KR20070116428A - Photoreceptor cartridge - Google Patents

Abstract

A photosensitive drum cartridge is provided to prevent the breakage of power transmission components when the photosensitive drum cartridge is mounted in a length direction of a photosensitive drum, have a simple structure, and reduce an installation space. A photosensitive drum has a cylindrical sleeve and a pair of flanges. A photosensitive layer is formed in the cylindrical sleeve. A pair of the flanges are inserted into both end parts of the sleeve. One shaft(610) is a rotary shaft of the photosensitive drum. The shaft(610) and a pair of the flanges are located on the same shaft along a length direction of the photosensitive drum. The photosensitive drum is rotated by the driving of the shaft(610).

Description

Photosensitive drum cartridge {Photoreceptor cartridge}

1 is a side view showing a conventional photosensitive drum cartridge.

Figure 2 is a plan view showing an assembly method of a conventional photosensitive drum.

Figure 3 is a side cross-sectional view showing various embodiments of the power transmission member in the conventional photosensitive drum.

Figure 4 is a perspective view showing the operation of attaching and detaching the photosensitive drum cartridge of the image forming apparatus main body of the present invention.

5 is a perspective view of a shaft of the present invention.

Figure 6 is a side view showing an assembled state of the photosensitive drum of the present invention.

Figure 7 is a side view showing a housing and a shaft inserted therein of the present invention.

Figure 8 is a side cross-sectional view showing a fastening state of the pin and the hook in the photosensitive drum of the present invention.

<Explanation of symbols for the main parts of the drawings>

500 ... Imager main body 510 ... slot

600 ... photosensitive drum cartridge 610 ... shaft

612 ... pin hole 614 ... coupling insert

620 ... pin 630 ... bush

640 ... shaft coupling 643 ... shaft insert

645 body coupling 647 coupling gear

649 Gear 650 Housing

651 ... Charge Roller Retainer 655 ... Bush Retainer

656 ... pin penetrations 690 ... charge roller

700 ... sleeve 710,720 ... flange

721 ... shaft hole 722 ... hook portion

The present invention relates to a photosensitive drum cartridge, and more particularly, to a photosensitive drum cartridge detachably provided to a main body of an electrophotographic image forming apparatus and having improved assembly tolerance.

An electrophotographic image forming apparatus such as a printer or a copying machine is an apparatus for printing an image on a printing medium by an electrophotographic process. In the electrophotographic image forming apparatus, an electrostatic latent image is formed on the outer periphery of the photosensitive drum, and the electrostatic latent image is developed into a toner image by a developing roller. The photosensitive drum cartridge may include a charging roller, a developing roller, a toner storage unit, etc. according to the type of the image forming apparatus as well as the photosensitive drum, and may be detachably installed on the main body of the image forming apparatus.

In order to form a good electrostatic latent image in the electrophotographic image forming apparatus, the photosensitive drum must be charged with a uniform bias voltage, and therefore, an assembly tolerance between the charging roller and the photosensitive drum must be regulated.

On the other hand, the apparatus for developing the electrostatic latent image into a toner image can be divided into two types according to whether the developing roller and the photosensitive drum outer peripheral surface are in contact with each other. When the developing roller is in contact with the photosensitive drum outer circumferential surface, a developing nip is formed, and a developing action is performed at the developing nip. When the developing roller and the photosensitive drum outer circumferential surface do not contact each other, a developing gap Gap is formed and a developing action is performed in the developing gap.

For good charging and developing operation, the photosensitive drum should be regulated within a certain range of the axis alignment, axis parallelism, run out, and the like for the axis alignment, the developing roller, the charging roller, and the like. If the shaft alignment, the parallelism between the axes, the shaft shake, and the runout are misaligned, the uniformity such as the charging bias voltage or the developing gap or the developing nip may be degraded, resulting in poor print quality. For example, a fatal printing defect occurs such that an image is not printed on the print medium at regular intervals (White-Void), or the left and right density of the printed image is uneven.

