JPH06266267A - Cleaning device and image forming device - Google Patents

Abstract

PURPOSE:To prevent a toner leak and an exhaust leak and hold the airtightness of a device. CONSTITUTION:An image forming device is provided with a rotary cylinder brush 13a removing the unnecessary developer on a cleaned body 4, a box 13b rotatably supporting the rotary cylinder brush 13a and capable of rocking the rotary cylinder brush 13a to come into contact with or to separate from the cleaning body 4, a suction mechanism 13c rockably supporting the box 13b and applying the suction negative pressure into the box 13b, a carry-out port 13e of a developer on a shaft serving as the rocking center of the box 13b, and a lubricating shield ring concurrently serving as the thrust pressure receiver of the box portion is provided between the rocking center shaft of the box 13b having the developer carry-out port 13e and the suction mechanism 13c. A toner leak and an exhaust leak due to the sliding abrasion at the connection section can be prevented, and the airtightness of the device can be held at the same time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine or a printer, and more particularly to a cleaning apparatus for removing an unnecessary developer on an object to be cleaned such as an image carrier.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, in a cleaning device for removing unnecessary developer on an object to be cleaned, a plate spring 52 is pressed by an eccentric cam 51, and the brush case 53 is pressed by this pressing force. The brush 54 swinging around the shaft 53a and rotatably supported by the brush case 53 comes into contact with the object 55 to be cleaned. In this state, the developer on the member to be cleaned 55 adheres to the brush 54 rotated by a rotary drive actuator (not shown) and is taken into the inside of the brush case 53 to which suction negative pressure is applied. Further, the developer adhering to the brush 54 is peeled off by a scraper blade 56 provided inside the brush case 53, which is located at the opposite position of the abutting point between the cleaning object 55 and the brush 54, and passes through the developer transport path 53b. It is taken into the illustrated suction mechanism.

[0003]

However, in the above-described conventional example, since the brush case 53 swings and the developer carrying path 53b also moves around the shaft 53a, the developing device is provided in the duct of the suction mechanism (not shown). The developer transport path 53b must be provided with a slidable hole 57 and a flange 53b1 must be provided at the tip of the developer transport path 53b.
There is a problem that sliding wear occurs between the duct and the long hole 57 of the duct, which causes toner leakage and exhaust gas leakage to impair the airtightness of the apparatus.

Therefore, an object of the present invention is to prevent the above-mentioned toner leakage and exhaust leakage and maintain the airtightness of the apparatus.

[0005]

A typical cleaning device according to the present invention for attaining the above-mentioned object comprises a rotary cylindrical brush for removing an unnecessary developer on an object to be cleaned, and a rotary cylindrical brush. A casing that is rotatably supported and is swingable so that the rotating cylindrical brush comes into contact with and separates from the object to be cleaned, and a casing that is swingably supported to apply a suction negative pressure to the inside of the casing. A suction mechanism, and a developer carrying-out port is provided on a shaft serving as a swinging center of the casing, and further, a swinging center shaft of the casing having the developer carrying-out port and the suctioning unit. It is characterized in that a shield ring having a lubricity functioning also as a thrust pressure receiving member of the housing portion is provided between the shield ring and the mechanism.

[0006]

In the cleaning device having the above structure,
A swing-out central axis of a casing having the rotating cylindrical brush is provided with a developer carrying-out port that connects the suction mechanism, and a swinging central axis of the casing provided with the developer carrying-out port and the suction mechanism. Since a shield ring having lubricity that also serves as a thrust pressure receiver of the housing portion is provided between the two, it is possible to prevent toner leakage and exhaust leakage due to sliding wear at the coupling portion, and at the same time. The airtightness of the device can be maintained.

[0007]

【Example】

[First Embodiment] Next, a first embodiment of the image forming apparatus according to the present invention will be specifically described with reference to the drawings. 1. FIG. 1 is an overall configuration diagram of a laser beam printer which is one mode of the image forming apparatus.

