JPH0394279A - Image forming device - Google Patents

Abstract

PURPOSE:To efficiently perform the thermal decomposition of ozone in exhaust air and to reduce cost by guiding air which is sucked by a suction means to an exhaust means and heating the exhaust air by a heating means. CONSTITUTION:The device is provided with a sucking fan 26 functioning as the suction means for sucking the air in the device and guiding it in a duct 25 at an aperture part at the inside end of the duct 25 for exhausting the air in a copying machine outside. And the device is provided with a heater 29 connected with a lead wire 28, for heating the duct 25 at the aperture part at the outside end of the duct 25, and an ozone filter 30 for adsorbing and decomposing the ozone in the exhaust air is connected to the aperture part at the outside end of the duct 25. Thus, the thermal decomposition of the ozone contained in the exhaust air can be facilitated, so that even a small-sized ozone filter 30 can be used and the cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to image forming apparatuses such as copying machines and printers, and particularly to an image forming apparatus that removes ozone generated by corona discharge.

<Prior Art> Today, with the progress and development of information processing technology, various image forming apparatuses such as electrophotographic apparatuses and laser beam printers have been developed and put into practical use. Among these, image forming apparatuses using electrophotography are widely used.

This method involves uniformly charging a drum-shaped photoreceptor, which is an image carrier, with a corona discharger, then exposing the photoreceptor to light to form an electrostatic latent image, and toner being attached to this latent image. After the image is visualized, it is transferred to a transfer material to form an image.

When the photoreceptor is charged or neutralized by the corona discharger, ozone (02), nitrogen oxides (NOX), etc. are generated. If these concentrations are high, ozone may cause deterioration of the surface of the photoreceptor and cause image deterioration, so it is necessary to exhaust the air outside the apparatus.

Since air containing the above-mentioned high concentration of ozone may have an adverse effect on the human body, it is desirable that the ozone generated within the apparatus is not discharged as it is outside the apparatus as much as possible.

For this reason, air containing high concentration of ozone around the corona discharger is sucked in by a fan and blown onto an ozone filter, and the ozone is adsorbed and removed by the ozone filter, and the air is exhausted outside the device.

That is, as shown in FIG. 5, the charging wire 50a of the charger 50
The ozone generated by corona discharge around the
flow inside.

The airflow is controlled by an activated carbon filter installed near the exhaust port. Alternatively, most of the ozone in the exhaust gas is adsorbed by passing through the ozone filter 53 made of a metal catalyst filter, so that the ozone concentration in the exhaust gas is suppressed to a very small amount.

<Problems to be Solved by the Invention> However, in the above-mentioned conventional technology, the ozone filter 53 provided in the duct 52 is one of the most expensive parts and tends to increase the cost.

Further, as the ozone filter 53 is generally used, its ozone adsorption performance deteriorates, and periodic replacement is often required.

The present invention solves the above-mentioned problems of the prior art and provides an image forming apparatus with improved ozone decomposition efficiency at low cost.

<Means for Solving the Problems> A typical means for solving the above-mentioned problems of the prior art and applied to the embodiments described below is to generate an image by exposing an image carrier charged with a corona discharger. an image forming means for forming an image; a suction means for suctioning air within the apparatus;
The apparatus includes an exhaust means for exhausting the air sucked by the suction means to the outside, and a heating means for heating the exhaust means.

Effect> According to the above means, ozone in the exhaust gas can be thermally decomposed efficiently by guiding the air sucked by the suction means to the exhaust means and heating the exhaust means using the heating means.

Furthermore, since ozone in the exhaust gas is thermally decomposed, the ozone filter, which is an expensive component, can be simplified or omitted, resulting in lower costs and easier maintenance.

In particular, when the exhaust means is constructed of a highly thermally conductive member, the efficiency of heat transfer to the air flow by the heating means can be increased.

