JPH0449631Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention [Field of Industrial Application] The present invention relates to a process cartridge that is detachable from the main body of an image forming apparatus such as an electrophotographic copying machine or an electrostatic recording device.

[Prior Art] An image forming apparatus with a removable process cartridge uses a certain number of process devices, such as an image carrier (electrophotographic photoreceptor, static A common cartridge housing used as a process cartridge (unit) that can be attached to and removed from the main body of the image forming apparatus as a whole for processing devices such as electric recording dielectrics, developing devices, cleaning devices, charging devices, etc. This is a device that is assembled together.

By making the image forming apparatus removable with a process cartridge as described above, maintainability, serviceability, etc. of the image forming apparatus are improved. In addition, the user can prepare multiple process cartridges with different functions, such as developing colors, and then install the cartridges with the functions that suit the purpose into the main body of the image forming apparatus in exchange, so that the same image can be produced. This method has advantages such as the ability to use the main body of the forming apparatus for multiple functions, and has been put to practical use as one of the construction methods for, for example, a personal type small and lightweight image forming apparatus.

FIG. 2 shows a schematic configuration of an example of an image forming apparatus (electrophotographic copying machine) with a removable process cartridge. FIG. 3 is an enlarged cross-sectional view of the removed process cartridge.

In the figure, reference numeral 1 denotes an exterior casing of the apparatus, and numeral 2 denotes a document table glass that is driven to reciprocate in the left and right directions a and b on the upper surface of the exterior casing 1. The original O is placed at a predetermined position on the original table glass 2 with the image to be copied facing downward, and is set by covering the original holding plate 3 thereon.

During the reciprocating or backward movement of the document table glass 2, the downward image surface on the glass 2 passes through the slit illumination section 4, and the image surface is sequentially illuminated by illumination lamps 5 from one end to the other end. Ru. 6 and 7 indicate an optical filter and a reflection plate of the illumination system.

Illumination reflected light from the downward image surface of the document passing through the slit illumination unit 4 enters a lens array 8 (for example, a self-occurring lens array), and an electrophotographic photosensitive drum 9 is driven to rotate at a predetermined circumferential speed in the direction of the arrow. (slit exposure L). The circumferential surface of the photosensitive drum 9 is uniformly charged positively or negatively by a charger 10 . Then, by subjecting the charged surface to slit exposure L of the original image,
Electrostatic latent images corresponding to the original image are sequentially formed on the circumferential surface of the drum.

The latent image formed on the peripheral surface of the drum is developed by a developing device 11, and the developed image is transferred onto a transfer material P by a transfer charger 12. The transfer material P is transferred to the transfer material cassette 13.
One sheet is fed out from inside by a paper feed roller 14 and a separating claw 15, and is fed between the drum 9 and the transfer charger 12 by a pair of registration rollers 16 in synchronization with the rotation of the photosensitive drum 9. The developed images on the 9th side are sequentially transferred.

The transfer material P that has undergone the image transfer is separated from the surface of the drum 9, sent to the fixing device 19 by the conveying device 18, undergoes image fixing processing, and is discharged to a tray 20 outside the machine as a copy. Ru.

On the other hand, the surface of the photosensitive drum 9 from which the transfer paper P has passed through the position of the transfer charger 12 is separated by the cleaning device 1.
In step 7, the developer remaining after transfer is removed and cleaned, and the image is repeatedly formed.

In the device of this example, a photoreceptor drum 9, a charger 1
A common cartridge housing 21 is used as a process cartridge A that can be attached to and removed from the main body of the image forming apparatus as a whole for four process devices: 0, developing unit 11, and cleaning unit 17.
They are assembled together. Then, the process cartridge A is inserted into a predetermined portion within the main body of the image forming apparatus along the guide support rails 22, 22, and conversely is pulled out and taken out.

When the process cartridge A is fully inserted and installed into the main body of the image forming apparatus, the mutual coupling members of the mechanical drive system and electric circuit system on both sides are connected, although not shown in the figure, and the cartridge A is
is mechanically and electrically integrated into the main body of the image forming apparatus.

