JP2006065228A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of preventing, by a simple configuration, recording paper from being obliquely conveyed on the downstream side of a transfer unit. <P>SOLUTION: The image forming apparatus includes: an image forming means which has a developing unit for developing a latent image formed on a photoreceptor by an electrophotographic process and a transfer unit for transferring the toner image to the surface of the recording paper and forms a toner image developed on the photoreceptor, on recording paper; and a fixing means 40 for fixing the unfixed toner image to the recording paper. In the image forming apparatus, a moving means 70 is disposed on the downstream side of the transfer unit in the conveying direction Y of the recording paper so as to support a pair of rollers conveying the recording paper and move at least one of the axial ends of each of the pair rollers in the direction of the conveyance of the recording paper. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly, to an image forming apparatus having a function of preventing a recording sheet from being conveyed obliquely on the downstream side after a transfer unit.

  In general, in an image forming apparatus such as a copying machine, a printer, or a facsimile, a recording sheet fed from a sheet feeding unit by a sheet feeding roller forms an image using a conveyance path having various pairs of conveyance rollers. The toner image developed on the photosensitive member is transferred onto the recording paper, and then the unfixed toner image is fixed on the recording paper, and the fixed recording paper is discharged onto the discharge tray. It is configured to do.

  By the way, the various rollers used for transporting the recording paper are configured to transport the recording paper by rotating a drive transmission mechanism including a stepping motor and a gear. However, these drive transmission mechanisms have variations from device to device due to dimensional errors and assembly errors that are allowed during production, and the leading edge of the recording paper is aligned in the nip formed by the roller pair. It is difficult to enter. As a result, there is a problem in that the recording paper enters the nip obliquely and is conveyed along the conveying path in a skewed state, causing deflection and wrinkles.

As a countermeasure, in a paper feed mechanism that supports a paper feed roller drive shaft having a paper feed roller that comes into contact with a recording paper stored in a tray of a paper feed device and that can be separated, a paper feed roller Some drive shafts are arranged so as to be tiltable with respect to the normal conveyance direction of the recording paper so that the inclination angle of the feed roller drive shaft can be adjusted.
(For example, refer to Patent Document 1).
Japanese Patent No. 2001-335166

  However, in the configuration described in the above-mentioned patent document, correction is performed with respect to the oblique conveyance at the time of paper feeding, but this cannot be corrected when the oblique conveyance occurs in the subsequent conveyance process. In general, when feeding to the image forming unit, countermeasures against oblique conveyance are taken by the registration rollers. In this case as well, as in the configuration described in the above-mentioned patent document, When the oblique conveyance occurs, there is a problem that this cannot be corrected, and there is a problem that the recording paper is wrinkled or an image is blurred.

  The present invention has been made to solve the above-described problems, and provides an image forming apparatus capable of preventing the recording paper from being conveyed obliquely on the downstream side after the transfer unit with a simple configuration. For the purpose.

  In order to achieve the above object, according to the first aspect of the present invention, a developing unit for developing a latent image formed on a photoconductor by an electrophotographic process and a toner image developed on the photoconductor are recorded. An image forming apparatus comprising: a transfer unit that transfers onto a sheet; and an image forming unit that forms a toner image on a recording sheet; and a fixing unit that fixes the unfixed toner image on the recording sheet. A movement for supporting a pair of rollers for transporting the recording paper and moving at least one end portion in the axial direction of the pair of rollers in the transporting direction of the recording paper on the downstream side in the transport direction of the recording paper after the transfer unit. Means are provided.

According to the second aspect of the present invention, the movement of the roller pair by the moving means allows the nip formed by the roller pair to be inclined with respect to the reference axis that goes straight in the recording sheet conveyance direction.
According to a third aspect of the present invention, the roller pair is a heating roller and a pressure roller provided in the fixing unit.

According to a fourth aspect of the present invention, the moving means is formed with a display unit that can recognize the movable position of the moving means.
According to the fifth aspect of the present invention, at least one end of the roller pair in the axial direction can be moved stepwise by the moving means in the conveyance direction of the recording paper.

