JP4716405B2 - Photosensitive drum rotation drive device and image forming apparatus - Google Patents

Description

The present invention is a copying machine, a printer, a facsimile or the rotary drive of the photosensitive drum to be mounted in their functions to the image forming apparatus in complex,及 beauty, an image forming apparatus This is is mounted.

  In the image forming apparatus, when a DC brushless motor (DCBLM) is used for driving the photosensitive drum, the stop accuracy of DCBLM is not as accurate as that of the stepping motor (STM) and may be violated by a load or the like. Therefore, the phase shift is corrected by controlling the phase alignment based on the number of stops for the stop position shift caused thereby. However, when the number of phase alignments increases, the number of times that a waiting time (WAIT time) occurs increases accordingly.

  Therefore, the present invention uses the fact that the deviation of the stop position differs in each mode (monochrome, color, high image quality, etc.), makes the count of the number of stops variable in each mode, reduces the number of corrections, and reduces the number of occurrences of WAIT time. The purpose is to reduce the color shift caused by the shift of the stop position due to the phase adjustment.

  In addition, by making the photosensitive drum detachable, the operability and service maintenance are improved, and the fact that the stop position shift is different in each mode (monochrome, color, high image quality, etc.) An object is to make the count variable in each mode, to reduce the number of times and to reduce the number of occurrences of WAIT time, and to prevent color misregistration caused by deviation of the stop position by phase matching.

The rotation driving device for a photosensitive drum according to the present invention uses a DC brushless motor for driving the photosensitive drum, and the rotation driving device in which the photosensitive drum for black and the photosensitive drum for color are separately driven. Because
In order to correct the deviation of the stop positions of the black and color photosensitive drums caused by the stop accuracy of the DC brushless motor being inaccurate, the rotation of the black and color photosensitive drums is stopped. In the rotary drive device that performs correction control to match the phases of the black and color photoconductive drums according to the number of times of stoppage ,
A control means for performing the correction control to determine the count by the number of stops stopping the photosensitive drum for the color black-by the count for the phasing of the photosensitive drum for color and one for the black Have
In order to reduce the number of times of the correction control by the control means , the control means counts the stop times of the black and color photosensitive drums in various image forming modes such as monochrome, color, and high accuracy . It is variable according to the difference in the amount of deviation of the stop position of the black and color photosensitive drums .

An image forming apparatus according to the present invention includes the photosensitive drum rotation driving device according to claim 1 .

  According to the present invention, it is possible to reduce the number of stop times for correction to reduce the number of occurrences of WAIT time, and to prevent color misregistration that occurs due to misalignment of the stop position by phase matching.

According to the present invention, by a detachable photosensitive drum, operability, improve service maintenance, and to vary the count of number of stops monochrome, color, each seed image forming mode such as a high-precision Thus, the number of corrections can be reduced, the number of times of waiting ( WAIT ) time can be reduced, and color misregistration caused by deviation of the stop position can be prevented by phase matching.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  FIG. 1 is a schematic cross-sectional view showing a configuration of a tandem type image forming apparatus according to an embodiment of the present invention, and includes a photoreceptor driving device according to the present invention. The illustrated image forming apparatus is configured as a printer, and includes four photosensitive drums 1 in the apparatus main body 10 (specifically, 1Bk, 1Y, 1C, 1M: Bk is black, Y is yellow, C is cyan, and M is magenta). A magenta toner image, a cyan toner image, a yellow toner image, and a black toner image are respectively formed on the photosensitive drum 1. Further, a recording material conveyance belt 11 is disposed opposite to the photosensitive drum 1, and this recording material conveyance belt 11 is wound around a plurality of support rollers 12 and is driven to run in the direction of arrow A in the figure. It has become so.

  FIG. 2 is slightly different from the contents shown in FIG. 1 such as top and bottom, left and right, and order of arrangement, but the photosensitive drum 1 (1Bk, 1Y, 1C, 1M) and the recording material transport belt 11 in the tandem color image forming apparatus. And an example of a structure of the roller 12 (12a-12f) is shown. In the figure, 12a is an entrance roller, 12b is a secondary transfer roller, 12c is a driving roller, 12d is a cleaning facing roller, 12e is a brush roller, 12f is a primary transfer roller, and the primary transfer roller 12f is a photosensitive drum 1 (1Bk, 1Y, 1C, 1M).

  FIG. 3 is a schematic sectional view showing a configuration of an image forming apparatus according to another embodiment of the present invention. The image forming apparatus shown here is configured as a copying machine, and has one photosensitive drum 1 in the apparatus main body 20.

