JP2733439B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge having a photosensitive drum and a process means acting on the photosensitive drum, which is detachable and capable of attaching an image to a transfer material. The present invention relates to an image forming apparatus for forming an image. 2. Description of the Related Art Conventionally, there is known an image forming apparatus in which a process cartridge having a photosensitive drum and a process means acting on the photosensitive drum is detachably mountable and forms an image on a transfer material. . In an image forming apparatus using the process cartridge, it is desired to easily and accurately position the process cartridge with respect to the apparatus main body. An object of the present invention is to provide an image forming apparatus capable of easily and accurately positioning a process cartridge with respect to an apparatus main body. is there. According to the present invention, there is provided a process cartridge having a photosensitive drum and charging means provided along the photosensitive drum for charging the photosensitive drum. An image forming apparatus for forming an image on a transfer material in a state where the process cartridge is mounted, wherein a housing and a rotation center axis of the photosensitive drum provided in the housing are coaxial with the housing. An upwardly open groove for fitting with the projecting member of the process cartridge for positioning the process cartridge having a projecting member projecting from a longitudinal end of the photosensitive drum on a line; and the housing. Fixing means for fixing a toner image transferred from the photosensitive drum to the transfer material, provided on the housing; Conveying means for conveying the transfer material, provided on the housing, a laser light irradiating means for irradiating the photosensitive drum of the process cartridge mounted on the housing with laser light, A cover rotatable with respect to the housing, and a cover rotatable upward with respect to the housing to mount and remove the process cartridge with respect to the housing; and a process cartridge mounted on the housing. A block that can be in contact with a frame having the process cartridge by dropping the projecting member of the process cartridge into the groove, and causing the frame of the process cartridge to contact the block. An image forming apparatus configured to position a cartridge. According to the present invention, the process cartridge can be positioned by dropping the projecting member of the process cartridge into the recess. Hereinafter, the present invention will be described with reference to examples. The illustrated apparatus scans an electrophotographic photosensitive member with laser light to form an image. In the embodiment described below, an image forming apparatus uses a process cartridge in which at least one or more of image forming means such as a developing device, a cleaning device, and a charging device are integrated and supported by a supporting means in addition to a photoreceptor. The present invention relates to an image forming apparatus, such as a facsimile or an electrophotographic copying machine, for outputting an image such as a character or a drawing to a recording material. FIGS. 1 and 2 are sectional views of an apparatus in which the same configuration as that of the present invention is applied to positioning of a process cartridge with respect to the apparatus main body, which is different from the present invention.
FIG. 2 shows a state where the main body of the apparatus shown in FIG. 1 is opened. In FIG. 1, a general laser scanner 14 exposes the photosensitive drum 12 by an image signal. The photosensitive drum 12 rotates in the direction of the arrow, and the photosensitive drum 12 is uniformly charged by the corona charger 10. An electrostatic latent image formed by exposing the uniformly charged photosensitive drum to a light image by the laser scanner 14 is developed with the toner of the developing device 11. The photosensitive drum, the developing device, the cleaning device 13,
The charger is formed integrally with the frame, and the process cartridge 9 is formed.
Is composed. 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. Thereafter, 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 discharge roller 7 to a tray on an opening / closing cover 8 which is a part of the upper housing B. On the other hand, toner remaining without being transferred onto the photosensitive drum 12 is collected by the cleaning device 13. In FIG. 1, reference numeral 15 denotes a pre-exposure lamp, 16 denotes a hinge which is the center of rotation of an opening / closing cover 8 constituting an upper housing, 17 denotes a spring for pressing the process cartridge 9 downward, and 18 denotes both ends of the photosensitive drum 12. Shafts 12a, 12b
A positioning block 19 for engaging and holding the process cartridge 19 is an abutment block for stopping the rotation of the process cartridge 9. As shown in FIG. 2, the apparatus having the above structure is divided and connected to an open / close cover 8 as an upper housing and a lower housing A by a hinge 16, and the open / close cover is pivoted upward about the hinge 16. I do. The opening / closing cover has 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 are arranged. In the lower housing, a paper feed roller 2, a registration roller 3, a transfer guide plate 4, a fixing device 6, a laser scanner 14 constituting a main part of an optical system, a positioning block 18, a butting block 19 and the like are arranged. The cartridge 9 may be attached and detached in the rotation axis direction of the drum 12. In the state shown in FIG. 2, the process cartridge 9 is pressed downward by a spring 17 while being merely mounted on the guide 9a in the opening / closing cover 8, and is easily detached from the guide 9a by a stopper (not shown). Has not been maintained. In this state, if the force is applied upward against the force of the spring 17, it can be easily lifted. Next, when the opening / closing cover 8 is closed (FIG. 1), the rotation center shaft 1 of the drum at both ends of the photosensitive drum 12 is opened.
