JP2002108173A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the operation when a process cartridge is attached and detached, in an image forming device having the process cartridge freely detachably attached to the main body of the image forming device. SOLUTION: A positioning part 37 and a receiving part 38 are provided on a main body side plate 34 of the main body 1 of the image forming body. A first projecting part 32 provided on the process cartridge 29 is brought in press contact with the positioning part 37, and a second projecting part 33 is brought in press contact with the receiving part 38 to attach the process cartridge to the main body of the image forming device.

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 having a process cartridge detachably mounted on an image forming apparatus main body.

[0002]

2. Description of the Related Art In an image forming apparatus of the above-mentioned type configured as a copying machine, a printer, a facsimile or a multifunction machine having at least two of these functions, the process cartridge is easily attached to the image forming apparatus main body. Since the process cartridge can be detached, the process cartridge can be exchanged, repaired, or maintained and inspected efficiently. The process cartridge is configured as, for example, an image carrier unit having an image carrier and a unit case supporting the image carrier, a fixing unit, or a duplex unit.

In this type of conventional image forming apparatus,
A lock lever is provided on the process cartridge, and when the process cartridge is mounted on the image forming apparatus main body, the lock lever is engaged with a pin on the image forming apparatus main body side,
The process cartridge is positioned and held in the main body of the image forming apparatus (see JP-A-11-109830). However, according to this configuration, the operator needs to rotate the lock lever when attaching and detaching the process cartridge, so that the operation is complicated.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned disadvantages of the prior art, to allow the process cartridge to be more easily attached to and detached from the image forming apparatus main body, and to simplify the structure. Another object of the present invention is to provide an image forming apparatus of a type.

[0005]

According to the present invention, in order to achieve the above-mentioned object, in an image forming apparatus of the type described at the beginning, the process cartridge is press-contacted with a positioning portion provided on a main body of the image forming apparatus. 1 and a second protrusion that presses against a receiving portion provided on the image forming apparatus main body, and the second protrusion is used when the process cartridge is inserted into the image forming apparatus main body. Regarding the insertion direction of
An image forming apparatus is provided which is located on the rear side of the first protrusion (claim 1).

At this time, it is advantageous that the receiving portion is inclined from the upper end side to the lower end side so as to approach the first projection pressed against the positioning portion. 2).

Further, in the image forming apparatus according to the second aspect, the center of the second protrusion pressed against the receiving portion may be centered on the center of the first protrusion pressed against the positioning portion. When considering a passing arc, it is advantageous that the angle between the tangent of the arc at the axis of the second projection pressed against the receiving portion and the receiving portion is set to 5 ° to 10 ° ( Claim 3).

Further, in the image forming apparatus according to any one of claims 1 to 3, the process cartridge has a rotating body that is driven to rotate, and the first protrusion is configured to rotate the rotating body. Advantageously, it is arranged concentrically with respect to the center (claim 4).

Further, in the image forming apparatus according to the fourth aspect, when the rotating body of the process cartridge mounted on the main body of the image forming apparatus is driven to rotate, and the process cartridge is urged to rotate, the attachment is performed. It is advantageous that the rotation direction of the rotating body is set so that the second protrusion is pressed against the receiving portion by the force (claim 5).

Further, in the image forming apparatus according to any one of the first to fifth aspects, it is advantageous that the second projection is formed in a columnar shape and the diameter thereof is set to 5 to 10 mm. (Claim 6).

In the image forming apparatus according to any one of claims 1 to 6, when the process cartridge is inserted into the main body of the image forming apparatus, the second protrusion is guided toward the receiving portion. Advantageously, a guide is provided on the main body of the image forming apparatus, and the guide is inclined so that its height decreases in the direction of insertion of the process cartridge.

Further, in the image forming apparatus according to any one of claims 1 to 7, when the process cartridge is inserted into the main body of the image forming apparatus, the second protrusion is guided toward the receiving portion. Advantageously, a guide is provided on the main body of the image forming apparatus, and the guide is inclined so that its height becomes higher in the insertion direction of the process cartridge.

Further, in the image forming apparatus according to any one of claims 1 to 8, the second projection pressed against the receiving portion with the center of the axis of the first projection pressed against the positioning portion as a center. It is advantageous to provide a handle in a portion of the process cartridge that is radially outward of an arc passing through the axis of the portion and that is on the rear side in the insertion direction of the process cartridge.

Further, in the image forming apparatus according to any one of the first to ninth aspects, it is advantageous to provide a pressing member for pressing the second protrusion against the receiving part (claim 10).

Further, in the image forming apparatus according to any one of claims 1 to 10, the process cartridge supports an image carrier on which a toner image is formed on a surface, and rotatably supports the image carrier. An image carrier unit having at least two unit cases may be provided.

Further, in the image forming apparatus according to any one of claims 1 to 10, the process cartridge may be a fixing unit for fixing a toner image formed on a recording material. ).

The image forming apparatus according to any one of claims 1 to 10, wherein the process cartridge forms a toner image on the other surface of a recording material having a toner image formed on one surface. The recording material may be a double-sided unit for re-feeding the recording material (claim 13).

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a vertical sectional view showing an example of the image forming apparatus. The image forming apparatus shown here is configured as a laser printer. A drum-shaped photoconductor 2 which is an example of an image carrier disposed inside the image forming apparatus main body 1 includes:
During the image forming operation, the photosensitive drum 2 is rotated clockwise in FIG. 1, and at this time, the surface of the photoconductor 2 is uniformly charged to a predetermined polarity by a charging roller 3 as an example of a charging unit.
The charged surface of the photoconductor 2 is irradiated with a light-modulated laser beam L emitted from an optical writing unit 4 which is an example of an exposure device, whereby an electrostatic latent image is formed on the surface of the photoconductor. This electrostatic latent image is visualized as a toner image by a powdery developer carried and conveyed by the developing roller 6 of the developing device 5.

