JPH05197226A - Image forming device - Google Patents

Abstract

(57) [Abstract] [Purpose] To facilitate the loading of the cartridge to the image forming apparatus. A developer carrier of the developing unit is mounted in a direction of the image carrier of the process cartridge in order to load a process cartridge having at least an image carrier, a developing unit, and a developing unit having a developing unit. Positioning means for urging the process cartridge loaded into the developing unit and the developing unit are positioned. [Effect] Since the developing unit is biased toward the process cartridge and positioned by the positioning means,
It becomes easy to load a process cartridge or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a color copying machine or a color printer using an electrophotographic method, and more specifically, a process cartridge detachable from the main body of the apparatus and a developing unit separate from the process cartridge. The present invention relates to an image forming apparatus that can be loaded with.

[0002]

2. Description of the Related Art An image forming apparatus such as a copying machine forms a latent image by selectively exposing a uniformly charged image carrier to form a latent image, and the latent image is visualized with toner. Image recording is performed by transferring the toner image to the recording material. In such an apparatus, the toner has to be replenished each time it runs out, but this toner replenishment work is not only troublesome, but it may be contaminated. In addition, maintenance of each member can be performed only by a specialized service person, which often causes inconvenience to the user. Therefore, the image carrier, the charging unit, the developing unit, the cleaning unit, and the like are integrated into a cartridge to form a cartridge, and the user loads the cartridge into the apparatus main body to replenish the toner or to reach the end of the life of the image. The one in which parts such as the carrier can be replaced and the maintenance is easy has been put into practical use.

[0003]

However, the above-mentioned cartridge formation does not cause a problem in a single-color image forming apparatus because the toner is one color, but in a full-color image forming apparatus, yellow, magenta, and cyan are used. In order to use the toner of four colors of black, when the toner is made into a cartridge, it is necessary to replace the entire cartridge each time, even if the toner of any one of the colors forming the full color is used up. For example, since black toner is often used when printing a document or the like having a small proportion of color, the black toner is faster than the other three color toners as compared with the three color toners of yellow, magenta and cyan. Lost. At this time, if the cartridge is replaced to replenish the black toner, the yellow, magenta, and cyan toners are wasted.

Therefore, the applicant of the present application discloses in Japanese Patent Laid-Open No. 3-214172 that a cartridge in which an image carrier and a developing device are integrally incorporated is detachably attached to the main body of the device, and the cartridge is Separately, we proposed an image forming apparatus in which the black developing device is detachably attached to the main body of the apparatus.
In the above device, when the black toner is used up, only the black developing device needs to be replaced, the other chromatic color toner is not wasted, and it is possible to flexibly cope with the difference in the toner usage amount. It becomes possible.

An object of the present invention is to further develop the image forming apparatus, and a process cartridge including an image carrier and a developing means for developing an image formed on the image carrier, and a developing unit. (EN) An image forming apparatus capable of easily positioning and loading a developing unit having means.

[0006]

A typical means of the present invention for achieving the above object comprises an image carrier and a developing means for developing an image formed on the image carrier. First loading means for loading the process cartridge,
Second loading means for loading a developing unit equipped with a developing means, and a developer carrying member of the black developing unit is biased toward the image carrying member of the process cartridge, and the loaded process cartridge and black developing unit. It is characterized in that the image forming apparatus is configured by providing a positioning means for positioning and.

[0007]

According to the image forming apparatus according to the above-mentioned means, when the process cartridge and the developing unit are loaded in the respective mounting portions in the apparatus main body and the developing unit is urged toward the process cartridge, the both are positioned by the positioning means. It As a result, the developer of the process cartridge and the developing unit can be separately supplied, and the process cartridge and the developing unit can be easily positioned and mounted.

[0008]

【Example】

First Embodiment Next, an image forming apparatus according to the first embodiment of the present invention will be described with reference to FIGS.

[Overall Description of Image Forming Apparatus] First, the overall configuration of the image forming apparatus will be briefly described. 1 is an explanatory view of the overall structure of a laser beam printer which is one mode of the image forming apparatus, FIG. 2 is an explanatory view of the structure of a process cartridge, and FIG. 3 is an external perspective view of the process cartridge.
As shown in FIG. 1, this apparatus forms an image by winding a recording material 2 fed from a feeding portion 1 around a transfer drum 3, and loading a process cartridge 4 and a black developing unit 5 on the recording material 2. Part to form a color image by the multiple transfer method. Then, the recording material 2 is conveyed to the fixing section 6 to fix the color image on the recording material 2, and is discharged by the discharge roller pair 7 to the discharging section 8 in the upper part of the apparatus. The process cartridge 4 and the black developing unit 5 are separately attachable to and detachable from the apparatus main body 9 as described later.

