JP2007248811A - Gas collecting apparatus for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technology to efficiently collect and remove water vapor generated from a copy sheet, the odor substance of toner and the evaporated substance at thermal fixation, concretely, to newly provide a gas collecting apparatus on the downstream side of a thermal fixing apparatus as the generation source of the substances in the apparatus, to efficiently collect the substances, then, to prevent the dew condensation in the apparatus, to stabilize image quality, also, to trap the odor, and to eliminate and prevent the occurrence of the odor. <P>SOLUTION: The image forming apparatus includes the gas collecting apparatus at a paper conveying process on the downstream side of the fixing apparatus. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine or a laser printer, and more particularly to a gas collecting apparatus that efficiently removes a gas such as water vapor generated when heat-fixing copy paper.

  Printing and copying of image forming apparatuses such as copiers and laser printers are performed by fixing toner onto a copy paper, and this is generally a method in which powder toner is heated and pressed to be fused to the paper. It is used as a heat fixing device. In this heat fixing device, a heating roller, a pressure roller, and the like inside are heated to a temperature of about 150 to 180 ° C. to fuse the toner to paper. At this time, the temperature of the paper reaches about 120 ° C., and various gases are generated from the copy paper and toner. The main thing is water vapor. This is what evaporated when the moisture contained in the copy paper was heated. In addition, resin components and fixing oil components of the toner are also evaporated.

  However, recent copying machines and printers have been increased in speed and color, and a larger amount of paper is copied than in the past, and the amount of these vapors generated has increased. Furthermore, recently, the entire apparatus has been designed to be small, such as space saving and miniaturization. For this reason, the various units and members incorporated in the apparatus are miniaturized and the units are arranged at a high density, so that a sufficient air flow path for exhausting gas has been secured in the past. A situation has arisen where design is difficult. As a result, what has conventionally been easy to exhaust these gases with a fan together with heat will stay in the machine, causing various problems.

  One of the problems is water vapor generated from copy paper that has passed through the heat fixing device. This water vapor is originally contained in the copy paper, but is heated to become water vapor when the toner is fused. Although most of the water vapor is discharged, some of the water vapor circulates in various parts of the machine due to the airflow of the fan, and may cause condensation by touching metal plates or lenses. However, due to insufficient exhaust and increased copy amount as described above, condensation of water vapor has become a major problem. In particular, when a cooling device or a liquid cooling method is used to efficiently cool the inside of the machine, dew condensation occurs more frequently, so a countermeasure is required.

  As a conventional technique, in Patent Document 1, an exhaust port is provided in the upper part of the paper discharge unit, and a device for exhausting heat and water vapor to the outside by a chimney effect, or in Patent Document 2, a paper discharge guide conveyed from the nip portion of the fixing unit. There are passages and holes for the escape of water vapor. In addition to these, devices such as a fan and a passage for discharging water vapor to the outside of the machine have been devised. However, in these methods, since a sufficient spatial exhaust space cannot be secured with the miniaturization of equipment, the exhaust cannot be performed efficiently, and water vapor stays or remains, causing a problem. In addition, there is a case in which exhaust cannot be made in time for a high-speed machine with a copy speed of 100 or more per minute, and the problem cannot be solved.

JP 2005-91566 A JP 2004-90221 A

  The present invention has been made in view of the above circumstances, and relates to a technique for efficiently collecting and removing water vapor and toner odorous substances and evaporated substances generated from copy paper during heat fixing, and specifically, in-machine these. A new gas collection device is installed downstream of the heat fixing device that is the source of generation, and these are efficiently collected to prevent condensation in the machine, stabilize image quality, and trap odors. It is to prevent it.

That is, the said subject is achieved by (1)-(8) of this invention.
(1) An image forming apparatus characterized in that a device for collecting gas is provided in the paper conveyance process downstream of the fixing device.
(2) The image forming apparatus as described in (1) above, wherein the inside of the gas collecting device has a negative pressure higher than that of the fixing device and its surroundings.
(3) The image forming apparatus according to (1), wherein the gas collecting device includes means for transferring a gas generated by a fixing device.
(4) The image forming apparatus according to any one of (1) to (3), wherein a gas collecting agent is disposed in the gas collecting device.
(5) The image forming apparatus according to any one of (1) to (4), wherein the collecting agent has air permeability.
(6) The image forming apparatus according to (5), wherein the collecting agent is a porous molded body.
(7) The image forming apparatus according to any one of (1) to (4), wherein a substance having a photocatalytic action is arranged in the gas collecting device.
(8) The image forming apparatus according to (7), wherein a light irradiation unit is provided.

