Image forming device

Abstract

The present invention provides an image forming device. A fixing unit allows a sheet carrying a toner image to pass through a clamping portion formed by pressing a rotating fixing component and a rotating pressure component against each other, thereby thermally fixing the toner image on the sheet. The image forming device includes: an image forming device body having a fixing unit storage portion for storing the fixing unit in a pluggable manner; and a heating portion, which is arranged on the image forming device body and heats the rotating fixing component of the fixing unit installed on the fixing unit storage portion from the radial outside. The plugging and unplugging direction of the fixing unit relative to the fixing unit storage portion is consistent with the axial direction of the rotating pressure component.

Description

Technical Field

[0001] The present invention relates to an image forming device. Background Art

[0002] Generally, an electrophotographic image forming apparatus includes a fixing unit that fixes a toner image on a sheet using a fixing roller and a pressure roller that rotate in a state of being pressed against each other.

[0003] In the fixing unit, when the sheet passes through a nip formed between the fixing roller and the pressure roller, the toner image on the sheet is heated and pressurized and fixed to the sheet.

[0004] The image forming apparatus body is provided with a heating unit for heating a fixing roller of a fixing unit. An IH heating unit as an example of the heating unit includes a bracket and a plurality of IH coils supported by the bracket. The bracket includes a cylindrical recessed portion into which a surface portion of the fixing roller on the side opposite to the clamping portion side enters. The IH heating unit heats the peripheral surface of the fixing roller from the radially outer side via the recessed portion.

[0005] The fixing unit is formed separately from the IH heating part and can be installed in the fixing unit storage part in the image forming apparatus body in an insertable and removable manner. The inserting and removing direction of the fixing unit is set to the direction facing the inner surface of the recess of the bracket (the direction orthogonal to the axial direction of the fixing roller).

[0006] In conventional image forming apparatuses, since the fixing unit is inserted and removed in a direction opposite to the inner surface of the recess of the bracket of the IH heating unit (heating unit), other devices (such as drive gears, etc.) can only be arranged at a position closer to the heating unit than the fixing unit, and the freedom of arrangement of the devices is significantly limited. Summary of the invention

[0007] The present invention has been made in view of this point, and an object of the present invention is to increase the degree of freedom in arrangement of other devices around a fixing unit.

[0008] The image forming device involved in the present invention is characterized in that it includes: a fixing unit, which allows a sheet carrying a colorant image to be thermally fixed on the sheet by passing through a clamping portion formed by pressing a rotating fixing component and a rotating pressure component against each other; an image forming device main body, which has a fixing unit storage portion that can freely accommodate the fixing unit; and a heating portion, which is arranged on the image forming device main body and heats the rotating fixing component of the fixing unit installed on the fixing unit storage portion from the side opposite to the clamping portion, and the insertion and extraction direction of the fixing unit relative to the fixing unit storage portion is consistent with the axial direction of the rotating pressure component.

[0009] According to the present invention, it is possible to improve the degree of freedom in arranging other devices around the fixing unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram showing an image forming apparatus according to an embodiment.

[0011] Figure 2 This is a perspective view showing the right end portion of the main frame as seen obliquely from the front right side, showing a state in which the fixing unit is installed in the fixing unit storage portion and the second maintenance door is fully closed.

[0012] Figure 3 This is a perspective view showing the right end portion of the main frame as seen from the front and right side, showing a state in which the fixing unit is being inserted or removed.

[0013] Figure 4 This is a status indicating that the fixing unit is removed from the fixing unit storage section. Figure 2 Quite a picture.

[0014] Figure 5 It is a front view showing the discharge unit as seen from the front side.

[0015] Figure 6 yes Figure 2 VI-VI line cross-sectional view.

[0016] Figure 7 yes Figure 2 VII-VII line cross-sectional view.

[0017] Figure 8 This is a schematic side view of the fixing unit as seen from the opening side.

[0018] Fig. 9 This is a plan view showing a state in which the fixing unit is installed in the fixing unit housing portion and the second maintenance door is fully closed.

[0019] Fig.10 This indicates that the second maintenance door is fully opened. Fig. 9 Quite a picture.

[0020] Fig.11 yes Fig.10 XI-XI line cross-sectional view. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In addition, the present invention is not limited to the following embodiments.

[0022] Implementation Method

[0023] Figure 1 1 is a schematic diagram showing the structure of the image forming apparatus 1 according to the embodiment. In the following description, the front side and the rear side refer to the front side and the rear side of the image forming apparatus 1 ( Figure 1 The left side and the right side refer to the front side and the back side in the vertical direction of the paper surface), and the left side and the right side refer to the left side and the right side when the image forming apparatus 1 is viewed from the front side.

