnrädern (8Y, 8C, 8M) getrennt wurden,
    die Bilderzeugungsvorrichtung ein Mittel zum Berühren/Trennen (12) aufweist, das die Zahnräder für Farbe (10Y, 10C, 10M) so bewegt, dass sie sich in Bezug auf die entsprechenden Antriebszahnräder (8Y, 8C, 8M) im eingreifenden Zustand oder im nicht-eingreifenden Zustand befinden,
    ein Mittel zum Erkennen einer Drehposition (16) in der lichtempfindlichen Schwarztrommel bereitgestellt ist und eine Drehposition der lichtempfindlichen Schwarztrommel (2K) erkennt, wobei das Mittel zum Erkennen einer Drehposition (16) die Anhalteposition der Drehung der lichtempfindlichen Schwarztrommel (2K) im Farbmodus erkennt und speichert, und
    eine Steuereinheit (36) im monochromen Modus die lichtempfindliche Schwarztrommel (2K) dazu steuert, an derselben Position angehalten zu werden wie die gespeicherte Anhalteposition der Drehung der lichtempfindlichen Schwarztrommel (2K) im Farbmodus; gekennzeichnet dadurch, dass:
    das Mittel zum Berühren/Trennen (12) eine Führungsfläche (12b) aufweist, auf der abwechselnd eine konvexe Oberfläche (12b2), die die Zahnräder für Farbe (10Y, 10C, 10M) der lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) nach oben schiebt, so dass sie sich in Bezug auf die Antriebszahnräder (8Y, 8C, 8M) in einem nicht-eingreifenden Zustand befinden, und eine konkave Oberfläche (12b1) angeordnet ist, auf der die Zahnräder für Farbe (10Y, 10C, 10M) nach unten gedrückt werden, so dass sie sich in Bezug auf die Antriebszahnräder (8Y, 8C, 8M) im eingreifenden Zustand befinden, und
    die Bilderzeugungsvorrichtung weiter ein Antriebsmittel (11) aufweist, das das Mittel zum Berühren/Trennen (12) in eine Anordnungsrichtung der lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) bewegt, wobei das Antriebsmittel (11) das Mittel zum Berühren/Trennen (12) dazu steuert, in die Anordnungsrichtung der lichtempfindlichen Trommeln (2Y, 2C, 2M) bewegt zu werden, so dass die Zahnräder für Farbe (10Y, 10C, 10M) im monochromen Modus von der konvexen Oberfläche (12b2) nach oben geschoben und von den Antriebszahnrädern (8Y, 8C, 8M) getrennt werden, um sich im nicht-eingreifenden Zustand zu befinden, und das Mittel zum Berühren/Trennen (12) dazu zu steuern, in die Anordnungsrichtung der lichtempfindlichen Trommeln (2Y, 2C, 2M) bewegt zu werden, so dass die Zahnräder für Farbe (10Y, 10C, 10M) im Farbmodus nach unten zur konkaven Oberfläche (12b1) gedrückt werden, um sich im eingreifenden Zustand zu befinden.
  2. Bilderzeugungsvorrichtung nach Anspruch 1, gekennzeichnet dadurch, dass
    die Antriebsquelle ein Antriebsmotor ist, von dem die Zahnräder für Farbe (10Y, 10C, 10M) und das Zahnrad für Schwarz (10K) angetrieben und gedreht werden.
  3. Bilderzeugungsvorrichtung nach Anspruch 1 oder 2, gekennzeichnet dadurch, dass
    die den Zahnrädern für Farbe (10Y, 10C, 10M) entsprechenden Antriebszahnräder (8Y, 8C, 8M) und die Antriebsquelle von mehreren anderen Kopplungszahnrädern (6, 7a-d) angetrieben und gekoppelt werden.
  4. Bilderzeugungsvorrichtung nach Anspruch 1, 2 oder 3, gekennzeichnet dadurch, dass
    die lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) und die lichtempfindliche Schwarztrommel (2K) linear parallel zueinander angeordnet sind und die chromatischen Tonerbilder und das schwarze Tonerbild, die auf den lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) beziehungsweise der lichtempfindlichen Schwarztrommel (2K) gebildet wurden, jeweils an ein Endlosband (4) übertragen werden, das parallel zur Anordnungsrichtung der lichtempfindlichen Trommeln (2Y, 2C, 2M, 2K) angeordnet ist und unendlich in die Anordnungsrichtung bewegt wird.
