JPS6265049A - Process cartridge and image forming device using said cartridge - Google Patents

Abstract

PURPOSE:To prevent damages and deformation through the outside and to scale down a device and to lighten its weight by constituting a drum drive spindle at a device main body side and a receiving part at a cartridge side with respect to the positioning spindle of a cartridge so as to lie in a cartridge case. CONSTITUTION:First, the tip of the drive spindle 4 also acting as positioning the cartridge is fitted in the drive spindle receiving part 2f of a resin flange 2, and the cartridge and a photosensitive body 1 are positioned with respect to the device main body. When the cartridge is further pushed up to a recess, the projecting part 10a of a drive transmitter 10 engages with the receiving part of the flange 2, and linkage between the drive spindle 4 and the drum is completed. The gear part 2b of a process cartridge engages with a gear 14a rotating the developing sleeve of a developing unit 14 integrally supported in the cartridge and with a gear 15a rotating a screw in order to forcibly convey the toner of a cleaning unit 1 integrally supported in a similar way. Since the receiving parts at the cartridge side are all in a cartridge case 3, damages and deformation caused by the outside can be prevented, whereby the device can be scaled down and its weight can be lightened.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an image bearing drum such as a photosensitive drum or an insulating drum,
The process means used to form an image on the drum is integrally configured with at least one process means such as a charging device, a developing device, a transfer device, a cleaning device, etc., and is detachable from the main body of the apparatus. related to process cartridges. Furthermore, the present invention relates to image forming apparatuses such as electrophotographic copying machines and recording devices to which such a process cartridge is applied.

(Prior Art) Conventionally, there are copying machines, printers, etc. that apply electrophotography as process cartridges and devices that drive the cartridges. An example of these cartridges will be explained with reference to FIG. 9 and FIG. 1O. FIG. 9 is a perspective view showing the connecting part of the cartridge to the main body of the apparatus, and FIG. 10 is a sectional view illustrating the connection of the cartridge to the main body of the apparatus. Processing means such as the following are supported together with the photosensitive drum 4, but detailed explanation thereof will be omitted here.

In the figure, a cartridge main shaft 5A formed by deforming a portion of the photosensitive drum 4A and a drive transmission gear 6A fitted to the main shaft 5A are exposed on the side surface of the cartridge housing that is connected to the apparatus main body. This gear 6A is partially modified and has a drive pin receiving rib 6C for receiving the drive pin 3B on the device main body side. On the other hand, the photosensitive drum 4A is supported with respect to the housing 7A with the cartridge housing engaging portion 6B being pivotally supported by the housing 7A.
A drum drive gear 3A is attached to a person so that it can rotate freely.The gear 3A is driven by a drive means (not shown), and has a drive pin that is movable in the left and right direction and is held by a spring so as to always protrude in the direction of the cartridge shown in the figure. It has 3B on it. With the above configuration, when the cartridge is moved in the direction of the arrow and completely installed in the apparatus main body, the cartridge main shaft 5A engages with the main bearing 2A of the apparatus main body, and the cartridge is positioned. When the drum drive gear 3A rotates in this state, the rotating drive pin 3B engages with the drive pin receiving rib and pushes the drum 4A in the rotating direction, and as a result, the photosensitive drum 4A rotates.

(Problems to be Solved by the Invention) The above configuration has the effect of downsizing the cartridge, but if the diameter of the photosensitive drum becomes small or the length in the rotation axis direction becomes longer than the diameter, drum 4
Since the support position of A and the position where the driving force is transmitted to this drum are misaligned in the direction of the rotation axis, a biased force is applied, causing the drum 4A to vibrate or become unable to rotate smoothly. It may happen.

