JP2007212521A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus where a replacement component such as a transfer roller can be replaced without detaching a drum shutter. <P>SOLUTION: The drum shutter 26 which swings to a protection position A where a photoreceptor drum 3 is covered on the side of an attachment/detachment opening 2a associatively with removal of a developing unit 25 from an apparatus main body 2 and also swings to a standby position D or B where the drum shutter retracts from the protection position A associatively with loading of the developing unit 25 in the apparatus main body 2 is configured to swing to the standby position D or B and the protection position A while the developing unit 25 is taken out of the apparatus main body 2 and the drum shutter swings to the protection position A. Consequently, when a replacement component such as the transfer roller 15a is replaced, the drum shutter 26 is only swung to the standby position D or B and then the replacing operation can be completed by inserting a hand into the attachment/detachment opening 2a etc., without detaching the drum shutter 26. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile machine, and a multifunction machine having these functions.

  2. Description of the Related Art Conventionally, there is an image forming apparatus in which a transfer roller is provided on an opening / closing cover for a photosensitive drum in an apparatus body, and the transfer roller is covered with a protective shutter when the opening / closing cover is opened (Patent Document). 1).

  By the way, the applicant of the present invention is provided with a developing unit for supplying toner to the photosensitive drum in the apparatus main body so that the toner can be taken in and out with respect to the opening / closing opening of the apparatus main body. A drum shutter that swings to a protection position that covers the loading / unloading opening side of the photosensitive drum and swings to a retreat position that retracts from the protection position in conjunction with the development unit being loaded into the apparatus main body. Has proposed an image forming apparatus provided in the company.

  This drum shutter is for protecting the photosensitive drum from being damaged when the developing unit is taken out of the apparatus main body and a hand is inserted through the loading / unloading opening for JAM processing.

The photosensitive drum itself can be pulled out from the apparatus main body in the maintenance direction, but replacement parts such as a transfer roller located below the photosensitive drum are attached to the apparatus main body. For this reason, since the hand cannot be inserted all the way through the extraction opening of the photosensitive drum, it is necessary to insert the hand from the insertion / removal opening and perform an exchange operation.
JP 11-288209 A

  However, since the developing unit is removed from the apparatus main body, the drum shutter swings to a protective position that covers the loading / unloading opening side of the photosensitive drum, so that the replacement work cannot be performed by inserting a hand through the loading / unloading opening. .

  For this reason, in the replacement work, a work for removing the drum shutter and a work for reattaching the drum shutter are required, so that the workability is deteriorated and there is a problem that an assembly error is likely to occur during the work of reattachment.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus in which replacement parts such as a transfer roller can be replaced without removing a drum shutter. is there.

  In order to solve the above-described problems, the present invention provides a developing unit for supplying toner to a photosensitive drum in the apparatus main body so that it can be taken in and out with respect to a loading / unloading opening of the apparatus main body, while the developing unit is removed from the apparatus main body. In conjunction with this, the photoconductive drum swings to a protective position that covers the loading / unloading opening side of the photosensitive drum, and swings to a retreat position that retracts from the protective position in conjunction with loading of the developing unit into the apparatus main body. In the image forming apparatus in which the drum shutter is provided in the apparatus main body, the drum shutter can be swung between the retracted position and the protective position when the developing unit is removed from the apparatus main body and is swung to the protective position. An image forming apparatus characterized by being configured is provided.

  According to a second aspect of the present invention, the drum shutter is disposed between the photosensitive drum and the developing unit, the retracted position interlocked with the developing unit is on the developing unit side, and the retracted position of the swing operation is the photosensitive unit. It is preferable that the structure is on the body drum side.

  According to a third aspect of the present invention, the drum shutter is preferably held at the retracted position when the retracting position is swung.

  According to a fourth aspect of the present invention, the drum shutter is preferably configured to be locked at the protection position when the protection position is swung.

