Imaging device and fixing unit

Abstract

An image forming apparatus includes: an image forming section configured to form a toner image on a sheet; a fixing section configured to heat and press the sheet carrying the toner image so as to fix the toner image to the sheet; a gate configured to be movable to an open position at which the gate opens an opening through which the sheet conveyed toward the fixing section can pass and a closed position at which the gate closes the opening; a push section configured to push the gate toward the open position; and an abutting section against which the gate pushed toward the open position by the push section abuts so as to be positioned at the open position.

Description

Technical Field

[0001] The present invention relates to an imaging device and a fixing unit. Background Technology

[0002] Imaging devices typically include a fixing portion and a fixing frame, the fixing portion being heated to a high temperature, and the fixing frame surrounding the fixing portion. Such a fixing frame usually has an opening through which the sheet passes. Japanese Patent Application Publication No. 2003-140480 discloses an imaging device including a gate that opens and closes the opening of the fixing frame, such that when a user opens an external opening / closing component, the user's fingers will not pass through the opening of the fixing frame and come into contact with the fixing portion.

[0003] However, the gate disclosed in Japanese Patent Application Publication No. 2003-140480 is pushed to a closed position to close the opening, thus requiring a linkage member that moves in conjunction with the opening / closing member to move the gate. Therefore, due to manufacturing tolerances of the linkage member, opening / closing member, etc., it is difficult to position the gate with high precision when opening. Summary of the Invention

[0004] According to a first aspect of the invention, an imaging apparatus includes: an imaging section configured to form a toner image on a sheet; a fixing section configured to heat and pressurize the sheet carrying the toner image to fix the toner image onto the sheet; a gate configured to be movable to an open position and a closed position, wherein in the open position the gate opens an opening through which sheet material being conveyed toward the fixing section can pass, and in the closed position the gate closes the opening; a pushing section configured to push the gate toward the open position; and an abutting section against which the gate material pushed toward the open position by the pushing section abuts, thereby positioning the gate at the open position.

[0005] According to a second aspect of the invention, a fixing unit includes: a fixing portion configured to heat and pressurize a sheet carrying a toner image to fix the toner image onto the sheet; a gate configured to be movable to an open position and a closed position, wherein in the open position the gate opens an opening through which sheet material being conveyed toward the fixing portion can pass, and in the closed position the gate closes the opening; a pushing portion configured to push the gate toward the open position; and an abutting portion against which the gate material pushed toward the open position by the pushing portion abuts, thereby positioning the sheet in the open position.

[0006] Other features of the invention will become clear from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of a printer used as an example of an imaging apparatus according to the first embodiment.

[0008] Figure 2 This is a perspective view of the fixing unit according to the first embodiment.

[0009] Figure 3A This is a cross-sectional view of the fixing unit according to the first embodiment.

[0010] Figure 3B This is a cross-sectional view of the fixing unit according to the first embodiment.

[0011] Figure 4 This is a perspective view of the linkage mechanism and fixing unit according to the first embodiment.

[0012] Figure 5A This is a cross-sectional view of the linkage mechanism and fixing unit according to the first embodiment.

[0013] Figure 5B This is a cross-sectional view of the linkage mechanism and fixing unit according to the first embodiment.

[0014] Figure 6A This is a cross-sectional view of the fixing unit, linkage mechanism, and opening / closing cover according to the first embodiment.

[0015] Figure 6B This is a cross-sectional view of the fixing unit, linkage mechanism, and opening / closing cover according to the first embodiment.

[0016] Figure 7 It is a cross-sectional view of the fixing unit based on the first variation instance.

[0017] Figure 8 This is a perspective view of the fixing unit, linkage mechanism, and front opening / closing cover of a printer used as an example of an imaging apparatus according to the second embodiment.

[0018] Figure 9A This is a cross-sectional view of the fixing unit, linkage mechanism, and front opening / closing cover according to the second embodiment.

[0019] Figure 9B This is a cross-sectional view of the fixing unit, linkage mechanism, and front opening / closing cover according to the second embodiment.

[0020] Figure 10 This is a perspective view of the fixing unit, linkage mechanism, and rear opening / closing cover of a printer used as an example of an imaging apparatus according to the third embodiment.

[0021] Figure 11A This is a cross-sectional view of the fixing unit, linkage mechanism, and rear opening / closing cover according to the third embodiment.

[0022] Figure 11B This is a cross-sectional view of the fixing unit, linkage mechanism, and rear opening / closing cover according to the third embodiment.

[0023] Figure 12 This is a perspective view of the fixing unit, linkage mechanism, and processing box of a printer used as an example of an imaging apparatus according to the fourth embodiment.

[0024] Figure 13A This is a perspective view of the fixing unit, linkage mechanism, and processing box according to the fourth embodiment.

[0025] Figure 13B This is a perspective view of the fixing unit, linkage mechanism, and processing box according to the fourth embodiment. Detailed Implementation

[0026] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] First Embodiment

[0028] Figure 1 This is a schematic longitudinal sectional view of a printer 100 used as an example of an imaging apparatus according to the first embodiment. The printer 100 is a laser beam printer of an electrophotographic system that forms monochrome toner images.

[0029] Printer 100 includes a device body 101 and an exterior 102 covering the device body 101. The device body 101 includes: a body frame 110; a sheet supply section 120 for supplying sheet S; and a transfer roller pair 130 for conveying the sheet S supplied by the sheet supply section 120. Additionally, the device body 101 includes: an imaging section 140 for forming a toner image on the sheet S conveyed by the transfer roller pair 130; and a fixing unit 150 including a fixing section 300 for fixing the toner image formed on the sheet S. Furthermore, the device body 101 includes an ejector roller pair 160 for ejecting the sheet S onto an ejector tray 161. Examples of sheet S include recording media such as paper (e.g., plain paper and envelopes), plastic film for overhead projectors (overhead title film: OHT), and cloth.

[0030] At least a portion of the outer 102 (in the first embodiment, a portion of the upper portion of the outer 102) is an opening / closing cover 103, which serves as an example of an opening / closing component. The opening / closing cover 103 is supported so that it can be opened and closed relative to the body frame 110 in the vertical direction.

[0031] The body frame 110 is a frame body formed of metal sheet and includes a pair of side plates (not shown). The body frame 110 directly or indirectly supports the sheet supply section 120, the transfer roller pair 130, the imaging section 140, the fixing unit 150, and the discharge roller pair 160, either directly or indirectly through components (not shown).

[0032] When an imaging job is input to printer 100, imaging unit 140 begins imaging processing based on image information input from an external computer or the like connected to printer 100. Imaging unit 140 includes a processing cartridge 200 (example of a cartridge), a laser scanner 250 (example of an exposure unit), and a transfer roller 202 (example of a transfer unit).

[0033] The processing box 200 is inserted into the body frame 110 along a guide (not shown) so that it can be pulled out. The processing box 200 is pushed by a pressing member (not shown) when inserted into the body frame 110, thus abutting against a resisting portion (not shown), and thus positioning itself relative to the body frame 110.