[0024] [Overall Structure of Image Forming Apparatus 1]

[0025] The image forming apparatus 1 is a copier of an internal paper ejection type, and includes an image forming apparatus body 2 and an image reading device 3 provided on the upper side of the image forming apparatus body 2. The image reading device 3 optically reads a document image and generates image data thereof.

[0026] An image forming unit 4 is provided in the image forming apparatus body 2. The image forming unit 4 transfers an image onto a paper P (an example of a sheet) based on the image data of the original document read by the image reading device 3. A transfer unit 6 is arranged above the image forming unit 4. The transfer unit 6 includes an endless intermediate transfer belt 6a extending in the left-right direction, four primary transfer rollers 6b arranged in the left-right direction on the inner side of the intermediate transfer belt 6a, and a drive roller 6c for rotating and driving the intermediate transfer belt.

[0027] An exposure device 5 for irradiating laser light is arranged below the image forming unit 4. A paper feed unit 7 for storing paper P is arranged below the exposure device 5. A fixing unit 8 for performing a fixing process on the image transferred and formed on the paper P is arranged above the right side of the transfer unit 6. An internal paper discharge space S is provided between the image forming apparatus main body 2 and the image reading device 3, and the paper P subjected to the fixing process by the fixing unit 8 is discharged to the internal paper discharge space S.

[0028] A paper discharge tray 9 for receiving the paper P discharged to the internal paper discharge space S is formed on the upper surface of the image forming apparatus main body 2. A paper conveying path T extending from the paper supply unit 7 toward the paper discharge tray 9 is provided in the image forming apparatus main body 2. Below the fixing unit 8 in the paper conveying path T, a secondary transfer roller 10 is provided to face the driving roller 6c across the intermediate transfer belt 6a. Above the fixing unit 8 in the paper conveying path T, a pair of paper discharge rollers 11 for discharging the paper P toward the paper discharge tray 9 in a substantially horizontal manner is provided.

[0029] A rectangular opening 2a is formed on the right side of the image forming apparatus body 2 adjacent to the paper conveying path T. The opening 2a can be opened and closed by an opening and closing cover 2b. The opening and closing cover 2b is supported so as to be rotatable relative to a support shaft 2f extending along the lower side edge of the opening 2a. The opening and closing cover 2b is opened by rotating to the right side from the closed state with the support shaft 2f as a fulcrum. By opening the opening and closing cover 2b, the paper stuck in the paper conveying path T can be removed.

[0030] The image forming section 4 includes drum units 20 and developing units 30 provided for each color of yellow, magenta, cyan and black. The drum unit 20 has a rotatable photosensitive drum 21. The surface of the photosensitive drum 21 is irradiated with laser light based on predetermined image data from the exposure device 5 to form an electrostatic latent image.

[0031] The developing unit 30 includes a developing container 31 and a developing roller 32. Each developing container 31 is supplied with and contains a toner as a developer from a corresponding toner container (not shown) of each color. The developing roller 32 is exposed from the right side wall of the upper portion of the developing container 31 and is supported so as to be rotatable. A potential difference is generated between the developing roller 32 and the surface of the photosensitive drum 21, so that the toner moves from the developing roller 32 to the surface of the photosensitive drum 21. The electrostatic latent image on the surface of the photosensitive drum 21 is developed and visualized by the toner moving from the developing roller 32.

[0032] The toner images of each color of each photosensitive drum 21 visualized by the developing unit 30 are sequentially transferred and superimposed on the intermediate transfer belt 6a by the bias applied by the primary transfer roller 6b arranged on the upper side of each photosensitive drum 21. The superimposed toner images are transferred to the paper P when the paper P supplied from the paper supply unit 7 passes between the intermediate transfer belt 6a and the secondary transfer roller 10. The paper P to which the toner images are transferred is sent to the fixing unit 8.

[0033] The fixing unit 8 includes a fixing roller 81 and a pressure roller 82 which are opposed to each other in the left-right direction across the paper conveying path T. The fixing unit 8 sandwiches and conveys the paper P on which the toner image is formed by the fixing roller 81 and the pressure roller 82. The toner image on the paper P is heated and pressurized when passing between the fixing roller 81 and the pressure roller 82, and is thermally fixed on the paper P. The paper P on which the toner image is thermally fixed is discharged to the paper discharge tray 9 by the paper discharge roller pair 11 arranged on the upper side of the fixing unit 8.