In view of the above-mentioned problems, the present invention provides a process cartridge having a photosensitive drum positioning and drive transmission mechanism that can sufficiently withstand the reduction in the diameter of the photosensitive drum, the increase in the length in the rotational direction, and the thinning of the drum. It provides: At the same time, by eliminating the cartridge main shaft 5 provided on the photosensitive drum 4 as shown in each of the above figures and concentrating each function within the width of the drum, we have created a process cartridge that also has the effect of sufficiently protecting the cartridge against shock. provide. Further, as the diameter of the photosensitive drum becomes smaller, it becomes possible to use a flange made of an insulating material such as resin, thereby realizing a reduction in the size and weight of the cartridge.

(Means for solving problems) The process cartridge that solved the above problem.

A bearing part is provided at the end of the image carrying drum, and when this cartridge is loaded into the apparatus main body, it fits with a positioning shaft for the image carrying drum attached to the apparatus main body, and a rotation center of the image carrying drum. a driving force receiving means provided integrally and concentrically with the image bearing drum with respect to the shaft and receiving a rotational driving force for rotationally driving the drum, a positioning bearing portion for the drum and a driving force receiving means; are arranged at least partially overlapping positions in the radial direction from the center of rotation of the drum.

Further, in a process cartridge using an insulating flange, an image comprising a metal drum member, an insulating flange member at the end, and a conductive member fixed to the inner circumferential surface on the back side of the flange member of the drum member. a bearing drum, and a bearing portion provided on the flange of the image bearing drum, which engages with a positioning shaft for the image bearing drum attached to the apparatus main body when the cartridge is loaded into the apparatus main body;
a driving force receiving means that is provided integrally and concentrically with the image bearing drum with respect to the central axis of rotation of the image bearing drum and that receives a rotational driving force for rotationally driving the drum; The bearing portion and the driving force receiving means are arranged at least partially overlapped in the radial direction from the rotation center of the drum, and the conductive member of the image bearing drum is arranged at a position in contact with the positioning shaft in a loaded state. .

The present invention provides the above-mentioned process cartridges and an image forming apparatus having an apparatus main body in which these cartridges are loaded.

(Example) FIGS. 1 and 2 are cross-sectional views for explaining the process cartridge to which the present invention is applied and its connection with the main unit. In FIG. A driving gear part 2a and a housing engaging part 2b,
A resin flange 2 having a receiving portion 2f for a drum drive shaft in the center is fitted and fixed. Reference numeral 3 denotes a housing of the cartridge, and a part of the drum receiving part 3a supports the drum 1 by receiving a flange engaging part 2b. The drum drive shaft 4 is a member that positions the drum 1 by fitting into the drive shaft bearing part 2f, and is pivotally supported on the side plate 7 of the main body of the apparatus by a spring bearing member/bearing 5 and a bearing 6.

It is rotationally driven by a chain sprocket 8. A drive transmitter lO that transmits the rotation of the drive shaft 4 to the drum is held by a fixed member 11 with respect to the drive shaft 4 so as not to idle in the circumferential direction, and is movable in the axial direction of the drive shaft 4. , are always urged toward the drum by the coil spring 12. Further, the drive transmitter 10 has a protrusion 10a,
When the drive shaft 4 rotates, this protrusion 10a becomes the resin flange 2.
The drive transmission mechanism rotates the photosensitive drum 4 by engaging with the portion 2d.

Note that a conductive plate 13 is firmly fixed to the inner wall of the drum.
, and when the cartridge is loaded into the main body of the device,
The spring portion 13a contacts the drive shaft 4 and establishes electrical continuity with the main body of the device.

In the above configuration, when the cartridge is installed in the main body,
First, the tip of the drive shaft 4, which also serves to position the cartridge, fits into the drive shaft bearing portion 2f of the resin flange 2, and the positions of the cartridge and the photosensitive drum 1 with respect to the main body of the apparatus are determined. If you push the cartridge further in, the drive transmitter l
The protruding portion 10a of the O engages with the receiving portion 2d of the flange 2, and feeding between the drive shaft 4 and the drum is completed. Projection 10a
If the position of the protruding part 10a and the receiving part 2d do not match, the tip of the protruding part 10a will be pushed against the surface 2e and the transmitter will be pushed to the left in the figure, but the drive shaft 4 will further rotate and the protruding part 10a and the receiving part will be pushed. When the position of the portion 2d is aligned, the coil spring 12 moves the transmitter 10 to the right in the figure, so that the protruding portion 10a and the receiving portion 2d are engaged, and the photosensitive drum rotates while being grounded (see Fig. 2). ).

