JPS59148074A - Dry type developing device - Google Patents

Abstract

PURPOSE:To prevent toner from scattering and to obtain a stable, excellent recording image by providing a toner scatter preventing body (flexible material) to the gap part between a developing unit and a photosensitive body cassette. CONSTITUTION:A holding member 118 is attached onto a doctor blade 116 lengthwise. The holding member is equipped with the toner scatter preventing body at its external surface part which extends perpendicularly to cover the gap formed between the photosensitive body 16 and a developing sleeve 108. When nap of toner formed by a magnetic brush sticks to the surface of the photosensitive body, some of the toner 106 scatters, but falls on the lower part of a casing 102 by the holding member and toner scatter preventing body. This preventing body (made of rubber, sponge, etc.) is arranged slanting at an acute angle to the perpendicular direction to prevent the photosensitive body from being damaged when the photosensitive cassette is attached.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a developing device for a recording device such as a printer during copying, and more particularly to an improvement of a dry developing device that develops a latent image using a dry developer. It is related to.

As conventional dry developing devices, as is well known, magnetic brush type, cascade type, fur brush type, spray type, etc. have been proposed and put into practical use. For example, the magnetic brush type has a configuration as shown in FIGS. 1 to 3. In the example shown in Figure 1,
A developing unit 12 is provided on the right end side of the cassette receiver 10, and an example of the configuration of this developing unit 12 is shown in FIGS. 2 and 3. The photoreceptor cassette 14 includes a belt-like or sheet-like photoreceptor 16 as a latent image carrier.
is suspended between left and right sets of roller mechanisms 18 and 20, and a driving gear 22 is connected to the roller mechanisms 20. The photoreceptor cassette 14 is mounted on the cassette receiver 10 from the direction of arrow FA in the figure, and a part of the surface of the photoreceptor 16 faces the developer 12. At this time, the bearings 19 and 21 of the cassette 14 engage with the positioning groove 11 and the regulating groove 13 of the cassette receiver IO, respectively, and an appropriate developing gap is secured between the photoreceptor 16 and the sleeve 32.

Therefore, an electrostatic latent image is formed on the surface of the photoreceptor 16 by a means not shown, and a developing unit,
A developer is applied to the plate 12 to perform development.

FIGS. 2 and 3 show an example of the structure of the developing unit 12, and a developing sleeve 32 is rotatably provided inside the casing 30 at the bottom thereof. An agitator 36 is provided at the top of the casing 30 to agitate the developer (hereinafter simply referred to as "toner") 34 contained therein. The toner 34 is introduced into the casing 30 through a lid portion that can be opened and closed in the direction of arrow FB shown in FIG. 1, and an increase or decrease in the amount is detected by a sensor 38.

Further, a doctor blade 40 is provided at a position exposed from the casing 30 of the developing sleeve 32, and its acute-angled tip faces the surface of the developing sleeve 32 while maintaining a predetermined distance. . Developing sleeve 32
A suitable number of magnets 42 are provided inside the magnet 4.
The toner 34 is attached to the surface of the developing sleeve 32 by the magnetic force generated by the toner 2 . The amount of adhered toner 34 is appropriately regulated by a doctor blade 40.
Furthermore, it adheres onto the photoreceptor 16.

In this developing operation, the speed of the photoreceptor 16 is
The toner 34 is transported at a relative speed of 7 to 7 times and is fused or collided with the photoreceptor 16. Unfortunately, upon contact, there is a phenomenon in which the toner 34 scatters inside the device. If this scattered toner 34 adheres to other parts of the apparatus such as the chart, optical system, etc., it causes uneven charging and uneven exposure. That will happen.

Furthermore, if the toner 34 adheres to the power supply electrical equipment, drive transmission unit, or other mechanical parts due to the influence of airflow, there is a problem that electrical and mechanical malfunctions and troubles may occur.

In order to prevent such inconvenience, conventionally, as shown in FIG. 2, a toner scattering prevention body 44 having an oval-shaped cross section is provided with respect to the doctor blade 40 so as to cover the exposed portion of the developing sleeve 32. It is provided. In this example, although the photoreceptor cassette 14 can be easily attached and detached, scattering of the toner 3-4 is not sufficiently prevented. In the example shown in FIG. 3, the tip of the toner scattering prevention member 46 extends in the direction of the photoreceptor 16, and although the scattering of the toner 34 is well prevented, when the photoreceptor cassette 14 is attached or removed, the toner It is necessary to attach and detach the scattering prevention body 46.

OBJECTS The present invention has been made in view of the above points, and an object of the present invention is to provide a dry developing device that can effectively prevent toner scattering while reducing interference with the actions or functions of other components. That purpose.

