Fixing apparatus and image forming apparatus

Abstract

It guides the sheet precisely within the nip area of ​​the fixing device. [Solution] The fixing device includes a sheet guide 60 capable of guiding the sheet toward the nip region. The sheet guide 60 includes a guide member 61 extending along the sheet transport direction S and a fixing member 65 that fixes the guide member 61 to the casing of the fixing device. The fixing member 65 includes a first fixing part 651 that is inclined toward one side of the sheet being transported and a second fixing part 652 that is inclined toward the other side, so that the mounting position of the guide member 61 and the fixing member 65 can be adjusted.

Description

Technical Field

[0001] The present disclosure relates to a fixing device and an image forming apparatus including the fixing device.

Background Art

[0002] Conventionally, as an image forming apparatus, there is known a configuration in which an unfixed toner image transferred onto a sheet is fixed onto the sheet in a nip region formed between a rotating member and a pressing member. In this type of image forming apparatus, a sheet guide may be provided in order to properly guide the sheet on which the toner image has been transferred along the sheet conveyance direction.

[0003] For example, Patent Document 1 discloses an entrance guide plate of a fixing device including a transfer paper guide surface, a mounting portion including a hole for a fixing screw and a positioning protrusion, and a base portion having a missing portion formed between the mounting portions.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In some cases, it is desirable that the sheet guide be adjusted in position with respect to the nip region within a minute dimensional range of about 2 mm in accordance with the conveyed sheet. However, in the configuration of the conventional entrance guide plate, the mounting portion extends in one direction with respect to the transfer paper guide surface, making fine adjustment difficult and not sufficient for accurately guiding the sheet with respect to the nip region.

[0006] The present disclosure has been made in view of the above problems, and an object thereof is to provide a fixing device and an image forming apparatus capable of accurately guiding a sheet to a nip region and improving the quality of image formation. [Means for solving the problem]

[0007] The present disclosure provides a fixing device comprising a rotating member, a pressing member that rotates in contact with the rotating member, and a casing that houses the rotating member and the pressing member, wherein a sheet transport path is formed within the casing, passing through a nip region between the rotating member and the pressing member, the casing is provided with a sheet guide capable of guiding a sheet toward the nip region, the sheet guide comprises a guide member extending along the sheet transport direction in the sheet transport path and a fixing member that fixes the guide member to the casing, the fixing member comprises a first fixing portion inclined toward one side of the sheet being transported and a second fixing portion inclined toward the other side, and the mounting position of the guide member with respect to the fixing member is adjustable.

[0008] In the fixing device described above, the guide member is provided with a connection portion for the fixing member on the upstream side in the sheet transport direction, and a guide plate continuous with the connection portion on the downstream side, and it is preferable that the mounting position with respect to the fixing member at the connection portion is adjustable, and that the position of the guide member with respect to the nip region is adjustable in a direction intersecting the sheet transport path by the mounting position.

[0009] Furthermore, in the fixing device, the guide member may have a first connecting portion that is joined to the first fixing portion and a second connecting portion that is joined to the second fixing portion as the connecting portion, and may be attached to the fixing member by selectively using either the first connecting portion or the second connecting portion.

[0010] Furthermore, in the fixing device, it is preferable that the guide member is provided such that the first connecting portion, the second connecting portion, and the guide plate have a substantially Y-shaped cross-section.

[0011] Furthermore, in the fixing device, the angle between the first connection portion and the horizontal plane and the angle between the second connection portion and the horizontal plane may be equal.

[0012] Furthermore, in the fixing device, it is preferable that the connecting portion is provided with an elongated mounting hole that is long in a direction intersecting the sheet transport path, and that the guide member is adjustablely fixed to the fixing member through the mounting hole.

