JP2006189579A - Fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To use a paper separating claw over a long period of time by reducing a scratch on a fixing roller surface caused by the paper separating claw provided on the fixing roller, and preventing sticking of toner to the paper separating claw and wear of the paper separating claw itself due to contact with the fixing roller. <P>SOLUTION: The paper separating claw 4 is positioned so that a claw part on its tip is brought into contact with the fixing roller 2 surface. Furthermore, a groove 10 formed on an end part in the longitudinal direction of the fixing roller 2, a guide member 11 engaged with the groove 10 and rocked in the longitudinal direction of the fixing roller 2 by being guided by the groove 10 and a rocking means 5 for the paper separating claw 4 including a supporting member 12 supporting the paper separating claw 4 and the guiding member 11 so as to be movable integrally are included. The paper separating claw 4 is rocked in the longitudinal direction of the fixing roller 2 along the rotational drive of the fixing roller 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fixing device and an image forming apparatus.

  In an electrophotographic image forming apparatus, an electrostatic latent image is formed by exposing signal surface based on image information to a charged photosensitive member surface, and toner is supplied to the electrostatic latent image to form a toner image. An image is formed by forming and transferring and fixing the toner image to a recording medium.

  For fixing the toner image to the recording medium, for example, a fixing device including a fixing roller (heating roller) and a pressure roller that is in pressure contact with the fixing roller is used, and a pressure contact portion between the fixing roller and the pressure roller is used. The recording medium is introduced into the recording medium, and the toner image is fixed on the recording medium by heating and pressing. At this time, the recording medium may be wound around the surface of the fixing roller, causing the fixing roller to malfunction. In order to prevent the recording medium from being wound, a sheet peeling claw is provided so as to lightly contact the surface of the fixing roller. Since the sheet peeling claw contacts the same position on the surface of the fixing roller, in order not to damage the fixing roller, it is manualized to change the contact position at the time of maintenance work performed once every two to three months.

  However, since the sheet peeling claw is always in contact with the surface of the fixing roller that is driven to rotate, the toner remaining on the surface of the fixing roller adheres particularly to the contact portion with the fixing roller and its vicinity, and the toner adhesion portion gradually grows. However, it has a problem of being cured by being exposed to a high temperature and damaging the surface of the fixing roller. In addition, there is a problem that the toner adhering to the paper peeling claw stains the recording medium that is sequentially fed. Furthermore, the sheet peeling claw always comes into contact with the surface of the fixing roller, so that there is a problem that wear is increased in a short period of time. If the paper peeling claw is made of a material having high wear resistance to prevent wear, the surface of the fixing roller is markedly damaged and the toner image may be insufficiently fixed. In order to solve these problems, it is necessary to replace parts with a considerable frequency. However, considering the number of popular electrophotographic image forming apparatuses, such part replacement is very difficult. Therefore, there is a need for a paper peeling claw that is difficult for toner to adhere to and has a small amount of wear.

  In order to meet such requirements, various proposals have been made regarding the material and shape of the sheet peeling claw. For example, a paper peeling claw is proposed in which the main body is made of a highly wear-resistant material such as polyimide resin, and a tip made of a fluororesin such as polytetrafluoroethylene is formed at the tip, and further a tip made of a fluororesin It has been proposed to provide a sheet peeling claw so that is in contact with the surface of the fixing roller (see, for example, Patent Document 1). In the technique of Patent Document 1, a predetermined gap is provided between the paper peeling claw main body and the fixing roller, thereby reducing the adhesion of toner and the wear of the paper peeling claw itself, and the fluorine in which the toner is difficult to adhere to the gap. By interposing a chip made of resin, it is intended to exert a function of preventing the paper from being wound around the original fixing roller of the paper peeling claw. In other words, this paper peeling claw is formed in a chip form of fluororesin having low hardness to reduce the frictional force due to contact with the fixing roller, thereby reducing the wear of the fluororesin and enabling long-term use. Configured.

  However, the paper peeling claw is provided so that a gap is formed between the paper peeling claw body and the fixing roller, and the fluororesin chip that should be present in the gap can be prevented from being worn by rubbing with the fixing roller. Therefore, the effect of preventing the recording medium from being wound around the fixing roller becomes insufficient.

