JPH0364071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an image forming apparatus such as a copying machine or an electrostatic printer using toner.

Structure of the conventional example and its problems In order to obtain a good toner image by an image forming method using fine light-transmitting conductive toner, it is necessary to arrange the toner on a photoreceptor in a single layer.

Conventionally, methods for layering toner on a photoreceptor include an air jet method in electronic scribing and a vibration method described in Japanese Patent Publication No. 56-2338. However, in order to completely remove only unnecessary toner without affecting the necessary toner that should remain on the photoreceptor, these methods require delicate adjustments to the way air is blown and the way vibrations are applied. It is technically very difficult to obtain good images. Furthermore, even if it were possible, if these devices were to be incorporated into a device, there would be problems in that the device would be complicated and large, and noise caused by vibrations, toner scattering, etc. would occur.

Another method is a dielectric roller method as shown in FIG. The principle is, for example, after spraying conductive toner 2 onto a negatively charged photoreceptor 1,
Next, an electric field is created between the dielectric material 4 positively charged by the corona charger 3 and the photoconductor 1, and the multilayer conductive toner 2 on the photoconductor 1 is polarized, and the top layer of the conductive toner 2 is polarized. The negatively polarized conductive toner 2 is caused to fly and electrostatically adhere to the dielectric material 4 on the positive side by electrostatic attraction, and the second and higher layers of conductive toner 2 on the photoreceptor 1 are removed. .

In this method, a multilayer conductive toner 2 on a photoconductor 1 is formed.
In order to make the conductive toner 2 on the photoreceptor 1 into a single layer, the conductive toner 2 on the photoreceptor 1 is sequentially polarized and made to fly, so the dielectric material 4 is adjusted to the peripheral speed of the photoreceptor 1 so that the conductive toner 2 on the photoreceptor 1 is It was necessary to rotate at a high speed twice as many times as the number of layers, and to reliably clean the conductive toner 2 electrostatically adhered to the dielectric 4 with the doctor 5 pressed against the dielectric 4. Therefore, although this method has a simple configuration, it has the following drawbacks. That is, in order to rotate the dielectric 4 at high speed, the doctor 5
The end face of the dielectric 4 and the surface of the dielectric 4 are damaged by frictional heat,
The ability to clean the conductive toner 2 on the dielectric body 4 deteriorated, making it difficult to layer the conductive toner on the photoreceptor 1. Therefore, there was a problem that the layering process speed of this method was slow.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a toner removing device that overcomes the above-mentioned conventional drawbacks and converts multiple layers of toner on a photoreceptor into a single layer.

Composition of the Invention The toner removing device of the present invention includes: a hopper having an opening and storing toner; a moving body such as a Se or ZnO photoreceptor that forms an electrostatic latent image in contact with the toner in the opening; The moving body is equipped with a doctor made of a rubber blade or the like pressed against the moving body, and an applicator made of a wire electrode or a dielectric roller or the like that faces the moving body with a certain gap and applies a voltage. The hopper, doctor, and applicator are arranged in sequence in the direction of movement of the body.

Description of examples FIG. 2 shows an embodiment of the device according to the invention.

6 is the toner, 7 is the hopper that stores the toner,
It has an outlet section 7a at one end. 8 is a mobile object,
For example, on the aluminum surface of the base 8a, ZnO,
It is coated with a photosensitive material 8b such as Se or OPC, and is provided at a position where a portion of the outlet portion 7a of the hopper 7 contacts the toner 6. Reference numeral 9 denotes a first corona charger, which charges the surface of the photosensitive material 8b by applying a negative corona when the photosensitive material 8b is ZnO and a positive corona when the photosensitive material 8b is Se from the first high voltage power source 10. Further, the charged portion on the surface of the photosensitive material 8b causes the toner 6 at the outlet portion 7a of the hopper 7 to electrostatically adhere thereto. Reference numeral 11 denotes a doctor made of a rubber blade, which is provided in pressure contact with the movable body 8 at a predetermined angle with respect to the movable body 8, and scrapes off the multilayer toner 6 electrostatically adhered to the movable body 8. The toner 6 is made uniform in several layers. 12 is an applicator, which has multiple wire electrodes 12;
a, and is provided at a position facing the movable body 8 with a certain gap therebetween. Reference numeral 13 denotes a second high-voltage power supply that applies a voltage between the base 8a of the moving body 8 and the electrode 12a to fly several layers of toner 6 on the moving body 8 toward the electrode 12a to form a single layer. It is something to do. A thin plate 14 is made of a dielectric material such as polyester and is fixed to the hopper 7 to fill the gap between the movable body 8 and the hopper 7 and prevent the toner 6 from leaking from the hopper 7.

The operation of the toner removing device of the first embodiment configured as described above will be explained below.

In FIG. 2, in order to make the operation easier to understand, the photosensitive material 8b of the movable body 8 is made of ZnO, and the toner 6 is made of conductive toner. A negative corona is applied to the first corona charger 9 by the first high voltage electrode 10 to negatively charge the entire surface of the ZnO 8b. Next, the movable body 8 moves, and the conductive toner 6 at the outlet portion 7a of the hopper 7 electrostatically adheres to the charged portion of the ZnO 8b in about 12 layers. When the movable body 8 moves further, the doctor 11 scrapes off the multi-layered conductive toner 6 on the movable body 8, and makes the conductive toner on the movable body 8 uniform in about 2 to 3 layers.

