JP2008026363A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which improves the maintenance properties of a photoreceptor unit. <P>SOLUTION: The image forming apparatus 10 comprises an image forming apparatus body 12, a photoreceptor unit 26 which is freely attachably and detachably provided to the image forming apparatus body 12, and has a plurality of photoreceptors 40 forming at least toner images, an optical writing device 56 which forms latent images on the plurality of the photoreceptors 40, a fixing device 30 which is fixed to the image forming apparatus body 12, and fixes the toner images formed by the photoreceptors 40 to a sheet, and an opening/closing cover 64 which is disposed on the surface of the image forming apparatus body 12 in such a manner that the attachment and detachment of the photorector unit 26 can be performed from the space between the fixing device 30 and the optical writing device 56. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, or a facsimile.

  An image forming apparatus of this type is known that includes a photoconductor unit having a plurality of photoconductors. When attaching / detaching the photosensitive unit to / from the main body of the image forming apparatus, if the photosensitive unit is moved in the vertical direction, a force is easily applied and the attaching / detaching operation is facilitated. However, it is difficult for the photoreceptor unit and the fixing device disposed above the photoreceptor unit to interfere with each other and to move the photoreceptor unit in the vertical direction to be attached or detached. Therefore, a technique is known in which the fixing unit is swingably supported on the housing of the printer, and the fixing unit is opened so that the photosensitive unit can be attached and detached in the vertical direction (for example, Patent Document 1).

JP 2000-105493 A

  However, in the above prior art, since the fixing device is rotated, there is a problem that the position of the fixing device varies, and a rotation mechanism for rotating the fixing device is required, which is costly. There was also a problem.

  An object of the present invention is to provide an image forming apparatus that solves the above-described conventional problems and improves the maintainability of the photoreceptor unit.

  To achieve the above object, an image forming apparatus main body, a photoconductor unit having at least a plurality of photoconductors for forming toner images, an optical writing apparatus for forming latent images on the plurality of photoconductors, and the image forming apparatus A fixing device fixed to a main body and fixing a toner image formed by the photosensitive unit on the sheet, and the image forming so that the photosensitive unit can be attached and detached between the fixing device and the optical writing device. An image forming apparatus having opening / closing means provided on an upper surface of the apparatus main body. Therefore, the photosensitive unit can be moved and detached in the vertical direction where force is easily applied, and the maintainability of the photosensitive unit is improved.

  Preferably, at least a part of the photosensitive unit is disposed below the fixing device.

  Preferably, the image forming apparatus includes a transfer unit that transfers a toner image formed on the photoconductor to the sheet, and the photoconductor unit is provided to be movable in a substantially horizontal direction between the transfer unit and the optical writing device. It has been.

  Preferably, the photoconductor unit has a support shaft that rotatably supports the photoconductor unit, and the photoconductor unit is rotatably provided with the support shaft as a fulcrum.

  According to the present invention, the photoconductor unit can be moved and detached in the vertical direction where force is easily applied, so that the photoconductor unit can be easily attached to and detached from the image forming apparatus main body, and the maintainability of the photoconductor unit is improved. Can be improved.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an image forming apparatus 10 according to a first embodiment of the present invention. The image forming apparatus 10 includes an image forming apparatus main body 12. A sheet supply device 14 is disposed at a lower portion of the image forming apparatus main body 12, and a discharge unit 16 is disposed at the upper portion of the image forming apparatus main body 12. Is formed.

  The sheet supply device 14 includes a sheet cassette 18, and a large number of sheets are stacked on the sheet cassette 18. A feed roll 20 is disposed on one upper end of the sheet cassette 18, and a retard roll 22 is provided facing the feed roll 20. The uppermost sheet of the sheet cassette 18 is picked up by the feed roll 20, and the sheet is rolled and conveyed by the cooperation of the feed roll 20 and the retard roll 22.

  The sheet conveyed from the sheet cassette 18 is temporarily stopped by the registration roller 24, and passes through a fixing unit 30 between a photosensitive unit 26 and a transfer unit 28, which will be described later, and a discharge roller 32 to the discharge unit 16 at a predetermined timing. Discharged.

