JP3854935B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus that forms an image by an electrophotographic method, such as a copying machine, a facsimile machine, and a printer.
[0002]
[Prior art]
2. Description of the Related Art Image forming apparatuses that form an image by an electrophotographic method are widely used. In such an image forming apparatus, a toner image is formed on a photosensitive member, and the formed toner is transferred to a sheet. The toner image on the paper is then thermally fixed and discharged.
Such an electrophotographic image forming apparatus includes a conveyance unit for conveying a sheet on which an image is transferred (formed), a fixing unit for fixing a sheet conveyed from the conveyance unit, and a fixing unit. A discharge unit for discharging the conveyed paper.
[0003]
These transport unit, fixing unit, and discharge unit are each fixed to the image forming apparatus main body with screws or the like. The transport unit and the discharge unit can be opened and closed so that the paper can be taken out when the paper is jammed.
[0004]
[Patent Document 1]
JP-A-9-325543
[Problems to be solved by the invention]
The transport unit and the discharge unit have the following inconveniences unless the mutual positional relationship with the fixing unit is accurately determined.
If the mutual positional relationship between the conveyance unit and the fixing unit is not accurate, the sheet conveyed from the conveyance unit is not conveyed to the position of the fixing roller of the fixing unit, and the image before fixing moves on the sheet and the image is distorted. May occur, wrinkles may occur depending on the paper, and the paper may skew.
[0006]
In addition, if the mutual positional relationship between the fixing unit and the discharge unit is not accurate, the paper conveyed from the fixing unit is not conveyed to the position of the discharge roller of the discharge unit, and the paper is wrinkled or the paper is skewed. May occur.
Therefore, it is necessary to correctly position the transport unit and the fixing unit relative to each other or to position the fixing unit and the discharge unit correctly.
However, as described above, considering that the transport unit and discharge unit have an open / close structure, direct positioning between the transport unit and the fixing unit and direct positioning between the fixing unit and the discharge unit are difficult. It was.
[0007]
For example, in Japanese Patent Laid-Open No. 9-325543, a hook is attached to a transport unit (referred to as a “transfer unit” in this publication), and the hook can be hooked on a pin passed through a side plate of the image forming apparatus main body. A structure in which a contact member having a groove is fixed to the fixing unit and the groove is brought into contact with the pin is disclosed. In the disclosure of this publication, since the pin that mediates the positioning of the transport unit and the fixing unit is attached to the side plate of the image forming apparatus main body, it can be said that the transport unit and the fixing unit are directly positioned. Absent.
[0008]
SUMMARY An advantage of some aspects of the invention is that it realizes an image forming apparatus having a structure capable of directly positioning a conveyance unit and a fixing unit.
Another object of the present invention is to realize an image forming apparatus having a structure capable of directly positioning a fixing unit and a discharge unit.
[0009]
[Means for Solving the Problems and Effects of the Invention]
The image forming apparatus according to claim 1, wherein the upper portion of the frame provided in the image forming apparatus main body, and on both sides of the conveying path on which the image has sheet formed is conveyed, at least in the vertical direction for supporting the optical unit Each of the two support columns is provided, and a transport unit that transports the sheet on which the image is formed is configured to be openable and closable around a rotation shaft attached to the frame. the fixing unit that fixes the sheet conveyed in the upward direction, and fixed between the front SL two posts, with the closed front Symbol conveying unit, mutually the transport unit and the fixing unit a first engaging portion and second engaging portion for positioning is provided, wherein the first engaging portion is attached to the transport unit, said second engaging portion is attached to said fixing unit It is characterized in.
[0010]
According to this configuration, the conveyance unit and the fixing unit can be directly positioned relative to each other with the conveyance unit closed by the engagement of the first engagement portion and the second engagement portion attached to each unit. it can.
This configuration is particularly effective when the frame of the main body of the image forming apparatus is made of resin (claim 2).