On the other hand, a paper supply unit 7 is disposed below the image forming apparatus main body 1, and a recording material P made of a transfer paper, a resin film, a resin sheet, or the like stored in the paper supply cassette 8 is supplied. By the rotation of the roller 9, the sheet is fed one by one from the paper feed cassette 8 in the direction of arrow A. The fed recording material P is transferred to the transfer roller 11, which is an example of a transfer unit, by the registration roller pair 10 at a timing matching with the toner image formed on the surface of the photoconductor 2.
The toner image on the photoreceptor is transferred to one surface of the recording material P when the sheet is passed therethrough.
Toner remaining on the surface of the photoconductor without being transferred to the recording material P is removed from the surface of the photoconductor by the cleaning member 13 of the cleaning device 12, and the surface is cleaned.

The recording material that has passed through the transfer section is continuously conveyed in the direction of arrow B and passes through the fixing unit 14. FIG.
The fixing unit 14 has a fixing case 15, a fixing roller 16 and a pressure roller 17 housed therein and rotatably supported by the case 15, and the fixing roller 16 is not shown. Built-in heater.

The fixing roller 16 and the pressure roller 17 rotate in the directions of the arrows in FIG. 1 while being pressed against each other, and the recording material P passes between them. At this time, the fixing roller 16 is heated by the heater, and the unfixed toner image carried on the recording material surface is fixed on the recording material by the heat and the pressure from the rollers 16 and 17. As described above, the fixing unit 14 serves to fix the toner image formed on the recording material, and is detachably attached to the image forming apparatus main body 1. The recording material that has passed through the fixing unit 14 is conveyed in the direction of arrow C, and is discharged onto a discharge tray 20 by a pair of discharge rollers 19. The image forming apparatus main body 1 of the present example has an exterior cover 21 and a main body frame, and a paper discharge tray 20 is configured by an upper wall of the exterior cover 21.

The image forming apparatus shown in FIG. 1 has a duplex unit 18 so that an image can be formed on the other surface of the recording material P.
have. As described above, the recording material P is transferred to the discharge tray 20.
When the sheet is ejected upward, the switching claw 22 swingably supported by the fixing case 15 of the fixing unit 14 occupies the position shown by the solid line in FIG. When forming, the switching claw 22 is switched to the position shown by the chain line. As a result, the recording material that has passed between the fixing roller 16 and the pressure roller 17 is conveyed in the direction of arrow D and sent into the double-sided case 23 of the double-sided unit 18. At this time, the switching claw 24 swingably supported by the double-sided case 23 occupies the position indicated by the solid line, whereby the recording material is conveyed by the pair of reversible rollers 25 and is placed inside the double-sided case 23. The recording material is fed to the tray 26 as shown by the arrow E, and then the reversible roller pair 25 rotates in the reverse direction, so that the recording material is conveyed in the direction of the arrow F and sent to the re-feed tray 27.

When the re-feed roller 28 disposed in the double-sided case 23 rotates at a predetermined timing, the recording material fed onto the re-feed tray 27 is re-fed in the direction of arrow G, and When the recording material passes through the transfer section, the toner image formed on the photoconductor 2 is transferred to the other recording material surface in the same manner as described above. Next, the recording material passes through the fixing unit 14, is conveyed in the direction of arrow C, and is discharged onto the discharge tray 20.

As described above, the duplex unit 18 is used for re-feeding the recording material so as to form a toner image on the other surface of the recording material having the toner image formed on one surface. It is detachably attached to the device body.

The photosensitive member 2, charging roller 3, developing device 5 and cleaning device 12 shown in FIG. 1 are constituted as an integral process cartridge 29. The developing case 30 of the developing device 5 containing the developer and the cleaning case 31 of the cleaning device 12 containing the toner removed from the photoconductor 2 are constituted by a part of the unit case 132 of the process cartridge 29. The charging roller 3 and the photosensitive member 2 are rotatably supported by 132.

FIG. 2 is a partial sectional view of the process cartridge 29.
3, 133A, concentrically arranged bearing members 13
4,134A are fixed immovably. Photoconductor 2
Is composed of a cylindrical photoreceptor main body 135 and flange members 136 and 136A fixed to respective axial ends thereof.
The photoconductor main body 135 includes a drum-shaped conductive base and a photosensitive layer laminated on an outer peripheral surface thereof. Each flange member 1
The bearings 36 and 136A are rotatably supported by the bearing members 134 and 134A, and a gear 137 is constituted by a part of one of the flange members 136A. This gear 137 is
The driving gear 128 meshes with a driving gear 128 rotatably supported by a main body frame of the image forming apparatus main body 1.
Is rotated by a motor (not shown), and the rotation is transmitted to a gear 137, whereby the photoreceptor 2 is driven to rotate clockwise in FIG.

The bearing members 134 and 134A are made of, for example, metal, and the unit case 132 is made of, for example, resin. However, the bearing members 134, 134A and the unit case 132 may be made of an integral molded product.

Further, as shown in FIG.
The charging roller 3 rotatably supported by the photosensitive member 2
And rotates following the rotation of the photoconductor 2. The laser light L emitted from the optical writing unit 4 shown in FIG. 1 enters the process cartridge 29 through an opening 129 formed in the upper wall of the unit case 132, and exposes the surface of the photoconductor.

