JP4893030B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including a fixing device that fixes an unfixed toner image. In particular, the present invention relates to a fixing device that is removable from an image forming apparatus.

  An image forming apparatus that forms an image is equipped with a fixing device that heats and pressurizes and fixes a toner image transferred onto a sheet. As such a fixing device, for example, a heating roll having a heating source therein and a pressure roll that is in pressure contact with the heating roll are provided, and paper is passed through a nip portion between the heating roll and the pressure roll. Things are known.

However the fixing device is to include a heating roll heated to a high temperature, and from the viewpoint of safety, and also unitized from viewpoint of maintaining accuracy of the mechanism is performed.

  However, when the paper is transported through the image forming apparatus, if the paper feed timing is delayed from the paper supply unit, the paper may slip or become jammed during transport (so-called jam). . In this case, it is necessary to put a hand in the fixing device unitized in order to remove the jammed paper from the inside of the device.

  Therefore, various proposals have been made so that the operator can easily and safely remove the jammed paper.

  In Japanese Patent Laid-Open No. 2004-260260, only when the fixing unit is removed from the image forming apparatus, the guide unit that guides the sheet moves to the non-guide position so that the sheet jammed in the apparatus can be removed.

JP-A-2005-157032

However, the fixing unit of Patent Document 1 cannot remove the jammed paper unless it is removed from the image forming apparatus. Also, if the fixing unit is replaced during image formation, there is a risk that the guide unit will be mistakenly moved to the non-guide position, and the operator may touch the high temperature portion of the fixing unit. Further, since the guide portion is urged by a spring or the like, the jammed paper must be removed while supporting the guide member with one hand, which makes it difficult for an unfamiliar operator to remove.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image forming apparatus that can easily remove paper jammed in a fixing unit and ensures safety when the fixing device is removed. And

To achieve this object, an image forming apparatus of the present invention includes a heating roll and a pressure roll for fixing an image formed on a sheet to the sheet, and a heating roll side housing provided as a housing on the heating roll side. When the opening of the pressure roll side housing provided as the pressure roll side housing, the heating roll side housing, and the pressure roll side housing is closed, the opening is opened. The pressure roll side housing is fixed to the heating roll side housing so that the pressure roll side housing is not engaged, and the receiving member provided on the pressure roll side housing is engaged with the receiving member provided on the heating roll side housing. A fixing device having an engaging member; and when the fixing device is disposed at a mounting position where the fixing device is mounted. A first restricting member that abuts a part of the engaging member so that the opening can be opened, and restricts the engaging member so that the engaging member does not engage with the receiving member; A main body device to which the fixing device can be mounted, and the engaging member engages with the receiving member when the fixing device is detached from the main body device, and the pressurizing unit prevents the opening from being opened. The roll side housing is fixed to the heating roll side housing.
Therefore, when the fixing device is mounted at the mounting position of the main body device, the engagement between the engaging member and the receiving member is released by the first restricting member, and the opening of the housing can be opened. In addition, when the fixing device is removed from the main body device, the first regulating member does not come into contact with the engaging member. Therefore, the engaging member engages with the receiving member and the opening is not opened so that the opening is not opened. The housing can be fixed to the heating roll side housing.

In the image forming apparatus, the main body device has an exterior cover that opens and closes the ejection port of the fixing device, and the pressure roll side housing when the exterior cover is closed and the ejection port is closed. And a second regulating member that fixes the pressure roll housing so that the closed opening is not opened.

  According to the present invention, it is possible to easily remove the paper jammed in the fixing unit, and it is possible to ensure safety when the fixing device is removed.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a configuration of an image forming apparatus 1 equipped with a fixing device 10. The image forming apparatus 1 includes a photosensitive drum 2a as a latent image carrier that rotates in the direction of an arrow, a charging roll 2b that uniformly charges the surface of the photosensitive drum 2a, and a surface of the charged photosensitive drum 2a. An exposure device 2c that forms an exposure image according to image information (an image read from an original in the case of a copier, an input image input from an external device in the case of a printer, etc.) and forms an electrostatic latent image; A developing device 2d that visualizes the electrostatic latent image formed on the surface of the drum 2a with a developer, and a recording paper P that is transported from the paper feed tray 3 by the transport roll 4 and supplied at a predetermined timing by the resist roll 5. A transfer roll 2e for transferring the toner image visualized by the developing device 2d, a fixing device 10 for fixing the toner image on the recording paper P by the transfer roll 2e, and the toner image for recording. To remove residual toner and the like remaining on the surface of the photosensitive drum 2a after being transferred to the P and a cleaning device 2f like cleaning. After fixing the unfixed toner image by the fixing device 10, the recording paper P is discharged from the conveying roll 6 on the downstream side of the conveying path of the fixing device 10 (above the fixing device 10 in FIG. 1) to the outside of the apparatus. Yes.

  As shown in FIG. 1, the fixing device 10 is a roll nip type fixing device including a heating roll 11 and a pressure roll 12 that rotate while being pressed against each other, and the heating roll 11 and the pressure roll 12 are placed in a housing. Contained. As shown in FIG. 2, the housing includes a heating roll side housing 13 (corresponding to the first casing of the present invention) 13 on the heating roll 11 side and a pressure roll side housing (second section of the present invention) on the pressure roll 12 side. 14) (corresponding to the housing). The pressure roll side housing 14 also has a function of a paper conveyance guide part that guides the paper that has passed through the nip part between the heating roll 11 and the pressure roll 12 in the discharge port direction.

