JPH11288169A - Image forming device - Google Patents

Abstract

(57) Abstract: An electrode other than a shaft is not required for a developing cartridge, and a developing bias is reliably supplied to a swingably supported developing cartridge. SOLUTION: A receiver electrode member 134 provided on a receiver 130 of a developing cartridge 70 is brought into sliding contact with a main body side fixed electrode member 13. The receiver electrode member 134 urges the shaft 73 of the developing roller 71 in the
Contact with.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus such as a printer, a facsimile, a copying machine, etc., capable of forming an image using an electrophotographic technique. In particular, the present invention relates to an electrode structure for supplying a developing bias to the developing cartridge (also simply referred to as a cartridge).

[0002]

2. Description of the Related Art In general, an image forming apparatus using an electrophotographic technique applies a latent image carrier (for example, a photoconductor) on a surface of which a latent image is formed and a developer (for example, a toner) to the latent image. And a developing means for forming a visible image.

As a developing means, as shown in FIG.
A sleeve-shaped flexible toner conveying member 2 having a diameter larger than that of the driving roller 1 is externally mounted on the driving roller 1, and both ends of the toner conveying member 2 in the axial direction are substantially the same as the outer diameter of the driving roller 1. A semicircular guide member 3 having an inner diameter of a diameter is provided, and the guide member 3 causes the toner conveying member 2 to be in pressure contact with a driving roller at a portion other than a developing region facing the image carrier 4, and to form an image. It is known that the toner conveying member 2 is protruded from the driving roller 1 toward the image carrier 4 in the developing area facing the carrier 4 so as to be in soft contact with the surface of the image carrier 4 (Japanese Patent Laid-Open No. H10-163873). 3-140977 gazette).

A developing bias to the toner conveying member 2 is supplied via a shaft 1 a of the driving roller 1 and the driving roller 1.

As a developing means, there is known a developing cartridge which is detachable from an image forming apparatus main body. When the developing means is made into a cartridge,
A problem arises in how to configure an electrode for supplying a developing bias.

FIG. 13 shows an example of a developing cartridge (Japanese Patent Publication No. 4-49943).

In FIG. 13, reference numeral 5 denotes a case which contains toner. A developing roller 7 is attached to the case 5 by a conductive shaft 6, and the developing roller 7 applies toner to the latent image carrier.

The electrode structure for supplying a developing bias to the developing roller 7 is as follows.

That is, a terminal 8 is provided on the shaft end of the developing roller 7 and a power supply terminal 9 (see FIG. 13B) is provided on the corresponding apparatus main body side. Fig. 13
As shown in (b), the terminal 8 on the cartridge side and the spring terminal 9a of the power supply terminal 9 on the main body side are connected.

[0010]

<Problem 1> In the image forming apparatus using the developing cartridge shown in FIG. 13, it is necessary to provide the terminal 8 on the cartridge side, so that there is a problem that the number of parts increases. In particular, since the cartridge is often configured as a consumable, resources are wasted.

<Problem 2> In recent years, there has been an increasing demand for forming a color image using a plurality of color developers.

As one measure for forming a color image, a plurality of cartridges containing developers of different colors are arranged on a latent image carrier, and these cartridges are swingably supported. A position where the latent image on the latent image carrier is developed, and a position where the latent image is not developed, and a structure in which a desired color image is formed by selectively swinging a plurality of cartridges. obtain.

In such a configuration, the cartridge swings, so that the electrode structure shown in FIG. 13 is not desirable. This is because when the cartridge swings, the contact between the terminal 8 on the cartridge side and the spring terminal 9a of the power supply terminal 9 on the main body side may be cut off, or the contact state may become unstable.

A first object of the present invention is to solve the above problem 1 and to provide an image forming apparatus capable of reducing the number of parts of a developing cartridge often configured as a consumable.

A second object is to provide an image forming apparatus capable of reliably supplying a developing bias to a swingably supported developing cartridge.

[0016]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a latent image carrier having a latent image formed on a surface thereof; A case accommodating a developer for developing the latent image, and a case having a conductive shaft rotatably attached to the case so as to be rotatable around the axis, and being electrically connected to the shaft, the developer is supplied with the latent image. A developing cartridge having a developer carrier applied to the carrier and configured to be detachable from the image forming apparatus main body; and a developing cartridge provided on the apparatus main body side for supplying a developing bias to the developer carrier. An electrode member that is connected to the power supply of the developing cartridge and that can be brought into contact with and separated from the shaft of the developing cartridge. When the developing cartridge is mounted on the apparatus main body, the shaft and the electrode member come into contact with each other. Features.

According to a second aspect of the present invention, there is provided the image forming apparatus according to the first aspect.
In the above image forming apparatus, the contact between the shaft and the electrode member is a point contact.

According to a third aspect of the present invention, there is provided the image forming apparatus according to the first aspect.
3. The image forming apparatus according to claim 2, wherein the electrode member includes an urging member that urges the shaft in a thrust direction.

The image forming apparatus according to the fourth aspect is the third aspect.
In the image forming apparatus described above, the urging member may be formed of a leaf spring having an inclined portion that gradually urges the shaft in a thrust direction when the developing cartridge is mounted on the apparatus main body. Features.

In order to achieve the second object,
An image forming apparatus according to claim 5, wherein a latent image carrier on which a latent image is formed, a case containing a developer for developing the latent image on the latent image carrier, and the developer And a developing cartridge configured to be attachable to and detachable from the image forming apparatus main body, and a developing cartridge provided in the apparatus main body and provided at least when the developing cartridge is mounted. A guide for guiding the latent image is provided, and a position for developing the latent image and a position for not developing the latent image by swinging the receiving member and the developing cartridge together are provided. An image forming apparatus that can be adopted, wherein an electrode structure for supplying a developing bias to the developer carrier is fixed to an apparatus main body, and is connected to a power supply for supplying the developing bias. And a receiver electrode member attached to the receiver, connected to the developer carrier of the mounted developing cartridge, swinging with the receiver, and slidingly contacting the fixed electrode member. It is characterized by being.

