JPH0352629B2 - - Google Patents

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 electrophotographic copying machines, the photoconductor, which deteriorates depending on the amount of use and has a limited service life, or the process means containing this photoconductor, can be made into a kit that can be attached to and detached from the main unit. It is conceivable that the system could be configured to facilitate the replacement of consumables. Examples of replacing consumables due to this kit include replacing deteriorated photoconductors, developing devices that are reaching the limit of their use due to toner consumption, cleaning devices that are reaching the limit of their use due to the accumulation of used toner, and even It would also be effective to integrate a corona discharger or the like that 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 photoreceptor that needs to be replaced due to use or other consumables including the photoreceptor can be attached to and removed from the main unit is referred to as a process kit herein. The components included in such a process kit may include only a photoreceptor, or a combination of a developing device, a cleaning device, a corona discharge device, and the like.

If such a process kit is configured to be replaceable with respect to the main unit, as an extension of this, multiple kits can be prepared depending on the purpose of use and the kit suitable for the purpose can be loaded into the main unit.
The same main body can be used for multiple functions.

The housing containing the photoreceptor of such a process kit must have sufficient strength to prevent damage or deformation when the process kit is attached/detached, stored, or carried alone. In other words, strict positional accuracy is required for forming a stable latent image for photoreceptor originals and for each processing means surrounding the photoreceptor, and when handling these process kits, there is a risk of deformation or damage due to external forces. It shouldn't be. However, the casing of this process kit must have at least an opening for pre-exposure, an opening for image exposure, and an opening for transferring the image to the transfer paper, which inevitably leads to a decrease in strength. In particular, if the housing of the process kit is made of a molded product such as synthetic resin or thin metal in order to increase productivity and lower costs, the area around the elongated opening in the longitudinal direction of the photoconductor may have low physical strength. I have no choice but to.

SUMMARY OF THE INVENTION An object of the present invention is to provide a process kit that avoids deterioration in the strength of the process kit casing due to the above-mentioned openings and does not reduce exposure performance.

Hereinafter, the present invention will be explained in more detail with reference to an electrophotographic copying machine.

FIGS. 1 and 2 are diagrams illustrating the construction of an embodiment of an electrophotographic copying machine filled 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 table 1 onto the OPC photosensitive drum 3. Note that the photosensitive drum 3 rotates in the direction of the arrow. 4 is a corona charger which uniformly charges the photosensitive drum. It is also a developing device, which develops with toner an electrostatic latent image formed by exposing a uniformly charged photosensitive drum to light using the array 2.

On the other hand, the transfer sheet P is fed onto the surface of the drum 3 by a feeding roller 6 and a register roller 7, and is transferred as a toner image on the drum by a transfer charger 8. Thereafter, the sheet is separated from the drum by the separating means 13, 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 a fixing device 10, and the sheet is discharged onto a tray 12 by a discharge roller 11. On the other hand, toner remaining on the photosensitive drum 3 without being transferred is collected by a cleaning device 14. Further, 15 is an illumination member 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 by a support shaft 19 in a separable manner, and the upper housing 17 rotates upward around this support shaft 19. It is configured to move. This upper housing 17 includes illumination optical systems 2, 15, photosensitive drum 3,
Image forming means such as a developing means 5 and a cleaning device 14 are arranged. In addition, the lower housing 18 includes
A feeding roller 6, a transfer charger 8, a separation means 13, a guide 9, a fixing device 10, and the like are arranged on the sheet conveyance path.

Furthermore, in this embodiment, image forming means such as a developing device 5, a cleaning device 14, and a charging device 4 arranged around the photosensitive drum 3 are integrated into a housing 3 having a light-shielding wall.
0a to form a process kit 30, and when the photosensitive drum is replaced, each process means in the kit 30 is replaced at the same time, thereby reducing maintenance work. To attach and detach this process kit to and from the main unit, attach the kit 30 to the rail 3 on the copying machine main body side.
1 and 32 in the direction of the rotation axis of the drum 3.

