JPH066355Y2 - Process cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a process cartridge (hereinafter abbreviated as PC cartridge) that can be attached to and detached from a main body of an image forming apparatus.

Here, the image forming apparatus includes an electrophotographic copying machine, an electrostatic recording device, and the like.

[Prior Art] A PC cartridge detachable image forming apparatus generally includes a plurality of process devices out of all process devices for image formation, such as an image carrier (electrophotographic photoreceptor, electrostatic recording dielectric, etc.).
A device having a structure in which all process devices such as a developing device, a cleaning device, and a charging device are collectively attached to a common cartridge housing as a PC cartridge (unit) that can be attached / detached to / from the image forming apparatus main body. Is.

By making the image forming apparatus detachable from the PC cartridge as described above, the maintainability and serviceability of the image forming apparatus are improved. Further, as the PC cartridge, for example, a user prepares a plurality of PC cartridges having different functions such as developing colors, and the PC cartridge having the function suitable for the purpose is exchangeably attached to the main body of the image forming apparatus.
There is an advantage that the same image forming apparatus main body can be used for multiple functions. Therefore, for example, it has already been put into practical use as one of the configuration methods of a personal type small and light image forming apparatus.

Here, the dry developing device uses a one-component magnetic toner developer or a non-magnetic toner as a developer, and coats a thin layer on the surface of the developer carrying member to magnetically or magnetically coat the surface of the developer carrying member. Is a method of electrostatically adhering and carrying it on the surface of the image carrier, or a method of using a two-component developer and carrying it on the surface of the developer carrying member and applying it to the surface of the image carrier. The ones are in practical use. However, both of them are in operation, a developing area which is an opposed portion of the image bearing member and the developer bearing member on the developing device side, and a downstream side portion in the surface moving direction of the image bearing member (hereinafter referred to as developing device). The lower side) and the upstream side (hereinafter referred to as the upper side of the developing device)
More or less, the developer scatters.

The scattered developer is one of the causes of deteriorating the function of the equipment by contaminating the process equipment in the image forming apparatus, for example, the discharge line of the charger, the optical member, etc. There is a risk of causing soiling or fogging.

When the developing device is incorporated in the PC cartridge, a considerably severe vibration or shock given in the process of attaching and detaching the PC cartridge to the main body of the image forming apparatus, or the PC cartridge removed from the main body of the image forming apparatus is shaken. The developer is likely to be scattered due to vibrations or impacts that are given when tilted or stored in a storage shelf or the like. Therefore, there is a possibility that the scattered developer may cause the functional deterioration of the above-mentioned device and may cause the background stain or fogging on the image. Further, the scattered developer may leak to the outside of the PC cartridge and stain the operator's hands, clothes, floors and other peripheral articles.

Therefore, conventionally, with respect to the scattered developer on the lower side of the developing device, a collecting container for receiving the scattered developer is provided on the lower side of the developing device, or a sheet member is provided in contact with the developer carrying member. For the scattered developer on the side, the leading end portion is brought into contact with the image carrier surface portion on the upstream side in the surface moving direction of the image carrier relative to the developing area, and the seal sheet member (polyethylene terephthalate sheet (trade name Mylar) is used. Etc. are provided to block the scattered developer flow passage leading from the developing area to the exposure opening side of the image carrier.

With the above-described treatment structure, the scattered developer is considerably prevented from leaking out of the developing device or the PC cartridge.

[Problems to be Solved by the Invention] By the way, no effective treatment was found for the scattered developer generated on the upper side of the developing device. The scattered developer includes aggregates of toner particles as well as cloud-like bodies of individual toner particles. The scattered developer in the form of a cloud of individual toner particles adheres to the inner surface of the above-mentioned seal sheet member and is captured to a small extent. However, the scattered developer as an aggregate of toner particles may not be captured by the seal sheet member and may drop into the developing area again, enter the developer layer portion of the developing area, and accumulate in the portion. The toner particle agglomerates accumulated in the developer layer portion have a holding force by the developer holding member that is not particularly electrostatically or magnetically stronger than the individual toner particles, and thus is similar to a PC cartridge. In the case of a developing device that is frequently attached to and detached from the main body of the image forming apparatus and has strong vibrations and shocks built-in, the vibrations and shocks cause the toner particle aggregates to relatively easily develop in the development area. It moves downward in the agent layer portion. Then, the image quality is degraded as described above.

The present invention effectively captures the aggregates of toner particles contained in the floating developer generated in the process cartridge, and prevents not only the deterioration of image quality but also the aggregation of toner particles outside the PC cartridge. The purpose is to eliminate the problem of falling and scattering into the air.

[Means for Solving the Problems] The present invention provides a frame, an image carrier provided on the frame, and an image carrier on the frame in a process cartridge detachable from the main body of the image forming apparatus. And a developer carrying member provided to face the developer carrying member in the process cartridge in order to capture the scattered developer in the process cartridge. And a unit developer catching member having continuous porosity cells.

