JP2006139000A - Image forming apparatus - Google Patents

Abstract

An image forming apparatus capable of forming a cleaning unit as small and compact as possible and effectively reducing the size of the whole is provided.
A cleaning means includes cleaning members provided on a main body and an actuator provided on the main body. The actuator 46 is an actuator using a piezoelectric element and can be formed relatively small. Therefore, the cleaning means 34 is formed in a box shape and can be arranged in a narrow space between the image carriers 10Y, 10M, 10C, 10K and the exposure line head. The exposure line head unit 32 is provided with first and second left and right guide rails 53 and 59 for guiding the left and right direction of the main body 35, and an energizing member 60 for applying a voltage to the piezoelectric element.
[Selection] Figure 2

Description

  The present invention relates to an image forming apparatus using an electrophotographic system such as a printer, a copying machine, or a facsimile, and a cleaning unit that cleans parts extending in the axial direction of the image carrier such as an exposure unit, an image carrier, or a charging unit. TECHNICAL FIELD OF THE INVENTION

  2. Description of the Related Art Conventionally, in an image forming apparatus, many parts such as a charging unit, an exposure unit, a developing unit, or a charge eliminating unit are arranged near the periphery of an image carrier such as a photosensitive drum. When the charging unit and the exposure unit are arranged in the vicinity of the periphery of the image carrier in this way, foreign matters such as floating toner scattered around the image carrier may cause, for example, a charging wire of the charging unit or an optical lens of the exposure unit. As a result, the charged wires and lenses become dirty, and their functions cannot be fully exhibited.

Therefore, a conventional image forming apparatus is provided with a cleaning means for cleaning these charging wires and lenses.
As such a cleaning unit, for example, a movable transparent film is disposed between a converging photoconductor as an image writing unit and an image carrier, and a pair of film windings for winding the transparent film is used. There has been proposed an optical stain prevention device for an image forming apparatus in which a body is disposed on both sides of a converging photoconductor and a film cleaning member for cleaning both surfaces of a transparent film is provided (see Patent Document 1).
According to the optical system anti-smudge device disclosed in Patent Document 1, floating toner scattered around the image carrier is attached to the transparent film so as not to be attached to the converging photoconductor, and is attached to the transparent film. The floating toner is cleaned by a film cleaning member.

As another conventional cleaning means, there has been proposed an optical stain preventing apparatus for an image forming apparatus provided with a ventilation path for allowing air to flow between a lens as an image writing means and an image carrier (patent). Reference 2).
According to the optical system antifouling device disclosed in Patent Document 2, air is passed between the lens and the image carrier to eliminate floating toner scattered therein, so that the toner does not adhere to the lens. .

  Further, as other conventional cleaning means, a wire cleaner that cleans the charging wire of the charging means, a lens cleaner that cleans the lens of the exposure means, a rack and pinion mechanism that interlocks both cleaners, and a screw shaft are combined. A cleaning device for an image forming apparatus has been proposed (see Patent Document 3).

According to the cleaning device disclosed in Patent Document 3, the lens cleaner is moved in the extending direction of the lens by rotating the knob and rotating the screw shaft, and the lens cleaner is rubbed and cleaned with the lens cleaner. At the same time, the rotation of the screw shaft is converted into a linear motion of the wire cleaner by a rack and pinion mechanism, and the charged wire is rubbed and cleaned by the wire cleaner.
JP-A-58-35561. Japanese Patent Laid-Open No. 58-14860. JP 2003-248366 A.

  However, in the optical stain prevention apparatus disclosed in Patent Document 1, the transparent film can be disposed between the converging photoconductor and the image carrier, but the pair of film winding bodies is relatively large. It cannot be placed between the converging photoconductor and the image carrier. For this reason, a pair of film winding bodies must be arranged on both sides of the converging photoconductor, and the entire image forming apparatus becomes large. In particular, along with the recent demand for downsizing and compactness of image forming apparatuses, many parts are concentrated in the vicinity of the periphery of the image carrier. Therefore, such a pair of film winding bodies is installed. It is difficult to secure a space, and it is not possible to sufficiently meet the demand for such a compact size. In addition, the pair of film winding bodies that are the driving means of the transparent film are simply provided so as to be rotatable, and cannot be moved in the axial direction of the image carrier. It is necessary to set more than the width | variety of an area | region, and a film winding body will also become larger.

