JPH05134580A - Cooling structure for transfer material detecting means for fixing device - Google Patents

Abstract

PURPOSE:To reduce cost with simple structure by providing an outside air intake on the periphery of a part where a sensor is disposed, and a discharge port on the rear side, on a cover on which the sensor is disposed, and connecting a discharge fan and the discharge port with a hose. CONSTITUTION:The discharge fan 11 is attached to a rear side plate 12 via a duct for attaching a fan 10, outside the rear side plate 12. The outside air intake 7 is provided on the periphery of the part where the sensor 4 is disposed, on the cover 3, and the discharge port 8 is provided on the side surface of the side where the discharge fan 11 is attached. An elastic hose 9, as a ventilation means, is engaged with the duct 10, and the other end of the hose 9 is press-contacted to the tailing edge of the cover 3 and connected to the discharge port 8. The inside of the cover 3 can be efficiently ventilated through the hose 9, and the outside air flowing into the covet 3, mostly flows in from the outside air intake 7, so that the sensor 4 can be efficiently cooled. Therefore, it is unnecessary that an exclusive cooling fan for a transfer material detecting means is provided, and structure is made simple, and the cost is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a sensor unit mounted on a fixing device such as a copying machine.

[0002]

2. Description of the Related Art Conventionally, a fixing device is provided with electric parts such as a sensor for detecting a transfer material. However, since the temperature of the fixing device is high due to the heat of a heating means, the temperature of the sensor is kept below a heat resistant temperature. Therefore, a dedicated small cooling fan has been mounted in the vicinity of the mounting site of the above-mentioned sensor and the like. Further, a method has been performed in which a lever or the like of a transfer material detecting sensor is arranged at a portion where the temperature is not high via a link and the sensor is attached to the portion.

[0003]

However, according to the above-mentioned conventional example, there is a problem that the structure is complicated and the cost is increased because the small cooling fan is exclusively mounted.
Further, even in the method of disposing the lever of the sensor away from the detection portion, it is necessary to provide a plurality of intervening portions of the link, which also has a problem that the structure is complicated and the cost is high.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a cooling structure for a sensor for a fixing device which has a simple structure and can reduce the cost.

[0005]

According to the present invention, the above object is a cooling structure of a transfer material detecting means for a fixing device, wherein the fixing device is in the form of a roller or a film having a heating means therein. The casing includes a fixing unit, a pressure unit arranged to be in pressure contact with the fixing unit, and a release agent applying unit for applying a release agent to at least one surface of the fixing unit and the pressure unit. The transfer material detection means is disposed inside the body and has a discharge fan for discharging the release agent evaporated in the housing to the outside of the housing. The transfer material detection means is nipped and conveyed by the fixing means and the pressure means. In the cooling structure of the transfer material detecting means for the fixing device, which cools the transfer material detecting means when the means for detecting the presence or absence of the transfer material is disposed inside the housing outside the housing, the transfer material detecting means Transfer the above to the container of the means A first opening formed on a side surface around the arrangement portion of the detection means, and a second opening formed on the side surface or another side surface at a predetermined distance from the first opening portion. The second opening is achieved by being connected to the exhaust fan by a ventilation means so that the outside air flowing from the first opening can be exhausted through the second opening.

[0006]