  In the image forming apparatus main body 12, a photosensitive unit 26, a transfer unit 28, a power supply unit 34, and a control unit 36 are arranged. The photoconductor unit 26 includes a photoconductor unit main body 38, and for example, four photoconductors 40 are rotatably supported on the photoconductor unit main body 38. Around each photoconductor 40, a charging device 42 as a charging means provided with a charging roll for uniformly charging the photoconductor 40, and a latent image written on each photoconductor 40 is developed with a developer (toner). A developing device 44 as a developing means, a static eliminating device 46 for neutralizing the photoreceptor 40 after transfer, and a cleaning device 48 as a developer removing means for removing the developer remaining on the photoreceptor 40 after the transfer. Have The photoconductor unit 26 is obtained by integrating four photoconductors 40, a charging device 42, a developing device 44, a charge removal device 46, and a cleaning device 48, and at least a part of the photoconductor unit 26 is below the fixing device 30. And is detachable from the image forming apparatus main body 12. The photosensitive unit 26 is provided with a gripping portion 26a (shown in FIG. 2) that can be gripped by the user.

  The four toner boxes 50 are connected to the back side of the photoconductor unit 26. Each toner box 50 is for magenta, yellow, cyan, and black, and a toner supply unit 52 and a toner recovery unit 54 are integrated. The toner supply unit 52 is connected to the developing device 44 to supply each color toner to the developing device 44, and the toner recovery unit 54 is connected to the cleaning device 48 to recover each color toner.

  Each of the optical writing devices 56 is composed of a laser exposure device, and is arranged on the back side of the photoconductor unit 26 at a position corresponding to each photoconductor 40, and applies laser light to the uniformly charged photoconductor 40. Irradiation forms a latent image.

  The transfer unit 28 is on the front side of the photoconductor unit 26 and is arranged in the vertical direction facing the photoconductor unit 26. In the transfer unit 28, a conveyance belt 60 is hung on two support rolls 58 provided in the vertical direction. Further, a transfer roll 62 is provided so as to face each photoconductor 40 with the conveyance belt 60 interposed therebetween. Therefore, the transfer unit 26 transfers the toner image formed on each photoconductor 40 of the photoconductor unit 26 to a sheet.

  The fixing device 30 is disposed above at least a part of the photoreceptor unit 26 and is fixed to the image forming apparatus main body 12. The fixing device 30 fixes a toner image formed on each photoreceptor 40 of the photoreceptor unit 26 and transferred onto the sheet to the sheet.

  An opening / closing cover 64 as an opening / closing means is provided on the upper surface of the image forming apparatus main body 12 and is provided so as to be rotatable about a rotation fulcrum portion 66. The guide rail 68 is disposed substantially horizontally below the photosensitive unit 26 and is provided in the image forming apparatus main body 12 so as to slidably support the photosensitive unit 26. Therefore, the photoconductor unit 26 is provided so as to be movable in the substantially horizontal direction between the transfer unit 28 and the optical writing device 56. A stopper 68a is formed at one end of the guide rail 68. When the photosensitive unit 26 moves in the direction of the optical writing device 56, the photosensitive unit 26 and the stopper 68a come into contact with each other. The photosensitive unit 26 and the optical writing device 56 are not in contact with each other.

  Therefore, each photoconductor 40 is uniformly charged by the charging device 42, a latent image is formed by the optical writing device 56, and the latent image is visualized by toner by the developing device 44. The toner images formed on the respective photoconductors 40 are transferred to the conveyed sheet by the transfer roller 62 of the transfer unit 28 in order from below, and are fixed to the sheet by the fixing device 30.

Next, a method for attaching / detaching (replacing) the photosensitive unit 26 will be described with reference to FIG.
As shown in FIG. 2A, the opening / closing cover 64 is opened by rotating (in the direction of arrow a in FIG. 2A), and the gripping portion 26a of the photoconductor unit 26 is moved from the direction of the transfer unit 28 to the optical writing device. When pulled in the direction 56 (in the direction of arrow A in FIG. 2A), the photosensitive unit 26 moves (slides) substantially horizontally along the guide rail 68 toward the optical writing device 56.