[0034] [Storage Structure of Each Unit in Image Forming Apparatus Main Body 2]

[0035] Next, the storage structure of the drum unit 20 , the developing unit 30 , and the fixing unit 8 in the image forming apparatus main body 2 will be described.

[0036] The image forming apparatus main body 2 has a main frame 12 (see FIG. Figure 2 etc.) and an exterior cover (not shown) covering each side surface of the main frame 12.

[0037] The front exterior cover has a first maintenance door 13 (see Figure 1) and a second maintenance door 14 (equivalent to an opening and closing door). The first maintenance door 13 extends in a rectangular shape in the left-right direction and covers the entire front side of the image forming unit 4. The first maintenance door 13 is a double-leaf door divided into left and right sides with the center position in the left-right direction as the boundary. The second maintenance door 14 is a square-shaped door that covers the entire front side of the fixing unit 8. The second maintenance door 14 is a single-opening door that rotates with its left end as a fulcrum.

[0038] In the portion of the image forming apparatus body 2 facing the inner side of the first maintenance door 13 , four pairs of drum unit storage portions 2 c for storing the drum unit 20 and developer unit storage portions 2 d for storing the developer unit 30 are arranged adjacent to each other in the left-right direction of the image forming apparatus body 2 .

[0039] The drum unit storage portion 2c is formed of a hollow space extending in the front-rear direction, and has an insertion and removal opening at its front end for inserting and removing the drum unit 20. The drum unit 20 is inserted and removed in the front-rear direction through the insertion and removal opening.

[0040] The developing unit storage portion 2d is formed of a hollow space extending in the front-rear direction, and an insertion opening for inserting and removing the developing unit 30 is provided at the front end. The developing unit 30 is inserted and removed in the developing unit storage portion 2d through the insertion opening.

[0041] A fixing unit storage section 2e for storing the fixing unit 8 is provided in a portion of the image forming apparatus body 2 that is opposite to the inner side surface of the second maintenance door 14. The fixing unit storage section 2e is composed of a hollow space extending in the front-to-back direction, and an insertion and removal opening for inserting and removing the fixing unit 8 is provided at the front end (one end) thereof. A guide member (not shown) for guiding the fixing unit 8 in the front-to-back direction is provided in the fixing unit storage section 2e. When the fixing unit 8 is installed, the fixing unit 8 is positioned by the guide member so as to be unable to move in the left-right direction.

[0042] [Detailed Structure of Fixing Unit Accommodating Section 2e]

[0043] Reference Figure 2 to Figure 4 The fixing unit housing portion 2e will be described in detail. Figure 2 The fixing unit 8 is installed in the fixing unit storage portion 2e and the second maintenance door 14 is fully closed. Figure 3 The state in which the fixing unit 8 is being inserted or removed is shown. Figure 4 The fixing unit 8 is removed from the fixing unit storage portion 2e. Figure 2 Quite a picture.

[0044] The fixing unit storage section 2e is provided at the lower part of the inner space K of the protruding frame section 120 provided in the main frame 12. The protruding frame section 120 is provided adjacent to the right side of the internal paper discharge space S and covers the entire front-rear direction of the main frame 12. The protruding frame section 120 is constructed in a rectangular parallelepiped shape by combining frame components.

[0045] The discharge unit 40 including the discharge roller pair 11 is accommodated in the inner space K of the protruding frame portion 120, and the fixing unit accommodating portion 2e is constituted by the lower space below the discharge roller pair 11 in the inner space K. An opening for inserting and removing the fixing unit 8 is formed between a pair of left and right pillars 121 at the front end of the protruding frame portion 120.

[0046] [Structure of the Discharge Unit 40]

[0047] Figure 5 : is a schematic structural diagram of the discharge unit 40. The discharge unit 40 includes a discharge roller pair 11 and a support frame 41 that supports the discharge roller pair 11. The support frame 41 includes a pair of opposing plates 41a that support both side ends of the discharge roller pair 11 in the axial direction, a vertical plate 41b that connects the left side ends of the pair of opposing plates 41a and extends in the up-down direction, and a horizontal protruding plate 41c that protrudes horizontally to the right from the lower end of the vertical plate 41b.

[0048] An IH heating unit 50 for heating the fixing roller 81 is supported on the upper surface of the horizontal protruding plate 41c so as to be movable in the left-right direction. An opening 41d through which the IH heating unit 50 can pass is formed in the vertical plate 41b.

