JPS60104334A - Liquid injecting apparatus - Google Patents

Abstract

PURPOSE:To reduce the production cost of the titled apparatus and to prevent the sealing of foreign matters at the time of assembling, by arranging a liquid jet nozzle and a filter for filtering a liquid supplied to said nozzle while integrally forming the aforementioned nozzle and the filter. CONSTITUTION:The side of an orifice 12 provided to the righthand end side of a nozzle member 10 is arranged so as to be confronted in the vicinity of the inside bottom surface of an ink tank 13 arranged to the rear part of an ink jet head 14 and immersed in the ink 8 stored in the ink tank 13. The ink 8 in the ink tank 13 enters the nozzle member 10 from the orifice 12 and supplied to the side of an orifice 11 for emitting ink of the nozzle member 10. At the time of recording, an energy generating element 3 is driven by applying a recording pulse thereto from an electrode and, by pressurizing force generated as the result of driving, ink droplets are emitted from the orifice of the nozzle member 10.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a liquid injection device, and relates to a liquid injection device having a nozzle that injects liquid to a liquid injection device, and a filter that filters unnecessary substances in the liquid supplied to the nozzle. Regarding equipment.

[Prior art]

This type of liquid ejecting device is used, for example, in the recording head of an inkjet printer, and in this inkjet head, liquid ink is ejected as ink droplets from an orifice, which is a small diameter hole formed at the tip of a nozzle, to record Pfj. One medium reaches two, forming a dot,
Images or characters are recorded using dot patterns.

Such an inkjet head uses a so-called charge deflection method, in which ink is constantly ejected, and in areas where dots are not required, an electric field is applied to the ink flying area to deflect the ink and record the desired dots. Two on-demand methods are well known, in which ink is ejected only to certain areas.

For on-demand type inkjet heads,
A part of the nozzle is equipped with a pressure generating section that uses ejection energy generating elements such as piezoelectric elements, magnetostrictive elements, and electrothermal transducers, and when the ejection energy generating elements are driven, a sudden pressurizing force is applied to the ink inside the nozzle. A configuration in which ink is ejected from an orifice of a nozzle at a desired timing is well known.

This configuration has great advantages such as an ink deflection system that can safely use a high voltage as required in a charge deflection method, and no need for unnecessary ink collecting grooves, etc. However, on the other hand, it has the following disadvantages.

The ejection pressure of an on-demand ejection energy generating element is generally relatively small, and vibrations from the outside to the recording head, as well as unnecessary interference from the ejection energy generating element, may occur.
Alternatively, the ejection conditions may change slightly due to dust or air bubbles entering the nozzle, making it difficult to maintain stable ink ejection.

Therefore, a filter is connected to the supply pipe that supplies ink to the nozzle in order to prevent dust and air bubbles from entering the nozzle, suppress fluctuations in ink pressure within the nozzle, and maintain good ejection conditions. has been widely adopted.

The conventional structure of an on-demand type inkjet head provided with such a filter will be explained with reference to FIG.

In Fig. 1, the part indicated by numeral 2 is a nozzle member.
It is formed from a material such as glass into an elongated cylindrical shape, one end of which is constricted into a substantially truncated conical shape, and the above-mentioned orifice 1 is installed at the tip.
is formed. Around the nozzle member 2 on the side closer to the orifice 1, an ejection energy generating element 3 such as the piezoelectric element described above is provided, and the Hals described in 4.4 is applied from an electrode (not shown). VC is set to do so.

These parts and materials are housed in the inkjet head 9 and are rearranged to face the recording medium (corresponding to the left side in the figure). An ink tank 7 is formed in the inkjet printer 9, and ink 8 of a predetermined color is stored in the ink tank 7.

This ink tank 7 can be either a main ink tank or an IA ink tank that is a sub-ink tank that is successively supplied with ink from another main tank.

A hollow ink supply pipe 4 connected to the rear end of the nozzle member 2 extends into the ink tank 7,
Its tip is immersed in the stored ink 8. Therefore, in the nozzle member 2, the ink supply tube 4 is filled with the amount of ink ejected by the energy of the ejection energy generating element 3.
Ink 8 is supplied through the ink.

A pipe-shaped fixing member 6 is attached to the tip of the ink supply tube 4.
The filter 5 is installed and the ink 8
is supplied into the nozzle member 2 via this filter 5.

The filter 5 is formed into a cylindrical block shape from a material such as fibers or a porous material "N" having gaps and holes for filtering the ink.
This prevents air bubbles and dust from entering the nozzle member 2.

