JPH0822227A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate the need for separately providing an image forming device with a heating source and to avoid complicating of its structure by heating a heat pipe by utilizing the heat generated by a fixing means for ozone removal. CONSTITUTION:An exhaust fan 18 operates and the air contg. the ozone in a device body 1 is passed through an ozone removing means 19, by which the air is released outside from the aperture at the front end of a discharge section 8 after the ozone included in this air flow is removed by fins 21. At this time, the heat generated from a fixing roller 14 of the fixing means 5 is conducted via the heat pipe 20 whose base part is mounted on the upper stay 22 of the fixing means 5 and which penetrates the fins 21 in a horizontal direction to the fins 21 in the vertical direction coated with an ozone removing agent mixed with powders of metal oxides, such as manganese dioxide and lead peroxide; in addition, the fins 21 are heated by the hot air rising from the upper stay 22 and passing therebetween. As a result, the ozone is efficiently decomposed and removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus of this type is provided with a fixing means, a corona discharger, an exhaust fan, and an ozone removing means, and the temperature inside the apparatus is raised by the heat generated by a fixing roller. In order to prevent this from happening, the air inside the device is exhausted by the exhaust fan, and the ozone in the air generated by the corona discharger is removed by the ozone removing means and is also exhausted outside the device by the exhaust fan together with the air. It is supposed to be done.

The ozone removing means having an ozone removing member and a heat pipe for heating the member are
It is disclosed in JP-A-60-179115, JP-A-179117, etc. and is well known. However, in these,
The heat pipe is designed to be heated by a heat source dedicated to the heat pipe other than the means normally required for the image forming apparatus, and thus a heat source only for removing ozone must be provided separately. In addition to the complicated structure, there is a problem in that a space for installing the structure must be provided.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the problems of the conventional image forming apparatus as described above, and to utilize the heat generated by the fixing means for removing ozone to form a heat pipe. It is an object of the present invention to provide an image forming apparatus which does not need to separately provide a heating source for heating and does not complicate the structure and also does not require an extra space for its installation.

[0005]

In order to achieve the above-mentioned object, the present invention provides a fixing means, a corona discharger, and an exhaust fan for exhausting air in the apparatus. An ozone removing unit for removing ozone in the air is provided, and the ozone removing unit is an image forming apparatus having an ozone removing member and a heat pipe for heating the member, and the exhaust fan and the ozone removing unit are fixed to each other. And a plurality of fins that are arranged close to each other above the means, the ozone removing member is vertically arranged at intervals, and the fin is coated with an ozone removing agent, and the heat pipe is a base portion of the upper stay of the fixing means. Are attached and extend laterally through the plurality of fins. The invention of claim 2 is characterized in that, in the invention of claim 1, uneven portions are provided on the surfaces of the fins. According to a third aspect of the invention, in the first or second aspect of the invention, the number of revolutions of the exhaust fan is controlled by the surface temperature of the fixing roller, the surface temperature of the fins, and the presence / absence of copy operation. According to a fourth aspect of the present invention, a fixing unit, a corona discharger, an exhaust fan that discharges air in the apparatus, and an ozone removing unit that removes ozone in the air are provided, and the ozone removing unit is ozone. In an image forming apparatus having a removing agent and a heat pipe for heating the removing agent,
The exhaust fan and the ozone removing means are arranged close to each other above the fixing means, the ozone removing means has a plurality of through holes and is laterally arranged at intervals, and the ozone removing agent is applied. The heat pipe is provided with a plurality of fins, and the heat pipe has a base portion attached to an upper stay of the fixing means, and extends through the plurality of fins in a vertical direction. According to a fifth aspect of the present invention, in the fourth aspect, the plurality of through holes are provided at different positions for adjacent fins. According to a sixth aspect of the invention, in the fourth or fifth aspect of the invention, the pitch of the fins closer to the fixing means is smaller than the pitch of the fins farther from the fixing means.