2a (FIG. 4) is fitted into the groove of the positioning block 18a disposed on the lower body. Process cartridge 9
A part of the frame abuts against the abutment block 19 for positioning and supporting the frame of the cartridge, which results in the role of preventing the frame of the process cartridge 9 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 housing.
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 viewed from below. In FIG. 5, reference numeral 12b denotes a gear for receiving drive from the main body, which is fixed to an end of the photosensitive drum 12 integrally with the drum. FIG. 6 shows a driving mechanism of the drum 12. When a driving gear C provided on the lower housing A meshes with the gear 12 b as shown in the drawing, the drive from the lower housing is transmitted to the drum 12. Is done. Next, the image forming apparatus shown in FIG. 7 has a reflection mirror 14a in the upper housing as well as the scanner in the lower housing A as optical means. The reflection mirror 14a is fixed to a mirror holder 14c, and as shown in FIG.
4c are hooks 14 at the opening of the side wall of the opening / closing cover.
d and is urged downward from above by a pressing leaf spring 14b fixed to the upper housing. On the main body side, a mirror receiving stand 14e is positioned as shown in FIG. 11, in which the lower surfaces of both ends of the mirror holder 14c are abutted against this inclined surface. Numeral 14f denotes a scanner pedestal on which the laser scanner 14 is to be mounted and positioned. The drum pedestal 18b and the mirror pedestal are integrally molded with a reinforced plastic of a material such as glass carburetor together with the mirror pedestal so that dimensional accuracy and mechanical strength are mutually guaranteed. Frame structure. FIG. 9 shows a perspective view of the device when the upper housing is opened. With the above configuration, when the opening / closing cover 8 is in the closed state, the laser scanner 14 as a light source, the pair of registration rollers 3 for transporting paper, the photosensitive drum 12, and the reflection mirror 14a are integrally formed in relation to the lower housing. Not only can positioning be performed with high dimensional accuracy, but also vibration can be extremely reduced by sufficiently increasing the mechanical strength of the integrated frame. In FIG. 7, the arrow C indicates the direction in which the process cartridge is loaded. FIG. 8 is a cross-sectional view of the apparatus when the upper housing is closed to form an image, and FIG.
Reference numeral 0 denotes a partial side view of a state immediately before the reflection mirror 14a is positioned by the mirror receiving base 14e, and FIG. 11 shows a partial side view of the positioned state. As described above, by mixing the positioning member provided in the lower housing with the rotation center axis of the photosensitive member, accurate positioning with respect to the main part of the optical system which requires positional accuracy with the process cartridge can be performed. became. Further, the transfer guide plate, the transfer charger and the like can be automatically positioned at the same time, but they may be provided as needed. In addition, since the main part of the optical system is not provided in the upper housing, the structure for supporting the rotation of the housing may be simple, and an image forming apparatus which is light and easy to operate for the user can be provided. Even in the apparatus having the reflecting mirror shown in FIG. 7, when the opening and closing cover is simplified as much as possible and the process cartridge and the reflecting mirror incorporated in the opening and closing cover are closed without increasing the dimensional accuracy, Positioned correctly on the lower housing side. Further, since the laser scanner and the reflection mirror as the light source, the image forming means such as the registration roller pair and the photosensitive drum of the process cartridge are substantially integrally combined on the lower housing side, the positioning is performed with high accuracy. There is an effect that the image quality can be maintained extremely well. FIG. 12 shows an embodiment using the present invention. In the above apparatus, the process cartridge is loaded in the upper housing to be opened. However, as shown in FIG. 12, the process cartridge is loaded on the cartridge supporting portion 18b or the member 19 provided in the lower housing A, and is attached by the spring 17 of the upper housing. The final positioning may be performed similarly to the above. In the above-mentioned embodiment, as the main optical means, a means for conveying a sheet-shaped original as shown in FIG. 13 is used instead of the laser scanner 14 shown in FIG. In FIG. 13, reference numeral 20 denotes a transport roller. A document 24 passing through a