The image forming unit 4 is exposed by the scanner unit.
Sent from 10. That is, the image signal is a laser diode
When it is given to the laser beam 10a, the laser diode 10a irradiates the polygon mirror 10b with the image light corresponding to the image signal. The polygon mirror 10b is rotated at a high speed by a scanner motor 10c, and the image light reflected by the polygon mirror 10b is irradiated from the exposure section of the process cartridge 4 via the imaging lens 10d and the reflection mirror 10e to selectively image the image carrier. It is configured to be exposed to.

Next, the configuration of each part of the image forming apparatus will be sequentially described in detail. {Feeding unit} The feeding unit 1 feeds the recording material 2 to the image forming unit, and the paper feed cassette 1a containing a plurality of recording materials 2 is loaded in the inner bottom portion of the apparatus main body 9. .. At the time of image formation, the feeding roller 1b is driven and rotated in accordance with the image forming operation to separate and feed the recording materials 2 in the cassette 1a one by one, and guide them to the transfer drum 3 by the guide plate 1c. To do. The guide plate 1d in FIG. 1 is for loading a cassette (not shown) on the outer bottom portion of the apparatus main body 9 to guide the recording material 2 supplied from the insertion opening 1e, and the feeding roller 1f. Is for supplying the recording material 2 manually supplied from the insertion opening 1g.

{Transfer Drum} The transfer drum 3 winds the fed recording material 2 and rotates in the direction of the arrow in FIG. 1 in order to transfer each color toner onto the recording material 2. The transfer drum 3 according to the present embodiment has an elastic layer 3 such as sponge or rubber on the outer circumference of an aluminum cylinder 3a having a diameter of about 140 mm.
b is formed, the conductive layer 3c is formed on the outer periphery thereof, and the dielectric layer 3d is formed on the outermost periphery thereof. A rotary shaft 3e of the transfer drum 3 is rotatably supported by the main body 9 of the apparatus, and the driving force of a drive motor is transmitted to a gear (not shown) fixed to the rotary shaft 3e. Is configured to rotate in the direction of the arrow.

Further, a gripper 3f is attached to a predetermined position on the outer periphery of the transfer drum 3, and the fed recording material 2 is fed.
The electrostatic attraction roller 3g configured to be capable of contacting and separating from the outer periphery of the transfer drum 3 while holding the tip of the recording drum 2 is pressed against the transfer drum and the recording material 2 so as to sandwich the recording material 2 with the transfer drum 3, Roller 3g and conductive layer 3 around transfer drum 3
By applying a voltage between c and c, electric charges are induced in the recording material 2 that is a dielectric and the dielectric layer 3d of the transfer drum 3, and the recording material 2 is electrostatically attracted to the outer periphery of the transfer drum 3. .. The method of attracting the recording material 2 to the transfer drum 3 is not limited to the electrostatic attraction, but may be a suction method using air.

{Process Cartridge} Next, a process cartridge will be described. It has at least an image carrier and a developing means for developing an image formed on the image carrier. As an aspect thereof, for example, the image carrier, the charging means as the process means, the developing means, and the cleaning means are integrated into a cartridge, which is detachably mountable to the main body of the image forming apparatus. Alternatively, the image carrier, the developing means, and at least one of the charging means and the cleaning means as the process means are integrated into a cartridge, which is detachably mountable to the main body of the image forming apparatus. Alternatively, the image carrier and the developing means are integrated into a cartridge, which can be attached to and detached from the main body of the image forming apparatus. As shown in FIGS. 1 and 2, the process cartridge 4 of this embodiment has a charging means 4b, three color toners (developer) Y of yellow, magenta and cyan around an electrophotographic photosensitive drum 4a which is an image carrier. , M and C are respectively housed in three developing means 4c and a cleaning means 4d, which are covered with a cartridge cover 4e to integrally form a cartridge so that it can be attached to and detached from the apparatus main body 9. .. Next, each part of the process cartridge 4 will be individually described.

(Photosensitive drum) The photosensitive drum 4a has a diameter of about 70.
An aluminum photoconductor layer 4a2 is coated on the outer peripheral surface of an aluminum cylinder 4a1 of mm, and is rotatably supported by a cartridge cover 4e by a rotation shaft 4a3. The drive force of a drive motor (not shown) is transmitted to the gear 4a4 (see FIG. 3) fixed to one end of the rotary shaft 4a3, and the gear 4a4 rotates in the direction of the arrow in FIG. 1 in accordance with the image forming operation. ..

(Charging Means) The charging means 4b is disclosed in JP-A-63-14.
A so-called contact charging method as shown in Japanese Patent No. 9669 is used, in which a conductive roller is brought into contact with the photosensitive drum 4a,
The surface of the photosensitive drum 4a is uniformly charged by applying a voltage to the conductive roller.

