JP6245151B2 - Image forming apparatus and cleaning unit - Google Patents

Description

  The present invention relates to an image forming apparatus and a cleaning unit.

  Conventionally, an electrophotographic image forming apparatus having a photosensitive drum is known. In general, an electrophotographic image forming apparatus forms an image on a sheet by executing charging, exposure, development, and transfer processes.

  Specifically, first, in the charging step, the surface of the photosensitive drum is uniformly charged. Next, in the exposure step, the photosensitive drum is exposed to form an electrostatic latent image on the surface of the photosensitive drum. Next, in the developing process, toner is supplied to the photosensitive drum, the electrostatic latent image is developed, and a toner image is formed on the surface of the photosensitive drum. Thereafter, in the transfer step, the developed toner image is transferred to the intermediate transfer belt, and the toner image transferred to the intermediate transfer belt is transferred to the sheet.

  Charges remain on the photosensitive drum after the toner image is transferred to the intermediate transfer belt. Accordingly, it is necessary to remove the charge remaining on the photosensitive drum before performing the charging step again. For example, a light guide that extends along the longitudinal direction of the photosensitive drum is disposed close to the photosensitive drum, and the light emitter emits light toward the light guide. Then, the light guide body irradiates the photosensitive drum with light received from the light emitting body, thereby removing charges remaining on the photosensitive drum.

  However, since the light guide is disposed in the vicinity of the photosensitive drum, toner supplied to the photosensitive drum may adhere to the light guide in the development process. The toner adhering to the light guide may block the light emitted from the light guide, and the amount of irradiation of the light guide onto the photosensitive drum may vary depending on the irradiation location. Accordingly, unevenness occurs in the amount by which the light guide body removes the electric charge remaining on the photosensitive drum, and when the charging process is performed again, the surface of the photosensitive drum is charged unevenly. As a result, a density difference (drum ghost) may occur in an image formed on the sheet.

  The electrophotographic printing apparatus of Patent Document 1 includes a photoreceptor unit, an erase lamp that removes the surface potential of the photoreceptor unit, and a cleaning member. The cleaning member wipes the erase lamp as the photoconductor unit enters and exits.

Japanese Utility Model Publication No. 3-12274

  However, in a two-component development type image forming apparatus using a developer in which a toner and a carrier are mixed, a small amount of ferrite carrier may be included in the supplied toner in the development process. Therefore, when the cleaning member wipes the erase lamp, the erase lamp may be damaged by a small amount of ferrite carrier, and light emitted from the erase lamp may be irradiated to an unintended location. As a result, there is a possibility that the amount of irradiation on the photosensitive drum varies depending on the portion of the photosensitive drum irradiated.

  The present invention has been made in view of the above problems, and an object thereof is to provide an image forming apparatus that removes unnecessary materials attached to a light guide while suppressing damage to the light guide.

  According to a first aspect of the present invention, an image forming apparatus includes a cleaning unit, an image carrier, a contact portion, and a light guide. The image carrier is movable with respect to the cleaning unit. The contact portion moves in contact with the image carrier. The light guide irradiates the image carrier with light. The cleaning unit includes a container and a piston. The container has a spout opening that opens toward the light guide. The piston slides along the inner peripheral surface of the container.

  According to a second aspect of the present invention, the cleaning unit is provided in an image forming apparatus having a movable image carrier and a light guide that irradiates the image carrier with light. The cleaning unit includes a contact portion, a container, a piston, and a connecting member. The contact portion moves in contact with the image carrier. The container has a spout opening that opens toward the light guide. The piston slides along the inner peripheral surface of the container. The connecting member connects the contact portion and the piston.

  ADVANTAGE OF THE INVENTION According to this invention, the unnecessary thing adhering to a light guide can be removed, suppressing that a light guide is damaged.

1 is a cross-sectional view illustrating an image forming apparatus according to an embodiment of the present invention. 1 is a diagram illustrating an image forming unit of an image forming apparatus according to an embodiment of the present invention. FIG. 3A is a diagram illustrating a state in which the photosensitive drum of the image forming apparatus according to the embodiment of the present invention is housed in the main body of the image forming apparatus. FIG. 4B is a diagram illustrating a state where the photosensitive drum of the image forming apparatus according to the embodiment of the present invention is taken out from the main body of the image forming apparatus. FIG. 3 is a perspective view illustrating a cleaning unit of the image forming apparatus according to the embodiment of the invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof is not repeated. In the present specification, the X axis and the Y axis are parallel to the horizontal plane, and the Z axis is parallel to the vertical line.

  An image forming apparatus 1 according to this embodiment will be described with reference to FIG. FIG. 1 shows an image forming apparatus 1. The image forming apparatus 1 is, for example, a copying machine, a printer, a facsimile machine, or a multi-function peripheral (MFP: Multi Function Peripheral). The multi-function peripheral includes, for example, at least two devices among a copier, a printer, and a facsimile.

  The image forming apparatus 1 includes an image forming unit 5, an image reading unit 210, a storage unit 220, a transport unit 230, a transfer unit 250, a fixing unit 260, a discharge unit 270, and a control unit 280. The sheet S is transported inside the image forming apparatus 1 along the transport direction A of the sheet S. Details of the image forming unit 5 will be described later.

  The image reading unit 210 optically reads an image of a document to be copied and generates image data. The accommodating part 220 accommodates the sheet S. The sheet S is, for example, plain paper, copy paper, recycled paper, thin paper, thick paper, glossy paper, or an OHP (Overhead Projector) sheet. The accommodating part 220 accommodates the sheet S. The sheet S is fed from the storage unit 220 to the conveyance unit 230. The conveyance unit 230 conveys the sheet S fed from the storage unit 220 to the discharge unit 270 via the transfer unit 250 and the fixing unit 260.

  The transfer unit 250 includes an intermediate transfer belt 251, a secondary transfer roller 252, and a driven roller 253. The intermediate transfer belt 251 is an endless belt. Specifically, for example, the intermediate transfer belt 251 rotates along the rotation direction D. The rotation direction D is a direction in which the X axis facing the positive direction rotates counterclockwise. A toner image formed by the image forming unit 5 based on the image data is transferred to the intermediate transfer belt 251. The secondary transfer roller 252 is pressed against the driven roller 253 via the intermediate transfer belt 251. The toner image transferred to the intermediate transfer belt 251 is transferred to the sheet S when passing between the secondary transfer roller 252 and the driven roller 253.

  The fixing unit 260 includes a fixing member 261 and a pressure member 262. The fixing member 261 heats the sheet S and the pressure member 262 presses the sheet S, so that the toner image transferred to the sheet S is fixed to the sheet S. The discharge unit 270 discharges the sheet S on which the toner image is fixed to the outside of the image forming apparatus 1.

  The control unit 280 has a storage area. The storage area stores programs, setting information, image data, and the like. The storage area includes a RAM (Random Access Memory) and a ROM (Read Only Memory). The control unit 280 controls the overall operation of the components included in the image forming apparatus 1 by executing various control programs stored in advance in the ROM.

  Next, details of the image forming unit 5 of the image forming apparatus 1 will be described with reference to FIGS. 1 and 2. FIG. 2 shows the image forming unit 5 of the image forming apparatus 1. The image forming unit 5 includes a charge eliminating unit 10, a supply unit 20, a cleaning unit 30, an exposure unit 40, a photosensitive drum 50 as an image carrier, a primary transfer roller 53, a charging unit 60, and a cleaning unit 80. The neutralization unit 10, the supply unit 20, the cleaning unit 30, the exposure unit 40, the primary transfer roller 53, and the charging unit 60 are disposed around the photosensitive drum 50. Details of the charge removal unit 10 and the cleaning unit 80 will be described later.

  The photosensitive drum 50 is disposed on the outer peripheral surface of the intermediate transfer belt 251. The photosensitive drum 50 has a cylindrical shape and rotates along the rotation direction R. The rotation direction R is a direction in which the intermediate transfer belt 251 is rotated. A photosensitive layer having a thickness of 10 μm or more and several tens of μm or less is formed on the surface of the photosensitive drum 50. In this specification, the direction along the rotation axis of the photosensitive drum 50 is defined as the longitudinal direction of the photosensitive drum 50. The photosensitive drum 50 can be taken out from the main body of the image forming apparatus 1.

  The charging unit 60 includes a charging roller 601 and a cleaning brush 603. The charging roller 601 is disposed so as to be in contact with the photosensitive drum 50, and is driven to rotate as the photosensitive drum 50 rotates. The charging roller 601 applies a voltage to the surface of the photosensitive drum 50 to uniformly charge the surface of the photosensitive drum 50. The cleaning brush 603 is disposed below the charging roller 601 and rotates following the charging roller 601. The cleaning brush 603 removes toner attached to the surface of the charging roller 601.

  The exposure unit 40 irradiates the surface of the photosensitive drum 50 with light based on the image data generated by the image reading unit 210 or the image data stored in the control unit 280. As a result, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 50.

  The supply unit 20 supplies toner to the surface of the photosensitive drum 50 and develops the electrostatic latent image formed on the surface of the photosensitive drum 50. Specifically, the toner supplied from the supply unit 20 adheres to the electrostatic latent image formed on the surface of the photosensitive drum 50, and the electrostatic latent image is developed, that is, the surface of the photosensitive drum 50. In addition, a toner image corresponding to the electrostatic latent image is formed.

  The primary transfer roller 53 is disposed to face the photosensitive drum 50 with the intermediate transfer belt 251 interposed therebetween. The primary transfer roller 53 presses the photosensitive drum 50 so that the toner image formed on the surface of the photosensitive drum 50 is transferred to the outer peripheral surface of the intermediate transfer belt 251.

  The cleaning unit 30 includes a rubbing roller 301 and a toner collecting roller 303. The rubbing roller 301 is disposed so as to be in pressure contact with the photosensitive drum 50. The rubbing roller 301 rotates in the rotation direction Q. The rotation direction Q is a direction in which the photosensitive drum 50 rotates along the rotation direction R and rotates. The rubbing roller 301 rubs the surface of the photosensitive drum 50 and removes toner remaining on the photosensitive drum 50.

  The toner collection roller 303 is disposed adjacent to the rubbing roller 301. The toner collecting roller 303 collects toner adhering to the rubbing roller 301 by rotating in a direction opposite to the rotation direction Q of the rubbing roller 301 while being in contact with the surface of the rubbing roller 301. The toner collected by the toner collection roller 303 is dropped and collected in a residual toner conveyance path (not shown) disposed below the cleaning unit 30.

  Next, the static eliminating unit 10 and the cleaning unit 80 will be described with reference to FIG. 3A shows a state in which the photosensitive drum 50 is housed in the main body of the image forming apparatus 1, and FIG. 3B shows a state in which the photosensitive drum 50 is taken out from the main body.

  The neutralization unit 10 removes electric charges remaining on the surface of the photosensitive drum 50. The static eliminating unit 10 includes a light emitting unit 101 and a light guide 105. The light emitting unit 101 emits light toward the light guide 105. The light emitting unit 101 is, for example, an LED (Light Emitting Diode). The light guide 105 receives light emitted from the light emitting unit 101 and irradiates the photosensitive drum 50 with light received from the light emitting unit 101. The photoconductor drum 50 is irradiated on the light guide 105, and the charges attached to the surface are removed.

  The cleaning unit 80 is fixedly attached to the main body of the image forming apparatus 1. Accordingly, the photosensitive drum 50 that can be taken out from the main body of the image forming apparatus 1 is movable with respect to the cleaning unit 80. The cleaning unit 80 is disposed in the vicinity of the light guide 105. The cleaning unit 80 includes a container 801, a piston 807, a piston seal 809, a connecting member 811, a pressing member 813, and a contact portion 815.

  The container 801 is columnar. One end region of the container 801 is open. A jet port 801a and a connection port 801b are formed in the other end region of the container 801. The spout 801a opens toward the light guide 105. The connection port 801 b opens toward the contact portion 815. The area of the spout 801a is larger than the area of the connection port 801b.

  The piston 807 is housed inside the container 801 so as to block one end region of the container 801 to be opened. The piston 807 is made of synthetic rubber, for example. The piston 807 slides in the longitudinal direction of the container 801 along the inner peripheral surface of the container 801.

  The piston 807 has a connecting surface 807a. The connection surface 807a is a surface of the piston 807 that is close to the ejection port 801a. A space P is formed by the connecting surface 807a and the inner peripheral surface of the container 801 located closer to the jet port 801a than the connecting surface 807a. Air is accommodated in the space P.

  The space P is pressurized by the piston 807 approaching the ejection port 801a. As a result, the air accommodated in the space P is ejected from the ejection port 801a. Further, the space P is depressurized when the piston 807 is separated from the ejection port 801a. As a result, air is injected into the space P from the ejection port 801a. In addition, it is preferable that the area of the jet outlet 801a and the connection port 801b is a magnitude | size which is the extent which the leak of air is suppressed from the space P in the state where the space P is not pressurized or pressure-reduced.

  A piston seal 809 as an elastic body is attached to the periphery of the piston 807. The piston seal 809 is, for example, rubber or packing. The piston 807 presses the inner peripheral surface of the container 801 through the piston seal 809. Therefore, the piston seal 809 suppresses the air accommodated in the space P from leaking toward one end region of the container 801 to be opened through between the piston 807 and the inner peripheral surface of the container 801. .