Further, when the exhaust means is provided with a structure having large thermal conductivity and a large heat dissipating surface area, efficient heating can be achieved because the contact area with the air flow is large. Further, when the periphery of the exhaust means is covered with a heat insulating material, it is possible to increase the heating efficiency of the exhaust means and prevent the temperature inside the apparatus from rising.

Furthermore, when a catalyst-based ozone filter is used as the exhaust means, the air flow is heated before passing through the ozone filter, which increases the temperature of the catalyst and further activates the ozone decomposition efficiency. I can do it.

<Embodiment> An embodiment of an image forming apparatus to which the present invention is applied will be described below with reference to the drawings.

FIG. 1 is an explanatory cross-sectional view showing an exhaust structure for exhausting air within the apparatus, and FIG. 2 is an explanatory view showing a schematic configuration of an image forming apparatus to which the above-mentioned exhaust structure is applied.

First, the general structure of an image forming apparatus to which the present invention is applied will be explained with reference to FIG.

Reference numeral 1 denotes a copying machine capable of copying both sides of an original image onto a sheet material S such as plain paper or plastic sheet.

The copying machine 1 includes a photosensitive drum 2 which is an image bearing member constituting an image forming means, a primary charger 3 which is a corona discharger surrounding the photosensitive drum 2, a developing device 4 containing toner,
Post charger 2S5, which is a Gorona discharger, transfer charger 6,
A separation charger 7, a cleaner 8, etc. are provided.

To explain the operation of the image forming means, the reflected light from the document irradiation lamp 9 that exposed the document D is reflected by the mirror 10,
An image is formed on the photosensitive drum 2 through the lens 11. Then, toner is applied by the developing device 4 to form a visible image. Furthermore, the post charger 5 removes excess toner from the toner image.

On the other hand, cassette l-12. The sheet materials S stacked and stored on the feed rollers 13 are selectively moved to the feed rollers 14 and 13 by a feed signal.
15 and conveyed by a pair of conveying rollers 16. 17.
18, the registration roller pair 19, each of which is temporarily stopped, is suddenly fed, and the skew is corrected.

Then, the sheet material S is conveyed to the transfer section by a pair of registration rollers 19 in synchronization with the leading edge of the toner image formed on the photosensitive drum 2. The sheet material S is charged with a polarity opposite to that of j.ner by a transfer charger 86, and the toner image formed on the photosensitive drum 2 is transferred to the sheet material S. Thereafter, the sheet material S electrostatically attracted to the photosensitive drum 2 is neutralized by the separation charger 7 and separated from the photosensitive drum 2.

The sheet material S after the image transfer is conveyed to the fixing device 21 by the conveying device 20, and the transferred image is permanently fixed by passing between a pair of rollers that make up the fixing device 21. A flapper 22 is provided on the downstream side of the fixing device 21 in the conveyance direction of the sheet material S.

The operation of this flapper 22 is controlled so that the sheet material S is ejected from a wandering roller 23 in the single-sided copying mode, and the sheet material S is guided to the re-conveying path 24 in the double-sided copying mode.

In the vicinity of each corona discharger constituting the image forming means, there is an exhaust duct 25 for sucking and exhausting the air inside the apparatus.
An exhaust structure such as an exhaust fan 26 is provided.

Next, an exhaust structure applied to the copying machine 1 constructed as described above will be explained with reference to FIG.

In FIG. 1, 25 is a duct that constitutes an IF air means for exhausting the air inside the copying machine 1 to the outside. A suction fan 26 is provided as suction means for sucking air and guiding it into the duct 25.

The duct 25 is made of a metal duct with high thermal conductivity, and its outer peripheral surface is covered with a heat insulating material 27 across the front and back of the side plate 1a of the copy@1. This heat insulating material 27 increases the heating efficiency of the duct 25 and prevents the temperature inside the device from rising by allowing the heat of the duct 25 to escape.

Further, a heater 29 for heating the duct 25 to which the lead wire 28 is connected is provided at the tip opening of the duct 25 outside the device.

