JPH0419027B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a printing device that forms an image by ejecting ink droplets using electrostatic means.

Prior Art As shown in FIG. 9, a recording magnetic pole 102 is provided in an ink supply chamber 101 containing ink 100,
The tip of this recording magnetic pole 102 is connected to the ink supply chamber 101.
The orifice 103 formed in the orifice 103 is made to protrude and face the counter electrode 104, and an electric charge is applied between the recording magnetic pole 102 and the counter electrode 104 to cause ink droplets to fly from the orifice 103 to the recording paper 105.
It is known from Japanese Patent Application Laid-Open No. 55-154169, Japanese Patent Application Laid-Open No. 55-154170, etc.

Problems to be Solved by the Invention However, since the recording magnetic pole 102 is immersed in the ink 100, when the recording magnetic pole 102 is connected to an external circuit using the lead wire 106, the ink 102 is immersed in the ink 100.
0 permeates the lead wire 106 by capillary action,
This causes poor contact at the connection part, and wiring work is extremely troublesome.

The present invention has been made in view of these points, and an object of the present invention is to provide a printing device that can prevent poor contact and facilitate wiring work.

Means for Solving the Problem A counter electrode and a plurality of recording electrodes whose tips adhere to the tip by capillary action are arranged opposite to each other with a recording medium in between, and the electric field between these counter electrodes and the recording electrodes causes the In a printing device that forms an image on the recording medium by ejecting ink from the tip of a recording electrode, there is provided an ink supply tank in which the surface level of the ink is located below the recording electrode, and ink in this ink supply tank. an ink supply path for supplying the ink to the recording electrode; a circuit board connected to an external circuit is provided on the bottom outer surface of the ink supply tank; one end is in contact with a terminal portion of the circuit board, and the other end is connected to the ink supply channel; A plurality of single-core metal rods are provided, each connected to the recording electrode at a position away from the supply path.

Effect: Therefore, ink does not penetrate into the single-core metal rod, and the recording electrode can be easily connected to an external circuit by abutting the terminal portion of the circuit board against the end of the metal rod. It becomes possible.

Embodiment An embodiment of the present invention will be described based on FIGS. 1 to 8. A carriage 4 is slidably fitted onto a shaft 3 along a recording paper 2, which is a recording medium, held in front of the counter electrode 1. As shown in FIG. 3, a guide pin 5 and a locking piece 6 are formed on both sides of the carriage 4. A circuit board 7 and a head body 8 are fitted into the guide pin 5, and the head body 8 Locking pawls 9 that elastically engage with the locking piece 6 are formed on both sides. The circuit board 7 has a guide hole 7a that fits into the guide pin 5 and a flexible cable 10 that is connected to an external circuit, and is urged upward by an elastic body such as a rubber plate 11 laid on the carriage 4. . A plurality of ink cartridges 12 are held in the head body 8.

As shown in FIG.
are arranged side by side, and these holders 14 are held between a base 13 and a cover 15. That is, the base 13 has a guide hole 16 into which the guide pin 5 is fitted, and a screw 18 passed through a mounting hole 17 of the cover 15 is screwed into the upper part of the guide hole 16. The base 13 includes a plurality of ink tanks 20 that receive ink 19 from the ink cartridge 12.
, an ink supply tank 21 communicating with these ink tanks 20, and an ink reservoir 22 are formed.

Furthermore, each holder 14 holds a plurality of recording electrodes 23 with their tips facing the counter electrode 1, and a pressing member 24 that presses down these recording electrodes 23 from below is screwed. These needle-shaped recording electrodes 23 are made of twisted fiber materials,
Alternatively, a plurality of grooves are formed on the outer periphery along the longitudinal direction, or a through hole is formed inwardly along the longitudinal direction, both of which allow the ink 19 to flow through capillary action.

An impregnating member 25 for impregnating ink 19 is housed in an ink reservoir 22 whose one end is opened to the side below the tip of the recording electrode 23 .

Next, at the bottom of each ink supply tank 21, a sixth
As shown in the figure, a plurality of bosses 26 whose top and bottom are open
are arranged in a staggered pattern when viewed from above. Single-core metal rods 27 are inserted into these bosses 26 when the base 13 is molded. As shown in an enlarged view in FIG. 8, a coil spring 28 elastically fitted to the upper ends of these metal rods 27 is supported by the bottom of a recess 29 formed at the upper end of the boss 26, and is also connected to the recording electrode. The terminal portion 7b of the circuit board 7, which is elastically contacted with the metal rod 23 and urged upward by the rubber plate 11, elastically contacts the metal rod 27.
is in contact with the bottom edge of. In addition, the ink supply tank 2
An impregnation member 30 is provided which impregnates the ink 19 of No. 1 and supplies it to the recording electrode 23 . This impregnation member 30 functions as an ink supply path for supplying ink 19 to the recording electrode 23.

Further, in the holder 14, a slit-shaped ink resupply path 31 that opens at the upper end opening surface of the ink reservoir 22 and the outer periphery of the recording electrode 23 is formed so as to be located closer to the tip of the recording electrode 23 than the impregnation member 30. ing. The cover 15 is formed with a plurality of connecting portions 32 that are fitted into the ink tanks 20 of the base 13, and the supply ports 33 of the ink cartridge 12 are removably fitted into these connecting portions 32.
The opening ends of these supply ports 33 are lower than the upper ends of the bosses 26.