[0034] In this embodiment, the processing cartridge 200 is exposed to the outside by opening the open / close cover 103, so that the user can perform insertion / removal operations on the processing cartridge 200. The processing cartridge 200 includes a photosensitive drum 201 serving as an image carrying component, and a charging unit (not shown) and a developing unit (not shown) arranged around the photosensitive drum 201.

[0035] A pair of end portions of the photosensitive drum 201 along the longitudinal direction are rotatably supported by the housing of the processing cartridge 200. The driving force of a drive motor (not shown) is transmitted to one end portion of the photosensitive drum 201 via a drive transmission mechanism (not shown), thus the photosensitive drum 201 along... Figure 1 The direction of arrow A in the image is driven by rotation.

[0036] The surface of the photosensitive drum 201 is an organic photoconductor layer and is uniformly charged by a charging bias voltage from a charging roller (not shown) of a charging unit. A laser scanner 250 radiates laser light onto the photosensitive drum 201 based on input image information. The laser emitted from the laser scanner 250 exposes the surface of the photosensitive drum 201, thus forming an electrostatic latent image on the surface of the photosensitive drum 201. A developing unit (not shown) causes toner to adhere to the surface of the photosensitive drum 201 where the electrostatic latent image has been formed, thus developing the electrostatic latent image. Therefore, a monochrome toner image is formed on the surface of the photosensitive drum 201.

[0037] The sheet S is supplied from the sheet supply section 120 in parallel with the imaging process described above. The sheet supply section 120 includes a supply tray (not shown), an inner plate 121, a pickup roller 122, a supply roller 123, and a separating roller 124. The inner plate 121 is supported by the supply tray (not shown) so that it can rise and fall, and is pushed upward by an inner plate lifting mechanism (not shown). The inner plate 121 is pushed upward by the inner plate lifting mechanism (not shown), so that the downstream end of the sheet S supported on the inner plate 121 is pushed against the pickup roller 122. In this state, the pickup roller 122 supplies the uppermost sheet S of the sheet S supported on the inner plate 121 to the supply roller 123. The supply roller 123 is driven at predetermined timings by a drive motor (not shown) and a drive transmission mechanism (not shown), and conveys the sheet S supplied by the pickup roller 122 to the transfer roller pair 130. When multiple sheets S are supplied by pick-up roller 122, the multiple sheets S are separated by separation roller 124, and only the uppermost sheet S is conveyed to the transfer roller pair 130.

[0038] The sheet S, conveyed to the transfer roller pair 130, is then transferred to the transfer clamping section, where the photosensitive drum 201 and the transfer roller 202 abut against each other. A predetermined bias voltage is applied to the sheet S conveyed to the transfer clamping section via the transfer roller 202, thus transferring the toner image on the photosensitive drum 201 onto the sheet S.

[0039] The fusing unit 150 includes a fusing frame 310 that supports the fusing portion 300. The fusing frame 310 is attached to and fixed to the body frame 110, and is therefore supported by the body frame 110. Thus, the fusing unit 150 can be attached to and detached from the body frame 110, improving the ease of assembly and maintenance of the printer 100.

[0040] The fixing frame 310 includes a front portion 311 opposite to the transfer roller 202 and an upper portion 312 opposite to the discharge roller pair 160. An opening H1 through which the sheet S can pass is provided in the front portion 311 of the fixing frame 310. A generally horizontally extending transport guide 170 is arranged between the transfer roller 202 and the opening H1 of the fixing frame 310. The sheet S, on which a toner image has been transferred, is guided by the transport guide 170 to the fixing unit 150, thereby leading to the fixing section 300 through the opening H1.

[0041] The fixing section 300 includes a heating roller 301 and a pressure roller 302. The heating roller 301 is heated by a heat source. Examples of heat sources include heating elements (e.g., halogen lamps or ceramic heaters) and the heating mechanism of an induction heating system. The fixing clamping section N is formed by the heating roller 301 and the pressure roller 302 abutting against each other. A sheet S on which a toner image has been transferred is clamped and conveyed to the fixing clamping section N of the fixing section 300, and is thus subjected to predetermined heat and predetermined pressure. As a result, the toner image on the sheet S melts and adheres (i.e., fixing) onto the sheet S, thus forming an image on the sheet S.

[0042] An opening H2 through which the sheet S can pass is provided in the upper portion 312 of the fixing frame 310. Generally vertically extending transport guides 181 and 182 are arranged between the opening H2 of the fixing frame 310 and the discharge roller pair 160. The sheet S, on which an image has been formed by the fixing section 300, passes through the opening H2 and is transported to the outside of the fixing frame 310, guided by the transport guides 181 and 182 to the discharge roller pair 160, and discharged by the discharge roller pair 160 onto the discharge tray 161.

[0043] It should be noted that although the printer 100 of the first embodiment has a single-sided printing structure that can only form an image on the first surface of the sheet S, a double-sided printing structure that can form an image on both the first and second surfaces of the sheet S can be adopted. That is, a structure in which a dual transport path is provided downstream of the fixing section 300 along the sheet transport direction, and the sheet S with an image already formed on the first surface is guided to the transfer clamping section through the dual transport path.

[0044] Furthermore, although the case of the fixing section 300 including the heating roller 301 has been described, the construction is not limited to this. A fixing film consisting of a flexible sleeve including a heater (not shown) can be used instead of the heating roller 301.

[0045] Here, when the open / close cover 103 is opened and the processing cartridge 200 is pulled out from the body frame 110, the transfer roller 202, the transport guide 170, and the front portion 311 of the fuser frame 310 are exposed. Therefore, the user can easily remove the sheet stuck inside the printer 100.

[0046] Figure 2 This is a perspective view of the fixing unit 150 according to the first embodiment. Figure 3A and 3B This is a cross-sectional view of the fixing unit 150 according to the first embodiment.

[0047] The heating roller 301 and the pressure roller 302 (especially the heating roller 301) are heated by a heat source (e.g., a heater not shown), and therefore have portions that are heated to high temperatures. The fixing frame 310 is arranged around the fixing portion 300. The fixing frame 310 comprises, for example, a metal plate.

[0048] The longitudinal direction of the fixing section 300 (that is, the longitudinal direction of the heating roller 301 and the pressure roller 302) will be referred to as the X direction. The X direction is also used as the width direction of the sheet S. The fixing section 300 is arranged inside the fixing frame 310, and the two end portions of the fixing section 300 along the X direction are supported by the fixing frame 310. As described above, the fixing frame 310 has two openings H1 and H2 through which the sheet S can pass. Opening H1 is provided on the sheet inlet side of the fixing frame 310, and opening H2 is provided on the sheet outlet side of the fixing frame 310.

