JPH05257341A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To carry out the exchange operation of a photosensitive cartridge in a clean state by preventing soiling of the photosensitive cartridge containing the photosensitive belt. CONSTITUTION:Toner scattered and suspended from a developing device or the photosensitive body are prevented from soiling a lower surface area of a photosensitive cartridge 2 by intruding into ventilation space, without generating any complication in the structure of the device by forming the ventilation space 17 between the photosensitive cartridge 2 and a photosensitive cartridge inserting and detaching holder 11 where the photosensitive cartridge is mounted and ventilating clean air to the ventilation space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus, such as a copying machine or a printer, which uses an electrophotographic process, to prevent contamination of electrophotographic process executing means and stains during replacement of consumables such as photoconductors. Regarding prevention.

[0002]

2. Description of the Related Art An electrophotographic apparatus such as a color copying machine or a laser beam printer which uses an electrophotographic process is one in which a toner image of a plurality of colors formed by the electrophotographic process is polymerized to complete a color image. Target. A photoconductive photosensitive belt is used as a photoreceptor for forming the toner images of the respective colors, and electrostatic latent images of the respective colors sequentially formed on the photosensitive belt are developed to form toner images of the respective colors. The color toner image is completed by transferring the toner images of the respective colors onto the intermediate transfer drum, which is an intermediate transfer member, to complete a color toner image, and then the color toner image is fixed on the recording paper to print a color image ( 2. Description of the Related Art Electrophotographic devices that perform recording are known. It is known to use a photosensitive drum as a photoreceptor and an intermediate transfer belt as an intermediate transfer member in an electrophotographic apparatus, and the electrophotographic apparatus can be replaced with these components.

By the way, since the photoconductors in the electrophotographic apparatus, including the monochromatic electrophotographic apparatus, are consumable items, it is necessary to replace them each time a predetermined number of sheets are printed. Currently, the life of the photosensitive belt of the color electrophotographic apparatus is about 20,000 to 30,000 sheets, and it is necessary to frequently replace the photosensitive belt in the case of printing a large amount. Some ideas have been proposed to make it easier.

Further, a developing device in an electrophotographic apparatus generally uses a two-component developer in which a carrier and a fine powder toner are mixed, or a one-component developer in which a fine powder toner containing a magnetic powder is used alone. Although these toners are used, there is a problem that these toners easily scatter, and the scattered toner adheres to the surrounding components and stains them, or is discharged to the outside of the device and pollutes the indoor air. In order to remove even the generated ozone, a ventilation mechanism has been proposed that collects and filters air in the device.

As such an electrophotographic apparatus, a special table 1
No. 502062 and Japanese Patent Laid-Open No. 2-198476 disclose color electrophotographic apparatuses, and Japanese Utility Model Laid-Open No. 2-111140 and Japanese Patent Laid-Open No. 60-113277 disclose a mechanism for attaching and detaching a photosensitive belt. Japanese Patent Application Laid-Open No. 2-214880 and Japanese Patent Application Laid-Open No. 2-214880
No. 301774 discloses a ventilation mechanism.

[0006]

However, in the electrophotographic apparatus described in each of the above-mentioned patent publications, the replacement of the photoconductor is performed by reducing stains on the components that affect the replacement work of the photoconductor (photosensitive belt). Lack of attention to clean work. Therefore, the replacement of the photoconductor must be carried out while touching the dirty components, which is troublesome for the operator.

Therefore, an object of the present invention is to prevent contamination of the photoconductor cartridge and its surrounding components with a simple structure by devising a ventilation mechanism, so that replacement of parts and cleaning work can be performed cleanly. Especially.

[0008]

According to the present invention, there is provided an insertion / removal holder which is horizontally inserted into and removed from an apparatus main body, and the insertion / removal holder is placed on the insertion / removal holder from above. And a latent image forming unit that forms an electrostatic latent image by charging and exposing the surface of the photoconductor in a state where the insertion / removal holder is pushed in. In an electrophotographic apparatus including a developing device that develops the electrostatic latent image to form a toner image, a transfer unit that transfers the toner image to a recording sheet, and a ventilation unit that discharges contaminated air in the apparatus. The ventilation means is formed between the upper surface of the insertion / removal holder and the photoconductor cartridge, one of which is open to the outside in the pull-out direction of the insertion / removal holder, and the other has a ventilation space connected to an exhaust device with a filter. Provided in the space above the insertion / removal holder Characterized in that so as to vent the purification of air.

[0009]

In the ventilation space formed between the photoconductor cartridge and the insertion / removal holder on which the cartridge is mounted, clean outside air is introduced to ventilate the air, so that toner scattered from the developing device or the photoconductor is floating. Since it does not enter the ventilation space, the lower surface area of the photoconductor cartridge that is detached for replacement or cleaning work is not contaminated and can be handled cleanly.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a color printer according to the present invention will be described below with reference to the drawings.

A photoconductor cartridge 2 is arranged in the center of the printer body 1. The photoconductor cartridge 2 includes rotating rolls 5, 6, 7, 8 for rotatably stretching and holding the photoconductor belt 4 in a case 3, a cleaning blade 9 attached to the case 3, a shutter 10 and the like. Further, a charging window 3a, an exposure window 3b, and a charge eliminating window 3c are formed on the bottom wall of the case 3. The rotating rolls 5 and 6 are arranged so as to form a flat developing area on the photosensitive belt 4 which is exposed and rotated on the upper surface side of the photosensitive body cartridge 2, and the rotating rolls 6 and 7 are arranged inside the photosensitive body cartridge 2. The toner image transfer area, which will be described later, is arranged at the end portion, and the rotating roll 8 is arranged so as to form a stable exposure surface for scanning and exposing the photosensitive belt 4. The cleaning blade 9 is pressed against the photosensitive belt 4 on the rotating roll 7 to scrape off the toner remaining on the photosensitive belt 4. The shutter 10 is biased by a spring (not shown) so as to move to a position that covers the cleaning blade 9, and when the photoconductor cartridge 2 (photoconductor cartridge insertion / removal holder described later) is pulled out from the main body 1. The cleaning blade 9 is moved (advanced) by a spring force so as to cover it, and is moved (retracted) against the spring force so as to expose the cleaning blade 9 when pushed.

The photoconductor cartridge 2 is attached and detached from above on the photoconductor cartridge insertion / removal holder 5 which is provided so as to be inserted into and removed from (removed from) the main body 1 in order to facilitate the attachment / detachment for replacement or cleaning. It can be placed freely. The photoconductor cartridge insertion / removal holder 11 has a box-like shape with an open upper side, and the ridges 12 provided on the outer surfaces of both side walls of the photoconductor cartridge insertion / removal holder 11 slide on the concave groove rails 14 provided inside the both side frames 13 of the main body 1. It is slidably fitted through the child 15, and the exposure window 11 is provided on its bottom wall.
a and a detachable corona discharge type charger 16 are provided, an air intake window 11b is provided on the outer side wall in the inserting / removing direction, and the inner side wall in the inserting / removing direction has a short height.
And a space for advancing and retracting the shutter 10 are ensured between the and.

The upper portions of the outer surfaces of the lateral side walls of the case 3 of the photoconductor cartridge 2 are detachably fitted to the upper edges of the lateral side walls of the photoconductor cartridge insertion / removal holder 11 so as to be detachable. A ventilation space 17 is defined between the lower side and the photoconductor cartridge insertion / removal holder 11 to prevent toner from entering and adhering to the lower side of the photoconductor cartridge 2. In addition, ventilation windows 16a and 16b are formed in the discharge case of the charger 16 provided on the bottom wall of the photoconductor cartridge insertion / removal holder 11 so as to cross the ventilation space 17.

Positioning guides 18 for positioning the photoconductor cartridge 2 are provided inside the main body side frames 13 on both sides.
19 is provided. The guides 18 and 19 project from the photoconductor cartridge 2 near the end when the photoconductor cartridge insertion / removal holder 11 is pushed in.
There is an inclined groove that engages so as to pull up while receiving a and 6a, and the photosensitive body cartridge 2 is pulled up and positioned directly so that the photosensitive belt 4 comes into contact with a developing device described later. The positioning guide 18 on the outer side in the insertion / removal direction serves to prevent the rotary roll shaft 6a from engaging during the insertion / removal of the photoconductor cartridge insertion / removal holder 11 and the attachment / detachment of the photoconductor cartridge 2 to / from the insertion / removal holder 11. The rotation roll shaft 5a is installed at a wider interval than the end passing position, and the rotation roll shaft 5a has an axial length that engages with the positioning guide 18. In addition, a stopper (not shown) is provided at the limit position for pulling out the photoconductor cartridge insertion / removal holder 11 to prevent the photoconductor cartridge insertion / removal holder 11 from falling off when it is pulled out.