  6. A shutter driving arm that is linked to a drum shutter is provided inside a loading / unloading opening of the apparatus main body, and the drum shutter has one end shaft portion supported by the apparatus main body, and the other end shaft portion is a shutter. Supported by a gear boss that links the drive arm and drum shutter. The other end shaft and boss allow the drum shutter to swing from the protected position to the retracted position on the photosensitive drum side. A one-way clutch that prevents the developing unit side from swinging to the retracted position is formed, and one end shaft portion of the drum shutter is urged to swing toward the protection position and at the same time move toward the other end shaft portion. When the developing unit is loaded in the apparatus main body, the developing unit pushes the shutter drive arm to push the drum shutter to the biasing unit. The drum shutter is configured to swing in the protection position direction by the biasing force of the biasing member when the developing unit is removed from the apparatus body. On the other hand, when the drum shutter is swung to the retracted position on the photosensitive drum side while the drum shutter is swung to the protection position, the drum shutter is held at the retracted position by the moving biasing force of the biasing member and When swinging from the retracted position on the body drum side to the protected position, the one-way clutch can be locked at the protected position.

  According to the present invention, the drum shutter that swings between the protection position and the retracted position in conjunction with the loading / unloading of the developing unit can be operated to swing between the retracted position and the protection position while swinging to the protection position. Therefore, when exchanging replacement parts such as the transfer roller, simply replace the drum shutter by swinging it to the retracted position, and insert the hand through the opening / closing opening etc. without removing the drum shutter. Will be able to. When the replacement work is completed, the drum shutter can be swung to the original protected position.

  This eliminates the need to remove and reattach the drum shutter when exchanging replacement parts. This improves workability and eliminates the problem of assembly errors during reattachment.

  According to the second aspect, if the retracted position of the swing operation of the drum shutter is set to the photosensitive drum side, the drum shutter is positioned at the retracted position even if it is forgotten to return to the original protected position. Since the photosensitive drum does not enter because it becomes an obstacle when the photosensitive drum extracted from the apparatus body in the lateral direction is inserted again, it is possible to prevent the drum shutter from being forgotten to be returned.

  According to the third aspect, if the drum shutter is held at the retracted position, the replacement work for the replacement part will not be obstructed.

  According to the fourth aspect, if the drum shutter is locked at the protection position, it can be accurately returned to the protection position.

  According to the fifth aspect of the present invention, the following effects can be obtained with a simple configuration in which a one-way clutch is formed between the drum shutter and the gear, and the urging member that moves and urges the drum shutter at the same time is provided. it can. (A) Since the retracted position of the swing operation of the drum shutter can be set on the photosensitive drum side as in the second aspect, even if the forgoing return to the original protected position is made, the drum shutter is positioned at the retracted position. If this is the case, it becomes an obstacle to re-inserting the photosensitive drum that has been pulled out from the main body of the apparatus, and the photosensitive drum does not enter, so that it is possible to prevent forgetting to return the drum shutter. (B) Similarly to the third aspect, the drum shutter can be held at the retracted position, so that it does not interfere with the replacement work of the replacement parts. (C) Since the drum shutter can be locked at the protection position as in the fourth aspect, it can be accurately returned to the protection position.

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

  FIG. 1 is a schematic configuration diagram of a printer 1 which is an example of an image forming apparatus according to an embodiment of the present invention. The present invention is not limited to a printer but can be applied to other image forming apparatuses such as a copying machine, a facsimile machine, and a multifunction machine.

  The printer 1 forms an image on a sheet based on image data sent from a terminal or the like in the middle of conveying the sheet along the conveyance path L. A photoconductor is provided inside the box-shaped apparatus main body 2. An image forming unit 4 that forms a toner image on the surface of the drum 3 and then transfers the toner image to a sheet, a paper feeding unit 5 that supplies the sheet to the image forming unit 4, and a fixing unit that fixes the toner image to the sheet 6 is provided.

  The conveyance path L includes a horizontal portion L1 extending in the left-right direction and a vertical portion L2 rising substantially vertically from the left end portion of the horizontal portion L1.

  The paper feed section 5 has a paper feed cassette 10 disposed below the horizontal portion L1 of the transport path L. The paper stored in the paper feed cassette 10 is taken out by a pickup roller 12a and the paper is Are fed one by one to the horizontal portion L1 of the conveyance path L by the paper feed rollers 12b to 12e, and the sheet fed to the conveyance path L is temporarily waited by the registration roller 12f and supplied to the image forming unit 4 at a predetermined timing. It is supposed to be.

  The image forming unit 4 includes a photosensitive drum 3 disposed substantially at the center of the horizontal portion L1 of the conveyance path L, a charging unit 13 disposed above the photosensitive drum 3, and a right side of the photosensitive drum 3. A developing unit 14 disposed on the side, a transfer unit 15 disposed below the photosensitive drum 3, a cleaning unit 16 disposed on the left side of the photosensitive drum 3, a charging unit 13, and a cleaning unit. 16 and a laser scanner unit (LSU) 17 disposed above the fixing unit 6.