FIG. 3 is a partially sectional perspective view showing a state in which the cartridge is engaged with the main body of the apparatus.

FIG. 4 is a partially sectional perspective view showing the positioning/driving shaft 4 side of the resin flanges 2 that directly engage with each other. FIG. 5 is a perspective view showing how the conductive plate 13 is attached to the photosensitive drum l, in which the protrusion 13b is engaged with the inner peripheral surface of the drum.

As shown in FIG. 6, the process cartridge has a gear portion 2b that includes a gear 14a that transmits a driving force to rotate the developing sleeve of a developing device 14 integrally supported within the cartridge, and a gear 14a that forces toner from a cleaning device 15 that is also integrally supported. It meshes with a gear 15a that transmits the driving force that rotates the screw for conveyance.

When the rotational force of the flange 2 is further transmitted to other means by the gear portion 2b in this manner, the force that tends to eccentrically shift the flange 2 with respect to the drum drive shaft 4 increases due to the load of each transmitted gear.

However, as in the present invention, the drive shaft 4 and flange 2 of the drum
When a high load is applied to the gear part due to at least a part of the fitting part 2C with the gear part 2b being placed in a position where at least part of it overlaps in a direction perpendicular to the direction of the rotation axis. However, deformation and eccentricity of the gear portion 2b can be well suppressed.

On the other hand, in the present invention, since the transmission from the main body of the apparatus to the process cartridge is carried out within the width of the photosensitive drum l, as shown in FIG. The rotation center shaft of the photosensitive drum does not protrude, and the flange with a complicated shape for receiving the drive does not become exposed to a large extent.Therefore, the positioning member becomes an important structure in connection with the main body of the device. The drive member will not be damaged or deformed even by rough handling.

FIG. 8 is a sectional view of the main parts of an electrophotographic copying apparatus to which the process cartridge of the present invention is applied.

The illustrated apparatus 19 is a copying apparatus using electrophotography, in which a photosensitive drum l having a photoconductive layer provided on a conductive drum base is rotatably supported in the direction of the arrow. This drum
Around the drum, a corona discharger 1 is installed according to the direction of rotation of the drum.
6. Short focus optical element array 17. Developing device 14. A transfer corona discharger 1g and a cleaning device 15 are provided.

In this device t16, the photosensitive drum 1, the discharger 16, the developing device 14, and the cleaning device 14 are integrally supported by the housing 3. This casing 3 is guided and supported by guide rails 20 fixed to the main body side, and is attached to and removed from the main body device. Note that the developing device 14 is
It has a conventionally well-known hopper 14a in the upper part for storing developer, and has a developing roller 14b in the lower part for supplying toner to the photosensitive drum 2. Specifically, as the developer, a two-component developer using magnetic toner or a two-component developer using toner and a magnetic carrier can be used.

Further, as the developing roller 14b, it is possible to use a rotating magnetic roller having a magnetic pole on its surface, or a rotating magnetic roller having a magnetic roller inside and a non-magnetic sleeve provided along the surface of the roller. Further, as the cleaning device, one using a blade plate or one using a fur brush can be used.

In the copying apparatus described above, the surface of the photosensitive drum l is uniformly charged with a predetermined polarity by the corona discharger 16, and then the document on the document table 21 that moves back and forth at the upper part of the apparatus main body is illuminated by the lamp 22, and the reflected light is transmitted to the element array. 17 to form a latent image on the drum l. The formed latent image is developed by a developing device 14, and the developed image is transferred by a transfer corona discharger 18. The transfer material is supplied to the transfer material supply cassette 23 by an operator's manual operation, and is conveyed to the transfer section via a conveyance roller 24 and a timing roller 25. After the transfer, the transfer material is sent to the fixing device 27 via the moving path 26 and fixed thereon, and then sent to the paper ejection tray 30 via the ejection roller 29.
sent upwards.

