JPH04257881A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image forming device provided with a filter excellent in the inhaling properties of outside air and the collecting ability of fine powder and dust, on the intake of the outside air. CONSTITUTION:When positive and negative high voltages are applied to the filters 4 and 5 from an external feeder part, materials which have positive and negative potentials and are induced/electrified, such as the fine powder and the dust 15-17 in the outside air which are sucked from a cooling fan 2, are attracted/collected to the filter mediums 4 and 5. On the other hand, the dust or the fine powder 18 which are not electrically attracted, are mechanically filtered. Thus, the meshes of the filter mediums 4 and 5 are roughened, and the sucking resistance of the cooling fan 2 is reduced, so that the cooling fan 2 can be made small. Further, wind cutting noises on the filter mediums 4 and 5 are reduced.

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 laser beam printer or an electrophotographic copying machine, which is equipped with a cooling device that cools the apparatus by forcibly generating air flow.

0002

[Prior Art] An image recording device using a light beam scans a modulated light beam onto a photoreceptor to form a latent image on the photoreceptor, which is then turned into a visible image in a developing unit. The image is transferred onto a sheet of paper that has been transported, and is fixed by being pressed against it by a heated roller of a fixing device. Conventionally, image forming apparatuses with this type of configuration are equipped with cooling fans to prevent the generated heat and ozone from accumulating inside the apparatus, and when the apparatus is in operation, the air inside the apparatus is vented to the outside. Or, outside air was being led into the equipment. Also, at that time, fine powder and dust present in the outside air accumulates on electrical boards etc. due to long-term use, increasing leakage current and reducing image quality, so do not allow this fine powder and dust to enter the device. For this reason, the outside air intake is equipped with a dust filter with fine mesh that prevents fine particles and dust from passing through. The same applies to electrophotographic copying machines.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, it is necessary to increase the density of the filter material of the dust-proof filter to a certain extent in order to ensure the ability to take in outside air. There was fine powder and dust that could get inside.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus equipped with a filter at an intake port for the outside air, which has good outside air suction properties and has an excellent ability to collect fine powder and dust.

[0005]

[Means to solve the problem]. The present invention provides an image forming apparatus equipped with a cooling air blowing means for sucking outside air into the interior and a dustproof filter at an intake port for the outside air by the cooling air blowing means in order to cool an internal image forming means. The image forming apparatus is characterized by having a charging means for charging the device to a predetermined potential.

[0006]

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention, in which a duct 4 penetrating an exterior cover of an image forming apparatus is shown as a whole.
It is set to 0. That is, the protective cover 1 for protecting the filtration device of the present invention from external physical action is disposed on the outermost side. When the innermost cooling fan 2 and the filter of the present invention are installed between the innermost cooling fan 2 and the protective cover 1, which are conventionally attached to the device, there is a space other than the filter. A gasket 3 is arranged to cut off outside air from the outside, and filters 4 and 5 are placed on the outside
is arranged to maintain the filters 4 and 5 at a constant interval,
A spacer 6 is interposed to prevent them from coming into contact with each other. Conductors 7 and 8 for applying a certain potential to the filters 4 and 5 are coupled to the filters 4 and 5, respectively. A connector means 9 is provided for insulating the conductors 7 and 8 and facilitating connection between the conductors 7 and 8 and an external power supply section.

The connector means 9 is connected to an external power supply means (not shown in FIG. 1) to maintain the filters 4 and 5 at a high voltage potential.

[0008] FIG. 2 schematically shows the movement of the device shown in FIG. 1 in order to explain its operation, and the gasket 3 and spacer 6 shown in FIG. 1 are not shown. External power supply unit (high voltage power supply) for supplying high voltages of different signs to filters 4 and 5, respectively.
10 are provided. The hatching shown above and below the cooling fan 2 indicates the members that partition the inside and outside of the device.
In FIG. 2, the right side of the hatching indicates the inside of the device. In FIG. 2, it is assumed that there is no intrusion of outside air from the duct 40 indicated by the dotted line.

Now, let us assume that the cooling fan 2 tries to take in outside air in an environment where plus, minus, neutral, and other dust and fine particles 15 to 18 exist as shown in FIG. . There is no dust or fine powder on the outside of the device.
8 is present and is drawn towards the device by the air flow generated by the cooling fan 2. The dust and fine particles 15 to 18 attracted to the device pass through the protective cover 1, pass through the filter 4, and reach the filter 5. At this time, a positive high voltage is applied to the filter 4 from the external power supply unit 10. Among the dust and fine particles 15 to 18 passing through the filter 4, the dust and fine particles 16 and 17 are negatively charged, so
Furthermore, since the particles are dielectrically separated, they are attracted to the filter 4 by electric attraction and filtered. Further, other dust or fine powder 18 is filtered out by the mechanical filtration action of the original filter material of the filter 4.

