JPS5975265A - Picture forming device - Google Patents

Abstract

PURPOSE:To facilitate picture formation by impressing an electruic field which moves toner as electrified particles from a base electrode to a signal electrode in a specific aperture of an aperture board only when an alternating electric field which moves the toner from a conveying member to the aperture board operates between the conveying member and base electrode 3 by an AC power source. CONSTITUTION:When an AC electric field with an output waveform (b) from the AC power source 8 is impressed between the toner conveying member 7 and base electrode 3, an output voltage is supplied from a signal source 10 to a signal electrode 1 to pass the toner 11 through an aperture 4 all the time only when AC electric field polarity between the members 7, 3 is the polarity directing the toner 11 from the conveying member 7 to the base electrode 3; and the signal output is synchronized with the output waveform from the AC power source 8 to obtain a uniform picture free of dot absence and picture unevenness. Further, it is unnecessary to increase an AC frequency and the control response speed of the toner 11 is also increased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus that utilizes an electric field generated in an aperture, and in particular to an image forming apparatus that directly controls the passage of a powder-like agent (hereinafter referred to as toner) through an aperture using an electric signal. The present invention relates to an image forming apparatus that uses a method (charged particle flow modulation type image forming method) to obtain the following.

U.S. Patent No. 368 is a conventional direct recording technology of this type.
This is proposed in the specification of No. 9935. In this method, two electrodes are provided with an insulating layer interposed between them, and a number of holes are formed in a row (toner control member).

Hereinafter, it will be referred to as an aperture board. ), the passage of charged toner is controlled by this aperture board, and an image is obtained by the toner passing through a recording member (receiver) provided with an IF on the opposite side of the toner supply source. It is.

Figure 1 shows the principle of acid formation in the above image forming method.
is the aperture board. As shown in FIG. 2 as a partial plan view and as shown in FIG. 3 as a vertical cross-sectional view, the aperture board A has an insulating member 2 inside it, with the insulating member 2 arranged independently along the length of the insulating member on its H surface. Numerous signal electrodes 1 (first electrode) formed
and a base electrode 3 (second electrode or reference electrode) formed on the lower surface.

It is a horizontally long board consisting of apertures 4 of approximately the same area formed through the nuclear signal electrode 1, the insulating member 2, and the base electrode 3 for each signal electrode 1. The number of signal electrodes 1 may be one row along the length of the board, but there may be nine. In order to further improve the degree of deoxidation, two rows of signal electrodes are provided along the upper and lower longitudinal sides of the board in Figure 2F. This figure shows a structure in which two rows of apertures are arranged close to each other. 1a is a lead wire of each signal electrode. The base electrode covers the entire opening 41/i' of the board.

Alternatively, a plurality of pieces are consecutively formed into a set.

6 LL A back electrode disposed close to the surface of the signal electrode 1 side of the above 7 aperture board A; 5 is a recording member such as paper; the recording member is introduced between the aperture board A and the back electrode 6, and the back electrode From 6Vr close contact 1 to 6Vr, it is transported (sub-scanning movement) in the direction of the arrow at a predetermined speed.

Reference numeral 7 denotes a toner conveying member made of a non-magnetic material that moves in the direction of the arrow as it approaches the surface f on the pace electrode 6 side of the aperture board A, and the one-component insulating toner 11 is uniformly applied to the surface on the board A side. It is coated.

8 are the base electrodes 3 and 1 of the aperture board A. +) between the toner conveying members 7j (an AC 1! source that applies an AC voltage or a DC-biased AC voltage; a voltage g that applies a DC voltage between the back electrode 6 and the base electrode 3 of the aperture board A);
, io is a signal power source that selectively applies an electric signal between each signal electrode 1 and base electrode 3 of the aperture board A in accordance with the time-series pixel signal f of the image group to be formed. The time-series pixel signals are calculated and output from, for example, a photoelectric image reading device or an electronic computer.

1. In the above configuration, the base electrode 3 and the toner transport member 7
When an alternating current voltage or a DC biased alternating current voltage is applied between them, the toner 11 on the conductive material 7 moves between the base electrode 3 and the toner conveyor 7. At this time,
When a voltage is applied to the signal electrode 1 and the base electrode 3 from the signal power supply 10, the toner 11 that is moving passes through the aperture 4 and is attracted to the signal electrode 1. Further, since a DC voltage is applied between the back electrode 6 and the base electrode 3 from the DC power source 9, the toner 11 is further accelerated and adheres to the recording member 5.

When there is no signal voltage from the signal power source 10 to the signal electrode 1 and base electrode 3, or when an electric field in the opposite direction is applied,
The dynamic toner does not pass through the aperture 4. In addition, between the base electrode 3 and the toner conveyor 7, the toner moves back and forth due to the action of an alternating current voltage, and at the same time has a cleaning effect.

Thus, a signal power source 1 is connected between each signal electrode 1 and the base electrode ff13.
By selectively applying an electrical signal corresponding to the time-series pixel signal of the number of strokes to be formed from 0 (main scanning), and transporting the recording member 5 in the direction of the arrow at a predetermined speed (sub-scanning), the recording member 5 is By selectively passing the toner through the openings described above, gaps between toner surfaces are sequentially formed on the five surfaces. This formed toner image is then fixed to the surface of the cleaning member using a pressure-type, heat-type, or other fixing device (not shown).

When the polarity of the toner particles 11 has a negative H charge, the polarity of the voltage supplied from the signal power supply 10 is the base electrode 3V negative (to), the signal electrode 1 positive f-1-1, and the DC power supply 9 The supply voltage polarity from base i! Negative (-) at the pole.

