JP2007031000A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To flexibly meet a user's requirement for the alignment accuracy of a resist roll. <P>SOLUTION: The image forming device is provided with a resist roll for feeding paper to an image transferring part; an adjustment member 39 for adjusting inclination of the resist roll; and a unit body 26 mounted with the adjustment member 39. The adjustment member 39 has first mounting means (54, 55, 57) for mounting the adjustment member 39 to a unit body 26 in the state that inclination of the resist roll can be adjusted; and second mounting means (58, 59, 60, 61) for mounting the adjustment member 39 to the unit body 26 in the state that inclination of the resist roll is unnecessary to be adjusted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer.

  2. Description of the Related Art Image forming apparatuses such as copying machines and printers incorporate a paper conveyance device that conveys a sheet to be subjected to image formation along a paper conveyance path. A plurality of transport rolls are disposed on the paper transport path. Each transport roll is rotationally driven using a motor or the like as a drive source, and the paper is transported from the upstream side to the downstream side in the transport direction according to the rotation of the transport roll.

  In an image forming apparatus provided with such a paper transport device, if a paper skew or misalignment occurs during paper transport, the image is formed in a state of being shifted from the paper. Therefore, for example, in Patent Document 1 described below, the pre-regist roll is used to form a sheet of paper by disposing the rotation axis of the pre-regist roll disposed at a position immediately before the resist roll (upstream in the transport direction) at a predetermined angle. Is disclosed, and the side edge of the paper is aligned with a desired position when the paper reaches the registration roll.

Japanese Patent Laid-Open No. 10-147455

  However, the positional accuracy of the image finally formed on the paper depends on the alignment accuracy of the resist roll with respect to the image carrier that carries the image before transfer. For this reason, even if the position of the side edge of the sheet is adjusted by the pre-registration roll before the registration roll, if the alignment accuracy of the registration roll with respect to the image carrier is incorrect, the image is formed on the sheet in a shifted state.

  For this reason, some conventional image forming apparatuses have a resist roll alignment adjustment function. The registration roll alignment adjustment function refers to a function of adjusting the inclination of the registration roll in the paper transport direction. The alignment accuracy of the resist roll with respect to the image carrier is the relative positional accuracy between the image carrier and the resist roll. For example, if the image carrier is a photosensitive drum, the rotation axis of the photosensitive drum And the degree of parallelism of the rotation axis of the resist roll.

  Such an alignment adjustment function is provided in high-end models and some middle range models that require high image quality, but not in low-end models. This is mainly due to cost reasons. That is, in a model equipped with an alignment adjustment function, the manufacturing cost increases because an extra man-hour for alignment adjustment is required in the manufacturing process of the image forming apparatus. On the other hand, in models that do not have an alignment adjustment function, the alignment accuracy of the resist roll is assured with the dimensional accuracy and assembly accuracy of the components (hereinafter also referred to as “component accuracy”). It does not take work man hours for.

  However, even a user who uses a low-end model may require high alignment accuracy. In such a case, the conventional image forming apparatus could not satisfy the user's request other than replacement with a high-end model or a middle range model equipped with an alignment adjustment function.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of flexibly responding to a user's request for alignment accuracy of a resist roll.

  An image forming apparatus according to the present invention includes a registration roll that feeds a sheet to an image transfer unit, an adjustment member that adjusts the inclination of the registration roll in a direction along the conveyance direction of the sheet, and a target to which the adjustment member is attached. The adjustment member adjusts the inclination of the registration roll and the first attachment means for attaching the adjustment member to the attached member in a state where the inclination of the registration roll can be adjusted. And a second attachment means for attaching the adjustment member to the attachment member in an unnecessary state.

  In the image forming apparatus according to the present invention, when adjusting the inclination of the registration roll, the first attachment means is used to attach the adjustment member to the attached member, and when the inclination of the registration roll is not adjusted, By using the attachment means 2 to attach the adjustment member to the attached member, the adjustment member can be used properly.

