JPH04305664A - Image forming device - Google Patents

Abstract

PURPOSE:To postpone the interval of exchanging a dustproof filter by providing a driving means for switching the dustproof filter which is wider than the cross section of an air conducting path and the position of the dust suction surface of the dustproof filter. CONSTITUTION:The take-up type dustproof filter 1 for removing dust such as toner or paper powder in the air is arranged halfway through a duct 12. The cross section 22 of the duct 12 at a part where the filter 1 is provided is enlarged to be larger than the cross section 21. Then, a motor 3 for driving a rotary shaft 4 which takes up the filter 1 is provided. Ozone evolved by corona discharge around the electrostatic charging line 10a of an electrostatic charger 10 is sucked by a suction fan 11 and flows in the duct 12. Air flow passes through the filter 1, passes through an ozone filter 14 provided near an exhaust port 16 and is exhausted. At such a time, the filter 1 is taken up little by little by the motor 3.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to an image forming apparatus such as a copying machine or a printer, and more particularly to an image forming apparatus including an ozone removing means for removing ozone generated by corona discharge and a dustproof filter provided in front of the ozone removing means. It is related to the device.

0002

2. Description of the Related 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.

[0003] 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.

[0004] When the photoreceptor is charged or neutralized by the corona discharger, ozone (O3) and nitrogen oxides (NOx) are emitted.
) etc. occur. 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.

[0005] Air containing the above-mentioned high concentration of ozone may have an adverse effect on the human body, so it is desirable that the ozone generated within the apparatus is not discharged to the outside of the apparatus as much as possible.

[0006] For this reason, air containing high concentration of ozone around the corona discharger is sucked in by a fan and passed through an ozone filter, and the ozone is adsorbed and removed by the ozone filter, and the air is exhausted outside the device. Further, a dustproof filter is provided in front of the ozone filter to prevent dust such as toner and paper dust in the air from adhering to the ozone filter.

That is, as shown in FIGS. 5 and 6, a charger 10
Ozone generated by corona discharge around the charged wire 10a is sucked in by the intake fan 11 and flows into the duct 12 as shown by the arrow in the figure.

[0008]The airflow passes through the dustproof filter 13 installed near the exhaust port 16, and toner and paper dust in the air are adsorbed, so the ozone decomposition performance of the ozone filter is prevented by the dust. is prevented. Furthermore, the air flow is controlled by an activated carbon filter installed on the exhaust port 16 side.
Or an ozone filter 14 made of a metal catalyst filter
By passing through the exhaust gas, most of the ozone in the exhaust gas is adsorbed or decomposed, so the ozone concentration after exhaust gas is suppressed to a very small amount.

[0009]

[Problems to be Solved by the Invention] However, in the above-mentioned prior art, dust such as toner and paper powder scattered in the air inside the device is blown onto the filter surface and adsorbed by the dustproof filter 13. If the amount continues to increase, there is a risk that the dust adsorption performance of the dust filter 13 will decrease or that the air flow will deteriorate.

[0010] Therefore, the dust filter 13 needs to be periodically cleaned and replaced by a service person, resulting in high maintenance costs.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a dustproof filter that is wider than the cross section of the air conduction path, and a drive means for switching the position of the dust suction surface of the dustproof filter, and to replace the dustproof filter. The present invention provides an image forming apparatus that can extend the interval.

0012

[Means for Solving the Problems] The present invention provides an image forming means for forming an image by exposing an image bearing member charged by a corona discharger, a suction means capable of suctioning air within the apparatus, and a suction means capable of suctioning air within the apparatus. a conductive path for guiding the air sucked by the device out of the device; a dust-proof filter provided in the conductive path for removing dust in the exhaust gas; and a dust-proof filter that is wider in cross-section than the conductive path, and the dust-proof filter adsorbs dust. The image forming apparatus has a drive means for switching the position of the surface, and an ozone filter for removing ozone in exhaust gas, which is provided on the downstream side of the dustproof filter in the conduction path.