[Overall Configuration] First, the overall configuration of the image forming apparatus will be briefly described. As shown in FIG. 1, this apparatus feeds a recording medium 2 housed in a cassette 1 constituting a stacking means of this embodiment. It is fed by the means 3 and wound around the peripheral surface of the transfer drum 4 which constitutes the transfer means. On the other hand, the optical unit 5 irradiates the image carrier unit 6 with light according to a color image to form a latent image on the image carrier, and the latent image is developed by mounting four developing devices capable of rotating and moving. The image is developed by the means 7 and multiple-transferred onto the recording medium 2 on the transfer drum 4 to form a color image. Then, the recording medium 2 is conveyed to the fixing means 8 to fix the transferred image on the recording medium 2, and is ejected to the ejection portion 10 at the upper part of the apparatus by the ejection roller pair 9.

The image carrier unit 6 and the developing device in the developing means 7 are detachable from the apparatus main body 11.

Next, the structure of each part of the image forming apparatus will be sequentially described in detail.

{Loading Means} The loading means is for loading the recording media 2 and setting it on the apparatus main body 11. In this embodiment, a loading means for loading the cassette 1 on the inner bottom of the apparatus is provided. There is. That is, as shown in FIG.
A mounting recess of the cassette 1 is provided on the inner bottom portion of the disk, and a guide rail 11a is provided on the surface facing the recess in the front and back directions of FIG. On the other hand, on both sides of the cassette 1, there are provided locking projections 1a which are locked to the guide rails 11a and are slidable.

Thus, the cassette 1 is provided with a handle recess (not shown), and the cassette 1 can be inserted or removed along the guide rail 11 from the front side to the rear side of the apparatus body. By setting the cassette 1, the recording medium 2 is set in the apparatus main body 11.

The means for stacking the recording medium 2 may be the one in which the cassette 1 can be attached to and detached from the mounting portion as described above, or the apparatus main body 11 without being removed.
It is also possible to provide a recording medium stacking base that is slidable with respect to 11 and set the recording medium 2 on this stacking base.

[Feeding means] The feeding means 3 feeds the recording medium 2 in the cassette 1 to the image forming section, and the cassette containing a plurality of recording media 2 in the inner bottom of the apparatus main body 11. 1 is loaded, the feeding rollers 3a and 3b are driven and rotated according to the image forming operation at the time of image formation, the recording medium 2 in the cassette 1 is separated and fed one by one from the uppermost portion, and is guided by the guide plate 3c. Then, the sheet is fed so as to abut against the registration roller pair 3d. And the registration roller pair 3
The recording medium 2 is driven so that d is synchronized with the image forming operation.
To the transfer drum 4.

[Transfer Means] The transfer means is for transferring the developed image developed by the developing means 7 onto the recording medium 2. In this embodiment, the recording medium 2 is wound around the transfer drum 4 and the developer of each color is developed. (Toner) is transferred to the recording medium 2.

In the transfer drum 4 according to this embodiment, an elastic layer 4b such as sponge or rubber is formed on the outer periphery of a conductive substrate 4a such as an aluminum cylinder, a resistance layer 4c is formed on the outer periphery thereof, and a dielectric layer is formed on the outermost periphery. The body layer 4d is formed. The transfer drum 4 is rotatably supported by a fixed shaft 4e, and the driving force of a drive motor is transmitted to a gear (not shown) fixed to the transfer drum 4, so that the image forming operation shown in FIG.
It is configured to rotate in the direction of the arrow.

Further, a gripper 4f is provided at a predetermined position on the outer circumference of the transfer drum 4, and holds the leading end of the fed recording medium 2. Further, the electrostatic attraction roller 4g is the transfer drum 4
The recording medium 2 is press-contacted to the outer periphery of the transfer drum 4 such that the recording medium 2 is sandwiched between the electrostatic adsorption roller 4g and the transfer drum 4, and the electrostatic adsorption roller 4g and the transfer drum 4 are provided. A voltage is applied between the recording medium 2 and the dielectric layer 4d of the transfer drum 4 to induce an electric charge, and the recording medium 2 is electrostatically attracted to the outer periphery of the transfer drum 4. is doing.

The method of attracting the recording medium 2 to the transfer drum 4 is not limited to the electrostatic attraction, but may be a suction method using air or the like.

In FIG. 1, reference numeral 12 is a separation claw for separating the recording medium 4 from the transfer drum 4 after gripping by the gripper 4f, and 13 is for contacting the surface of the transfer drum 4 to clean the surface. Cleaning device. The separating claw 12 and the cleaning device 13 are each configured to be swingable in the direction of the arrow in FIG.

