JP2003280322A - Color image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color image forming apparatus where uneven rotation at an image formation part is restrained as far as possible. <P>SOLUTION: A motor is provided in each unit. In the case of a black unit K where a black toner image is formed and transferred to an intermediate transfer body or paper, for example, the motor 2 is disposed in the black unit K so as to form a driving line from the motor 2 to a photoreceptor drum 6, a rubbing roller 7 and a developing roller 8, and a driving line from the motor 2 to an MG roller 3, a mixer 4 and a toner container 5. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention
The present invention relates to a color image forming apparatus such as an X or a copying machine, and more particularly to a color image forming apparatus in which a plurality of units each integrating a photosensitive drum and a developing unit are arranged. 2. Description of the Related Art In a conventional color image forming apparatus, yellow (Y), magenta (M), and cyan (C) toners using four units each integrating a photosensitive drum and a developing device are used. , Black (K). For driving each unit, a motor is attached to the main body of the color image forming apparatus, and connected to each unit by a gear, a belt, a shaft joint, or the like, thereby transmitting the drive of the motor. More specifically, as shown in FIG. 4, each of a yellow unit Y, a magenta unit M, a magenta unit M, and a black unit K uses a motor 12 of a color image forming apparatus as a drive source. Power is transmitted. For example, the black unit K includes a drive system of the photosensitive drum 16, the rubbing roller 17, and the waste toner conveying screw 19 from the motor 12, a developing roller 18, an MG roller 13, and a mixer in the developing device. 14, a drive system of the toner container 15. [0004] However, in the conventional color image forming apparatus, a motor is mounted on the apparatus main body, and each unit is driven via a gear, a belt, or a shaft joint. The motor to be driven must be arranged in a positional relationship distant from the unit via gears and the like, and it is necessary to maintain a constant center-to-center distance in order to sufficiently exhibit the performance of the gear to reduce rotation errors However, there has been a problem that the accuracy is difficult to obtain due to accumulated errors between the units as replacement parts. In addition, when each unit receives drive from the motor of the apparatus main body, a biased moment is applied to each unit, so that the rigidity of each unit itself is also required excessively, and the positional accuracy of the parts and the like supported by this unit is reduced. There is a problem that variations occur, which is the largest factor that causes errors, and leads to deterioration of image reproducibility. Further, there is a problem that the load of the motor itself of the apparatus body is large, and a motor having a large output is required. Further, when a developing device is integrated into the unit to save space, and a developer stirring mechanism is provided in the developing device, differences in stirring resistance, such as the amount and unevenness of the powdery developer, impose a load. Periodic or aperiodic fluctuations occur, and the parts fluctuate with each other, so that a considerable amount of rotation error or the like occurs in the image forming unit, which may have an adverse effect on image formation. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and comprises a plurality of units each having a photosensitive drum and a developing unit integrated therein. In a color image forming apparatus in which a motor serving as a drive source is disposed for each unit, a color image in which the drive source of the motor is transmitted to the image forming unit and the drive to the toner stirring unit in different systems is transmitted. It is a forming device. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows each unit of a yellow unit Y, a magenta unit M, a cyan unit C, and a black unit K which are detachably attached to a tandem type color printer which is a color image forming apparatus of the present invention. Yellow on body and paper, etc.
By forming each of magenta, cyan, and black toners, color printing can be performed. The present invention is characterized in that a motor is formed in each unit. In the case of the black unit K, for example, the motor 2 in the unit transfers the photosensitive drum 6, the rubbing roller 7, and the developing roller 8 to each other. And a drive train for the MG roller 3, the mixer 4, and the toner container 5 are formed. By arranging the motor 2 in each unit as described above, it is possible to sufficiently cope with a low output motor.
The drive configuration is simple, rotation unevenness due to positioning with the printer body does not occur, and the backlash between the motor 2 and the gear does not vary due to the same unit. It is less likely to be scratched. Further, a large number of precision gears are not required in the drive train, which leads to cost reduction. Also, since the drive train is completed in each unit,
There is no load fluctuation such as paper feeding or fixing. The rubbing roller 7 is a roller that polishes the photosensitive drum 6 by rubbing the photosensitive drum 6 with residual toner on the photosensitive drum 6 formed on the roller surface. This is similar to the rubbing roller disclosed in Japanese Patent No. 2922050. The developing roller 8 and the MG roller 3 are similar to the developing roller and the magnetic roller disclosed in Japanese Patent Application No. 2001-206331, for example. A roller serving as an image forming unit for developing the electrostatic latent image on the body drum 6;
The MG roller is a roller serving as an agitator that supplies only toner to the developing roller 8 by generating a magnetic brush with a carrier included in the developer by a magnet disposed inside the sleeve. The mixer 4 stirs the developer in the developing device, and the toner container 5 stores the toner and appropriately replenishes the toner in the developing device, and may have a conventionally known configuration. . In this embodiment, the case where the rubbing roller 7 is used has been described. However, a cleaning roller such as a fur brush may be used. Further, in the present embodiment, M
Although the developing device using the G roller 3 and the developing roller 8 has been described, the developing roller 8 is a normal developing roller which does not constitute the MG roller 3 but is a rotatable sleeve having a magnet therein. Is also good. FIG. 2 is a perspective view showing the internal structure of the black unit K. As shown in FIG. 2, by disposing the motor 2 above the black unit K, the motor 2
, So that the black unit K is less likely to be directly affected by the heat generation. In FIG. 2, the toner container 5 is omitted. FIG. 3 is a diagram showing a drive sequence of the black unit K. According to the present invention, an image is formed from a low-load high-speed rotation output shaft of the motor 2 (above the motor of each unit in FIG. 1)
It is also characterized in that the drive train is distributed to the agitating portion (below the motor of each unit in FIG. 1). Specifically, the light is transmitted from the motor 2 to the photosensitive drum 6, which is an image forming part, and then transmitted to the developing roller 8, the rubbing roller 7, and the waste toner conveying screw 9, while being stirred via the relay gear 2a. To the mixer 4, which is the
To communicate. The waste toner conveying screw 9
Is a screw for transporting the residual toner not transferred to the intermediate transfer member or the paper to the collection container. As described above, by dividing the drive system of the image forming portion and the drive system of the stirring portion, it is possible to prevent the influence of the load fluctuation of the stirring portion from directly affecting the image forming portion. Further, in the drive sequence, the rotation unevenness of the photosensitive drum 6 immediately becomes a horizontal line image unevenness, so that the drive series of the photosensitive drum 6 is most susceptible to the influence of the rotation unevenness on the image. The larger the gear, the more stable it is. However, the smaller the gear, the harder it is to obtain accuracy, the weaker the strength, and the more likely it is to generate rotational waste. Here, the rubbing roller 7 and the developing roller 8
Gear must be small, and the torque of each roller is low. For this reason, it is preferable that the photosensitive drum 6 be directly connected from the motor 2 without the intervention of a gear or the like. In this embodiment, the photosensitive drum 6 is transmitted from the motor 2 to the rubbing roller 7 and the developing roller 8 via the photosensitive drum 6. It is preferred that As described above, according to the color image forming apparatus of the present invention, the motor serving as the drive source of the unit is provided for each unit, so that the rotation unevenness of the image forming portion is minimized. Thus, it is possible to provide a color image forming apparatus that prevents color shift, jitter, bumping, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration block diagram showing each unit in a color image forming apparatus of the present invention. FIG. 2 is a perspective view showing the inside of the unit. FIG. 3 is a diagram showing a drive sequence in a unit. FIG. 4 is a configuration block diagram illustrating a conventional color image forming apparatus. [Description of Signs] 2, 12: Motor 3, 13: MG roller 4, 14: Mixer 5, 15: Toner container 6, 16: Photoconductor drum 7, 17: Rubbing roller 8, 18: Developing roller 9, 19 : Waste toner transport screw Y, M, C, K, 11: Unit

   ────────────────────────────────────────────────── ─── Continuation of front page    F-term (reference) 2H035 CA07 CB04 CG03                 2H171 FA02 FA04 GA04 GA08 JA23                       JA29 JA31 JA34 LA05 LA08                       QA04 QA08 QA13 QB32 QB38                       QC23 QC26 QC42 WA12 WA23                 2H300 EA05 EB04 EB07 EB12 EJ09                       EJ22 EJ26 EJ51 EL02 EL03                       EL08 GG01 GG02 GG03 GG11                       GG25 GG34 GG38 HH32 HH35                       TT04

Claims (1)

Claims: 1. A color image comprising: a plurality of units each having a photosensitive drum and a developing unit integrated therein; and a motor serving as a drive source for the units arranged for each unit. A color image forming apparatus, wherein the driving source of the motor is transmitted to the image forming unit and the toner agitating unit in different systems.