JPS61205965A - Moving type developing device - Google Patents

Abstract

PURPOSE:To decrease scattering of toner to the inside of a device by providing a dust-proof seal member so as to cover the opening part of a developing sleeve, withdrawing it to the inside at the time of a movement, and advancing it to the outside at the time of development. CONSTITUTION:In a rotary station 102 of a moving type developing device 101, plural pieces of developing devices 103 are provided. Also, on its opening part, dust-proof seal members 120, 121 are provided. On the members 120, 121, guide members 120a, 121a are provided protrusively on the tip, and the other end is supported so as to be turnable by axes 122, 123. The members 120, 121 are withdrawn into the station when the station 102 is rotated and do not contact the outside peripheral surface of a drum 22. At the time of development, the members 120a, 121a abuts on the outside peripheral surface of the drum 22, and a gap between said drum and the drum 22 can be kept very small. Also, seal members 130, 131 are provided, a gap between the members 120, 121 and upper and lower cover members 109, 110 is filled up.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a mobile developing device, particularly to a developing device for color copying and color recording devices such as copying machines and laser beam printers, and more specifically to a developing device for color copying and color recording devices such as copying machines and laser beam printers. The present invention relates to an improved mobile developing device that can prevent carrier and toner from scattering.

(rl) Prior Art Conventionally, a color image forming apparatus (hereinafter simply referred to as a copying apparatus)
The developing device 1, as shown in FIG.

It is constructed by juxtaposing developing units 4, 5, and 6.7 containing toners of magenta M, cyan C, and black Bk.
When an electrostatic latent image corresponding to each color is sequentially formed on the photoreceptor F ram 2 constituting the image carrier, development is performed by a developing device for each color, and the developed toner image of each color is The images are sequentially transferred in a superimposed manner onto a transfer material, that is, copy paper, on a transfer drum 10'' and then fixed to form a color image. In such a side-by-side type developing device 1, the four developing units 4 to 7 arranged side by side occupy a large proportion around the photosensitive drum 2, and the transfer drum io arranged around the photosensitive drum 2 occupies a large proportion. , cleaner ii, secondary charger 12, optical system 13, etc., the space for arranging other image forming units such as , cleaner ii, secondary charger 12, optical system 13, etc. becomes narrow, so it is necessary to secure space for appropriately arranging these other image forming units around photoreceptor drum 2. A method has been adopted in which the diameter of the photoreceptor drum is increased. As a result, the size of the copying device itself inevitably became larger, which was one of the reasons for the increase in the cost of the copying device. Therefore, the arrangement of the developing units 4 to 7 with respect to the photoreceptor drum 2 was devised to reduce the diameter of the photoreceptor drum 2. In order to reduce the size of the main body of the copying apparatus and thereby reduce the cost, a rotary moving type developing device, which will be described hereinafter, has been proposed.

Rotating moving type developing device v! At t15, as shown in FIG. 6, yellow Y, magenta M,
4 containing each color toner of cyan C and black Bk
It is composed of developing devices 17, 18, 19° 20 arranged radially, and when an electrostatic latent image corresponding to each color is sequentially formed on the photoreceptor drum 22, each developing device is arranged in a radial manner. It is rotated to a position facing the photosensitive drum 22 to perform development, and the developed toner images of each color are sequentially superimposed and transferred onto a transfer material, that is, copy paper, on the transfer drum 23, so that a color image is formed. It has become. When each of the developing devices is rotated to a developing position facing the photosensitive drum 22, the toner stored in the developing device is transferred onto the photosensitive drum 22 and applied thereto, as shown in FIG. As shown in an enlarged view, a magnetic brush type developing sleeve 24
is arranged so as to protrude slightly and face the photosensitive drum 22 through the opening 23, and the developing sleeve 24
When the toner is transferred toward the surface of the photoreceptor drum 22 by the rotation of the photoreceptor drum 22, or when the toner is collected into the developing device again without being transferred to the surface of the photoreceptor drum 22, the toner is transferred to the copying machine. A cover member 25 is installed to cover both sides of the protrusion of the developing sleeve 22 to prevent it from scattering inside.
, 26 are fixedly installed. In this way, by configuring the developing device 15 as a rotationally movable type, as shown in FIG.
The cleaner 1 can be used without increasing the outer diameter of the photoreceptor drum 22.
8. Other image forming units such as the charger 29 and the optical system 30 can be arranged with plenty of room.