[0006]

In the inventions of claims 1 and 2 as described above, when the apparatus is in operation, the exhaust fan is operated to discharge the air containing ozone in the apparatus main body to the outside from the tip opening of the exhaust section. , The ozone contained in the air stream will be removed by the fins of the ozone removing means. At this time, the ozone removing agent mixed with the powder of metal oxide such as manganese dioxide or lead peroxide was applied. In addition to conducting the heat of the fixing means to the fins through the heat pipe, the fins are heated by the hot air that rises from the upper stays and passes between them to efficiently decompose and remove ozone. Become. At this time, since the fins are provided with the uneven portions, the passage resistance of ozone when passing through the ozone removing means is increased, and the removal efficiency is improved.

According to the third aspect of the present invention, the number of revolutions of the exhaust fan is controlled by the surface temperature of the fixing roller, the surface temperature of the fins, and the copying operation being turned on and off. When turned on, the surface temperature of the fixing roller and fins of the fixing means rises. However, when the copy operation is not turned on, the rotation speed of the exhaust fan is rotated at a low speed. (ii) Then, when the copy operation is turned on,
Switch the rotation speed of the exhaust fan to high speed. (iii) Then, even if the copying operation is turned off, the rotation speed of the exhaust fan is kept at high speed in consideration of the temperature rise due to the residual heat. (iv) After that, the rotation speed of the exhaust fan is switched to low speed rotation. (v) After that, copy operation is turned on again P4
Then, if this is continued for a long time, the surface temperature of the fixing roller gradually decreases due to heat exchange of the sheet passing through and the fin contacting the heat pipe. (vi) Then, when this temperature reaches a fixing temperature, the rotation speed of the exhaust fan is switched to a low speed rotation in order to reduce heat exchange by the fins. (vii) When the surface temperature of the fixing roller and the fins rises due to such low speed rotation of the exhaust fan to a temperature at which fixing and ozone removal are possible, the rotational speed of the exhaust fan is changed to high speed again.

In the fourth and fifth aspects of the invention, similarly to the first and second aspects of the invention, when the apparatus is in operation, the exhaust fan is operated and the air containing ozone in the apparatus body is exhausted. The ozone discharged from the tip end opening of the and contained in the air flow is removed by the fins in the lateral direction of the ozone removing means. At this time, the base is attached to the upper stay of the fixing means, and the heat generated from the fixing means is conducted via the heat pipe vertically penetrating the fin. Is heated by hot air passing through the ventilation holes of the fins to efficiently decompose and remove ozone.
Furthermore, since a plurality of through holes are provided at different positions for adjacent fins, the flow of hot air that rises from the upper stay and passes through the through holes is suppressed, and the time of contact with the surface of the fins is increased. This improves the heat exchange efficiency.

In the invention of claim 6, the pitch of the lower fins near the fixing roller is smaller than the pitch of the upper fins far away, so that the fins as a whole are smaller in the high temperature region than the temperature at which ozone can be removed. The temperature gradient is maintained and a good ozone removal function is exhibited.

[0010]

1 to 6, a corona discharger 3, a developing means 4, a fixing means 5 and a corona discharger are provided inside a main body 1 of a device, around a photoreceptor 2 and its periphery. The transfer unit 6, the cleaning unit 7, the paper feeding unit 9, and the optical writing unit 11 are provided. When such an apparatus starts to operate, the photoconductor 2 is rotationally driven in a predetermined direction, at which time it is charged by the corona discharger 3 and is irradiated with the laser light from the optical writing means 11, so that the surface of the photoconductor 2 is irradiated. An electrostatic latent image is formed, and the electrostatic latent image is visualized with toner by the developing unit 4, is fed from the sheet feeding unit 9 by the sheet feeding roller 12, and is registered on the lower portion of the photoconductor 2 by the pair of registration rollers. The transferred paper is transferred to the conveyed paper. Then, this sheet is guided by the conveyance guide, conveyed between the fixing roller 14 and the pressure roller 16 of the fixing means 5 to fix the visible image, and guided by the sheet discharge roller to the sheet discharge section 13 to be stacked. To be done.