The first engaging portion includes an engaging claw that engages with the second engaging portion, a handle portion that moves integrally with the engaging claw, and an elastic member that biases the engaging claw in a direction in which the engaging claw is engaged. (Claim 3).
[0011]
According to this configuration, the engaging claw is held in the engaged state that is biased and positioned by the elastic member in a state where the transport unit is closed. When the handle portion is operated, the engagement of the engaging claws is released and the transport unit is opened.
The image forming apparatus according to claim 4, wherein two vertical columns supporting the optical unit are respectively provided on both sides of a conveyance path through which a sheet on which an image is formed is conveyed of the image forming apparatus main body. from the conveying unit for conveying the sheet on which the image is formed, a fixing unit for fixing the sheet conveyed in the upward direction, and fixed between the front SL two posts, it is conveyed from the fixing unit provided with a discharge unit for discharging the sheet on top of the fixing unit, in a state where the around the pivot shaft that is mounted in the main housing of the image forming apparatus openably and configure, and closing the discharge unit, wherein a third engagement portion and the fourth engagement portion for positioning the discharge unit and the fixing unit to each other is provided, said third engaging portion is attached to the discharge unit, wherein the fourth engagement It is characterized in that mounted on the fixing unit.
[0012]
According to this configuration, the discharge unit and the fixing unit can be directly positioned to each other with the discharge unit closed by the engagement of the first engagement portion and the second engagement portion attached to each unit. it can.
The third engaging portion includes an engaging claw that engages with the fourth engaging portion, a handle portion that moves integrally with the engaging claw, and an elastic member that biases the engaging claw in a direction in which the engaging claw is engaged. (Claim 5).
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings by taking a copying machine as an example of an image forming apparatus.
FIG. 1 is a perspective view showing an external configuration of the copying machine 1. The copying machine 1 is divided into a main body housing 10 having an image forming unit, a paper tray, and the like, and an optical unit 11 supported by a column 16 of the main body housing 10.
[0014]
The optical unit 11 incorporates a reading mechanism for reading a document, and an operation panel (not shown) is provided on the upper surface thereof.
The main body housing 10 includes an upper housing 12 and a lower housing 13.
The lower housing 13 incorporates various paper trays and a transport path for taking out and transporting paper from the paper tray.
[0015]
The upper housing 12 includes an image forming unit for forming a toner image, a transport unit for transferring the formed toner image and transporting the paper, a fixing unit for fixing the transferred paper, and a post-fixing unit. A discharge unit for discharging paper is built in.
A sheet receiving tray 14 for receiving and stacking sheets discharged from the discharge unit is provided in the middle of the upper housing 12 in the vertical direction.
[0016]
2 is a rear view of the copying machine 1 as viewed from the direction of arrow A in FIG. 1, and FIG.
The fixing unit 33 having the heating roller 52 is fixed to the support column 16 of the upper housing 12, and the discharge unit 31 is opened above the optical unit 11 and centered on the support shaft 32 passed through the upper housing 12. It is provided so that it can be opened and closed so that the jammed paper can be removed.
[0017]
Below the fixing unit 33, a transport unit 34 for feeding the paper transferred by the transfer roller 54 to the fixing unit 33 is jammed in an open state around a support shaft 35 passed through the resin frame 16 a of the upper housing 12. It is provided so that it can be opened and closed so that the paper can be removed.
As described above, the support column 16 that supports the fixing unit 33 and the discharge unit 31 is a sheet metal, and the resin frame 16a that supports the transport unit 34 is made of a synthetic resin. When a synthetic resin frame is used, positioning of the transport unit 34 and the like tends to be out of order due to insufficient strength of the resin. Therefore, the transport unit 34 to be engaged with the fixing unit 33 and the fixing unit 33 are accurately positioned. There is a risk of not. According to the present invention, this problem is solved by providing third and fourth engaging portions (described below) for positioning between the transport unit 34 and the fixing unit 33.