According to a sixth aspect of the present invention, there is provided the image forming apparatus according to the fifth aspect.
In the above image forming apparatus, a sliding contact position between the fixed electrode member and the receiving member electrode member is located near the center of swing of the receiving member.

According to a seventh aspect of the present invention, there is provided the image forming apparatus according to the fifth aspect.
7. The image forming apparatus according to claim 6, wherein a range of a portion of the fixed electrode member which can slide on the receiver electrode member is wider than a swing range of the receiver electrode member with respect to the fixed electrode member. .

According to an eighth aspect of the present invention, in the image forming apparatus of the fifth, sixth or seventh aspect, the receiver electrode member is constituted by a leaf spring.

[0024]

According to the first aspect of the present invention, there is provided an image forming apparatus comprising: a latent image carrier having a latent image formed on a surface thereof; and a case accommodating a developer for developing the latent image on the latent image carrier. A developer carrier attached to the case so as to be rotatable about the axis by a shaft having conductivity, and electrically connected to the shaft to apply the developer to the latent image carrier; Since the developing cartridge is provided detachably with respect to the forming apparatus main body, an image can be formed by attaching the developing cartridge to the apparatus main body.

Further, an electrode member connected to a power supply for supplying a developing bias to the developer carrier and capable of coming in contact with and separating from the shaft of the developing cartridge is provided on the apparatus main body side. When the cartridge is mounted on the apparatus main body, the shaft and the electrode member are configured to be in contact with each other. Therefore, it is not necessary to provide an electrode member other than the shaft on the developing cartridge side.

Therefore, according to the image forming apparatus of the first aspect, it is possible to reduce the number of parts of the developing cartridge which is often configured as a consumable. Therefore, the structure of the cartridge can be simplified, the assemblability can be improved, and the cost can be reduced.

According to the image forming apparatus of the second aspect, in the image forming apparatus of the first aspect, the point of contact between the shaft and the electrode member is point contact. , The torque loss can be minimized.

Therefore, it is possible to improve the driving stability of the developer carrier.

According to a third aspect of the present invention, in the image forming apparatus of the first or second aspect, the electrode member is constituted by an urging member for urging the shaft in the thrust direction. Therefore, the contact state between the electrode member and the shaft is stabilized, and therefore, the supply state of the developing bias is stabilized.

Moreover, the electrode member urges the shaft in the thrust direction (does not urge the shaft in a direction perpendicular to the shaft).
Therefore, bending of the shaft can be prevented. Therefore, it is possible to prevent the radial force acting on the developer carrier from being different between the electrode member side and the opposite side. Further, since the urging force does not act in the mounting / removing direction of the developing cartridge, the attitude of the cartridge during the developing operation is also stabilized.

Accordingly, uneven development due to uneven rotation of the developer carrier can be suppressed.

According to the image forming apparatus of the fourth aspect, in the image forming apparatus of the third aspect, the urging member is
When the developing cartridge is mounted on the apparatus main body, the shaft is constituted by a leaf spring having an inclined portion that gradually urges the shaft in the thrust direction. A smooth contact state with the shaft is obtained.

According to a fifth aspect of the present invention, there is provided an image forming apparatus, comprising: a latent image carrier on which a latent image is formed on a surface; a case containing a developer for developing the latent image on the latent image carrier; A developer cartridge for applying the developer to the latent image carrier, and a developing cartridge detachably mounted to the image forming apparatus main body. It is possible to form an image by mounting the image on a sheet.

A receiving member for receiving the mounted developing cartridge is provided on the main assembly side of the apparatus, and the receiving member and the developing cartridge are swung together to develop the latent image. And a non-developing position, so that a color image can be formed by providing a plurality of cartridges each containing a receiver and a developer of a different color.

Further, since the receiving body is configured to guide the developing cartridge at least when it is mounted,
The cartridge can be mounted smoothly.

Further, an electrode structure for supplying a developing bias to the developer carrier is fixed to an apparatus main body, and a fixed electrode member connected to a power supply for supplying the developing bias; The image forming apparatus further includes a receiving member electrode member attached to the body and connected to the developer carrier of the mounted developing cartridge, and swings with the receiving member and slidably contacts the fixed electrode member. Despite the body swinging, it is possible to reliably supply the developing bias.

In the case where the cartridge and the receiver are configured to swing, it is possible to directly connect the power source of the apparatus main body and the electrode member attached to the receiver by, for example, an electric wire. Since the receiving body is swingable, there is a problem that disconnection is likely to occur.

On the other hand, according to the image forming apparatus of the fifth aspect, since the receiver electrode member and the fixed electrode member are in sliding contact with each other, the above problem can be prevented. Can be.

According to the image forming apparatus of the sixth aspect, in the image forming apparatus of the fifth aspect, the sliding contact position between the fixed electrode member and the receiving member electrode member is close to the center of swing of the receiving member. Since it is located, the amount of movement (sliding contact range) of the receiving electrode member with respect to the fixed electrode member can be reduced, the stability of the connection state between the fixed electrode member and the receiving electrode member, and the durability of both electrode members Performance can be improved. Further, both electrode members can be reduced in size.

Further, since the resistance due to the sliding contact (the resistance to the torque required for rocking the receiving body and the cartridge) can be reduced, the rocking of the receiving body and the cartridge can be smoothly performed.

According to the image forming apparatus of the seventh aspect, in the image forming apparatus of the fifth or sixth aspect, the area of the fixed electrode member that can be slidably contacted with the receiver electrode member is the fixed electrode member. Since it is wider than the swing range of the receiver electrode member with respect to the member, even when the receiver and the developing cartridge are at the position where the latent image is not developed,
This means that the fixed electrode member is electrically connected to the receiver electrode member.

