JPH07266606A - Device for applying ultrasonic vibration to printing head - Google Patents

Abstract

PURPOSE:To efficiently transmit ultrasonic vibration generated by an ultrasonic vibrator to a printing head. CONSTITUTION:In a device applying ultrasonic vibration to a printing head, an ultrasonic vibrator 120 and an ultrasonic vibration transmission member 130 transmitting the ultrasonic vibration generated from the ultrasonic vibrator 120 are provided. The ultrasonic vibration transmission member 130 is equipped with the vibrator fixing part 131 having the ultrasonic vibrator 120 placed and fixed thereon and a plurality of vibration transmitting ridges 132 extending outwardly from a plurality of the parts receiving the transmission of directionally different ultrasonic vibrations strongly outputted from the ultrasonic vibrator 120 of the outer edge of the vibrator fixing part 131 and extending toward a matrix electrode part to be fixed to the printing head 100 at the tip parts thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head ultrasonic vibration imparting device for imparting ultrasonic vibration to a print head of a powder jet image forming apparatus.

[0002]

2. Description of the Related Art The applicant has already developed a powder jet image forming apparatus as shown in FIG. This powder jet image forming apparatus has a print head 2 that controls passage of toner charged with a predetermined polarity, for example, negative polarity.
A toner supply roller 1 for supplying toner to the print head 2, a recording paper transport roller 3 for guiding the recording paper P to the print head 2, and a toner transferred onto the recording paper P. And a fixing roller 4 for fixing.

As shown in FIG. 5, the print head 2 includes an insulating substrate 20, and frame members 31 and 32 provided at both front and rear ends of the insulating substrate 20 in the recording paper conveying direction (direction indicated by arrow A).
And a matrix-shaped electrode portion 40 formed on the rear half of the insulating substrate 20 in the recording paper conveyance direction, and an ultrasonic vibration source 50 provided on the first half of the insulating substrate 20 in the recording paper conveyance direction. .

As shown in FIGS. 6 and 7, the matrix-shaped electrode section 40 includes a plurality of first electrodes 21 formed on the surface of the toner supply roller 1 of the insulating substrate 20 and recording paper of the insulating substrate 20. The transport roller 3 is provided with a plurality of second electrodes 22 formed on the surface of the cotton. The plurality of first electrodes 21 and the plurality of second electrodes 22 form a matrix electrode portion. A toner passage hole 23 penetrating the print head 2 is formed at each intersection of each first electrode 21 and each second electrode 22.

An on-voltage (for example -100V) and an off-voltage (for example + 300V) are selectively applied to each first electrode 21. Each second electrode 22 has an on-voltage (for example, 0 V) and an off-voltage (for example, -200 V).
V) and are selectively applied. FIG. 8 shows each first electrode 21.
Of the applied voltage V1-0 to V1-7. As shown in FIG. 8, each first electrode 21 is dynamically scan-controlled, and the applied voltage is sequentially turned on at predetermined unit time intervals. Then, only when the applied voltage to both the first electrode 21 and the second electrode 22 is the on-voltage, the toner passes through the toner insertion hole 23 at the intersection thereof, and the dot printing is performed.

The recording paper P is moved in the direction perpendicular to the first electrode 21 by the recording paper conveying roller 3 and in the direction in which control by dynamic scanning of the first electrode 21 proceeds (direction shown by arrow A in FIGS. 5 and 6). Be transported. A voltage of +500 V is applied to the recording paper carrying roller 3. The toner supply roller 1 is grounded and its surface potential is 0V.

The ultrasonic vibration generating source 50 includes a toner insertion hole 2
Ultrasonic vibration is applied to the print head 2 in order to prevent the toner from being clogged in 3 and to allow the toner to smoothly pass through the toner insertion hole 23. The ultrasonic vibration generation source 50 is composed of four ultrasonic vibrators 50a. The vibration frequency of each ultrasonic transducer 50a is about 300.
It is about 500 KHz.

