JP2002148938A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent drop and adhesion of the developer that a developer stored between a photoreceptor and a film seal to seal its gap is hardened b vibration in the case of operation on the surface of a development roller and to prevent staining of a light output surface part of an exposure device arranged at a lower part of a developing device. SOLUTION: This image forming device is constituted by approximating a housing of a developing device 14 to the photoreceptor 11 and mounting a film-like member 50 on a part adjacent to an electrostatic charging device 12 so that its top part is abutted to the surface of the photoreceptor 11.

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 typified by an electrophotographic printer, a copying machine, a facsimile, a multifunction machine, etc., and more particularly, to exposing a photosensitive member to light corresponding to image information. The present invention relates to an image forming apparatus of a type in which a light emitting surface portion of an exposure device for forming an electrostatic latent image is disposed at a position below a developing device.

[0002]

2. Description of the Related Art In this type of image forming apparatus, FIG.
As shown in FIG. 2, basically, the surface of the drum-shaped photoconductor 110 rotating in the direction of the arrow is uniformly charged by the charging device 120, and then the image of the charged photoconductor is exposed from the exposure device 130. The electrostatic latent image is formed by exposing light H corresponding to the information, and then the electrostatic latent image is passed through the developing device 140 from the inside of the housing 141 via a developer carrier 142 such as a developing roll. The image is developed by developing with a supplied developer, and the developed image is transferred to a recording medium such as recording paper directly or via an intermediate transfer member, and fixed to form an image. In particular, the light H of the exposure device 130 is
There is a case where a light emitting surface portion (a transparent glass window, a reflecting mirror, a lens, or the like) 135 that emits light toward the lower side of the developing device 140 is provided.

In this case, the light emitting surface portion 1 is roughly divided.
In the case where 35 is disposed at a position below the developing device 140 together with the main body 131 including the light source and the like of the exposure device 130 (FIG.
However, there is a case where the main body 131 is disposed at the same height position as the developing device 140 or at a position higher than that (FIG. 2B). In particular, in the latter case, the light emitting surface portion 135 has a configuration in which optical devices such as a reflection mirror that forms an optical path for guiding the light emitted from the main body portion 131 to the photoconductor 110 are arranged.

[0004]

However, the exposure apparatus 1
The image forming apparatus of the type in which the 30 light output surface portions 135 are disposed below the developing device 140 has the following problems.

That is, the light exit surface 13 of the exposure device 130
Since 5 is located below the developing device 140, a small amount of developer may fall from the developing device 140 onto the light emitting surface portion 135, and the light emitting surface may become dirty. In this case, the light H that is emitted from the light emitting surface portion 135 and exposed to the photoconductor 110 due to the contamination is not normally emitted, and the photoconductor 1
In this case, an electrostatic latent image cannot be satisfactorily formed on the optical disk 10, and there is a problem that image quality defects occur.

Conventionally, in order to prevent the developer supplied from the developing device to the photoreceptor from flying up and leaking from the developing device to the inside of the apparatus and being contaminated, the developing device is provided on the surface of the photoreceptor. It is known to provide a film seal that abuts and seals a gap between the photoconductor and the like (Japanese Patent Laid-Open No. 10-10864). However, in this case, the developer accumulates between the film seal or the seal and a mounting portion (e.g., a housing of the developing device), and the accumulated developer may be vibrated during operation or may be subjected to an external impact. In a hardened state, it may fall and adhere to the surface (developer layer) of the developing roll. Then, when the development is performed in a state where such a solidified state of the developer is adhered, there is a possibility that a development defect and an image quality defect may occur. Therefore, the proposed means cannot be an effective solution to the above problem.

The present invention has been made in view of such circumstances, and a main object of the present invention is to provide a type in which the light emitting surface of the above-described exposure apparatus is disposed below the developing apparatus. In the image forming apparatus of the present invention, it is possible to provide an image forming apparatus capable of reliably preventing the light emitting surface portion of the exposure apparatus from being stained by a developer such as falling from the developing apparatus and obtaining good image quality without image quality defects. is there.