Therefore, the ON / OFF of the supply of the developing bias to the developer carrier can be performed only by the electrical ON / OFF, and a stable bias switching operation with a small time lag can be performed.

According to an eighth aspect of the present invention, in the image forming apparatus according to the fifth, sixth or seventh aspect, one of the fixed electrode member and the receiver electrode member is formed of a leaf spring. As a result, a reliable sliding contact between the two members can be obtained.

[0044]

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

FIG. 1 is a schematic diagram showing an embodiment of an image forming apparatus according to the present invention, and FIG. 2 is a schematic diagram showing a frame configuration thereof.

First, an outline of the image forming apparatus will be described.

This image forming apparatus forms a single-color image and a full-color image using a developing cartridge with four color toners (developer) of yellow (Y), cyan (C), magenta (M), and black (K). It is a device that can do it.

In FIG. 1, reference numeral 50 denotes a photoreceptor unit, and a photoreceptor 51 as a latent image carrier is rotationally driven in a direction indicated by an arrow in FIG.

The photosensitive member 51 has a thin cylindrical conductive base material and a photosensitive layer formed on the surface thereof.

Around the photoreceptor 51, a charging roller 52 as a charging unit, an exposure unit 60 as an exposure unit, and a developing unit as a development unit constitute an image forming unit together with the photoreceptor 51 along the rotation direction. Cartridge 70
(Y, C, M, K), and the intermediate transfer unit 80. Further, a cleaning unit 53 is provided.
The photoconductor unit 50 incorporates a photoconductor 51, a charging roller 52, and a cleaning unit 53.

The charging roller 52 contacts the outer peripheral surface of the photoreceptor 51 to uniformly charge the outer peripheral surface. The outer peripheral surface of the uniformly charged photoconductor 51 is selectively exposed L1 according to desired image information by the exposure unit 60, and an electrostatic latent image is formed on the photoconductor 51 by the exposure L1. .

The electrostatic latent image is developed with toner applied by a developing cartridge 70.

As the developing cartridges, a developing cartridge 70Y for yellow and a developing cartridge 7 for cyan
0C, a magenta developing cartridge 70M, and a black developing cartridge 70K are provided.

Each of the developer cartridges is rotatably mounted on a case 72 containing toner and a rotatable shaft 73 with a conductive shaft 73. Toner 5
A developing roller 71 as a developer carrier to be applied to 1;
A supply roller 74 for supplying the toner in the case 72 to the developing roller 71 is provided.

These developing cartridges 70Y, 70C,
70M and 70K are configured to be swingable as described later, so that only a developing roller 71 as a developer carrying member of one developing cartridge can selectively contact the photosensitive member 51. . Therefore, these developing cartridges 70 include yellow, cyan, magenta,
One of the black toners is applied to the surface of the photoconductor 51 to develop the electrostatic latent image on the photoconductor 51.

The developed toner image is transferred onto an intermediate transfer belt 86 forming an intermediate transfer body of the intermediate transfer unit 80.

After the transfer, the cleaning means 53
The cleaning device includes a cleaner blade for scraping off the toner remaining on and adhering to the outer peripheral surface of the photoreceptor 51, and a receiving portion for receiving the toner scraped off by the cleaner blade.

The intermediate transfer unit 80 includes a driving roller 81
And four driven rollers 82, 83, 84, 85, and an endless intermediate transfer belt 86 as an intermediate transfer member stretched around these rollers.

The driving roller 81 is substantially connected to the photosensitive member 51 by a gear (not shown) fixed to the end of the driving roller 81 meshing with a driving gear (not shown) provided at the end of the photosensitive member 51. The intermediate transfer belt 86 is driven to rotate at the same peripheral speed, so that the intermediate transfer belt 86 is driven to circulate at substantially the same peripheral speed as the photosensitive member 51 in the direction of the arrow in the figure.

The driven roller 85 is disposed at a position where the intermediate transfer belt 86 is pressed against the photosensitive member 51 by its own tension between the driven roller 85 and the driven roller 81. In the primary transfer section T1
Are formed. The driven roller 85 is disposed near the primary transfer portion T1 on the upstream side in the circulation direction of the intermediate transfer belt 86.

The driving roller 81 has an intermediate transfer belt 86
A primary transfer voltage is applied to the intermediate transfer belt 86 via the electrode roller (not shown).

The driven roller 82 is a tension roller, and urges the intermediate transfer belt 86 in the direction of its tension by urging means (not shown).

The driven roller 83 is a backup roller that forms the secondary transfer portion T2. A secondary transfer roller 88 as a secondary transfer unit is opposed to the backup roller 83 via an intermediate transfer belt 86. The secondary transfer roller 88 can be moved toward and away from the intermediate transfer belt 86 by a contact / separation mechanism (not shown). A secondary transfer voltage is applied to the secondary transfer roller 88.

The driven roller 84 is a backup roller for the belt cleaner 89. Belt cleaner 89
Is a cleaner blade 89 which comes into contact with the intermediate transfer belt 86 and scrapes off the toner remaining and adhering to the outer peripheral surface thereof.
a, and a receiving portion 89b for receiving the toner scraped off by the cleaner blade 89a. The belt cleaner 89 can be moved toward and away from the intermediate transfer belt 86 by a contact / separation mechanism (not shown).

The intermediate transfer belt 86 is composed of a multilayer belt having a conductive layer and a resistive layer formed on the conductive layer and pressed against the photosensitive member 51. The conductive layer is formed on an insulating substrate made of a synthetic resin, and a primary transfer voltage is applied to the conductive layer via the above-described electrode roller.

In the course of the intermediate transfer belt 86 being driven to circulate, the toner image on the photosensitive member 51 is transferred onto the intermediate transfer belt 86 in the primary transfer portion T1, and the intermediate transfer belt 8
The toner image transferred onto the sheet 6 is transferred to a sheet (recording material) S such as a sheet supplied between the secondary transfer roller 88 and the secondary transfer section T2.

