JP2564748Y2 - Fixing unit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a fixing unit of an electrophotographic recording apparatus. Recently, with the expansion of office automation (OA), an output device that can use plain paper and has high print quality has been used.

For this reason, copiers and facsimile apparatuses using an electrophotographic recording method have been realized. In these apparatuses, cleaning of the fixing roller is also important in order to fix the toner image transferred to the sheet with high quality.

[0003]

2. Description of the Related Art As shown in a schematic view of FIG. 3, an electrophotographic recording apparatus to which the present invention is applied is a photosensitive drum 1 which is an image carrier having a photosensitive layer whose conductivity changes in response to light.
A developing device 2 for adhering toner to the surface of the photosensitive drum 1 with a potential difference from the surface of the photosensitive drum 1; a charging device 3 for uniformly charging the surface of the photosensitive drum 1; An optical system 4 for forming an electrostatic latent image by changing the charge amount, a transfer unit 6 for transferring a toner image on the photosensitive drum 1 to a sheet 5, and a halogen lamp for heating and fixing the toner image transferred to the sheet 5 And the like.

The fixing unit 7 is a conventional fixing unit shown in FIG.
As shown in the side view of the heat roller 8 and another example of the conventional fixing unit in FIG.
The heat roller 8 and the pressure roller 9 can be separated from each other due to maintenance requirements.

That is, the heat roller 8 is fixed to the fixed frame 10.
The pressure roller 9 is rotatably mounted on a rotation frame 11, and the rotation frame 11 is rotatable about a fulcrum 12 in the direction of arrow A.

When the toner remains on the heat roller 8, the toner adheres and is fixed on a succeeding sheet to deteriorate the recording quality. To prevent this, a cleaning member 13 such as a felt is pressed against the heat roller 8.

[0007] The cleaning member 13 is pivotally opened as shown in FIG.
As shown in the released state , the fixed frame 10 is supported by a support portion 10a via a holding member 13a. Therefore, when the cleaning member 13 is to be replaced, the cleaning member 13 is pulled out with the holding portion 13b protruding from the holding member 13a.

[0008] Alternatively, the cleaning member 13, in FIG. 5 times
A holding member 13a for holding the cleaning member 13 is supported by a paper guide member 14 fixed to the rotating frame 10 as shown in the dynamic open state .

The paper 5 onto which the toner image on the photosensitive drum 1 has been transferred by the transfer unit 6 shown in FIG. 3 is pressed by a pressure roller 9 and pressed against a heat roller 8, and is heated by the heat roller 8 to form a toner. The image is fixed on the sheet 5.

[0010]

As described above, the cleaning member opens the rotating frame and performs maintenance such as removal and replacement. However, in the case of FIG. 5, there is a danger of being burned by touching the high-temperature heat roller. is there.

[0011] Also, there is no fear of burns in the case of FIG. 5, the cleaning member rotates the rotating frame when pressed against the heat roller, the wrinkles on the cleaning member as shown in enlarged view of FIG. 6 As a result, there is a problem that the adhesion becomes poor with a gap G between the heat roller and the heat roller, and the cleaning effect is not sufficient.

An object of the present invention is to secure safety when replacing a cleaning member and to improve adhesion.

[0013]

In the present invention, FIG.
As shown in the side view of a fixed frame 10 which supports the heat roller 8, the sheet 5 and support the pressure roller 9 which Ru is pressed against the heat roller 8 and against the tips of the heat roller 8
Fix the paper guide member 14 that guides the discharged paper to discharge.
Te, the pivoting frame 11 to the fixed frame 10 that is mounted rotatably, can floating on the paper guide member 14 in the axial direction perpendicular
And it is detachably supported, when the pressure roller 9 Ru is pressure contact with the heat roller 8 by rotating the pivoting frame 11, a cleaning member for cleaning the surface in pressure contact with the heat roller 8
15 is a fixing device .

[0014] Then, when Ru is pressure against the cleaning member 15 rotates the rotating frame 11 to the heat roller 8, the pressing member for pressing the guide and allowed and in close contact with the predetermined position of the cleaning member 15 to the heat roller 8 16 above, with
It is a wearing device .