  Further, in the optical system anti-smudge device disclosed in the above-mentioned Patent Document 2, it is necessary to provide a ventilation path and a ventilation means for ventilating air between the lens as the image writing means and the image carrier, so that image formation The apparatus is inevitably formed in a large size, and cannot meet the demand for a compact and compact image forming apparatus. In addition, air must be constantly sent between the lens and the image carrier. However, when the image forming apparatus is stopped, the ventilation of the air is also stopped. Therefore, the effect of eliminating floating toner cannot be sufficiently expected.

  Further, in the cleaning device disclosed in the above-mentioned Patent Document 3, the knob cannot be made too small for handling, and the screw shaft needs to be provided long in the lens extending direction. Considering this, the screw shaft cannot be made too thin. Moreover, since the rack and pinion mechanism is used, it is difficult to reduce the size of the charging wire cleaning means.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an image forming apparatus in which the cleaning unit can be formed as small and compact as possible, and the whole can be effectively downsized. It is to be.

  In order to solve the above-mentioned problems, an invention according to claim 1 includes an image carrier on which a latent image is formed, and an optical head that is arranged around the image carrier and writes the latent image on the image carrier. In the image forming apparatus including at least a cleaning unit for cleaning, the cleaning unit includes a cleaning member for cleaning the lens of the optical head and a driving unit for moving the cleaning member, and the cleaning unit The member and the driving means are provided so as to be movable integrally. Further, the optical head is energized for applying a voltage to the guide means and the driving means for guiding the cleaning means when the cleaning means is moved. It is characterized in that at least one of the parts is provided.

The invention of claim 2 is characterized in that the cleaning means is disposed in a space between the image carrier and a member used for the image formation.
Further, the invention of claim 3 is characterized in that the driving means is an actuator made of a piezoelectric element, and an AC voltage is applied to the piezoelectric element through the energizing portion.

  According to the image forming apparatus according to the present invention configured as described above, since the cleaning member and the driving unit are provided integrally, the configuration of the cleaning unit can be simplified, and the cleaning unit can be formed in a compact and compact manner. The image forming apparatus including the cleaning unit can be reduced in size. In particular, since at least one of the guide portion of the cleaning means and the energization portion for applying a voltage to the drive means is provided in the optical head, the optical head integrally provided with the cleaning means can be formed more compactly. .

  Further, since the cleaning member and the driving means are provided so as to be movable together, the driving force transmission mechanism of the driving means can be simplified, and the number of parts can be reduced. Thereby, since the cleaning means can be formed more compactly, the installation space of the cleaning means can be reduced. Therefore, even if miniaturization is required in recent years and parts for forming an image are concentrated in the vicinity of the periphery of the image carrier, the cleaning means can be efficiently arranged.

  Furthermore, since the driving means is constituted by an actuator made of a piezoelectric element, the driving means can be formed in an ultra-small size by using an ultra-small actuator. As described above, since the ultra-compact driving means is used, the cleaning means can be formed small even if the cleaning member and the driving means are provided integrally, and between the lens of the optical head and the image carrier. It can be arranged so as to face the image carrier in a relatively narrow space. Thereby, this narrow space can be used effectively, and the image forming apparatus can be formed even more compactly.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing an example of an embodiment of an image forming apparatus according to the present invention.
As shown in FIG. 1, the image forming apparatus 1 of this example is a tandem type color image forming apparatus, and has a housing body 2, in which an image forming unit 3 and an intermediate transfer unit (hereinafter referred to as “intermediate transfer unit”). 4), a paper feeding unit 5, a secondary transfer unit 6, a fixing unit 7, and a recording medium conveying means 8 are provided. The consumables in the image forming unit 3 and the paper feeding unit 5 are configured to be detachable from the housing body 2, and these can be removed and repaired or exchanged including the primary transfer unit 4.

  The image forming unit 3 has a plurality of different colors (in this example, four colors, but for example, two or three of the four colors may be used; hereinafter, described as four colors), that is, yellow (Y) A yellow image forming station 9Y, a magenta image forming station 9M, a cyan image forming station 9C, and a black image forming station 9K that respectively form magenta (M), cyan (C), and black (K) images. I have. In this case, in this example, the arrangement order of the image forming stations 9Y, 9M, 9C, and 9K for the respective colors Y, M, C, and K is linearly arranged in this order in the diagonally lower right direction in FIG. . The arrangement order of the image forming stations 9Y, 9M, 9C, and 9K for each color is not limited to this, and can be arbitrarily set.