[0008]

By the way, when the ultrasonic transducer 50a is applied to the print head 2 to apply vibration of a constant frequency, a standing wave is generated. The generation mechanism of this standing wave will be described. Assuming that the ultrasonic vibration sources (excitation points) are present at two points A and B as shown in FIG. 9A, the vibrations from the excitation points A and B are transmitted to the point C. To be done. At this time, if there is a difference between the distance between A and C and the distance between B and C, even if the oscillations at both excitation points A and B have the same phase, at the time point when they are transmitted to the point C. , Each excitation point A,
A phase difference occurs in the vibration from B.

If this phase difference is 180 degrees like vibration A1 and vibration B2 in FIG. 9B, the vibration (A1 +
As in B2), the vibrations cancel each other out. Therefore, in this case, the node portion of the standing wave corresponds to the point C. If the phase difference between the vibration points A and B at the point C is 0 degree (the same phase) as the vibration A1 and the vibration B1 in FIG. 9B, the vibration (A1 + B1) in the figure is generated. ), The vibrations are mutually strengthened. Therefore, in this case, the antinode portion of the standing wave corresponds to the point C.

On the actual print head 2, not a combination of two vibrations but a large number of vibrations including a reflected wave at the end face of the print head 2 are combined to generate a standing wave.

As described above, when a standing wave is generated in the print head 2 by the ultrasonic transducer 50a, in the matrix electrode portion 40 of the print head 2, there are places where vibration is strong and places where vibration is weak. In a place with strong vibration, toner control is performed smoothly, but in a place with weak vibration,
The toner will not be controlled normally. As a result, the image density decreases in a place where vibration is weak, or in the worst case,
The toner may fall into a state where it cannot pass through the toner insertion hole.

Therefore, the present applicant has developed an ultrasonic vibration imparting device 60 as shown in FIG. In the print head 100 shown in FIG. 10, the matrix-shaped electrode portion 40 is formed in the latter half of the insulating substrate 20 in the recording paper conveyance direction (the direction indicated by arrow A). Since the structure of the matrix electrode part 40 is the same as that shown in FIG. 5, the description thereof will be omitted.

The ultrasonic vibration applying device 60 includes an ultrasonic vibration generating source 70 and a rectangular ultrasonic vibration transmitting plate 80 when viewed from a plane for transmitting the vibration generated from the ultrasonic vibration generating source 70 to the print head 100. Consists of. Ultrasonic vibration transmission plate 8
A comb-shaped projection 81 is formed at the rear end of the recording paper conveyance direction 0. At the front end of the ultrasonic vibration transmitting plate 80 in the recording paper conveyance direction, a vibration reflecting portion 82 protruding upward is integrally formed over the entire front edge.

Comb-shaped projection 8 on the upper surface of ultrasonic vibration transmission plate 80
The ultrasonic vibration generation source 70 is fixed between 1 and the vibration reflection portion 82. The ultrasonic vibration generation source 70 is composed of four rectangular ultrasonic vibrators 70a arranged in a straight line in a direction perpendicular to the recording paper conveyance direction A. The tip of the comb-shaped projection 81 faces the matrix electrode part 40, and the tip of the comb-shaped projection 81 is placed on the front end of the insulating substrate 20 in the recording paper conveyance direction and fixed on the upper surface of the insulating substrate 20. Has been done.

The ultrasonic vibration generated from the ultrasonic vibration generating source 70 is transmitted to the print head 100 through the comb tooth-shaped projection 81 of the ultrasonic vibration transmitting plate 80. Therefore, the transmission range of ultrasonic vibrations output from the tips of the comb-shaped projections 81 toward the matrix-shaped electrode portion 40 is narrowed. Therefore, the ultrasonic vibration output from each comb-tooth-shaped projection 81 slightly interferes with the ultrasonic vibration output from the adjacent comb-tooth-shaped projection 81, but from the other comb-tooth-shaped projections 81. It is transmitted to the matrix-shaped electrode portion 40 without interfering with the output ultrasonic vibration.

