JPH0364072B2 - - 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 using an image forming method using fine light-transmitting conductive toner, it is necessary to arrange the toner in a single layer on the photoreceptor.

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. Further, even if it were possible, if these devices were to be integrated into a device, there would be problems such as the device becoming complicated and large, and noise caused by vibrations, toner scattering, etc. occurring.

Further, as another method, there 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,
An electric field is created between the dielectric body 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 conductive toner polarized to the negative side is generated. The 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 the conductive toner 2 on the photoreceptor 1 are removed.

In order to make the multi-layered conductive toner 2 on the surface of the photoreceptor 1 into a single layer using this method, the conductive toner 2 in the uppermost layer on the photoreceptor 1 is sequentially polarized and made to fly. While rotating at a high speed times the number of layers of conductive toner 2 on the photoreceptor 1 with respect to the circumferential speed of
The doctor 5 pressed against the dielectric 4
It was necessary to reliably clean the conductive toner 2 electrostatically adhered to the surface. Therefore, although this method has a simple configuration, it has the following drawbacks. That is, since the dielectric body 4 is rotated at high speed, the end face of the doctor blade 5 and the surface of the dielectric body 4 are damaged by frictional heat, and the ability to clean the conductive toner 2 on the dielectric body 4 is degraded. It was difficult to layer the conductive toner on top. 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 removal device that overcomes the above-mentioned conventional drawbacks and converts multiple layers of toner on a photoreceptor into a single layer.

Structure of the Invention The toner removing device of the present invention includes a hopper having an opening and containing toner, a movable body such as a Se or ZnO photoreceptor that forms an electrostatic latent image with which the toner at the outlet comes into contact, and a movable body such as a Se or ZnO photoreceptor. It consists of an electrode made of one or more wires that faces the body with a certain gap and applies a voltage, and a dielectric roller etc. that is rotatably provided and faces the moving body with a certain gap. a doctor made of a rubber blade or the like pressed against the dielectric at a position away from the facing portion of the movable body and the dielectric; By arranging an electrode and a dielectric and applying a voltage between the movable body and the electrode and dielectric to create an electric field, the toner on the movable body is caused to fly and is captured by the electrode and the dielectric. It is configured as follows.

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. The moving body 8 is provided at a position where a portion of the moving body 8 contacts the toner 6 at the outlet portion 7a of the hopper 7. Reference numeral 9 denotes a first corona charger, which applies 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 supply 10, depending on the photosensitive material 8b. It charges the surface. 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 an electrode composed of a plurality of wires, and is provided at a position facing the moving body 8 with a certain gap therebetween. Reference numeral 12 denotes a second high-voltage power supply that applies a voltage between the base 8a of the movable body 8 and the electrode 11 to fly the multilayer toner 6 on the photosensitive material 8b toward the electrode 11 side, so that it becomes almost a single layer. It is something to do.

A dielectric 13 is a metal roller 13a whose surface is coated with a dielectric material such as polyvinylidene fluoride or polyester, and is provided at a position facing the movable body 8 with a certain gap therebetween. 14 is the third
15 is a second corona charger,
A third high-voltage power source is applied to charge the surface of the dielectric 13. Also, the charged dielectric 13
When facing the moving body 8, the moving body 8 and the dielectric body 1
A strong electric field is generated between the photosensitive material 8b and the photosensitive material 8b, and the toner 6, which has formed a substantially single layer on the photosensitive material 8b, is flown onto the dielectric material 13 and is electrostatically deposited thereon, thereby reliably forming a single layer. 16 is a doctor, which is composed of a rubber blade. The doctor 16 is provided in pressure contact with the movable body 8 and the dielectric 13 and removes the toner 6 electrostatically attached to the dielectric 13. 17
is a receiver which stores the toner 6 removed by the doctor 16. A thin plate 18 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.

Next, this operation will be explained.

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.

-6 KV is applied to the first corona charger 9 using the first high voltage electrode 10 to generate a negative corona, and the entire surface of the ZnO 8b is charged to -300V to -400V. Next, the movable body 8 moves, and approximately 12 layers of conductive toner 6 at the outlet portion 7a of the hopper 7 are electrostatically adhered to the charged portion of ZnO as shown in A of FIG. Next, considering the air pressure resistance (1.5 KV/mm) between the base 8a of the movable body 8 and the electrode 11, the movable body 8 is
The electrode strength between the base 8a and the electrode 11 is
Set it to 0.7KV/mm.

Next, the approximately
Approximately 12 layers of conductive toner 6 are applied to the base 8a of the moving body 8.
When placed in the electric field between the electrode 11 and the electrode 11, it becomes polarized. Next, the conductive toner 6 polarized to the negative side flies to the positive electrode 11 due to electrostatic attraction and falls into the hopper, and as shown in FIG.
The conductive toner 6 on the charging portion 8b forms about 1 to 2 layers. Next, +6 KV is applied to the second corona charger 15 by the third high voltage power supply 14 to generate a positive corona and charge the surface of the dielectric 13 to +2.5 KV. Further, the electric field strength between the base 8a of the movable body 8 and the dielectric 13 is set to 5 KV/mm by the dielectric 13 charged at that time.

Next, approximately 1 to 2 layers of conductive toner 6 electrostatically adhered to the charged portion of the ZnO 8b is applied to the base 8 of the moving body 8.
When placed in a strong electric field between a and the dielectric 13, it becomes polarized. Next, one or more layers of conductive toner 6 polarized on the negative side fly to the dielectric material 13 on the positive side and electrostatically adhere thereto, thereby ensuring that the conductive toner 6 is formed into a single layer. Next, the conductive toner 6 electrostatically adhered to the dielectric material 13 is removed by the doctor 16, and the conductive toner 6 is stored in the receiver 16.

Effects of the Invention The toner removing device according to the present invention has the following effects because of the configuration described above.

(1) Since the toner on the moving object is layered using electrostatic attraction caused by the electric field between the moving object, electrodes, and dielectric materials, compared to conventional air jet and vibration methods, this method has less influence on the remaining toner. Stable layering can be achieved without any problems. There is also less toner scattering and noise.

(2) Since the electrostatic attraction caused by the weak electric field between the movable body and the electrode is used to form toner on the movable body in about 1 to 2 layers, the amount of toner removed by the dielectric can be small. To explain in more detail, since the amount of toner removed is about 1/11 compared to the conventional dielectric roller method, the speed of the dielectric can be slowed down. Therefore, the life of the dielectric and doctor is extended. You can also move faster.

[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 showing an embodiment of the toner removing device of the present invention, and FIG.
The figure is a diagram showing the relationship between the electrode voltage and the height of the toner on the moving body after the toner is removed by the electrode. 6... Toner, 7... Hopper, 7a... Opening, 8... Moving body, 11... Electrode, 13... Dielectric, 16... Doctor.

Claims (1)

[Scope of Claims] 1. A hopper having an opening and containing toner, a moving body forming an electrostatic latent image in contact with the toner in the opening, facing the moving body with a certain gap, and applying voltage to the hopper. a dielectric body rotatably provided facing the movable body with a certain gap therebetween; and a doctor pressure-welded to the dielectric body at a position away from the facing portion of the movable body and the dielectric body. A toner removing device comprising: the hopper, the electrode, and the dielectric body arranged in sequence with respect to the moving direction of the movable body. 2. The toner removing device according to claim 1, wherein the electrode is composed of one or more wires.