According to the present invention, when the fixing device starts to operate, the heating of the fixing means is started, the temperature inside the housing reaches a predetermined high temperature, and the release agent applied to the fixing means or the pressurizing means is heated. It evaporates and fills the housing. However, the evaporated release agent is discharged to the outside of the casing by the discharge fan, and prevents the release agent from adhering to the photoconductor or the like in the image forming apparatus. on the other hand,
Although the temperature inside the container of the transfer material detecting means gradually rises due to the heating, a first opening is formed on the side surface of the container around the area where the transfer material detecting means is arranged. A second opening is formed on the side surface that is a predetermined distance away from the opening,
The second opening is connected to the exhaust fan via a ventilation means, so that the outside air flowing in from the first opening passes through the inside of the container and cools the inside of the container to open the second opening. And is further discharged from the discharge fan through the ventilation means. As a result, the temperature inside the container becomes a predetermined low temperature, and the transfer material detecting means is protected from the high temperature.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment and a second embodiment of the present invention will be described with reference to the drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a fixing device of this embodiment used in an electrophotographic copying machine. In FIG. 1, reference numeral 1 denotes a fixing device. Inside the fixing device 1, a fixing roller 6 as a fixing means having a heater (not shown) as a heating means and a pressure roller 12 as a pressure means are provided. Has been done. An entrance guide 13 is disposed in front of the fixing roller 6 and the pressure roller 12, and a transfer material on which a toner image is formed by a known electrophotographic process is fixed along the upper surface of the entrance guide 13. 6 and the nip of the pressure roller 12 are guided. As a result, the unfixed developer image on the transfer material passing through the nip is fixed by the fixing roller 6 and the pressure roller 12.
It is heated and pressurized to be fixed on the transfer material.

A transport path 14 is provided in front of the nip in the transport direction of the transfer material.
A transfer material detecting lever 5 is disposed at the front end of the sheet conveying direction 4 of the sheet. Therefore, the transfer material fixed as described above passes through the transfer material detecting lever 5 on the transport path 14 while swinging, and is discharged onto an external tray (not shown).

Further, a sensor 4, which is a transfer material detecting means, is mounted above the transfer material detecting lever 5, and the timing of the transfer material is sent as a signal to a controller on the main body side to detect an abnormality such as a paper jam. It is supposed to do. The sensor 4 and its supporting plate are attached to the stay 2. The stay 2 serves as a container so that the high temperature portion is not touched by the hand when the fixing device 1 is pulled out to the front side of the main body due to paper jam processing or the like. Covered with cover 3. The cover 3 is partially cut out so that the transfer material detecting lever 5 can swing.

A web 15 is provided above the fixing roller 6 as a releasing agent applying means for applying a releasing agent such as oil to the surface of the fixing roller 6, and the fixing roller 6 is provided. Prevents adhesion of toner, etc. to the surface. However, the release agent may evaporate due to the heat of the fixing roller 6 and stain the photoreceptor (not shown) and the like. Therefore, in the apparatus of this embodiment, as shown in FIG. 2, an exhaust fan 11 is provided outside the casing of the fixing device to exhaust the oil mist to the outside of the apparatus.

The fixing roller 6 of the apparatus of this embodiment as described above
As described above, a heater (not shown) is incorporated in the inside of the sheet, so that the surface temperature of the fixing roller 6 can be maintained at a high temperature and the fixing of the transfer material can be stably performed. Therefore, the internal temperature of the stay 2 and the cover 3 arranged near the fixing roller 6 also rises, and the temperature of the sensor 4 may exceed the heat resistant temperature.

Therefore, the apparatus of this embodiment is provided with the following cooling mechanism for the sensor. FIG. 2 is a view of the vicinity of the portion where the sensor 4 of FIG. In FIG. 2, reference numeral 12 denotes a rear side plate that supports the rear side of the main body, and the above-described exhaust fan 11 is attached to the rear side plate 12 outside the rear side plate 12 via a fan mounting duct 10. Further, the cover 3 is provided with an outside air intake 7 which is a first opening around the arrangement portion of the sensor 4, and a discharge opening which is a second opening is provided on the side surface on the side where the discharge fan 11 is attached. 8 are provided. And the duct 1
An expandable hose 9 is engaged with 0 as a ventilation means, and the other end of the hose 9 is arranged so as to be slightly pressed against the rear end of the cover 3 and connected to the discharge port 8.

With the above structure, the inside of the cover 3 can be efficiently ventilated through the hose 9, and most of the outside air flowing into the cover 3 flows from the outside air intake 7. Therefore, the outside air intake 7
The sensor 4 in the vicinity of can be cooled efficiently.

Therefore, it is not necessary to mount a cooling fan dedicated to the sensor 4 on the cover 3, and it is not necessary to mount the sensor 4 at a position away from the conveying path 14, so that the transfer material detecting lever 5 is simple. It can be a structure.

