JPH08137369A - Process cartridge - Google Patents

Abstract

PURPOSE: To reduce the number of parts and size in a longitudinal direction by integrally forming a shaft part holding a magnet roller and a developing sleeve with a holder. CONSTITUTION: Both end parts of the core metal part 101a of the magnet roller 101 are fixed on the holders 111a and 111b fixed in a developing unit main body 110 and one side 101a of the core metal part of the magnet roller is engaged with the shaft part 111c of the holder 111a. On the other hand, flange members 104a and 104b are force-fitted or stuck in both end parts of the developing sleeve 100 respectively, the flange member 104b is pivotally supported by the developing unit main body 110 via a bearing member 102 and the flange member 104a is engaged with the holder shaft part 111c, to be held. Thus, the shaft part 111c protruded from the holder 111a has the function of holding the end part of the core metal 101a on the nondriving side of the magnet roller 101 and the flange member 104a, so that the holding can be attained without providing bearing member 102 provided on a driving side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge for an image forming apparatus such as a copying machine or a laser printer which employs electrophotography.

[0002]

2. Description of the Related Art In many image forming apparatuses of copying machines, a process cartridge is detachably disposed in the main body of the apparatus to facilitate maintenance of the apparatus. An example of such a process cartridge will be described.

A copying machine is provided with a developing device for developing an electrostatic latent image formed on a photosensitive drum, which is an image carrier, through a developer (toner). A developing roller is provided in the developing device, and the toner in the developing device is supplied to the photosensitive drum by the action of the magnetic force of the developing roller.

Such a developing roller is, as shown in FIG. 7, a cylindrical developing sleeve 100 rotating in a fixed direction and a magnet roller 1 disposed in the developing sleeve 100.
01 and 01.

The magnet roller 101 has a core 10
Both ends of 1a are fixed to a holder 111 fixed to the developing device main body 110, and the developing sleeve 100 is arranged so as to cover the magnet roller 101 with a slight gap from the magnet portion 101b of the magnet roller 101. Both ends thereof are pivotally supported by the developing device main body 110 via bearing members 102.

Here, the magnet roller 101 maintains its rigidity by penetrating and adhering a core metal portion 101a made of a metal material such as iron to a comparatively soft rubber-based or vinyl chloride-based cylindrical magnet portion 101b. . Further, there is also one in which the core metal portion 101a and the cylindrical magnet portion 101b are integrally formed by injection molding using a plastic material.

[0007]

However, with the recent demand for downsizing of copying machines, downsizing of the developing device structure has also been required. Above all, there are severe restrictions on the space in the horizontal direction, and there is a demand for downsizing in units of several millimeters. There is a limit in the developing device configuration, and the length of the magnet roller 101 determines the space in the lateral direction, so that a compact design cannot be achieved.

A first invention according to the present application aims to solve the above problems and to provide a process cartridge which can be made compact.

In addition to the above object, the second invention of the present application aims to provide a process cartridge which can be made more compact.

Further, in addition to the above object, a third invention of the present application aims to provide a process cartridge capable of reducing the number of parts.

In addition to the above object, a fourth invention of the present application aims to provide a process cartridge having a magnet roller holding design which is easy.

[0012]

According to the first invention of the present application, the above object is to provide a process cartridge having a developing device having a magnet roller and a developing sleeve having the magnet roller therein. This is achieved by providing the holder supporting at least one end side of the magnet roller with the shaft portion supporting the developing sleeve.

According to the second invention of the present application, the above object is achieved by the shaft portion provided in the holder for supporting the magnet roller in the first invention being located in the developing sleeve. To be achieved.

Further, according to the third invention of the present application,
The above object is achieved in the above-mentioned second invention, in that the shaft portion provided in the holder for supporting the magnet roller also directly supports the developing sleeve.

Further, according to a fourth invention of the present application, in the above-mentioned first or second invention, the end shape of the supported magnet roller is concave, and the end of the concave shape is the same. This is achieved by engaging the shaft portion provided on the holder with the portion and supporting the magnet roller.

[0016]

According to the first invention of the present application, since the shaft portion provided in the holder for supporting the magnet roller holds the developing sleeve, a bearing member for holding the developing sleeve is not required, and the parts are Since the number of points is reduced and the bearing member is not required, the dimension in the longitudinal direction is shortened.

