JPH08202244A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device which does not generate abnormal images, such as image blur and drop-out, even if the environment around the device contains NOx at a high density. CONSTITUTION: A suction duct 41 for introducing the outdoor air into the image forming device and guiding the air near to a photoreceptor is provided with a water containing section 42 and a water container 43 is arranged therein to contain the water. The inflow outdoor air is humidified by utilizing the natural evaporation of the water in the container 43, by which the concn. of the NOx is lowered.

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 printer and a facsimile, and more particularly to an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, since corona discharge is performed in a latent image forming step, an image transferring step, etc., ozone, NOx (nitrogen oxide), etc. are generated in the apparatus. These discharge products adversely affect the photoconductor and cause abnormal images such as image blur and white spots.

Conventionally, various image forming apparatuses have been proposed in which the influence of discharge products on the photoconductor is prevented.

[0004]

However, in such a conventional image forming apparatus, it is intended to suppress the influence of discharge products such as ozone and NOx generated in the apparatus on the photoconductor. However, if the air introduced from outside the device contains NOx or the like, it cannot be dealt with. That is, when an oil stove or the like is used in the winter, the NOx concentration in the room rises, sometimes reaching a high value of around 10 ppm. In such an environment, when an image forming apparatus configured to introduce the air outside the machine to the vicinity of the photoconductor is used, a high concentration of NOx affects the photoconductor,
There is a problem that abnormal images such as image blurring and white spots occur.

An object of the present invention is to solve the above-mentioned problems in the conventional image forming apparatus and to provide an image forming apparatus which does not generate an abnormal image such as image blurring or white spots even in a high density NOx environment. And

[0006]

SUMMARY OF THE INVENTION According to the present invention, the above object is to provide, in an image forming apparatus having a photoconductor and an outside air introducing mechanism, a humidifying means for humidifying the introduced outside air into the outside air introducing path of the outside air introducing mechanism. It is solved by providing.

In order to solve the above-mentioned problems, the present invention proposes to provide means for adjusting the amount of humidification of the humidifying means.

Further, in order to solve the above-mentioned problems, the present invention proposes that the humidifying amount adjusting means is controlled according to an image forming operation.

Further, in order to solve the above-mentioned problems, the present invention proposes that the outside air introducing mechanism has an intake fan, and the humidification amount adjusting means is controlled according to the operation of the fan.

Further, in order to solve the above-mentioned problems, the present invention has a temperature measuring means for measuring the temperature inside the machine, and the humidifying amount adjusting means is controlled according to the measurement result of the temperature measuring means. To propose.

Further, in order to solve the above-mentioned problems, the present invention has a nitrogen oxide concentration measuring means for measuring the nitrogen oxide concentration of the outside air around the device or the outside air introduced into the device, and the humidification It is proposed that the amount adjusting means is controlled according to the measurement result of the nitrogen oxide concentration measuring means.

[0012]

The humidifying means is installed in the outside air introduction path of the outside air introduction mechanism provided in the image forming apparatus to humidify the introduced outside air.
As a result, the concentration of nitrogen oxides contained in the introduced air is reduced, and the influence on the photoconductor is prevented.

Other functions will be apparent from the description of the embodiments below.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the schematic arrangement of a color copying machine according to an embodiment of the present invention. This color copier 100
Is composed of a color image reading unit (hereinafter referred to as a color scanner) 1 and a color image recording unit (hereinafter referred to as a color printer) 2.

FIG. 2 is an enlarged view showing the vicinity of the photoconductor of the color printer 2.

The details of the color scanner 1 and the color printer 2 will be described later, but in the copying machine of this embodiment, FIG.
An air blowing system as shown in is provided. That is, the photoconductor 9 arranged in the approximate center of the color printer 2
An intake duct 41 for guiding the air outside the machine to the vicinity is provided. A suction fan 40 is provided at the suction port of the duct 41. The air sucked from the outside by the suction fan 40 is guided to the duct 41 and blown onto the surface of the photoconductor drum 9 from above the charger 12. This blower system uses ozone generated by the discharge of a charger,
This is for eliminating NOx and the like. Note that reference numeral 19
Is an intermediate transfer belt adjacent to the photoconductor 9.

