JP4340223B2 - Electrostatic adsorption device and image forming apparatus using the same - Google Patents

Description

  The present invention relates to an electrostatic adsorption device that adsorbs and conveys a recording medium such as paper, and an image forming apparatus such as an ink jet recording apparatus using the electrostatic adsorption device.

Giving an electric field to the surface by the charging means while circulating the endless belts, thereby adsorbing the recording medium such as paper, and electrostatic attraction apparatus for conveying, the image forming apparatus such as an ink jet recording apparatus using the same Many proposals have been made regarding problems associated with cleaning.
JP 2004-168550 A Japanese Patent Application Laid-Open No. 08-222801 JP-A-10-161436 Japanese Patent Laid-Open No. 04-128859 JP 09-222805 A

  By the way, in such an image forming apparatus such as an ink jet recording apparatus, various contrivances have been made to greatly extend the life of the apparatus by, for example, 10 times by exchanging many components and components. In relation to this, it is necessary to replace the suction belt provided in the electrostatic suction device.

  Also, due to the extended life of the device, problems such as the cleaning mylar and cleaning brush for cleaning the surface of the charging belt provided in the electrostatic adsorption device become dirty with paper dust, etc., and cleaning cannot be performed properly. There is a need to replace these as well.

  In order to perform such replacement work, it is necessary to remove the electrostatic attraction apparatus from the main body of the image forming apparatus such as an ink jet recording apparatus. At that time, in the conventional structure, the entire electrostatic attraction apparatus must be removed. . This is because it is not designed based on the idea that only the charging belt can be removed. In addition, in image forming apparatuses such as inkjet recording apparatuses that use electrostatic adsorption devices, there are carriage rods that support the carriage in many cases. However, the electrostatic adsorption device has to be divided into units and divided into units. However, there has been no design based on such an idea.

  In order to make it easy to remove the charging belt, the separation claw can be removed from the main body of the electrostatic adsorption device. However, as described above, consumables such as a cleaning mylar and a cleaning brush (in this specification, consumables). When you say, including parts that need regular cleaning.) It is becoming more and more necessary to remove or replace, so it is possible to remove only the separation claw. It will be necessary to take separate measures.

  In view of these problems, the present invention not only makes it easy to remove the charging belt, but also allows consumables such as a cleaning mylar and a cleaning brush to be integrally removed, thereby enabling efficient replacement and cleaning operations. Is to provide.

Among the electrostatic attraction devices according to the present invention, an electrostatic suction device according to claim 1 is an electrostatic device that attracts and conveys a recording medium by applying an electric field to the surface of the belt member by charging means while rotating an endless belt member. The suction device includes a separation claw holding unit separate from the charging unit, the separation claw holding unit includes a consumable part other than the separation claw, and the separation claw holding unit includes an electrostatic device including the charging unit. A first plate-like portion guided by the electrostatic adsorption device body for movement for attachment when attached to the adsorption device body, and a stopper for movement of the plate-like portion to the electrostatic adsorption device body A consumable part is provided on the first plate-like part, and the consumable part is a cleaning mylar that cleans the belt surface. Gumaira and characterized Rukoto is sliding in the trailing direction with respect to the mounting direction of the counter direction a and the separation pawl holding unit with respect to the rotational direction of the belt.

Those according to the claim 2 is the electrostatic attraction apparatus according to claim 1, characterized in Rukoto comprises removably said consumable part from said separation pawl holding unit.

Which according to the claim 3 is the electrostatic attraction apparatus according to claim 1, wherein the cleaning Myra, the distance of the separation pawl holding unit to said belt at a position attached to the electrostatic chuck body A. When the distance to the belt immediately before the separation claw holding unit is removed from the electrostatic chuck main body is B, the positional relationship between the belt and the separation claw holding unit is set so that B> A. and wherein a set Rukoto.

