JPS6343166A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent an image forming device from toner dispersion by providing the device with a positioning member to be abutted upon a cartridge at the time of closing an upper case body and a supporting means fitted to the upper case body to attachably/detachably support the cartridge. CONSTITUTION:The process cartridge 9 is pressed downward by a spring 17 under a state simply set up on a guide 9a in an opening/closing cover 8 and held at a state not to be easily disengaged from the guide 9a by a stopper (unshown). The cartridge 9 can be easily lifted by applying force upward against the force of the spring 17 under said state. When the cover 8 is closed, a drum rotation center axis on both the ends of a photosensitive drum 12 is engaged with a groove part of a positioning block 18a arranged on a lower body. Since a part of a frame body of the cartridge 9 is butted upon a butting block 19 for positioning and supporting the frame body of the cartridge 9, the frame body of the cartridge can be prevented from being rotated.

Description

Detailed Description of the Invention (Industrial Utilization Field of the Invention) The present invention provides an image-forming means including at least one image forming means such as a developing device, a cleaning device, a charging device, etc., in addition to a photoreceptor, and supporting it by a supporting means. This is an image forming apparatus that uses a process cartridge, and relates to an image forming apparatus for outputting images such as characters and drawings onto a recording material, such as a facsimile machine or an electrophotographic copying machine.

(Prior Art) Conventionally, in an image forming apparatus using a process cartridge, in order to easily attach and detach the process cartridge to and from the apparatus body, the apparatus body is made openable and closable, the process cartridge is attached to the upper housing, and a cover is closed. There is a type of device that can be closed and stored inside the device body.

In such a device in which the process cartridge is placed in the upper housing, if the cartridge is placed in the upper housing together with the main part of the optical system, the volume of the upper housing will increase, and the support mechanism for the upper housing will become larger. Furthermore, the vibrations of the opening and closing movements distort the optical system, causing adverse effects such as uneven scanning, making it impossible to expose a clear image, and causing toner to scatter from the cartridge.

(Problems to be Solved by the Invention) An object of the present invention is to provide an image forming apparatus that does not cause the various problems that tend to occur when the conventional process cartridge is disposed in the upper housing. .

(Means for Solving the Problems) A positioning mechanism for a process cartridge of an image forming apparatus according to the present invention that achieves the above object has the following. That is,
a lower housing, an upper housing that can be opened and closed with respect to the lower housing, a process cartridge that has at least a photoreceptor and a process means that contributes to image formation and is removable from the main device; an optical means provided on the body and irradiating optical information based on a document image onto a photoreceptor of the cartridge; a positioning member also provided on the lower casing and abutting on the cartridge; and an optical means provided on the upper casing or the lower casing. and support means for removably supporting the process cartridge.

Further, when the present invention has an upper housing that can be opened and closed with respect to the lower housing, the positioning of optical members such as mirrors for changing the optical path with respect to the lower housing is provided in the lower housing as in the above cartridge. It is effective to bring this optical member into contact with the positioning member.

(Examples) The present invention will be explained below according to Examples. An exemplary device scans a laser beam onto an electrophotographic photoreceptor to form an image.

1 and 2 are cross-sectional views of an apparatus to which the present invention is applied. Note that FIG. 2 shows a state in which the main body of the device shown in FIG. 1 is opened. In FIG. 1, a general laser scanner 14 exposes a photosensitive drum 12 using an image signal. Note that the photosensitive drum 12 rotates in the direction of the arrow, and the photosensitive drum 12 is uniformly charged by the corona charger lO. Further, an electrostatic latent image formed by exposing a uniformly charged photosensitive drum to a light image using a laser scanner 14 is developed with toner in a developing device 11 .

Note that the photosensitive drum, the developing device, the cleaning device 13, and the charger are integrally formed in the frame to constitute the process cartridge 9.

The transfer material 1 is sent 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 ejected to a tray on the open/close cover 8, which is a part of the upper housing B, by a paper ejection roller. On the other hand, the toner remaining on the photosensitive V ram 12 without being transferred is removed by a cleaning device! 3
recovered by.

