JPH03101754A - Process cartridge for image forming device - Google Patents

Abstract

PURPOSE:To prevent developer from being scattered which is caused by the entrainment of air under the opening and closing of a protective cover by partially allowing the leading edge part of the protective cover to abut on the part of a developing device in a bus direction of an image carrier. CONSTITUTION:The process cartridge is provided with the protective cover 5 which opens and closes the aperture part 11 through which the part of the image carrier 1 is faced to an external part, the leading edge part of the protective cover 5 is provided with rectangular projecting parts 5b and 5b and a recessed part 5c... which are alternately formed, and the projecting parts 5b and 5b abut on the developing cover leading edge part 3d of the developing device 3 so that the strength against an external force of the protective cover 5 may be secured. Then, at the time of loading and unloading the process cartridge 100 to the device main body, the protective cover 5 is turned around the shaft 5a so as to open and close the aperture part 11 of the housing 10, and the air enclosed by the protective cover 5 is exhausted outside through plural recessed parts 5c... as shown by an arrow A. Thus, the failure such as the scattering of the toner (t) in a toner container 3b which is caused by the entrainment of air surrounding the protective cover 5, etc., can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a process cartridge for an image forming apparatus such as an electrophotographic copying apparatus, an electrostatic recording apparatus, or a laser beam printer. (Prior Art) Such a process cartridge includes specific equipment among all process equipment for image formation, such as an image carrier, a charging device, a developing device, a cleaning device, etc., in a common housing at predetermined mutual positions. It is assembled and configured while maintaining the relationship, and is attached to and detached from the main body of the image forming apparatus. By adopting a method for attaching and detaching a process cartridge as described above to an image forming apparatus, it is possible to improve the maintainability and serviceability of the image forming apparatus. By the way, the process cartridge has an opening through which a part of the surface of the image carrier contained therein faces the outside.
It is equipped with a protective cover that opens and closes this opening. The protective cover is opened when the process cartridge is installed in the image forming apparatus main body, and at this time, the protective cover is placed against the surface of the image carrier facing outside from the opening of the process cartridge. Predetermined process equipment such as an image transfer means provided therein is located opposite to the image transfer means.

On the other hand, when the process cartridge is removed from the image forming apparatus main body and stored, the protective cover is closed, and the protective cover hides the surface portion of the image carrier that faces outside from the process cartridge opening. It serves to protect the device from damage caused by collision with other objects, staining due to adhesion of dust, etc., and deterioration due to exposure to external light. (Problem to be solved by the invention) As such a protective cover, a thin plate-like plastic molded product with a smooth outer surface is often used to reduce the weight and cost of the process cartridge. It is opened and closed by a mechanical mechanism. In this case, since the protective cover has an arcuate shape along the image carrier, it envelops the nearby air when it is opened and closed.

For this reason, the toner storage section of the developing device, etc., which is disposed at a position facing the circumference of the image carrier
This air may cause problems such as the toner inside the toner storage unit scattering. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image forming system that can eliminate problems such as developer scattering caused by air entrapment when a protective cover is opened and closed. Our purpose is to provide a process cartridge for the device.

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured to be detachable from an image forming apparatus main body and include at least an image carrier and a developing device, and the image carrier In a process cartridge for an image forming apparatus, the process cartridge has a protective cover that opens and closes a part of the opening facing the outside;
The developing device is characterized in that a part of the developing device is configured to partially abut against the generatrix direction of the t-carrying member, and specifically, an uneven portion is formed at the tip of the protective cover, An oblong hole is drilled.

(Function) According to the present invention, a path through which air passes is formed at the tip of the protective cover, so when the protective cover is opened and closed, the surrounding air flows through that path. Air entrapment is eliminated, and problems such as developer scattering due to air entrapment are effectively eliminated.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

1 and 2 are longitudinal sectional views of a process cartridge according to the present invention, and FIGS. 3(a) and 3(b) are a side view and a front view, respectively, of a protective cover.

First, the basic structure of the process cartridge 100 will be explained based on FIG. 1 and FIG. The image transfer process section is exposed to the outside from the opening 11 on the right side of the housing 10, but when the process cartridge 100 is removed from the main body of the image forming apparatus (not shown) and stored, the protective cover 5 is installed as shown in FIG. The protective cover 5 protects the photosensitive drum l from damage caused by collision with other objects, staining caused by dirt, etc., and deterioration caused by exposure to external light. Ru. Further, the left side of the photosensitive drum l constitutes a photoimage exposure process section l9, and in the state shown in FIG. The section 19 is connected to the housing 10 through a slit-shaped exposure window 6 formed on the left side of the cartridge housing 10 from an image exposure device (not shown) on the apparatus main body side.
It is irradiated with optical image exposure light L (slit exposure of M draft image, laser beam scanning exposure, etc.) that enters the inside almost horizontally.

Furthermore, the cleaning device 4 and the developing device 3 are arranged above and below the optical path 17, respectively, with a substantially horizontal optical image exposure optical path l7 extending from the exposure window 6 toward the optical image exposure process section 19 of the photosensitive drum 1 as a boundary. has been done. The developing device 3 includes a developing roller 3a and a toner container 3b, and the toner container 3b houses a toner t and a toner stirring rod 3c for stirring the toner t.

