JPS5934557A - Process kit - Google Patents

Abstract

PURPOSE:To avoid deterioration in the strength of a process kit housing due to openings and to prevent the performance of exposure from degrading, by forming discontinuous openings as slit exposure parts, and making the area of an opening larger at an end part than at a center part. CONSTITUTION:The openings 33 for pre-exposure of the process kit 30 are reinforced by reinforcing members 34 which extends slantingly to the rotation direction of a photosensitive drum, and the housing 30a never deteriorates in strength regardless of the openings 33. The reinforcing member 34 and adjacent member 34b overlap with each other in the rotation direction of the photosensitive drum. Then, the quantities of light for pre-exposure at the same distance of the starting position which crosses the opening 33 by the rotation of the photosensitive drum 3 are uniform at any position, e.g. B, C, or D on the photosensitive drum surface. The quantity of light is corrected by increasing the area of the opening 33 toward an end part, by decreasing the thickness of the reinforcing member 34a toward the end part, or reducing the number of them according to the characteristics of a light source to obtain a picture of uniform quality while preventing the strength deterioration of the kit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process kit that includes a photoreceptor and is detachable from a main unit.

Conventionally, in image forming apparatuses such as Shimiko photocopiers, a photoconductor whose durability has been limited due to the progress of deterioration depending on the amount of use, or a process means containing this photoconductor, has been made into a kit and used for the main device. It is conceivable to configure the device so that it can be removable and to facilitate the replacement of consumables. Examples of replacing consumables using this kit include replacing a deteriorated photoconductor, a developing device that reaches its usage limit due to toner consumption, and a cleaning device that reaches its usage limit due to the accumulation of used toner. Furthermore, it may be effective to integrate a corona discharger or the like which tends to cause discharge failure due to toner adhesion and replace it at the same time as the photoreceptor.

As described above, a structure in which a photoconductor that requires replacement after use, or other consumables including this photoconductor, can be attached to and detached from the main unit is referred to as a process kit. The only components included in the kit are the photoreceptor;
Or other developing equipment.

A combination of a cleaning device, a corona discharger, etc. can be considered.

If such a process kit can be configured to be replaceable with the main unit, it will be possible to prepare multiple kits depending on the purpose of use and load the kit that suits the purpose into the main unit. Furthermore, the same main body can be used for multiple functions.

The housing that houses the photoreceptor of such a process kit is
It must have sufficient strength to prevent damage or deformation when attaching/detaching the process kit, storing it, or carrying the process kit alone. In other words, the photoreceptor is required to have a strict positional accuracy relative to the document, and each process means surrounding the photoreceptor must have precise positioning in order to form a stable latent image.
When handling these process kits, there must be no deformation or damage due to external forces. However, the housing of this process kit must have a small number of openings (one for pre-exposure, one for image exposure, and one for transferring the image to the transfer paper), and it is difficult to maintain its strength. In particular, if the housing of the process kit is made of molded synthetic resin or thin metal in order to increase productivity and lower prices,
The physical strength around the elongated opening in the longitudinal direction of the photoreceptor must be low.

An object of the present invention is to provide a process kit that avoids a decrease in the strength of the process kit housing due to the above-mentioned openings and does not reduce exposure performance.

The present invention will be explained in more detail below using an electrophotographic copying machine as an example.

Figure m1 and Figure 2 are explanatory diagrams of the configuration of an embodiment of an electrophotographic copying machine loaded with the process kit of the present invention. Note that FIG. 2 is a diagram showing the copying machine shown in FIG. 1 in an open state.

In FIG. 1, reference numeral 1 denotes a document mounting table made of a transparent member, which reciprocates in the direction of the arrow.

Reference numeral 2 denotes an imaging element array that slit-exposes a light image of the original image on the original platen 1 onto the OPC photosensitive drum 6 . Note that the photosensitive drum 6 rotates in the direction of the arrow. 4 is a corona charger which uniformly charges the photosensitive drum. Further, a developing device 5 develops an electrostatic latent image formed on a uniformly charged photosensitive drum by forming an optical image N by the array 2 with toner.

On the other hand, the transfer sheet P is fed onto the 3 sides of the sheet tray by the feeding roller 6 and the register roller 7, and the upper toner image is transferred to the sheet tray by the transfer charger 8. Thereafter, the sheet is separated from the υ drum by the separating means 1'5, passes over the guide 9, and is sent to the fixing device 10 by the roller 9a located at the end of the conveyance path. The toner image on the sheet is fixed by the fixing device 1D, and the sheet is transferred to the sheet tray 1 by the discharge roller 11.
2 is discharged on top. On the other hand, toner remaining on the photosensitive drum 3 without being transferred is collected by a cleaning device 147. Furthermore, 15 is an illumination system for exposing the original, and 16 is a filter such as a heat ray absorption filter.