In the figure, 15 is a pre-exposure lamp, 16 is a hinge that is the center of rotation of the opening/closing cover 8 constituting the upper housing, 17 is a spring for pressing down the process cartridge 9, and 18 is a shaft 12a at both ends of the photosensitive drum 12. , 12b, and a positioning block 19 for stopping the process cartridge 90 from rotating.

As shown in FIG. 2, the device of the present invention having the above-mentioned configuration has a hinge 1 that can be divided into an open/close cover 8 which is an upper casing and a lower casing A.
6, and the opening/closing cover pivots upward about this hinge 16. A paper discharge roller 7, a pre-exposure lamp 15, a process cartridge 9, a cartridge receiving guide 9a, a spring 17, etc. are arranged on this opening/closing cover. In addition, the lower housing includes a paper feed roller □U2, a registration roller 3, a transfer guide plate 4, a fuser □6,
A laser scanner 14, a positioning block 18, an abutment block 19, etc., which constitute the main parts of the optical system, are arranged. The Naori-tridge 9 may be attached and detached in the direction of the rotation axis of the drum 12.

In the 221st state, the process cartridge 9 is open/closed.
) It is held down by a spring 17 while simply playing against the guide 9a within the bar 8, and a stopper (not shown) keeps the guide 9a from easily coming off.

In this state, it can be easily lifted by applying upward force against the force of the spring 17.

Next, when this opening/closing cover 8 is closed (FIG. 1), the drum rotation center shaft 12a at both ends of the photosensitive drum 12 (FIG. 4)
is fitted into the groove of the positioning block 18a disposed on the lower body. Further, a portion of the frame of the process cartridge 90 abuts against the abutment block 19 that positions and supports the frame of the cartridge, which serves to prevent the frame of the process cartridge 9 from rotating. Further, a transfer guide plate 4 is fixed to the positioning block 18a, and the relative positional accuracy between the photosensitive drum 12 and the transfer guide plate 4 is automatically guaranteed by closing the upper housing.

FIG. 5 is a perspective view of the process cartridge viewed from the bottom. In the figure, reference numeral 12b denotes a gear for receiving drive from the main body, and is fixed to the end of the photosensitive drum 12 integrally with the drum.

Further, FIG. 6 shows one drive mechanism (one motor) for the drum 12, and the drive gear C provided in the lower housing A meshes with the gear 12b as shown in the figure, thereby driving the drum 12 from the lower housing. is transmitted to the drum 12.

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

This reflection mirror 14a is fixed to a mirror boulder 14c, and as shown in No. 109, both ends of the mirror holder 14c are engaged with hooks 14d in the opening of the side wall of the opening/closing cover, and are held from above to the upper housing. Fixed suppression leaf spring 1
It is urged downward at 4b.

On the main body side, reference numeral 14e designates a mirror holder on which the lower surfaces of both ends of the mirror holder 14c are abutted against the slopes to be positioned, as shown in FIG. 14F is a scanner pedestal on which the laser scanner 14 is mounted and positioned, and is integrally molded with a drum bearing pedestal 18b and a mirror pedestal from reinforced plastic made of glass-filled polycarbonate or the like.
This is a frame structure that guarantees both dimensional accuracy and mechanical strength. 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 which is the light source, the registration roller pair 3 which is the key for paper conveyance, the photosensitive drum 12 and the reflection mirror 14a are integrally high in relation to the lower housing. Not only does positioning become possible with precision, but the integral frame provides sufficient mechanical strength, making it possible to extremely reduce vibration.

Note that in FIG. 7, arrow C indicates the loading direction of the process cartridge. FIG. 8 shows a cross section of the device when the upper housing is closed and an image is being formed, and a state where the first O reflection mirror 14a is just before being determined at the position r) by the mirror holder 14e. FIG. 11 shows a partial side view of the positioned state.

As explained above, by hingeing the positioning member provided on the lower housing and the rotation center axis of the photoreceptor, it is possible to accurately position the main parts of the optical system that require positional accuracy with respect to the process cartridge. . Furthermore, it is possible to automatically position the transfer guide plate, transfer charger, etc. at the same time.
It may be provided if necessary. Furthermore, since the main part of the optical system is not provided in the upper casing, the same structure as the casing for rotational support may be required, making it possible to provide an image forming apparatus that is lightweight and easy to operate for the user. Ta.

