JP2013011775A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus which improves replacement workability of a replacement unit by providing a place to place the replacement unit and prevents contamination by scattered toner.SOLUTION: An image forming apparatus is constituted by housing a replaceable replacement unit in a device body provided with an openable/closable front cover 21. When the replacement unit is taken out from the device body, the front cover 21 is opened, and the front cover 21 is used as a work bench on which the replacement unit which has been taken out is temporarily placed. On the inner surface of the front cover 21, libs 24 to 28 are integrally formed for positioning or support of the replacement unit. In addition, on the inner surface of the front cover 21, a pocket part 30 for receiving scattered toner is formed long in the width direction.

Description

  The present invention relates to an image forming apparatus in which a replaceable exchange unit is built in an apparatus main body having a front cover that can be opened and closed.

  In an image forming apparatus such as a copying machine or a printer that forms an image on a recording material such as paper by an electrophotographic method, an image carrier such as a photosensitive drum whose surface is uniformly charged by a charger is exposed by an optical scanning device. Scanning is performed, and an electrostatic latent image corresponding to image information is formed on the surface. The electrostatic latent image formed on the image carrier is developed by a developing device using toner as a developer to be visualized as a toner image, and the toner image is transferred onto a recording material. The recording material onto which the toner image has been transferred in this way is conveyed to a fixing device, heated and pressurized by the fixing device, and after being fixed on the toner image, is discharged out of the apparatus, thereby performing a series of image forming operations. Is completed.

  By the way, in such an image forming apparatus, in order to facilitate maintenance such as removing jammed paper or replacing consumable parts, the photosensitive drum, the charger and the cleaning device are used as a drum unit, and the developing device is used as a developing unit. The fixing device is configured to be exchangeable with respect to the main body of the device as a fixing unit.

  Regarding the removal of the replacement unit, Japanese Patent Application Laid-Open No. 2004-228561 discloses an image forming apparatus in which the image reading unit is disposed above the image forming unit and the replacement unit is accessed and replaced from above. Has proposed a configuration in which the image reading apparatus is moved in a substantially horizontal direction with respect to the image forming unit.

JP 2007-052045 A

  However, in the conventional image forming apparatus including the image forming apparatus proposed in Patent Document 1, there is no place for the replacement unit taken out from the apparatus body when replacing the replacement unit, or the replacement unit is placed when the replacement unit is placed. There was a problem that the toner adhering to the unit was scattered to contaminate the surroundings.

  The present invention has been made in view of the above problems, and the object of the process is to secure a place for the replacement unit to improve the replacement workability of the replacement unit and to prevent contamination by scattered toner. An object is to provide an image forming apparatus.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided an image forming apparatus including a replaceable exchange unit in an apparatus main body provided with an openable / closable front cover, and taking out the replacement unit from the apparatus main body. At this time, the front cover is opened, and the front cover is used as a work table for temporarily placing the removed replacement unit.

  According to a second aspect of the present invention, in the first aspect of the present invention, a rib for positioning or supporting the replacement unit is integrally formed on the inner surface of the front cover.

  A third aspect of the invention is characterized in that, in the first or second aspect of the invention, a pocket portion for receiving scattered toner is formed long in the width direction on the inner surface of the front cover.

  According to the first aspect of the present invention, when taking out the replacement unit from the apparatus body when replacing the replacement unit, the front cover is opened and used as a work table, and the replacement unit is temporarily placed on the front cover. Therefore, it is possible to secure a place for the replacement unit and improve the replacement workability of the replacement unit.

  According to the second aspect of the present invention, since the rib for positioning or supporting the replacement unit is integrally formed on the inner surface used as a work table of the front cover, the removed replacement unit is positioned or supported on the front cover. It is temporarily placed in a state where it has been placed, and its fall and damage are prevented.

  According to the third aspect of the present invention, even if the toner attached to the replacement unit when the replacement unit taken out from the apparatus main body is temporarily placed on the front front cover falls on the front cover, the toner remains When the front cover is closed after the replacement work is completed, the toner is dropped and collected in a pocket formed on the inner surface of the front cover so as to extend in the width direction. Contamination is prevented.