  In addition, an image forming apparatus that has means for separating the paper peeling claw from the fixing roller to make it non-contact, and separating the paper peeling claw from the fixing roller when the fixing roller is not driven (when the image is not formed) is proposed. (For example, see Patent Document 2). Although this is expected to be effective in preventing the toner adhering to the paper peeling claw from being cured by the residual heat of the fixing roller and reducing scratches on the surface of the fixing roller, it is effective in reducing toner adhesion. Less is.

JP-A-6-149114 JP 2004-279927 A

  The object of the present invention is that the surface of the fixing roller is less likely to be damaged, the toner can be prevented from being attached to the paper peeling claw and the paper peeling claw itself coming into contact with the fixing roller, and the paper peeling claw can be used for a long period of time. It is an object of the present invention to provide a fixing device and an image forming apparatus including a sheet peeling claw swinging means.

The present invention includes a fixing roller for fixing a toner image on a recording medium and a pressure roller provided so as to be in pressure contact with the fixing roller;
A paper peeling claw provided to contact the surface of the fixing roller and for peeling the recording medium wound around the fixing roller;
And a paper peeling claw swinging means for swinging the paper peeling claw in the longitudinal direction of the fixing roller in conjunction with rotation of the fixing roller.

  The fixing device of the present invention is characterized in that the paper peeling claw swinging means swings the paper peeling claw with a width equal to or larger than the claw width.

Further, in the fixing device of the present invention, the swinging means of the paper peeling claw is
A groove provided at at least one end in the longitudinal direction of the fixing roller;
A guide member that engages with the groove and is guided by the groove to swing in the longitudinal direction of the fixing roller;
It includes a support member that supports the sheet peeling claw and the guide member so as to be integrally operable.

  Furthermore, the fixing device of the present invention is characterized in that a groove provided at at least one end in the longitudinal direction of the fixing roller is formed in a wavy curved shape or a zigzag shape.

  Further, in the fixing device of the present invention, the groove provided in at least one end portion in the longitudinal direction of the fixing roller is formed in the longitudinal end portion of the fixing roller at a portion that is out of the sheet conveyance area of the fixing roller. It is characterized by that.

  Furthermore, the fixing device of the present invention is characterized in that at least the tip portion of the surface of the paper peeling claw is covered with a fluororesin.

  Further, the fixing device of the present invention includes a second sheet peeling claw provided to come into contact with the surface of the pressure roller and for peeling the recording medium wound around the pressure roller.

The present invention also provides a photosensitive member, a charging unit for charging the photosensitive member, an exposure unit for exposing the charged photosensitive member to signal light to form an electrostatic latent image, and an electrostatic latent image on the surface of the photosensitive member. An electrophotographic system comprising a developing means for developing the toner image to form a toner image, a transfer means for transferring the toner image on the photoreceptor to the recording medium, and a fixing means for fixing the toner image on the recording medium to the recording medium. In the image forming apparatus,
The image forming apparatus is characterized in that the fixing unit is any one of the above-described fixing devices.

  According to the present invention, a fixing device of an electrophotographic image forming apparatus including a fixing roller and a pressure roller is provided so as to be in contact with the surface of the fixing roller and prevents the recording medium from being wound around the fixing roller. In this way, the paper peeling claw that peels the recording medium from the fixing roller is configured to swing in the longitudinal direction of the fixing roller in conjunction with the rotation driving of the fixing roller, thereby preventing the toner from adhering to the paper peeling claw. In addition, the toner once adhered can be removed, the flaws of the fixing roller can be reduced, and the wear due to the contact of the sheet peeling claw with the fixing roller can be reduced.

  According to the present invention, by swinging the paper peeling claw with a width equal to or larger than the claw width by the paper peeling claw swinging means, the contact point of the paper peeling claw to the fixing roller is not concentrated on one part, Since it is appropriately dispersed, the fixing roller is less damaged.

  According to the present invention, the swinging means of the sheet peeling claw is, for example, a groove provided at at least one end in the longitudinal direction of the fixing roller, and engages with the groove and is guided by the groove in the longitudinal direction of the fixing roller. And a support member that supports the sheet peeling claw and the guide member so as to be integrally operable. With this configuration, the sheet peeling claw can be moved in the longitudinal direction of the fixing roller. Can be easily swung.

  According to the present invention, by forming the groove provided at the longitudinal end of the fixing roller in the shape of a wavy curve or zigzag, the guide member and thus the sheet peeling claw can be swung more smoothly.