  The photosensitive drum 3 rotates clockwise in FIG. 1. After the surface of the photosensitive drum 3 is uniformly charged by the charging unit 13, a laser based on image data is output by the laser scanner unit 17. An electrostatic latent image is formed by irradiating light between the charging unit 13 and the developing unit 14, and toner is further supplied from the developing unit 14 to the surface on which the electrostatic latent image is formed. An image is formed.

  The paper supplied from the paper supply unit 5 is conveyed while being pressed against the photoconductive drum 3 by the transfer roller 15a of the transfer unit 15, so that the surface of the photoconductive drum 3 is transferred to the surface (transfer surface). The toner image formed on the toner image is transferred and then sent to the fixing unit 6. Note that the toner and residual charges remaining on the surface of the photosensitive drum 3 after the transfer are removed by the cleaning unit 16.

  The fixing unit 6 includes a heat roller 6a and a pressure roller 6b. The toner image is transferred to the paper by heat and pressure by sandwiching the paper on which the toner image is transferred by the rollers 6a and 6b. It has become established.

  Then, the sheet on which the toner image is fixed is discharged by a discharge roller 18 to a discharge unit 19 formed on the upper surface of the apparatus main body 2.

  In the printer 1 of this embodiment, a switchback unit 20 is provided between the horizontal portion L1 of the transport path L and the paper feed cassette 10, so that images can be formed on both sides of the paper. . Reference numeral 21 denotes a manual feed unit.

  In the printer 1 of the present embodiment, a developing unit 25 in which the developing unit 14 and the toner container 23 are integrated is provided, and can be taken in and out from an oblique direction with respect to the loading and unloading opening 2 a on the upper surface of the apparatus body 2. Yes. That is, the developing unit 25 can be loaded into the apparatus main body 2 from the direction of the arrow IN that is obliquely downward, and can be removed from the apparatus body 2 in the direction of the arrow OUT that is obliquely upward.

  As shown in detail in FIGS. 2 and 3, a drum shutter 26 is disposed between the photosensitive drum 3 and the developing unit 25 in the apparatus main body 2. The drum shutter 26 swings to a protective position A (see FIG. 2) covering the loading / unloading opening 2a side of the photosensitive drum 3 in conjunction with the development unit 25 being taken out from the apparatus main body 2, and the development unit 25. Is swayed to a first retraction position B (see FIG. 3) that retreats from the protection position A (see an arrow) in conjunction with being loaded into the apparatus main body 2.

  Specifically, as shown in FIGS. 4, 6 and 7, the drum shutter 26 is formed in a rectangular plate shape extending in the axial direction of the photosensitive drum 3, and has an upper end shaft portion ( The left end shaft portion 26a in FIG. 4 is pivotally supported by the boss portion 27 of the frame of the apparatus body 2, and the other end shaft portion (right end shaft portion in FIG. 7) 26b is a final that will be described later. The boss 31a of the gear 31 is pivotally supported so as to be swingable.

  The shaft portions 26a and 26b of the drum shutter 26 are pivotally supported by the boss portions 27 and 31a so as to be movable in the axial direction C.

  In FIG. 4, a wire coil spring (biasing member) 32 is wound around one end shaft portion 26a of the drum shutter 26, and one end portion of the wire coil spring 32 is locked to the boss portion 27, and the other end portion is a drum shutter. The drum shutter 26 is urged so as to swing to the protection position A. The wire coil spring 32 also urges the drum shutter 26 to move axially in the direction of the final gear 31.

  A shutter drive arm 29 having a fan-shaped gear 29a and a final gear 31 are provided at a predetermined interval on the frame of the apparatus body 2 on the other end shaft portion 26b side of the drum shutter 26 inside the loading / unloading opening 2a of the apparatus body 2. The fan-shaped gear 29a meshes with the final gear 31 via idle gears 30a and 30b.

  The final gear 31 is formed with a boss portion 31a that pivotally supports the other end shaft portion 26b of the drum shutter 26 so as to swing and move.

