JP5235431B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to a configuration for making steam vapor generated from a sheet and coming out of a sheet discharge port inconspicuous when a sheet is heated to fix a toner image.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a printer, a facsimile machine, a copying machine, or a multifunction printer, when an image is formed on a sheet, a toner image is first formed on a photosensitive drum and then the toner image is transferred to the sheet. Next, the sheet on which the toner image is transferred is conveyed to a fixing unit, and the toner image is fixed on the sheet by heating and pressing the sheet. Then, the sheet on which the toner image is fixed is discharged from the sheet discharge port to the sheet stacking unit by the discharge roller pair.

  By the way, when the sheet is heated by the fixing means, a large amount of water vapor may be generated depending on the moisture absorption state of the sheet. May mistakenly determine that an abnormality has occurred.

  Here, in the conventional image forming apparatus, for example, as shown in FIG. 14, the surface cover member 85 provided above the pair of discharge rollers 83 and 84 is extended from the sheet discharge port 86 in the sheet discharge direction. There is a thing (refer patent document 1). And when extending the surface cover member 85 in this way, water vapor | steam is disperse | distributed and steam becomes inconspicuous.

JP 2006-171372 A

  By the way, in some conventional image forming apparatuses, the process cartridge is detachably provided on the apparatus main body. When the process cartridge is attached or detached, the cover provided on the upper surface of the apparatus main body is opened to attach or detach the process cartridge. Like to do.

  However, in such a conventional image forming apparatus, when the steam is made inconspicuous by extending the surface cover member as described above, the cover collides with the extended surface cover member when attaching or detaching the process cartridge. There is a problem of end.

  Here, if the front cover member is configured to be openable, the cover can be prevented from colliding with the front cover member when the cover is opened. However, when the surface cover member can be opened as described above, a gap is generated between the surface cover member and the apparatus main body, and steam leaks from the gap. And when steam comes out of the gap between the surface cover member and the apparatus main body in this way, there is a problem that the user judges that an abnormality has occurred in the apparatus.

  Accordingly, the present invention has been made in view of such a current situation, and an object thereof is to provide an image forming apparatus capable of making steam less noticeable.

The present invention provides an image forming apparatus that discharges a sheet on which an image is fixed to a sheet stacking unit by a sheet discharge unit, a cover member provided above the sheet discharge unit, and the cover member orthogonal to the sheet discharge direction. and, around the plane parallel to the axis of the sheet to be discharged, the is pressed against the sheet discharged by the sheet discharge means is held in rotation to so that the width perpendicular to the sheet conveying direction of the sheet stacking portion A plate-like rotating member having a length equal to the length in the direction, and a downstream end portion of the cover member in the sheet discharging direction and an upstream end portion of the rotating member in the sheet discharging direction. It is characterized by being arranged so as to overlap in the entire area and in the sheet discharging direction.

  As in the present invention, the rotating member is held on the cover member so as to be rotatable and protrudes downstream in the sheet discharging direction of the sheet discharging unit, and the rotating member and the cover member overlap in the sheet discharging direction. By arranging in this way, steam can be made inconspicuous.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a perspective view of a printer that is an example of an image forming apparatus according to a first embodiment of the present invention, and FIG. 2 is a diagram illustrating a schematic configuration thereof.

  In FIG. 1, 50 is a printer, 51 is a printer main body which is an apparatus main body, 52 is provided in the printer main body 51, and an image forming unit for forming an image by an electrophotographic method, 3 is a sheet P fed to the image forming unit 52 This is a sheet feeding device.

  Here, the image forming unit 52 includes a laser exposure device 1, a photosensitive drum 7 that forms a toner image, a transfer roller 4 a that transfers the toner image formed on the photosensitive drum 7 to a sheet P, and the like. Note that C is a process cartridge provided with a photosensitive drum 7, a charging roller (not shown), developing means, and the like. The process cartridge C is detachably mounted on the printer main body 51.