[0049] The fact that the fixing frame 310 surrounds the fixing portion 300 does not mean that the fixing frame 310 seals the fixing portion 300, but rather that the fixing frame 310 partially covers the fixing portion 300. That is, in addition to openings H1 and H2, the fixing frame 310 may have other openings, and the fixing frame 310 does not necessarily need to cover parts of the fixing portion 300; it only needs to make it difficult for the user's hand to touch the hot parts of the fixing portion 300. For example, as... Figure 2 As shown, the two end portions of the fixing frame 310 along the X direction can be open. Additionally, an opening of a size that cannot be passed through by a user's fingers can be provided in the fixing frame 310. Furthermore, for example, an opening can be provided in the fixing frame 310 at a location difficult for the user's hands to reach. Additionally, for example, a gap can be provided between the fixing frame 310 and the body frame 110, and the end of the fixing portion 300 along the X direction can be exposed from the fixing frame 310 through this gap.

[0050] Openings H1 and H2 are each sized such that the two ends of the largest sheet S in the sheet that can be imaged by the printer 100 can pass through the openings H1 and H2 in the X direction without contacting the fixing frame 310. In this embodiment, each of the openings H1 and H2 is an elongated hole with a rectangular shape extending in the X direction. It should be noted that the shapes of the openings H1 and H2 are not limited to this; for example, the end portions of the openings H1 and H2 in the X direction can extend to the end portions of the fixing frame 310 in the X direction.

[0051] With the cover 103 open and the processing box 200 pulled out from the main frame 110, opening H1 is within reach of the user's hand, while opening H2 is difficult for the user's hand to reach. In this embodiment, the fixing unit 150 includes a gate 320 for opening and closing opening H1. Gate 320 will be referred to as the fixing gate below. It should be noted that... Figure 3A This indicates that the fixing shutter 320 is open, and Figure 3B This indicates that the fixing gate 320 is closed.

[0052] The fixing shutter 320 is configured to be movable to Figure 3A The opening position P1 and shown Figure 3B The closed position P2 is shown. In the open position P1, the fuser gate 320 opens the opening H1, and in the closed position P2, the fuser gate 320 closes the opening H1. Here, when the fuser gate 320 moves to the closed position P2, the entire opening H1 can be covered by the fuser gate 320, or a portion of the opening H1 can be left uncovered, as long as the user's finger does not enter the opening H1. For example, the end portion of the opening H1 along the X direction does not need to be covered by the fuser gate 320, or an opening (e.g., a hole or slit) can be provided in the fuser gate 320, which has a size through which the user's finger cannot pass.

[0053] The fixing unit 150 includes a retainer 330 that supports the fixing gate 320, allowing the fixing gate 320 to move between an open position P1 and a closed position P2. The retainer 330 is attached and fixed to the fixing frame 310. Therefore, the fixing gate 320 is supported by the body frame 110 via the retainer 330 and the fixing frame 310. In this embodiment, the fixing gate 320 is pivotally (i.e., swingably) supported by the retainer 330. The fixing gate 320 can move between the open position P1 and the closed position P2 by pivoting relative to the retainer 330 (i.e., the fixing frame 310). Specifically, the fixing gate 320 includes a gate body 321 extending in the X direction and a support shaft 322 disposed in the gate body 321. The support shaft 322 is pivotally supported by the retainer 330. Therefore, the fixing gate 320 is supported by the retainer 330 so that it can pivot about the support shaft 322.

[0054] Additionally, the fixing unit 150 includes: a fixing gate spring 340, which serves as an example of a pushing portion; and an abutment portion 335 against which the fixing gate 320 abuts to be positioned in the open position P1. The fixing gate spring 340 is a spring that pushes the fixing gate 320 toward the open position P1 by a pushing force F1, and in this embodiment, it is a torsion coil spring. The coil portion of the fixing gate spring 340 is mounted on the support shaft 322, the first end of the fixing gate spring 340 abuts against the gate body 321 of the fixing gate 320, and the second end of the fixing gate spring 340 abuts against the fixing frame 310. Therefore, the pushing force F1 of the fixing gate spring 340 acts on the fixing gate 320. Moreover, as Figure 3A As shown, the fixing gate 320 is pivoted counterclockwise by the pushing force F1 of the fixing gate spring 340 and abuts against the abutting part 335.

[0055] The abutment portion 335 is fixed to the retainer 330, which is fixed to the fuser frame 310. That is, the abutment portion 335 is indirectly fixed to the fuser frame 310 via the retainer 330, and thus indirectly fixed to the body frame 110 via the retainer 330 and the fuser frame 310. As described above, the abutment portion 335 is precisely positioned and fixed via the fuser frame 310 (i.e., the body frame 110). Therefore, the fuser gate 320 is precisely positioned at the open position P1 by abutting against the precisely positioned abutment portion 335.

[0056] like Figure 3A As shown, by utilizing the pushing force F1 of the fuser gate spring 340, the fuser gate 320 is moved to the open position P1, and the fuser clamping part N of the fuser section 300 is exposed to the outside of the fuser frame 310 through the opening H1. Furthermore, since the gate body 321 of the fuser gate 320 abuts against the abutment part 335, the fuser gate 320 is precisely positioned in the open position P1. Therefore, a sheet transport path with sufficient width for the sheet S to pass through in the opening H1 can be ensured without increasing the size of the printer 100. Therefore, contact between the sheet S, which is guided to the fuser clamping part N through the opening H1 during imaging, and the fuser frame 310 or the fuser gate 320 can be reduced. Therefore, jamming of the sheet S in the opening H1 and interference with the toner image formed on the sheet S can be reduced.

[0057] Furthermore, since the fuser gate 320 pivots about the support shaft 322 to move to the open position P1 and the closed position P2, the size of the printer 100 can be reduced compared to the case where the fuser gate moves to the open and closed positions by linear motion.

[0058] like Figure 3B As shown, the fixing gate 320 includes an abutment portion 323 disposed at the end portion of the gate body 321 along the X direction. This abutment portion 323 is arranged outside the sheet transport path. The fixing frame 310 includes an abutment portion 336, which abuts against when the fixing gate 320 moves to the closed position P2. Because the abutment portion 323 of the fixing gate 320 abuts against the abutment portion 336, the fixing gate 320 is precisely positioned in the closed position P2. Because the fixing gate 320 moves to the closed position P2, the fixing clamping portion N of the fixing portion 300 is covered by the fixing gate 320.

[0059] In this embodiment, the printer 100 includes a linkage mechanism 350, which opens and closes the fuser gate 320 in a manner linked to the opening / closing operation of the cover 103, such as... Figure 1 As shown. The linkage mechanism 350 causes the fixing gate 320 to move to the closed position P2 by overcoming the pushing force F1 of the fixing gate spring 340 according to the opening operation of the opening / closing cover 103.

[0060] Figure 4 This is a perspective view of the linkage mechanism 350 and the fixing unit 150 according to the first embodiment. Figure 5A and 5B This is a cross-sectional view of the linkage mechanism 350 and the fixing unit 150 according to the first embodiment. It should be noted that... Figure 5A This indicates that the fixing shutter 320 is open. Figure 5B This indicates that the fixing gate 320 is closed.

[0061] The linkage mechanism 350 is arranged at a position corresponding to the abutment portion 323 of the fixing gate 320. The linkage mechanism 350 includes: a switching link 351, which serves as an example of a first linkage component; a movable link 352, which serves as an example of a second linkage component; and a switching link spring 353, which serves as an example of a linkage pushing portion.

