JPH10207307A - Image forming device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To sufficiently remove ozone, suppress a temperature rise in the apparatus, and effectively use exhaust gas. An opening (32) having a smaller resistance than the ozone filter (31) is provided by closing the opening / closing shutter (33) during image formation and opening the opening / closing shutter (33) during idling.
Through the image forming unit 20 by the exhaust fan 30
Since the inside of the apparatus is configured to be exhausted, ozone generated during image formation can be sufficiently removed, the temperature inside the apparatus can be suppressed, and the exhaust can be used effectively.

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 provided with an image forming unit for forming an image on transfer paper by an electrophotographic process.

[0002]

2. Description of the Related Art An image forming apparatus such as a printer or a copying machine employs a known electrophotographic process in which a toner image is formed on a photoreceptor by respective steps of charging, exposure and development, and is transferred onto a transfer paper and fixed. However, at the time of charging and transferring in the electrophotographic process, ozone is generated which adversely affects the human body. In addition, it has a heat source such as a heating element of the fixing device for fixing the toner image, and the temperature inside the device rises, and each mechanism in the device may be heated and cause trouble or accelerate deterioration. was there.

In order to remove ozone and lower the temperature inside the apparatus, for example, as described in JP-A-56-14248, the inside of the image forming apparatus is exhausted by an exhaust fan through an ozone filter. I am trying to do it.

[0004]

However, in the above-described image forming apparatus, since the air is exhausted through the ozone filter, the resistance of the ozone filter becomes a resistance, and the amount of exhaust is reduced, thereby causing a rise in the temperature inside the apparatus. Alternatively, in order to suppress a rise in temperature, the number of rotations of the exhaust fan is increased and the amount of exhaust is increased (excessive exhaust is performed), so that power is consumed and the running cost is increased.

Accordingly, an object of the present invention is to sufficiently remove ozone, suppress a rise in temperature inside the apparatus, and effectively use exhaust gas.

[0006]

The above object is achieved by the following constitution.

(1) In an image forming apparatus having an image forming unit for forming an image on transfer paper by an electrophotographic process, the inside of the image forming unit is evacuated through an image exhaust path communicating with the image forming unit. Exhaust means, an ozone filter provided on the image exhaust path, an opening, and an opening and closing shutter for opening and closing the opening, and when the image is formed, the opening and closing shutter is closed, and when idling, An image forming apparatus, wherein the opening / closing shutter is opened.

(2) The image forming apparatus has an optical system unit having a scanning optical system for relatively moving the original and reading the image of the original, and based on the image read by the scanning optical system, Forming an image by the image forming unit,
The image forming apparatus according to (1), wherein an optical exhaust path communicating with the optical system unit is provided so that the inside of the optical system unit can be exhausted by the exhaust unit.

(3) The image forming apparatus according to (1) or (2), wherein the amount of exhaust by the exhaust means is smaller during idling than during image formation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a copying machine to which the present invention is applied, and FIG.
1 is a perspective view showing an opening 32 and an opening / closing shutter 33.

The copying machine according to the present embodiment has an optical system unit 10 having a scanning optical system for reading a document image by moving relative to the document, and an image read by the scanning optical system is visualized on a transfer paper. And an image forming unit 20 to be formed. The copying machine shown in FIG. 1 is of a so-called analog type in which an image read by a scanning optical system is directly guided to the photosensitive drum 21. However, the present invention is not limited to this. Thereafter, a so-called digital type in which a latent image is formed on the photosensitive drum 21 by laser light or the like, or a so-called printer without the scanning optical system unit 10 may be used.

