JPH0712673B2 - Ink supply device for printer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink supply device of a printing device that ejects ink droplets by electrostatic means to form an image.

Prior Art Conventionally, as described in JP-A-56-8266,
2. Description of the Related Art There is an ink supply device in which a nozzle and an ink tank are connected by a conduit in a printing device of a type in which ink is ejected from a nozzle for printing.

Problems to be Solved by the Invention In such a case, since ink is evaporated in the conduit when the ink is not supplied, there is a problem that ink dregs are accumulated and the conduit is clogged.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an ink supply device of a printing device capable of preventing clogging in an ink supply path.

Means for Solving the Problems A counter electrode and a recording electrode to which ink is attached to a tip portion by a capillary phenomenon are arranged to face each other via a recording body, and the recording electrode is formed by an electric field between the counter electrode and the recording electrode. In a printing device in which the ink is ejected from the tip of the recording medium to form an image on the recording medium, an ink penetrating portion including an impregnating member that sucks the ink in the ink supply tank by capillary development and supplies the ink to the recording electrode is provided. It was installed inside the head body without exposing it to the outside.

Therefore, as long as ink remains in the ink supply tank, it prevents the evaporation of ink in the ink supply path.

Embodiment An embodiment of the present invention will be described with reference to the drawings. A carriage 4 is slidably fitted to a shaft 3 along a recording paper 2 which is a recording medium held on the front surface of the counter electrode 1.
As shown in the third, guide pins 5 and locking pieces 6 are formed on both sides of the carriage 4, and a circuit board 7 and a head main body 8 are fitted to the guide pins 5 so that the head main body 8 Locking claws 9 that are elastically engaged with the locking pieces 6 are formed on both sides. The circuit board 7 is a guide hole for the guide pin 5.
It has a flexible cable 10 connected to 7a and an external circuit, and is urged upward by an elastic body such as a rubber plate 11 laid on the carriage 4. The head body 8 holds a plurality of ink cartridges 12.

As shown in FIG. 4, the head main body 8 has a plurality of holders 14 arranged side by side on a base 13 held by the carriage 4, and the holders 14 are sandwiched between the base 13 and a cover 15. That is, the base 13 has the guide hole 16 fitted into the guide pin 5, and the screw 18 passed through the mounting hole 17 of the cover 15.
Is screwed onto the upper portion of the guide hole 16. Base 13 has
A plurality of ink tanks 20 for receiving ink 19 from the ink cartridge 12, a plurality of ink supply tanks 21 communicating with each of these ink tanks 20, and a plurality of ink reservoirs 22 are formed.

Further, each holder 14 holds a plurality of recording electrodes 23 with their tips facing the counter electrode 1, and a pressing member 24 for pressing these recording electrodes 23 from below is screwed. These acicular needle-shaped recording electrodes 23 are formed by twisting fiber materials, formed with a plurality of grooves on the outer circumference along the longitudinal direction, or formed with through holes inward along the longitudinal direction. Each of them is capable of sucking the ink 19 by the capillary phenomenon.

An impregnation member 25 that impregnates the ink 19 is housed in the ink reservoir 22 having one end opened to the lower side of the tip of the recording electrode 23.

Next, as shown in FIG. 6, a plurality of bosses 26 having upper and lower openings are formed in a staggered arrangement when viewed from above, at the bottom of each ink supply tank 21. And these bosses
A single-core metal rod 27 is inserted into 26 when the base 13 is molded. As shown enlarged in FIG. 8, the coil spring 28 elastically fitted to the upper ends of these metal rods 27 is
The terminal portion 7b of the circuit board 7, which is supported by the bottom of the recess 29 formed at the upper end of the boss 26 and elastically contacts the recording electrode 23 and is urged upward by the rubber plate 11, elastically moves. It is in contact with the lower end of the metal rod 27. Further, an impregnation member 30 which is an ink permeation portion that sucks the ink 19 in the ink supply tank 21 by a capillary phenomenon and supplies the ink 19 to the recording electrode 23 is provided.

Further, the holder 14 has a slit-shaped ink re-supply path that opens to the upper end opening surface of the ink reservoir 22 and the outer periphery of the recording electrode 23.
32 is formed at a position closer to the tip end of the recording electrode 23 than the impregnation member 30. A plurality of connecting portions 32 fitted to the ink tank 20 of the base 13 are formed on the cover 15, and the supply ports 33 of the ink cartridge 12 are detachably fitted to these connecting portions 32. The open ends of these supply ports 33 are bosses.
Lower than the top of 26.

Then, the recording electrode 23, the holder 14, the ink cartridge 12,
The ink tank 20 and the ink supply tank 21 are arranged along the printing line direction. All the recording electrodes 23 are grouped in the print row direction for each individual holder 14, and the ink 19 is supplied from the ink supply tank 21 for each group. Yellow, magenta, cyan, and black inks are supplied to the respective ink supply tanks 21 from the ink cartridge 12 in order from the left when viewed from the counter electrode 1.

In such a structure, a negative charge is applied to the counter electrode 1 and a positive charge is applied to the recording electrode 23, which is to form a dot in the process of moving the carriage 4 along the recording paper 2, through the metal rod 27. The ink 19 supplied from the ink supply tank 21 to the tip of the recording electrode 23 via the impregnation member 30 is caused to fly to the recording paper 2.

