JP2560749B2 - Development device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device such as a copying machine, and in particular, a pair of side seal parts is provided at both ends of an opening of a device housing to allow toner to escape from both ends. The present invention relates to an improvement of a developing device that prevents scattering.

[Prior Art] Conventionally, as a developing device of a copying machine or the like, a magnetic brush developing device shown in FIG. 9 will be described as an example, and a cylindrical sleeve (b) disposed opposite to a photosensitive drum (a) will be described. ) And a magnetic roller (c), and a developer provided on the back side of the developing roller (d), which is composed of toner and carrier, is supplied onto the outer peripheral surface of the developing roller (2). A paddle wheel (e), a trimmer plate (f) provided above the developing roller (d) for scraping off an excessive amount of the developer supplied to the developing roller (d), and the scraped developer A developer transport plate (g) for transporting the developer to a position away from the developing roller (d), and a toner dispense roller (i) provided at a lower end portion above the developer transport plate (g) in the transport direction. Toner consumed in preparation A toner box (j) for replenishing the amount of the toner forms a main part of the toner box (j), and a magnetic brush (k) formed of toner and a carrier formed on the developing roller (d) serves to keep the photosensitive drum (a) stationary. There is known a device in which an electrostatic latent image is rubbed and the toner in the magnetic brush (k) is transferred to the latent image forming surface of the photosensitive drum (a) to visualize the latent image.

By the way, in this type of developing device, the toner floating inside the device and the toner on the developing roller (d) not involved in the development are accompanied by the rotation of the developing roller (d) which rotates at a high speed, and thus the device housing (h). There is a drawback that the inside of the main body of the copying machine such as a copying machine is contaminated by the toner.

Therefore, in the conventional developing device, as shown in FIG. 10, magnetic seal members (n) and (n) are arranged on both upper and lower ends of the opening (m) along the lengthwise direction thereof, Side seal portions (s) and (s) are provided on both ends of the opening (m), and toner scattered from the front side of the opening (m) is magnetically attracted and captured by the magnetic seal members (n) and (n). At the same time, a method is adopted in which the toner leaking from both ends of the opening (m) is blocked by the side seal members (s) (s) to prevent the toner from scattering.

As for the side seal portion (s), as shown in FIG. 11, the side member (s1) attached to both ends of the opening (m) of the housing (h) and the side member (s1) are adjacent to each other. And a sheet member (s2) which is provided on the side and is formed of a flexible sheet, and this sheet member (s2) is attached to the opening (m) for reasons of work and development. For the purpose of reducing the contact pressure to the roller (d) surface, a pair of sheet pieces (s3) (s3) cantilevered on the base end side at the upper and lower edges of the opening (m).
The side portion (s1) is brought into sliding contact with the outer peripheral surface of the photosensitive drum (a) to close the gap between the photosensitive drum (a) and the housing (h), while the sheet member ( By s2), the end side of the opening (m) is covered to prevent the toner from escaping from the end of the opening (m).

[Problems to be Solved by the Invention] As described above, in the conventional developing device, the side seal portion (s) is composed of the separate side member (s1) and sheet member (s2), and There is a problem that it is necessary to perform positioning and to attach it to a predetermined portion of the opening (m) of the housing (h), which makes the attachment work complicated, and
Since the sheet member (s2) is composed of a pair of sheet pieces (s3) (s3), these sheet pieces (s3) (s3)
Deforms over time, and the leading end of the developing roller (d)
There is a problem in that the toner may be curled toward the side or the opposite side, and the end side of the opening (m) cannot be covered, and the toner cannot be completely prevented from scattering.

[Means for Solving Problems] The present invention has been made in view of the above problems, and it is an object of the present invention to easily form a side seal portion and to disperse toner during development. It is an object of the present invention to provide a developing device capable of preventing the above problems for a long time.

That is, the present invention is provided with a developing roller arranged to face the latent image carrier, supplies toner to the latent image carrier through the opening of the apparatus housing, and forms a pair of side walls at both ends of the opening. Assuming a developing device equipped with a seal to prevent toner from escaping from both sides of the opening,
Regarding the side seal portion, a curved side member for slidingly contacting the outer peripheral surface of the latent image bearing member to close a gap between the latent image bearing member and the device housing, and a side edge portion of the opening. And a side seal body provided with the side member on the end portion side, and the side seal body is provided with a curved portion that curves in a direction opposite to the side member and covers the outer peripheral surface of the developing roller. It is characterized by that.