  Further, the piston seal 809 closely contacts the peripheral edge of the piston 807 and the inner peripheral surface of the container 801, and smoothly slides the piston 807 along the inner peripheral surface of the container 801. Therefore, the piston seal 809 prevents the piston 807 from sliding in an unstable state. Specifically, for example, the piston seal 809 is configured such that the piston 807 slides in any position on the inner peripheral surface of the container 801 or the piston 807 is inclined with respect to the inner peripheral surface of the container 801. Suppresses sliding.

  The contact portion 815 is attached to the outer peripheral surface of the container 801. The contact portion 815 moves along the outer peripheral surface of the container 801. In a state where the photosensitive drum 50 is housed in the main body of the image forming apparatus 1, the contact portion 815 presses the photosensitive drum 50. When the photosensitive drum 50 is taken out from the main body of the image forming apparatus 1, a force that is greater than the pressing force of the contact portion 815 and resists the pressing force received from the contact portion 815 is applied to the photosensitive drum 50. Accordingly, when the photosensitive drum 50 is taken out from the main body of the image forming apparatus 1, that is, when the photosensitive drum 50 moves in the positive direction of the X axis, the contact portion 815 contacts the photosensitive drum 50. Moves in contact.

  The connecting member 811 connects the connecting surface 807a of the piston 807 and the contact portion 815. The connecting member 811 is inserted through the connecting port 801b. The connecting member 811 is, for example, a wire. In response to the contact portion 815 moving away from the connection port 801b, the piston 807 is pulled toward the other end region of the container 801 where the spout 801a and the connection port 801b are formed. The That is, when the photosensitive drum 50 is taken out from the main body of the image forming apparatus 1, the piston 807 is pulled along the inner peripheral surface of the container 801 in a direction approaching the ejection port 801 a. As a result, the space P is pressurized, and the air accommodated in the space P is ejected toward the light guide 105 from the ejection port 801a.

  The pressing member 813 is confiscated inside the container 801. The pressing member 813 is, for example, a coil spring. The pressing member 813 presses the piston 807 in a direction away from the ejection port 801a. As shown in FIG. 3A, when the photosensitive drum 50 is housed in the main body of the image forming apparatus 1, the pressing member 813 stops the piston 807 at a preset position. As a result, substantially constant air is accommodated in the space P. The preset position of the piston 807 can be arbitrarily set by the user.

  The pressing force of the pressing member 813 is the force applied to the photosensitive drum 50 when the photosensitive drum 50 is removed from the main body, that is, the contact portion 815 pulls the piston 807 when the photosensitive drum 50 is extracted from the main body. Smaller than the traction force Therefore, when the photosensitive drum 50 is taken out from the main body of the image forming apparatus 1, the piston 807 is pulled in a direction approaching the ejection port 801a. As a result, the air accommodated in the space P is ejected from the ejection port 801a toward the light guide 105.

  According to this embodiment, the contact part 815 and the piston 807 are connected. Therefore, the piston 807 moves along the inner peripheral surface of the container 801 in a direction approaching the jet outlet 801a in accordance with the movement of the contact portion 815 in contact with the photosensitive drum 50. As a result, the air accommodated in the space P is ejected from the ejection port 801a toward the light guide 105.

  Moreover, according to this embodiment, the area of the jet outlet 801a is wider than the area of the connection port 801b. Therefore, when the space P is pressurized, a larger amount of air is ejected from the ejection port 801a than the amount of air ejected from the connection port 801b. As a result, the air accommodated in the space P removes unnecessary substances attached to the light guide 105.

  Further, according to the present embodiment, the contact portion 815 is in contact with the photosensitive drum 50. Accordingly, when the photosensitive drum 50 is removed from the main body of the image forming apparatus 1 and the contact portion 815 and the photosensitive drum 50 are not in contact with each other, the pressing force by which the photosensitive drum 50 presses the contact portion 815 is increased. The pressing force with which the pressing member 813 presses the piston 807 is greater. As a result, the piston 807 returns to a predetermined position, and air is injected into the space P from the ejection port 801a and substantially constant air is accommodated.

  Next, the outer peripheral surface of the cleaning unit 80 will be described with reference to FIG. FIG. 4 is a perspective view showing the cleaning unit 80. A pair of grooves 801 c are formed on the outer peripheral surface of the container 801. The pair of grooves 801 c extend along the longitudinal direction of the container 801. The contact portion 815 includes a contact plate 819 and a pair of rollers 817. When the photosensitive drum 50 is accommodated in the main body of the image forming apparatus 1, the contact plate 819 contacts the photosensitive drum 50. The pair of rollers 817 fits in the pair of grooves 801c and moves along the pair of grooves 801c.