By the way, a humidifying means as shown in FIG. 4 is provided in the middle of the suction duct 41. This humidifying means is provided in the water storage portion 42 provided in the middle of the duct.
3 is installed. As the water storage container 43, for example, a can can be used. In this way, the water storage unit 42 is provided in the middle of the duct 41 that guides the air outside the machine to the vicinity of the photoconductor 9.
By disposing the water storage container 43 by providing the
The inflowing air can be humidified by utilizing the natural evaporation of the water in 3, and the NOx concentration of the air blown to the photoconductor 9 can be reduced even when the atmosphere outside the apparatus is a high concentration NOx environment. You can Therefore, it is possible to prevent the NOx in the outside air from adversely affecting the photoconductor 9. The reason why the NOx concentration decreases when the humidity rises is that NOx bonds with water molecules in the air. When all the water in the storage container 43 is consumed (evaporated), the container may be replaced or water may be replenished.

Since only the water container is arranged in the suction duct 41, the inflowing air can be humidified at low cost. Further, the water storage container 43 may be heated in order to increase the humidification amount of the inflowing air. That is, as shown in FIG. 5, a heater 44 is attached to the water storage container 43 to heat the water in the container. As a result, the evaporation of water in the container 43 is promoted, the humidity of the inflow air rises, and the decomposition of NOx is promoted.

The amount of water evaporated changes depending on the ambient temperature in which the water is placed. That is, the amount of evaporation is high in the high temperature state, and the amount of evaporation is low in the low temperature state. Therefore, if the temperature inside the device is detected and the humidification amount is controlled, water can be used without waste. As a temperature detecting method, a thermistor or the like may be provided inside the machine to measure the ambient temperature, but it is preferable to measure the ambient temperature near the place where water is installed as much as possible.

As a structure for controlling the amount of humidification, when the water container 43 is not provided with a heater, the water container 43 or the water container 42 is opened and closed by a lid. That is, as shown in FIG. 6, the lid 46 is openably and closably attached to the upper opening of the water container 43 installed in the water container 42.
The lid 46 is pivotally attached to the container 43 by a shaft 47, and a spring 45 is locked to one of the opposite ends. The other end of the spring 45 is locked to the wall surface of the water storage unit 42, etc.
6 is given an urging force in the direction of closing the lid. A solenoid 48 is installed adjacent to the water storage unit 42.
The plunger 48a of the solenoid 48 is pivotally attached to the other end 46a of the lid 46. Therefore, when the solenoid 48 is turned on, the lid 46 is opened, and when it is turned off, the lid 46 is opened.
Is supposed to close.

Alternatively, as shown in FIG. 7, the water storage unit 4
2 and the duct 41, the semicircular opening 5 provided on the bottom surface 51
Contact by 1a. Then, a semicircular lid 49 is attached to the bottom surface 51 and is rotated by the stepping motor 50. As a result, the opening 51a is opened and closed by the lid 49.

On the other hand, when the heater 44 is attached to the water container 43, the humidification amount can be accurately adjusted by controlling the temperature of the heater 44. In this case, the temperature of the water in the container is measured assuming that the temperature in the machine and the water temperature in the container are proportional, and when the measured water temperature is lower than the reference temperature set in advance, It may be determined that the humidification amount is insufficient and the water in the container is warmed by the heater 44 until the reference temperature is reached.

By the way, if the NOx concentration in the outside air of the apparatus is measured and the humidification amount is controlled based on the measurement result, the humidification amount can be adjusted to an appropriate amount. That is, N
The humidification amount may be increased when the Ox concentration is high, and may be decreased when the NOx concentration is low. As the NOx concentration, the NOx concentration outside the device may be measured, or the NOx concentration of the air introduced into the intake duct 41 may be measured. As a configuration for controlling the amount of humidification, when the heater is not provided, the method according to FIG. 6 or 7 can be used. However, according to the configuration of FIG. 7, the amount of rotation of the stepping motor 50 is controlled. This is advantageous because the opening / closing amount of the lid 49 can be adjusted stepwise.

Further, if the humidification amount is controlled in accordance with both the NOx concentration of the outside air and the temperature inside the machine, the humidification amount can be adjusted more appropriately, and the abnormal image due to the NOx of the outside air is generated under the optimum condition. Can be prevented. Also,
It is possible to prevent wasteful consumption of humidifying water and reduce maintenance work.

