JPH0622844Y2 - Rotary developing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention has a developing device containing a developer, and includes a developing unit rotatably supported facing a latent image carrier. The developer conveying member provided is brought to the developing position by the rotation of the developing unit, and the developer conveying member brought to the developing position conveys the developer to the developing area between the member and the latent image carrier, The present invention relates to a rotary developing device that visualizes an electrostatic latent image formed on a latent image carrier using this developer.

2. Description of the Related Art A developing device of the above type used in an image forming apparatus such as a copying machine or a printer is well known. In this type of developing device, a powdery developer is stored in the developing device, and the developer is carried to a developing area by a developer carrying member brought to a developing position to form an electrostatic latent image. . At that time, the developer existing in the developing area, especially the toner, may be scattered, but if left unattended, the scattered developer adheres to various elements in the image forming apparatus, especially optical elements, and There is a risk of degrading the function or contaminating the area around the device.

In order to prevent this inconvenience, a method may be considered in which a seal member that comes into contact with the latent image carrier is supported by the developing unit to prevent the developer from scattering. However, when the seal member is supported by the rotating developing unit, the seal member comes into sliding contact with the latent image carrier when the unit rotates, so that if the seal member is made of a hard material, the developing unit rotates during rotation. The seal member that is in sliding contact with the latent image carrier may damage the latent image carrier. Therefore, the seal member needs to be made of a soft material that does not damage the latent image carrier. However, if such a seal member is used, the pressure at which the seal member contacts the latent image carrier is reduced during normal developing operation. As a result, the sealing property itself deteriorates, and the effect of preventing the developer from scattering is impaired.

OBJECT The present invention is based on the above-mentioned novel recognition, and an object of the present invention is to provide a developing device of the type described at the beginning that can effectively prevent the scattering of the developer.

In order to achieve the above-mentioned object, the present invention is provided with a first seal member and a second seal member for preventing the scattering of the developer existing in the developing area, the first seal member being provided in the developing device and the developing device. A rotary developing device is proposed which is configured so as to be brought into and out of contact with the latent image carrier by the rotation of the unit, and the second seal member is always brought into contact with the latent image carrier.

Embodiment An embodiment in which the present invention is applied to a rotary developing device for a multicolor copying machine will be described below with reference to the drawings.

In order to understand the present invention, first, the overall structure of the developing device shown and its operation will be clarified.

In FIGS. 1 and 2, reference numeral 1 denotes a developing unit of a developing device which is supported by an image forming apparatus main body (multicolor copying machine main body in this example) 2 so as to be freely drawn out. FIG. 2 shows a state in which the developing unit 1 is pulled out from the copying machine main body 2.
In the developing unit 1, a proper number of three developing devices 3, 3R, 3B are integrally incorporated in the illustrated example.
The developer chambers 4, 4R, 4B of 3R, 3B include three partition walls 6, 6R, 6B of a casing member 5 made of a non-magnetic material such as aluminum, and two end walls 7, 8 fixed to both ends thereof. It is divided by (FIG. 2). The developer chambers 4, 4R, 4B have different colors of developer 9, 9R,
9B is accommodated, and in this example, each of these developers is black, red, and blue. Cyan, yellow and magenta toner developers are stored in each developer chamber,
It is also possible to configure so as to form a full-color image, or it is possible to store developers of the same color in each developer chamber and selectively use them. Although a one-component developer containing no carrier can be used as the developer, a two-component developer containing a carrier and a toner, at least a part of which is a magnetic material, is used in the example of the figure. Is used.

Although the first to third developing devices 3, 3R, 3B are arranged radially around the central axis O of the developing unit 1, since the structures are all the same, the description will be mainly given with reference to the first The configuration of the developing device 3 is clarified, and with respect to each part of the other developing devices 3R and 3B, the reference numerals assigned to the respective elements of the first developing device 3 are denoted by R and B, and the duplicate description thereof is omitted. To do.

As will be described later, the developing unit 1 is rotatably supported about its central axis O, and each developing device (more accurately, its developing roller) rotates to a predetermined developing position to perform a developing operation. FIG. 1 shows a state in which the first developing device 3 occupies the developing position.

In FIG. 1, a developer transport member provided in the first developing device 3, the developing roller 10 in the illustrated example, has two partition walls 6, 6.
Partial exposure from the opening formed by R (see also FIG. 2) and predetermined development on the latent image carrier (photosensitive drum 11 in this example) rotatably supported by the copying machine main body 2 Occupy a position. It is well known that a latent image carrier composed of a photosensitive belt may be used, or a latent image carrier composed of a dielectric belt or a dielectric drum may be used depending on the model of the image forming apparatus. The developing roller 10 is positioned parallel to the photoconductor drum 11 with a predetermined minute gap.

Inside the developing roller 10, as shown in FIG. 1, a magnet 21 having an S pole and an N pole is fixedly arranged on the casing member 5 of the developing unit 1. As a result, when the developing roller 10 brought to a predetermined developing position with respect to the photosensitive drum 11 is rotationally driven in the counterclockwise direction in FIG. 1, the impeller 16 rotationally driven in the counterclockwise direction causes stirring and charging. The developer 9 supplied to the developing roller 10 while being carried is carried on the surface of the developing roller 10 by the magnetic force of the magnet 21 and is conveyed counterclockwise. The transported developer is the casing member 5.
A predetermined amount of the developer, which has been scraped by the doctor blade 22 fixed to the blade 22, is sent to the photosensitive drum 11 with its layer thickness regulated.

