JPH0451158A - Image producing device - Google Patents

Abstract

PURPOSE:To prevent contamination in a process unit by providing an electret having a reverse polarity to toner on the inside surface of a unit frame attachably/detachably mounted in a supporting structural body. CONSTITUTION:The process unit 140 is provided with a unit frame 142 and an image output means 144. The image output means 144 includes a photosensitive drum 166, a developing device 168 in which toner is used as developer,a cleaning device 170 and an electrostatic charging device 172. Then, the electret e having the reverse polarity to the toner is provided on the inside surface of the unit frame 142. Since the toner scattering and suspending in the process unit 140 has the reverse polarity to the electret, it is attracted to the inside surface of the unit frame 142, that means, the surface of the electret E provided on the inside surface of the unit frame so as to be captured. Thus, the contamination of the inside surface of the unit frame is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image generating apparatus such as an electrostatic copying machine or an electrostatic printing machine, and particularly to an image generating apparatus that prevents contamination by toner.

[Conventional technology]

In general, image generation is performed by electrostatically attaching charged fine particles (toner), which is a developer, to an electrostatic latent image formed on the surface of a photoreceptor to create a visible image, which is then transferred and fixed onto copy paper. The device has been well known and widely put into practical use.

An electrostatic copying machine as an example of this type of image generation device includes:
A unit frame that is detachably mounted in a support structure (housing) and a process unit that includes an image output means such as a photosensitive drum (rotary drum) that is rotatably supported by the unit frame. Exists (Jitsukai Showa 6)
3-86639). The electrostatic copying machine disclosed in the publication will be explained as a conventional technique with reference to FIG.

The illustrated electrostatic copying machine includes a box-shaped housing generally designated by the number 2. The housing 2 is comprised of a so-called shell-shaped support structure consisting of a lower support frame 4 and an upper support frame 6 attached to the lower support frame 4. The lower left end of the upper support frame 6 is rotatably connected to the lower support frame 4 via a shaft 8 extending in the front-rear direction of the lower support frame 4, that is, in the direction perpendicular to the paper plane in FIG. There is.

On the upper surface of the housing 2, ie, on the upper surface of the upper support frame 6, a document mounting means 10 is mounted so as to be able to reciprocate in the left-right direction. The document placing means 10 includes a transparent plate 12 on which a document to be copied is placed, and a document cover (not shown) that can be opened and closed to cover the transparent plate 12 and the document placed thereon. ).

A process unit 14 located at the center of the housing 2 is removably attached to the upper support frame 6. The mounting structure is as follows.

That is, the upper support frame 6 has a pair of support rails 16 and 1 extending in a direction perpendicular to the plane of the paper at intervals in the left-right direction.
8 is fixed. On the other hand, the process unit 14 has a process unit frame 20 (unit frame 20), and supported parts 22 and 24 are provided at both left and right ends of the unit frame 20, extending in a direction perpendicular to the plane of the drawing. The supported parts 22 and 24 of this unit frame 20 are positioned on the support rails 16 and 18 of the upper support frame body 6, respectively,
By sliding the unit frame 20 in a direction perpendicular to the plane of the paper, the process unit 14 is detachably attached to the upper support frame 6.

At the center of the unit frame 20, a photoreceptor drum (rotating drum) 2 is provided with a suitable electrostatic photoreceptor on its circumferential surface.
6 is rotatably attached.

The unit frame 20 further includes a charging device (corona discharger for charging) 30, a developing device 32, and a cleaning device around the photosensitive drum 26, which is rotationally driven in the direction shown by an arrow 28. A device 34 is attached.

The developing device 32 includes a magnetic brush mechanism 36 that supplies toner, which is a developer, to the circumferential surface of the photosensitive drum 26 . The cleaning device 34 also includes an elastic blade 38 that comes into contact with the circumferential surface of the photoreceptor drum 26 and a toner collection chamber 40 .

The above-described photosensitive drum 26, charging device 30, and developing device 3
2, the cleaning device 34, and the like constitute an image output means. Regarding the above process unit 14,
This will be described further below.