When the amount of humidification is controlled by opening and closing the lid, the suction fan 40 is used as the timing for opening and closing the lid.
If the lid is opened during the operation of and the lid is closed at other times, the inflow air can be humidified only when the outside air is actually introduced. Alternatively, the opening and closing of the lid may be synchronized with the image forming timing. As a representative of the image formation timing, for example, when the charging device is energized or when the photosensitive member is rotated, an appropriate one can be selected. As a result, the inflow air can be humidified only when the image is actually formed. Needless to say, even when the amount of humidification is adjusted by controlling the heating means, it is effective if the amount of humidification is controlled in synchronization with the operation of the suction fan 40 or the image formation timing.

The following structure can be adopted as another example of the humidifying means. That is, an evaporation dish 57 as shown in FIG. 8 is installed in the water storage unit 42, and a high frequency output device 55 such as a magnetron is arranged above it to emit ultrasonic waves to the water W stored in the evaporation dish 57. Then, steam is generated. This method is advantageous because the humidification amount can be increased without increasing the temperature inside the machine. Reference numeral 56 is a high-voltage unit for driving the high-frequency output device 55.

Alternatively, as shown in FIG. 9, a water accommodating recess 52 is provided in the bottom surface 51 of the suction duct 41 to pour water W therein.
A cloth 54 such as gauze is attached to the upper wall 53 of the duct, and the lower end portion of the hanging cloth 54 is immersed in the water W in the recess 52. Water is sucked up by the cloth 54 due to the capillary phenomenon. Therefore, the air outside the machine introduced through the duct 41 can be humidified by passing through the two cloths 54, and the NOx concentration can be reduced. In addition, the size of the cloth 54 may be a circle of several centimeters square or several centimeters in diameter, and the humidifying means can be downsized. Further, the material of the cloth 54, the number of the cloth 54, the interval, and the like can be arbitrarily set.

Next, details of the color scanner 1 and the color printer 2 will be described with reference to FIGS.

The color scanner 1 forms an image of the original 3 illuminated by the illumination lamp 4 on the color sensor 7 via the mirror group 5 and the lens 6, and outputs the color image information of the original 3 to, for example, blue or green. , Red (hereinafter, B,
G and R) are read for each color-separated light and converted into an electrical image signal. And B obtained by the color scanner 1,
An image processing unit (not shown) performs color conversion processing based on the G and R color-separated image signal intensity levels, and black (hereinafter referred to as Bk), cyan (hereinafter referred to as C), and magenta ( Hereinafter, color image data of M) and yellow (hereinafter, Y) are obtained. This color image data is visualized by Bk, C, M, and Y by the color printer 2, and these are superposed to form a four-color full-color image.

Next, the color printer 2 will be briefly described. The writing optical unit 8 converts the color image data from the color scanner 1 into an optical signal and performs optical writing corresponding to the original image, and the photosensitive drum 9 is formed. An electrostatic latent image is formed on. The writing optical unit 8 includes a laser 8a, a light emission drive control unit (not shown), and a polygon mirror 8b.
And a rotation motor 8c, an f / θ lens 8d, a reflection mirror 8e, and the like.

FIG. 2 is an enlarged view showing in detail the photosensitive member of the color printer 2 and the vicinity of the intermediate transfer belt. As shown in this figure, a cleaning unit (including a pre-cleaning static eliminator) 10 and a static elimination lamp 1 are provided around the photoconductor 9.
1, charger 12, potential sensor 13, Bk developing device 14, C
A developing device 15, an M developing device 16, a Y developing device 17, a developing density pattern detector 18, an intermediate transfer belt 19 and the like are arranged.

Since the constructions and operations of the color developing units 14, 15, 16 and 17 are all the same, the Bk color developing unit will be described as a representative. The Bk color developing device 14 includes a developing sleeve 14a, a developing paddle 14b, a toner density sensor 14c, and the like. The developing paddle 14b pumps up and agitates the developer. The developing sleeve 14a rotates,
The brush of the developer drawn up by the developing paddle 14b is brought into contact with the outer peripheral surface of the photoconductor 9 to develop the electrostatic latent image formed on the photoconductor 9. However, in the standby state, the developing sleeve 1
4a does not rotate, and the developer is in a state of being cut off from the surface of the photoconductor 9 (development inoperative).

Next, each color developing device 14, 15, 16, 17
The developing operation according to the above will be described assuming that the developing order (that is, the color image forming order) is Bk, C, M, and Y. However, the color image forming order (that is, the developing order) is not limited to this embodiment.