According to a fourth aspect of the present invention, in the electrostatic attraction device according to any one of the first to third aspects, a diameter of a roller positioned on the separation claw holding unit side of the pair of rollers for winding the belt is different from the other. It is characterized by being smaller than the roller diameter .

Those according to the claim 5, characterized in electrostatic chuck according to claim 4, wherein a roller is a tension roller located in the separation pawl holding unit side, the other roller to Oh Rukoto the drive roller And

An image forming apparatus according to claim 6 uses the electrostatic attraction apparatus according to any one of claims 1 to 5.

    The present invention has an effect that the separation claw can be easily removed and the charging belt can be easily removed, and consumables such as a cleaning mylar can be removed integrally with the separation claw, and work such as replacement and cleaning can be made efficient.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  FIG. 1 is a schematic configuration diagram showing an overall configuration of an ink jet printer which is an example of an image forming apparatus to be an embodiment of the present invention, and FIG. 2 is a plan view of an image forming unit and a sub-scanning conveying unit of the apparatus.

  The image forming apparatus includes an image forming unit 2 for forming an image, a sub-scanning conveying unit 3, and the like inside the apparatus main body 1 (housing), and a paper feeding unit 4 provided at the bottom of the apparatus main body 1. To a recording medium (hereinafter referred to as “paper”, but the material is not limited to paper) 5 is separated and fed one by one, and the paper 5 is imaged by the sub-scanning conveyance unit 3. The image forming unit 2 ejects liquid droplets onto the paper 5 while forming (recording) a desired image while intermittently transporting it at a position facing the forming unit 2. The paper 5 is discharged onto a paper discharge tray 7 formed on the upper surface.

  The image forming apparatus also has an image reading unit (scanner) for reading an image above the discharge tray 7 above the apparatus main body 1 as an input system for image data (print data) formed by the image forming unit 2. Part) 11. The image reading unit 11 is configured to move a scanning optical system 15 including an illumination light source 13 and a mirror 14 and a scanning optical system 18 including mirrors 16 and 17 to move an image of an original placed on the contact glass 12. The scanned original image is read as an image signal by the image reading element 20 disposed behind the lens 19, and the read image signal is digitized and image-processed, and the image-processed print data can be printed. Note that a pressure plate 10 is provided on the contact glass 12 to hold the document.

  Furthermore, this image forming apparatus uses an information processing apparatus such as an external personal computer, an image reading apparatus such as an image scanner, and an imaging apparatus such as a digital camera as an input system for image data (print data) formed by the image forming unit 2. Print data including image data from the host side such as can be received via a cable or a network, and the received print data can be processed and printed.

  Here, as shown in FIG. 2, the image forming unit 2 of the image forming apparatus holds the carriage 23 movably in the main scanning direction by a carriage guide 21 and a guide stay (not shown), and is driven by a main scanning motor 27. It moves and scans in the main scanning direction via a timing belt 29 spanned between the pulley 28a and the driven pulley 28b.

  A recording head 24 including a droplet discharge head for discharging droplets of each color is mounted on the carriage 23, the carriage 23 is moved in the main scanning direction, and the sheet 5 is transferred to the sheet by the sub-scanning conveyance unit 3. A shuttle type is used in which droplets are ejected from the recording head 24 while feeding in the transport direction (sub-scanning direction) to form an image.

  The recording head 24 has two droplet discharge heads 24k1 and 24k2 that discharge black (Bk) ink, respectively, and one each that discharges cyan (C) ink, magenta (M) ink, and yellow (Y) ink. A total of five liquid droplet ejection heads (hereinafter simply referred to as “heads”), ie, liquid droplet ejection heads 24 c, 24 m, and 24 y, and each color ink is supplied from each sub tank 25 mounted on the carriage 23.

  On the other hand, as shown in FIG. 1, recording liquid containing black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink from the front of the apparatus main body 1 to the cartridge mounting portion 26A. Each color ink cartridge 26 can be detachably mounted as a cartridge, and ink is supplied from each color ink cartridge 26 to each color sub-tank 25. The black ink is supplied from one ink cartridge 26 to the two sub tanks 25.