[0049] The IH heating unit 50 is driven between a heating position and a retreat position by a drive mechanism (drive unit) 60 described later. The heating position is a position where the surface of the fixing roller 81 can be heated by the IH heating unit 50 with a predetermined heating performance. The retreat position is a position where the IH heating unit 50 is moved to the left side from the heating position and retreated to the outside of the moving path of the fixing unit 8.

[0050] Reference Figure 6 The fixing unit 8 and the IH heating unit 50 will be described in detail. Figure 6 yes Figure 2 The VIVI line cross section shows the state where the IH heating unit 50 is located at the heating position.

[0051] As described above, the fixing unit 8 includes the fixing roller 81 , the pressure roller 82 , and the fixing housing 83 .

[0052] The fixing roller 81 and the pressure roller 82 are formed into a substantially cylindrical shape that is long in the front-rear direction. The fixing roller 81 includes an elastic layer 81b laminated on the outer peripheral surface of a metal core rod 81a and a fixing belt 81c covering the outer peripheral surface of the elastic layer 81b. The pressure roller 82 includes an elastic layer 82b laminated on the outer peripheral surface of a core rod 82a and a release layer 82c covering the outer peripheral surface of the elastic layer 82b.

[0053] The fixing housing 83 is formed in a substantially rectangular parallelepiped shape that is long in the front-to-back direction. A concave handle portion 83a is formed on the front side surface of the fixing housing 83 (see Figure 3 The left end portion of the lower surface of the fixing housing 83 is supported by the horizontal protruding plate 41c of the discharge unit 40 (see Figure 5 The front end and the rear end of the fixing housing 83 are respectively formed by a beam 122 protruding from the front side plate of the main frame 12 and a beam 123 protruding from the rear side plate (see Figure 2 ) support.

[0054] A paper receiving opening 83c for receiving paper P conveyed from the upstream side of the paper conveying path T is formed on the lower surface of the fixing housing 83. A paper discharge opening 83d for discharging the paper P that has passed through the fixing roller 81 and the pressure roller 82 is formed on the upper surface of the fixing housing 83. A rectangular opening 83b extending in the left-right direction is formed on the left side wall of the fixing housing 83, and the left half of the fixing roller 81 is exposed to the outside of the fixing housing 83 from the opening 83b.

[0055] The IH heating unit 50 is arranged on the side opposite to the clamping portion N side (left side) with the fixing roller 81 interposed therebetween. The IH heating unit 50 has a semi-cylindrical bracket 50a open to the fixing roller 81 side, a plurality of IH coils 50b supported by the bracket 50a, and an arched magnetic core 50c formed of a ferromagnetic body such as ferrite and covering the IH coils 50b. A semi-cylindrical recess 50g is formed on the inner surface of the bracket 50a, and when the IH heating unit 50 is in the heating position, the surface of the fixing roller 81 on the side opposite to the clamping portion N side enters into the recess 50g. Both the bracket 50a and the arched magnetic core 50c are arranged to extend throughout the entire front-to-back direction opposite to the fixing roller 81. The two ends of the bracket 50a and the arched magnetic core 50c in the front-to-back direction are aligned with the positioning block portion 50d (refer to Figure 4 )connect.

[0056] During the fixing process, the pressure roller 82 is connected to a motor (not shown) via a gear train, etc., and rotates around the axis by the driving force of the motor. The fixing roller 81 rotates around the axis driven by the pressure roller 82. Each IH coil 50b receives power from a power source (not shown) to generate a high-frequency magnetic field to heat the fixing belt 81c. The fixing roller 81 heats the toner image on the paper P passing through the clamping portion N while rotating. The pressure roller 82 applies pressure to the paper P passing through the clamping portion N while rotating. In this way, the toner image is fixed on the paper P. In addition, the fixing roller 81 can be driven to rotate and the pressure roller 82 can be driven to rotate.

[0057] [Positioning Structure of IH Heating Unit 50]

[0058] As described above, the IH heating unit 50 is configured to be movable between the heating position and the retreat position. At the heating position, the IH heating unit 50 is positioned such that the gap between the inner surface of the recess 50g of the holder 50a and the outer peripheral surface of the fixing roller 81 is a predetermined distance.

[0059] Reference Figure 4 , Figure 7 as well as Figure 8 The structure for positioning the IH heating unit 50 will be described.

