JPH0455882A - Recovered toner quantity detecting device - Google Patents

Abstract

PURPOSE:To comparatively easily and surely detect recovered toner quantity by providing a transparent electret in a toner recovery container and disposing an optical sensor for detecting the recovered toner quantity in the toner recovery container through the electret. CONSTITUTION:This device is provided with the toner recovery container 122 in which the toner recovered from a photosensitive drum 26 is stored. The transparent electret E having the same polarity as the toner is provided so as to constitute one part of the inner wall surface of the container 122 in the container 122. Then, the optical sensor 128 for detecting the recovered toner quantity in the container 122 through the electret E is disposed near the electret E. Thus, it is detected that the quantity of the toner stored in the container 122 attains a specified recovery quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a toner recovery amount detection device applied to an image generating device such as an electrostatic copying machine or an electrostatic printing machine.

[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 is a photoreceptor drum (rotating drum) 2 on which an appropriate electrostatic photoreceptor is disposed on the 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 sleeve mechanism 36 that supplies toner, which is a developer, to the circumferential surface of the photoreceptor drum 26 .

The cleaning device 34 also includes an elastic blade 38 that comes into contact with the circumferential surface of the photosensitive drum 2B and a toner recovery 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 earthen wall 48 .

At the center of the lower support 4, there 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 680, 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 heating roller 88 of the heating fixing roller pair 82 .

The unit 120 in the process unit 14 has a front wall and a rear wall (none of which are shown) that are spaced apart from each other in a direction perpendicular to the plane of the paper. Between the front wall and the rear wall, the above-mentioned upper wall 48, left side wall 102, right side wall 1
04 and a bottom wall 100 are provided.

A stepped portion is provided at the center of the width direction of the earthen wall 48, and the exposure opening 50, which is elongated in the front-rear direction, is formed in the center of this stepped portion. 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 sleeve 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.

On the other hand, the photoreceptor drum 26 continues to rotate further, and the toner remaining on the photoreceptor after the 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 configured to process the nozzling 2 as described above.
It is removably installed inside. For this attachment and detachment, the process unit 14 is provided with a known handle (not shown), and is also provided with suitable locking means between the nozzle 1 and the rear substrate within 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]

The above-mentioned conventional electrostatic copying machine having the process unit 14 removably mounted within the housing 2 is provided with the toner collection chamber 40 as described above. The toner collection chamber 40 is specifically a toner collection container (tank), and when the collected toner reaches a predetermined amount, it is detected by a toner collection amount detection device (not shown).

This conventional toner collection amount detection device uses an optical sensor and is configured to detect when a predetermined amount of toner collection has been reached by a change in the amount of light transmitted through the sensor.

However, in the conventional toner collection amount detection device described above, the sensor detection part becomes dirty due to toner adhesion, and the sensor incorrectly detects that the toner collection amount has reached a predetermined amount even though it is less than the predetermined amount. It has its drawbacks.

If the detection of the amount of collected toner is used to detect the life of the process unit 14, the process unit 1
4 is discarded as the lifespan is earlier than the actual lifespan,
This will result in huge waste.

On the other hand, even in a general type electrostatic copying machine that does not include the process unit as described above, when the toner collection container becomes full of collected toner, it is detected by a toner collection amount detection device similar to the above. In this type of electrostatic copying machine, this is the time to replace the toner collection container, or it is also the time for maintenance of the copying machine. Therefore, similarly to the above, if the sensor detection section becomes dirty due to toner adhesion, false detection will be performed, and replacement or maintenance will be performed earlier than actually.

This is a waste of resources and is also unreasonable.

For any type of electrostatic copying machine, for the above reasons,
Although there is a desire for a device that accurately detects the amount of toner collected in a toner collection container, the reality is that it has not yet been realized.

Therefore, an object of the present invention is to provide a toner collection amount detection device that can accurately and relatively easily detect the amount of toner collected in a toner collection container.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an image generating device having an image output means including a photosensitive drum rotatably supported within a support structure, wherein the image generating device is configured to collect images from the photosensitive drum. A transparent electret having the same polarity as the toner contained in the toner collection container covers a part of the inner wall surface of the toner collection container. An optical sensor is disposed near the electret to detect the amount of toner collected in the toner collection container via the electret. A sensing device is obtained.

[Effect]

A transparent electret having the same polarity as the toner contained in the toner collection container is provided in the toner collection container so as to form a part of the inner wall surface of the toner collection container. An optical sensor is provided to detect the amount of toner collected in the toner collection container.

As is well known, an electret is a charged body that generates an electric field semi-permanently outside and has electric polarization characteristics. The surface of the electret, which forms part of the inner wall surface of the toner collection container, is held at the same polarity as the toner (for example, negative polarity), so the toner is electrically repelled and does not adhere to the surface.

When the amount of toner collected in the toner collection container does not reach a predetermined amount, the level of the collected toner in the container is at a low level that does not reach the portion where the electret is provided.

Even if the scattered toner tries to adhere to the surface of the electret during the process of collecting the toner in the toner collection container, it is electrically repelled as described above and does not adhere. Therefore, the transparent electret portion continues to remain transparent until the amount of collected toner reaches a predetermined level and the level does not reach the detection portion of the electret.

Therefore, this state can be detected by the optical sensor.
It is accurately detected that the amount of toner contained in the toner collection container has not reached the predetermined collection amount, and no false detection occurs.

As the copying machine is used, the collected toner reaches a predetermined amount, and this level reaches the electret part.
Only when a predetermined inwardly facing surface of the toner collection container is covered, is it detected by the optical sensor that the amount of toner contained in the toner collection container has reached a predetermined collection amount.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

First, FIGS. 1 and 2 show an embodiment in which the present invention is applied to an electrostatic copying machine equipped with a process unit 14 shown in FIG. Therefore, the same parts as in FIG. 6 are indicated by the same reference numerals.

In the figure, the toner collection container 122 is constituted by the unit frame 20 of the process unit 14 in this example. Toner 124 removed from the surface of photoreceptor drum 26 by elastic blade 38 is collected into toner collection container 122 . The toner collection container 122 is attached to the unit frame 20
It is integrally molded as a part of a synthetic resin such as ABS resin, nylon resin, vinyl chloride resin, etc. Further, the toner collection container 122 may be formed separately from the unit frame 20 and attached to a predetermined portion of the unit frame 20. In that case, it is necessary to form a window hole or a transparent portion in a portion of the unit frame 20 through which light from an optical sensor to be described later passes.

The side wall of the toner collection container 122 (that is, the unit frame 2
The left side wall 102) of 0 is provided with a convex portion 126 that projects outward. The convex portion 126 has an upright cube shape in this example. A concave portion (space) along the convex portion 126 is formed inside the convex portion 126 and forms a part of the inner wall surface of the toner collection container 122 . The convex portion 126 may be integrally formed with the toner collection container 122 or may be attached separately, but it is necessary to be made of a transparent member.

A film-like electret (electret) E is attached to each inner wall surface of the convex portion 126 with an adhesive.

Transparent members are selected for both Electret E and the adhesive.

As described above, the electret is a charged body that semipermanently generates an electric field outside, has electric polarization characteristics, and is 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; Preferably, the method involves performing a corona Mt treatment on the surface of the film so that charges are trapped on the surface to generate electrets.

The transparent film-like electret (electret) E thus made into an electret is shaped into an appropriate shape so that it can be attached to substantially the entire surface of each inner wall surface (in the illustrated example, five surfaces) of the convex portion 126. , are attached using an adhesive (see the shaded area of the convex portion 126 in FIG. 2). Electret) E constitutes a part of the inner wall surface of the toner collection container 122, and the surface of the inner wall surface exposed inside the toner collection container 122 has the same polarity as the toner 124 (the toner 124
It is important that it is attached to the inner wall surface of the convex portion 126 so that it becomes the same negative pole if it is a negative pole. It is also conceivable that the convex portion 126 itself be made of electret E. In this case as well, it is important that the surface on the inner wall side be positioned so as to have the same polarity as the toner 124.

Near the electret E, that is, the process unit 14
Externally, an optical sensor 128 is placed in position by suitable known support means, such as a bracket (not shown). Specifically, the sensor 128 is a transmission type detector in which a light-emitting element and a light-receiving element face each other, and the light-receiving element directly detects light from the light-emitting element.

Sen f-1281;! When the process unit 14 is installed in the copying machine, the light emitting element 128a and the light receiving element 128b are arranged to face each other with the convex portion 126 interposed between the upper and lower sides. Sensor 128 also remains on the copier even when process unit 14 is removed from the copier.

If the amount of collected toner 124 in the toner collection container 122 does not reach the predetermined amount, the container 122 of the collected toner 124
The level inside is at a low level that does not reach the part where electret E is installed (see Figure 1). In the process where the toner 124 is collected into the toner collection container 122 by the elastic blade 38, the toner 124 is scattered.
Even if 24 tries to adhere to the surface of the electret E in the convex portion 126, it is electrically repelled as described above and does not adhere. Therefore, the transparent electret) E part is
The toner 124 continues to remain transparent until the amount of collected toner 124 reaches a predetermined level and the level does not reach the electret E serving as the detection unit. Therefore, this state is determined by the optical sensor 128.
It is accurately detected that the amount of toner contained in the toner collection container 122 has not reached the predetermined collection amount.

As the copying machine is used, the collected toner 124 reaches a predetermined amount, and when the level reaches the electret E and covers a predetermined inwardly facing surface of the toner collection container 122, For the first time, the optical sensor 128 detects the toner 12 in the toner collection container 122.
It is detected that the storage amount of No. 4 has reached the predetermined collection amount.

By connecting the sensor 128 to a known warning means, such as an alarm lamp or a buzzer (none of which are shown), the detection result can be transmitted to the process unit 14.
It can be notified as the lifespan (replacement time).

In the above embodiment, the electret) E has the convex portion 126
Although the sensor 128 is provided on each inner wall surface of the sensor 128, the purpose can be achieved by providing the sensor 128 on at least a portion of the wall through which the light of the sensor 128 passes (in the figure, the upper and lower opposing walls). but,
The wider the installation surface of the electret E, the greater the repulsion effect on the toner, which is advantageous in improving the detection function.

3 and 4 show other embodiments in which the present invention is applied to an electrostatic copying machine equipped with the process unit 14 shown in FIG. 6, and are the same as FIGS. 1 and 2. The parts are indicated by the same reference numerals, and only the different parts will be explained.

Toner collection container 122 configured by unit frame 20
The toner 124 is stored therein in the same manner as described above.

A rectangular window hole 130 is formed in the side wall portion of the toner collection container 122 (left side wall 102 of the unit frame 20).

A transparent film-like electret E is attached to the inner wall surface of the toner collection container 122 with an adhesive so as to cover the window hole 130. The electret E constitutes a part of the inner wall surface of the toner collection container 122. The electret E may also be configured by being attached to the surface of a transparent plate member serving as a base, and may be attached from inside the window hole 130 in the same manner as described above.

If the toner collection container 122 is made of a transparent member, the electret E may be directly attached to the inner wall surface of the container without forming the window hole 130.

A reflective member 133 is attached to the inner wall surface of the toner collection container 122 at the position where the window hole 130 is formed. The reflective member 133 is composed of a white synthetic resin plate, an iron plate, or a synthetic resin plate painted with white paint. The reflective member 133 also has a portion parallel to the inner wall surface at a predetermined interval inside the window hole 130,
The end portion is bent into an L-shape and attached by a fixing means such as adhesive or screws. Reflective member 13
3, the inner side facing the window hole 130 (two sides in this example)
A transparent film-like electret E similar to that described above is attached to the holder with an adhesive. In this case as well, it can be said that the electret E constitutes a part of the inner wall surface of the toner collection container 122.

The electret E constitutes a part of the inner wall surface of the toner collection container 122;
It is important that the inner exposed surface be positioned to have the same polarity as the toner 124 (eg, negative polarity).

In this example, the wall of the toner collection container 122 is formed integrally with the wall of the unit frame 20 of the process unit 14 shown in FIG. 6, but a separate container may be installed within the unit frame 20. . Conditions and the like in that case are the same as in the previous embodiment.

electrons outside the process unit 14)E
An optical sensor 132 is arranged near the.

In this embodiment, the sensor 132 is a reflection type detector that irradiates light from a light emitting element onto the surface of electrons (E) and detects the reflected light with a light receiving element.

Note that the function of detecting the amount of collected toner 124 in this embodiment can be easily understood from the explanation of the previous embodiment, so a duplicate explanation will be omitted. The difference from the above embodiment is as follows.
The function of the reflecting member 133 will be explained.

If the amount of toner 124 collected in toner collection container 122 does not reach a predetermined amount, the level is lower than window hole 130 . Toner 124 does not exist in the space between window hole 130 and reflective member 133. Also window hole 130
The opposing surfaces of the reflecting member 133 and the surfaces located therebetween are composed of electrons (E) having the same polarity as the toner 124, so the toner 124 is electrically repelled and does not adhere. The light from the light emitting element of the sensor 132 passes through each electron (E), is reflected by the reflecting member 133 that maintains white color, and is detected by the light receiving element. Therefore, this state is accurately detected by the sensor 132 as indicating that the amount of toner 124 collected in the toner collection container 122 has not reached the predetermined amount.

When the amount of toner 124 collected in the toner collection container 122 reaches a predetermined amount, the level exceeds the window hole 130. Toner 12 is placed in the space between the window hole 130 and the reflective member 133.
4 is filled. Therefore, as can be easily understood, this state is detected by the sensor 132 in the toner collection container 1.
It is detected that the amount of collected toner 124 in 22 has reached a predetermined amount.