  The recording head 24 uses a piezoelectric element as a pressure generating means (actuator means) for pressurizing the ink in the ink flow path (pressure generation chamber) to deform the vibration plate that forms the wall surface of the ink flow path. A so-called piezo type that discharges ink drops by changing the volume in the flow path, or a so-called discharge that discharges ink drops with a pressure generated by heating the ink in the ink flow path using a heating resistor to generate bubbles. The thermal type, the diaphragm that forms the wall surface of the ink flow path and the electrode are placed opposite to each other, and the diaphragm is deformed by the electrostatic force generated between the vibration plate and the electrode, thereby reducing the volume of the ink flow path. It is possible to use an electrostatic type that discharges ink droplets by changing.

  A maintenance / recovery device 121 including a head cleaning device for maintaining and recovering the state of the nozzles of the recording head 24 is disposed in a non-printing area on one side of the carriage 23 in the scanning direction. The maintenance / recovery device 121 includes five moisturizing caps 122k2, 122k1, 122c, 122m, and 122y for capping the nozzle surfaces of the five recording heads 24 (“moisturizing caps” when colors are not distinguished). 122 ”), a single suction cap 123, a wiper blade 124 for wiping the nozzle surface of the recording head 24, an idle discharge receptacle 125 for performing idle discharge, and the like.

  FIG. 3 is an enlarged explanatory view of an example of a sub-scanning conveyance unit provided in the apparatus shown in FIGS. The sub-scanning conveyance unit 3 includes a conveyance roller 32 and a tension roller that are driving rollers for conveying the paper 5 fed from below by facing the image forming unit 2 by changing the conveyance direction by approximately 90 degrees. An endless transport belt 31 spanned between the driven rollers 33, a charging roller 34 which is a charging means to which a high voltage as an alternating voltage is applied from a high voltage power source to charge the surface of the transport belt 31, and a transport A guide member 35 that guides the belt 31 in a region opposite to the image forming unit 2, a pressing roller (pressure roller) 36 that presses the paper 5 against the conveying belt 31 at a position facing the conveying roller 32, and the image forming unit 2. A separation claw 37 for separating the sheet 5 on which the image is formed from the conveyance belt 31 and a conveyance roller 38 for sending the separated sheet 5 to the paper discharge conveyance unit 6 are provided.

  The transport belt 31 of the sub-scan transport unit 3 is rotated in the paper transport direction (sub-scan direction) in FIG. 2 by rotating the transport roller 32 from the sub-scan motor 131 through the timing belt 132 and the timing roller 133. It is comprised so that it may do. The transport belt 31 includes, for example, a surface layer that is a sheet adsorption surface formed of a pure resin material that is not subjected to resistance control, such as ETFE pure material, and a back layer that is subjected to resistance control using carbon with the same material as the surface layer. A two-layer structure with (medium resistance layer, earth layer) can be employed.

  In addition, a cleaning unit (mylar is used here) 135 for removing paper dust and the like adhering to the surface of the conveyor belt 31 between the driven roller 33 and the charging roller 34, and the surface of the conveyor belt 31. And a static elimination brush 136 for removing electric charges.

  The paper feed unit 4 can be inserted into and removed from the apparatus main body 1, and a paper feed cassette 41 for stacking and storing a large number of papers 5 and a paper feed for separating and feeding the papers 5 in the paper feed cassette 41 one by one. A paper roller 42 and a friction pad 43, and a paper feed conveyance roller 44 that conveys the fed paper 5 to the sub-scanning conveyance unit 3 are provided. The paper feed roller 42 is rotated by a paper feed motor (drive source) 45 formed of an HB type stepping motor via a paper feed clutch (not shown), and the paper feed transport roller 44 is also rotationally driven by the paper feed motor 45.