Further, according to the second invention of the present application, in the first invention, the shaft portion provided in the holder for supporting the magnet roller is located in the developing sleeve. The dimensions are shortened.

Further, according to the third invention of the present application,
In the second aspect of the invention, since the shaft portion provided in the holder that supports the magnet roller directly supports the developing sleeve, the number of parts is further reduced.

According to a fourth aspect of the present invention, in the first or second aspect of the invention, the supported end portion of the magnet roller has a concave shape, and the concave shape is provided on the holder. Since the formed shaft portion is engaged, various shapes such as a hole shape and a groove shape are allowed as the end shape of the magnet roller formed by injection molding, which facilitates the holding configuration design of the magnet roller.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 shows a cross section of a process cartridge 6, in which 1 is a photosensitive drum that is an image bearing member that rotates in a fixed direction. Around the photosensitive drum 1, a charging device 2, a developing device 3, and a cleaning device. Process equipment such as No. 4 is provided. And
These devices are integrally incorporated in the cartridge container 6a and are detachably provided as the process cartridge 6 in the main body of the image forming apparatus, so that, for example, the photosensitive drum 1 reaches the end of its life or the developing device. When the toner (developer) T in 3 is used up, the entire process cartridge 6 is replaced to facilitate maintenance.

The developing unit 3 is oriented toward the photosensitive drum 1 and has a developing section 10 having a developing roller 12 which is a developer carrying member, and a developing section 10 which holds toner T therein and supplies the toner T to the developing section 10. Although it is composed of the agent storage section 11, a lid member 13 having an opening 13 a is sandwiched and held between the developing section 10 and the developer storage section 11. A sealing device (not shown) is attached to the opening 13a of the lid member 13, and the toner T in the developer accommodating portion 11 moves to the developing portion 10 when not in use, so that the toner T is transferred to the outside of the process cartridge 6. In addition to preventing the toner T from flowing out, when the process cartridge 6 is mounted in the main body of the image forming apparatus for use, the developer is operated by operating the sealing device to open the opening 13a. Storage 1
The toner in 1 can be supplied to the developing unit 10.

The cleaning device 4 includes a cleaning blade 4a for rubbing the photosensitive drum 1 to remove residual toner on the photosensitive drum 1, and a waste toner storage portion 4b for storing the waste toner removed by the cleaning blade 4a. The residual toner on the photosensitive drum 1 is cleaned to prepare the photosensitive drum 1 for the next image formation.

Reference numeral 5 is a shutter for protecting the photosensitive drum 1. When the process cartridge 6 is mounted in the main body of the image forming apparatus, the shutter 5 is retracted to one side of the photosensitive drum 1. Has become.

That is, when the photosensitive drum 1 uniformly charged by the charger 2 is exposed to the image light L from the scanning optical system (not shown), an electrostatic latent image is formed on the photosensitive drum 1. It The electrostatic latent image is directed toward the developing device 3 as the photosensitive drum 1 rotates, and the toner T is supplied by the developing roller 12 of the developing device 3 to be visualized as a toner image. Then, this toner image is transferred onto a transfer sheet via a transfer unit (not shown), and the photosensitive drum 1 after transfer is cleaned of residual toner by a cleaning device 4,
Prepared for the next image formation.

The transfer paper is sent to the photosensitive drum 1 from inside a paper feed cassette (not shown), and after receiving the transfer of the toner image from the photosensitive drum 1, the transfer paper is transferred to a fixing device (not shown). Then, the toner image is fixed by the fixing device.

Further, referring to FIG. 2, a cross section of the developing roller 12 is, as shown in FIG. 2, a cylindrical developing sleeve 100 rotating in a fixed direction and a magnet arranged in the developing sleeve 100. It is composed of a roller 101. The magnet roller 101 is fixed to holders 111a and 111b fixed to the developing device main body 110 at both ends of the core metal portion 101a, and one of the magnet roller core metal portions 101a is a shaft portion 111 of the holder 111a.
c is engaged. Further, flange members 104a and 104b are adhered or press-fitted to both ends of the developing sleeve 100, and the flange member 104b is pivotally supported by the developing device main body 110 via the bearing member 102, and the flange member 104 is provided.
a is retained by engaging with the holder shaft portion 111c. As a result, the developing sleeve 100 and the magnet portion 101b of the magnet roller 101 are arranged with a slight gap. The flange member 104b has a gear 1
03 is engaged and driven by a gear (not shown) of the photosensitive drum 1 to rotate the developing sleeve 100 in a fixed direction.
Further, the spacers 112 arranged at both ends of the developing sleeve contact the photosensitive drum 1, and the developing sleeve 100 rotates while keeping the distance between the photosensitive drum 1 and the developing sleeve 100 constant by the thickness of the spacer 112.

