JP5896283B2 - Sheet conveying apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus and an image forming apparatus such as a copying machine, a printer, and a facsimile machine including the sheet conveying apparatus.

  In recent years, printers that are image forming apparatuses, particularly low-end printers, are required to be reduced in size. However, since the sheet conveying device cannot be made smaller than the size of the sheet, it meets the demand within a limited range such as optimization of the support structure in the device and omission of parts by optimizing the function. Yes.

  As part of optimizing this support structure, there is a technique for simplifying the shaft support structure of a rotating member such as a registration roller disposed in a sheet conveying apparatus. In Patent Document 1, in order to simplify the structure of the shaft support portion of the rotating member, the bearing member attached to the drive roller is fitted into the support member in which a part of the notch is formed, and the shaft is not provided with a component such as a retaining ring. A technique for directional positioning is disclosed.

  Further, in Patent Document 2, a chassis in which a pair of reel bearing holes is formed, and a support portion that is disposed on the lower surface side of the chassis and that supports a movable part is formed on one side surface opposite to the chassis. When the plastic bracket is integrally formed with the bracket and the connecting portion with the first engaging portion facing one side of the bracket, the bracket is disposed on the lower surface side of the chassis. When the second engaging portion is composed of a pair of bearing bodies facing the upper surface side of the chassis through the bearing holes, the first connecting portion is cut after the placket is arranged and the connecting portion is cut to rotate the first bearing body. A tape recorder bearing device is disclosed in which an engaging portion is engaged with one side of the bracket and a second engaging portion is engaged with the upper surface of the chassis.

  By the way, in some image forming apparatuses, in order to facilitate jam processing due to sheet jamming in the vicinity of the transfer roller, a sheet conveyance path in the vicinity of the transfer roller can be opened. This is because a cover member is disposed on the side surface of the image forming apparatus main body so that it can be opened and closed, and one roller of a transfer roller or a pair of registration rollers is disposed inside the cover member, and one roller is opened by opening the cover member. Are separated from other rollers. With this structure, the cover member can be opened to open the sheet conveyance path before and after the transfer roller and before and after the timing roller pair, and jamming can be easily performed.

  However, the one described in Patent Document 1 is applied to a sheet conveying apparatus or an image forming apparatus that can release the sheet conveying path as described above because the support member has a notch and the rigidity is lowered. I can't.

  Further, the device described in Patent Document 2 is for a reel of a tape recorder and cannot be applied to a sheet conveying apparatus or an image forming apparatus that can release the sheet conveying path as described above.

  The present invention has been made in view of the above-described points. One of the roller pairs can be separated from the other to release the sheet conveyance path, and the structure is simple and space saving can be achieved. It is an object to provide a sheet conveying device and an image forming apparatus.

Sheet conveying apparatus according to the present invention is disposed in the sheet conveyance path for conveying the sheet to be subjected to image forming processing, and the roller pair consisting of two rollers that contact across the sheet, at least before Symbol of the sheet conveying path a cover member for covering the arrangement position of Russia Ra pair openably movement, it comprises a, without the roller pair registration roller pair, hand roller before kilo Ra pairs, the opening and closing movement of the cover member Accordingly, the roller moves together with the cover member so as to be separated from and come into contact with the other roller of the roller pair , and the one roller has a bearing member that rotatably holds the shaft of the one roller, and an outer periphery of the bearing member. And a support member that is swingably attached to the cover member and is attached to the cover member. A main body that rotatably holds the shaft of the roller, and at least two protrusions formed at different locations in the axial direction on the outer periphery of the main body, and the support member has an insertion hole for inserting the bearing member The insertion hole has a shape that can pass through one of the main body part and the two protrusions, and the main body part and the one protrusion part are inserted into the insertion hole. After passing through the insertion hole, by rotating the bearing member, the one and the other projections sandwich the support member, and the bearing member is axially set on the support member. To do.

  According to the present invention, a separate member for fixing the roller is not required, the cost can be reduced, and a simpler structure, space saving, and high accuracy can be achieved.