(Transfer Drum Cleaning Device) A schematic structure of the cleaning device 13 will be described with reference to FIGS. The cleaning device 13 is for removing unnecessary developer (toner) on the transfer drum 4 as a cleaning target, and as shown in FIG. 2, a rotation for removing the toner on the transfer drum 4. The cylindrical brush 13a has a shaft 13a1 which is the center of rotation thereof, so that the casing 13b
It is rotatably supported by. The casing 13b is swingably supported by a suction mechanism 13c so that the rotating cylindrical brush 13a comes into contact with and separates from the transfer drum 4. The suction mechanism 13c is attached to the shaft 13d which is the swing center of the housing 13b.
A toner carry-out port 13e is provided for coupling with the.

Further, as shown in FIG. 3, it also serves as a thrust pressure receiving member between the swinging central shaft 13d of the casing 13b having the carry-out port 13e and the suction mechanism 13c. A shield ring 13f having excellent lubricity is provided. The shield ring 13f is fixed to the suction mechanism 13c, and the swing center axis of the housing 13b provided with the carry-out port 13e.
13d is rotatably inserted in the shield ring 13e. The other swing center shaft (not shown) of the casing 13c is a swing center shaft 13d provided with the carry-out port 13e.
Is coaxial with and is rotatably supported by a bearing (not shown). The toner outlet may be provided on the other swing center shaft.

Further, a negative suction pressure is applied to the inside of the housing 13b by an exhaust fan 13g of the suction mechanism 13c, and the toner sucked by the exhaust fan 13g can be detachably attached to the suction mechanism 13c. It is collected by the collecting filter 13h provided. The collecting filter 13h is attached and detached from the slit 13c1 provided in the suction mechanism 13c.
Usually, the slit 13c1 is closed by a lid (not shown).

The cleaning device 13 is integrally formed as a unit and is detachably attached to the image forming apparatus main body 11.

Next, the operation of the cleaning device 13 will be described. When the transfer drum 4 is cleaned, the eccentric cam 13i makes a half rotation (position indicated by a solid line in the figure) to press the leaf spring 13b1 integrally provided outside the housing 13b, so that the housing 13b is removed. The housing 13b having the rotating cylindrical brush 13a is rocked and regulated by hitting the bottom plate 14, and is positioned at the cleaning position (solid line position in the figure). At the same time, the rotary cylindrical brush 13a comes into contact with the transfer drum 4, and the toner on the transfer drum 4 adheres to the rotary cylindrical brush 13a rotated by a rotary drive actuator (not shown) to apply suction negative pressure by the exhaust fan 13g. It is taken into the inside of the casing 13b. The toner adhering to the rotating cylindrical brush 13a is peeled off by a scraper blade 13j provided inside the casing 13b, which is in contact with the contact position between the transfer drum 4 and the rotating cylindrical brush 13a, and the casing 13b swings. The suction mechanism 13c is passed through the carry-out port 13e provided on the central shaft 13d.
It is collected by the collecting filter 13h.

When the transfer drum 4 is not cleaned, the eccentric cam 13i makes a half rotation again, and
The housing 13b with the swing center shaft 13d provided with 13e as the center.
Torsion coil spring 13k biasing the eccentric cam 13i side
The housing 13b is swung again due to the restoring force, and the rotating cylindrical brush 13a is separated from the transfer drum 4.

Further, as shown in FIG. 4, an arbitrary number of disk-shaped protrusions 13d1 are provided in parallel with each other on the outer periphery of the swing center shaft 13d of the housing 13b, and further, the disk-shaped protrusions are provided on the inner periphery of the shield ring 13f. A groove 13f1 corresponding to 13d1 may be provided. The shield ring 13f includes an upper half ring 13f2 and a lower half ring 13f.
It is formed so that it can be divided into f3 and the half ring 13f2,
13f3 is formed by positioning dowel 13f4 and positioning hole 13f5.
It is configured so that f1 can be assembled without deviation.

Further, the casing 13b serving as the swing center and the suction mechanism
Considering only the airtightness of the joint with 13c, the shield ring 13f can be eliminated by providing only the groove 13f1 of the shield ring 13f in the suction mechanism 13c.

