JP2556636B2 - Image forming apparatus to which process cartridge can be attached - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge and an image forming apparatus using the process cartridge, which is used as a recording material for recording images such as characters and drawings in computers, facsimiles, personal computers, copying machines, word processors and the like. The present invention relates to an image forming apparatus for outputting to.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using a process cartridge, the apparatus main body can be opened / closed in order to easily attach / detach the process cartridge to / from the apparatus main body, and the process cartridge is attached to the upper casing to cover the same. A configuration is conceivable in which the device is closed and housed in the main body of the device.

The present invention is a further development of the above configuration.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process cartridge and an image forming apparatus in which the positioning accuracy with respect to the image forming apparatus is improved and the operability of attaching and detaching with respect to the image forming apparatus is improved.

A typical present invention for achieving the above object is, in an image forming apparatus for forming an image on a transfer material, a, a photosensitive drum, an image forming unit acting on the photosensitive drum, and the photosensitive member. A process cartridge having a frame body that integrally supports the drum and the image forming unit, and a rotation center shaft that projects from the longitudinal side end of the photosensitive drum; and b, for positioning the process cartridge, A lower casing having an upwardly opened recess for fitting the rotation center shaft of the process cartridge; and c, for attaching and detaching the process cartridge,
An upper housing which is openable and closable with respect to the lower housing and has a mounting portion for mounting the process cartridge; and the upper housing in a state where the process cartridge is mounted in the mounting portion. By closing the body
The image forming apparatus is characterized in that the rotation center shaft of the process cartridge is dropped into and fitted into the recess provided in the lower housing to position the process cartridge.

Further, another typical present invention for achieving the above-mentioned object is attachable to and detachable from an image forming apparatus having a lower housing and an upper housing which can be opened and closed with respect to the lower housing. In the process cartridge, the photosensitive drum,
When the process cartridge is mounted in the image forming apparatus, the process cartridge is positioned with respect to the image forming apparatus, the image forming section acting on the photosensitive drum, the frame body integrally supporting the photosensitive drum and the image forming section, and the process cartridge. In order to do so, a rotation center shaft that protrudes from the longitudinal side end of the photosensitive drum and that fits into an upwardly opened recess provided in the lower housing is provided in the upper housing. When the upper housing is closed while being mounted on the mounting portion, the rotation center shaft is dropped into the recessed portion provided in the lower housing to be fitted and positioned with respect to the apparatus main body. It is a characteristic process cartridge.

[0007]

According to the present invention, the projecting member of the process cartridge can be dropped into and fitted into the recess used in the upper portion of the lower housing.

[0008]

EXAMPLES In the examples described below, a process cartridge in which two or more image forming means such as a photoconductor, a developing device, a cleaning device, and a charging device are integrally supported by a supporting means,
Further, the present invention relates to an image forming apparatus using the process cartridge, which is an image forming apparatus for outputting an image such as characters and drawings of a computer, a facsimile, a personal computer, a copying machine, a word processor and the like to a recording material.

In the image forming apparatus described below, the upper casing and the lower casing are openably and closably supported, and the upper casing is provided with a supporting means for the cartridge to facilitate the attachment and detachment of the process cartridge. The main part of the optical system is provided in the lower housing. The positioning of the process cartridge and the optical system is performed by fitting the rotation center axis of the means for supporting the photosensitive member of the cartridge into a bearing member provided in the lower housing for receiving the rotation center axis. is there.

The rotation center axis of the photoreceptor is the rotation center axis of the drum when the photoreceptor is a drum, and the rotation center axis of the roller that supports the belt when the photoreceptor is a drum.
Further, the process cartridge may be one that integrally supports two or more means used for image formation, and for example, a combination of a photoconductor and a developing device, a photoconductor and a cleaning device, a photoconductor and a developing device and a cleaning device, and the like. There is. The present invention will be described below with reference to examples. The illustrated apparatus scans a laser beam on a photoconductor to form an image.

1 and 2 are sectional views of an apparatus to which the present invention is applied. 2 shows a state in which the main body of the device shown in FIG. 1 is opened. In FIG. 1, a laser scanner 14 exposes an image signal on the photosensitive drum 12. The photosensitive drum 12 rotates in the direction of the arrow, and the corona charger 10 uniformly charges the photosensitive drum 12. Further, the electrostatic latent image formed by exposing the uniformly charged photosensitive drum to light image by the laser scanner 14 is developed with the toner of the developing device 11. The photosensitive drum, the developing device, and the cleaning device 1
3. The charger is formed integrally with the frame to form the process cartridge 9.

The transfer material 1 is fed to the surface of the drum 12 through the transfer guide plate 4 by the paper feed roller 2 and the register roller 3, and the toner image on the drum is transferred by the transfer charger 5. After that, the transfer material is separated from the drum and sent to the fixing device 6. The toner on the transfer material is fixed by the fixing device 6, and the transfer material is discharged by a paper discharge roller 7 to a tray on an opening / closing cover 8 which is part of the upper housing B. On the other hand, the toner remaining on the photosensitive drum 12 without being transferred is collected by the cleaning device 13.