  In the image forming unit 52 having such a configuration, when an image forming operation is started, light corresponding to the image signal is firstly charged from the laser exposure apparatus 1 and rotated in the direction of the arrow while the surface is charged. The photosensitive drum 7 is irradiated. Then, by irradiating light according to such an image signal, a latent image is formed on the photosensitive drum. Next, the latent image on the photosensitive drum is developed with the toner supplied by the developing means and visualized as a toner image.

  The sheet feeding device 3 includes a paper feed tray 2 provided in the printer main body 51 so as to be openable and closable, and a paper feed roller 3 a that feeds the sheet P stored in the paper feed tray 2. Here, the paper feed tray 2 is provided so as to be slidable in a direction (hereinafter referred to as a width direction) perpendicular to the sheet conveyance direction of the sheet P and a stacking base 2a that can rotate in the vertical direction on which the sheets P are stacked. In addition, a multi-slider 26 that regulates both end positions of the sheet P in the width direction is provided. The multi-slider 26 can align both end positions of not only standard size sheets such as A4 size and letter size but also non-standard size sheets P such as postcards and envelopes.

  Further, a separation pad 3b that is in pressure contact with the sheet feed roller 3a is provided on the downstream side of the sheet feeding direction of the sheet feed tray 2, and the separation pad 3b is in pressure contact with the sheet feed roller 3a by a separation pad spring 3c. It has become. In such a sheet feeding device 3, the sheet P is fed from the sheet feeding tray 2 by the sheet feeding roller 3a during image formation, and thereafter the sheet P is pressed against the sheet feeding roller 3a. The pads 3b are separated one by one.

  Next, an image forming operation in the printer 50 having such a configuration will be described.

  When a print start signal is input, the sheet P set in the sheet feed tray 2 is sent out by friction with the sheet feed roller 3a. Thereafter, the sheet P is separated by the separation pad spring 3c. The sheets are separated one by one by 3b and fed.

  Next, the sheet P is conveyed by the conveyance roller 9, and when a photosensor (not shown) detects the passage of the sheet P, the laser exposure apparatus 1 irradiates the photosensitive drum 7 with laser light. Thereby, an electrostatic latent image is formed on the photosensitive drum, and the electrostatic latent image is visualized by developing the electrostatic latent image with toner. Thereafter, the visualized toner image on the photosensitive drum is transferred to the sheet P in the transfer unit 4 by applying a voltage having a polarity opposite to that of the toner image formed on the photosensitive drum 7 to the transfer roller 4a. .

  Next, the sheet P to which the toner image has been transferred is conveyed to a fixing unit 5 including a driving roller 5a that rotates and a fixing unit 5b including a heater 5c, and passes between the driving roller 5a and the fixing unit 5b. In this case, it is pressurized and heated. As a result, the toner image is permanently fixed on the sheet. The sheet P on which the toner image is fixed is placed in a face-down state in which the image surface faces downward from the sheet discharge port 53 as a sheet discharge port by a sheet discharge roller pair 6b provided in the sheet discharge unit 6 as a sheet discharge unit. The sheets are stacked in the page order on the upper surface of the stacking guide member 8 constituting the sheet stacking unit.

  Here, in the present embodiment, the stacking guide member 8 is provided in the printer main body 51 so as to be openable and closable, and is opened when the process cartridge C detachably attached to the printer main body 51 is attached or detached. It has become. That is, in the present embodiment, the stacking guide member 8 also serves as a process cartridge attachment / detachment cover. The process cartridge C is attached to and detached from the printer main body 51 by opening the stacking guide member 8 above the printer main body.

  By the way, in the present embodiment, as shown in FIG. 2, the fixing unit 5 is provided in the vicinity of the paper discharge port. For this reason, when a sheet containing a lot of moisture passes through the fixing unit 5, the moisture evaporates, and if the ambient temperature in the vicinity of the sheet discharge port is low, steam will come out from the sheet discharge port 53. There is. Then, as described above, the user may erroneously determine that an abnormality has occurred in the printer 50 when viewing it.

  Therefore, in the present embodiment, as shown in FIGS. 1 and 2, the rotating member 10 protrudes downstream in the sheet discharge direction from the sheet discharge port 53 and in the horizontal direction in order to make the steam inconspicuous. I have to. By doing so, water vapor is dispersed and becomes inconspicuous.