The intermediate transfer unit 80 also incorporates the electrode roller, biasing means for the tension roller 82, a secondary transfer roller 88, and a belt cleaner 89.

The recording material S is fed to a sheet feeding device 90 serving as a sheet feeding means.
And is supplied to the secondary transfer portion T2 at a predetermined timing by the gate roller pair G. Reference numeral 91 denotes a paper feed cassette for stacking and holding the recording materials S, and reference numeral 92 denotes a pickup roller.

The recording material S to which the toner image has been transferred in the secondary transfer portion T2 passes through a fixing unit 100 serving as a fixing means, and the toner image is fixed.

The fixing unit 100 includes a heating roller 101 having a heat source and a pressure roller 10 pressed against the heating roller 101.
The rollers 101 and 102 heat the passing recording material S while pinching it, thereby fusing and fixing the toner image on the recording material S.

The recording material S that has passed through the fixing unit 100 is
Eventually, the sheet is discharged onto a sheet receiving portion 41 formed on a case 40 of the apparatus main body through a sheet discharging path 110. In this image forming apparatus, the recording material S passing through the fixing unit 100 is A reversing return path 110 'is provided for reversing the front and back and returning the recording material S to the secondary transfer portion T2 again. That is, the conveying means of the recording material S in the present embodiment includes the sheet discharge path 110 or the reverse return path 1
10 '.

The reverse return path 110 ′ is connected to the fixing unit 1
The switchback path 1 has two independent paper discharge paths 111 and 112 that can carry in the recording material S that has passed through the sheet feeding unit 00 and reversely feed the recording material S once carried in.
13 and a return path 114 for returning the recording material S sent back from the switchback path 113 back to the secondary transfer portion T2. Therefore, the recording material S returned to the secondary transfer portion T2 again by the reverse return path 110 'is turned over and returned to the secondary transfer portion T2.

Such an image forming apparatus can form an image only on the front surface (first surface) of the recording material S, or form an image on both surfaces (first and second surfaces, front and back). You can also.

Reference numeral 120 denotes a control section, which constitutes control means for controlling the entire apparatus.

The outline of the operation of the entire image forming apparatus as described above is as follows.

(I) When a print command signal (image forming signal) from a host computer or the like (personal computer or the like) not shown is input to the control unit 120 of the image forming apparatus, each roller of the photosensitive member 51 and the developing cartridge 70 is 7
1, and the intermediate transfer belt 86 is driven to rotate.

(Ii) The outer peripheral surface of the photosensitive member 51 is uniformly charged by the charging roller 52.

(Iii) The outer peripheral surface of the uniformly charged photoreceptor 51 is selectively exposed L1 in accordance with the image information of the first color (for example, yellow) by the exposure unit 60, and a yellow electrostatic latent image is formed. An image is formed.

(Iv) Only the developing roller of the developing cartridge 70Y for the first color (for example, yellow) comes into contact with the photosensitive member 51, whereby the electrostatic latent image is developed.
A first color (for example, yellow) toner image is formed on the photoconductor 51.

(V) A primary transfer voltage having a polarity opposite to that of the toner is applied to the intermediate transfer belt 86, and the toner image formed on the photoconductor 51 is transferred to the intermediate transfer belt 86 at the primary transfer portion T1. Is transferred to At this time, the secondary transfer roller 88 and the belt cleaner 89 are separated from the intermediate transfer belt 86.

(Vi) After the toner remaining on the photoreceptor 51 is removed by the cleaning means 53, the photoreceptor 51 is discharged by the discharging light L2 from the discharging means 61.

(Vii) The above operations (ii) to (vi) are repeated as necessary. That is, the second color, the third color, the fourth color,
Is repeated on the intermediate transfer belt 86 to form a toner image corresponding to the content of the print command signal.

(Viii) The recording material S is supplied from the paper feeding device 90 at a predetermined timing, and immediately before or after the leading end of the recording material S reaches the secondary transfer portion T2 (in short, a desired image on the recording material S) (At the timing when the toner image on the intermediate transfer belt 86 is transferred) to the secondary transfer roller 88
Is pressed against the intermediate transfer belt 86 and a secondary transfer voltage is applied, so that the toner image on the intermediate transfer belt 86 (basically, a full-color image in which four color toner images are superimposed) is formed on the recording material S. Transcribed. Further, the belt cleaner 89 comes into contact with the intermediate transfer belt 86, and the toner remaining on the intermediate transfer belt 86 after the secondary transfer is removed.

(Ix) When the recording material S passes through the fixing unit 100, the toner image is fixed on the recording material S,
Thereafter, the recording material S is conveyed toward a predetermined position (toward the sheet receiving portion 41 in the case of non-double-sided printing, or to the return path 114 via the switchback path 113 in the case of double-sided printing).

That is, when an image is formed only on the front surface (first surface), the recording material S fed from the paper feeding device 90 is used.
After the toner image is transferred to the first surface by the secondary transfer portion T2 and fixed by the fixing unit 100,
The sheet is discharged onto the sheet receiving section 41 through 1 or 112. In addition, the entrance portion 110 of the paper discharge paths 111 and 112
A is provided with a path switching unit (not shown), which determines which of the paper discharge paths (111, 112) the recording material S is carried in.

When an image is formed on both sides (first and second sides), the recording material S fed from the sheet feeding device 90 is used.
After the toner image is transferred to the first surface by the secondary transfer unit T2 and fixed by the fixing unit 100, the toner image temporarily enters the paper discharge path 111 or 112 (the switchback path 74), is reversely fed, and is returned. After 73, the sheet is returned to the secondary transfer portion T2 again at a predetermined timing by the gate roller pair G, and the toner image is also transferred to the second surface. After that, the image (toner image) is also fixed on the second surface by the fixing unit 100, and is passed through the sheet discharge path 111 or 112 to the sheet receiving section 4.
It is discharged on 1.

The outline of the image forming apparatus of this embodiment has been described above. Next, the frame configuration will be described.

