JPS6219879A - Electrophotographic recording method - Google Patents

Abstract

PURPOSE:To simplify circuit constitution without applying any high voltage by charging toner electrostatically through a semiconductor switching element to the opposite polarity from the electrostatic charging polarity of a recording electrode. CONSTITUTION:Numbers of recording electrodes 2 are provided on the surface of an insulating base 1 and the magnetic toner 3 is stuck on surfaces of the base 1 and electrodes 2. This toner 3 is supplied from a toner reservoir 4 and its thickness is controlled by a toner layer thickness control member 5. Further, an electrostatic charger 9 is arranged behind recording paper 8 which is conveyed in parallel opposite the electrodes to charge the recording paper 8 positively. The semiconductor switching element 6 is connected to the electrodes 2, and a driving signal generating means 7 is connected to the base of the element 6, whose emitter is connected to a negative bias power source. Then, the toner 3 is charged through the element 6 to the opposite polarity from the electrodes 2 and thus the circuit constitution is simplified without applying and high voltage to reduce the size of an electrophotographic recording device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic recording method for forming an image on recording paper by controlling toner adhesion using electrical signals corresponding to image information.

(Prior Art) As a conventional technology, for example, there is USP-3816840. A rotating magnet is installed inside a conductive hollow cylindrical toner transport member, and a number of signal electrodes made of magnetic material are installed on the surface of the toner transport member, electrically insulated from each other. It is. A character generator is connected to this signal electrode. A portion of the toner conveying member is embedded in a toner container containing conductive magnetic toner. The insulating recording body is close to and facing the signal electrode, and the back electrode is in close contact with the back surface of the recording body. When the magnet rotates counterclockwise, for example, the conductive magnetic toner moves clockwise along the surface of the toner transport member while forming spike-like toner chains as the magnetic field changes. When this moving conductive magnetic toner reaches the signal electrode, a spike of conductive magnetic toner is formed at the tip of the signal electrode.

At this time, by applying a signal voltage according to the image information from the character generator to the signal electrode, the recording medium is charged through the ears of conductive magnetic toner formed by the voltage difference between the voltage applied to the signal electrode and the back electrode. The conductive magnetic toner adheres to the surface of the recording medium.

Furthermore, since the recording medium is moving rightward, images are continuously formed on the recording medium.

An improved version of the above-mentioned device uses a method that combines photoconductive magnetic toner and light instead of conductive magnetic toner, and divides the recording signal electrode to form a toner image on the recording medium. There is a device (Japanese Unexamined Patent Publication No. 59-104959). In addition, each of the signal electrodes is partially formed of a photoconductive material, and electrical connection between the tip of the electrode and the signal voltage source can be realized only through the photoconductive material.
These electrodes are divided into multiple groups, and each group is provided with a light source that shines light on the photoconductive material of the electrode group, and the corresponding electrodes of each group are connected to a common electrical connection line for recording. There is an apparatus (Japanese Unexamined Patent Publication No. 146865/1983) that uses a method of forming a toner image on the body. Furthermore, a linear conductor is stretched on the toner conveying surface in a direction perpendicular to the moving direction of the moving magnetic pole, and the electromotive force induced between the ends of this wire is detected, and this is used to determine the magnetic pole position and image signal voltage application. There is a device (Japanese Unexamined Patent Publication No. 59-152875) designed to synchronize the following.

(Problems to be Solved by the Invention) In the above-mentioned USP-3816840, the toner adheres to the recording medium because the toner is conductive, so each toner chain substantially becomes one conductor, and when a voltage is applied, the toner adheres to the recording medium. Charges of opposite polarity to the charges on the back side of the insulating material layer of the recording medium are induced at the tip of the toner chain through the toner chain, and the electrostatic attractive force of these two charges overcomes the magnetic force of the magnet to attract the toner particles at the tip of the recording medium. It is attached by suction to. Therefore, a sufficient charge must be induced at the tip of the toner chain, and a sufficient voltage must be applied to each electrode. If the recording medium is set to 218 mm and a resolution of 10 lines per L mm is to be obtained, 2160 electrodes are required.
The same number of drive power supplies are required, which has the drawbacks of increased cost and increased size of the device. The above-mentioned Japanese Patent Application Laid-Open No. 59-104959, which is an improvement on this drawback, uses a method of combining photoconductive magnetic toner and light instead of conductive magnetic toner and dividing the signal electrode for recording. The wiring is arranged in each block, and each block is sequentially scanned. However, in this case, it is necessary to sequentially or selectively drive the divided light sources and sequentially or selectively drive the electrodes for each block, and it cannot be said that this is a sufficient improvement. Further, in JP-A-59-146865, since a photoconductive material is used, an optical lens system that does not affect other blocks is required. In all of these conventional techniques, it is necessary to induce the charge necessary for adhesion of the toner itself to the tip of the toner chain, and the drive system must be capable of sequentially or selectively applying a relatively high voltage to each electrode. However, it is complicated and costly.