{Optical Unit} The optical unit 5 irradiates light to form an electrostatic latent image on the image carrier. As shown in FIG. 1, when the image signal is applied to the laser diode 5a, the laser diode 5a outputs the image light corresponding to the image core to the polygon mirror 5 as shown in FIG.
Irradiate b. The polygon mirror 5b is rotated at high speed by the scanner motor 5c, and the image light reflected by the polygon mirror 5b is irradiated from the exposure section of the image carrier unit 6 through the image forming lens 5d and the reflecting mirror 5e to expose the image carrier. Selectively expose.

{Image bearing unit} Image bearing unit 6
Is an image carrier 6a, which is a photoconductor drum, and the image carrier 6a.
It has a charging means 6b and a cleaning means 6c as process means acting on a.

(Image Carrier) Image carrier 6a according to the present embodiment.
Is formed by applying a photoconductor such as OPC, A-Si, CdS, or Se as a photosensitive layer on the outer peripheral surface of a conductive base such as an aluminum cylinder, and rotating the rotary shaft 6a1 around the frame of the image carrier unit. The shaft is freely supported. By transmitting the driving force of a drive motor (not shown) to the rotary shaft 6a1, the image carrier 6a is rotated in the arrow direction of FIG. 1 in accordance with the image forming operation. Further, a charging means 6b and a cleaning means 6c are arranged on the circumference of the image carrier 6a, and the image carrier unit 6 is detachable from the apparatus main body 11. That is, it can be replaced according to the life of the image carrier 6a.

(Charging Means) The charging means 6b according to this embodiment.
Uses a so-called contact charging method as disclosed in JP-A-63-149669, in which a conductive roller is attached to the image carrier 6.
The surface of the image carrier 6a is uniformly charged by bringing the surface of the image bearing member 6a into contact with the conductive roller and applying a voltage to the conductive roller.

(Cleaning Means) Cleaning Means 6
Reference numeral c is for cleaning the toner remaining on the image carrier 6a after the toner visualized on the image carrier 6a by the developing means 7 is transferred to the recording medium 2. The cleaning means 6c according to this embodiment scrapes off the toner on the image carrier 6a by the cleaning blade 6c1 and sends it to the waste toner container attached to the side surface of the main body by the waste toner carrying screw 6c2. When the toner inside the waste toner container is full, it is taken out and replaced.

[Developing Means] The developing means 7 is for making the latent image formed on the image carrier 6a visible, and in the present embodiment, magenta, cyan, yellow and black color development is performed. Four developing devices 7a, 7b, 7 that enable
c, 7d.

Each of the developing devices 7a to 7d is rotatably attached to the developing unit 7e, and the developing unit 7e is rotatably attached to the apparatus main body 11 about a shaft 7f. Then, a rotation gear (not shown) provided at the rotation center of each of the developing devices 7a to 7d meshes with a revolution gear (not shown) provided on the rotation shaft 7f of the developing unit 7e, so that each of the revolutions of the developing unit 7e is rotated. Developing devices 7a-7
The rotation of d causes the developing units 7a to 7d to always maintain a constant posture even when the developing unit 7e rotates.

When forming an image, magenta, cyan,
Developing device 7a for yellow and black color development
7d rotates about the shaft 7f, the predetermined developing device stops at a position facing the image carrier 6a, and the developing sleeve faces the image carrier 6a with a minute gap (about 300 μm). After being positioned, a developed image is sequentially formed on the image carrier 6a with the toner of the color.

That is, the developing device containing the toner corresponding to the color to be developed sends the toner to the coating roller 7g by the toner feeding mechanism, and the toner layer is formed on the outer periphery of the developing sleeve 7i rotated by the rotating coating roller 7g and the developing blade 7h. And a charge is applied to the toner by frictional charging. By applying a developing bias between the developing sleeve 7i and the image carrier 6a on which a latent image is formed, toner development is performed on the image carrier 6a according to the latent image.

The developing sleeves 7i of the developing units 7a to 7d are connected to high-voltage power sources for color development provided in the apparatus main body 11 when the developing units are rotationally moved to the developing position.
A selective voltage is applied for each development of each color.