The process cartridge 4 is provided with an exposure section 4f for irradiating the photosensitive drum 4a charged by the charging means 4b with the image light from the scanner section 10 to form a latent image. ..

(Developing Means) In order to visualize the latent image, three developing means 4c capable of developing each color of yellow, magenta and cyan are arranged. As shown in FIG. 2, the construction of these three developing means 4c is such that a toner feeding mechanism as shown in Japanese Patent Application No. 3-268646 is provided at the bottom of a container 4c1 for storing toner. That is, a plate member having a groove portion or a hole portion surrounding the toner on the surface facing the bottom surface of the container is provided so as to be slidably contactable with the bottom surface of the container 4c1. Is configured to move in sliding contact with the bottom surface of the container, and to move apart in the return path to send the toner to the tip of the container. An application roller 4c3, a blade 4c4, and a sleeve 4c5 which is a developer carrier are attached to the tip of the container to which the toner is fed by the feeding mechanism 4c2. Then, the yellow, magenta, and cyan toners Y, M, and C are stored in the container 4c1 of the three developing means 4c in this order from the top.

At the time of image formation, yellow, magenta,
The developing means 4c corresponding to each color development of cyan is driven to sequentially form a visible image by the toner on the photosensitive drum 4a. That is, the toner in the container 4c1 corresponding to the color to be developed is fed to the coating roller 4c3 by the feeding mechanism 4c2, the toner is thinly coated on the outer periphery of the rotating coating roller 4c3 and the sleeve 4c5 rotated by the blade 4c4, and the toner is applied to the toner. Charge is given (triboelectric charging). With this sleeve 4c5,
By applying a developing bias between the latent image and the photosensitive drum 4a, toner development is performed on the photosensitive drum 4a according to the latent image.

The three developing means 4c are sleeves 4
The c5 and the photosensitive drum 4a are positioned so as to face each other with a minute gap (about 250 μm), and the driving force is selectively transmitted to each developing means 4c by a drive switching means (not shown). That is, in the case of forming a full-color image, first, the developing means containing the yellow toner Y is driven, and at this time, the developing means containing the other magenta and cyan toners M and C are not driven, and only the yellow toner is driven. The photosensitive drum 4a is developed. Similarly, the drive is switched so that the toner is developed on the photosensitive drum 4a in the order of magenta and cyan. Further, the sleeve 4c5 of each developing means 4c is connected to a high voltage power source for developing each color provided in the apparatus main body 9, and a voltage is selectively applied for each color development.

(Positioning of sleeve with respect to photosensitive drum) As shown in FIG. 4A, the sleeve 4c5 of the developing means 4c is positioned with respect to the photosensitive drum 4a by positioning members 4g on both sides of the photosensitive drum 4a. 4 is attached to the positioning member 4g as shown in FIG.
As shown in (b), 4
The individual adjustment member 4h and the sleeve contact member 4i are attached.

The adjusting member 4h is provided with an eccentric cam portion 4h2 centered on the fitting hole 4h1, and the fitting hole 4h1 is rotatably fitted to the boss 4g1 of the positioning member 4g. Further, the sleeve abutting member 4i has an arcuate abutting portion with which the sleeve 4c5 abuts, and the base 4i1 is guided by the boss 4g2 of the positioning member 4g so as to be slidable in the arrow direction of FIG. 4B. It is attached so that the edge portion 4i2 abuts the eccentric cam portion 4h2 of the adjusting member 4h. By rotating the adjusting member 4h, the sleeve abutting member 4i can finely adjust the amount of protrusion in the direction of the arrow in FIG. 4B, so that the adjusting member 4h does not rotate after the fine adjustment.
In addition, the boss 4g is attached so that the sleeve contact member 4i does not move.
Fix by crushing 1,4g2. The arcuate abutting portion of the sleeve abutting member 4i fixed to the positioning member 4g in this manner is rotatable about the support shaft 4c6 with respect to the positioning member 4g as shown in FIG. 4 (b). The attached developing means 4c is biased in the arrow direction by its own weight and a pressing member (not shown), and the shaft portion of the sleeve 4c5 abuts against the arcuate contact portion. As a result, the photosensitive drum 4a
And the sleeve 4c5 are positioned so as to have a minute gap δ.

As shown in FIG. 4 (b), four sleeve abutting members 4i are fixed to the positioning member 4g, three of which are attached to the three developing means 4c of the process cartridge 4. The sleeve 4c5 is abutted and positioned, and the remaining one is a black developing unit 5 which will be described later.
The sleeve is brought into contact with and positioned.

