JP2010224062A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of long term use of a driving motor which drives a cleaning member of a charging wire of an electrifier. <P>SOLUTION: The image forming apparatus 100 includes a configuration in which the electrifier 1 is removed independently of the driving device 2 from an apparatus body 50 of the image forming apparatus. The driving device includes: a motor support member 104 which rockably supports a driving motor 110 such that the driving motor is brought into and out of contact with a spiral shaft 120; a first biasing member 105 for making the motor support member rock and biasing the driving motor toward the spiral shaft; and a second biasing member 103. When the electrifier is fixed at a predetermined position in the apparatus body, the second biasing member regulates a position in the longitudinal direction of the electrifier by pressing a pressing part 101a, provided in the electrifier, against the motor support member. When the electrifier is removed from the apparatus body, the second biasing member holds the driving motor at a position separated from the spiral shaft and also biases the electrifier in the removing direction from the apparatus body. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile apparatus using an electrophotographic system.

  2. Description of the Related Art Conventionally, an image forming apparatus including a step of electrostatically transferring a toner image electrostatically formed on the surface of a photoreceptor onto a transfer material such as paper is well known. In this type of apparatus, a corona discharger (corona charger) is used to form an electric field when the surface of the photoreceptor is uniformly charged or when a toner image formed on the photoreceptor is transferred to a transfer material. ) Is widely used as a charging device.

  FIG. 9 is a plan view of a charging device using a charger. Such a charging device uses a charger configured to stretch a charging wire 301 over substantially the entire length in the axial direction of the photosensitive member and apply a bias voltage thereto.

  However, in this type of charger, since the charging wire 301 is exposed to the space, if foreign matter such as dust or floating toner existing in the image forming apparatus adheres to the charging wire 301, uneven charging and abnormal discharge occur. May cause image quality degradation.

  In order to avoid such a problem, a cleaning member (not shown) such as a pad for holding the charging wire 301 is held by the cleaning member holding member 302 and is moved back and forth along the charging wire 301 to charge the charging wire. There is one that cleans 301 (see Patent Document 1).

  Further, when the above-described cleaning means is employed, there is a configuration in which the cleaning member holding member 302 is moved as follows. FIG. 10 shows the configuration of the moving means of the cleaning member holding member 302. That is, the spiral shaft 303 is disposed in the vicinity of the charger, and the spiral shaft 303 and the cleaning member holding member 302 are connected. Then, by rotating the spiral shaft 303, the cleaning member holding member 302 is moved, and the charging wire 301 is rubbed and cleaned with the cleaning member held by the cleaning member holding member 302. For example, the spiral shaft 303 is disposed in a frame 304 having a guide slit 404a in the longitudinal direction. When the spiral shaft 303 is driven by the motor 305, the cleaning member holding member 302 screwed to the spiral shaft 303 moves in the horizontal direction in the drawing along the spiral shaft 303 and is held by the cleaning member holding member 302. The charging wire 301 is cleaned by the cleaning member.

JP-A-8-194365

  However, in the conventional charging wire cleaning device for the charger, the drive motor is provided in the charger unit, and therefore the drive motor is discarded at the same time as the life of the charger.

  This is not preferable from the viewpoint of cost and effective use of resources when the life of the drive motor is longer than the life of the charger.

  Accordingly, an object of the present invention is to provide an image forming apparatus that enables long-term use of a drive motor that drives a cleaning member of a charging wire of a charger.

  The above object is achieved by the image forming apparatus according to the present invention. In summary, the present invention is a charger in which a charging wire for charging an object to be charged by corona discharge is stretched, and holds a cleaning member that slidably rubs the charging wire and holds the longitudinal direction of the charging wire. A charger having a cleaning member holding member movable along a direction, a spiral shaft for moving the cleaning member holding member along a longitudinal direction of the charging wire, and a drive for rotating the spiral shaft An image forming apparatus having a motor, wherein the charger can be taken out from the apparatus main body of the image forming apparatus independently of the drive apparatus, and the drive apparatus is configured with the spiral shaft. A motor support member that swingably supports the drive motor so as to be movable toward and away from the motor, and swings the motor support member to direct the drive motor toward the spiral shaft. In a state where the first urging member for urging and the charger is mounted at a predetermined position in the apparatus main body, a pressing portion provided in the charger is pressed against the motor support member. A position in the longitudinal direction of the charger is defined, and when the charger is taken out from the apparatus main body, the drive motor is held at a position separated from the spiral shaft and the charger is taken out from the apparatus main body. And a second biasing member biasing in the direction.