1 is an external view of an image forming apparatus according to the present invention. 1 is a cross-sectional view of an image forming apparatus according to the present invention. FIG. 4 is a perspective view of the front cover of the image forming apparatus according to the present invention as viewed from the inner surface side. FIG. 4 is a perspective view of the front cover of the image forming apparatus according to the present invention as viewed from the inner surface side. It is the A section enlarged detail drawing of FIG. It is a perspective view showing the state where the drum unit was temporarily placed on the front cover. It is the fragmentary perspective view which looked at the B section of Drawing 6 from another direction. It is the C section enlarged detail drawing of FIG. It is the fragmentary perspective view which looked at the C section of Drawing 6 from another direction. FIG. 4 is a perspective view showing a state where the fixing unit is temporarily placed on the front cover. It is the D section enlarged detail drawing of FIG. It is the E section enlarged detail drawing of FIG. It is the F section enlarged detail drawing of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is an external view of an image forming apparatus according to the present invention, and FIG. 2 is a longitudinal sectional view of the image forming apparatus. The illustrated image forming apparatus 1 is a laser printer, and an image forming unit 2 is disposed above the inside of the apparatus main body 1A, and a sheet storage unit 3 is disposed in the lower half of the apparatus main body 1A. A front cover 21 that can be opened and closed is provided on the front surface of the apparatus main body 1A. Although not shown, a rectangular opening image for maintenance is formed on the front surface of the apparatus main body 1A, and this opening is opened and closed by the front cover 21.

  The image forming unit 2 forms an image by an electrophotographic method. The image forming unit 2 is a photosensitive drum 4 as a rotatable image carrier, a charger 5 disposed around the photosensitive drum 4, a developing device 6, and the like. In addition to the transfer roller 7 and the cleaning device 8, the developing device 6 is provided with a toner hopper 9 for supplying toner as a developer. Next to the image forming unit 2, an optical scanning device (laser scanner unit (LSU)) 10 according to the present invention is arranged. An image reading device 11 is disposed on the upper portion of the apparatus main body 1A.

  The paper storage unit 3 includes detachable upper and lower two-stage paper feed cassettes 11 and 12 in which a plurality of paper sheets are stacked and accommodated. A pick roller 13 for sequentially taking out the sheets in the upper and lower layers, and a feed roller 14 and a retard roller 15 for separating and feeding out the taken sheets one by one are provided.

  Further, in the apparatus main body 1A, a first transport path S1 from the paper storage unit 3 to the image forming unit 2 and a second transport path S2 from the image forming unit 2 to the paper discharge tray 16 are arranged. A registration roller 17 and the transfer roller 7 are provided in the first conveyance path S1, and a fixing device 18, a conveyance roller 19, and a paper discharge roller 20 are provided in the second conveyance path S2. Here, the fixing device 18 includes a fixing roller 18 a and a pressure roller 18 b that rotate in a pressure contact state.

  In this embodiment, the photosensitive drum 4, the charger 5, and the cleaning device 8 are unitized as a drum unit U1, the developing device 6 as a developing unit U2, and the fixing device 18 as a fixing unit U3. It can be exchanged by being attached to and detached from the apparatus main body 1A as an exchange unit.

  Next, an image forming operation of the image forming apparatus 1 configured as described above will be described.

  When the image forming operation is started, the photosensitive drum 4 is driven to rotate counterclockwise in FIG. 2 by a driving unit (not shown) in the image forming unit 2, and the surface thereof is uniformly set to a predetermined potential by the charger 5. Charged. When a laser beam based on an electrical signal transmitted from a personal computer or the like is output from the optical scanning device 10 and the surface of the photosensitive drum 4 is exposed and scanned, an electrostatic latent image corresponding to image information is formed on the photosensitive drum 4. Is formed. The electrostatic latent image formed on the photosensitive drum 4 is developed by the developing device 6 using toner as a developer to be visualized as a toner image.

  By the way, when cassette feeding is performed, the sheets stored in, for example, the sheet feeding cassette 12 of the sheet storage unit 3 are picked up from the uppermost one by the pick roller 13 and one by one by the feed roller 14 and the retard roller 15. It is separated and conveyed to the registration roller 17 through the first conveyance path S1. In the registration roller 17, after the paper is temporarily in a standby state, the paper is supplied to the image forming unit 2 at a predetermined timing synchronized with the toner image on the photosensitive drum 4.