In this embodiment, an exhaust fan 18 is provided in the exhaust portion 8 above the fixing means 5 in order to discharge the excess heat generated in the fixing means 5 inside the apparatus main body 1 to the outside of the apparatus main body 1.
And an ozone removing means 19 for removing ozone generated by the corona discharger 3 and the transfer means 6 are provided in the vicinity of the exhaust fan 18, and the ozone removing means 19 are vertically arranged with a space therebetween. The heat pipe 20 has a plurality of fins 21 to which an ozone removing agent is applied and a heat pipe 20 for heating the fins 21. Extending laterally through. The fin ozone removing means 19 is provided with a thermistor 17, and the fixing means 5 is provided with a fixing thermistor 26. The fins 21 are provided with irregularities on their surfaces. In the example of FIG. However, the example of FIG. 5 is provided with a large number of raised portions 25 on one side, and the example of FIG. 6 is formed in a zigzag shape.

During operation of such an embodiment, the exhaust fan 18 is operated to allow the air containing ozone in the apparatus main body 1 to be included in the air flow by passing through the ozone removing means 19. After the ozone is removed by the fins 21, the air is discharged to the outside through the tip opening of the exhaust unit 8. At this time, the base is attached to the upper stay 22 of the fixing means 5 on the vertical fin 21 coated with the ozone removing agent mixed with the powder of metal oxide such as manganese dioxide or lead peroxide. In addition to the heat generated from the fixing roller 14 of the fixing means 5 being conducted through the heat pipe 20 penetrating laterally through the fin 21, the fin 21 rises from the upper stay 22 and moves between them. It is heated by the hot air passing therethrough and efficiently decomposes and removes ozone. At this time, the convex portion 23 or the raised portion 25 is formed on the fin 21.
Etc., or the zigzag shape as a whole, increases the passage resistance when ozone passes through the ozone removing means 19 and improves the removal efficiency.

In this embodiment, as shown in FIG. 7, (1) the rotation speed R of the exhaust fan 18 is set to (2) the fixing roller.
14 surface temperature t1, (3) fin 21 surface temperature t2, (4)
The copy operation is controlled by turning it on and off. In such a case, (i) when the apparatus is turned on at time T0, the fixing roller 14 and the fin 21 of the fixing unit 5 are
Although the surface temperatures t1 and t2 of (1) rise, the copying operation is not turned on, and therefore the rotation speed R of the exhaust fan 18 is rotated at a low speed as indicated by (1). (ii) Next, when the copy operation is turned on P1 at time TI, the rotation speed R of the exhaust fan 18
Is switched to high speed rotation as shown in (1). (iii)
Even when the copy operation is turned off P2 at time T2, the rotation speed R of the exhaust fan 18 is considered in consideration of the temperature rise due to the residual heat.
Remains at high speed. (iv) After that, at time T3, the rotation speed R of the exhaust fan 18 is switched to the low speed rotation as shown in (1). (v) After that, when the copying operation is turned on P4 again at time T4 and this continues for a considerable period of time, the surface temperature t1 of the fixing roller 14 becomes equal to that of (1) due to the heat exchange of the fin 21 contacting the paper and the heat pipe 20. So that it gradually decreases. (vi) Then, when the temperature t1 becomes the fixing temperature t3, the fixing thermistor 26 which is in contact with the surface of the fixing roller 14 detects this and the exhaust fan 18 exchanges heat with the fins 21. In order to reduce the above, the rotation speed R of the exhaust fan 18 is switched to the low speed rotation as shown in (2) at time T5. (vii) With such a low speed rotation of the exhaust fan 18, the surface temperature t1 of the fixing roller 14 and the surface temperature t2 of the fins 21 rise to reach the fixing and ozone removing temperatures t3 and t4.
Then, the rotation speed of the exhaust fan 18 is changed to high speed again. In this way, the surface temperature t1 of the fixing roller 14 and the fin 21 are
The surface temperature t2 can be kept substantially constant, the ozone removal capability can be stabilized, and unnecessary noise can be prevented from increasing.