Reference numeral 15 in the drawing denotes a pre-exposure lamp, 1
6 is a hinge which is the center of rotation of the opening / closing cover 8, 17 is a spring for pressing the process cartridge 9 downward, 18 is a positioning block for engaging and holding both end shafts 12a, 12a of the photosensitive drum 12, and 19 is a process cartridge. It is an abutment block for the rotation stop of 9.

As shown in FIG. 2, the device of the present invention having the above-mentioned structure is as follows.
The opening / closing cover 8 as the upper housing and the lower housing A are separably joined by a hinge 16, and the opening / closing cover pivots upward around the hinge 16. The opening / closing cover is provided with a paper discharge roller 7, a pre-exposure lamp 15, a process cartridge 9, a guide 9a for receiving the cartridge, a spring 17 and the like. Further, a paper feed roller 2, a registration roller 3, a transfer guide plate 4, a fixing device 6, a laser scanner 14 which constitutes a main part of an optical system, a positioning block 18, an abutment block 19 and the like are arranged in the lower housing. . The cartridge 9 may be attached or detached in the rotation axis direction of the drum 12.

In the state of FIG. 2, the process cartridge 9
The spring is pressed downward by the spring 17 while being simply placed on the guide 9a inside the opening / closing cover 8 and is kept in a state in which it cannot be easily removed from the guide 9a by a stopper (not shown). In this state, if a force is applied upward against the force of the spring 17, the spring 17 is easily lifted.

Next, when the open / close cover 8 is closed (FIG. 1), the rotation center shaft 1 of the drum at both ends of the photosensitive drum 12 is closed.
2a (FIG. 4) fits into the groove of the positioning block 18a arranged on the lower body. Further, a part of the frame body of the process cartridge 9 abuts on the butting block 19 for positioning and supporting the frame body of the cartridge, and the process cartridge 9
As a result, it plays a role of preventing the frame body from rotating. Further, the transfer guide plate 4 is fixed to the positioning block 18a, and the photosensitive drum 1 is closed by closing the upper casing.
The relative positional accuracy between the transfer guide plate 2 and the transfer guide plate 4 is also automatically guaranteed.

FIG. 5 is a perspective view of the process cartridge as seen from below. In the figure, 12b is a gear for receiving a drive from the main body, and is fixed to the end of the photosensitive drum 12 integrally with the drum.

FIG. 6 shows a drive mechanism for the drum 12. The drive gear C provided on the lower housing A meshes with the gear 12b as shown in the drawing, so that the drive from the lower housing is performed by the drum 12. Be transmitted to.

Next, the image forming apparatus shown in FIG. 7 has a reflection mirror 14a in the upper housing in addition to the scanner in the lower housing A as optical means.

The reflection mirror 14a is fixed to the mirror holder 14c, and as shown in FIG.
Both ends of 4c are hooks 14 at the opening of the side wall of the opening / closing cover.
It is held by being engaged with d and is urged downward from above by a pressing leaf spring 14b fixed to the upper casing.

On the main body side, 14e is a mirror pedestal on which the lower surfaces of both ends of the mirror holder 14c are abutted by the inclined surfaces and positioned as shown in FIG. Reference numeral 14f denotes a scanner pedestal on which the laser scanner 14 is mounted and positioned. The scanner pedestal 14f and the drum bearing pedestal 18b and the mirror pedestal are integrally formed of a reinforced plastic material such as glass-filled polycarbonate to ensure dimensional accuracy and mechanical strength. It is a frame structure. FIG. 9 shows a perspective view of the device when the upper housing is opened.

With the above construction, when the open / close cover 8 is closed, the laser scanner 14 as a light source, the registration roller pair 3 which is a key for sheet conveyance, the photosensitive drum 12, and the reflection mirror 1 are provided.
Not only can the 4a be positioned integrally with the lower housing with high dimensional accuracy, but vibration can be extremely reduced by sufficiently increasing the mechanical strength of the integrated frame.

In FIG. 7, the arrow C indicates the loading direction of the process cartridge. FIG. 8 is a sectional view of the apparatus in a state in which the upper casing is closed and an image is formed,
FIG. 11 shows a partial side view of the 0-reflecting mirror 14a immediately before being positioned by the mirror pedestal 14e.

According to the embodiment described above, the positioning member provided in the lower housing and the rotation center shaft of the photosensitive member are fitted to each other so that the position accuracy with respect to the process cartridge and the main part of the optical system are required. It became possible to perform various positioning. Further, the positioning of the transfer guide plate, the transfer charger and the like can be automatically performed at the same time, but they may be provided if necessary. Moreover, since the main part of the optical system is not provided in the upper housing,
The structure for supporting the rotation in the same manner as the case may be simple, and it is possible to provide an image forming apparatus that is light and easy to operate for the user.

