JPH0980994A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which is capable of obtaining an image of high quality by eliminating an adverse influence on an image caused by the flowing of the outside air into a machine and is provided with a circulating mechanism accompanied by a cooling mechanism. SOLUTION: A circulating means 13 for circulating air is provided to execute the cooling and heating of each part in the machine, ozone removal processing for the air, etc., in the circulating path of the air and form the image by an electrophotographic process. The circulating means 13 circulates the air, when a change from conditions for inhibiting an image forming operation to conditions for enabling the image forming operation is made. Further, a temperature detecting means is provided in an arbitrary position in the device and at the time of starting the machine, the air can be circulated until the temperature detecting means detects a fixed temp. or more. The circulating means 13 is provided on the outside of a device body and plural air vents for the device body can be provided as well.

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 applicable to, for example, a copying machine, a facsimile, a laser beam printer and the like.

[0002]

2. Description of the Related Art In an image forming apparatus applied to, for example, a copying machine, a facsimile, a laser beam printer or the like, an image is usually formed on a recording sheet by the following procedure. 1. A latent image is optically formed on the uniformly charged photoconductor by the corona discharge of the charging charger. 2. Next, the developing unit supplies toner to the photoconductor to develop the latent image on the photoconductor into a visible image. 3. The visible image formed by the toner on the photoconductor is transferred to the recording paper conveyed by the registration rollers by the transfer separation charger. 4. The recording paper on which the image is transferred is conveyed to a fixing unit by a paper conveying member to fix the image, and is ejected. 5. After the transfer, the toner remaining on the photoconductor is scraped off by the cleaning unit and prepared for the next image forming operation.

[0003]

In the image forming apparatus as described above, a corona discharger is used to charge the photoconductor. The corona discharger discharges by applying a high voltage to a small diameter metal wire to cause dielectric breakdown in the air around the metal wire. Normally, the metal wire is formed uniformly, but this is because it does not cause uneven discharge, and if it is not formed uniformly, part of it becomes uneven discharge, and this uneven discharge charges the photoreceptor. It becomes defective and is converted. If this happens, the image quality of the image formed on the photoconductor will be adversely affected, and black streaks will occur in the originally white portion.

It should be noted that none of the metal wires as products are non-uniform and cause uneven discharge. However, even with a uniform metal wire, stains may be attached over time and uneven discharge may occur. The dirt that adheres is
It may be toner floating in the image forming apparatus or various compounds generated when corona discharge occurs in the metal wire.

One of the causes of the generation of various compounds as described above is that air is introduced into the image forming apparatus by a fan or the like for cooling, and a substance contained in the inflowing air causes corona discharge. This is because it is oxidized by the generated ozone. In particular, when a humidifier or the like is used near the image forming apparatus, the above tendency is remarkable.

Further, the temperature inside the image forming apparatus rises due to radiant heat when fixing the image transferred onto the recording paper and due to heat generation of the circuit board unit for controlling and driving each part. However, when the image forming apparatus is started up, the internal temperature of the image forming apparatus is low and it is difficult to reach a predetermined temperature, and if the image forming apparatus is operated in such a state, defective cleaning or background stains may occur on the screen. Is likely to occur. Especially in winter, such problems are likely to occur.

In order to solve the above problems, Japanese Patent Laid-Open Nos. 03-137656 and 64-09525 have been used.
No. 1, JP 64-095252 A, JP 6
4-095253, JP-A-64-095254, JP-A-64-095255, and JP-A-64-
Various image forming apparatuses such as those described in JP-A-095256 and JP-A-64-095257 have been proposed. These are those in which harmful substance removing means is provided in the path of the internal circulation device, those in which an electrophotographic device and a heat source are provided with an air curtain to prevent thermal influences, and in the circulating air flow by the circulating air flow generating means. The technical contents are those provided with cooling means.

However, although the above-mentioned conventional image forming apparatus is provided with the internal circulation device, it suffers from a problem due to the temperature inside the machine being too low, and a problem when the outside air enters the machine due to paper jam processing by the user. I can't respond. Further, in the image forming apparatus provided with the air curtain and the cooling means, although there is an effect due to the temperature rise, it is still not possible to cope with the problem when the outside air enters. Further, in any of the image forming apparatuses, cooling air is circulated in the apparatus main body, but since the cooling air is circulated without touching the outside air, the temperature does not decrease and only rises. Therefore, a forced cooling method is required to cool the air circulating inside the image forming apparatus, but an expensive unit is required for the forced cooling method, so a circulation mechanism with a cooling mechanism is required. Is not realized yet.