First, when the copying operation by the copying machine 100 is started, the color scanner 1 starts reading the Bk image data of the original 3 at a predetermined timing.
Then, based on this image data, optical writing / electrostatic latent image formation by the laser light of the writing optical unit 8 is performed on the photoconductor 9 that rotates counterclockwise in the figure (direction of arrow L) (hereinafter, The electrostatic latent image based on the Bk image data is B
It is referred to as a k latent image. The same applies to C, M, and Y).

In order to develop the Bk latent image formed on the photosensitive member 9 from its tip, the developing sleeve 14a is started to rotate before the latent image tip reaches the developing position of the Bk developing device 14, The developer is spiked and the Bk latent image is developed with Bk color toner. Then, the developing operation of the Bk latent image area is continued, but when the trailing edge of the latent image passes the developing position of the Bk developing device 14, the developer on the developing sleeve 14a is quickly cut off to make the developing operation inoperative. Put in a state. This cutting is completed at least before the leading edge of the C latent image by the next C image data reaches the Bk developing device 14. The cutting of the developer is performed by switching the rotation direction of the developing sleeve 14a to the opposite direction to that during the developing operation, and thereafter, the rotation of the developing sleeve 14a is stopped.

Now, the Bk formed by developing the Bk latent image
The toner image is transferred onto the intermediate transfer belt 19 that is in contact with the surface of the photoconductor 9 and is moving at a uniform speed (hereinafter, referred to as the photoconductor 9).
Transfer of the toner image from the intermediate transfer belt 19 to the intermediate transfer belt 19). The belt transfer is performed by applying a predetermined bias voltage to the transfer bias roller 20 while the photoconductor 9 and the intermediate transfer belt 19 are in contact with each other.

Next, the reading of the C image data of the original 3 by the color scanner 1 is started at a predetermined timing. Then, as in the case of Bk color, laser light writing by C image data is performed to form a C latent image. The C-color developing device 15 starts the rotation of the developing sleeve 15a before the trailing end of the Bk latent image passes through the developing position and before the leading end of the C latent image reaches the developing position. Perform ear stand. Then, the C latent image is developed with C color toner.
Hereinafter, for M color and Y color, the image data is read, the latent image is formed, and the development with the corresponding color toner is performed, but the operation is the same as the operation for the Bk color and the C color described above. Is omitted.

By the way, on the intermediate transfer belt 19 to which the Bk toner image has been transferred, C, which are sequentially formed on the photoconductor 9,
The toner images of the colors M and Y are sequentially aligned and transferred to the previous toner images, and a belt transfer image of four colors is formed. Then, the belt transfer images of four colors are collectively transferred onto the transfer paper.

Here, the unit including the intermediate transfer belt 19 will be described.

The intermediate transfer belt 19 includes a belt transfer bias roller 20, a driving roller 21 and a driven roller 25a.
It is stretched around b and is driven by a drive motor (not shown). The belt cleaning unit 22 for cleaning the intermediate transfer belt 19 includes a brush roller 22a,
It includes a rubber blade 22b, a contact / separation mechanism 22c from the intermediate transfer belt 19, and the like. The belt cleaning unit 22 is separated from the belt surface by the contact / separation mechanism 22c while the toner images of the second, third, and fourth colors are transferred on the belt after the Bk toner image of the first color is transferred on the belt. .

The paper transfer unit 23 for transferring the four-color belt transfer image formed on the belt 19 onto the transfer paper includes a transfer bias roller 23a, a roller cleaning blade 23b, and a contact / separation mechanism from the transfer belt 19. Two
3c and the like. Transfer bias roller 23a
Is normally separated from the belt surface, but is pressed by the contact / separation mechanism 23c at a timing when the belt transfer image on the intermediate transfer belt 19 is collectively transferred onto the transfer paper, and is pressed against the intermediate transfer belt 19. It Then, a predetermined bias voltage is applied, and the belt transfer image is collectively transferred onto the transfer paper P guided between the transfer bias roller 23 a and the intermediate transfer belt 19. The transfer paper P is the intermediate transfer belt 19
The paper is fed by the paper feed roller 24 and the registration roller 26 (each shown in FIG. 1) at the timing when the leading end of the upper belt transfer image reaches the paper transfer position.

By the way, the following three methods are conceivable as the operation method of the intermediate transfer belt 19 after the belt transfer of the Bk toner image of the first color is completed up to the rear end portion. Alternatively, it is operated by a combination of efficient methods (in terms of copy speed, etc.) according to the copy size.

