JP2012068671A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus having an improved assembly performance of an opening/closing cover.SOLUTION: The image forming apparatus includes: an opening/closing cover provided on an apparatus body in an openable/closable manner; an image holding unit for holding a toner image; a cassette which is provided on the apparatus body in an attachable/detachable manner and houses a recording medium to which the toner image held on the image holding unit is transferred; and a support member for supporting the opening/closing cover on the apparatus body in an openable/closable manner. The supporting member is attachable/detachable to/from the apparatus body through a space where the cassette is removed.

Description

  The present invention relates to an image forming apparatus having a belt member.

  2. Description of the Related Art Conventionally, an image forming apparatus that forms an image by transferring and fixing a toner image on a surface of a photosensitive member (image holding member) onto a sheet (recording medium) on a conveyance belt is known. In such an image forming apparatus, when a sheet conveyed by the conveying belt is jammed, an opening / closing cover is provided in the apparatus body so that the sheet can be removed, and the opening / closing cover is opened to thereby remove the conveying belt. Can be separated from the photoconductor.

  For example, in Patent Document 1, an open / close cover and a belt unit are supported so as to be openable / closable with respect to the apparatus main body, and the open / close cover can be opened following the opening of the belt unit. The opening / closing cover is always urged by a spring that pulls in the closing direction, and elastically deforms following the opening / closing of the opening / closing cover so that a damper effect is obtained for the opening / closing cover and the belt unit when the opening / closing cover is opened. As a result, the belt unit is prevented from opening vigorously, and the support part of the belt unit is prevented from being damaged by an impact at the time of opening.

JP 2003-241466 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus in which an opening / closing cover is easily assembled.

  According to a first aspect of the present invention, there is provided an open / close cover provided to be openable / closable with respect to the apparatus main body, an image carrier unit carrying a toner image, and a detachable cover provided to the apparatus main body, A cassette containing a recording medium to which a toner image carried on the body unit is transferred, and a support member that supports the opening / closing cover to be openable / closable with respect to the apparatus main body. It is detachable with respect to the apparatus main body through the space to be removed.

  The invention according to claim 2 is characterized in that the opening / closing cover is also detached from the apparatus main body by removing the support member from the apparatus main body.

  The invention according to claim 3 is characterized in that the support member cannot be removed when the cassette is mounted on the apparatus main body.

  According to a fourth aspect of the present invention, the support member is not exposed to the outside when the cassette is mounted on the apparatus main body.

  In the invention according to claim 5, the support member includes a cylindrical body that is fitted into a shaft hole formed in the opening / closing cover and the apparatus main body, and a flexure piece that is formed by cutting an outer surface of the cylindrical body. An operation piece that is formed integrally with the flexible piece and extends in the axial direction of the cylindrical body and is exposed to the outside of the shaft hole, and a claw portion that is provided on the outer surface of the flexible piece and is hooked on the shaft hole. The pivot pin is characterized in that by operating the operating piece, the flexible piece is elastically deformed, and the state where the claw portion is caught in the shaft hole is released.

  According to the first aspect of the present invention, an image forming apparatus in which the opening / closing cover is easily assembled can be provided. The invention according to claim 2 is advantageous in improving workability because the opening / closing cover is also removed by removing the support member.

  According to the third aspect of the present invention, it is possible to prevent the detachable support member from being accidentally removed. Moreover, since the support member is hidden by the cassette, the invention according to claim 4 can suppress the support member from being accidentally removed.

  According to the fifth aspect of the invention, by operating the operation piece constituting the pivot pin, the flexible piece formed by cutting the outer peripheral surface of the cylindrical body fitted into the shaft hole formed in the opening / closing cover and the apparatus main body. Is elastically deformed. Accordingly, the pivot pin can be removed from the shaft hole by moving the claw portion provided on the outer surface of the flexure piece and hooked by the shaft hole.