The toner 124 in the space between the reflective member 133 and the window hole 130 is always the same as the toner 124 in the toner collection container 122.
It is important to maintain the amount collected at a level that accurately captures the amount recovered. Various modifications can be made to this effect, such as a configuration in which the upper part of the reflective member 133 is not closed.

Although the present invention has been described above using a copying machine equipped with a process unit as shown in FIG. 6 as an example, it goes without saying that it is widely applicable to general electrostatic copying machines that are not equipped with a process unit. FIG. 5 shows an embodiment in which the present invention is applied to a general electrostatic copying machine, which is similar to the embodiment shown in FIGS. 1 and 2.

In FIG. 5, toner collected by a cleaning device of the copying machine (not shown) is conveyed via a spiral roller 140 and the like, and collected into a toner collection container 142. A convex portion 144 similar to that shown in FIGS. 1 and 2 is formed at a position above the side wall of the toner collection container 142.
On its inner wall surface are electrons) E (see the shaded area in the figure).
is provided. An optical sensor 146 is disposed near the electron (electron) E.

By connecting the sensor 146 to a known warning means, such as an alarm lamp or a buzzer (none of which are shown), the detection results can be sent to the toner collection container 142.
It can be notified when it is time to replace the machine or when it is time for maintenance of the copying machine.

The toner collection amount detection function in this embodiment can also be easily understood from the explanation of the previous embodiment, so the explanation will be omitted.

It has been explained that a transparent member is selected for the toner collection container and the like in the portion where the electret E1 and the electret E are provided. In short, the light from the optical sensor can pass through,
The present invention can be implemented as long as the toner has transparency to the extent that the presence or absence of toner can be detected through electrons) E. Therefore, in this specification, "transparent" includes the above meaning.

〔Effect of the invention〕

According to the invention described above based on the embodiments, there is provided a toner collection amount detection device that can relatively easily and reliably detect the amount of toner collected in the toner collection container. You can get an effect like this.

(1) It is possible to accurately determine when toner is to be collected or when to perform maintenance on an image generating device. As a result, the image generation device can be used with maximum efficiency without waste, thereby extending the life of the image generation device and significantly improving its reliability.

(2) When the above-mentioned toner recovery amount detection device is provided in an image generating apparatus equipped with a process unit, it can be used as a simple means for checking the lifespan of the process unit.

(3) Since the above-mentioned toner collection amount detection device is composed of a transparent electret and a known optical sensor, it can be easily installed on the toner collection container and has a highly reliable detection function, which has practical value. is extremely high.

Although the present invention has been described in detail based on the embodiments above, the present invention is not limited to the Kamikita embodiments, 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 showing an embodiment in which the present invention is applied to a process unit. FIG. 2 is a schematic perspective view showing a part of FIG. 1 in an enlarged manner. FIG. 3 is a schematic cross-sectional view partially showing another embodiment of the invention. 4 is a schematic perspective view showing a part of FIG. 3; FIG. FIG. 5 is a schematic perspective view showing still another embodiment of the invention. FIG. 6 is a schematic cross-sectional view of a conventional electrostatic copying machine equipped with a process unit. 14...Process unit 20...Unit frame 40...Toner collection chamber 100...Bottom wall 102...Left wall 120...Toner collection amount Detection device 122.142
・・・Toner collection container 124 ・ ・ ・ ・ ・
Toner 126.144... Convex portion 12B, 132.146... Optical sensor 1
30... Window hole 133... Reflective member E... Electret

Claims (1)

[Scope of Claims] 1. An image generation device having an image output means including a photoconductor drum rotatably supported within a support structure, wherein the image generation device stores toner collected from the photoconductor drum. The toner collection container is provided with a transparent electret having the same polarity as the toner contained in the toner collection container so as to form part of an inner wall surface of the toner collection container. . A toner collection amount detection device, characterized in that an optical sensor is disposed near the electret to detect the amount of toner collected in the toner collection container via the electret. 2. The image generating device includes a process unit having a unit frame detachably mounted within the support structure and the image output means including the photosensitive drum rotatably supported by the unit frame. 2. The toner collection amount detection device according to claim 1, wherein the electret and the optical sensor are provided to detect the amount of toner collected in the toner collection container in the process unit. 3. The toner collection container is constituted by the unit frame of the process unit, the electret is provided so as to constitute a part of the inner wall surface of the unit frame, and the optical sensor is provided on the outside of the unit frame. and detects that when the process unit is installed in the image generating apparatus, the optical sensor is positioned so as to be able to detect the amount of toner collected in the toner collection container via the electret. The toner recovery amount detection device according to claim 2.