2 is a schematic diagram illustrating an internal structure of the image forming apparatus according to Embodiment 1. FIG. FIG. 2 is a schematic diagram showing an internal structure of the image forming apparatus when a cover member is opened. FIG. 2 is a schematic diagram illustrating an internal structure of the image forming apparatus when a cover member is closed. It is a side view which shows the attachment state of the registration roller of the sheet conveying apparatus. It is a perspective view which shows the bearing member of the sheet conveying apparatus. It is a top view which shows the connection state of the bearing member and support member of the sheet conveying apparatus. It is a side view showing the 1st projection part and the 2nd projection part of the bearing member of the sheet conveyance device. It is a side view which shows the bearing member and support member of the sheet conveying apparatus. It is a perspective view which shows the connection state of the bearing member and support member of the sheet conveying apparatus. FIG. 6 is a partial perspective view of a sheet conveying apparatus according to a second embodiment. It is a side view which shows the same sheet conveying apparatus. FIG. 10 is a side view illustrating a sheet conveying apparatus according to a third embodiment.

  Hereinafter, a sheet conveying device and an image forming apparatus according to an embodiment for carrying out the present invention will be described.

<Embodiment 1>
First, an image forming apparatus according to Embodiment 1 will be described with reference to the drawings. In the present application, “image forming apparatus” refers to an apparatus that forms an image by attaching a developer or ink to a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. means. “Image formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium. “Sheet” is not limited to paper, but includes the above-described OHP sheet, cloth, and the like, and means that a developer or ink adheres to the recording medium, recording medium, recording paper, recording paper. It is used as a general term for things including what is called. Further, the image forming apparatus and the sheet conveying apparatus are not limited to the following description, and can be applied to various types of apparatuses.

  FIG. 1 is a schematic diagram showing the internal structure of the image forming apparatus according to the first embodiment, FIG. 2 is a schematic diagram showing the internal structure of the image forming apparatus when the cover member is opened, and FIG. 3 is when the cover member is closed. FIG. 2 is a schematic diagram illustrating an internal structure of the image forming apparatus.

  The image forming apparatus includes an image forming unit 25 that forms a toner image, an exposure unit 26 that generates an exposure laser beam based on image data, a paper feeding unit 27 that stores a sheet on which an image is formed by the image forming unit 25, A sheet conveying path 28 that conveys a sheet from the paper unit 27 through the image forming unit 25, a transfer unit 29 that transfers a toner image to the sheet, a fixing device 30 that fixes the toner image on the sheet, and a sheet when printing on both sides of the sheet Is provided.

  The image forming unit 25 includes process units 21, 22, 23, and 24. The process units 21, 22, 23, and 24 form toner images with black, yellow, magenta, and cyan developers corresponding to the color separation components of the color image. The process units 21, 22, 23, and 24 are each provided with a charging device, a developing device, a cleaning unit, a static eliminator, etc. (not shown) in addition to the photoreceptors 6, 7, 8, and 9 that are image carriers.

  The exposure unit 26 includes a laser diode that emits exposure laser light based on image data from the host device. The laser diode irradiates the photoreceptors 6, 7, 8, and 9 of the process units 21, 22, 23, and 24 with laser light, and forms latent images corresponding to the respective color images on the photoreceptors 6, 7, 8, and 9. To do.

  The sheet feeding unit 27 includes a sheet feeding cassette 32 that stores the sheet bundle P1. Sheets are fed one by one from the sheet bundle P1 accommodated in the sheet feeding cassette 32 by a sheet feeding roller and a pickup roller 1 (not shown) to the sheet conveyance path 28. Discharge.

  The sheet conveyance path 28 includes a pair of conveyance rollers (not shown) in addition to a registration roller pair 19 including two registration rollers 2 and 3. In the sheet conveyance path 28, after the sheet reaches the registration roller pair 19, the paper feeding roller continues to rotate, and the skew of the paper is corrected at the nip of the registration roller pair 19. Then, once the rotation of the paper feed roller is stopped, the registration rollers 2 and 3 start to rotate at the timing when the toner image reaches the transfer unit 29.

  The transfer unit 29 includes an intermediate transfer belt 4 a and transfer rollers 4 b and 5. The intermediate transfer belt 4a sequentially transfers the toner images formed by the photoreceptors 6, 7, 8, and 9 of the process units 21, 22, 23, and 24 to form a color toner image. The sheet is fed from the registration rollers 2 and 3 in accordance with the timing when the color toner image on the intermediate transfer belt 4a reaches the transfer rollers 4b and 5, and the color toner image is secondarily transferred to the sheet in the transfer rollers 4b and 5. The