In the rectangular ultrasonic vibrator 70a used in the ultrasonic vibration imparting device 60, ultrasonic vibration is strongly output in the direction perpendicular to each side. Therefore, the ultrasonic vibration transmitting plate 8 of the ultrasonic vibration applying device 60 is
At 0, the ultrasonic vibration output from one side of the ultrasonic transducer 50a can be efficiently transmitted to the print head 100, but the ultrasonic vibration output from the other three sides can be efficiently transmitted.
00 cannot be efficiently transmitted, so there is a problem that the ultrasonic transmission efficiency is not good.

An object of the present invention is to provide a device for applying ultrasonic vibration to a print head, which can efficiently transmit the ultrasonic vibration generated by the ultrasonic vibrator to the print head.

[0018]

An ultrasonic vibration imparting device for a print head according to the present invention is formed on one surface of an insulating substrate and extends in a direction orthogonal to a recording paper conveyance direction.
Alternatively, a matrix-shaped electrode portion is formed by the plurality of first electrodes and the plurality of second electrodes formed on the other surface of the insulating substrate, and the developer is provided at each intersection of the first electrode and the second electrode. An ultrasonic vibration imparting device for imparting ultrasonic vibration to a print head having an insertion hole, wherein the ultrasonic vibration is transmitted to the ultrasonic transducer and the ultrasonic vibration generated from the ultrasonic transducer. The ultrasonic vibration transmitting member includes a transducer fixing portion on which the ultrasonic transducer is mounted and fixed, and a direction strongly output from the ultrasonic transducer among the outer edges of the transducer fixing portion. A plurality of vibration transmitting ridges extending outward from a plurality of portions to which different ultrasonic vibrations are transmitted and having tips extending toward the matrix electrode portion and fixed to the print head. And

When the ultrasonic transducer has a disk shape, examples of the ultrasonic vibration transmitting member include a circular transducer fixing portion on which the ultrasonic transducer is mounted and fixed, and a transducer fixing member. A plurality of vibration-transmitting ridges extending in the radial direction from the peripheral edge of the portion and then extending toward the matrix-like electrode portion and having the tips fixed to the print head are used.

When the ultrasonic transducer has a rectangular plate shape,
Examples of the ultrasonic vibration transmitting member include a rectangular vibrator fixing portion on which an ultrasonic vibrator is mounted and fixed, and a matrix shape extending from one side of the vibrator fixing portion to the outside of the vibrator fixing portion. A plurality of first vibration-transmitting projections whose tip ends are fixed to the print head toward the electrode section, and matrix-shaped electrodes which extend from the other side of the vibrator fixing section to the outside of the vibrator fixing section. A plurality of second vibration transmitting projections whose tip ends are fixed to the print head are used.

[0021]

In the ultrasonic vibration imparting device for a print head according to the present invention, the ultrasonic vibration transmitting member includes a vibrator fixing portion on which the ultrasonic vibrator is mounted and fixed, and an outer edge of the vibrator fixing portion. Of these, a plurality of vibrations that extend outward from multiple parts to which ultrasonic vibrations of different directions that are strongly output from the ultrasonic vibrator are transmitted and that extend toward the matrix electrode part and are fixed to the print head And a transmission ridge. Therefore, the plurality of ultrasonic vibrations of different directions which are strongly output from the ultrasonic vibrator are transmitted to the print head by the vibration transmitting projections of the ultrasonic vibration transmitting member.

[0022]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows an ultrasonic vibration applying device attached to a print head.

In the print head 100 shown in FIG. 1, the matrix-shaped electrode portion 40 is formed on the rear half of the insulating substrate 20 in the recording paper conveying direction (the direction indicated by arrow A). The structure of the matrix-shaped electrode portion 40 is the same as that of the matrix-shaped electrode portion 40 shown in FIG. A plurality of ultrasonic vibration imparting devices 110 are arranged side by side in a direction orthogonal to the recording paper conveyance direction A of the print head 100, and each ultrasonic vibration imparting device 110 is fixed to a front end portion of the print head 100 in the recording paper conveyance direction. ing.