Back electrode 6 Make sure that +IR is positive (G). Also,
Although the ground potential may be placed anywhere, the base electrode is usually grounded. If the polarity of the toner 11 is reversed 1 (positive←→, the above-mentioned polarity is reversed).

By the way, in the image forming apparatus as described above, if the AC frequency from the AC power source 8 and the signal voltage from the signal power source 10 are not synchronized, the toner may not pass through the apertures 4. , or a frequency higher than the signal time must be used, which is not efficient.

This will be explained using the voltage waveform diagram shown in FIG.

a is a signal waveform from the signal power source 10, and b is an AC voltage waveform from the AC power source 8. Signal electrode 1 as shown in part C now
If a signal voltage of 1ca is applied, the IC at that point 1
(IC where the alternating current voltage polarity is dynamic) It is sufficient if it acts as an electric field with a force that directs the toner 11 from the toner conveying member 7 to the base electrode, but the signal voltage a(τ On the other hand, if an electric field with a force such that the AC voltage polarity at that point 1/i' pushes the toner 11 back from the base electrode 3 toward the toner transport member 7 side acts in a timely manner, the toner 11 will not reach the recording member 5 at all. If there is no or the amount is small, unevenness and missing dots occur during image formation.In order to prevent this, attempts are being made to solve this by increasing the output frequency from the AC power supply 8, but as the frequency increases, The toner 11 cannot respond to the AC electric field IF and cannot perform reciprocating motion, making it difficult to form an image.

The present invention aims to solve this problem, and an alternating electric field that directs the toner 11 as charged particles from the conveying member 7 to the aperture board A, which is connected to the control member 1- is an alternating current [#RV The present invention is characterized in that an electric field is applied in which toner moves from the base electrode 3 to the signal electrode 1 within a predetermined opening of the aperture board only when the toner acts between the conveying member 7 and the pace electrode 3.

That is, this will be explained using the voltage waveform diagram in FIG.

When an AC electric field with an output waveform like b is applied from the AC power supply 8 between the toner transport member 7 and the base electrode 3, the polarity of the AC electric field between the members 7 and 3 causes the toner 11 to be transferred from the transport member 7 to the base electrode. If the output voltage from the signal power source 10 is applied to the signal electrode 1 only when the polarity is such that the toner 11 is directed toward the toner 3, the toner 11 will always pass through the aperture 4, and the problem described above with reference to FIG. 4 will not occur. . By synchronizing the signal output with the output waveform from the AC power supply 8, it is possible to obtain a uniform image without missing dots or image unevenness, and there is no need to increase the AC frequency. -110
It has also become possible to increase control response speed.

Columns 4 and 5 of the same figure show how the input signal a is applied to one pixel at a time, but there is no problem even if the signal voltage a is continuously applied after the AC voltage starts. .

FIG. 6 shows an example of a circuit for synchronizing the output waveform of the AC power source 8 and the signal output a.

In the figure, reference numeral 12 denotes a signal processing circuit that processes image signals obtained from a solid-state camera such as a CCD to measure the original density.

The time per pixel (Glock pulse) in the sub-scanning direction of an electrical signal from a computer, communication line, etc. is read, and this clock pulse in the sub-scanning direction is given to the AC power supply 8, and this pulse frequency is used as the AC frequency and internal to the AC power supply 8. is amplified.

This is applied as a high-voltage AC output voltage to the base electrode 6 and the toner transport member 7. Furthermore, the above Glock pulses are supplied to an AND circuit 13 in the character generator 15, and are processed all at once so that a signal is output only when a Glock pulse is applied, thereby achieving synchronization.

The frequency of the above-mentioned clock pulses can also be multiplied by an integral number by a multiplier circuit 14 before entering the AC-type clock pulse.

In addition, when the apertures 4 are arranged in a staggered arrangement or in a staggered arrangement of six or more rows or a variation thereof, the gap iD between each row of the apertures is set as shown in Fig. 7, and X is set to the value in the main scanning direction. , all openings are uniformly supplied with toner.

In the example shown above, the toner 11 is used as the charged particles, and the toner 11 is selectively adhered to the 5 surfaces of the recording member to directly form a visible band. A charged particle generator such as an AC corona latent electrode is disposed on the surface of the recording member, and the charged particles are selectively attached to the recording member's 5 surfaces ((()) and once an electrostatic latent image is formed (()). The present invention can also be applied to a device that subsequently visualizes the latent trace (synchronizes the frequency of the AC power source and the signal power source).

[Brief explanation of the drawing]

Fig. 1 is a schematic view of the essential parts of one row of the image forming device which is the object of the present invention, Fig. 2 is a plan view of a part of the aperture board, Fig. 3 is a vertical sectional view thereof, and Fig. 4 is Correspondence graph of AC voltage waveform and signal voltage waveform with out-of-synchronization parts, Fig. 5 is the same graph as above when synchronized, Fig. 6 is synchronous trunk rotation 18
For example, FIG. 7 is an explanatory diagram of the relationship between the arrangement of apertures and the linear density. A is an aperture board, 5 is a recording member, 6 is a back electrode,
7-piece toner conveying member.

Claims (1)

[Claims] (1) A developing agent conveying member that holds and conveys the charged powder developing agent, a receiving body that receives the developing agent from the conveying member, and an opening that allows the developing agent to pass through; A control member having a reference electrode and a signal electrode facing each other with an insulating layer disposed between the control member and the acid body. means for applying a voltage to the signal electrode to generate an electric field within the aperture of the control member; means for generating an alternating voltage between the transport member and the control member; and a means for generating a DC electric field between the apertures, and only when an alternating electric field acts such that the charged particles move from the transport part to the control member, an electric field is generated in the aperture that causes the charged particles to move from the reference electrode to the signal electrode. An image forming apparatus characterized by applying a voltage.