To prevent this, it is necessary to manage assembly tolerances for a plurality of driving components for driving the photosensitive drum and for positioning components for determining the assembly position of the photosensitive drum. For example, US Pat. No. 5,749,028 “Multi-size photoreceptor flange bearing” and US Pat. No. 5,444,546 “Photoreceptor drum axle improvement” include a photosensitive drum fixing device in which a two-stage shaft supports both ends of the photosensitive drum, respectively. Is disclosed.

Another conventional example of the drive part and the positioning part is shown in FIGS. 1 is a side view showing a conventional photosensitive drum cartridge 120. 2 is a plan view illustrating an assembly method of a conventional photosensitive drum (130). 3 is a side cross-sectional view illustrating various embodiments of a power transmission member in the conventional photosensitive drum 130. 3 shows a first gear 223 and a second gear 260 inscribed therein or a second gear 250 circumscribed therein. Either of the two embodiments of the second gears 250, 260 selectively engages the first gear 223.

Referring to these drawings, there is shown a photosensitive drum cartridge 120 detachably provided in the image forming apparatus main body. The photosensitive drum 130 is installed at a predetermined position of the main body of the image forming apparatus by the assembly operation of the photosensitive drum cartridge 120. The housings 210a and 210b are provided with shaft fixing parts 211a and 211b to which the shafts 212a and 212b are fixed, and the shafts 212a and 212b rotatably support the photosensitive drum 130. The toner image developed around the photosensitive drum 130 is transferred to the printing medium P passed between the photosensitive drum 130 and the transfer roller 170.

The photosensitive drum 130 is installed to expose a portion of its outer circumferential surface and rotates in a predetermined direction. The photosensitive drum 130 includes a cylindrical sleeve 131 having a photosensitive layer and flanges 220a and 220b fixed to both ends of the sleeve 131. Shaft fixing portions 211a and 211b are provided at left and right portions of the housings 210a and 210b, respectively. The pair of shafts 212a and 212b are fixed to the shaft fixing parts 211a and 211b, respectively, and the photosensitive drum 130 is rotated by driving the flange 220b rotatably fitted to one shaft 212b. At this time, since the shafts 212a and 212b rotatably supporting the flanges 220a and 220b are separately provided on the left and right sides of the housings 210a and 210b, it is difficult to restrict the shaft alignment, the parallelism between the axes, the shaft shake, and the runout. There is a problem.

The first gear 223 is provided on the outer circumference of the flange 220b to drive the flange 220b. Second gears 250 and 260 meshing with the first gear 223 of the flange 220b are provided in the image forming apparatus main body. The second gears 250 and 260 are connected to a driving source (not shown) provided in the image forming apparatus main body to receive power.

When the photosensitive drum cartridge 120 having the second gear 250 of the reference numeral 250 is detached from the x-axis or z-axis direction, the teeth of the first gear 223 and the second gear 250 may be smoothly assembled to each other. . However, when the photosensitive drum cartridge 120 slides in the y-axis direction and is detached from the main body of the image forming apparatus, the radial direction of the first gear 223 and the second gear 250 in the radial direction is displaced. Since the contact is started under load, the gear may be damaged by the impact. In addition, the flange 220b and a power transmission structure therefor may be complicated.

On the other hand, when the first gear 223 is engaged with the inner circumference of the second gear 260, the outer diameter of the second gear 260 is larger than the outer diameter of the flange 220b and the photosensitive drum 130, so The disadvantage is that the space for installing other components is reduced.

SUMMARY OF THE INVENTION The technical problem of the present invention is to improve the above-described problems, and it is easy to regulate axial alignment, axis parallelism, shaft shake, runout, and the like, and when the photosensitive drum cartridge is detached in the longitudinal direction of the photosensitive drum, It is to provide a photosensitive drum cartridge which is prevented from being damaged and has a simple structure and reduces installation space.

In order to achieve the above object, the photosensitive drum cartridge of the present invention,

A photosensitive drum having a cylindrical sleeve having a photosensitive layer formed thereon, and a pair of flanges respectively fitted to both ends of the sleeve;

One shaft serving as a rotation axis of the photosensitive drum; Including;

The shaft and the pair of flanges are located on the same axis along the longitudinal direction of the photosensitive drum, characterized in that the photosensitive drum is rotated by the drive of the shaft.