  According to the image forming apparatus of the present invention, the adjustment member can be used properly depending on whether or not the inclination of the registration roll is adjusted. That is, when adjusting the inclination of the resist roll, high alignment accuracy can be ensured by attaching the adjustment member using the first attachment means. Further, when the inclination of the resist roll is not adjusted, the alignment accuracy can be guaranteed with the component accuracy by attaching the adjustment member using the second attachment means. For this reason, it becomes possible to respond flexibly to the user's request for the alignment accuracy of the resist roll.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing a configuration example of an image forming apparatus to which the present invention is applied. The illustrated image forming apparatus includes a sheet conveying device. The paper transport device includes two paper storage trays 1 and 2 and transports the paper stored in each of the paper storage trays 1 and 2 along the paper transport path. The sheet conveyance path is formed so as to pass through an image transfer section described later. The paper storage trays 1 and 2 each store a predetermined number of paper sheets, and are arranged in two upper and lower stages. Each of the paper storage trays 1 and 2 basically has the same configuration although the size of the entire tray differs depending on the size and type of paper to be stored.

  Further, in the vicinity of the paper storage tray 1 arranged on the upper side, a calling roll 3 and a delivery roll 4 are arranged as paper feeding rolls. The calling roll 3 calls a sheet from the sheet storage tray 1 by rotating in contact with the uppermost surface of the sheet stored in the sheet storage tray 1. The delivery roll 4 separates and feeds the sheets called by the calling roll 3 one by one, and is a pair of rolls in which one (upper) roll is used for paper conveyance and the other (lower) roll is used for separation. It is configured. Similarly, in the vicinity of the sheet storage tray 2 disposed on the lower side, a call roll 5 and a delivery roll 6 are also disposed as sheet feeding rolls.

  A plurality of (four in the illustrated example) transport rolls 7, 8, 9, and 10 are provided at predetermined intervals on the paper transport path to which the paper fed from the respective paper storage trays 1 and 2 is sent. It has been. Each of the transport rolls 7, 8, 9, and 10 transports the paper downstream in the transport direction by rotating the paper while nipping (nipping) the paper. Among the plurality of transport rolls 7, 8, 9, and 10, the transport roll 10 disposed on the most downstream side is a resist roll, and transport disposed on the front side (upstream side in the transport direction) of the resist roll. Roll 9 is a pre-resist roll. Therefore, in the following description, the conveyance roll 10 is referred to as a resist roll 10 and the conveyance roll 9 is referred to as a pre-registration roll 10.

  The registration roll 10 feeds a sheet to be image-formed to an image transfer unit (described later) at a predetermined timing and aligns the sheet at the time of feeding. The registration roll 10 is disposed in front of the image transfer unit (upstream side) in the sheet conveyance direction. The registration of the sheet by the registration roll 10 is performed by correcting the skew by abutting the leading edge of the sheet against the registration roll 10, or adjusting the sheet conveyance start timing (rotation start timing of the registration roll 10) after the skew correction. Is done.

  A photosensitive drum 11 and a vacuum transport unit 12 are disposed at the paper destination of the registration roll 10. The photosensitive drum 11 is rotationally driven in the counterclockwise direction in the figure. Around the photosensitive drum 11, as a means for forming an image (toner image) to be transferred onto a sheet, for example, a charger (not shown) for uniformly charging the surface of the photosensitive drum 11, and this An image writing device (not shown) for writing an electrostatic latent image by irradiating the surface of the photosensitive drum 11 charged by the charger with a laser beam, and a photosensitive drum on which the electrostatic latent image is written by the image writing device. A developing device (not shown) for supplying toner to the surface of the paper 11, a transfer roll 13 for transferring the toner image developed by the developing device to the paper, and the surface of the photosensitive drum 11 without being transferred to the paper. A cleaner (not shown) for removing the remaining unnecessary toner and a static eliminator (not shown) for discharging the surface of the photosensitive drum 11 are sequentially arranged in the rotation direction of the photosensitive drum 11.

  The vacuum transport unit 12 includes an endless transport belt 14 and two rolls 15 and 16 that support the transport belt 14. In the vacuum transport unit 12, the paper fed by the registration roll 10 is placed on the transport belt 14, and the back surface of the paper (the surface opposite to the surface on which the image is transferred) is vacuumed on the transport belt 14. The sheet is conveyed in the direction of the arrow (rightward) as the conveying belt 14 travels as the belt supporting roll 15 (or 16) rotates while adsorbing.

  The transfer roll 13 is disposed at a position facing the photosensitive drum 11 via the conveyance belt 14 of the vacuum conveyance unit 12. Accordingly, the sheet conveyed by the vacuum conveying unit 12 passes through the opposite part of the photosensitive drum 11 and the transfer roll 13 during conveyance, and the image is transferred from the photosensitive drum 11 to the sheet at the opposite part. Therefore, the facing portion between the photosensitive drum 11 and the transfer roll 13 corresponds to the image transfer portion.