(Protective Cover) The toner visualized on the photosensitive drum 4a by the developing means 4c positioned on the photosensitive drum 4a and the black developing unit 5 is transferred onto the recording material 2 on the transfer drum 3. Since the image is transferred, the photosensitive drum 4 a is exposed during image formation and faces the transfer drum 3. However, since the process cartridge 4 is attached to and detached from the apparatus main body 9, if the photosensitive drum 4a is exposed when the process cartridge 4 is removed from the apparatus main body 9, dust or the like is attached or external light is emitted. Deteriorates when exposed to. Therefore, in this embodiment, as shown in FIG. 2, the cartridge cover 4e is provided with a protective cover 4j that can be opened and closed. The protective cover 4j is attached to a first cover 4j2 which can be opened and closed around the shaft 4j1 as shown by the solid line and the broken line in FIG. 2 and an arm 4j4 which is rotatable around the shaft 4j3. It is composed of a second cover 4j5 that is slidable. The first cover 4j2 and the second cover 4j5
Are biased in the closing direction by springs or the like (not shown), and are normally in the closed state as shown by the solid line in FIG. 2 so that external light does not strike the photosensitive drum 4a. Then, the process cartridge 4 is attached to the apparatus main body 9
When loaded in the first cover 4 by a mechanism (not shown)
The j2 and the second cover 4j5 are opened as shown by the broken line in FIG. 2, and the photosensitive drum 4a is exposed to face the transfer drum 3.

(Cleaning Means) The cleaning means, after the toner visualized on the photosensitive drum 4a by the developing means 4c of the process cartridge 4 and the developing means of the black developing unit 5 described later is transferred to the recording material 2, The toner remaining on the photosensitive drum 4a is cleaned, and the cleaning means 4d of this embodiment comprises a lower waste toner container 4d1 and an upper waste toner container 4d2 as shown in FIG. Is detachably housed in the lower waste toner container 4d1. The toner remaining on the photosensitive drum 4a is removed by the blade 4d3 as the photosensitive drum 4a rotates.
After scraping off and storing in the lower waste toner container 4d1,
The toner is stored in the upper waste toner container 4d2 by a feed roller 4d4 having a sponge layer such as urethane which rotates in the direction of arrow. When the waste toner in the upper waste toner container 4d2 is full, the waste toner container 4d2 is removed and replaced. The upper waste toner container 4d2 is provided with a backflow prevention sheet 4d5 and a scraper 4d6 so that the waste toner contained in the upper waste toner container 4d2 does not return to the lower waste toner container 4d1 due to vibration or the like.

{Black developing unit} The black developing unit 5 is for developing black on the photosensitive drum 4a, and its configuration is such that, as shown in FIG. A toner feeding mechanism 5b and a rotating member 5g, which are similar to those of the process cartridge 4, are provided in the container 5a to be stored, and a coating roller 5c, a blade 5d, and a developing unit are provided at the tip of the container to which the black toner is fed by the feeding mechanism 5b and the rotating member 5g. A sleeve 5e, which is an agent carrier, is attached. As a result, the black toner in the container 5a is fed to the coating roller 5c by the feeding mechanism 5b and the rotating member 5g, a thin layer of toner is applied to the outer periphery of the rotating coating roller 5c and the sleeve 5e rotated by the blade 5d, and the toner is charged. Is given. By rotating the sleeve 5e in synchronization with the photosensitive drum 4a on which the latent image is formed, black development is performed on the photosensitive drum 4a.

The black developing unit 5 is formed separately from the process cartridge 4, and the process cartridge 4 and the black developing unit 5 are independently attachable to and detachable from the apparatus main body 9.

{Mounting Structure of Process Cartridge and Black Developing Unit on Apparatus Main Body} Next, a structure for attaching and detaching the process cartridge 4 and the black developing unit 5 to the apparatus main body 9 will be described. As shown in FIG. 5A, the device main body 9 has an upper opening / closing cover 12 around the shaft 11.
Is mounted so that it can be opened and closed, and is also rotatable about the shaft 11 so that the process cartridge holding frame 13
Also, a black developing unit holding frame 14 is attached. Both holding frames 13 and 14 are configured to be fixedly positioned with respect to the apparatus main body 9 when the upper opening / closing cover 12 is closed.

The process cartridge holding frame 13
As shown in FIG. 5B, the cross section is formed in a "U" shape, and guide rails 13a for supporting both ends of the process cartridge 4 are provided on both side walls so as to face each other. This guide rail 13a has a lower guide portion 13a as shown in FIG. 5 (a).
It has an a1, a bent portion 13a2, a middle guide portion 13a3 and an upper guide portion 13a4, and each of the guide portions 13a1, 13a3, 13a4 is configured to be inclined obliquely downward. On the other hand, a lower guide boss 4e1 and an upper guide boss 4e2 are formed on both side walls of the process cartridge cover 4e so that when the process cartridge 4 is loaded into the holding frame 13, as shown in FIG. The boss 4e1 is guided by the lower guide portion 13a1 and the rotary shaft 4a3 protruding from both side walls of the process cartridge 4 is guided by the middle guide portion 13a3 and inserted, and when the lower guide boss 4e1 abuts on the bent portion 13a2. As shown in FIG. 7, the process cartridge 4 is rotated in the arrow direction around the lower guide boss 4e1 to support the upper guide boss 4e2 by the upper guide portion 13a4. As a result, the process cartridge 4 is fixed to the guide rail of the holding frame 13.
The bosses 4e1 and 4e2 are engaged with the bent portion 13a2 and the upper guide portion 13a4 with respect to 13a, and the positioning in the front-rear direction (left-right direction in FIG. 7) is performed. When removing the process cartridge 4 from the holding frame 13, the process cartridge 4 can be pulled out in the reverse order.