On the other hand, the photosensitive drum 11 is rotationally driven in the clockwise direction in FIG. 1, and an electrostatic latent image corresponding to an original (not shown) image is known by itself on its surface by charging / exposure means not shown. Is formed. This latent image is a developing area D where the photosensitive drum 11 and the developing roller 10 face each other.
When the temperature reaches, the charged toner in the developer, which is also conveyed to the area D, electrostatically transfers to the electrostatic latent image, and the latent image is visualized. The visible image is transferred onto a transfer paper (not shown) by a transfer device (not shown), and the transferred visible image is fixed by a fixing device (not shown). The developer that has passed through the developing area D is returned to the inside of the developer chamber 4 again, mixed with other developers in this chamber, and used again.

As the developing operation described above progresses, the toner in each developer chamber is sequentially consumed, so that the toner supply device 4 shown in FIG.
4,44R, 44B for each developer chamber 4,4R, 4B
Is replenished with toner. In FIG. 1, only the position of the toner supply device is shown by a chain line. Further, the developing unit 1 in this example is carried on a unit carrier as described below.

That is, as shown in FIGS. 1 and 2, the slider 62 is pulled out toward the front side (direction of arrow G in FIG. 2) of the copying machine main body 2 by a slide guide device 61 known per se, or conversely, at the back side. The copying machine main body 2 is slidably supported so as to be pushed in (also in the direction of the arrow H), and the developing unit storage base 63 is supported by the slider 62.

The slider 62 has front and rear support plates 65 and a substrate 66 connecting these to each other. The first and third support plates 65 extend in parallel to each other in the sliding direction of the slider 62.
The respective end portions of the connecting rods 67, 68, 69 of are fixed to each other, and the connecting rods 67, 68, 69 of the both support plates 6
5 is reinforced.

The storage base 63 also has a front side support arm 70 and a back side support arm 71, and a lower cover 72 is fixed to these arms 70, 71. Further, the storage table 63 has a pivot pin 7
The upper cover 75 is rotatably pivoted in the direction of arrow J via 3, and the upper cover 75 is normally held in the closed position shown in FIG. 1 (the position indicated by the chain line in FIG. 2).

On the other hand, the outer peripheral surfaces of the front end wall 7 and the rear end wall 8 of the developing unit 1 are both formed in a cylindrical shape, and the upper portions 70a, 71a of both supporting arms 70, 71 of the storage base 63 are the end walls 7, It is formed in an arc shape that fits the outer peripheral surface of 8. The support arm 70 on the front side has two support rollers 76, 77.
Is rotatably supported, and the outer peripheral surface of the front end wall 7 of the developing unit 1 is supported by these supporting rollers 76 and 77.
Supported in some places. When the slider 62 is pulled out from the main body 2 of the copying machine, the cylindrical end wall 8 on the back side of the developing unit 1 is rotatably supported on the arc-shaped upper portion 71a of the support arm 71 on the back side. The developing unit 1 can rotate around its central axis O while being supported by the storage table 63.

When the developing unit 1 is set, it is sufficient to push the slider 62 in the direction of arrow H (FIG. 2) while holding the developing unit 1 in the storage base 63. When this pushing operation is completed, The end wall 8 on the side,
A positioning pin 78 protruding from the central axis O of the unit 1 is rotatably fitted in a positioning hole (also not shown) formed in a side plate (not shown) on the back side of the copying machine body 2. As a result, the back side of the developing unit 1 is positioned with respect to the copying machine main body 2, and thus the photosensitive drum 11 supported at a predetermined position of the main body 2. The front end wall 7 has two support rollers 76, 7 even after the developing unit 1 is set.
Although it is rotatably supported by 7, the pin 82 protruding from the support arm 70 on the front side of the storage base 63 is fitted into the positioning hole formed in the front side plate of the copying machine main body 2 or the pin. It fits in the center hole of the attached receiving member 85, and the front side of the storage table 63 is positioned with respect to the photosensitive drum 11.

When a visible image is formed by the red or blue developer housed in the second or third developing device 3R, 3B, the developing unit 1 set at a predetermined position in the main body of the copying machine is rotated by the motor 88.
Is driven to rotate clockwise, for example, in FIG. 1 via a transmission device, and the developing roller 10R or 10B of the second or third developing device 3R, 3B is moved to the first developing device 3 shown in FIG.
The developing roller 10 is brought to the developing position where the developing roller 10 is located and the developing operation is performed.