[0013] Furthermore, an image forming apparatus equipped with a fixing device related to each of the solutions described above also falls within the scope of the technical concept of this disclosure. [Effects of the Invention]

[0014] According to this disclosure, it is possible to provide an image forming apparatus that can accurately guide a sheet to the nip region of a fixing device. [Brief explanation of the drawing]

[0015] [Figure 1] This is an explanatory diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present disclosure. [Figure 2] This is a cross-sectional view showing the configuration of a fixing device provided in an image forming apparatus. [Figure 3] This is a perspective view showing the configuration of the sheet guide provided in the fixing device. [Figure 4] This is a perspective view showing the guide member of the seat guide. [Figure 5] This is a perspective view showing the fixing member of the seat guide. [Figure 6] This is a cross-sectional view of the sheet guide shown by section AA in Figure 3. [Figure 7] This is an explanatory diagram showing an example of adjusting the mounting position of the guide member. [Figure 8] This is an explanatory diagram showing other examples of adjustments to the mounting position of the guide member. [Modes for carrying out the invention]

[0016] The fixing device and the image forming apparatus according to embodiments of the present disclosure will be described with reference to the drawings.

[0017] (Image forming apparatus) FIG. 1 is an example of an image forming apparatus 1 according to an embodiment of the present disclosure, and is an explanatory diagram showing the overall configuration of the image forming apparatus 1. In the drawings, reference sign X indicates the depth direction of the image forming apparatus, the -X direction (minus X direction) is the front direction, and the +X direction (plus X direction) is the rear direction. Further, reference sign Y indicates the left-right direction orthogonal to the width direction X, the -Y direction (minus Y direction) is the left direction, the +Y direction (plus Y direction) is the right direction, and reference sign Z indicates the up-down direction, the -Z direction (minus Z direction) is the downward direction, and the +Z direction (plus Z direction) is the upward direction. These directions do not limit the usage form of the image forming apparatus 1, and are directions shown for the explanation of the embodiment.

[0018] The image forming apparatus 1 is a multifunction device having a scanner function, a copier function, a printer function, a facsimile function, etc., transmits the image of the document read by the image reading device 18 to the outside, and also forms an image of the read document image or the image received from the outside on a sheet in color or monochrome. This image forming apparatus 1 includes a photosensitive drum 11, a charging device 12, an optical scanning device 13, a developing device 14, a drum cleaning device 15, a transfer device 19, a fixing device 10, a paper feeding device 17, and the like.

[0019] In the image forming apparatus 1, image data corresponding to a color image using each of the colors black (K), cyan (C), magenta (M), and yellow (Y), or a monochrome image using a single color (for example, black) is handled. The image reading apparatus 18 reads a document or a document conveyed from the document conveyance unit (ADF) to generate image data. The image forming apparatus 1 according to the exemplary embodiment includes four photoreceptor drums 11, four charging devices 12, four developing devices 14, and four drum cleaning devices 15 for forming four types of toner images, each of which is unitized to correspond to each of the colors black, cyan, magenta, and yellow, and four process units Pa, Pb, Pc, and Pd are provided.

[0020] The photoreceptor drum 11 is an image carrier having a photosensitive layer on its surface that has insulating properties in a dark place and changes its conductivity in the area irradiated with light, and is rotatable around a rotation axis. Here, the charging device 12 is a scorotron type charger that charges the surface of the photoreceptor drum 11 to a predetermined potential. The optical scanning device 13 exposes the charged surface of each photoreceptor drum 11 based on the image data to form an electrostatic latent image.

[0021] The developing device 14 develops the electrostatic latent image formed on the surface of the photoreceptor drum 11 with toner to form a toner image on the surface of the photoreceptor drum 11. The developing device 14 has a developing roller 141 that holds a developer containing toner on its surface and is supplied with a developing bias, which is a predetermined voltage, from a power source not shown. Due to the potential difference between the developing bias supplied to the developing roller 141 and the electrostatic latent image, the toner on the developing roller 141 is supplied to the electrostatic latent image to form a toner image.