Similarly to the process cartridge holding frame 13, the black developing unit holding frame 14 is formed in a U-shaped cross section, and both side walls are provided with both ends of the black developing unit 5 as shown in FIG. Bearing part 14 for rotatably supporting
a is provided. A boss 5f is formed on both side walls of the black developing unit 5 so that the black developing unit 5 can be rotatably mounted on the holding frame 14 by locking the boss 5f to the bearing portion 14a. To do. At this time, the tip end portion of the black developing unit 5, that is, the side on which the coating roller 5c and the sleeve 5e are provided is biased upward by the pressing spring 15.

{Replacement of process cartridges} The upper opening / closing cover 12 has two hooks 16 as shown in FIG.
a and 16b and slide levers 17a and 17b are provided. When the opening / closing cover 12 is closed as shown in FIG.
16a is locked to the process cartridge holding frame 13,
The lower hook 16b is configured to engage with the black developing unit holding frame 14. Therefore, the slide lever 17
When the opening / closing cover 12 is opened with the upper and lower hooks 16a and 16b unlocked by sliding a and 17b, as shown in FIG.
As shown in (a), only the opening / closing cover 12 opens upward.
As a result, the process cartridge 4 can be attached and detached.

The upper cover 16a is locked to the process cartridge holding frame 13, and the lower hook 16b and the black developing unit holding frame 14 are unlocked.
When opened, the process cartridge holding frame 13 is opened upward together with the opening / closing cover 12, and as shown in FIG.
The process cartridge 4 loaded in the frame 13 moves upward. As a result, the black developing unit 5 can be easily attached and detached. When the open / close cover 12 is opened with the upper hook 16a locked to the process cartridge holding frame 13 and the lower hook 16b locked to the black developing unit holding frame 14, both open / close cover 12 and both holding frames 13 and 14 are raised. To each frame as shown in Fig. 9 (c).
The process cartridge 4 and the black developing unit 5 loaded in the units 13 and 14 move upward. As a result, the recording material 2
Since the conveyance path of is exposed, it is possible to easily perform a jam (paper jam) process.

{Connecting Guide for Process Developing Cartridge and Black Developing Unit} As shown in FIG. 8, the connecting to the black developing unit 5 is guided on both sides of the process cartridge cover 4e in the side direction (front and back direction of FIG. 8). A guide member 4e3 for doing so is formed so as to protrude downward. As a result, when the process cartridge 4 and the black developing unit 5 are respectively loaded into the holding frames 13 and 14 as shown in FIG.
As shown in FIG. 4, the guide member 4e3 of the process cartridge cover 4e holds both sides of the black developing unit 5, and the side directions of the process cartridge 4 and the black developing unit 5 are positioned.

When the opening / closing cover 12 is further closed from the state shown in FIG. 8, the sleeve 5e of the black developing unit 5 contacts the sleeve contact member 4i of the process cartridge 4.
At this time, the tip of the black developing unit 5 is pressed by the spring 15.
It is pushed down slightly against the bias of. As a result, the sleeve 5e reliably contacts the sleeve contact member 4i by the urging force of the pressing spring 15, and the sleeve 5e and the photosensitive drum 4
Positioning with a is performed, and a minute gap is secured between the two. Therefore, the process cartridge 4 is held by the frame 13
The process cartridge 4 and the black developing unit 5 are positioned and loaded in the apparatus main body 9 by simply loading the black developing unit 5 into the holding frame 14 and closing the opening / closing cover 12.

[Fixing Section] Next, the fixing section 6 is for fixing the image formed on the recording material 2 wound around the transfer drum 3 by the process cartridge 4 and the black developing unit 5, as shown in FIG. A driving roller 6a that is driven and rotated, and a fixing roller 6b that presses against the driving roller 6a to apply heat to the recording material 2. That is, when the recording material 2 separated from the transfer drum 3 passes through the fixing portion 6, the driving roller 6
While being conveyed by a, heat and pressure are applied by the fixing roller 6b. As a result, the image forming toner is fixed on the recording material 2. A cleaning member 6c is in contact with the fixing roller 6b, and the toner attached to the roller 6b is removed by the cleaning member 6c.