[0062] The conversion linkage 351 is set to be movable to Figure 5A The separation positions shown are P3 and Figure 5B The shown abutment position P4 is different from the separation position P3, where the switching link 351 is separated from the abutment portion 323 of the fixing gate 320. At abutment position P4, the switching link 351 abuts against the abutment portion 323 of the fixing gate 320. In this embodiment, the switching link 351 is pivotally (swingably) supported by a retainer (not shown). The retainer (not shown) is fixed to... Figure 1The main body frame 110 is used for the conversion link 351. The conversion link 351 can move between a disengaged position P3 and an abutted position P4 by pivoting relative to a retainer (not shown). Specifically, the conversion link 351 includes a link body 3511 and a support shaft 3512 disposed in the link body 3511. The support shaft 3512 is pivotally supported by a retainer (not shown). Therefore, the conversion link 351 is supported by a retainer (not shown) so that it can pivot about the support shaft 3512.

[0063] The switching link spring 353 is a spring that pushes the switching link 351 toward the abutment position P4 by a pushing force F2, and in this embodiment it is a torsion coil spring. The pushing force F2 of the switching link spring 353 is set to be greater than the pushing force F1 of the fixing gate spring 340. The switching link spring 353 is mounted on the support shaft 3512 of the switching link 351.

[0064] The movable link 352 is based on Figure 1 The closing operation of the open / close cover 103, as shown, overcomes the pushing force F2 of the switching link spring 353, causing the switching link 351 to move to the disengaged position P3. The movable link 352 is linearly supported by a retainer (not shown). The retainer (not shown) is fixed to... Figure 1 The movable link 352 moves linearly relative to the retainer (not shown) on the main body frame 110, and can therefore abut against or separate from the switching link 351.

[0065] like Figure 5A As shown, the movable link 352 abuts against and presses the conversion link 351, thereby causing the conversion link 351 to pivot counterclockwise in a first direction against the pushing force F2 of the conversion link spring 353, so that the conversion link 351 moves to the separation position P3. Therefore, when the conversion link 351 is positioned in the separation position P3, the fixing gate 320 is positioned in the open position P1 by being pushed by the fixing gate spring 340. That is, the restriction of the conversion link 351 is eliminated, and the fixing gate 320 pivots counterclockwise against the abutting portion 335 by the pushing force F1 of the fixing gate spring 340, and is therefore positioned in the open position P1 with high precision.

[0066] In addition, such as Figure 5BAs shown, when the movable link 352 is separated from the switching link 351, the switching link 351 pivots clockwise in a second direction opposite to the first direction due to the pushing force F2 of the switching link spring 353, so as to contact the abutment portion 323. The pushing force F2 of the switching link spring 353 is greater than the pushing force F1 of the fixing gate spring 340. Therefore, the switching link 351 overcomes the pushing force F1 of the fixing gate spring 340 by the pushing force F2 of the switching link spring 353 and presses the abutment portion 323 of the fixing gate 320, and moves to the abutment position P4 while pivoting the fixing gate 320 in a clockwise direction. Therefore, when the switching link 351 is positioned at the abutment position P4, the switching link 351 overcomes the pushing force F1 of the fixing gate spring 340 and presses the fixing gate 320, so the fixing gate 320 is positioned at the closed position P2. In other words, the fixing gate 320 pivots clockwise around the support shaft 322 via the abutment portion 323 (which is pressed by the pivoting conversion link 351). Moreover, since the conversion link 351 pivots to the abutment position P4, the abutment portion 323 abuts against the abutment portion 336, and the fixing gate 320 is precisely positioned in the closed position P2.

[0067] Figure 6A and 6B This is a cross-sectional view of the fixing unit 150, the linkage mechanism 350, and the opening / closing cover 103 according to the first embodiment. It should be noted that... Figure 6A This indicates that the fixing shutter 320 is open. Figure 6B This indicates that the fixing gate 320 is in the closed state. The open / close cover 103 is supported by the body frame 110 so that it can pivot about the support shaft 1031. The open / close cover 103 has a recessed portion 1032 into which one end portion of the movable link 352 can be fitted and separated.

[0068] like Figure 6AAs shown, when the open / close cover 103 transitions from the open state to the closed state, one end portion of the movable link 352 is fitted into the recessed portion 1032 of the open / close cover 103, thus the movable link 352 moves in the direction of arrow A1. Since the movable link 352 moves in the direction of arrow A1 according to the closing operation of the open / close cover 103, the movable link 352 abuts against the switching link 351, causing the switching link 351 to pivot counterclockwise against the pushing force F2 of the switching link spring 353. Therefore, the switching link 351 moves to the separation position P3, in which the switching link 351 separates from the abutting portion 323 of the fixing shutter 320. Since the switching link 351 separates from the fixing shutter 320, the fixing shutter 320 abuts against the abutting portion 335 by the pushing force F1 of the fixing shutter spring 340, and is thus positioned in the open position P1. Therefore, the fixing clamping part N is exposed through the opening H1.

[0069] In addition, such as Figure 6B As shown, when the open / close cover 103 transitions from the closed state to the open state, one end portion of the movable link 352 separates from the recessed portion 1032 of the open / close cover 103 and is thus pressed by the open / close cover 103 in the direction of arrow A2, opposite to the direction of arrow A1. Therefore, the movable link 352 moves in the direction of arrow A2 according to the opening operation of the open / close cover 103. Because the movable link 352 moves in the direction of arrow A2, it separates from the switching link 351, and the switching link 351 pivots clockwise by the pushing force F2 of the switching link spring 353. Because the switching link 351 moves to the abutment position P4 against the pushing force F1 of the fixing shutter spring 340, the abutment portion 323 of the fixing shutter 320 abuts against the abutment portion 336, and the fixing shutter 320 is in the closed position P2. Therefore, the fixing clamping part N is covered by the fixing gate 320.

[0070] As described above, according to the first embodiment, the switching link 351 of the linkage mechanism 350 is separated from the fixing gate 320 by closing the opening / closing cover 103. Because the fixing gate 320 is pushed toward the open position P1 by the pushing force F1 of the fixing gate spring 340, the fixing gate 320 pivots to abut against the abutment portion 335, and is thus positioned with high precision in the open position P1.

[0071] Furthermore, the fuser spring 340, mounted on the support shaft 322 of the fuser 320, is a component that moves the fuser 320 to the open position P1. Therefore, compared to a structure where the fuser retracts from the sheet transport path via a linkage component that operates in conjunction with the closing operation of the open / close cover, the structure for retracting the fuser 320 from the sheet transport path can be simplified, and the size of the printer 100 can be reduced. Thus, even with a reduced size of the printer 100, the fuser 320 can reliably retract from the sheet transport path.

[0072] Furthermore, in the first embodiment, the pushing force F2 of the switching link spring 353 is set greater than the pushing force F1 of the fixing gate spring 340. When the user opens the open / close cover 103 to remove the jammed sheet or replace the processing cartridge 200, the interior of the device body 101 is exposed. In this state, the pushing force F2 of the switching link spring 353 overcomes the pushing force F1 of the fixing gate spring 340, positioning the fixing gate 320 in the closed position P2. Therefore, it is possible to prevent the user's fingers from passing through the opening H1 and contacting the hot part of the fixing section 300.

[0073] Furthermore, if a sheet jam occurs upstream of the fixing section 300 while the sheet is clamped within it, the user performs a paper removal operation by pulling the sheet out through the opening H1. The pushing force F1 of the fixing gate spring 340 assists the user in pulling out the jammed sheet, and the pushing force F2 of the switching link 351 is reduced by the pushing force F1, which helps to pull out the jammed sheet. Therefore, the availability of removing paper jams upstream of the fixing section 300 is improved.

[0074] First example of change

[0075] It should be noted that although the attachment and fixation of the retainer 330 to the fixing frame 310 has been described in the first embodiment, the construction is not limited thereto. Figure 7 This is a cross-sectional view of the fixing unit 150 of the first variation instance. For example, as... Figure 7 As shown, the retainer 330 (with the abutment portion 335 fixed to it) can be fixed to the body frame 110. Furthermore, although its illustration is omitted, the abutment portion 335 can be directly attached and fixed to the fixing frame 310, rather than being attached and fixed to the fixing frame 310 via the retainer 330.

[0076] Second Embodiment

[0077] The printer used as an example of the imaging apparatus according to the second embodiment will now be described. Figure 8This is a perspective view of the fixing unit 150, linkage mechanism 350A, and front opening / closing cover 103A of a printer used as an example of an imaging apparatus according to the second embodiment. Figure 9A and 9B This is a cross-sectional view of the fixing unit 150, the linkage mechanism 350A, and the front opening / closing cover 103A according to the second embodiment.

[0078] In the first embodiment, the structure of the fuser gate 320 of the fuser unit 150 opening and closing the opening H1 according to the opening / closing operation of the opening / closing cover 103 has been described. In the second embodiment, the structure of the fuser gate 320 of the fuser unit 150 opening and closing the opening H1 according to the opening / closing operation of the front opening / closing cover 103A will be described. It should be noted that the components in the printer of the second embodiment, except for the front opening / closing cover 103A and the linkage mechanism 350A, are substantially the same as the components in the printer 100 of the first embodiment, except for the opening / closing cover 103A and the linkage mechanism 350A, and therefore their description will be omitted.

[0079] The printer of the second embodiment includes a fuser unit 150, a linkage mechanism 350A, and a front opening / closing cover 103A. The front opening / closing cover 103A serves as an example of an opening / closing component. The front opening / closing cover 103A is part of the printer's exterior, specifically the front portion of the exterior. The front opening / closing cover 103A is supported and can be positioned relative to... Figure 1 The ontology frame 110 is opened and closed.

[0080] The fixing unit 150 includes a fixing portion 300, a fixing frame 310, a fixing gate 320, a fixing gate spring 340, a retainer 330, a stop portion 335, and a stop portion 336, as described in the first embodiment. The opening / closing operation of the fixing gate 320 is the same as described in the first embodiment. It should be noted that... Figure 9A This indicates that the fixing shutter 320 is open. Figure 9B This indicates that the fixing gate 320 is closed.

[0081] The front opening / closing cover 103A is supported by the body frame 110 so that it can pivot about the support shaft 1031A. The linkage mechanism 350A includes a switching link 351 and a switching link spring 353 arranged as described in the first embodiment. The switching link 351 serves as an example of a first linkage component, and the switching link spring 353 serves as an example of a linkage pushing portion. Additionally, the linkage mechanism 350A includes a movable link 352A, which serves as an example of a second linkage component; and a retaining link 354A.

[0082] The movable link 352A is a link component that moves linearly in the horizontal direction in conjunction with the opening / closing operation of the front opening / closing cover 103A, and is linearly supported by a retainer (not shown). The retainer (not shown) is fixed to... Figure 1 The movable link 352A moves linearly relative to the retainer (not shown) on the main body frame 110, and can therefore abut against or separate from the changeover link 351.

[0083] In the second embodiment, the configuration for opening or closing the front open / close cover 103A enables linear movement of the movable link 352A via a retaining link 354A. The retaining link 354A is supported by a support shaft 1032A of the front open / close cover 103A, allowing it to pivot about the support shaft 1032A. The retaining link 354A has an elongated hole 3541A. A pin 3521A located at one end portion of the movable link 352A is inserted into the elongated hole 3541A of the retaining link 354A, allowing it to slide along the elongated hole 3541A. Therefore, the movable link 352A moves linearly in the horizontal direction according to the opening / closing operation of the front open / close cover 103A.

[0084] like Figure 9A As shown, the movable link 352A moves in the direction of arrow A1 according to the closing operation of the front open / close cover 103A. The movable link 352A, moving in the direction of arrow A1, abuts against the conversion link 351, causing the conversion link 351 to move to the separated position P3, overcoming the pushing force F2 of the conversion link spring 353. Therefore, when the conversion link 351 is positioned in the separated position P3, the fuser gate 320 is positioned in the open position P1 by being pushed by the fuser gate spring 340 and abutting against the abutting portion 335. That is, by eliminating the restriction of the conversion link 351, the fuser gate 320 is pivoted by the pushing force F1 of the fuser gate spring 340 to abut against the abutting portion 335, and thus is positioned with high precision in the open position P1. Therefore, a sheet transport path with a sufficient width to allow the sheet to pass through can be ensured in the opening H1 without increasing the size of the printer. Therefore, contact between the sheet guided to the fixing clamping part N through the opening H1 and the fixing frame 310 or fixing gate 320 during imaging can be reduced. Consequently, jamming of the sheet in the opening H1 and interference with the toner image formed on the sheet can be reduced.

[0085] In addition, such as Figure 9BAs shown, according to the opening operation of the front open / close cover 103A, the movable link 352A moves in the direction of arrow A2, which is opposite to the direction of arrow A1. Since the movable link 352A, which moves in the direction of arrow A2, separates from the switching link 351, the switching link 351 pivots due to the pushing force F2 of the switching link spring 353. The pushing force F2 of the switching link spring 353 is greater than the pushing force F1 of the fixing shutter spring 340. Therefore, the switching link 351 overcomes the pushing force F1 of the fixing shutter spring 340 by the pushing force F2 of the switching link spring 353 and presses the abutment portion 323 of the fixing shutter 320, thereby moving to the abutment position P4 while pivoting the fixing shutter 320. Therefore, when the switching link 351 is in the abutting position P4, the switching link 351 overcomes the pushing force F1 of the fixing gate spring 340 and presses the fixing gate 320, thus the fixing gate 320 is in the closed position P2. That is, the fixing gate 320 is pressed by the switching link 351 so that it pivots about the support shaft 322 and abuts against the abutting portion 336, and is therefore positioned with high precision in the closed position P2. Therefore, it is possible to prevent the user's fingers from passing through the opening H1 and contacting the hot part of the fixing portion 300.

