JP5002410B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile machine, or a multifunction machine, and more particularly to a structure of a fixing unit that fixes a toner image transferred onto a sheet to the sheet.

  A fixing device of an image forming apparatus heats an unfixed toner image transferred onto a sheet by a heating roller, and conveys the toner image on the sheet by conveying it through a nip between the heating roller and the pressure roller. It is fixed. In order to raise the temperature of the surface of the heating roller, in addition to the radiation heating method in which a heat source such as a halogen lamp is installed therein, an induction heating method in which the heating roller itself generates heat is adopted. In this induction heating method, it is possible to raise the temperature of the heating roller early by eddy current due to electromagnetic induction.

As a prior art related to a fixing device adopting an induction heating method, there is one having a structure in which a bobbin having an induction heating function is arranged inside a cylindrical heating roller (see, for example, Patent Document 1). The bobbin also has a cylindrical shape, and an induction coil, a ferrite core, and the like are disposed inside the bobbin. Since the heating roller and the bobbin are configured separately, and the wiring connected to the induction coil is housed inside the bobbin, the heating roller can freely rotate. In particular, in the prior art, one end of the bobbin is fixed to the side plate of the main body of the image forming apparatus. For this reason, when removing the fixing device, since the bobbin remains on the main body side of the image forming apparatus, it is considered that operations such as disassembly and reassembly can be easily performed when the heating roller is replaced.
Japanese Patent Laid-Open No. 2002-311729 (FIG. 1)

  However, in the structure in which the bobbin remains in the main body of the image forming apparatus as in the prior art, the circuit board or the like that supplies current to the coil also remains in the main body together with the bobbin. For this reason, in order to perform maintenance / inspection work on the circuit board, after removing the fixing device, the operator extends his hand to the back of the image forming apparatus main body, and removes, replaces, or attaches the circuit board. Must be done. Such an operation is particularly difficult when the space after the fixing device is removed is small.

  An object of the present invention is to improve workability such as maintenance and inspection for a fixing device.

  An image forming apparatus according to an aspect of the present invention includes a main body, an image forming unit that is housed in the main body, forms a toner image based on image data, and transfers the toner image to a transfer material, and the main body The toner includes: a drawer unit that is housed in the body so as to be able to be pulled out; a heating member that is detachably attached to the drawer unit; and a pressure member that comes into contact with the heating member with a predetermined pressure. The transfer material on which the image has been transferred is sandwiched between the heating member and the pressure member and conveyed, and the fixing unit fixes the toner image to the transfer material with the heat from the heating member, and the fixing unit is attached to the drawer unit. A heating device that is positioned in the vicinity of the heating member in a mounted state and raises the temperature of the heating member, and the heating device is a separate mounting portion from the heating member It has been fixed to the drawer unit, wherein also the fixing unit is operation performed is detached from the drawer unit, and maintains a fixed state with respect to the drawer unit (claim 1).

  In this case, the heating member is a heating rotator, the pressure member is a pressure rotator, and the pressure rotator is brought into contact with the heating rotator with a predetermined pressure to form a nip portion. It is preferable that the transfer material on which the toner image is transferred is sandwiched and conveyed by the nip portion.

  An image forming apparatus according to another aspect of the present invention includes a main body, and an image forming unit that is accommodated in the main body, forms a toner image based on image data, and transfers the toner image to a transfer material. A transfer unit that is housed in the main body body so as to be slidable to the outside, and that transfers the transfer material onto which the toner image has been transferred, through a predetermined transfer path, and is detachably attached to the transfer unit, And a pressure rotator that is brought into contact with the heating rotator at a predetermined pressure to form a nip portion. The transfer material conveyed through the conveyance path is sandwiched and conveyed by the nip portion, and the heating rotation A fixing unit for fixing a toner image to the transfer material by heat from the body, an induction coil for generating an induction current in the heating rotator, and a mounting part separate from the heating rotator The fixing unit is mounted on the transport unit and is positioned in the vicinity of the heating rotator. The induction coil is held at this position, and the fixing unit is mounted on the transport unit. And a coil holding member that maintains a fixed state with respect to the transport unit even when an operation of being detached from the unit is performed (Claim 3).

  According to the image forming apparatus as described above, the heating device or the coil holding member is accommodated in the vicinity of the heating member at the time of operation (at the time of fixing the toner image), and the heating member is appropriately placed at this position. The function of raising the temperature can be exhibited.