In FIG. 2, reference numeral 10 denotes a first frame;
Is a second frame, and 30 is a third frame. These first, second, and third frames 10, 20, and 30 are each composed of separate frames.

The first frame 10 includes the photosensitive unit 5
0, the developing cartridge 70 (Y, C, M, K), the intermediate transfer unit 80, and their driving means (driving motor, gear or gear train, etc.) are supported. The photoconductor unit 50 and the intermediate transfer unit 80 are arranged side by side in the vertical direction. As will be described later, the photoconductor unit 50 and the intermediate transfer unit 80 are located on the second frame 20 side with respect to the first frame 10. (The right side in FIG. 2). Each developing cartridge 70 is configured to be detachable from the first frame 10 from the third frame 30 side (the left side in FIG. 2) as described later.

The second frame 20 includes the exposure unit 6
0, a sheet feeding device 90, and a gate roller pair G are supported. The second frame 20 has an upper frame 21 and a lower frame 22. The upper frame 21 supports the exposure unit 60, and the lower frame 22 supports the sheet feeding device 90 and the gate roller pair G. .

The third frame 30 includes the fixing unit 10
0, a paper discharge path 110, and a reverse return path 110 'are supported.

The second frame 20 is configured to be horizontally separated from the first frame 10.

As shown in FIG. 3, the third frame 30 is configured to be separated from the first frame 10 in the horizontal direction (the direction of the arrow X2).

Further, the third frame 30 has a horizontal frame 31 arranged in a substantially horizontal direction and a vertical frame 32 arranged in a substantially vertical direction. By being connected, the vertical frame 32 is configured to be rotatable around the axis 33 with respect to the horizontal frame 31. In the horizontal frame 31, a return path 114 of the reverse return path 110 'and its driving means (a gear train (not shown) for driving the transport roller R) are provided.
The vertical frame 32 has a switchback path 113 (which is also a paper discharge path 111, 112) of the reverse return path 110 'and its driving means (a gear train (not shown) for driving the transport roller R). Is mainly provided. The fixing unit 100 is a horizontal frame 3
1 and is detachably mounted on the horizontal frame 31 in a substantially vertical direction (directions of arrows Y1 and Y2) with the vertical frame 32 rotated as shown in FIG. .

As described above, the first frame 10 and the third frame
A space A2 is formed between the developing cartridge 7 and the frame 30.
0 can be easily attached to and detached from the first frame 10. The mounting / removing direction of each developing cartridge 70 is a direction substantially toward the center of the photoconductor 51.

As shown in FIG. 4, a receiver 130 for the developing cartridge 70 is provided in the apparatus main body.

The receiving body 130 includes a bottom plate 131 and a pair of side plates 13 formed by standing and bending both sides of the bottom plate 131.
2, 132 (only one is shown in FIG. 7), and the mounting direction of the developing cartridge 70 (arrow VII in FIG. 4).
Direction) (see FIG. 7). The receiving member 130 guides the developing cartridge 70 at least at the time of mounting, and receives the mounted developing cartridge 70.

A support shaft 133 (see FIG. 9) is provided on the outer side surface (or the first frame 10) of the pair of side plates 132, 132, and the receiving body 130 is moved by the support shafts 133 and 133. It is swingably supported by the frame 10.

The fixing structure between the receiver 130 and the developing cartridge 70 may employ an appropriate structure.

For example, as shown in FIG. 5, a pair of engaging pins 131b (only one of which is shown in FIG. 5) having a flange bottom plate 131a are provided on both sides of the top surface on the distal end side of the bottom plate 131, and the bottom of the case 72 of the developing cartridge 70 is provided. The engaging pin 131b and the engaging piece 72a are provided integrally with the engaging pin 131b on the distal end side so that the engaging pin 131b and the engaging piece 72a are engaged with each other. Lock levers 75, 75 as shown are rotatably mounted on a common shaft 75a, and a lock claw 75b formed at the tip of the lock lever 75 is engaged with a lock pin 132a provided on the inner surface of the side plate 132 of the receiving body 130. By doing so, a structure in which the developing cartridge 70 is fixed to the receiving body 130 can be adopted.

When such a structure is adopted, the pair of lock levers 75, 75 can be used as a handle of the developing cartridge 70. That is, when the developing cartridge 70 is mounted on the receiving body 130, the lock levers 75, 75 are grasped and the developing cartridge 70 is inserted in the direction of the arrow VII in FIG.
After the engaging pin 2a is engaged with the engaging pin 131b2, the lock lever 75 is rotated from the position indicated by the imaginary line in FIG. 70 receiving body 13
Can be fixed to zero. When removing the developing cartridge 70 from the receiving body 130, the lock levers 75, 7
5 can be easily removed by grasping and rotating it as shown by a virtual line in FIG.

When the developing cartridge 70 is mounted on the receiving member 130, the developing cartridge 70 and the receiving member 130
Can swing together around the support shaft 133.

An unillustrated urging means (for example, a tension spring) is provided between the receiving body 130 and the first frame 10. The urging means moves the receiving body 130 clockwise in FIGS. The developing roller 71 of the developing cartridge 70 fixed to the receiving member 130 is urged in a direction in which the developing roller 71 is pressed against the photosensitive member 51, and the space between the first frame 10 and the receiving member 130 is clockwise. There is provided a regulating mechanism including a cam or the like capable of regulating the swing of the cam.

Therefore, when the regulation is released by the operation of the regulation mechanism, the receiving member 130 and the developing cartridge 70 swing clockwise by the urging force of the urging means, and the developing roller 71 is moved to the photosensitive member. When the developing mechanism is in the developing position where it is pressed against the developing roller 51 (see FIG. 4) and the above-described restriction is performed by the operation of the restriction mechanism, the receiving member 130 and the developing cartridge 70 swing counterclockwise, and the developing roller 7 is rotated.
1 is separated from the photoreceptor 51 and becomes a position where development is not performed.
In FIG. 9, the virtual line side plate 132 ′ indicates the position (development position) of the receiver 130 when the developing roller 71 is pressed against the photoconductor 51, and the virtual line side plate 132 ″ indicates that the developing roller 71 is The position of the receiving body 130 when separated from 51 is shown.