  The paper discharge conveyance unit 6 includes a pair of paper discharge conveyance rollers 61 and 62 for conveying the paper 5 on which image formation has been performed, a paper discharge conveyance roller pair 63 and a paper discharge roller 64 for sending the paper 5 to the paper discharge tray 7. And.

  4 is a side sectional view showing an example of a unitized configuration of the sub-scanning conveyance unit 3 shown in FIGS. 1 and 3, that is, a recording paper conveyance device used in the illustrated ink jet printer, and FIG. FIG. 1 to 3 are denoted by common reference numerals. A part of the configuration shown in FIG. 3 is also omitted.

  The sub-scanning conveyance unit 3 constituting the electrostatic adsorption device is unitized so as to be detachable from the apparatus main body 1 of the ink jet printer. That is, a support member 82 (82A) attached to the side plate 81 is also wound around the conveyance belt 31, which is a member for charging a pair of rollers (driven roller 33 and conveyance roller 32) pivotally supported on the side plate 81 (only one is shown). 82B), a charging unit 83 that is mounted on one support member 82A and includes a charging roller 34 for charging the conveying belt 31, and the charging unit 83 is configured separately from the charging unit 83. It is comprised with the separation nail holding | maintenance unit 84 which was detachable with respect to.

  The separation claw holding unit 84 is attached to the charging unit 83 using the support member 82B on the driven roller 33 side, and is a plate-like shape that guides movement on the support member 82B when attached to the charging unit 83. A holding base 87 including a base portion 85 and a stopper portion 86 formed in a state of hanging downward at an end portion of the base portion 85 on the driven roller 33 side is provided, and is conveyed outside the driven roller 33 side of the base portion 85. A separation claw holding portion 88 including a plurality of separation claws 37 for separating the recording paper sucked and conveyed by the belt 31 from the conveyance belt 31 is provided.

  As shown in FIG. 6, the plate-like base portion 85 has a concave portion located below the driven roller 33 in a state where it is mounted on the charging unit 83, and the inclined surface is located on a portion located on the conveying roller 32 rather than the concave portion 89. A portion 90 is formed. The inclined surface portion 90 is formed so that the conveying roller 32 side is low and the driven roller 33 side is high, and a cleaning mylar 135 for cleaning the belt surface is attached to the inclined surface. Therefore, the cleaning mylar 135 moves to the conveyor belt 31 in the counter direction with respect to the rotation direction of the conveyor belt 31 (arrow X in the figure) and in the trailing direction with respect to the removal direction of the separation claw holding unit 84 (arrow Y in the figure). It will be in sliding contact. Needless to say, the cleaning efficiency is improved by the sliding contact of the cleaning mylar 135 with the conveying belt 31 in the counter direction.

  Further, a concave groove 91 is formed in a portion of the plate-like base portion 85 located on the conveying roller 32 relative to the inclined surface portion 90 described above, and a cleaning brush 92 for cleaning the surface of the conveying belt 31 is formed in that portion. Is provided. Further, a stepped portion 93 is formed so that a portion located on the transport roller 32 is lowered by one step, and a neutralizing brush 136 is disposed on the surface on the transport roller 32 side.

  Since the detailed configurations and operations of the cleaning mylar 135, the cleaning brush 92, and the static elimination brush 136 are well known, description thereof will be omitted. Of course, other forms may be adopted instead of the forms shown in the drawings.

  When the separation claw holding unit 84 is mounted on the support member 82B while sliding in the direction opposite to the arrow Y, the stopper portion 86 abuts against the end portion of the support member 82B so as not to go beyond a predetermined position. It becomes. That is, the structure of the separation claw holding unit 84 is separated according to function, and the efficiency of replacement described later is improved in accordance with the mounting shape.

  The separation claw holding portion 88 is an L-shaped portion for holding the separation claw 37, and is a plurality of pieces joined to the end of the base portion 85 so as to be positioned just outside the driven roller 33 in the removal direction (Y). In order to pivotally support the separation claw 37 in a rotatable manner, U-shaped grooves 94 that are open upward are formed at the upper end portions, and a shaft 95 provided at the lower end portion of the separation claw 37 is provided there. It is attached to.