[Image Forming Operation] Next, the operation of forming an image by the apparatus having the above-described structure will be described. The feeding roller 1b shown in FIG. 1 is rotated to remove the recording material 2 in the paper feeding cassette 1a. The sheets are separated and fed to the transfer drum 3.
The transfer drum 3 rotates in the direction of the arrow in FIG. 1 and holds the front end of the recording material 2 fed by the gripper 3f and electrostatically adsorbs it on its peripheral surface. The photosensitive drum 4a is rotated in the direction of the arrow in FIG. 1 in synchronism with the rotation of the transfer drum 3, and the drum surface of the drum 4a is uniformly charged by the charging means 4b. Irradiation is performed to form a yellow latent image on the photosensitive drum 4a. Simultaneously with the formation of the latent image, the yellow developing means 4c of the process cartridge 4 is driven to drive the photosensitive drum 4
A yellow voltage is applied by applying a voltage having the same polarity as the charging polarity of the photosensitive drum 4a and substantially the same potential so that the yellow toner adheres to the latent image on a, and a voltage having the opposite polarity to the toner is applied to the transfer roller 3. The toner on the photosensitive drum 4 a is transferred onto the recording material 2 on the transfer drum 3. During the yellow development and transfer, the magenta and cyan developing means 4 is used.
c and the black developing unit 5 are not driven.

When the transfer of the yellow toner is completed as described above, the formation of a magenta, cyan and black latent image and the toner transfer are sequentially performed in the same manner to form a color image on the recording material 2. After the image is formed, the recording material 2 is separated from the transfer drum 3 and conveyed to the fixing unit 6, where the toner is fixed in the fixing unit 6 and then discharged to the discharge tray 8 by the discharge roller pair 7 to form an image. finish.

[Other Embodiments] In the above-described first embodiment, as shown in FIG. 8, an example is shown in which the tip of the black developing unit 5 is pressed against the process cartridge 4 by the pressing spring 15. As shown in FIGS. 10 and 11, a leaf spring 18 is provided in the process cartridge 4 or the black developing unit 5, and when the process cartridge 4 and the black developing unit 5 are loaded, the leaf spring 18 is used in the process cartridge 4 or the black developing unit. The unit 5 may be pressed, and the reaction force of the unit 5 may rotate the black developing unit 5 about the boss 5f so that the sleeve 5e is pressed against the sleeve contact member 4i.

Further, in the above-mentioned first embodiment, as shown in FIG. 8, the guide member 4e3 is provided on the process cartridge cover 4e.
The black developing unit 5 is provided by the guide member 4e3.
Although an example in which both sides of the process cartridge are sandwiched and positioned in the side direction is shown, as shown in FIGS. 12 and 13, fork-shaped guide members 19 are provided on both sides of the process cartridge cover 4e. The guide member 19 is on both sides of the sleeve 5e of the black developing unit 5 or the boss 5 on which the rotation is centered
It may be configured to engage with f. In this way, the process cartridge 4 and the black developing unit 5 can be more reliably positioned in the side direction.

Further, as shown in FIG. 14, the black developing unit 5
A guide collar 20 is provided at the tip of the process cartridge 4, and a guide roller 21 is provided on the process cartridge 4 facing the guide collar 20.
The guide collar 20 may sandwich the guide roller 21 when the and are loaded. In this way, the process cartridge 4 and the black developing unit 5 can be more reliably positioned in the front-rear direction.

Further, as shown in FIG. 15, if the process cartridge 4 is provided with a guide protrusion 22 and the black developing unit 5 is provided with a fork member 23 that engages with the guide protrusion 22, the structure is the same as in the case of FIG. You can get the effect.

In the above-described first embodiment, the process cartridge 4 is loaded by rotating it around the bent portion 13a2 of the holding frame 13, as shown in FIG.
As shown in (b), rotation fulcrum receiving portions 24 are provided on both sides of the process cartridge 4, and the rotation fulcrum receiving portions 24 are rotatably mounted on the boss 5f which is the rotation center of the black developing unit 5. Then, the process cartridge 4 may be rotated and loaded around the boss 5f. Further, as shown in FIGS. 17A and 17B, a common rotation fulcrum shaft 25 for the process cartridge 4 and the black developing unit 5 is provided, and the process cartridge 4 and the black developing unit 5 are rotated on the rotation fulcrum shaft 25. It may be movably attached and loaded.

Further, in the above-described first embodiment, the formation of a full-color image is performed using four colors of yellow, magenta, cyan and black.
Although an example in which color is used is shown, it is needless to say that a full color image may be formed with three colors of yellow, magenta, and cyan.