  Subsequently, as shown in FIG. 2B, when the holding unit 26 a of the photoconductor unit 26 is held and the photoconductor unit 26 is pulled upward (in the direction of arrow B in FIG. 2B), the photoconductor unit 26. Is removed from the image forming apparatus main body 12 through the fixing device 30 and the optical writing device 56 and through an opening formed by opening the opening / closing cover 64.

  As described above, in the image forming apparatus 10 of the present embodiment, the photosensitive unit 26 is attached and detached by moving the photosensitive unit 26 in the vertical direction. Therefore, the maintainability of the photoreceptor unit 26 can be improved. Further, since the fixing unit 30 can be fixed to the image forming apparatus main body 12 and the photosensitive unit 26 can be attached and detached, the rotation of the fixing apparatus 30 can be prevented while preventing variations in the position of the fixing apparatus. The moving mechanism becomes unnecessary. Therefore, it is possible to reduce the cost while maintaining the quality of the output image.

  In the image forming apparatus 10 according to the present embodiment, the distance (optical path) between the photoconductor 40 and the optical writing device 56 can be increased, and the optical writing device 56 can be downsized. . That is, as shown in FIG. 3, when the distance (optical path) between the photosensitive member 40 and the optical writing device 56 is increased (for example, from the distance L1 to L2 in FIG. 3), the optical writing device 56 is increased in the width direction. It is known that the length can be reduced (eg, reduced from the length W1 to W2 in FIG. 3).

  In the image forming apparatus 10 of the present embodiment, the space between the photoconductor unit 26 and the optical writing device 56 can be effectively used as a space for attaching / detaching (moving) the photoconductor unit 26. .

  Next, an image forming apparatus 100 in a comparative example of the image forming apparatus 10 of the present invention will be described with reference to FIG.

  The image forming apparatus 100 in this comparative example has an image forming apparatus main body 102, and a photoconductor unit 104, a transfer unit 106, an optical writing device 108, and the like are provided in the image forming apparatus main body 102. An open / close cover 102a is provided on the side surface (left side surface in the figure) where the transfer unit 102 of the image forming apparatus main body 102 is disposed. As shown in FIG. 6, the photoconductor unit 104 is attached to and detached from the image forming apparatus main body 12 by opening the opening / closing cover 102 a and rotating the transfer unit 102 until it becomes substantially horizontal. In the image forming apparatus 100, when the photosensitive unit 104 is attached or detached, the photosensitive unit 104 and the transfer unit 106 may come into contact with each other, and the transfer unit 106 may be damaged.

  Compared to the image forming apparatus 100 in the first comparative example, the image forming apparatus 10 according to the present invention has a photosensitive unit 26 from the upper surface of the image forming apparatus main body 12 through the fixing device 30 and the optical writing device 56. Therefore, the transfer unit 28 can be prevented from being damaged when the photoconductor unit 26 is attached or detached.

  Next, an image forming apparatus 10 according to a modification of the first embodiment will be described with reference to FIG.

  As shown in FIG. 4, the image forming apparatus 10 in this modification has an image forming apparatus main body 12, and an extension unit 70 such as a document reading device is disposed on the upper surface of the image forming apparatus main body 12. . In this example, the front surface of the image forming apparatus main body 12 is a side surface (right side surface in the drawing) on which the optical writing device 56 is disposed.

  As shown in FIG. 4B, the photosensitive unit 26 and the sheet cassette 18 are attached and detached from the front side of the image forming apparatus main body 12 (in the direction of arrow C in FIG. 4B). The jam processing is performed by removing the photosensitive unit 26 from the image forming apparatus main body 12.

  As described above, the image forming apparatus 10 according to the present modification performs at least the removal of the sheet discharged to the discharge unit 16, the attachment / detachment of the photosensitive unit 26, the attachment / detachment of the sheet cassette 18, and the jam processing. Since it can be performed from the right side in the drawing), the back surface (left side in the drawing) of the image forming apparatus main body 12 can be disposed near the wall.