In one embodiment, the photosensitive drum cartridge,

A housing in which the photosensitive drum is assembled and the shaft is rotatably fixed; It further comprises, The shaft is assembled with the pair of flanges while being inserted into the housing along the longitudinal direction of the photosensitive drum. Preferably, the shaft is longer than the photosensitive drum.

In one embodiment, a pin is fitted to the shaft, a hook portion is provided on at least one of the pair of flanges, and the driving force is directly transmitted from the shaft to the photosensitive drum by fastening the pin to the hook portion.

In addition, a main body coupling coupled to a driving source is provided in the image forming apparatus main body in which the photosensitive drum cartridge is slid along the longitudinal direction of the photosensitive drum, and drives the shaft by engaging with the main body coupling during the sliding. Preferably, a shaft coupling is provided at one end of the shaft.

The housing preferably includes a pin penetrating portion through which the pin penetrates and a bush fixing portion for fixing a bush rotatably supporting the shaft.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; Embodiments of the invention are not limited to what is shown in the accompanying drawings, it is to be understood that various modifications can be made within the scope of the same invention.

4 is a perspective view illustrating an operation in which the photosensitive drum cartridge 600 of the present invention is attached to or detached from the image forming apparatus main body 500. The photosensitive drum cartridge 600 of the present invention is mounted in the slot 510 of the image forming apparatus main body 500 while sliding along the longitudinal direction of the photosensitive drum. 5 is a perspective view of the shaft 610 of the present invention. 6 is a side view showing the assembled state of the photosensitive drum of the present invention. 7 is a side view illustrating the housing 650 and the shaft 610 inserted therein of the present invention. 8 is a side cross-sectional view showing the fastening state of the pin 620 and the hook portion 722 in the photosensitive drum of the present invention.

4 to 8, the configuration and operation of the photosensitive drum cartridge 600 will be described in detail. The photosensitive drum has a sleeve 700 and a pair of flanges 710 and 720 respectively fitted to both ends of the sleeve 700. The sleeve 700 has a cylindrical shape and a photosensitive layer is formed on the outer circumference thereof. One shaft 610, which is a rotation axis of the photosensitive drum, is provided, the shaft 610 and the flanges 710 and 720 are rotated together, and the driving force is transmitted to the shaft 610 is distinguished from the conventional. That is, the shaft 610 and the pair of flanges 710 and 720 are positioned on the same axis along the length direction of the photosensitive drum, and the photosensitive drum is rotated by driving the shaft 610. Shaft alignment, inter-axis parallelism, shaft as a pair of flanges (710,720) are fixed with one shaft (610) on the same axis and fit in a tight tolerance range such that the flanges (710,720) cannot be rotated with respect to the shaft (610). It is easy to regulate shake and runout.

The photosensitive drum cartridge 600 has a housing 650 in which a photosensitive drum is assembled and the shaft 610 is rotatably fixed. The shaft 610 is assembled to the pair of flanges 710 and 720 while being inserted into the housing 650 along the length direction of the photosensitive drum. Thus, the shaft 610 is longer than the photosensitive drum.

A bush 630 is provided to rotatably support the shaft 610. The inner circumference of the bush 630 slides and supports the outer circumference of the shaft 610, and the outer circumference of the bush 630 is fixed to the bush fixing part 655 provided in the housing 650. The housing 650 includes a bush fixing part 655 for penetrating the shaft 610 and fixing the outer circumference of the bush 630, and a pin penetrating part 656 for penetrating the pin 620 fitted to the shaft 610. do. For example, when the charging roller 690 is assembled to the photosensitive drum cartridge 600, the charging roller fixing part 651 supporting the rotating shaft of the charging roller 690 may be provided in the housing 650.