  In FIGS. 1 and 2, reference numeral 11 denotes a cover member provided on the upper surface of the printer body 51, that is, above the paper discharge unit 6 and the fixing unit 5. Then, as shown in FIG. 3, the rotating member 10 has a boss portion 10 a protruding from the side wall surface and a boss portion protruding from the opposite side wall surface (not shown) as an axis in the hole portion 11 a of the cover member 11. By being supported, the cover member 11 is held so as to be rotatable upward.

  That is, the rotating member 10 is rotatable about a boss portion 10a (axis) orthogonal to the sheet discharge direction and parallel to the surface of the discharged sheet, and downstream of the discharge port 53 in the sheet discharge direction. It is held by the cover member 11 so as to protrude.

  The rotating member 10 constitutes the upper surface of the sheet discharge path R through which the sheet discharged from the sheet discharge section 6 shown in FIG. 4 passes, and also serves as a guide member for guiding the sheet upper surface. And this rotation member 10 is normally controlled by the stopper part not shown provided in the cover member 11 to rotate downward, and is hold | maintained at the guide position shown in FIG. In FIG. 4, reference numeral 54 denotes a guide member that guides the sheet that has passed through the fixing unit 5 to the sheet discharge port 53.

  Here, as shown in FIG. 4, a sheet delivery portion 11 b for delivering the sheet P to the rotating member 10 is provided at the downstream end of the cover member 11 in the sheet discharge direction. The sheet delivery portion 11 b is provided over the entire width direction of the upper surface of the paper discharge path R provided between the paper discharge roller pair 6 b and the paper discharge port 53.

  In addition, on the upstream side of the sheet discharge direction of the rotating member 10, an overlap portion 10d is provided that has a predetermined interval above the sheet delivery portion 11b of the cover member 11 and overlaps in the sheet discharge direction. It is formed over the entire width direction of the paper path R.

  In the present embodiment, the sheet delivery portion 11b provided at the downstream end portion of the cover member 11 in the sheet discharge direction and the overlap portion 10d provided at the upstream end portion of the rotating member 10 are arranged in the vertical direction. They are shifted and overlapped in the sheet discharge direction. In other words, the downstream end portion of the cover member 11 in the sheet discharge direction and the upstream end portion of the rotating member 10 in the sheet discharge direction are arranged so as to overlap in the sheet discharge direction.

  Then, by providing the overlap portion 10d of the rotating member 10 so as to overlap the sheet delivery portion 11b provided in the cover member 11 in this manner, steam is formed between the rotating member 10 and the cover member 11. It is possible not to go out from 12 to the top.

  The rotating member 10 has a plurality of holes 10c as shown in FIGS. 1 and 3 in order to suppress the temperature rise inside the printer main body due to the heat of the fixing unit 5 trapped below the rotating member 10. Is provided. Further, in order to make it easy to escape heat and to prevent the sheet from buckling when it hits against the rotating member 10, the rotating member 10 is inclined upward by a predetermined angle D from the horizontal direction, that is, the sheet is discharged. The state is such that the direction downstream side is higher than the upstream side.

  5 and 6 show a state when the process cartridge C is taken out. When taking out the process cartridge C, the stacking guide member 8 is opened upward, and then the process cartridge C is taken out in the arrow X direction. ing.

  Here, in the present embodiment, when the stacking guide member 8 is opened upward, the rotating member 10 does not interfere with the opening operation of the stacking guide member 8 and the attaching / detaching operation of the process cartridge C. In conjunction with the stacking guide member 8 is opened upward. That is, the rotating member 10 is configured to rotate in conjunction with the opening / closing operation of the stacking guide member 8, and the rotating member 10 is opened upward in conjunction with the opening operation of the stacking guide member 8. Yes.

  7 is an enlarged view of the F portion shown in FIG. 5 and an enlarged view of the E portion shown in FIG. 6 so that the rotating member 10 is opened upward in conjunction with the stacking guide member 8 in this way. As shown in FIG. 8, the stacking guide member 8 is provided with ribs 8a. Further, at both end portions of the rotating member 10, contact portions 10b that contact the ribs 8a are provided. Accordingly, when the stacking guide member 8 is rotated upward, the rib 8 a of the stacking guide member 8 comes into contact with the contact portion 10 b of the rotating member 10, and the rotating member 10 is also integrated with the stacking guide member 8. Rotate upward.