The waste toner discharging means 20 is the rotating roll 7
Installed below the gutter 21 for receiving the waste toner scraped off by the cleaning blade 9 pressed against the photosensitive belt 4 on the rotating roll 7 and the screw 22 for discharging the waste toner accumulated on the gutter. When the photoconductor cartridge insertion / removal holder 11 is pushed in, the front end of the shutter 10 of the photoconductor cartridge 2 is pushed by the end of the gutter 21 to retract the shutter 10.

The shutter 10 has a static elimination window 10a. When the shutter 10 moves backward, the static elimination window 10a coincides with the static elimination window 3c formed in the case 3 of the photosensitive cartridge 2, and the static elimination lamp 2 is installed.
It is possible to irradiate the photosensitive belt 4 with the light of 3.

An exposure unit base 24 is arranged below the photoconductor cartridge insertion / removal holder 11, and a laser beam scanning exposure unit 25 is installed thereon. A laser beam 25a emitted from the exposure unit 25 in accordance with a video signal given from a higher-order image signal generator.
Exposes the photosensitive belt 4 rotating on the rotating roll 8 through the exposure window 11a formed in the photoconductor cartridge insertion / removal holder 11 and the exposure window 3b formed in the case 3 of the photoconductor cartridge 2, The electrostatic latent images corresponding to the respective colors are sequentially formed on the photosensitive belt.

Above the photoconductor cartridge 2, the developing devices 26, 27, 28 and 29 are detachably arranged so as to face the developing area in which the photosensitive belt 4 rotates flat, and the developing rolls 26a, 27a are arranged. , 28a, 29a, the developer magnetic brush is rubbed against the surface of the photosensitive belt to develop the electrostatic latent image. A developer containing yellow (Y) color toner is used for the developing unit 26, and magenta (M) is used for the developing unit 27.
A developer containing a color toner is used, a developer containing a cyan (C) color toner is used in the developing unit 28, and a developer containing a black (K) color toner is used in the developing unit 29. To use. And, these developing devices 26, 27, 28, 2
9 to the photosensitive belt 4 selectively according to the corresponding color of the electrostatic latent image.
By acting on the electrostatic latent images above, the electrostatic latent images of the respective colors are converted into toner images of the corresponding colors.

The intermediate transfer drum 30 is installed so as to rotate while contacting the photosensitive belt 4 positioned in the printer body 1 in the toner image transfer area, and the toner image formed on the photosensitive belt 4 is transferred to the intermediate transfer drum 30. Electrostatic transfer is performed in the toner image transfer area. On the outer periphery of the intermediate transfer drum 30,
The pre-charging device 31 and the transfer device 32 are opposed to the outer peripheral surface thereof.
And the drum cleaner 33 is installed.

The precharger 31 is a corona discharger,
When the completed color toner image is transferred onto the recording paper on the outer peripheral surface of the intermediate transfer drum 30, the corona discharge is generated by being biased in order to precharge the color toner image.
In the discharge case of the preliminary charger 31, the preliminary charger 31
Ventilation windows 31a and 31b for ventilating the inside are formed. The transfer device 32 includes two corona dischargers. The corona discharger in the former stage generates a corona discharge for giving a charge for electrostatically transferring the charged color toner image onto the recording paper to the back surface of the recording paper, and the corona discharger in the latter stage develops the color toner image on the recording paper. After the transfer, the corona discharge that reduces the electric charge remaining on the back surface of the recording paper is generated. The drum cleaner 33 can be operated to separate from and contact with the outer peripheral surface of the intermediate transfer drum 30, and a toner image of a different color is superposed and transferred from the photosensitive belt 4 to the outer peripheral surface of the intermediate transfer drum multiple times to transfer a color toner image. In the process of forming the outer peripheral surface, the outer peripheral surface is operated to separate from the outer peripheral surface, and after the completed color toner image is transferred onto the recording paper, the outer peripheral surface is removed in order to remove the toner remaining on the outer peripheral surface of the intermediate transfer drum. It is operated so that it touches.

A space defined by the photoconductor cartridge insertion / removal holder 11, the photoconductor cartridge 2, the waste toner discharging means 20, the exposure unit base 24, the exposure unit 25, the intermediate transfer drum 30, and the precharger 31. 34
Serves as a guide space for guiding the clean air in the ventilation space 17 to the exhaust device.