The receiving member 130 and the regulating mechanism as described above are provided for all the developing cartridges 70 (Y, C, M, K), and therefore control the rotation of the regulating mechanism such as the cam. Thus, only one of the developing rollers 71 can be brought into contact with the photoconductor 51.

7 to 11 are views showing an electrode structure for supplying a developing bias to the developing roller 71 of the developing cartridge 70. FIG. 7 is a partially enlarged view taken along the line VII in FIG. 4, and FIG. 9 is a front view, FIG. 9 is a partially omitted view taken in the direction of the arrow IX in FIG. 7, FIG. 10 is a view seen in the direction of the arrow (X) in FIG. 7, and FIG. FIG.

In FIGS. 7 and 8, reference numeral 134 denotes a receiver electrode member, which corresponds to the electrode member of the first aspect. 13 is a fixed electrode member.

The receiver electrode member 134 is mounted on the side plate 132 of the receiver 130 via a mounting member 136 made of an insulating material. Therefore, this receiver electrode member 1
34 swings with the receiving body 130.

The receiver electrode member 134 is attached to the mounting member 136.
Is formed of a substantially inverted U-shaped leaf spring so that it can be fitted into the
Has an inclined portion 134b inclined with respect to the attaching / detaching direction of the developing cartridge 70 (the direction of the arrow a in FIG. 8) and a parallel portion 134c substantially parallel to the attaching / detaching direction of the developing cartridge 70. Therefore, when the developing cartridge 70 is mounted on the receiver 130, the one end 73 a of the shaft 73 of the developing roller 71 gradually comes into contact with the inclined portion 134 b of the receiver electrode member 134 in the process. The shaft 73 is gradually urged in the thrust direction, and when the one end 73a of the shaft 73 reaches the parallel portion 134c, the shaft 73 is
Is completely urged in the thrust direction.

The one end 73a of the shaft 73 is formed in a hemispherical shape, so that the one end 73a of the shaft 73 and the receiver electrode member 134 come into point contact.

Outer hanging portion 134 of receiver electrode member 134
d is bent toward the fixed electrode member 13 so as to slide on the fixed electrode member 13. Outside hanging part 134d
Is formed with a hemispherical portion 134e that is in sliding contact with the fixed electrode member 13.

The attachment member 136 includes the receiver electrode member 13.
An electrode member 135 basically having the same configuration as that of No. 4 is also attached. The electrode member 135 is for supplying a supply bias to the supply roller 74 (see FIG. 1) of the developing cartridge 70. The electrode member 135 has an inclined portion 135b and a parallel portion 135c formed in an inner hanging portion 135a and an outer portion 135a. A hemispherical portion 135e that is in sliding contact with the fixed electrode member 14 similar to the fixed electrode member 13 is formed in the hanging portion 135d.

Reference numeral 76 denotes a shaft of the supply roller 74, and one end 76a of the shaft 76 is also formed in a hemispherical shape so as to make point contact with the electrode member 135.

The fixed electrode members 13 and 14 are mounted on the side plate 11 of the first frame 10 of the apparatus main body via the mounting member 15 made of an insulating material.

The fixed electrode members 13 and 14 are attached to the mounting member 15.
Is formed of a substantially inverted U-shaped leaf spring so as to be able to be fitted from above to the inner side thereof.
As described above, 14a is in sliding contact with the hemispherical portion 134e of the outer hanging portion 134d of the receiver electrode member 134 and the hemispherical portion 135e of the electrode member 135.

The range of the portion of the fixed electrode members 13 and 14 that can be in sliding contact with the hemispherical portion 134e of the receiver electrode member 134 and the hemispherical portion 135e of the electrode member 135, that is, the size of the inner hanging portions 13a and 14a is shown in FIG. As shown in FIG. 9, the receiver electrode members 134, 134 with respect to the fixed electrode members 13, 14,
The swing range of the electrode member 135 (see arrows b1 and b2 in FIG. 9).
Is wider than.

Further, the sliding contact position between the fixed electrode members 13 and 14 and the receiver electrode members 134 and 135 is located near the swing center (support shaft 133) of the receiver 130 as shown in FIG. I have.

As shown in FIG. 10, the fixed electrode member 13
Of the fixed electrode member 14 is connected to a power source (not shown) for supplying a developing bias to the developing roller 71 via the receiver electrode member 134 and the shaft 73. The power supply 14 b is connected to a power supply (not shown) for supplying a supply bias to the supply roller 74 via the electrode member 135 and the shaft 76 via the electric wire 17. Reference numeral 18 denotes a screw connecting the terminal 19 of the electric wire to the outer hanging portions 13b, 14b of the fixed electrode members 13, 14.

The electrode structure as described above is provided for all the developing cartridges 70 (see FIG. 11).

According to the above-described image forming apparatus, the following operation and effect can be obtained.

(A) Photoreceptor 51 having a latent image formed on its surface
A case 72 in which toner for developing the latent image on the photoconductor 51 is accommodated; and a case 73 rotatably attached to the case 72 by a conductive shaft 73 around the shaft 73. A developing roller 71 that is electrically connected to the shaft 73 and applies the toner to the photoconductor 51;
Since the developing cartridge 70 is provided detachably with respect to the image forming apparatus main body, an image can be formed by attaching the developing cartridge 70 to the apparatus main body.

The developing roller 71 is provided on the main assembly side.
Is provided with an electrode member 134 which is connected to a power supply for supplying a developing bias to the shaft 73 of the developing cartridge 70 and is detachable from the shaft 73 of the developing cartridge 70. Shaft 73 and electrode member 13
4, there is no need to provide an electrode member other than the shaft 73 on the developing cartridge 70 side.