Further, an ozone filter 30 for adsorbing and decomposing ozone in the exhaust gas is installed at the tip opening of the duct 25 outside the device.
are connected. As the ozone filter 30, an activated carbon filter with a thickness of about 10 to 20 mm or a metal catalyst filter made of manganese, titanium, aluminum, silicon, etc. is used.

The operation of the exhaust structure configured as described above will be described. Air inside the copying machine 1 sucked by the suction fan 26 flows into the duct 25, passes through the ozone filter 30, and is exhausted to the outside. At this time, since the duct 25 is heated by the heater 29, the air flow is
The temperature rises inside. This promotes thermal decomposition of ozone contained in the exhaust gas. Therefore, the ozone concentration in the exhaust gas at the time it passes through the ozone filter 30 decreases,
Since the ozone filter 30 further adsorbs and decomposes ozone, the ozone concentration in the exhaust gas can be reduced.

In the case of this embodiment, the dependence of ozone removal on the ozone filter 30 is low, so even a smaller ozone filter 30 (lower adsorption capacity) than conventional ozone filters can be used, and cost reduction can be achieved. .

In addition, even if the durability of the ozone filter 30 deteriorates, the amount of increase in the ozone concentration in the exhaust gas can be reduced compared to the conventional case, so it is possible to reduce the cost required for maintenance.

Furthermore, when a catalyst filter is used as the ozone filter 30, as the temperature of the air increases due to the heater 29, the temperature of the catalyst also increases, and the chemical equilibrium advances in the direction of ozone decomposition, increasing the ozone decomposition efficiency. It is possible.

The chemical thermal decomposition of ozone begins to become active around 35°C, so it is ideal to heat the air above 35°C, but this depends on the amount of heat that can be supplied, the heat resistance of the surrounding area, and the heating space. If there are such restrictions, it is possible to move the chemical equilibrium due to heating in the direction of ozone decomposition and effectively remove ozone in the exhaust gas without heating to 35° C. or higher.

Furthermore, the amount of heating of the duct 25 by the heater 29 should be as large as the temperature rise in the surrounding area allows, but if cost constraints are severe, heating may be performed without the heat insulating material 27. Effects can be obtained.

Furthermore, the present invention is applicable not only to the copying machine 1 but also to other devices.

Other Embodiments Next, other embodiments of the air pressure structure applied to the copying machine 1 in the above embodiment will be described with reference to FIGS. 3 and 4.

In FIG. 3, a metal honeycomb structure 32 with high thermal conductivity and a large surface area is provided near the opening at the end of a duct 31 outside the device, which has high thermal conductivity and heat insulation. A heater 29 to which lead wires 28 are connected is attached.

When the air inside the copying machine 1 that is sucked into the duct 31 by the suction fan 26 passes through the metal honeycomb structure 32 heated by the heater 29, the gas temperature rises and ozone is thermally decomposed and released to the outside. It is something that is exhausted.

- According to the above structure, the metal honeycomb structure 32 has a very large surface area per unit volume and has a large contact area with air, so the amount of heat transferred to the air is larger than that of the metal honeycomb structure 32. Therefore, the gas temperature can be increased by 3 in a short heating period.
It is easy to raise the temperature to 5°C or higher, and the ozone in the exhaust gas can be thermally decomposed efficiently.

Further, in this embodiment, removal of ozone from exhaust gas relies only on thermal decomposition, and an expensive ozone filter is not required, so that a significant cost reduction can be achieved.

Furthermore, the ozone removal performance does not deteriorate in terms of durability, and there is no need to regularly replace the ozone filter.
Maintenance can also be made easier.

Next, Fig. 4 shows a duct 31 with high thermal conductivity and heat insulation properties.
A metal screw 33 having high thermal conductivity and a large surface area is provided near the opening at the tip outside the device, and a heater 29 to which a lead wire 28 is connected is attached to the metal screw 33.