[0086] Third Embodiment

[0087] The printer used as an example of the imaging apparatus according to the third embodiment will now be described. Figure 10 This is a perspective view of the fixing unit 150B, linkage mechanism 350B, and rear opening / closing cover 103B of a printer used as an example of an imaging apparatus according to the third embodiment. Figure 11A and 11B This is a cross-sectional view of the fixing unit 150B, the linkage mechanism 350B, and the rear opening / closing cover 103B according to the third embodiment.

[0088] The opening and closing mechanism of the fuser frame on the sheet inlet side has been described in the first and second embodiments. In the third embodiment, the opening and closing mechanism of the fuser frame on the sheet outlet side will be described. It should be noted that the components in the printer of the third embodiment, except for the fuser unit 150B, the rear opening / closing cover 103B, and the linkage mechanism 350B, are substantially the same as the components in the printer 100 of the first embodiment, except for the fuser unit 150, the opening / closing cover 103, and the linkage mechanism 350, and therefore their description will be omitted.

[0089] The printer of the third embodiment includes a fusing unit 150B, a linkage mechanism 350B, and a rear opening / closing cover 103B. The rear opening / closing cover 103B serves as an example of an opening / closing component. The fusing unit 150B includes a fusing portion 300 arranged as described in the first embodiment. Additionally, the fusing unit 150B includes a fusing frame 310B surrounding the fusing portion 300. The fusing frame 310B has an opening H11 on the sheet inlet side and an opening H12 on the sheet outlet side. The rear opening / closing cover 103B is part of the printer's exterior and is the rear portion of the exterior. The rear opening / closing cover 103B is composed of… Figure 1 The main body frame 110 is supported so that it can pivot about the support shaft 1031B. Therefore, the rear opening / closing cover 103B pivots about the support shaft 1031B, thus enabling it to pivot relative to the support shaft 1031B. Figure 1 The main frame 110 can be opened and closed. In addition, the rear opening / closing cover 103B and the transfer guide 181 are integrally formed, and the transfer guide 181 can be opened and closed together with the rear opening / closing cover 103B.

[0090] When the transfer guide 181 is opened together with the rear opening / closing cover 103B, the cover can be opened by... Figure 1 The sheet transport path is defined by transport guides 181 and 182. Therefore, it is easier to remove sheet material jammed at transport guides 181 and 182. To prevent the user's fingers from contacting the hot portion of the fixing section 300 through the opening H12 during paper jam removal, the fixing unit 150B of the third embodiment includes a fixing gate 320B that opens and closes the opening H12. It should be noted that... Figure 11A This indicates that the fixing shutter 320B is open. Figure 11B This indicates that the fixing gate 320B is closed.

[0091] The fixing gate 320B is configured to be able to move to Figure 11A The opening position P11 and shown Figure 11B The closed position P12 is shown. In the open position P11, the fuser gate 320B opens the opening H12. In the closed position P12, the fuser gate 320B closes the opening H12. Here, when the fuser gate 320B moves to the closed position P12, the opening H12 can be completely covered by the fuser gate 320B, or a part of the opening H12 can be left uncovered by the fuser gate 320B, as long as the user's finger cannot enter the opening H12.

[0092] The fixing unit 150B includes a retainer 330B that supports a fixing gate 320B, allowing the fixing gate 320B to move between an open position P11 and a closed position P12. The retainer 330B is attached to and fixed to the fixing frame 310B. Therefore, the fixing gate 320B is controlled by the retainer 330B and the fixing frame 310B. Figure 1 The fuser is supported by the body frame 110. In this embodiment, the fuser gate 320B is pivotally (i.e., swingably) supported by the retainer 330B. The fuser gate 320B can move between an open position P11 and a closed position P12 by pivoting relative to the retainer 330B (i.e., the fuser frame 310B). Specifically, the fuser gate 320B includes a gate body 321B extending in the X direction and a support shaft 322B disposed in the gate body 321B. The support shaft 322B is pivotally supported by the retainer 330B. Therefore, the fuser gate 320B is supported by the retainer 330B so that it can pivot about the support shaft 322B.

[0093] Additionally, the fixing unit 150B includes: a fixing gate spring 340B, which serves as an example of a pushing portion; and an abutment portion 335B against which the fixing gate 320B abuts to be positioned in the open position P11. The fixing gate spring 340B is a spring that pushes the fixing gate 320B toward the open position P11 by a pushing force F3; in this embodiment, it is a torsion coil spring. The fixing gate spring 340B is mounted on a support shaft 322B to apply the pushing force F3 to the fixing gate 320B.

[0094] The abutment portion 335B is fixed to the retainer 330B, which is fixed to the fuser frame 310B. In other words, the abutment portion 335B is indirectly fixed to the fuser frame 310B via the retainer 330B, and thus indirectly fixed to the body frame 110 via the retainer 330B and the fuser frame 310B. As described above, the abutment portion 335B is precisely positioned and fixed via the fuser frame 310B (i.e., the body frame 110). Therefore, the fuser gate 320B is precisely positioned in the open position P11 by abutting against the precisely positioned abutment portion 335B. It should be noted that the abutment portion 335B can be directly mounted on the fuser frame 310B.

[0095] Additionally, the fixing gate 320B includes an abutment portion 323B disposed at the end portion of the gate body 321B along the X direction. A linkage mechanism 350B is arranged at a position corresponding to the abutment portion 323B. The linkage mechanism 350B includes a switching link 351B, serving as an example of a first linkage member; a pressing portion 352B, serving as an example of a second linkage member; and a switching link spring 353B, serving as an example of a linkage pushing portion.

[0096] The conversion linkage 351B is set to be movable to Figure 11A The separation positions shown are P13 and Figure 11B The shown abutment position P14 is different from the separation position P13, where the switching link 351B separates from the abutment portion 323B of the fixing gate 320B. At the abutment position P14, the switching link 351B abuts against the abutment portion 323B of the fixing gate 320B. In this embodiment, the switching link 351B is pivotally (swingably) supported by a retainer (not shown). The retainer (not shown) is fixed to... Figure 1 The main body frame 110 is used. The conversion link 351B can move between a disengaged position P13 and an abutted position P14 by pivoting relative to a retainer (not shown). Specifically, the conversion link 351B includes a support shaft 3512B that is pivotally supported by a retainer (not shown).

[0097] The switching link spring 353B is a spring that pushes the switching link 351B toward the abutment position P14 by a pushing force F4. In this embodiment, it is a torsion coil spring. The pushing force F4 of the switching link spring 353B is set to be greater than the pushing force F3 of the fixing gate spring 340B. The switching link spring 353B is mounted on the support shaft 3512B of the switching link 351B.

[0098] The pressing part 352B is a linkage component that overcomes the pushing force F4 of the switching linkage spring 353B according to the closing operation of the rear opening / closing cover 103B, causing the switching linkage 351B to move to the disengaged position P13. The pressing part 352B is fixed to the rear opening / closing cover 103B. When the rear opening / closing cover 103B is opened or closed, the pressing part 352B abuts against or separates from the switching linkage 351B.