[0013]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of the present invention, and FIG. 1 is a horizontal cross-sectional view that best represents the features of the present invention. The charging wire 10a uniformly charges the photoreceptor.
Equipped with An intake fan 11 is interposed in an exhaust gas passage provided from the charger 10 to an exhaust port 16 provided in the exterior cover 15 as a suction means for sucking air containing ozone generated by corona discharge around the charging wire 10a. . The conduction path covers the charger 10 and collects the ozone generated by the charger 10 together with the air and guides it into the intake fan casing part 17 that houses the intake fan 11, and one end is connected to the intake part on the discharge side of the intake fan 11. It is formed of a duct 12 and the like connected to the fan casing 17 and the other end connected to the exhaust port 16.

A retractable dustproof filter 1 is disposed in the middle of the duct 12 to remove dust such as toner and paper dust from the air. A dustproof filter case 2 to which the retractable dustproof filter 1 is attached is attached to the duct 12. A motor 3 is provided to drive a rotating shaft 4 for winding up the wind-up type dustproof filter 1. An ozone filter 14, which is ozone removal means for removing ozone contained in the air inside the apparatus and exhausting it outside the apparatus, is removably attached to the exterior cover 15 so as to cover the exhaust port 16.

The area of the cross section 21 of the duct 12 is selected so that the head loss of exhaust gas is small, but the cross section 22 of the part where the dust filter 1 is provided is enlarged to a larger cross sectional area than the cross section 21; The part is a square. This is intended to reduce the resistance of air passing through the dustproof filter 1, prevent a decrease in exhaust volume, and maintain filtration performance for a long time.

As shown in FIG. 2, the cross section 22, that is, the area between the inlet side of the dust filter 1 and the exhaust port 16 is a uniform rectangular cross section.
A slit 19 is arranged on the opposite wall of this part, and the band-shaped dustproof filter 1 passes through the slit 19. A flocked airtight material 23 is fixed to the duct 12 on both sides of the slit 19 in contact with the dustproof filter 1, and the airtightness material 23 is in contact with the dustproof filter 1 to ensure airtightness. Both edges of the dust filter 1 are held by an airtight material (not shown) provided on a wall perpendicular to the wall in which the slit 19 is provided. Dust filter 1
is wound around a delivery shaft 24 rotatably supported by the dust-proof filter case 2 to form a dust-proof filter roll 25. On the other hand, the dust filter 1 pulled out from the dust filter roll 25 crosses the duct 12 through the slit 19.
The dustproof filter 1 that has come out of the duct 12 through the other slit 19 has its end fixed to a rotating shaft 4 in the dustproof filter case 2 and is wound around the shaft. The rotating shaft 4 is connected to the motor 3.

The rotating shaft 4 is driven to rotate at a low speed by the motor 3 during the image forming operation, and the dust-proof filter 1 that has absorbed dust comes out of the duct 12 and is wound around the rotating shaft 4, and is replaced by a dust-proof filter roll 25. A control device is provided so that the unadsorbed portion comes out into the duct 12.

To explain the operation of the exhaust structure configured as described above, first, when an image forming operation is performed, ozone generated by corona discharge around the charging wire 10a of the charger 10 is sucked by the intake fan 11. Introduction part 18
As a result, the liquid flows into the duct 12 as shown by the arrow in FIG. As the airflow passes through the dustproof filter 1, most of the dust such as toner and paper dust in the air is adsorbed, so the dust adheres to the ozone filter 14 on the downstream side, deteriorating the ozone decomposition performance. This is prevented. Since the dustproof filter 1 is wound up little by little by the motor 3, even if dust adheres to it, there is no need to replace it until the entire surface of the dustproof filter 1 capable of attracting dust is wound up. Dust filter 1
The airflow that has passed through the exhaust port 16 passes through the ozone filter 14, which is an activated carbon filter or a metal catalyst filter, and most of the ozone in the exhaust gas is adsorbed. ozone concentration is suppressed to a very small amount.