[0008]

An image forming apparatus according to the present invention (first invention) capable of solving the above-mentioned problems includes a photosensitive member rotating in a fixed direction, a charging device for charging the surface of the photosensitive member, An exposure device that exposes the surface of the photoreceptor charged by the charging device to light corresponding to image information to form an electrostatic latent image, and that the electrostatic latent image formed by the exposure device is A developing device that develops with the supplied developer, and the image forming apparatus is configured such that the exposure device arranges the light emitting surface portion of the light at a position below the developing device. A film-like member is attached to a portion of the housing of the apparatus that is close to the photoconductor and adjacent to the charging device, with an upper end portion of the film-shaped member being in contact with the surface of the photoconductor.

The image forming apparatus of the present invention (second invention) is the same as the image forming apparatus of the first invention,
A path forming member that forms a path through which air flows along the exposure direction of the light emitted from the light emitting surface portion between the charging device and the developing device is disposed to a position close to the photoconductor, and A film-like member is provided at the upper end of the film-like member at a portion of the housing of the device that is close to the photoconductor and adjacent to the charging device or at a portion of the passage forming member that is close to the photoconductor and adjacent to the developing device. It is characterized in that it is attached in a state of contact with the surface of the body.

In the image forming apparatus according to the first and second aspects of the present invention, the film-like member is provided between the housing portion or the passage-forming member portion to which the film-like member is attached and toward the upper end of the film-like member. At the time when the photoconductor and the developing device are set to the proper mounting position, the upper end side of the film-shaped member is set at the upper end of the photoconductor, in which a gap space having a gradually expanding cross-sectional shape is formed in advance. The photoconductor is bent in a state in which it is pressed toward the surface and bends toward the housing portion or the passage forming member portion side serving as the attachment portion, and touches at least the leading edge of the housing portion or the passage forming portion to close the gap space. It is good to constitute so that it may contact the surface.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIGS. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a schematic diagram showing an image forming apparatus to which the present invention is applied. FIG.

The image forming apparatus includes four image forming units 10
The four color toner images of yellow (Y), magenta (M), cyan (C), and black (K) individually formed by Y, 10M, 10C, and 10K are formed on the surface of the intermediate transfer belt 20 of the intermediate transfer mechanism. This is a color image forming apparatus capable of forming a so-called full-color image by performing primary transfer so as to be superimposed and then performing secondary transfer from the intermediate transfer belt 20 to a recording paper P side as a recording material. Further, this apparatus includes a part of four image forming units, for example, a black image forming unit 10K.
It is also possible to form a monochrome image such as a black-and-white image by operating only one of them.

First, each of the image forming units 10
Each of the above-described four color toner images is formed by an electrophotographic process. The toner image is formed in a horizontal state at a position substantially below the intermediate transfer belt 20 at a substantially central portion of the main body 1 of the image forming apparatus. It is arranged in. Also,
Each of the image forming units 10 basically includes a photosensitive drum 11 having an organic photosensitive layer or the like disposed on an outer peripheral surface of a drum that is driven to rotate in a direction indicated by an arrow at a predetermined speed, and a surface of the photosensitive drum 11. A charging roller 12 for uniformly charging, and an exposure device 1 as a latent image forming device for forming an electrostatic latent image by exposing the surface of the charged photosensitive drum 11 to light corresponding to image information.
3, a developing device 14 for developing the electrostatic latent image with a developer of a predetermined color, and a primary transfer roll 1 for electrostatically transferring a toner image formed by the development to the intermediate transfer belt 20
5 and a blade-type drum cleaning device 16 for cleaning the surface of the photosensitive drum 11.