According to the sixth aspect of the present invention, at least one end of the pair of rollers in the axial direction can be continuously moved by the moving means in the conveyance direction of the recording paper.
According to a seventh aspect of the present invention, the apparatus further includes a driving unit that moves the moving unit, and a control unit that receives a type signal corresponding to the type of the recording paper and determines a moving range of the moving unit based on the type signal. The control unit controls the driving unit based on the input type signal.

  According to the configuration of the first aspect of the invention, on the downstream side after the transfer unit, the roller pair for conveying the recording paper is supported, and at least one end portion in the axial direction of the roller pair is connected to the recording paper. Since the moving means for moving in the transport direction is provided, the support position of the roller pair can be adjusted by the moving means. Therefore, it is possible to absorb and correct the dimensional error and assembly error of each part that are allowed at the time of manufacture with a simple configuration, and to eliminate variations among devices, to cause wrinkles on the recording paper, and to generate images. No fading occurs and a good image can be obtained.

  According to the configuration of the second aspect of the present invention, the nip formed by the roller pair can be tilted with respect to the reference axis orthogonal to the recording sheet conveyance direction by the movement of the roller pair by the moving means. The movement reference is clear and the adjustment can be performed very easily.

  According to the configuration of the invention described in claim 3, since the roller pair adjusted by the moving means is the heating roller and the pressure roller provided in the fixing means, the nip formed by the heating roller and the pressure roller. In addition, the leading edge of the recording paper enters in a straight line. Accordingly, the recording paper is not wrinkled or the image is not blurred, and an extremely good image can be obtained.

  According to the configuration of the fourth aspect of the invention, since the moving unit is formed with the display unit that can recognize the movable position of the moving unit, the adjustment state of the support position of the roller pair can be easily confirmed. .

  According to the fifth aspect of the present invention, at least one end portion of the roller pair in the axial direction can be moved stepwise by the moving means in the recording sheet conveyance direction. Therefore, the adjustment operation of the support position of the roller pair can be performed while confirming at each stage.

  According to the structure of the sixth aspect of the present invention, at least one end in the axial direction of the roller pair can be continuously moved by the moving means in the conveyance direction of the recording paper. Therefore, the adjustment of the support position of the roller pair can be continuously performed, and the support position can be finely adjusted.

  According to the configuration of the seventh aspect of the invention, since adjustment is performed according to the type of recording paper, the support position of the roller pair can be adjusted according to each type of recording paper. Therefore, image processing can be performed in an optimal state regardless of the type of recording paper.

(First embodiment)
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a schematic configuration when applied to a copying machine as an image forming apparatus according to a first embodiment of the present invention.

  A paper feeding unit 20 is disposed at the bottom of the main body of the copying machine 1 that is the image forming apparatus shown in FIG. An image forming unit 30 is disposed above the sheet feeding unit 20, and a fixing unit 40 is disposed on the upper left side of the image forming unit 30. Above the image forming unit 30 and the fixing unit 40, although not shown, an image reading unit for irradiating an original with an exposure light source and reading an image is disposed. Further, a paper transport unit 50 is formed from the recording paper P to the paper discharge unit 20 through the image forming unit 30 and the fixing unit 40. The paper transport unit 50 is provided with a bypass transport path 51 from the manual feed cassette 21 and a switchback transport path 52 for duplex copying.

  The image reading means irradiates light from below the contact glass toward the image surface of the document, receives reflected light from the document, and converts it into an electrical signal (image data) to read the image information of the document. The read image information is stored in, for example, a storage unit of a control unit (not shown) described later and is transmitted to the optical scanning unit 33.

  The paper feed unit 20 feeds a bundle of recording papers P stacked on the paper feed cassette 21 to the paper transport unit 50 one by one. The paper transport unit 50 transports the recording paper P fed from the paper feed unit 20 toward the image forming unit 30 by the paper feed roller 53, the transport roller pair 54, and the registration roller pair 55, and further the image forming unit. A predetermined toner image is formed in the fixing unit 40 from 30 and the fixed recording paper P is discharged onto the discharge tray 57 by the discharge roller pair 56.