1 is a schematic side view showing a configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a schematic side view showing a state in which an opening / closing cover of an image forming apparatus according to an embodiment of the present invention is opened. 3 is a schematic perspective view illustrating a relationship between a shaft portion of an opening / closing cover and a sheet cassette of the image forming apparatus according to the embodiment of the present invention. FIG. FIG. 3 is a schematic cross-sectional view illustrating a relationship between a shaft portion of an opening / closing cover and a sheet cassette of the image forming apparatus according to the embodiment of the present invention. 1 is a schematic perspective view showing a state in which an opening / closing cover and a transfer unit of an image forming apparatus according to an embodiment of the present invention are opened. FIG. 3 is a schematic perspective view showing a state where the opening / closing cover of the image forming apparatus according to the embodiment of the present invention is removed and the transfer unit is opened. FIG. 3 is a schematic perspective view showing a state where the transfer unit is closed on the photosensitive unit of the image forming apparatus according to the embodiment of the present invention. FIG. 3 is an enlarged perspective view showing a state in which the transfer unit is closed by the photosensitive unit of the image forming apparatus according to the embodiment of the present invention. FIG. 3 is an enlarged perspective view showing a state in which a transfer unit is closed on the photosensitive unit of the image forming apparatus according to the embodiment of the present invention. FIG. 6 is a schematic perspective view showing a modification example in which the transfer unit is closed on the photosensitive unit of the image forming apparatus according to the embodiment of the present invention. FIG. 6 is a modified example showing a state where the transfer unit is closed on the photosensitive unit of the image forming apparatus according to the embodiment of the present invention, and is an enlarged perspective view.

  Next, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show an image forming apparatus 10 according to an embodiment of the present invention. The image forming apparatus 10 includes an image forming apparatus main body 12, and a photoconductor unit 14, an optical writing device 16, and a transfer unit 18 are disposed in the image forming apparatus main body 12. A sheet discharge unit 20 is formed at the upper part of the image forming apparatus main body 12, and a sheet feeding unit 22 is disposed at the lower part of the image forming apparatus main body 12.

  The sheet feeding unit 22 includes a sheet cassette 24 in which a large number of sheets (recording media) are stacked and accommodated. The sheet cassette 24 is detachably attached to the image forming apparatus main body 12. A feed roll 26 is disposed on the upper end of the sheet cassette 24, and a retard roll 28 is provided facing the feed roll 26.

  The uppermost sheet of the sheet cassette 24 is taken out by the feed roll 26, and the sheet is rolled and conveyed by the cooperation of the feed roll 26 and the retard roll 28. The conveyed sheet is temporarily stopped by a resist roll 30 disposed on the downstream side (hereinafter simply referred to as “downstream side”) along the sheet conveyance direction, and conveyed to the transfer unit 18 side at a predetermined timing. It will be.

  On the other hand, as shown in FIGS. 3 and 4, a pair of substantially rectangular parallelepiped support portions 60 project from the lower front portion of the image forming apparatus main body 12 with the sheet cassette 24 interposed therebetween. Are arranged so that the side wall of the support portion 60 is sandwiched between a pair of shaft plates 62 respectively provided on the left and right sides.

  Then, with the sheet cassette 24 removed, the inner shaft plate 62 and the support portion 60 facing each other are formed with shaft holes 62A and 60A (the outer shaft plate 62 has a shaft hole 62A). A pivot pin 64 is fitted into the shaft holes 62A and 60A from the inner shaft plate 62 side. As a result, the opening / closing cover 31 can be rotated (openable / closable) with respect to the image forming apparatus main body 12.

  As shown in FIG. 5, the image forming apparatus main body 12 accommodates a photoreceptor unit 14 to be described later, and a shaft 19 (see FIG. 1) is provided below the photoreceptor unit 14. The transfer unit 18 is rotatably supported. A boss 66 protrudes from the free end side of the transfer unit 18.

  On the other hand, on the inner surface side of the opening / closing cover 31, a pair of guide ribs 68 extends from the base side of the opening / closing cover 31 toward the free end side, and guide grooves 70 extend on the inner walls of the guide ribs 68, and transfer is performed. The boss 66 of the unit 18 can be engaged.

  As a result, when the opening / closing cover 31 is opened / closed, the transfer unit 18 moves through the guide groove 70 and the boss 66, and the transfer unit 18 moves toward and away from the photoreceptor unit 14. Then, with the open / close cover 31 closed, the transfer unit 18 faces the photoconductor unit 14 and is biased and positioned by the open / close cover 31 toward the photoconductor unit 14.

  Here, as shown in FIGS. 1 and 2, in the transfer unit 18, a conveyance belt 36 is wound around a driving roll 32 and a driven roll 34 provided in the vertical direction, and the sheet is conveyed by the conveyance belt 36. It is possible. Further, between the driving roll 32 and the driven roll 34, a transfer roll 35 for transferring a toner image on the surface of each photoconductor 40 (image holding body), which will be described later, to a sheet on the conveying belt 36 is spaced at a predetermined interval for each color. Arranged.

  The transfer roll 35 is configured to come into pressure contact with each photosensitive member 40 with a predetermined pressure with the conveying belt 36 interposed therebetween when the open / close cover 31 is closed, and rotates following the traveling of the conveying belt 36. It is supposed to be.