  Further, a leaf spring 96 is connected to the shaft 95 of the separation claw 37, and the urging force resists an operation in which the separation claw 37 rotates toward the conveyance belt 31 by its own weight and attempts to contact the surface of the conveyance belt 31. In other words, it is designed to act as a back pressure. Such a shape of the separation claw 37 is an example, and as a biasing means for resisting the rotation, a coil spring or the like may be used instead of a leaf spring, but in any case, the separation claw It is possible to extend the life of the conveyance belt 31 by allowing the recording paper 37 to rotate toward the conveyance belt 31 by its own weight and apply little or no pressure to the conveyance belt 31 so that the recording paper can be peeled off. Preferred above.

  In order to remove the separation claw holding unit 84 from the image forming apparatus such as the ink jet recording apparatus, the unit including the discharge roller 38 or the like is removed or removed so as not to get in the way, and the base of the separation claw holding unit 84 is removed. The part 85 is pulled out in the direction of arrow Y in the figure while sliding on the support member 82B. Of course, if the separation claw holding unit 84 is screwed to the support member 82B, it is after the removal.

  When the separation claw holding unit 84 is removed, the conveyor belt 31 can be easily and easily replaced by removing the minimum necessary members. Further, by attaching consumables such as the cleaning mylar 135 provided on the base plate 85 to the holding unit of the separation claw, it is possible to easily replace them without removing the belt. Of course, not only the cleaning mylar 135 but also each consumable can be replaced independently, and only necessary members can be replaced to eliminate waste. In order to attach the separation claw holding unit 84, an operation reverse to the above is performed.

  In the illustrated example, the driven roller 33 is smaller in diameter than the conveying roller 32, and the conveying belt 31 is positioned lower on the conveying roller 32 side than on the driven roller 33 side. It is designed to be diagonal. Therefore, as shown in FIG. 7, the distance between the proximal end of the cleaning mylar 135 and the conveyor belt 31 is such that the distance A at the mounting position is lower than the distance B immediately before the separation claw holding unit 84 is removed. The positional relationship can be set to be slightly smaller (A <B) by the amount of inclination. With this configuration, the tip of the cleaning mylar 135 that is in sliding contact with the conveyance belt 31 in the counter direction can be prevented from being bent due to contact with the conveyance belt 31 when the separation claw holding unit 84 is removed. As a comparative example, FIG. 8 shows a case where the driven roller 33 and the conveying roller 32 have the same diameter, and the conveying belt 31 is horizontal in both the upper and lower circumferences. With such a setting, the distances A and B are the same distance (A = B) between the proximal end of the cleaning mylar 135 and the conveyance belt 31. For this reason, the cleaning mylar 135 and the lower surface of the conveyor belt 31 are kept at the same distance until the separation claw holding unit 84 is completely removed, and therefore the same frictional force is continuously applied. It becomes easier to bend.

  In addition, since the driven roller 33 has a smaller diameter than the conveying roller 32, the conveying belt 31 is horizontal in the upper side rotation state, and is inclined at the lower side rotation so as to be inclined below the driven roller 33. A space for mounting the separation claw holding unit 84 is created. Therefore, the positional relationship between the conveyance belt 31 and the separation claw holding unit 84 is simple and simple as in the illustrated example.

