JPS62142648A - Ink recovery device in printer - Google Patents

Abstract

PURPOSE:To prevent an unnecessary consumption of ink, by a method wherein an excess ink which was not supplied to a recording electrode is collected in an ink reservoir, and after foreign matters etc. in the ink are removed due to capillarity, the ink is again supplied to the recording electrode through an ink recycle path. CONSTITUTION:When the amount of an ink 19 supplied to a recording electrode 23 is more than required for printing, the excess ink 19 dripping out of the tip end of the recording electrode 23 is collected in an ink reservoir 22. Since foreign matters and ink residues changing in its quality in the collected ink 19 are caught by an impregnating member 25, only the normal ink 19 of high fluidity is again supplied to the recording electrode 23 through an ink recycle path 31, which prevents an unnecessary consumption of ink. The recycle path 31 is disposed nearer to the tip end of the recording electrode 23 than an impregnating member 30 in an ink supply tank 21, therefore the ink 19 in the ink reservoir 22 which has been in contact with air once is again supplied to the recording electrode 23 prior to the other ink, which prevents the used ink 19 from accumulating in the ink reservoir 22.

Description

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

BACKGROUND ART Conventionally, as described in Japanese Patent Application Laid-Open No. 58-168570, in a printing device that prints by ejecting ink from a nozzle, air bubbles, foreign matter, and quality changes that have entered the ejection system such as the nozzle have been reported. In order to remove the ink and the like, there is an operation that pressurizes the ink inside the head and discharges the ink from the nozzle and collects it, which is called purge.

However, this kind of ink requires periodic purging operations, and the ink recovered by purging is discarded, so there is a problem of wasting ink.

Further, as shown in FIG. 9, a recording electrode 102 is provided in an ink supply chamber 101 containing ink 100, and the tip of this recording electrode 102 is made to protrude into an orifice 103 formed in the ink supply chamber 101, and a counter electrode 104 is formed. facing the
Applying a charge between the recording electrode 102 and the counter electrode 104,
The method of ejecting ink droplets from the orifice 103 onto the recording paper 105 is known from Japanese Patent Laid-Open Nos. 55-154169 and 1987-154170.

The problem to be solved by the invention is that the ink 100 in the ink supply chamber 101
Since the ink does not dry, purging can be made unnecessary, but the ink 100 overflowing from the orifice 103 must be collected. However, this recovered ink 100 deteriorates in quality while being left unattended and is therefore discarded.
You will be wasting 0.

The present invention has been made in view of these points, and an object of the present invention is to provide an ink recovery device for a printing device that prevents wastage of ink.

Means for Solving the Problem A counter electrode and a recording electrode whose tip is allowed to adhere ink by capillary action are arranged opposite to each other with a recording body interposed therebetween, and an electric field between these counter electrodes and the recording electrode causes the recording electrode to In a printing device that forms an image on a recording medium by ejecting ink from the tip of the recording electrode, an ink supply path is provided to supply ink from an ink supply tank to the recording electrode, and surplus ink at the tip of the recording electrode is removed. An ink reservoir is provided for collection, and an ink resupply channel is provided that is located closer to the tip of the recording electrode than the ink supply channel and resupplies ink from the ink reservoir to the recording electrode by capillary action.

Operation Note #c Excess ink supplied to the electrode is collected by an ink reservoir, and this ink is re-supplied to the recording electrode after removing foreign matter etc. from the ink re-supply path by capillary action.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 8. A carriage 4 is slidably fitted onto a shaft 3 that extends along a recording paper 2 that 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, and a circuit board 7 and a head body 8 are fitted into the guide pin 5. Locking pawls 9 that elastically engage with the locking piece 6 are formed on both sides. The circuit board 7 is the guide pin 5
It has a guide hole 7a that fits into the guide hole 7a 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 main body 8.

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 these holders 14 are sandwiched between the base 13 and a cover 15. That is, the base 13 is connected to the guide pin 5
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 contains ink 1 from the ink cartridge 12.
9, an ink supply tank 21 communicating with these ink tanks 20, and an ink reservoir 22 are formed.

Also, are there multiple records in each holder 14? The Ia electrodes 23 are held with their tips facing the counter electrode 1, and a pressing member 24 for pressing these recording electrodes 23 from below is screwed. These needle-shaped recording electrodes 23 are made of twisted fiber materials, have a plurality of grooves formed on the outer periphery along the longitudinal direction, or have through holes formed inside along the longitudinal direction. In both cases, the ink 19 can 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, as shown in FIG. 6, a plurality of bosses 26, which are open at the top and bottom, are formed in a staggered arrangement 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 end of these metal rods 27
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 circuit board 6, is elastically contacted by the recording electrode 23, and is urged upward by the rubber plate 11, elastically contacts the metal terminal portion 7b. It is in contact with the lower end of the rod 27. Further, an impregnating member 30 is provided which impregnates the ink 19 in the ink supply tank 21 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 cartridges 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, the head body 8 is mounted on the carriage 4.
To assemble, first place the rubber plate 11 on the base 13, fit the guide hole 7a of the circuit board 7 and the guide hole 16 of the spatula body 8 into the guide bin 5, and then tighten the locking claw 9. It engages with the locking piece 6. At this time, the lower end of each metal rod 27 elastically contacts the terminal portion 7b of the circuit board 7, and the upper end is connected to the recording electrode 23 via the coil sprig 28.

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 Ink 19 supplied from the supply tank 21 to the tip of the recording electrode 23 via the impregnating member 30 is caused to fly onto the recording paper 2.

At this time, the recording electrode 23 is exposed to the ink 19 due to capillary action.
is supplied to the recording electrode 2, so coarse particles such as foreign matter are
I won't go to 3. Further, the ink 19 is always in circulation and the ink 19 never runs out. Therefore, there is no need for purging. On the other hand, is it a record? ! ! In some cases, the pole 23 is supplied with more ink 19 than is necessary for printing, but in this case, the ink 19 falling from the tip of the recording electrode 23 is
can be collected in 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 re-supplied from the ink re-supply path 31 to the recording electrode 23. do. Since the ink re-supply path 31 is closer to the tip of the recording electrode 23 than the impregnated member 3° of the ink supply tank 21, the ink 19 in the ink supply tank 21 will continue to flow as long as the amount of ink re-supplied from the ink re-supply path 31 is not insufficient. will not be supplied. That is, the ink 19 in the ink reservoir 22 that has once been exposed to air is preferentially resupplied to the recording electrode 23, and old ink 19 does not accumulate in the ink reservoir 22. Impregnated member 2 exhibiting a filtering effect on ink reservoir 22
5, the ink 19 advances through the slit-shaped ink re-supply path 31 by capillary action, so a filtering effect can be obtained.

Ink 19 is supplied from the ink cartridge 12 to the ink supply tank 21 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 of the ink cartridge 12 becomes negative pressure as the ink supply progresses.

Effects of the Invention Since the present invention is constructed as described above, ink is supplied to the recording electrode by capillary action, thereby preventing foreign matter from being supplied to the recording electrode and preventing the ink in the recording electrode from drying out. This makes it possible to omit purging, and also collects the excess ink supplied to the recording electrode in the ink reservoir, and recycles the excess ink from the re-supply path to the recording electrode while removing foreign matter etc. by capillary action. Therefore, it is possible to prevent ink from being wasted.

[Brief explanation of drawings]

Figures 1 to 8 show an embodiment of the present invention, in which Figure 1 is a longitudinal side view, Figure 2 is a perspective view, and Figure 3 shows how the circuit board and head body are attached to the carriage. FIG. 4 is an exploded perspective view showing the structure of the head body, FIG. 5 is a longitudinal sectional front view taken along line A-A in FIG. 1,
Fig. 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 an enlarged view showing the connection structure between the recording electrode and the circuit board. FIG. 9 is a vertical side view showing a conventional example. 1... Counter electrode, 2... Recording paper (recording body), 19.
... ink, 21 ... ink supply tank, 22 ... ink reservoir, 23 ... recording electrode, 30 ... impregnation member (ink supply path), 31 ... ink re-supply path 30 diagram: T3 q Diagram (moat a) Cusp ↓ Procedural amendment band (kiri) February 3, 1986 Patent application by Mr. Michibe Uga, Commissioner of the Patent Office, 1986-2
No. 83294 2, Title of invention Ink collection device for printing device 4, Agent 〒107 5, No date of amendment order 6, Subject of amendment

Claims (1)

[Scope of Claims] 1. A counter electrode and a recording electrode to which ink is attached to the tip by capillary action are arranged opposite to each other with a recording body interposed therebetween, and an electric field between these counter electrodes and the recording electrode causes the recording electrode to In a printing device that forms an image on the recording medium by ejecting ink from the tip of the recording medium, an ink supply path is provided to supply ink from an ink supply tank to the recording electrode, and excess ink at the tip of the recording electrode is removed. An ink reservoir is provided for collecting the ink, and an ink re-supply channel is provided which is located closer to the tip of the recording electrode than the ink supply channel and re-supplies the ink in the ink reservoir to the recording electrode by capillary action. Ink collection device for printing equipment. 2. The ink recovery device for a printing device according to claim 1, wherein the ink resupply path is formed in a slit shape.