As described above, the process cartridge 29 of this embodiment has the charging roller 3, the developing device 5, the cleaning device 12, and the like in addition to the photosensitive member 2, which is an example of an image carrier. The process cartridge may be configured by incorporating the above elements. Alternatively, conversely, the charging roller, the developing device, the cleaning device, and the like may be separated from the process cartridge, and these may be configured as elements other than the process cartridge. As described above, the process cartridge shown here is configured as an image carrier unit having at least two of the image carrier on which the toner image is formed on the surface and the unit case which rotatably supports the image carrier. ing.

The process cartridge 29 is detachably mounted on the main body of the image forming apparatus, and the configuration related to this will be described below.

The operator who operates the image forming apparatus shown in FIG. 1 is usually located on the right side of the image forming apparatus. Therefore,
The right side of the image forming apparatus in FIG. 1 is the front side. A front cover 130 is supported on the front side of the image forming apparatus main body 1 so as to be rotatable about a pivot pin 131 at a lower portion thereof. Normally, the front side of the image forming apparatus main body 1 is shown in FIG. As described above.

When an operator located on the front side of the image forming apparatus main body 1 grasps the upper portion of the front cover 130 and pulls it forward, the front cover 130 is pivoted as shown in FIG. And the front side of the image forming apparatus main body 1 is opened. Therefore, the process cartridge 29
Can be pulled forward as shown by the arrow H in FIG. 3 to remove the process cartridge 29. Further, the process cartridge 29 can be inserted into the image forming apparatus main body 1 as shown by an arrow I, and the process cartridge 29 can be set in the image forming apparatus main body 1 as shown in FIG. Thus, the process cartridge 2
9 is replaced with a new one, or the process cartridge 29 removed from the image forming apparatus main body 1 is repaired, or a hand is inserted into the image forming apparatus main body at the mark where the process cartridge 29 is removed, and the recording material jammed here is caught. Can be removed.

FIG. 4 shows the image forming apparatus main body 1 with the process cartridge 29 removed from the image forming apparatus main body 1.
5 is a perspective view showing the main body frame and the process cartridge. FIG. 5 is a view of the process cartridge 29 as viewed in the direction of arrow V in FIG. As shown in these figures and FIG. 3, the unit case 132 of the process cartridge 29 has concentric first
Projections 32, 32A and the second projection 3 which is also concentric.
3, 33A are provided respectively. Second protrusion 3
Reference numerals 3 and 33A denote rearward sides of the first protrusions 32 and 32A with respect to an insertion direction when the process cartridge 29 is inserted into the image forming apparatus main body 1, that is, a direction indicated by an arrow I in FIGS. It is located in. Each protrusion 3
The form of 2, 32A, 33, 33A can be set appropriately,
In the illustrated example, each projection is formed in a columnar shape.

On the other hand, the left and right main body side plates 34 and 34A constituting the main body frame of the main body 1 of the image forming apparatus have first notches 35 extending in the front-rear direction of the main body of the image forming apparatus (left and right directions in FIGS. 3 and 5). , 35A are formed above, and a second above is formed.
Notches 36, 36A are formed. First notch 3
5, 35A extend farther (leftward in FIGS. 3 and 5) than second notches 36, 36A. Each second notch 3
Among the edges of the main body side plates 34, 34A that define the 6, 36A, the edge facing the back side constitutes the receiving portions 38, 38A for the second protrusions 33, 33A.

In order to attach the process cartridge 29 to the image forming apparatus main body 1, as shown in FIG.
3, the operator grasps the process cartridge 29 by hand and inserts it in a substantially horizontal direction toward the back of the image forming apparatus main body 1 as shown by an arrow I in FIG. The first protrusions 32, 32A are respectively inserted into the first notches 35,
35A, and then each second protrusion 33, 3
3A is inserted into each of the second notches 36, 36A.
When the process cartridge 29 is pushed all the way in,
Each first projection 32, 32A is provided with a respective first notch 35, 35.
A is pressed against the innermost positioning portions 37, 37A and pressed against the positioning portions 37, 37A, respectively. In this state, the rear side 29A in the insertion direction of the process cartridge 29 is slightly lowered, and the process cartridge 29 is rotated clockwise about the axis X of the first protrusions 32, 32A. 2 projections 33, 33A
Is dropped into the above-mentioned receiving portions 38 and 38A as shown in FIG. 5, and is pressed against the receiving portions 38 and 38A.

As described above, the first projections 32, 32A and the second projections 33, 33 of the process cartridge 29 are provided.
A are positioning portions 37, 3 which are located substantially opposite to each other.
7A and the receiving portions 38, 38A, respectively, so that the process cartridge 29 does not rattle in the front-rear direction (the left-right direction in FIG. 5) and the up-down direction of the image forming apparatus main body 1.
The process cartridge 29 is securely held, is correctly positioned with respect to the image forming apparatus main body 1, and is mounted immovably. At this time, the gear 137 on the process cartridge meshes with the drive gear 128 on the image forming apparatus main body side. Next, the front cover 130 can be closed as shown in FIG. 1 to execute the above-described image forming operation. By performing the reverse operation, the process cartridge 29 can be taken out of the image forming apparatus main body.

