JPH0374835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses, for example, a light-transmitting toner and an electrophotographic photoreceptor to form a latent image on the photoreceptor depending on the amount of light transmitted through the toner. The present invention relates to a toner removing device for development that is applied to image forming methods and the like in which toner images are obtained by selectively removing toner.

Structure of conventional example and its problems In an image forming method using fine light-transmitting toner, in order to obtain a good toner image, development is required to remove only unnecessary toner from the toner arranged in a single layer on the photoreceptor. A process is necessary.

Conventionally, as a method for developing toner on such a photoreceptor, there is a vibration method described in Japanese Patent Publication No. 56-2338, which is an air jet method in an electronic scribing method. However, these methods do not affect the necessary toner that should remain on the photoconductor, and in order to completely remove only unnecessary toner, delicate adjustments are required in the way air is blown and the way vibrations are applied. However, obtaining good images is technically extremely difficult. Also, even if it were possible, when converting these into devices,
There were problems in that the device became complicated and large, and noise caused by vibration and toner scattering occurred.

Another way to solve these problems is to
There is a dielectric roller method as shown in FIG. The principle is, for example, after arranging light-transmitting toner 2 in a layer on a negatively charged photoreceptor 1, an optical part 3
A pattern light image is projected onto the photoreceptor 1 via toner to form a latent image. Next, the photoreceptor 1 is charged by the dielectric roller 5 charged by the corona charger 4.
The unnecessary toner 2 having a weak electrostatic adhesion force is caused to fly and electrostatically adhere to the surface of the dielectric roller 5. Next, the toner 2 adhering to the dielectric roller 5 is scraped off by the blade 6. Although this method has a simple structure, it has the disadvantage that the electric field strength between the dielectric roller 5 and the photoreceptor 1 is constant, so that the brightness reproduction range is narrow.
The reason for this is that the electrostatic adhesion force between the photoreceptor 1 and the toner varies depending on the difference in development of the pattern light image. However, since the electric field strength between the dielectric roller 5 and the photoreceptor 1 is constant, the toner removal force of the dielectric roller 5 removes all toner having a brightness above a predetermined brightness, and cannot remove any other toner. Therefore, the reproduction range of brightness becomes narrower.

OBJECT OF THE INVENTION The present invention solves the conventional problems, and enables development with a wide reproduction range of brightness.
It is an object of the present invention to provide a toner removal device that does not require highly accurate adjustment.

Structure of the Invention The toner removing device of the present invention comprises a moving body made of zinc oxide, selenium, etc. that forms an electrostatic latent image and supports toner, and a polyvinylidene fluoride material that partially extends over the moving body and moves together with the moving body. , a dielectric sheet using a dielectric material such as polyester, and an electrode using an electrode roller, a fixed electrode, a corona charger, etc. provided at a position facing the moving body through the dielectric sheet. a second toner remover comprising the first toner remover and a metal roller whose surface is coated with a dielectric material such as polyvinylidene fluoride or polyester, which is rotatably provided facing the moving body with a certain gap therebetween; The first toner remover and the second toner remover are sequentially arranged with respect to the movable body.

DESCRIPTION OF EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG.

Reference numeral 7 denotes a light-transmitting toner, and 8 a moving body, for example, an aluminum surface of a base 8a coated with a photosensitive material 8b such as zinc oxide or selenium. The photosensitive material 8b is charged by a well-known charger depending on the photosensitive material 8b, for example, negative in the case of zinc oxide,
In the case of selenium, apply a positive corona.
Reference numeral 9 denotes an optical section that projects a pattern light image onto the moving body 8 via the toner 7 arranged in a single layer on the moving body 8, thereby forming a latent pattern image on the photosensitive material 8b.

10 is a dielectric sheet made of dielectric material such as polyvinylidene fluoride or polyester;
It is formed into a belt shape. 11, 12, 13, 1
4 is a roller, 15 is a rotating lever, and 16 is a tension spring. The rollers 11 and 12 are opposed to the moving body 8 with a fixed gap through the dielectric sheet 10, and when the dielectric sheet 10 is stretched, the rollers 11 and 12 and a part of the dielectric sheet 10 are connected to the moving body 8. It is located at a position where it wraps around 8. Further, the roller 11 is connected to the moving body 8 by a gear. The rotary lever 15 is provided with the roller 13 at one end, and is rotatably provided at the other end about the axis of the roller 12. The tension spring 16 has one end connected to the rotating lever 1.
5, the other end is provided on the main body side, and the dielectric sheet 1
It is set to 0.

