JP2003271044A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which prevents a temperature rise in the apparatus and reduces power consumption by insulating a space between a heat generating source and a temperature rise restricting part in the image forming apparatus. <P>SOLUTION: A fixing cover 5 including a vacuum layer 4 is disposed so as to surround the vicinity of the upper part of a fixing device 1. An air duct 6 is disposed in the vicinity of the vacuum layer 4. Air flow into the air duct is caused by a blowing means. In order to form the vacuum layer 4, a vacuum insulator in which an insulating core material is vacuum-sealed is used. <P>COPYRIGHT: (C)2003,JPO

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 a copying machine, a laser printer and a laser FAX.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using an electrophotographic system forms an electrostatic latent image on the surface of a photosensitive drum which is an image carrier, and the electrostatic latent image on the photosensitive drum is a toner which is a developer. Etc. to develop it into a visible image, transfer the developed image to a transfer material with a transfer device, carry the image on the transfer material, and transfer the toner image on the transfer material with a fixing device using pressure or heat. An image is formed by performing each step of fixing on the material.

Although an image can be obtained through these processes, in order to miniaturize the image forming apparatus, each member such as a photosensitive drum, a cleaning device, a developing device, a transfer device and a fixing device should be arranged close to each other. become. For this reason, the cleaning device may be placed near a heat source such as a fixing device that has a high temperature. In that case, the toner inside the cleaning device is melted and agglomerated due to the influence of heat, and the collected toner is discharged outside the machine. It became difficult to do so.

In order to avoid such a problem, as means for suppressing the temperature rise in the image forming apparatus, the image forming apparatus takes in the air outside the image forming apparatus into the image forming apparatus and the exhaust of the taken-in outside air. As well as providing an outlet,
As shown in FIG. 3, the exhaust fan 8 cools the periphery of the fixing device by the outside air taken in from the intake port, and at the same time, the hot air generated at the same time is positively discharged to the outside of the image forming apparatus.

Further, as the efficiency of the air flow has been improved in recent years, as shown in FIG. 8 of Japanese Patent Laid-Open No. 2000-227730, another cover 102 is provided between the upper cover 101 of the fixing device 1 and the developing device thereon. Fix the fixing device 1
The intake fan 1 is provided between the first air flow path for allowing the hot air inside to flow outside by the exhaust fan 8, the cover 102, and the catch pan 103 for receiving toner spilled from the developing device.
There is a method of suppressing the temperature rise in the image forming apparatus by forming a second air flow path for taking in and flowing the outside air and discharging the outside air again at 04.

[0006]

However, in the conventional structure, the heat of the fixing device itself is also taken away by the exhaust fan provided in the vicinity of the fixing device, so that the fixing heater for keeping the fixing device at a predetermined temperature is used. There has been a problem that the power consumption increases as the energization time increases.

Further, when the cleaning device is arranged close to the fixing device, the heat of the fixing device is easily transferred to the cleaning device by heat conduction, heat radiation, etc. even though the inside of the fixing device is cooled by the fan. Therefore, it is necessary to increase the distance between the cleaning device and the fixing device so that the cleaning device is not overheated excessively, and the image forming apparatus has been increased in size.

In addition, the cooling fan is made powerful,
There is also a method to improve the cooling capacity, but the fan becomes larger and the image forming apparatus becomes larger due to the space,
There was a problem of high cost. Further, since it is a large-sized exhaust fan that rotates at high speed, there has been a problem that noise and power consumption increase due to it.

Therefore, according to the present invention, between the fixing device in the image forming apparatus and the temperature rise suppressing portion which needs to keep the temperature of the cleaning device low without sacrificing the function and downsizing of the image forming apparatus. An object of the present invention is to provide an image forming apparatus capable of preventing the temperature rise in the image forming apparatus by performing the heat insulation and keeping the inside of the fixing apparatus to reduce the power consumption.

[0010]

In order to achieve the above object, the invention according to claim 1 of the present application provides an image carrier, and
In an image forming apparatus having a fixing device for fixing the toner image formed by the image carrier on a transfer material, a vacuum layer is provided around the fixing device.

The invention according to claim 2 according to the present application is characterized in that, in the invention according to claim 1, a vacuum heat insulating material in which a heat insulating member is vacuum sealed is used for the vacuum layer.

The invention according to claim 3 of the present application is characterized in that, in the invention according to claims 1 and 2, a cover for forming an air layer is provided around the vacuum layer. The invention according to claim 4 of the present application is defined by claim 1.
The invention according to any one of claims 1 to 3 is characterized in that cover means for forming an air layer is provided around the vacuum layer, and air is caused to flow to the air layer in the cover means by a blowing means.

According to the above structure, since the vacuum layer is provided around the upper portion of the fixing device, the heat generated from the fixing device is effectively insulated, so that it is necessary to keep the temperature of the cleaning device low. It is possible to prevent the temperature rise of the temperature suppression unit. Further, by surrounding the vacuum layer with a cover and flowing air into the cover, the fixing device and the temperature rise suppressing unit can be isolated from each other, so that the temperature rise in the image forming apparatus can be prevented and the temperature rise suppressing unit is adversely affected. It is possible to perform image formation, etc. Further, since the high temperature air inside the fixing device is not exhausted, the inside of the fixing device can be kept warm and the power consumption can be reduced. Also,
Since the heat from the fixing device is insulated by the vacuum layer,
Since it is not necessary to provide a wide space between the fixing device and the temperature rise suppressing portion and the heat can be effectively exhausted with a small amount of air, it is possible to exhaust even a small fan with a low rotation speed. As a result, the image forming apparatus can be downsized and the cost can be reduced, and the noise and power consumption of the fan can be reduced.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a sectional view of a fixing device 1 according to an embodiment of the present invention. Figure 2
Shows an image forming apparatus A having a temperature rise suppressing section 12 which is required to keep the temperatures of the fixing device 1 and the cleaning device, which are embodiments of the present invention, low. In FIG. 1, a fixing device 1 has a fixing roller 2 and a pressure roller 3 which are a pair of rotating bodies, and a heater (not shown) in the fixing roller 2 brings the surface of the fixing roller 2 to a predetermined temperature. By passing the transfer material S carrying the toner image between the fixing roller 2 and the pressure roller 3 in a heated state, the transfer material S is heated and pressed to fix the toner image on the transfer material S. Has become. The transfer material S that has passed through the fixing device 1 is then discharged through a paper discharge path 11 to a paper discharge tray (not shown).

In this embodiment, a fixing cover 5 including a vacuum layer 4 is arranged so as to surround the upper portion of the fixing device 1. The fixing cover 5 including the vacuum layer 4 covers the fixing device 1 in the longitudinal direction up to the rear end of the fixing device 1. The fixing cover 5 is made of a material having a low thermal conductivity such as resin. Further, in order to form the vacuum layer 4, the heat insulating core material 1
A vacuum heat insulating material 13 in which 4 is vacuum-sealed is used (Fig. 3
reference).

The vacuum heat insulating material 13 used in this embodiment is used in a heat insulating container such as an electric water heater, and has a high degree of vacuum, and therefore has a higher heat insulating performance than other heat insulating materials such as glass wool. .

The vacuum heat insulating material 13 is disclosed in
No. 01-8828, detailed description will be given here with reference to the drawings. FIG. 3 shows a sectional view of the vacuum heat insulating material 13. Reference numeral 14 is a core material 14 of the vacuum heat insulating material 13. The laminated film 15 is composed of a seal layer 16, a gas barrier layer 17, and a protective layer 18. The vacuum heat insulating material 13 is a packaging material made of the laminated film 15 in which a heat insulating core material 14 is sealed and evacuated. Gas barrier layer 17
Include those using a metal foil such as aluminum foil and those using a vapor deposition layer such as aluminum vapor deposition.

As shown in FIG. 4, the vacuum heat insulating material 13 is a flat plate having a rectangular shape. Reference numeral 19 is a portion containing the core material 14 and having a heat insulating property as the vacuum heat insulating material 13.
Is a heat-sealed portion, which is a portion where the seal layer 16 is welded, and is a portion where the core material 14 is not contained.

When actually incorporating the fixing cover 5, the fixing cover 5 shown in FIG.
As shown in the above, it is bent into a U-shape according to the size of the fixing cover 5. At this time, the heat seal portion 20 is attached to the folding fixing cover 5 so that the heat seal portion 20 is located outside the U-shape. By doing so, the heat seal portion 20 has a high temperature in the fixing device 1.
Since there is no direct contact with the side, heat deterioration is reduced. In the present example, in the gas barrier layer 17 in the laminated film 15, a metal foil such as an aluminum foil was used inside the U-shape exposed to high temperature (on the fixing device 1 side). In addition, a vapor deposition layer such as aluminum vapor deposition was used on the outside of the U-shape where the temperature is low because it is insulated. The metal foil is excellent in gas barrier property at high temperature, whereas the vapor deposition layer is excellent in heat insulating property as compared with the metal foil because the vapor deposition layer is very thin, but is inferior in gas barrier property at high temperature. Therefore, by using the metal foil on the high temperature side, it is possible to sufficiently maintain the vacuum state,
The heat insulating property does not deteriorate for a long period of time, and by using the vapor deposition layer on the low temperature side, the heat flowing through the metal foil from the high temperature side can be suppressed, and the heat insulating performance of the entire vacuum heat insulating material 13 can be improved. it can.

Since the fixing device 1 is not provided with a suction port or an exhaust port, the heat inside the fixing device 1 is unlikely to escape to the outside, so that the inside of the fixing device 1 is kept at a high temperature.

An air duct 6 is arranged around the vacuum layer 4. The air duct 6 is attached from below to a partition wall 7 that divides the inside of the image forming apparatus into an upper portion where the exposure unit is arranged and other portions. That is,
The upper surface of the air duct 6 is formed by a part of the partition wall 7. Air taken in from the outside of the image forming apparatus flows into the air duct 6 in a direction perpendicular to the paper surface of FIG. 2 and is exhausted to the outside of the image forming apparatus by the exhaust fan 8.