Reference numeral 23 denotes an exposure slit window formed at the top plate position of the cartridge housing corresponding to the top surface position of the photosensitive drum 9, and when the cartridge A is inserted into the image forming apparatus main body, the lens array 8 on the image forming apparatus main body side is opened. located corresponding to the light output side. In the developing device 11, 11b is a developing sleeve that is rotationally driven in the direction of the arrow, 11c is a layer thickness regulating blade for a developer layer formed on the circumferential surface of the sleeve, and 11d is
indicates a rotating member that transports and stirs the developer (not shown) contained in the developing device toward the developing sleeve. In the cleaning device 17, 17a indicates a cleaning blade.

Now, if the process cartridge A does not include at least the image carrier, that is, the photosensitive drum 9 in the above example apparatus, when the process cartridge A is installed in the image forming apparatus main body, the bottom surface of the drum 9 will be in the image forming apparatus main body. In order to face the transfer charger 12 on the side, the process cartridge A has a form in which the lower surface side of the photosensitive drum 9 is relatively largely exposed on the lower surface side.

However, if the bottom surface of the photoreceptor drum 9 is left exposed in this way, when the cartridge A is removed from the image forming apparatus main body and stored, the surface of the drum 9 may be damaged by collision with other objects or exposed to strong external forces. Since there is a great possibility that light may cause optical memory, the process cartridge A is provided with a protective cover (protective cover) that covers and hides the exposed lower surface of the drum 9.

In FIGS. 2 and 3, reference numeral 24 denotes a protective cover, which is attached to the cartridge housing 21 via a link mechanism (not shown) or the like so as to be able to open and close freely relative to the exposed lower surface of the drum 9. When the process cartridge A is inserted into the image forming apparatus main body, this protective cover 24 is manually moved to the open position (indicated by the two-dot chain line in FIG. 3), or when the cartridge A is inserted into the image forming apparatus main body. It is automatically opened in conjunction with the insertion movement to. In addition, after the process cartridge A is removed from the image forming apparatus main body, it is manually moved to the closed position (shown by the solid line in FIG. 3) to hide and protect the exposed lower surface of the drum 9, or the cartridge A is removed. It will automatically close accordingly. Reference numerals 25 and 25 indicate light-shielding seal members that close the gap between the cover periphery and the drum exposure opening edge when the protective cover 24 is in the closed state.

[Problems to be solved by the invention] By the way, in the conventional process cartridge A as described above, the drum exposed lower surface protection cover 24 provided on the lower surface side is in the shape of an arc plate corresponding to the drum lower surface. Further, when the cover 24 is closed, its arcuate convex outer surface 24a projects downward from the lower surface of the cartridge A.

For this purpose, the process cartridge A is removed from the image forming apparatus main body and the cover 24 is closed, or the process cartridge A with the cover 24 automatically closed is placed on a storage stand or on the floor with its lower side facing down for storage. When placed on a surface etc., the arcuate convex outer surface 2 of the cover 24
Since the cartridge 4a was received against the storage table or the floor, the process cartridge A was actually uncomfortable and unstable. Therefore, when external force is applied due to external vibration or other objects getting caught,
Items that can easily swing unstably, shift, flip over, or fall from high places such as storage tables or desk surfaces; There was a risk that cartridge A would be damaged or developer would leak due to such impact.

The present invention makes it possible to stabilize the seating of the process cartridge A which has been removed from the main body of the image forming apparatus and placed on a mounting surface such as a storage mounting table, and also prevents the protective cover from being opened inadvertently. The purpose is to eliminate the

B. Structure of the invention [Means for solving the problems] To achieve the above object, the present invention provides an image bearing member and an action on the image bearing member in a process cartridge that can be attached to the main body of an image forming apparatus. a protective cover that is movable between a protective position that protects the image carrier and a retracted position that is evacuated from the protective position, and a flat portion provided on the protective cover, the protective cover The process cartridge is characterized in that the process cartridge can be placed on the placement surface by placing the flat portion on the placement surface while the process cartridge is located at the protected position.

[Function] Due to the presence of the flat portion provided on the protective cover, the process cartridge placed on the mounting surface of the mounting member is in a stable sitting state on the mounting surface of the mounted member. This eliminates the problems caused by the unstable sitting position that existed in the past. In addition, when the process cartridge is placed on the mounting surface, the weight of the process cartridge itself is added to the protective cover, so this weight regulates the opening of the protective cover, and also controls the opening of the protective cover. By making it larger than the contact area with the placement surface, movement (opening) of the protective cover can be restricted.