The exposure device 13 is housed in a housing box 17 provided below the four image forming units 10, and is separated for each color from four semiconductor lasers (not shown). Laser light LB-Y, LB-M, LB-C, LB-K emitted according to the image signal is irradiated on the rotary polygon mirror 18 via a predetermined optical system (such as a lens) to perform deflection scanning. Scanning exposure is performed obliquely from below on each of the photosensitive drums 11 facing each other via a plurality of reflection mirrors (not shown). Reference numeral 17a in the figure is
It is a light emitting surface portion provided with a transparent glass surface for transmitting and emitting each of the laser beams LB from the inside of the housing closed box 17 to the photosensitive drum 11 of each image forming unit 10.

Each developing device 14 uses a two-component developer composed of a toner and a carrier as a developer G, and as shown in FIG. The developer G is accommodated in the section 41 and is agitated and transported by two developer agitating and transporting members (for example, augers) 42 and 43 rotating in a parallel state, and finally opposes the photosensitive drum 11 of the housing 40. The developer is supplied to a developing roll 45 that is driven to rotate into an opening 44 that is to be rotated. Further, each of the developing devices 14 includes a toner cartridge 1 containing a toner T (or developer G) of the corresponding color (Y, M, C, K).
9Y, 19M, 19C, and 19K, via a developer supply device (not shown), the developer accommodating and circulating conveyance path portion 4
1 is appropriately supplied. Further, a primary transfer bias having a polarity opposite to the charging polarity of the toner image on the photosensitive drum 11 is applied to the primary transfer roll 15 from a bias power supply device (not shown).

In each of the image forming units 10, the surface of the photosensitive drum 11 rotating in the direction of the arrow is uniformly charged by the charging roll 12, and the charged surface is subjected to color separation from the exposure device 13. The electrostatic latent image is written by scanning and exposing the laser beam LB corresponding to the image signal through the light emitting surface portion 17a, and then the latent image is transferred to the toner T of the developer G supplied from the developing device 14. To form a toner image, and finally, the toner image is sequentially primary-transferred onto the surface of the intermediate transfer belt 20 passing between the photosensitive drum 11 and the primary transfer roll 15. The surface of the photosensitive drum 11 after the transfer is cleaned by removing the residual toner and the like by the blade of the drum cleaning device 16.

Next, the intermediate transfer belt 20 has a two-layer structure in which a surface layer such as silicone rubber is laminated on a belt base material such as a polyimide film in which a volume resistivity is adjusted by containing a conductive material or the like. An endless belt, which is stretched around a driving roll 21, a backup roll 22 of a secondary transfer unit, and a plurality of driven rolls 23, 24,... Are arranged so as to be in contact with the photosensitive drums 11 of
The motor is driven to rotate in the direction of arrow B by the rotational power of the drive roll 21.

Around the intermediate transfer belt 20, there is provided a secondary transfer roll 25 for pressing the intermediate transfer belt 20 against a backup roll 22 to form a pressure contact area of a secondary transfer portion. In addition, the backup roll 22
Power supply member 2 for supplying a secondary transfer bias having the same polarity as the charging polarity of the toner image on the intermediate transfer belt 20 from a bias power supply device (not shown) to the conductive shaft of
7 are provided so as to be in contact with each other. Further, a blade-type belt cleaning device 26 that cleans the surface of the intermediate transfer belt 20 is disposed at a position facing the drive roll 21.

On such an intermediate transfer belt 20 (multiple)
The transferred toner image is conveyed to a secondary transfer section opposed to a secondary transfer roll 25 disposed opposite to the backup roll 22 as the belt 20 rotates. The toner image on the intermediate transfer belt 20 is exposed to the exposure device 1 in accordance with the toner image formation and the secondary transfer timing.
3 is sent out by a sheet sending mechanism 31 from a sheet storage tray 30 disposed below the registration roll 32.
Is electrostatically secondary-transferred to a recording sheet P of a predetermined size which is conveyed to a secondary transfer unit through a paper conveyance path on which the paper is arranged. The surface of the intermediate transfer belt 20 after the secondary transfer is cleaned by removing residual toner and the like by a blade of a belt cleaning device 26. The dashed line in FIG. 1 indicates the transport path of the recording paper P.

