JPH0764088B2 - Driving method for electrostatic latent image forming apparatus - Google Patents

Description

The present invention relates to a method for driving an electrostatic latent image forming apparatus that modulates an ion flow to form an electrostatic latent image on a dielectric.

[Conventional technology]

Generally, the principle of electrostatic recording using an ion stream will be described with reference to FIG. 5. Ions generated in the electrostatic recording head 11 form an electrostatic latent image 13 on the recording medium on the surface of the rotating drum 12, A developer such as toner is attached to the electrostatic latent image 13 by the developing device 14 to form a toner image 15, and the toner image 15 is transferred to the recording sheet 17 at the transfer section 16 to perform electrostatic recording. . Then, after the charge of the recording medium is removed by the charge removing unit 18, the remaining developer is removed by the toner removing unit 19 to prepare for the next recording.

Conventionally, as the ion flow generation method in the electrostatic latent image forming apparatus, the pin-shaped electrodes are arranged in a line and brought into contact with the dielectric,
A direct electrostatic recording method is known in which a direct discharge is generated between the dielectric and the dielectric, but the gap between the electrode and the dielectric must be maintained with high accuracy, and the discharge cannot be stabilized. There was a defect that the electrodes were worn out.

Various indirect electrostatic recording methods are known to eliminate the above-mentioned drawbacks. For example, FIG. 6 shows a system proposed in Japanese Patent Application Laid-Open No. 57-101863, in which a corona ion generator 11 is used.
Has a corona wire 21 built in a shield 20, and a common electrode 22 is provided below the ion generator 11 with an insulating layer 23 interposed therebetween.
a and a control electrode 22b are provided, and ions generated in the ion generator 11 are led out from the ion passage hole 24 to charge the dielectric 25 in accordance with the electric field strength between the common electrode 22a and the control electrode 22b. Is.

Also, FIG. 7 shows a system proposed in Japanese Patent Laid-Open No. 58-132571, in which discharge electrodes 27a and 27b are provided on one surface of the insulating substrate 26.
Are arranged to face each other, and an accelerating electrode 28 is provided on the other surface of the insulating substrate 26, and voltage pulses having different polarities are applied between the discharge electrodes 27a and 27b, thereby causing discharge to generate positive and negative. Are generated, and the dielectric 25 is charged with positive or negative ions in response to the voltage pulse to the acceleration electrode 28.

Further, FIG. 8 shows a method proposed in US Pat. No. 4,160,257, in which a driving electrode 31 and a control electrode are sandwiched with a dielectric 30 interposed therebetween.
32 is formed, and further, the common electrode 34 is formed via the insulating layer 33. The drive electrode 31 and the control electrode 32 are arranged in a matrix so that the directions thereof are different from each other, and the insulating layer 33 and the common electrode 34 are provided with a plurality of openings 35 and 36 corresponding to the matrix. And a plurality of drive electrodes
By selectively applying an AC voltage between the control electrode 31 and the control electrode 32, positive and negative ions are generated in the vicinity of the discharge electrode 32 corresponding to the selected portion of the matrix, and the bias between the discharge electrode 32 and the common electrode 34. Positive or negative ions depending on the polarity of the voltage are derived from the openings 35 and 36 and electrostatic recording is performed.

[Problems to be solved by the invention]

However, in the method of discharging with the wire shown in FIG. 6 described above, since the ions generated by the corona discharge are far to the opening region, they are almost absorbed by the shield 20, and the ions passing through the aperture electrodes 22a and 22b are absorbed. There is a problem that the flow is small and the utilization efficiency of ions is poor.

Further, in the method of discharging by the electrodes shown in FIG. 7, the electrodes are exposed, so that they are liable to leak, and because the electrodes are directly discharged, the electrodes are easily damaged, and the number of electrodes is large. There is a problem that it is difficult to achieve high density or wiring.

Further, in the example in FIG. 8, although the above-mentioned problems are relatively small, matrix driving is indispensable,
When a latent image is formed on one line, data rearrangement and alignment are required, and it is difficult to increase the speed.
As a result, there is a problem that a complicated control circuit is required and the device becomes large.

The present invention solves the above-mentioned problems, and provides a driving method of an electrostatic latent image forming apparatus, which has a high ion utilization efficiency, enables stable discharge, and can achieve high speed and high density. The purpose is to

[Means for solving problems]

Therefore, the driving method of the electrostatic latent image forming apparatus of the present invention includes a group of electrodes arranged independently of each other on a substrate, a common electrode opposed to the group of electrodes with an insulating layer interposed therebetween, and a space between the groups of electrodes. In an electrostatic latent image forming apparatus including an opening formed in the common electrode facing the common electrode and a dielectric layer arranged facing the common electrode, a DC power source connected to the common electrode, AC voltage application multiplied by DC voltage on the electrode group, switching means for producing any state of DC voltage application or float state, and a determination means for determining switching of the switching means according to input data, When a DC voltage is applied to one of the adjacent independent electrodes and an AC voltage in which the DC voltage is multiplied is applied to the other of the adjacent independent electrodes, ions are derived to form an electrostatic latent image on the dielectric layer. It is a feature.