[0099] like Figure 11AAs shown, when the rear open / close cover 103B is closed, the pressing part 352B abuts against the conversion link 351B, thereby overcoming the pushing force F4 of the conversion link spring 353B and causing the conversion link 351B to move to the disengaged position P13. Therefore, when the conversion link 351B is in the disengaged position P13, the fixing gate 320B is pushed by the fixing gate spring 340B against the abutting part 335B and is in the open position P11. That is, the restriction of the conversion link 351B is eliminated, and the fixing gate 320B is pivoted by the pushing force F3 of the fixing gate spring 340B to abut against the abutting part 335B, and thus is positioned with high precision in the open position P11. Therefore, it is possible to prevent the sheet material guided to the outside of the fixing clamping part N through the opening H12 from contacting the fixing frame 310B or the fixing gate 320B. Therefore, it is possible to prevent the sheet material from getting stuck in the opening H12.

[0100] In addition, such as Figure 11B As shown, when the rear opening / closing cover 103B is opened, the pressing part 352B separates from the switching link 351B. Therefore, the switching link 351B pivots under the pushing force F4 of the switching link spring 353B to abut against the abutting part 323B of the fixing shutter 320B. The pushing force F4 of the switching link spring 353B is greater than the pushing force F3 of the fixing shutter spring 340B. Therefore, the switching link 351B, through the pushing force F4 of the switching link spring 353B, overcomes the pushing force F3 of the fixing shutter spring 340B to press against the abutting part 323B of the fixing shutter 320B, and moves to the abutting position P14 while pivoting the fixing shutter 320B. Therefore, when the switching link 351B is in the abutting position P14, the switching link 351B overcomes the pushing force F3 of the fixing gate spring 340B to press the fixing gate 320B, thereby placing the fixing gate 320B in the closed position P12. That is, the fixing gate 320B is pivoted clockwise about the support shaft 322B by being pressed by the switching link 351B so as to abut against the abutting part 336B, and thus is positioned with high precision in the closed position P12.

[0101] In this way, the fuser gate 320B pivots about the support shaft 322B to move to the open position P11 and the closed position P12. Therefore, compared with the case where the fuser gate moves to the open and closed positions by linear motion, the size of the printer can be reduced.

[0102] As described above, according to the third embodiment, the switching link 351B of the linkage mechanism 350B is separated from the fixing gate 320B by closing the rear open / close cover 103B. Because the fixing gate 320B is pushed toward the open position P11 by the pushing force F3 of the fixing gate spring 340B, the fixing gate 320B pivots to abut against the abutting portion 335B, and is thus positioned with high precision in the open position P11.

[0103] Furthermore, the fuser gate spring 340B, mounted on the support shaft 322B of the fuser gate 320B, is the component that moves the fuser gate 320B to the open position P11. Therefore, compared to a structure where the fuser gate retracts from the sheet transport path via a linkage component that operates in conjunction with the closing operation of the open / close cover, the structure for retracting the fuser gate 320B from the sheet transport path is simplified, and the printer size can be reduced. Thus, even with a reduced printer size, the fuser gate 320B can reliably retract from the sheet transport path.

[0104] Furthermore, in the third embodiment, the pushing force F4 of the switching link spring 353B is set greater than the pushing force F3 of the fixing gate spring 340B. When the user opens the rear opening / closing cover 103B to remove the jammed sheet, the sheet conveying path formed by the conveying guide 108 is exposed. In this state, the fixing gate 320B is positioned in the closed position P12 by overcoming the pushing force F3 of the fixing gate spring 340B through the pushing force F4 of the switching link spring 353B. Therefore, it is possible to prevent the user's fingers from contacting the hot part of the fixing section 300 through the opening H12.

[0105] Furthermore, in the event of a sheet jamming on the downstream side of the fixing section 300 while the sheet is clamped within it, the user performs a paper removal operation by pulling the sheet out through the opening H12. The pushing force F3 of the fixing gate spring 340B assists the user in pulling out the jammed sheet, and the pushing force F4 of the switching link 351B is reduced by the pushing force F3, which helps to pull out the jammed sheet. Therefore, the usability for removing paper jams on the downstream side of the fixing section 300 is improved.

[0106] Fourth embodiment

[0107] The printer used as an example of the imaging apparatus according to the fourth embodiment will now be described. Figure 12 This is a perspective view of the fixing unit 150, linkage mechanism 350C, and processing box 200 of a printer used as an example of an imaging apparatus according to the fourth embodiment. Figure 13A and Figure 13B This is a cross-sectional view of the fixing unit 150, the linkage mechanism 350C, and the processing box 200 according to the fourth embodiment.

[0108] In the first to third embodiments, a structure in which the fuser gate moves in conjunction with the opening / closing operation of the opening / closing component has been described. In the fourth embodiment, a structure in which the fuser gate 320 moves in conjunction with the insertion / removal operation of the processing cartridge 200 will be described. It should be noted that the components in the printer of the fourth embodiment, except for the linkage mechanism 350C, are substantially the same as the components in the printer 100 of the first embodiment, except for the linkage mechanism 350, and therefore their description will be omitted.

[0109] The printer of the fourth embodiment includes a fuser unit 150, a processing cartridge 200, and a linkage mechanism 350C. The fuser unit 150 and the processing cartridge 200 have the same structure as those described in the first embodiment.

[0110] The linkage mechanism 350C includes a switching link 351 and a switching link spring 353. The switching link 351 serves as an example of a first linkage component. The switching link spring 353 serves as an example of a linkage pushing portion. The switching link 351 and the switching link spring 353 are constructed as described in the first embodiment. That is, the switching link 351 is supported by a retainer (not shown) so that it can be moved to a separated position P3 and an abutting position P4, in which the switching link 351 is separated from the fixing gate 320, and in which the abutting position P4 the switching link 351 abuts against the fixing gate 320. The switching link spring 353 is a spring that pushes the switching link 351 toward the abutting position P4. The pushing force F2 of the switching link spring 353 is greater than the pushing force F1 of the fixing gate spring 340. Furthermore, when the switching link 351 is in the disengaged position P3, the fixing gate 320 is in the open position P1 by being pushed by the fixing gate spring 340. Additionally, when the switching link 351 is in the abutted position P4, the switching link 351 overcomes the pushing force F1 of the fixing gate spring 340 to press the fixing gate 320, thus positioning the fixing gate 320 in the closed position P2.

[0111] Additionally, the linkage mechanism 350C includes a movable link 352C, which serves as an example of a second linkage component. The movable link 352C is a linkage component that, upon insertion of the processing box 200 into the body frame 110, overcomes the pushing force F2 of the conversion link spring 353, causing the conversion link 351 to move to the disengaged position P3. The processing box 200 includes a pressing portion 210 arranged at a position corresponding to the linkage mechanism 350C. The pressing portion 210 is part of a side plate included in the housing of the processing box 200.