In such a configuration, in order to assemble the head body 8 to the carriage 4, first place the rubber plate 11 on the base 13, and connect the guide hole 7a of the circuit board 7 and the guide hole 16 of the head body 8 with a guide pin. 5, and the locking claw 9 is engaged with the locking piece 6. At this time, the lower end of each metal rod 27 is connected to the terminal portion 7 of the circuit board 7.
b, and the upper end is connected to the coil spring 2.
8 to the recording electrode 23.

During printing, a negative charge is applied to the counter electrode 1, and in the process of moving the carriage 4 along the recording paper 2, a positive charge is applied via the metal rod 27 to the recording electrode 23 where dots are to be formed, and the ink is Supply tank 2
Ink 19 supplied from 1 to the tip of the recording electrode 23 via the impregnating member 30 is made to fly onto the recording paper 2.

At this time, since the recording electrode 23 is supplied with the ink 19 by capillary action, coarse particles such as foreign matter do not go toward the recording electrode 23. In addition, the recording electrode 23 has an amount of ink 19 in excess of that required for printing.
In this case, the ink 19 falling from the tip of the recording electrode 23 can be collected into the ink reservoir 22. Even if the collected ink 19 contains foreign matter or ink slag of changed quality, it is captured by the impregnation member 25, and only normal ink 19 with high fluidity is returned to the recording electrode 23 from the ink re-supply path 31. , ink reservoir 2
No old ink 19 is deposited on 2.

The ink cartridge 1 is connected to the ink supply tank 21.
The ink 19 is supplied from the ink cartridge 2 according to the consumption amount, but the level of the ink 19 in the ink supply tank 21 always matches the lower end opening surface of the supply port 33 of the ink cartridge 12. This is because the ink cartridge 12 is closed except for the supply port 33, and the space above the ink level in the ink cartridge 12 becomes negative pressure as the ink supply progresses.

Further, the metal rod 27 has a single core and is inserted into the boss 26, and the upper open end of the boss 26 is also located above the ink level of the ink supply tank 21, and further,
Since the metal rod 27 is removed from the ink supply path from the impregnation member 30 to the recording electrode 23 and contacts the recording electrode 23 via the coil spring 28, a large amount of ink 19 does not come into contact with the metal rod 29. The ink 19 does not travel along the metal rod 27 and adhere to the terminal portion 7b of the circuit board 7. Therefore, it is possible to prevent poor contact at the electrical connection portion.

In addition, recording electrodes 2 are provided in each ink supply tank 21.
Since the bosses 26 through which the metal rods 27 corresponding to the cartridges 6 are inserted are arranged in a staggered manner, the arrangement pitch of the recording electrodes 23 can be narrowed. Boss 2 with horizontal sway arranged in a staggered manner
6 prevents this by acting like a tetrapod.

Effects of the Invention Since the present invention is configured as described above, the recording electrode can be easily connected to an external circuit by abutting the terminal part of the circuit board against the end of the metal rod, and the recording electrode can be easily connected to an external circuit. The metal rod does not allow ink to penetrate, and therefore has the effect of preventing electrical contact failure caused by ink penetration.

[Brief explanation of drawings]

Figures 1 to 8 show an embodiment of the present invention, with Figure 1 being a longitudinal side view, Figure 2 being a perspective view, and Figure 3 showing how the circuit board and head body are mounted on the carriage. 4 is an exploded perspective view showing the structure of the head body, and FIG. 5 is an exploded perspective view showing the structure of the head body.
6 is a plan view showing a part of the base, FIG. 7 is an exploded perspective view showing the mounting structure of the holding member to the holder, and FIG. 8 is the recording magnetic pole and FIG. 9 is a partially enlarged vertical side view showing a connection structure with a circuit board, and FIG. 9 is a vertical side view showing a conventional example. 1... Counter electrode, 2... Recording paper (recording body), 7
... Circuit board, 7b ... Terminal section, 19 ... Ink, 21 ... Ink supply tank, 23 ... Recording electrode,
27... Metal rod, 30... Impregnation member (ink supply path).

Claims (1)

[Scope of Claims] 1. A counter electrode and a plurality of recording electrodes whose tips are allowed to adhere ink by capillary action are arranged to face each other with a recording body interposed therebetween, and the recording is performed by an electric field between these counter electrodes and the recording electrodes. In a printing device that forms an image on the recording medium by ejecting ink from the tip of an electrode, the ink supply tank has an ink surface level lower than that of the recording electrode, and the ink in this ink supply tank is an ink supply path for supplying the recording electrode, and a circuit board connected to an external circuit on the bottom outer surface of the ink supply tank;
A printing device characterized in that a plurality of single-core metal rods are provided, one end of which is in contact with the terminal portion of the circuit board, and the other end of which is connected to the recording electrode at a position away from the ink supply path. 2. The printing device according to claim 1, wherein the metal rods are arranged in a staggered manner when viewed from the axial direction.