  On the other hand, since the fixing unit is further detachably attached to the drawer unit or the transport unit that can be pulled out from the inside of the main body of the image forming apparatus, the drawer unit and the transport unit are first removed from the main body of the image forming apparatus. When pulled out, the fixing unit is exposed to the outside of the main body together with these units.

  Next, when the fixing unit is removed from the drawer unit or the transport unit, the temperature rising device or the coil holding member is relatively separated from the position near the heating member, and remains in the drawer unit or the transport unit. . In this case, since the temperature raising device or the coil holding member is exposed outside the main body of the image forming apparatus, operations such as maintenance and inspection, parts replacement, and repair can be easily performed.

  For the heating member and the pressure member, for example, a rotary member such as a roller or an endless belt can be used. In particular, when the heating member is constituted by a cylindrical roller, the temperature is increased in a space formed inside the heating member. An instrument or a coil holding member is inserted and arranged. In such a case, when the fixing unit is attached, the heating device or the coil holding member is accommodated inside the heating roller, and when the fixing unit is removed, the heating device or the coil holding member is relatively moved from the inside of the heating member. It will come out and will be exposed.

  Therefore, the maintenance work of the fixing unit becomes extremely easy. Moreover, it is not necessary to carry out the complicated wiring of the temperature rising device and the coil holding member, and the necessary work can be efficiently performed on the coil holding member and the current supply unit.

  The said structure WHEREIN: It is desirable to provide further the electric current supply part which is attached to the said conveyance unit and supplies an electric current to the induction coil of the said coil holding member (Claim 4). In this case, it is particularly preferable that the current supply unit is a circuit board, the transport unit has a frame plate on the rear end side in the sliding direction, and the circuit board is attached to the frame plate ( Claim 5).

  According to this configuration, it is possible to easily perform maintenance / inspection, replacement of parts, and repair work for the current supply unit together with the coil holding member. Further, since the coil holding member does not remain in the main body of the image forming apparatus as in the prior art, it is not necessary to lengthen the wiring in accordance with the pulling operation of the transport unit or to complicate its handling.

  In the above configuration, the transport unit can be slid out of the main body body in a direction orthogonal to the paper transport direction, and the fixing unit can be pulled in a direction orthogonal to the paper transport direction with respect to the transport unit. The coil holding member extends in a direction perpendicular to the paper conveyance direction with respect to the conveyance unit, and the fixing unit is It is desirable to be inserted through a space formed inside the heating rotator while being mounted on the transport unit.

  According to this configuration, for example, when the heating member or the pressure member is constituted by a rotary roller or belt, the sliding direction of the fixing unit is the rotation axis of the heating roller, the pressure roller, the heating belt, the pressure belt, or the like. Since a structure matching the direction can be employed, interference between the heating member (roller, belt, etc.) and the coil holding member is less likely to occur during the attaching / detaching operation.

  In this case, the transport unit includes a bottom plate, and a guide rail extending in a direction perpendicular to the paper transport direction is provided on the bottom plate, and the fixing unit supports the heating rotator and the pressure rotator. Preferably, the support plate includes a leg that is guided by the guide rail.

  According to this configuration, the operator can easily remove the fixing unit from the transport unit.

  According to the image forming apparatus of the present invention, the maintenance work of the fixing unit becomes extremely easy. Moreover, it is not necessary to carry out the complicated wiring of the temperature rising device and the coil holding member, and the necessary work can be efficiently performed on the coil holding member and the current supply unit.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic cross-sectional view showing a configuration of an image forming apparatus 100 according to the first embodiment of the present invention. The image forming apparatus 100 has a function as, for example, a copying machine, a facsimile transmitter / receiver, a multifunction peripheral, or a multifunction peripheral device (MFP). The image forming apparatus 100 includes a main body 100B, a document feeding section 4 disposed on the top of the main body 100B, and an optical reading section 5 disposed at a position corresponding to the lower side of the document feeding section 4. . When copying a document or transmitting a facsimile, the user loads and uses a document on which images such as characters, graphics, and patterns are drawn on the document feeding unit 4. When there are a plurality of documents, the document feeding unit 4 separates and transports the documents one by one, and the optical reading unit 5 reads the image.

  The image forming apparatus 100 includes an image forming unit 6 accommodated in the main body 100B. The image forming unit 6 forms an image based on image data obtained by processing an image read by the optical reading unit 5 or image data received through a network. Specifically, the image forming unit 6 forms an electrostatic latent image on the surface of the photosensitive drum provided therein, and further develops the electrostatic latent image with toner to form a toner image.

  Further, the image forming apparatus 100 includes a paper feeding unit 70 at the lower part of the main body. The paper feed unit 70 includes a three-stage paper feed cassette 7. The sheet feeding cassette 7 is a so-called front loading type, and each of the sheet feeding cassettes 7 can be slid out of the image forming apparatus 100 to the front side (front side as viewed in FIG. 1). In each paper feed cassette 7, paper P such as cut paper before printing is stacked and accommodated. From the paper supply unit 70, the paper P stacked in the paper supply cassette 7 is separated and sent out one by one.

  Different paper sizes and paper types can be set in the upper, middle, and lower paper feed cassettes 7 at respective positions. For example, the uppermost sheet cassette 7 can be used for multiple purposes, and can accommodate OHP sheets, thick paper, thin paper, and the like. The middle sheet cassette 7 can store A4 plain paper, which is relatively frequently used, and the bottom sheet cassette 7 can store sheets larger than A4. The paper size, paper type, and the like stored in each stage of paper feed cassette 7 can be set in the image forming apparatus 100 in advance.

  A manual paper feed unit 14 is provided on the right side surface of the main body 100B so as to protrude rightward. On the manual paper feed unit 14, paper P having a size not included in the paper feed unit 70 or paper to be fed one by one such as an OHP sheet is placed. The manual sheet feeder 14 may be configured to be folded and stored on the right side surface of the main body 100B.

  The image forming apparatus 100 includes a paper transport unit 80 on the right side of the main body 100B. When viewed from the relationship with the paper feed unit 70, the paper transport unit 80 is located to the right, which is the paper feed direction. The paper P delivered from the paper supply unit 70 is conveyed vertically upward along the side of the main body by the paper conveyance unit 80, and the paper P delivered from the manual paper supply unit 14 is conveyed horizontally.

  The image forming apparatus 100 includes a registration roller 8 that feeds the sheet conveyed by the sheet conveying unit 80 to the image forming unit 6. The registration roller 8 corrects the oblique feeding of the paper P and feeds the paper P toward the image forming unit 6 while synchronizing with the toner image formed by the image forming unit 6. The image forming unit 6 transfers the toner image from the surface of the photosensitive drum to the paper P.

  The image forming apparatus 100 includes a transport unit 9 (drawer unit) disposed in a section from the lower side of the image forming unit 6 to the left side thereof. The transport unit 9 transports the paper P on which the toner image is transferred by the image forming unit 6 toward the fixing unit 10.

  The fixing unit 10 includes a heating roller 10a (heating member: heating rotator) and a pressure roller 10h (pressure member: pressing rotator) that is brought into contact with the heating roller 10a with a predetermined pressure to form a nip portion. Including. The fixing unit 10 sandwiches and conveys the paper P at the nip portion, and pressurizes the paper P while heating it, thereby fixing the toner image on the paper P. In the present embodiment, the fixing unit 10 is incorporated in the transport unit 9 due to its structure.

  Further, the image forming apparatus 100 includes a paper discharge / branching unit 11 at a position adjacent to the transport unit 9. When double-sided printing of images is not performed (in the case of single-sided printing), the paper P transported by the transport unit 9 via the fixing unit 10 is directly discharged from the paper discharge / branch unit 11 to the paper receiving tray 13 outside the main body 100B. Paper.

  The image forming apparatus 100 includes a double-sided printing unit (double-sided printing mechanism) 12. When double-sided printing is performed in the image forming apparatus 100, the paper P discharged from the transport unit 9 is sent to the double-sided printing unit 12 through the paper discharge / branching unit 11. The transport direction of the paper P sent to the duplex printing unit 12 is subsequently switched by the paper reversing device 12 a provided in the duplex printing unit 12, and from here through the paper transport unit 80 and the registration roller 8 again. The image is sent to the image forming unit 6.

  The sheet reversing device 12a includes a switchback mechanism 12c and a shift mechanism 12d. The switchback mechanism 12c is for reversing the transport direction of the paper P. The shift mechanism 12d is for correcting a positional deviation in the width direction of the paper. A sensor 12b for detecting a positional deviation in the width direction of the paper P is provided at a position closer to the paper discharge / branching unit 11 than the shift mechanism 12d in the paper transport direction.