  A fixing device 17 is disposed at the destination of the sheet transported by the vacuum transport unit 12. The fixing device 17 fixes the image (toner image) transferred to the paper by the image transfer unit on the paper surface. The fixing device 17 has a fixing roll for heating and pressing, and fixes an image (toner) on the sheet by heating and pressing when the sheet is conveyed while being nipped by the fixing roll. Further, a discharge roll (not shown) is provided on the downstream side of the fixing device 17, and the paper is discharged to a discharge tray (not shown) by the discharge roll.

  In addition, a plurality of (seven in the illustrated example) paper detection sensors (paper) are detected on the paper conveyance path including the paper feeding portion in order to detect the occurrence of the jam when the paper is conveyed. Detection means) 18 to 24 are provided. Each of the paper detection sensors 18 to 24 is arranged at a different position in the paper transport direction. That is, the paper detection sensor 18 is disposed in the vicinity (downstream side) of the feed roll 4 provided in the paper feeding unit of the upper paper storage tray 1, and the paper detection sensor 19 is supplied to the lower paper storage tray 2. It is arranged in the vicinity (downstream side) of the feed roll 6 provided in the paper section. The paper detection sensor 20 is disposed in the vicinity (downstream side) of the transport roll 7 disposed on the most upstream side in the transport direction, and the paper detection sensor 21 is in the vicinity of the transport roll 8 on the downstream side of the transport roll 7 ( The sheet detection sensor 22 is disposed in the vicinity (downstream side) of the pre-registration roll 9 on the further downstream side than the transport roll 8. The paper detection sensor 23 is disposed in the vicinity (upstream side) of the registration roll 10, and the paper detection sensor 24 is disposed in the vicinity (downstream side) of the fixing device 17.

  Each of the paper detection sensors 18 to 24 is composed of, for example, a reflective photosensor in which a light emitting element and a light receiving element are arranged on the same sensor surface, and a position facing the sensor surface in the vicinity (hereinafter referred to as a sensor detection position). When a sheet is present, the printer is turned on, and when not present, the printer is turned off. Therefore, each of the paper detection sensors 18 to 24 switches from the off state to the on state when the leading edge of the paper passes through the sensor detection position, and then when the trailing edge of the paper passes through the sensor detection position. Switch from on to off. Accordingly, it is possible to detect the passage of the paper (passing through the leading edge and passing through the trailing edge) based on the on / off state of each of the paper detection sensors 18 to 24.

  Next, the operation of the image forming apparatus having the above configuration will be described. First, assuming that the paper storage tray selected by the user input operation or the automatic tray selection function is the upper paper storage tray 1, for example, the rotation of the calling roll 3 and the feed roll 4 corresponding to the paper storage tray 1 The sheets stored in the sheet storage tray 1 are separated and sent out one by one in order from the top.

  The paper thus sent out from the paper storage tray 1 to the paper transport path is then transported to the downstream side in the transport direction (upper side in FIG. 1) by the rotation of the transport roll 8 and sent to the pre-registration roll 9. Next, the sheet is fed into the registration roll 10 according to the rotation of the pre-registration roll 9. The rotation of the registration roll 10 is stopped before the paper is fed by the pre-registration roll 9. For this reason, the leading edge of the sheet fed by the pre-registration roll 9 comes into contact with the nip portion of the registration roll 10 in a rotation stopped state. Further, by feeding a predetermined amount of paper by the pre-registration roll 9 in this abutting state, the paper is bent in a loop shape before the registration roll 10, that is, the paper skew is corrected, and this state Press to pause the paper.

  Thereafter, the resist roll driving clutch is turned on in accordance with the timing at which the electrostatic latent image written on the surface of the photosensitive drum 11 by the image writing device (not shown) is developed into a toner image and sent to the image transfer unit. As a result, the rotation of the resist roll 10 is started. As a result, the sheet whose skew has been corrected as described above is sent to the image transfer unit according to the rotation of the registration roll 10. In the image transfer unit, the sheet fed by the registration roll 10 is placed on the conveyance belt 14 of the vacuum conveyance unit 12, and the image transfer unit (transferred to the photosensitive drum 11 and the transfer drum 14) by the traveling of the conveyance belt 14. It moves so as to pass through a portion facing the roll 13). At this time, the toner image arrives at the image transfer portion in accordance with the timing when the leading edge of the paper reaches the image transfer portion, and the transfer roll 13 imparts a charge having a polarity opposite to that of the toner, whereby the surface of the photosensitive drum 11 is exposed. The toner image is transferred to the paper.