Furthermore, the present invention is not limited to the case of forming a full-color image as described above, but is also applicable to the case of forming a multi-color image such as a single-color image of a plurality of colors (for example, a two-color image, a three-color image, etc.). It is preferably used. Therefore, in the above-described first embodiment, the example in which the black toner is stored in the black developing unit 5 has been shown, but the color toner other than black (for example, red toner) may be stored in the unit 5. Further, the process cartridge 4 may be provided with one developing means to store only one color toner.

As the developing method, various known developing methods such as a two-component magnetic brush developing method, a cascade developing method, a touchdown developing method and a cloud developing method can be used.

As for the structure of the charging means, the so-called contact charging method was used in the above-described first embodiment, but a tungsten wire which has been conventionally used as another structure is provided with a metal shield such as aluminum around three sides. It is of course possible to use a configuration in which positive or negative ions generated by applying a high voltage to the tungsten wire are moved to the surface of the photosensitive drum 4a and the surface of the drum 4a is uniformly charged. ..

Further, as a method for cleaning the toner remaining on the photosensitive drum 4a, the cleaning means may be constituted by using a blade, a fur brush, a magnetic brush or the like.

Further, in the above-described first embodiment, when forming an image on the recording material 2, yellow, magenta, cyan,
An example of using a so-called multiple transfer system in which each color toner of black is transferred to the recording material 2 has been described. However, as this transfer system, another system such as latent image formation of each color on the photosensitive drum 4a, A so-called multiple development batch transfer system may be adopted in which images are superimposed on the photosensitive drum 4a by repeating development and the superimposed toner images of respective colors are collectively transferred to the recording material 2. The latent images of each color are sequentially formed on the body belt so that they do not overlap with each other, and this is developed, and the developed toner is transferred as an image superimposed on the transfer belt, which is an intermediate transfer body, and then transferred collectively onto the recording material. It is also possible to adopt a transfer method.

Although the laser beam printer is shown as an example of the image forming apparatus in the above-mentioned embodiments, the present invention is not limited to this, and can be used in other image forming apparatuses such as a copying machine. is there.

[0050]

As described above, according to the present invention, when the process cartridge and the black developing unit are loaded in the respective loading portions in the apparatus main body and the black developing unit is rotated and biased toward the process cartridge, the positioning means is used. Since the two are positioned, the chromatic color developer and the black developer can be separately supplied, and the process cartridge and the black developing unit can be easily positioned and mounted. In addition, by rotating the process cartridge about the center of rotation and loading the process cartridge, the rotation fulcrum of the process cartridge can be placed at a predetermined position without providing a complicated mechanism or a highly accurate cartridge mounting mechanism. This makes it possible to easily perform the loading and positioning of the process cartridge. Further, by providing the process cartridge or the black developing unit with the connecting member, the positioning of the both can be easily performed without the operator's confirmation, and the operability of loading the process cartridge or the like can be improved. ..

[Brief description of drawings]

FIG. 1 is an overall schematic explanatory view of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a process cartridge.

FIG. 3 is an external perspective view of a process cartridge.

FIG. 4 is an explanatory diagram of a positioning configuration of a developing sleeve with respect to a photosensitive drum.

FIG. 5 is an explanatory diagram of a guide rail for loading a process cartridge.

FIG. 6 is an explanatory diagram of a loading configuration of a process cartridge.

FIG. 7 is an explanatory diagram of rotating and loading a process cartridge.

FIG. 8 is an explanatory diagram of a configuration in which a black developing unit is rotatably loaded.

FIG. 9 is an explanatory diagram when a process cartridge and a black developing unit are replaced and a jam is removed.

FIG. 10 is an explanatory diagram of another embodiment in which a plate spring is provided in the process cartridge for urging the black developing unit toward the process cartridge.

FIG. 11 is an explanatory view of another embodiment in which a plate spring is provided in the black developing unit in order to bias the black developing unit in the process cartridge direction.

FIG. 12 is an explanatory view of another embodiment in which a connecting member for positioning the process cartridge and the black developing unit in the side direction is provided.

FIG. 13 is an explanatory view of another embodiment in which a connecting member for positioning the process cartridge and the black developing unit in the side direction is provided.

FIG. 14 is an explanatory diagram of another embodiment in which a connecting member for positioning the process cartridge and the black developing unit in the side direction is provided.

FIG. 15 is an explanatory view of another embodiment in which a connecting member for positioning the process cartridge and the black developing unit in the side direction is provided.

FIG. 16 is an explanatory diagram of another embodiment in which the rotation center of the process cartridge is made common to the rotation center of the black developing unit.

