JPH0213783B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process kit in which a process means for forming an image is detachably attached to a main unit.

Conventionally, it has been possible to construct process means, including photoreceptors, etc., which deteriorate depending on the amount of use and have a limited service life, into a kit that can be attached to and detached from the main unit, making it easier to replace consumables. Conceivable. Examples of replacing consumables due to this kit structure include developing devices whose usability reaches the limit due to toner consumption at the same time as photoconductor replacement, cleaning devices where used toner accumulates, and even discharge problems caused by toner adhesion. It may also be effective to replace the corona discharger and the like at the same time as the photoreceptor.

A structure in which consumables that require replacement due to use as described above can be attached to and detached from the main unit is referred to herein as a process kit. As the process means of such a process kit, a combination of a photoreceptor, a developing device, a cleaning device, a corona discharger, etc. can be considered.

By the way, the manner in which the process kit is used and its management is left to the user who actually purchased the process kit. Process kits are frequently replaced with and removed from the main body, not only when the process kit itself reaches the end of its lifespan, but also with functional process kits having different developing characteristics. Therefore, the handle for handling the process kit becomes an important component for the user's operation.

However, for devices such as developing units and cleaning units that include containers in which the amount of toner inside changes depending on the usage status of the process kit, the amount of toner located in each unit changes depending on the usage status of the process kit. As a result, the weight balance of the entire process kit changes. Therefore, even if the kit has a handle, even if it is easy to hold immediately after starting use, if the collected toner remains in the cleaning device during use, it becomes extremely difficult to hold.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a process kit that is configured to be able to be lowered into the most preferable state at all times regardless of how the process kit is used.

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

FIGS. 1 and 2 are explanatory diagrams of an embodiment of the process kit of the present invention applied to an electrophotographic copying machine. 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 which slit-exposes the optical image of the original image on the original table 1 onto the OPC photosensitive drum 3 serving as an image carrier. Note that the photosensitive drum 3 rotates in the direction of the arrow. 4 is a corona charger that uniformly charges the photosensitive drum. A developing device 5 develops an electrostatic latent image formed by exposing a uniformly charged photosensitive drum to light using the array 2 with toner.

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 the toner image on the drum is transferred 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 the fixing device 10, and the sheet is transferred to the tray 12 by the ejection roller 11.
is discharged to the top. On the other hand, toner remaining on the photosensitive drum 3 without being transferred is collected by a cleaning device 14. 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 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, the image forming means such as the developing device 5, the cleaning device 14, the charging device 4, etc. arranged around the photosensitive drum 3 are integrated and wrapped with a light-shielding wall to constitute the process kit 20. At the time of replacement, each unit in the kit 20 is replaced at the same time, thereby reducing maintenance work. The process kit is attached to and detached from the main unit by moving the kit 20 along the rails 21 and 22 on the copying machine main body side in the direction of the rotation axis of the drum 3. In addition,
The case of taking out the kit 20 from the main body will be described below.

23 located at the bottom of the kit is made of an opaque material, e.g. black, made of the same material as the wall 20a of the process kit.
This cover shields and protects the exposed surface of the drum 3 made of ABS resin from light.

FIG. 3 is a perspective view of the rear side of the process kit of the present invention showing the connecting portion with the main body.

In the figure, 24 is a grip portion for pulling out the kit body along the rails 21, 22, and 25 is a handle portion for lifting the removed kit. There is an opening 26 for exposure at the top of the kit 20, and in this embodiment, a rotatable light shielding plate 27 is disposed along this opening. By folding the light shielding plate 27 in the direction of arrow a to close the opening 26, the photosensitive drum 3 can be completely shielded from surrounding light, thereby preventing memory development caused by light irradiation onto the photosensitive drum. There is no.

Further, as shown in FIG. 3, on the back wall of the process kit 20, there are positioning pins 28 for correcting the position of the kit loaded in the main unit, and a positioning pin 28 for supplying high voltage to the charger 4. Connector 2
9, and a drive transmission gear 3 that drives the photosensitive drum 3.
0, and a connector 31 for applying a bias voltage to the developing unit 5. The gear 30 transmits the driving force of the main body to the drum 3 by fitting its concavo-convex portion with the concave-convex portion of the drive gear on the main body side.

By the way, in the process kit 20, all the toner is enclosed in the container 5a of the developing device 5 when it is not in use. Therefore, there is no collected toner in the cleaning device 14 yet. The center of gravity of the process kit at this time is at point A. On the other hand, if this kit 20 is continued to be used, the toner in the developing device will be consumed and reduced, and at the same time, the residual toner on the photosensitive drum 3 will be collected and accumulated in the cleaning device 14.
As a result, the center of gravity of the process kit moves to point B.

In a kit where the center of gravity of the process kit moves as the toner is consumed, depending on the mounting position of the handle provided on the wall 20a of the kit, when the kit is lifted up and down when it is not in use and when it is in use. The feel may be different. Furthermore, as the center of gravity of the kit shifts, the inclination of the kit when gripped by the handle changes as the kit is used, making it difficult to hold.

For example, in the process kit 20 shown in FIG. 4, if the handle 25 is attached near the exposure opening 26, the inclination of the kit when lifted will change significantly due to consumption of toner in the developing device. That is clear.

The present invention solves the above problems, and the center of gravity A
The developing device 5 and the cleaning device 14 are disposed at a position where the straight line AA connecting the handle 25 and the straight line BB connecting the center of gravity B and the handle 25 are placed close to each other.
5. The cleaning device 14, the photosensitive drum 3, and the developing device 5 are arranged in a substantially straight line. In this example, the handle, cleaning device, photosensitive drum,
The developing units are arranged in order to prevent the process kit from tilting as much as possible due to toner consumption when lifted.

Incidentally, the cleaning device 14 may be removed from the configuration shown in FIG. 4, and the developing bias may be controlled so that the developing device 5 also serves as a cleaning device depending on the image forming process.

With the above configuration, regardless of the amount of toner consumed,
When the process kit is lifted by the handle, it always maintains a stable balance and does not cause the user to feel uncomfortable or the center of gravity of the kit to shift and tilt to a state where it is difficult to lift the kit.

The process kit of the present invention can also be applied to a recording device in which an insulated drum is provided in place of the photosensitive drum, and a latent image is formed by multi-stylus electrodes inserted onto the insulated drum through the opening 26. .

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts of a copying machine loaded with a process kit to which the present invention is applied, FIG. 2 is a sectional view of the apparatus shown in FIG. The perspective view and FIG. 4 show a sectional view of the kit for explaining the present invention. In the figure, 5 is a developing device, 14 is a cleaning device, 20 is a process kit, 20a is a wall of the kit, and 25 is a handle.

Claims (1)

[Scope of Claims] 1. A process kit that includes an image carrier, a developing device and a cleaning device around the image carrier, and is removable from an image forming apparatus. 1. A process kit having a handle for lowering the kit, the handle, the image carrier, the developing device, and the cleaning device being arranged substantially in a straight line.