Configuration The configuration of the present invention will be described below based on examples.

FIGS. 4 and 5 show a first embodiment of a dry type developing device according to the present invention. FIG. 4 is a partially cutaway perspective view of the main part, and FIG. 5 is a side view seen from the direction of arrow V in FIG. 4. These figures 4 and 5
In the figure, the developing unit 100 includes a casing 102
The upper part is box-shaped, and the lower part is funnel-shaped.
/? formed into a shape. A lid 104 is provided on the top of the casing 102 so that it can be opened and closed.
4, the toner 106 can be replenished. At the lower part of the casing 102, the developing sleeve 1 is maintained at an appropriate distance from the inner wall of the casing 102.
08 is rotatably provided. An agitator 110 for stirring the toner 106 is provided above the casing 102, and a sensor 1 for detecting an increase or decrease in the toner 106 is provided at an appropriate position outside the casing 102.
12 are provided.

On the other hand, an opening 1 is provided in the lower side of the casing 102.
14 is provided, and a portion of the developing sleeve 108 is exposed from this opening 114. A doctor blade 116 is provided at a portion of the end of the casing 102 constituting the outer peripheral end of the opening 114 that is close to the surface of the developing sleeve 108.
It faces the surface of the developing sleeve 1080 while maintaining a predetermined distance therebetween. The doctor blade 116 is provided along the length of the developing sleeve 108, and a holding member 118 is attached onto the doctor blade 116 by a screw mechanism 120 (not shown in FIG. 4). This holding member 118 is provided along the longitudinal direction of the doctor blade 1'l16, and has a cross-sectional shape that is bent in a hook shape along the doctor blade 116 and extends in the vertical direction. There is. A toner scattering prevention material 122 is provided on the vertically extending outer surface of the holding member 118 in the longitudinal direction.
is attached by appropriate means. The photoreceptor force set 14 explained in FIG. 1 is installed from the front left side in FIG. 4, that is, from the left side in FIG. A toner scattering prevention material 122 is interposed.

The holding member 118 is made of a non-magnetic metal such as aluminum, brass, or resin, and the toner scattering prevention material 122 is made of a highly flexible material such as a comb, a comb, a flocked brush, or the like. .

An appropriate number of magnets 124 are inserted into the developing sleeve 108 along its outer periphery in the longitudinal direction. The polarities of these magnets 124 are arranged to be opposite to each other, and brush-like spikes of toner 106 are formed on the outer surface of the developing sleeve 108 by lines of magnetic force generated by the magnets 124 .

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

First, a latent image is formed on the surface of the photoreceptor 16 by known means. The photoreceptor 16 on which the latent image has been formed is sequentially opposed to the developing sleeve 1.08 by rotation of the roller mechanism 18.20 (see FIG. 1). - On the other hand, in response to the movement of the photoreceptor 16, the developing sleeve 108
is also rotationally driven, and spikes of toner 106 are formed on its outer surface. The height of this spike of toner 106 is regulated by a doctor blade 116. Further, the spikes of toner 106 are applied to the photoreceptor 16 as the developing sleeve 108 rotates.
The latent image contacts or collides with the surface of the photoreceptor 16 and adheres to the surface of the photoreceptor 16 in correspondence with the latent image. At this time, some of the toner 106 tries to scatter, but is prevented from scattering by the aforementioned holding member 118 or toner scatter prevention material 122, and falls below the casing 102.

On the other hand, in this embodiment, the toner scattering prevention material 122
is interposed between the photoreceptor cassette 14 and the developing sleeve 108, so the photoreceptor cassette 14 can be easily attached and removed.

Next, another embodiment of the dry developing apparatus according to the present invention will be described. Note that the same reference numerals are used for the same components as in the above-described embodiment, and the explanation thereof will be omitted.

FIG. 6 shows a developing unit 200 which is a second embodiment of the present invention. In this embodiment, the tip portion of the holding member 218 fixed to the doctor blade 116 by the screw mechanism 220 is θA with respect to the vertical direction.
Therefore, the toner scattering prevention material 222 also has an angle of θA with respect to the vertical direction. Therefore, compared to the embodiments shown in FIGS. 4 and 5, the toner scattering prevention material 222 is configured to cover a portion of the photoreceptor cassette 14.

The closer the tip of the toner scattering prevention material 222 is to the photoreceptor 16, the greater the effect of preventing the toner 106 from scattering, and the distance therebetween is preferably 0.5 mm or less or a slight contact.