The second embodiment of the present invention shown in FIGS.
Since many parts are similar to those of the first embodiment, description of these parts will be omitted, and different parts will be mainly described. The ozone removing means 29 has a plurality of through holes 33 and is laterally arranged at intervals and has a plurality of fins 31 to which an ozone removing agent is applied.
The base 30 is attached to the upper stay 22 of the fixing means 5,
The fins 31 extend through the holes 34 in the vertical direction.

During operation of such an embodiment, the first
In the same manner as in the embodiment, the exhaust fan 18 operates to discharge the air containing ozone in the apparatus main body 1 to the outside from the tip opening of the exhaust unit 8 to remove the ozone contained in the air flow. The fins 31 of the ozone removing means 29 remove the ozone. At this time, the base portion is attached to the upper stay 22 of the fixing means 5 on the lateral fins 31, and the fixing means 5 is connected via the heat pipe 30 penetrating the fins 31 in the vertical direction.
In addition to conducting the heat generated from the fixing roller 14, the fin 31 is heated by the hot air passing through the through hole 33 of the upper stay 22 and efficiently decomposes and removes ozone. At this time, the plurality of through holes 33 are provided at different positions for the adjacent fins 31, so that the flow of hot air that rises from the upper stay 22 and passes through the through holes 33 is suppressed, and the fins 31 come into contact with the surfaces of the fins 31. Therefore, the heat exchange efficiency is improved, and ozone is decomposed and removed efficiently.

FIG. 10 shows a third embodiment of the present invention, which is a lower fin 31 close to the fixing roller 14.
The pitch a is smaller than the pitch b of the distant upper fins 31, and the other points are the same as the second embodiment. Due to this, when the pitch is uniform, the temperature t5 becomes lower toward the upper fin 31 as shown by the chain line in FIG. It is unavoidable that the temperature becomes lower, but by setting the pitch as described above, as shown by the solid line in FIG. It will function.

[0017]

The present invention is as described above. According to the invention of claim 1, the fixing means, the corona discharger, the exhaust fan for discharging the air in the apparatus, and the ozone in the air are removed. In an image forming apparatus provided with ozone removing means, the ozone removing means having an ozone removing member and a heat pipe for heating the ozone removing member, the exhaust fan and the ozone removing means are arranged close to each other above the fixing means. Is
The ozone removing member has a plurality of fins that are vertically arranged at intervals and has an ozone removing agent applied thereto, and the heat pipe has a base portion attached to an upper stay of the fixing means, and the plurality of fins are attached to the heat pipe. It extends through in the lateral direction,
Further, since the fins are provided with uneven portions, the heat generated by the fixing means is used to heat the heat pipe, so that the heat generated by the fixing means is conducted to the fins and the fixing is performed. Since the fins are heated by the hot air that rises from the means and passes between the fins, ozone is efficiently removed, and there is no need to provide a separate heat source for heating the heat pipe, which may complicate the structure. In addition to the above, there is no need to provide an extra space for its installation, and there is an effect that the passage resistance when ozone passes through the ozone removing means is increased and the removal efficiency can be improved. According to a third aspect of the present invention, in the first or second aspect of the present invention, the number of revolutions of the exhaust fan is controlled by the surface temperature of the fixing roller, the surface temperature of the fin, and the presence / absence of copy operation. In addition to being able to keep it almost constant and stabilizing the ozone removal capacity, there is an effect that unnecessary noise can be prevented from increasing. According to a fourth aspect of the present invention, a fixing unit, a corona discharger, an exhaust fan that discharges air in the apparatus, and an ozone removing unit that removes ozone in the air are provided, and the ozone removing unit is ozone. In the image forming apparatus having the removing member and the heat pipe for heating the removing member, the exhaust fan and the ozone removing unit are arranged close to each other above the fixing unit, and the ozone removing unit has a plurality of through holes. The heat pipe has a plurality of fins arranged laterally at intervals and coated with an ozone removing agent, and the heat pipe has a base portion attached to an upper stay of a fixing unit, and vertically penetrates the plurality of fins. Since the fins are extended, in addition to the heat transfer by the heat pipe, the fins are heated by the hot air rising from the fixing means and passing through the through holes, and ozone can be efficiently removed. There is a cormorant effect. According to the invention of claim 5, in the invention of claim 4, since the plurality of through holes are provided at different positions for adjacent fins, the flow of hot air that rises from the upper stay and passes through the through holes is suppressed. Thus, there is an effect that the time of contact with the surface of the fin is increased, thereby improving the heat exchange efficiency and efficiently decomposing and removing ozone. According to a sixth aspect of the invention, in the fourth or fifth aspect of the invention, the pitch of the fins closer to the fixing means is smaller than the pitch of the fins farther from the fixing means. There is an effect that a small temperature gradient can be maintained in a higher temperature region to exhibit a good ozone removal function.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a first embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional front view of the main part of the above.

