JPS61233548A - Printing apparatus - Google Patents

Abstract

PURPOSE:To always obtain a good printing state by preventing the evaporation of ink, by forming a cap, which blocks the leading end part of the recording electrode provided to the front surface of a printer head from the open air, into a flat plate shape. CONSTITUTION:A carrier 3 is attached to two horizontal guide shafts 2 provided to a printer main body 1 in a state freely reciprocally moving to the left and right and a printer head 4 is arranged to said carrier 3. The opposed electrode 5 opposed to the head 4 is horizontally attached to the central part of the printer main body 1 and a tractor 7 for feeding recording paper 6 is provided behind the opposed electrode 5. An operation knob 8 is connected to the tractor 7. In this constitution, because no current is supplied to a solenoid 23 at the time of non-printing, a movable iron core 24 is pushed up by the force of a spring 25 and the closing surface of a cap 26 blocks the leading end part 15 of the recording head 16 from the open air to prevent the evaporation of ink 11. Therefore, the state of the leading end part 15 of the recording electrode 16 is always kept constant and a stable printing state is obtained.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention is characterized in that dots are formed on a recording medium by ejecting liquid ink using an electric field, and images such as characters and figures are formed by the combination of these dots. The present invention relates to printing devices.

BACKGROUND ART Conventionally, so-called inkjet printers eject liquid ink droplets from a nozzle to form an image on a recording medium.
Many inventions have been made and improvements have been made for reasons such as less noise during printing and advantages in terms of running costs when printing in multiple colors compared to other printing methods. . However, countermeasures against nozzle clogging due to ink evaporation are not sufficient and have become a practical problem.

In order to eliminate the occurrence of such nozzle clogging, a type of printer using liquid ink that is different from the above-mentioned inkjet printer is being considered.

First, to give an example, as described in JP-A-56-170 and JP-A-56-4467,
A slit-shaped opening is formed in place of a nozzle that is prone to clogging, and an electric field is applied between opposing electrodes facing this opening to cause ink to fly.

This type of ink has a problem in that the structure for releasing ink droplets from the slit-shaped opening is delicate and lacks stability. .

In addition, as for other methods, Japanese Patent Application Laid-Open No. 54-2353
As seen in Japanese Patent No. 4 and Japanese Patent Laid-Open No. 59-159355, ink is guided to the tip of a needle-like member along the outer periphery, and the ink is caused to fly by an electric field.

In this type of product, magnetic ink must be used to guide the ink to the tip of the needle-like member, and this magnetic ink has a high degree of freedom in color selection due to the ground color of the magnetic powder contained in it. The disadvantage is that there is no

Problems to be Solved by the Invention In order to solve the disadvantages of the above-mentioned inkjet printer using liquid ink while maintaining its features, it is necessary to avoid clogging in the part where the ink is ejected. is absolutely necessary.

Furthermore, the use of magnetic ink as the liquid ink is undesirable due to its color, and it must be possible to print with ordinary water-based ink.

Means for Solving the Problems The tip of the recording electrode is exposed from the front of the printer head, and a cap is provided on the front so that it can be opened and closed. This cap is a flat plate that moves forward and backward along the front of the printer head.6 Since the operational cap is flat, its structure is simple, and its drive can be driven by linear reciprocating motion. The parts are connected directly by a solenoid, etc.

Embodiment A first embodiment of the present invention will be explained based on FIGS. 1 to 6. First, two guide shafts 2 (only one is shown in FIG. 1) are provided horizontally on the front side of the printer main body 1, and a carrier 3 is reciprocated from side to side on these guide shafts 2. It can be installed freely. A printer head 4 is placed on this carrier 3. Further, a counter electrode 5 facing the printer head 4 is horizontally attached to the center of the printer main body 1.

A tractor 7 for feeding a recording paper 6 as a recording medium is provided behind the counter electrode 5. An operating knob 8 projecting outward is coupled to the tractor 7.