  5. Bilderzeugungsvorrichtung nach Anspruch 4, gekennzeichnet dadurch, dass
    das Mittel zum Berühren/Trennen (12) so angeordnet ist, dass die entsprechenden lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) zur gleichen Zeit vom Endlosband (4) getrennt werden, zu der die Zahnräder für Farbe (10Y, 10C, 10M) der lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) von den entsprechenden Antriebszahnrädern (8Y, 8C, 8M) getrennt werden, was zur Folge hat, dass die Trennungsrichtung der Zahnräder (10Y, 10C, 10M) für Farbe von den Antriebszahnrädern (8Y, 8C, 8M) dieselbe ist wie die Trennungsrichtung der lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) vom Endlosband (4).
  6. Bilderzeugungsvorrichtung nach einem der Ansprüche 1 bis 5, gekennzeichnet dadurch, dass
    wenn der Drehzyklus der Zahnräder für Farbe (10Y, 10C, 10M) als T und ein Winkel zwischen einer Belichtungsposition und einer Übertragungsposition eines Tonerbilds der lichtempfindlichen Trommel (2Y, 2C, 2M) als α dargestellt wird, die Anzahl der Zähne der Antriebszahnräder (8Y, 8C, 8M), die den Zahnrädern für Farbe (10Y, 10C, 10M) entsprechen, so eingestellt ist, dass der Drehzyklus T2 der Antriebszahnräder (8Y, 8C, 8M) durch T2 = T x (α/360)/N ausgedrückt wird, wobei N eine ganze Zahl ist.
  7. Bilderzeugungsvorrichtung nach einem der Ansprüche 1 bis 6, gekennzeichnet dadurch, dass
    die Zahnräder für Farbe (10Y, 10C, 10M) von derselben Form geformt sind.
  8. Bilderzeugungsvorrichtung nach einem der Ansprüche 1 bis 7, gekennzeichnet dadurch, dass
    die lichtempfindlichen Farbtrommeln (2Y, 2C, M) ein Mittel zum Erkennen von Drehpositionen (16) aufweisen, das Drehpositionen der lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) erkennt.
  9. Bilderzeugungsvorrichtung nach einem der Ansprüche 1 bis 8, gekennzeichnet dadurch, dass
    die lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) integral mit entsprechenden Entwicklungseinheiten (20Y, 20C, 20M) gekoppelt sind und die Entwicklungseinheiten (20Y, 20C, 20M) zusammen mit den lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) bewegt werden, die dann bewegt werden, wenn die Zahnräder für Farbe (10Y, 10C, 10M) von den Antriebszahnrädern (8Y, 8C, 8M) getrennt werden.
  10. Bilderzeugungsvorrichtung nach einem der Ansprüche 1 bis 9, gekennzeichnet dadurch, dass
    die lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) entfernbar an einem Hauptkörper (100) der Bilderzeugungsvorrichtung angebracht sind.
  11. Bilderzeugungsvorrichtung nach Anspruch 10, gekennzeichnet dadurch, dass
    die Entfernungsrichtung der lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) von dem Hauptkörper (100) der Bilderzeugungsvorrichtung und die Trennungsrichtung der Zahnräder für Farbe (10Y, 10C, 10M) von den Antriebszahnrädern für Farbe (8Y, 8C, 8M) dieselben sind.
  12. Bilderzeugungsvorrichtung nach Anspruch 10 oder 11, gekennzeichnet dadurch, dass die lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) ein Mittel zum Erkennen (534) aufweisen, das das Entfernen der lichtempfindlichen Farbtrommeln (2Y, 2C, 2M) erkennt.
EP08252838.1A 2007-09-14 2008-08-28 Bilderzeugungsvorrichtung Expired - Fee Related EP2037328B1 (de)

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JP3324714B2 (ja) * 1993-12-24 2002-09-17 株式会社東芝 感光ドラム駆動機構
JP3186559B2 (ja) * 1995-12-25 2001-07-11 カシオ電子工業株式会社 画像形成装置
JPH1184799A (ja) * 1997-09-05 1999-03-30 Casio Electron Mfg Co Ltd 画像形成装置
JP3496566B2 (ja) 1999-03-29 2004-02-16 ミノルタ株式会社 画像形成装置
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JP2004347781A (ja) * 2003-05-21 2004-12-09 Ricoh Co Ltd 画像形成装置
JP2005070596A (ja) * 2003-08-27 2005-03-17 Ricoh Co Ltd 画像形成装置
JP2006078851A (ja) * 2004-09-10 2006-03-23 Canon Inc カラー画像形成装置、その調整方法およびソフトウエア
JP4622524B2 (ja) * 2005-01-07 2011-02-02 ブラザー工業株式会社 画像形成装置
JP4586726B2 (ja) * 2005-12-27 2010-11-24 ブラザー工業株式会社 画像形成装置
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