As described above, the process cartridge 29 of the image forming apparatus according to the present embodiment has the first projection 3 which is in pressure contact with the positioning portions 37 and 37A provided on the image forming apparatus main body 1.
2 and 32A, and second projections 33 and 33A that are in pressure contact with receiving portions 38 and 38A provided in the image forming apparatus main body 1. The first projections 32 and 32A are positioned by positioning portions 37 and 32A.
The process cartridge 29 can be correctly positioned and mounted on the image forming apparatus main body 1 only by being pressed against the 37A and pressed against the second projections 33, 33A against the receiving portions 38, 38A. It is not necessary to provide a lock lever on the process cartridge as in the related art, which not only reduces the cost of the image forming apparatus, but also simplifies the operation of attaching and detaching the process cartridge 29.

Although the form of the receiving portions 38 and 38A can be set as appropriate, as shown in FIG. 6, the receiving portions 38 and 38A are positioned from the upper end UE side toward the lower end LE side. It is preferable that the first projections 32, 32A, which are in pressure contact with each other, be inclined so as to gradually approach the axis X thereof. The first part pressed against the positioning parts 37 and 37A
Centering on the axis X of the projections 32, 32A of the
The axial center Y of the second projections 33, 33A pressed against the 8, 38A
When a circular arc J passing through is considered, the tangent T of the circular arc J at the axis Y of the second protrusions 33, 33A pressed against the receiving parts 38, 38A and the receiving parts 38, 38A have an angle α (> 0). It is doing.

With the above configuration, the process cartridge 2
9 is rotated clockwise about the axis X of the first projections 32, 32A to receive the second projections 33, 33A.
When it falls on the surface of 8, 38A, its second projection 3
3, 33A can be smoothly dropped without being disturbed by the upper end UE of the receiving portions 38, 38A. Moreover, when the second protrusions 33, 33A are pressed against the receiving portions 38, 38A, the protrusions 33, 33A exert an external force F1 on the receiving portions 38, 38A. F12 in FIG.
The component force of the force F1 in the direction perpendicular to 8,38A is shown,
F13 indicates the component force in the direction orthogonal to the component force F12, but the second projections 33 and 33A have the component force F12.
Reaction force acts. Thereby, the second protrusions 33, 33
A receives a large frictional force from the receiving portions 38, 38A, and the first protrusions 32, 32A
7, 37A is pressurized by the force F2. In this way, the process cartridge 29 is held in the image forming apparatus main body 1 without rattling, and the holding function is enhanced.

The above-mentioned angle α can be set to an appropriate size, but it is particularly preferable to set it to 5 ° to 10 ° (in the figure, an angle larger than this angle is shown). If the angle α is larger than 10 °, the receiving portions 38, 3
Since the inclination of 8A becomes small, the second protrusions 33, 33A
May easily move upward with respect to the receiving portions 38 and 38A, and the positional accuracy of the process cartridge 29 with respect to the image forming apparatus main body 1 may be reduced. Conversely, if the angle α is smaller than 5 °, the inclination of the receiving portions 38, 38A increases, and the second protrusions 33, 33A
When the process cartridge 29 is taken out of the process cartridge 29 by being pressed into the process cartridge 29 excessively strongly, the second protrusions 33, 33
A becomes difficult to remove from the receiving portions 38 and 38A.

By setting the angle α to 5 ° to 10 °, the above-described problem is prevented from occurring, the process cartridge 29 is always correctly positioned and held with respect to the image forming apparatus main body 1, and the process cartridge 29 is maintained. 29
When removing the process cartridge 29, the second protrusions 33 and 33A are easily removed from the receiving portions 38 and 38A.
Can be detached from the image forming apparatus main body 1.

The first projections 32 and 32A can be provided at appropriate locations on the unit case 31.
In the image forming apparatus of the present embodiment, as shown in FIG. 2, a part of the bearing members 134 and 134A protrude outward from the respective side walls 133 and 133A of the unit case 132,
The protruding portions are configured as first protrusions 32, 32A. Thereby, the first projections 32 and 32A are
It is located concentrically with the photoconductor 2 and the gear 137 that are driven to rotate.

As described above, during the image forming operation, the gear 137 fixed to the photosensitive member 2 is rotated by being transmitted from the drive gear 128 on the image forming apparatus main body side. Process cartridge 2 for
If the position accuracy of 9 is poor, the two gears 137 and 128 do not mesh properly, which causes a slight speed fluctuation on the photoconductor 2, resulting in uneven density of the toner image formed on the photoconductor 2, and the image quality becomes poor. There is a risk of deterioration. Further, immediately after the process cartridge 29 is mounted on the image forming apparatus main body, the driving force is transmitted from the drive gear 128 to the gear 137 even if the process cartridge 29 is correctly positioned and mounted on the image forming apparatus main body 1. In this case, if a large load is applied to the gear 137 and the positional accuracy of the process cartridge 29 with respect to the image forming apparatus main body 1 deteriorates, the same problem as described above occurs.

On the other hand, in the image forming apparatus of this embodiment, as described above, the first projections 32 and 32A are arranged concentrically with respect to the rotation center of the photosensitive member 2 and the gear 137, and Since the first protrusions 32 and 32A are strongly pressed against the positioning portions 37 and 37A and are firmly held with respect to the image forming apparatus main body 1, the photoconductor 2 and the gear 137 with respect to the image forming apparatus main body 1 are provided. The position accuracy is particularly enhanced, so that they do not rattle. As a result, the two gears 137 and 128 always mesh properly, so that the above-described problem can be prevented, and a high-quality toner image can always be formed on the photoconductor. This effect can be obtained even when the process cartridge has a rotating body other than the photoconductor.