  According to the present embodiment, the pair of rollers 817 moves while fitted into the pair of grooves 801 c formed on the outer peripheral surface of the container 801. Accordingly, the movement of each of the pair of rollers 817 is stable.

  The embodiment of the present invention has been described above with reference to the drawings (FIGS. 1 to 4). However, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof (for example, (1) to (5) shown below). In order to facilitate understanding, the drawings schematically show each component as a main component, and the thickness, length, number, and the like of each component shown in the drawings are different from the actual for convenience of drawing. . Moreover, the shape, dimension, etc. of each component shown by said embodiment are an example, Comprising: It does not specifically limit, A various change is possible in the range which does not deviate substantially from the effect of this invention.

  (1) As described with reference to FIG. 3, the cleaning unit 80 is attached to the main body. However, the cleaning unit 80 may be attached to the image forming unit 5.

  (2) As described with reference to FIG. 4, the container 801 has a columnar shape, but may be a columnar shape. Accordingly, the container 801 may have a polygonal shape having three or more sides.

  (3) As described with reference to FIG. 4, the contact portion 815 has a pair of rollers 817. However, the contact portion 815 may have a single roller or may have a plurality of three or more rollers. In that case, the container 801 has a number of grooves corresponding to the number of rollers.

  (4) As described with reference to FIG. 2, the static eliminating unit 10 is disposed between the supply unit 20 and the primary transfer roller 53 along the rotation direction R of the photosensitive drum 50. However, the static eliminating unit 10 may be disposed between the primary transfer roller 53 and the cleaning unit 30 along the rotation direction R of the photosensitive drum 50.

  (5) As described with reference to FIG. 1, the image forming unit 5 of the image forming apparatus 1 includes the four photosensitive drums 50. The four photosensitive drums 50 form toner images in any one of yellow, magenta, cyan, and black, respectively. The photosensitive layer of the photosensitive drum 50 is formed of a material mainly composed of, for example, an organic photosensitive member or amorphous silicon. The photosensitive layers of the four photosensitive drums 50 may be mainly formed of different materials.

  The present invention can be used in the field of image forming apparatuses.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 105 Light guide 50 Photoconductor drum 80 Cleaning unit 801 Container 801a Spout 801b Connection port 801c Groove 807 Piston 809 Piston seal 811 Connection member 813 Press member 815 Contact part 817 Roller

Claims (8)

A cleaning unit;
An image carrier movable with respect to the cleaning unit;
A light guide for irradiating the image carrier with light, and
The cleaning unit includes
A contact portion that moves in contact with the image carrier;
A container in which a spout opening toward the light guide is formed;
A piston sliding along the inner peripheral surface of the container;
Have a connecting member for connecting the piston and the abutment,
Of the one end region and the other end region of the container, the jet port is formed in the other end region,
When the image carrier moves along the container in a direction from the outlet of the container toward the one end region of the container, the piston moves from the one end region of the container to the one end region. An image forming apparatus that moves in a direction toward a jet port . The cleaning unit further includes a pressing member to be taken into the container,
The image forming apparatus according to claim 1, wherein the pressing member presses the piston in a direction away from the ejection port.
The container is further formed with a connection port through which the connection member is inserted,
The image forming apparatus according to claim 1, wherein an area of the ejection port is larger than an area of the connection port.
The contact portion includes a roller,
A groove is formed on the outer peripheral surface of the container,
The image forming apparatus according to claim 1, wherein the roller moves along the groove.
The image forming apparatus according to claim 1, wherein the cleaning unit further includes an elastic body attached to a peripheral edge of the piston.
The image forming apparatus according to claim 1, wherein the connecting member is a wire.
The image forming apparatus according to claim 2, wherein the pressing member is a coil spring.
A cleaning unit provided in an image forming apparatus having a movable image carrier and a light guide for irradiating the image carrier with light,
A contact portion that moves in contact with the image carrier;
A container in which a spout opening toward the light guide is formed;
A piston sliding along the inner peripheral surface of the container;
A connecting member for connecting the abutment portion and the piston;
Of the one end region and the other end region of the container, the jet port is formed in the other end region,
When the image carrier moves along the container in a direction from the outlet of the container toward the one end region of the container, the piston moves from the one end region of the container to the one end region. A cleaning unit that moves in the direction toward the spout .

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