The paper feed mechanism is the exposure unit base 24.
Make up the space below. In the manual paper feeding system, the recording paper is fed from the manual paper feeding tray 35 provided to be rotatable so as to open and close the insertion / removal window of the photoconductor cartridge insertion / removal holder 11 to the paper feeding roll 38 by the paper feeding rolls 36 and 37. The automatic paper feeding system is configured so that the recording paper 40 stored in the paper feeding cassette 39 is extracted by the paper feeding roll 38.

A registration roll 41, which aligns the conveyance timing of the color toner image formed on the intermediate transfer drum 30 and the recording paper 40 on which the toner image is transferred, is provided between the paper feed roll 38 and the transfer device 32, and feeds the paper. The transfer timing of the recording paper 40 sent from the roll 38 is adjusted to adjust the transfer device 32.
Send to.

A transfer guide 42, a fixing device 43, and a paper discharge roll 44 are provided behind the transfer device 32, and a printed matter sent from the paper discharge roll 44 (the recording paper 4 on which the toner image is fixed).
0) is formed on the upper surface of the printer body.

The exhaust device is provided with an exhaust fan 46, an ozone filter 47, and a duct 48, and the tip of the duct 48 extends to the vicinity of the preliminary charger 31 and a ventilation window 31a formed in the discharge case of the preliminary charger 31. , 31b and the inside of the discharge case to suck air from the ventilation space 34.

Although a control circuit device for controlling the operation of the color printer is installed in the printer body 1, it is not shown in the drawing.

Next, the printing operation will be described.

When color printing is started, a video signal for forming an electrostatic latent image for each color is sent from the upper image signal generator in the order of yellow Y, magenta M, cyan C and black K. The laser beam scanning exposure unit 25 turns on and off the emitted laser beam 25a by this video signal, exposes the photosensitive belt 4 uniformly charged by the charger 16 to expose an electrostatic latent image corresponding to each color on the photosensitive belt 4. Are exposed to form.

The electrostatic latent image corresponding to the first formed yellow color is developed by the developing device 26 using a yellow developer to form a yellow toner image on the photosensitive belt 4,
The toner image is temporarily transferred onto the intermediate transfer drum 30. Then, the formed electrostatic latent image corresponding to magenta color is developed by a developing device 27 using a magenta color developer to form a magenta color toner image, and the toner image is transferred onto the intermediate transfer drum 30. The transferred toner image is overlaid on the yellow toner image. By repeating such toner image formation and transfer for cyan and black in the same manner, a full-color toner image is completed on the intermediate transfer drum 30. While the toner images are being transferred and superposed on the intermediate transfer drum 30, the drum cleaner 33 is kept away from the intermediate transfer drum 30.

On the other hand, the recording paper 40 on which the color toner image is transferred is extracted from the paper cassette 39 by the paper feed roll 38.
The paper is fed and conveyed to the registration roll 41. The registration roll 41 starts to rotate so as to convey the recording paper 40 so that the color toner image on the intermediate transfer drum 30 and the recording paper 40 are aligned at the transfer position, and the recording paper 40 is transferred to the transfer device 3
Send to 2. The transfer device 32 starts corona discharge at the timing when the recording paper 40 reaches the transfer position, and electrostatically transfers the color toner image on the intermediate transfer drum 30 to the recording paper 40.
Then, the recording paper 40 on which the color toner image has been transferred is separated from the intermediate transfer drum 30 and passed through a fixing device 43 to fix the color toner image on the recording paper 40 and eject it onto a paper ejection tray 45. To paper.

Next, replacement of the photoconductor cartridge 2 will be described.

When it is determined that the life of the photosensitive belt 4 has reached the end due to the increase in the number of image stains and irregularities, the photosensitive cartridge 2 is replaced. First, the manual feed tray 3
5 is opened, and the photoconductor cartridge insertion / removal holder 11 is pulled out together with the photoconductor cartridge 2. When the photoconductor cartridge insertion / removal holder 11 is pulled out by about 5 mm, the rotating roll shafts 5a, 6a protruding from the photoconductor cartridge 2 are lowered by about 2 mm along the inclined grooves of the positioning guides 18, 19 to develop the photosensitive belt 4 and the developing belt. A gap is created between the devices 26 and 29. The shutter 10 is pushed out by a spring force in conjunction with the pulling out of the photoconductor cartridge insertion / removal holder 11 and moves so as to cover the cleaning blade 9, and the cleaning blade 9 and the toner in the vicinity thereof are stored in the photoconductor cartridge 2. Prevent it from falling out. Further, when the photoconductor cartridge insertion / removal holder 11 is pulled out, the photoconductor cartridge insertion / removal holder 11 is stopped by the action of the stopper at the pullout limit position. Here, by gripping and lifting the handle 3d formed on the case 3 of the photoconductor cartridge 2, the photoconductor cartridge 2 can be detached from the photoconductor cartridge insertion / removal holder 11 and removed to the front upper side.