[0010] Next, the outside air filtered by the filter 4 further passes through the filter 5 and is led into the inside of the device. At this time, a negative high voltage is applied to the filter 5 from the external power supply unit 10, and the dust and fine particles 15 to 1 passing through the filter 5 are applied to the filter 5.
Of the particles 8, dust or fine powders 15 and 17 are positively charged and are dielectrically separated, so that they are attracted to the filter 5 by electric attraction and filtered. Further, other dust or fine powder 18 is filtered out by the mechanical action of the original filter material of the filter 5.

[0011] In this way, the outside air that has been filtered through the double-walled filter is introduced into the inside of the device.

0012

[Other Embodiments] FIG. 3 shows another embodiment. A protective cover 1 for protecting the filtration device from external physical effects is arranged on the outermost side, and a cooling fan 2 conventionally attached to the device is arranged on the innermost side. This embodiment is similar to the previous embodiment in that it includes a gasket 3 for blocking outside air from other than the filter 20 when the cooling fan 2 and the filter, generally designated by the reference numeral 20, are attached. Filter media 11a, 11b made of a large number of plate-shaped materials are arranged so that their plate surfaces follow the ventilation direction. A spacer 11 is provided to maintain the filter media 11a and 11b at a constant interval and prevent them from coming into contact with each other. The filter media 11a, 11b each have conductors for applying potentials of opposite signs alternately, and these are connected to an external power supply device (not shown). Further, a filter material (a non-conductor, not shown in FIG. 3) is filled between the filter materials 11a and 11b, so that a certain degree of filtration effect is exhibited even with normal air flow.

FIG. 4 schematically shows the operation of FIG. 3, and shows an external power supply section (high voltage power supply) for supplying high voltages of opposite signs to the filter media 11a and 11b. 10 is wired. Further, the hatching shown above and below the cooling fan 2 indicates members that partition the inside and outside of the device, and in FIG. 4, the right side of the hatching shows the inside of the device. Further, in FIG. 4, it is assumed that there is no intrusion of outside air from the duct 40 indicated by the dotted line. A filter member 13 made of a non-conductor is filled between the filter media 11a and 11b.

Now, assume that the cooling fan 2 attempts to take in outside air in an environment such as that shown in FIG. Dust and fine powder 15 to 18 exist outside the device, but are drawn into the device by the air flow generated by the cooling fan 2. Dust and fine powder attracted to the device pass through the protective cover 1 and reach the filter 20, but at this time, a positive high voltage is applied to the filter medium 11a from the external power supply unit 10, and the filter 11b is Dust and fine particles 15 that pass through the filter when a negative high voltage is applied from the external power supply unit 10
Since the dust or fine powders 15, 16 and 17 among the particles 18 to 18 are electrically charged and dielectrically separated, they are attracted to the filter medium 11a or 11b by electric attraction and filtered. Also, other dust or fine powder18
is mechanically filtered by the action of the filter medium 13.

[0015] In this way, the outside air that has been filtered through the double-walled filter is guided into the inside of the device.

[0016]

Effects of the Invention As explained above, by attaching a filtration member to the cooling fan of the device and applying a potential, it is possible to reduce the static pressure of the cooling fan more than necessary when trying to obtain the effect of a filter. Although it was necessary to design the air volume to compensate for the obstruction caused by the filter, it is now possible to obtain the same filtration effect even if the amount of filter material in the filter is reduced, which reduces the static pressure and air volume of the cooling fan. It is possible to provide a more economical cooling system. Additionally, since the air resistance caused by the filter can be reduced, unnecessary noise such as wind noise can be suppressed as much as possible.

[Brief explanation of the drawing]

FIG. 1 is a perspective view that best illustrates the structure of a cooling fan section in which the present invention is implemented.

FIG. 2 is a schematic diagram illustrating the actual operation of a cooling fan section embodying the present invention.

FIG. 3 is a perspective view that best represents the structure of another embodiment of the present invention.

FIG. 4 is a schematic diagram showing the actual operation of another cooling fan unit implementing the present invention.

[Explanation of symbols]

1 Protective cover 2 Cooling fan 3 Gasket 4 Filter 5. Filter 6 Spacer 7 Conductor 8 Conductor 9 Connector means

Claims (1)

[Claims] Claim 1: For cooling the internal image forming means,
An image forming apparatus equipped with a cooling air blower for sucking outside air into the interior, and a dustproof filter at an intake port for the outside air by the cooling airflow means, further comprising a charging means for charging the dustproof filter to a predetermined potential. An image forming apparatus characterized by: