JPH0414464A - Printing method and printing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a printing device, and more particularly to a printing device in which an ink solution is turned into a mist, charged, and selectively adhered to paper.

(Prior Art) As a conventional printing apparatus that selectively attaches charged ink mist to a recording medium using an electric field shutter type head, there is an apparatus as shown in FIG. In this device, an ultrasonic vibrator 110 applies ultrasonic vibration energy to the water surface of an ink solution 9 to generate an ink mist 10, and the ink mist 10 is sent between an electric field shutter 1 and a corona wire 3. As a result, the ink mist 10 is charged, an arbitrary electric field distribution is created in the opening 104 of the electric field shutter 1 by the control electrode of the electric field shutter 1, and the ink mist is selectively directed from the opening 104 of the electric field shutter 1 toward the back electrode 4. The liquid is ejected to obtain a record on the recording paper 2.

(Problems to be Solved by the Invention) In the above-described printing device, in order to achieve high image quality and high speed, it is necessary to reduce the pixel size of the opening 104 and to reduce the amount of ink mist ejected per time. It becomes necessary to increase. However, under such conditions, in the conventional printing device, the ink mist 10 is trapped in the opening 104 of the electric field shutter.
Since the structure is such that the ink mist 10 easily adheres to the inside of the opening 104, the opening 104 closes due to the adhered ink. In addition, the opening 104
Even if it does not close, a leakage current is generated between the control electrodes of the electric field shutter 1 due to the adhered ink, and in some cases, a problem arises in that the drive IC that controls the voltage of the control 1 electrode is damaged.

(Means for Solving the Problems) The printing method of the present invention is a printing method in which ink mist is charged and attached to a recording medium, and after controlling ions generated by an ion generating means with an electric field shutter, the ink mist is charged and attached to a recording medium. The ink mist is passed through a mist, and the ink mist is selectively charged and attached to the recording medium.

Furthermore, the printing apparatus of the present invention is characterized in that it is provided with an ink mist generator that forms an ink mist flow between the electric field shutter and the back electrode.

(Example) An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

1 is an electric field shutter, which includes an upper electrode 101 and a lower electrode 10.
2 and an insulator 103 disposed between both electrodes. In the center thereof, there is a slit-shaped (or a large number of thank you) opening 10 for the ions 50 to pass through.
4 is formed.

The upper mold 81i101 and the lower electrode 102 are connected to a drive circuit 115 that generates a drive waveform according to a recording signal, and the ion 5 is
0 can be ejected from the opening 104 or not.

2 is a recording paper, and 3 is a corona wire that generates ions by applying a high voltage from a power source 200. In this example, the corona wire 3 has a diameter of 60 μm.
uses tungsten wire. Further, the distance between the corona wire 3 and the lower TL pole 102 is set to 1 mm or less, and the potential is maintained at about 3 kV by the power source 200.

4 is a back electrode located on the back of the recording paper 2, and a power source 201
A potential gradient is generated between the corona wire 3 and the corona wire 3. Due to this potential gradient, ions and ink mist charged by the ions fly toward the recording paper and adhere to the recording paper 2 . In this embodiment, the potential of the back electrode 4 is set to -4 kV.
The distance between the upper electrode 101 and the back electrode 4 was adjusted between 3 mm and 5 mm to obtain optimal recording conditions. Under conditions where the distance between the back electrode 4 and the upper electrode 101 greatly exceeds the above range, movement of the ink mist does not occur.

Reference numeral 5 denotes a mist generator that turns the ink solution 9 into a mist and supplies it to the recording section, and an ultrasonic vibrator 111 that generates ultrasonic vibrations.
This makes it possible to vibrate the ink solution 9 and generate a large amount of ink mist 10 inside it. In this embodiment, 4 to 12 circular bimorph type oscillators (resonance frequency 1.7 MHz) are used as the ultrasonic oscillators 111, so that the concentration of ink mist generated is constant regardless of environmental conditions. ing.

Air flows 31 and 32 generated by the pump 30 send the generated ink mist 10 between the electric field shutter l and the back electrode 4. The air flow 31 has the role of separating the tar 1 and the ink mist flow.

Among the ink mist lO supplied in this manner, the unnecessary material is collected by the mist collector 7. In the mist collector 7 , air containing the ink mist 10 is taken in by the pump 38 and passed through the porous material 71 to liquefy the ink mist 10 . The liquefied ink solution 9 is sent to the mist generator 5 again by the pump 35.
It can be sent to and reused.

The recording operation according to this embodiment will be explained with reference to FIG.

FIG. 2(a) shows the state during printing, and FIG. 2(b) shows the state during non-printing.