  The image forming unit 30 forms a predetermined toner image on the recording paper P by an electrophotographic process. For example, a drum-shaped photoconductor 31 that is rotatably supported around the photoconductor 31. A charging unit 32, an optical scanning unit 33, a developing unit 34, a transfer unit 35, a cleaner 36, and a charge eliminating unit (not shown) are provided along the rotation direction. The charging unit 32 applies a predetermined potential to the surface of the photoreceptor 31 by corona discharge. The optical scanning unit 33 irradiates the photosensitive member 31 with a light beam, for example, a laser beam LB, modulated according to the image information of the document read by the image reading unit. Thereby, the potential of the surface of the photoconductor 31 is selectively attenuated, and an electrostatic latent image is formed on the surface to be scanned which is the surface of the photoconductor 31. The developing unit 34 develops the electrostatic latent image with toner to form a toner image on the surface of the photoreceptor 31. The transfer unit 35 transfers the toner image on the surface of the photoreceptor 31 onto the recording paper P. The cleaner 36 removes toner remaining on the surface of the photoreceptor 31 after transfer, and the charge eliminating unit removes residual charges on the surface of the photoreceptor 31.

  The fixing unit 40 is arranged on the downstream side of the image forming unit 30 in the conveyance direction of the recording paper P, and the recording paper P on which the toner image is transferred in the image forming unit 30 is transferred to the heating roller 41 and the heating roller 41. The toner image is fixed on the recording paper P by being heated by being sandwiched between nips formed by a pressure roller 42 pressed against the toner.

  Further, the image reading apparatus 1 of the present embodiment includes an automatic document conveying device 60 for performing document reading. The automatic document feeder 60 includes a document feed tray 61, a paper feed unit 62 that feeds a document stacked on the document feed tray 61, and a document transport path for transporting the fed document. 63, a document discharge conveyance path 64 for discharging the document, and a document discharge tray 65 on which the discharged document is stacked.

In addition, the copying machine 1 includes an adjusting unit (not shown) that can automatically adjust the irradiation position of light such as a laser beam to the photoconductor 31.
A basic operation state of the copying machine 1 will be briefly described. The photoconductor 31 that rotates clockwise in FIG. 1 is uniformly charged by the charging unit 32, and based on the image information read by the image reading means, for example, a laser from an optical scanning unit 33 comprising a laser scanning device or the like. An electrostatic latent image is formed on the photoreceptor 31 by the beam LB, and the electrostatic latent image is developed by the developing unit 34 to form a toner image.

  The recording paper P is conveyed from the paper supply unit 20 to the image forming unit 30 toward the photoreceptor 31 on which the toner image is formed as described above. At this time, the recording paper P is conveyed by the registration roller pair 55 while synchronizing with the toner image formed on the photoconductor 31. Thereafter, the toner image on the surface of the photoreceptor 31 is transferred to the recording paper P by the transfer unit 35 in the image forming unit 30. Then, the recording paper P carrying the unfixed toner image is conveyed to the fixing means 40 and the toner image is fixed. The recording paper P that has passed through the fixing unit 40 is discharged onto a discharge tray 57 by a discharge roller pair 56.

  After the transfer by the transfer unit 35, the photosensitive member 31 is charged with the charging unit 32 again after removing residual toner and residual charges with the cleaner 36 and the charge removing unit.

  Thus, in accordance with the present invention, on the downstream side after the transfer unit 35, at least one end in the axial direction of the roller pair that transports the recording paper P is moved in the transporting direction of the recording paper P. The structure supported by the above will be described with reference to FIGS. 2 is a perspective view showing the vicinity of the fixing unit in the copying machine 1 according to the embodiment of the present invention, FIG. 3 is a front view showing the vicinity of the fixing unit in the copying machine 1 according to the embodiment of the present invention, and FIG. FIG. 5 is a perspective view showing an example of the moving unit, FIG. 6 is a perspective view showing an example of the moving unit, and FIG. 6 is a nip formed by a photoconductor and a transfer roller, and a heating roller. It is a conceptual diagram for demonstrating the relationship with the nip formed with a pressure roller.