(C) Problems to be Solved by the Invention By the way, in the above-mentioned rotary movement type developing device 15,
In order for the rotation station 16 to be able to rotate, the positions of the tips of the cover members 25 and 26 facing the photoreceptor drum 22 are set inside the rotational outer diameter of the rotation station 16, as clearly shown in FIG. (If placed on the outside, it would come into contact with the photoreceptor drum and damage it when rotating). Therefore, in the rotationally movable developing device 15, a gap 32, 33 is inevitably formed between the tip of the cover member 25, 26 and the photoreceptor drum 22, and the rotation of the photoreceptor drum 22 and the developing sleeve 24 is During operation, the toner and toner carrier are scattered from the gaps 32 and 33, and the interior of the copying apparatus is contaminated with the scattered toner.

In other words, in such a developing device, since the cover member does not come close to the photoreceptor drum (0.5 to lll11), the dustproof effect during development is low, and toner and carrier scatter around the developing device, especially upstream and downstream of the sleeve. This was a problem as it caused dirt inside the machine and fogged images.

(d) Means for Solving the Problem The present invention aims to reduce the above-mentioned problem, that is, the scattering of carrier, toner, etc. during development etc. in a mobile developing device. A dustproof seal member is provided to cover the opening of the developing sleeve in
The dust-proof seal member is moved inward during movement, and moved outward during development, and is positioned close to the outer peripheral surface of the photoreceptor drum. .

(Book) Operation By employing the above means, the developing device can be moved to face the photosensitive drum without the dust-proof sealing member colliding with or coming into contact with the surface of the photosensitive drum, and during development,
By bringing the dust-proof sealing member closer to the surface of the photoreceptor drum, the gap therebetween is reduced as much as possible, and toner is largely prevented from scattering into the copying device during development and the like.

(f) Example Hereinafter, an example embodying the present invention will be described along with the drawings.

FIG. 1 shows a first embodiment of the present invention, in which a plurality of developing devices (among them, only developing device 103 is shown) are arranged in a rotating station 102 of a rotary moving type developing device 101. In the developing device 103, a developing device 1 is arranged in a direction facing the photoreceptor drum 22 during development.
．． A developing sleeve 106 constituting a 4-developing toner feeding rotary body is provided so as to slightly protrude from the photoconductor drum 22 through an opening 105 and rotate in the direction of the arrow. Yellow, magenta, cyan, and black color toners 107 stored in the container are transferred to the surface of the photosensitive drum 22. Upper and lower cover members 109 and 110 are provided on the front surface of the developing device 103 so as to cover both upper and lower sides of the opening portion 105 of the protruding developing sleeve 106. In addition, this cover 109°110
The tip of the photoreceptor drum 22 is further away from the photoreceptor drum 22 compared to that shown in FIG. 7 (conventional example).

Furthermore, 120 and 121 are upper and lower dust-proof seal members, and guide members 120a and 121a are provided protruding from their tips, one end is rotatably fixed and the other end (tip) is movable. In other words.

The dust-proof seal members 120 and 121 are connected to the support arm 124 at the rear end.
125, and the support arms 124, 125 are pivotably supported by shafts 122, 123. Note that the guide member 120a.

121a are formed at both ends as shown in FIG.
They face both ends of the photoreceptor drum 22.

As shown in FIG. 1, the guide members 120a and 121a are in contact with the outer circumferential surface of the photoreceptor drum 22 to maintain a small gap between the tips of the dustproof seal members 120 and 121 and the photoreceptor drum 22. can.

130.131 is a sealing member, dust-proof sealing member 120
, 121 and the upper and lower cover members 109° and 110 are preferably made of an elastic material, and press the dustproof seal members 120° and 121 toward the photoreceptor drum 22 side.

Next, the operation of the above configuration will be explained.

A developing device corresponding to each color (Y, M, C, Bk) is selected by rotation of the rotation station 102, in which an electrostatic latent image corresponding to each color (Y, M, C, Bk) is formed on the photoreceptor drum 22.

Then, the rotation station 102 rotates to the left from the state shown in FIG. As the rotation station 102 rotates, the developing device 103 and the dust-proof seal members 120 and 121 also move, and the guide member 121a of the dust-proof seal member 121 on the downstream side is gradually pressed by the outer periphery of the photoreceptor drum 22. Due to this suppression, the dustproof seal member 121 rotates to the left (or bends) via the shaft 123 and retreats. Therefore, despite the rotation of the rotation station 102, the dustproof seal member 121
The tip of the photosensitive drum 22 does not come into contact with the outer periphery of the photosensitive drum 22 .

As the dust-proof seal member 121 passes through the outer periphery of the photoreceptor drum 22, the dust-proof seal member 121 is restored from its left-handed (bent) state to its original state.

On the other hand, the dust-proof seal members of other developing devices that enter the developing station instead of developing device 103 in FIG.
20) operates in the same manner as described above, passes through the photosensitive drum 22, and returns to its original state after passing through the development position. If the developing unit is selected, the rotating station 102 stops at the developing position, the developing sleeve magnet rotates, and development is performed.