At this time, since the recording electrode 23 is supplied with the ink 19 by the capillary phenomenon, foreign matters such as foreign particles do not go to the recording electrode 23. Further, the impregnating body 30 always sucks the ink 19 by the capillary phenomenon and supplies it to the recording electrode 23 as long as the ink 19 is present in the ink supply tank 21, and the recording electrode 23 itself also sucks the ink 19 by the capillary phenomenon. The ink 19 is constantly filled in the supply path and does not evaporate. Therefore, there is no need for purging.

It should be noted that the recording electrode 23 has been supplied with more ink 19 than is necessary for printing, but in this case, the ink 19 dropped from the tip of the recording electrode 23 can be collected in the ink reservoir 22. The collected ink 19 is captured by the impregnating member 25 even if foreign matter or ink slag of varying quality is mixed therein, and only the normal ink 19 having high fluidity is supplied to the ink resupply path.
It is supplied again from 31 to the recording electrode 23.

Since the ink resupply path 31 is closer to the tip of the recording electrode 23 than the impregnation member 30 of the ink supply tank 21, the ink supply tank 31 is supplied unless the amount of ink resupplied from the ink resupply path 31 is insufficient.
21 inks 19 are never supplied. That is, the ink 19 in the ink pool 22 that has once been exposed to air is preferentially re-supplied to the recording electrode 23, and the old ink 19 does not accumulate in the ink pool 22. Impregnation member showing a filter action to the ink pool 22
Even when there is no 25, the ink 19 advances in the slit-like ink resupply path 31 by a capillary phenomenon, so that a filter action can be obtained.

Ink is supplied from the ink cartridge 12 to the ink supply tank 21.
Although 19 is supplied according to the consumption amount, the level of the ink 19 in the ink supply tank 21 always coincides with 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 of the ink cartridge 12 becomes negative pressure as the ink supply progresses.

Although the ink permeation portion is formed by the impregnation member 30 in the above-described embodiment, even if the head main body 8 is formed with pores in which one end contacts the ink 19 in the ink supply tank 21 and the other end contacts the recording electrode 23. Good. These pores are also an example of an ink permeation portion that sucks the ink 19 in the ink supply tank 21 and supplies it to the recording electrode 23 by the capillary phenomenon.

EFFECTS OF THE INVENTION As described above, according to the present invention, the counter electrode and the recording electrode for adhering the ink to the tip portion by the capillary phenomenon are arranged to face each other via the recording body, and the electric field between the counter electrode and the recording electrode is applied. In a printing device in which ink is ejected from the tip of the recording electrode to form an image on the recording body, an ink composed of an impregnating member which sucks the ink in an ink supply tank by a capillary phenomenon and supplies the ink to the recording electrode. Since the penetrating part is provided inside the head body without being exposed to the outside, the ink penetrating part sucks the ink in the ink supply tank by the capillary phenomenon, and the recording electrode sucks the ink in the ink penetrating part by the capillary phenomenon. As long as ink is present in the ink supply tank, the ink supply path is always filled with ink to prevent evaporation of ink and clogging caused by this evaporation. It has the effect of being able to

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a vertical side view, FIG. 2 is a perspective view, and FIG. 3 is an exploded perspective view showing a mounting state of a circuit board, a head body, and the like on a carriage. FIG. 4 is an exploded perspective view showing the structure of the head main body, FIG. 5 is a vertical sectional front view of the line AA in FIG. 1, FIG. 6 is a plan view showing a part of the base, and FIG. 7 is a holder. FIG. 8 is an exploded perspective view showing an attachment structure of the pressing member to the, and FIG. 8 is a partial vertical side view showing an enlarged connection structure of the recording electrodes and the circuit board. 1 ... Counter electrode, 2 ... Recording paper (recording body), 19 ... Ink, 21 ... Ink supply tank, 23 ... Recording electrode, 30 ... Impregnation member (ink permeation part)

Claims (4)

[Claims] 1. A counter electrode and a recording electrode for adhering ink to the tip portion by a capillary phenomenon are arranged to face each other via a recording body, and an electric field between the counter electrode and the recording electrode causes a tip portion of the recording electrode. In a printing device configured to eject more ink to form an image on the recording medium, an ink penetrating portion made of an impregnating member that sucks the ink in the ink supply tank by capillary development and supplies the ink to the recording electrode is exposed to the outside. An ink supply device for a printing device, characterized in that the ink supply device is provided inside the head main body without being operated. 2. An ink supply device for a printing apparatus according to claim 1, wherein a plurality of recording electrodes and a plurality of ink supply tanks are arranged along the printing line direction. 3. A plurality of ink supply tanks for accommodating any of the basic colors of yellow, magenta, cyan, and black are arranged, and the plurality of ink supply tanks are also arranged. Ink supply device for printing devices. 4. A plurality of recording electrodes are divided into a plurality of groups along the printing line direction, and a plurality of ink supply tanks corresponding to the respective groups are provided. Alternatively, the ink supply device of the printing device according to the third aspect.