  The fixing device 30 includes fixing rollers 10 and 11 and heat-fixes the color toner image on the sheet. The paper discharge rollers 12 and 13 discharge the fixed sheet to the paper discharge stack unit 14. In addition, when performing double-sided printing on a sheet, the sheet printed on one side is conveyed from the fixing rollers 10 and 11 to the reversing device 31. In the reversing device 31, the branching claw 15 rotates clockwise with energization of a solenoid (not shown) with respect to the leading end of the paper, and conveys the sheet between the paper discharge roller 13 and the reversing roller 16. The paper discharge roller 13 is reversely rotated at a timing at which the trailing edge of the paper cannot pass through the paper discharge roller 13 and the reverse roller 16, and is conveyed to a double-sided path having the double-sided rollers 17 and 18. The paper that has passed through the double-sided path passes through the registration rollers 2 and 3 again, passes through the above-mentioned single-sided paper passing path, and the double-sided printing is completed.

  Further, in this image forming apparatus, when a sheet jam occurs in the sheet conveyance path 28, the cover member 34 is opened from the image forming apparatus main body 33 as shown in FIG. can do. Therefore, the lower part of the cover member 34 is rotatably attached to the image forming apparatus main body 33. In addition, one of the registration roller pairs 19 disposed in the sheet conveying device 19, the transfer roller 5, the fixing roller 11 of the reversing device 31, and the reversing device 31 are disposed on the cover member 34.

  When a jam occurs due to a sheet jam in the sheet conveyance path 28 during printing, the cover member 34 is opened from the image forming apparatus main body 33. By this opening operation, a nip portion of a roller pair constituted by rollers is released, and one roller is separated from the other roller.

  In the image forming apparatus according to the first embodiment, the registration roller pair 19 includes a registration roller 2 on one side (driven side) disposed on the cover member 34, and a main body side registration roller on the other (driving side) of the image forming apparatus main body 33. 3 is provided. Therefore, as shown in FIG. 2, when the cover member 34 is separated from the image forming apparatus main body 33, the registration rollers 2 and 3 can be separated from each other. In this state, the transfer rollers 4b and 5 and the fixing rollers 10 and 11 are also separated from each other.

  On the other hand, as shown in FIG. 3, when the cover member 34 is closed with respect to the image forming apparatus main body 33, each roller pair comes into contact to form a nip portion, and the sheet is conveyed, transferred, and fixed. It becomes.

  Next, the attachment state of the registration roller 2 to the cover member 34 will be described. FIG. 4 is a side view showing a registration roller attached state of the sheet conveying apparatus according to the first embodiment. In the sheet conveying apparatus according to the first embodiment, the registration roller 2 is disposed so as to be swingable (arrow A in FIG. 4) and forward / backward (arrow B) in the cover member 34 by the bearing member 40 and the support member 50. Yes. That is, the base portion (right side in the figure) of the support member 50 is swingably supported by the cover member 34, and the bearing member 40 is disposed on the distal end side (left side in the figure) of the support member 50. Place. A long hole 71 is formed in the base portion of the support member 50 along the advancing / retreating direction, and a projection 35 formed on the cover member 34 is fitted into the long hole 71 to cover the support member 50 so as to be swingable and slidable. Attach to member 34.

  The support member 50 is attached to the cover member 34 such that the attachment position of the bearing member 40 is above the attachment position at the protrusion 35, and the pressing direction of the pressing means 72 (arrow B in the figure) It is assumed that the longitudinal direction of the hole 71 coincides. For this reason, the registration roller 2 together with the support member 50 can be brought into contact with the main body side registration roller 3 along the long hole 71.

  Further, pressing means 72 such as a coil spring is disposed at the base of the support member 50, and the bearing member 40 is pressed against the main body side registration roller 3 on the image forming apparatus main body 33 side. 4 indicates a fixing portion of the pressing means 72.

  Here, in the first embodiment, the support member 50 is pressed by the pressing unit 72 in order to press the registration roller 2 against the main body side registration roller 3. On the other hand, the registration roller 2 can be directly pressed against the registration roller 3 on the main body side, but pressing means can be provided, but the pressing means must be arranged in a narrow area near the registration roller 2 arranged at the tip of the support member 50. However, there are restrictions on the arrangement.

  In the sheet conveying apparatus according to the first embodiment, the rotation amount of the rotation shaft of the registration roller 2 and the support member 50 is large. For this reason, it is effective to attach the registration roller 2 with a simpler structure and space saving. On the other hand, the supporting member 50 is disposed in a state in which only the swing is possible along the vertical direction, the registration roller 2 is disposed at the tip, and pressing means for pressing the registration roller 2 along the swinging arc is provided. If it is provided, the amount of oscillation is small, so that a great effect cannot be expected.