[0022] The toner image formed on each photoreceptor drum 11 is intermediately transferred to an intermediate transfer belt 21 provided in the transfer device 19. After the toner image has been intermediately transferred to the intermediate transfer belt 21, the drum cleaning device 15 removes and recovers any residual toner remaining on the surface of the photoreceptor drum 11. The process units Pa, Pb, Pc, and Pd of this disclosure consist of a photoreceptor unit in which the photoreceptor drum 11, charging device 12, and drum cleaning device 15 are combined into a single unit, and a developing unit consisting of a developing device 14.

[0023] The transfer device 19 includes an intermediate transfer belt 21 and a (secondary) transfer section 25, etc. An intermediate transfer roller 16 is positioned above each photoreceptor drum 11 via the intermediate transfer belt 21. The intermediate transfer belt 21 is stretched by a drive roller 22 and a tension roller 23 and rotates (moves in a circular motion) in the direction of arrow C. The tension roller 23 applies a predetermined tension to the intermediate transfer belt 21. The intermediate transfer roller 16 brings the intermediate transfer belt 21 into contact with the corresponding photoreceptor drum 11, forming an intermediate transfer nip area. The toner images of each color formed on the surface of each photoreceptor drum 11 are sequentially transferred (primary transfer) onto the intermediate transfer belt 21 in the intermediate transfer nip area and superimposed. As a result, a color toner image is formed on the surface of the intermediate transfer belt 21.

[0024] The transfer roller 26 of the transfer unit 25 is positioned opposite the drive roller 22 and is in contact with the intermediate transfer belt 21, forming a transfer nip area (secondary transfer position) between it and the intermediate transfer belt 21. The intermediate transfer roller 16 traps the sheet conveyed through the sheet conveying path 31 in the transfer nip area and conveys it. The sheet conveyed through the sheet conveying path 31 has the toner image that was intermediately transferred transferred to the surface of the intermediate transfer belt 21 in the transfer nip area and is then conveyed to the fixing device 10.

[0025] The fixing device 10 transports the sheet onto which the toner image has been transferred by sandwiching it in the nip region, while heating and melting the toner image transferred onto the sheet and fixing it to the sheet by pressure. The sheet with the toner image fixed is discharged to the sheet discharge unit 37, which will be described later.

[0026] The paper feeder 17 houses the sheets used for image formation and is located below the optical scanning device 13. The sheets are pulled out of the paper feeder 17 by the pickup roller 33, transported through the sheet transport path 31, and transported to the sheet discharge section 37 via the paper discharge roller 36, passing through the transfer nip area, the fuser 10, etc. The sheet transport path 31 is equipped with multiple transport rollers 34 to facilitate sheet transport, a registration roller 35 that temporarily stops the sheet to align its leading edge and then starts transporting the sheet in accordance with the toner image transfer timing, and multiple pairs of rollers such as the paper discharge roller 36.

[0027] If image formation is to be performed on both the front and back surfaces of the sheet, the sheet is transported in the reverse direction from the paper discharge roller 36 to the sheet reversal transport path 32 to reverse the front and back surfaces of the sheet, and then guided back to the registration roller 35. Image formation is performed on the back surface in the same manner as the front surface, and the sheet is then transported to the sheet discharge section 37.

[0028] Although the image forming apparatus 1 is described above as a multifunction printer, the image forming apparatus of this disclosure is not limited to this, and any device that performs various types of image forming, such as a printer, facsimile machine, or copier, may be used.

[0029] (Fusing device) Figure 2 is a cross-sectional view showing the configuration of a fixing device 10 provided in an image forming apparatus 1. The fixing device 10 comprises a rotating member 50, a pressing member 51 that rotates in contact with the rotating member 50, a casing 52 that houses these, and a sheet guide 60.

[0030] In the exemplary embodiment, the rotating member 50 includes a fixing roller 501, a heating roller 502, a fixing belt 503, and a heat source 504.