  In the image forming unit 2, the sheet supplied to the transfer nip between the photosensitive drum 4 and the transfer roller 7 is conveyed while being pressed against the photosensitive drum 4 by the transfer roller 7, so that the surface of the sheet is exposed to the photosensitive drum. The toner image on 4 is transferred. Then, the sheet on which the toner image is transferred is conveyed to the fixing device 18 and heated and pressed in the process of passing through the fixing nip between the fixing roller 18a and the pressure roller 18b of the fixing device 18 to form the toner image. Get fixed. The toner remaining on the surface of the photosensitive drum 4 (transfer residual toner) after the transfer of the toner image onto the paper is removed by the cleaning device 8, and the photosensitive drum 4 whose surface has been cleaned is prepared for the next image forming operation.

  Thus, the sheet having the toner image fixed on the surface thereof by the fixing device 18 is transported toward the paper discharge roller 20 by the transport roller 19 through the second transport path S2, and is transported to the paper discharge tray 16 by the paper discharge roller 20. This completes a series of image forming operations.

  Incidentally, in the image forming apparatus 1 according to the present embodiment, as described above, the drum unit U1, the developing unit U2, and the fixing unit U3 can be exchanged as exchange units, and these can be attached to and detached from the apparatus main body 1A. It is configured.

  Thus, in the present embodiment, when the drum unit U1, the developing unit U2 or the fixing unit U3 as the replacement unit is replaced, when removing them from the apparatus main body 1A, the front cover 21 is opened and the front cover 21 is removed. The drum unit U1, the developing unit U2 or the fixing unit U3 that is used as a work table is temporarily placed on the front cover 21.

  Here, details of the configuration of the front cover 21 will be described with reference to FIGS.

  3 and 4 are perspective views of the front cover as seen from the inner surface side, FIG. 5 is an enlarged detail view of part A in FIG. 4, and the front cover 21 is a U-shaped hinge provided at the lower left and right ends thereof. A hinge shaft 23 directed to the tip of the arm 22 is rotatably supported on the front surface of the apparatus main body 1A as shown in FIG. 1, and opens and closes an opening (not shown) that opens on the front surface of the apparatus main body 1A. When the front cover 21 is fully opened, the front cover 21 is held in a horizontal state at an intermediate height of the paper feed cassette 12.

  As shown in FIG. 2, L-shaped positioning ribs 24 are integrally formed on the upper left and right sides of the inner surface of the front cover 21, and block-shaped positioning ribs 25 stand integrally on the outside of each positioning rib 24. It is installed. Further, a block-shaped positioning rib 26 is erected integrally at the intermediate portion in the width direction of the upper surface of the front cover 21, and a rectangular cylindrical positioning rib 27 is erected integrally at the lower right side of the inner surface of the front cover 21. It is installed. Further, a support rib 28 is erected integrally at the intermediate height position on the left side of the inner surface of the front cover 21.

  A pocket portion 30 is formed in the lower portion of the inner surface of the front cover 21 in the width direction between the inner surface of the front cover 21 by a horizontal rib 29 extending in the width direction. When the front cover 21 stands up vertically because the 21 is closed as shown in FIG. 4, it functions as a pocket that opens upward.

  Next, the replacement operation of the drum unit U1 will be described below with reference to FIGS. 6 is a perspective view showing a state where the drum unit is temporarily placed on the front cover, FIG. 7 is a partial perspective view of the portion B of FIG. 6 seen from another direction, and FIG. 8 is an enlarged detail view of the portion C of FIG. 9 is a partial perspective view of the portion C of FIG. 6 as viewed from another direction.

  When exchanging the drum unit U1, the front cover 21 is fully opened and kept in a substantially horizontal state, the drum unit U1 is taken out from an opening opening on the front surface of the apparatus main body 1A, and the drum unit U1 is shown in FIG. It is placed on the inner surface of the front cover 21 and temporarily placed, and the front cover 21 is used as a work table. Specifically, the drum unit U1 taken out from the apparatus main body 1A is received by a support rib 28 whose drum shaft 31 is erected on the left side of the inner surface of the front cover 21 as shown in FIG. As shown in FIGS. 8 and 9, the front cover 21 is temporarily placed on the inner surface of the front cover 21 in a state of being positioned in contact with positioning ribs 25 and 27 erected on the right and upper sides on the inner surface of the front cover 21.

  Then, with the drum unit U1 temporarily placed on the front cover 21 as described above, a new drum unit U1 is incorporated into the apparatus main body 1A and the drum unit U1 is replaced.