(Other Embodiment 1) In the above-described embodiment apparatus, the driving force for positioning the drive of the photosensitive drum 1 and the rotation of the drive shaft is transmitted to the inside of the drum. However, the positioning shaft provided in the main body of the apparatus does not necessarily rotate. There's no need to be.

FIG. 11 is a sectional view showing the engaged state of the process cartridge and the apparatus main body, and the cartridge positioning shaft 31 fixed to the side plate 7 of the apparatus main body is fitted into the engaging portion 2f of the resin 7 flange 2 of the photosensitive drum l. are mated. In this state, the drum drive gear 32 on the apparatus main body side is engaged with the gear portion 2b of the flange 2, and as the drum drive gear 32 rotates, the second flange 2 rotates, and as a result, the photosensitive drum l rotates. do. Of course, the gear portion 2b of this flange 2 is
As shown in FIG. 6 above, gears for driving the process means within the cartridge may also be engaged with each other.

FIG. 12 is a perspective view showing how the flange 2 and the drum driving gear 32 are engaged.

The gear 32 and other gears 33 are supported by a gear support side plate 34. This support side plate 34 is pivotally supported by a swing center shaft 35, and assumes an engaged position and a disengaged position in conjunction with attachment and detachment of the cartridge.

In the above embodiment as well, the fitting portion 2f where the cartridge positioning shaft 31 fits into the flange 2 is the drum gear portion 2b to which the driving force is transmitted.

Or to the drum gear section 2b that transmits this transmitted driving force to the drive gear of the process means in the cartridge,
They overlap in a direction perpendicular to the central axis direction.

Therefore, even if an eccentric external force is applied to the photosensitive drum, it is possible to hold the flange 2 in the most stable state. Also in this embodiment, the photosensitive drum l has a small portion protruding from the housing 3 of the cartridge, and each part for positioning and drive transmission is also protected by the housing 3.

In the above embodiment, the photosensitive drum 1 is composed of a metal drum member that forms the cylindrical portion and a resin flange (for example, a polycarbonate resin containing fluorine is used) that forms the flange.

In this way, by overlapping the positioning position and the drive delivery position to the photosensitive drum in the radial direction of the drum, a large biased force is not generated, making it possible to widen the selection range of materials for the flange.

(Other Example 2) In the above example, the photosensitive drum l and the flange 2 were constructed as separate members, but the flange 3 was formed by molding.
This is also effective for the photosensitive drum 39 in which 6 is integrated.

FIG. 13 shows a photosensitive drum 39 that employs a positioning mechanism corresponding to the configuration shown in FIG.
9 through the bearing material 37. Further, a gear 38 is fixedly attached to the flange portion 36 by press fitting or adhesive.

In this embodiment, the positioning of the drum and the relationship between this positioning position and the position of the gear 38 employ the configuration of the present invention described above.

Further, FIG. 14 employs a positioning mechanism corresponding to the configuration of FIG. 11, and achieves the effects of the present invention in the same manner as FIG. 13 described above.

(Other Embodiment 3) In the above embodiments, a photosensitive drum was used as an example of the image bearing drum, but when forming a latent image using modulated ions or multi-stylus electrodes, an insulated drum can be used instead of the photosensitive drum.

Next, let's talk about the structure of the process cartridge.

Although the case where the image bearing drum, the corona discharger, the developing device, and the cleaning device are integrally supported by the casing has been exemplified, for example, the image bearing drum and the discharger, or the image bearing drum and the cleaning device,
Alternatively, the image bearing drum, the developing device, and further other process means of the main body of the apparatus may be selectively integrated by a housing.