FIG. 17 is an explanatory diagram of another embodiment in which the rotation center of the process cartridge is shared with the rotation center of the black developing unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Feeding part 1a ... Paper feed cassette, 1b ... Feeding roller, 1c, 1d ...
Guide plate, 1e ... Insertion port, 1f ... Feeding roller, 1g ... Insertion port 2 ... Recording material 3 ... Transfer drum 3a ... Aluminum cylinder, 3b ... Elastic layer 3c
... conductor layer, 3d ... dielectric layer, 3e ... rotary shaft, 3f ... gripper, 3g ... electrostatic attraction roller 4, process cartridge 4a ... photosensitive drum, 4a1 ... aluminum cylinder, 4
a2 ... Organic photoconductor layer, 4a3 ... Rotating shaft, 4a4 ... Gear, 4b
... charging means 4c ... developing means, 4c1 ... container, 4c2 ... developer feeding mechanism,
4c3 ... coating roller, 4c4 ... blade, 4c5 ... sleeve,
4c6 ... Spindle 4d ... Cleaning means 4d1 ... Lower waste toner container 4d2
… Top waste toner container, 4d3… Blade, 4d4… Feed roller, 4d5… Backflow prevention sheet, 4d6… Scraper 4e… Cartridge cover, 4e1, 4e2… Guide boss,
4e3 ... Guide member 4f ... Exposure unit, 4g ... Positioning member, 4h ... Adjusting member,
4i ... Sleeve contact member 4j ... Protective cover, 4j1 ... Shaft,
4j2 ... First cover, 4j3 ... Shaft, 4j4 ... Arm, 4j5 ... Second cover 5 ... Black developing unit 5a ... Container, 5b ... Toner feeding mechanism, 5c ... Coating roller, 5d ... Blade, 5e ... Sleeve, 5f ... Boss 5,
g ... Rotating member 6 ... Fixing unit 6a ... Drive roller, 6b ... Fixing roller, 6c ... Cleaning member 7 ... Discharging roller, 8 ... Discharging unit, 9 ... Device body 10 ... Scanner unit 10a ... Laser diode, 10b ... Polygon mirror, Ten
c ... Scanner motor, 10d ... Image forming lens, 10e ... Reflective mirror 11 ... Axis, 12 ... Upper opening / closing cover 13 ... Process cartridge holding frame 13a ... Guide rail, 13a1 ... Lower guide part, 13a2 ... Bending part, 13a3 ... Middle guide Part, 13a4 ... upper guide part 14 ... black developing unit holding frame, 14a ... bearing part 15 ... pressing spring, 16a, 16b ... hook, 17a, 17b
... Slide lever 18 ... Leaf spring, 19 ... Guide member, 20 ... Guide collar, 21 ... Guide roller, 22 ... Guide protrusion, 23 ... Fork member, 24 ... Rotation fulcrum receiving part, 25 ... Rotation fulcrum shaft

Claims (9)

[Claims] 1. A first loading unit for loading a process cartridge including an image carrier and a developing unit for developing an image formed on the image carrier; and a developing unit including a developing unit. Second loading means for loading the black developing unit, and positioning for urging the developer carrier of the black developing unit toward the image carrier of the process cartridge to position the loaded process cartridge and the black developing unit. An image forming apparatus comprising: 2. A first loading unit for loading a process cartridge including an image carrier and a developing unit for developing an image formed on the image carrier, and a developing unit including a developing unit. An image forming apparatus, comprising: a second loading unit for loading the image forming apparatus; and a rotation center portion for rotating the process cartridge with respect to the first loading unit for positioning and loading. 3. A first loading means for loading a process cartridge including an image carrier, a developing means for developing an image formed on the image carrier, and a connecting guide member for connecting to the developing unit. An image forming apparatus, comprising: a second loading unit for loading a developing unit having a developing unit. 4. A first loading unit for loading a process cartridge including an image carrier and a developing unit for developing an image formed on the image carrier, a developing unit, and the process cartridge. An image forming apparatus, comprising: a second loading unit configured to load a developing unit including a connection guide member for connecting the developing unit and the developing unit. 5. The process cartridge according to claim 1, wherein at least an electrophotographic photosensitive member as an image bearing member and a developing unit are integrally formed into a cartridge, which is attachable to and detachable from the apparatus main body. The image forming apparatus according to any one of 4 above. 6. The process cartridge integrally comprises an electrophotographic photosensitive member as an image bearing member, a developing unit, and a charging unit or a cleaning unit as a process unit acting on the electrophotographic photosensitive member. The image forming apparatus according to any one of claims 1 to 4, wherein the image forming apparatus is detachable from the apparatus body. 7. The process cartridge comprises an electrophotographic photosensitive member as an image bearing member, a charging unit, a developing unit,
The image forming apparatus according to any one of claims 1 to 4, wherein the cleaning unit and the cleaning unit are integrally formed into a cartridge and can be attached to and detached from the apparatus main body. 8. The image forming apparatus according to claim 1, wherein the process cartridge has a developing unit for developing each color of yellow, magenta, and cyan as a developing unit. 9. The image forming apparatus according to claim 1, wherein the developing unit has a developing unit for performing black development.