According to this structure, the high temperature air in the fixing device 1 is sealed and is insulated by the vacuum layer 4,
The inside of the fixing device 1 can be maintained at a high temperature with minimum heating. This leads to a reduction in the power consumption of the fixing device 1.

By providing the vacuum layer 4 around the upper portion of the fixing device 1, the heat generated from the fixing device 1 is effectively insulated, so that the temperature rise in the image forming apparatus can be prevented. Further, by surrounding the vacuum layer 4 with the air duct 6 and flowing the air into the air duct 6, the fixing device 1 and the temperature rise suppressing portion 12 can be isolated from each other, so that the temperature rise in the image forming apparatus can be prevented and the temperature rise can be suppressed. Image formation and the like can be performed without adversely affecting the section 12. Further, since the heat from the fixing device 1 is thermally insulated by the vacuum layer 4, the fixing device 1 and the temperature rise suppressing unit 1
Since it is not necessary to make a wide space between the two and the heat can be effectively exhausted with a small amount of air, it can be exhausted even by a small fan with a low rotation speed. As a result, the image forming apparatus can be downsized and the cost can be reduced, and the noise and power consumption of the fan can be reduced.

In the above construction, the small-sized, low-rotation exhaust fan 8 is used exclusively for the fixing device 1. However, since a small air volume is required, another exhaust fan 8 in the image forming apparatus is used instead of the dedicated exhaust fan 8. The exhaust fan 8 may be connected by a duct and air from another exhaust fan 8 may be used. As a result, it is possible to realize lower cost, lower noise, and lower power consumption.

Further, as shown in FIG. 3, the reflection sheet 9 may be attached inside the fixing cover 5 including the vacuum layer 4 (on the fixing roller 2 side). The reflection sheet 9 is an aluminum sheet, the surface of which is mirror-finished, and reflects radiant heat generated from the fixing roller 2. By providing the reflection sheet 9, the radiant heat generated from the fixing roller 2 is reflected into the fixing device 1, so that the air in the fixing device 1 can be kept at a higher temperature and the outside of the fixing device 1 can be moved. Radiant heat can be reduced. As a result, the temperature rise of the image forming apparatus can be further prevented, and the power consumption of the fixing device 1 can be reduced.

[0026]

As described above, by providing the vacuum layer around the upper portion of the fixing device, the heat generated from the fixing device is effectively insulated, so that the temperature rise in the image forming apparatus can be prevented. .

By surrounding the vacuum layer with an air duct and allowing air to flow in the air duct, the fixing device and the temperature rise suppressing unit can be isolated from each other, so that the temperature rise in the image forming apparatus can be prevented and the temperature rise suppressing unit can be prevented. Image formation and the like can be performed without adverse effects.

Further, since the high temperature air inside the fixing device is not exhausted, the inside of the fixing device can be kept warm and the power consumption can be reduced.

Further, since the heat from the fixing device is insulated by the vacuum layer, a space is not required between the fixing device and the temperature rise suppressing portion, and the heat can be effectively discharged with a small amount of air, so that the heat is low. Even a small rotating fan can exhaust air. As a result, the image forming apparatus can be downsized and the cost can be reduced, and the noise and power consumption of the fan can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a fixing device and an air duct surrounded by a vacuum layer according to an exemplary embodiment of the present invention.

FIG. 2 is a front sectional view of an image forming apparatus including a fixing device of the present invention.

FIG. 3 is a sectional view of a vacuum heat insulating material used in an example of the present invention.

FIG. 4 is a plan view of a vacuum heat insulating material used in an example of the present invention.

FIG. 5 is a mounting view of a vacuum heat insulating material used in an embodiment of the present invention.

FIG. 6 is a diagram in which a reflection sheet is drawn in FIG.

FIG. 7 is a sectional view illustrating a conventional fixing device.

FIG. 8 is a sectional view illustrating a conventional fixing device.

[Explanation of symbols]

1 ... Fixing device 2 ... Fixing roller 3 ... Pressure roller 4 ... Vacuum layer 5: Fixing cover 6 ... Air duct 7 ... Partition 8 ... Exhaust fan 9 ... Reflective sheet 10 ··· Cleaning device 11 ... Paper discharge path 12 ... Temperature rise suppression unit 13 ... Vacuum insulation 14 ... Core material 15 ... Laminated film 16 ... Seal layer 17 ... Gas barrier layer 18 ... Protective layer 19 ... Parts containing core material 20 ... Heat seal part A ... Image forming apparatus S: Transfer material

Claims (4)

[Claims] 1. An image forming apparatus having an image carrier and a fixing device for fixing a toner image formed by the image carrier onto a transfer material, wherein a vacuum layer is provided around the fixing device. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein a vacuum heat insulating material in which a heat insulating member is vacuum sealed is used for the vacuum layer. 3. The cover means for forming an air layer is provided around the vacuum layer.
Alternatively, the image forming apparatus described in 2. 4. A cover means for forming an air layer is provided around the vacuum layer, and air is blown into the air layer in the cover means by a blower means.
The image forming apparatus according to any one of 1 to 3.