The process kit 30 has an opening 33 between the corona discharger 4 of the photosensitive drum 3 and the cleaning device 14 for guiding pre-exposure light from the lamp 15.

3 is a sectional view of the process kit, and FIG. 4 is a perspective view of the process kit 30 as viewed from the rear. The opening 33 for guiding light for pre-exposure is
There are a plurality of reinforcing members 34 extending in a direction diagonal to the rotational direction of the photosensitive drum, and the strength of the process kit housing 30a is not reduced by the presence of the opening 33.

FIG. 5 is a partially enlarged plan view of the opening 33. As shown in FIG. In the figure, the photosensitive drum 3 is rotating in the direction of arrow A. The reinforcing member 34a has a region that partially overlaps the reinforcing member 34b adjacent thereto in the rotational direction of the photosensitive drum 3.
Even if the points in the direction of the rotation axis of the photosensitive drum 3 are taken, for example, positions B, C, D, etc., the distance of the photosensitive drum surface at each position where the opening 33 is crossed by the rotation of the photosensitive drum 3 is the same. Therefore, the photosensitive drum 3
If the amount of light given from each opening 33 during rotation is constant, the amount of light for pre-exposure in the direction of the rotation axis of the photosensitive drum will be uniform regardless of the position on the photosensitive drum.

In this embodiment, the distance that the photosensitive drum 3 crosses the aperture 33 is made exactly the same at each point, but the distance that the photosensitive drum 3 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 rotational direction 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 edges due to the characteristics of the light source becomes a problem, the aperture 3
By increasing the opening area of No. 3 toward the ends, decreasing the thickness of the reinforcing member 34a toward the ends, or decreasing the number of reinforcing members toward the ends, either alone or in combination. , the amount of light can be corrected.

FIG. 6 is a partially enlarged plan view of an opening showing another embodiment in which the shape of the reinforcing member 34c is changed, and each opening 33a and 33b forms an opening that does not overlap in the rotational direction of the photosensitive drum. This is the point above 3. For example, in E and F, the distance across the opening 33 is the same. In this case, as in the case of FIG. 5, the amount of light can be corrected, for example, by changing the area of each opening or by changing the thickness of the reinforcing member 34c.

As explained above, by making the exposure amount on the photosensitive drum uniform in the aperture used for pre-exposure of the process kit, and by providing a reinforcing member for this aperture, it is possible not only to obtain a homogeneous image but also to ,
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. Further, with the above configuration, the above object is achieved without the reinforcing member having any adverse effect on the latent image.

[Brief explanation of drawings]

1 and 2 are structural explanatory diagrams of an embodiment of the present invention applied to an electrophotographic copying machine, FIG. 3 is a sectional view of the process kit, FIG. 4 is a perspective view of the process kit, and FIG. The figure is a plan view of the exposure aperture, and FIG. 6 is a plan view of the exposure aperture of another embodiment. In the figure, 3 is a photosensitive drum, 30 is a process kit, 33 is an opening, and 34 is a reinforcing member.

Claims (1)

[Scope of Claims] 1. A process kit that has a housing having at least a photoreceptor therein and is removably attached to an image forming apparatus, such that the photoreceptor passes through an opening at any position in the axial direction of the photoreceptor. forming a plurality of independent openings in the housing along the axial direction of the photoreceptor;
A process kit characterized in that a photoreceptor is exposed to light through the plurality of openings. 2. The process kit according to claim 1, wherein the opening is a pre-exposure opening for exposing the photoreceptor to light prior to image formation. 3. The process kit according to claim 1 or 2, wherein the distance between the openings in the moving direction of the photoreceptor is larger at the end of the photoreceptor than at the center of the photoreceptor. 4. The process kit includes a charging means, a developing means,
4. A process kit according to claim 1, wherein at least one of the cleaning means is provided.