That is, when the inkjet head 9 is installed on a carriage (not shown) that reciprocates along the recording medium as in other types of printers, the inkjet head 9 may oscillate (as a result of which air bubbles may be generated), and long-term non-operation may occur. Depending on the use, the ink 8 may be contaminated with agglomerates, and the filter 5 serves to prevent these undesirable contaminants from entering the nozzle member 2. The filter 5 also prevents movement of the carriage. The unit consisting of the nozzle supply pipe 4, the filter 5, and the filter fixing member 6 is called a henod unit.

When assembling the head unit, first clean the above four parts to prevent dust from entering, then fit and join one end of the ink supply pipe 4 to the nozzle member 2, and then attach the ink supply pipe to the nozzle member 2. One side of the filter fixing member 60 is fitted to the other end of the filter fixing member 6 to be joined, and one side of the filter soil is further fitted to the other end of the filter fixing member 6 to be joined. Of course, this bonding may be performed in a different order.

A head unit with such a configuration has a large number of parts and many joints during assembly, requiring frequent work, and there is a limit to the reduction in manufacturing costs.

Also, if there are many joining steps in assembling the head unit,
Another problem is that there is a high probability that external dust will enter the nozzle member 2 or the ink co-supply pipe 4 during the joining operation.

On the other hand, as mentioned above, the filter 5 is made of fibers, porous materials, etc., which have gaps and pores through which the ink can pass, so it is easily damaged when force is applied to it.
Particularly, the corners of the fitting part collapse during fitting and joining to the filter fixing member 6 where force is applied, and the pieces enter the ink supply pipe 4 or the nozzle member 2 inside the head unit. 11t of good liquid (
There were cases where 吋 was not completed.

The above drawbacks are not limited to the single unit mentioned above, but apply to all liquid ejecting devices having a similar configuration.

〔the purpose〕

The present invention has been made in view of the above circumstances, and can be manufactured at low cost with a small number of parts and assembly man-hours.
It is an object of the present invention to provide a liquid ejecting device suitable for use in an inkjet head, etc., which can prevent foreign matter such as dust from being sealed inside during assembly.

〔Example〕

Part 2 below. The present invention will be described in detail based on the embodiment shown in FIG. Here, examples and embodiments in which the present invention is applied to the head unit of the above-mentioned inkjet head are shown.

[First example]

The second embodiment shows the first embodiment of the present invention, and in the structure of the inkjet head shown in the same figure, the one designated by the reference numeral 10 has a cylindrical glass or other material like the conventional one on the nozzle side. The both ends are constricted into a substantially truncated conical shape -11, and an orifice 11.12, which is a small diameter hole, is formed at each half end.

This nozzle member 10 is housed as a whole in an inkjet head indicated by reference numeral 14, and an orifice 11 for discharging ink droplets on the left end side in the figure is arranged facing a recording medium (not shown) corresponding to the left side in the figure. Ru. Also this orifice 1
Around the nozzle member 10 on the side closer to 1, the same ejection energy generating element 3 as in the conventional configuration shown in FIG. 1 is provided.

On the other hand, the orifice 12 side on the right end side in the figure of the nozzle member 10 is arranged facing near the inner bottom surface of the ink tank 13 arranged at the rear of the inkjet head 14, and the ink 8 stored in the ink tank 13 is is immersed in.

The orifice 12 is formed by the same squeezing process as the orifice 11, but its diameter is the same as the ink 8 in the ink tank 13.
It is formed in an appropriate size to allow only the ink to pass through and to block the passage of foreign substances such as air bubbles and dust in the ink 8.

With the above configuration, the ink 8 in the ink tank 13 enters the nozzle member 10 from the orifice 12, and the ink 8 in the ink tank 13 enters the nozzle member 10.
The ink is supplied to the orifice 11 side for ejecting ink droplets.

During recording, the energy generating element 3 is driven by applying a recording pulse from an electrode (not shown), and ink droplets are ejected from the orifice 11 in the nozzle member 10 by the pressure generated as a result.

One dot is formed by this ink droplet adhering to the recording medium facing the orifice 11, and by repeating this operation, recording is performed in a dot pattern.

Here, each time an ink droplet is successively ejected from the orifice 1, the same amount of ink 8 is successively supplied from the ink tank 13 through the orifice 12 into the nozzle member 10.

In the above operation, the orifice 12 of the nozzle member 10
The same filter function as before was achieved. That is, when foreign matter such as air bubbles or dust exists in the ink 8 in the ink tank 13, the orifice 12 prevents the foreign matter from entering the nozzle member 10. Furthermore, even if pressure fluctuations occur in the ink 8 in the ink tank 14, the pressure fluctuations are blocked or weakened by the orifice 12, so that pressure fluctuations 4D that affect the jetting of the ink in the nozzle portion 10 occur. It was never communicated.