Although the illustrated developing device is configured as described above, when the developing operation described above is performed by the developing device, the developer existing in the developing area D conveyed by the developing roller 10, particularly the toner, may be scattered to some extent. It is unavoidable.
However, if this is left unattended, the developer scatters in all directions, as described above, and adheres to various elements inside the copier body, especially optical elements, degrading the function of the copier, or causing the peripheral area of the copier. There is a risk of soiling. Therefore, in order to prevent the developer from scattering, as shown in FIG. 1, the casing member 5 of the developing unit 1 has, for example, an elastic film made of synthetic resin, a sheet (polyester film, polyurethane rubber sheet, etc.), or The root portion of the first seal member 93 made of a flexible brush or the like is fixed, and the developing roller 1
When 0 is at the developing position, the tip of the first seal member 93 comes into contact with the surface of the photosensitive drum upstream of the developing area D, and the developer is prevented from scattering above the seal member 93. ing. Developing devices 3R and 3B other than the developing device 3
Similarly, the first seal members 93R and 93B attached to the casing member 5 of the developing unit 1 are also provided, and the developing rollers 10R and 1R of these developing units 3R and 3B are provided.
When 0B is brought to the developing position, the respective first seal members 93R and 93B come into contact with the surface of the photosensitive drum 11 just like the first seal member 93 shown in FIG. The scattering of the developer existing in the area D is prevented. In this way, the respective first seal members 93, 93R, 93B are configured so as to be able to come into contact with and separate from the photoconductor 11.

By the way, when the developing unit 1 is rotated by the drive motor 88 as described above in order to select the developing device to be used, the first sealing members 93, 93R, 93B also rotate together with the unit 1, so these sealing members are It makes sliding contact with the peripheral surface of the photosensitive drum 11. Therefore, as described above, if the first seal member is made of a hard material, the member may damage the surface of the photosensitive drum. Therefore, the first seal members 93, 93R, 93B must be made of a soft material that does not scratch the drum surface. However, if these seal members are made of such a soft material, the pressure at which the seal members 93, 93R, 93B contact the photoconductor drum 11 during a normal developing operation is lowered, which inevitably reduces the sealing function.

Therefore, in the illustrated configuration according to the present invention, the second seal member 94 is supported at the tip of the upper cover 75, and the tip thereof is in contact with the peripheral surface of the photosensitive drum 11. That is, when the first developing roller 10 is brought to the developing position, the developing roller or the developing region D is formed by the two sealing members 93 and 94 belonging to the developing device. The area around is sealed. The same applies to other developing devices. The second seal member is always in contact with the photosensitive drum 11 during a normal developing operation.

Individual seal members 93, 93R, 93B as described above;
Even if 94 is soft and its sealing function is slightly low, a double sealing provides a reliable sealing effect.

In addition, the first seal member 9 that is in contact with the photosensitive drum 11
Since 3,93R or 93B and the second seal member 94 seal the developer in the vicinity of the developing area D, the sealing function can be effectively enhanced. In particular, as in this example, the developing units 3, 3R, and 3B contain different color developers, and the covers 7 are provided above and below the developing unit 1.
In the case where Nos. 5 and 72 are provided, the first seal member prevents the developer in the developing area from scattering, thereby effectively mixing the colors of the toners between the developing devices caused by the floating of the developer (toner) in the cover. The second seal member 94 can prevent the developer from scattering outside the cover.

The second seal member 94 can also be composed of, for example, a synthetic resin elastic film, a sheet, a flexible brush, or the like, and the second seal member 94 can be provided at an appropriate place other than the upper cover 75, for example, in the copying machine main body 2. May be mounted on the side.

According to the present invention, when the developer transport member is a member other than the developing roller, for example, a transport belt, or the developer transport member does not rotate, the magnet provided therein rotates, or both of them rotate. It is needless to say that the present invention can be applied to an apparatus, a developing device using a non-magnetic developer, and also to a developing device of an image forming apparatus such as a printer other than a copying machine.

Effect According to the present invention, since the developer is sealed by the plurality of sealing members, the sealing performance can be improved even when each sealing member is made of a soft material.

[Brief description of drawings]

FIG. 1 is a sectional view of the developing device, and FIG. 2 is a perspective view showing a state in which the developing unit is pulled out from the main body of the copying machine and the unit is removed from the storage base. 1 ... Developing unit 3,3R, 3B ... Developer 9,9R, 9B ... Developer 93,93R, 93B ... First seal member 94 ... Second seal member D ... Development area

Continuation of the front page (56) Reference JP-A-58-134663 (JP, A) JP-A-58-172660 (JP, A) JP-A-61-205965 (JP, A) JP-A-61-113078 (JP , A) JP 61-77875 (JP, A) JP 61-59372 (JP, A) JP 61-124986 (JP, A) JP 60-239770 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A developer transporting member provided in the developing device, comprising a developing unit having a developer accommodating a developer and rotatably supported facing the latent image carrier. The developing unit is rotated to bring it to the developing position, and the developer conveying member brought to the developing position conveys the developer to a developing area between the member and the latent image carrier, and uses the developer to form a latent image. In a rotary developing device for visualizing an electrostatic latent image formed on a carrier, a first seal member and a second seal member for preventing scattering of a developer existing in a developing area are provided, and The seal member is provided on the developing device and is configured to be contactable with and separated from the latent image carrier by the rotation of the developing unit, and the second seal member is configured to always contact the latent image carrier. Rotating type developing device.