[Fixing Means] The fixing means 8 is for fixing the transfer image formed on the recording medium 2 wound around the transfer drum 4 by the developing means 7, and as shown in FIG. The fixing roller 8b is in pressure contact with the recording medium 2 and applies heat and pressure to the recording medium 2.

When the recording medium 2 separated from the transfer drum 4 passes through the fixing means 8, it is conveyed by the driving roller 8a and heat and pressure are applied by the fixing roller 8b, whereby the image forming toner is recorded on the recording medium. Settles in.

A cleaning member 8c is in contact with the fixing roller 8b, and the toner adhering to the roller 8b is removed by the cleaning device 8c.

[Image Forming Operation] The operation for forming an image by the above-mentioned apparatus will now be described. The feeding rollers 3a and 3b shown in FIG. 1 are rotated to separate one recording medium 2 in the cassette 1. , U-turning, the recording medium 2 is turned upside down and fed to the transfer drum 4.
The transfer drum 4 rotates in the direction of the arrow in FIG. 1 and grips the leading end of the recording medium 2 fed by the gripper 4f, and electrostatically adsorbs the peripheral surface of the transfer drum 4, which is the upper surface when set in the cassette 1. The surface (recording medium surface) is conveyed toward the photosensitive drum 6a.

The image carrier 6a is rotated in the direction of the arrow in FIG. 1 in synchronism with the rotation of the transfer drum 4, the surface of the image carrier 6a is uniformly charged by the charging means 6b, and the optical unit 5 is used. The magenta image is irradiated with light to form a magenta latent image on the image carrier 6a. At the same time as the formation of this latent image, a developing device containing magenta toner is attached to the image carrier 6a.
By driving so as to face the image carrier 6a, magenta development is performed by applying a voltage having substantially the same potential as the charging polarity of the image carrier 6a so that the magenta toner adheres to the latent image on the image carrier 6a. .

Further, a voltage having a polarity opposite to that of the toner is applied to the transfer drum 4 to transfer the toner on the image carrier 6a.
Transfer to the upper recording medium 2.

After the transfer, the toner remaining on the image carrier 6a is scraped off by the cleaning blade 6c1 and sent to the waste toner container by the waste toner carrying screw 6c2.

When the transfer of the magenta toner is completed as described above, the developing device accommodating the toner of the next color is rotationally moved and positioned at a position facing the image carrier 6a, similarly to the magenta development and transfer. A cyan, yellow, and black latent image formation and toner transfer are sequentially performed to form a color image on the recording medium 2.

After the image is formed, the recording medium 2 is separated from the separating claw 12.
After peeling from the transfer drum 4 and transporting it to the fixing means 8, the toner is fixed by the fixing means 8, and then it is transported again U-turn to reverse the front and back surfaces of the recording medium 2 so that the image forming surface faces downward. The pair of discharge rollers 9 discharge the sheet to the discharge section 10 to complete the image formation.

[Other Embodiments] In the above-described embodiments, the transfer drum is used as the member to be cleaned by the cleaning device of the present invention. However, the present invention is not limited to this. Can also be applied.

In the above-described embodiment, an apparatus for forming a color image is provided by providing four developing devices. However, the image forming apparatus according to the present invention is not a color image forming apparatus but has a single developing device. It can also be applied to an image forming apparatus.

Further, the present invention can be applied to an image forming apparatus for forming an image by mounting a process cartridge in which an image carrier unit and a developing device are integrally made into a cartridge.

Further, although the laser beam printer has been illustrated in the above-mentioned embodiment, it is naturally possible to apply the present invention to, for example, a copying machine, a facsimile machine or the like in addition to the aspect of the apparatus.

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

As for the structure of the charging means, the so-called contact charging method was used in the above-described embodiment, but a tungsten wire which has been conventionally used as another structure is provided with a metal shield such as aluminum around the three sides, It is of course possible to use a configuration in which positive or negative ions generated by applying a high voltage to the tungsten wire are moved to the surface of the image carrier to uniformly charge the surface of the image carrier. . As the charging method, other than the roller type,
Blade type (charging blade), pad type, block type,
A rod type, a wire type or the like may be used.

As a method of cleaning the toner remaining on the image carrier, the cleaning means may be constituted by using a blade, a fur brush, a magnetic brush or the like.