[0018]
A support shaft 43 is rotatably provided in the discharge unit 31 through holes of ribs (not shown) formed integrally with the outer wall of the discharge unit 31, and the fixing unit 33 is located near both ends of the support shaft 43. A hook 42 (corresponding to the third engaging portion) that engages with the fixed pin 41 (corresponding to the fourth engaging portion) is attached so as to rotate integrally with the support shaft 43. Further, a handle portion 44 that is touched when the discharge unit 31 is opened is attached to the center portion of the support shaft 43 so as to rotate integrally with the support shaft 43. Reference numeral 51 denotes a discharge roller for feeding paper to the paper receiving tray 14.
[0019]
A support shaft 37 is also rotatably provided in the transport unit 34 through a hole in a rib (not shown) formed integrally with the outer wall of the transport unit 34, and the fixing unit 33 is located near both ends of the support shaft 37. A hook 36 (corresponding to the first engaging portion) that engages with the fixed pin 38 (corresponding to the second engaging portion) is provided so as to rotate integrally with the support shaft 37. A handle portion 39 that is touched when the transport unit 34 is opened is attached to the center portion of the support shaft 37 so as to rotate integrally with the support shaft 37. Reference numeral 54 denotes a transfer roller provided to face the photosensitive drum 53.
[0020]
FIG. 4 is a perspective view showing the hook 36 and the handle portion 39 attached to the support shaft 37 of the transport unit 34.
A spiral spring 60 for biasing the hook 36 in the direction T of the pin 38 is provided. At the tip of the hook 36, an inclined portion 36 b is formed which hits a pin 38 fixed to the fixing unit when the transport unit 34 is closed. When the inclined portion 36 b overcomes the force of the spiral spring 60 and passes over the pin 38. An engaging portion 36 a that engages with the pin 38 is formed. The handle portion 39 is for releasing the engagement of the hook 36. When the handle portion 39 is pulled in the direction of the arrow U, the engagement of the hook 36 is released.
[0021]
Note that the structures of the hook 42 and the handle portion 44 of the discharge unit 31 are basically the same as the structures of the hook 36 and the handle portion 39 of the transport unit 34, and thus the description thereof is omitted.
FIG. 5 is a rear view of the copying machine 1 in a state in which the discharge unit 31 and the transport unit 34 are opened, and FIG. 6 is a side view of the main part.
Pins 41 for engaging with the hooks 42 are projected in a horizontal direction and fixed at predetermined positions near both ends of the upper portion of the fixing unit 33, and hooks 36 are fixed at predetermined positions near both ends of the lower portion of the fixing unit 33. A pin 38 for engagement is projected and fixed in the horizontal direction.
[0022]
With reference to FIG.5 and FIG.6, the opening / closing operation | movement of the discharge unit 31 and the conveyance unit 34 is demonstrated.
When closing the discharge unit 31 and the transport unit 34, when the discharge unit 31 and the transport unit 34 are tilted in the directions of arrows V and W, respectively, the hook 42 of the discharge unit 31 engages with the pin 41 of the fixing unit 33, and the transport is performed. The hook 36 of the unit 34 engages with the pin 38 of the fixing unit 33, and the discharge unit 31 and the transport unit 34 can be closed.
[0023]
When the discharge unit 31 is closed, the hook 42 of the discharge unit 31 is engaged with the pin 41 of the fixing unit 33, so that the distance between the hook 42 and the pin 41 is fixed, and the discharge unit 31 and the fixing unit 33 are fixed. The distance to is fixed. That is, the positional relationship between the discharge unit 31 and the fixing unit 33 is determined.
Even when the transport unit 34 is closed, the hook 36 of the transport unit 34 engages with the pin 38 of the fixing unit 33, the distance between the hook 36 and the pin 38 is fixed, and the distance between the transport unit 34 and the fixing unit 33 is increased. Fixed. That is, the positional relationship between the transport unit 34 and the fixing unit 33 is determined.
[0024]
When opening the discharge unit 31, if a hand is put in the opening 40 of the discharge unit 31 and the handle 44 is pushed up, the hook 42 is disengaged and the discharge unit 31 is rotated upward and discharged. Unit 31 can be opened.
