JPH0211157B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process kit that includes a photoreceptor and a discharge means that acts on the photoreceptor and is detachable from an image forming apparatus.

In general, when an image forming apparatus that uses electrophotography is used for a long period of time, it is necessary to replace the photoreceptor, supply and replace the developer, clean the corona discharge wire that serves as the discharge electrode, and make other adjustments and replacements. Such maintenance work is performed by specialized service personnel.

However, in order to keep the image forming apparatus operating in good condition at all times, a method has been proposed in which maintenance work is performed without relying on service personnel with the above-mentioned specialized knowledge. One example is simply replacing the image forming components such as a discharger, a developing device, and a photosensitive drum, either singly or in combination (hereinafter referred to as a process kit), with a new one.

Furthermore, if such a process kit could be easily replaced with the main unit, the user would be able to prepare various process kits with developing characteristics and image reproducibility according to the purpose of copying and select the appropriate kit. It can be used as For example, a process kit having a developing device for black, red, etc. can be considered.

When using such a process kit, the discharger is set so that under normal usage conditions, no maintenance is required, such as dirt on the discharge wire, during the life of the process kit when it is replaced. However, there is no guarantee that it will always be satisfied depending on the conditions of use. For example, if the process kit is used in a very dusty location or if a kit that was left outside was installed when replacing the kit, the process kit may
Although the probability is very low, it is possible for external dust to enter and adhere to the corona discharge wire, resulting in staining the image.

In view of the above-mentioned points, the present invention provides a process kit in which the discharge electrode of the discharge means can be easily cleaned from the outside of the process kit.

The details of the present invention will be explained below with reference to examples and drawings.

First, an image forming apparatus to which a process kit is applied will be described with reference to FIG. FIG. 1 is a sectional view thereof.

In the figure, an image forming apparatus 1 such as a copying machine is based on an electrophotographic system, and a photosensitive drum 2 is supported at the center of the apparatus so as to be rotatable in the direction of arrow a. Along the circumference of the photosensitive drum 2, a corona discharger 3, a short focus optical element array 4, a developing device 5, a transfer corona discharger 6,
A cleaning device 7 and the like are arranged.

In the illustrated example, a process kit K includes a photosensitive drum 2, a corona discharger 3, a developing device 5, and a cleaning device 7, which can be integrally attached to and detached from the main body of the apparatus. 8 is a side plate of the frame that moves these components together. Further, 9 is a reciprocating document table, and 10 is a document table illumination lamp. 11 is a transfer material supply tray, 12 is a registration roller, 13
14 and 14a are conveyance rollers, and guide members 14 and 14a guide the transfer material between the transfer corona discharger 6 and the photosensitive drum 2. Further, 15 is a moving path for moving the transfer material after the transfer is completed, 16 is a fixing device, 17 is a discharge roller, 18 is a copy tray, and 19 is a color correction filter.

FIG. 2 is a perspective view of the above-mentioned device, showing a state in which the kit K, which integrally includes the photosensitive drum 2, the corona discharger 3, etc., is pulled out with the pre-installation door 19' opened. However, the figure does not include the kit housing.

The image forming operation of the above-mentioned configuration apparatus is as follows.

The photosensitive drum 2 is charged to a predetermined polarity by a corona discharger 3, and then reflected light from an illumination lamp 10 that illuminates the document on the document table 9 is irradiated via the short focus optical element array 4, and the photosensitive drum 2 is charged with a predetermined polarity by a corona discharger 3. An electrostatic latent image is formed on the second surface. The formed electrostatic latent image is developed by a developing device 5, and the developed image is transferred onto a transfer material by a transfer corona discharger 6. The transfer material after the transfer passes through the fixing device 16 and is transferred to the copy tray 18.
is discharged to. On the other hand, the surface of the photosensitive drum 2 after the transfer is cleaned by a cleaning device 7,
Prepared for reuse.

Figure 3 is a perspective view of the process kit K itself.
This is from the front side when pulling out from the main body of the device. FIG. 4 is a perspective view of the kit from the back when inserted into the main body of the device.

The housing 20 of the process kit K is made of light-shielding colored synthetic resin, such as noryl resin, polycarbonate resin, ABS resin, or the like. Also, metal or the like may be used. An opening 21 is provided in the casing 20 near the corona discharger position. The slit-shaped opening 21 is provided substantially parallel to the direction in which the discharge wire of the corona discharger 3 is stretched, and is used for cleaning the wire.

A colored light-shielding flexible sheet member 22 is provided in the opening 21 so as to be openable and closable.
The opening 21 is closed by the waist of the flexible sheet member 22 itself. . In other words, if the photoreceptor drum is exposed to external light for a long time, it will deteriorate, and if only the opening position is exposed, the brightness will change compared to other parts of the photoreceptor drum, which will adversely affect image formation. , the above-mentioned configuration of automatically closing the opening 21 except when necessary is effective. In the illustrated example, a 250 μm polyester sheet was used and a good shielding effect against dust, light, etc. was obtained.
Furthermore, as will be described later, when cleaning the flexible sheet member 22, only the part where the cleaning member is inserted can be opened, and the other opening parts can be kept in a light-shielded state.
It is extremely suitable for protecting the photoreceptor drum.

As shown in FIG. 4, on the back side of the process kit K, there are a positioning pin 24 for correcting the position of the kit loaded in the tip end device, and a connector 25 for supplying high voltage to the discharger 3. , a drive transmission gear 26 for driving the photoreceptor drum 2, and a connector 27 for applying a bias voltage to the developing device 5. The gear 26 transmits the driving force of the main body to the drum 2 by fitting its concavo-convex portion with the concave-convex portion of the drive gear on the main body side.

The final positioning of the process kit K with respect to the main body is achieved by fitting a positioning hole 28 provided on the wall surface opposite to the back wall portion 8 with a pin (not shown) on the main body side. Ru. 29 is a photosensitive drum shaft.

FIG. 5 shows a sectional view of the opening in a plane including the discharge wire, and FIG. 6 shows a sectional view of the opening in a plane perpendicular to the discharge wire.

By the way, the illustrated example corona discharger 3 has a mechanism for keeping the wire position constant with respect to the surface of the photoreceptor drum 2.

30 is a shield case, and 31 is a discharge wire. Reference numeral 32 denotes a wire regulating member, which is in contact with the wire at its upper end and has a roller 33 at its lower end so as to be rotatable about a shaft 34. This wire regulating member is held so as to be movable in the vertical direction in the drawing according to the position of the roller that comes into contact with and follows the surface of the photosensitive drum. This wire regulating member 3
Since the wire 31 also moves up and down according to the movement of 2,
At the same time as the photosensitive drum is mounted, the position of the wire 31 is fixed. In this way, the corona discharger itself can be set without the need for wire positioning. Since the photosensitive drum itself is set at a predetermined position in the process kit housing, the wire 31 and the photosensitive drum axis maintain a parallel relationship.

Therefore, if the wall surface 23 of the housing where the opening 21 is installed is kept parallel to the photosensitive drum axis, the wire 31 and the opening wall surface can be made parallel. If this wall surface is used as a guide for cleaning with a cleaning member to be described later, an excessive load is not applied to the wire 31, and therefore, cleaning can be performed without damaging or cutting the wire. Of course, if the wall surface itself where the opening is provided is not parallel,
Of course, a guide section parallel to the wire may be provided along the opening.

FIG. 7 is an explanatory diagram showing a state in which the cleaner is applied to the discharge wire through the opening 21, and FIG. 8 is a perspective view of the cleaner.

The discharge wire cleaner 36 mainly includes a base 37, an arm 38, and a cleaning member 39. Both the base 37 and the arm portion 38 are made of synthetic resin that does not deform. The base 37 has a U-shaped groove on the side that contacts the housing (that is, the side where the arm portion 38 is installed) so as to straddle the housing opening installation portion. The arm portion 38 provided at the bottom portion 40 of the U-shaped groove is set to be slightly shorter than the distance from the housing opening guide portion to the discharge wire 31. On the other hand, the position of the cleaning surface of the cleaning member provided at the tip of the arm is set to be greater than the distance from the bottom 40 to the discharge wire 31. The cleaning member itself is configured to undergo sufficient elastic deformation upon contact with the discharge wire 31 so as not to damage the discharge wire. The cleaning member may have an integral structure such as a felt brush, or it may have a multilayer structure consisting of a buffer layer 40 made of maltblen, sponge, etc., and a brush-like cleaning surface layer 41 densely planted with short hair fibers, as shown in FIG. Also good. The brush-like cleaning surface layer is
It is suitable because it has low frictional resistance during sliding. Nylon nonwoven fabric, velveteen, etc. are also effective. If the bristles are too short, it will be difficult to clean the entire circumference of the wire, while if the bristles are too long, the contact pressure may be weakened, so it is best to keep the bristles at an appropriate length. With the cleaner 36 having such a configuration, cleaning is accomplished by holding the base 37 along the opening and moving it back and forth. At this time, since the surface 40 of the base of the cleaner 36 moves along the housing guide surface 23, the cleaning member 39 of the cleaner 36 is always in contact with the discharge wire, so there is no risk of poor cleaning. Furthermore, since the wire is not pushed excessively, there is no risk of damage or breakage of the wire. Also, since the illustrated example cleaner base has a U-shaped groove,
The side surface 41 also contributes to the stable movement of the cleaner along the opening.