  In the present embodiment, a pair of rollers provided to transport the recording paper P downstream from the transfer unit 35 is a heating roller 41 and a pressure roller 42 provided in the fixing unit 40. The heating roller 41 and the pressure roller 42 are rotatably supported in the housing 43 by a support mechanism (not shown). At least one end in the axial direction of the heating roller 41 and the pressure roller 42 that are the longitudinal direction of the fixing unit 40, that is, in the example shown in FIG. It is supported by the moving means 70 via the leg portion 44 so that it can be moved stepwise in the transport direction Y of the recording paper P.

  The moving means 70 is fixed by fixing means such as a bolt 77 so as to be removable from the main body frame 11 at a predetermined position after adjustment described later. Further, the other side of the heating roller 41 and the pressure roller 42 in the longitudinal direction of the moving means 70, that is, the rear surface side B of the apparatus main body in FIG. 2, can be removed from the main body frame 11 by a fixing means (not shown). It is fixed to.

  As shown in FIG. 5, the moving means 70 is made of, for example, a synthetic resin, and a slide portion 72 is provided on the upper portion of a body portion 71 formed in a box shape, and a support surface 73 that is an upper surface of the slide portion 72 is provided. It is formed in steps. With this configuration, when the moving means 70 is moved left and right in FIG. 4, the contact position between the leg portion 44 of the housing 43 and the support surface 73 that supports the leg portion 44 is moved stepwise.

  That is, as shown in FIG. 6, the nip 40N formed by the roller pair including the heating roller 41 and the pressure roller 42 can be tilted with respect to the reference axis X orthogonal to the conveyance direction Y of the recording paper P. It is configured. For example, when the moving means 70 is moved to the right side (z1 direction in FIG. 4), the leg portion 44 provided on the front side A of the apparatus main body is supported on the support surface 73 on the lower side of the staircase of the moving means 70. Therefore, the front side A of the apparatus main body, which is one end portion in the axial direction of the roller pair including the heating roller 41 and the pressure roller 42, is lowered. Therefore, the nip 40N formed by the roller pair including the heating roller 41 and the pressure roller 42 is in a state where the front side A of the apparatus main body is lowered with respect to the reference axis X. On the contrary, when the moving means 70 is moved to the left side (z2 direction in FIG. 4), the leg portion 44 provided on the front side A of the apparatus main body is placed on the support surface 73 on the higher side of the staircase of the moving means 70. Since it is supported, the front side A of the apparatus main body, which is one end in the axial direction of the roller pair including the heating roller 41 and the pressure roller 42, is raised. Therefore, the nip 40N formed by the roller pair including the heating roller 41 and the pressure roller 42 is in a state where the front side A of the apparatus main body is raised with respect to the reference axis X.

  A plurality of ribs 81 are provided on the body 71 of the moving means 70 at the same pitch as the stairs formed on the support surface 73 as shown in FIG. Further, the housing 43 is provided with an instruction portion 82 for indicating one of the plurality of ribs 81 to form a display portion 80. By this display unit 80, it is possible to easily determine the engagement relationship between the leg part 44 and the support surface 73 that supports the leg part 44, that is, what number of stairs and the support surface 73 are engaged with. It is configured to be able to.

  Next, the adjustment by the moving means 70 described above will be described. The adjustment by the moving unit 70 is performed, for example, at the time of adjustment before shipment or image adjustment at the time of maintenance. At that time, the formed image was confirmed, and the recording paper P was wrinkled or the image was blurred due to the recording paper P being transported obliquely downstream from the transfer unit 35. If so, the moving means 70 is moved. As shown in FIG. 6, the moving means 70 is moved left or right so that the leading edge of the recording paper P enters a nip 40N formed by a pair of rollers including a heating roller 41 and a pressure roller 42. Thus, the nip 40N and the reference axis X perpendicular to the conveyance direction Y of the recording paper P are aligned. That is, the leg portions 44 and the support surface 73 of the housing 43 are set so that the distances A1 and B1 between both ends of the nip 40N and both ends of the nip 30N formed by the photosensitive member 31 and the transfer roller 37 are substantially the same distance. Make adjustments while checking the contact position in steps. By this adjustment, wrinkles and blurring of the recording paper P due to the recording paper P being conveyed obliquely on the downstream side after the transfer unit 35 do not occur.