[0015]

The cleaning member 15 is supported by the paper guide member 14 so as to be freely movable in the direction perpendicular to the axial length. Therefore, when the rotating frame 11 is rotated Ru is brought into contact with the cleaning member 15 to the heat roller 8, the cleaning member 15 is subjected to radial and sliding direction of the force to the surface of the heat roller 8,
This is resolved by the movement of the movement and the inclination ,
Move to the specified position, contact the entire surface, press
Contact pressure direction. Therefore, the cleaning member 15 is not subjected to the force in the sliding direction by the heat roller 8 and no wrinkles are generated.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, as shown in the side view of FIG. 1, a stationary frame 10 for supporting a heat roller 8 and a rotating frame for supporting a pressure roller 9 for pressing the paper 5 against the heat roller 8. The moving frame 11 and the paper guide member 14 of the rotating frame 11 are supported movably in a direction perpendicular to the axial length.
And a cleaning member 15 which is pressed by the surface of the heat roller 8 when it is rotated to come into contact with the heat roller 8, moves and inclines, automatically aligns and comes into close contact with each other.

Accordingly, no force is applied to the cleaning member 15 in the sliding direction by the heat roller 8, and no wrinkles are generated. When the rotating frame 11 is rotated to bring the cleaning member 15 into contact with the heat roller 8, the cleaning member 15 is guided to a predetermined position on the heat roller 8, and the cleaning member 15 is pressed against the heat roller 8. This is provided with a leaf spring-shaped pressing member 16.

The means for supporting the cleaning member 15 on the paper guide member 14 so as to be freely movable in the direction perpendicular to the axial length is a holding member 15 for holding the cleaning member 15 as shown in the plan view of FIG.
The two L-shaped tongues 14a and 14b projecting from the paper guide member 14 are loosely fitted and held in the two U-shaped projections 15b and 15c projecting from the sheet guide member 14.

That is, the U-shaped projections 15b and 15c are fitted with a sufficient gap in the height direction to the L-shaped tongues 14a and 14b. One of the L-shaped tongues 14a and 14b, for example, 14a has a hook-shaped tip and a U-shaped projection 15a.
Once inserted into b, removal becomes difficult.
However, if the hook at the tip is budded with a finger, it can be easily pulled out
Succoth can, Ru can be removed.

Accordingly, the cleaning member 15 is securely held by the paper guide member 14.

[0021]

According to the present invention, the cleaning member can be replaced safely by the operator,
It has a great economic and industrial effect, such as being able to properly contact the heat roller to improve the cleaning performance.

[Brief description of the drawings]

Figure 1 is a side view of a fixing unit of the present invention, (a) rotating
Open state (b) Rotation closed state

FIG. 2 is a plan view showing a loose fitting structure of a cleaning member of the fixing unit according to the present invention;

FIG. 3 is a schematic diagram of an electrophotographic recording apparatus to which the present invention is applied;

FIG. 4 is a side view of a conventional fixing unit ;
Release state (b) Rotation closed state

FIG. 5 is a side view of another example of a conventional fixing unit.
(A) Rotation open state (b) Rotation closed state

FIG. 6 is an enlarged view of a main part when wrinkles are generated in the cleaning member .

[Description of Signs] 1 photosensitive drum, 2 developing device, 3 charging device, 4 optical system, 5 paper, 6 transfer device, 7 fixing unit, 8 heat roller, 9 pressure roller, 10 fixing frame, 10a support portion, 11 Rotating frame, 12 fulcrum, 13,15 cleaning member, 13a, 15a holding member, 13b gripper, 14 paper guide member, 14a, b L-shaped tongue, 15b, c U-shaped projection, 16 pressing member,

Claims (2)

(57) [Scope of request for utility model registration] A fixing frame for supporting the heat roller, wherein the fixing unit heat-fixes the sheet on which the toner image on the image carrier is transferred by pressing the sheet against a heat roller; wherein said sheet supporting the pressure roller Ru is pressed against (9) to the heat roller (8), and tip contact with the heat roller (8)
The paper guide member (14) that guides the discharged paper
Constant to, the the fixed frame (10) to rotatably attached that pivoting frame (11), movably and in the axial direction perpendicular to the front Symbol for paper guiding member (14)
Is detachably supported, the pressure roller (9) when Ru is pressure contact with the rotating frame (11) Te <br/> rotates the heat roller (8), pressed against the heat roller (8) And a cleaning member (15) for cleaning the surface . Wherein said pivoting frame (11) is rotated by the cleaning member (15) when Ru is pressure contact with the heat roller (8), wherein the cleaning member (15) said heat roller (8)
Pressing members (1 to cause the guided to and adhered to a predetermined position by pressing
The fixing unit according to claim 1, further comprising ( 6).