When opening the transport unit 34, if a hand is put into the opening 30 of the transport unit 34 and the handle 39 is pushed down, the hook 36 is disengaged and the transport unit 34 is rotated downward to transport the transport unit 34. Unit 34 can be opened.
[0025]
Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to those described above, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, the configuration of the engaging portion is such that the conveyance unit 34 or the discharge unit 31 is provided with a hook, and the fixing unit 33 is provided with a pin. The discharge unit 31 may be provided with a pin, and the fixing unit 33 may be provided with a hook. Further, although two engaging portions are attached near both ends of the transport unit 34 and the discharge unit 31, only one engaging portion may be attached to one end.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external configuration of a copying machine.
FIG. 2 is a rear view of the copying machine 1 as viewed from the direction of arrow A in FIG.
FIG. 3 is a side view of the main part of the copying machine 1 as seen from the side with one of the columns 16 removed.
4 is a perspective view showing structures of a hook 36 and a handle 39 attached to a support shaft 37 of the transport unit 34. FIG.
FIG. 5 is a rear view of the copying machine 1 in a state in which the discharge unit 31 and the transport unit 34 are opened.
FIG. 6 is a side view of a main part of the copying machine 1 in a state where the discharge unit 31 and the transport unit 34 are opened.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Copier 10 Main body housing 11 Optical unit 12 Upper housing 13 Lower housing 14 Paper receiving tray 16 Post 16a Frame 31 Discharge unit 32 Support shaft 33 Fixing unit 34 Conveyance unit 36 Hook 37 Support shaft 38 Pin 39 Handle part 41 Pin 42 Hook 43 Spindle 44 Handle part

Claims (5)

An image forming apparatus having a structure in which an optical unit is placed on a main body of an image forming apparatus,
Provided upper portion of the frame provided in the image forming apparatus main body, and on both sides of the conveying path on which the image has sheet formed is conveyed, the two columns in the vertical direction for supporting the optical unit, respectively,
A transport unit for transporting a sheet on which an image is formed is configured to be openable and closable around a rotation shaft mounted on the frame.
On top of the transport unit, from the transport unit, a fixing unit for fixing the sheet conveyed in the upward direction, and fixed between the front SL two posts,
Wherein in the closed state of the transport unit is provided with a first engagement portion and a second engagement portion for positioning the transport unit and the fixing unit to each other,
It said first engaging portion is attached to the transport unit,
It said second engagement portion, the image forming apparatus characterized by being attached to the fixing unit.   The image forming apparatus according to claim 1, wherein a frame of the main body of the image forming apparatus is made of resin.   The first engaging portion includes an engaging claw that engages with the second engaging portion, a handle portion that moves integrally with the engaging claw, and an elastic member that biases the engaging claw in a direction in which the engaging claw is engaged. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. An image forming apparatus having a structure in which an optical unit is placed on a main body of an image forming apparatus,
Provided in the image forming apparatus main body, on both sides of the conveying path on which the image has sheet formed is conveyed, the two columns in the vertical direction for supporting the optical unit, respectively,
From the conveying unit for conveying the sheet on which the image is formed, a fixing unit for fixing the sheet conveyed in the upward direction, and fixed between the front SL two posts,
Wherein the discharge unit for discharging the sheet conveyed from the fixing unit is provided on the upper portion of the fixing unit, and open structured around a rotation shaft which is mounted in the main housing of the image forming apparatus,
Wherein in the closed state of the discharge unit, providing the third engaging portion and the fourth engagement portion for positioning the discharge unit and the fixing unit to each other,
The third engaging portion is attached to the discharge unit,
The fourth engagement portion, an image forming apparatus, characterized in that attached to the fixing unit.   The third engaging portion includes an engaging claw that engages with the fourth engaging portion, a handle portion that moves integrally with the engaging claw, and an elastic member that biases the engaging claw in a direction in which the engaging claw is engaged. The image forming apparatus according to claim 4.

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