As described above, the shaft portion 111c protruding from the holder 111a has a function of holding the end portion of the core metal 101a on the non-driving side of the magnet roller 101 and the flange member 104a, so that it is provided on the driving side. Bearing member 102
Since it can be held without the provision of a component, the number of parts can be reduced and the dimension in the longitudinal direction can be shortened, which enables a compact design.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as shown in FIG. 3, the holder 111b is provided with a shaft portion of 111d and is engaged with the flange member 104b as in the case of the first embodiment. Similarly, the bearing member 102 can be eliminated,
Further compact design is possible.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as shown in FIG. 4, the function of the flange member 104a is changed to the holder shaft portion 1 in the structure on the non-driving side.
11c is also an example. By engaging the outer diameter of the holder shaft portion 111c with the inner diameter of the developing sleeve, the flange member 1
04a can be eliminated, and the number of parts can be further reduced by combining with the first and second embodiments.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as shown in FIG. 5, a magnet roller 101 is used in which a core metal portion 101a and a cylindrical magnet portion 101b are integrally formed by injection molding with a plastic material. It is an example of when. Since the magnet roller of this embodiment is formed by injection molding, the shape of the magnet roller 101a that engages with the holder shaft portion 111c can be a hole shape, a groove shape, or the like, which can be achieved without increasing the cost. For this reason,
The variation of the holding configuration design of the magnet roller 101 is increased, and the holding design is facilitated. Needless to say, by using this magnet roller, the configuration of the second embodiment as shown in FIG. 6 is possible and the configuration of the third embodiment is also possible.

[0035]

As described above, the first aspect of the present application
According to the invention, since the shaft portion for holding the magnet roller and the developing sleeve is integrally formed with the holder, a bearing member for holding the developing sleeve is not required, the number of parts is reduced, and the dimension in the longitudinal direction is reduced. It can be shortened and a compact design can be achieved.

According to the second invention of the present application, in the first invention, the shaft portion of the holder for supporting the magnet roller is located in the developing sleeve, so that the dimension in the longitudinal direction is further shortened. It is possible to achieve compactness.

Further, according to the third invention of the present application,
In the second aspect of the invention, since the shaft portion that supports the magnet roller directly supports the developing sleeve, the number of parts can be further reduced.

Further, according to the fourth invention of the present application, in the first or second invention, the end shape of the supported magnet roller is concave, and the shaft of the holder is opposed to the concave shape. Since the parts are engaged, the end shape of the magnet roller molded by injection molding can be various shapes such as hole shape and groove shape, and the holding configuration design of the magnet roller can be facilitated. .

[Brief description of drawings]

FIG. 1 is a sectional view of a process cartridge according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a developing roller according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a developing roller according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a developing roller according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a developing roller according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of another developing roller in the fourth embodiment of the invention.

FIG. 7 is an explanatory diagram of a conventional developing roller.

[Explanation of symbols]

 3 developing device 6 process cartridge 12 developing roller 101 magnet roller 111a, 111b holder 111c, 111d shaft part

Claims (4)

[Claims] 1. In a process cartridge having a developing device including a magnet roller and a developing sleeve having the magnet roller therein, a holder for supporting at least one end side of the magnet roller has a shaft for supporting the developing sleeve. A process cartridge, which is provided with a section. 2. The process cartridge according to claim 1, wherein the shaft portion provided on the holder that supports the magnet roller is located inside the developing sleeve. 3. The process cartridge according to claim 2, wherein the shaft portion provided on the holder that supports the magnet roller also directly supports the developing sleeve. 4. The magnet roller to be supported has a concave end shape, and a shaft portion provided on a holder engages with the concave end to support the magnet roller. The process cartridge according to claim 3.