[0112] When the processing box 200 is inserted into the main body frame 110, the pressing part 210 of the processing box 200 abuts against the movable link 352C and presses the movable link 352C in the direction of arrow A1, as shown. Figure 13A As shown. Then, the movable link 352C moves in the direction of arrow A1 to abut against and press the switching link 351. The switching link 351 overcomes the pushing force F2 of the switching link spring 353 and moves along... Figure 13A The mechanism pivots counterclockwise. Therefore, the switching link 351 separates from the abutment portion 323 of the fixing gate 320, and the fixing gate 320 is thus propelled along the direction of the fixing gate spring 340 by the pushing force F1. Figure 13A The fuser rotates counterclockwise. Then, the fuser gate 320 abuts against the abutment portion 335 and is thus positioned in the open position P1. Since the fuser gate 320 is positioned in the open position P1, the fuser clamping portion N of the fuser portion 300 is exposed through the opening H1.

[0113] Additionally, when the processing box 200 is pulled out from the main frame 110, the pressing part 210 of the processing box 200 separates from the movable link 352C, as... Figure 13B As shown. Therefore, the switching link 351 moves along the switching link spring 353 by the pushing force F2. Figure 13B The movable link 352C is pressed by the switching link 351 and rotated clockwise, moving in the direction of arrow A2. Then, the switching link 351 abuts against the abutting portion 323 of the fixing gate 320 to press the fixing gate 320 and pivots clockwise until the abutting portion 323 of the fixing gate 320 abuts against the abutting portion 336. Then, since the abutting portion 323 abuts against the abutting portion 336, the fixing gate 320 is positioned in the closed position P2. Since the fixing gate 320 is positioned in the closed position P2, the fixing clamping portion N of the fixing portion 300 is covered by the fixing gate 320.

[0114] As described above, according to the fourth embodiment, by inserting the processing box 200 into the body frame 110, the switching link 351 of the linkage mechanism 350C is separated from the fixing gate 320. Since the fixing gate 320 is pushed to the open position P1 by the pushing force F1 of the fixing gate spring 340, the fixing gate 320 pivots to abut against the abutting portion 335, and is thus positioned with high precision in the open position P1.

[0115] Furthermore, the fuser spring 340, mounted on the support shaft 322 of the fuser 320, is the component that moves the fuser 320 to the open position P1. Therefore, compared to a structure where the fuser retracts from the sheet transport path via a linkage component that operates in conjunction with the insertion / removal operation of the processing cartridge, the structure for retracting the fuser 320 from the sheet transport path is simplified, and the printer size can be reduced. Thus, even with a reduced printer size, the fuser 320 can reliably retract from the sheet transport path.

[0116] Furthermore, in the fourth embodiment, the pushing force F2 of the switching link spring 353 is set greater than the pushing force F1 of the fixing gate spring 340. When the user pulls the processing cartridge 200 out of the main body frame 110, the fixing unit 150 is exposed. In this state, the fixing gate 320 is positioned in the closed position P2 by overcoming the pushing force F1 of the fixing gate spring 340 through the pushing force F2 of the switching link spring 353. Therefore, it is possible to prevent the user's fingers from passing through the opening H1 and contacting the hot part of the fixing section 300.

[0117] Furthermore, in the event of a sheet jamming on the upstream side of the fixing section 300 while the sheet is clamped within it, the user performs a paper removal operation by pulling the sheet out through the opening H1. The pushing force F1 of the fixing gate spring 340 assists the user in pulling out the jammed sheet, and the pushing force F2 of the switching link 351 is reduced by the pushing force F1, which helps to pull out the jammed sheet. Therefore, the usability for removing paper jams on the upstream side of the fixing section 300 is improved.

[0118] According to the present invention, the gate can be positioned with high precision when the gate is opened.

[0119] This invention is not limited to the above embodiments, and variations can be made within the technical concept of this invention. Furthermore, the effects described in the embodiments are merely examples of the most preferred effects obtainable from this invention, and the effects of this invention are not limited to those described in the embodiments.

[0120] Although a monochrome printer in an electrophotographic system has been described as an example of an imaging device in the above embodiments, the present invention is not limited thereto. For example, the present invention can be applied to a full-color printer in an electrophotographic system that includes multiple processing cartridges. Furthermore, in addition to printers, the present invention can also be applied to copiers, fax machines, multifunction devices having these functions, etc.

[0121] Furthermore, although the above embodiments have described the imaging device as an electrophotographic system, the present invention is not limited thereto. For example, the present invention can be applied to imaging devices of electrostatic recording systems or magnetic recording systems.

[0122] Furthermore, although the cases of cartridges that can be inserted into and removed from the body frame have been described in the above embodiments, the present invention is not limited thereto. For example, the present invention can also be applied to cases where the cartridge is a toner cartridge that supplies toner to the developing unit.

[0123] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be interpreted in the broadest sense to cover all such variations and equivalent structures and functions.

Claims

1. An imaging device, comprising: The imaging section is configured to form a toner image on the sheet; The fixing section is configured to heat and pressurize the sheet carrying the toner image so as to fix the toner image onto the sheet. Ontology framework; An opening / closing component is supported on the body frame so that it can be opened and closed relative to the body frame; A gate, configured to move between an open position and a closed position, wherein in the open position the gate opens an opening through which sheet material to be conveyed toward the fixing section can pass, and in the closed position the gate closes the opening; The pushing part is configured to push the gate towards the open position; The abutting part is abutted by a gate that is pushed toward the open position by the pushing part, so as to be positioned in the open position; as well as A linkage mechanism is configured to overcome the pushing force of the pushing portion and move the gate to the closed position according to the opening operation of the opening / closing component; The linkage mechanism includes a linkage component capable of moving to a separated position and an abutting position. In the separated position, the linkage component is separated from the gate; in the abutting position, the linkage component abuts against the gate. Specifically, when the connecting rod component is in the separated position, the gate is in the open position by being pushed by the pushing part, and when the connecting rod component is in the abutting position, the gate is in the closed position by the connecting rod component pressing the gate against the pushing force of the pushing part.

2. The imaging apparatus according to claim 1, wherein: The gate is configured to pivot between the open and closed positions.

3. The imaging device according to claim 1, further comprising: A fixing frame, wherein the opening is disposed in the fixing frame; as well as A retainer, which is attached to the fixing frame, The abutting portion is fixed to the fixing frame by a retainer.

4. The imaging apparatus according to claim 3, wherein: The shutter is supported by the fixing frame via a retainer.

5. The imaging apparatus according to claim 1, wherein: Linkage mechanisms include: The connecting rod pushing portion is configured to push the connecting rod component toward the abutting position; and The second linkage component is configured to move to a disengaged position by overcoming the pushing force of the linkage push portion according to the closing operation of the opening / closing component.

6. The imaging apparatus according to claim 5, wherein: The pushing force of the connecting rod is greater than the pushing force of the other part.

7. The imaging apparatus according to claim 1, wherein: The opening / closing component forms at least a portion of the exterior of the imaging device.

8. The imaging apparatus according to any one of claims 1 to 7, wherein, The imaging component includes a housing that can be inserted into and removed from the body frame. The linkage mechanism is configured to overcome the pushing force of the pushing part and move the gate to the closed position according to the operation of pulling the box out of the body frame.

Images