  An intermediate tray 12e is installed further on the image forming unit 6 side of the switchback mechanism 12c when viewed in the direction of entry into the sheet reversing device 12a. The intermediate tray 12e temporarily stores the paper P printed on one side. The switchback mechanism 12c temporarily stores the paper P in the intermediate tray 12e, and then switches it back to switch the transport direction.

  The paper P that has been switched back is subjected to position correction by the shift mechanism 12d, and then reversed so as to sink downward at a position downstream of the transport direction. Then, the sheet P is sent to the right by the plurality of conveying rollers 12f below the image forming unit 6, and then merges into the sheet conveying unit 80 while slightly rising. As a result, the paper P is sent to the image forming unit 6 with the first printed surface facing downward, and printing is performed on both sides of the paper P. The paper P on which double-sided printing has been performed is discharged to the paper receiving tray 13 through the paper discharge / branching unit 11. Alternatively, the paper P is reversed again by the paper reversing device 12 a, then conveyed upward along the left side portion of the main body 100 </ b> B, and discharged to the paper receiving tray 13.

  In the image forming apparatus 100 having the above-described configuration, for example, an operation for copying a document is performed as follows.

  First, in image processing involving copying of a document, when a user presses a start button on an operation unit (not shown) with the document placed on the document feeding unit 4, the following processing is performed according to this operation. First, when a paper sensor (not shown) built in the document feeding unit 4 detects a document sheet, the document feeding unit 4 transports the document one by one, and the optical reading unit 5 in the middle of the document The image is scanned. The image data read at this time is stored in units of one job by a control unit (not shown).

  The control unit performs preprocessing such as image noise removal on the image data, performs image processing according to various settings, and supplies the data to the image forming unit 6 for each page. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum of the image forming unit 6, and the electrostatic latent image is developed with toner.

  On the other hand, inside the image forming apparatus 100, the paper P taken out from the paper supply unit 70 is sent to the registration roller 8 and is temporarily stopped here. When the photosensitive drum of the image forming unit 6 reaches a predetermined rotation angle, the paper P is conveyed again by the registration rollers 8 at this timing, and thereby the toner image is transferred to the paper.

  If double-sided printing is set for the current job, the paper onto which the toner image has been transferred is heated and pressurized through the fixing unit 10, and then the conveyance direction branches downward in the paper discharge / branching unit 11. Then, it is sent out toward the duplex printing unit 12.

  Next, the conveyance unit 9 and the fixing unit 10 will be described in detail. FIG. 2 is a perspective view showing the configuration of the transport unit 9. In FIG. 2, the diagonally lower right side coincides with the front side (front direction) of the main body, and the diagonally upper left side coincides with the heel side (rear direction) of the main body. Here, the transport unit 9 is shown alone, but the transport unit 9 is supported by the main body 100B of the image forming apparatus 100 via, for example, two slide rails 90. These slide rails 90 are, for example, telescopic linear motion guides, and thereby allow the user to pull out the transport unit 9 from the main body to the front side or push it into the main body. Note that the user can put in and out the transport unit 9 with an exterior cover (not shown) covering the front of the main body opened.

  In this way, the transport unit 9 is slidable so as to protrude from the main body 100B in a direction (here, the front direction) orthogonal to the paper transport direction. Therefore, when the image forming apparatus 100 is maintained / inspected or a paper jam is removed, the operation can be easily performed by pulling out the transport unit 9 to the outside of the main body.

  The transport unit 9 has two frame plates 9b that are paired in the front-rear direction when viewed in the sliding direction. These frame plates 9b are arranged in parallel at a constant interval, and are connected to each other by two connecting members 9f. These connecting members 9f are located at both the left and right ends of the transport unit 9 and extend in the front-rear direction. The two slide rails 90 are attached along the outer surface of each connecting member 9f. Further, the transport unit 9 has a bottom plate 9e, which also extends horizontally so as to connect the front and rear frame plates 9b.

  A conveyance roller 9c and a conveyance belt 9d are disposed between the front and rear frame plates 9b. The conveyance roller 9c conveys the sheet on which the toner image is transferred by the image forming unit 6 toward the conveyance belt 9d. The conveyance belt 9 d travels on a sheet on which a toner image is transferred, and conveys the sheet to the fixing unit 10.

  The fixing unit 10 is installed on the bottom plate 9 e of the transport unit 9. When the fixing unit 10 receives the sheet from the conveying belt 9d, the fixing unit 10 conveys the sheet while heating and pressurizing it, and fixes the toner image on the sheet.

  In the present embodiment, the fixing unit 10 is roughly divided into two due to the structure. One is a main body including a heating roller 10a and a pressure roller 10h, and the other is a coil shaft 10b (coil holding member; heating device) disposed inside the heating roller 10a. Of these, the main body includes a heating plate 10f and a pressure roller 10h, a support plate 10f that rotatably supports them, and a cleaner 10g that cleans the surface of the heating roller 10a. The support plates 10f are arranged in pairs on the front and rear sides of the sheet conveyance path, and the cleaner 10g is attached above the heating roller 10a so as to connect the support plates 10f. Both ends of the heating roller 10a pass through the support plate 10f, and are rotatably supported on the outer periphery thereof.

  On the bottom plate 9e of the transport unit 9, two guide rails 9a are arranged in parallel. These guide rails 9a extend in a direction perpendicular to the sheet conveyance path (the front-rear direction of the image forming apparatus 100), and the cross section has a uniform groove shape (U-shape). The supporting plate 10f of the fixing unit 10 is formed with two legs 10e at the lower end portions, and these legs 10e are in a positional relationship so as to fit into the grooves of the guide rails 9a. In this state, the main body of the fixing unit 10 can be slid along the guide rail 9a in a direction perpendicular to the sheet conveyance direction (the front-rear direction of the image forming apparatus 100).

  FIG. 3 is a perspective view showing only the main body of the fixing unit 10. The main body of the fixing unit 10 can be separated from the coil shaft 10b and further removed from the transport unit 9 to the near side (the front side of the image forming apparatus 100). At this time, the main body slides while being guided by the guide rail 9a as described above. In addition, since a well-known thing is applicable to the heating roller 10a, the pressure roller 10h, the cleaner part 10g, etc., the detail is demonstrated here.

  FIG. 4 is a perspective view showing the transport unit 9 with the main body of the fixing unit 10 removed. FIG. 5 is a perspective view showing the transport unit 9 from the rear side of the image forming apparatus 100. In FIG. 5, the upper right direction coincides with the front direction of the image forming apparatus 100, and the lower left direction coincides with the rear direction of the image forming apparatus 100.

  When the main body of the fixing unit 10 is removed, the coil shaft 10 b of the fixing unit 10 remains in the transport unit 9. More specifically, the base end portion 10c of the coil shaft 10b is fixed to the rear frame plate 9b, and extends from the base end portion 10c in a direction perpendicular to the sheet transport direction. The coil shaft 10b has an elongated cylindrical shape, and although not shown in detail in FIGS. 4 and 5, electrical components such as an induction coil and a ferrite core are disposed therein.

  In the present embodiment, a circuit board 10d (current supply unit) is attached to the frame plate 9b on the rear side of the transport unit 9. The circuit board 10d is formed with an electric circuit (for example, an inverter) for supplying a high-frequency current to the coil shaft 10b. Here, an example in which the circuit board 10d is disposed in the vicinity of the base end portion 10c of the coil shaft 10b is shown, but the position is not particularly limited to the illustrated position.

  When the transport unit 9 is pulled out to the front side of the image forming apparatus 100 during maintenance / inspection work, the circuit board 10d is also pulled out to the front side of the image forming apparatus 100 accordingly. Further, when the main body of the fixing unit 10 is removed from the transport unit 9, as shown in FIGS. 4 and 5, the circuit board 10d and its wiring are exposed together with the coil shaft 10b.

  In the image forming apparatus 100 including the transport unit 9 and the fixing unit 10 having the above-described configuration, when an operation such as periodic maintenance / inspection or replacement / repair of any part is performed, the operator performs, for example, the following procedure. Work can be performed on the coil shaft 10b and the circuit board 10d.

  FIG. 6 is an explanatory view of the state in which the transport unit 9 and the fixing unit 10 are pulled out from the image forming apparatus 100 as viewed from the sheet receiving tray 13 side (left side surface of the image forming apparatus 100). First, the operator shuts off the power supply of the image forming apparatus 100 and opens a front cover (not shown).

  Next, the operator grasps the transport unit 9 and pulls it toward the front, and pulls it out to the outside of the main body of the image forming apparatus 100. At this time, the slide of the transport unit 9 is smoothly guided by the slide rail 90 described above.

  In this pulled out state, the operator can easily perform operations such as manually removing, disassembling, or removing the jammed paper from the exposed portions of the conveyance roller 9c and the conveyance belt 9d. .