The recording paper P on which the toner image has been transferred from the intermediate transfer belt 20 is naturally separated from the intermediate transfer belt 20 when passing through the secondary transfer portion, and then heated by a heating roll 36 in a fixing device 35. And a pressure member (pressure pad, pressure roll, or the like) 37 to be passed through a pressure contact area to perform a heat fixing process. ). Through the above process, a desired color image or the like is formed on the recording paper P.

In this image forming apparatus, as shown in FIGS. 2 and 3, a film-like member 50 is provided on the housing 40 of the developing device 14 in each image forming unit 10 so that the upper end 50a of the film-like member 50 is on the surface of the photosensitive drum 11. Installed in abutting condition.

The film-like member 50 is provided in the housing 4
The charging unit 12 is attached to a portion 40 </ b> A which is close to the photosensitive drum 11 and adjacent to the charging device 12. In this example, it is attached to the end of the opening 44 of the housing 40 near the charging device 12. The film-shaped member 50 is not particularly limited as long as it does not wear and damage the surface of the photosensitive drum 11 due to the contact, and is a film-like material that is easily and uniformly in contact with the surface. Materials such as films are used. In addition, the thickness, dimensions, and the like of the film-shaped member 50 are appropriately selected.

This film-shaped member 50 is similar to that shown in FIG.
As shown in FIG. 5, a gap space E having a cross-sectional shape (for example, a wedge shape or a V-shaped cross-section) gradually expanding in advance toward the upper end portion side of the film-shaped member 50 between the housing portion 40A serving as the attachment portion and the housing portion 40A. Are mounted in such a way that a is formed. In this example, a notch taper surface 46 is formed in advance at the tip end of the end of the housing portion 40A, which is the mounting portion, so as to be inclined away from the surface of the photosensitive drum 11 and approach the developing roll 45 side. The upper end 50a of the film member 50 faces the tapered surface 46 so as to be a free end, and the remaining lower end 50b is connected to the housing portion 40A.
Is fixed to the original outer peripheral surface by an appropriate fixing means such as an adhesive. In addition, as shown in FIG. 3B, when the photosensitive drum 11 and the developing device 14 are set to the proper mounting positions, the upper end portion 50a of the film member 50 is indicated by a dotted arrow F as shown in FIG. 3B. Like photosensitive drum 1
1 and is bent so as to fall down toward the housing portion 40A side while being pressed against the surface of the housing portion 40A.
Is mounted so as to contact at least the front edge of the photosensitive drum 11 so as to close the gap space E by touching at least the leading edge. In this example, the upper end side 50a of the film-shaped member 50 is deformed so as to entirely contact the notch tapered surface 46, whereby the photosensitive drum 11 is in a state where the gap space E disappears (is eliminated).
3 shows a case where the surface comes into contact with the surface of the device.

Therefore, in this image forming apparatus, by attaching the film member 50 as described above, the gap between the end 40A of the housing 40 of the developing device 14 near the charging device 12 and the surface of the photosensitive drum 11 is reduced. Since the developer G is closed, only the toner of the developer G or the toner and the carrier from the developing device 14 is prevented from dropping to the light emitting surface 17a of the exposure device 13 located below the developer G, and the light emitting surface 17a is Almost no soiling. As a result, at the time of image formation, the laser beam LB from the exposure device 13 normally emits from the light emitting surface portion 17a and irradiates the surface of the photosensitive drum 11,
A good latent image can be formed, and a good image can be formed without image quality defects due to stains on the light exit surface 17a.

Further, the film-like member 50 is mounted in advance such that the above-mentioned gap space E is formed between the film-like member 50 and the housing portion 40A.
When the developing device 1 and the developing device 14 are set at the proper mounting positions, the upper end 50A thereof is bent toward the surface of the photosensitive drum 11 and comes into contact with the surface of the photosensitive drum 11 in such a state that the gap E is closed. With such a configuration, there is no space between the film-shaped member 50 and the housing portion 40A where the film-shaped member 50 is attached, in which the developer G is accumulated.