[0053]

As described above, the developer carrying-out port for connecting the suction mechanism to the swing center axis of the housing having the rotating cylindrical brush is provided, and the housing having the developer carrying-out port is further provided. By providing a shield ring having lubricity which also functions as a thrust pressure receiver of the casing portion between the swing center axis of the body and the suction mechanism, toner leakage due to sliding wear in the joint portion and Exhaust gas leakage can be prevented, and at the same time, the airtightness of the device can be maintained.
Further, since the cleaning device is integrally unitized and configured to be attachable to and detachable from the main body of the image forming apparatus, it is possible to facilitate maintenance and downsize the apparatus.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the overall configuration of a laser beam printer that is an aspect of an image forming apparatus of the present invention.

FIG. 2 is an enlarged explanatory view showing a schematic configuration of a cleaning unit according to the present invention.

FIG. 3 is an essential part explanatory view showing a connecting portion between a casing and a duct in the cleaning means.

FIG. 4 is an explanatory view of a main part showing a connecting portion between a housing and a duct in the cleaning unit.

FIG. 5 is an explanatory diagram of a conventional technique.

[Explanation of Codes] 1 ... Cassette, 1a ... Locking convex portion, 2 ... Recording medium, 3 ... Feeding means, 3a, 3b ... Feeding roller, 3c ... Guide plate, 3
d ... Registration roller, 4 ... Transfer drum, 4a ... Conductive substrate, 4b ... Elastic layer, 4c ... Resistive layer, 4d ... Derivative layer,
4e ... Fixed shaft, 4f ... Gripper, 4g ... Electrostatic attraction roller, 5 ... Optical unit, 5a ... Laser diode, 5
b ... Polygon mirror, 5c ... Scanner motor, 5d ...
Imaging lens, 5e ... Reflective mirror, 6 ... Image carrier unit, 6a ... Image carrier, 6a1 ... Rotation axis, 6b ... Charging means,
6c ... Cleaning means, 6c1 ... Cleaning blade, 6c2 ... Waste toner conveying screw, 7 ... Developing means, 7
a to 7d ... Developing device, 7e ... Developing unit, 7f ... Rotating shaft, 7g ... Coating roller, 7h ... Developing blade, 7i ... Developing sleeve, 8 ... Fixing means, 8a ... Driving roller, 8b ...
Fixing roller, 8c ... Cleaning device, 9 ... Ejecting roller, 10 ... Ejecting section, 11 ... Device body, 11a ... Guide rail,
12 ... Separation claw, 13 ... Cleaning device 13a ... Rotating cylindrical brush 13a1 ... Shaft 13b ... Housing 13b1 ... Leaf spring 13c ... Suction mechanism 13c1 ... Slit 13d ... Oscillating central axis 13d1 ... Discoid projection 13e ... Toner outlet 13f ... Shield ring
13f1… Groove 13f2 Upper half ring 13f3… Lower half ring 13f4
… Positioning dowel 13f5… Positioning hole 13g… Exhaust fan
13h ... Collecting filter 13i ... Eccentric cam 13j ... Scraper blade 13k ... Torsion coil spring 14 ... Bottom plate

Claims (4)

[Claims] 1. A rotary cylindrical brush for removing unnecessary developer on an object to be cleaned, and a rotary cylindrical brush rotatably supported so that the rotary cylindrical brush comes into contact with and separates from the object to be cleaned. A casing capable of swinging, and a suction mechanism that swingably supports the casing and applies a suction negative pressure to the inside of the casing. A cleaning device having an outlet. 2. A shield ring having lubricity which doubles as a thrust pressure receiving member of the housing portion is provided between the swinging central shaft of the housing having the developer carrying-out port and the suction mechanism. The cleaning device according to claim 1, wherein the cleaning device is a cleaning device. 3. The cleaning device according to claim 1, wherein the cleaning device is integrally formed into a unit. 4. A latent image is formed on an image carrier according to image information, the latent image is developed by developing means, the developed image is transferred to a recording medium by transfer means, and then the image is carried on the image carrier. An image forming apparatus for removing the remaining developer by a cleaning unit, wherein the cleaning apparatus according to claim 3 is configured to be removable.