Therefore, according to the image forming apparatus of this embodiment, it is possible to reduce the number of components of the developing cartridge 70 which is often configured as a consumable. Therefore, the structure of the cartridge 70 can be simplified, the assemblability can be improved, and the cost can be reduced. Note that the developing cartridge 70 of this embodiment is configured as a consumable.

(B) Since the shaft 73 of the developing cartridge 70 is in point contact with the electrode member 134, the shaft 7
The torque loss for rotationally driving the motor 3 can be minimized.

Therefore, the driving stability of the developing roller 71 can be improved.

(C) Since the electrode member 134 is constituted by a leaf spring that urges the shaft 73 in the thrust direction, the contact state between the electrode member 134 and the shaft 73 is stabilized, and therefore, the supply of the developing bias is performed. The state becomes stable.

In addition, the electrode member 134 urges the shaft 73 in the thrust direction (not in the direction orthogonal to the axis), so that the shaft 73 can be prevented from bending. Therefore, the radial force acting on the developing roller 71 is
The electrode member 134 side and the opposite side may not be different. Further, since the urging force of the electrode member 134 does not act in the mounting / detaching direction of the developing cartridge 70 (the direction of the arrow a in FIG. 8), the cartridge 7 during the developing operation is not operated.
The posture of 0 is also stable.

Therefore, uneven development due to uneven rotation of the developing roller 71 can be suppressed.

Further, the electrode members 134 and 135 urge the shaft 73 of the developing roller 71 and the shaft 76 of the supply roller 74 toward the side opposite to the electrode member.
1. The supply roller 74 is prevented from moving in the thrust direction.

Therefore, deterioration of the sealing property of the toner is also prevented.

(D) The electrode member 134 is constituted by a leaf spring having an inclined portion 134b for gradually urging the shaft 73 in the thrust direction when the developing cartridge 70 is mounted on the apparatus main body. When the device 70 is mounted on the apparatus main body, a smooth contact state between the electrode member 134 and the shaft 73 is obtained.

(E) A receiving member 130 for receiving the mounted developing cartridge 70 is provided on the apparatus main body side, and the receiving member 130 and the developing cartridge 70 swing together with the photosensitive member. Since a configuration in which a latent image on the image 51 can be developed and a position in which the latent image is not developed can be adopted, a color image is formed by providing a plurality of the cartridges 70 containing the toner 130 and toners of different colors. It is possible.

Further, since the receiving body 130 is configured to guide the developing cartridge 70 at least at the time of mounting, the cartridge 70 can be mounted smoothly.

The electrode structure for supplying the developing bias to the developing roller 71 is fixed to the main assembly of the apparatus.
The fixed electrode member 13 connected to the power supply for supplying the developing bias, and the developing roller 71 of the mounted developing cartridge 70 attached to the receiving member 130 and swinging together with the receiving member 130, Further, since the receiver electrode member 134 is provided in sliding contact with the fixed electrode member 13, the developing bias can be reliably supplied despite the swinging of the cartridge 70 and the receiver 130.

When the cartridge 70 and the receiving member 130 are configured to swing, the power supply of the apparatus main body and the electrode member (134) attached to the receiving member 130 are connected to each other.
For example, although it is possible to directly connect with the electric wire 16,
In this case, since the receiving body 130 can swing,
There is a problem that disconnection easily occurs.

On the other hand, according to the image forming apparatus of this embodiment, the receiver electrode member 134 and the fixed electrode member 13
And slidably contact with each other, so that the above problem can be prevented.

(F) The sliding contact position between the fixed electrode member 13 and the receiver electrode member 134 is determined by the swing center 133 of the receiver 130.
Since it is located near, the amount of movement (sliding range) of the receiver electrode member 134 with respect to the fixed electrode member 13 can be reduced, and the fixed electrode member 13 and the receiver electrode member 134
And the durability of both electrode members 13 and 134 can be improved. Also, both electrode members 1
3,134 can be reduced in size.

In addition, the resistance due to the sliding contact (the receiving body 13)
0 and the torque required to swing the cartridge 70) can be reduced.
In addition, the swing of the cartridge 70 is smoothly performed.

(G) Since the range (13a) of the portion of the fixed electrode member 13 which can slide on the receiver electrode member 134 is wider than the swing range of the receiver electrode member 134 relative to the fixed electrode member 13. Even when the receiving member 130 and the developing cartridge 70 are at positions where the latent image is not developed, the fixed electrode member 13 and the receiving member electrode member 134 are electrically connected.

Therefore, the ON / OFF of the bias supply to the developing roller 71 and the supply roller 74 is determined by the electric O.
This can be performed only with N and OFF, and a stable bias switching operation with a small time lag can be performed. Further, it is possible to stably switch the bias even in a small space, and to obtain an effect that the durability is excellent.

Here, if the bias ON / OFF is to be switched by a mechanical contact, a conducting portion and a non-conducting portion are required. Therefore, it is necessary to increase the stroke between ON and OFF of the contact. And the electrode structure becomes large. If an attempt is made to realize such an electrode structure in a small space, the stroke of the electrode contact cannot be increased, so that it is difficult to control the timing of electrode conduction due to component tolerances, mounting errors, and the like, and the operation is unstable. become. Further, when the bias is switched between ON and OFF by using a mechanical contact, the contact repeatedly moves between the conductive portion and the non-conductive portion, which causes a difficulty in durability. Further, when the non-conductive portion is made of an insulator or the like, the shavings adhere to the electrode contacts and cause poor conduction.

On the other hand, according to the present embodiment, the range (13a) of the portion of the fixed electrode member 13 that can be brought into sliding contact with the receiver electrode member 134 is limited by the swing of the receiver electrode member 134 relative to the fixed electrode member 13. Since the moving range is wider than the moving range, even when the receiving body 130 and the developing cartridge 70 are at positions where the latent image is not developed, the fixed electrode member 13
And the receiver electrode member 134 are electrically connected,
ON / OFF of the bias supply to the developing roller 71 and the supply roller 74 can be performed only by electrical ON / OFF, and a stable bias switching operation with a small time lag can be performed. Further, it is possible to stably switch the bias even in a small space, and to obtain an effect that the durability is excellent.

(H) Since both the fixed electrode member 13 and the receiver electrode member 134 are constituted by leaf springs, both members 1
3,134 reliable sliding contact states can be obtained.

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of the present invention.

For example, in the above-described embodiment, the developing roller is used as the developer carrying member, but a configuration using a flexible toner conveying member as shown in FIG. 12 may be used instead. .

In the above embodiment, the fixed electrode member 13
And both the receiving member electrode member 134 are configured by leaf springs,
Even if only one of them is made of a leaf spring, a reliable sliding contact between the two members can be obtained.

[0147]

According to any of the image forming apparatuses according to the first to fourth aspects, the number of parts of the developing cartridge which is often configured as a consumable can be reduced.

Further, according to the image forming apparatus of the present invention, the driving stability of the developer carrier can be improved.

According to the image forming apparatus of the third aspect, the supply state of the developing bias is stabilized, and the unevenness in the development due to the uneven rotation of the developer carrier can be suppressed.

According to the image forming apparatus of the fourth aspect, when the cartridge is mounted on the apparatus main body, a smooth contact state between the electrode member and the shaft can be obtained.

On the other hand, with any of the image forming apparatuses according to the fifth to eighth aspects, a color image can be formed, the cartridge can be mounted smoothly, and the developing bias can be reliably supplied. can do.

Further, according to the image forming apparatus of the present invention, it is possible to improve the stability of the connection state between the fixed electrode member and the receiver electrode member and to improve the durability of both electrode members, and to use both electrode members. The size can be reduced. In addition, the receiving body and the cartridge are smoothly swung.

According to the image forming apparatus of the present invention, the ON / OFF of the supply of the developing bias to the developer carrier can be performed only by the electrical ON / OFF, and a stable bias with a small time lag can be obtained. Switching operation becomes possible.

According to the image forming apparatus of the eighth aspect, a reliable sliding contact state between the fixed electrode member and the receiver electrode member can be obtained.

[0155]

[Brief description of the drawings]

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

FIG. 2 is a schematic diagram showing a frame configuration.

FIG. 3 is a schematic diagram showing a frame configuration.

FIG. 4 is a partially omitted front view showing a developing cartridge 70 and a receiver 130.

FIG. 5 is a partially omitted plan view of FIG. 4;

FIG. 6 is a perspective view showing an example of a lock lever.

FIG. 7 is a diagram showing an electrode structure, and is a partially enlarged view as seen in the direction of arrow VII in FIG. 4;

FIG. 8 is a plan view when FIG. 7 is a front view.

FIG. 9 is a partially omitted view taken along arrow IX in FIG. 7;

FIG. 10 is a view taken in the direction of the arrow (X) in FIG. 7;

FIG. 11 is a view showing a side plate 11 on the near side of the first frame 10;

FIG. 12 is an explanatory diagram of a conventional technique.

FIGS. 13A and 13B are explanatory diagrams of a conventional technique.

[Explanation of symbols]

 13 Fixed Electrode Member 51 Photoconductor 51 (Latent Image Carrier) 70 Developing Cartridge 71 Developing Roller (Developer Carrier) 72 Case 73 Shaft 130 Receiver 133 Supporting Shaft (Swinging Center) 134 Receiver Electrode Member (Electrode Member)

Claims (8)

[Claims] 1. A latent image carrier on which a latent image is formed, a case accommodating a developer for developing the latent image on the latent image carrier, and a conductive A developer carrier that is rotatably mounted around the shaft by a shaft having the above, and is electrically connected to the shaft to apply the developer to the latent image carrier, and is detachably attached to the image forming apparatus main body. A developing cartridge, and an electrode member provided on the apparatus main body side, connected to a power supply for supplying a developing bias to the developer carrying member, and capable of coming in contact with and separating from the shaft of the developing cartridge. An image forming apparatus, wherein when the developing cartridge is mounted on the apparatus main body, the shaft and the electrode member come into contact with each other. 2. The image forming apparatus according to claim 1, wherein the contact between the shaft and the electrode member is a point contact. 3. The image forming apparatus according to claim 1, wherein the electrode member comprises an urging member for urging the shaft in a thrust direction. 4. The device according to claim 1, wherein the biasing member is formed of a leaf spring having an inclined portion that gradually biases the shaft in a thrust direction when the developing cartridge is mounted on the apparatus main body. The image forming apparatus according to claim 3. 5. A latent image carrier on which a latent image is formed, a case containing a developer for developing the latent image on the latent image carrier, and the latent image carrier A developer cartridge having a developer carrier for applying to the body, and configured to be detachable from the image forming apparatus main body; and provided on the apparatus main body, for guiding the developer cartridge at least at the time of mounting, and An image forming apparatus that can take a position where the latent image is developed by swinging together with the receiving member and the developing cartridge, and a position where the latent image is not developed. An electrode structure for supplying a developing bias to the developer carrier, the fixed electrode member being fixed to an apparatus body, and connected to a power supply for supplying the developing bias; A receiver electrode member attached to the receiver and connected to the developer carrier of the mounted developing cartridge, swinging with the receiver, and slidingly contacting the fixed electrode member. Image forming apparatus. 6. The image forming apparatus according to claim 5, wherein a sliding contact position between the fixed electrode member and the receiver electrode member is located near a swing center of the receiver. 7. The fixed electrode member according to claim 5, wherein a range of a portion of said fixed electrode member that can slide with said receiver electrode member is wider than a swing range of said receiver electrode member relative to said fixed electrode member. 7. The image forming apparatus according to 6. 8. The image forming apparatus according to claim 5, wherein one of the fixed electrode member and the receiver electrode member is formed of a leaf spring.