  As shown in FIG. 7, the boss portion 31a is formed with a concave portion 31b, and the other end shaft portion 26b of the drum shutter 26 is formed with a convex portion 26c that can be fitted into the concave portion 31b from the axial direction. In addition, inclined surfaces 31c and 26d are formed in the concave portion 31b and the convex portion 26c, respectively. The convex portion 26c of the drum shutter 26 and the concave portion 31b of the final gear 31 constitute a one-way clutch.

  Therefore, as shown in FIG. 2, when the developing unit 25 is removed from the apparatus main body 2, the drum shutter 26 swings clockwise to the protection position A by the urging force of the wire coil spring 32. The fan-shaped gear 29a is rotated via the idle gears 30a and 30b, and the shutter drive arm 29 is positioned in the illustrated rotation state.

  As shown in FIG. 3, when the developing unit 25 is loaded into the apparatus main body 2, the shutter driving arm 29 is pushed by the developing unit 25, and the final gear 31 is moved from the fan-shaped gear 29a through the idle gears 30a and 30b. And the drum shutter 26 swings counterclockwise to the first retraction position B on the developing unit 25 side.

  On the other hand, when exchanging replacement parts such as the transfer roller 15 a located below the photosensitive drum 3, the photosensitive drum 3 itself can be extracted from the apparatus main body 2 in the lateral direction.

  However, since the developing unit 25 is removed from the apparatus main body 2, the drum shutter 26 swings to the protection position A that covers the loading / unloading opening 2a side of the photosensitive drum 3 as shown in FIG. The replacement work cannot be performed by inserting a hand through the access opening 2a.

  Therefore, when the drum shutter 26 in the state of swinging to the protection position A is inserted into the extraction opening or the opening 2a of the photosensitive drum 3 and the hand is pushed strongly in the clockwise swinging direction from the protection position A with a finger or the like, The inclined surface 26d of the convex portion 26c of the other end shaft portion 26b of the drum shutter 26 slides up the inclined surface 31c of the concave portion 31b of the final gear 31, and the drum shutter 26 resists the axial urging force of the wire coil spring 32 and has one end shaft. It swings clockwise while moving in the axial direction toward the portion 26a.

  Then, at the retracted position D (see FIG. 5) on the photosensitive drum 3 side where the front end surface 26e of the convex portion 26c of the drum shutter 26 rides on the front end surface 31d of the boss portion 31a of the final gear 31, a finger or the like from the drum shutter 26 5, the drum shutter 26 is in a state where the tip surface 26 e of the convex portion 26 c is pressed against the tip surface 31 d of the boss portion 31 a of the final gear 31 by the urging force in the axial direction of the wire coil spring 32. Thus, it is held at the retracted position D.

  With the configuration described above, the drum shutter 26 that swings between the protection position A and the first retraction position B in conjunction with the loading and unloading of the developing unit 25 is swung to the protection position A with a finger or the like. By performing the clockwise swing operation, the swing operation can be performed to the second retracted position D. Therefore, when the replacement part such as the transfer roller 15a is replaced, the drum shutter 26 can be simply operated by swinging the drum shutter 26. Without removing 26, it is possible to insert the hand from the insertion / removal opening 2a or the like and perform the replacement work.

  When the replacement work is completed, similarly, when the drum shutter 26 is swung counterclockwise with a finger or the like, the tip surface 26e of the convex portion 26c of the drum shutter 26 becomes the tip surface of the boss portion 31a of the final gear 31. When the convex portion 26c of the drum shutter 26 matches the concave portion 31b of the final gear 31 by slidingly moving 31d, the drum shutter 26 is moved by the urging force in the axial direction of the wire coil spring 32 while the convex portion 26c is fitted into the concave portion 31b. The drum shutter 26 can be locked at the original protection position A by moving in the axial direction toward the end shaft portion 26b.

  Accordingly, when the replacement part is replaced, the operation of removing the drum shutter 26 and the operation of reattaching it become unnecessary, so that the workability is improved and the problem that an assembly error occurs during the operation of reattachment is eliminated. .

  Further, the drum shutter 26 disposed between the photosensitive drum 3 and the developing unit 25 has the first retracted position B linked to the developing unit 25 as the developing unit 25 side, and the second retracted position D of the swing operation. Is on the photosensitive drum 3 side, even if it is forgotten to return to the original protection position A, if the drum shutter 26 is located at the second retracted position D, it is pulled out from the apparatus body 2 in the lateral direction. Since the photosensitive drum 3 does not enter due to an obstacle when the photosensitive drum 3 is inserted, forgetting to return the drum shutter 26 can be prevented in advance.