  According to the present embodiment having the above configuration, the roller pair for conveying the recording paper P is supported on the downstream side after the transfer unit 35, and at least one end in the axial direction of the roller pair is supported on the recording paper P. Since the moving means 70 for moving in the transport direction Y is provided, the supporting position of the roller pair can be adjusted by the moving means 70. Therefore, it is possible to absorb and correct the dimensional error and assembly error of each part that are allowed at the time of manufacture with a simple configuration, and to eliminate variations among devices, to cause wrinkles on the recording paper, and to blur the image. Can be prevented, and a good image can be obtained.

  Further, the movement of the roller pair by the moving means 70 allows the nip formed by the roller pair to be inclined with respect to the reference axis X perpendicular to the conveyance direction of the recording paper P. Adjustments can be made very easily.

  In addition, since the roller pair adjusted by the moving unit 70 is the heating roller 41 and the pressure roller 42 provided in the fixing unit 40, the nip 40N formed by the heating roller 41 and the pressure roller 42 is covered with the covered roller. The leading edge of the recording paper P enters a straight line. Therefore, the recording paper P is not wrinkled or blurred, and a very good image can be obtained.

Moreover, since the display part 80 which can recognize the movable position of a moving means is formed in the moving means 70, the adjustment state of the support position of a roller pair can be confirmed easily.
Further, in the transport direction Y of the recording paper P, at least one end portion of the roller pair in the axial direction can be moved stepwise by the moving means 70. Therefore, the adjustment operation of the support position of the roller pair can be performed while confirming at each stage.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a schematic configuration diagram showing a schematic configuration of a copying machine which is an image forming apparatus according to the second embodiment of the present invention. In FIG. 7, the portions denoted by the same reference numerals as those in FIGS. 1 to 6 described above indicate substantially the same parts, and thus detailed description thereof is omitted here. Hereinafter, the difference from the above-described first embodiment will be mainly described.

  As shown in FIG. 7, the copying machine 1 includes an image display unit 10, a paper feeding unit 20, an image forming unit 30, a fixing unit 40, a paper transport unit 50, an operation display unit 95 that functions as various input key switches, and the like. Control means 90 for controlling the entire copying machine 1 is provided. The control unit 90 controls the movement of the moving unit 70 as will be described later. The operation display unit 95 includes an operation unit including a print key for inputting a print instruction, a numeric keypad for inputting the number of prints, and the like, a liquid crystal for displaying various functions operable by the copier 1, trouble situations such as a paper jam. And a display device such as a panel.

  The control unit 90 stores a control program and conditions for the apparatus main body and the moving unit 70, stores data temporarily and stores image data of the original obtained by the image reading unit 10, and serves as a work area. It is composed of a microcomputer with a built-in RAM. Then, when a start key (not shown) of the operation display unit 95 is pressed, the control unit 90 sends a control signal for performing a copying operation to the image reading unit 10, the paper feeding unit 20, the image forming unit 30, the fixing unit 40, and the paper. It outputs to each block of the conveyance part 50 and the moving means 70, and controls the operation | movement.

  Further, the control unit 90 is suitable for each type of recording paper P, for example, plain paper, cardboard, recycled paper, OHP film, etc., in order to control the moving range of the moving unit 70 as will be described later. The control condition, that is, the contact position between the support surface 73 of the moving means 70 and the leg portion 44 is stored for each type. Further, such control conditions can be set and updated while operating the input key switch of the operation display unit 95 at the time of adjustment before shipment or image adjustment at the time of maintenance while confirming with the display device.

  In the present embodiment, the moving unit 70 is configured such that the front side A of the apparatus main body, which is at least one end in the axial direction of the roller pair including the heating roller 41 and the pressure roller 42, is recorded on the recording paper P by the moving unit 70. Is supported so as to be continuously movable in the transport direction Y. That is, in the example shown in FIG. 7, the front side A of the apparatus main body is movably supported by the moving means 70 via the leg portion 44 provided at the lower part of the housing 43, and the moving range of the moving means 70 is The recording paper P can be changed according to the type of the recording paper P.