  Further, as shown in FIG. 3, the pressure roll side housing 14 is rotatably attached to the heating roll side housing 13. By rotating the pressure roll side housing 14, The nip portion of the pressure roll 12 is exposed. Therefore, the paper jammed in the fixing device 10 can be removed. 4 and 5 show the entire image of the fixing device 10, FIG. 4 shows a state in which the pressure roll side housing 14 is closed, and FIG. 5 shows a state in which the pressure roll side housing 14 is opened.

  However, when the fixing device 10 is taken out from the image forming apparatus 1 by replacing the fixing device 10 or the like, it is preferable that the housing is locked so that the user does not accidentally touch the high temperature portion in the fixing device 10. Therefore, in this embodiment, as shown in FIG. 6, a fixing member 20 for fixing the pressure roll side housing 14 to the heating roll side housing 13 is provided at the longitudinal end portion of the fixing device 10. As shown in FIG. 7, the fixing member 20 includes a receiver 40 provided on the pressure roll side housing 14 and an engagement member 30 provided on the heating roll side housing 13 and engaged with the receiver 40. I have.

  When the fixing device 10 is outside the image forming apparatus, the engaging member 30 is engaged with the receiving member 40 and fixed so that the pressure roll side housing 14 does not rotate. FIG. 7 shows a state in which the engaging member 30 is engaged with the receiving tool 40.

When the fixing device 10 is attached to a predetermined position in the image forming apparatus 1, the position regulating member 50 provided in the image forming apparatus 1 comes into contact with the engaging member 30, and the engaging member 30 is engaged with the receiving tool 40. Move to a position where it cannot. FIG. 8 shows this state.
The engaging member 30 is attached to the heating roll side housing 13 so as to be able to rotate around the rotating shaft 31 shown in FIG. 7, and engages with the receiving member 40 in a state where there is no pressing force by the position restricting member 50. It is urged to take a position where it can be formed (the illustration of the spring, spring, etc. that urges the engaging member 30 is omitted). The position regulating member 50 is provided in the image forming apparatus main body, and when the fixing device 10 is moved from the mounting position of the image forming apparatus main body, the position regulating member 50 is separated from the fixing device 10.

  Further, the exterior cover 60 of the image forming apparatus 1 is provided with a regulating member 61 shown in FIG. When the exterior cover 60 is closed, the restricting member 61 contacts the pressure roll side housing 14 of the fixing device 10 and fixes the pressure roll side housing 14 so as not to open. Therefore, when the fixing device 10 is mounted in the image forming apparatus, the restricting member 61 presses the pressure roll side housing 14 to restrict the housing from being opened. Further, when the exterior cover of the image forming apparatus 1 is opened, there is no restriction by the fixing member 20 and the restriction member 61, so that the pressure roll side housing 14 can be opened. Further, when the fixing device 10 is moved from the mounting position in the image forming apparatus, the position restricting member 50 is not restricted to the engaging member 30, and the engaging member 30 is engaged with the receiving member 40. Therefore, when the fixing device 10 is taken out from the image forming apparatus 1, the housing can be locked, and the danger that the user accidentally touches the high temperature portion in the fixing device 10 can be prevented.

  The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

1 is a diagram illustrating a configuration of an image forming apparatus. It is a figure which shows the structure of a fixing device, and is a figure which shows the state which closed the pressure roll side housing. It is a figure which shows the structure of a fixing device, and is a figure which shows the state which opened the pressure roll side housing. FIG. 3 is a diagram illustrating an entire image of the fixing device, and a state in which a pressure roll side housing is closed. FIG. 2 is a diagram illustrating an entire image of a fixing device, and a diagram illustrating a state where a pressure roll side housing is opened. It is a figure which shows the attachment position of a fixing member. It is a figure which shows the structure of a fixing member, and is a figure which shows the state which the engaging member engaged with the receiver. It is a figure which shows the structure of a fixing member, and is a figure which shows the state from which engagement of the engaging member and the receiver was released. It is a figure which shows the position control member attached to the exterior cover.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2b Charging roll 2c Exposure apparatus 2d Developing apparatus 2e Transfer roll 2f Cleaning apparatus 3 Paper feed tray 4 Conveyance roll 5 Registration roll 10 Fixing apparatus 11 Heating roll 12 Pressure roll 13 Heating roll side housing 14 Pressure roll side housing 14 DESCRIPTION OF SYMBOLS 20 Fixing member 30 Engagement member 31 Rotating shaft 40 Receiving tool 50 Position control member 60 Exterior cover

Claims (2)

A heating roll and a pressure roll for fixing an image formed on a sheet to the sheet, a heating roll side housing provided as a housing on the heating roll side, and a pressure roll provided as a housing on the pressure roll side When the opening of the housing formed by the side housing, the heating roll side housing, and the pressure roll side housing is closed, the pressure roll side housing is connected to the heating roll side housing so that the opening is not opened. A fixing device having a receiving member provided on the pressure roll side housing and an engagement member provided on the heating roll side housing and engaged with the receiving member;
When the fixing device is disposed at a mounting position where the fixing device is mounted, the fixing device abuts a part of the engaging member so that the opening of the housing can be opened, and the engaging member A first restriction member that restricts the engagement member so as not to engage with a receiver, and a main body device to which the fixing device can be attached,
The engaging member engages with the receiver when the fixing device is detached from the main body device, and fixes the pressure roll side housing to the heating roll side housing so that the opening is not opened. An image forming apparatus. The main body device includes an exterior cover that opens and closes a take-out port of the fixing device, and the outer cover is closed, and when the take-out port is closed, the main body device contacts the pressure roll side housing and is closed. The image forming apparatus according to claim 1 , further comprising a second regulating member that fixes the pressure roll side housing so that the opening is not opened .

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