  These image forming stations 9Y, 9M, 9C, and 9K are respectively provided around the image carriers 10Y, 10M, 10C, and 10K including photosensitive drums, and the image carriers 10Y, 10M, 10C, and 10K. Charging means 11Y, 11M, 11C, and 11K that are arranged to charge the image carriers 10Y, 10M, 10C, and 10K, and image writing means 12Y that writes latent images on the image carriers 10Y, 10M, 10C, and 10K, 12M, 12C, and 12K, and developing means 13Y, 13M, 13C, and 13K that develop the latent images on the image carriers 10Y, 10M, 10C, and 10K are provided. Although not shown, the image carriers 10Y, 10M, 10C, and 10K are neutralized on the downstream side in the rotation direction of the image carriers 10Y, 10M, 10C, and 10K of the developing units 13Y, 13M, 13C, and 13K. Static elimination means is provided.

  Image carriers 10Y, 10M, 10C, and 10K for image forming stations 9Y, 9M, 9C, and 9K for each color, charging units 11Y, 11M, 11C, and 11K, image writing units 12Y, 12M, 12C, and 12K, and developing units 13Y, Each of 13M, 13C, and 13K has the same configuration for each color Y, M, C, and K.

  Each of the charging means 11Y, 11M, 11C, and 11K is composed of a conductive brush roller connected to a high voltage generation source, and each brush outer periphery moves backward with respect to each of the image carriers 10Y, 10M, 10C, and 10K. The surface of each image carrier 10Y, 10M, 10C, 10K is uniformly charged by abutting and rotating in the direction and at a peripheral speed that is two to three times the peripheral speed of each image carrier 10Y, 10M, 10C, 10K. . By using such charging means 11Y, 11M, 11C, and 11K, the surface of the image carrier can be charged with a very small current, so that the inside and outside of the apparatus is contaminated by a large amount of ozone as in the corona charging method. There is no. Further, since the contact between the charging units 11Y, 11M, 11C, and 11K and the image carriers 10Y, 10M, 10C, and 10K is soft, the transfer residual toner generated when using the roller charging method is applied to the charging roller. It is difficult for sticking to occur, and stable image quality and reliability of the apparatus can be ensured.

  For each of the image writing means 12Y, 12M, 12C, and 12K, an exposure line head unit having an LED line head in which LED lamps are arranged in a line in the axial direction of the image carriers 10Y, 10M, 10C, and 10K is used. Yes. Since the LED line head has a shorter optical path length than the laser scanning optical system and is more compact, the LED line head can be disposed close to the image carriers 10Y, 10M, 10C, and 10K, and the apparatus main body can be downsized. Have.

  The developing means 13Y, 13M, 13C, and 13K are respectively provided with developing device housings 14Y, 14M, 14C, and 14K, and toner storage portions 15Y, 15M, and 15K formed in the developing device housings 14Y, 14M, 14C, and 14K, respectively. 15C, 15K, toner supply rollers 16Y, 16M, 16C, 16K provided in the developing device housings 14Y, 14M, 14C, 14K, and toner supply rollers provided in the developing device housings 14Y, 14M, 14C, 14K, respectively. 16Y, 16M, 16C, and 16K, and developing rollers 17Y, 17M, 17C, and 17K disposed so as to be in contact with the image carriers 10Y, 10M, 10C, and 10K, respectively.

  Although not shown, each of the developing means 13Y, 13M, 13C, and 13K has a toner agitating member provided in each of the toner storage portions 15Y, 15M, 15C, and 15K, and each toner storage portion 15Y, similarly to the conventionally known developing means. , 15M, 15C, and 15K, partitioning members that separate the toner storage portions 15Y, 15M, 15C, and 15K from the toner supply rollers 16Y, 16M, 16C, and 16K, A blade that contacts the toner supply rollers 16Y, 16M, 16C, and 16K and a regulating blade that regulates the thickness of the toner layer on each of the developing rollers 17Y, 17M, 17C, and 17K are provided.

  The developing rollers 17Y, 17M, 17C, and 17K and the toner supply rollers 16Y, 16M, 16C, and 16K are driven to rotate counterclockwise in the direction opposite to the rotation direction of the image carriers 10Y, 10M, 10C, and 10K. The toners of the respective colors stirred by the stirring members in the toner storage units 15Y, 15M, 15C, and 15K are respectively supplied to the toner supply rollers 16Y, 16M, 16C, and 16K, and these toners are further supplied to the toner supply rollers 16Y, 16M. , 16C, and 16K, the developing roller 17Y, 17M, and the developing roller 17Y, 17M, by the adhesion force due to the frictional band power rubbed with the blade and the mechanical adhesion force on the surface uneven portions of the toner supply rollers 16Y, 16M, 16C, 16K It is supplied to the surface of 17C and 17K. The toner supplied to the developing rollers 17Y, 17M, 17C, and 17K is regulated to a predetermined layer thickness by the regulating blades, and the toner layers that are thinned by this regulation are the image layers 10Y, 10M, It is transported to 10C and 10K. The developing rollers 17Y, 17M, 17C, and 17K are in contact with the image carriers 10Y, 10M, 10C, and 10K, and are conveyed by the developing rollers 17Y, 17M, 17C, and 17K at and near the nip portion. The latent image portions of the image carriers 10Y, 10M, 10C, and 10K are developed by the toner.

  In this example, image forming stations 9Y, 10M, 10C, and 10K for image forming stations 9Y, 9M, 9C, and 9K for respective colors Y, M, C, and K, charging means 11Y, 11M, 11C, and 11K, and image writing means. 12Y, 12M, 12C, and 12K and developing means 13Y, 13M, 13C, and 13K are integrated into a process cartridge for each color. These process cartridges are set so as to be individually replaceable on a cartridge support guide (not shown) provided in the housing body 2. Further, the image supporting members 10Y, 10M, 10C, and 10K are positioned relative to each other by the cartridge support guide so that the intervals between the adjacent image supporting members are the same.

  The primary transfer unit 4 includes a driving roller 18 that is rotationally driven by a driving source (not shown) disposed below the housing body 2, a driven roller 19, and a stretch between the driving roller 18 and the driven roller 19. And an intermediate transfer belt 20 that is driven to rotate counterclockwise as indicated by an arrow in FIG.

  The image carriers 10Y, 10M, 10C, and 10K in the image forming unit 3 come into contact with the belt tension side portion of the intermediate transfer belt 20, and the respective color toner images are primary from the image carriers 10Y, 10M, 10C, and 10K. Primary transfer (intermediate transfer) is performed at the transfer portion. In that case, in the primary transfer portion of each color, primary transfer members 21Y, 21M, 21C, and 21K including transfer rollers disposed so as to face the image carriers 10Y, 10M, 10C, and 10K are formed on the intermediate transfer belt 20. The belt tension side portion is elastically pressed against the image carriers 10Y, 10M, 10C, and 10K. Each image carrier 10Y, 10M, 10C, 10K is rotated clockwise as indicated by an arrow in FIG. 1, that is, the contact portion with the belt tension side portion of the image carriers 10Y, 10M, 10C, 10K is the belt tension side. The belt of toner images on the image carriers 10Y, 10M, 10C, and 10K is driven to rotate in the same direction as the conveyance direction of the portion and applies a transfer bias to the primary transfer members 21Y, 21M, 21C, and 21K. Primary transfer to the tension side portion is performed.

  Suitable materials for the intermediate transfer belt 20 include PC resin, PET resin, polyimide resin, urethane resin, silicon resin, polyether resin, polyester resin, and the like. For the purpose of setting the degree, coefficient of friction and the like to desired characteristics, a corresponding additive or the like may be added. In addition, the rigidity can be set to a desired rigidity by setting the thickness. In FIG. 1, reference numeral 22 denotes a test pattern sensor provided close to the driving roller 18. The test pattern sensor 22 positions each color toner image on the intermediate transfer belt 20 and density of each color toner image. Is a sensor for correcting color misregistration and image density of each color image.