  Next, the bearing member 40 will be described. FIG. 5 is a perspective view illustrating a bearing member of the sheet conveying apparatus, and FIG. 6 is a plan view illustrating a connection state between the bearing member and the support member of the sheet conveying apparatus. 7 is a side view showing the first protrusion and the second protrusion of the bearing member of the sheet conveying apparatus, FIG. 8 is a side view showing the bearing member and the support member of the sheet conveying apparatus, and FIG. It is a perspective view which shows the connection state of the bearing member and support member of a sheet conveying apparatus.

  The bearing member 40 includes a cylindrical main body 41 having a shaft hole 46 that rotatably holds the shaft member 2 a of the registration roller 2, and a first protrusion 42 formed so as to protrude to the outer peripheral surface of the main body 41. And the second protrusion 43. The first protrusion 42 and the second protrusion 43 are formed of a conductive resin material integrally with the main body 41. The second projecting portion 43 includes a collar portion 44 formed around the body portion 41 and a projecting portion 45 projecting from the first projecting portion 42 side of the collar portion 44.

  As shown in FIG. 6, the first projecting portion 42 and the projecting portion 45 of the second projecting portion 43 are disposed at opposing positions with the center O around the body portion 41, and the axial distance between the end surfaces 42 a and 45 a. Is approximately the same dimension d (D <d) as the thickness dimension D of the bearing member 40. Further, since the bearing member 40 is configured in this way, as shown in FIG. 6, the first protrusion 42 and the second protrusion 43 are independently formed at positions separated from each other and viewed from the axial direction. Even if the shape is different, it can be formed in a position that does not overlap. For this reason, it is not necessary to use a slide or the like as a resin-molding mold when the bearing member 40 is manufactured, and the workability is good. As a result, the processing cost can be suppressed.

  Further, as shown in FIG. 8, the support member 50 is configured by opening an insertion hole 52 into which the bearing member 40 is inserted into a substrate 51 formed at the distal end portion of the support member 50. The insertion hole 52 is configured such that the main body 41 and the first protrusion 42 of the bearing member 40 can be inserted. That is, the insertion hole 52 includes a circular portion 53 that contacts the outer peripheral surface of the inserted bearing member 40 and a cutout portion 54 that communicates with the circular portion 53 and through which the first protrusion 42 passes. The notch 54 can pass through the first protrusion 42 only when the angular positions of the first protrusion 42 and the notch 54 coincide with each other as the rotation center of the shaft member 2 a of the registration roller 2.

  In order to attach the bearing member 40 to the support member 50, the main body 41 and the first protrusion 42 of the bearing member 40 are inserted into the insertion hole 52 of the support member 50, and the first protrusion 42 passes through the insertion hole 52. Then, the bearing member 40 is rotated (arrow C in FIG. 8). As a result, as shown in FIG. 5, the bearing member 40 is positioned on the support member 50 in the axial direction with the substrate 51 of the support member 50 sandwiched between the protrusions 45 of the first protrusion 42 and the second protrusion 43. Fix it.

  In this state, the registration roller 2 can be fixed as a part of the unit constituting the cover member 34. Since the support member 50 is sandwiched between the first protrusion 42 and the second protrusion 43 of the bearing member 40, the position of the support member 50 can be fixed in the axial direction of the registration roller 2. For this reason, the shaft member 2a of the registration roller 2 can be rotatably held without using another member. Conventionally, the registration roller 2 is fixed by a separate member, for example, a retaining ring such as an E-ring. On the other hand, in the sheet conveying apparatus according to the first embodiment, such a retaining ring is unnecessary, and the cost can be reduced. In addition, since the influence of component variations can be reduced, the space can be saved and high accuracy can be achieved.

  Further, since the bearing member 40 is formed of a resin material, the first protrusion 42 and the second protrusion 43 can be easily formed integrally. Unlike a metal material, the resin material is rich in elasticity, so that it can be positioned with a single member such as a snap fit or can be reduced in weight because the density is smaller than that of a metal. Furthermore, since a conductive resin material is used, a grounding state for preventing malfunction due to static electricity or the like can be easily realized.

  Conventionally, a registration roller mounted for general use in an image forming apparatus or the like is often covered with rubber in order to secure a conveyance force. However, since rubber is an insulating material, static electricity is accumulated in the cored bar, and there is concern about the effect on the machine operation and image quality, so it is desirable to make sure that it is grounded.