In addition to electrophotographic copying machines, image forming apparatuses employing process cartridges having the above-mentioned photosensitive drums include printers that use modulated laser light instead of reflected light from a document.

(Effect of invention) i, ? Recently, the receiving part on the cartridge side for the drum drive shaft and the cartridge positioning shaft on the body side is inside the cartridge housing, so it is safe from being scratched or deformed from the outside.

2. Since the positioning section, driving amount section, or transfer section does not protrude from the cartridge housing, the cartridge can be made smaller and the apparatus main body can be made smaller and lighter.

3. With respect to the position of the gear that transmits the driving force to the inside of the cartridge or the gear that directly receives the driving force, the position where the shaft is supported for positioning is at least partially overlapped in the direction perpendicular to the central axis of the positioning shaft. Because it supports the gear, eccentricity and deformation of the gear can be suppressed even under high loads.

[Brief explanation of the drawing]

FIG. 1 and FIG. 4Z are partial sectional views of a process cartridge and an apparatus main body according to an embodiment of the present invention. FIG. 8 is a sectional view of an electrophotographic copying machine to which the cartridge of the present invention is applied; FIG. 9 is a perspective view of a conventional cartridge; FIG. FIG. 11 is a partial cross-sectional view of a cartridge and apparatus main body of another embodiment, FIG. 12 is a partial perspective view of the apparatus shown in FIG. 11, and FIGS. 13 and 14 are flange portions of a photosensitive drum to which the present invention is applied. A partial cross-sectional view illustrating an embodiment of the invention is shown. In the figure, l is a photosensitive drum, 2 is a resin 2-lunge, 3 is a cartridge housing, 4 is a drum drive shaft, 10 is a drive transmission element, 13 is a conductive plate, 19 is an electrophotographic copying machine, 31 is a cartridge positioning shaft, 38 is a press-fit gear, and 39 is a photosensitive drum.

Claims (11)