  As will be apparent from the following detailed and specific description, the fixing device in the image forming apparatus melts the toner by heat and simultaneously fuses the toner to the heated paper. Therefore, various material components in the toner melt and evaporate or volatilize to generate gas. Among them, the resin component in the toner, the silicone oil applied to the heating roller, or the water in the paper becomes water vapor and stays in the machine, or it is scattered in various places, impairing the reliability of the device, or contaminating it. However, according to the present invention, by providing the air flow collecting device on the downstream side of the fixing device in the image forming apparatus, the gas is It was possible to improve the reliability and the image quality by being able to collect mostly.

Hereinafter, the present invention will be described in more detail.
The fixing device of the image forming apparatus heats and fuses the toner to the copy paper while being pressed. In this pressurization and heating, in addition to the moisture contained in the paper, the resin component in the toner is heated. Various components such as an oil component applied to the roller evaporate to become a gas such as water vapor and flow out to the downstream side where the paper is conveyed. In the present invention, a gas such as water vapor generated in the fixing device is effectively removed by providing a gas collecting device in the paper conveyance process downstream of the fixing device.
In the gas collection device, it is preferable to collect the gas without leakage by sucking the internal air and lowering the pressure from the surroundings to obtain a negative pressure.
Since the gas is generated when the paper passes through the heating roller of the fixing device, the gas collecting device is moved from the heating roller position to the gas collecting device by various methods, for example, a means such as a flow channel duct and a fan or a suction pump. The generated gas can be transferred to a gas collecting device, the leakage to the surroundings can be reduced to minimize the influence, and the collection efficiency can be improved.
The gas generated from the fixing device is preferably collected by, for example, disposing a collecting agent in the generating and collecting device. That is, for example, the generated gas is sucked, and the gas is trapped by the collection agent disposed in the collection device. Thus, conventionally, gas was discharged like fan exhaust, but according to the present invention, after gas generation, it can be absorbed before it dissipates to the surroundings, so it can be collected efficiently, and outside the machine. Since it is not discharged, it is also suitable for cleaning the office environment.
If the desiccant absorbs water vapor well as the scavenger, or other types of gas, a material that absorbs efficiently according to the properties is placed in the scavenger as the scavenger, and the fixing device The gas generated in can be processed immediately.
In order to efficiently absorb the gas generated in the trapping agent in the gas trapping device, the trapping agent is formed into a sheet and provided with air holes, or by laminating this sheet-like material, It is preferable to vent the gas up to the inside of the collecting agent to widen the contact area between the gas and the collecting agent so that the gas is efficiently absorbed by the collecting agent. Alternatively, the gas can be efficiently absorbed by various methods such as making the collecting agent porous or arranging it in a granular form. That is, since the collection agent is powder or granular, the gas absorption efficiency is not so high as it is. Therefore, in order to improve the gas absorption efficiency, a sheet-like molded article having high air permeability is formed. Is most efficient and convenient for replacement.
In the present invention, a desiccant or a hygroscopic agent is used as the scavenger. However, a substance having a deodorizing agent or a photocatalytic action may be disposed inside the gas collector as having other functions. The substance may be used in combination with a scavenger. In particular, when a substance having a photocatalytic action is used, it is possible to extend the life of the collecting agent or to deodorize it by decomposing the pollutants or odorous substances such as sulfur oxide, nitrogen oxide or organic gas. The efficiency of the effect can be increased. When a substance having a photocatalytic action is disposed, it is desirable to provide a light source in the gas trapping device in order to activate the photocatalytic action. In this case, it is also possible to guide the scanner light or static elimination light for image exposure to serve as a light source. According to such means, it is not necessary to install a new light source, It is possible to remove or purify harmful gases without complication.

Examples will be described below.
FIG. 1 is a diagram showing an outline of a fixing device, a gas collection device of the present invention, and a paper transport system in an image forming apparatus of the present invention.
In the apparatus of FIG. 1, a gas collecting device is provided downstream of the fixing device composed of a heating roller and a pressure roller, and the copy paper is transferred to the gas collecting device immediately after leaving the fixing device by the paper conveying means. And is configured to be discharged from the apparatus.
The copy sheet is conveyed along the guide plate from the right side of the drawing, and is thermally fixed by passing between the heating roller and the pressure roller of the fixing device. The fixing temperature varies depending on the model and linear speed, but is usually about 150 ° C. When passing between these rollers, the water in the copy paper evaporates to generate water vapor, or the toner resin And the components evaporate and generate odor. The generated gas such as vapor is collected by a gas collecting device provided on the downstream side of the fixing device.