In such technical means, the side seal portion is
It is composed of a side seal body and a side member attached to one end side of the side sheet body. Regarding the side seal body, a flexible sheet material such as polyester sheet, polyethylene terephthalate (PET), polyimide, polypropylene , Teflon (trade name), and the like, while the side member can be made of urethane foam, foam rubber, or the like.

As a method of forming the curved portion on the side seal body, for example, a notch may be provided at a boundary portion of the side seal body with the side member, and the curved portion may be formed through the notch. When this technical means is applied to a phenomenon device including a magnetic roller, magnetic force lines are generated along the axial direction on the end side of the developing roller, and a magnetic brush along the magnetic force lines is formed on the end side. For this reason, the curved portion of the side seal body and the magnetic brush come into contact with each other, and a toner cloud is likely to occur. Therefore, in such a case, it is advisable to adopt a method in which a cutout concave portion is formed on the end portion side of the side seal body facing the side member so that contact between the magnetic brush and the curved portion does not occur.

The scope of application of this technical means can naturally be applied to a two-component magnetic brush developing device as well as a one-component developing device that does not use a carrier as a developer.

Also, for copiers etc. that incorporate these developing devices,
Normally, a monochrome copying machine, a full-color copying machine that arranges a plurality of developing devices along the moving path of a latent image carrier to make color copies of color originals, and a developing device is detachably attached to the latent image carrier. The target is a flat color copying machine or the like that appropriately changes the developing device to make a copy of a desired color.

[Operation] According to the technical means as described above, the side seal portions are attached to the curved side member that closes the gap between the latent image carrier and the device housing, and the side end portion of the opening. And a side seal main body having the side member on the end side, and the side seal main body is provided with a curved portion that curves in a direction opposite to the side member and covers the outer peripheral surface of the developing roller. Since the side seal part is composed of a single member, the mounting work can be simplified and the curved part of the side seal body is less likely to be deformed than the conventional sheet member, so that the curved part can be used for a long time. It becomes possible to cover the outer peripheral surface of the developing roller.

[Embodiment] An embodiment in which the present invention is applied to a small-sized magnetic brush developing device using a screw auger will be described in detail with reference to the drawings.

First, FIG. 7 shows an electrophotographic copying machine in which the magnetic brush developing device is incorporated. This copying machine is a platen (2) provided on the upper surface side of the copying machine main body (1).
And a photosensitive drum (3) provided on the lower side of the photosensitive drum (3), a charger (4) sequentially provided along the outer peripheral surface of the photosensitive drum (3), an optical system (5), and a color and a black one. 2, magnetic brush developing devices (6) and (7), a transfer device (8), and the like, five paper trays (9) to (9) provided below the photosensitive drum (3), and paper reversal. The copy paper (p) is provided with the section (10) and the main part is constituted by the paper transport path (11) for transporting the copied paper (p) to the photosensitive drum (3) side again. It has functions such as double-sided copying, single-sided multiplex copying, and partial color copying.

Then, the magnetic brush developing device (6) (7) of the above 2
As shown in FIG. 1, each of them is arranged by being divided into a device accommodating portion (1A), and among these developing devices (6) and (7), the developing device for color copying ( 6) is constituted by the developing device according to this embodiment.

That is, this developing device is arranged so that milk can be received through the holding portion (1B) provided near the photosensitive drum (3).
As shown in FIG. 6 to FIG. 6, a developing roller (6a) arranged on the photosensitive drum (3) side and a first screw provided side by side with a partition (6b) on the back side of the developing roller (6a). Auger (6c) and second screw auger (6d)
And a third screw auger (6f) provided above these augers (6c) (6d) via a receiving plate (6e)
And a magnetic seal member (not shown) provided on the upper end side of the opening (H1) of the housing (H) and side seal members (6A) (6A) attached to both ends of the opening (H1). The main part is configured, and the toner agitating coil auger (6g) is provided on the back side of the housing (H).
A toner box (6j) having a toner transport screw auger (6h) is arranged.

First, as in the conventional case, the developing roller (6a) is composed of a cylindrical sleeve (6r) that rotates in the direction of the arrow and a magnetic roller (6s) fixedly arranged inside the sleeve. ), The excess developer is scraped off by a trimmer bar (6t), and a fixed amount of magnetic brush (6u) is formed on the outer peripheral surface thereof.