[Action]

In the present invention, for example, in the voltage application state shown in FIG. 1, in the discharge area A between the electrodes 2a and 2b, an alternating electric field is formed and an air breakdown or a creeping discharge is generated to generate ions. And the product ions are
Due to the electric field formed between the common electrode 4 and the independent electrode group 2, the ions are emitted from the discharge region A and are extracted from the opening 5 of the common electrode 4, and the extracted ions are extracted from the common electrode 4 and the dielectric layer 7.
It is accelerated by the electric field formed between the base layer 6 and the base layer 6 and reaches the surface of the dielectric layer 7 to form an electrostatic latent image. On the other hand, no alternating electric field exists between the electrodes 2b and 2c and between the electrodes 2c and 2d, no ions are generated, and no electrostatic latent image is formed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. First
1 is a sectional view showing an embodiment of an electrostatic latent image forming apparatus to which the present invention is applied, FIG. 2 is a perspective view of an electrode portion in FIG. 1,
FIG. 3 is a block diagram showing an embodiment of the driving method of the electrostatic latent image forming apparatus of the present invention, and FIG. 4 is a diagram for explaining the operation of the present invention. In the figure, 1 is a substrate, 2 is an electrode group, and 2a to 2d
Is an electrode, 3 is an insulating layer, 4 is a common electrode, 5 is an opening, 6 is a base layer, 7 is a dielectric layer, 8 and 9 are DC power supplies, 10 is an AC power supply,
X indicates data input means, Y indicates judgment means, and Z indicates switching means.

In FIGS. 1 and 2, electrodes 2a, 2b, 2c, 2d, ... Forming an electrode group 2 independent from each other are arranged in parallel on a base 1, and each of the electrodes 2a to 2d is arranged in parallel. The insulating layer 3 is covered, a common electrode 4 is disposed on the insulating layer 3, and an opening 5 is formed in the common electrode 4 so as to face each other between the electrodes 2a to 2d. Further, a dielectric layer 7 is formed on the base layer 6, the dielectric layer 7 is arranged to face the common electrode 4, and the base layer 6 is grounded.
On the other hand, a bias voltage is applied to the common electrode 4 from a DC power supply 8, a DC voltage is applied to the electrode 2a from a DC power supply 9, and an AC voltage multiplied by the DC voltage is applied to the electrode 2b. The electrodes 2c and 2d are in a floating state in which a voltage is applied to the electrodes 2c and 2d by the power source 10.

Next, the operation of the present invention having the above-described structure will be described. In the voltage application state shown in FIG. 1, an alternating electric field is formed in the discharge region A between the electrodes 2a and 2b, and air breakdown or A creeping discharge is generated and ions are generated. The generated ions are discharged from the discharge region A to the outside through the opening 5 of the common electrode 4 by the electric field formed between the common electrode 4 and the electrode group 2 independent of each other, and the extracted ions are It is accelerated by the electric field formed between the dielectric layer 7 and the base layer 6 and reaches the surface of the dielectric layer 7 to form an electrostatic latent image. On the other hand, no alternating electric field exists between the electrodes 2b and 2c and between the electrodes 2c and 2d, no ions are generated, and no electrostatic latent image is formed.

The polarity of the electrostatic latent image to be formed, that is, the polarity of the extracted ions, can be changed to positive or negative by changing the polarities of the DC voltage applied to the electrode group 2 and the common electrode 4 and the bias voltage applied to the common electrode 4. Can also be changed. For example, if the DC voltage is kept at -800V and the bias voltage at -600V, a negative latent image can be formed, and if the DC voltage is kept at + 800V and the bias voltage is + 600V, a positive latent image can be formed. Further, the voltage of the AC power source needs to be set higher than the voltage at which the discharge is started between the electrode groups 2 and low so that abnormal discharge does not occur, but the set value is determined by the distance between the electrodes and the like. The AC frequency may be any value as long as it causes discharge, but it can be used over a range of several 10 Hz to several MHz.