[0031] The fixing roller 501 is supported by the casing 52 so as to be rotatable in the direction of the rotation axis along the X direction. The heating roller 502 has a built-in heat source 504. For example, a lamp heater such as a halogen lamp can be used as the heat source 504. The fixing belt 503 is an endless belt suspended from the fixing roller 501 and the heating roller 502 and rotatable in the direction of the rotation axis along the X direction. The fixing belt 503 is heated to a predetermined temperature (fixing temperature) by the heat source 504 via the heating roller 502. In this embodiment, the fixing belt 503 rotates in association with the rotational drive of the pressurizing member 51.

[0032] The pressurizing member 51 is a member that abuts against the outside of the fixing belt 503 toward the fixing roller 501, and is supported by the casing 52 in a state that allows it to rotate in the direction of the rotation axis along the X direction. The pressurizing member 51 is, for example, a pressurizing roller and is rotationally driven by a drive unit (not shown). The pressurizing member 51 is also biased toward the fixing belt 503 by a biasing member (not shown).

[0033] A nip region N (see Figure 2) is formed between the pressurizing member 51 and the rotating member 50, through which the sheet passes, allowing for the transport of the largest possible sheet size (for example, an A3 size sheet in the vertical feeding direction or an A4 size sheet in the horizontal feeding direction). The pressurizing member 51 and the rotating member 50 are configured to melt the unfixed toner on the sheet with heat in the nip region N, and then transport the sheet downstream while holding it in place to fix the toner.

[0034] The casing 52 is formed from a metal material such as galvanized steel sheet. In the casing 52, an inlet 53 is formed on the upstream side of the sheet conveying direction S relative to the nip region, and an outlet 54 is formed on the downstream side of the sheet conveying path 31 relative to the nip region N. The sheet conveying path 31 passes through the nip region N between the rotating member 50 and the pressurizing member 51 within the casing 52.

[0035] The sheet guide 60 is a component that guides the sheet on which the toner image has been transferred into the casing 52 of the fuser unit 10 from the upstream side of the sheet transport path 31, and is provided at the inlet 53 of the casing 52. The sheet guide 60 is also called a paper guide, and in the example configuration, it is fixed to the bottom side of the casing 52.

[0036] Figure 3 is a perspective view showing the configuration of the seat guide 60. The seat guide 60 comprises a guide member 61 and a fixing member 65. The guide member 61 and the fixing member 65 can be made of a metal material such as a stainless steel plate. The guide member 61 of the seat guide 60 is attached to and supported by the fixing member 65.

[0037] Figure 4 is a perspective view showing the guide member 61 of the sheet guide 60, Figure 5 is a perspective view showing the fixing member 65 of the sheet guide 60, and Figure 6 is a cross-sectional view of the sheet guide 60 shown by the AA section in Figure 3.

[0038] As shown in Figure 4, the guide member 61 comprises a connecting portion 62 and a guide plate 64. The guide plate 64 is provided in a plate shape that is long in the X direction. The connecting portion 62 extends from one side edge that extends in the longitudinal direction of the guide plate 64 and is formed near both ends in the X direction.

[0039] In the exemplary embodiment, the guide member 61 is provided with a first connecting portion 621 and a second connecting portion 622 near one end in the X direction, with the first connecting portion 621 and the second connecting portion 622 being positioned at an angle to the guide plate 64 and extending in opposite directions. Similarly, the first connecting portion 621 and the second connecting portion 622 are provided near the other end in the X direction. Referring to Figure 6, for example, the guide member 61 is provided such that the first connecting portion 621, the second connecting portion 622 and the guide plate 64 form a substantially Y-shaped cross-section.

[0040] Returning to Figure 4, the two first connecting parts 621 are positioned at both ends of the guide plate 64 in the X direction. The space between these first connecting parts 621 forms a sheet transport path 31 through which the sheet passes. The two second connecting parts 622 are positioned further inward in the X direction than the first connecting parts 621.