[Second Embodiment] FIG. 4 is an enlarged view showing a main part in a second embodiment of the present invention. The image forming apparatus according to the second embodiment is different from the image forming apparatus according to the first embodiment in that a passage forming member 60 is provided as shown in FIG. It has the same configuration as the image forming apparatus.

The passage forming member 60 forms a passage between the charging device 12 and the developing device 14 through which air flows along the exposure direction of the laser beam BK emitted from the light emitting surface 17a. In this example, as shown in FIGS. 4 and 5,
As the passage forming member 60, three first to third partition panels 61 to 63 are used.

The first partition panel 61 is disposed so as to partition between the light emitting surface 17a and the (housing 12a) of the charging device 12 so as to close a gap therebetween. The partition panel 62 is arranged at a predetermined interval near the developing device 14 of the first partition panel 61, and partitions the light emitting surface 17a and the vicinity of the photosensitive drum 11 to close the gap therebetween. It is arranged in a state. A first air passage 65 is formed between the first partition panel 61 and the second partition panel 62 along the exposure direction of the laser beam LB emitted from the light emitting surface 17a. The third partition panel 63 is a developing device 1 of the second partition panel 62.
While being arranged at a predetermined interval toward the four sides,
The developing device 14 is also arranged at a distance from the housing 40. This third partition panel 63
Defines a second air passage 66 adjacent to and adjacent to the first air passage 65 with the second partition panel 62. Moreover, the third partition panel 63 forms a third air passage 67 adjacent to the second air passage 66 between the third partition panel 63 and the outer peripheral surface of the housing 40 of the developing device 14. Each of the partition panels 61 to 63 is made of a metal plate, an AB
It is formed of a plastic molding plate such as S. Reference numeral 69 in the drawing denotes a seal member for closing a gap between the upper end of the first partition panel 61 and the housing 12a of the charging device 12.

The third member in the passage forming member 60
The upper end portion 63A of the partition panel 63 of the first embodiment
Is attached. Also in this example, a notched tapered surface 63b is formed at the upper end of the third partition panel 63 so that the gap space E is formed between the film-shaped member 50 and the upper end of the third partition panel 63 in advance. (Figure 5
a).

In the image forming apparatus according to the second embodiment, when the photosensitive drum 11 and the developing device 14 are set at the proper mounting positions, as shown in FIGS. The film-like member 50 attached to the upper end portion 63A of the third partition panel 63 is deformed in the same manner as in the first embodiment, and the upper end portion 60a comes into contact with the surface of the photosensitive drum 11. As a result, the gap between the upper end 63A of the third partition panel 63 and the surface of the photosensitive drum 11 is closed by the film-shaped member 50, so that the developer G from the developing device 14 falls to the first air passage 65 side. Intrusion is prevented.

In this image forming apparatus, since the first air passage 65, the second air passage 66, and the third air passage 67 are formed by the passage forming member 60, for example, the main body of the image forming apparatus is formed. When an exhaust fan is provided in the first air passage 1, the air moves so as to rise in the first air passage 65 (dotted line arrow N1), and in the second air passage 66, the suction force by the exhaust fan is reduced. After the air N1 that has risen in the first air passage 65 and flows into the air passage 65, the air N1 moves toward the lower side of the passage 66 after flowing in (dashed line arrow N2). The suction force acts and the air flows through the passage 67.
Is moved so as to flow downward (dot-dash line arrow N3). Thus, after the air in the first air passage 65 rises, an air flow is generated so as to flow into and out of the second air passage 66 (dashed-dotted arrows N1, N2). The developer G in the passage 65
Does not fall and enter. Further, the airflow at that time is reliably generated because the gap between the upper end portion 63A of the third partition panel 63 and the surface of the photosensitive drum 11 is closed by the film-shaped member 50.
Further, when a cloud or the like in which the toner particles float near the opening 44 of the developing device 14, the toner or the like is discharged through the third air passage 67.