  According to the present invention, a fixing operation by the fixing roller is formed by forming a groove provided in the longitudinal end portion of the fixing roller at the longitudinal end portion of the fixing roller and further away from the sheet conveyance area of the fixing roller. The sheet peeling claw is reliably swung without hindering the above.

  According to the present invention, by covering at least the tip portion of the paper peeling claw with the fluororesin, the release property of the surface of the paper peeling claw is maintained for a long period of time, coupled with the swing of the paper peeling claw. Further, it is possible to minimize the adhesion of toner to the paper peeling claw and further prevent the recording medium peeling performance of the paper peeling claw from being deteriorated.

  According to the present invention, the winding of the recording medium around the pressure roller is reduced by providing the second sheet peeling claw for peeling the recording medium wound around the pressure roller so as to contact the surface of the pressure roller. In addition, the contamination of the recording medium passing through the pressure contact portion between the fixing roller and the pressure roller is further reduced.

  According to the present invention, there is provided an electrophotographic image forming apparatus using the above-described fixing device of the present invention as fixing means. In the image forming apparatus of the present invention, the fixing roller is hardly damaged in the fixing unit, and toner adhesion to the paper peeling claw and wear of the paper peeling claw are also small. Cost is low.

  FIG. 1 is a side view schematically showing a configuration of a main part of a fixing device 1 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the configuration of the fixing device 1 shown in FIG. FIG. 3 is a side view showing the shape of the groove provided at the longitudinal end of the fixing roller 2 in the fixing device 1 shown in FIG. FIG. 4 is a perspective view showing the appearance of the sheet peeling claw 4 in the fixing device 1 shown in FIG.

  The fixing device 1 includes a fixing roller (heating roller) 2, a pressure roller 3, a paper peeling claw 4, a swinging means 5 for the paper peeling claw 3, a second paper peeling claw 6, and a temperature sensor 7. It is comprised including.

  The fixing roller 2 is supported by a driving unit (not shown) so as to be rotatable around its axis, that is, in the direction of the arrow 8, and heater lamps 9 a and 9 b are provided therein. A wavy curved groove 10 is formed on the surface of one end of the fixing roller 2 in the longitudinal direction. The groove 10 constitutes a part of the swinging means 5 described later. The fixing roller 2 may be one commonly used in the field of electrophotographic image formation (hereinafter referred to as “this field”). For example, a coating layer 2b containing a fluororesin on the surface of a cylindrical aluminum base tube 2a. A roller formed by forming In the case of this roller, heater lamps 9a and 9b are arranged inside the aluminum base tube 2a. For example, a motor is used as the driving means (not shown). The motor is provided with a variable drive speed, and the rotation speed of the fixing roller 2 can be changed. Further, by providing the clutch portion, the fixing roller 2 can be rotated forward and backward.

  The pressure roller 3 faces and is in pressure contact with the fixing roller 2 and is rotatably provided. The pressure roller 3 rotates following the rotation of the fixing roller 2. As the pressure roller 3, those commonly used in this field can be used. For example, a roller including an aluminum element tube 3 a and an elastic body layer 3 b formed on the surface of the aluminum element tube 3 a is used. Although there is no restriction | limiting in particular as an elastic body which comprises the elastic body layer 3a, A silicone rubber is preferable. By using silicone rubber, the following advantages can be obtained. The hardness of the surface layer of the fixing roller 2 is high, and the silicone rubber constituting the elastic body layer 3a that is the surface layer of the pressure roller 3 is rich in elasticity, so that the pressure contact portion between the fixing roller 2 and the pressure roller 3 (hereinafter, “ In the nip portion, the surface layer of the pressure roller 3 is deformed, so that the recording medium is slightly wound around the surface of the fixing roller 2, and the fixing of the toner image to the recording medium further proceeds. The recording medium wound around the fixing roller 2 is easily peeled off from the surface of the fixing roller 2 by the paper peeling claw 4. Further, the area of the nip portion is increased, and the heating capacity for the recording medium is increased. Further, by applying pressure with a flexible pressure roller 3, the toner can be fixed without being deformed.

  A recording medium carrying a toner image is fed to a nip portion between the fixing roller 2 and the pressure roller 3 via a paper entry guide plate 15 that guides paper entry into the nip portion. At this time, the recording medium is fed so that the toner image carrying surface is in contact with the surface of the fixing roller 2. Note that a pair of upper and lower unloading guide plates (not shown) for guiding the sheet ejection from the fixing device 1 are provided on the exit (sheet ejection port) side of the nip portion.

  The fixing roller 2 and the pressure roller 3 rotate under pressure to heat and press the recording medium supplied with the toner image to the nip portion to fix (fuse) the toner image to the recording medium. .

  The sheet peeling claw 4 is provided so as to lightly contact the surface of the fixing roller 2 on the downstream side of the nip portion in the rotation direction of the fixing roller 2, that is, in the direction of the arrow 8. Although a plurality of sheet peeling claws 4 are provided in the present embodiment, a single sheet peeling claw 4 may be provided. As shown in FIG. 4, the sheet peeling claw 4 has a bowl-like appearance, and a body portion 4 a having a through hole 4 c through which a support member 12 that operably supports the sheet peeling claw 4 is attached. And a claw portion 4b that is continuous with the body portion 4a and extends from one end portion thereof and has a tip portion formed in a wedge shape. Here, the claw width of the sheet peeling claw 4 means a width d in the same direction as the longitudinal direction of the fixing roller 2 at the wedge-shaped tip where the claw portion 4b contacts the surface of the fixing roller 2. The wedge-shaped tip of the claw portion 4 b comes into contact with the surface of the fixing roller 2. For the paper peeling claw 4, a material commonly used in this field can be used, and examples thereof include synthetic resins such as polyimide and polyamideimide. Although not shown, at least the tip of the sheet peeling claw 4 can be coated with a fluorine resin such as polytetrafluoroethylene (PTFE) or (PFA). As a result, the adhesion of toner to the paper peeling claw 4 is further reduced, and the function as the paper peeling claw 4 is maintained for a longer period of time.

  The swinging means 5 of the sheet peeling claw 4 engages with the groove 10 provided in at least one of the longitudinal directions of the fixing roller 2 and is guided by the groove 10 to swing in the longitudinal direction of the fixing roller 2. It includes a guide member 11, and a support member 12 that supports the sheet peeling claw 4 and the guide member 11 so as to be integrally operable.

  The groove 10 is preferably formed on the surface of the end portion in the longitudinal direction of the fixing roller 2 and at a portion outside the sheet conveyance area of the fixing roller 2. As a result, the sheet conveyance proceeds more smoothly without hindering the fixing operation. The groove 10 is formed in a wavy curve in the rotation direction of the fixing roller 2 (the direction of the arrow 8). By changing the amplitude (the magnitude of the wave) of the waveform curve in the longitudinal direction of the fixing roller 2, the swinging width of the sheet peeling claw 4 can be adjusted as appropriate. The swinging width of the sheet peeling claw 4 is preferably a width equal to or larger than the claw width. With such a swinging width, concentrated contact of the sheet peeling claw 4 with a part of the surface of the fixing roller 2 is prevented, and damage to the fixing roller 2 is prevented.

  The guide member 11 engages with the groove 10, and is guided in the longitudinal direction of the fixing roller 2 by the rotation of the fixing roller 2, and swings in the direction of the arrows 13 and 14. On the other hand, the guide member 11 is supported by the support member 12 so as to be able to operate integrally with the sheet peeling claw 4. The engaging portion of at least the guide member 11 with the groove 10 is preferably formed in a cylindrical shape. The guide member 11 is preferably formed using a material having good heat resistance and slipperiness such as polyimide and polyamideimide. Thereby, the followability to the rotation of the groove 10 is further improved.

  The support member 12 is mounted so as to be inserted into the through-hole 4c of the paper peeling claw 4 provided with a plurality, and supports the paper peeling claw 4. The support member 12 is a rod-like member that extends parallel to the axis of the fixing roller 2, and is attached to the apparatus main body of the fixing device 1 so as to reciprocate in the axis direction of the fixing roller 2. In the present embodiment, the support member 12 is formed to have a length that is greater than or equal to the axial length of the fixing roller 2 and faces the sheet peeling claw 4 at a position facing the portion where the groove 10 of the fixing roller 2 is formed. The guide member 11 is mounted so as to be parallel. That is, the support member 12 supports the sheet peeling claw 4 and the guide member 11 so as to be able to operate integrally. Therefore, as the guide member 11 swings, the support member 12 and thus the sheet peeling claw 4 swings.

  According to the swinging means 5 of the sheet peeling claw 4, the guide member 11 engaged with the groove 10 on the end surface of the fixing roller 2 swings as the fixing roller 2 rotates, and the guide member 11 swings. Is transmitted to the sheet peeling claw 4 via the support member 12, and the sheet peeling claw 4 swings on the surface of the fixing roller 2 in the longitudinal direction.

  The sheet peeling claw 4 that contacts the surface of the fixing roller 2 is provided with a swinging means because the surface of the fixing roller 2 is in contact with the toner image adhering surface of the recording medium and the toner is more dirty than the pressure roller 3. It is because it is easy to remain.

  The second paper peeling claw 6 is provided so as to lightly contact the surface of the pressure roller 3 on the downstream side of the nip in the rotation direction of the pressure roller 3 that is the same direction as the rotation direction of the fixing roller 2. The recording medium wound around the roller 3 is peeled off from the surface of the pressure roller 3. The second paper peeling claw 6 is formed in the same shape as the paper peeling claw 4 and is supported by a support member similar to the support member 12. The second paper peeling claw 6 can also be provided with the same swinging means as the paper peeling claw 5, but has much less toner adhesion than the fixing roller 2 that directly contacts the toner image carrying surface of the recording medium. Since the pressure roller 3 is a target, the swinging unit may not be provided. According to the second paper peeling claw 6, the recording medium wound around the pressure roller 3 is peeled off from the surface of the pressure roller 3.

  The temperature sensor 7 is provided on the opposite surface of the fixing roller 2 to the nip portion, and controls the surface temperature of the fixing roller 2 by detecting the surface temperature of the fixing roller 2. For the temperature sensor 7, for example, a thermistor is used. The detection result of the temperature sensor 7 is sent to a CPU (not shown) that controls the entire operation of the image forming apparatus including the fixing device 1, and the CPU calculates a difference from a predetermined surface temperature according to the detection result, A control signal is sent to a power supply means (not shown) that applies a voltage to the heater lamps 9a and 9b so that the error becomes 0, and the surface temperature of the fixing roller 2 is controlled by controlling the heat generation temperature of the heater lamps 9a and 9b. Control.

  According to the fixing device 1, a recording medium carrying a toner image is fed to the nip portion between the fixing roller 2 and the pressure roller 3, and the toner image is fixed to the recording medium by receiving heat and pressure. At that time, the sheet peeling claw 4 provided so as to come into contact with the fixing roller 2 contacts the surface of the fixing roller 2 while swinging in the longitudinal direction of the fixing roller 2 as the fixing roller 2 is driven to rotate. In addition to preventing the recording medium from being wound around the fixing roller 2, scratches on the surface of the fixing roller 2, toner adhesion to the paper peeling claw 4, and wear and tear of the paper peeling claw 4 are prevented. Further, the second sheet peeling claw 6 is also provided on the surface of the pressure roller 3 to prevent the recording medium from being wound around the pressure roller 3.

  FIG. 5 is a side view schematically showing a configuration of a main part of the fixing roller 2x provided in the fixing device according to the second embodiment of the present invention. Since the fixing device according to the present embodiment is configured in the same manner as the fixing device 1 according to the first embodiment except for the fixing roller 2x, a diagram illustrating the entire configuration is omitted, and only the main configuration of the fixing roller 2a is illustrated. Show.

  The fixing roller 2x provided in the fixing device of the present embodiment is characterized by the shape of the groove 10x formed at one end portion in the longitudinal direction, and is formed in a zigzag shape in the rotation direction of the fixing roller 2x. The fixing device of the present embodiment configured as described above can achieve the same effects as those of the fixing device 1 of the first embodiment.

  Next, the image forming apparatus of the present invention will be described. The image forming apparatus of the present invention can have the same configuration as that of a conventional image forming apparatus except that the fixing device of the present invention is provided as a fixing unit that fixes a toner image on a recording medium.

FIG. 6 is a cross-sectional view schematically showing the configuration of the image forming apparatus 20 according to the third embodiment of the present invention. FIG. 7 is a cross-sectional view showing a configuration of a main part of the image forming apparatus 20 shown in FIG.
The image forming apparatus 20 includes an image forming unit 21 and a paper supply unit 22.

  The image forming unit 21 includes a photoconductor 23, a charging unit 24, an exposure unit 25, a developing unit 26, a transfer unit 27, a cleaning unit 28, and the fixing device 1.

  The photosensitive member 23 is supported by a driving unit (not shown) so as to be rotatable around an axis, and includes a cylindrical or columnar conductive substrate (not shown) and a photosensitive layer formed on the surface of the conductive substrate. The As the photoreceptor, those commonly used in this field can be used. For example, the photoreceptor includes an aluminum base tube which is a conductive substrate and an organic photosensitive layer formed on the surface of the aluminum base tube, and has a diameter connected to the GND potential. An example is a 30 mm photoconductor. The organic photosensitive layer is formed by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. The organic photosensitive layer may include a charge generation material and a charge transport material in one layer. The layer thickness of the organic photosensitive layer is, for example, 20 μm. Further, an underlayer may be provided between the photoreceptor and the organic photosensitive layer.

  The charging unit 24 charges the surface of the photoconductor 23 to a predetermined polarity and potential. In the present embodiment, a charging roller is used as the charging unit 24, but the charging unit 24 is not limited thereto. For example, a brush type charger, a charger type charger, a corona charger such as a scorotron, or the like can be used.

  The exposure unit 25 irradiates the charged surface of the photosensitive member 23 with the signal light 25a corresponding to the image information, and forms an electrostatic latent image corresponding to the image information on the surface of the photosensitive member 23. For the exposure means 25, a semiconductor laser or the like is used. Image information is transmitted from a CPU (not shown).

  The developing unit 26 includes a toner supply unit 26a and a toner storage unit 26b. The toner supply unit 26a is in pressure contact with the surface of the photoconductor 23, supplies toner to the electrostatic latent image on the surface of the photoconductor 23, and develops the electrostatic latent image to form a toner image. The toner storage unit 26b stores toner and supplies the toner to the toner supply unit 26a according to the toner consumption amount in the toner supply unit 26a.

  The transfer unit 27 is in pressure contact with the surface of the photoconductor 23, and in synchronization with the toner image on the photoconductor 23 reaching the pressure contact portion between the photoconductor 23 and the transfer unit 27, the photoconductor from the paper supply unit 22 described later. The toner image on the surface of the photoconductor 23 is transferred to the recording medium fed to the pressure contact portion between the transfer unit 27 and the transfer unit 27 by pressing. For the transfer means 27, for example, a transfer roller is used.

  The cleaning unit 28 is provided so as to contact the surface of the photoconductor 23 and removes toner, paper powder, and the like remaining on the surface of the photoconductor 23 after the transfer of the toner image to the recording medium, and cleans the surface of the photoconductor 23. .

  Since the fixing device 1 has the same configuration as the fixing device 1 shown in FIG. 1, the same reference numerals are given to corresponding portions, and description thereof is omitted. The fixing device 1 has a pair of upper and lower frames 38 provided with a paper inlet 38a and a paper outlet 38b. The fixing device 1 includes a paper inlet 38a and a paper inlet side of the nip portion, and a paper outlet 38b and a paper outlet of the nip portion. It is accommodated so as to correspond to the paper mouth side. The fixing device 1 fixes the toner image on the recording medium, and an image is formed on the recording medium.

  The recording medium on which the image is formed by the fixing device 1 is discharged via a discharge roller 29 to a paper discharge tray 30 provided outside the image forming device 20.

  According to the image forming unit 21, the surface of the photoconductor 23 that is rotationally driven in the axial direction is charged by the charging unit 24, and then the exposure unit 25 irradiates the signal light 25a corresponding to the image information to form an electrostatic latent image. Then, the toner is supplied from the developing unit 26 to obtain a toner image, and the toner image is transferred to the recording medium by the transfer unit 27 and further fixed by the fixing device 1. The recording medium on which the image is thus formed is discharged to an external paper discharge tray 30 via a discharge roller 29. On the other hand, the surface of the photoconductor 23 after the toner image is transferred is cleaned by the cleaning unit 28. This series of steps is repeated to form an image.

  In the present embodiment, the image forming unit 21 forms a single color image, but a configuration for forming a color image may be employed.

  The paper supply unit 22 includes paper cassettes 31, 32, 33, and 34 and paper transport paths 35, 36, and 37.

  Each of the paper cassettes 31, 32, 33, and 34 accommodates a recording medium. These paper cassettes may contain recording media of the same size, or may contain recording media of different sizes.

  The recording media accommodated in the paper cassettes 31, 33, and 34 are fed to a contact portion between the photoconductor 23 and the transfer unit 27 in the image forming unit 21 via the paper conveyance path 35.

  The recording medium accommodated in the paper cassette 32 is fed to a contact portion between the photoconductor 23 and the transfer unit 27 in the image forming unit 21 via the paper conveyance path 36.

  The paper transport path 37 is used when images are formed on both sides of the recording medium. That is, the recording medium on which the toner image is fixed by the fixing device 1 and the image is formed on one side is returned to the sheet conveying path 35 via the sheet conveying path 37, and the toner image is transferred and fixed on the other side. Note that before the recording medium having an image formed on one side is fed to the paper conveyance path 37, the front and back of the recording medium are reversed by a reversing mechanism (not shown).

  According to the paper supply unit 22, the recording medium accommodated in the paper cassettes 31, 32, 33, 34 is fed to the press contact portion between the photosensitive member 23 and the transfer unit 27 via the paper conveyance path 35 or 36. The When images are formed on both sides, the recording medium on which the image is formed on one side is returned to the paper transport path 35 via the paper transport paper transport path 36 and used for image formation again.

  According to the image forming apparatus 20, a toner image is formed on the surface of the photoconductor 23 based on image information input to the image forming CPU, and this is transferred to a recording medium fed from a paper supply unit and fixed. To form an image.

FIG. 8 is a cross-sectional view schematically showing a configuration of an image forming apparatus 40 according to the fourth embodiment of the present invention. The image forming apparatus 40 has a configuration similar to that of the image forming apparatus 20, and corresponding portions are denoted by the same reference numerals and description thereof is omitted.
The image forming apparatus 40 is characterized in that the paper supply unit 41 includes a manual feed unit 42.

  The manual feed means 42 includes a manual feed tray 43 on which a recording medium is placed, a pair of take-in rollers 44 for taking the print medium placed on the manual feed tray 43 into the image forming apparatus 40, and a print medium taken in by the take-in roller 44. And a sheet conveying path 45 for feeding the sheet to the sheet conveying path 36.

  According to the manual feed unit 42, the recording medium placed on the manual feed tray 43 is taken into the image forming apparatus 40 by the take-in roller 44, and is fed to the paper transport path 36 via the paper transport path 45. It is used for image formation.

  According to the image forming apparatus 40, the recording medium can be fed not only from the paper cassettes 31, 32, 33, 34 but also from the manual feed tray 43 to the image forming unit 21, and to recording media having various shapes and / or materials. Image formation can be easily performed.

  FIG. 9 is a cross-sectional view schematically showing a configuration of an image forming apparatus 50 according to the fifth embodiment of the present invention. The image forming apparatus 50 has a configuration similar to that of the image forming apparatus 40, and corresponding portions are denoted by the same reference numerals and description thereof is omitted.

  The image forming apparatus 50 is characterized in that the paper supply unit 51 includes an additional paper cassette 52.

  The paper supply unit 51 includes paper cassettes 31, 32, 33, 34, 52, paper conveyance paths 35, 36, 37, 53, and manual feed means 42.

  The paper cassette 52 has a larger capacity than the other paper cassettes 31, 32, 33, and 34, and is suitable for accommodating a recording medium having a size that is frequently used. The recording medium accommodated in the paper cassette 52 is supplied to the image forming unit 21 via the paper conveyance path 53 and the paper conveyance path 36.

  According to the image forming apparatus 50, the recording medium can be fed from the paper cassettes 31, 32, 33, 34, 52 and the manual feed tray 43 to the image forming unit 21, and images on recording media having various shapes and / or materials can be supplied. Formation is easy. In particular, the sheet cassette 52 has a large capacity and can accommodate a large amount of frequently used recording media, so that the number of operations for storing the recording medium in the sheet cassette 52 can be reduced.

  FIG. 10 is a cross-sectional view schematically showing a configuration of an image forming apparatus 55 according to the sixth embodiment of the present invention. The image forming apparatus 55 is similar to the image forming apparatus 20, and corresponding portions are denoted by the same reference numerals and description thereof is omitted.

  The image forming apparatus 55 is characterized in that the take-in roller 44 of the manual feed unit 57 in the paper supply unit 56 is provided outside the image forming apparatus 55.

  The manual feed unit 57 includes a manual feed tray 43, a take-in roller 44, and a paper feed path 58 that feeds a recording medium fed into the image forming apparatus 55 by the take-in roller 44 to the paper feed path 36. Composed.

  According to the manual feed means 42, the recording medium placed on the manual feed tray 43 is fed into the image forming apparatus 55 by the take-in roller 44, and the image is further passed through the paper transport path 58 and the paper transport path 36. It is fed to the forming unit 21.