  By the way, when the sheet discharged from the arrow G direction shown in FIG. 7 comes into contact with the rotating member 10, the rotating member 10 may be pressed by the sheet and rotate upward. Here, as described above, the overlap portion 10 d of the rotating member 10 overlaps above the sheet delivery portion 11 b of the cover member 11. That is, the overlap portion 10 d of the rotating member 10 overlaps above the sheet delivery portion 11 b of the cover member 11.

  Further, in the present embodiment, even if the rotating member 10 is rotated upward, the overlap portion 10d of the rotating member 10 is only close to the sheet transferring portion 11b of the cover member 11 and is not moved to the sheet transferring portion 11b. On the other hand, the overlapped state is maintained. As a result, even if the sheet abuts and the pivot member 10 pivots upward, the amount of steam coming out of the gap 12 between the pivot member 10 and the cover member 11 can be reduced, and the steam becomes inconspicuous. Can do.

  In this way, the rotating member 10 is held on the cover member 11 so as to be rotatable upward and protrude in the horizontal direction from the paper discharge port 53, and the rotating member 10 and the cover member 11 are held in the sheet discharging direction. By arranging them in an overlapping manner, steam can be made inconspicuous. Further, the rotating member 10 is provided on the cover member 11 so as to be capable of rotating upward, so that the rotating member 10 can rotate upward integrally with the stacking guide member 8, so that the rotating member 10 opens the stacking guide member 8 and the process cartridge. C can be prevented from being hindered.

  Further, the overlapping portion 10d of the rotating member 10 is arranged so as to overlap with a predetermined interval above the sheet delivery portion 11b of the cover member 11, so that the overlapping portion even if the rotating member 10 rotates upward. It is possible to prevent 10d from entering the paper discharge passage. Thereby, it is possible to prevent the rotating member 10 from affecting the sheet discharge.

  Next, a second embodiment of the present invention will be described.

  FIG. 9 is a diagram illustrating a configuration of a paper discharge unit of a printer that is an example of the image forming apparatus according to the present exemplary embodiment. In FIG. 9, the same reference numerals as those in FIG. 4 described above indicate the same or corresponding parts.

  In FIG. 9, reference numeral 10 f denotes a guide portion that is provided at the upstream end of the rotating member 10 in the sheet discharging direction and guides the conveyed sheet while being guided by the guide member 54. By providing such a guide portion 10f, the rotating member 10 can transfer a sheet and prevent the leading end of the second sheet from being caught during continuous sheet passing.

  Also in the present embodiment, the rotating member 10 and the cover member 11 are arranged so as to overlap in the sheet discharging direction, in other words, overlap in the sheet discharging direction. Further, a positioning portion 10e is provided on the upper surface of the guide portion 10f, and the normal posture of the rotating member 10 is determined by bringing the positioning portion 10e into contact with the cover member 11 from below.

  In the present embodiment, the positioning portion 10e for positioning the rotating member 10 is provided over the entire width direction of the paper discharge passage R. And by making this positioning part 10e contact | abut to the cover member 11 from the downward direction, it can prevent that steam leaks out of a printer main body.

  Further, in the present embodiment, a protrusion 11c, which is a protrusion for preventing steam from coming out of the printer main body, protrudes downward (on the rotation member side) at the end of the cover member 11 on the rotation member side. It has been. The protrusion 11c and the positioning portion 10e that comes into contact with the cover member 11 from below prevent the steam from flowing upward from the gap 12 between the rotating member 10 and the cover member 11 during sheet discharge.

  Note that when the sheet discharged from the arrow G direction shown in FIG. 10 comes into contact, the rotating member 10 may rotate upward. However, since the cover member 11 overlaps above the positioning portion 10e of the rotating member 10, the amount of steam coming out from the gap 12 between the rotating member 10 and the cover member 11 can be reduced, and the steam can be reduced. It can be made inconspicuous.