[Operation] The scattered developer generated inside the process cartridge due to vibration or impact when the PC cartridge is attached to or detached from the main body of the image forming apparatus is a scattered developer as a cloud-shaped body of individual toner particles, and a toner particle aggregate. Any of the scattered developers as described above is permeated into the cell of the above-mentioned trapping member to be trapped, and is stably held by the trapping member.

[Embodiment] FIG. 1 shows a main part of an example of a PC cartridge detachable electronic copying apparatus.

The embodiments described below include at least an image carrier and a dry developing device for developing a latent image on the surface of the image carrier, which is a process cartridge detachable from the main body of the image forming apparatus. An increased exposure opening for the carrier,
A process cartridge attachable to and detachable from an image forming apparatus, in which a catching member is disposed in a space between a developer carrying member on the developing device side and a developing area facing the image carrier.

In the figure, A is a PC cartridge which can be freely attached to and detached from the main body of the electronic copying apparatus, and in the case of the apparatus of this example, a photosensitive drum 1 as an example of an image carrier and a charger for charging the peripheral surface of the drum 1. 2, the developing device 3, and the cleaning device 4, which are four process devices, are collectively put together in a cartridge housing 10 as a PC cartridge that can be attached to and detached from the main body of the electronic copying device in a predetermined mutual arrangement relationship. It is assembled. The PC cartridge A
Is a guide rail 11.1 for a predetermined part in the main body of the electronic copying apparatus.
It is inserted and mounted along the direction 1 and at a right angle to the drawing, and is pulled out in the opposite direction and taken out.

When the PC cartridge A is fully inserted and mounted in the main body of the electronic copying apparatus, the mutual coupling members (not shown) of the mechanical driving system and the electric circuit system on both sides of the main body of the electronic copying apparatus and the PC cartridge A side are connected. Integrate mechanically and electrically.

The photosensitive drum 1 is rotationally driven around the shaft 1a in a direction of an arrow at a predetermined peripheral speed, and in the course of the rotation, the peripheral surface of the photosensitive drum 1 is positively or negatively charged uniformly, and then the housing of the PC cartridge A. Image exposure opening 5 formed on the ceiling surface of 10
Through the optical image exposure device (not shown) on the main body side of the electronic copying device, the optical image is subjected to slit exposure L or laser beam scanning exposure. As a result, electrostatic latent images corresponding to the exposed image are sequentially formed on the peripheral surface of the photosensitive drum 1.

The latent image is then sequentially developed with toner by the developing device 3,
The developer is sequentially transferred to the transfer material P by the transfer device 13 on the electronic copying apparatus main body side. The transfer material P is fed from a paper feed unit (not shown), synchronized with the rotation of the photosensitive drum 1 by the registration roller pair 12, and fed between the drum 1 and the transfer device 13 to form a developed image on the drum 1 side. Are sequentially transferred.

The transfer material P that has undergone image transfer is sequentially separated from the surface of the drum 1 and sent to a fixing device (not shown) to undergo image fixing, and is discharged outside the machine as a copy.

On the other hand, the surface of the photosensitive drum 1 which has passed the position of the transfer device 13 and from which the transfer material P has been separated is cleaned by the cleaning device 4 after the transfer residual developer is removed. Next, the pre-exposure opening 6 formed on the ceiling surface of the housing 10 of the PC cartridge A
Through the pre-exposure device 14 (not shown) on the electronic copying apparatus main body side.
Then, the residual charge is removed by receiving the uniform pre-exposure 1 on the entire surface, and the charge is again uniformly charged by the charger 2 to be repeatedly used for image formation.

In the developing device 3 of this example, a two-component β developer T composed of magnetic particles and non-magnetic toner is used as a developer, and the magnet roller 32 as a magnetic field generating means is inserted therein without rotation. A non-magnetic developing sleeve 31 as an example of a built-in developer carrying member that is rotationally driven in the direction of the arrow is supplied on the developer container 33 side. And the layer thickness regulation plate 34
The thickness of the layer is regulated by the magnetic field to be magnetically carried on the surface of the developing sleeve 31, and the carried developer is spilled into the developing area a facing the photosensitive drum 1 by the rotation of the developing sleeve 31 to develop the latent image. It is a method of making it.

FIG. 2 is an enlarged model diagram of the developing area a, in which the photosensitive drum 1 and the developing sleeve 31 face each other with a predetermined gap. An appropriate developing bias is generally applied between the both 1 and 31. In the developing area portion a, the carried developer on the side of the developing sleeve 31 has the magnetic particles c in the developing sleeve 3 due to the developing magnetic pole 32a of the magnet roll 32 existing in the developing sleeve 31.
1 and the photosensitive drum 1 are in contact with the surface of the photosensitive drum 1 while standing in a gap between them. Toner particles t are electrostatically contained in the magnetic particles c which are erected, and the toner particles t selectively adhere to the latent image pattern on the side of the photosensitive drum 1 and are transferred to sequentially form latent images. The toner is developed.