  The operator then removes the main unit from the coil shaft 10b while further sliding the fixing unit 10 toward the front side. At this time, since the leg 10e is guided along the guide rail 9a, the operator can easily remove the main body of the fixing unit 10. When the main body of the fixing unit 10 is removed in this manner, the coil shaft 10b and the circuit board 10d remain in the transport unit 9. In this case, the operator can easily perform maintenance and inspection operations on the exposed coil shaft 10b and the circuit board 10d while visually checking them in the vicinity.

  In this regard, in the structure in which the coil shaft 10b and its circuit board 10d remain in the main body of the image forming apparatus 100, after the conveyance unit 9 is pulled out, the hand is extended to the back, and the coil shaft 10b and the circuit board 10d are searched. You cannot work without touching. On the other hand, this embodiment is extremely useful in that the work can be easily performed while directly viewing the coil shaft 10b and the circuit board 10d.

  In the case where the coil shaft 10 b remains in the main body of the image forming apparatus 100 as described above, it is possible to attach only the circuit board 10 d to the transport unit 9. However, such a structure is inconvenient because it is necessary to lengthen the wiring so as to match the amount of pulling out of the transport unit 9 and to take measures to prevent the wiring from being caught at the time of loading and unloading. On the other hand, in the present embodiment, since the coil shaft 10b and its circuit board 10d are pulled out from the main body of the image forming apparatus 100 together with the transport unit 9, the above problem does not occur.

  As described above, in the present embodiment, the coil shaft 10b and the circuit board 10d that are exposed to the outside of the image forming apparatus 100 are viewed at a close distance while confirming the troubled part or the troubled part. Therefore, it is possible to easily work by considering appropriate countermeasures. At this time, since both the coil shaft 10b and the circuit board 10d are fixed to the transport unit 9, it is particularly necessary to lengthen the wiring corresponding to the slide movement of the transport unit 9 or to study the handling in a complicated manner. There is no.

  Usually, immediately after the printing operation, the periphery of the fixing unit 10 including the fixing unit 10 is in a high temperature state. However, in this embodiment, the coil shaft 10b can be directly visually recognized at the time of work, so that compared with the case of working by groping. There is very little danger that an operator touches the hot part.

  In the above-described embodiment, the fixing unit 10 is detachably supported by the transport unit 9. However, a drawer unit different from the transport unit 9 is supported so as to be pulled out from the main body of the image forming apparatus 100. It may be an embodiment. In this case, the drawer unit does not particularly have the conveyance roller 9c and the conveyance belt 9d, and only the fixing unit 10 is detachably supported by the drawer unit.

  In the above embodiment, the induction heating type heating roller 10a is illustrated, but the present invention may be an embodiment in which the heating roller is heated by a heat source such as a halogen lamp. In this case, a heating device for heating such as a halogen lamp is attached to the transport unit 9 instead of the coil shaft 10b.

[Second Embodiment]
FIGS. 13A and 13B are schematic cross-sectional views illustrating the configuration of an image forming apparatus 100 ′ according to the second embodiment of the present invention. The image forming apparatus 100 ′ is a so-called in-body discharge type apparatus in which the image reading unit 40 is disposed on the upper portion of the main body 100 </ b> B ′ via the discharge unit 130. Inside the main body 100B ′, an image forming unit 6 ′ and a fixing unit 10 ′ having substantially the same configuration as those described in the first embodiment are provided.

  In the first embodiment, the fixing unit 10 is mounted on the transport unit 9, and the fixing unit 10 is exposed to the outside by sliding the transport unit 9. Instead, in the second embodiment, the fixing unit 10 ′ is detachably mounted on the unit cover 131 (one embodiment of “drawer unit”) disposed on the side surface of the main body 100B ′. Show.

  The unit cover 131 is coupled to the side surface of the main body 100B ′ by a hinge 132. With the hinge 132 as a rotation support point, the closed position shown in FIG. 13A and the opening shown in FIG. The posture can be changed between the postures. The fixing unit 10 ′ is exposed to the outside by opening the unit cover 131.

  14A and 14B are a perspective view and a top view of the image forming apparatus 100 ′. In these drawings, the fixing unit 10 'is removed from the unit cover 131 in the open posture. The unit cover 131 is provided with a coil shaft 10b ′ as a temperature raising device and a circuit board 10d ′.