Further, the nozzle member 10 here plays the same role as the ink supply pipe 4 in the conventional configuration shown in FIG.

The nozzle part 10 corresponds to a head unit consisting of a nozzle member 2, an ink supply pipe 4, a filter 5, and a filter fixing member 6 in the conventional configuration shown in FIG. 1, but as described above, in the present invention, only one part is used. Consisting of.

Therefore, the head unit according to the present invention (nozzle part efficiency 1
0) can be manufactured at low cost because the number of parts is significantly reduced compared to the conventional method. In the manufacturing process of Kadako's head unit, since it is made of one single part, there is no assembly process required for conventional configurations, and the manufacturing process is 18 units. The intrusion of garbage will be eliminated.

Further, the orifice 12, which corresponds to the filter 5 of the conventional structure, is formed by the drawing process in the same way as the orifice 11, and no fragments are generated in a part of the nozzle member 10 in the same process, so it is not possible to assemble the conventional head unit. Nothing corresponding to the entrapment of fragments of the filter 5 into the nozzle member 2 during operation does not occur.

[Second Embodiment] In the above embodiment, the end of the nozzle portion 10 on the side of the ink tank 13 is formed into a truncated cone shape, and the end of the nozzle portion 10 on the side of the ink tank 13 is shaped like a truncated cone.
Although the V-shaped orifice 12 is formed, the shape of the end thereof is not limited to this, but may be any other suitable shape, and the number of holes corresponding to the orifice 12 is not limited to one, but may be plural.

An example of such a configuration is shown in FIG. 3 as a second embodiment of the present invention. Here, in the configuration of the inkjet head 18 shown in the figure, the configuration of the parts other than the nozzle members is the same as that of the above embodiment, and therefore the explanation thereof will be omitted.

The nozzle member designated by the reference numeral 15 in FIG. 3 is formed of a material such as glass as in the above embodiment, and the end facing the recording medium (not shown) on the left side of the figure has a substantially truncated conical shape. The orifice 16 as described above was formed at its tip ('c).

On the other hand, the right end side of the nozzle part 15 in the figure is the ink tank 13.
The ink 8 in the ink tank 13 is placed near the bottom of the ink tank 13.
immersed in it. In this embodiment, a right end surface having a substantially arcuate shape is integrally formed at the right end of the nozzle member 15, and a microhole 17a is formed in the center of the right end surface.

Further, other microholes 1713 and 17C are formed on the outer peripheral surface of the nozzle member 15 near the right end surface by bt and JI of the nozzle member 15. These micro holes 17a to 17c are formed using, for example, a laser, and each diameter is the same as the diameter of the orifice 12 in the above-mentioned embodiment.
It is formed to an appropriate size to allow only the ink 8 inside to pass through, and to block the passage of foreign substances such as air bubbles and dust in the ink 8.

According to the above configuration, the micro holes 17a to 17c perform the same filter function as the orifice 12 described above, and
Similarly to ζ, since the function of the head unit is performed by the nozzle member 15 which is integrated as a whole, the same effects as in the previous embodiment were obtained.

Although the present invention has been described above as an example in which the present invention is applied to a head unit of an inkjet head, the present invention is not limited thereto and can be applied to all liquid ejecting devices.

〔effect〕

As is clear from the description below, according to the present invention, in a liquid ejecting device having a nozzle for ejecting liquid and a filter through which the liquid supplied to the nozzle passes, the nozzle and filter are integrated. Since the number of parts and manufacturing processes can be completely reduced, it is possible to achieve a significant cost reduction, and it also prevents foreign matter such as VC dust from getting into the device during manufacturing, making it possible to prevent inkjet heads, etc. A suitable liquid ejecting device can be provided using this method.

[Brief explanation of drawings]

Broom 1 is a schematic sectional view showing the structure of an inkjet head using a conventional head unit, FIG. 2 is a schematic sectional view 1 showing the structure of an inkjet head according to an embodiment of the present invention, and FIG. 1 is a schematic cross-sectional view showing the configuration of an inkjet head according to an example. 3... Ejection energy generating element 8... Ink 10,
'5... Nozzle member 11, 12. 16... Orifice 13... Ink tank 14.18... Inkjet head 17a-17c... Micro hole patent applicant Canon Inc. 'Yoshiro Rihito Patent Attorney Taku Kato j

Claims (1)

[Claims] A liquid ejecting device having a nozzle for ejecting liquid and a filter for filtering unnecessary substances in the liquid supplied to the nozzle, characterized in that the nozzle and filter are integrally formed. .