As shown in FIG. 1, the paper feeding unit 5 includes a paper feeding cassette 23 in which recording media P such as paper are stacked and held, and a pickup roller 24 that feeds the recording media P from the paper feeding cassette 23 one by one. And a paper feed unit. In addition, the housing body 2 is provided with a registration roller pair 25 that defines the timing of feeding the recording medium P to the secondary transfer portion.
The secondary transfer unit 6 includes a secondary transfer roller 26 that presses the intermediate transfer belt 20 against the driving roller 18 in the secondary transfer portion. At this time, the drive roller 18 of the primary transfer unit 4 also serves as a backup roller for the secondary transfer roller 26.

Further, the fixing unit 7 includes a rotatable heating roller 27 incorporating a heating element such as a halogen heater, and a pressure roller 28 that presses and biases the heating roller 27. The color image secondarily transferred to the recording medium P by the secondary transfer portion is fixed to the recording medium P at a predetermined temperature in the nip portion formed by the heating roller 27 and the pressure roller 28 of the fixing unit 7. The
Further, a pair of paper discharge rollers 30 for discharging the fixed recording medium P to the paper discharge tray 29, and a duplex printing conveyance path 31 for conveying the recording medium P to form images on both sides of the recording medium P are provided. It is arranged.

  In the image forming operation of the image forming apparatus 1 of this example, the image carriers 10Y, 10M, 10C, and 10K that have been neutralized are uniformly charged by the charging units 11Y, 11M, 11C, and 11K, respectively, A latent image of each color is written on each of the image carriers 10Y, 10M, 10C, and 10K by the image writing means 12Y, 12M, 12C, and 12K. The latent images on the image carriers 10Y, 10M, 10C, and 10K are developed by the developing units 13Y, 13M, 13C, and 13K, respectively, to form toner images. The toner images of the respective colors of the image carriers 10Y, 10M, 10C, and 10K are sequentially superimposed on the intermediate transfer belt 20 by the primary transfer unit 4 and transferred to the recording medium P by the secondary transfer unit 6. Next transferred. Finally, the color-superposed toner image on the recording medium P is heated and pressurized and fixed by the fixing unit 7, and the recording medium P on which the color fixed image is formed is conveyed to the paper discharge tray 29.

  2A to 2C, each of the writing means 12Y, 12M, 12C, and 12K has an exposure line head unit 32 having the same configuration, and this exposure line head unit 32. Includes a cleaning means 34 for cleaning the lens 33 of the LED line head. In that case, the cleaning means 34 is provided integrally with the exposure line head unit 32. Further, the exposure line head unit 32 constitutes the optical head of the present invention.

  The cleaning means 34 includes a main body 35 movably provided in the extending direction of the lens 33, and a pair of the main body 35 provided at a predetermined interval in the extending direction of the lens 33 to clean the surface of the lens 33. Lens cleaning members 36, 37, driving means 38 provided on the main body 35 for moving the main body 35, and four wheels on the left and right in FIGS. 2A and 2B provided rotatably on the main body 35. 39, 40, 41, 42. Therefore, the lens cleaning members 36 and 37 and the driving means 38 are integrally provided.

  The driving means 38 includes an actuator stay 45 provided on the main body 35 so as to be movable in a direction orthogonal to the extending direction of the lens 33, an actuator 46 supported by the actuator stay 45, and the actuator stay 45 shown in FIG. And in (b), it consists of a pressurizing spring 47 that always urges to the right.

  As shown in FIGS. 3A and 3B, the actuator 46 includes a rectangular plate-like diaphragm 48, and the diaphragm 48 includes a pair of upper and lower rectangular plate-like piezoelectric elements 49 and 50. The piezoelectric elements 49 and 50 made of, for example, SUS sandwiched between the piezoelectric elements 49 and 50 and bonded to each other, and a rectangular plate-shaped shim material 51 having the same size in plan view are formed into a three-layer structure. Yes. At the right end of the shim material 51, a pecking portion 52 having a flat surface end 52a is formed as shown in FIG. 3A, and this pricking portion 52 is moved from the rectangular plate-shaped diaphragm 48 to the right. The end 52 a is protruded so as to be able to contact the reaction rail 53. Similarly, in the plan view, at the center of the shim 51 in the left-right direction, support portions 54, 55 are provided so as to be orthogonal to the vertical direction from the diaphragm 48, and these support portions 54, 55 are provided in the actuator stay 45. Are elastically supported by fixing members 56 and 57 such as screws.