The flexible sheet member that blocks the housing opening 21 is opened near the position where the arm portion 38 of the cleaner 36 passes, but the other portion remains closed. Moreover, since the cleaner base provided with the arm portion 38 is in close contact with the openings at the front and rear of the arm portion, the surface of the photoreceptor drum is maintained in a substantially light-shielded state.

Therefore, the above-mentioned apparatus is excellent in that the wire can be cleaned from the outside by providing an opening in the process kit housing, and that it does not cause optical fatigue of the photoreceptor.

In the above embodiment, a flexible sheet member was used as the closing member for the opening, but a rigid sheet member may be attached to the opening with a hinge mechanism and always biased to the closed position by an elastic spring or the like. good. At this time,
The rigid sheet member is preferably divided into sections so that each subsection can be opened and closed.

FIG. 10 shows a modification of the cleaner for the image forming apparatus described above, in which a cleaning member for the optical surface of the process kit (for example, the short focus optical element array 4) is provided on the base surface opposite to the mounting surface of the discharge wire cleaning member. Indicate the case.

The cleaner 42 has a U-shaped groove similar to the cleaner 36 described above on one side of a base 43, and a wire cleaner portion with an arm 44 and a cleaning member 45 on the bottom thereof, and furthermore, on the opposite side of the base,
A cleaning member 46 such as a sponge is provided at the tip of the arm portion 45'. The cleaning member 46 cleans the optical surface of the short focus optical element array, etc. At this time, the arm portion 45' mounting portion side of the base portion 43 is provided with a step as shown at 47 to match the shape of the wall surface of the cleaning portion (not shown).

As explained above, according to the present invention, by forming an opening for cleaning the discharge electrode along the discharge means in the housing of the process kit, it is possible to easily clean the discharge electrode from the outside. Become. Moreover, since the opening is provided with a movable cover, there is no risk of exposing the photoreceptor to unnecessary light, and good image formation is possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a specific example image forming apparatus based on the present invention, FIG. 2 is a perspective view thereof, FIG. 3 is a front perspective view of a process kit, and FIG. 4 is a rear perspective view thereof. , FIG. 5 is a sectional view of the kit opening, and FIG. 6 is a sectional view of the kit opening.
5 is a sectional view orthogonal to FIG. 5, FIG. 7 is an explanatory diagram of the cleaning state of the discharge wire, FIG. 8 is a perspective view of the cleaner, FIG. 9 is an enlarged view of the tip of the cleaner, and FIG. 10 is a modified example of the cleaner. Perspective view. In the figure, 1; image forming device; 2; photosensitive drum;
3; corona discharger, 4; short focus optical element array,
5; Developing device.

Claims (1)

[Scope of Claims] 1. A photoreceptor, a discharge means acting on the photoreceptor, and an opening for supporting the photoreceptor and the discharge means and cleaning the discharge electrode of the discharge means along the discharge means. A process kit comprising: a housing provided with the housing; and a cover movable between a first position that blocks an opening of the housing and a second position evacuated from the first position. 2. a photoreceptor, a discharge means that acts on the photoreceptor, a housing that supports the photoreceptor and the discharge means and is provided with an opening for cleaning the discharge electrode of the discharge means along the discharge means; a cover that is movable between a first position that blocks the opening of the housing and a second position that is evacuated from the first position; and a cleaner that cleans the discharge electrode through the opening of the housing. A process kit comprising: a guide section for a cleaner; and a guide section for a cleaner.