Since the configuration of the first embodiment is northward, when the rotation station 102 is rotated, the dustproof seal m material 12
0 and 121 are stored inside the rotation outer diameter of the rotation station 102. Therefore, when the one-rotation station 102 rotates, the dustproof seal members 120 and 121 do not collide with or come into contact with the surface of the photoreceptor drum 22, and the rotation station 102 is rotated smoothly. Furthermore, during development, as shown in FIG.
2 to prevent the toner 107 from scattering during development.

FIG. 3 shows a modification of the dust-proof seal member. The dust-proof seal member 220 (221) has a tip portion 220b (221b) made of a hard material so as not to bend, and a thin stainless steel,
It is composed of a flexible portion 220c (221c) made of an elastic flexible material such as phosphor bronze or mylar. If this dustproof member 220 is used, it is possible to see through the seal members 130 and 131 shown in FIG. That is, this is because the guide member 220a (221a) at the tip is pressed against the photosensitive drum 22 by the elastic force of the in4 portion of the guide member 220a (221a).

FIG. 4 shows yet another modification of the dust-proof seal member, and the difference from FIG. 2 is that the dust-proof seal member has a two-stage slit-like structure. The slit-like structure has the effect of further increasing dustproofness.

In addition, the above 2. The operation of the third embodiment can be easily inferred from the operation of the first embodiment, so a description thereof will be omitted below.

Further, although the above embodiments have been described with respect to a color copying apparatus using a photosensitive drum, it is of course applicable to an apparatus using a dielectric drum, and is not limited to a color copying apparatus, but can also be applied to a color recording apparatus. Of course, it can also be applied. Furthermore, although a pair of dust-proof sealing members are provided so as to cover both sides of the opening, it goes without saying that the present invention also includes a case in which the dust-proof sealing members are provided only on one side of the opening, for example, on the lower side.

In addition, in the above explanation, the dustproof seal member is placed against the edge of the photoreceptor drum, but an appropriate regulating member is provided in or near the developing device, and a guide member is brought into contact with this, so that the outer periphery of the photoreceptor drum is Alternatively, the position of the dustproof seal member may be shown.

(g) As described in detail, according to the present invention, in a mobile developing device, a dustproof seal member is provided to cover the opening of the developing toner feeding rotary body in each developing device disposed therein. The dust-proof sealing member is arranged so that when moving, the dust-proof seal member is retracted inward, and during development, the dust-proof seal member is advanced to the outside and positioned close to the outer circumferential surface of the image carrier (photoreceptor drum). Therefore, when the image carrier is moved to selectively face the developing device containing appropriate color toner, the dust-proof seal member can smoothly move without colliding with or coming into contact with the image carrier. will be moved to During development, by bringing the dust-proof seal member close to the surface of the image carrier, the gap where toner is scattered is reduced as much as possible, thereby effectively reducing the scattering of toner into the image forming apparatus. , it becomes possible to maintain the inside of the device clean.

[Brief explanation of drawings]

FIG. 1 is a partial vertical sectional view showing a mobile developing device according to a first embodiment of the present invention, FIG. 2 is a perspective view of the dustproof seal member shown in FIG. 1, and FIG. 3 is a modification of the dustproof seal member. FIG. 4 is a perspective view showing yet another modification of the dust-proof seal member; FIG. 5 is a schematic configuration diagram showing image formation in a color copying apparatus having a conventional side-by-side developing device; The figure is a schematic configuration diagram showing an image forming section of a rotary moving type developing device which is the basis of the present invention, and FIG. 7 is an enlarged configuration diagram of a part of the image forming section shown in FIG. 6. 101 --- One-rotation moving type developing device 102 --- One-rotation stillage 22 --- Image carrier (photosensitive drum) 106 ---
--Developing toner feeding rotary body (developing sleeve)

Claims (4)

[Claims] (1) In a mobile developing device that includes an electrostatic latent image carrier and a plurality of developing units, and in which the developing units sequentially face the electrostatic latent image carrier and perform development, a device provided at the opening of the developing unit. a dustproof sealing member whose tip is movable; and a regulating member that comes into contact with an end of the dustproof sealing member to regulate a gap between the tip of the dustproof sealing member and the electrostatic latent image carrier, The tip of the dust-proof seal member is close to the electrostatic latent image carrier at the developing position, and the tip of the dust-proof seal member is regulated so as not to come into contact with the electrostatic latent image carrier when the developing device is moved. A mobile developing device. (2) The mobile developing device according to claim (1), wherein the regulating members are at both ends of the electrostatic latent image carrier. (3) A mobile developing device according to claim (1) or (2), in which a plurality of developing devices are provided on a certain circumference and rotate and move on this circumference. (4) Claims (1) to (3) characterized in that the dustproof seal member has a multi-stage slit-like configuration.
) The mobile developing device according to any one of the items.