  In the sheet conveying apparatus according to the first embodiment, the main body side bearing member 60 to which the main body side registration roller 3 is rotatably attached is also formed of the same conductive resin material as the bearing member 40. And when the cover member 34 is made into a closed state, it comprises so that the bearing member 40 and the main body side bearing member 60 may contact (refer FIG. 4). Since the registration roller 2 is grounded by the grounding means, the main body side registration roller 3 is also grounded by bringing the bearing member 40 and the main body side bearing member 60 into contact with each other. There is no need to ground on the image forming apparatus main body 33 side, and there is no need to arrange parts for that purpose, thereby saving space.

  Next, the transfer unit 29 will be described. In the transfer portion 29 shown in FIG. 1, a nip portion is formed between the transfer roller 5 and the transfer roller 4b via the intermediate transfer belt 4a. A transfer roller 5 is applied with a bias having a polarity opposite to that of the toner from the non-image surface side of the transfer unit 29, and an electric field is formed between the opposite intermediate transfer belt 4a to attract and transfer the toner image to the sheet. It is. In this case, particularly in a high-humidity environment, the resistance value decreases because the sheet contains moisture, and a bias applied from a grounded roller or the like that is different from the transfer portion through the sheet material escapes. Things happen.

  As a result, toner image transfer failure occurs, and image quality is impaired. Therefore, in such a configuration, in order not to affect the bias application in the transfer unit 29, a bias member from the resist is provided by providing a resistance member having a predetermined value or more (not shown) in the ground path of the resist roller pair 19. Prevent escape. Further, when the maximum sheet length of the sheet to be used is L, it is preferable that the roller member installed at a position smaller than the length L in the sheet material conveyance path with the transfer unit 29 as a reference is also grounded via a resistance member. . As a result, the bias does not escape while the transfer portion 29 and the sheet are in contact with each other, and image quality defects can be prevented regardless of the size of the printed sheet.

  In addition, the resist roller 2 and the main body side resist roller 3 also improve wear resistance without impairing grounding reliability by disposing conductive grease conductive grease at the contact portions with the respective bearing members 40 and 60. Can do.

  Further, if the structure in which the bearing member 40 of the registration roller 2 and the main body side bearing member 60 of the main body side registration roller 3 are in contact with each other is configured similarly at both ends in the width direction of both the registration rollers 2 and 3, poor contact is obtained. This can be prevented and is more preferable.

<Embodiment 2>
Next, a sheet conveying apparatus according to the second embodiment will be described. In the sheet conveying apparatus according to the second embodiment, the registration roller 2 presses in a direction inclined by a predetermined angle with respect to a line segment connecting the center of the registration roller 2 and the center of the main body side registration roller 3. Then, the main body side bearing member 60 prohibits the movement of the bearing member 40 and stops the bearing member 40 at a predetermined position.

  FIG. 10 is a partial perspective view of the sheet conveying apparatus according to the second embodiment, and shows a contact state of the registration rollers 2 and 3 when the cover member 34 is closed. FIG. 11 is a side view showing the sheet conveying apparatus according to the second embodiment. In the sheet conveying apparatus according to the second exemplary embodiment, the registration roller 2 is in contact with the main body side registration roller 3 at the nip point 83, and the pressing unit 72 (see FIG. 4) includes the center O1 of the registration roller 2 and the main body side registration roller. The registration roller 2 is pressed with a force FN along a line segment 82 that forms an angle θ> 0 with respect to a line segment 81 that connects the centers O2 of the rollers 3. Then, a force F <b> 1 in the direction of the line segment 81 and a force F <b> 2 that causes the registration roller 2 to rotate clockwise around the center O <b> 2 of the main body side registration roller 3 act on the registration roller 2.

  In the sheet conveying apparatus according to the second embodiment, a contact portion 65 that contacts the outer periphery of the bearing member 40 is formed on the main body side bearing member 60. The bearing member 40 pressed by the pressing means 72 comes into contact with the inner surface 66 formed by the contact portion 65 of the main body side bearing member 60 (reference numeral 84) and its movement is restricted. The contact between the bearing member 40 and the main body side bearing member 60 is further ensured by the force F2 that the bearing member 40 abuts against the contact portion 65, and the grounding state is ensured.