Now, as shown in FIG. 2, this copying machine is divided into an upper housing 17 and a lower housing 18, which are connected to each other by a support shaft 19, and the upper housing 17 rotates upward about this support shaft 19. It is configured to do this. Image forming means such as a 17% illumination optical system 2-15, a photosensitive drum 6, a developing means 5, and a cleaning device 14 are arranged in this upper housing. Further, in the lower housing 18, a feeding roller 6, a transfer charger 8, a separating means 16, a guide 9, a fixing device 10, and the like are arranged on the sheet conveyance path.

Furthermore, in this embodiment, the process kit 30 is constructed by integrating the image forming means such as the developing device 5 cleaning device 1411 and the charging device 4 disposed around the photosensitive drum B and surrounding it with the casing 30a having a light-shielding wall. , Kit 6 when replacing the photosensitive drum
By replacing each process means in 0 at the same time, maintenance work is reduced. The process kit is attached to and detached from the main unit by moving the kit 30 along the rails 61 and 32 on the copying machine main body side in the direction of the rotation axis of the drum 30.

The process kit 60 has an opening 63 for guiding pre-exposure light from the lamp 15 between the corona discharger 4 of the photosensitive drum B and the cleaning device 14.

FIG. 6 is a sectional view of the process kit, and FIG. 4 is a perspective view of the process kit 30 viewed from the rear. The opening 66 for guiding the pre-exposure light is reinforced by a reinforcing member 34 extending in a direction diagonal to the rotating direction of the photosensitive drum.The strength of the process kit housing 30a is determined by the opening 6.
It will not go down depending on the presence of 6.

FIG. 5 is a partially enlarged plan view of the opening 33. As shown in FIG.

In the figure, the photosensitive drum 6 is rotating in the direction of the arrow. The reinforcing member 34a partially overlaps the reinforcing member 34b adjacent thereto in the rotation direction of the photosensitive drum 60).
Having an area that was.

Then, points in the direction of the rotation axis of the photosensitive drum 6, for example, B and C.
, D, the distance of the photosensitive drum surface at each position across the opening 63 (by rotation of the photosensitive drum 3) is the same. Therefore, if the amount of light from each opening 63 that is applied from the opening 33 while the photosensitive drum 6 is rotating is constant, the amount of light for pre-exposure in the direction of the rotation axis of the photosensitive drum can be determined at any position on the photosensitive drum. Even if it becomes uniform.

In this embodiment, the distance that the photosensitive drum 6 crosses the aperture 66 at each point is set to be the same, but the distance that the photosensitive drum 6 crosses the aperture may be different to the extent that unevenness does not appear in the image.

Incidentally, in the above case, if the light source emits a uniform amount of light over the entire area in the direction of the rotation axis of the photosensitive drum, or if non-uniformity of the light amount is not a problem, the above embodiment can be applied. However, if a decrease in the amount of light at the ends due to the characteristics of the light source becomes a problem, the opening area of the opening '5B should be made larger at the end, or the thickness of the reinforcing member 34ρ should be made thinner towards the end.
Furthermore, the amount of light can be corrected by reducing the number of reinforcing members at the ends, singly or in combination.

FIG. 6 is a partially enlarged plan view of the openings showing another embodiment in which the shape of the reinforcing member 34C is changed.
3b is a point on the photosensitive drum 3 that forms openings that do not overlap in the rotational direction of the photosensitive drum. For example, in E and F, the distance across the opening 63 is the same. In this case as well, as in the case of FIG. 5, it is possible to correct it. For example, the area of each opening may be changed, or the thickness of the reinforcing member 34C may be changed.

As explained above, it is possible to obtain a homogeneous image by ensuring that the exposure amount on the photosensitive drum is uniform in the opening used for pre-exposure of the process kit, and by providing a reinforcing member for this opening. Not only this, but also it is possible to prevent a decrease in the strength of the process kit due to the opening.

Note that the present invention is not limited to pre-exposure of a photosensitive drum, but can also be applied to image exposure and other types of exposure. Moreover, the above-mentioned structure achieves the above-mentioned purpose without causing the reinforcing member to have any adverse effect on the latent image.

[Brief explanation of drawings]

1 and 2 are configuration explanatory diagrams of an embodiment of the present invention applied to an electrophotographic copying machine, the third section is a sectional view of the process kit, and the fourth section is a diagram of the process kit, where 3 is a photosensitive drum, 30 is process 42

Claims (2)

[Claims] (1) In a process kit containing a photoreceptor and detachable from the main unit, the casing holds the photoreceptor inside, and the slit-shaped exposure portion for the photoreceptor is a discontinuous opening. A process kit characterized by: (2) The process kit according to claim (1), wherein the discontinuous opening has a larger opening area at the center and at the end.