[0041] The fixing member 65 of the seat guide 60 supports the guide member 61 and fixes the guide member 61 to the casing 52. As shown in Figure 5, the fixing member 65 includes a first fixing part 651 and a second fixing part 652.

[0042] In the exemplary embodiment, the fixing member 65 has a rectangular flat frame 653 that is elongated in the X direction. Inside the frame 653, there is a rectangular opening 68 that is elongated in the X direction. The opening 68 of the fixing member 65 is provided with a width in the width direction (in this embodiment, the X direction) perpendicular to the sheet transport direction S that is wider than the width of the largest sheet size to which the toner image can be transferred (for example, A3 size in the vertical feed direction or A4 size in the horizontal feed direction).

[0043] As shown in Figure 5, the first fixing portion 651 extends inward from one edge of the opening 68 that extends in the longitudinal direction. The first fixing portions 651 are each positioned near both ends in the X direction. The second fixing portion 652 is formed to be long in the X direction along the other edge of the opening 68 that extends in the longitudinal direction, and extends inward from the opening 68. The second fixing portion 652 is positioned opposite the two first fixing portions 651.

[0044] As a result, in the fixing member 65, the first fixing portion 651 is inclined toward one side of the sheet being conveyed in the sheet conveying direction S, and the second fixing portion 652 is inclined toward the other side of the sheet. The first fixing portion 651 and the second fixing portion 652 are bent to form the same angle with respect to the plane of the frame 653. Both the fixing member 65 and the guide member 61 with this configuration can be manufactured from a single piece of metal.

[0045] The fixing member 65 is positioned at the inlet 53 of the casing 52, and the frame 653 is fixed to the casing 52 using fasteners such as screws (not shown) or by joining by welding. The space between the two first fixing parts 651 is an opening located at the inlet 53, which is the part through which the sheet is inserted.

[0046] The connection portion 62 of the guide member 61 is fixed to the casing 52 via a fixing member 65 so as to be located on the upstream side in the sheet conveying direction S. On the downstream side in the sheet conveying direction S, the guide member 61 is provided with a guide plate 64 that is continuous with the connection portion 62. The guide plate 64 extends in a direction intersecting the frame 653 of the fixing member 65 and is provided rising from the fixing member 65.

[0047] As shown in Figure 6, the angle α between the first fixing portion 651 and the second fixing portion 652 of the fixing member 65 corresponds to the angle between the first connecting portion 621 and the second connecting portion 622 of the guide member 61. The first connecting portion 621 of the guide member 61 is joined to the first fixing portion 651 of the fixing member 65. The second connecting portion 622 of the guide member 61 is joined to the second fixing portion 652 of the fixing member 65.

[0048] The angle between the first connecting portion 621 and the horizontal plane (for example, the upper surface of the frame 653), and the angle between the second connecting portion 622 and the horizontal plane may be formed to be equal, as shown in the figure. By increasing this angle, it becomes possible to increase the amount of adjustment of the height position of the guide plate 64.

[0049] Returning to Figure 4, the first connecting portion 621 and the second connecting portion 622, as connecting portions 62, each have elongated mounting holes 63 that are long in the direction intersecting the sheet transport path 31. The guide member 61 is fixed to the fixing member 65 through these mounting holes 63. The fixing member 65 is provided with screw holes 66 in the first fixing portion 651 and screw holes 67 in the second fixing portion 652, corresponding to the mounting holes 63.

[0050] The first connecting portion 621 of the guide plate 64 is positioned on the lower surface of the first fixing portion 651 of the fixing member 65, and is fixed by fastening fasteners 70 (see Figure 3) such as screws to the mounting holes 63 and screw holes 66 and 67. Similarly, the second connecting portion 622 of the guide plate 64 is positioned on the lower surface of the second fixing portion 652 of the fixing member 65 and is fixed thereto. The sheet is transported in the sheet transport direction S through the opening 68 on the first connecting portion 621 side.