  Next, replacement work of the fixing unit U3 will be described below with reference to FIGS. 10 is a perspective view showing a state in which the fixing unit is temporarily placed on the front cover, FIG. 11 is an enlarged detail view of a D portion in FIG. 10, FIG. 12 is an enlarged detail view of an E portion in FIG. 10, and FIG. It is F section enlarged detail drawing.

When replacing the fixing unit U3, the fixing unit U3 is taken out from the opening opening on the front surface of the apparatus main body 1A and is fully opened to maintain the horizontal state. However, the front cover 21 is used as a work table, and the taken out fixing unit is used. U3 is placed on the inner surface of the front cover 21 and temporarily placed as shown in FIG. Specifically, the fixing unit U3 taken out from the apparatus main body 1A has its left and right and widthwise center portions abutted against the positioning ribs 24 and 26 formed on the inner surface of the front cover 21 as shown in FIGS. It is temporarily placed on the inner surface of the front cover 21 while being positioned in contact.

  Then, with the fixing unit U3 temporarily placed on the front cover 21 as described above, a new fixing unit U3 is incorporated into the apparatus main body 1A and the fixing unit U3 is replaced.

  As described above, in the present embodiment, when the drum unit U1 and the fixing unit U3, which are replacement units, are replaced, when the drum unit U1 and the fixing unit U3 are taken out from the apparatus main body 1A, the front cover 21 is opened and is used as a work table. Since the drum unit U1 and the fixing unit U3 can be temporarily placed on the front cover 21, it is possible to secure a place for the drum unit U1 and the fixing unit U3 and to replace them. Sexuality is enhanced. In this case, the support rib 28 for supporting the drum shaft 31 of the drum unit U1, the positioning ribs 25 and 27 for positioning the drum unit U1, and the positioning rib for positioning the fixing unit U3 are used on the inner surface used as a work table of the front cover 21. Since 24 and 26 are integrally formed, the taken-out drum unit U1 and fixing unit U3 are temporarily placed in a state where they are positioned or supported on the front cover 21, and their fall or damage is prevented.

  In the present embodiment, the toner attached to the drum unit U1 and the fixing unit U3 when the drum unit U1 and the fixing unit U3 taken out from the apparatus main body 1A are temporarily placed on the front cover 21 is disposed on the inner surface of the front cover 21. Even if the toner drops, the toner is dropped and collected in the pocket portion 30 formed in the inner surface of the front cover 21 in the width direction when the front cover 21 is closed and the front cover 21 is closed. The toner is not scattered around, and the effect of preventing the surrounding contamination by the toner can be obtained.

  Although the above description has been made on the replacement operation of the drum unit U1 and the fixing unit U3 among the replacement units, the replacement operation of the developing unit U2 can be performed in the same manner. In the above, the embodiment in which the present invention is applied to a monochrome laser printer has been described. However, the present invention is similarly applied to any image forming apparatus other than a printer, whether monochrome or color. Of course, it is possible.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1A Image forming apparatus main body 2 Image forming part 3 Paper storage part 4 Photosensitive drum 5 Charger 6 Developing device 7 Transfer roller 8 Cleaning device 9 Toner hopper 10 Optical scanning device 11 Image reading device 12 Paper feed cassette 13 Pick roller 14 Feed Roller 15 Retarder Roller 16 Discharge Tray 17 Registration Roller 18 Fixing Device 18a Fixing Roller 18b Pressure Roller 19 Conveying Roller 20 Discharge Roller 21 Front Cover 22 Hinge Arm 23 Hinge Shafts 24-27 Positioning Rib 28 Support Rib 29 Rib 30 Pocket part 31 Drum shaft S1 1st conveyance path S2 2nd conveyance path U1 Drum unit (exchange unit)
U2 Development unit (exchange unit)
U3 fixing unit (exchange unit)

Claims (3)

In the image forming apparatus comprising a replaceable exchange unit in the apparatus body having a front cover that can be opened and closed,
An image forming apparatus, wherein when the replacement unit is taken out from the apparatus main body, the front cover is opened and the front cover is used as a work table for temporarily placing the taken out replacement unit.   2. The image forming apparatus according to claim 1, wherein a rib for positioning or supporting the replacement unit is integrally formed on an inner surface of the front cover. 3. The image forming apparatus according to claim 1, wherein a pocket portion for receiving scattered toner is formed on the inner surface of the front cover so as to be long in the width direction.

Images