JPS58195865A - Separator for transfer material in electrophotographic device - Google Patents

Abstract

PURPOSE:To separate a transfer material formed thereon with the image of a one-component magnetic toner always satisfactorily with simple constitution, by specifying the quantity of destaticization to be applied on a destaticizer for sepn. of the transfer material and making combination use of a magnetic for sepn. CONSTITUTION:A specified quantity of destaticization at which a transfer material 4 having a solid white forward end can be separated from a photosensitive drum 1 is applied on a destaticizer 3 for sepn., so that the material 4 is separated surely from the drum 1. On the other hand, if the forward end is solid black, the one component magnetic toner transferred on the paper 4 wherein the attractive force to the drum 1 is generated by the excessive destaticization is sucked by a magnet member 5 provided together with the destaticizer 3 and the material 4 is separated surely from the material 1. The transfer material formed thereon with the image of the one-component magnetic toner is thus separated from the photoreceptor always satisfactorily with the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer material peeling device in which a part of a separation static eliminator is provided with a member having magnetic force.

Regarding peeling off of conventional transfer materials, in those that have been put into practical use, immediately after the toner image on the latent image carrier is transferred by irradiating a DC corona with a polarity opposite to that of the toner charge, an AC corona or the like is used to remove the toner image. ] The transfer material is separated by eliminating static electricity, but in the case of flat black and flat white, the transfer material is separated KI! The effective static elimination current is different, and there is a superimposition to control this.

As a control method, ■ MuC
KDC is superimposed and the discharge current is adjusted to
A method of controlling the discharge current by changing the cv pel.
A method using f1 constant current difference transformer, etc. has been proposed.

However, if a part of the leading edge of the transfer material is slightly black, and the machine has a relatively fast copying speed, the change will occur]4-/
The A4 ivy circuit has sufficient response speed and does not cause separation failure.

In a conventional electrophotographic apparatus having a transfer charger and a separation charge remover, 1. A toner image formed by a latent image forming plate and a drop device without a photosensitive dot is first applied to a transfer material by the action of a transfer charger. After being transferred, the transfer material is subjected to a transfer corona discharge, lands on the sensitive drum, and comes to the separation logic area where the separation static eliminator acts in the nine-state state. When it comes to ζO, the tip of the transfer material is sometimes flat white and sometimes flat black.
It is necessary to remove more static electricity when it is white than when it is solid white.This is related to the characteristics of the photoconductor, but the latent scratch potential is different when it is solid white and when it is black. This is due to the differences between the transfer material and the photoreceptor, and when pressure is applied to apply a certain amount of charge removal sufficient to stably separate solid white, there will be too much charge removal for flat black, resulting in transfer failure. Immediately after the charge is removed, it becomes reversely charged and adsorbed to the photoreceptor, resulting in poor separation. If a constant amount of static electricity is removed for a solid black that is smaller than that for a flat white that is sufficient for stable separation, the amount of static electricity removed will be insufficient for a solid white, resulting in poor separation as well. Become. Therefore, regardless of whether the tip of the transfer material is flat white or black, it is desirable to equalize the potential after transfer, but it is difficult to achieve this. K requires a complicated control device.

The present invention has been made in consideration of the above-mentioned circumstances, and is provided with a magnetic member that acts on the magnetic toner to exert a separating action, and the separating static eliminator is equipped with a magnetic toner that can be used when the leading edge of the transfer material is completely white. The various problems of the prior art can be solved by a simple structure that provides a constant amount of charge removal sufficient to separate the two. In other words, this invention O1! This includes a transfer charger for electrostatically transferring a one-component magnetic toner image from a latent image carrier to a transfer material, and a separation device for electrostatically separating the transfer material from the latent image carrier. In an electrophotographic apparatus equipped with a static eliminator, 1
The separation static eliminator is designed to provide a certain amount of static electricity removal sufficient to separate the isthmus at the tip of the transfer material (in the case of sunset O), and is equipped with a magnet S material that does not exert a separating effect on this part. The transfer material separation device is characterized by:

Embodiments of the present invention will be described in detail below with reference to the drawings. Figure 1 shows that the corona wire in the separation static eliminator is 1
An example in the case of a book is shown, and the second FjA also shows an example in the case of two corona wires. In these figures, l is a photosensitive drum, 2 is a transfer charger, B, 3
' is a separation static eliminator, 4 is a transfer material, and 5 is a magnet member that forms part of the gist of the present invention.

In the embodiment shown in FIG. 1, the magnet member 5 is disposed with its magnetic pole close to the photosensitive drum 1 on the transfer material 4 entry side of the separation static eliminator 3), and in the embodiment shown in FIG. is disposed at an intermediate portion Ktii of the two corona wires in the separation static eliminator 3', with its magnetic pole close to the photosensitive drum l. And separation static eliminator 3 prongs a
3'Kti, when the leading edge of the transfer material 4 is completely white, a certain amount of static electricity removal sufficient to separate the armpit portion is applied.

To explain the operation of the present invention having the above configuration,
The toner particles formed on the photosensitive drum IK by a latent image forming means and developing device (not shown) are transferred to the transfer material 4 by the transfer charger 2.
The transfer material 4 enters the region where the static eliminator 3 is disposed in close contact with the photosensitive drum 1 (due to the action of transfer corona discharge by the transfer charger). Assuming that the tip of the transfer material 4 is a flat white, the transfer material 4 can be easily separated because the separation device 3 is given a certain amount of charge removal sufficient to separate the armpit region. . Furthermore, if the leading edge of the transfer material 4 entering the separation static elimination area is a solid black, the static electricity will be removed excessively as described above, and an adhesion force to the photosensitive drum l will be developed due to reverse charging. The magnetic attraction force of the magnet member 5 acts on the transferred one-component magnetic toner, overcomes the ai force, and easily separates the transfer material 4 before the static electricity is removed too much.

Furthermore, if the magnet st electromagnet is set to generate a magnetic force of one polarity with the toner only when the leading edge of the transfer material 4 passes in synchronization with the paper feed timing, the subsequent image on the transfer material 4 will not be disturbed. First, it has an excellent effect of not accumulating scattered toner.

When using two or more 1-separation static elimination corona wires as in the 2nd WA, some corona wires can be controlled to provide an appropriate amount of static elimination without passing any static elimination current. In this case as well, the magnetic force of the magnet member 5 makes the separation more stable.

As is clear from the above description, according to the present invention,
The separation static eliminator has a simple structure that provides a certain amount of static electricity removal sufficient to separate the isthmus when the tip of the transfer material is flat white, and is provided with a magnet member that exerts a separating action on the isthmus. , regardless of whether it is solid white or solid black, the transfer material can be separated stably at all times, and it contributes to improving the performance of electrophotographic equipment without disturbing the transferred image or accumulating scattered toner. The place is extremely large.

[Brief explanation of drawings]

FIG. 1 is a schematic side sectional view showing one embodiment of a transfer material separating device according to the present invention, and FIG. 2 is a schematic side sectional view showing another embodiment. 1: Photosensitive drum, 2: Transfer charger, 3: Separation static eliminator, 4: Transfer material, 5: Magnet member. Figure 1 Figure 2

Claims (1)

[Claims] - a transfer charger for electrostatically transferring the component magnetic toner from the latent image carrier to the transfer material; - a separation static eliminator for electrostatically separating the transfer material from the latent image carrier; In an electrophotographic apparatus equipped with the above-mentioned separating static eliminator, a constant O#11 that is sufficient to separate the chain portion when the leading edge of the transfer material is flat white is used.
A transfer material separation device characterized by being provided with a magnetic member that provides a separation effect on a chain portion.