Accordingly, in this image forming apparatus, the developer G falling from the developing device 14 is blocked by the film member 50 and the passage forming member 60
Therefore, the light exit surface portion 17a is further prevented from being stained by the developer G because the air flow is also blocked by the above-described air flow through each of the passages formed. As a result, during image formation, the laser beam LB from the exposure device 13
Is normally emitted from the light emitting surface portion 17a and is irradiated on the surface of the photosensitive drum 11, so that a good latent image is formed and, consequently, a good image formation without image quality defects due to contamination of the light emitting surface portion 17a is performed. Can be. Further, since the attachment of the film-shaped member 50 is performed in the same manner as in the first embodiment, the above-described operation and effect can be obtained substantially in the same manner as in the first embodiment.

In the second embodiment, a blower fan or the like is connected to the first air passage 65 to blow air gently, if necessary.
Alternatively, an air intake fan or the like may be connected to the third air passages 66, 67 to positively suck air. As a result, the above-described air flow is more reliably generated, and as a result, it is possible to more reliably prevent the developer from entering the first air passage 65.

In the second embodiment, the passage formed by the passage forming member 60 may have a configuration as shown in FIGS. 6 and 7, if necessary. The configuration examples shown in FIGS. 6 and 7 correspond to the third example in the second embodiment.
Instead of using the partition panel 63, the first air passage 6 is formed using the first partition panel 61 and the second partition panel 62.
Since the fifth and second air passages 66 are formed, the third air passage 67 as described above is not formed. In this configuration example, a part of the outer peripheral surface of the housing 40 of the developing device 14 is also used as a passage forming member that forms the second air passage 66. Then, in the case of such a configuration, except that the third air passage 67 is not formed and thus the movement of the ventilation (N3) by the passage is not generated, the same as the case of the second embodiment described above. An effect can be obtained.

[Embodiment 2] FIGS. 8 and 9 show Embodiment 3 of the present invention. FIG. 8 is a schematic view showing a main part of the image forming apparatus, and FIG. 9 is a film-like member. It is explanatory drawing which shows the attachment state of.

As shown in FIG. 8, the image forming apparatus according to this embodiment integrates related components (the drive roll 21, the primary transfer roll 15, the cleaning device 26, etc.) around the intermediate transfer belt 20. To the “intermediate transfer unit 200”, and the photosensitive drum 11, the charging device 12, and the cleaning device 1 in each image forming unit 10.
6 according to the first embodiment except that the intermediate transfer unit 200 and the process cartridge 100 are vertically moved up and down by a predetermined up-and-down movement mechanism after integrating the process cartridge 6 into a “process cartridge 100”. It has the same configuration as the forming apparatus. That is, in this image forming apparatus, the intermediate transfer unit 200 and the process cartridge 100 are both moved upward (in the direction of the arrow X) from the regular mounting position by operating the elevating mechanism during maintenance work, component replacement, and the like. It moves up to a predetermined evacuation position. At this time, the developing device 14 does not move up and is at a fixed position. The intermediate transfer unit 200 and the process cartridge 100 are stopped at a predetermined distance K when the intermediate transfer unit 200 and the process cartridge 100 are moved up to their retracted positions.

Thus, the process cartridge 100
The photosensitive drum 11 (especially, the photosensitive drum 11) is separated from the developing device 14. Further, the surface of the photosensitive drum 11 is maintained in a state separated from the intermediate transfer belt 20. In this state, maintenance work and replacement work of the process cartridge 100 and the intermediate transfer unit 200 are performed. Then, when the operation is completed, the intermediate transfer unit 200 and the process cartridge 100 are moved downward (in the direction of arrow Y) by operating the lifting / lowering mechanism again, and stopped at the proper device position. ing.