  Thereafter, the sheet is sent to the fixing device 17 by the vacuum conveyance unit 12, and the image is fixed on the sheet surface of the sheet by a pressurizing action and a heating action applied between the fixing rolls. Next, the sheet fed from the fixing device 17 is transferred to a discharge roll (not shown), and is discharged to a discharge tray (not shown) by this discharge roll. Although the case where an image is formed on one side of a sheet has been described here, the present invention can be similarly applied to an image forming apparatus provided with a “double-sided printing function” that forms an image on both sides of a sheet.

  In the operation of the apparatus described above, since the skew of the paper is corrected by abutting the leading edge of the paper fed by the pre-registration roll 9 against the nip portion of the registration roll 10, the posture of the paper after the skew correction is the inclination of the registration roll 10. It depends on. In addition, the paper whose skew has been corrected by being abutted against the registration roll 10 is then sent to the image transfer unit in a direction corresponding to the inclination of the registration roll 10. Therefore, the inclination of the registration roll 10 is an important factor for determining the relative positional relationship between the paper and the image. Therefore, the image forming apparatus according to the embodiment of the present invention includes an adjustment member for adjusting the inclination of the registration roll 10 in the Y direction along the sheet conveyance direction.

  Incidentally, the inclination of the registration roll 10 described here refers to the inclination of the rotation axis of the registration roll 10 with respect to a virtual straight line orthogonal to the paper conveyance direction on the paper conveyance path in the vicinity of the nip position of the registration roll 10. For this reason, the inclination of the registration roll 10 is such that both ends of the rotation axis of the registration roll 10 are moved in opposite directions along the conveying direction, or only one end of the rotation axis of the registration roll 10 is not moved. Can be adjusted by moving in the conveying direction. In the present embodiment, the latter method is adopted, but the former method can also be adopted.

  FIG. 2 is a perspective view showing an entire image of the paper transport unit including the registration roll 10 and the adjustment member, and FIG. 3 is a perspective view showing a state in which some components are removed from the paper transport unit. The illustrated paper conveyance unit 25 is attached to a main body frame (not shown) of the image forming apparatus, and mainly includes a registration roll 10, a unit main body 26, a paper conveyance guide 27, a drive transmission unit 28, and an inclination adjustment. The configuration includes a portion 29 and a driven side holding member 30.

  The resist roll 10 includes a drive roll 10A and a driven roll 10B. A plurality (six in the example) of driving rolls 10A are attached to a rotating shaft (not shown) at a predetermined interval. A plurality (six in the example) of the driven rolls 10B are attached to the rotation shaft 31 parallel to the rotation shaft of the drive roll 10A at the same interval as the drive roll 10A. Both end portions of the rotating shaft 31 of the driven roll 10B are positioned and supported by a pair of left and right bearing portions 32 formed integrally with the unit body 26. Each bearing portion 32 is formed with a substantially U-shaped groove 33 into which the end of the rotating shaft 31 can be fitted and removed.

  The unit body 26 is made of, for example, resin, and corresponds to the attached member in the present invention. In addition to the pair of left and right bearing portions 32 described above, the unit main body 26 integrally includes a sheet take-in guide 34. The unit body 26 supports the rotation shaft of the drive roll 10A described above. And the drive transmission part 28 is provided in the one end side of the rotating shaft of 10 A of drive rolls, and the inclination adjustment part 29 is provided in the other end side.

  The paper transport guide 27 guides the transport direction of the paper taken along the paper take-in guide 34 of the unit main body 29. The paper transport guide 27 is made of, for example, a metal plate (sheet metal), and is fixed to the unit body 26 with screws 35. Further, the paper transport guide 27 is formed with a plurality of openings 36 along the rotation axis of the drive roll 10 </ b> A, and one drive roll 10 </ b> A is disposed in each of the openings 36.

  The drive transmission unit 28 is configured using an input gear 37 and a clutch member 38. The input gear 37 is disposed so as to mesh with a gear that rotates using a conveyance motor (not shown) as a drive source. The clutch member 38 intermittently transmits driving force between the rotating shaft of the driving roll 10 </ b> A and the input gear 37.

  The inclination adjusting unit 29 is a part that adjusts the inclination of the resist roll 10 described above. The inclination adjusting unit 29 is formed integrally with the unit main body 26 at one side end of the unit main body 26. An adjustment member 39 for adjusting the inclination is attached to the inclination adjusting unit 29. The adjustment member 39 is made of, for example, resin, and is attached to the side end portion of the unit main body 26 using two screws 40 and 41.

  The driven side holding member 30 holds the driven roll 10 </ b> B and its rotating shaft 31. The driven side holding member 30 is made of, for example, a metal plate, and forms a paper transport path with the paper transport guide 27 described above, and guides the transport direction of the paper along the paper transport path. Further, the driven side holding member 30 is formed with a plurality of openings 42 in the same positional relationship as the paper conveyance guide 27, and the driving roll 10 </ b> A and the driven roll 10 </ b> B are pressed by the pinch spring 43 through the openings 42. It comes to be pressed with. The spring pressure of the pinch spring 43 acts as a biasing force that draws the rotating shaft 31 of the driven roll 10B toward the rotating shaft side of the drive roll 10A, and acts on the rotating shaft of the driven roll 10B.

  The left and right end portions of the driven side holding member 30 are pressed toward the unit body 26 by a pair of coil springs 44. The pair of coil springs 44 elastically holds the position of the driven side holding member 30 with respect to the unit body 26 using the spring pressure. Therefore, when the direction of the unit main body 26 is changed, the direction of the driven side holding member 30 is also changed following the change.

  FIG. 4 is a perspective view showing a state in which the adjustment member 39 is removed from the inclination adjustment unit 29 of the paper transport unit 25. As shown in the figure, the tilt adjusting portion 29 is provided with two screw holes 46 and 47 for attaching the adjusting member 39 and two guides 48 and 49 engaged with the adjusting member 39. Among these, the two screw holes 46 and 47 are formed to fix the adjusting member 39 by screwing. Each of the two guide pins 48 and 49 has a round pin structure with a circular cross section and a tapered tip, and is provided so as to protrude outward from the surface to which the adjustment member 39 is attached. Yes.

  4 is formed in the unit main body 26 in order to attach the paper transport guide 27 to the unit main body 26. The screw hole 50 shown in FIG. Therefore, the screw 35 described above is screwed into the screw hole 50. The positioning pin 51 is provided on the unit main body 26 in order to position the paper transport guide 27 with respect to the unit main body 26.

  5A and 5B are perspective views of the adjustment member 39 attached to the inclination adjustment unit 29 as seen from different directions. The adjustment member 39 has a structure in which a plate-like base portion 52 and a protruding portion 53 protruding from one surface of the base portion 52 are integrally formed. A reference position for attaching the adjustment member 39 without adjustment is set in the inclination adjustment unit 29. And in the state which attached the adjustment member 39 according to this reference position, it has the structure by which the protrusion part 53 is arrange | positioned substantially coaxially with the rotating shaft of 10 A of drive rolls.

  The protrusion 53 is formed in a substantially cylindrical shape, and is engaged and supported by the main body frame when the paper transport unit 25 is attached to the main body frame of an image forming apparatus (not shown). Accordingly, when the attachment position of the adjustment member 39 is shifted along the conveyance direction by the inclination adjustment unit 26, the inclination of the registration roll 10 when the paper conveyance unit 25 is attached to the main body frame is attached to the adjustment member 39. It changes according to the position shift.

  In the base portion 52, two attachment holes 54 and 55, one guide groove 56, and one guide hole 57 are formed as first attachment means. Among these, the two attachment holes 54 and 55 are formed in a long hole shape. Further, the guide groove 56 and the guide hole 57 are formed on the same straight line passing through the center of the protruding portion 53 in a positional relationship sandwiching the protruding portion 53 described above. The guide groove 56 is formed in a long groove shape, and the guide hole 57 is formed in a long hole shape. Further, the mounting holes 54 and 55, the guide groove 56 and the guide hole 57 are formed in directions parallel to each other.

  The base portion 52 is formed with two attachment holes 58 and 59 and two positioning holes 60 and 61 as second attachment means. Of these, the two attachment holes 58 and 59 are each formed in a circular shape. In addition, the positioning holes 60 and 61 are formed on the same straight line passing through the center of the protruding portion 53 in a positional relationship sandwiching the protruding portion 53 described above. However, the positions of the positioning holes 60 and 61 and the positions of the guide groove 56 and the guide hole 57 described above are set at different positions in the rotation direction around the protruding portion 53. One positioning hole 60 is formed in a circular shape, and the other positioning hole 61 is formed in a long hole shape. The interval between the attachment holes 58 and 59 is set to the same interval as that of the screw holes 46 and 47 described above. The positioning hole 60 is disposed on the extended line of the long axis of the positioning hole 61.

  FIG. 6 is a view showing a state in which the adjustment member 39 is attached to the inclination adjustment unit 29 using the first attachment means. In the drawing, the screw hole 46 is disposed in the hole of the attachment hole 54, and the screw hole 47 is disposed in the hole of the attachment hole 55. A guide pin 48 (not shown) is engaged with a guide groove 56 (not shown), and a guide pin 49 is engaged with a guide hole 57. In this state, the screw hole 46 is an intermediate portion in the longitudinal direction of the attachment hole 54, the screw hole 47 is an intermediate portion in the longitudinal direction of the attachment hole 55, a guide pin 48 (not shown) is an intermediate portion in the longitudinal direction of the guide groove 56 (not shown), A guide pin 49 is disposed in the middle portion of the guide hole 57 in the longitudinal direction. Further, the protruding portion 53 of the adjustment member 39 is disposed substantially coaxially with the rotation shaft of the drive roll 10A.

  When the adjustment member 39 is attached using the first attachment means as described above, the adjustment member 39 is adjusted by the engagement between the guide pin 48 and the guide groove 56 and the engagement between the guide pin 49 and the guide hole 57. The member 39 is supported movably in a predetermined direction (longitudinal direction of the guide groove 56 and the guide hole 57). Therefore, as shown in FIG. 8A, the attachment position of the adjustment member 39 is shifted in the Y1 direction, and as shown in FIG. 8B, the attachment position of the adjustment member 39 is changed in the Y2 direction (Y1 direction). In the opposite direction). At this time, if the attachment position of the adjustment member 39 is shifted in the Y1 direction or the Y2 direction, the relative positional relationship between the paper transport unit 25 and the apparatus frame changes accordingly, and the inclination of the registration roll 10 is as shown in FIG. It changes in the Y direction.

  Therefore, when the adjustment member 39 is attached using the first attachment means, the adjustment member 39 is attached in a state where the inclination of the registration roll 10 can be adjusted. In addition, the adjustment member 39 that has been tilt-adjusted is obtained by screwing and tightening the screws 40 and 41 into the screw holes 46 and 47, respectively, in a state where the attachment position of the adjustment member 39 is appropriately shifted in the Y1 direction and the Y2 direction. Can be fixed to the inclination adjusting unit 29.

  FIG. 7 is a view showing a state in which the adjustment member 39 is attached to the inclination adjustment unit 29 using the second attachment means. In the drawing, the screw hole 46 is arranged in the hole of the attachment hole 58, and the screw hole 47 is arranged in the hole of the attachment hole 59. The guide pin 48 is engaged with the attachment hole 60, and the guide pin 49 is engaged with the attachment hole 61. In this state, the screw hole 46 is arranged concentrically with the attachment hole 58, and the screw hole 47 is also arranged concentrically with the attachment hole 59. Further, the guide pin 48 engages with the positioning hole 60 with almost no gap, and the guide pin 49 is disposed at the middle portion of the positioning hole 61 in the longitudinal direction. Further, the protruding portion 39 of the adjustment member 39 is disposed substantially coaxially with the rotation shaft of the drive roll 10A.

  Thus, when the adjustment member 39 is attached using the second attachment means, the adjustment pin 39 is engaged by the engagement between the guide pin 48 and the positioning hole 60 and the engagement between the guide pin 49 and the positioning hole 61. The attachment position of the member 39 is uniquely determined. That is, the adjustment member 39 is positioned at the reference position by the engagement thereof. For this reason, the inclination of the resist roll 10 depends on the component accuracy of the unit main body 26 and the adjustment member 39. Therefore, the alignment accuracy of the resist roll 10 is guaranteed by the component accuracy.