  In the second embodiment, the coil shaft 10b 'is fixed to the unit cover 131 at a mounting portion separate from the fixing unit 10'. Therefore, when the operator opens the unit cover 131 and removes the fixing unit 10 ', the operator can easily maintain and inspect the exposed coil shaft 10b' and circuit board 10d 'while viewing them closely. Etc. can be performed.

[Other Embodiments]
In the above-described embodiment, the heating member and the pressure member of the fixing unit are both configured as roller members. However, these members can be configured by a combination of a roller and an endless belt. Hereinafter, various forms of the fixing unit will be exemplified.

(1) Heat roller method When the heating member of the fixing unit is a roller-shaped member, the pressure member may be formed of an endless belt or film. FIG. 7 is a schematic diagram illustrating an example in which a belt-type pressing member 101h is used. The pressure member 101h is formed by a belt 113 being wound around a pair of rollers 111 and 112. The belt 113h circulates while being in contact with the heating roller 10a on the outer peripheral surface of the belt, so that a sheet is put on the contact portion. A nip for sandwiching is formed.

  FIG. 8 is a schematic diagram showing an example in which a film-type pressure member 102h is used. The film 114 is supported by the pad 115 on its inner peripheral surface while following the rotation of the drive roller. In this state, the film 114 circulates in contact with the heating roller 10a, thereby forming a nip between the outer peripheral surface and the heating roller 10a.

(2) External heating method Even if the heating member itself is not a heat generation source, it can function as a fixing unit by being indirectly heated and heated from the outside. FIG. 9 is a schematic diagram showing a heating member 101a using an endless heating belt 116. As shown in FIG. The heating member 101a is formed by a heating belt 116 being wound between a heating roller 118 provided with a halogen heater 117 and the like, and a fixing roller 119. The heating belt 116 receives heat from the heating roller 118 and circulates while contacting the pressure roller 10h via the fixing roller 119, thereby forming a nip with the pressure roller 10h.

  Alternatively, as shown in FIG. 10, a heating member 102 a in which the heating roller 118 is brought into contact with the outer peripheral surface of the fixing roller 119 and the fixing roller 119 is heated from the outside may be employed.

(3) Heat belt system Further, an endless belt containing a metal material can be used as a heating member, and the metal-containing belt can be heated by an induction coil. FIG. 11 is a schematic view showing such a heating member 103a. The heating member 103a includes a belt 120 and a ceramic heater array 121 (which may be another heating element). The ceramic heater array 121 is arranged inside the heating belt 120 while being held by a predetermined holding member, and the heating belt 120 is driven by a driving roller (not shown) and circulates. A nip is formed between the two.

(4) External induction coil system In the above embodiment, an example is shown in which the induction coil (coil shaft 10b) is arranged inside the heating roller 10a. The induction coil is in the vicinity along the outer peripheral surface of the heating roller 10a. The aspect arrange | positioned may be sufficient. 12A and 12B show heating members 104a and 105a in which an induction coil 124 is disposed outside.

  In FIG. 12A, a heating belt 123 is wound around the fixing roller 121 and the support roller 122, and the induction coil 124 is disposed so as to face the outer peripheral surface of the support roller 122. In FIG. 12B, an induction coil 124 is arranged opposite to the outer peripheral surface of the fixing roller 125 that can be induction-heated.

  In addition, although the induction coil is wound on the inner side of the coil shaft in the above embodiment, the induction coil may be wound on the outer peripheral surface of the coil shaft. Moreover, in the said embodiment, although the cylindrical coil axis | shaft is mentioned as a coil holding member, the specific shape of a coil holding member is not specifically limited. Furthermore, even if the coil shaft of the above embodiment is not used, the ferrite core of the induction coil can also be used as a holding member, and the induction coil itself wound in a spiral shape has a certain degree of rigidity. Only the induction coil can be placed inside the heating roller as a temperature raising device.

  Further, in the above-described embodiment, a copying machine, a multifunction machine, and the like are exemplified as the image forming apparatus. However, the present invention can be implemented as a printer.