[0060] First refer to Figure 4 as well as Figure 7 Positioning block portions 50d are provided at both ends of the IH heating unit 50 in the front-rear direction (at Figure 4 Only the rear block is shown in the figure). A cylindrical surface continuously connected to the inner surface of the recessed portion 50g of the bracket 50a is formed on the right side of each positioning block portion 50d. An upper engaging groove 50e and a lower engaging groove 50f are respectively formed on the upper and lower sides of each positioning block portion 50d across the cylindrical surface. The upper engaging groove 50e and the lower engaging groove 50f are composed of semi-cylindrical grooves extending in the front-rear direction.

[0061] like Figure 7 as well as Figure 8 As shown, the fixing unit 8 includes an upper engaging pin 85 engaged with the upper engaging groove 50 e of each positioning block portion 50 d and a lower engaging pin 86 engaged with the lower engaging groove 50 f of each positioning block portion 50 d.

[0062] The upper engaging pin 85 and the lower engaging pin 86 are mounted on the supporting member 84 supporting the fixing roller 81 and the pressure roller 82. The supporting member 84 is composed of, for example, a metal sheet metal member. The supporting member 84 has a pair of vertical supporting plates 84a that are opposed to each other in the front-to-back direction and support the fixing roller 81 and the pressure roller 82 at both ends, and a connecting plate 84b that connects the lower ends of the pair of vertical supporting plates 84a. The upper engaging pin 85 protrudes from the upper left corner of each vertical supporting plate 84a to the inner side in the front-to-back direction. The lower engaging pin 86 protrudes from the lower left corner of each vertical supporting plate 84a to the inner side in the front-to-back direction.

[0063] like Figure 7 As shown, the IH heating unit 50 is positioned at the heating position by engaging the upper engaging groove 50 e and the lower engaging groove 50 f of the positioning block portion 50 d with the upper engaging pin 85 and the lower engaging pin 86 of the fixing unit 8 , respectively.

[0064] When the IH heating unit 50 is located at the heating position, a portion of the positioning block portion 50d overlaps a portion of the support member 84 of the fixing unit 8 when viewed from the front-back direction. Therefore, the IH heating unit 50 cannot be inserted or removed in the front-back direction. Therefore, in the present embodiment, when the user opens the second maintenance door 14 (an example of an operation unit) to perform an insertion or removal operation of the fixing unit 8, the IH heating unit 50 is moved from the heating position to the retreat position by the driving mechanism 60.

[0065] [Driving Mechanism 60 of IH Heating Unit 50]

[0066] Reference Fig. 9 An example of the driving mechanism 60 will be described. Fig. 9 The state where the IH heating unit 50 is driven to the heating position by the driving mechanism 60 is shown. In the description of each component of the driving mechanism 60, unless otherwise specified, the IH heating unit 50 is described as being located at the heating position.

[0067] The driving mechanism 60 is composed of a link mechanism that is linked to the opening and closing action of the second maintenance door 14. Specifically, the driving mechanism 60 includes a door-side link 62 connected to the second maintenance door 14, a pair of parallel links 63 connected to the upper surface of the cooling duct 51 of the IH heating unit 50, and an intermediate link 64 connecting the door-side link 62 and the pair of parallel links 63.

[0068] The door-side link 62 is a plate-shaped member bent into a "ㄑ" shape in a plan view, and extends from the front side to the rear side, and then extends obliquely to the left side and rearward.

[0069] The middle portion of the door side link 62 is supported to be rotatable about a door side fixed shaft 61 provided at the left oblique rear of the second maintenance door 14. The door side fixed shaft 61 is provided to protrude from the front side cross beam 122 (see Figure 4 ).

[0070] The front end portion of the door-side link 62 is connected to the left end portion of the second maintenance door 14 via a connection pin 66. The door-side link 62 and the second maintenance door 14 are connected to each other so as to be rotatable around the connection pin 66.

[0071] The rear end of the door-side link 62 is connected to the front end of the intermediate link 64 via a connecting pin 67. The intermediate link 64 is connected to the door-side link 62 so as to be rotatable around the connecting pin 67.

[0072] The intermediate link 64 is composed of a plate-like member, which extends linearly toward the rear side, bends in a step-like manner, and extends linearly toward the rear side. The pair of parallel links 63 are connected to the rear end of the intermediate link 64 via connecting pins 68. The intermediate link 64 and the pair of parallel links 63 are connected in a manner that can rotate around each connecting pin 68.