The central portion of one flange 720 is provided with a shaft hole 721 into which the shaft 610 is fitted and a hook portion 722 to which the pin 620 is fastened. One end of the shaft 610 passes through the bush fixing portion 655, the shaft hole 721 of one flange 720, and the shaft hole (not shown) of the other flange 710, and is not shown. It is rotatably supported by

The other end of the shaft 610 is provided with a pin hole 612 in the radial direction, the pin 620 is fastened to the pin hole 612. The pin 620 is fitted to the shaft 610, the hook portion 722 is provided on at least one of the pair of flanges 710 and 720, and the pin 620 is fastened to the hook portion 722, thereby providing the shaft 610. The driving force is directly transmitted to the photosensitive drum. Therefore, there is an advantage that the structure of the power transmission component for transmitting the driving force to the photosensitive drum is very simple.

A coupling insertion part 614 is provided at the other end of the shaft 610. The shaft coupling part 643 is provided at the shaft coupling 640 that transmits power to the shaft 610. The coupling inserting portion 614 and the shaft inserting portion 643 are shaped to coincide with each other, for example, having a long hole shape in which a portion of the circumference is cut.

The image forming apparatus main body 500 includes a driving source (not shown) and a main body coupling 645 connected to the driving source. When the main body coupling 645 and the shaft coupling 640 are fastened when the photosensitive drum cartridge 600 is slid, driving force is transmitted to the photosensitive drum. A coupling gear 647 is formed in the shaft coupling 640 and the body coupling 645. The coupling gear 647 preferably has an inclined surface formed along the longitudinal direction of the photosensitive drum such that the coupling gear 647 is not damaged by the fastening contact between the main body coupling 645 and the shaft coupling 640.

Since the shaft coupling 640 is fitted to the outer circumference of the shaft 610, the shaft coupling 640 has a larger outer diameter than the outer circumference of the shaft 610. Unlike the conventional embodiment in which the driving force is transmitted to the flange, in the present invention, the outer diameter of the shaft coupling 640 need not be larger than the photosensitive drum or the flanges 710 and 720. Since the size of the shaft coupling 640 is reduced, it is easy to secure space for installing other components. In this embodiment, an auger (not shown) for collecting toner or a gear 649 for driving the charging roller 690 may be provided in the shaft coupling 640.

As described above, the photosensitive drum cartridge of the present invention can be easily regulated such as shaft alignment, interaxial parallelism, shaft shaking, and runout, and prevents damage to the power transmission component when the photosensitive drum cartridge is detached in the longitudinal direction of the photosensitive drum. The structure and installation space of the power transmission component are simplified, and the gear train for driving other components can be installed in the shaft coupling.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art to which the art belongs can make various modifications and other equivalent embodiments therefrom. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the claims below.

Claims (6)

A photosensitive drum having a cylindrical sleeve having a photosensitive layer formed thereon, and a pair of flanges respectively fitted to both ends of the sleeve; One shaft serving as a rotation axis of the photosensitive drum; Including; The shaft and the pair of flanges are located on the same axis along the longitudinal direction of the photosensitive drum, the photosensitive drum cartridge, characterized in that the photosensitive drum is rotated by the drive of the shaft. The method of claim 1, A housing in which the photosensitive drum is assembled and the shaft is rotatably fixed; More, And the shaft is assembled to the pair of flanges while being inserted into the housing along the longitudinal direction of the photosensitive drum. The method of claim 2, And the shaft is longer than the photosensitive drum. The method according to any one of claims 1 to 3, A pin is fitted to the shaft, At least one of the pair of flanges is provided with a hook portion, The photosensitive drum cartridge, characterized in that the driving force is directly transmitted from the shaft to the photosensitive drum by the pin is fastened to the hook portion. The method of claim 4, wherein A main body coupling is connected to a driving source in the image forming apparatus main body in which the photosensitive drum cartridge slides along the length direction of the photosensitive drum. The photosensitive drum cartridge, characterized in that the shaft coupling for driving the shaft by engaging with the body coupling when the sliding is provided at one end of the shaft. The method of claim 4, wherein The housing, And a pin fixing portion for fixing the pin penetrating portion through which the pin passes, and a bush for rotatably supporting the shaft.

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