JPS5997158A - Novel developing method - Google Patents

Abstract

PURPOSE:To enable development in a simple system without requiring any special device by charging a developer with a charging means installed in a developer feed vessel, and feeding it through a conductive mesh screen to the surface of a photoreceptor. CONSTITUTION:The developer feed vessel 6 arranged near the surface 1 of a photosensitive body bearing an electrostatic latent image 4 is provided with a charging means 8 for charging the developer in the inside, and with an electrically conductive mesh screen 5 in an opening for feeding the developer. An electric field is formed by applying bias voltage between the screen 5 and the photosensitive surface 1, and the developer 7 supported with the screen 5 so as not to be dropped by the gravity is transferred through the opening of the screen 5 to the photosensitive body surface 1 by the action of this electric field, resulting in forming a visible image corresponding to the electrostatic latent image 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel developing method, and more specifically, a conductive mesh is provided in close proximity to the surface of a photoreceptor having an electrostatic latent image, and the electrostatic latent image (second image) is developed through the mesh. Electrostatic force C: relates to a developing method characterized in that developer particles are transferred to the surface of a photoreceptor and the electrostatic latent image is developed.

In the conventional electrostatic photography method, for example, a developer and glass beads are combined, and this is dropped near the surface of a photoreceptor containing electrostatic a-bacteria, and only the developer is transferred to the surface of the photoreceptor by electrostatic force. The cascade method for image development,
Using so-called magnetic toner or magnetic carrier and toner developer, this is supplied onto a sleeve that has a magnet inside,
A magnetic brush development 1W method is known in which a magnetic brush of developer is formed and the electrostatic latent image is developed by sliding this magnetic brush against a photoreceptor.

However, such conventional developing methods require a developer having special components and a special device, which makes the device complicated.

That is, the object of the present invention is to use a developer that does not contain any special components, for example, a developer in which a coloring agent such as c-nicarbon is dispersed in a binding resin, without requiring any special equipment. It is an object of the present invention to provide a developing method that can carry out development in a simple manner.

The method of the present invention will be explained below based on specific examples shown in the attached drawings.

In FIG. 1 for explaining the method of the present invention, as shown in (A), the photoreceptor surface l1lr11 (2 is given a sufficient charge by the charging charger 2, and then (0) (2 is shown as shown in Image exposure is performed by the exposure mechanism 3, and the electrostatic a
My 4 is formed. Furthermore, as shown in (c), the electrostatic latent image 4 is visualized by the developing method of the present invention, and then,
After being transferred to transfer paper or as it is, it is fixed by a known method.

An important feature of the present invention is that a charging means 8 for charging the developer is provided inside the photoreceptor surface 1 having the electrostatic latent image 4, and a conductive member is provided in the developer supply opening. Providing a developer storage container 6 equipped with a mesh screen 6 (there are two types).

That is, the developer storage container 6 (the second is the mesh screen 5
This is because the 2 working units are housed in such a way that they do not fall due to gravity.

In the present invention, a bias voltage is further applied between the conductive mesh screen 5 and the photoreceptor surface 1 as shown in (2) (e). An electric field is formed in the darkness, and the developer 7, which is supported by the mesh screen 6, is prevented from falling due to gravity.
The electrostatic latent image 4 is transferred to the photoreceptor surface 1 through the opening, and a visible image corresponding to the electrostatic latent image 4 is formed.

As the developer used in the present invention (2), either a conductive toner or an insulating toner can be used. Also, in the present invention, by bringing the mesh screen 5 close to the photoreceptor surface 1, the developer 7 can be used. Although the exact reason why the visible image corresponding to the electrostatic layer image 4 is formed on the surface of the photoreceptor 1 is not clear, it is presumed that this is due to the following reason.

That is, when a conductive toner is used as the developer 7 (as shown in FIG. As a result, the mesh screen 5 and the developer 7 serve as a developing electrode, and the surface of the photoreceptor 1 is
(=The conductive toner moves onto the surface of the photoreceptor with a high surface potential on which the electrostatic latent image 4 is formed according to the formed electric field, and a visible image corresponding to the electrostatic latent image 4 is formed. It seems likely that

Furthermore, when insulating toner is used as the developer 7,
As shown in FIG. 3, the insulating toner particles are charged to a positive or negative charge due to friction between the particles or between the particles and the mesh screen 5.