In the image forming apparatus having the mechanism for moving the intermediate transfer unit 200 and the process cartridge 100 up and down, as shown in FIG.
In particular, the mounting portion (the housing portion 40A of the developing device) is inclined toward the developing device 14 with respect to the vertical movement direction of the process cartridge 100 (the directions of arrows X and Y, which also correspond to the vertical direction). Or the passage forming member). That is, the mounting is performed so that the angle θ formed by the film-shaped member 50 with respect to the direction of the vertical movement is larger than 0 °. Preferably, the angle θ is 10
It is set to be about 30 °.

In this image forming apparatus, since the film-like member 50 is attached as described above, as shown in FIG.
00, the upper end 5 of the film member
0a is separated from or comes into contact with the surface of the photosensitive drum 11. However, since the angle θ is set to an angle larger than 0 °, the upper end of the film-shaped member is in contact with the photosensitive drum 11 when descending. The surface 50a comes into soft contact with the surface (cylindrical surface) of the photosensitive drum 11 and is flexibly bent. As a result, the upper end portion 50a of the film-shaped member may be deformed or the surface of the photosensitive drum 11 may be damaged. Is prevented.

The film-like member 50 is attached to the developing device 14 with respect to the vertical movement direction of the process cartridge 100 so as to be inclined toward the developing device 14. At the time of separation, even if it is restored to a state where it is separated from the housing portion 40A or the like of the mounting portion, the inclined state is still maintained. As a result, even if the developer adheres to the inner side surface (the surface on the developing device side) of the upper end portion 50a of the film-shaped member at that time, the developer drops into the inside of the housing 40 and the light emitting surface portion 17a of the exposure device 13 There is an advantage that it is difficult to fall on the side with the mark. Accordingly, it is also possible to prevent the light emitting surface 17a from being stained by the falling developer.

[Other Embodiments] In the first to third embodiments, as means for attaching the film-shaped member 50 to the housing portion 40A or the like as an attachment portion so as to form a gap space E, the attachment portion is used. Although the case where the notch taper surface 46 and the like are formed on the side to cope with this is exemplified, as shown in FIG. 11A, the mounting surface of the housing portion 40A or the like, which is the mounting portion, is flat, After the lower end 50b side of the member 50 is fixed, the member 50 may be mounted in advance so that the upper end 50a side is separated from the mounting surface. Even in this configuration, when the photosensitive drum 11 and the developing device 14 are set to the proper mounting positions, the film-shaped member 50 is deformed so as to bend toward the mounting surface side as shown in FIG. With the space E closed, it comes into contact with the surface of the photosensitive drum 11. Also in this case, the process cartridge 100
Is configured to move up and down as described above, the angle θ of the film-like member 50 is set to the developing device 14 side with respect to the moving direction (the directions of the arrows X and Y).
It is desirable to mount it in a state of being inclined to a certain degree.

Further, in the first to third embodiments, when the film-like member 50 is attached to the housing portion 40A or the passage forming member portion 60 (63) of the developing device 14, the film-like member 50 must be present in the gap space E. You may comprise so that soft elastic materials, such as a sponge, may be attached. In such a configuration, the film member 50 is connected to the housing portion 40.
When it is deformed so as to fall into A or the passage forming member portion 60 (63), it is possible to accurately avoid the formation of a useless gap between the mounting portions thereof and the developer or the like where the developer or the like accumulates. .

In the first to third embodiments, the exposure apparatus 1
In the present invention, the main body 3 is disposed at a height equal to or higher than that of the developing device 14, and the light exit surface portion (17) is provided.
The same applies to an image forming apparatus having a configuration in which only a) is disposed below the developing device 14.

Further, in the first to third embodiments, the drum-shaped photosensitive member (11) is exemplified, but a belt-shaped photosensitive member may be used in the present invention. Further, the case where the intermediate transfer belt 20 is used has been described. However, in the present invention, an image forming apparatus that does not use the intermediate transfer method may be used.