FIG. 3 shows the fixing device 1 pulled out to the front side of the main body. The end of the hose 9 facing the cover 3 is in a slightly extended state, but when the fixing device 1 is set again as shown in FIG. 2, the hose 9 is pushed by the cover 3 and comes into close contact with the discharge port 8. The fixing device 1 slides on a support plate (not shown) on the main body side as usual, or is supported by a linear motion rail (not shown) supported on the main body side. It can be slid back and forth with the plate.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as shown in FIG. 4, the cover 3 '
This is an example in which the rear portion of the hose 9'is extended and the cover 3'is inserted into the inner diameter portion of the end of the hose 9 '. On the other hand, in the first embodiment, the end portion of the hose 9'is contracted so that the cover 3'is
It is designed to be coupled in the discharge port 8 of. The same effects as those of the first embodiment can be obtained by this embodiment as well.

In the first and second embodiments described above, the present invention is applied to the case where the roller is used as the fixing means, but the present invention is not limited to this, and the fixing means formed into a film shape. Even when it is applied to the fixing device including the above, the above-described effects can be obtained.

[0020]

As described above, according to the present invention,
The cooling structure of the transfer material detecting means has a structure in which first and second openings are provided in a container of the transfer material detecting means, and the second opening and the discharge fan of the fixing device are connected to the ventilation means. Therefore, the outside air that has flowed in through the first opening and passed through the container is discharged by the discharge fan through the second opening, so that the cooling fan dedicated to the transfer material detection unit can be efficiently provided. It is possible to lower the temperature inside the container and protect the transfer material detecting means from high temperatures. Further, since it is not necessary to provide a cooling fan dedicated to the transfer material detecting means, the cost can be reduced. Further, since the transfer material detecting means can be cooled efficiently as described above, it is not necessary to dispose the transfer material detecting means far from the fixing means, and the detecting lever and the like can be made into a simple structure to reduce the cost. Can be made

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a device according to a first embodiment of the present invention.

FIG. 2 is a top view of the vicinity of a transfer material detecting means arrangement portion of the apparatus shown in FIG.

FIG. 3 is a top view showing a state in which the fixing device is pulled out to the front side of the image forming apparatus main body in FIG.

FIG. 4 is a top view showing a schematic configuration of a second embodiment device of the present invention.

[Explanation of symbols]

 1 Fixing Device 3 Cover (Container) 4 Sensor (Transfer Material Detecting Means) 6 Fixing Roller (Fixing Means) 7 Outside Air Intake (First Opening) 8 Exhaust (Second Opening) 9 Hose (Ventilation Means) ) 11 discharge fan 12 pressure roller (pressurizing means) 15 web (release agent applying means)

Claims (2)

[Claims] 1. A cooling structure of a transfer material detecting means for a fixing device, wherein the fixing device is provided with a roller or a film-like fixing means having a heating means therein, and so as to be in pressure contact with the fixing means. The pressure applying means and the release agent applying means for applying the release agent to the surface of at least one of the fixing means and the pressure applying means are provided in the housing, and the release agent evaporated in the housing is provided. The transfer material detecting means is provided with a discharge fan for discharging the mold material and the like to the outside of the housing, and the transfer material detecting means detects the presence or absence of the transfer material nipped and conveyed by the fixing means and the pressing means outside the housing. In a cooling structure of a transfer material detecting means for a fixing device that cools the transfer material detecting means when the transfer material detecting means is arranged in the container, the transfer material detecting means is provided in the container of the transfer material detecting means. Formed on the side surface around the part And a second opening formed on the side surface or another side surface at a predetermined distance from the first opening, and the second opening is the first opening. A cooling structure for transfer material detecting means for a fixing device, characterized in that the outside air flowing in through an opening is connected to the discharge fan by a ventilation means so as to exhaust the outside air through the second opening. 2. The fixing device is movably arranged so as to project to the outside of the main body of the image forming apparatus, and the second opening of the container of the transfer material detecting means is connected to the ventilation means so as to be able to come into contact with and separate from it. The cooling structure of the transfer material detecting unit for the fixing device according to claim 1.