  Moreover, as for the moving means 70, the support surface 73 of the slide part 72 of the upper part of the trunk | drum 71 which consists of synthetic resins, for example is formed in the continuous slope. A rack 75 is formed on the bottom 74 of the body 71 and a pinion 76 is provided so as to engage with a groove of the rack 75. By rotating the pinion 76, the body 71 and the slide part 72 formed integrally with the body 71 are integrated with the rack 75 to the right (z1 in FIG. 7) or the left (FIG. 7). 7 move to z2).

  By the movement of the body portion 71 and the slide portion 72, the contact position between the leg portion 44 and the support surface 73 that supports the leg portion 44 is continuously moved. For example, the moving means 70 is the same as in the first embodiment. Is moved to the right side (z1 direction in FIG. 7), the leg portion 44 provided on the front side A of the apparatus main body is supported on the support surface 73 on the lower inclination side of the moving means 70. The front side A of the apparatus main body, which is one end portion in the axial direction of the roller pair composed of 41 and the pressure roller 42, is lowered. Therefore, the nip 40N formed by the roller pair including the heating roller 41 and the pressure roller 42 is in a state where the front side A of the apparatus main body is lowered with respect to the reference axis X. On the other hand, when the moving means 70 is moved to the left side (z2 direction in FIG. 7), the legs 44 provided on the front side A of the apparatus main body are placed on the support surface 73 on the side of the moving means 70 on which the inclination is high. Since it is supported, the front side A of the apparatus main body, which is one end in the axial direction of the roller pair including the heating roller 41 and the pressure roller 42, is raised.

  Therefore, the nip 40N formed by the roller pair including the heating roller 41 and the pressure roller 42 is in a state where the front side A of the apparatus main body is raised with respect to the reference axis X. Thereby, the distance A1 between the nip 30N and the nip 40N shown in FIG. 6 is adjusted. As a result, the recording paper P conveyed from the nip 30N formed by the photoconductor 31 and the transfer roller 37 enters the nip 40N formed by the roller pair including the heating roller 41 and the pressure roller 42. The tip of P can be adjusted so as to enter in a straight line.

  As the driving means 91 that rotationally drives the pinion 76, for example, a stepping motor that rotates by a certain angle by applying a pulse signal is used. The driving unit 91 is controlled by the control unit 90. Then, when the type instruction button 96 of the recording paper P of the operation display unit 95 is pressed, the control unit 90 supports the support surface 73 suitable for the recording paper P of the type based on the instructed type signal. The moving range of the moving means 70 is determined so as to be the contact position between the leg portion 44 and the driving means 91.

  Next, the adjustment by the moving means 70 described above will be described. In the present embodiment, the recording paper P is recorded on the downstream side of the transfer unit 35 on the downstream side of each recording paper P having different waist strength during adjustment before shipment or image adjustment during maintenance. Whether the recording paper P is wrinkled or image blurring due to being conveyed obliquely, the contact relationship between the leg portion 44 and the support surface 73 supporting the leg portion 44 is sequentially moved. It is verified while moving 70. Based on the verification result, the positional relationship is determined for each type of recording paper P, and is set and stored in the control means 90.

  Then, for example, when the user presses the instruction button 96 corresponding to the recording paper P during a copy operation, the moving range of the moving unit 70 is determined by the control unit 90 based on the type signal, The drive means 91 is driven and controlled. Thereby, the pinion 76 is rotated by the driving means 91, the rack 75, that is, the body portion 71 and the slide portion 72 move together, and the contact position between the leg portion 44 and the support surface 73 that supports the leg portion 44 is The relationship is suitable for the type of the recording paper P. Thereafter, the copy button is pressed and image formation is performed.

  According to the present embodiment having the above-described configuration, at least one end portion of the roller pair in the axial direction can be continuously moved by the moving unit 70 in the recording sheet conveyance direction. Therefore, the adjustment of the support position of the roller pair can be continuously performed, and the support position can be finely adjusted.