  3A, when an AC drive signal (AC voltage) is applied to the plate-like piezoelectric elements 49, 50 from the drive circuit D via electrodes (not shown), these piezoelectric elements are applied. The elements 49 and 50 expand and contract in the left-right direction α (longitudinal direction of the piezoelectric elements 49 and 50), and longitudinal vibration in the left-right direction α is generated in the diaphragm 48. Further, when the diaphragm 48 is excited by the longitudinal vibration by applying the drive signal to the piezoelectric elements 49 and 50 in this way, the rotational moment centered on the center of gravity of the diaphragm 48 is caused by the unbalance of the weight balance of the diaphragm 48. appear. This rotational moment induces a bending vibration in which the diaphragm 48 swings in the width direction (that is, the vertical direction indicated by the dotted line β and the alternate long and short dash line γ in FIG. 3A).

  As described above, longitudinal vibration and bending vibration are generated in the vibration plate 48, and these two vibrations are combined, so that the end 52a of the abutting portion 52 of the vibration plate 48 becomes an ellipse shown in FIG. It will move along the trajectory. Then, when the pecking part 52 draws an elliptical orbit, the pecking part 52 is pressed against the reaction guide rail 53 with a large pressing force when it swells to the reaction rail 53 side, and when it is retracted from the reaction rail 53 side, The distance between the reaction rail 53 and the reaction rail 53 may be contacted with a small pressing force without being separated from the reaction rail 53. Therefore, the actuator 46 presses the reaction rail 53 in the displacement direction of the elliptical orbit of the picking portion 52 when the picking portion 52 bulges to the reaction rail 53 side and the pressing force to the reaction rail 53 is large. At this time, if the reaction rail 53 is fixed and immovable, the reaction direction of the pressing force of the picking portion 52 against the reaction rail 53 causes the picking portion 52, that is, the actuator 46 to move in the displacement direction of the elliptical orbit of the picking portion 52. And try to move in the opposite direction. Accordingly, the main body 35 moves in the up-down direction, that is, in the extending direction of the lens 33 in FIG. Thus, the reaction rail 53 also functions as a first left / right guide rail 53 that guides the guide body 35 in the left / right direction, as will be described later.

  The actuator using this piezoelectric element is described in detail in, for example, Japanese Patent Application Laid-Open No. 2002-291264, Japanese Patent Application Laid-Open No. 2003-250284, and the like, and can be understood with reference to these publications. Is omitted. Further, as described in these publications, an actuator using a piezoelectric element is used in a small portable device such as a wristwatch, and can be formed extremely thin and extremely small.

  Thus, since the actuator 46 is ultra-compact, even if the actuator 46 is integrally provided with the lens cleaning members 36 and 37 in the main body 35 of the cleaning means 34, the cleaning means 34 is formed in a compact and compact manner. It can be arranged so as to face each image carrier 10Y, 10M, 10C, 10K in a relatively narrow space between the image carrier 33 and each image carrier 10Y, 10M, 10C, 10K.

The reaction rail 53 is also provided on the exposure line head unit 32 as a first left and right guide rail 53 having a vertical plane that is orthogonal to the upper surface of the lens 30 and extends in the extending direction of the lens 30. Further, another second left and right guide rail 59 is provided on the exposure line head unit 32 so as to face and be parallel to the first left and right guide rail 53. As described above, the end 52a of the sticking portion 52 of the actuator 46 can be brought into contact with the vertical surface of the first left and right guide rail 53, and the pair of right wheels 41 and 42 are in elastic contact with each other. Yes. Further, the pair of left wheels 39 and 40 are in elastic contact with the vertical surface of the second left and right guide rail 59.
The main body 35 is guided and moved in the left-right direction, that is, in a direction parallel to the upper surface of the lens 33 and perpendicular to the extending direction of the lens 33 by the first and second left and right guide rails 53 and 59.

  Further, the exposure line head unit 32 is provided with first and second pressing members 69 and 70 adjacent to the first and second first left and right guide rails 53 and 59, respectively. These first and second pressing members 69, 70 are provided so as to extend in the extending direction of the lens 33, and slidably press the upper surface of the main body 35. That is, the lower surfaces of the first and second pressing members 69 and 70 guide the main body 35 in the vertical direction. At this time, the first and second pressing members 69, 70 press the upper surface of the main body 35, so that the pair of lens cleaning members 36, 37 come into light contact with the upper surface of the lens 30 with a relatively small pressure. Yes.