Reference numeral t'denotes an aggregate of toner particles contained in the developer carried on the developing sleeve 31 (magnetic brush of the developer). Such toner particle aggregates t'are substantially absent at the initial stage of use of the developing device (before the endurance), but gradually occur as they are used (as the endurance progresses). The toner particle aggregate t ′ is also generated in the heat fixing toner, but is remarkably generated in the pressure fixing toner which is apt to aggregate.
Further, when the particle size of the toner t is small, it tends to occur.

Thus, such toner particle aggregates t'are included in the scattered developer generated by the vibration and shock at the upper side of the developing device during the operation of the developing device or the attaching / detaching operation of the PC cartridge A. As shown in the first illustration, the tip of the scattered toner component in the scattered developer as a cloud-shaped body is formed on the surface of the photosensitive drum 1 upstream of the developing area a in the surface moving direction of the photosensitive drum 1. The seal sheet member 7 (25 μm thick polyethylene terephthalate sheet) provided in contact with each abdomen adheres to and is collected on the inner surface side. On the other hand, the toner particle agglomerates are not captured but fall again and stay in the developer magnetic brush in the developing area a or on the magnetic brush (FIG. 2).
The accumulated toner particle agglomerates t ′ easily pass through the developer magnetic brush in the developing area a due to vibration or impact when the PC cartridge A is attached or detached, and the image quality is deteriorated. It will fall out of the cartridge and be scattered.

In FIG. 1, reference numeral 8 denotes an image exposure opening 5 for the photosensitive drum 1 and a developing sleeve 31 facing the photosensitive drum 1 in accordance with an embodiment to which the present invention is applied in order to solve the above problems as much as possible. A foaming member is provided in the space between the area a and the inner surface of the housing 10 of the PC cartridge A so as to face the upper surface of the developing sleeve 31 and to be attached over the entire length of the developing sleeve 31. The foam member 8 is a continuous porosity, for example, a sponge or Everlite Scott (trade name) having 15 to 40, preferably 20 to 35 cells per 25 mm ² , and other felt having a relatively small density.

Thus, among the scattered developer generated on the upper side of the developing device, the scattered developer as a cloud-like body of individual toner particles adheres to the inner surface of the seal sheet member 7 or the surface of the foam member 8 or the foam member. It enters into the cell of 8 and is captured. Further, the toner particle aggregates permeately enter the cells of the foaming member 8 and are captured, are stably held by the foaming member 8, and once enter the cells of the foaming member 8 and are captured, the toner particle aggregates are PC. Even if the cartridge A is attached or detached, it does not easily fall even if violent vibration or shock is applied. Therefore, the toner particle agglomerates are not collected and fall again, and enter the developing area a, so that the image quality is deteriorated and the toner particle agglomerates t ′ (FIG. 2) are scattered to the outside of the PC cartridge. The problem of is solved as much as possible.

The foaming member 8 is preferably on the upper facing surface of the developing sleeve 31, but if it exists in the space between the image exposure opening 5 and the developing area a, the same effect as described above can be expected. or,
By using together with the seal sheet member 7 in FIG. 1, it is possible to prevent the toner from scattering from the image exposure opening portion 5, and further improvement in the handleability of the PC cartridge A can be expected.

In the embodiment shown in FIG. 1, the foam member 8 is attached to the inner surface of the cartridge housing 10, but it may be attached to the upper portion of the developing device 3 itself. Further, it may be sandwiched between the inner surface of the cartridge housing 10 and the developing device 3.

Further, in this embodiment, the developing device of the type in which the two-component developer T is used and the developer is carried on the developing sleeve 31 and is brought into contact with the photosensitive drum 1 in the developing area a, is described as an example. The formula may be used, and the developer scattering prevention effect can be similarly expected in the case of a developing device using a one-component developer.

[Advantages of the Invention] As described above, according to the present invention, it is possible to reduce the amount of floating toner in the process cartridge caused by handling of the PC cartridge, and thereby to remove the toner aggregates in the developing area, thereby improving the image quality. We were able to achieve stabilization. Further, it was possible to prevent the toner from leaking to the outside of the process cartridge.

[Brief description of drawings]

FIG. 1 is a sectional view of a process cartridge portion to which an embodiment of the present invention is applied, and FIG. 2 is an enlarged model view of a facing developing portion of a photosensitive drum and a developing sleeve. In the figure, A is a process cartridge, 1 is a photosensitive drum, 3 is a developing device, and 8 is a foaming member (capturing member).

Claims (3)

[Scope of utility model registration request] 1. A process cartridge detachably mountable to an image forming apparatus main body, comprising: a frame; an image carrier provided on the frame; and a developer provided on the frame so as to face the image carrier. A carrying member, and a developing device having continuous pores, which is provided above the developer carrying member in the frame so as to face the developer carrying member and capture the scattered developer in the process cartridge. A process cartridge comprising: an agent capturing member; 2. The continuous porosity cell comprises 15 per 25 mm ^2.
The process cartridge according to claim (1), wherein the utility model registration has 40 to 40 cells. 3. The process cartridge according to claim 1, wherein the developer capturing member is a sponge or a felt having a relatively low density.