As described above, when the process cartridge has a rotating body that is driven to rotate, the first protrusion is arranged concentrically with respect to the center of rotation of the rotating body.
Speed fluctuations of the rotating body can be eliminated.

The second projections 33, 33A of this embodiment are:
As shown in FIG. 7, the base is buried and fixed in the side walls 133 and 133A of the unit case 132 made of, for example, resin, and the second protrusions 33 and 33A are made of, for example, metal. The protrusions 33, 33A and the unit case 132 may be formed as a single molded product.

The photosensitive member 2, which is an example of a rotating member provided in the process cartridge 29,
The driving force is transmitted from the gear 8 to the gear 137, and the gear 137 is rotated. When the element provided in the unit case 132 is in contact with the photosensitive member 2, the process cartridge 29 is rotated.
Are urged in the direction of rotation about the center of rotation of the photoconductor 2. In the example shown in FIG. 1, the base end of the cleaning member 13 composed of a blade is fixed to the cleaning case 31, the front end of the cleaning member 13 is pressed against the surface of the photoconductor 2, and the charging roller 3 supported by the unit case 132. Also contact the photoreceptor surface. Further, when the gear 137 shown in FIG. 2 is a helical gear, the gear 137 is urged in the axial direction when the photoconductor 2 rotates, and the end face 39 of the gear 137 is fixed to the unit case 132. It may be in pressure contact with the bearing member 134A. When the member on the unit case side comes into contact with the photoconductor 2 during the rotation of the photoconductor 2, the entire process cartridge 29 is urged to rotate in the rotation direction of the photoconductor 2, that is, clockwise in FIG. .

As described above, the process cartridge 29
Are rotationally urged about the axis X of the first projections 32, 32A. At this time, the second projections 33, 33A provided on the process cartridge 29 are received by the receiving parts 38, 38.
A accepts it. For this reason, the process cartridge 29 does not actually rotate or rattle,
The process cartridge 29 is always positioned and held correctly. Not only that, the urging force applied to the process cartridge 29 causes the second protrusions 33, 33A to come into pressure contact with the receiving portions 38, 38A with a greater force, so that the force shown in FIG. F1 gets bigger,
The process cartridge 29 is more reliably held in the image forming apparatus main body 1, and the holding stability and the positioning accuracy of the process cartridge are enhanced. The same applies to a case where the rotating body driven to rotate is other than the photosensitive body.

In order to prevent the process cartridge 29 from actually rotating or rattling when the process cartridge is urged to rotate, a dedicated receiving member for receiving the process cartridge is provided in the main body of the image forming apparatus. However, this not only increases the number of parts of the image forming apparatus and increases the cost, but also causes the receiving member to be an obstacle when the process cartridge is attached to and detached from the image forming apparatus main body. Therefore, there is a possibility that the process cartridge cannot be smoothly attached and detached.
In the image forming apparatus of the present embodiment, the second protrusion 3 of the process cartridge 29 which is rotationally urged by the receiving portions 38 and 38A for positioning and holding the process cartridge 29.
3, 33A is received, so that the above-mentioned drawback does not occur.

It is also possible to set the rotation direction of the photosensitive member 2 in the counterclockwise direction in FIG. 1 and to arrange other image forming elements in accordance with the rotation direction. The process cartridge 29 is urged to rotate in the counterclockwise direction in FIG. 5, so that the second protrusions 33, 33A press the receiving portions 38, 38A.
1 (FIG. 6) becomes very small, and the external force applied to the process cartridge 29 during the image forming operation causes
The second protrusions 33 and 33A move out of a predetermined position where the second protrusions 33 and 33A are correctly pressed against the receiving portions 38 and 38A, and the positional accuracy of the process cartridge 29 with respect to the image forming apparatus main body 1 deteriorates. Poor meshing may occur. In the illustrated example, the occurrence of such a problem can be prevented.

When the rotating body of the process cartridge 29 mounted in the main body of the image forming apparatus, in the illustrated example, the photosensitive member 2 is driven to rotate, and the process cartridge is urged to rotate, the urging force causes the second force. Projections 33, 33
By setting the rotation direction of the rotating body so that A is pressed against the receiving portions 38, 38A, the positional accuracy of the process cartridge 29 with respect to the image forming apparatus main body 1 and the stable holding thereof can be achieved without each of the above-mentioned problems. It is possible to enhance the sex without fail.

As described above, the second projections 33 and 3 of the present embodiment are used.
3A is formed in a cylindrical shape, and its diameter can be set to an appropriate size. It is particularly advantageous to set this diameter to 5 to 10 mm. The reason is as follows.