The air inside the copying machine 1, which is sucked into the ducts 1 and 3 by the suction fan 26, increases in gas temperature as it passes through the spiral ventilation path along the blades of the metal screw 33, which is heated by the heater 29. The ozone is then thermally decomposed and exhausted to the outside.

According to the above configuration, the airflow passing through the metal screw 33 has a long ventilation path, so the airflow stays inside the duct 31 for a long time, and the contact area between the screw 33 and the airflow is large, so the inside of the duct 31 is closed. The air passing through can be heated efficiently.

Therefore, as mentioned above, the gas temperature can be increased to 35°C in a short heating period.
It is easy to raise the temperature above the level above, and thermal decomposition of ozone in the exhaust gas can be carried out efficiently.

Note that it is also possible to diffuse the exhausted heated gas by providing a driven fan or the like to lower the temperature again, thereby eliminating the influence on other electrical components and the like.

<Effects of the Invention> As described above, the present invention can efficiently thermally decompose ozone in the exhaust gas by guiding the air sucked in by the suction means to the exhaust means and heating the exhaust means by the heating means.

Furthermore, since ozone in the exhaust gas is thermally decomposed, the ozone filter, which is an expensive component, can be simplified or omitted, resulting in lower costs and easier maintenance.

In particular, when the exhaust means is constructed of a highly thermally conductive member, the efficiency of heat transfer to the air flow by the heating means can be increased.

Further, when the exhaust means is provided with a structure having high thermal conductivity and a large heat dissipating surface area, efficient heating can be achieved because the contact area with the air flow is large.

Further, when the exhaust means is surrounded by a heat insulating material, it is possible to increase the heating efficiency of the exhaust means and to prevent the temperature inside the apparatus from rising.

Therefore, in either case, the ozone decomposition efficiency can be further improved.

Furthermore, when a catalyst-based ozone filter is used as the exhaust means, the air flow is heated before passing through the ozone filter, which increases the temperature of the catalyst and further activates the ozone decomposition efficiency. I can do it.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional explanatory diagram showing an exhaust structure for exhausting air inside the apparatus, FIG. 2 is an explanatory diagram showing a schematic structure of an image forming apparatus to which the above-mentioned exhaust structure is applied, and FIGS. 3 and 4. is an explanatory diagram of another example, and FIG. 5 is an explanatory diagram of a conventional example. D is the original, S is the sheet material, ■ is the copying machine, 2 is the photosensitive drum, 3 is the primary charger, 4 is the developer, 5 is the post charger, 6
1 is a transfer charger, 7 is a separation charger, 8 is a cleaner, 9 is an original irradiation lamp, 10 is a reflection mirror, l1 is a lens, 1
2, 1.3 is a cassette, 14. 15 is a feeding roller;
16. 17. 18 is a pair of conveying rollers, 19 is a pair of registration rollers, 20 is a conveying device, 21 is a fixing device, 22 is a flapper, 23 is an ejection port roller, 24 is a re-conveying path, 25. 3
1 is a duct, 26 is a suction fan, 27 is a heat insulator, 2 is a lead wire, 29 is a heater, 30 is an ozone filter,
32 is a metallic honeycomb structure, and 33 is a metallic screw.

Claims (5)

[Claims] (1) An image forming means that forms an image by exposing an image carrier charged with a corona discharger, a suction means for sucking air inside the apparatus, and an air sucked by the suction means to the outside. An image forming apparatus comprising: an exhaust means for exhausting air; and a heating means for heating the exhaust means. (2) Claim (2) wherein the exhaust means is made of a highly thermally conductive member.
1) The image forming apparatus described above. (3) The image forming apparatus according to claim 1, wherein the exhaust means has a structure having high thermal conductivity and a large heat dissipation surface area. (4) The image forming apparatus according to claim (1), wherein the exhaust means is surrounded by a heat insulating material. (5) The image forming apparatus according to claim 1, wherein the exhaust means includes an ozone filter for adsorbing and decomposing ozone in the exhaust gas.