In FIG. 3, positive charging is taken as an example. The charged polarity of the toner particles is determined by the material of the mesh screen 5 and the material of the toner particles, and a combination may be selected so as to be opposite to the polarity of the electrostatic latent image 4. Therefore, in the case of FIG. 3, it is considered that positive (bi-banded) toner particles migrate onto the surface of the photoreceptor having a high surface potential, and the electrostatic latent image 4 is developed. By applying a bias voltage between the photoreceptor screen 5 and the photoreceptor surface 1, the toner particles can be transferred quickly.

In the present invention, a two-band type means 8 is further provided in the developer storage container 6 so as to sufficiently apply an electric charge to the developer 7. transfer is further promoted, and a visible image with high image density is formed corresponding to the electrostatic latent image 4. This charging means 8
As shown in FIG. 4, a conductive mesh screen 9 to which a bias voltage is applied so as to give the developer 7 a charge of opposite polarity to the electrostatic latent image 4 is placed inside the developer storage container 6 (separate from the opening). It is sufficient to provide two.The voltage to be applied is 100μ to +
A range of 000V is desirable. Further, when the developer is an insulating toner, a stirring device 10 made of an insulating material can be used as the charging means, as shown in FIG. in this case,
As described above, the combination of the insulating material of the stirring device 10 and the insulating toner may be selected in consideration of the polarity of the toner particles due to frictional charging.

In the present invention, conductive mesh screen 5 used
It is generally desirable to have a screen opening of 50 to 300 meshes, although it varies depending on the particle size of the developer particles used. Since the particle size of the developer particles commonly used is in the range of 2 to 15 microns, if the mesh size is smaller than the above range, the developer particles supported by the mesh screen 5 will pass through the openings. However, even if an electric field is formed between the mesh screen 5 and the photoreceptor surface 1, the developer particles do not migrate to the photoreceptor surface 1, and in the end, they do not transfer to the electrostatic latent image 4. No visual image is formed.

Furthermore, if the mesh is smaller than the above range, the developer particles will not be supported by the mesh screen, and the amount of developer particles transferred to the photoreceptor surface 1 cannot be controlled.

Further, in the present invention, the mesh screen 5 must be provided at a distance of at least 3 spaces from the photoreceptor surface 1.

In the case W1 in which the mesh screen 5 is provided at a distance from the above range, the electric field formed between the mesh screen 5 and the photoreceptor surface 1 is weak, so that the developer particles are This is because it becomes difficult to transfer to the photoreceptor surface 1.

Historically, in the present invention, the developer used may be conductive or insulating as described above, and may be either the conventionally used one-component developer or the two-component developer. Can be used.

However, when a conductive developer is used, it is only necessary to apply a bias voltage between the mesh screen 5 and the surface of the photoreceptor 1 in order to impart an electric charge to the developer particles. It is desirable that the voltage is normally in the range of +000V or less. When the bias voltage is low, the voltage formed is weak and the transfer of developer particles to the photoreceptor surface 1 is reduced, and when it is higher than the above range, discharge occurs and developer particles are formed on the photoreceptor surface 1. Electrostatic latent image 4. This causes the inconvenience that the electric charge is lost.

Furthermore, when an insulating developer is used, since the developer particles are charged by friction, it is not necessary to apply a bias voltage between the mesh screen 5 and the photoreceptor surface 1. Although it is not absolutely necessary, it is desirable to apply a bias voltage in the range of usually 600 V or less (secondarily, it is desirable to strengthen the electric field that is formed to quickly transfer the developer particles to the photoreceptor surface 1).

Also, of course, this P! When a positively charged electrostatic image is formed on the photoreceptor surface 1, the edge-type developer is of the two-phase type, and the negatively charged electrostatic image is formed by friction. If it is formed, it must be of the type that is positively charged by koto-shiro.

In the present invention, when applying a bias voltage, it goes without saying that the front side of the photoreceptor must have the same polarity as the charge of the electrostatic image formed thereon.

As mentioned above, the present invention has the feature that it can use any of the commonly used conductive and insulating developers, but the most important thing is that it uses a developer with a relatively simple structure. In such a case, the second embodiment of the present invention will be an embodiment in which an insulating developer is used.

Further, although the present invention uses a developer having a simple structure, it has the advantage that no special device such as a magnetic brush mechanism is required.

The invention is illustrated by the following example.

Example 1 A zinc oxide photoreceptor made by blending zinc oxide and resin was prepared on an 80μ aluminum plate as a photoreceptor.

Next, a developing container having an 80-mesh mesh screen (made of brass) provided at its opening was installed so that the mesh screen faced the surface of the photoreceptor prepared earlier with an interval of 1.5 mm. A mesh screen (made of brass) with 60 meshes is provided inside this developing container.

Next, this developer container was filled with conductive toner, and it was confirmed that no toner leaked from the mesh screen.

Furthermore, the photoreceptor is charged with an applied voltage of -6.5 KV, and then image exposure is performed, so that the potential of the white background part becomes -40 KV.
Exposure was continued until the potential of the V, j11++ image area reached 1800 V+. After confirming the surface potential of the photoreceptor (11), the mesh screen at the opening is set to +500cm.
When a bias voltage of +650V was applied to the charging mesh screen and the developing container was passed over the latent image on the photoreceptor at a distance of 1.5 cm, the image area was 0.7 and the non-image area was O0 old. An image with a reflection density of .

Example 2 As a photoreceptor, zinc oxide,
A zinc oxide photoreceptor blended with resin was prepared.

Next, a developing container having an 80-mesh mesh screen (made of brass) installed in its opening was prepared and installed so that the mesh screen faced the surface of the photoreceptor prepared earlier at an interval of 20 meshes. This developer container is equipped with a stirring roller whose surface is coated with Teflon.

Next, this developer container was filled with insulating toner (toner for 2436 machines manufactured by Sanda Kogyo KK), and it was confirmed that no toner leaked from the mesh screen.

Furthermore, the photoreceptor is charged with an applied voltage of -6.5 Kvolts, and image exposure is performed continuously.
I continued to expose to light until it became .

After confirming that the surface potential of the photoreceptor reaches the above state,
ii) While rotating the stirring roller and applying a bias voltage of +200 volts to the screen mesh, the photoreceptor layer ('! .85, non-image area 0.
An image with a reflection density of 0.01 was obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a copying process using the developing method of the present invention, FIG. 2 is a principle diagram for explaining the developing method of the present invention using conductive toner, and FIG. 1 is a principle diagram for explaining the developing method of the present invention using an insulating toner. FIGS. 4 and 5 are diagrams showing embodiments of the present invention. 1... Photoreceptor 4... Electrostatic latent image 5...
・Mesh screen 6...Developer supply container 7・
...Developer 8...Charging means 9...Mesh screen 10...Agitating roller Fig. 2 7 @4 Fig. 5

Claims (1)

[Scope of Claims] (1) A photoconductor and a developer supply container having a supply opening near the surface of the photoconductor are provided, and the Coulomb force between the electrostatic latent image formed on the surface of the photoconductor and the developer particles is In the developing edge method in which the developer particles are transferred to the surface of the photoreceptor to form a visible image, the developer is charged by a charging means provided in the developer supply container, and the developer is supplied to the developer supply container. A mesh screen made of conductive mesh is provided in the opening,
A developing method characterized in that developer particles are transferred to the surface of a photoreceptor through the openings of the mesh screen. (2) Claim 1, in which the mesh screen Ml is provided at a distance of 3= or less from the surface of the photoreceptor.
The current method described in Section [Both methods. The developing method described in item 2 or item 2. (4) The method according to any one of claims 1 to 3, wherein the charging means is a conductive mesh screen to which a bias voltage is applied between the charging means and the photoreceptor. (5) The development according to Claims 1 to 3, wherein the charging means is a stirring device made of an insulating material, and the developer is an insulating toner. Method.