The present invention has been made in order to solve the above problems of the prior art.
An image forming apparatus having a circulation mechanism with a cooling mechanism is provided while eliminating adverse effects on images caused by the outside air having an abnormally low temperature and the outside air having an abnormally high humidity flowing into the machine. The purpose is to provide. Another object of the present invention is to provide an image forming apparatus capable of optimizing the performance of each unit by circulating air having a temperature suitable for each unit by utilizing the heat dissipation function of the air flow path.

[0010]

According to the first aspect of the present invention,
An image forming apparatus that has a circulation means for circulating air, performs cooling, heating, and ozone removal processing of each part in the machine in a circulation path of air, and forms an image using an electrophotographic process, It is characterized in that the circulation means performs circulation when the condition for prohibiting the image forming operation is changed to the condition for enabling the image forming operation.

According to a second aspect of the present invention, temperature detecting means is provided at an arbitrary position in the apparatus, and when the machine is started up,
It is characterized in that the circulation is performed until the temperature detecting means detects a temperature equal to or higher than a predetermined temperature.

According to the third aspect of the present invention, the circulation means is provided outside the apparatus main body, and the air outlet from the circulation means to the apparatus main body can discharge the air having a temperature adjusted to each part of the apparatus main body to the apparatus main body. It is characterized in that it is divided into a plurality of parts as described above.

When the door of the image forming apparatus is opened, the image forming operation is prohibited, and when the door is closed, the image forming operation is made possible. When the image forming operation is changed from the image forming operation prohibited state to the image forming operation possible state, an image is formed. The air in the apparatus is circulated, and ozone removal and dust removal processing in the air is performed in the air circulation system path. In the case where the apparatus has a temperature detecting means, the circulating means operates until the temperature reaches a predetermined temperature or higher, and stops when the temperature exceeds the predetermined temperature.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an image forming apparatus according to the present invention will be described below with reference to the drawings.
In FIG. 1, the upper surface of the image forming apparatus is the optical reading unit 1.
A document to be read is placed on the optical reading unit 1. A door 12 that can be opened and closed is formed on the front side of the housing 2 of the image forming apparatus. A photoconductor 3 is mounted inside the housing 2, and a charging charger 15, a developing unit 4, a registration roller 5, a sheet conveying member 6, a transfer separation charger 8, and a cleaning unit 9 are provided around the photoconductor 3. Various members are attached, a fixing unit 10 is attached subsequently to the transfer / separation charger 8, and a circuit board unit 7 is attached below the fixing unit 10. Further, an air circulation device 13 as a circulation means is attached to the rear side inside the housing 2.

In the image forming apparatus, an image is formed on the recording paper by the following procedure. First, the photoconductor 3 is uniformly charged by the corona discharge of the charging charger 15,
Next, by an exposure unit including an optical system (not shown),
The image of the original set on the optical reading unit 1 is exposed to form a latent image on the photoconductor 3. Next, toner is supplied to the photoconductor 3 by the developing unit 4, and the latent image on the photoconductor 3 is developed with the toner to be visualized. Next, the recording paper is conveyed by the resist roller 5 to the photoconductor 3 on which the visible image is formed, and the visible image by the toner on the photoconductor 3 is transferred onto the recording paper. Next, the recording paper onto which the image has been transferred is conveyed to the fixing unit 10 by the paper conveying member 6 and an image fixing process is performed. After the fixing process, the recording paper is ejected outside the image forming apparatus. Next, the toner remaining on the photoconductor 3 is scraped off by the cleaning unit 9 to prepare for the next image forming operation.

As shown in FIG. 2, the air circulation device 13 used in the image forming apparatus having the above-described structure is hollow, and the air suction port 13 is formed on the same plane at both ends in the longitudinal direction.
a, an air outlet 13b, and a fan (not shown). The inside of the air circulation device 13 is partitioned by a plurality of ribs 13c formed in the longitudinal direction except for the air intake port 13a and the air exhaust port 13b, and each space partitioned by these ribs 13c is an air flow. It is the road 13d. Further, a plurality of ribs 1 are provided on the upper surface of the air circulation device 13.
A heat dissipation plate 13e having a shape in which 3c protrudes upward is integrally formed. When air is made to flow inside the air circulation device 13 having such a configuration, the heat of the air causes the heat radiating plate 1 to pass through the rib 13c.
It is conducted to 3e and released to the outside by the heat dissipation plate 13e. Therefore, the air can be cooled by flowing the air through the air circulation device 13 to circulate the air. The heat dissipation plate 13e is preferably exposed from the outer surface of the housing 2 of the image forming apparatus.