  FIG. 4 is a schematic view showing a configuration of the process cartridge 200 including the photosensitive drum 1, and is a substantially central sectional view. A photosensitive drum unit 100 including a rear flange and the like on the photosensitive drum 1 is detachable along a drive shaft in a state where a regulating member (face plate) (not shown) is removed. Members and units related to image formation are integrally formed on the photosensitive drum 1 and can be attached and detached along the drive shaft. The unit including the photosensitive drum 1 shown in FIG. 4 integrates a process cartridge 200 by integrating a cleaning unit 8 and a charging unit 9 for cleaning the surface of the photosensitive drum 1 with the photosensitive drum unit as a member related to the image formation. It is composed.

  For example, in the example shown in FIG. 5, in addition to the cleaning means 8 and the charging means 9 for cleaning the surface of the photosensitive drum unit, the developing means 5 is integrated with the photosensitive drum unit as a member related to image formation, and the process cartridge 300 is assembled. Can be configured.

  6 and 7 are cross-sectional views for explaining the drive system of the process cartridge as described above. A flange 6 as another member is assembled in the end opening of the photosensitive drum 1 which is a rotating body in the process cartridge, and a groove 6a extending in the axial direction at a predetermined pitch in the circumferential direction on the inner peripheral surface of the flange. Is provided. Also, a joint 7 is assembled to the drive shaft 2 of the drive train of the machine body, and the joint 7 is provided with claws 7a at a predetermined pitch in the circumferential direction on the surface facing the photosensitive drum 1 side. The groove 6a and the claw 7 are coupled by coupling, and a driving force is transmitted from the motor 4 of the machine body to the photosensitive drum 1.

  In the various apparatuses configured as described above, the black photosensitive drum 1Bk is driven by one drive motor (not shown), and the remaining three color photosensitive drums 1Y, 1C, and 1M are driven by another drive. When operated by a motor (not shown) (output gears 13Bk and 13Y of the drive motor; 13i in the figure is an idler gear), as shown in FIG. 8A, Bk and Y photosensitive drums 1Bk and 1Y. The large-diameter drum gear DG (Bk to M) provided in the motor is configured to be engaged with the output gears 13Bk and 13Y and driven, and this driving is detected using the photo interrupter 14 as shown in FIG. 8B. Try to have a system.

In this drive system, if there is a shift amount (a stop position shift angle in the illustrated example ) as shown in FIG. 9A in various image forming modes such as monochrome, color, and high accuracy due to the above-described causes . Then, as shown in FIG. 9B, the count of the number of stops is changed depending on the difference in deviation.

Ie, by utilizing the fact that the deviation of stop positions are different in each mode (monochrome, color, quality, etc.), if the variable counting the number of stops in each mode, WAIT to reduce the number of stops for correction The number of occurrences of time can be reduced. In addition, it is possible to prevent color misregistration caused by the shift of the stop position by phase matching.

1 is a schematic cross-sectional view showing a configuration of a tandem type image forming apparatus according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of a configuration of a photosensitive drum, a recording material conveyance belt, and a roller in a tandem color image forming apparatus. Schematic sectional view showing the configuration of an image forming apparatus according to another embodiment of the present invention. Schematic diagram showing the configuration of a process cartridge including a photosensitive drum Schematic showing another configuration of a process cartridge including a photosensitive drum Sectional drawing for demonstrating the drive system of a process cartridge Sectional drawing for demonstrating the drive system of a process cartridge The figure which shows the drive detection system in the process cartridge of FIG. FIG. 6 is a diagram illustrating an example of control in the drive system of the photosensitive drum illustrated in FIGS.

Explanation of symbols

1 (1Bk, 1Y, 1C, 1M) Photosensitive drum 2 Drive shaft 4 Motor 5 Developing means 6 Flange 6a Groove 7 Joint 7a Claw 8 Cleaning means 9 Charging means 10 Device body 11 Recording material conveying belt 12 (12a to 12f) Support Roller 13Bk, 13Y Drive motor output gear 13i Idler gear 14 Photointerrupter 20 Device body 100 Photosensitive drum unit 200 Process cartridge 300 Process cartridge DG Large diameter drum gear

Claims (2)

A rotary drive device that uses a DC brushless motor to drive the photosensitive drum, and the photosensitive drum for black and the photosensitive drum for color are separately driven,
In order to correct the deviation of the stop positions of the black and color photosensitive drums caused by the stop accuracy of the DC brushless motor being inaccurate, the rotation of the black and color photosensitive drums is stopped. In the rotary drive device that performs correction control to match the phases of the black and color photoconductive drums according to the number of times of stoppage ,
A control means for performing the correction control to determine the count by the number of stops stopping the photosensitive drum for the color black-by the count for the phasing of the photosensitive drum for color and one for the black Have
In order to reduce the number of times of the correction control by the control means , the control means counts the stop times of the black and color photosensitive drums in various image forming modes such as monochrome, color, and high accuracy . A photosensitive drum rotation driving device, wherein the photosensitive drum is varied in accordance with a difference in a shift amount of a stop position of the black and color photosensitive drums . An image forming apparatus comprising the photosensitive drum rotation driving device according to claim 1.