slit glass 21 is illuminated by a lamp 22 and is exposed on a drum 12 by an imaging lens 23. Each of these optical means is fixed to the lower housing. Of course, as shown in FIG. 7, a mirror 14a provided on the upper housing may be used together. The rotation center axis of the photosensitive member is the rotation center axis of the drum when the photosensitive member is a drum, and the rotation center axis of the roller 12c supporting the belt 12d as shown in FIG. 12e, and the closer to the exposure position, the higher the positioning effect. The process cartridge may be any one that integrally supports two or more means used for image formation. For example, a set of a photoconductor and a developing device, a photoconductor and a cleaning device, and a photoconductor, a developing device and a cleaning device, etc. There is alignment, and for example, a configuration as shown in FIGS. 13A to 13F of USP 4,462,677 may be used. As described in detail above, according to the present invention, the process cartridge can be easily and accurately positioned with respect to the apparatus main body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an apparatus sectional view showing a positioning principle of the present invention. FIG. 2 is a sectional view of the device shown in FIG. 1 in a state where an opening / closing cover is opened. FIG. 3 is a partial side view of the positioning means. FIG. 4 is a plan view of the means shown in FIG. 3; FIG. 5 is a perspective view of the process cartridge viewed from below. FIG. 6 is a perspective view of a driving mechanism. FIG. 7 is a 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 device shown in FIG. 7 when an 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. FIG. 12 is an apparatus sectional view showing an embodiment of the present invention. FIG. 13 is a sectional view of an apparatus showing an embodiment of the present invention. FIG. 14 is a partial side view showing a positioning state in a case where the photosensitive member is in a belt shape. [Description of Signs] 9 Process Cartridge 12 Photosensitive Drums 12a, 12b Both End Shafts of Photosensitive Drum 14 Laser Scanner 14a Mirror 17 Spring 18 Positioning Block 19 Member 20 Transport Roller 21 Slit Glass 22 Lamp 23 Lens 24 Document A Lower Case B Upper Case

Continuation of front page    (72) Inventor Tadashi Yagi               3-30-2 Shimomaruko, Ota-ku, Tokyo               Non Corporation (72) Inventor Nobuka Adachi               3-30-2 Shimomaruko, Ota-ku, Tokyo               Non Corporation (72) Inventor Takeshi Setoriyama               3-30-2 Shimomaruko, Ota-ku, Tokyo               Non Corporation (72) Inventor Yasuyoshi Hayakawa               3-30-2 Shimomaruko, Ota-ku, Tokyo               Non Corporation                (56) References JP-A-58-182682 (JP, A)                 Showa 60-169639 (JP, U)

Claims (1)

(57) [Claims] A photosensitive drum, provided along the photosensitive drum ,
A detachable process cartridge having a charging means for performing charging to the photosensitive drum, said process
In the image forming apparatus for forming an image on a transfer material a scan cartridge while wearing, housing and, disposed in the housing, the longitudinal direction of the photosensitive drum in the rotational center axis coaxial line of the photosensitive drum An upwardly open groove for fitting with the projecting member of the process cartridge for positioning the process cartridge having a projecting member projecting from a side end ; and the photosensitive drum provided in the housing. a fixing unit for fixing the toner image transferred to the transfer material from, provided on the housing, and conveying means for conveying the transfer material, provided on the housing, wherein the housing wherein the laser beam irradiating means for irradiating a laser beam to the photosensitive drum, rotatable relative to the housing, the housing having the said process cartridge mounted to Wherein in order to attach and detach the process cartridge, and the cover can be pivoted upward relative to the housing, the frame having a process cartridge mounted to the housing with respect to
And a block capable of contacting the body, wherein the projecting member of the process cartridge is
Plunge into the groove portion, and said process cartridge
An image forming apparatus configured to contact the block with the block to position the process cartridge. 2. The image forming apparatus according to claim 1, wherein the protruding member is a shaft of the photosensitive drum. 3. 2. The image forming apparatus according to claim 1 , wherein the process cartridge has a developing unit for developing a latent image formed on the photosensitive drum. 4. The image forming apparatus according to claim 1 , wherein the process cartridge further includes a cleaning unit configured to remove toner remaining on the photosensitive drum.