FIG. 3 shows a method of driving the electrodes 2a, 2b, 2c, 2d, and each electrode is switchably connected to only the DC power source 9 or the AC power source 10 and the DC power source 9 through the switching means Z, and the switching is performed. The means Z has switches Sa, Sb, Sd, and the switches are controlled by the output signals of the data input means X and the judging means Y. Each of the switches Sa to Sd is composed of a contact point G connected to a DC power source, a contact point A connected to an AC power source, and a contact point F at a neutral position, and each electrode is switched to a DC voltage via a switching means Z. Is it connected to the AC power supply that has been piled up?
It is possible to create any one of neutral so-called float states, which are either connected to a DC power source or not connected to any place.

An example of the operation will be described with reference to FIG. In the figure, A indicates AC application, G indicates DC application, F indicates float state, and
O indicates controlled dots, O indicates non-printed dots, and ● indicates printed dots. (A) shows a case where all dots are printed, which is achieved by alternating alternating current application and direct current application. (B) shows a case where all dots are not printed, and all electrodes are floated. (C),
(D) shows the case where two or more unprinted dots continue, and during the repetition of A and G (the number of unprinted dots-
If the electrode of 1) is floated, an electric field is not formed between G-F and F-A, so that ions are not generated and printing is not performed. Further, (e) to (g) show the case where one or more unprinted dots do not continue, and the electrode states of the adjacent non-printed dots may be made the same, and the repetition of the subsequent print dots may be reversed. . That is, by setting both electrodes of dots not to be printed in the AA or GG state, an alternating electric field does not exist between the two electrodes, so that the unprinted state can be obtained.

The electrode driving method is not limited to the example shown in FIG. 4, and various methods can be considered. In short, the electrodes on both sides of the dot to be printed are in the relationship of A-G, and when one is in the state of A, the other is in the relationship of A or F. In the state, the other may have a relationship of G or F. The driving state of the electrodes is
Switching by the judging means Y according to the input data Switching means Z
It is achieved by ordering. Specifically, it can be achieved by a method similar to the method of data compression often used in the field of communication technology, for example, by comparing the input data with the permutation written in the ROMP table, which is facilitated in advance. Of course, the method is not limited to the above method, and various methods can be used.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention provides an electrostatic latent image forming apparatus having an electrode group arranged independently of each other on a substrate and a common electrode opposed to the electrode group with an insulating layer interposed therebetween. , The switching means and the judging means are provided, and the AC electrode is applied with the DC voltage, the DC voltage is applied, or the floating state is generated according to the input data. The effect is played.

(A) Since the discharge is performed between the electrodes through the insulating layer, the ion efficiency is good, and abnormal discharge such as leakage between the electrodes is prevented, and stable discharge can be obtained.

(B) It is not necessary to form a matrix for printing, and one-line printing can be performed at a high speed.

(C) Since the electrode groups are arranged in parallel, the manufacturing is simple, the number of electrodes is small, the wiring is easy, and the density can be increased.

(D) Compared to the direct electrostatic recording method, it is not necessary to maintain a narrow gap between the electrode and the dielectric and wear of the electrode is less.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an electrostatic latent image forming apparatus to which the invention is applied, FIG. 2 is a perspective view of an electrode portion in FIG. 1, and FIG. 3 is an electrostatic latent image of the invention. Forming device driving method 1
FIG. 4 is a block diagram showing an embodiment, FIG. 4 is a diagram for explaining the operation of the present invention, FIG. 5 is a diagram for explaining the principle of the electrostatic latent image forming apparatus, FIG. 6, FIG. 7 and FIG. FIG. 8 is a diagram for explaining a conventional electrostatic latent image forming device. 1 ... Substrate, 2 ... Electrode group, 2a-2d ... Electrode, 3 ... Insulating layer, 4 ... Common electrode, 5 ... Opening, 6 ... Base layer, 7 ...
… Dielectric layer, 8, 9 …… DC power supply, 10 …… AC power supply, X
...... Data input means, Y ...... determination means, Z ... switching means.

Claims (1)

[Claims] 1. An electrode group arranged independently of each other on a substrate, and a common electrode facing the electrode group with an insulating layer interposed therebetween.
In an electrostatic latent image forming apparatus including an opening formed in the common electrode facing each other between the electrode groups, and a dielectric layer disposed facing the common electrode, the electrostatic latent image forming device is connected to the common electrode. DC power source, switching means for generating an AC voltage application in which a DC voltage is applied to the electrode group, DC voltage application or a floating state, and switching of the switching means is determined according to input data. When a DC voltage is applied to one of the adjacent independent electrodes and an AC voltage multiplied by the DC voltage is applied to the other of the adjacent independent electrodes, ions are derived and electrostatic charges are applied to the dielectric layer. A method for driving an electrostatic latent image forming device, which comprises forming a latent image.