The new photoconductor cartridge 2 can be installed by placing the photoconductor cartridge 2 on the photoconductor cartridge insertion / removal holder 11 that has been pulled out and pushing in the photoconductor cartridge insertion / removal holder 11. it can. The shutter 10 opens in association with the pressing of the photoconductor cartridge insertion / removal holder 11, and the photoconductor belt cartridge 2 is installed in a operable state at a predetermined location.

By the way, while the color printer is operating,
Since the magnetic brushes of the developing units 26 to 29 are rotating and the cleaning blade 9 scrapes the toner from the photosensitive belt 4, the toner is scattered in the printer body 1,
Part of it floats and adheres to the components. If this toner adhesion occurs on the lower surface area of the photoconductor cartridge 2 which is a replacement part or the upper surface part of the photoconductor cartridge insertion / removal holder 11 on which the photoconductor cartridge 2 is mounted, the above-mentioned replacement work of the photoconductor cartridge 2 is troublesome. become.

Therefore, a ventilation mechanism devised to reduce these stains due to the toner adhesion and to remove ozone generated by the corona discharger will be described.

Ventilation inside the printer body 1 is generated by exhausting the internal air by the exhaust fan 46. The clean air flowing in through the air intake window 11b provided in the photoconductor cartridge insertion / removal holder 11 is located in the ventilation space 17 formed between the photoconductor cartridge insertion / removal holder 11 and the photoconductor cartridge 2 and in the space. Charger 1
6, reaches the guide space 34, passes through the pre-charger 31 and is sucked from the duct 48, and the ozone filter 47
And discharged to the outside of the printer body 1. Developing device 26-
The toner scattered from 29 is deposited on the photoconductor cartridge 2, but between the photoconductor cartridge 2 and the photoconductor cartridge insertion / removal holder 11, the lateral side surface is fitted and the projection 12 and the rail 14 are fitted. Since the ventilation space 17 is closed by the combination, the scattered toner does not enter the ventilation space 17. Therefore, the lower surface of the photoconductor cartridge 2 is always in contact with clean air, so that the lower surface of the photoconductor cartridge 2 is kept clean, and it is easy to clean or replace the photoconductor cartridge 2. It does not get dirty.

Further, since the clean air flowing in the ventilation space passes through the discharge case of the charger 16 and the preliminary charger 31, the ozone generated by these is removed by the ozone filter 4.
It is possible to lead to 7 and decompose and remove.

[0038]

According to the present invention, since a ventilation space for passing clean outside air is formed between the photosensitive cartridge and the insertion / removal holder on which the cartridge is mounted, the structure is particularly complicated. In addition, it is possible to prevent the toner scattered from the developing device or the photoconductor from entering the ventilation space and contaminating the lower surface region of the photoconductor cartridge, and to perform the handling for replacement and cleaning work cleanly. You can

[Brief description of drawings]

FIG. 1 is a vertical sectional side view.

FIG. 2 is an exploded perspective view showing a relationship between a main body side frame, a photoconductor cartridge, and a photoconductor cartridge insertion / removal holder.

FIG. 3 is a partially cutaway perspective view showing a fitting relationship between them.

FIG. 4 is a vertical cross-sectional side view showing the fitting portion.

FIG. 5 is a partially cutaway plan view thereof.

FIG. 6 is an exploded perspective view showing a ventilation path.

FIG. 7 is a vertical cross-sectional side view showing a detached state of the photoconductor cartridge.

[Explanation of symbols]

1 ... Printer body, 2 ... Photosensitive cartridge, 3 ... Case, 4 ... Photosensitive belt, 5, 6, 7, 8 ... Rotating roll, 5
a, 6a ... rotating roll shaft, 9 ... cleaning blade,
Reference numeral 10 ... Shutter, 11 ... Photoconductor cartridge insertion / removal holder, 11b ... Air intake window, 12 ... Projection, 13 ... Side frame,
14 ... Groove rail, 15 ... Slider, 16 ... Charger, 16
a, 16b ... Ventilation window, 17 ... Ventilation space, 18, 19 ... Positioning guide, 20 ... Waste toner discharging means, 24 ... Exposure unit base, 25 ... Scanning exposure unit, 25a ... Laser beam, 26-29 ... Developing device, 30 ... Intermediate transfer drum, 31 ... Pre-charger, 31a, 31b ... Ventilation window, 34
... Guide space, 46 ... Exhaust fan, 47 ... Ozone filter, 48 ... Duct.

