JPH0690572B2 - Copier developing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device of a copying machine, and more specifically, to prevent the developer from escaping from a gap between a photoconductor and the developing device. The present invention relates to a developing device of a copying machine for the purpose.

[Prior Art] Generally, as a developing device of a copying machine, a developing roll is provided in a developing device housing opened at a portion facing a photosensitive drum, which is a photoconductor, and is housed in the housing by the developing roll. There is known a structure in which a developer is supplied to the photosensitive drum. In this type of developing device, the developing roll is moved toward the photosensitive drum holding an electrostatic latent image through the opening of the housing. A developer is supplied to develop the electrostatic latent image into a visible image.

[Problems to be Solved by the Invention] However, in the conventional developing device, the developer floating in the developing device or the developer on the developing roll that is not involved in the development does not contact the opening of the housing and the photosensitive drum. There was an adverse effect that the inside of the copying machine was contaminated by scattering from the gap to the outside.

Therefore, in order to prevent the above-mentioned harmful effects, conventionally, various measures have been taken in the lower shape on the opening side of the developing device housing to prevent the developer from escaping inside the body.
A wide magnet or a catch pan was provided below the developing device to collect the scattered developer. However, the present situation is that it is not sufficiently satisfactory and the inside of the aircraft cannot be sufficiently prevented from being damaged.

Further, in order to prevent the above-mentioned adverse effect, as shown in FIG. 4, a structure in which a gap between the photosensitive drum a and the developing device housing b is sealed by a seal member c has been considered, but this structure is used. Is the developer e on the tip of the magnet d.
However, there is a risk that the toner image on the photosensitive drum a may be disturbed by the contact of the seal member c with the surface of the photosensitive drum a, which causes a problem that the latent image for copying is lowered. Further, there is a problem that not only the structure becomes complicated but also the entire device becomes large.

[Means for Solving Problems] The present invention has been made in view of the above circumstances, and in order to solve the above technical problem, the gap between the photoconductor of the copying machine and the developing device housing is not sealed, that is, the photoconductor. Without damaging the surface of the photoconductor by contact, the airflow generated between the photoconductor and the housing is effectively used to collect the developer falling in the gap between the photoconductor and the housing, and the developer is released into the copier body. The present invention provides a developing device for a copying machine, which is characterized in that it is prevented from scattering.

That is, according to the present invention, an opening for collecting the developer falling from the gap between the housing and the photoconductor is provided in the lower portion of the opening of the developing device housing, and the chamber cooperates with the opening lower piece. Forming a pocket having a base with an L-shaped cross section, and providing a ventilation portion at a fixed side base portion which is a bottom portion on the side opposite to the opening portion of the pocket and facing the opening side lower piece of the housing. A developer guide inclined portion that bends inward is formed at the tip of the opening side base portion at a bending angle θ with respect to the base portion, and the bending angle θ of the developer guide inclined portion is The extension angle is set so that the contact angle α formed by the tangent line of the contact point with the photosensitive member is within the range of 0 ° <α <90 °, and the air flow generated by the rotation of the photosensitive pair and the developing roll is set. Introduced into the pocket with this developer guide ramp It is an object of the present invention to provide a developing device for a copying machine, which is characterized in that it abuts at least the opening side base.

In the present invention, the ventilation part of the pocket may be composed of only a ventilation hole formed in the fixed side base part that is the bottom part of the pocket, but it is possible to prevent the developer from escaping into the body. For further prevention, it is possible to configure the ventilation part with a ventilation hole formed in the fixed base portion of the pocket and a filter for separating the air passing through the ventilation hole and the developer. The developer guiding inclined portion is formed so as to be inclined so as to have the above-mentioned specific bending angle, and may be formed at least at the lower edge portion of the opening portion of the pocket. It is also possible to further improve the collection rate of the developer by forming the developer guiding inclined portion on the upper edge portion of the portion in the same manner.

[Operation] The above technical means operates as follows.

Since the air flow generated between the photoconductor and the developing roll passes through the ventilation part provided at the bottom of the pocket, the developer floating in the developing device due to this air flow and the developing roll on the developing roll not involved in the development It is possible to prevent the developer from being collected in the pocket and to be scattered into the main body of the copying machine, and thus to prevent the inside of the copying machine from being damaged.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a main part of a developing device according to a first embodiment of the present invention, in which a developing roll 4 is provided in a developing device housing 3 having an opening 2 at a portion facing a photosensitive drum 1 constituting a photoconductor of a copying machine. And the developer 5 housed in the housing 3 by the developing roll 4 is supplied to the photosensitive drum 1.

In the developing device of the present invention, a pocket 8 having an opening 7 for collecting the developer 5 falling from the gap 6 between the housing 3 and the photosensitive drum 1 is formed in the lower portion of the housing 3 on the opening 2 side. In addition, the pocket 8 is provided with the ventilation portion 9, and the developer guiding inclined portion 10 is formed on the edge portion on the side of the opening portion 7. In this case, the pocket 8 has a cross-section L-shaped base portion 11 that cooperates with the opening-side lower piece 3a of the housing 3 to form a chamber 8a, and an opening-side base portion 11a on the opening portion 7 side of the base portion 11. The developer guide inclined portion 10 is bent from the tip toward the photosensitive drum 1 at a bending angle θ, and the ventilation portion 9 is provided on the fixed side base portion 11b which is the bottom portion of the base portion 11 of the pocket 8. The constituent ventilation holes 12 are provided. In this case, the bending angle θ of the developer guiding inclined portion 10 is such that the contact angle α with the tangent line A at the point where the extension line of the inclined portion 10 contacts the photosensitive drum 1 is 0 ° <α <90 °. It is appropriately selected so as to fall within the range. By providing the developer guiding inclined portion 10 with the opening side base portion 11a inclined at the specific bending angle θ, the air flow generated by the rotation of the photosensitive drum and the developing roll is guided by the guiding inclined portion. The fixed side base portion 11 that is accurately guided by 10 and is sent into the pocket 8 and the air flow thereof is the bottom portion of the pocket 8.
Since the developer collides with b, the developer carried by the air flow can be reliably collected by being retained in the pocket, particularly in the opening side base portion 11a.

In the copying machine equipped with the developing device of the present invention configured as described above, when the photosensitive drum 1 rotates clockwise and the developing roll 4 rotates counterclockwise, the developer contained in the housing 3 5 is attached to the developing roll 4, and the developer 5 is supplied from the developing roll 4 to the photosensitive drum 1 toward the photosensitive drum 1 holding the electrostatic latent image through the opening 2, and the electrostatic charge of the photosensitive drum 1 is increased. The latent image is developed into a visible image. In this case, the developer 5 floating in the housing 3 or the developer 5 on the developing roll 4 not involved in the development falls from the gap 6 between the opening 2 of the housing 3 and the photosensitive drum 1 and inside the copying machine main body. However, in the present invention, since the pocket 8 for collecting the developer is formed in the lower portion of the housing 3 on the opening side, the developer 5 falling from the gap 6 can be collected. It is possible to prevent the inside of the copying machine from being soiled. That is,
Since the air flow generated by the rotation of the developing roller 4 of the photosensitive drum 1 passes through the ventilation part 9 of the pocket 8, the developer 5 dropping through the gap 6 by this air flow positively enters the pocket 8. In addition, the developer 5 is reliably collected in the pocket 8 in combination with the guide action of the developer guiding inclined portion 10 formed in the opening 7 of the pocket 8.

FIG. 2 shows a second embodiment of the developing device of the present invention, which is a case where the developer 5 can be collected more reliably. That is, when the filter 13 is attached to the ventilation hole 10 formed in the pocket 8 so that the developer 5 can be separated from the air passing through the ventilation hole 10 and reliably collected in the pocket 8. Is. In this case, if the opening-side lower piece 3a of the housing 3 is inclined similarly to the developer guiding inclined portion 10, the collection of the developer 5 will be more reliable. Further, the filter 13 is provided in the pocket 8
If it is attached to the plate 15 that can slide along the inner wall of the
Can be cleaned and the collected developer on the plate 15 can be collected.

The filter 13 is made of a porous material such as urethane. Of course, the filter 13 is not limited to urethane, and may be a porous one that allows air to pass but does not pass the developer 5.

FIG. 3 shows a third embodiment of the developing device of the present invention. The developer 5 stays in the corners 14 of the inclined portion of the opening side lower piece 3a of the housing 3 provided in the second embodiment. This is a case where it is prevented. That is, the ventilation hole 12 is provided at a position near the corner portion 14 of the housing 3.
This is a case in which the developer 5 staying in the corner portion 14 can also be collected in the pocket 8 by the air flow passing through the ventilation hole 12a by forming the hole a.

In each of the above embodiments, the ventilation holes 12 and 12a forming the ventilation portion 9 may be a plurality of small holes or long holes arranged at appropriate intervals, or may be provided in a slit shape. May be. Further, if the base 11 constituting the pocket 8 is detachably engaged with the housing 3, the developer 5 collected to some extent can be taken out to the outside.

[Effects of the Invention] As described above, according to the developing device of the present invention, the opening portion for collecting the developer falling from the gap between the housing and the photoconductor is provided in the lower portion of the developing device housing on the opening side. A pocket having a base having an L-shaped cross section, which has a chamber formed in cooperation with the lower piece on the opening side, is formed, and a ventilation portion is provided on the fixed side base which is the bottom opposite to the opening of the pocket. In addition, at the tip of the opening side base portion facing the opening side lower piece of the housing, a developer guide inclined portion that bends inward with a bending angle θ with respect to the base portion is provided at a specific bending angle θ. Since it is formed with an inclination, the air flow generated between the photosensitive drum and the developing roll can be guided into the air pocket, so that the developer floating in the developing device can be reliably collected in the pocket. , Inside the copier body Thereby preventing the escape of agent, it is possible to soiling copier body. Further, according to the developing device of the present invention, since no contact portion is required on the surface of the photosensitive drum, it is possible to extend the life of the photosensitive drum without damaging the photosensitive drum and facilitate maintenance and inspection. Since it has an excellent effect such as, the utility value is remarkable.

[Brief description of drawings]

FIG. 1 is a sectional view of the essential portions of a developing device according to the first embodiment of the present invention, FIG. 2 is a sectional view of the essential portions of a second embodiment of the developing device according to the present invention, and FIG. FIG. 4 is a sectional view showing a main part of a third embodiment of the apparatus, and FIG. 4 is a sectional view showing a developer collecting section of a conventional developing apparatus. Explanation of symbols (1) …… Photoconductor (photosensitive drum) (2) …… Opening (3) …… Developing device housing (3a) …… Lower piece on opening side (4) …… Developing roll, (5) …… Developing Agent (6) …… Gap, (7) …… Opening (8) …… Pocket (8a) …… Chamber (9) …… Aeration part (10) …… Developer guide inclined part (11a) …… Opening Part side base, (11b) …… Fixed side base (12), (12a)… Ventilation hole (13) …… Filter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Inoue 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Zero Tsux Co., Ltd.Ebina Business Office (72) Inventor Koji Aikawa 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Zero Tux Co., Ltd.Ebina Business In-house (56) References JP 58-11970 (JP, A) JP 54-74756 (JP, A) Actual opening 57-90446 (JP, U) Actual opening 53-117245 (JP, U)

Claims (2)

[Claims] 1. A developing roll is provided in a housing which is opened at a portion facing a photoconductor of a copying machine, and the developer contained in the housing is supplied to the photoconductor by the developing roll. In the developing device, an opening for collecting the developer falling from the gap between the housing and the photoconductor is formed in the lower portion of the opening side of the housing, and a chamber is formed in cooperation with the lower piece on the opening side. Forming a pocket having a base having an L-shaped cross section, and providing a ventilation portion at a fixed side base portion which is a bottom portion on the side opposite to the opening portion of the pocket, and at the opening side facing the opening side lower piece of the housing. A developer guiding inclined portion that bends inward is formed at the tip of the base portion at a bending angle θ with respect to the base portion, and the bending angle θ of the developer guiding inclined portion is the extension line of this inclined portion. Contact of points that come in contact with the photoconductor The contact angle α with the line is 0 ° <α <90
The air flow generated by the rotation of the photosensitive member and the developing roll is introduced into the pocket provided with the developer guiding inclined portion and strikes at least the opening side base portion. A developing device for a copying machine, which is characterized in that 2. A ventilation part of the pocket is constituted by a ventilation hole formed in a fixed side base part which is a bottom part of the pocket, and a filter for separating the air passing through the ventilation hole from the developer. A developing device for a copying machine according to claim 1, including the following.