Even in the apparatus having the reflection mirror shown in FIG. 7, when the opening / closing cover is simplified as much as possible and the process cartridge and the reflection mirror incorporated in the opening / closing cover are closed without increasing the dimensional accuracy, Correctly positioned on the lower housing side. Further, since the laser scanner and the reflection mirror as the light source, the registration roller pair, and the image forming means such as the photosensitive drum of the process cartridge are substantially integrally coupled on the lower housing side, the positioning can be performed with high accuracy. There is an effect that the image quality can be maintained extremely good.

[0026]

As described above, according to the present invention, by closing the upper casing with the process cartridge mounted in the upper casing, the process cartridge is inserted into the recess provided in the lower casing. The process cartridge can be positioned by dropping and fitting the rotation center axis of the process cartridge. Therefore, according to the present invention,
It was possible to improve the positioning accuracy of the process cartridge and the mounting operability when mounting the process cartridge in the apparatus main body.

[Brief description of drawings]

FIG. 1 is a sectional view of an apparatus showing an embodiment of the present invention.

2 is a cross-sectional view of the device shown in FIG. 1 in a state in which an opening / closing cover is opened.

FIG. 3 is a partial side view of positioning means.

FIG. 4 is a plan view of the positioning unit shown in FIG.

FIG. 5 is a perspective view of the process cartridge as seen from below.

FIG. 6 is a perspective view of a drive mechanism.

FIG. 7 is a cross-sectional view of an apparatus having a reflection mirror.

FIG. 8 is a cross-sectional view of an apparatus having a reflection mirror.

9 is a perspective view of the apparatus shown in FIG. 7 when the upper housing is opened.

FIG. 10 is a partial side view showing a positioning state of a reflection mirror.

FIG. 11 is a partial side view showing a positioning state of a reflection mirror.

[Explanation of symbols]

 A lower housing B upper housing 1 transfer material 5 transfer charger 6 fixing device 8 opening / closing cover 9 process cartridge 9a process cartridge guide 10 corona charger 11 developing device 12 photosensitive drum 12a rotation center shaft 13 cleaning device 14a reflection mirror 14e Mirror stand 17 Spring 18a ・ 18b Positioning block 19 Butting block

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Yagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Innovator Shinwa Adachi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Yasuyoshi Hayakawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takeshi Setoriyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. In-house (56) References JP-A-57-88461 (JP, A) JP-A-57-154255 (JP, A) Actual development Sho-58-13526 (JP, U)

Claims (10)

(57) [Claims] 1. An image forming apparatus for forming an image on a transfer material, comprising: a) a photosensitive drum, image forming means acting on the photosensitive drum, and the photosensitive drum and the image forming means are integrally supported. A process cartridge having a frame body and a rotation center axis projecting from a longitudinal side end of the photosensitive drum; b, for positioning the process cartridge,
A lower casing having an upwardly opened recess for fitting the rotation center axis of the process cartridge; c, capable of being opened and closed with respect to the lower casing for attaching and detaching the process cartridge, and An upper casing having a mounting portion for mounting the process cartridge, and being provided in the lower casing by closing the upper casing with the process cartridge mounted in the mounting portion. An image forming apparatus characterized in that the rotation center shaft of the process cartridge is dropped into and fitted into the recessed portion, and the process cartridge is positioned. 2. The lower housing further comprises an abutment block for restricting movement of a frame body of the process cartridge in order to prevent the process cartridge from rotating. The image forming apparatus described. 3. The image forming apparatus according to claim 1, wherein the cover further includes a spring for urging the process cartridge downward. 4. The lower housing has a drive gear, and the drive gear meshes with a gear provided at an end portion of the photosensitive drum so that the driving force from the lower housing is The image forming apparatus according to claim 1, wherein the image forming apparatus transmits the image to a photosensitive drum. 5. A transfer guide for guiding the transfer material to the photosensitive drum is fixed to the positioning block provided with the recess in the lower housing. The image forming apparatus according to Item 1. 6. The exposure device for exposing the photosensitive drum of the process cartridge in accordance with an image signal, the exposure device being provided in the lower housing. Image forming device. 7. A process cartridge which is attachable to and detachable from an image forming apparatus having a lower housing and an upper housing which can be opened and closed with respect to the lower housing, wherein a photosensitive drum and an image forming which acts on the photosensitive drum are formed. Means, a frame body that integrally supports the photosensitive drum and the image forming means, and when mounting the process cartridge in the image forming apparatus,
A center axis of rotation projecting from a longitudinal side end of the photosensitive drum, which fits into an upwardly-opened recess provided in the lower housing to position the process cartridge with respect to the image forming apparatus. Then, in a state where it is mounted on the mounting portion provided on the upper housing,
A process cartridge characterized in that, when the upper casing is closed, the rotation center shaft is dropped into and fitted into the recess provided in the lower casing to perform positioning with respect to the apparatus main body. 8. The process cartridge according to claim 7, wherein the image forming unit is a charging unit for charging the photosensitive drum. 9. The process cartridge according to claim 7, wherein the image forming unit is a cleaning unit that collects toner remaining on the photosensitive drum from the photosensitive drum. 10. The process cartridge according to claim 7, wherein the image forming unit is a developing unit that develops the electrostatic latent image formed on the photosensitive drum with toner.