An object of the present invention is to provide a simple electrophotographic process with a small number of steps, eliminate the need for high voltage, simplify the circuit configuration, and provide an electrophotographic recording method that can quickly transfer toner to paper. It's about doing.

(Means for Solving the Problems) The electrophotographic recording method of the present invention includes providing a plurality of recording electrodes 2 on the surface of an insulating support 1 at small intervals and insulated from each other,
Uncharged toner 3 is uniformly adhered to the surfaces of the insulating support 1 and the recording electrode 2 located opposite the recording paper 8, the recording paper 8 is charged, and the semiconductor switching element 6 connected to the recording electrode is charged. A charge having a polarity opposite to that of the recording paper 8 is injected into the toner 4 on the recording electrode through the toner, and the toner injected with the opposite polarity is attached to the recording paper by attraction Coulomb force.

(Function) In the electrophotographic recording method of the present invention, a charge having a polarity opposite to that of the recording paper 8 is injected into the toner 3 on the recording electrode 2 via the semiconductor switching element 6, and the charged recording paper 8
Since the adhesive is attached to the recording paper by suction Coulomb force, there is no need for a back electrode on the back of the recording paper, and the circuit configuration is simple. Further, only one high-voltage power source is required, which is the charger 9 for charging the recording paper 8.

(Example) FIG. 1 shows a principle diagram of an electrophotographic recording method according to the present invention. A large number of recording electrodes 2 are provided on the surface of the insulating support 1. For example, 2,160 of these recording electrodes are provided insulated from each other at a pitch corresponding to the resolution or at intervals smaller than that, and are arranged in a line in a direction perpendicular to the conveyance direction of the recording paper 8 as shown in the second figure. It is a provision. Magnetic toner 3 is adhered to the surfaces of the insulating support 1 and the recording electrode 2. The toner 3 is supplied from a toner reservoir 4, and is adjusted to have a thin and uniform layer by a toner layer thickness adjusting member 5.

adjusted. The recording paper 8 that is conveyed in parallel facing each of the recording electrodes 2 is charged by a charger 9 disposed on the back side thereof.
In this example, it is charged positively. A weak suction Coulomb force acts between the toner 4 and the positively charged recording paper 2, but the toner 4 is transferred to the recording paper! The toner is not transferred at this stage because the force is not strong enough to do so. Recording electrode 2
is connected to the collector of an NPN type transistor as the semiconductor switching element 6, and the drive signal generating means 7 is connected to the base of the transistor 6. Further, the emitter of the transistor 6 is connected to a negative bias power supply, and this bias power supply is connected to the base of the transistor 6 via a resistor R. Recording electrode 2 and semiconductor switching element 6
and the drive signal generating means 7 in one-to-one correspondence.

Note that the semiconductor switching element may be a PNP type transistor, or may be one that charges the recording paper 8 negatively and injects positive charges into the toner 3, and appropriate connections are made depending on each. Further, as the semiconductor switching element, an FET or the like can be used instead of a transistor.

During recording, the toner 3 is conveyed to the surface of the insulating support 1 with a uniform thin layer thickness by the toner layer thickness adjusting member 5, and is conveyed to the surface of the recording electrode 2. When the drive signal from the drive signal generating means 7 flows to the base of the semiconductor switching element 6, and thereby a collector current flows, charges of opposite polarity to the charges on the recording paper 8 are injected into the toner on the recording electrode 2. . The negatively charged toner that has been injected with charges of opposite polarity receives an attraction Coulomb force between it and the recording paper 8 that is positively charged by the charger 9, and repulses between the negatively charged toner and the recording electrode 2. Coulomb force acts and the toner is transferred to the recording paper 2.

(Effects of the Invention) As described above, the present invention injects a charge having a polarity opposite to that of the recording electrode into the toner via a semiconductor switching element, so there is no need to apply a high voltage as in the conventional method. This simplifies the circuit configuration, making it possible to reduce the size and cost of the device. In addition, it is a high voltage power supply of several kilovolts,
In this case, there is only one charger for the recording paper, and the bias power supply for injecting charge into the recording electrodes only needs to be several hundred V.
The configuration can be simplified.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention, and FIG. 2 is a partially cutaway plan view showing recording electrodes. DESCRIPTION OF SYMBOLS 1... Insulating support body, 2... Recording electrode, 3... Toner, 6... Semiconductor switching element. 8... Recording paper, 9... Charger. that's all

Claims (1)

[Claims] A plurality of recording electrodes are provided at small intervals and insulated from each other on the surface of an insulating support, and a plurality of recording electrodes are provided on the surface of the insulating support and the recording electrodes located opposite to the recording paper. Charged toner is uniformly attached, the recording paper is charged, and a charge having a polarity opposite to that of the recording paper is injected into the toner on the recording electrode via a semiconductor switching element connected to the recording electrode. . An electrophotographic recording method, characterized in that the toner injected with charges of opposite polarity is made to adhere to the recording paper by suction Coulomb force.