JP3408055B2 - Fixing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device that can be used in an electrophotographic device such as a printer or a copying machine.

[0002]

2. Description of the Related Art As a prior art related to the present invention, as described in Japanese Utility Model Publication No. 2-120454,
When a jam (paper jam) occurs in the device, the jam paper cutting device that unlocks the lock member of the unit and cuts the jammed paper by the cutter provided on the upstream side or the downstream side of the unit mounting location is known. Has been. Further, as described in Japanese Patent Application Laid-Open No. 62-10657, there is known a double-sided copying machine having a structure in which the fixing unit cannot be pulled out until the paper discharge unit is pulled out from the apparatus main body. Furthermore, JP-A-61-1
As described in Japanese Patent No. 251872, there is known a recording apparatus in which a fixing unit and a paper discharge unit are movable as a unit, and a sheet passing unit is opened when these units are moved as a unit.

As a conventional fixing device, there are provided various fixing devices, but a fixing device which heats and fixes a sheet is most commonly used. In such a system, the fixing roller and the pressure roller are rotated in pressure contact with each other to guide the sheet transferred between the both rollers, and the sheet is heated to a set temperature, and the heated sheet is separated by the separating claw. A configuration is adopted in which the rollers are separated from each other, guided between the paper discharge rollers, and conveyed to a predetermined position.
In the fixing device having such a configuration, the jamming process is performed by pulling out the fixing device unit from the main body of the apparatus so that the jammed paper can be easily removed when a jam occurs for some reason.

[0004]

However, when the paper is jammed across the fixing device section and the paper discharging apparatus section, the paper is fixed by pressing the fixing / pressing roller pair when the fixing device section is pulled out from the main body of the apparatus for jam processing. Since it is sandwiched and fixed between the paper ejection roller pair and the paper ejection roller pair, the paper is torn between the fixing device section and the ejection apparatus section and is torn, leaving pieces of paper in places that are difficult to remove inside the ejection apparatus section or fixing device. The parts adjacent to the sheet ejection unit and the sheet ejection unit may be damaged or deformed.

Further, when the pressure of the pair of discharge rollers is high, the fixing of the image is poor at the time of fixing the thick paper at a low temperature, and the image is rubbed by the discharge roller, and rubbing marks adhere to the paper. Or a trace of the roller may remain when the thin paper is conveyed by the discharge roller. On the other hand, when the pressure applied to the pair of paper discharge rollers is low, it may happen that curled and strong paper cannot be conveyed sufficiently due to insufficient conveyance force.

Further, when the fixing device section pulled out from the apparatus main body is returned to the apparatus main body after the jam processing, the sheet may not be fed due to a defective setting of the guide member, or may be damaged by the collision between the guide member and the fixing apparatus section. There is.

The inventions described in the above-mentioned respective publications can solve these problems to some extent, but are still not sufficient to solve the problems. The present invention has been made in view of the problems of the related art, and even if a jam occurs in the fixing device portion, the paper piece can be easily removed and the fixing device portion and the paper discharging device portion are damaged. An object of the present invention is to provide a fixing device that does not deform.

The present invention also solves the problem that the transfer paper has a roller mark and cannot be conveyed when the paper is strong, and when the fixing device is returned to the main body of the transfer paper, the paper is not fed. An object of the present invention is to provide a fixing device in which damage due to a collision between the guide member and the fixing device portion does not occur.

[0009]

In order to solve the above-mentioned problems, the present invention according to claim 1 is such that a fixing roller which is heated and rotates, a temperature detecting element which comes into contact with the surface of the fixing roller, and the fixing roller are brought into pressure contact with each other to rotate. A fixing device unit having a pressure roller and detachably attached to the apparatus main body, a discharge roller pair provided downstream of the fixing device unit for conveying the transfer paper in the discharge direction, and one of the discharge roller pair. In a fixing device having a paper discharge device section having a guide member rotatable about a fulcrum, the rotatable guide member is supported by the fixing device section and interlocked with an operation of pulling out the fixing device section from the apparatus main body. And a means for opening the guide member is provided.

In order to solve the above-mentioned problems, the invention according to claim 2 is characterized in that, in the fixing device according to claim 1, means for changing the supporting position of the guide member is provided.