The charging device M2 is composed of a contact charging roller or a frictional charging roller, which is disposed in the illustrated recess 20, and is located upstream of the photoimage exposure process section 19 in the rotational direction (counterclockwise direction) of the photosensitive drum. It is in contact with the outer peripheral surface of the photosensitive drum 1 at this position. By the way, in the state shown in FIG. 2 in which the process cartridge lOO is installed in the main body of the apparatus, the protective cover 5 is open, and at this time the housing 1
The transfer charger 8 on the apparatus main body side is located opposite to the right side surface of the photosensitive drum l exposed to the outside through the opening 11 of the image transfer process section. Note that the mechanical drive system and electric circuit system provided in each of the apparatus main body and the process cartridge 100 are coupled to each other via a cup song (not shown).

When a copy button (not shown) is pressed in the state shown in FIG. 2, the photosensitive tram 1, charging device 2, developing roller 3a, and toner stirring rod 3c are rotated in the direction of the arrow shown in the drawing. Note that predetermined voltages (charging voltage, developing bias) are applied to the charging device 2 and the developing roller 3a, respectively.

The photosensitive drum 1 is uniformly charged positively or negatively by the charging device 2, and an electrostatic latent image is formed on its surface by receiving the photoimage exposure light L in the photoimage exposure process section 19. The image is developed as a toner image by the developing roller 3a.

This toner image is transferred to the photosensitive drum in the image transfer process section.
The images are sequentially transferred onto a transfer material P fed from a paper feed mechanism (not shown) between the transfer charger 8 and the transfer charger 8. After receiving the toner image transfer,
The transfer material P separated from the surface of the photosensitive drum 1 is conveyed to a fixing device (not shown), undergoes image fixation, and is discharged outside the machine as a copy. After image transfer, the surface of the photosensitive tram 1 is wiped off by a plate 4a of a cleaning device 4 to remove waste toner and other deposits, and is then turned over and used for image formation.

By the way, the protective cover 5 is attached to the shaft 5 as shown in FIG.
It rotates around a, but at its tip there is a rectangular convex part sb,
sb and recesses 5c... are formed alternately, and the protrusions 5b, 5b come into contact with the developing cover tip 3d of the developing device 3, as shown in FIG. 1, to increase the strength of the protective cover 5 against external forces. is ensured.

The protective cover 5 rotates around the shaft 5a to open and close the opening 11 of the housing 10 (see FIGS. 1 and 2) when the process cartridge 1OO is attached to and removed from the main body of the apparatus. The air trapped in 5 is the third
As shown by arrow A in figure (a), a plurality of recesses 5C...
Since the toner t is discharged to the outside through the toner t, problems such as scattering of the toner t in the toner container 3b caused by the envelopment of air around the protective cover 5 are effectively eliminated.

Next, a modified embodiment of the present invention is shown in FIGS. 4(a) and 4(b).

That is, FIG. 4(a). (b) is a partially cutaway side view and a front view of the protective cover, respectively, and in this embodiment, a plurality of oblong holes 5d are bored at the tip of the protective cover 5.

Also in this embodiment, when the protective cover 5 is opened and closed, the air trapped in the protective cover 5 is
), the liquid is discharged to the outside through a plurality of oblong holes 5d formed at the tip of the protective cover 5, so that the same effect as that obtained in the above embodiment can be obtained. can get.
It should be noted that since the oblong holes 5d are provided at the tip of the protective cover 5, there will be no inconvenience such as direct light passing through them and adversely affecting the photosensitive drum 1 and the like.

(Effects of the Invention) As is clear from the above description, according to the present invention, the image forming apparatus is removably attached to the main body of the image forming apparatus, and includes at least the image bearing member and the developing device. In a process cartridge for an image forming apparatus, the process cartridge is provided with a protective cover that opens and closes an opening with a part facing the outside, and a front end of the protective cover is attached to a part of the developing device in the generatrix direction of the image carrier. Because it is configured so that it comes into partial contact with the
This has the effect of effectively eliminating problems such as developer scattering caused by air entrapment when the protective cover is opened and closed.

[Brief explanation of drawings]

1 and 2 are longitudinal sectional views of a process cartridge according to the present invention, and FIG. 3(a). (b) is a side view and front view of the protective cover, and Fig. 4 (a) is respectively. (b) is a partially cutaway side view and a front view of a protective cover showing modified embodiments of the present invention, respectively. 1... Photosensitive drum (image carrier), 3... Developing device,
5...Protective cover, 5b...Convex portion, 5C...Concave portion, 5d...Oval hole, 11...Housing opening, i
oo--Process cartridge.

Claims (3)

[Claims] (1) The image forming apparatus has a protective cover that is detachable from the main body of the image forming apparatus and that includes at least an image carrier and a developing device, and that opens and closes an opening through which a part of the image carrier faces the outside. In the process cartridge for an image forming apparatus comprising: Equipment process cartridge. (2) The process cartridge for an image forming apparatus according to claim 1, wherein a concave and convex portion is formed at a tip of the protective cover. (3) The process cartridge for an image forming apparatus according to claim 1, wherein a plurality of oblong holes are formed at the tip of the protective cover.