The upper support frame 6 further includes the process unit 14.
Irradiation lamp 42 and reflection plate 44 located above
, and an optical system consisting of SELFOC Micro Lens (trade name) 46 and the like. Light from the irradiation lamp 42 passes through the transparent plate 12 and irradiates the document placed thereon, as shown by the dashed line. The reflected light from the original is transmitted through the SELFOC microlens 46 and the unit frame 20.
The light is projected onto the circumferential surface of the photoreceptor drum 26 in an exposure area 52 through an exposure opening 50 formed in the upper wall 48 .

Although not shown, an exposure lamp for static elimination may be provided above the unit frame 20 and to the left of the upper support frame 6.

In this case, a static elimination light opening is formed in the clay wall 48 of the unit frame 20 at a position between the cleaning device 34 and the charging device 30. The static eliminating light from the exposure lamp is projected through the static eliminating light opening onto the circumferential surface of the photoreceptor drum 26, which is the static eliminating area located between the cleaning device 34 and the charging device 30, to perform static eliminating. Ru.

At the center of the lower support 4 is a transfer device (
A transfer corona discharger 56 and a stripping static eliminator 58 located downstream thereof are provided.

At the right end of the lower support 4, there is provided a copy paper supply means, generally indicated by the number 60, and at the left end, there is provided a copy paper tray 6.
2 is provided. A copy paper conveying system 64 for conveying the copy paper through the transfer area 54 is provided between the copy paper supply means 60 and the copy paper tray 62.

The copy paper supply means 60 includes a paper feed tray 66 and a pair of paper feed rollers 68 provided on the downstream side thereof.

Therefore, when copy paper is placed on the paper feed table 66 and inserted through the open lower 2 formed on the right wall 70 of the housing 2 to the paper feed roller pair 68, the paper feed roller rotates in the direction of the arrow. Due to the action of pair 68, copy paper is fed to copy paper transport system 64 through guide plate 74.

The copy paper transport system 64 includes a transport roller pair 76 and a lower guide plate 78.
, a guide member 80, a pair of heating and fixing rollers 82, and a pair of discharge rollers 84. These components define a copy paper transport path 86 that guides the copy paper fed from the copy paper supply means 60 to the copy paper tray 62. A heating means 90 is provided inside the upper heat roller 88 of the heat fixing roller pair 82 .

The unit frame 20 in the process unit 14 is
(both not shown) having a front wall and a rear wall spaced apart in a direction perpendicular to the plane of the paper. The above-described top wall 48, left side wall 102, right side wall 104, and bottom wall 100 are provided between the front wall and the rear wall.

A step is provided at the center of the upper wall 48 in the width direction, and the exposure opening 50, which is elongated in the front-rear direction, is formed in the center of the step. In addition, in the widthwise central part of the bottom wall 100,
A transfer opening 110 extending in the front-rear direction is formed. The lower part of the photosensitive drum 26 is exposed to the outside through the transfer opening 110.

A developing device 32 and a cleaning device 34 are provided along with the photosensitive drum 26 between the front wall and the rear wall of the unit frame 20.

The photosensitive drum 26 is rotatably supported between the front wall and the rear wall via shaft portions (not shown) provided at both ends thereof. The upper support frame 6 at the rear of the rear wall of the unit frame 20 (at the back in the direction perpendicular to the paper) is provided with a rear board extending vertically, and a gear is rotatably installed on the rear board. (none shown). When the unit frame 20 is attached to the upper support frame 6 and set in the operating position, the shaft portion of the photoreceptor drum 26 is drivingly coupled to the gear via a clutch means (not shown).

This gear is connected to a drive source (not shown) via another gear (not shown). When each gear is rotated by this drive source, the photosensitive drum 26 is rotated in the direction shown by an arrow 28.

In the electrostatic copying machine configured as described above, while the photosensitive drum 26 is rotationally driven in the direction shown by the arrow 28,
The charging device 30 substantially uniformly charges the photoreceptor of the photoreceptor drum 26 to a specific polarity, for example, a positive polarity. Next, in the exposure area 52, the image of the original on the transparent plate 12 is projected onto the photoreceptor through the exposure aperture 50 by the optical system, and a charged area corresponding to the image of the original, that is, an electrostatic latent image, is formed on the photoreceptor. is formed. This electrostatic latent image is developed into a toner image by supplying toner charged to a specific polarity, for example, a negative polarity, from the magnetic brush mechanism of the developing device 32.