  Further, since the adjustment is made according to the type of recording paper, the support position of the roller pair can be adjusted according to each type of recording paper P. Therefore, image processing can be performed in an optimum state regardless of the type of recording paper P.

  Each embodiment described above is a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

  For example, in the first embodiment described above, the moving means 70 for moving one end portion of the roller pair in the axial direction in the transport direction Y of the recording paper P is provided, and the other end portion of the roller pair in the axial direction is provided. Although fixed to the main body frame 11, instead of this, the other axial end of the roller pair may be supported by moving means 70 that moves in the transport direction Y of the recording paper P. In this way, the support position can be further finely adjusted.

  In the second embodiment described above, the instruction button 96 for instructing the type of the recording paper P is provided on the operation display unit 95 to indicate the type of the recording paper P to the control unit 90, and the operator presses the instruction button 96. Instead of this, a discrimination sensor for discriminating the type of the recording paper P is installed in the paper feed unit 20 or the paper transport unit 50, and a type signal from this discrimination sensor is input to the control means 90 for further automation. Of course, it is also possible to plan.

  In Embodiment 2 described above, it is needless to say that the movement of the moving means 70 at the time of verification may be controlled from an operation unit provided with the driving means 91 or manually.

  As an application example of the present invention, there is an image forming apparatus including an image forming unit and a fixing unit.

1 is a schematic configuration diagram showing a schematic configuration when applied to a copying machine as an image forming apparatus according to a first embodiment of the present invention. 1 is a perspective view showing the vicinity of fixing means in a copying machine 1 according to an embodiment of the present invention. 1 is a front view showing the vicinity of fixing means in a copying machine 1 according to an embodiment of the present invention. It is the schematic for demonstrating the moving means which is the principal part of this invention. It is a perspective view which shows an example of a moving means. It is a conceptual diagram for explaining the relationship between a nip formed by a photoconductor and a transfer roller and a nip formed by a heating roller and a pressure roller. It is a schematic block diagram which shows schematic structure of the copying machine which is an image forming apparatus which concerns on 2nd Embodiment of this invention.

Explanation of symbols

1 Image forming device (copier)
DESCRIPTION OF SYMBOLS 30 Image forming means 31 Photoconductor 34 Developing unit 35 Transfer unit 30N Nip 40 Fixing means 41 Heating roller 42 Pressure roller 40N Nip 70 Moving means 80 Display part 90 Control means 91 Driving means P Recording paper X Reference axis Y Transport direction

Claims (7)

A developing unit that develops a latent image formed on a photoconductor by an electrophotographic process; and a transfer unit that transfers a toner image developed on the photoconductor onto a recording paper. An image forming apparatus comprising: an image forming unit that forms a toner image on a sheet; and a fixing unit that fixes the unfixed toner image on the recording sheet.
On the downstream side in the transport direction of the recording paper after the transfer unit, the roller pair for transporting the recording paper is supported, and at least one end in the axial direction of the roller pair is transported of the recording paper. An image forming apparatus comprising a moving means for moving in a direction.   2. The nip formed by the pair of rollers by the movement of the pair of rollers can be tilted with respect to a reference axis perpendicular to the conveyance direction of the recording paper. Image forming apparatus.   The image forming apparatus according to claim 1, wherein the roller pair is a heating roller and a pressure roller provided in the fixing unit.   The image forming apparatus according to claim 1, wherein the moving unit is formed with a display unit capable of recognizing a movable position of the moving unit.   5. The at least one end portion in the axial direction of the roller pair is movable in a stepwise manner by the moving means in the conveyance direction of the recording paper. The image forming apparatus described in 1.   5. The at least one end portion in the axial direction of the roller pair is continuously movable by the moving means in the conveyance direction of the recording paper. The image forming apparatus described in 1.   A driving unit that moves the moving unit; and a control unit that receives a type signal corresponding to the type of the recording paper and determines a moving range of the moving unit based on the type signal. 4. The image forming apparatus according to claim 1, wherein the driving unit is controlled based on an input type signal. 5.

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