1 is a schematic cross-sectional view illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention. It is a perspective view of a conveyance unit. FIG. 6 is a perspective view showing a main body (a state where there is no coil shaft) of the fixing unit. FIG. 6 is a perspective view showing the transport unit with the main body of the fixing unit removed. FIG. 3 is a perspective view illustrating a transport unit from the rear side of the image forming apparatus. FIG. 4 is a left side view illustrating a state in which a conveyance unit and a fixing device are pulled out from the image forming apparatus. FIG. 6 is a diagram schematically illustrating a configuration example of another fixing unit. FIG. 6 is a diagram schematically illustrating a configuration example of another fixing unit. FIG. 6 is a diagram schematically illustrating a configuration example of another fixing unit. FIG. 6 is a diagram schematically illustrating a configuration example of another fixing unit. FIG. 6 is a diagram schematically illustrating a configuration example of another fixing unit. FIG. 6 is a diagram schematically illustrating a configuration example of another fixing unit. It is a schematic sectional drawing which shows the structure of the image forming apparatus which concerns on 2nd Embodiment of this invention. (A) is a perspective view of an image forming apparatus according to the second embodiment, and (B) is a top view thereof.

Explanation of symbols

6 Image forming section 7 Paper feed cassette 9 Transport unit (drawer unit)
10 Fixing unit 10a Heating roller (heating member: heating rotating body)
10b Coil shaft (coil holding member: temperature riser)
10c Base end part 10d Circuit board 10e Slide part 10h Pressure roller (Pressure member: Pressure rotator)
70 Paper Feeding Unit 80 Paper Conveying Unit 90 Slide Rail 100 Image Forming Apparatus 100B Main Body

Claims (7)

Body body,
An image forming unit housed in the main body, forming a toner image based on image data, and transferring the toner image to a transfer material;
A drawer unit that is housed in the main body body so that it can be pulled out to the outside,
A heating member and a pressure member that is detachably attached to the drawer unit and is brought into contact with the heating member with a predetermined pressure. A transfer material on which the toner image has been transferred is the heating member and the pressure member. And a fixing unit that fixes the toner image on the transfer material by heat from the heating member,
A heating device for heating the heating member located in the vicinity of the heating member in a state where the fixing unit is attached to the drawer unit;
The heating device has a mounting part separate from the heating member and is fixed to the drawer unit, and the fixing unit is fixed to the drawer unit even when the fixing unit is detached from the drawer unit. An image forming apparatus characterized by maintaining the above. The heating member is a heating rotator, and the pressure member is a pressure rotator,
The pressure rotator is brought into contact with the heating rotator at a predetermined pressure to form a nip portion, and the transfer material onto which the toner image is transferred is sandwiched and conveyed by the nip portion. Item 2. The image forming apparatus according to Item 1. Body body,
An image forming unit housed in the main body, forming a toner image based on image data, and transferring the toner image to a transfer material;
A transport unit that is housed in the main body body so as to be slidable to the outside and transports the transfer material onto which the toner image has been transferred through a predetermined transport path;
A transfer material that is detachably attached to the transport unit and includes a heating rotator and a pressure rotator that is brought into contact with the heating rotator with a predetermined pressure to form a nip portion, and is transferred through the transport path. A fixing unit for fixing the toner image on the transfer material with heat from the heating rotator,
An induction coil for generating an induction current in the heating rotor;
The heating rotator has a mounting portion that is separate from the heating rotator and is attached to the transport unit. The fixing unit is mounted on the transport unit and is positioned in the vicinity of the heating rotator. A coil holding member that maintains a fixed state with respect to the transport unit even when the fixing unit is detached from the transport unit.
An image forming apparatus comprising:   The image forming apparatus according to claim 3, further comprising a current supply unit attached to the transport unit and configured to supply a current to the induction coil of the coil holding member. The current supply unit is a circuit board,
The transport unit has a frame plate on the rear end side in the sliding direction,
The image forming apparatus according to claim 4, wherein the circuit board is attached to the frame plate. The transport unit can be slid out of the main body body in a direction orthogonal to the paper transport direction, and can be pulled out.
The fixing unit is slidable in a direction perpendicular to the transport direction of the sheet with respect to the transport unit and in the same direction as the pull-out direction of the transport unit, and is removable.
The coil holding member extends in a direction perpendicular to the paper transport direction with respect to the transport unit, and is a space formed inside the heating rotator in a state where the fixing unit is mounted on the transport unit. The image forming apparatus according to claim 3, wherein the image forming apparatus is inserted into the image forming apparatus. The transport unit includes a bottom plate, and the bottom plate is provided with a guide rail extending in a direction orthogonal to the paper transport direction;
The fixing unit includes a support plate that supports the heating rotator and the pressure rotator, and legs that are guided by the guide rails are formed on the support plate. The image forming apparatus described.

Images