[0051] The guide member 61 can be fixed while adjusting its mounting position to the fixing member 65 within the range of the elongated hole of the mounting hole 63. In other words, the position of the guide member 61 can be changed depending on the mounting position of the connecting portion 62 to the fixing member 65. By fine-tuning the position of the guide member 61, it is possible to position the tip portion 64a of the guide plate 64 to correspond to the nip region N. For example, by positioning the tip portion 64a of the guide plate 64 to correspond to the nip region N, it becomes possible to guide the sheet toward the nip region N.

[0052] The sheets onto which the toner image is transferred come in various thicknesses, from very thin to relatively thick, and may also be curled. Depending on the direction of the curl, it may not be possible to smoothly trap and transport the sheet in the nip region N. In such cases, adjusting the mounting position of the guide member 61 is effective.

[0053] As shown in Figure 2, the guide member 61 of the sheet guide 60 is attached to the casing 52, and the guide plate 64 is positioned to extend along the sheet transport path 31. The tip 64a of the guide plate 64 is positioned toward the nip region N, which allows the sheet to be smoothly guided toward the nip region N. Furthermore, the closer the tip 64a of the guide plate 64 is to the nip region N, the more accurately the sheet being transported can be guided toward the nip region N.

[0054] Here, as shown in Figure 6, if the mounting position of the guide member 61 to the fixing member 65 is moved in the Y direction, which intersects with the sheet transport direction S of the sheet transport path 31, not only does the position of the tip portion 64a of the guide plate 64 change in the Y direction, but the height of the tip portion 64a also changes.

[0055] In other words, in the figure, the guide member 61 shown by the solid line has its first connecting portion 621 joined to the first fixing portion 651 and its second connecting portion 622 joined to the second fixing portion 652, and is positioned approximately in the center in the Y direction, with its tip portion 64a at the highest position. In contrast, the guide member 61 shown by the dashed line has its mounting position adjusted to the left or right in the Y direction, and the position of its tip portion 64a changes to a lower position.

[0056] In this way, the mounting position of the guide member 61 can be adjusted within the range of the elongated holes of the mounting holes 63, and by moving and fixing it in the Y direction, the position of the upward-extending guide plate 64 can be adjusted. Since the sheet is transported in the sheet transport direction S along the guide plate 64, by positioning the tip 64a of the guide plate 64 to correspond to the nip region N and positioning it closer to the nip region N, smooth sheet transport becomes possible.

[0057] Furthermore, when adjusting the mounting position of the guide member 61, it is not necessary to remove the fasteners 70 such as screws screwed into the mounting hole 63 and screw holes 66 and 67. With the screws loosened, the guide member 61 can be slid within the range of the elongated hole of the mounting hole 63, allowing the mounting position to be adjusted with a simple operation.

[0058] Figure 7 is an explanatory diagram showing an example of adjusting the mounting position of the guide member 61, and Figure 8 is an explanatory diagram showing another example of adjusting the mounting position of the guide member 61.

[0059] When fixing the guide member 61 to the fixing member 65, it is also possible to selectively use the first connecting portion 621 and the second connecting portion 622 for fixing. For example, from the state shown by the solid line in Figure 6, the second connecting portion 622 of the guide member 61 can be slid diagonally downward along the second fixing portion 652 of the fixing member 65, and as shown in Figure 7, the second connecting portion 622 and the second fixing portion 652 can be fixed with the fastener 70 to adjust the mounting position to the right in the Y direction. In this case, the first connecting portion 621 of the guide member 61 is not used for fixing to the fixing member 65, and it is fixed to the fixing member 65 only by the second connecting portion 622.

[0060] Furthermore, as shown in Figure 8, for example, the guide member 61 may be fixed to the fixing member 65 using only the first connecting portion 621, and the mounting position of the guide member 61 can be adjusted to the left in the Y direction. In either case, the sheet is conveyed in the sheet conveying direction S between the two first connecting portions 621 and smoothly guided to the nip region N along the guide plate 64.