  According to the present invention, it is possible to use the drive motor for driving the cleaning member of the charging wire of the charger for a long period of time.

1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention. It is a front view which shows the charger and cleaning drive apparatus in one Example of this invention. It is a left view which shows the charger and cleaning drive apparatus in one Example of this invention. FIG. 2 is a perspective view showing the charger and the cleaning drive device in a state before the charger in the embodiment of the present invention is mounted on the apparatus main body. FIG. 2 is a perspective view showing the charger and the cleaning driving device in a state after the charger in the embodiment of the present invention is mounted on the apparatus main body. FIG. 3 is a front view of a charger and a cleaning driving device for explaining an example of a configuration in which a leaf spring pushing portion has a role of grounding in an embodiment of the present invention. FIG. 6 is a front view of the periphery of the charger for explaining an example of a method for positioning the charger with respect to the photosensitive drum. 1 is a schematic diagram illustrating a schematic overall configuration of a charging device according to an embodiment of the present invention. It is a top view which shows an example of the conventional charging device. It is a schematic diagram which shows an example of the conventional charging device.

  The image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

Example 1
1. First, the overall configuration and operation of an embodiment of the image forming apparatus according to the present invention will be described. FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 of this embodiment. In this embodiment, the image forming apparatus 100 is an electrophotographic copying machine.

  A document table 51 made of a transparent glass plate is fixedly provided on an upper portion of a main body (apparatus main body) 50 of the image forming apparatus 100. The document pressing plate 52 presses and fixes the document Q placed at a predetermined position on the document table 51 with the image surface facing downward. Below the document table 51, a lamp 53 for illuminating the document Q, and reflecting mirrors 54, 55, 56 for guiding the light image of the illuminated document Q to the image memory unit 57 and an imaging lens 60 are provided. An optical system is provided. The lamp 53 and the reflecting mirrors 54, 55, and 56 scan the original Q by moving at a predetermined speed in the direction of the arrow a.

  The image forming unit is provided with a drum-type photosensitive member (electrophotographic photosensitive member) as an image carrier, that is, a photosensitive drum 61. In the image forming unit, the following units are provided around the photosensitive drum 61. First, there is a charging device 62 as a primary charging means for uniformly charging the surface of the photosensitive drum 61. Next, an electrostatic latent image (electrostatic image) is formed on the photosensitive drum 61 by irradiating the surface of the photosensitive drum 61 charged by the charging device 62 with a light image according to image information from the image memory unit 57. This is a scanner 58 as an exposure means. Next, a developing device 63 as developing means for developing the electrostatic latent image formed on the photosensitive drum 61 by the scanner 58 to form a toner image to be transferred onto the transfer material (sheet material) S. . Next, a transfer charging device 68 as transfer means for transferring the toner image formed on the surface of the photosensitive drum 61 onto the transfer material S is shown. Next, a separation charging device 69 for separating the transfer material S on which the toner image is transferred from the photosensitive drum 61 from the photosensitive drum 61 is provided. Next, there is a cleaner 75 as a cleaning unit for removing toner remaining on the photosensitive drum 61 after the toner image is transferred from the photosensitive drum 61. Further, the apparatus main body 50 is provided with a CPU 76 as control means for controlling each part of the image forming apparatus 100.

  Here, for example, an image forming operation when an image is formed on one surface of the transfer material S and the image surface is discharged with the image surface facing up is as follows.

  When a copy start button (not shown) is pressed, the transfer material S in the feed tray 81 (or the feed tray 82) is transferred to the transfer material feeding means 85 (feed tray) composed of feed rollers 85a, 85b, 85c. 82 is sent out by the transfer material feeding means 86). The transfer material S is conveyed by a plurality of conveyance roller pairs 87, and the skew feeding of the transfer material S is corrected by the registration roller pairs 95.