  Next, a third embodiment of the present invention will be described.

  FIG. 11 is a diagram illustrating a configuration of a paper discharge unit of a printer that is an example of the image forming apparatus according to the present embodiment. In FIG. 11, the same reference numerals as those in FIG. 9 described above indicate the same or corresponding parts.

  In FIG. 11, reference numeral 13 denotes a spring as an example of an urging means that urges the positioning portion 10 e in a direction in which the positioning portion 10 e is pressed against (abuts) the cover member 11. The positioning part 10e for determining the pressure can be brought into pressure contact with the cover member 11. Then, in a state where the rotating member 10 and the cover member 11 are overlapped in the sheet discharging direction, the positioning portion 10e is pressed against the cover member 11 in this manner, so that the positioning member 10e and the cover member 11 are not pressed. Steam is prevented from leaking outside the printer.

  In the present embodiment, the magnitude of the spring force of the spring 13 is set such that the turning member 10 does not turn with the force of the discharged sheet. Further, the magnitude of the spring force of the spring 13 is such that when the stacking guide member 8 is opened upward, if the force is applied to the rotating member 10 via the stacking guide member 8, the rotating member 10 rotates. It is set to a large size.

  Thereby, even when the amount of water vapor from the sheet increases with an increase in the image forming speed in the printer 50, it is possible to more effectively reduce the leakage of steam to the outside of the printer body so that the steam does not stand out. Can be.

  In the present embodiment, the cover 11 is provided with a protrusion 11c, and even if a water vapor forms a gap due to component accuracy between the rotating member 10 and the cover member 11 during sheet discharge, the protrusion 11c discharges the sheet. Water vapor can be prevented from coming out of the mouth. In the above description, the spring 13 is provided separately from the rotating member 10. However, the spring 13 is formed integrally with the rotating member 10 as a mold spring having flexibility. Anyway.

  Next, a fourth embodiment of the present invention will be described.

  FIG. 12 is a diagram illustrating a configuration of a paper discharge unit of an electrophotographic printer that is an example of the image forming apparatus according to the present exemplary embodiment. In FIG. 12, the same reference numerals as those in FIG. 9 described above indicate the same or corresponding parts.

  In FIG. 12, reference numeral 14 denotes one of the rotating member 10 and the cover member 11. In the present embodiment, 14 is a flexible member attached to the positioning portion 10 e of the rotating member 10. The flexible member 14 is provided over the entire width direction of the paper discharge passage R, and is elastically pressed against the rotating member 10 or the other cover member 11 of the cover member 11.

  In addition, by pressing the flexible member 14 against the cover member 11 in this way, the gap between the rotating member 10 and the cover member 11 can be closed, and steam is thereby generated between the cover member 11 and the printer. Prevents leakage outside the body.

  As shown in FIG. 13, even when the sheet discharged from the G direction comes into contact and the rotating member 10 rotates upward, the flexible member 14 presses against the cover member 11, so that the rotating member The gap 12 between the cover member 11 and the cover 10 can be closed.

  In each of the above-described embodiments, the electrophotographic image forming apparatus including the fixing unit that fixes the toner image has been described as an example. However, the present invention is not limited to this. For example, the present invention is effective as long as it is an image forming apparatus that heats and fixes an image in a wet electrophotographic method using a developer or an ink jet method in which an image is formed by spraying ink.

1 is a perspective view of a printer that is an example of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of the printer. The figure which shows the structure for hold | maintaining the rotation member provided in the said printer to the cover member so that rotation is possible upwards. The figure which shows the structure of the said rotation member and a cover member. FIG. 3 is a diagram illustrating a state when a process cartridge that is detachably attached to the printer is taken out. FIG. 5 is another view showing a state when a process cartridge that is detachably attached to the printer is taken out. The principal part enlarged view of FIG. The principal part enlarged view of FIG. FIG. 6 is a diagram illustrating a configuration of a paper discharge unit of a printer that is an example of an image forming apparatus according to a second embodiment of the present invention. The figure which shows a state when the rotation member provided in the said paper discharge part rotates upwards. FIG. 10 is a diagram illustrating a configuration of a paper discharge unit of a printer that is an example of an image forming apparatus according to a third embodiment of the present invention. FIG. 10 is a diagram illustrating a configuration of a paper discharge unit of a printer that is an example of an image forming apparatus according to a fourth embodiment of the present invention. The figure which shows a state when the rotation member provided in the said paper discharge part rotates upwards. FIG. 6 is a diagram illustrating a configuration of a paper discharge unit of a conventional image forming apparatus.