(1) Constant speed constant direction rotation system a. Even after the Bk toner image is transferred onto the belt, it continues to rotate in the same direction at a constant speed.

B. Then, when the front end position of the Bk toner image on the surface of the belt 19 reaches the contact portion with the photosensitive member 9 again, that is, the belt transfer position, the front end portion of the next C toner image on the photosensitive member 9 is just at that position ( Bk toner image tip position)
The image is formed at the right time. As a result, the C toner image is accurately aligned with the Bk toner image and is transferred onto the intermediate transfer belt 19 in a superimposed manner.

C. After that, by the same operation, M, Y
Proceeding to the image process, a belt transfer image of four colors is obtained.

D. Subsequent to the belt transfer process of the Y toner image of the fourth color, the belt transfer images of the four color layers on the surface of the belt 19 are collectively transferred onto the transfer paper P while rotating as it is.

(2) Skip constant direction rotation system a. When the belt transfer of the Bk toner image is completed, the photoconductor 9
The intermediate transfer belt 19 is separated from. Then, it is skipped in the same direction at a high speed, and when a predetermined amount is moved, the initial rotation speed is restored. After that, the belt 1 is again attached to the photoreceptor 9.
9 is contacted.

B. When the front end position of the Bk image on the surface of the belt 19 reaches the belt transfer position again, the photosensitive member 9
An image is formed on the top of the C toner image at a timing so that the front end portion of the C toner image is exactly at that position. As a result, the C toner image is accurately aligned with the Bk toner image and is transferred onto the intermediate transfer belt 19 in a superimposed manner.

C. After that, by the same operation, M, Y
Proceeding to the image process, a belt transfer image of four colors is obtained.

D. Subsequent to the belt transfer process of the Y toner image of the fourth color, the belt transfer images of the four color layers on the surface of the belt 19 are collectively transferred onto the transfer paper P at the same speed.

(3) Reciprocating rotation system a. When the belt transfer of the Bk toner image is completed, the photoconductor 9
The intermediate transfer belt 19 is separated from. Then, at the same time when the rotation is stopped, a high speed return is performed in the opposite direction. The returned belt 19 is stopped after the front end position of the Bk image on the belt surface has passed the belt transfer position in the opposite direction and further moved by a preset distance.
Then, the standby state is set.

B. Next, when the front end of the C toner image on the photoconductor 9 reaches a predetermined position before the belt transfer position, the transfer belt 19 is rotated again in the initial direction. Then, the transfer belt 19 is brought into contact with the photoconductor 9 again. At this time, the C toner image is transferred under the condition that it is accurately overlapped with the Bk image on the surface of the belt 19.

C. After that, by the same operation, M, Y
Proceeding to the image process, a belt transfer image of four colors is obtained.

D. Following the belt transfer process for the Y toner image of the fourth color, it rotates at the same speed without returning,
The four-color belt transfer image on the surface of the belt 19 is collectively transferred to the transfer paper P.

The transfer paper P on which the toner images of four colors are collectively transferred from the intermediate transfer belt 19 is transferred to the fixing device 28 by the transfer paper transfer belt 27. Then, the fixing roller 28a and the pressure roller 28b, which are controlled to a predetermined temperature,
The unfixed toner image on the transfer paper P is fused and fixed by being sandwiched between and conveyed to complete a full-color copy. After that, the transfer paper P is carried out to the paper discharge tray 29. The surface of the photoconductor 9 after the belt transfer is cleaned by the photoconductor cleaning unit 10. In addition, the static elimination lamp 1
The charge is uniformly removed by 1. On the other hand, the intermediate transfer belt 19 after transferring the toner image onto the transfer paper P has a contact / separation mechanism 22a.
The surface of the belt 19 is cleaned by the belt cleaning unit 22 which is pressed by and is pressed against the belt 19.

For repeat copying, the first Y (4
Subsequent to the (color) image process, the original image is read and a latent image is formed on the photosensitive member 9 at a predetermined timing, and the second Bk (first color) image process is performed. Further, in the intermediate transfer belt 19, after the batch transfer process of the first four-color superimposed image onto the transfer paper, the second BK toner image is transferred to the area where the belt cleaning unit 22 has cleaned the surface of the belt. Transcribed. The subsequent color image process is the same as that for the first sheet.