In order to solve the above-mentioned problems, the invention according to claim 3 is the fixing device according to claim 1, wherein the fixing device portion is mounted on the main body of the device so that the open guide member is moved to a predetermined position. It is characterized in that means for moving is provided.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of the fixing device unit 3 and the paper discharge device unit 11. The fixing device unit 3 is
The fixing roller 4 that rotates while being heated by the built-in heater 6 and the temperature detecting element 8 that contacts the surface of the fixing roller 4.
And a pressure roller 5 that rotates while being pressed against the fixing roller 4 from below. The paper discharge device unit 11 is provided downstream of the fixing device unit 3, and has a paper discharge drive roller 14 that conveys the transfer paper in the discharge direction, a paper discharge driven roller 15 arranged below the discharge drive roller 14, and a pair of upper and lower rollers. Guide members 12, 13 arranged
The paper discharge driven roller 15 is pressed against the paper discharge drive roller 14 by the elastic force of the elastic member 18 attached to the guide member 13.

The sheet 1 after transfer, which has been conveyed from the right side of FIG. 1 by the transfer / conveyance device 2, is fed into the nip between the fixing roller 4 and the pressure roller 5 from the entrance of the fixing device section 3. The fixing roller 4 is a heater 6 in the fixing roller 4.
Is heated by. The temperature detecting element 8 is supported by the elastic member 7, detects the surface temperature of the fixing roller 4 while being pressed against the fixing roller 4 with a weak force, and the fixing roller 4 is controlled to the temperature required for fixing. When the sheet 1 passes through the nip, the image is fixed by being heated and pressed by the fixing roller 4 and the pressure roller 5. Paper 1 after image fixing
Is pressed against the peripheral surface of the fixing roller 4 or the pressure roller 5, so that the fixing roller 4 or the separating claw 10 whose tip is pressed against the peripheral surface of the fixing roller 4 or the pressure roller 5 is used. Separated from the pressure roller 5, the paper discharge device section 11
While being guided between the guide member 12 and the guide member 13, the sheet is driven by the sheet discharge driving roller 14 and the sheet discharge driven roller 15 to the discharge direction or to the sorter or the double-sided / reversing section which is the next processing section.

The guide member 13 of the paper discharge device section 11 is a fulcrum 16 located downstream of the paper discharge driven roller 15 in the conveying direction.
Can be rotated in the direction of arrow A (clockwise) around
When the fixing device unit 3 is mounted in the apparatus main body, the guide member 13 is supported at a predetermined position by mounting the tip of the guide member 13 on the support member 17 attached to the fixing device unit 3. .

The fixing device section 3 includes a fixing roller 4 from the main body of the device.
Also, the support member 17 can be pulled out in the axial direction of the pressure roller 5, and the size of the support member 17 in the pull-out direction of the fixing device 3 is limited. Escapes from the guide member 13, the guide member 13 is rotated about its fulcrum 16 in the direction of the arrow A by its own weight to open, and the elastic force of the elastic member 18 attached to the guide member 13 presses the discharge drive roller 14. The paper discharge driven roller 15 that is being discharged is also depressurized and separated from the paper discharge drive roller 14. As described above, the paper discharge device unit 11 includes the one roller 15 of the paper discharge roller pair 14 and 15 and has the guide member 13 rotatable about the fulcrum 16.

FIG. 2 is a perspective view showing a state in which the sheet 1 is sandwiched between the fixing device section 3 and the sheet discharging apparatus section 11. When the sheet 1 is jammed across the fixing device unit 3 and the sheet discharging device unit 11 as described above, if the fixing device unit 3 is pulled out from the main body of the device for jam processing, the sheet 1 is fixed by the conventional technique. And the sheet ejection device section 11 and are torn, and a piece of paper remains in a place where the sheet ejection apparatus section 11 is difficult to pick up, or the fixing device section 3 and components adjacent to the sheet ejection apparatus section 11 are damaged or deformed. Sometimes.

However, according to the above-described embodiment of the present invention, as shown in FIG. 3, since the guide member 13 is rotatable around the fulcrum 16 and is held by the support member 17, The guide member 13 rotates downward in association with the operation of pulling out the fixing device section 3 from the main body of the apparatus, and the paper transport path is opened. Therefore, the sheet 1 straddling the fixing device section 3 and the sheet discharging device section 11 can be pulled out of the apparatus main body while the sheet 1 is held in the fixing apparatus section 3, and the sheet exposed to the outside from the apparatus main body. 1 can be removed easily and without damaging or deforming the device.

Next, various modifications of the fixing device according to the present invention will be described. In the embodiment shown in FIGS. 4 to 6, the supporting member 17 is freely attached by selecting one of the holes of the plurality of mounting portions 20 to 22 formed in the fixing device portion 3 in the vertical direction. is there. In this way, by changing the support position of the guide member 13 up and down, the elastic member 18
The load applied to the sheet discharge roller changes, the contact pressure of the sheet discharge driven roller 15 with respect to the sheet discharge drive roller 14 can be changed, and the contact pressure can be adjusted appropriately.