The ultrasonic vibration transmitting member 110 includes an ultrasonic vibrator 120 and an ultrasonic vibration transmitting member 130 for transmitting the ultrasonic vibration generated from the ultrasonic vibrator 120 to the print head 100. As the ultrasonic vibrator 120, a circular one is used when viewed from a plane. Specifically, the ultrasonic transducer 120 has a thickness of 1.0 mm,
The one having a diameter of 5.0 mm and a resonance frequency of 400 KHz is used. The directivity of such an ultrasonic transducer 120 is
Almost uniform over 360 °. That is, the ultrasonic transducer 120 radially outputs ultrasonic vibrations of substantially uniform magnitude.

The ultrasonic vibration transmitting member 130 includes a circular vibrator fixing portion 131 as viewed from a plane on which the ultrasonic vibrator 120 is placed and fixed, and a print head 100 at the periphery of the vibrator fixing portion 131. A plurality of vibration transmitting ridges 132 extending from different positions within the range of half the width and having the same width and thickness.

Each vibration transmitting projection 132 is a vibrator fixing portion 1.
It extends from the peripheral edge of 31 in the radial direction and then toward the matrix-shaped electrode portion. Then, each vibration transmitting ridge 1
With the tips of 32 aligned so as to be comb-shaped,
The tip of each of the vibration transmitting projections 132 is fixed to the upper surface of the print head 100.

The ultrasonic vibration transmitting member 130 as described above is
For example, it is manufactured by subjecting a metal plate such as an aluminum plate and a stainless plate having a thickness of 1.0 mm to wire electric discharge machining, laser machining, etching machining or press working.

From the ultrasonic vibrator 120, ultrasonic vibrations of uniform intensity are radially output. Ultrasonic transducer 120
The ultrasonic vibrations radially output from are transmitted to the print head 100 by the vibration transmitting projections 132 of the ultrasonic vibration transmitting member 130, and are sent to the matrix electrode portion 40. Therefore, in this ultrasonic vibration imparting device 110,
About half of the ultrasonic vibration radially and uniformly output from the ultrasonic vibrator 120 can be efficiently transmitted to the matrix-shaped electrode portion 40 of the print head 100. Therefore, the ultrasonic vibration generated from the ultrasonic vibrator 120 can be efficiently transmitted to the print head 100.

As described above, since the vibration transmission efficiency is high, as compared with the case where the ultrasonic vibration imparting device 60 of FIG. 10 is used,
The total volume of all transducers can be reduced, and the cost can be reduced. Further, the intensity of ultrasonic vibration output from each vibration transmitting projection 132 of the ultrasonic vibration transmitting member 130 is constant, and the traveling direction thereof is the vibration transmitting projection 13.
2 is the direction in which the tip end faces, so each vibration transmitting ridge 13
Since the interference of the ultrasonic vibration output from 2 is slight, all the toner insertion holes 23 of the matrix electrode part 40 are
Vibration in the vicinity can be made uniform.

In the above embodiment, the vibration transmitting ridge 1 is used.
Although 32 is formed only in the half range of the peripheral edge of the oscillator fixing portion 131, the vibration transmitting projection may be formed on the entire peripheral edge of the oscillator fixing portion 131.

FIG. 2 shows another ultrasonic vibration imparting device.

In FIG. 2, one ultrasonic vibration imparting device 14 is provided.
Although only 0 is shown, the print head 100 is actually
A plurality of ultrasonic vibration imparting devices 140 are arranged side by side in a direction orthogonal to the recording paper conveying direction A, and each ultrasonic vibration imparting device 140 is fixed to the front end portion of the insulating substrate 20 of the print head 100 in the recording paper conveying direction. ing.

The ultrasonic vibration transmitting member 140 includes an ultrasonic vibrator 150 and an ultrasonic vibration transmitting member 160 for transmitting the ultrasonic vibration generated by the ultrasonic vibrator 150 to the print head 100. As the ultrasonic transducer 150, a rectangular one is used when viewed from a plane. In such an ultrasonic transducer 150, ultrasonic vibration is output from each side of the ultrasonic transducer 150 in a direction perpendicular to each side.