Further, as shown in FIG. 3, the air circulation device 1
An ozone filter 15 is attached in the middle of the air passage 3 to remove ozone generated in the charging charger 15 and the transfer / separation charger 8. further,
As shown in FIG. 4, a part of the air circulation device 13 includes:
An air retention portion 13f that protrudes above the other portions is formed, and the inside of this air retention portion 13f is a space that communicates with the air flow path 13d. Further, the lower portion of the air retention portion 13f also projects downward, and a dust receiving pad 13g that can be pulled out to the outside is attached to the portion that protrudes downward. The air taken into the air circulation device 13 is the air retention part 13f.
Garbage receiving pad 13g
Dust such as toner is stored in.

By circulating the air in the air circulating device 13, the heat of the air is dissipated by the heat radiating plate 13e and the ozone is retained by the ozone filter 15 and the air retention portion 13
Since dust such as toner floating in the air can be removed with f, dirt on the metal wire of the corona discharger is eliminated and the image of the subject latently formed on the photoconductor is improved. can do.

The housing 2 of the image forming apparatus is basically hermetically sealed, and the air inside the housing 2 circulates inside the housing 2 without flowing out. However, in an image forming apparatus or the like, since the door 12 is opened and processing is performed at the time of paper jam or maintenance, it is conceivable that outside air including dust and dirt may flow into the housing 1.

Therefore, the image forming apparatus is provided with a switch or other sensor for detecting the opening / closing operation of the door 12. This switch or sensor can output a signal according to the opening / closing operation of the door 12, and the operation of the image forming apparatus is restricted according to the output signal.

For example, as shown in FIG. 5, when the door 12 is opened due to paper jam processing, maintenance processing, or the like, a sensor outputs a door open signal to detect the image forming operation prohibited state, and the operation of the image forming apparatus. Is prohibited. After that, when the paper jam processing or the maintenance processing is completed and the door 12 is closed, a door closing signal is output from the sensor and waits until the image forming operable state is detected,
After the air is circulated by the air circulation device 13 and dust such as toner, dust, and dust is removed by the air retention portion 13f, the operation prohibition of the image forming apparatus is released.

According to the image forming apparatus having the above-mentioned structure, the sensor detects the opening / closing of the door 12, and when the door 12 changes from the open state to the closed state, that is, the image forming operation is prohibited. Air circulator 1 when the conditions change
3 is started to allow the air inside the housing 2 to flow into the air circulation device 13, the heat is dissipated by the heat radiating plate 13e, the ozone is removed by the ozone filter 15, the dust is removed by the air retention portion 13f, and the air is cleaned. can do. Therefore, it is possible to eliminate the adverse effect on the image caused by the outside air containing dust and the like flowing into the housing 2.
High quality images can be obtained.

The photoconductor 3 and the cleaning unit 9
It is also possible to arrange temperature detection sensors (not shown) in the vicinity of, for example, and control the air circulation operation by these detection signals. As shown in FIG. 6, when the switch is turned on to start up the image forming apparatus, the temperature detection sensors A and B arranged near the photoconductor 3 and the cleaning unit 9 are checked to detect the temperature. If the sensors A and B detect a temperature equal to or lower than a predetermined temperature, the air circulation device 13 performs the air circulation operation. After the circulation operation is started, the sensors A and B are further checked, and if the temperature is equal to or higher than a predetermined temperature, the image forming state is set. If the temperature is lower than the predetermined temperature, the air circulation device 13 continues the air circulation operation. The air circulation operation by the air circulation device 13 is continued until the sensors A and B reach a predetermined temperature or higher. By doing so, it is possible to use the image forming apparatus immediately after the image forming apparatus is started up while the members such as the photoconductor 3 and the cleaning unit 9 have reached a sufficient temperature. Problems such as stains on the screen can be eliminated.

Next, another embodiment of the image forming apparatus will be described with reference to the drawings. Since the basic configuration and operation of the image forming apparatus are the same as those of the above-described embodiment of FIG. 1, the same components are designated by the same reference numerals, and duplicate description will be omitted. In FIG. 7, one air exhaust port 20 and three air exhaust ports 21 are formed on the back side of the housing 2 of the image forming apparatus, and the air exhaust port 20 and the air intake port 21 are straddled. An air circulation device 13 is attached. The air exhaust port 20 overlaps the air intake port 13a of the air circulation device 13, and the air intake port 21 overlaps the air exhaust port 13b of the air circulation device 13. A fan 16 for sending the air in the housing 2 into the air inlet 13a is loaded into the housing 2, and a fan 17 for sending the air passing through the air circulating device 13 into the housing 2 is fed into the air outlet 13b. Is attached. Air circulation device 1
3 has the same structure as that shown in FIGS. 2, 3 and 4.
According to the embodiment shown in FIG. 7, since the air circulation device 13 is exposed and attached to the outside of the housing 2, there is an advantage that the cooling effect is high.

Another embodiment of the air circulation device is shown in FIG. In FIG. 8, the air circulation device 23 is hollow and has a U-shaped outer shape, and an air intake port 23a and two air discharge ports 23b, 23c are provided on the upper front side from the left side.
Is provided. Further, an air discharge port 23d is formed in a lower portion of the front surface of the air circulation device 23 and below the air suction port 23a. Air inlet 23
The air discharge ports 23b, 23c, and 23d correspond to one air discharge port 20 and three air suction ports 21 formed in the housing 2 of the image forming apparatus shown in FIG. 7, respectively.
By attaching the air circulation device 23 to the back surface of the housing 2, the air discharge port 20 is the air suction port 23a, and the three air suction ports 21 are the air discharge ports 23b and 2b, respectively.
It overlaps with 3c and 23d. Air inlet 23a,
Fans (not shown) are attached to the air outlets 23b, 23c, and 23d, and the air in the housing 2 is forcibly circulated in the air circulation device 23 by the fans.

A circulation path inside the air circulation device 23, that is,
The air passages are the upper part 23x, the lower part 23z and the upper part 23x.
It is composed of three parts, an intermediate part 23y connecting x and the lower part 23z. Of these, the upper part 23x and the intermediate part 23y
The air flow path is divided by a plurality of ribs (not shown), and each rib is connected to a plate-shaped heat radiating plate 25 projectingly formed on the upper end surface of the air circulation device 23. Therefore, in the air taken into the air circulation device 23, heat is conducted from the ribs to the radiator plate 25, and moreover, the radiator plate 25.
Is emitted from the outside. Therefore, the air taken into the air circulation device 23 can be cooled. Since the air circulation device 23 is attached to the outside of the housing 2, a particularly high heat dissipation effect is obtained and the degree of cooling of the air is large. The cooled air is supplied to the air outlet 23b,
23c and 23d again flow into the inside of the housing 2, and the inflowing air cools the device inside the housing 2.

Further, although air outlets 23b, 23c and 23d are provided in the flow path of the air circulation device 23, the air discharged from the air outlet 23d farthest from the air inlet 23a is the air. Air outlet 2 closest to inlet 23a
The distance traveled in the air flow path is longer than that of the air discharged from 3d, and the degree of cooling is also increased accordingly. Since the fixing unit 10 or the like mainly serves as a heat source in the members inside the housing 2 of the image forming apparatus, the fixing unit 10 or the like is supplied with air having a large degree of cooling discharged from the air discharge port 23d. You can send it. Also,
With respect to the charging charger 15 and the like around the photoconductor 3, it is better to send air at a high temperature to some extent to obtain better results in terms of image formation. Therefore, air may be sent to such a place from the air discharge port 23b having a small degree of cooling.

Further, an ozone filter (not shown) is attached in the air flow path of the air circulation device 23,
Ozone generated by corona discharge and contained in the air can be removed by this ozone filter, and ozone-free air can be sent into the housing 2.

According to the image forming apparatus as described above, the air circulating device 23, which is a circulating means, is provided outside the machine, and a plurality of air outlets 23 which are inlets to the main body of the device.
Since b, 23c, and 23d are provided in the air flow path, it is possible to perform cooling adapted to each part in the device. For example, the fixing unit 10 or the like, which generates a large amount of heat, can be efficiently cooled by the air having a relatively low temperature discharged from the air discharge port 23d that is farthest from the air discharge suction 23a. Alternatively, the air discharge port 23a closest to the air discharge port 23a may be provided at a location such as the charging charger 15 around the photoconductor 3 where the characteristic that it is desirable to send air at a certain temperature is obtained. Can send air with a small degree of cooling. Further, the air circulation device 23 is
Since it is provided outside the housing 2, the degree of cooling is greater than when it is installed inside the housing 2. Therefore, an expensive unit for cooling is unnecessary, which can contribute to cost reduction. Further, since an ozone filter is provided in the air circulation device 23 and ozone in the air can be removed by this ozone filter, it is possible to eliminate the contamination of the metal wire of the corona discharger. As a result, the image of the subject latently formed on the photoconductor 3 can be improved.

Although the air circulation device 23 used in the image forming apparatus has a U-shape, it is not limited to this. It can be changed according to the arrangement of devices in the housing 2. Moreover, the number and shape of the air outlets are not particularly limited, and can be changed according to the arrangement of the devices in the housing 2.

Further, as in the above-described embodiment, an air retention part may be provided in a part of the air circulation device 23 so that dust such as toner, dust, and dust in the air can be removed. Furthermore, after paper jams and maintenance processing, the door 12
The air in the housing 2 may be forcibly sent into the air circulation device 23 when the housing is closed to remove the dust contained in the outside air. Alternatively, when the image forming apparatus is started up, the housing 2 is closed. The air circulation device 23 may be configured to circulate until a specific location therein reaches a constant temperature.

[0032]

According to the first aspect of the present invention, there is provided a circulation means for circulating air, and cooling, heating, and ozone depletion treatment of each part in the machine are carried out in the air circulation path, and electrophotography is carried out. An image forming apparatus for forming an image using a process, wherein circulation is performed when the image forming operation prohibition condition changes to a condition in which the image forming operation can be performed, so dust from the outside or image forming operation is performed. It becomes possible to obtain a high-quality image by eliminating dust that adversely affects the image and eliminating the adverse effect on the image.

According to the second aspect of the present invention, the temperature detecting means is provided at an arbitrary position inside the machine, and when the machine is started up, the temperature detecting means circulates until a predetermined temperature is reached. Therefore, the image forming apparatus can be used in a state in which the apparatus has reached a sufficient temperature, and it is possible to eliminate defects on the screen such as poor cleaning and background stains.

According to the third aspect of the invention, since the circulation means is provided outside the apparatus main body, a sufficient cooling effect can be obtained. In addition, since the circulation means has a plurality of air outlets for circulating the air to the apparatus main body, it is possible to send air at an appropriate temperature according to the internal apparatus.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a perspective view showing an embodiment of a circulation unit used in the image forming apparatus.

FIG. 3 is a perspective view showing an embodiment of a circulation unit used in the image forming apparatus.

FIG. 4 is a perspective view showing an embodiment of a circulation unit used in the image forming apparatus.

FIG. 5 is a block diagram showing an operation example of the above image forming apparatus.

FIG. 6 is a block diagram showing an operation example of the image forming apparatus.

FIG. 7 is a perspective view showing another embodiment of the image forming apparatus according to the present invention.

FIG. 8 is a perspective view showing another embodiment of the circulation means used in the image forming apparatus.

[Explanation of symbols]

 13 Circulation means

Front page continuation (72) Inventor Toshiyuki Uchida 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd.

Claims (3)

[Claims] 1. An image forming apparatus, which has a circulation means for circulating air, cools and heats various parts in the machine in the air circulation path, performs ozone removal processing on the air, and forms an image using an electrophotographic process. An image forming apparatus, wherein the circulation means performs circulation when the condition for prohibiting the image forming operation is changed to the condition for enabling the image forming operation. 2. A temperature detecting means is provided at an arbitrary position in the apparatus, and when the machine is started up, circulation is performed until the temperature detecting means detects a temperature equal to or higher than a predetermined temperature. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 3. An image forming apparatus which has a circulating means for circulating air, cools and heats various parts inside the machine in a circulation path of the air, and removes ozone from the air, and forms an image using an electrophotographic process. In the device, the circulating means is provided outside the device body, and the air outlet from the circulating means to the device body is divided into a plurality of parts so that air having a temperature matched to each part of the device body can be discharged to the device body. An image forming apparatus characterized in that the image forming apparatus is arranged.