FIG. 3 is a perspective view of the fixing unit and the ozone removing unit of the above.

FIG. 4 is a perspective view of an example of fins of the above ozone removing means.

FIG. 5 is a perspective view of another example of fins of the ozone removing means of the above.

FIG. 6 is a perspective view of yet another example of fins of the ozone removing means of the above.

FIG. 7 is a correlation diagram of the surface temperature of the fins, the rotation speed of the exhaust fan, the copy operation, and the fixing roller of the same.

FIG. 8 is a perspective view of a fixing unit and an ozone removing unit according to a second embodiment of the present invention.

FIG. 9 is an enlarged perspective view of a part of the above fin.

FIG. 10 is a perspective view of a fin according to a third embodiment of the present invention.

FIG. 11 is a correlation diagram between the positions of the fins of the equal pitch fins and the unequal pitch fins, and the temperature.

[Explanation of symbols]

 1 Device Main Body 2 Photoreceptor 3 Corona Discharger 5 Fixing Means 8 Exhaust Unit 14 Fixing Roller 18 Exhaust Fan 19 Ozone Removing Means 20 Heat Pipe 21 Fins 22 Upper Stay 23 Convex 24 Holes 25 Bolts 29 Ozone Removing Means 30 Heat Pipe 31 fin 33 through hole 34 hole

Claims (6)

[Claims] 1. A fixing means, a corona discharger, an exhaust fan for discharging air in the apparatus, and an ozone removing means for removing ozone in the air are provided, and the ozone removing means is an ozone removing member. In an image forming apparatus having a heat pipe and a heat pipe for heating the same, the exhaust fan and the ozone removing unit are arranged in proximity to each other above the fixing unit, and the ozone removing member is arranged vertically with a space therebetween, and An image having a plurality of fins to which an ozone removing agent is applied, the heat pipe having a base attached to an upper stay of a fixing unit, and extending laterally through the plurality of fins. Forming equipment. 2. The image forming apparatus according to claim 1, wherein the fin has an uneven portion on the surface thereof. 3. The image forming apparatus according to claim 1, wherein the number of revolutions of the exhaust fan is controlled by the surface temperature of the fixing roller, the surface temperature of the fin, and the presence / absence of copy operation. 4. A fixing unit, a corona discharger, an exhaust fan for discharging air in the apparatus, and an ozone removing unit for removing ozone in the air are provided, and the ozone removing unit is an ozone removing member. In the image forming apparatus having the heat pipe and the heat pipe for heating the same, the exhaust fan and the ozone removing unit are arranged close to each other above the fixing unit, and the ozone removing member has a plurality of through holes and is spaced from each other. The heat pipe has a plurality of fins arranged in a horizontal direction and coated with an ozone removing agent.The heat pipe has a base attached to an upper stay of the fixing unit and extends vertically through the plurality of fins. An image forming apparatus characterized in that 5. The image forming apparatus according to claim 4, wherein the plurality of through holes are provided at different positions for adjacent fins. 6. The image forming apparatus according to claim 4, wherein the pitch of the fins closer to the fixing means is smaller than the pitch of the fins farther from the fixing means.