The copy paper supplied from the copy paper supply means 60 and conveyed by the copy paper conveyance system 64 is brought into close contact with the circumferential surface of the photoreceptor drum 26 in the transfer area 54, and by the action of the transfer device 56, the copy paper is transferred onto the photoreceptor drum 26. The toner image is transferred onto the copy paper. Next, by the action of the stripping static eliminator 58,
The copy paper is peeled off from the photosensitive drum 26.

The peeled copy paper is conveyed through a pair of heating and fixing rollers 82, and the toner image on the copy paper is heated and fixed. The copy paper with the toner image fixed thereon is passed through an opening 94 in the left wall 92 of the housing 2 by a pair of ejection rollers 84 and delivered to the copy paper tray 6.
2.

- Force The photoreceptor drum 26 continues to rotate further, and toner remaining on the photoreceptor after transfer is removed by the action of the elastic blade 38 of the cleaning device 34. The removed toner is collected into the toner collection chamber 40.

The process unit 14 is detachably mounted within the housing 2 as described above. For this attachment and detachment, the process unit 14 is provided with a known handle (not shown), and is also provided with a suitable locking means between it and the housing 2. Therefore, if a trouble occurs in the image output means such as a photosensitive drum provided in the process unit 14, or if a predetermined life span is reached, the process unit 14 can be easily replaced with a new one.

[Problem to be solved by the invention]

In the conventional electrostatic copying machine described above, an image output means including a photosensitive drum 26, a developing device 32, etc. is provided in a process unit 14 that is detachably mounted in the housing 2. Inside the developing device 32, toner, which is charged fine particles, is stored as a developer. That is, since toner is used as a developer, it scatters as the copying machine operates, and adheres to and contaminates undesirable areas. Below, aspects of toner contamination and the resulting problems (problems to be solved) related to this invention will be listed.

(1) As the copying machine operates, toner scatters and floats inside the process unit 14. The scattered and floating toner contaminates parts of the process unit 14 where contamination is undesirable. That is, when wiping the inside of the process unit 14,
It adheres to the peripheral surface of the photoreceptor drum 26, the charging device 30, etc.
contaminate them.

As a result, the copy paper becomes smeared, the image becomes unclear, and the life of the image output means including the photosensitive drum 26 and the like, and therefore the life of the process unit 14, is shortened. Since the space within the process unit 14 is generally small, the effect of toner contamination is greater.

(2) On the other hand, a part of the scattered toner flows out through the opening B (including the openable/closable part) of the process unit 14, that is, the unit frame 20, and damages the parts of the outside where contamination is undesirable, especially near the opening. To contaminate. In other words, some of the toner is near the optical path (the exposure aperture 50, the static elimination light aperture if provided) or the transfer aperture 11.
From 0, it flows out to the outside. In particular, the optical system arranged near the opening (-lens for boat fishing, in this example Selfoc micro lens 46, exposure lamp, stationary mirror, etc.), transfer device 56, static eliminator 58 for peeling, copy paper conveyance It adheres to the system 64, the copy paper conveyance path 86, etc., and contaminates them.

As a result, images become blurred due to lens contamination, copy paper becomes stained, and the lifespan of these devices and equipment is shortened.

Regarding contamination of the optical system, copying machines without a process unit, such as Japanese Patent Laid-Open No. 64-69
A similar phenomenon occurs in the copying machine disclosed in Publication No. 36. As disclosed in the same publication, this type of copying machine is generally provided with a partition plate inside the housing that partially partitions the upper and lower parts.

An optical system is arranged above the partition plate, and an image output means such as a photoreceptor drum is arranged below. The partition plate is provided with an exposure aperture, and light from the optical system is projected onto the circumferential surface of the photoreceptor drum through this aperture. A suitable cover plate is provided above the partition plate, and is configured to cover a part of the optical path of the optical system together with the partition plate. A part of the toner scattered below the partition plate flows out through the exposure aperture, flows along the optical path, and adheres to a stationary mirror, a non-stick, etc., and contaminates them. Particularly in the case where a part of the optical system scans, the toner flows more easily along the optical path, and the above-mentioned tendency becomes even stronger.