  The transfer material S can also be supplied from the manual feed tray 89. In this case, the transfer material S on the manual feed tray 89 is sent out by members 90 and feed rollers 91 and 92 constituting transfer material feeding means. Then, the sheet is conveyed by the conveyance roller pair 93 and the skew feeding is corrected by the registration roller pair 95.

  The transfer material S whose skew feeding has been corrected is sent out in the direction of the image forming unit at a predetermined timing by the registration roller pair 95, and the toner image is transferred from the photosensitive drum 61 by the action of the transfer charging device 68 in the image forming unit. Is done.

  On the downstream side of the image forming unit, a belt conveyance unit 70 for conveying the transfer material S on which the toner image is transferred, and a toner image on the transfer material S conveyed by the belt conveyance unit 70 are fixed to the transfer material S. A fixing device 71 is provided for this purpose. The transfer material S on which the toner image is fixed by the fixing device 71 passes through the inner discharge roller pair 72, is guided by the upper surface of the flapper 98, and is discharged from the apparatus main body 50 by the outer discharge roller pair 73. A discharge tray 74 is provided outside the apparatus main body 50, and the transfer material S discharged by the outer discharge roller pair 73 is received by the discharge tray 74, and the image forming operation is completed.

2. Next, the charging device 62 in the present embodiment will be described.

  FIG. 8 shows an overall schematic configuration of the charging device 62 of the present embodiment. The charging device 62 includes a charger (corona charger, corona discharger) 1 having a charging wire 11 and the like, and a cleaning drive device 2 that drives a cleaning device 13 that cleans the charging wire 11 of the charger 1.

  The charger 1 has a shield plate (frame body, shield case) 12 as a shield member having a substantially U-shaped cross section. Further, a front block (first block member) 101 and a rear block (second block member) 102 are respectively provided at one end and the other end in the longitudinal direction of the shield plate 12. The front block 101 is provided at one end in the longitudinal direction of the charger 1 located on the front side of the apparatus main body 50 when the charger 1 is mounted on the apparatus main body 50 and disposed along the longitudinal direction of the photosensitive drum 61. Yes. The rear block 102 has the other end in the longitudinal direction of the charger 1 located on the back side of the apparatus main body 50 when the charger 1 is mounted on the apparatus main body 50 and disposed along the longitudinal direction of the photosensitive drum 61. Is provided. In this embodiment, the shield plate 12 is made of a conductive metal material, and the front block 101 and the rear block 102 are made of a resin material. The shield plate 12 is fixed to the front block 101 and the rear block 102 so as to couple the front block 101 and the rear block 102.

  A charging wire 11 whose tension is controlled by a spring is stretched between the front block 101 and the rear block 102. A lower portion of the shield plate 12 in the drawing is opened, and a surface to be charged, that is, a surface of the photosensitive drum 61 in this embodiment is opposed to the charging wire 11.

  Above the shield plate 12 in the figure, a spiral shaft 120 that is pivotally supported by a support portion provided in each of the front block 101 and the rear block 102 is provided. A cleaning member holding member 21 that holds a cleaning member (not shown) that slides and charges the charging wire 11 in the charger 1 is screwed onto the spiral shaft 120. The cleaning member holding member 21 is connected to the spiral shaft 120 through a slit 12 a provided in the shield plate 12. As the cleaning member, for example, a pad formed of an elastic material such as felt or sponge that holds the charging wire 11 can be suitably used.

  In the present embodiment, the cleaning device 13 includes the cleaning member, the cleaning member holding member 21 that holds and moves the cleaning member, and the spiral shaft 120. In this embodiment, the charger 1 includes the front block 101, the rear block 102, the charging wire 11, the shield plate 12, and the cleaning device 13.

  Then, the drive is transmitted from the cleaning drive device 2 to the spiral shaft drive gear 109 (FIG. 2) provided at the end of the spiral shaft 120 on the front block 101 side, and the spiral shaft 120 rotates. As a result, the cleaning member holding member 21 screwed into the spiral shaft 120 moves (reciprocates) along the longitudinal direction of the charger 1, and the charging wire is moved by the cleaning member held by the cleaning member holding member 21. 11 is cleaned.

  In the present embodiment, the charger 1 can be attached to and detached from the apparatus main body 50 independently of the cleaning drive device 2. For example, the charger 1 can be replaced due to the life of the charger 1. On the other hand, the cleaning drive device 2 is attached to the apparatus main body 50 separately from the charger 1.

3. Cleaning Driving Device Next, a cleaning driving device 2 for driving the cleaning device 13 that cleans the charging wire 11 of the charger 1 will be described with reference to FIGS.

  One of the objects of the present embodiment is to arrange the cleaning drive motor 110, which has been discarded along with the life of the charger 1 in the past, outside the charger 1, thereby reducing costs and improving serviceability. It is.

  FIG. 2 is a front view showing the cleaning drive device 2 and the charger 1 mounted on the device main body 50.

  The charger 1 is attached to the apparatus main body 50 by being pushed through the notch 113a of the front plate 113 of the apparatus main body 50 to the back side of the drawing (in the direction of arrow B in FIG. 4).

  In the cleaning drive device 2, a cleaning drive motor 110 is fixed to a motor support plate 104 as a motor support member. The motor support plate 104 is attached to the front side plate 113 so as to be rotatable (swingable) about the support shaft 112. Further, the motor support plate 104 is pressed toward the charger 1 by a drive connecting spring (torsion coil spring) 105 as a first urging member. One end of the drive coupling spring 105 engages with a locking portion 113 b provided on the front side plate 113, and the other end engages with the motor support plate 104.

  FIG. 3 is an enlarged view around the cleaning drive motor 110 on the left side surface in FIG. A motor gear 107 as a first drive transmission member is attached to the cleaning drive motor 110. The cleaning drive motor 110 transmits the drive to the drive idler gear 108 as the second drive transmission member attached to the motor support plate 104 via the motor gear 107. In this embodiment, an abutment roller (first positioning portion) 106 is provided adjacent to the drive idler gear 108 and coaxially with the drive idler gear 108. The abutment roller 106 plays a role of guaranteeing the inter-gear distance between the drive idler gear 108 and the spiral shaft drive gear 109 provided at one end of the spiral shaft 120 in the longitudinal direction.

  FIG. 4 is a view showing a state before the charger 1 is mounted at a predetermined position from a viewpoint from the back side in FIG. 2 (the front plate 113 is not shown). FIG. 5 is a view showing a state in which the charger 1 is mounted at a predetermined position, as viewed from the back side in FIG. 2 (the front plate 113 is not shown).

  With reference to FIG. 4, the operation of mounting the charger 1 at a predetermined position from the state before the charger 1 is mounted at the predetermined position will be described. Before the charger 1 is mounted at a predetermined position, the plate spring (motor fixing spring) 103 as the second urging member fixed to the front side plate 113 is in a free length state. In this state, the motor support plate 104 is on the bending surface 103 a as a support portion of the plate spring 103. As a result, the drive idler gear 108 and the spiral shaft drive gear 109 are separated from each other. Thus, one of the leaf springs 103 serves as a means for holding the cleaning drive motor 110 in a state of being separated (released) from the spiral shaft 120.

  When the operator pushes the charger 1 in the direction indicated by the arrow B (from the front side of the apparatus main body 50 toward the back side) from the state before the charger 1 is mounted at a predetermined position, the leaf spring 103 is moved forward. The block 101 is pushed in the direction of arrow B by a leaf spring pushing portion 101b as a spring receiving portion. As a result, the motor support plate 104 that has been on the bending surface 103a of the plate spring 103 loses support, and is rotated in the direction of the spiral shaft 120 (arrow C direction) about the support shaft 112 by the drive connecting spring 105. Move. Then, the abutment roller 106 abuts against the abutment portion 101c of the front block 101 (FIG. 3). As a result, the distance between the drive idler gear 108 and the spiral shaft drive gear 109 is guaranteed.

  With the above operation, the charger 1 as shown in FIG. 5 is mounted in a predetermined position. The front block 101 is urged in the same direction when the leaf spring pushing portion 101b is pressed by the leaf spring 103 in the illustrated arrow A direction (from the back side of the apparatus main body 50 toward the front side). However, at this time, the positioning surface 101a as the pressing portion of the front block 101 abuts against the surface (regulating portion) of the motor support plate 104 rotated in the direction of the spiral shaft 120 by the drive connecting spring 105 (FIG. 3). The position of the charger 1 in the longitudinal direction is fixed. As described above, one of the leaf springs 103 serves as a means for defining the position of the charger 1 in the longitudinal direction.

  In addition, as shown in FIG. 6, the pushing plate material 201 formed with the electroconductive material of the member different from the front block 101 can be used as the said leaf | plate spring pushing part 101b. The pushing plate member 201 and the shield plate 12 are electrically connected via the varistor 202, so that when the charger 1 is installed in the apparatus main body 50, the shield plate 12 is electrically connected to the leaf spring 103 and the shield plate 12. Overcurrent can be prevented. That is, with this configuration, the leaf spring pushing portion 101b can have a role of grounding.

  Next, with reference to FIG. 5, the operation when the charger 1 is removed will be described. When the operator rotates the motor support plate 104 in the direction indicated by the arrow D, that is, away from the spiral shaft 120, the contact between the positioning surface 101a and the surface of the motor support plate 104 is released, and the plate The spring 103 returns to the free length position. As a result, the leaf spring pushing portion 101b of the front block 101 is pressurized in the direction indicated by the arrow A, and the charger 1 is pulled out in the direction indicated by the arrow A. As described above, one of the leaf springs 103 serves as means for urging the charger 1 in the direction in which it is removed from the apparatus main body 50. Further, since the leaf spring 103 has returned to the position of the free length, the motor support plate 104 rides on and is supported on the bending surface 103 a of the leaf spring 103.

  The rotation of the motor support plate 104 may be performed by an operator operating a lever or the like connected to the motor support plate 104.

  Next, the positioning of the charger 1 in the direction of the photosensitive drum 61 will be described with reference to FIG. In this embodiment, the charger 1 is provided with a protruding portion (second positioning portion) 101d, which is abutted against the abutting member 61a on the photosensitive drum 61 side, and the charger 1 is positioned with respect to the photosensitive drum 61. To do. The abutting member 61 a is provided by being fitted to the shaft of the photosensitive drum 61.

  That is, in this embodiment, when the charger 1 is mounted on the apparatus main body 50, the abutment roller 106 of the cleaning drive device 2 abuts against the abutment portion 101 c of the front block 101, so that the charger 1 is attached to the photosensitive drum 61. Use pressure in the direction. Thus, the protruding portion 101 d of the charger 1 is pressed against and abutted against the abutting member 61 a to position the charger 1 with respect to the photosensitive drum 61.

  As in the case of the front block 101 side, a pressure spring (not shown) is also arranged on the rear block 102 side, and the charger 1 is attached to pressurize the charger 1 with this pressure spring. Further, it can be configured to abut against the abutting member on the photosensitive drum 61 side. As a result, the distance between the charger 1 and the photosensitive drum 61 can be regulated more satisfactorily.

  As described above, the image forming apparatus 100 according to the present exemplary embodiment includes the charger 1 on which the charging wire 11 for charging the object to be charged by corona discharge is stretched. The charger 1 includes a cleaning member holding member 21 that holds a cleaning member that rubs the charging wire 11 and is movable along the longitudinal direction of the charging wire 11. The charger 1 has a spiral shaft 120 that moves the cleaning member holding member 21 along the longitudinal direction of the charging wire 11. Further, the image forming apparatus 100 includes a driving device 2 including a driving motor 110 for rotating the spiral shaft 120. The charger 1 can be taken out from the apparatus main body 50 independently of the driving device 2. The drive device 2 includes a motor support member 104 that supports the drive motor 110 so that the drive motor 110 can swing with respect to the spiral shaft 120. The drive device 2 also includes a first biasing member 105 for swinging the motor support member 104 and biasing the drive motor 110 toward the spiral shaft 120. Furthermore, the driving device 2 has a second urging member 103. In a state where the charger 1 is mounted at a predetermined position in the apparatus main body, the second urging member 103 presses the pressing portion 101a provided in the charger 1 against the motor support member 104, thereby Define the longitudinal position. In addition, the second urging member 105 holds the drive motor 110 at a position separated from the spiral shaft 120 and removes the charger 1 from the apparatus body 50 when the charger 1 is removed from the apparatus body 50. Energize in the direction.

  That is, according to the present embodiment, the image forming apparatus 100 includes the drive motor 110 for rotating the spiral shaft 120 disposed outside the charger 1, supports the drive motor 110, swings and spirals. A motor support plate 104 for separating from the shaft 120 is provided. Further, a torsion spring 105 for swinging and pressing the motor support plate 104 toward the spiral shaft 120 and a plate spring 103 for supporting the motor support plate 104 at a position spaced from the spiral shaft 120 are provided. Furthermore, a spring receiving portion 101b that pushes the charger 1 forward of the apparatus main body 50 by contacting the leaf spring 103, and a pressing portion 101a for suppressing the charger 1 from jumping forward by the spring receiving portion 101b. The front block member 101 provided with is provided.

  As described above, according to the present embodiment, the cleaning drive device 2 for driving the cleaning device 13 for cleaning the charging wire 11 of the charger 1 disposes the drive motor 110 outside the charger 1, thereby driving the drive motor. Can be used for a long time, and cost can be reduced. Further, the drive motor 110 can be swung to guarantee the distance between the gear on the spiral shaft 120 side and the gear on the drive motor 110 side, so that the front of the image forming apparatus 100 can be reduced in size. The charger 1 can be attached and detached. Further, according to the present embodiment, when the charger 1 is mounted on the apparatus main body 50, the charger 1 is disposed at a predetermined position and easily taken out by the action of the leaf spring 103 and the drive connecting spring 105. Therefore, serviceability can be maintained by using screwless.

DESCRIPTION OF SYMBOLS 1 Charger 2 Cleaning drive device 11 Charging wire 12 Shield plate 13 Cleaning device 21 Cleaning member holding member 61 Photosensitive drum 62 Charging device 101 Front block 103 Motor fixing spring (plate spring)
104 Motor support plate 105 Drive coupling spring (torsion coil spring)
106 Abutting roller 107 Motor gear 108 Drive idler gear 109 Spiral shaft drive gear 110 Cleaning drive motor 113 Front plate 120 Spiral shaft

Claims (3)

A charger in which a charging wire for charging an object to be charged by corona discharge is stretched, and a cleaning member that holds a cleaning member that rubs the charging wire and is movable along the longitudinal direction of the charging wire. A charging device including a member holding member, a spiral shaft that moves the cleaning member holding member along the longitudinal direction of the charging wire, and a driving device including a driving motor for rotating the spiral shaft; In an image forming apparatus having
The charger can be taken out of the main body of the image forming apparatus independently of the driving device,
The drive device includes a motor support member that swingably supports the drive motor so as to be movable toward and away from the spiral shaft, and swings the motor support member to direct the drive motor toward the spiral shaft. In a state where the first urging member for urging and the charger is mounted at a predetermined position in the apparatus main body, a pressing portion provided on the charger is pressed against the motor support member. The position of the charger in the longitudinal direction is defined, and when the charger is taken out from the apparatus main body, the drive motor is held at a position separated from the spiral shaft and the charger is taken out from the apparatus main body. An image forming apparatus comprising: a second urging member for urging in a direction to be moved.   The charger is provided so as to couple the first and second block members to the first and second block members that respectively hold one end and the other end in the longitudinal direction of the charging wire. And a receiving portion provided on the first block member that contacts the second urging member when urging the charger in a direction of being removed from the apparatus main body. The image forming apparatus according to claim 1, wherein the image forming apparatus is made of a conductive material and electrically connects the shield member and the first biasing member.   The drive motor is positioned with respect to the charger by a first positioning portion provided on the motor support member being struck by the bias of the first biasing member, and the first motor is positioned with respect to the charger. The charger is positioned with respect to the external member by the second positioning portion provided in the charger contacting the external member of the charger by the biasing of the biasing member. The image forming apparatus according to claim 1.

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