The optical system unit 10 includes a platen 11 made of a transparent glass plate on which a document is placed, a platen cover 12 that covers the document placed on the platen 11, and a platen placed on the platen 11. A first scanning base 13 that relatively moves with a document including an illumination lamp 131 that is a light source for irradiating the document with light and a first reflection mirror 132 that reflects light reflected by the illumination lamp 131 from the document; A second reflecting mirror 141 that reflects the light reflected by the first reflecting mirror 132 and a third reflecting mirror 142 that reflects the light reflected by the second reflecting mirror 141. A second scanning base 14 that moves at a speed, a lens unit 15 that forms an image of a document on a photosensitive drum 21 described later, and a fixed second unit that reflects light passing through the lens unit 15 to the photosensitive drum 21. 4 And a morphism mirror 16. Therefore, the image of the document on the document table 11 illuminated by the illumination lamp 131 includes the first reflection mirror 132, the second reflection mirror 141, the third reflection mirror 142, and the lens unit 1.
5, and an image is formed on the photosensitive drum 21 via the fourth reflection mirror 16. Then, the first scanning gantry 13 and the second scanning gantry 14 moving at half the speed of the first scanning gantry 13
Scans the entire surface of the original document that is stationary on the original table 11. Since the illumination lamp 131 emits light only when scanning a document, the illumination lamp 131 serves as a heat source during a copying operation.
The temperature in the optical system unit 10 (the temperature of the document table 11 is particularly problematic) rises.

The image forming unit 20 forms a toner image on transfer paper by an electrophotographic process, and the process itself is well known, so that detailed description is omitted. The image forming unit 20 includes a photosensitive drum 21 having a photoconductive photosensitive layer, which is an image carrier that rotates clockwise in the figure, and a charging unit 22 that uniformly charges the photosensitive drum 21. Developing means 23 for developing an electrostatic latent image formed by exposing the above-described image light from the optical system unit 10 onto the charged photosensitive drum 21 as a toner image, and transfer separately transported Transfer / separation means 24 for transferring a toner image onto paper and separating the photoreceptor and the transfer paper
Cleaning means 25 for removing the toner remaining on the photosensitive drum 21 after transferring the toner image; and toner transferred onto the transfer paper by passing the transfer paper between a heating roller 261 and a pressure roller 262. Fixing means 26 for fusing and fixing the image.

The charging means 22 and the transfer / separation means 2
In No. 4, ozone is generated during image formation because a discharger is used. Further, the fixing unit 26 maintains the temperature of the heating roller 261 for fusing and fixing the toner image at a predetermined temperature (for example, 195 ° C., respectively) during the copying (copying) operation and during the standby (idling). The heat source 26 provided in the heating roller 261
3 is controlled by a CPU (not shown). Therefore, the temperature inside the image forming unit 20 increases.

In this embodiment, the air in the optical system unit 10 is exhausted by its own rotation as the exhaust means 30 for exhausting and cooling the interior of the optical system unit 10 and the image forming unit 20. An exhaust fan 30 for exhausting the air in the image forming unit 20 is also provided. The rotation of the exhaust fan 30 exhausts the air in the optical system unit 10 to the outside through the optical exhaust path 42 communicating with the optical system unit 10 and also removes the air in the image forming unit 20 from the image. The air is exhausted outside the apparatus via an image exhaust path 41 communicating with the forming unit 20. The optical system unit 10 and the image forming unit 20 are respectively housed in a housing, and the boundary between the optical system unit 10 and the image forming unit 20 is separated by a partition wall 43.
Is divided by

In the present embodiment, an ozone filter 31 as shown in detail in FIG. 2 and an opening 32 formed in the ozone filter 31 and an opening / closing shutter 33 for opening and closing the opening 32 are provided on the image exhaust path. Are provided. The ozone filter 31 is provided in the image forming unit 2.
By passing the air inside the chamber, the ozone generated by the charging means 22 and the transfer / separation means 24 is adsorbed, and the amount of ozone discharged outside the apparatus is reduced. Opening 3
Reference numeral 2 denotes a configuration in which the inside of the image forming unit 20 can be evacuated without passing through the ozone filter 31. In the present embodiment, the ozone filter 31 is notched. The opening / closing shutter 33 is a member that opens and closes the opening 32. When the opening / closing shutter 33 is in the open position, air can be exhausted through the opening 32, and when the opening / closing shutter 33 is in the closed position, air is exhausted through the ozone filter 31. In this embodiment, the opening / closing shutter 33 is provided so as to be rotatable about a support shaft 331. The opening and closing of the opening / closing shutter 33 is performed by a driving unit (not shown) based on control from a control unit such as a CPU (not shown).

This operation will be described with reference to the flow chart of the exhaust fan 30 and the opening / closing shutter 33 shown in FIG.
First, when the power of the copying machine is turned on (S1), the copying machine is initialized (S2). At this time, the exhaust fan 30 is set to L
o (for example, 1200 rpm), the opening / closing shutter 33 is set to the open position, the exhaust fan 30 exhausts air from the optical unit 10 and the image forming unit 20, and the exhaust air from the image forming unit 20 passes through the opening 3.
2 (slightly via the ozone filter 31) to prevent the fixing unit 26 from raising the temperature inside the apparatus. Then, the standby (idling) state is maintained until the copying operation is started in S3.

When the copying operation is started (S3), the exhaust fan 30 is rotated at a higher Hi rotation (for example, 30 rotations).
00 rpm), and a drive unit (not shown) is driven by a control unit (not shown) to set the opening / closing shutter 33 to the closed position so that exhaust from the inside of the image forming unit 20 is performed via the ozone filter 31. Ozone generated in the process is removed, and the temperature inside the device is prevented from rising (S4). Then, the copying operation ends (S
5), that is, in a standby (idling) state until the next copying operation is started, the exhaust fan 30 is again set to Lo rotation (for example, 1200 rpm), which is a lower rotation point than during the copying operation, and , Opening and closing shutter 33
Is set to the open position, exhaust by the exhaust fan 30 is performed from the optical system unit 10 and the image forming unit 20, and exhaust from the image forming unit 20 is further performed from the opening 32 (slightly through the ozone filter 31). The temperature inside the apparatus is prevented from rising due to the fixing unit 26 (S6).

As described above, in the present embodiment, attention is paid to the fact that ozone is generated during image formation, and during image formation, the opening / closing shutter 33 is closed to exhaust air through the ozone filter 31. At the time of idling, the opening / closing shutter 33 is opened to exhaust air from the image forming unit 20 through the opening 32 having a smaller resistance than the ozone filter 31. Ozone can be sufficiently removed, the temperature inside the apparatus can be suppressed from rising, and the exhaust gas can be used effectively.

Here, a comparison experiment was performed between the copying machine of the present embodiment and a conventional copying machine (a copying machine provided with the ozone filter 31 and not provided with the opening 32 and the opening / closing shutter 33). Table 1 shows the results. In Table 1, ○ indicates that the discharged ozone concentration and the temperature rise of each part (document table, image forming unit) are within the allowable range, and × indicates that the rise is out of the allowable range.

[0022]

[Table 1]

As is clear from Table 1, in the present embodiment, ozone generated during image formation is sufficiently removed.
In addition, the temperature rise in the apparatus can be suppressed, and the exhaust can be effectively used. In particular, the temperature rise in the image forming unit 20 during idling can be suppressed.

In this embodiment, the exhaust fan 30 exhausts not only the image forming unit 20 but also the optical system unit 10, so that the cost can be reduced. The structure can be simplified and the control can be simplified. Furthermore, in this case, the open / close state of the open / close shutter 33 is switched between the time of image formation and the time of idling. That is, when idling (the open / close shutter 33 is open), the exhaust air in the image forming unit 20 mainly passes through the opening 32. (Slightly through the ozone filter 31), and when the image is formed (the open / close shutter 33 is closed), the exhaust in the image forming unit 20 is performed through the ozone filter 31 (from the time of idling to the time of image forming). Is greater in resistance when exhausted from the inside of the image forming unit 20), so that the ratio of the exhaust amount exhausted from the optical system unit 10 to the exhaust amount exhausted from the image forming unit 20 by the exhaust fan 30 (= “The amount of exhaust gas exhausted from the optical system unit 10” / “the exhaust gas exhausted from the image forming unit 20” )), When idling is smaller than during image formation, the temperature rise due to heat generated from the illumination lamp 131 is suppressed during the copying operation, and dust flowing into the optical system unit 10 from the gap in the standby (idling) state. Can be suppressed, and the optical system is less likely to be stained.

As described in the present embodiment, one exhaust fan 30 exhausts the air in the optical system unit 10 and the air in the image forming unit. However, the present invention is not limited to this. The exhaust of 10 may be performed by an exhaust fan different from the exhaust fan 30.

In the present embodiment, the exhaust fan 30
By reducing the number of rotations during idling compared to the time of image formation, that is, by reducing the amount of exhaust by the exhaust fan 30, power consumption during standby can be reduced, and even in that case, In addition, it is possible to suppress the temperature rise in the image forming unit 20 by effectively utilizing the small amount of exhaust gas.

In this embodiment, the opening and closing of the opening / closing shutter 33 is performed by the CPU, not shown, which controls the sequence of the copying machine main body during the copying operation and during the standby state.
Not limited to this, a main motor (not shown) for rotationally driving the photosensitive drum 21 which is a driving member in the image forming unit 20, or the first scanning frame 13 and / or the second scanning frame which is a scanning optical system. The open / close shutter 33 may be opened / closed in conjunction with an optical system motor (not shown) for driving the motor 14. In this case, the open / close shutter 33 is located at the closed position while the main motor and the optical system motor are driven. Linked together.

Further, in the present embodiment, the opening 32 is provided by cutting out the ozone filter 31 (see FIG. 2). However, the present invention is not limited to this, and as shown in FIG. In the place, as a bypass,
When the opening / closing shutter 33 is in the open state, the inside of the image forming unit 20 may be evacuated via the bypass without passing through the ozone filter 31 (sometimes through the ozone filter 31).

[0029]

As described in detail above, according to the present invention,
During image formation, the opening / closing shutter is closed to exhaust air through the ozone filter, and when idling, the opening / closing shutter is opened to open the image forming unit through the opening having a smaller resistance than the ozone filter. Because exhaust is performed, ozone generated during image formation can be sufficiently removed, temperature rise in the apparatus can be suppressed, and exhaust can be used effectively.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a copying machine to which the present invention is applied.

FIG. 2 is a perspective view showing an ozone filter, an opening, and an opening / closing shutter.

FIG. 3 is a flow chart of the exhaust fan 30 and the opening / closing shutter 33.

FIG. 4 is a cross-sectional configuration diagram of a main part of a copying machine showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Optical system unit 20 Image forming unit 30 Exhaust means (exhaust fan) 31 Ozone filter 32 Opening 33 Opening / closing shutter 41 Image exhaust path 42 Optical exhaust path

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Junichi Koiso 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation

Claims (3)

[Claims] 1. An image forming apparatus comprising: an image forming unit that forms an image on transfer paper by an electrophotographic process; and an exhaust that exhausts the inside of the image forming unit through an image exhaust path that communicates with the image forming unit. Means, an ozone filter provided on the image exhaust path,
An image forming apparatus comprising: an opening; and an opening and closing shutter for opening and closing the opening, wherein the opening and closing shutter is closed when an image is formed and the opening and closing shutter is open when idling. . 2. The image forming apparatus according to claim 1, further comprising: an optical system unit having a scanning optical system that reads an original image by moving relative to the original. The optical exhaust path communicating with the optical system unit is provided so that an image can be formed by the forming unit and the inside of the optical system unit can be exhausted by the exhaust unit. Image forming device. 3. The image forming apparatus according to claim 1, wherein the amount of exhaust by the exhaust unit is smaller during idling than during image formation.