A stage 9 is provided on the carrier 3, and the printer head 4 is mounted on the stage 9. An ink chamber 12 for storing ink 11 is formed in the case 10 of the printer head 4, and a recess 14 is formed in the front face 13 of the ink chamber 12. Then, a recording electrode 16 with only its tip 15 exposed in this recess 14
is provided. This recording electrode 16 has electrical conductivity and ink impregnating property. A guide groove 17 is formed in the front side wall of the printer head 4. As shown in FIG. Furthermore, power sources 19 and 20 are connected between the recording electrode 16 and the counter electrode 5 with a high voltage switch 18 interposed therebetween. The connection midpoints of these power sources 19 and 20 are grounded.

Further, a print control circuit 21 that generates a control signal according to a print signal is connected to the high voltage switch 18.

Next, a support stand 22 is provided inside the stage 9, and a solenoid 23 is mounted on the support stand 22. The movable core 24 of the solenoid 23 is vertically positioned through the support base 22 and is constantly urged upward by a spring 25 attached between it and the carrier 3.

A cap 26 is fixed to the upper end of the solenoid 23. The cap 26 is bent into an L-shape, and its vertical surface is a flat closed surface 27, which is slidably attached to the guide groove 17.

In such a configuration, when not printing, the solenoid 23
Since the movable core 24 is not energized, the movable core 24 is pushed up by the force of the spring 25 as shown in FIG. 11 is prevented from evaporating. Therefore, the state of the tip 15 of the recording electrode 16 is always maintained constant, and a stable printing state can be obtained.

When a print start signal is received, the solenoid 23 is energized, and the movable core 24 descends against the force of the spring 25.
As a result, the cap 26 opens the tip 14 of the recording electrode 16 as shown in FIG. 2, making it ready for printing. When the high voltage switch 18 opens and closes in response to a control signal from the print control circuit 21, the recording electrode 16 and the counter electrode 5
An electric field sufficient to fly the ink 11 is generated between the recording paper 6 and the ink 11, and the ink 11 flies and adheres to the recording paper 6 to form a dot. Through such repetition, the dots are combined to form characters or figures.

Next, a second embodiment of the present invention will be described based on FIG. That is, in this embodiment, a guide groove 17 is formed on the outer surface of the case 10 of the printer head 4, and guide protrusions 28 are formed by bending both side edges of the cap 26 inward to engage with the guide groove 17. It is.

Effects of the Invention In the present invention, as described above, the cap that blocks the tip of the recording electrode provided on the front of the printer head from the outside air is formed as a flat plate. The structure can be extremely simple, and the drive can be linearly driven, so it can be formed with a simple device such as directly connecting a solenoid, preventing ink evaporation and ensuring good printing conditions at all times. It is something that can be obtained.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view showing a first embodiment of the present invention, FIG. 2 is a partially cutaway side view in an open state, FIG. 3 is a perspective view thereof, and FIG. The figure is a plan view with a part of the printer head cut away, FIG. 5 is a vertical side view showing the printing principle, FIG. 6 is a perspective view of the printer body, and FIG. 7 is a second embodiment of the present invention. FIG. 3 is a partially cutaway plan view of the printer head. 4... Printer head, 5... Counter electrode, 6...
Recording paper (recording body), 11... Ink, 13... Front, 15... Leading edge, 16... Recording electrode, 26...
Cap applicant: Tokyo Electric Co., Ltd. 3" figure, %Z figure "

Claims (1)

[Claims] forming a recording electrode having conductivity and ink impregnability, and providing a counter electrode facing the recording electrode via a recording body;
Printing in which an image is formed by electrostatically flying ink impregnated into the recording electrode from the recording electrode toward the recording medium in response to an image signal between the counter electrode and the recording electrode. In the apparatus, a printer head that holds a recording electrode is formed, the tip of the recording electrode is exposed in front of the printer head, and the tip of the recording electrode is moved back and forth in a direction along the front of the printer head. A printing device characterized in that it is provided with a flat cap that blocks the air from the outside air.