  According to the image forming apparatus 55, it is very easy to place the recording medium on the manual feed tray 43 of the manual feed means 42, and the lengths of the manual feed tray 43 and the take-in roller 44 in the longitudinal direction can be increased. Therefore, even a large-sized recording medium can be fed into the image forming apparatus 55 manually.

FIG. 3 is a side view schematically showing a configuration of a main part of the fixing device according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the configuration of the fixing device shown in FIG. 1. FIG. 2 is a side view showing a shape of a groove provided at a longitudinal end portion of a fixing roller in the fixing device shown in FIG. 1. FIG. 2 is a perspective view illustrating an appearance shape of a sheet peeling claw in the fixing device illustrated in FIG. 1. FIG. 6 is a side view schematically showing a configuration of a main part of a fixing roller provided in a fixing device according to a second embodiment of the present invention. It is sectional drawing which shows typically the structure of the image forming apparatus which is 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the principal part of the image forming apparatus shown in FIG. It is sectional drawing which shows typically the structure of the image forming apparatus which is 4th Embodiment of this invention. It is sectional drawing which shows typically the structure of the image forming apparatus which is 5th Embodiment of this invention. It is sectional drawing which shows typically the structure of the image forming apparatus which is 6th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixing device 2, 2x Fixing roller 2a Aluminum elementary tube 2b Covering layer 3 Pressure roller 3a Aluminum elementary tube 3b Elastic layer 4 Paper peeling claw 4a Body part 4b Claw part 4c Through-hole 5 Oscillating means 6 Second Paper peeling claw 7 Temperature sensor 8, 13, 14 Arrows 9a, 9b Heater lamp 10, 10x Groove 11 Guide member 12 Support member 15 Paper entry guide plate 20, 40, 50, 55 Image forming apparatus 21 Image forming unit 22, 41 , 51, 56 Paper supply unit 23 Photoconductor 24 Charging means 25 Exposure means 25a Signal light 26 Developing means 26a Toner supply means 26b Toner storage means 27 Transfer means 28 Cleaning means 29 Discharge roller 30 Paper discharge trays 31, 32, 33, 34 , 52 Paper cassette 35, 36, 37, 45, 53, 58 Paper transport path 38 Frame 38a Paper port 38b Desi port 42,57 Bypass supply means 43 bypass tray 44 uptake roller

Claims (8)

A fixing roller for fixing a toner image on a recording medium and a pressure roller provided so as to be in pressure contact with the fixing roller;
A paper peeling claw provided to contact the surface of the fixing roller and for peeling the recording medium wound around the fixing roller;
A fixing device comprising: a paper peeling claw swinging means for swinging the paper peeling claw in the longitudinal direction of the fixing roller in conjunction with rotation of the fixing roller.   2. The fixing device according to claim 1, wherein the paper peeling claw swinging means swings the paper peeling claw with a width equal to or larger than the claw width. The swinging means of the paper peeling claw
A groove provided at at least one end in the longitudinal direction of the fixing roller;
A guide member that engages with the groove and is guided by the groove to swing in the longitudinal direction of the fixing roller;
The fixing device according to claim 1, further comprising a support member that supports the sheet peeling claw and the guide member so as to be integrally operable. A groove provided at at least one end in the longitudinal direction of the fixing roller is
The fixing device according to claim 3, wherein the fixing device is formed in a corrugated curve shape or a zigzag shape. A groove provided at at least one end in the longitudinal direction of the fixing roller is
5. The fixing device according to claim 3, wherein the fixing device is formed at an end portion of the fixing roller in a longitudinal direction, and is deviated from a sheet conveyance area of the fixing roller.   The fixing device according to claim 1, wherein at least a front end portion of the surface of the paper peeling claw is covered with a fluororesin.   Furthermore, it includes a second paper peeling claw provided to come into contact with the surface of the pressure roller and for peeling a recording medium wound around the pressure roller. The fixing device according to one. A photosensitive member; a charging unit that charges the photosensitive member; an exposure unit that exposes a charged photosensitive member to signal light to form an electrostatic latent image; and a toner that develops the electrostatic latent image on the surface of the photosensitive member In an electrophotographic image forming apparatus comprising: a developing unit that forms an image; a transfer unit that transfers a toner image on a photosensitive member to a recording medium; and a fixing unit that fixes the toner image on the recording medium to the recording medium.
An image forming apparatus, wherein the fixing unit is any one of the fixing devices according to claim 1.

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