In the embodiment shown in FIG. 5, the guide member 1 is obtained by mounting the support member 17 in the hole of the lowest mounting portion 20.
The supporting position of No. 3 is lowered, and the elastic amount of the elastic member 18 for contacting the paper ejection driven roller 15 with the paper ejection driving roller 14 is decreased to lower the contact pressure.

In the embodiment shown in FIG. 6, the guide member 1 is obtained by mounting the support member 17 in the hole of the uppermost mounting portion 22.
3, the supporting position of 3 is increased, the load of the elastic member 18 is increased, the contact pressure is increased, and the conveying force by the paper discharge drive roller 14 and the paper discharge driven roller 15 is increased.

In the embodiment shown in FIG. 7, the fixing device 3 has a supporting member 31 with an inclined surface and a plate-like guide member 30 following the supporting member 31, and the fixing device 3 has an arrow mark. As shown by B, it is provided so as to be parallel to the paper surface and movable in the horizontal direction. In the fixing device section 3 pulled out from the apparatus main body, after the leading end of the guide member 13 drops from the support member 31 and opens in the direction of arrow A in FIG.
The guide member 13 is guided by the guide member 30. When the fixing device section 3 is mounted on the main body of the apparatus, the guide member 30 guides the guide member 13 to the inclined support member 31.
Is guided, and the guide member 13 is scooped up by the inclination of the support member 31 and set to a predetermined position.

[0022]

According to the first aspect of the present invention, since the rotatable guide member is supported by the fixing device portion and the guide member is opened in association with the operation of pulling out the fixing device portion from the apparatus main body, The jammed paper that straddles the fixing device section and the paper discharge device section can be easily taken out of the apparatus main body without breaking it, and the parts inside the apparatus are not damaged.

According to the second aspect of the present invention, since the means for changing the supporting position of the rotatable guide member is provided, it is possible to change the pressing force of the pair of discharge rollers in the discharge device section. It is possible to prevent rubbing traces and roller traces of the image on the paper due to the paper discharge rollers, and also prevent non-feeding due to insufficient conveyance force.

According to the third aspect of the present invention, since the fixing device section is mounted on the main body of the apparatus, it is provided with means for moving the open guide member to a predetermined position.
After finishing the processing of the fixing device section pulled out from the apparatus main body for the jam clearance, when the fixing device section is mounted on the main body of the apparatus with the guide member opened, the paper may not be fed due to a defective setting of the guide member. It is possible to prevent damage due to a collision between the guide member and the fixing device section.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a fixing device according to the present invention.

FIG. 2 is a perspective view showing an example of a state in which a sheet is sandwiched between a fixing device section and a sheet discharging apparatus section in the embodiment.

FIG. 3 illustrates an example of a state in which the fixing device unit is pulled out of the main body of the apparatus while holding a sheet in the above embodiment.

FIG. 4 is a side view showing another embodiment of the fixing device according to the present invention.

FIG. 5 is a side view showing an example in which the support position of the guide member is changed in the same embodiment.

FIG. 6 is a side view showing an example in which the support position of the guide member is further changed in the same embodiment.

FIG. 7 is a side view showing still another embodiment of the fixing device according to the present invention.

[Explanation of symbols]

3 Fixing device section 4 fixing roller 5 pressure roller 8 temperature measuring element 11 Paper ejection device section 13 Guide member 14 Paper ejection drive roller 15 Paper ejection driven roller 16 fulcrums

Claims (3)

(57) [Claims] 1. A fixing device unit, which has a fixing roller which is heated and rotates, a temperature detecting element which comes into contact with the surface of the fixing roller, and a pressure roller which comes into pressure contact with the fixing roller to rotate and which is detachable from an apparatus main body, A discharge roller pair provided downstream of the fixing device section for conveying the transfer sheet in the discharge direction; and a discharge device section having a guide member including one of the discharge roller pair and rotatable about a fulcrum. In the fixing device having the fixing device, the rotatable guide member is supported by the fixing device portion, and means for opening the guide member is provided in association with the operation of pulling out the fixing device portion from the apparatus main body. 2. The fixing device according to claim 1, further comprising means for changing a supporting position of the guide member. 3. The fixing device according to claim 1, further comprising means for moving the open guide member to a predetermined position by mounting the fixing device portion on the main body of the device.