[0061] In a fuser 10 equipped with a sheet guide 60 configured as described above, the sheet onto which the toner image has been transferred can be smoothly guided to the nip region N along the sheet transport direction S, thereby suppressing the occurrence of image defects and improving the quality of image formation.

[0062] In this disclosure, the image forming apparatus 1 is shown as an example of a multifunction device capable of forming multicolor or monochrome images on a recording medium in response to image data transmitted from an external source or image data read from a document by a scanner, but the image forming apparatus is not limited to this. The fixing device 10 is configured to include a rotating member 50 and a pressurizing member 51, and the rotating member 50 is not limited to a belt fixing system with a fixing belt 503, but may be a rotating member 50 consisting of a roller with a heat source 504 provided inside, without a separate fixing belt. The pressurizing member 51 may also be provided with a heat source inside.

[0063] This disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the technical essence thereof. All technical matters included in the technical idea described in the claims are subject to this disclosure. The embodiments described above are preferred examples, but various modifications can be realized from the disclosed content, and such modifications are also included in the technical scope described in the claims. [Explanation of symbols]

[0064] 1. Image forming apparatus 10 Fixing device 11 Photoconductor drum 111 Rotation axis 12 Charging device 13 Optical scanning device 14. Developing device 141 Developing Roller 19 Transfer device 31 Sheet transport path 50 Rotating Member 501 Fixing roller 502 Heating roller 503 Fixing belt 504 Heat source 51 Pressurizing member 52 Casing 53 Inlet 54 Outlet 60-seat guide 61 Guide member 62 Connection part 621 First connection section 622 Second connection section 63 mounting holes 64 Guide Plate 65 Fixing member 651 1st fixed part 652 2nd fixed part N-nip region S Sheet transport direction

Claims

1. Rotating member and A pressing member that rotates while being pressed against the aforementioned rotating member, In a fixing device having a casing that houses the rotating member and the pressurizing member, A sheet transport path is formed within the casing, passing through the nip region between the rotating member and the pressurizing member. The casing is provided with a sheet guide that can guide the sheet toward the nip region. The sheet guide comprises a guide member extending along the sheet transport direction in the sheet transport path, and a fixing member for fixing the guide member to the casing. The fixing device is characterized in that the fixing member comprises a first fixing portion that is inclined toward one side of the sheet being conveyed and a second fixing portion that is inclined toward the other side, and the guide member is adjustable in its mounting position relative to the fixing member.

2. In the fixing device according to claim 1, The guide member has a connection portion with the fixing member on the upstream side in the sheet transport direction, and a guide plate continuous with the connection portion on the downstream side. A fixing device characterized in that the mounting position with respect to the fixing member at the connection portion is adjustable, and the position of the guide member with respect to the nip region is adjustable in a direction intersecting the sheet transport path depending on the mounting position.

3. In the fixing device according to claim 2, The guide member has, as the connecting portion, a first connecting portion that is joined to the first fixing portion and a second connecting portion that is joined to the second fixing portion. A fixing device characterized in that it can be attached to the fixing member by selectively using the first connecting portion or the second connecting portion.

4. In the fixing device according to claim 3, The fixing device is characterized in that the guide member is provided such that the first connecting portion, the second connecting portion, and the guide plate have a substantially Y-shaped cross-section.

5. In the fixing device according to claim 3, A fixing device characterized in that the angle between the first connection portion and the horizontal plane and the angle between the second connection portion and the horizontal plane are equal.

6. In the fixing device according to claim 2, The fixing device is characterized in that the connecting portion has an elongated mounting hole that is long in a direction intersecting the sheet transport path, and the guide member is adjustablely fixed to the fixing member through the mounting hole.

7. An image forming apparatus comprising a fixing device according to any one of claims 1 to 6.

Images