The ultrasonic vibration transmitting member 160 has a rectangular vibrator fixing portion 161 when viewed from a plane on which the ultrasonic vibrator 150 is mounted and fixed, and a front side of the vibrator fixing portion 161 when viewed from the print head 100. Comb-shaped first that extends forward from the side of the
The vibration transmitting projection 162 and the second comb-like vibration transmitting projection 1 that extends rearward from a rear side of the vibrator fixing portion 161 when viewed from the print head 100, is bent, and has a front end extending forward.
It consists of 63. The distance between the tips of the first vibration transmitting protrusions 162 and the distance between the tips of the second vibration transmitting protrusions 163 are equal.

The tip end of the first vibration transmitting ridge 162 and the second
It is arranged alternately with the tip end portion of the vibration transmitting protrusion 163. The tip of the first vibration transmitting protrusion 162 and the second
The tip of the vibration transmitting ridge 163 is mounted and fixed on the insulating substrate 20 of the print head 100. As a material of the ultrasonic vibration transmitting member 160, aluminum, stainless steel or the like is used.

The ultrasonic vibration imparting device 140 is manufactured, for example, as follows. First, thickness 1.0mm
The expanded shape member 160a of the ultrasonic vibration transmitting member 160 shown in FIG. 3 is obtained by etching or pressing the above aluminum plate. This expanded shape member 160
a is a rectangular vibrator fixing portion 161 and a vibrator fixing portion 1 when viewed from a plane on which the ultrasonic vibrator 150 is mounted and fixed.
A first vibration transmitting ridge 162 extending from the front side of 61 to the front
And a second vibration transmitting protrusion 163 extending rearward from the rear side of the vibrator fixing portion 161.

Next, after the ultrasonic vibrator 150 is fixed to the vibrator fixing portion 161 of the expanded shape member 160a of FIG. 3,
The second vibration transmitting ridges 163 are bent, and the tips thereof are arranged alternately with the first vibration transmitting ridges 162. In this case, the gap between the adjacent first vibration transmitting ridges 162 and second vibration transmitting ridges 163 is made constant. Thereby, the ultrasonic vibration imparting device 140 is obtained. After that, as shown in FIG. 2, the tips of the first vibration transmitting ridges 162 and the tips of the second vibration transmitting ridges 163 are placed and fixed on the insulating substrate 20 of the print head 100.

In the ultrasonic vibration imparting device 140 of the above embodiment, the ultrasonic vibrations outputted from the front side and the rear side of the ultrasonic vibrator 150 can be efficiently transmitted to the print head 100. Therefore, compared with the ultrasonic vibration imparting device 60 of FIG. 10, the ultrasonic vibration generated from the ultrasonic vibrator 150 can be efficiently transmitted to the print head 100. As described above, since the vibration transmission efficiency is high, the total volume of all transducers can be reduced and the cost can be reduced as compared with the case where the ultrasonic vibration imparting device 60 of FIG. 10 is used. Further, each vibration transmission ridge 16 of the ultrasonic vibration transmission member 160
Since the intensity of the ultrasonic vibration output from Nos. 2 and 163 is constant, the vibration in the vicinity of all the toner insertion holes 23 of the matrix electrode portion 40 can be made uniform.

In addition, the first vibration transmitting ridges 162 and the second vibration transmitting ridges 1 adjacent to the ultrasonic vibration transmitting member 160 are arranged.
When the gap with 63 is made equal to the gap between adjacent comb tooth-shaped projections 81 of the ultrasonic vibration transmitting plate 80 used in the conventional example of FIG. 10, the ultrasonic vibration transmitting member 160 has
The gap between the first vibration transmitting ridges 162 and the gap between the second vibration transmitting ridges 163 are significantly widened as compared with the gap between the adjacent comb tooth-shaped protrusions 81 of the ultrasonic vibration transmitting plate 80 of the conventional example. Therefore, it is possible to manufacture by press working or etching suitable for mass production.

In the above embodiment, the vibration transmitting ridge 1 is used.
62 and 163 are formed on the front side and the rear side of the vibrator fixing portion 161, but if the vibration transmitting projections are formed on two or more sides of the four sides of the vibrator fixing portion 161, Of course, the side on which the vibration transmitting ridge is formed is not limited to the above embodiment.