On the other hand, the screw augers (6c) to (6f) are the fifth
As shown in the figure, the drive shafts (6w) to (6w) are rotated at low speed by a drive motor (not shown) via drive gears (6v) to (6v).
w) and conveying blades (6x) to (6x) spirally formed along the lengthwise direction of these rotating shafts (6w) to (6w), and the first screw Regarding the auger (6c), its conveying blade (6x) is made of non-magnetic stainless steel material (non-magnetic SUS 304) so that it is not affected by the magnetic force of the magnetic roller (6s). Further, as shown in FIG. 6, an opening (6k) for supplying the toner conveyed by the second screw auger (6d) to the first screw auger (6c) is provided on one end side of the partition (6b). On the other hand, the toner conveyed by the second screw auger (6d) hits the side wall of the housing (H) and is supplied to the third screw auger (6f) at both ends of the receiving plate (6e). An opening (6m) for opening the toner box and an opening (6n) for supplying the toner conveyed by the third screw auger (6f) to the first screw auger (6c) are provided. The toner supplied from (6j) is conveyed to the first screw auger (6c) through the second screw auger (6d) and the third screw auger (6f), and the toner is supplied from the first screw auger (6c) to the developing roller (6a). ) Is an attendant It is being paid.

As shown in FIGS. 3 to 4, the side seal members (6a) are arranged at both ends of the opening (H1) of the housing (H), and the side seal main body (6B) made of a polyester sheet is provided. It is composed of a urethane foam side member (6D) attached to one end of this body (6B), and
The side member (6D) is attached to the side seal body (6A).
A cut (6E) is provided at the boundary with the curved portion (6E) for covering the outer circumference of the developing roller (6a) through the cut (6E).
F) is formed. Also, the side member (6D)
Is curved in a direction opposite to the curved portion (6F) and is slidably arranged on the outer peripheral surface of the photosensitive drum (3) to form a gap on the end side between the photosensitive drum (3) and the housing (H). And the end portion of the curved portion (6F) of the side seal body (6B) is in contact with the magnetic brush formed on the end portion of the developing roller (6a). A notch recess (6G) is formed to prevent it.

Further, on the rear side of the toner box (6j), a spring (6p) for urging the housing (H) in a direction of separating it from the photosensitive drum (3) and a urging force of the spring (6p) are resisted. A retracting means (12) including a housing (H) and an eccentric cam (6q) for bringing the photosensitive drum (3) side closer to each other is provided, and the housing (H) is alternated between a developable position and a non-development position. It is designed to be coordinated with.

Furthermore, a magnetic seal member (1E) composed of a magnet and iron powder, as shown in FIGS. 1 and 2, is provided on the tip side of the partition part (1D) of the device accommodating part (1A). The color developing device (7) is disposed along the length direction of the portion (1D) and captures toner falling from the color developing device (6) disposed on the upper side, while the black developing device (7) disposed on the lower side. (4) is used to prevent the toner color mixture between the developing devices (6) and (7).

The black developing device (7) disposed below the color developing device (6) includes a developing roller (7a), a paddle wheel (7b), and an agitator (7) as shown in FIG.
c) and screw auger (7d) for black toner supply
And a retraction means (13) composed of a spring (7e) and an eccentric cam (7f) is arranged on the back side of the housing (H), and the copying machine main body ( 1) Based on a signal from an operation panel (not shown) arranged on the upper surface side, the color developing device (6) and the black developing device (7) are alternately retracted. In this case, as shown in FIG. 8, one rectangular cam (6z) is arranged on the back side of the housing (H), and this eccentric cam (6q) (7f) is also used by this cam (6z). It goes without saying that the configuration can be adopted. Further, in the developing device (7), a magnetic roller (7) made of an iron strip is provided on the lower side of the housing (H).
The magnetic seal member (7A) magnetized by (s) is fixedly arranged to capture the toner falling from the housing (H), and the magnetic seal member (7)
A box-shaped catch pan (7B) is fixedly arranged on the lower side of A), the housing (H) is arranged at a non-developing position, and is based on the magnetic roller (7s) of the magnetic seal member (7A). When the magnetic attraction force decreases, this magnetic seal member (7
The toner falling from A) is collected in the catch pan (7B).

In order to make a color copy using the color developing device (6) configured as described above, the respective retract means (12) (13) are operated by operating the operation panel to enter the color mode. As shown in FIG. 1, the color developing device (6) is arranged at the developable position, while the black developing device (7) is arranged at the non-developing position.

Then a normal copy operation is performed in this state,
The electrostatic latent image formed on the photosensitive drum (3) is developed with color toner to scratch the visible image, and the color toner image is transferred to the paper (p) side by the transfer device (8) and fixed. It is fixed by a container (14) to obtain a color copy.

At this time, in the developing device (6), the toner is not scattered from both ends of the opening (H1) by the action of the side seal member (6A) attached to the housing (H), and the opening is Magnetic seal member provided on the upper edge of (H1), and partition part (1D) of the device accommodating part (1A)
Due to the action of the magnetic seal member (1E) provided in, the toner will not be scattered from both the upper and lower sides of the opening (H1).
Therefore, the interior of the copying machine main body (1) is not contaminated by the toner, and further, the color mixing of the toner between the developing devices (6) and (7) can be reliably prevented.

Moreover, since the side seal member (6A) is composed of a single member integrally formed with the side member (6D) and the side seal body (6B), it is possible to simplify the mounting work. In addition, since the curved portion (6F) formed on the side seal body (6B) does not easily deform, it is possible to cover the outer peripheral surface of the developing roller (6a) on the end side for a long period of time. Therefore, it has an advantage that the toner can be surely prevented from escaping.

In addition, in order to make a normal black copy with this copying machine, by operating the above operation panel to set it to the black mode,
The black developing device (7) is arranged at a developable position, while the color developing device (6) is arranged at a non-developing position for black development. Further, in this copying machine, the paper (p) on which the black toner is fixed is retransmitted to the photosensitive drum (3) side through the paper conveying path (11), and the image is formed by the color developing device (6). By doing so, single-sided multicolor multiplex copying is performed, while on the other hand, by forming an image on the black developing device (7), single-sided single color multiplex copying is performed. Further, double-sided copying can be performed by re-sending to the photosensitive drum (3) side via the sheet reversing section (10) of the sheet conveying path (11). Furthermore, a plurality of the color developing devices (6) are facilitated so that the developing devices (6) to
It is also possible to obtain a color copy of a desired color by accommodating different color toners in (6) and alternately exchanging each developing device (6) for development.

EFFECTS OF THE INVENTION As described above, according to the present invention, a curved side member that seals the side seal portion between the latent image carrier and the apparatus housing, and the side member attached to the side end portion of the opening are provided. Since the side seal body is provided with a side seal main body provided on the end side, and the side seal main body is provided with a curved portion that curves in a direction opposite to the side member and covers the outer peripheral surface of the developing roller, the side seal portion is As a single member, the mounting work can be simplified, and the curved portion of the side seal body is less likely to be deformed than the conventional sheet member, so that the outer peripheral surface of the developing roller can be covered for a long time. It will be possible.

Therefore, the development device can be mass-produced, and the toner contamination inside the machine body such as a copying machine can be reliably prevented.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention. FIG. 1 is a sectional view of a developing device according to the embodiment, FIG. 2 is a front perspective view thereof, and FIG. 3 is a partially enlarged view thereof. FIG. 4 (A) is a perspective view of the side seal member incorporated in the developing device, FIG. 4 (B) is a front view thereof, and FIG. 4 (C) is a side view thereof.
3D is a side view of FIG. 3, FIG. 5 is a rear perspective view of the developing device, FIG. 6 is a plan view of the same, and FIG. 7 is a structural explanatory view of a copying machine incorporating this developing device. FIG. 8 is a side view of a developing device according to another embodiment, and FIGS.
FIG. 11 shows a conventional developing device, FIG. 9 is a sectional view thereof, FIG. 10 is a perspective view thereof, FIG. 11 (A) is a perspective view of mounting a side seal portion thereof, and FIG. 11 (B). Is its front view, No.
FIG. 11C shows a side view thereof. [Description of symbols] (3) …… Opening drum (6a) …… Developing roller (H) …… Housing (H1) …… Opening part (6A) …… Side seal member (6B) …… Side seal body (6D) …… Side member (6F) …… Bent part (6E) …… Notch (6G) …… Notched recess

Claims (3)

(57) [Claims] 1. A developing roller disposed opposite to a latent image bearing member to supply toner toward the latent image bearing member through an opening of a device housing, and a pair of side seals at both ends of the opening. In a developing device in which a portion is provided to prevent toner from escaping from both sides of the opening, the side seal portion is slidably brought into contact with the outer peripheral surface of the latent image carrier to form an end portion between the latent image carrier and the device housing. And a side seal body that is attached to the side end of the opening and includes the side member on the end side, and the side member is attached to the side member. A developing device, which is provided with a curved portion that is curved in a direction opposite to that and covers the outer peripheral surface of the developing roller. 2. The side seal portion is composed of a side member made of urethane foam and a side seal body made of a polyester sheet, and the side seal portion is provided with a notch provided at a boundary portion between the side seal body and the side member. The phenomenon device according to claim 1, wherein a curved portion is formed. 3. The side seal main body is provided with a cutout concave portion for preventing contact between the side seal main body and toner on the developing roller on the end side facing the side member. The developing device according to claim 1.