Explanation of symbols

5 Fixing portion 6 Paper discharge portion 6b Paper discharge roller pair 8 Stacking guide member 10 Rotating member 10a Boss portion 10b Contact portion 10c Hole 10d Overlap portion 10e Positioning portion 10f Guide portion 11 Cover member 11a Hole portion 11b Sheet delivery portion 11c Projection 12 Gap 13 Spring 14 Flexible member 50 Printer 51 Printer main body 52 Image forming unit 53 Paper discharge port C Process cartridge P Sheet R Paper discharge path

Claims (11)

In an image forming apparatus that discharges a sheet on which an image is fixed to a sheet stacking unit by a sheet discharging unit,
A cover member provided above the sheet discharging means;
Wherein the cover member, perpendicular to the sheet discharging direction, around the plane parallel to the axis of the sheet to be discharged, is pressed are kept in rotation to so that the sheet discharged by said sheet discharge means, said sheet A plate-like rotating member having a length equivalent to the length in the width direction orthogonal to the sheet conveying direction of the stacking unit ,
An image forming apparatus characterized in that the downstream end portion of the cover member in the sheet discharge direction and the upstream end portion of the rotating member in the sheet discharge direction are arranged so as to overlap in the entire width direction and in the sheet discharge direction. . A sheet delivery unit that is located at the downstream end of the cover member in the sheet discharge direction and below the upstream end of the rotation member in the sheet discharge direction, and delivers the sheet from the sheet discharge unit to the rotation member. Set up a section,
A sheet discharge direction downstream end portion of the cover member so that an upstream end portion of the rotation member in the sheet discharge direction is close to a sheet delivery portion of the cover member when the rotation member is rotated upward; The image forming apparatus according to claim 1, wherein the sheet delivery portion of the member is arranged to be shifted in the vertical direction. A guide portion for guiding the sheet from the sheet discharging means is provided at the upstream end portion of the rotating member in the sheet discharging direction,
The image forming apparatus according to claim 1, wherein the rotating member is positioned by bringing the guide portion into contact with a downstream end portion of the cover member in a sheet discharging direction.   The image forming apparatus according to claim 3, wherein a protrusion that protrudes toward the rotating member is provided on the downstream side of the cover member with respect to the sheet discharge direction from a position where the guide portion of the rotating member contacts. .   5. The image forming apparatus according to claim 3, further comprising an urging unit that urges the rotating member in a direction in which the cover member abuts on the guide portion.   6. The image forming apparatus according to claim 5, wherein the urging unit is formed integrally with the rotating member.   One of the downstream end of the cover member in the sheet discharging direction and the upstream end of the rotating member in the sheet discharging direction, and the downstream end of the covering member in the sheet discharging direction and the upstream of the rotating member in the sheet discharging direction. 5. The image forming apparatus according to claim 3, further comprising a flexible member that is in pressure contact with the other end. The sheet stacking unit is provided in the apparatus main body so as to be openable and closable,
The image forming apparatus according to claim 1, wherein the rotating member is rotated in conjunction with an opening / closing operation of the sheet stacking unit. A process cartridge is detachably attached to the apparatus body,
The image forming apparatus according to claim 8, wherein when the process cartridge is attached or detached, the sheet stacking unit is opened and closed.   The image forming apparatus according to claim 1, wherein the rotating member includes a plurality of holes.   11. The rotating member protrudes downstream in the sheet discharging direction of the sheet discharging unit in a state where the rotating member is inclined so that the downstream side in the sheet discharging direction is higher than the upstream side in the sheet discharging direction. The image forming apparatus according to any one of the above.

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