  Incidentally, a charging roll 38 is disposed opposite to the driving roll 32 with the conveying belt 36 therebetween, and a predetermined voltage is applied to the charging roll 38. For this reason, when the charging roll 38 comes into contact with the conveyance belt 36, the conveyance belt 36 is charged, a potential difference is provided between the conveyance belt 36 and the sheet, and the sheet is attracted to the conveyance belt 36 and conveyed.

  On the other hand, the photoreceptor unit 14 holds an image to be transferred to the transport belt 36 or a sheet transported by the transport belt 36. Here, yellow (Y), magenta (M), cyan (C), black ( K) four photoreceptors 40 are rotatably supported.

  Around each photoconductor 40, a charging roll 42 for uniformly charging the photoconductor 40, a developing device 44 for developing a latent image written on each photoconductor 40 with a developer (toner), and a post-transfer A neutralization device 46 for neutralizing the photoconductor 40 and a cleaning device 48 for removing the developer remaining on the surface of the photoconductor 40 after transfer is provided.

  The photoconductor unit 14 is integrated with the four photoconductors 40, the charging roll 42, the developing device 44, the charge eliminating device 46, and the cleaning device 48, and is detachable from the image forming apparatus main body 12 together with the transfer unit 18. It has become.

  As shown in FIG. 5, screw members (knob members) 72 are provided on the top, bottom, left, and right of the front side of the photoreceptor unit 14. The photosensitive unit 14 is disposed in the image forming apparatus main body 12 and is aligned with a screw portion (not shown) of the screw member 72 and a positioning hole (not shown) on the image forming apparatus main body 12 side.

  In this state, the plate-like knob portion 72A provided on the head of the screw member 72 lies sideways, and when the knob portion 72A is rotated about 45 degrees to stand up, the screw member 72 is moved to the main body of the image forming apparatus. The photoconductor unit 14 is screwed into the rear side of a positioning hole (not shown) on the 12 side, and the photosensitive unit 14 is positioned at a predetermined position of the image forming apparatus main body 12.

  In the state where the knob portion 72A is laid down, the transfer unit 18 interferes when the opening / closing cover 31 is closed, so that it can be seen whether or not the photosensitive unit 14 is positioned at a predetermined position of the image forming apparatus main body 12. It has become.

  Further, as shown in FIGS. 1 and 2, toner boxes 50 containing yellow, magenta, cyan and black toners supplied to the developing device 44 are connected to the back side of the photosensitive unit 14, respectively. ing. In each toner box 50, a toner supply unit 52 and a toner collection unit 54 are integrated, and the toner supply unit 52 is connected to the developing device 44 to supply toner of each color to the developing device 44. The toner collecting unit 54 is connected to the cleaning device 48 and collects toner of each color.

  Further, on the back side of the photoconductor unit 14, an optical writing device 16 is disposed at a position corresponding to each photoconductor 40. Each of the photowriters 16 includes a laser exposure device. A latent image is formed on the surface of 40.

  Further, a fixing device 56 is provided on the downstream side of the photosensitive unit 14, and an unfixed toner image on the sheet is heated and pressed to be fixed on the sheet. A discharge roll 58 is disposed on the downstream side of the fixing device 56 and discharges the sheet on which the toner image is fixed onto the sheet discharge unit 20.

  Next, the operation of the image forming apparatus 10 having the above configuration will be described.

  First, the uppermost sheet of the sheet cassette 24 is taken out by the feed roll 26, and the sheet is rolled by the cooperation of the feed roll 26 and the retard roll 28, and the transfer unit 18 side at a predetermined timing by the registration roll 30. It is conveyed to.

  On the other hand, in the photoconductor unit 14, first, the surface (circumferential surface) of the photoconductor 40 is uniformly charged by the charging roll 42. Then, a laser is irradiated from the optical writing device 16 to scan the surface of the photoconductor 40, and a latent image based on the image data is formed on the surface of the photoconductor 40. Thereafter, the latent image is developed with toner by the developing device 44, and a visible image (toner image) is formed on the surface of the photoreceptor 40.

  This toner image is transferred onto a sheet conveyed by the conveyance belt 36 by a transfer roll 35, and a full color toner image (unfixed image) in the order of yellow (Y), magenta (M), cyan (C), and black (K). Is transferred to the fixing device 56 by the conveyor belt 36.

  Then, the sheet conveyed to the fixing device 56 is discharged onto the sheet discharge unit 20 by the discharge roll 58 after the unfixed toner image is heated and pressed to be fixed on the sheet. Note that after the transfer of the toner image onto the sheet is completed, the surface of the photoreceptor 40 is cleaned by the cleaning device 48 to prepare for the next image forming process.

  Next, the gist of the image forming apparatus 10 according to the present embodiment will be described.

  As shown in FIGS. 3 and 4, in the present embodiment, a support portion 60 is provided in the lower front portion of the image forming apparatus main body 12 with the sheet cassette 24 interposed therebetween, and provided on the left and right sides of the lower end portion of the opening / closing cover 31. With the pair of shaft plates 62 sandwiching the side wall of the support portion 60 and the sheet cassette 24 removed, the pivot pins 64 are fitted into the shaft holes 62A and 60A from the inner shaft plate 62 side facing each other. The shaft plate 62 is rotatable.

  Thus, the pivot pin 64 is normally hidden by the sheet cassette 24 and is not exposed to the outside, so that the appearance is not impaired and the pivot pin 64 is not accidentally removed. Such a structure is advantageous in improving the assemblability of the opening / closing cover 31 and the workability when the opening / closing cover 31 is removed, and repairs things that are used by customers or the like when they are produced in factories or the like. This is advantageous.

  In this embodiment, as shown in FIG. 5, a guide rib 68 is provided on the opening / closing cover 31, and the boss 66 of the transfer unit 18 is engaged with the guide groove 70 of the guide rib 68, thereby opening / closing the opening / closing cover 31. Following this, the transfer unit 18 can be opened and closed. As a result, the transfer unit 18 is not opened with force when the open / close cover 31 is opened, and the transfer unit 18 is not damaged.

  By the way, the service engineer opens / closes the image forming apparatus main body 12 when the transfer unit 18 or a density sensor (CTD sensor) or a relay connector (not shown) for detecting the density of the toner image is replaced (during repair). There is a case where the work is performed with 31 removed.

  In this case, as shown in FIG. 6, the transfer unit 18 is removed from the open / close cover 31 by removing the boss 66 of the transfer unit 18 from the guide groove 70 of the open / close cover 31, but the transfer unit 18 is open / closed. Since the cover 31 is positioned by being urged toward the photoconductor unit 14, the transfer unit 18 remains open without the opening / closing cover 31.

  For this reason, during the above-described operation, the transfer unit 18 is supported by hand or the transfer unit 18 is temporarily fixed with a tape or the like. However, since the workability is poor and the stability is poor, the transfer unit 18 has its own weight. There is also concern that the bearing portion of the transfer unit 18 may be damaged due to the opening.

  Accordingly, it may be possible to add a mechanism such as a damper function or a stopper so that the transfer unit 18 is not shocked. However, if these are dealt with, problems such as an increase in the size and cost of the image forming apparatus main body 12 arise separately. End up.

  Therefore, in the present embodiment, as shown in FIG. 7, a fixing hole 74 is provided in the side wall of the photoreceptor unit 14 so that a pivot pin 64 (described later) and the like can be inserted. Then, with the one end side of the pivot pin 64 in contact with the front surface of the transfer unit 18, the other end side of the pivot pin 64 is inserted into the fixing hole 74, whereby the transfer unit 18 is restricted in movement by the pivot pin 64 and closed. Thus, it is possible to prevent the transfer unit 18 from being opened during the work of the service engineer. Thereby, since the photoconductor 40 is not exposed to the outside, light fatigue of the photoconductor 40 can be suppressed.

  As shown in FIG. 4, the opening / closing cover 31 can be opened and closed with respect to the image forming apparatus main body 12 via a pivot pin 64. However, when the opening / closing cover 31 is removed, the pivot pin 64 is open. Is detached from the image forming apparatus main body 12. For this reason, as shown in FIGS. 8 and 9, the pivot pin 64 is used, the head portion 64 </ b> A of the pivot pin 64 is brought into contact with the front surface of the transfer unit 18, and the shaft portion 64 </ b> B is fixed to the fixing hole 74 of the photosensitive unit 14. Plug in.

  As described above, it is necessary to separately use a member for closing the transfer unit 18 by closing the transfer unit 18 by using the pivot pin 64 to be removed when the opening / closing cover 31 is removed from the image forming apparatus main body 12. There is no. For this reason, it is not necessary to secure a space by providing a separate member, and no extra cost is required. Further, there is no risk of losing the pivot pin 64 in a series of operations.

  In FIG. 7, two pivot pins 64 are used. However, only one pivot pin 64 may be used as long as the transfer unit 18 can be closed. In addition to the pivot pin 64, a driver or the like may be inserted.