(3) The toner that has flowed out of the process unit 14 also adheres to and contaminates areas on the outer surface of the process unit 14, that is, the outer surface of the unit frame 20, where contamination is not desirable. That is, the toner that has flowed out of the process unit 14 from the above-mentioned opening is attached to the handle that the user touches when attaching and detaching, or to easily accessible outer surfaces such as the top wall 48, the left and right side walls 102 and 104, and the bottom wall 100, and is thus removed. To contaminate.

For this reason, when attaching and detaching the process unit 14, the user's hands and clothes, the floor, peripheral equipment, etc. are soiled, resulting in hygienic and environmental problems.

Conventionally, despite the existence of problems to be solved regarding toner contamination as described above, the reality is that no countermeasures have been taken.

Therefore, a first object of the present invention is to prevent contamination of areas in a process unit where toner contamination is undesirable.

A second object of the present invention is to prevent contamination of areas on the outer surface of the process unit where toner contamination is undesirable.

A third object of the present invention is to prevent contamination of areas within the process unit and on the outside of the process unit where toner contamination is undesirable.

A fourth object of the present invention is to prevent contamination of areas around the openings on the outside of the process unit where toner contamination is undesirable.

A fifth object of the invention is to prevent contamination of the optical system by toner.

[Means to solve the problem]

In order to achieve the first object, the present invention includes a unit frame detachably mounted in a support structure and an image output means including a photosensitive drum rotatably supported by the unit frame. An image generating apparatus including a process unit is obtained, characterized in that an electret having a polarity opposite to that of the toner is provided on the inner surface of the unit frame.

In order to achieve the second object, the present invention includes a unit frame detachably mounted within a support structure and an image output means including a photosensitive drum rotatably supported by the unit frame. An image generating apparatus including a process unit is obtained, characterized in that an electret having the same polarity as the toner is provided on the outer surface of the unit frame.

In order to achieve the third object, the present invention includes a unit frame detachably mounted within a support structure and an image output means including a photosensitive drum rotatably supported by the unit frame. An image generating apparatus including a process unit, characterized in that an electret having a polarity opposite to that of the toner is provided on the inner surface of the unit frame, and an electret having the same polarity as the toner is provided on the outer surface of the unit frame. An image generation device is obtained.

In order to achieve the fourth object, the present invention includes a unit frame detachably mounted within a support structure and an image output means including a photosensitive drum rotatably supported by the unit frame. An image generating apparatus including a process unit is obtained, characterized in that an electret having a polarity opposite to that of the toner is provided around an opening formed in the unit frame.

In order to achieve the fifth object, the present invention includes: an image output means including a rotatably supported photoreceptor drum in a support structure; an optical system, and is configured such that light from the optical system is projected onto the surface of the photoreceptor drum through an optical path including an opening formed in the partition plate. An image generating device is obtained, characterized in that an electret having a polarity opposite to that of the toner is provided near the optical path of the system.

[Effect]

(1) In an image generating apparatus equipped with a process unit having a unit frame removably mounted within a support structure and an image output means including a photosensitive drum rotatably supported by the unit frame; In an image generation device in which an electret having a polarity opposite to that of the toner is provided on the side surface, the toner scattered or floating inside the process unit has a polarity opposite to that of the electret, so is adsorbed and captured on the surface of the electret provided on the electret.

As is well known, an electret is a charged body that generates an electric field semi-permanently outside and has electric polarization characteristics. Since the surface of the electret provided on the inner surface of the unit frame is held in a polarity opposite to that of the toner, the toner once adsorbed is captured semi-permanently and will not scatter again. It can be said that the inner surface of the unit frame provided with the electret functions as a toner dust collector.

Therefore, before the toner adheres to parts of the process unit where contamination is undesirable, such as the photoreceptor drum, the toner is adsorbed and captured on the inner surface of the unit frame, thereby preventing contamination.

The wider the area in which the electret is provided on the inner surface of the unit frame, the more effectively the above action is performed.