[0073] A pair of parallel links 63 is composed of a plate-like member extending in the left-right direction. Each parallel link 63 has an elliptical long hole 63a extending from its right end to near the center. A fixing pin 69 is inserted through each long hole 63a. The fixing pin 69 is protrudingly arranged on the upper surface of the cooling duct 51 of the IH heating unit 50. The cooling duct 51 supplies air taken into the image forming device body 2 by an air supply fan (not shown) to between the arched magnetic core 50c and the bracket 50a of the IH heating unit 50. The IH coil 50b is cooled by the supplied air. In addition, Fig. 9 Reference numeral 50f in FIG. 5 denotes a ventilation hole formed through the upper wall portion of the arch core 50c.

[0074] [Description of Operation of Driving Mechanism 60]

[0075] Next, refer to Fig. 9 as well as Fig.10 The operation of the drive mechanism 60 accompanying the opening and closing operation of the second maintenance door 14 will be described. Fig. 9 Indicates the state in which the second maintenance door 14 is closed (hereinafter referred to as the fully closed state), Fig.10 The second maintenance door 14 is shown in a state where it is rotated 90 degrees forward from the fully closed state with the fixing pin 15 as a fulcrum (hereinafter referred to as the fully open state).

[0076] If the second maintenance door 14 is moved from the fully closed state ( Fig. 9When the door side link 62 rotates in the clockwise direction (D1 direction) around the fixing pin 15 (in the fully opened state), the front end of the door side link 62 moves along the circular track around the fixing pin 15 to the right and rearward together with the connecting pin 66. Concomitantly, the door side link 62 rotates in the counterclockwise direction (D2 direction) around the door side fixing shaft 61, and the intermediate link 64 is pulled forward (D3 direction) by the door side link 62. As a result, a pair of parallel links 63 connected to the rear end of the intermediate link 64 rotate in the counterclockwise direction (D4 direction) with the connecting pin 68 as a fulcrum. When the pair of parallel links 63 rotates, the fixing pin 69 inserted into the long hole 63a moves relatively in the longitudinal direction of the long hole 63a while being pressed to the left by the inner surface of the long hole 63a. As a result, the IH heating unit 50 moves to the left together with the fixing pin 69. Then, when the second maintenance door 14 rotates to the fully opened state, as shown in FIG. Fig.10 As shown in FIG. 8 , the IH heating unit 50 moves to a retracted position outside the insertion and extraction path of the fixing unit 8 .

[0077] When the IH heating unit 50 moves to the retreat position, Fig.11 As shown, the positioning block portion 50d of the IH heating unit 50 is entirely retracted to the left side of the support member 84 of the fixing unit 8, and the engagement between the engagement pins 85, 86 and the engagement grooves 50e, 50f is released.

[0078] Therefore, by moving the IH heating unit 50 to the retracted position, the fixing unit 8 can be inserted and removed in the front-rear direction without interfering with the IH heating unit 50 .

[0079] [Effects]

[0080] As described above, in the present embodiment, the insertion and extraction direction (front-rear direction) of the fixing unit 8 with respect to the fixing unit housing portion 2 e coincides with the axial direction of the pressure roller 82 .

[0081] According to this structure, compared with the case where the insertion and extraction direction of the fixing unit 8 is set to a direction orthogonal to the axial direction of the pressure roller 82 (left-right direction), the configuration freedom of other components can be improved. As an example of other components, a driving gear for driving the pressure roller 82 can be cited. The driving gear transmits the power of the motor to the roller gear fixed to the core shaft 82a of the pressure roller 82. In the previous image forming apparatus, since the fixing unit 8 needs to be taken out from the fixing unit storage section 2e to the right, the driving gear cannot be arranged on the right side of the roller gear. Therefore, depending on the configuration position of the driving gear, sometimes a load that reduces the clamping pressure (the component of force in the direction of causing the pressure roller 82 to leave the fixing roller 81) acts on the roller gear.

[0082] On the other hand, in the present embodiment, since the drive gear can be arranged on any one of the front, rear, left, and right sides of the roller gear, the drive gear can be arranged at an appropriate position where the clamping pressure does not decrease.

[0083] In addition, in the present embodiment, the image forming device 1 has a driving mechanism 60 for moving the IH heating unit 50, and the driving mechanism 60 is configured to drive the IH heating unit 50 between a predetermined heating position capable of heating a fixing roller 81 of the fixing unit 8 installed in the fixing unit storage portion 2e and a retreat position in which the IH heating unit 50 moves to the left side (radially outward of the fixing roller 81) of the heating position and retreats to the outside of the insertion and removal path of the fixing unit 8.

[0084] Furthermore, the drive mechanism 60 is configured to selectively switch the position of the IH heating unit 50 between the heating position and the retreat position in conjunction with the opening and closing operation of the second maintenance door 14 as an operation unit operable by a user.