The transfer paper cassette 30 shown in FIG.
Transfer papers of various sizes are stored in 31, 32, and 33. Then, the paper is fed toward the registration rollers 26 at a timing from a storage cassette of a size designated by an operation panel (not shown). Paper such as OHP paper or thick paper is fed from the manual feed tray 34.

The above description is for the copy mode in which four full colors are obtained, but in the case of the three-color copy mode and the two-color copy mode, the same operation as above is performed for the designated number of colors and the number of times. It will be. In the case of the single-color copy mode, until the predetermined number of sheets are completed, only the developing device for that color is in the developing operation (development of developer), and the intermediate transfer belt 19 remains in contact with the photoconductor 9. A constant speed rotation is performed, and the copying operation is performed while the belt cleaning unit 22 is also in contact with the transfer belt 19.

[0060]

As described above, according to the image forming apparatus of the present invention, since the humidifying means is provided in the outside air introduction path, the inflowing outside air is humidified to reduce the NOx concentration and influence on the photoconductor. It is possible to suppress the occurrence of abnormal images such as image blurring and white spots.

According to the second aspect of the present invention, the amount of humidification can be adjusted. Therefore, excessive or insufficient humidification can be prevented, and abnormal images due to NOx can be prevented under optimal conditions.

According to the third aspect of the present invention, the humidification amount is adjusted according to the image forming operation of the apparatus, so that the humidification can be effectively performed only when necessary (during image formation).

According to the configuration of claim 4, the humidification amount is adjusted according to the operation of the suction fan, so that the humidification can be effectively performed only when the outside air is introduced.

According to the fifth aspect of the present invention, the amount of humidification is adjusted according to the temperature inside the machine, so that the optimum amount of humidification can always be performed in consideration of the difference in the evaporation amount of water depending on the temperature.

According to the sixth aspect of the present invention, the humidification amount is adjusted according to the NOx concentration of the outside air. Therefore, when the NOx concentration is high, the humidification amount is high, and when the NOx concentration is low, the optimum humidification can always be performed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a copying machine according to an embodiment of the present invention.

FIG. 2 is a detailed view of the vicinity of a photoconductor and a developing device of the copying machine.

FIG. 3 is a perspective view showing an air blowing system in the copying machine.

FIG. 4 is a perspective view showing a humidifying means provided in a duct of the blower system.

FIG. 5 is a perspective view showing an example in which a heater is attached to the humidifying means.

FIG. 6 is a plan view showing a humidification amount adjusting mechanism of the humidifying means shown in FIG.

7A and 7B show another example of the humidification amount adjusting mechanism, where FIG. 7A is a plan view and FIG. 7B is a side view.

FIG. 8 is a side view showing another example of the humidifying means.

FIG. 9 is a perspective view showing still another example of the humidifying means.

[Explanation of symbols]

 1 Color Scanner 2 Color Printer 9 Photoreceptor 19 Intermediate Transfer Belt 40 Intake Fan 41 Intake Duct 42 Water Storage 43 Water Storage Container 44 Heater 46, 49 Lid 48 Solenoid 50 Stepping Motor 51a Semicircular Opening 52 Water Storage Recess 54 Cloth 55 High Frequency Output device 56 High-pressure unit 57 Evaporation dish 100 Color copier

Claims (6)

[Claims] 1. An image forming apparatus having a photoconductor and an outside air introducing mechanism, wherein an humidifying means for humidifying the introduced outside air is provided in an outside air introducing path of the outside air introducing mechanism. 2. The image forming apparatus according to claim 1, further comprising means for adjusting a humidification amount of the humidifying means. 3. The image forming apparatus according to claim 2, wherein the humidifying amount adjusting means is controlled according to an image forming operation. 4. The outside air introducing mechanism has an intake fan,
The image forming apparatus according to claim 2, wherein the humidification amount adjusting unit is controlled according to the operation of the fan. 5. The image forming apparatus according to claim 2, further comprising temperature measuring means for measuring an in-machine temperature, wherein the humidification amount adjusting means is controlled according to a measurement result of the temperature measuring means. apparatus. 6. A nitrogen oxide concentration measuring means for measuring the nitrogen oxide concentration of the outside air around the apparatus or the outside air introduced into the apparatus, wherein the humidification amount adjusting means measures the nitrogen oxide concentration measuring means. It is controlled according to the result,
The image forming apparatus according to claim 2.