In the case of the present embodiment, the dustproof filter 1 has a wider filter surface than the conventional filter which is equivalent to the cross section of the duct, so that the dustproof filter can be replaced at longer intervals and maintenance costs can be reduced.

Furthermore, since dust is adsorbed by the dustproof filter, it is possible to prevent the ozone filter from adsorbing dust and deteriorating its ozone decomposition performance, thereby improving the durability of the ozone filter and reducing costs.

[0021]

[Other Embodiments] Next, with reference to FIGS. 3 and 4, another embodiment will be described in which the winding interval of the windable dustproof filter is controlled by changes in the wind force.

This embodiment has an anemometer 5 in the duct 12 for measuring changes in the wind speed in the duct 12, and detects a decrease in the wind speed to drive the rotating shaft of the windable dustproof filter. A control device 6 for controlling the motor 3 is provided.

To explain the operation of the exhaust structure configured as described above, first, when an image forming operation is performed, ozone generated by corona discharge around the charging wire 10a of the charger 10 is sucked by the intake fan 11. , flows into the duct 12 as shown by the arrow in FIG. Then, the air flow passes through the wind-up type dustproof filter 1 which is stopped, thereby removing dust such as toner and paper powder in the air. Furthermore, since most of the ozone in the exhaust gas is adsorbed by passing through the ozone filter 14, the ozone concentration in the exhaust gas is suppressed to a very small amount.

[0024] Furthermore, since the dust filter 1 continues to adsorb dust in the air that is continuously sent while it is stopped,
The dust adsorbed on the filter 1 becomes an obstacle to the air flow, reducing the wind speed. Then, when the wind speed measured by the anemometer 5 decreases below a certain constant value, the control device 6 instructs the motor 3 to be driven. That is, the static pressure detected by the anemometer 5 is piezoelectrically converted and compared with a reference voltage by a comparator, and when it becomes lower than the reference voltage, the drive circuit of the motor 3 is energized. Then, the part of the dustproof filter 1 to which dust has adhered is wound up, and the next unused dustproof filter 1 comes out into the duct 12, so that the wind speed recovers and increases. As a result, the static pressure detected by the anemometer 5 has increased, so the piezoelectrically converted voltage becomes higher than the reference voltage, and the motor 3 stops.

As in this embodiment, the dust filter can be effectively wound up by controlling the amount of dust attached to the dust filter by changing the wind speed.

[0026]

Effects of the Invention As described above, the present invention provides a driving means for changing the position of the dust suction surface of the dust filter, which is wider than the cross section of the air conduction path, provided in front of the ozone filter, thereby making it possible to replace the dust filter. By being carried out efficiently, the effect of eliminating clogging of the ozone filter can be obtained over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a horizontal sectional view showing an exhaust structure in an apparatus embodying the present invention.

FIG. 2 is an enlarged sectional view taken along line AA in FIG. 1;

FIG. 3 is a horizontal cross-sectional view of another embodiment.

FIG. 4 is an enlarged sectional view taken along line BB in FIG. 3;

FIG. 5 is a horizontal sectional view of a conventional example.

FIG. 6 is an enlarged sectional view taken along line CC in FIG. 5;

[Explanation of symbols]

1 Dustproof filter 2. Roll-up dustproof filter case 3 Motor 4 Rotation axis 5　Anemometer 6 Control device 10 Charger 11 Intake fan 12 Duct 14 Ozone filter

Claims (1)

[Claims] 1. An image forming means for forming an image by exposing an image bearing member charged by a corona discharger, a suction means capable of sucking air inside the apparatus, and a suction means for sucking the air inside the apparatus. A conductive path for guiding the air to the outside, a dust-proof filter provided in the conductive path for removing dust in the exhaust gas, and a dust-proof filter that is wider than the cross-section of the conductive path, and a position of a dust-adsorbing surface of the dust-proof filter are switched. An image forming apparatus comprising: a driving means; and an ozone filter for removing ozone in exhaust gas, which is provided on the downstream side of the dust filter in the conduction path.