In this embodiment, when the photoreceptor cassette 14 is mounted, the photoreceptor cassette 14 moves in the direction of the inclination of the toner scattering prevention material 222, so that the contact between the photoreceptor 16 and the toner scattering prevention material 222 is prevented. It is extremely smooth and will not damage the photoreceptor 16.

On the other hand, when the photoreceptor cassette 14 is attached or detached, the photoreceptor cassette 14 moves in the direction opposite to the direction of the inclination of the toner scatter prevention material 222, so the contact between the photoreceptor 16 and the toner scatter prevention material 222 is not necessarily smooth. No, photoreceptor 1
6. However, in general, the photoreceptor force may be damaged.

When the photoconductor 14 is attached and detached, it is time to replace the photoconductor 16.
Actually, there is no inconvenience at all.

FIG. 7 shows a third embodiment of the present invention, a phenomenon unit 300. In this example,
The tip of the holding member 318 fixed to the doctor blade 116 by the rotation mechanism 320 has an angle θB of approximately 90° with respect to the vertical direction, and therefore the toner scattering prevention material 322 also has an angle θB of approximately 90° with respect to the vertical direction. It has an angle of θB.

In this embodiment, if the toner scattering prevention material 322 is extended too long in the direction of the photoconductor cassette 14, the photoconductor 16 will be seriously damaged when the photoconductor force center 140 is attached or removed. It is necessary to consider the location of the parts.

In the above embodiment, the toner scattering prevention material and the holding member are attached to the doctor blade part, but they may also be attached to the upper part of the casing. rivet means,
Adhesion/pressure bonding, fitting, suspension, or other means may be used.

Further, in any of the embodiments, the toner scattering prevention body is composed of a toner scattering prevention material and a holding member, but it is also possible to construct these integrally with a comb, plastic, etc. .

In particular, with regard to the shape and arrangement of the toner scattering prevention body, it is preferable to take into consideration the relationship between the air flow within the apparatus and toner scattering, the moving speed of the photoreceptor and the photosensitive sleeve, or the relative speed thereof.

Although the above embodiments show the case where the photoreceptor is of a cassette type, photoreceptors generally have a finite lifespan and can be attached and detached not only in the cassette type. Therefore, the present invention can be effectively applied to recording apparatuses using other types, for example, drum-shaped photoreceptors.

Furthermore, the present invention is basically applicable not only to the magnetic brush type but also to other types of developing devices.

Effects As described above, according to the present invention, a toner scattering prevention member is provided in the gap between the developing unit and the photoreceptor cassette,
In addition, since at least the portion of the preventive member close to the photoreceptor is formed of a flexible material, it is possible to effectively prevent toner scattering and obtain stable and good recorded images over a long period of time. In addition, the present invention has an excellent effect in that the photoreceptor cassette can be attached and detached without any trouble.

In particular, if the inclination angle of the toner scattering prevention member is arranged at an acute angle with respect to the vertical direction, the photoreceptor will not be damaged when the photoreceptor cassette is attached.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of a magnetic brush type dry developing device, Fig. 2 is a partially cutaway side view showing an example of a magnetic brush type developing unit, and Fig. 3 is a partially cutaway side view showing an example of a magnetic brush type developing unit. FIG. 4 is a partially cutaway side view showing another example; FIG. 4 is a cutaway perspective view of the main parts of an embodiment of the dry developing device according to the present invention; FIG. 5 is a side view taken from arrow V in FIG. 4. 6 is a partially broken side view showing another embodiment of the present invention, and FIG. 7 is a partially broken side view showing still another embodiment of the present invention. Explanation of symbols of main parts 16... Photoreceptor 100, 200, 300... Developing unit 102...
- Casing 106... Toner 114... Opening 118, 218, 318... Holding member 122, 222
, 322...Toner scattering prevention material θA, θB...Inclination angle Patent applicant Ricoh Co., Ltd. Fig. 2, Fig. 2, 6, Fig. 3, Fig. 5, IU, Fig. 6, 00

Claims (1)

[Claims] 1. An opening is provided in a part of the casing in which the toner is accommodated, and the toner is deposited from the opening onto a latent image carrier disposed close to the opening. In the dry type developing device, a toner scattering prevention member is disposed near the opening to substantially cover a portion of the opening that is not closed on the surface of the latent image carrier, and a toner scattering prevention member is disposed near the opening, and at least the part of the toner scattering prevention member that is not closed on the surface of the latent image carrier is disposed. A dry developing device characterized in that the body side portion is made of a flexible material. 2. The dry developing device according to claim 1, wherein the toner scattering prevention member is arranged at an acute angle of inclination with respect to the vertical direction.