Claims (7)

[Claims] 1. An insertion / removal holder provided so as to be inserted / removed in a horizontal direction with respect to an apparatus main body, and detachably mounted on the insertion / removal holder from above in a state where the insertion / removal holder is pulled out. A photoconductor housed in a photoconductor cartridge, a latent image forming unit that forms an electrostatic latent image by charging and exposing the surface of the photoconductor while the insertion / removal holder is pushed in, and the electrostatic latent image is developed. In the electrophotographic apparatus, a developing device that forms a toner image by means of the above, a transfer unit that transfers the toner image onto a recording sheet, and a ventilation unit that discharges contaminated air in the apparatus are provided. A space is formed between the upper surface of the demounting holder and the photoconductor cartridge, one of which is opened to the outside in the pulling-out direction of the inserting / removing holder, and the other has a ventilation space connected to an exhaust device with a filter. Pass clean air through the space Electrophotographic apparatus, characterized in that the the to. 2. The latent image forming means according to claim 1, further comprising a corona discharge charger provided on the insertion / removal holder and positioned so as to cross the ventilation space, the charger being provided on a side wall of the discharge case. An electrophotographic apparatus having a ventilation window. 3. The electrophotographic apparatus according to claim 1, wherein the photosensitive member is a photosensitive belt. 4. An insertion / removal holder provided so as to be inserted / removed in a horizontal direction with respect to the main body of the apparatus, and detachably mounted on the insertion / removal holder from above in a state where the insertion / removal holder is pulled out, A photoconductor cartridge containing a photosensitive belt that is rotated in the insertion / removal direction of the insertion / removal holder, and a surface of the photosensitive belt which is charged and exposed while the photosensitive belt is rotated while the insertion / removal holder is being pressed. A latent image forming unit that forms a latent image, a developing device that develops the electrostatic latent image to form a toner image, a transfer unit that transfers the toner image onto a recording sheet, and discharges contaminated air in the apparatus. In the electrophotographic apparatus provided with a ventilation unit, the ventilation unit is formed between the upper surface of the insertion / removal holder and the photoconductor cartridge, one of which is opened at an outer side in the pull-out direction of the insertion / removal holder, and the other is For exhaust system with filter Comprising a comprising ventilation space, the electrophotographic apparatus being characterized in that so as to vent the clean air in the space on the insertion and removal holder. 5. The electrophotographic apparatus according to claim 4, wherein the photosensitive belt is installed in the photosensitive cartridge by being stretched around a rotating roll so as to form a flat portion on an upper side of a rotation path. .. 6. The transfer device according to claim 4, wherein the transfer means generates a transfer drum to which the toner image formed on the photosensitive belt is transferred, and a corona discharge that charges the toner image temporarily transferred to the transfer drum. An electrophotographic apparatus, wherein the exhaust device of the ventilation unit communicates with the ventilation space through a ventilation window formed on a side wall of a discharge case of the preliminary charger. 7. An insertion / removal holder provided so as to be inserted / removed in a horizontal direction with respect to a main body of the apparatus, and detachably mounted on the insertion / removal holder from above in a state where the insertion / removal holder is pulled out, A photoconductor cartridge having a photosensitive belt mounted therein so as to be rotatable in the insertion / removal direction of the insertion / removal holder, and a surface of the photosensitive belt that is charged and exposed while the photosensitive belt is rotated while the insertion / removal holder is pushed in. A latent image forming unit that forms a latent image, a developing device that develops the electrostatic latent image to form a toner image, a transfer unit that transfers the toner image onto a recording sheet, and discharges contaminated air in the apparatus. In the electrophotographic apparatus including a ventilation unit, the ventilation unit is partitioned between an upper surface of the insertion / removal holder and a photoconductor cartridge mounted on the insertion / removal holder, one of which is the insertion / removal holder. Open on the outer side of the It is provided with a ventilation space communicating with the exhaust system with a filter, an electrophotographic apparatus being characterized in that so as to vent the clean air in the space on the insertion and removal holder.