  Here, as shown in FIG. 1, a plurality of parts such as a plurality of photoreceptors 40 and a charging roll 42 are arranged in the photoreceptor unit 14, and a plurality of spring members 76 are used for positioning and holding the parts. However, as shown in FIG. 9, when the pivot pin 64 is inserted into the fixed hole 74 by providing the fixed hole 74 at the position where the spring member 76 is disposed, the pivot pin The 64 shaft portions 64 </ b> B can be sandwiched between the spring members 76. As a result, the reaction force of the spring member 76 is used to prevent the pivot pin 64 from coming off, and the closed state of the transfer unit 18 can be more reliably maintained.

  On the other hand, the shaft portion 64B of the pivot pin 64 is formed with an inverted U-shaped cut portion 64C along the axial direction of the shaft portion 64B, and is elastically deformed toward the inside of the shaft portion 64B inside the cut portion 64C. A possible flexible piece 64D is provided.

  A claw portion 64F is provided outside the flexible piece 64D so that it can be hooked on a mounted portion such as the shaft plate 62 of the opening / closing cover 31. In addition, an operating piece 64E extending along the axial direction of the shaft portion 64B is integrally provided on the flexible piece 64D. An opening 65 is provided in the head 64A so that the tip of the operation piece 64E is exposed.

  Thereby, the operation piece 64E and the flexible piece 64D can be elastically deformed from the outside through the opening 65, the state where the claw portion 64F is hooked on the attached portion can be released, and the pivot pin 64 can be easily removed. That is, it is not necessary to use a tool or the like to remove the pivot pin 64.

  In the present embodiment, the opening / closing cover 31 is removed from the image forming apparatus main body 12. However, the opening / closing cover 31 is not necessarily removed from the image forming apparatus main body 12. In this case, the boss 66 of the transfer unit 18 needs to be removed from the guide groove 70 of the guide rib 68 of the opening / closing cover 31 with the opening / closing cover 31 open. For example, the communication connecting the guide groove 70 to the end face of the guide rib 68 is performed. A hole (not shown) may be formed, and the transfer unit 18 may be removed from the opening / closing cover 31 by passing the boss 66 of the transfer unit 18 through the communication hole.

  At this time, since the pivot pin 64 is not removed, the transfer unit 18 is closed with parts other than the pivot pin 64 in the image forming apparatus main body 12. For example, as shown in FIGS. 10 and 11, a state in which the knob 72A of the screw member 72 for positioning the photosensitive unit 14 at a predetermined position of the image forming apparatus main body 12 is laid down and closed. Alternatively, the front surface of the transfer unit 18 may be hit.

  Here, all the four knob portions 72A of the screw member 72 are laid down side by side. However, since the transfer unit 18 may be closed, only one knob portion 72A may be laid down.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming apparatus main body 14 Photosensitive unit (Image holding body unit)
24 Sheet cassette (cassette)
31 Opening / Closing Cover 60A Shaft Hole 62A Shaft Hole 64 Pivot Pin (Support Member)
64B Shaft (cylinder, support member)
64D flexible piece (supporting member)
64E Operation piece (support member)
64F Claw (supporting member)

Claims (5)

An opening / closing cover provided to be openable / closable with respect to the apparatus main body;
An image carrier unit carrying a toner image;
A cassette that is detachably provided to the apparatus main body and that accommodates a recording medium onto which a toner image carried on the image holding unit is transferred;
A support member that supports the open / close cover so as to be openable and closable with respect to the apparatus main body;
With
The image forming apparatus, wherein the support member is detachable from the apparatus main body through a space from which the cassette is removed.   The image forming apparatus according to claim 1, wherein the opening / closing cover is also detached from the apparatus main body by removing the support member from the apparatus main body.   The image forming apparatus according to claim 1, wherein the support member cannot be removed in a state where the cassette is mounted on the apparatus main body.   The image forming apparatus according to claim 1, wherein the support member is not exposed to the outside when the cassette is mounted on the apparatus main body.   The support member is formed integrally with the opening and closing cover and a cylindrical body fitted into a shaft hole formed in the apparatus main body, a flexible piece formed by cutting an outer surface of the cylindrical body, and the flexible piece. A pivot pin comprising an operation piece extending in the axial direction of the cylindrical body and exposed to the outside of the shaft hole, and a claw portion provided on an outer surface of the flexible piece and hooked on the shaft hole, The image forming apparatus according to claim 1, wherein the flexible piece is elastically deformed by operating a piece to release a state where the claw portion is caught in the shaft hole.

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