  Next, an image forming apparatus 10 according to a second embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 5, the image forming apparatus 10 includes an image forming apparatus main body 12, and the image forming apparatus main body 12 is provided with a support shaft 72. The support shaft 72 is formed in a cylindrical shape and is disposed in the vicinity of the photoconductor unit 26.

  The unit support arm 74 is provided at the bottom of the photoconductor unit 26 and supports the photoconductor unit 26 and is rotatably engaged with the support shaft 72. The unit support arm 74 has a notch (not shown), and the unit support arm 74 and the support shaft 72 are detachably engaged. Therefore, the photosensitive unit 26 is provided so as to be rotatable with the support shaft 72 as a fulcrum, and is provided detachably with respect to the support shaft 72.

  As shown in FIG. 5 (a), the opening / closing cover 64 is opened by rotating (in the direction of arrow a in FIG. 5 (a)), and the gripping portion 26a of the photoconductor unit 26 is tilted downward (in FIG. 5 (a)). When rotated in the direction of arrow D), the photosensitive unit 26 rotates about the support shaft 72 as a fulcrum.

  Subsequently, as shown in FIG. 5B, when the photosensitive member unit 26 is lifted obliquely upward (in the direction of arrow E in FIG. 5B) by holding the holding portion 26a of the photosensitive member unit 26, the photosensitive member unit. 26, the engagement between the unit support arm 74 and the support shaft 72 is released, and the photoconductor unit 26 is provided between the fixing device 30 and the optical writing device 56, and an opening formed by opening the opening / closing cover 64. Through the image forming apparatus main body 12.

  As described above, in the image forming apparatus 10 of the present embodiment, the photosensitive unit 26 can be attached and detached without providing the guide rail 68 used in the first embodiment.

  As described above, the present invention can be used in an image forming apparatus having a photoconductor unit that is detachably provided on the main body of the image forming apparatus.

1 is a side view showing an image forming apparatus according to a first embodiment of the present invention. 2A and 2B show a method for attaching and detaching the photoconductor unit according to the first embodiment of the present invention, in which FIG. 1A shows a state in which the photoconductor unit is moved in a substantially horizontal direction, and FIG. FIG. It is a schematic diagram explaining the relationship between the distance (optical path) between a photoconductor and an optical writing device and the size in the width direction of the optical writing device. 2A and 2B show a modification of the image forming apparatus according to the first embodiment of the present invention, in which FIG. 3A shows a state where a sheet is discharged to a discharge unit, FIG. It is a side view which shows the state by which attachment / detachment was performed. FIG. 5 shows an image forming apparatus according to a second embodiment of the present invention, where (a) is a state in which the photosensitive unit is rotated, and (b) is a side view showing a state in which the photosensitive unit is removed. It is a side view which shows the image forming apparatus in the comparative example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming apparatus main body 26 Photoconductor unit 28 Transfer unit 30 Fixing apparatus 40 Photoconductor 56 Optical writing apparatus 64 Opening / closing cover 72 Support shaft

Claims (4)

An image forming apparatus main body;
A photoconductor unit that is detachably provided in the image forming apparatus main body and has at least a plurality of photoconductors that form toner images;
An optical writing device for forming latent images on the plurality of photoconductors;
A fixing device that is fixed to the image forming apparatus main body and fixes a toner image formed on the photosensitive member to the sheet;
An opening / closing means provided on the upper surface of the image forming apparatus main body so that the photoconductor unit can be attached and detached between the fixing device and the optical writing device;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein at least a part of the photosensitive unit is disposed below the fixing device.   A transfer unit that transfers the toner image formed on the photoconductor to the sheet, and the photoconductor unit is provided to be movable in a substantially horizontal direction between the transfer unit and the optical writing device; The image forming apparatus according to claim 1, wherein:   4. The support unit according to claim 1, further comprising a support shaft that rotatably supports the photoconductor unit, wherein the photoconductor unit is rotatably provided with the support shaft as a fulcrum. Image forming apparatus.

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