(2) In an image generation device equipped with a process unit similar to (1) above; In an image generation device in which an electret having the same polarity as the toner is provided on the outer surface of the unit frame, Even if some of the toner that has leaked out tries to adhere to the outer surface of the unit frame, the surface of the electret provided on the outer surface has the same polarity as the toner, so it will be repelled and will not adhere to the surface. Prevented.

Therefore, the toner does not adhere to areas outside the process unit where contamination is undesirable, such as the handle.
Its contamination is prevented and kept clean.

(3) In an image generation apparatus equipped with a process unit similar to (1) above; an electret having a polarity opposite to that of the toner is provided on the inner surface of the unit frame, and an electret having the same polarity as the toner is provided on the outer surface of the unit frame. In an image generating apparatus equipped with a process unit, the same action as described above is performed on the inner and outer surfaces of the unit frame, and the toner is prevented from adhering to areas inside and outside the process unit where contamination is not desirable, and the contamination is avoided. is prevented.

(4) In an image generation apparatus equipped with a process unit similar to that in (1) above; In an image generation apparatus in which an electret having a polarity opposite to that of the toner is provided around the opening formed in the unit frame, the process Even if the toner scattered or floating inside the unit attempts to flow out through the opening, it is adsorbed and captured by the electret provided around the opening.

Therefore, toner is prevented from flowing out from the process unit at the opening, and toner is prevented from adhering to areas outside the process unit where toner contamination is undesirable, such as the transfer device or the copy paper conveyance system, around the opening. contamination is prevented.

(5) The support structure includes an image output means including a rotatably supported photoreceptor drum, and an optical system disposed with respect to the photoreceptor drum via a partition plate, and light from the optical system is provided. In an image generating device configured to be projected onto the surface of a photoreceptor drum through an optical path including an opening formed in a partition plate; an image in which an electret having a polarity opposite to that of the toner is provided near the optical path of the optical system; In the generation device, some of the toner that flows out from the opening of the partition plate to the optical path side of the optical system flows along the optical path and even if it tries to adhere to mirrors, lenses, etc., it is adsorbed by the electret located near the optical path. , captured.

When the electret is provided around the opening of the partition plate near the optical path, the toner is attracted and captured at the opening and is prevented from flowing out to the optical path side of the optical system.

When the same electret is provided on the partition plate and the cover plate near the optical path, the toner is attracted and captured before it adheres to the mirror, lens, etc.

Therefore, toner contamination of the optical system is prevented.

In an image generating apparatus including a process unit as described above, this partition plate corresponds to the unit frame of the process unit, and toner adsorption and capture is performed by the same function as described above.

〔Example〕

Embodiments of an image generation device improved according to the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 to 7, substantially the same parts are indicated by the same reference numerals, and parts not particularly described are substantially the same as those described in FIG. 1.

FIG. 1 shows a process unit portion of an electrostatic copying machine to which the present invention is applied in order to achieve the first object. Note that, except for the parts related to this invention, the functions of the process unit and the electrostatic copying machine equipped with the process unit are substantially the same as those described with reference to FIG.

In FIG. 1, a process unit 140 has a unit frame 142 and an image output means 144.

In this example, the unit frame 142 includes an upper wall 146, a left side wall 148, a right side wall 150, a front wall (not shown because it is located on the near side in the direction perpendicular to the paper), and a rear wall 152.
, and a bottom wall 154. A handle, also not shown, is provided on the front wall. - For boat fishing, these should be integrally molded from synthetic resin whenever possible. A slit-shaped exposure opening 156 is formed in the center of the earthen wall 146, extending in the front-rear direction (direction perpendicular to the plane of the paper). Further, a similar static elimination light aperture 15B is formed on the left side thereof. Supported parts (supported rails) 160 and 162 are provided on the left side wall 148 and the right side wall 150, respectively. A transfer opening 164 extending in the front-rear direction is formed in the central portion of the bottom wall 154.

The image output unit 144 includes a photosensitive drum 166, a developing device 168 that uses toner as a developer, a cleaning device 170, and a charging device 172. these are,
It is set in the space within the unit frame 142 by known means. A portion of the circumferential surface of the photoreceptor drum 166 is connected to the bottom wall 1
It is exposed to the outside through the transfer opening 164 of 54.

Note that each opening of the unit frame 142, that is, the exposure opening 1
56, the static elimination light opening 158, the transfer opening 164, etc. are closed by known shielding means so that the peripheral surface of the photosensitive drum 1660 is not exposed until the process unit 140 is installed in the copying machine. These shielding means are configured to open each opening when the process unit 140 is installed in the copying machine.

Further, the configuration of the unit frame 142 is configured in consideration of the storage property of the image output means and the ease of molding, etc., and various forms are possible, but here, in order to facilitate understanding of the present invention, It is simplified and modeled as shown in the figure.

In the known process unit 140 as described above,
On the inner surface of the unit frame 142, an electret E having a polarity opposite to that of the toner is provided. In this example, the electret E (shaded area in the figure) includes an upper wall 146, a left side wall 148, a right side wall 150, a front wall (not shown), and a rear wall 152.
, and each inner surface of the bottom wall 154 over a wide range.

As described above, electret is a charged body that semipermanently generates an electric field outside, has electric polarization characteristics, and is also known to be formed from various polymeric materials. Electret E in this example is a film made of a copolymer of tetrafluoroethylene and hexafluoropropylene, which is suitable for having stable polarization characteristics, and is formed by a known electretization method.

Examples of the electret-forming means include applying a DC high voltage at high temperature to both sides of the film under predetermined conditions and then cooling it to room temperature to obtain an electret with different surface charges on both sides; A suitable method is to perform corona discharge treatment on the surface of the film so that charges are trapped on the surface to generate electrets.

The electret is provided on the inner surface of the unit frame 142 by pasting the film-like electret E, which has been made into an electret in this manner, onto the inner surface of the unit frame 142 with an adhesive as described above. It is important that the electret E is attached to the inner surface of the unit frame 142 so that its exposed surface has a polarity opposite to that of the toner. Note that the polarity of electret E means that of its exposed surface, and the same applies hereinafter.

The process unit 140 configured in this manner is attached to a copying machine via its supported rails 160 and 162 in the manner shown in FIG.

On the copying machine side, a SELFOC microlens 46 similar to that shown in FIG. An exposure lamp 176 is provided for the purpose. The rest of the structure and operation of the copying machine are substantially the same as described in FIG. 8, so their explanation will be omitted.

The toner scattered inside the process unit 140 is adsorbed and captured on the surface of the electret E attached inside the process unit 140.

FIG. 2 shows a process unit portion of an electrostatic copying machine to which the present invention is applied in order to achieve the second object.

An electret E having the same polarity as the toner is provided on the outer surface of the unit frame 142 of the process unit 140.

In this example, the electret E (shaded area in the figure) covers the entire outer surface of the top wall 146, left side wall 148, right side wall 150, front wall (not shown), rear wall 152, and bottom wall 154. It is set up over .

Even if some of the toner that has flowed out from inside the process unit 140 tries to adhere to the outer surface of the unit frame 142, the surface of the electret E provided on the outer surface is maintained in the same polarity as the toner. Therefore, it is repelled and does not stick.

FIG. 3 shows another embodiment of the invention shown in FIG. 2, in which an electret E (shaded area in the figure) having the same polarity as the toner is provided on the outer surface of a unit frame 142 of a process unit 140. 146, except that the relatively recessed portions 178 and 180 of the top wall 146 have been removed. This is because such parts are relatively difficult to touch by the user's hands or clothing. Note that an electret E is also provided on the outer surface of the handle 182 on the front wall.

FIG. 4 shows a process unit portion of an electrostatic copying machine to which the present invention is applied in order to achieve the third object.

An electret E having the opposite polarity to the toner is provided on the inner surface of the unit frame 142 of the process unit 140, and an electret E having the same polarity as the toner is provided on the outer surface (both shown with diagonal lines). ).

Toner scattered inside the process unit 140 is adsorbed and captured by the electret E on the inner surface thereof, and toner flowing outside is repelled by the electret E on the outer surface and does not adhere.

FIG. 5 shows a process unit portion of an electrostatic copying machine to which the present invention is applied in order to achieve the fourth object.

Electrets E (shaded areas) having a polarity opposite to that of the toner are provided around the openings formed in the unit frame 142 of the process unit 140, that is, in this example, around the exposure opening 156, the static elimination light opening 158, and the transfer opening 164. It is being The electret) E may be provided on either the internal or external surface or both surfaces of the unit frame 142, without being limited to the illustrated example, as long as it is around each opening.

Even if the toner scattered or floating inside the process unit 140 tries to flow out through each opening,
It is adsorbed and captured by the electret E provided around the opening.

FIG. 6 shows the main parts of an electrostatic copying machine to which the present invention is applied in order to achieve the fifth object.

This copying machine is of the form disclosed in Japanese Patent Application Laid-Open No. 64-6936 mentioned above, and inside a housing 184, which is a support structure, there are a lower part 186 and an upper part 188. A partition plate 190 is provided to partially partition the area. On the lower part 186 side of the partition plate 190, image output means including a photosensitive drum 192 and other devices (not shown) are arranged. Further, an optical system is provided on the upper portion 188 side.

The partition plate 190 is provided with an exposure aperture 194, and light from the optical system passes through the aperture 194 to the photoreceptor drum 1920.
Projected onto the circumferential surface. A suitable cover plate 196 is provided above the partition plate 190, and is configured to cover a part of the optical path of the optical system (see arrow in the figure) together with the partition plate 190. A lens 198 and a reflecting mirror 200, which are part of the optical system, are provided in a portion surrounded by the cover plate 196.

In such a copying machine, an electret E having a polarity opposite to that of the toner is provided near the optical path of the optical system. Specifically, they are provided around the exposure opening 194 of the partition plate 190 and on the inner surface of the cover plate 196. The electret (electret) E may be provided anywhere as long as it is near the optical path of the optical system.

A portion of the toner is attached to the mirror 200 and lens 198 of the optical system.
Even if it tries to adhere to the electret E, etc., it will be adsorbed and captured by the electret E located near the optical path.

FIG. 7 shows a process unit portion of an electrostatic copying machine to which the present invention is applied to achieve the fifth object.

An exposure opening 156 formed in the upper wall 146 of the unit frame 142 in the process unit 140 near the optical path
An electret E is provided around the static elimination light aperture 158. Further, electrets E are provided around the cover plates 202 and 204 of the SELFOC microlens 46 and the opening 206 of the cover 174 in which the exposure lamp 176 is housed. Each electret E has a polarity opposite to that of the toner.

Even if some of the toner tries to adhere to the SELFOC microlens 46, the exposure lamp 176, etc., it is adsorbed and captured by the electret (E) located near the optical path.

〔Effect of the invention〕

According to the invention described above based on the embodiments, the following effects can be obtained.

(1) In an image generation device in which an electret having a polarity opposite to that of the toner is provided on the inner surface of the unit frame,
Before the toner adheres to areas in the process unit where contamination is undesirable, such as photoreceptor drums, charging devices, etc.
Since they are adsorbed and captured on the inner surface of the unit frame, their contamination is prevented.

Therefore, clear images can be obtained and the lifespan (service life) of the process unit can be extended.

It is also possible to prevent stains on copy paper.

(2) In an image generation device in which an electret having the same polarity as the toner is provided on the outer surface of the unit frame,
Some of the toner that has leaked out from inside the process unit is repelled by the outer surface of the unit frame, preventing it from adhering to areas that are particularly easily touched by users, such as the handle, earthen wall, front wall, left and right side walls, etc. Ru.

Therefore, when attaching and detaching the process unit, the user's hands and clothes, the floor, peripheral equipment, etc. are not contaminated, hygienic and environmental problems are solved, and the ease of handling by the user is significantly improved.

(3) In an image generation device in which an electret having a polarity opposite to that of the toner is provided on the inner surface of the unit frame and an electret having the same polarity as the toner on the outer surface of the unit frame, the toner is stored inside and outside the process unit. Contamination is prevented from adhering to undesired areas.

Therefore, both effects (1) and (2) described above can be obtained.

(4) In an image generating device in which an electret having a polarity opposite to that of the toner is provided around an opening formed in the unit frame, the toner is prevented from flowing out from the process unit at the opening.

Therefore, toner contamination around the opening on the outside of the process unit does not adhere to undesirable parts, such as the transfer device, the copy paper conveyance system, etc., and contamination is prevented, thereby preventing the copy paper from becoming stained. , and each equipment/
Improve the lifespan (service life) of equipment.

If a part of the optical system, such as a lens or mirror, is disposed near the opening, toner contamination from these components is prevented and a clear image is maintained.

(5) In an image generation device in which an electret having a polarity opposite to that of the toner is installed near the optical path of the optical system, it is possible to prevent part of the toner from adhering to the lens, mirror, exposure lamp, etc. and contaminating them. be done.

Therefore, clear images are maintained for a long time.

Although the present invention has been described in detail based on the embodiments above, the present invention is not limited to the embodiments described above, and various modifications and modifications can be made within the scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an embodiment of the present invention in which an electret is provided on the inner surface of a process unit. FIG. 2 is a schematic cross-sectional view showing an embodiment of the present invention in which an electret is provided on the outer surface of a process unit. FIG. 3 is a schematic perspective view of another embodiment of the invention shown in FIG. 2, in which an electret is provided on the outer surface of the process unit. FIG. 4 is a schematic cross-sectional view showing an embodiment of the present invention in which electrets are provided on the inner and outer surfaces of a process unit. FIG. 5 is a schematic cross-sectional view showing an embodiment of the present invention in which an electret is provided around the opening of a process unit. FIG. 6 is a partial cross-sectional schematic diagram of a copying machine in which an electret is provided near the optical path of an optical system, which is an embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of a process unit according to an embodiment of the present invention, in which an electret is provided near the optical path of an optical system. FIG. 8 is a schematic cross-sectional view of a conventional copying machine equipped with a process unit. 46... Selfoc Micro Lens (product name) 140... Process unit 142 ・ 144 ・ 146 ・ 148 ・ 150 ・ 152 ・ 154 ・ 156 ・ 158 ・ 164 ・ 166 ・ 168 ・ 170 ・ 176 ・190 ・ 196 ・ Unit frame, image output means, soil wall, left side wall, right side wall, rear wall, bottom wall, exposure aperture, static elimination light aperture, transfer aperture, photosensitive drum, developing device, cleaning device Exposure lamp partition plate Cover plate Figure 3 Figure 6 Old 4

Claims (1)

[Scope of Claims] 1. Image generation comprising a process unit having a unit frame removably mounted within a support structure and a surface image output means including a photosensitive drum rotatably supported by the unit frame. An image generating device characterized in that an electret having a polarity opposite to that of the toner is provided on the inner surface of the unit frame. 2. In an image generating apparatus equipped with a process unit having a unit frame removably mounted within a support structure and an image output means including a photosensitive drum rotatably supported by the unit frame, An image generating device characterized in that an electret having the same polarity as a toner is provided on an outer surface. 3. In an image generating apparatus equipped with a process unit having a unit frame removably mounted within a support structure and an image output means including a photosensitive drum rotatably supported by the unit frame, An image generating device characterized in that an electret having a polarity opposite to that of the toner is provided on an inner surface, and an electret having the same polarity as the toner is provided on an outer surface of the unit frame. 4. In an image generating apparatus equipped with a process unit having a unit frame removably mounted in a support structure and an image output means including a photosensitive drum rotatably supported by the unit frame, An image generating device characterized in that an electret having a polarity opposite to that of the toner is provided around the formed opening. 5. The support structure is provided with an image output means including a rotatably supported photoreceptor drum, and an optical system disposed with respect to the photoreceptor drum via a partition plate, and the light from the optical system is is projected onto the surface of the photoreceptor drum through an optical path including an opening formed in the partition plate, in which an electret having a polarity opposite to that of the toner is provided near the optical path of the optical system. An image generation device characterized by being provided with. 6. The unit frame in a process unit in which the partition plate includes a unit frame removably mounted within the support structure and the image output means including the photosensitive drum rotatably supported by the unit frame. The image generating device according to claim 5, characterized in that: