JPH0347504B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image recording apparatus, particularly an apparatus for recording an image by applying a controlled voltage to an electrode group for image formation and selectively moving a developer to a recording medium. It is something.

Conventionally, several methods have been proposed in which a layer of developer powder (toner) is formed and a voltage is applied to a pin electrode or the like to partially transfer the toner to directly obtain an image on plain paper. These methods have the advantage that images can be directly obtained on a recording member using plain paper through simple steps. However, the toner adheres to the toner conveying member, and the adhesion force varies depending on the individual toner. For this reason, a large voltage is required for recording, and there is a drawback that the density is low and fogging tends to occur. Further, precision is required in the distance between the recording member surface and the toner, and even a slight change will change the conditions for forming the best image.

An object of the present invention is to eliminate the drawbacks of the above-mentioned conventional examples, and to reduce the adhesion force of toner to a toner transport medium at the recording position, reduce the applied voltage required for recording, and obtain clear images without fogging. An object of the present invention is to provide an image recording device that makes it possible to achieve this goal.

The present invention achieves the above object by disposing a recording member close to a toner layer on a toner carrying member, and disposing a recording member close to or in contact with the recording member on the opposite side of the recording member facing the toner carrying member. In a device that records an image by applying a controlled voltage to a set of arranged electrodes, an electrode is provided close to a toner carrying member near the upstream side of the electrode group, and an alternating voltage is applied between the electrode and the toner carrying member. is applied.

Hereinafter, the present invention will be explained in detail according to one embodiment.

FIG. 1 is a sectional view of a recording apparatus showing an embodiment of the present invention, in which 1 is a recording member, 2 is an electrode member for applying an image-like signal voltage, and 3 is means for transporting toner to a recording position. The toner 5 in the container 4 is a one-component magnetic toner, and a non-magnetic cylindrical toner conveying member 6 has a magnet 7 inside that rotates in the direction of the arrow, and uses a magnetic field to convey the toner in a direction opposite to the direction of rotation of the magnet. . The toner conveyed by the doctor blade 8 is made into a uniform thin layer and reaches the recording position. The toner that has reached the recording position 10 adheres to the recording member 1 when a voltage is applied to the electrode 9 in the width direction of the recording member, forming an image. The toner image on the recording member 1 may then be fixed by means such as heating or pressure, or the recording member 1 may be configured to be endless and the toner image on this member 1 may be transferred to another recording member. You can use it as well.

Next, the second image is an enlarged view of the vicinity of recording position 10.
As shown in the figure.

As shown in the figure, electrodes 11 are arranged near the upstream side of the recording position 10 when viewed in the direction of movement of the toner transport member 6, with a minute interval between them, and an alternating current is connected between the electrodes and the toner transport member. A modified AC voltage is applied. The toner that has moved to the vicinity of the electrode 11 receives a force that causes it to reciprocate between the electrode 11 and the toner transport member 6 due to the action of this alternating current electric field. When the toner is insulating, it is effective to mix or mix a charge control agent with the toner to facilitate charging to a specific polarity.

When the toner is subjected to the force of reciprocating movement between the electrodes in this way, and a voltage is applied to the electrode 9 while the toner is not attached to the toner conveying member 6 or the adhesion force is weakened, the toner is easily recorded. It moves to member 1 and attaches to it. Therefore, stable recording is possible with a low applied voltage. For high-speed recording, the electrodes 9 are preferably arranged in a state in which a large number of electrodes are arranged in the width direction of the recording member, as is well known.
~20 electrodes are arranged, and each electrode 9 is individually connected to a signal source. It is also effective to shift the positions of adjacent electrodes to form two rows in order to further increase the recording density.

The distance between the toner conveying member 6 and the recording member 1 is 50~
It is desirable that the thickness be 300 microns, and for example, when the thickness is 200 microns, image formation is possible with an applied voltage of about 200V. Further, the distance between the electrode 11 and the toner conveying member 6 is preferably approximately the same as the distance between the toner conveying member 6 and the recording member 1, and is preferably 100 to 500 microns. For example, when the spacing is 100 microns, the above effect occurs even with an AC voltage of about 200V. As for the method of applying the AC voltage, a constant DC voltage may be applied to one of the electrode 11 and the toner transport member 6, and an AC voltage may be applied only to the other, or as shown in FIG. The voltage may be applied only to 11. The frequency of the alternating voltage is selected from several hundred hertz to several tens of kilohertz depending on the recording speed.

As explained above, by applying an AC voltage to the toner on the toner conveying member near the recording position 10, the adhesion force of the toner to the toner conveying member is weakened, and by applying a low applied voltage, image recording is possible. Furthermore, changes in toner properties due to environmental changes and fluctuations in adhesion due to variations in individual toner particles have less influence on recording properties, so stable recording is always possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a recording device to which the present invention is applied;
FIG. 2 shows a partially enlarged sectional view of the recording position. In the figure, 1 is a recording member, 2 is a recording electrode, 6 is a toner conveying member, and 11 is an electrode to which an alternating voltage is applied.

Claims (1)

[Claims] 1. A recording member is disposed close to a toner layer on a toner carrying member, and a recording member is disposed close to or in contact with the recording member on the side opposite to the side facing the toner carrying member. In a device that records an image by applying a controlled voltage to an electrode group, an electrode is provided close to a toner carrying member near the upstream side of the electrode group, and an alternating voltage is applied between this electrode and the toner carrying member. image recording device.