FIG. 8 shows the second projections 33 and 33A when the process cartridge 29 is mounted on the image forming apparatus main body 1.
Projecting portion 3 is engaged with receiving portions 38 and 38A.
It is explanatory drawing which shows an example of the movement of 3,33A. The second protrusions 33, 33A are located at upper ends UE of the receiving portions 38, 38A,
The second protrusion 3 until it comes into pressure contact with the receiving portions 38, 38A.
The moving distance h of the third protrusions 33, 33A is preferably equal to or greater than the radius r of the second protrusions 33, 33A so that the second protrusions 33, 33A can be securely pressed against the receiving portions 38, 38A. preferable. Therefore, the diameter 2 of the second protrusions 33, 33A
As r increases, the moving distance h of the second protrusions 33, 33A also increases. The second protrusions 33, 33A are at this distance h.
9, the process cartridge 29 swings from the position indicated by the chain line to the position indicated by the solid line around the axis X of the first protrusions 32, 32A as shown in FIG.
At this time, if the moving distance h of the second protrusions 33, 33A is large, the swing amount K of the process cartridge 29 increases. Therefore, the rear side 2 of the process cartridge 29
When 9 </ b> A swings largely upward, the other elements located near the process cartridge 29 must be arranged far away from the process cartridge 29 so that they do not interfere with the process cartridge 29.
However, in this case, a large space must be secured in the main body of the image forming apparatus, which inevitably results in a disadvantage that the main body 1 of the image forming apparatus becomes large. In order to prevent such a problem, it is necessary to reduce the movement amount h of the second protrusions 33 and 33A so that the swing amount K of the process cartridge 29 decreases. For this purpose, it is preferable that the diameter of the second protrusions 33 and 33A is made as small as possible and the diameter is set to 10 mm or less. By thus reducing the diameter of the second protrusions 33 and 33A, the swing amount K of the process cartridge 29 can be reduced, and as a result, the size of the image forming apparatus main body 1 can be reduced.

However, if the diameter of the second protrusions 33, 33A is too small, the rigidity of the second protrusions 33, 33A decreases, and the second protrusions 3
This is deflected by an external force acting on 3, 33A, and the process cartridge 29 mounted in the image forming apparatus main body cannot be stably and accurately held. Therefore, it is preferable to set the diameter of the second protrusions 33 and 33A to 5 mm or more so as to prevent the rigidity of the second protrusions 33 and 33A from lowering and to fix the process cartridge 29 in a stable state. Thus, the second protrusions 33, 33
By setting the diameter of A in the range of 5 mm or more and 10 mm or less, it is possible to reduce the size of the image forming apparatus main body and increase the holding stability of the process cartridge set in the image forming apparatus main body. .

By the way, the form of the second notches 36, 36A can also be set as appropriate, and as shown in FIG. 10 in an enlarged manner, the edge 40 of the main body side plate above the receiving portions 38, 38A is formed horizontally. Or the edge 40 and the receiving portion 38,
The distance d between the upper end UE and the upper end UE of the second protruding portion 33, 3
It may be set much larger than the diameter of 3A.

However, when the second notches 36, 36A are formed in this manner, the second protrusions 33, 33A are inserted into the notches 36, 36A as shown by the arrow a in FIG. When this is dropped into the receiving portions 38, 38A, the receiving portions 38, 38A move freely within the cutouts 36, 36A, so that the process cartridge 29 cannot be set smoothly and may be confused for the operator. . This is the same when the process cartridge 29 is removed from the image forming apparatus main body 1.

Further, when the process cartridge 29 is rotated around the axis of the first protrusions 32, 32A in order to pull out the process cartridge 29 from the image forming apparatus main body 1, the second protrusions 33, 33A are rotated. Moves a relatively large distance h1 as shown by the arrow b in FIG.
0, but when the moving distance h1 is large as shown in FIG.
As described above in connection with the process cartridge 2,
9, the swing amount K of the image forming apparatus 9 becomes large, and the disadvantage that the image forming apparatus main body 1 becomes large is inevitable.

Therefore, as shown by a chain line in FIG. 10, it is conceivable to lower the edge portion 40 to reduce the distance d between the receiving portions 38, 38 and the edge portion 40. However, the movement distance h1 of the second protrusions 33 and 33A cannot be sufficiently reduced only by such a configuration. Moreover, when the process cartridge 29 is pulled out, it is normal to pull the process cartridge 29 toward the front side of the image forming apparatus main body with the rear side thereof lifted. However, when the edge 40 is horizontal, the process cartridge 29 is inclined. When the process cartridge 29 in the state is pulled, it is difficult to smoothly guide the second protrusions 33 and 33A by the edge portion 40.

Therefore, when the process cartridge 29 is inserted into the image forming apparatus main body 1, the second protrusions 33, 33
It is preferable that a guide for guiding the A toward the receiving portions 38 and 38A is provided in the image forming apparatus main body, and the height of the guide is gradually reduced toward the insertion direction of the process cartridge 29. For example, as shown in FIG. 11, a part of the upper edge portion 40 defining the second notches 36 and 36A is inclined so that the height thereof gradually decreases toward the insertion direction of the process cartridge 29. The inclined portion is referred to as a guide 41A. In this way, when the process cartridge 29 is inserted into the image forming apparatus main body 1 in an inclined state, the second protrusions 33 and 33A are guided while slidingly contacting the guide 41A, as indicated by an arrow a in FIG. Therefore, the process cartridge 29 can be mounted smoothly. Process cartridge 2
The same applies when taking out 9 from the image forming apparatus main body.
In this manner, the process cartridge 29 can be smoothly attached and detached without giving the operator a feeling of embarrassment.

Further, as shown in FIG.
The portion of the edge portion 40 above the upper portion 38A is also inclined toward the insertion direction of the process cartridge 29 so that the height thereof gradually decreases, and this portion can also be used as the guide 41B. The distance d between the upper end UE of the receiving portions 38 and 38A and the edge portion 40 is set slightly larger than the diameter of the second protrusions 33 and 33A (this is the example shown in FIGS. 11 and 13). The same applies to).

With the above structure, the operation of the structure shown in FIG. 11 can be obtained, and the height of the guide 41B can be reduced.
Since it can be made lower than in the case of FIGS. 10 and 11, as shown by the arrow b in FIG.
The distance h1 for moving the 3A from the receiving portions 38, 38A to the position where the 3A hits the guide 41B can be reduced. Accordingly, the swing amount K (FIG. 9) of the process cartridge 29 can be reduced, and as a result, the size of the image forming apparatus main body can be further reduced.