  Accordingly, the cleaning means 34 is guided in the vertical direction by the first and second pressing members 69 and 70 and in the horizontal direction by the first and second left and right guide rails 53 and 59 while being guided by the exposure line head unit 32. By relatively moving in the extending direction of the lens 33, the upper surface of the lens 30 is cleaned by the lens cleaning members 36 and 37.

Further, the exposure line head unit 32 is provided with an elongated strip-shaped energizing member 60 (corresponding to an energizing portion of the present invention) along the moving direction of the main body 35. The energization member 60 is connected to a drive circuit D that outputs an AC drive signal (AC voltage).
The main body 35 is provided with a wiring 61 connected via electrodes (not shown) of the piezoelectric elements 49 and 50, and an external terminal 62 connected to the wiring 61. The external terminal 62 is in contact with the energizing member 60 and is in sliding contact with the energizing member 60 when the main body 35 is moved. Then, an AC voltage is applied to the piezoelectric elements 49 and 50 through the energizing member 60, the external terminal 62 and the wiring 61.
In addition, a configuration in which a drive circuit for the actuator 46 is mounted in the main body 35 and power is supplied from the energization unit is also possible.

  In the image forming apparatus 1 of this example configured as described above, the cleaning unit 34 is provided above or below in FIG. 2B when image writing by exposure of the exposure line head unit 32 is not performed. Thus, it is retracted to a retracted position that does not interfere with exposure by the exposure line head unit 32 (in the following description, for convenience of explanation, the retracted position is provided below in FIG. 2B). When the cleaning means 34 is in the retracted state at this retracted position, the actuator 46 is not driven, and the end 52a of the pricking portion 52 abuts against the first left and right guide rails 53 with a small pressing force by the spring force of the pressure spring 47. ing.

  In order to operate the cleaning means 34 to clean the lens 33, the AC voltage is applied to the piezoelectric elements 49 and 50 of the actuator 46 from the drive circuit D in the direction in which the main body 35 moves upward in FIG. Apply to. Then, as described above, the driving means 38 is driven to move upward in FIG. 2B, that is, the main body 35 moves upward. By the upward movement of the main body 35, the pair of lens cleaning members 36 and 37 slide and clean the upper surface of the lens 33. When the main body 35 moves to the upper limit position, it stops. Then, an AC voltage is applied from the drive circuit D to the piezoelectric elements 49 and 50 in the direction in which the main body 35 moves downward in FIG. Then, the driving means 38 is driven in the reverse direction, and the main body 35 moves downward in FIG. By the downward movement of the main body 35, the pair of lens cleaning members 36 and 37 slide and clean the upper surface of the lens 33 again. When the main body 35 moves to the retracted position, it stops. Thus, the upper surface of the lens 33 is cleaned by the cleaning unit 34.

  In the above example, the main body 35 is reciprocated by a single cleaning operation. However, in the present invention, the main body 35 may be moved only one way by a single cleaning operation. In that case, it is necessary to provide a retracting position for the cleaning means 34 also in the upper direction in FIG. Further, the main body 35 can be reciprocated several times by one cleaning operation.

  According to the image forming apparatus 1 of this example, since the cleaning members 36 and 37 and the driving unit 38 are integrally provided in the main body 35, the configuration of the cleaning unit 34 can be simplified, and the cleaning unit 34 is formed in a compact and compact manner. In addition, the image forming apparatus 1 including the cleaning unit 34 can be downsized. In particular, the exposure line head unit 32 is provided with first and second left and right guide rails 53 and 59 which are guide portions of the cleaning means 34 and an energizing member 60 for applying an AC voltage to the piezoelectric elements 49 and 50 of the actuator 46. Therefore, the exposure line head unit 32 provided with the cleaning means 34 can be formed more compactly. Note that only one of the first and second left and right guide rails 53 and 59 and the energizing member 60 may be provided in the exposure line head unit 32.