Next, a voltage is applied between the base 8a of the movable body 8 and the electrode 12a by the second high-voltage power supply 13 so that the electrode 12a side becomes positive. Here, the said
When two to three layers of conductive toner 6 electrostatically adhered on ZnO 8b face the electrode 12a, the uppermost layer of conductive toner 6 on the moving body 8 spreads between the base 8a and the electrode 12a.
The conductive toner 6 is sequentially polarized negatively due to the electric field between a, flies to the positive electrode 12a due to electrostatic attraction, and falls into the hopper, forming a single layer of conductive toner 6 on the ZnO 8b.

Next, a second embodiment of the present invention will be described with reference to FIG.

This embodiment differs from FIG. 2 in the configuration of the applicator 12. That is, the applicator 12 is composed of a dielectric roller 15 provided facing the movable body 8 with a certain gap therebetween, and a cleaning doctor 16 pressed against the dielectric roller 15. The dielectric roller 15 is a metal electrode roller 15a whose surface is made of a dielectric material 15b such as polyester or polyvinylidene fluoride. Further, the cleaning doctor 16 is composed of a rubber blade. Reference numeral 17 denotes a third high-voltage power supply that applies voltage between the base 8a and the electrode roller 15a of the dielectric roller 15 to spread several layers of conductive toner 6 on the moving body 8.
It is made to fly toward the dielectric roller 15 side and electrostatically adhere to the surface of the dielectric roller 15b to form a single layer. Reference numeral 18 denotes a receiver for storing the conductive toner 6 removed by the cleaning doctor 16.

The operation of the toner removing device of the second embodiment configured as described above will be described below. Second
The operation of this embodiment is similar to that of the first embodiment until the multilayer conductive toner 6 on the movable body 8 is uniformly scraped off in about 2 to 3 layers by the doctor 11.
Next, a positive voltage is applied to the electrode roller 15a side between the base 8a of the moving body 8 and the electrode roller 15a of the dielectric roller 15 by the third high voltage power supply 17, and the dielectric roller 15a of the dielectric roller 15 is The surface of material 15b is polarized positively. Next, on the ZnO 8b, 2
When the conductive toner 6 electrostatically adhered to approximately three layers faces the dielectric roller 15, the uppermost layer of conductive toner 6 on the moving body 8 touches the base 8a and the electrode roller 15a.
ZnO8b is sequentially polarized negatively by the electric field between them, flies to the dielectric roller 15, and electrostatically adheres to the surface of the positively polarized dielectric material 15b.
The upper conductive toner 6 forms a single layer. Next, the conductive toner 6 electrostatically adhered to the dielectric roller 15 is removed by the cleaning doctor 16, and the conductive toner 6 is stored in the receiver 18.

In the second embodiment, a cleaning doctor 16 is provided in the method of cleaning the conductive toner 6 on the dielectric roller 15, but as in the third embodiment shown in FIG. A plurality of wire electrodes 19 may be provided with a certain gap between them. In this cleaning method, the dielectric roller 1
Voltage is applied between the fifth electrode roller 15a and the wire electrode 19 by the fourth high-voltage electrode 20 so that the wire electrode 19 is on the positive side, and the electrokinetic toner 6 on the dielectric roller 15 is made to fly. and cleaning.

Therefore, since this method performs cleaning without contact, there is an advantage that the conductive toner 6 is not damaged.

Effects of the Invention The toner removal device according to the present invention uses a doctor to scrape off toner on a moving body that has been electrostatically adhered in multiple layers to form several layers of toner, and then combines the several layers of toner into a single layer by the electrostatic attraction of an applicator. Therefore, it has the following effects.

(1) Compared to conventional air jet and vibration methods,
Stable layering is possible without affecting the remaining toner. Also, there is less toner scattering and noise.

(2) Compared to the conventional conductive roller method, the present invention provides a doctor so that the amount of donor removed by the applicator is small, so the layering process speed is increased.

(3) The doctor of the present invention is configured to come into pressure contact with the movable body and can scrape off the toner on the movable body in several uniform layers, so delicate adjustments are not required and the configuration is simple.

[Brief explanation of drawings]

FIG. 1 is a side view with main parts cut away of a conventional device using a dielectric roller method, FIG. 2 is a side view with main parts cut away of a toner removing device according to a first embodiment of the present invention, and FIG. FIG. 4 is a side view with main parts of the toner removing device in the second embodiment cut away, and FIG. 4 is a side view with main parts cut out of the toner removing device in the third embodiment. 6... Toner, 7... Hopper, 7a... Opening, 8... Moving body, 11... Doctor, 12...
Applicator, 12a...electrode, 15...dielectric roller, 16...cleaning doctor, 19...electrode.

Claims (1)

[Claims] 1. A hopper having an opening and storing toner;
A movable body on which an electrostatic latent image is formed in contact with the toner in the opening, a doctor in pressure contact with the movable body, and an applicator that faces the movable body with a certain gap and applies a voltage, A toner removal device characterized in that the hopper, doctor, and applicator are arranged in sequence in the direction of movement of the moving body. 2. The toner removal device according to claim 1, wherein the applicator is comprised of one or more wire electrodes. 3. The toner removal device according to claim 1, wherein the applicator comprises a dielectric body rotatably provided facing the movable body with a certain gap therebetween, and a cleaning doctor in pressure contact with the dielectric body. . 4. The applicator has a dielectric body rotatably provided facing the movable body with a certain gap therebetween, and a dielectric body provided with a certain gap in the dielectric body at a position away from the opposing part. Alternatively, the toner removing device according to claim 1, comprising a plurality of electrodes.