In the example shown in FIG. 12, the entire edge portion 40 is inclined at the same inclination to form the guides 41A and 41B. However, as shown in FIG. 13, the guide 41B above the receiving portions 38 and 38A. Is steeper than the inclination of the guide 41A on the outer side in the drawing direction of the process cartridge, the moving distance h1 can be further reduced, and the image forming apparatus main body can be more effectively miniaturized. In FIG. 13, similarly to FIGS. 10 to 12, reference numeral “a” indicates the movement of the second protrusions 33 and 33A when the process cartridge 29 is mounted, and reference numeral “b” indicates the movement when the process cartridge 29 is removed. 2 projections 33, 3
3A shows the movement.

The guides 41A and 41B described above are inclined so that their heights become lower in the direction of insertion of the process cartridge 29. However, as shown in FIGS. Alternatively, the edge of the main body side plate facing the above may be inclined so that its height gradually increases in the insertion direction of the process cartridge 29, and this may be used as a guide 41C. Process cartridge 29
When attaching and detaching, as shown by reference numeral c in FIG.
The second protrusions 33 and 33A can also be guided by contacting the guide 41C, whereby the process cartridge 29 can be smoothly attached and detached. By providing both the guide 41C and the guides 41A and 41B described above, when the process cartridge 29 is attached and detached,
Since the second protrusions 33 and 33A can be guided by any guide, the process cartridge 29 can be smoothly mounted or taken out even when the process cartridge 29 is attached or detached in any posture.

By the way, in order to enhance the holding stability of the process cartridge 29 set in the main body of the image forming apparatus, it is preferable that the second projections 33, 33A are frictionally engaged with the receiving portions 38, 38A. However, in this case, in order to pull out the process cartridge 29,
When this is rotated around the axis X of the first protrusions 32, 32A, the second protrusions 33, 33A are not received by the second protrusions 33, 33A unless a large force is applied to the process cartridge 29.
Operability is reduced.

Therefore, referring first to FIG. 6, the second projections 32 and 38A pressed against the receiving portions 38 and 38A are centered on the axis X of the first projections 32 and 32A pressed against the positioning portions 37 and 37A. The arc J passing through the axis Y of the portions 33 and 33A has been described. However, as shown in FIG. 5, the process cartridge portion radially outward of the arc J and located on the rear side in the insertion direction of the process cartridge 29. It is preferable to provide a handle 43 at the portion. When removing the process cartridge 29 around the axis X, the handle 43 is gripped and the process cartridge 29 is rotated. At this time, since the handle 43 is provided at the above-described position, the second protrusions 33, 33A are received by the receiving portions 38, 38.
A, the second protrusions 33, 33A are received by the receiving portions 38, 38A with a small force by the principle of leverage even if the second protrusions 33, 33A
Then, the process cartridge 29 can be easily rotated and taken out.

As shown in FIGS. 4 and 5, a pressing member 44 made of, for example, a leaf spring is attached to each of the main body side plates 34, 34A.
When the process cartridge 29 is set,
The process cartridge 29 is pressurized by the pressing member 44, and the second protrusions 33, 33 </ b> A are received in the receiving portions 38, 3.
The holding stability of the process cartridge 29 can be improved by strongly pressing the process cartridge 29. As described above, by providing the pressing member 44 for pressing the second protrusions 33, 33A against the receiving portions 38, 38A, the second protrusions can be provided without the operator pressing the process cartridge 29 downward particularly strongly. 33, 33A frictionally engages with the receiving portions 38, 38A. Instead of a configuration in which the pressing member presses the process cartridge 29, the pressing member uses the second protrusion 33,
33A may be configured to be pressed directly.

In the example described above, the process cartridge is constituted as an image carrier unit having at least two of an image carrier having a toner image formed on the surface thereof and a unit case rotatably supporting the image carrier. The image carrier is configured as a drum-shaped photoconductor,
Even when the process cartridge has an image carrier formed of a belt-shaped photoconductor wound around a plurality of rollers, the above-described configurations can be employed. At this time, it is preferable to provide the first protrusion concentrically with the drive roller for driving the belt among the rollers around which the belt-shaped photoconductor is wound. Further, when the image carrier is formed of a drum-shaped or belt-shaped intermediate transfer body on which a toner image is transferred from a photoconductor, the above-described configuration can be adopted.

Further, when the process cartridge is the fixing unit 14 or the double-sided unit 18 as shown in FIG. 1, each of the above-described configurations can be applied without any trouble. The fixing unit 14 and the duplex unit 18 shown in FIG. 1 are configured to be freely detachable from the image forming apparatus main body by opening a cover 46 on the back side of the image forming apparatus main body 1. Since the fixing roller 16 is normally driven to rotate by a motor on the side of the image forming apparatus main body, the fixing unit 14 is provided with a first projection concentrically with the fixing roller 16. Since the re-feed roller 28 is driven to rotate by the motor on the image forming apparatus main body side, it is desirable to provide the first protrusion concentrically with the re-feed roller 28.

The present invention is widely applicable to image forming apparatuses other than printers.

[0071]

According to the first aspect of the present invention, the process cartridge can be easily mounted on and removed from the image forming apparatus main body without operating the lock lever.

According to the second aspect of the invention, the holding stability of the process cartridge mounted on the image forming apparatus main body can be improved.

According to the third aspect of the present invention, it is possible to prevent a problem that the process cartridge is difficult to remove because the pressing force of the second protrusion against the receiving portion is too weak or too strong.