Reference numeral 17 denotes an electrode, which is constituted by a first corona charger 17a. The first corona charger 17a is located between the rollers 11 and 12, and is provided at a position facing the moving body 8 with the dielectric sheet 10 in between. 18 is a first high-voltage power supply that applies a DC voltage to the first corona charger 17a to charge the dielectric sheet 1.
It charges the surface of 0. Furthermore, when the charged dielectric sheet 10 comes to a position where the toner 7 arranged in a single layer on the movable body 8 on which the pattern latent image is formed faces, the unnecessary toner 7 is statically removed onto the surface of the dielectric sheet 10. It is something that is electrolytically deposited. Reference numeral 19 denotes a first doctor, which is made of a rubber blade. The first doctor 19 is in pressure contact with the dielectric sheet 10,
It is provided at a position facing the roller 14 with the dielectric sheet 10 in between, and removes the toner 7 electrostatically adhered to the surface of the dielectric sheet 10. 20 is the first
The toner 7 removed by the first doctor 19 is
It is meant to store. 21 and 22 are constituted by corona static eliminators. The corona static eliminators 21 and 22 are
A corona static eliminator 21 and a corona static eliminator 22 are provided facing each other with the dielectric sheet 10 in between. 23 is a second high-voltage power supply that supplies AC voltage to the corona static eliminator 2.
1 and 22 to neutralize the surface of the dielectric sheet 10 that has been charged by the first corona charger 17. Reference numeral 24 denotes a first toner remover, which is composed of a dielectric sheet 10 and a second high-voltage power source 23.

25 is a dielectric material, and the surface of the metal roller 25a is coated with a dielectric material such as polyvinylidene fluoride or polyester. The dielectric 25 is the movable body 8
They are placed opposite each other with a certain gap between them. 26 is a second corona charger.
The second corona charger 26 connects the moving body 8 and the dielectric body 2.
It is provided at a position facing the dielectric 25 with a constant gap at a position away from the facing portion of the dielectric 25 . Reference numeral 27 denotes a third high-voltage power supply that applies an AC voltage to the second corona charger 26 to charge the surface of the dielectric 25. The charged dielectric 25 also removes unnecessary toner 7 that could not be removed by the dielectric sheet 10. A second doctor 28 is made of a rubber blade. The second doctor 28 is located at a position away from the facing portion of the moving body 8 and the dielectric body 25.
It is provided in pressure contact with the dielectric 25 to remove the toner 7 electrostatically attached to the dielectric 25. Reference numeral 29 denotes a second receiver, which stores the toner 7 removed by the second doctor 28. Note that 30 is a second toner remover, which is composed of a dielectric 25 and a second receiver 29.

Regarding the first embodiment configured as above,
The operation 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 zinc oxide, and the toner 7 is made of conductive toner. Conductive toner 7 is placed on zinc oxide 8b which is negatively charged over the entire surface.
After arranging them in one layer, the optical section 9 projects the patterned optical image onto the moving body 8 via the conductive toner 7 to form a patterned latent image on the zinc oxide 8b. Next, the first high voltage power supply 18 is connected to the first corona charger 17.
Applying positive corona to dielectric sheet 1
Charge 0 positively. Next, the moving body 8 moves,
When the conductive toner 7 arranged on the zinc oxide 8b on which a pattern latent image is formed faces the positively charged dielectric sheet 10, the unnecessary conductive toner whose electrostatic adhesion on the zinc oxide 8b has weakened. 7 is electrostatically adhered to the surface of the dielectric sheet 10. At this time, the principle is unknown, but as an experimental fact, the conductive toner 7 on the moving body 8 forms a toner image according to the brightness difference of the pattern light image, and the brightest part of the pattern light image has a slight difference in brightness. Unnecessary conductive toner 7 remains, causing background fog.

Next, a positive corona is applied to the second corona charger 26 by the third high voltage power supply 27 to charge the dielectric material 2.
5 is positively charged. The amount of charge is the moving body 8
The electric field strength between the base 8a and the dielectric 25 is set to a value that can eliminate the background fog. Next, when the movable body 8 moves and the conductive toner 7 on the zinc oxide 8b on which the toner image with background fog is formed faces the positively charged dielectric body 25, the conductive toner 7 on the background fog is attracted by electrostatic attraction. The particles fly and electrostatically adhere to the surface of the conductor 25. At this time, the toner image on the moving body 8 becomes a beautiful toner image that corresponds to the brightness difference of the pattern light image without background fog.

The above principle is based on the difference in electrostatic adhesion due to the difference in brightness between the zinc oxide 8b and the conductive toner 7 after the pattern light image, and the difference in electrostatic adhesion force due to the difference in brightness between the zinc oxide 8b and the conductive toner 7 after the pattern light image is formed on the dielectric sheet 10. It is considered that a toner image corresponding to the brightness difference of the pattern light image is created by combining the difference in electric field strength due to the difference in the amount of adhesion.

Using this principle to explain the bright background fogging part, the electrostatic adhesion force between the bright unnecessary conductive toner 7 and the zinc oxide 8b is almost non-existent. Therefore, all of the unnecessary conductive toner 7 attempts to electrostatically adhere to the dielectric sheet 10, but as the amount of adhered to the dielectric sheet 10 gradually increases, the electric field between the moving body 8 and the dielectric sheet 10 increases. It is thought that the strength becomes very small and some residual fogging occurs on the zinc oxide 8b.

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

In the figure, 7 is a conductive toner, 8 is a moving body,
8a is the base, 8b is zinc oxide, 9 is the optical part, 10
11, 12, 13, 14 are rollers, 15 is a rotating lever, 16 is a tension spring,
19 is a first doctor, 20 is a first receiver, 21,
22 is a static eliminator, 25 is a dielectric, 25a is a metal roller, 28 is a second doctor, and 29 is a second receiver. The above configuration is the same as the configuration shown in FIG. What differs from FIG. 2 is the structure of the 17 electrodes and the method of forming polarization of the dielectric 23.

The electrode 17 is composed of a metal roller 17b.
The metal roller 17b is located between the rollers 11 and 12, is in contact with the conductive sheet 10, and is provided at a position facing the moving body 8 with the dielectric sheet 10 in between. Reference numeral 18a denotes a high-voltage power source 1a, which applies a DC voltage between the metal roller 17b and the base 8a of the moving body 8 to induce polarization of the dielectric sheet 10. Inductively polarized dielectric sheet 10
In this method, unnecessary toner 7 is electrostatically deposited on the surface of dielectric sheet 10 when toner 7 arranged in a single layer on movable body 8 on which a pattern latent image is formed comes to the opposing position.

The method for polarizing the dielectric 25 is to provide a third high-voltage power source 27a and apply a DC voltage between the metal roller 25a and the base 8a of the moving body 8 to polarize the dielectric 25. This is a method of induced polarization. The induced polarized dielectric 25 contains unnecessary toner 7 that could not be removed by the dielectric sheet 10.
It is intended to remove. Note that 24a is a first toner remover, which is made up of a dielectric sheet 10 and a second high-voltage source 23, and 30a is a second toner remover, which is made up of a dielectric 25 and a second receiver 29. be.

Regarding the second embodiment configured as above,
The operation will be explained below.

In FIG. 3, in order to make the operation easier to understand, the photosensitive material 8b of the movable body 8 is made of zinc oxide, and the toner 7 is made of conductive toner. Conductive toner 7 is placed on zinc oxide 8b which is negatively charged over the entire surface.
After arranging them in one layer, the optical section 9 projects the patterned optical image onto the moving body 8 via the conductive toner 7 to form a patterned latent image on the zinc oxide 8b. Next, a voltage is applied between the metal roller 17b and the base 8a using the first high-voltage power supply 18a so that the metal roller 17b is on the positive side, thereby inductively polarizing the dielectric sheet 10 and connecting the base 8a and the metal. Roller 17b
An electric field is generated between the Next, the moving body 8 moves, and the conductive toner 7 arranged on the zinc oxide 8b on which the pattern latent image is formed is transferred to the metal roller 17b.
When facing the zinc oxide 8b, the unnecessary conductive toner 7 whose electrostatic adhesion on the zinc oxide 8b has weakened is removed from the dielectric sheet 1.
0 electrostatically adheres to the surface. At this time, as explained in FIG. 2, the conductive toner 7 on the moving body 8 is
The toner image is created according to the difference in brightness of the pattern light image,
Further, some unnecessary toner 7 remains in the brightest part of the pattern light image, causing background fog. Next, a voltage is applied between the metal roller 25a and the base 8a using the third high-voltage power supply 27a so that the metal roller 25a is on the plus side, and the dielectric 25 is inducedly polarized, and the base 8a and the metal An electric field is generated between the roller 25a and the roller 25a. The electric field strength at that time is set to a value that can remove the background fog.

Next, when the movable body 8 moves and the conductive toner 7 on the zinc oxide 8b on which the toner image with background fog is formed faces the metal roller 25a, the conductive toner 7 with the background fog flies away due to electrostatic attraction. and electrostatically adheres to the surface of the dielectric 25. At this time, the toner image on the moving body 8 is a toner image that corresponds to the brightness difference of the pattern light image without background fog.