  Therefore, when the adjustment member 39 is attached using the second attachment means, the adjustment member 39 is attached in a state where the inclination of the registration roll 10 is not required to be adjusted. In addition, the adjusting member 39 positioned as described above can be fixed to the tilt adjusting portion 29 by screwing and tightening the screws 40 and 41 into the screw holes 46 and 47, respectively.

  As described above, in the image forming apparatus according to the embodiment of the present invention, the inclination adjusting portion 29 of the unit body 26 is used by using the mounting holes 54 and 55, the guide groove 56 and the guide hole 57 serving as the first mounting means. By attaching the adjusting member 39, the alignment accuracy of the resist roll 10 can be ensured with high accuracy by adjusting the inclination of the resist roll 10.

  Further, the inclination of the registration roll 29 is adjusted by attaching the adjustment member 39 to the inclination adjustment portion 29 of the unit body 26 using the attachment holes 58 and 59 and the positioning holes 60 and 61 as the second attachment means. Even if it does not do, the alignment accuracy of the resist roll 10 can be ensured with the component accuracy. That is, the adjustment member 39 can be used properly depending on whether the tilt adjustment of the registration roll 10 is unnecessary or not.

  Therefore, for example, for the quality requirements of users who use high-end models and some middle-range models that require high image quality, the adjustment member 39 is attached using the first attachment means, and the registration roll By performing the tilt adjustment of 10, it becomes possible to appropriately respond to the user's request.

  Further, in response to a low price requirement of a user who uses the low-end model, the adjustment member 39 is attached using the second attachment means so that the adjustment of the inclination of the registration roll 10 is not required, thereby requesting the user's request. It is possible to respond appropriately.

  Further, in response to a user's request for high image quality using the low-end model, the adjustment member 39 is attached using the first attachment means before the product shipment or after the product shipment to adjust the inclination of the resist roll 10. Thus, it becomes possible to appropriately respond to the user's request.

  In the above embodiment, the inclination of the registration roll 10 is adjusted in the direction Y along the paper transport direction. However, the present invention is not limited to this, and for example, a direction orthogonal to the paper transport direction (FIG. 1). The same applies to the case where the inclination of the registration roll 10 is adjusted in the vertical direction. However, in correcting the position and orientation of the sheet toward the image transfer unit, it is effective to adjust the inclination of the registration roll 10 in the direction Y along the sheet conveyance direction.

1 is a schematic diagram illustrating a configuration example of an image forming apparatus to which the present invention is applied. It is a perspective view which shows the whole image of the paper conveyance unit containing a registration roll and the member for adjustment. FIG. 6 is a perspective view illustrating a state in which some components are removed from the paper transport unit. FIG. 10 is a perspective view illustrating a state in which an adjustment member is removed from an inclination adjustment unit of the paper transport unit. It is a perspective view of the member for adjustment attached to an inclination adjustment part. It is a figure which shows the attachment state of the member for adjustment using a 1st attachment means. It is a figure which shows the attachment state of the member for adjustment using a 2nd attachment means. It is a figure explaining the member moving direction at the time of adjusting the inclination of a registration roll using the member for adjustment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Registration roll, 11 ... Photoconductor drum, 13 ... Transfer roll, 25 ... Paper conveyance unit, 26 ... Unit main body, 29 ... Inclination adjustment part, 39 ... Adjustment member, 46, 47 ... Screw hole, 48, 49 ... Guide pin 52 ... Base part 53 ... Projection part 54, 55, 58, 59 ... Mounting hole, 56 ... Guide groove, 57 ... Guide hole, 60, 61 ... Positioning hole

Claims (3)

An image forming apparatus comprising: a registration roll that feeds paper to an image transfer unit; an adjustment member for adjusting the inclination of the registration roll; and a mounted member to which the adjustment member is attached;
The adjustment member includes a first attachment means for attaching the adjustment member to the attached member in a state where the inclination of the registration roll can be adjusted, and the adjustment in a state where adjustment of the inclination of the registration roll is unnecessary. An image forming apparatus comprising: a second attaching means for attaching a member for attachment to the attached member. The first attachment means includes means for supporting the adjustment member movably in a predetermined direction;
The image forming apparatus according to claim 1, wherein the second attachment unit includes a unit that positions the adjustment member at a reference position. The image forming apparatus according to claim 1, wherein the adjustment member is for adjusting an inclination of the registration roll in a direction along a sheet conveyance direction.

Images