[Claims] (1) In a process cartridge that integrally supports an image-bearing drum and a process means, it is provided at the end of the image-bearing drum, and when this cartridge is loaded into the apparatus main body, the image-bearing drum installed on the apparatus main body side a bearing portion that fits with the positioning shaft of the image bearing drum; and a driving force receiving portion that is provided integrally and concentrically with the image bearing drum with respect to the rotation center axis of the image bearing drum and receives a rotational driving force for rotationally driving the drum. A process cartridge comprising: a positioning bearing for the drum and a driving force receiving means, wherein the drum positioning bearing and the driving force receiving means are arranged at least partially overlapping in a radial direction from the center of rotation of the drum. (2) In a process cartridge that integrally supports an image-bearing drum and a process means, it is provided at the end of the image-bearing drum, and when this cartridge is loaded into the apparatus main body, the image-bearing drum installed on the apparatus main body side a bearing portion that fits with the positioning shaft of the image bearing drum; and a driving force receiving portion that is provided integrally and concentrically with the image bearing drum with respect to the rotation center axis of the image bearing drum and receives a rotational driving force for rotationally driving the drum. and drive transmission means for the process means for transmitting the driving force of the receiving means to other process means in the cartridge, the positioning bearing for the drum, the driving force receiving means and the process means. A process cartridge characterized in that a drive transmission means for the drive means is disposed at a position that at least partially overlaps in a radial direction from the center of rotation of the drum. (3) The process cartridge according to claim (2), wherein the same member serves as the drive force receiving means and the drive transmission means for the process means. (4) In a process cartridge that integrally supports an image-bearing drum and a process means, there is a conductor fixed to the metal drum member, an insulating flange member at the end, and an inner circumferential surface on the back side of the flange member of the drum member. a bearing provided on the flange of the image carrying drum, which engages with a positioning shaft for the image carrying drum attached to the apparatus main body when the cartridge is loaded into the apparatus main body; and a driving force receiving means that is provided integrally and concentrically with the image bearing drum with respect to the rotation center axis of the image bearing drum and receives a rotational driving force for rotationally driving the drum, The positioning shaft bearing portion for the drum and the driving force receiving means are arranged at least partially overlapped in the radial direction from the rotation center of the drum, and the conductive member of the image bearing drum is arranged at a position in contact with the positioning shaft in a loaded state. A process cartridge characterized by: (5) The process cartridge according to claim (4), wherein the same member serves as the drive force receiving means and the drive transmission for the process means. (6) In an image forming apparatus that uses a process cartridge that integrally supports an image bearing drum and a process means, it is provided at the end of the image bearing drum, and when this cartridge is loaded into the apparatus main body, it is attached to the apparatus main body side. a bearing portion that fits with the positioning shaft for the attached image bearing drum; and a rotational drive unit that is provided integrally and concentrically with the image bearing drum with respect to the central rotational axis of the image bearing drum, and that rotates the drum. a drive force receiving means for receiving a force, the process cartridge having a drive force receiving means for receiving a force, wherein the drum positioning bearing portion and the drive force receiving means are arranged at a position where at least a portion thereof overlaps in a radial direction from the rotation center of the drum; , an image forming apparatus comprising: a guide means for attaching and detaching the cartridge; a positioning shaft that fits into a positioning shaft bearing portion of the image bearing drum; and a drive means for driving the image bearing drum. . (7) The image forming apparatus according to claim (6), wherein the same means serves as the positioning shaft and the driving means. (8) In an image forming apparatus using a process cartridge in which an image bearing drum and a process means are integrally supported, a process means arranged opposite to the image bearing drum and driven to operate, and an end portion of the image bearing drum. When this cartridge is loaded into the main body of the apparatus, a bearing part that fits with a positioning shaft for the image carrying drum attached to the main body of the apparatus, and a bearing part that fits with the positioning shaft for the image carrying drum attached to the main body side of the apparatus, and a shaft bearing part of the image carrying drum with respect to the central axis of rotation of the image carrying drum. A driving force receiving means that is provided integrally and concentrically with the drum and receives a rotational driving force for rotationally driving the drum, and a process means for transmitting the driving force from this receiving means to other process means in the cartridge. and a drive transmission means for the drum, wherein the positioning bearing for the drum, the drive force receiving means, and the drive transmission means for the process means are located at a position where at least a portion of them overlap in a radial direction from the rotation center of the drum. The present invention includes a disposed process cartridge, a guide means for attaching and detaching the cartridge, a positioning shaft that fits into a positioning shaft bearing portion of the image carrying drum, and a driving means for driving the image carrying drum. An image forming apparatus characterized by: (9) The image forming apparatus according to claim (8), wherein the same member serves as the drive force receiving means and the drive transmission means for the process means. (10) In an image forming apparatus using a process cartridge in which an image bearing drum and a process means are integrally supported, a metal drum member, an insulating flange member at the end, and an inner part on the back side of the flange member of the drum member. An image carrying drum equipped with a conductive member fixed to the circumferential surface, and a positioning member provided on the flange of the image carrying drum for positioning the image carrying drum attached to the apparatus main body when this cartridge is loaded into the apparatus main body. a bearing portion that fits with the shaft; and a driving force receiving means that is provided integrally and concentrically with the image bearing drum with respect to the rotation center axis of the image bearing drum and receives a rotational driving force for rotationally driving the drum. a process cartridge, wherein the positioning shaft bearing for the drum and the driving force receiving means are arranged at a position where they overlap at least partially in a radial direction from the center of rotation of the drum; and a guide for attaching and detaching the cartridge. a positioning shaft that fits into a positioning shaft bearing portion of the image bearing drum and engages with an electrically conductive member on the rear side of the flange; and a drive means for driving the image bearing drum. Image forming device. (11) The image forming apparatus according to claim (10), wherein the same member serves as the drive force receiving means and the drive transmission means for the process means.