  Further, the drum shutter 26 is held at the second retracted position D by the urging force in the axial direction of the wire coil spring 32 during the swing operation in the second retracted position D direction. No longer.

  In addition, the drum shutter 26 is accurately moved since the convex portion 26c of the drum shutter 26 is fitted into the concave portion 31b of the final gear 31 during the swinging operation in the protective position A direction, and the drum shutter 26 is locked to the protective position A. To the protected position A.

  In the above-described embodiment, the drum shutter 26 is retracted to the second retracted position D on the photosensitive drum 3 side by the swing operation. However, the drum shutter 26 is configured to be retracted to the first retracted position B on the developing unit 25 side. Is also possible.

  Further, the drum shutter 26 can be swung with a finger in addition to being swung with a finger, and can be swung with an actuator such as a solenoid or an electric motor driven by a button operation. it can.

1 is a schematic side view showing a configuration of a printer according to an embodiment of the present invention. It is a side view which shows the relationship between the drum shutter of a protection position, and a shutter drive arm. FIG. 6 is a side view showing a relationship between a drum shutter at a retracted position on the developing unit side and a shutter drive arm. FIG. 6 is a perspective view of the relationship between the drum shutter at the retracted position on the photosensitive drum side and the transfer roller as viewed from the opening / closing side. FIG. 5 is a side view showing a relationship between a drum shutter at a retracted position on the photosensitive drum side and a shutter drive arm. It is a perspective view which shows the relationship between the drum shutter of a protection position, and a shutter drive arm. It is a perspective view of the one-way clutch part of a drum shutter and a final gear.

Explanation of symbols

1 Printer (image forming device)
2 Device main body 2a Entry / exit opening 3 Photosensitive drum 15 Transfer portion 15a Transfer roller 25 Development unit 26 Drum shutter 26a One end shaft portion 26b Other end shaft portion 26c Convex portion 26d Slope 26e End surface 29 Shutter drive arm 31 Final gear 31a Boss portion 31b Boss portion 31c Slope 31d Tip surface 32 Wire coil spring (biasing means)
A Protective position B First retracted position D Second retracted position

Claims (5)

A developing unit for supplying toner to the photosensitive drum in the apparatus main body is provided in the apparatus main body so that the toner can be taken in and out. An image forming apparatus provided with a drum shutter that swings to a protection position that covers the opening side and swings to a retreat position that retracts from the protection position in conjunction with the development unit being loaded into the apparatus body In
The image forming apparatus, wherein the drum shutter is configured to be swingable between a retracted position and a protective position in a state where the developing unit is taken out from the apparatus main body and swings to the protective position.   The drum shutter is disposed between the photosensitive drum and the developing unit, the retracted position interlocked with the developing unit is on the developing unit side, and the retracted position of the swing operation is on the photosensitive drum side. The image forming apparatus according to claim 1, wherein:   The image forming apparatus according to claim 1, wherein the drum shutter is held at the retracted position during a swinging operation of the retracted position.   The image forming apparatus according to claim 1, wherein the drum shutter is locked at the protection position when the protection position is swung. A shutter drive arm that is linked to the drum shutter is provided inside the access opening of the apparatus body,
The drum shutter has one end shaft portion supported by the apparatus main body, the other end shaft portion is supported by a boss portion of a gear that interlocks the shutter drive arm and the drum shutter, and the other end shaft portion and the boss portion include: A one-way clutch is formed that allows a swing operation of the drum shutter from the protection position to the retracted position on the photosensitive drum side and prevents the swing operation to the retracted position on the developing unit side,
The one end shaft portion of the drum shutter is provided with a biasing member that swings and biases in the direction of the protective position and simultaneously moves and biases in the direction of the other end shaft portion.
When the developing unit is loaded in the apparatus main body, the developing unit pushes the shutter drive arm to swing the drum shutter to the retracted position on the developing unit side against the urging force of the urging member. The drum shutter is configured to swing in the protection position direction by the urging force of the urging member when is removed from the apparatus main body,
When the drum shutter is swung to the retracted position on the photosensitive drum side while the drum shutter is swung to the protection position, the drum shutter is held at the retracted position by the moving biasing force of the biasing member and 2. The image forming apparatus according to claim 1, wherein when the swinging operation is performed from the retracted position to the protection position, the image forming apparatus is locked at the protection position by a one-way clutch.

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