As another preferred example, the ultrasonic transducer is used as a square when viewed from the plane, and the ultrasonic vibration transmission member includes a vibrator fixing portion that is square when viewed from the plane and a print head of the vibrator fixing portion. For example, a vibration transmission ridge may be formed on the front side near the matrix electrode part and the left and right sides.

[0043]

According to the present invention, the ultrasonic vibration generated by the ultrasonic vibrator can be efficiently transmitted to the print head.

[Brief description of drawings]

FIG. 1 is a plan view showing a state in which an ultrasonic vibration transmitting member is attached to a print head.

FIG. 2 is a perspective view showing another ultrasonic vibration transmitting member.

FIG. 3 is a plan view showing a developed shape member of the ultrasonic vibration transmitting member of FIG.

FIG. 4 is a configuration diagram showing a schematic configuration of a powder jet image forming apparatus.

FIG. 5 is a schematic perspective view showing a conventional print head.

6 is a plan view showing a matrix-shaped electrode portion of FIG.

7 is a cross-sectional view taken along the line VII-VII of FIG.

FIG. 8 is a time chart showing changes in the voltage applied to the first electrode.

FIG. 9 is an explanatory diagram for explaining the mechanism of a standing wave.

FIG. 10 is a perspective view showing an ultrasonic vibration transmitting member that the present applicant has already developed.

[Explanation of symbols]

 20 Insulating Substrate 21 First Electrode 22 Second Electrode 23 Toner Insertion Hole 40 Matrix Electrode 100 Print Head 110 Ultrasonic Vibration Applying Device 120 Ultrasonic Vibrator 130 Ultrasonic Vibration Transmitting Member 131 Transducer Fixing Part 132 Vibration Transmitting Protrusion Article 140 Ultrasonic vibration imparting device 150 Ultrasonic vibrator 160 Ultrasonic vibration transmission member 161 Transducer fixing part 162 First vibration transmission ridge 163 Second vibration transmission ridge

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideki Sugimura 1-2-2 Tamatsukuri, Chuo-ku, Osaka City, Osaka Mita Industry Co., Ltd.

Claims (3)

[Claims] 1. One or a plurality of first electrodes formed on one surface of an insulating substrate and extending in a direction orthogonal to the recording paper conveyance direction, and a plurality of second electrodes formed on the other surface of the insulating substrate. A matrix-shaped electrode portion is formed by the electrodes, and ultrasonic vibration is applied to the print head in which a developer insertion hole is formed at each intersection of the first electrode and the second electrode. The applying device includes an ultrasonic vibrator and an ultrasonic vibration transmitting member that transmits the ultrasonic vibration generated from the ultrasonic vibrator, and the ultrasonic vibration transmitting member is fixed by mounting the ultrasonic vibrator. The vibrator fixing part and the outer edge of the vibrator fixing part extend outward from a plurality of parts to which ultrasonic vibrations of different directions strongly output from the ultrasonic vibrator are transmitted, and the tip part is a matrix electrode part. Print head Ultrasonic vibration imparting device to the print head, characterized in that it comprises a plurality of vibration transmission protrusion fixed. 2. The ultrasonic vibrator has a disk shape, and the ultrasonic vibration transmitting member includes a circular vibrator fixing portion on which the ultrasonic vibrator is mounted and fixed, and a vibrator fixing portion. 2. The print head according to claim 1, further comprising a plurality of vibration transmitting projections extending radially from the peripheral edge and extending toward the matrix-like electrode portion and having a tip end fixed to the print head. Ultrasonic vibration applying device. 3. The ultrasonic vibrator has a rectangular plate shape, and the ultrasonic vibration transmitting member includes a rectangular vibrator fixing portion on which the ultrasonic vibrator is mounted and fixed, and a vibrator fixing portion. A plurality of first vibration transmitting protrusions that extend from one side to the outside of the vibrator fixing portion and then extend toward the matrix-shaped electrode portion and have their tips fixed to the print head; To a print head characterized by comprising a plurality of second vibration transmitting projections extending from the sides to the outside of the vibrator fixing portion and then toward the matrix-like electrode portion and having the tip fixed to the print head. Ultrasonic vibration applying device.