JPH09101664A - Ion current recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form printing dots to nearly complete roundness and to make high-quality printing possible by defining one pixel by using two pairs of control electrodes adjacent to each other. SOLUTION: Respective controllers 171, 172, 173, 174,... are arranged in a plurality to two rows across a slit 19 in a main scanning direction. The respective control electrodes are constituted changeable over to a potential V2 and a potential V1 (in this case, ground potentials) by respective corresponding switches 181, 182, 183, 184,... under the commands of control means. The respective control electrodes are selectively controlled to the same potential at each of two pairs of the control electrode pairs adjacent to each other. For example, the control electrodes 171, 172, 273, 174 are assumed to define the pixel (a) on the left side and the next four control electrodes are assumed to define the pixel (b) and henceforce, the pixels are assumed to be successively defined in the same manner. The four control electrodes to define the pixel to be made into the black pixel are then connected to the potential V2 and any one pair or all of the control electrodes to be made into the white pixel are connected to the potential V1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention applies a predetermined electric field to ions generated by an ion generating means to generate an ion flow, and irradiates the ion flow on an image receiving medium according to an image signal to form a charge image. The present invention relates to an ion flow recording device.

[0002]

2. Description of the Related Art Generally, an ion flow recording apparatus of this type is provided with an ion generating section, a counter electrode section for generating a flow of ions by applying a predetermined electric field to the generated ions, and in proximity to the counter electrode section. An image receiving medium having a dielectric layer arranged therein, an ion flow control unit for allowing (accelerating) passage or closing of an ion flow toward the counter electrode section (image receiving medium) according to an image signal, and the image receiving medium as a predetermined unit. And a transfer means for transferring at a speed.

The ion generator uses a corotron or discharges air between two discharge electrodes to generate ions. By configuring the ion generating section in this way, generally, positive ions and negative ions can be generated. The counter electrode is connected to a DC power supply or an AC power supply, and generates a flow of ions toward the image receiving medium by applying a potential difference between the counter electrode and the ion generator. Depending on the image signal, the ion flow control unit passes the ion flow through the ion flow without applying or applying a forward electric field, or applies a reverse electric field to prevent passage of the ion flow. Or That is, the ion flow control unit controls the passage of the ion flow according to the black pixel of the image signal and the closing according to the white pixel. The image receiving medium transferred by the transfer means is arranged close to the counter electrode. Therefore, the ions that have passed through the ion flow controller are attached (charged) to the image receiving medium.
Then, a charge image is formed. The charge image is developed with toner having an opposite charge.

[0004]

By the way, in this type of ion flow recording apparatus, the ion flow control section generally includes a plurality of control electrodes 17. As shown in FIG. 3, the control electrode 17 had a configuration in which a pair of elongated conductors sandwiching the slit 19 were opposed to each other with their short sides facing each other. Then, the opposed control electrodes in a pair relationship are arranged in parallel at a predetermined interval. For example, when a potential V3 higher than the other potential V1 is applied to the third control electrode pair from the left in FIG. 3, a hole 17a that serves as a path for ions is formed in the opposing central portion. this is,
As shown in FIG. 4, the hole 17a serves as a high-potential portion and serves as a portion where the amount of passing ions increases. Therefore, it can be said that each pair of these control electrodes 17 defines each pixel to be printed according to the print signal. A predetermined image can be formed by operating each of these pairs of control electrodes 17 in accordance with a print signal defining each pixel. By the way, as shown in FIG. 3, in this method in which one hole 17a is defined for one corresponding control electrode 17 pair, the shape of the hole 17a becomes elliptical. It is considered that this is because the ions that should pass through are absorbed by the control electrode at the portions close to the respective short sides of the control electrode 17. As a result, the pixels of the image related to printing are elliptical, which is a drawback that must be taken into consideration in printing control. In this case, it is conceivable to increase the width of the slit 19 in order to improve this point, but this has the drawback that the control voltage (voltage applied to the control electrode 17 and the like) for ion flow control must be increased. is there. The present invention has been made to improve this point.

[0005]

Therefore, in the present invention, one ion passage hole is defined by two adjacent control electrode pairs.