  Further, since the cleaning members 36 and 37 and the driving means 38 are integrally provided so as to be movable in the axial directions of the respective image carriers 10Y, 10M, 10C and 10K, the driving force transmission mechanism of the driving means 38 is simplified. And the number of parts can be reduced. Thereby, since the cleaning means 34 can be formed more compactly, the installation space of the cleaning means 34 can be reduced. Therefore, even if there is a demand for downsizing in recent years and parts for forming images such as charging means and exposure means are concentrated near the periphery of each image carrier 10Y, 10M, 10C, 10K, the cleaning means 34 can be efficiently arranged.

  Furthermore, since the actuator 46 is composed of the piezoelectric elements 49 and 50, the actuator 46 can be formed in a very small size. Further, since this ultra-small actuator 46 is used as the driving means 38, the cleaning means 34 can be made relatively small even if the cleaning members 36 and 37 and the driving means 38 are provided integrally, and the lens. It can be arranged so as to face each image carrier 10Y, 10M, 10C, 10K in a relatively narrow space between the image carrier 33 and each image carrier 10Y, 10M, 10C, 10K. Thereby, this narrow space can be used effectively, and the image forming apparatus 1 can be formed even more compactly.

In each of the above-described examples, the present invention has been described by being applied to an intermediate transfer type tandem color image forming apparatus provided with an intermediate transfer medium. However, the present invention is not applicable to an intermediate transfer type as shown in FIG. And a primary transfer type tandem type in which the image carrier 10Y, 10M, 10C, 10K is directly transferred to a recording medium P such as paper and the toner image transferred to the recording medium P is fixed by the fixing unit 7. It can also be applied to the color image forming apparatus. Further, the present invention is not limited to such a tandem type color image forming apparatus, and needs to be cleaned, for example, along the axial direction of the image carrier such as a lens of an exposure line head or a charging wire. The present invention can be applied to any image forming apparatus as long as the image forming apparatus includes a member that is extended.

  The image forming apparatus of the present invention is an image forming apparatus that forms an electrostatic latent image on an image carrier such as an electrophotographic, electrostatic copying machine, printer, or facsimile, and needs to be cleaned, for example, an exposure line head It can be suitably used for an image forming apparatus provided with a member that extends along the axial direction of the image carrier, such as a lens or a charging wire.

1 is a cross-sectional view schematically showing an example of an embodiment of an image forming apparatus according to the present invention. FIG. 2 schematically shows a lens cleaning unit of an exposure line head of an image writing unit used in the image forming apparatus shown in FIG. 1, wherein (a) is a front view and (b) is a plan view. The actuator which is a drive means of the cleaning means shown in Drawing 2 is shown typically, (a) is a front view and (b) is a top view. It is a cross-sectional view which shows typically another example of embodiment of the image forming apparatus concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10Y, 10M, 10C, 10K ... Image carrier, 11Y, 11M, 11C, 11K ... Charging means, 12Y, 12M, 12C, 12K ... Image writing means, 13Y, 13M, 13C, 13K ... Developing means, 32 ... exposure line head unit, 33 ... lens, 34 ... cleaning means, 35 ... main body, 36,37 ... lens cleaning member, 38 ... driving means, 39,40,41,42 ... wheel, 45 ... actuator Sty, 46 ... Actuator, 47 ... Pressure spring, 48 ... Diaphragm, 49, 50 ... Piezoelectric element, 51 ... Shim material, 52 ... Pecking part, 52a ... Arc end, 53 ... Reaction rail (first left and right guide rail) ), 54, 55 ... support portion, 60 ... energizing member, 69 ... first pressing member, 70 ... second pressing member

Claims (3)

An image forming apparatus comprising at least an image carrier on which a latent image is formed, and a cleaning unit that is disposed around the image carrier and cleans an optical head that writes the latent image on the image carrier.
The cleaning means includes a cleaning member for cleaning the lens of the optical head and a driving means for moving the cleaning member, and the cleaning member and the driving means are provided so as to be movable together. And
Further, the optical head is provided with at least one of a guide part for guiding the cleaning means when the cleaning means is moved and an energization part for applying a voltage to the driving means. apparatus. The image forming apparatus according to claim 1, wherein the cleaning unit is disposed in a space between the image carrier and a member used for image formation. The image forming apparatus according to claim 1, wherein the driving unit is an actuator made of a piezoelectric element, and an AC voltage is applied to the piezoelectric element through the energization unit.

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