[0045]

As described above, according to the present invention,
In an image forming apparatus in which the light emitting surface of the exposure device is disposed at a position below the developing device, it is possible to reliably prevent the light emitting surface of the exposure device from being stained by a developer such as falling from the developing device. This makes it possible to form a good image without image defects due to stains on the light exit surface.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a color image forming apparatus according to a first embodiment.

FIG. 2 is a sectional view of a main part showing a configuration in which a film-shaped member is attached to each image forming unit.

FIG. 3 is an explanatory view showing an attached state of the film-like member of FIG. 2;

FIG. 4 is an essential part cross-sectional view showing a configuration in which a film-like member and a passage forming member are attached to each image forming unit of the image forming apparatus according to Embodiment 2;

FIG. 5 is an explanatory view showing an attached state of the film-like member of FIG. 4;

FIG. 6 is an essential part cross-sectional view showing a modification of the image forming apparatus according to the second embodiment.

FIG. 7 is an explanatory view showing an attached state of the film-like member of FIG. 7;

FIG. 8 is a schematic diagram illustrating a main part of an image forming apparatus according to a third embodiment.

9 is an explanatory view of a main part showing a configuration of a film-like member attached to each image forming unit of the image forming apparatus of FIG. 8;

FIG. 10 is a schematic explanatory view showing a state during a lifting operation in the image forming apparatus of FIG. 8;

FIG. 11 is an explanatory view showing another example of the configuration relating to the attachment of the film-shaped member.

FIG. 12 is a conceptual diagram showing a configuration example regarding the arrangement of a light emitting surface of an exposure apparatus.

[Explanation of symbols]

11: photosensitive drum (photoconductor), 12: charging device, 13:
Exposure device, 14 ... Developing device, 17a ... Light emitting surface portion, 40 ...
Housing, 40A: housing part, 50: film-like member, 50a: upper end, 60: passage forming member, 61 to 61
63: partition panel (passage forming member), 63A: passage forming member portion, E: gap space.

Claims (3)

[Claims] 1. A photoreceptor rotating in a fixed direction, a charging device for charging the surface of the photoreceptor, and a surface corresponding to image information is exposed to light on the surface of the photoreceptor charged by the charging device. An exposure device that forms an electrostatic latent image; and a developing device that develops the electrostatic latent image formed by the exposure device with a developer supplied from the inside of the housing. In the image forming apparatus in which the light emitting surface portion is disposed at a position below the developing device, a film-shaped member is provided on a portion of the housing of the developing device which is close to the photoconductor and is adjacent to the charging device. An image forming apparatus, wherein the image forming apparatus is mounted in a state where an upper end portion is in contact with a surface of the photoconductor. 2. A photoreceptor rotating in a fixed direction, a charging device for charging the surface of the photoreceptor, and a light corresponding to image information is exposed to the surface of the photoreceptor charged by the charging device. An exposure device that forms an electrostatic latent image; and a developing device that develops the electrostatic latent image formed by the exposure device with a developer supplied from the inside of the housing. Wherein the light emitting surface portion is disposed at a position below the developing device, wherein air flows along the exposure direction of light emitted from the light emitting surface portion between the charging device and the developing device. A passage forming member that forms a passage is disposed to a position close to the photosensitive member, and a portion of the housing of the developing device that approaches the photosensitive member and is adjacent to the charging device or in front of the passage forming member. The portion adjacent to closely and the developing device and the photosensitive member, an image forming apparatus, wherein a film-like member whose upper end mounted in contact with the state on the surface of the photosensitive member. 3. A gap space having a sectional shape gradually expanding toward the upper end side of the film-shaped member is formed between the film-shaped member and the housing portion or the passage-forming member portion serving as an attachment portion thereof. When the photoconductor and the developing device are set to the proper mounting position, the upper end side of the film-shaped member is pressed against the surface of the photoconductor, and the housing becomes the mounting portion. 3. The photoconductor according to claim 1, wherein the photoconductor is bent toward the portion or the passage forming member and contacts at least a front edge of the housing or the passage forming portion to close the gap. Image forming apparatus.