[Embodiment] Now, FIG. 1 shows an embodiment to which the present invention is applied, and constituent members common to those of the conventional one shown in FIG.

Note that the embodiments described below include an image carrier,
A process cartridge for an image forming apparatus, which has an opening/closing protective cover for an externally exposed surface of the image carrier, the process cartridge being removed from the main body of the image forming apparatus;
When the process cartridge with the protective cover closed to the externally exposed surface of the image carrier is placed on the mounting member mounting surface with the protective cover side facing down, the mounting member mounting surface The protective cover and another member located closer to the center of gravity of the process cartridge than the protective cover are provided with a stable sitting flat portion that makes surface contact with the protective cover.

In the figure, 24b is a stable sitting plane part (flat part) provided on the protective cover (protective cover) 24 that hides the externally exposed lower surface of the photosensitive drum 9, which is an image carrier, and 11a is a flat part provided on the lower surface of the developing device. It is a stable sitting flat part. In the case of the process cartridge A of this example, its center of gravity is located closer to the developing device 11 than the position of the protective cover 24, and therefore, in this example, other members that are paired with the stably seated flat portion 24a of the protective cover 24 are used. A stable plane portion 11a is provided on the lower surface of the developing device 11. That is, in this example, stable seating planes 24b and 11a are provided on the protective cover 24 side and the developing device 11 side, respectively, and the process cartridge A is positioned at a relative position such that the center of gravity of the process cartridge A is located approximately in the middle position between the two. Each of the above has been set.

The protective cover 24 is thus removed from the main body of the image forming apparatus, and the protective cover 24 is in the closed state (the state shown by the solid line in FIG. 1) with respect to the externally exposed surface of the photoreceptor drum 9, which is the image carrier. ), that is, a protective cover that is movable between a protective position that protects the image carrier and a retracted position that is evacuated from this protective position, protects the process cartridge A that is in the protective position from the protective cover side. When the process cartridge A is placed downward on the mounting member plane (placing surface) 30, the stable sitting flat portions 24b, 11a are in surface contact with the mounting member plane 30, and the process cartridge A is placed on the mounting member plane 30. It is in a stable sitting position, does not cause unstable rocking, and does not move even if some external force or vibration is applied. In addition, opening of the protective cover is restricted by the weight of the process cartridge itself, and by increasing the contact area between the protective cover and the mounting surface, careless opening of the protective cover can be restricted. .

C. Effects of the invention As described above, according to the invention, the protective cover is provided with a flat part, and the process cartridge is placed on the mounting surface with the protective cover in the protective position. Since it is configured to be able to be placed on the placement surface, it is possible to achieve the remarkable effect that the process cartridge can be placed in a stable placement state and that the protective cover can also be prevented from being opened inadvertently.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of a process cartridge according to the present invention, and FIG. 2 is a schematic configuration diagram of an example of an image forming apparatus with a removable process cartridge.
FIG. 3 is a cross-sectional view of an example of a conventional process cartridge. In the figure, A is a process cartridge, 24
1 is a protective cover, 24b is a stable sitting plane part (flat part) provided on the cover, 11 is a developing device, 11
A is a stable sitting flat portion provided on the lower surface of the developing device.

Claims (1)

[Claims for Utility Model Registration] (1) A process cartridge that can be attached to an image forming apparatus main body, comprising: an image carrier, a process means that acts on the image carrier, and a protection position that protects the image carrier. and a protective cover that is movable from the protective position to a retracted position; and a flat part provided on the protective cover, and the flat part is movable when the protective cover is in the protective position. 1. A process cartridge, characterized in that the process cartridge is configured to be placed on a placement surface so that the process cartridge can be placed on the placement surface. (2) The process cartridge according to claim 1, wherein the image carrier is a photosensitive drum. (3) The process means includes a charging means for uniformly charging the image carrier, a developing means for developing a latent image formed on the image carrier, and a cleaning means for cleaning the image carrier. The process cartridge according to claim 1, which is at least one utility model registered.