1 is a diagram conceptually illustrating a configuration of an inkjet printer that is an example of an image forming apparatus that is an object of the present invention. Plan view of image forming unit and sub-scanning conveying unit of same apparatus 1 and 2 are enlarged explanatory views of an example of a sub-scanning conveyance unit provided in the apparatus shown in FIGS. Side surface sectional view showing a unitized configuration example of a recording paper conveyance device such as the sub-scanning conveyance unit shown in FIGS. 1 and 3 Perspective view of the main part Also enlarged side view The figure which shows the example of the distance from the base end of a cleaning mylar to the conveyance belt which is a charging belt The figure which shows the other example of the distance from the base end of a cleaning mylar to a conveyance belt

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Image formation part 3 Sub-scanning conveyance part 4 Paper feed part 5 Recording medium 6 Paper discharge conveyance part 7 Paper discharge tray 10 Pressure plate 11 Image reading part (scanner part)
DESCRIPTION OF SYMBOLS 12 Contact glass 13 Illumination light source 14, 16, 17 Mirror 15, 18 Scan optical system 19 Lens 21 Carriage guide 23 Carriage 24 Recording head 25 Sub tank 26 Ink cartridge 27 Main scanning motor 28a Drive pulley 28b Driven pulley 29 Timing belt 31 Conveyor belt 32 Conveying roller 33 Followed roller 34 Charging roller 35 Guide member 36 Pressure roller 37 Separation claw 38 Conveying roller 41 Paper feeding cassette 42 Paper feeding roller 43 Friction pad 44 Paper feeding conveying roller 45 Paper feeding motor (drive source)
61, 62 Paper discharge roller pair 63 Paper discharge roller pair 64 Paper discharge roller 81 Side plate 82 (82A, 82B) Support member 83 Charging unit 84 Separating claw holding unit 85 Base portion 86 Stopper portion 87 Holding base 88 Separating claw holding portion 89 concave portion 90 slope portion 91 concave groove 92 cleaning brush 93 stepped portion 94 groove 95 shaft 96 leaf spring 121 maintenance recovery device 122 moisturizing cap 123 suction cap 124 wiper blade 125 idle discharge receiver 131 sub-scanning motor 132 timing belt 133 timing Roller 135 Cleaning mylar 136 Static neutralization brush A, B Distance between cleaning mylar and charging belt X Direction of rotation of charging belt Y Removal direction of separation claw holding unit

Claims (6)

In an electrostatic attraction apparatus for adsorbing and transporting a recording medium by applying an electric field to the surface of the belt member by charging means while rotating an endless belt member, the electrostatic chucking apparatus includes a separation claw holding unit separate from the charging means. The separation claw holding unit has a consumable part other than the separation claw, and the separation claw holding unit is attached by the electrostatic adsorption device main body when attached to the electrostatic adsorption device main body having the charging means. A holding base comprising a first plate-like portion guided for movement for movement and a second plate-like portion serving also as a stopper for moving the plate-like portion to the electrostatic attraction apparatus body, The consumable part is provided with the consumable part in a first plate-like portion, and the consumable part is a cleaning mylar that cleans the surface of the belt, and the cleaning mylar is countered with respect to the rotation direction of the belt In and electrostatic chuck according to claim Rukoto is sliding in the trailing direction with respect to the mounting direction of the separation pawl holding unit. In electrostatic chuck according to claim 1, electrostatic chuck according to claim Rukoto comprises removably said consumable part from said separation pawl holding unit. 2. The electrostatic chuck according to claim 1 , wherein the cleaning mylar has a distance A to the belt at a position where the separation claw holding unit is attached to the electrostatic chuck main body, and the separation claw holding unit is when the distance to the belt at a position immediately before removing from the electrostatic chuck main body and B, B> and wherein said belt and a set positional relationship of the separating pawl holding unit Rukoto such that a Electrostatic adsorption device. The electrostatic attraction apparatus according to any one of claims 1 to 3, wherein a diameter of a roller located on a side of the separation claw holding unit among a pair of rollers around which the belt is wound is made smaller than other roller diameters. Electrostatic adsorption device. In electrostatic chuck according to claim 4, wherein a position roller tension roller to the separation pawl holding unit side, an electrostatic adsorption system the other roller is characterized Oh Rukoto the drive roller. An image forming apparatus using the electrostatic attraction apparatus according to claim 1 .