According to the fourth aspect of the invention, it is possible to prevent a problem that a speed variation occurs in the rotating body that is driven to rotate.

According to the fifth aspect of the present invention, the second projection is pressed against the receiving portion by utilizing the rotation urging force of the process cartridge generated by the rotation of the rotating body, so that the process cartridge is in a stable state. Can be held.

According to the sixth aspect of the invention, it is possible to prevent the image forming apparatus main body from being enlarged, and to enhance the holding stability of the process cartridge.

According to the seventh and eighth aspects of the invention, the process cartridge can be smoothly attached to and detached from the image forming apparatus main body.

According to the ninth aspect, the process cartridge can be easily removed.

According to the tenth aspect, the holding stability of the process cartridge can be improved.

According to the eleventh aspect, it is possible to provide an image carrier unit having the above-described effects.

According to the twelfth aspect of the invention, it is possible to provide a fixing unit having the above-described effects.

According to the thirteenth aspect, it is possible to provide a double-sided unit having the above-described effects.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an image forming apparatus.

FIG. 2 is a partial sectional view of a process cartridge.

FIG. 3 is a schematic diagram showing a state when a process cartridge is taken out of the image forming apparatus main body.

FIG. 4 is a perspective view illustrating a state where a process cartridge is detached from a main body side plate.

FIG. 5 shows a state in which the process cartridge is mounted;
5 is a view as seen in the direction of arrow V.

FIG. 6 is an explanatory diagram showing details of a receiving unit.

FIG. 7 is a cross-sectional view illustrating an example of a first protrusion.

FIG. 8 is a diagram illustrating a moving distance of a second protrusion.

FIG. 9 is a diagram illustrating a state where the process cartridge swings.

FIG. 10 is a diagram illustrating the movement of a second protrusion.

FIG. 11 is a diagram illustrating a function of a guide.

FIG. 12 is a diagram showing another example of a guide.

FIG. 13 is a diagram showing still another example of the guide.

[Explanation of symbols]

 1 Image Forming Apparatus Main Body 14 Fixing Unit 18 Double-sided Unit 29 Process Cartridge 32 First Projection 32A First Projection 33 Second Projection 33A Second Projection 37 Positioning Part 37A Positioning Part 38 Receiving Part 38A Receiving Part 41A guide 41B guide 41C guide 43 Handle

Claims (13)

[Claims] 1. An image forming apparatus having a process cartridge detachably mounted on an image forming apparatus main body, wherein the process cartridge has a first projection which presses against a positioning portion provided on the image forming apparatus main body; A second protrusion that presses against a receiving portion provided in the image forming apparatus main body, wherein the second protrusion relates to an insertion direction when the process cartridge is inserted into the image forming apparatus main body.
An image forming apparatus, wherein the image forming apparatus is located rearward of the first protrusion. 2. The image forming apparatus according to claim 1, wherein the receiving portion is inclined from the upper end side to the lower end side so as to approach the first protrusion pressed against the positioning portion. apparatus. 3. An arc passing through the axis of a second projection pressed against the receiving portion with the center of the axis of the first projection pressed against the positioning portion being considered as a center. Second
3. The image forming apparatus according to claim 2, wherein an angle between a tangent of an arc at the axis of the projection and the receiving portion is set to 5 ° to 10 °. 4. The process cartridge according to claim 1, wherein the process cartridge has a rotating body driven to rotate, and the first protrusion is disposed concentrically with respect to a rotation center of the rotating body. An image forming apparatus according to any one of the above. 5. When the rotating body of the process cartridge mounted on the main body of the image forming apparatus is driven to rotate and the process cartridge is urged to rotate, the urging force causes the second protrusion to move to the receiving portion. To be pressed against
The image forming apparatus according to claim 4, wherein a rotation direction of the rotating body is set. 6. The method according to claim 1, wherein the second protrusion is formed in a cylindrical shape, and has a diameter of 5 to 10 mm.
The image forming apparatus according to any one of the above. 7. When the process cartridge is inserted into the image forming apparatus main body, a guide for guiding the second protrusion toward the receiving section is provided on the image forming apparatus main body, and the guide is provided on the process cartridge. Towards the insertion direction,
7. An incline according to claim 1, wherein said height is reduced.
The image forming apparatus according to any one of the above. 8. When the process cartridge is inserted into the image forming apparatus main body, a guide for guiding the second protrusion toward the receiving portion is provided on the image forming apparatus main body, and the guide is provided on the process cartridge. Towards the insertion direction,
8. The method according to claim 1, wherein the height is increased.
The image forming apparatus according to any one of the above. 9. A process cartridge radially outside of an arc passing through an axis of a second projection pressed against the receiving portion with respect to an axis of the first projection pressed against the positioning portion. 9. The image forming apparatus according to claim 1, wherein a handle is provided at a portion on the rear side in the insertion direction of the process cartridge. 10. The image forming apparatus according to claim 1, further comprising a pressing member configured to press the second protrusion against the receiving portion. 11. The image carrier unit having at least two of an image carrier having a toner image formed on a surface thereof and a unit case rotatably supporting the image carrier. 11. The image forming apparatus according to any one of claims 1 to 10. 12. The image forming apparatus according to claim 1, wherein the process cartridge is a fixing unit that fixes a toner image formed on a recording material. 13. A double-sided unit for re-feeding a recording material having a toner image formed on one surface thereof so as to form a toner image on the other surface of the recording material. The image forming apparatus according to any one of claims 10 to 13.