FIG. 2 is a diagram showing another installation layout of the gas collecting apparatus. According to this installation layout, the gas collection device is arranged immediately behind the fixing device.
In the present invention, the layout is not limited to this embodiment as long as the generated gas is efficiently collected.

  FIG. 3 is a diagram showing an example in which a suction device is provided in the gas collection device of the present invention. According to this, the inside of a collection device is made into a negative pressure rather than the circumference | surroundings of an apparatus by attracting | sucking air from one end of an airflow collection device using a fan or a small suction pump. As a result, a suction airflow is generated in the gas collecting device, and water vapor and other gases can be collected without escaping. In the case of a pump, the tube can be piped freely from the collection device, and is not necessarily integral with the collection device.

  FIG. 4 is a view showing an example in which a duct for air transfer is further provided between the fixing device and the gas collecting device. According to this, since the sheet is discharged from the heating roller of the fixing device and is transferred to the gas collecting device from the time when the sheet is transferred to the gas collecting device, most of the generated gas such as water vapor passes through the transfer duct. And sucked into the gas collector. Therefore, according to this apparatus, the collection effect can be improved.

FIG. 5 shows an example in which the collecting agent to be arranged in the gas collecting device is made into a sheet shape, the sheet-like material is arranged vertically and sucked from the back surface, and FIG. 6 shows the collecting agent and the gas. The example of the suction system using the air pump for making it contact is shown. The sheet of the collecting agent is provided so as to be ventilated, and the sucked gas such as water vapor is diffused and adsorbed inside the sheet. Examples of the method for forming a sheet-like material include a material in which a collection agent is carried on a fibrous material, and a method in which a granular collection agent is aggregated and bound to have air permeability through a binder resin. It is done. In addition, a container having air permeability, a package, or a net containing a granular or powdery collecting agent may be used instead of a sheet.
Examples of the collecting agent include various water absorbing and adsorbing materials such as silica gel, zeolite, activated carbon and the like. In addition, as a substance having a photocatalytic action, for example, titanium oxide or the like is used. The substance having the photocatalytic action can also be used, for example, in the form of a sheet as in the case of the collecting agent. It is more effective to use the collection agent and the substance having a photocatalytic action in combination, for example, by a method of laminating each sheet-like material.
FIG. 7 shows an example in which a substance having a photocatalytic action is arranged in a sheet shape on the gas collection device. The gas is sucked by suction means on the back side of the sheet-like material, and a light source for activating the photocatalytic action is provided on the front side. Titanium oxide or the like, which has an action of decomposing molecules of adsorbed gas by light, has a photoactive action and depends on the wavelength of light, but can decompose and clean a part of the collected gas. Various shapes such as LEDs can be used as the light source.
In the example of this figure, a new light source is provided. However, it is also possible to guide the scanner light or charge removal light and use it as the light source.

It is an installation outline figure of the gas collection device concerning the present invention. 1 is a schematic diagram of a fixing device and a gas collecting device according to the present invention. It is the figure which showed the example of the suction device of the gas collection apparatus which concerns on this invention. It is the figure which showed the duct of the gas transfer means which concerns on this invention. It is a schematic diagram of the gas collection apparatus which concerns on this invention. It is the figure which showed the air pump for suction and contact which concerns on this invention. It is an airflow collection apparatus figure provided with the light source which concerns on this invention.

Claims (8)

An image forming apparatus comprising a device for collecting a gas in a sheet conveyance process on a downstream side of a fixing device. The image forming apparatus according to claim 1, wherein the inside of the gas collecting device has a negative pressure higher than that of the fixing device and its surroundings. The image forming apparatus according to claim 1, further comprising means for transferring a gas generated by the fixing device to the gas collecting device. The image forming apparatus according to claim 1, wherein a gas collecting agent is disposed in the gas collecting device. The image forming apparatus according to claim 1, wherein the collecting agent has air permeability. The image forming apparatus according to claim 5, wherein the collecting agent is a porous molded body. The image forming apparatus according to claim 1, wherein a substance having a photocatalytic action is disposed in the gas collecting device. The image forming apparatus according to claim 7, further comprising a light irradiation unit.

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