  Here, the force for pressing the bearing member 40 against the main body side bearing member 60 is a force by which the pressing means 72 presses the registration roller 2 against the main body side registration roller 3, and the pressing member 72 presses the bearing member 40 against the main body side bearing member 60. There is no need to provide another means. For this reason, the configuration is simple and the cost can be reduced. Note that the force FN that presses the registration roller 2 against the registration roller 3 on the main body side is a size necessary for the force F1, a nip force sufficient to correct the skew of the sheet material with the registration roller, and a conveyance necessary for conveying the sheet material. This can be determined in consideration of the force, the size required for F2, and the set angle possible in the layout.

<Embodiment 3>
Next, a sheet conveying apparatus according to the third embodiment will be described. FIG. 12 is a side view illustrating the sheet conveying apparatus according to the third embodiment, and illustrates a pressing state of the registration roller pair. In the sheet conveying apparatus according to the third embodiment, a coil spring 91 is provided as a pressurizing unit that presses the bearing member 40 of the cover member 34 against the main body side bearing member 60 side. According to the third embodiment, since the bearing member 40 is pressed and brought into contact with the contact portion 61 of the main body side bearing member 60, the electrical connection between the main body side bearing member 60 and the bearing member 40 can be ensured, and the main body side bearing The grounding of the member 60 can be more reliably performed.

2: Registration roller (one roller)
2a: Shaft member 3: Main body side registration roller (the other roller)
19: Registration roller pair 28: Sheet conveyance path 33: Image forming apparatus main body 34: Cover member 40: Bearing member 41: Main body part 42: First protrusion part 43: Second protrusion part 44: Brim part 45: Protrusion part 46: Shaft hole 50: Support member 51: Substrate 52: Insertion hole 53: Circular portion 54: Notch portion 60: Body side bearing member

JP-A-9-212246 Japanese Utility Model Publication No. 01-116998

Claims (6)

Arranged in a sheet conveyance path for conveying the sheet to be subjected to image forming processing, and the roller pair consisting of two rollers that contact across the sheet, the opening-and-closing the arrangement position of the at least before kilo Ra pairs of said sheet transport path And a cover member that covers it,
The roller pair forms a registration roller pair,
Hand roller before kilo Ra pairs, spaced other roller of the roller pair in accordance with the opening and closing movement of the cover member moves together with the cover member so as to contact,
The one roller includes a bearing member that rotatably holds a shaft of the one roller, and a support member that holds the outer periphery of the bearing member and is swingably attached to the cover member. It is attached to the
The bearing member includes a main body that rotatably holds the shaft of the one roller, and at least two protrusions that are formed at different locations in the axial direction on the outer periphery of the main body.
The support member has an insertion hole into which the bearing member is inserted, and the insertion hole has a shape that can pass through one of the main body portion and the two protrusion portions,
The main body part and one protrusion are inserted into the insertion hole, and after the one protrusion passes through the insertion hole, the bearing member is rotated to support the one and other protrusions. A sheet conveying apparatus characterized in that a member is sandwiched and the bearing member is axially set on the support member.   The sheet conveying apparatus according to claim 1, wherein the bearing member is formed of a conductive resin material.   The sheet conveying device according to claim 1, wherein the protrusion of the bearing member is formed so that projection shapes in the axial direction of the rollers held by the bearing member do not overlap. The other roller is held by a bearing member, and at least one of the bearing member of the one roller and the bearing member of the other member is pressurized to bring the bearing member into pressure contact with the other bearing member sheet conveying apparatus according to any one of claims 1 to 3, characterized in that it comprises means. One roller of the pair of rollers is pressed against the other roller in a direction not parallel to the line segment connecting the centers of the rollers , and the bearing member of the roller pressed by the generated component force is already The sheet conveying device according to any one of claims 1 to 4 , wherein the sheet conveying device is in contact with one of the bearing members in a pressurized state . A transfer unit for transferring the toner image to the sheet is provided. The transfer unit applies a bias having a polarity opposite to that of the toner from the back side of the image surface, and forms an electric field with the opposing member to attract the toner image to the sheet. Image forming means for transferring
A sheet conveying device according to any one of claims 1 to 5,
The roller disposed on the apparatus main body side of the sheet conveying apparatus is in an insulated state with respect to the apparatus main body,
In the middle of the path grounded through the contact position of the bearing member of the roller disposed on the cover member side, a resistance member having a predetermined resistance value is installed ,
When a maximum length of a sheet to be used is L, a resistance member is provided in a grounding path of a roller member installed at a position equal to or less than the length L of the sheet material conveyance path with reference to the transfer unit Image forming apparatus.