Note that although the metal roller 17b is provided on the electrode 17 in the explanation, a fixed electrode can also have the same effect. In addition, in FIG. 2, the method for forming polarization of the dielectric material 25 is shown in
A similar effect can be obtained by using the polarization forming method shown in the figure.
In FIG. 2, the rollers 11 and 14 are made of metal rollers connected to the ground, and the rollers 12 and 13 are made of insulated rollers, so that unnecessary conductive toner 7 on the moving body can be more accurately removed from the dielectric sheet 10. The unnecessary conductive toner 7 electrostatically adhered on the dielectric sheet 10 can be removed by the first doctor 1.
9 can be easily removed. In FIGS. 2 and 3, the first toner remover 24, 24a and the second toner remover 30, 30a are arranged with respect to the moving direction of the moving body 8.
Although the first toner remover 24, 24a and the second toner remover 30, 30a are arranged in this order, the same effect can be obtained regardless of the order.

Effects of the Invention In the toner removing device using electrostatic attraction according to the present invention, a first toner remover removes toner on a moving body to form a toner image according to the brightness difference of a pattern light image, and then a second The toner remover removes the background fog remaining on the toner image to form a beautiful toner image corresponding to the difference in brightness of the pattern light image, and therefore has the following effects.

(1) Compared to conventional air jet and vibration methods, stable development is possible without affecting the remaining toner. It also eliminates the need for high-precision adjustment, and reduces toner scattering and noise.

(2) Compared to the conventional dielectric roller method, it is possible to form a beautiful toner image without background fog that corresponds to the difference in brightness of the pattern light image.

[Brief explanation of drawings]

FIG. 1 is a side view of a toner removing device using a conventional dielectric roller method, FIG. 2 is a side view of a toner removing device according to a first embodiment of the present invention, and FIG.
FIG. 3 is a side view of the toner removing device in the embodiment. 7... Light-transmitting toner, 8... Moving object, 10...
...Dielectric sheet, 17... Electrode, 24, 24a...
...first toner remover, 25...dielectric, 30,
30a...Second toner remover.

Claims (1)

[Scope of Claims] 1. A moving body that forms an electrostatic latent image and supports light-transmissive toner, a dielectric sheet that partially extends over the moving body and moves together with the moving body, and this dielectric sheet. a first toner remover constituted by an electrode provided at a position facing the movable body through the toner remover; and a second toner remover constituted by a dielectric body rotatably disposed opposite to the movable body with a predetermined gap therebetween. 1. A toner removing device comprising: a toner removing device, wherein the first toner removing device and the second toner removing device are sequentially arranged with respect to the movable body. 2. The toner removing device according to claim 1, wherein the electrode is comprised of a corona charger, an electrode roller, or a fixed electrode. 3. The first toner remover includes a dielectric sheet formed into a belt shape, first, second, and third rollers surrounded by the dielectric sheet, and electrodes that polarize the dielectric sheet by induction. , a static eliminator that eliminates static electricity from the dielectric sheet, a tension mechanism that stretches the dielectric sheet, and a doctor that removes toner adhering to the dielectric sheet, and the first and second The rollers are arranged in the order of a first roller and a second roller with respect to the moving direction of the movable body, and are provided at a position where the dielectric sheet wraps around the movable body, and the third roller is disposed in a position where the dielectric sheet wraps around the movable body. the electrodes are located between the first and second rollers, and the tension mechanism is located between the second and third rollers and at a position facing the moving body through the dielectric sheet; and a portion of the doctor is placed in contact with the dielectric sheet, and the doctor is placed in pressure contact with the dielectric sheet and faces a third roller via the dielectric sheet; Claim 1 or 2, wherein a static eliminator is located between the first and third rollers and facing the dielectric sheet.
Toner removal device as described in section. 4. The toner removing device according to claim 3, wherein the first and second rollers are constructed of metal rollers connected to ground, and the contact portion of the third roller and the tension mechanism is constructed of an insulator. . 5. The second toner remover includes a dielectric member rotatably provided facing the movable body with a certain gap therebetween, and a cleaning doctor press-contacted to the dielectric member at a position away from the opposing portion. A toner removing device according to any one of claims 1 to 4. 6. The second toner remover includes a dielectric member rotatably provided opposite the movable body with a predetermined gap therebetween, and a cleaning doctor press-contacted to the dielectric member at a position away from the opposing portion. The toner removing device according to any one of claims 1 to 4, comprising a corona charger provided with a certain gap in the dielectric body.