[0085] According to this structure, when the fixing unit 8 needs to be inserted or removed, the operation unit can be operated to move the IH heating unit 50 to the retreat position, and when the fixing process based on the fixing unit 8 is executed, the operation unit can be operated to move the IH heating unit 50 to the heating position. Therefore, even if the insertion and removal direction of the fixing unit 8 is set to the front-back direction, the fixing unit 8 and the IH heating unit 50 will not interfere with each other when the fixing unit 8 is inserted or removed.

[0086] In the present embodiment, the drive mechanism 60 is configured to place the IH heating unit 50 in the heating position when the second maintenance door 14 serving as the above-mentioned operating portion is in a fully closed state, and on the other hand, place the IH heating unit 50 in the retreat position when the second maintenance door 14 is in a prescribed open position in which the fixing unit 8 can be inserted and removed from the insertion and removal opening (in the example of the present embodiment, a state rotated 90° from the fully closed state).

[0087] According to this structure, the user does not need to perform an operation to place the IH heating unit 50 in either the heating position or the retreat position, and can move the IH heating unit 50 to an appropriate position according to the opening and closing operation of the second maintenance door 14. That is, when the user opens the second maintenance door 14 to perform the plugging and unplugging operation of the fixing unit 8, the IH heating unit 50 is moved to the retreat position by the drive mechanism 60, so the user does not need to perform the operation of moving the IH heating unit 50 to the retreat position separately from the operation of opening the second maintenance door 14. In addition, when the user installs the fixing unit 8 in the fixing unit storage section 2e and fully closes the second maintenance door 14, the IH heating unit 50 is moved to the heating position by the drive mechanism 60. Therefore, the user does not need to perform the operation of moving the IH heating unit 50 to the heating position separately from the operation of closing the second maintenance door 14. Therefore, the workload during the plugging and unplugging operation of the fixing unit 8 can be reduced.

[0088] In addition, in the present embodiment, an IH heating unit 50 is used as a heating portion for heating the fixing roller 81. The IH heating unit 50 includes: a bracket 50a having a recessed portion 50g for receiving the surface portion of the fixing roller 81 on the side opposite to the clamping portion N side; a plurality of IH coils 50b supported by the bracket 50a; and an arched magnetic core 50c covering the IH coils 50b.

[0089] Thus, when the IH heating unit 50 is used, the outer peripheral surface of the fixing roller 81 on the side opposite to the clamping portion N enters the recess 50g of the bracket 50a. Therefore, when the fixing unit 8 is inserted or removed along the axial direction, the fixing unit 8 and the IH heating unit 50 are likely to interfere with each other. In such a structure, the use of the driving mechanism 60 that can move the IH heating unit 50 to the retreat position is particularly effective in avoiding interference.

[0090] In addition, in the present embodiment, the image forming apparatus main body 2 includes: a drum unit storage section 2c for storing the drum unit 20 in a manner that allows the drum unit 20 to be inserted and removed in the same direction as the fixing unit 8; and a developing unit storage section 2d for storing the developing unit 30 in a manner that allows the developing unit 30 to be inserted and removed in the same direction as the fixing unit 8 (see FIG. Figure 1 ). In addition, the insertion and removal opening of the fixing unit 8 in the fixing unit storage section 2e, the insertion and removal opening of the drum unit 20 in the drum unit storage section 2c, and the insertion and removal opening of the developing unit 30 in the developing unit storage section 2d are opened on the same side (front side) of the image forming apparatus main body 2.

[0091] According to this structure, the user can perform maintenance work on the drum unit 20, the developing unit 30, and the fixing unit 8 from the front side of the image forming apparatus main body 2. Therefore, it is unnecessary to perform complicated work such as performing maintenance work on the drum unit 20 and the developing unit 30 from the front side of the image forming apparatus main body 2 and performing maintenance work on the fixing unit 8 from the right side of the image forming apparatus main body 2 as in the past. Therefore, it is possible to facilitate maintenance work on the image forming apparatus 1.

[0092] 《Other Implementation Methods》

[0093] In the above embodiment, the link mechanism (drive mechanism 60) is used as a drive unit for driving the IH heating unit 50 to the heating position and the retreat position, but it is not limited to this. The drive unit may also have a motor as a drive source. In this case, the second maintenance door 14 may also be linked to the drive switch of the motor. In addition, a command for driving the motor may also be issued from the operation panel of the image forming apparatus body 2.