Even if the device has the reflecting mirror shown in Fig. 7, the opening/closing cover should be simplified as much as possible and the dimensional precision I should not be increased (when the process cartridge and reflecting mirror incorporated in the opening/closing cover are closed, It is correctly positioned on the lower housing side.Furthermore, the laser scanner and reflective mirror that are light sources, and the image forming means such as the registration roller pair and the photosensitive drum of the process cartridge are actually integrally combined on the lower housing side. , positioning is performed with high precision, resulting in the effect that image quality can be maintained extremely well.

Incidentally, in the above-mentioned apparatus, the process cartridge is loaded into the open upper housing, but as shown in FIG. The final positioning may be carried out in the same manner as described above by applying force.

Further, in the present invention, the main optical means includes the first optical means.
Instead of the laser scanner 14 shown in the figure, a scanner for conveying a sheet-like original as shown in FIG. 13 is used. In FIG. 13, reference numeral 20 denotes a conveyance roller, the original 24 passing through the slit glass 21 is illuminated by a lamp 22, and the image forming lens 2
3, the drum 12 is exposed to light. 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 also be used.

Note that the rotation center axis of the photoreceptor is the rotation center axis of the drum when the photoreceptor is a drum, and the first rotation center axis when the photoreceptor is a belt.
This is the rotational center axis 12d of a roller 12c that supports the belt 12b like in 4WA, and the closer it is to the exposure position, the better the positioning effect becomes. Further, the process cartridge may be one that integrally supports two or more means used for image formation, such as a combination of a photoreceptor and a developing device, a photoreceptor and a cleaning device, a photoreceptor, a developing device, and a cleaning device, etc. For example, the structure shown in FIGS. 13A to 13F of US Pat. No. 4,462,677 may be used.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the device showing the positioning principle of the present invention, Figure 2
The figures are a cross-sectional view of the opening/closing cover shown in Fig. 1 with the cover open, Fig. 3 is a partial side view of the positioning means, Fig. 4 is a plan view of the means shown in Fig. 3, and Fig. 5 is a view of the process cartridge from below. 6 is a perspective view of the drive mechanism, FIGS. 7 and 8 are sectional views of the device with a reflecting mirror, and FIG. 9 is a perspective view of the device shown in FIG. 7 when the upper housing is opened. , FIG. 10 and FIG. 11 are partial side views showing the positioning state of the reflecting mirror, FIG. 12 and FIG. 13 are cross-sectional views of the device showing an embodiment of the present invention, and FIG. 14 is a case where the photoreceptor is in the form of a belt. It is a partial side view which shows the positioning state of. In the figure, 9 is a process cartridge, 12 is a photosensitive drum, 12a-12b are both end shafts of the photosensitive drum, 17 is a spring,
18 is a positioning block, 20 is a transport roller, 21 is a slit glass, 24 is a document, 22 is a lamp, 23 is a lens, A is a lower housing, and B is an upper housing.

Claims (2)

[Claims] (1) An image forming apparatus having a lower housing and an upper housing that can be opened and closed with respect to the lower housing, which has at least a photoreceptor and a process means that contributes to forming an image on the photoreceptor, and the main unit an optical means provided in the lower casing for each process cartridge that is removable from the cartridge, and for irradiating optical information based on a document image onto a photosensitive member of the cartridge; and an optical means provided in the lower casing, when the upper casing is closed. An image forming apparatus comprising: a positioning member that abuts the cartridge; and a support means that is provided on the upper housing and that removably supports the cartridge. (2) An image forming apparatus main body having a lower casing and an upper casing that can be opened and closed with respect to the lower casing, including at least a photoreceptor and a process means that contributes to forming an image on the photoreceptor; a process cartridge that is removable from the main device; an optical means that is provided in the lower housing and that irradiates optical information based on a document image onto a photoreceptor of the cartridge; and an optical device that is provided in the lower housing and that is attached to the upper housing An image forming apparatus comprising: a positioning member that comes into contact with the cartridge when the cartridge is closed; and a support means that is provided on the lower casing and that removably supports the cartridge.