[0006]

As shown in FIG. 2, it is assumed that the two central control electrode pairs have a potential V2 higher than the other potentials V1. At this time, the equipotential line 17b has a peak at almost the central portion of the four control electrodes 17 to which the potential V2 is applied, as shown in the figure, and gradually decreases. Therefore, the shape of the hole 17a formed by this method is close to a perfect circle. Therefore, the pixel based on this hole 17a is also close to a perfect circle, and the image to be printed is of high quality, and its control is easier than that of the conventional elliptical shape.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. First, the ion flow recording apparatus according to the present invention will be described with reference to FIG. In FIG. 4, 10 is a print head, 11 is an insulating plate, 12 is a pair of discharge electrodes, and
21 is a right discharge electrode pair, 122 is a left discharge electrode pair, 13 is an AC power supply, 14 is a dielectric, 15 is a common electrode, 16 is a DC power supply, 17 is a control electrode, 18 is a changeover switch, 19 is a slit, 20 is A charge image receiving medium, 21 is an AC power source, 22 is a counter electrode, 31 is a control unit, and 32 is a transfer unit for the image receiving medium 20.

The print head 10 has an ion chamber whose periphery is covered by upper, lower, left and right insulating plates 11 extending in the main scanning direction perpendicular to the drawing. Each of the left and right insulating plates 11 has a left discharge electrode pair 122 and a right discharge electrode pair 1 on its inner surface side.
21 are provided. Each of these discharge electrode pairs 121,
122 is covered with the dielectric 14.

Then, each of these discharge electrode pairs 121, 1
Reference numerals 2 and 22 denote the upper discharge electrodes denoted by the reference numeral 1
Each discharge electrode on the lower side marked with is connected to the output terminal of the common AC power supply 13. That is, the same potential difference is simultaneously applied to the left and right discharge electrode pairs. The discharge electrode pair and the dielectric can be formed by printing on an insulating substrate by a thick film printing method.

The lower insulating plate 11 is provided with a slit 19 for passing ions generated in the ion chamber. A common electrode 15 is provided on the inner surface side of the lower insulating plate 11 and a control electrode 17 is provided on the outer surface side thereof. The common electrode 15 is provided so that two metal plates (which may be formed of a conductive material by a thick film printing method) having a slender shape in the direction perpendicular to the drawing, that is, the main scanning direction, face each other with the slit 19 interposed therebetween. Has been. A voltage V1 is applied from the DC power supply 16 to the common electrode made of this metal plate.

The control electrode 17 has long and narrow strip-shaped electrodes which face each other with the slit 19 in between and which are arranged corresponding to pixels relating to printing. A plurality of these elongated strip-shaped electrodes are arranged in the main scanning direction with the slit 19 interposed therebetween so that a required print width can be secured. Each of these electrode pairs has two different voltages V1 and V2 via the changeover switch 18, respectively.
2 is selectively connected. It is desirable that the control electrode is also formed by printing on the back surface of the insulating substrate by a thick film printing method using a conductive material.

The charge receiving medium 20 has a dielectric layer formed on its surface. Below the slit 19 of the print head 10, a counter electrode 22 connected to an AC power source 21 with the charge receiving medium 20 interposed therebetween is provided. The counter electrode 22
Applied voltage is V3.

The control means 31 controls ON / OFF of the AC power supply 13 of the print head 10, control of the changeover switch 18, and transfer control of the charge receiving medium 20. The transfer means 32 has a structure in which a medium transfer motor (not shown) is driven at a constant speed based on a command from the control means 31 to transfer the charge image receiving medium 20 at a constant speed. Further, the transfer means 32 has an encoder for detecting the rotation angle of the medium transfer motor, and every time the charge image receiving medium 20 is transferred by a unit transfer amount,
It has a configuration for outputting a signal to the control means 31.

Now, the AC power supply 1 is instructed by the control means 31.
Assume that 3 is in the on state. To the two upper discharge electrodes labeled 1 and the two lower discharge electrodes labeled 2 of the print head 10, alternating positive and negative alternating voltages are sequentially applied in synchronization. That is, when a positive voltage is applied to the upper two discharge electrodes, a negative voltage is applied to the lower two discharge electrodes, and in the opposite case, a negative voltage is applied to the upper two discharge electrodes, A positive voltage is applied to each of the lower two discharge electrodes. Therefore, the discharge electrode pairs 121 and 122 formed on the left and right insulating plates 11 of the print head 10 are in a state in which the discharges with the same discharge direction are repeatedly performed in the vertical direction.

By the discharge operation as described above, positive and negative ions are generated in the ion chamber. The positive and negative ions have a uniform ion distribution when the central portion is viewed by the discharge electrodes on the left and right of the electrodes simultaneously discharging with the same polarity.

In such a state, an AC voltage ± V3 that fluctuates positively and negatively is applied to the counter electrode 22 connected to the AC power supply 21.
Is applied. The potential V1 of the common electrode 15 at this time
And the potential of the counter electrode 22 ± V3, -V3 << V1
<<< + V3. When + V3 is applied to the counter electrode 22, mainly negative ions in the ion chamber, and when -V3 is applied, mainly positive ions are generated, and the print head 10 is provided.
It jumps out from the slit 19. Since the positive and negative polarities of the potential of the counter electrode 22 are periodically changed, in reality, the same amount of positive and negative ions are ejected.

Now, this recording apparatus is used as the charge receiving medium 20.
It is assumed that a charge image is formed by negative charges (negative ions) on the top. In this case, since a charge image is formed on the image receiving medium 20, if the amount of the negative ions popped out is large in the part to be the black pixel, and the positive and negative ions are popped out in the same amount in the part to be the white pixel. Good.

It is assumed that the changeover switch 18 is operated via the control means 31 to connect the control electrode pair corresponding to the white pixel to the potential V1. At this time, the control electrode 17 and the common electrode 15 have the same potential and have no influence on the positive and negative ions. The counter electrode 22 has a high positive and negative voltage (several tens of KHz).
Since it is connected to an AC power source that fluctuates with
By connecting 7 to V1 by the change-over switch 18, both positive ions and negative ions can be made equal in amount, and no charge image is formed on the image receiving medium 20.

When the changeover switch 18 is connected to the DC potential V2 higher than V1 by the control means, a potential gradient is generated between the common electrode 15 and the control electrode 17 so that more negative ions can be ejected. Therefore, a desired charge image can be formed on the image receiving medium 20 by connecting the control electrode 17 corresponding to the black pixel to the potential V2.

FIG. 1 shows the control electrode section of this ion flow recording apparatus. Each control electrode 171, 172, 1
A plurality of 73, 174, ... Are arranged in two rows in the main scanning direction with the slit 19 interposed therebetween. Then, these respective control electrodes are provided with corresponding switches 181, 182, 183, 184, ... Under the command of the control means of FIG.
Is configured to be switchable between the potential V2 and the potential V1 (here, the ground potential). Then, each of these control electrodes is selectively controlled to the same potential for every two adjacent control electrode pairs.

For example, now control electrodes 171, 172, 1
Assuming that 73 and 174 define the left pixel a, the next four control electrodes define the pixel b, and so on, and so on, the four pixels defining the pixel to be the black pixel. In the case where the control electrode is connected to the potential V2 to form a white pixel, any one pair or all are connected to the potential V1.

By controlling by the control means 31 in this way, the black pixel can be made close to a perfect circle as shown in FIG. 2, and high quality printing can be performed. In this case, in the example shown in FIG. 1, all the pixels are printed by one driving operation. However, for example, when the white pixel and the black pixel are adjacent to each other like pixel B and pixel C, Appear. In such a case, they may influence each other and the gradation expression may be ambiguous. Therefore, instead of driving the adjacent pixels at the same time instead of such control, every other two pixels may be time-divided and one line may be printed by driving three times.

[0023]

As described above, according to the present invention, since one pixel is defined by using two pairs of adjacent control electrodes, the print dot can be made close to a perfect circle and high quality printing can be performed. it can. Further, in the present invention, as the discharger of the print head, the pair of discharge electrodes are formed on the insulating plate by the thick film printing method, so that the manufacturing process can be simplified and the print density can be increased. Further, in the present invention, as the discharger of the print head, discharge electrode pairs are respectively provided on the inner surfaces of the right and left side walls of the rectangular print head, and these discharge electrode pairs are configured to discharge the same polarity to each other. Can be made uniform in the ion chamber, and a margin can be given to the width and installation position of the slit 19.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory diagram of a control electrode unit of a recording apparatus according to the present invention.

FIG. 2 is a schematic diagram of a printing operation of the present invention.

FIG. 3 is a schematic diagram of a conventional printing operation.

FIG. 4 is an explanatory diagram showing the relationship between the potential and the amount of passing ions in FIG.

FIG. 5 is a configuration diagram of main parts of an ion flow recording apparatus according to the present invention.

[Explanation of symbols]

 10: print head 20: charge image receiving medium 30: controller

Claims (1)

[Claims] 1. An ion flow recording apparatus for forming a charge image by selectively irradiating an image receiving medium with ions, comprising:
In order to define a hole corresponding to each pixel of the charge image, a pair of control electrodes has a plurality of control electrodes arranged in parallel at predetermined intervals, and a predetermined potential is applied to the control electrodes according to a print signal. Then, in the ion flow recording apparatus for controlling the passage of the ions through the hole and irradiating the image receiving medium with the ions according to a print signal, at least two pairs of control electrodes adjacent to each other are driven at the same time. An ion flow recording device characterized in that the hole is defined approximately in the center of two control electrodes.