In FIG. 2(a), a high voltage (about 3 kV) is applied to the corona wire 3 by a power source 200. The lower electrode 102 of the electric field shutter 1 is grounded, and the distance between the corona wire 3 and the lower electrode 102 is about 1 mm. Therefore, between the corona wire 3 and the lower electrode 102 (
A strong electric field is formed especially around the corona wire, which ionizes the air near the corona wire 3 and generates a large amount of ions 50.

The generated ions 50 are attracted by the back electrode 4 to which a voltage of opposite polarity to the corona wire 3 is applied by the power source 201, and move upward in the figure. The electric field within the electric field shutter 1 is created by the output voltage of the drive circuit 115 (equivalently represented by the power supply 202), but here it is in the same direction as the electric field between the corona wire 3 and the back electrode 4. Therefore, the generated ions pass through the opening 104 and head toward the back electrode 4. At this time, the ion flow collides with the ink mist flow, so 50 ions are added to the ink mist 10.
is attached, and the ink mist 10 itself becomes positively charged.

The positively charged ink mist 10 has the above-mentioned ions 5.
0 is attracted to the back electrode 4 and adheres to the recording paper 2 located between the back electrode 4 and the electric field shutter 1 to form a visible image.

In FIG. 2(b), the direction of the output voltage of the drive circuit (equivalently represented by the power supply 204) is reversed from that in FIG. 2(a). In this case, the electric field within the opening 104 acts to move the ions 50 downward in the figure, so the ions 50 cannot pass through the opening 104. Therefore, the ions 50 are attracted to the lower electrode 102 around the opening, which has a lower potential than the corona wire 3. In this case, ink mist 10 between the recording paper 2 and the electric field shutter 1
Since the ink mist 10 is not charged, the ink mist 10 does not move toward the recording paper, and the ink mist 10 does not adhere to the recording paper 2.

Based on the above principle, using a head consisting of a line-shaped electric field shutter as shown in FIGS. 3(a) and 3(b),
By moving each control electrode on the recording paper while controlling it independently, ink mist can be attached to any desired position on the recording paper and a record can be obtained.

If such a recording method is used, only the ions 50 will pass through the aperture 104 of the electric field shutter 1, and no ink mist will be attached, and the above-mentioned problems associated with this will be solved. Also, the volume of ions passing through,
Since the mass is much smaller than that of the ink mist, the inertia is small, and control with a lower control voltage is possible, thereby reducing the cost of the drive IC.

Furthermore, since the amount of ink mist attached can be controlled by the amount of ions 50 passing through the opening 104 of the electric field shutter 1, by changing the width of the voltage pulse applied to the electric field shutter with each control electrode, By controlling the amount of ions passing through the aperture of the electric field shutter, it is possible to control the recording density on a pixel-by-pixel basis, and using three colors of ink: yellow, magenta, and cyan, each data of red, green, and blue can be recorded. High-definition, full-color images can be obtained by controlling the image according to the conditions.

In addition, in this implementation, corona discharge using a corona wire was used as the ion generation means, but other ion generation means may also be adopted in which ions are generated by causing a pulsed discharge between electrodes. .

(Effects of the Invention) According to the present invention, by causing ions controlled by an electric field shutter to collide with the ink mist, the ink mist can be selectively charged without passing the ink mist through the electric field shutter. Therefore, it is possible to solve the problems of printing defects and damage to the drive IC due to ink clogging the opening of the electric field shutter, which occurs as recording speeds and density increase.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a printing apparatus according to an embodiment of the present invention. FIGS. 2(a) and 2(b) are diagrams illustrating the principle of recording operation of the printing apparatus according to the embodiment of the present invention. FIG. 3(a) and FIG. 3(b) are diagrams showing an electric field shutter of a printing device according to an embodiment of the present invention. FIG. 4 is a diagram showing a conventional printing device. 0 ・ 0 ・ 1 ・ 2 ・ 0 ・ Ink mist pump Air flow Air flow Ion Ultrasonic transducer drive circuit Agent Patent attorney Kizobe Suzuki and 1 other applicant Seiko Epson Corporation Electric field shutter Recording paper Corona wire back electrode Mist generator Mist collector Ink solution 1...Electric field.../'5'- No. 5'-: Figure S1 (Q) (b) Figure 3 Figure 4

Claims (2)

[Claims] (1) In a printing device that charges an ink mist and attaches it to a recording medium, ions generated by an ion generating means are controlled by an electric field shutter and then passed through the ink mist to selectively charge the ink mist. A printing method characterized by making the image adhere to a recording medium. (2) The ion generating means for generating ions and the ions generated by this ion generating means have opposite polarity,
In a printing device equipped with a back electrode located on the back side of a recording medium, and an electric field shutter provided between these ion generating means and the back electrode to control the ion flow toward the back electrode, the ink mist flow is A printing device characterized by being provided with an ink mist generator formed between an electric field shutter and a back electrode.