[0094] In the above embodiment, the upper engaging groove 50e and the lower engaging groove 50f are formed in the positioning block portion 50d of the IH heating unit 50, and the engaging grooves 50e and 50f are engaged with the upper engaging pin 85 and the lower engaging pin 86 of the fixing unit 8, respectively, but the present invention is not limited thereto. For example, the lower engaging groove 50f and the lower engaging pin 86 may be eliminated, and positioning may be performed only by the upper engaging groove 50e and the upper engaging pin 85. That is, the positioning structure may be any structure as long as it can limit the distance between the inner surface of the recessed portion 50g of the bracket 50a and the outer peripheral surface of the fixing roller 81 to a predetermined distance.

[0095] In the above embodiment, the fixing roller 81 is cited as an example of the rotating fixing member, but the present invention is not limited thereto, and the rotating fixing member may also be an endless fixing belt. In addition, in the above embodiment, the pressure roller 82 is cited as an example of the rotating pressure member, but the present invention is not limited thereto, and the rotating pressure member may also be an endless pressure belt.

[0096] Possibility of industrial application

[0097] As described above, the present invention is useful for an image forming apparatus, and is particularly useful when applied to a printer, a facsimile machine, a copier, a multifunction peripheral (MFP), or the like.

Claims

1. An image forming device, characterized in that: include: A fixing unit having a rotating fixing member and a rotating pressing member, wherein a sheet carrying a toner image passes through a nip formed by pressing the rotating fixing member and the rotating pressing member against each other, thereby fixing the toner image on the sheet; The image forming apparatus body has a fixing unit storage portion for storing the fixing unit in an insertable and removable manner in the axial direction of the rotary pressure member; a heating portion, provided in the image forming apparatus body, for heating a rotating fixing member of the fixing unit installed in the fixing unit storage portion from a side opposite to the clamping portion; a driving mechanism for moving the heating portion between a heating position and a retreat position, wherein the heating position is a position preset for heating the rotating fixing member, and the retreat position is a position retreated further outward from an insertion and extraction path of the fixing unit than the heating position in a radial direction of the rotating fixing member; as well as an operating unit capable of being operated by a user, The drive mechanism selectively switches the position of the heating portion between the heating position and the retreat position in conjunction with an operation of the operating portion.

2. The image forming apparatus according to claim 1, wherein: The heating unit has a pair of positioning block portions, each of which is formed with a first engaging portion, and is disposed at both ends of the axial direction. The fixing unit includes a pair of support plates, the pair of support plates support both ends of the rotating fixing member and the rotating pressing member in the axial direction, and each of the pair of support plates is formed with a second engaging portion. The heating part is positioned at the heating position by the first engaging part and the second engaging part engaging with each other. When the heating portion is located at the heating position, a portion of the pair of positioning block portions overlaps with the pair of support plates when viewed in the axial direction.

3. The image forming apparatus according to claim 1, wherein: An insertion and removal opening for inserting and removing the fixing unit is formed at one end portion of the fixing unit storage portion in the insertion and removal direction of the fixing unit. The image forming apparatus further includes an opening and closing door capable of opening and closing the plugging and unplugging opening. The operating part is composed of the opening and closing door. The driving mechanism is configured to locate the heating portion at the heating position when the opening and closing door serving as the operating portion is in a fully closed state, and to locate the heating portion at the retreat position when the opening and closing door is in a prescribed open position at which the fixing unit can be inserted and removed through the insertion and removal opening.

4. The image forming apparatus according to claim 1, wherein: The image forming device further comprises: a drum unit including a photosensitive drum carrying a toner image; and a developing unit including a developing roller for forming a toner image on the photosensitive drum, The image forming apparatus body comprises: a drum unit storage portion for storing the drum unit in a manner that allows the drum unit to be inserted and removed freely in the same direction as the direction in which the fixing unit is inserted and removed; and a developing unit storage portion for storing the developing unit in a manner that allows the developing unit to be inserted and removed freely in the same direction as the direction in which the fixing unit is inserted and removed, The fixing unit insertion and removal opening in the fixing unit storage section, the drum unit insertion and removal opening in the drum unit storage section, and the developing unit insertion and removal opening in the developing unit storage section are all opened on the same side of the image forming apparatus body.

5. The image forming apparatus according to any one of claims 1 to 4, characterized in that: The heating section is an IH heating section having: a bracket having a recessed portion for receiving a side of the outer peripheral surface of the rotating fixing member opposite to the clamping portion side; A plurality of IH coils are supported by the bracket; and an arched magnetic core covers the IH coils.

Images