JPS62101452A - Liquid jet recording head - Google Patents

Abstract

PURPOSE:To obtain an effective and powerful injection force to an applied current and at the same time, a satisfactory frequency response characteristic by providing a means to supply an electric current in a direction almost at right tangles with the liquid flow channel of a nozzle and a means to generate a magnetic flux almost at right angles with the liquid flow channel and the current. CONSTITUTION:A nozzle 1 is formed with an insulator such as glass, and ink used for supplying to an ink flow channel 1c in the nozzle 1 through a tube 5 is a conductive ink 4. Further a pulse electrode 2 and a minus electrode 3 are arranged in a mutually opposed position on the inner surface of the ink flow channel 1c of the nozzle 1 so as to allow an electric current i in a direction almost at right angles with the conductive ink 4 as shown by an arrow marker. The electrode 2 is connected to a DC line voltage V+ through a switch 7 and the electrode 3 is grounded. In addition, a magnet or an electromagnet is arranged near the nozzle, thus generating a magnetic flux phi directed toward the inner part of paper as shown by an arrow marker, i.e. a magnetic flux almost at right angles with the ink flow channel 1c and the current I. Consequently, the recording liquid injection force suffers no loss in transmission, neither is it delayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a liquid jet recording head, and more specifically, a recording liquid or liquid ink is ejected from a liquid flow path of a nozzle and attached to a recording material to perform recording. The present invention relates to a liquid jet recording head.

[Prior Art] This type of so-called inkjet recording head includes a type that constantly jets ink liquid and an on-demand type that jets ink only when necessary. In conventional on-demand type heads, ink is ejected using the pressure generated by a piezoelectric element, or a heat source is installed, and the heat generated generates air bubbles in the ink, and the pressure generated when the air bubbles expand is used to eject ink. The bubble jet method is known.

[Problems to be Solved by the Invention] However, in the piezoelectric element method and the bubble jet method described above, the pressure generated for ejecting ink is indirectly applied to the ink through the nozzle in the former case, and through air bubbles in the latter case. act. Furthermore, the pressure described above escapes in directions other than the ink jetting direction, and does not act efficiently in the ink jetting direction. For this reason, there were problems in that the ink jetting force became weak and the frequency response characteristics deteriorated.

[Means for Solving the Problems] In order to solve the above-mentioned problems, in the liquid jet recording head according to the present invention, a liquid flow path of a nozzle to which a conductive recording liquid is supplied, and a liquid flow path within the liquid flow path. means for passing a current through the liquid in a direction substantially perpendicular to the liquid flow path, and means for generating a magnetic flux substantially perpendicular to the liquid flow path and the current, and generating between the magnetic flux and the current. A configuration is adopted in which recording is performed by jetting the liquid from the liquid flow path using electromagnetic force.

[Operation] According to such a configuration, the electromagnetic force described in "-" directly acts on the recording liquid in the liquid flow path of the nozzle. Further, depending on the direction of the current, the direction of action of the electromagnetic force can be the direction along the liquid flow path of the nozzle, which is the direction in which the recording liquid is ejected, or the opposite direction. Therefore, there is no loss or time delay in transmitting the force for ejecting the recording liquid.

[Example] Hereinafter, the present invention will be described in detail with reference to the attached drawings, but first, the principle of ink jetting of a liquid jet recording head, that is, an inkjet head according to the present invention will be explained.

FIG. 1 shows its basic configuration.

In the present invention, the nozzle indicated by the reference numeral 1 in FIG. 1 is formed from an insulator such as glass. Further, the conductive ink 4 is used as the ink supplied to the ink flow path IC in the nozzle l via the tube 5. A positive electrode 2 and a negative electrode 3 are provided on the inner surface of the ink flow path IC of the nozzle l for flowing the current I into the conductive ink 4 in a direction substantially perpendicular to the ink flow path 1c as shown by the arrow. are provided facing each other.

Electrode 2 is connected to DC power supply voltage V+ via switch 7, and electrode 3 is grounded. Furthermore, a magnet or electromagnet (not shown) is placed near the nozzle to generate a magnetic flux Φ that goes toward the back of the paper as shown by the blunder mark, that is, a magnetic flux Φ that is almost perpendicular to the ink flow path IC and the electric current. .

With this configuration, when the switch 7 is turned on and the electrode 2 is connected to the DC power supply voltage V+, a predetermined amount of current (2) flows from the electrode 2 to the electrode 3 through the conductive ink 4.

Here, according to Fleming's left-hand rule, an electromagnetic force shown by symbol F is applied to the part where the current ■ of the conductive ink 4 in the ink flow path lc flows in the direction shown by the arrow, that is, along the ink flow path 1c, and the ink flow path tip. It acts in the ink ejection direction toward the ejection port 1d. Let the magnetic flux density of magnetic flux Φ be B, and electrode 2
, 3 is 1, the magnitude of the electromagnetic force F is F=BX×I.

A part of the conductive ink 4 is ejected from the ejection port 1d by this electromagnetic force F.

Then, when the switch 7 is turned off, the current (2) becomes zero, the electromagnetic force F becomes zero, and the ejection of the ink droplets 4a stops, and a part of the previously ejected conductive ink 4 becomes the ink droplets 4a.

By turning the switch 7 on and off in this manner, the ejection of the conductive ink 4 can be controlled.

Next, the present invention will be explained in detail.

Fig. 2 is an exploded perspective view showing the structure of an inkjet head (hereinafter referred to as head) according to the first embodiment of the present invention. Overlapping,
It is composed of a fixed structure.

Starting from the bottom member, the reference numeral 9 is the yoke that guides the magnetic flux Φ described above, and is made of a high magnetic permeability material such as pure iron and has a substantially U-shaped cross section.

A magnet 8 is fixed on the bottom surface of the four parts 9a of the cork 9.

The magnet 8 is formed into a rectangular plate shape from a rare earth metal or the like, and is magnetized in the thickness direction as shown by the polar signs N and S and the arrow indicating the direction of magnetic flux.

On the magnet 8 is a rectangular glass substrate 1a that constitutes a nozzle.
, lb are fixed. A groove is formed as an ink flow path 1c on the upper surface of the lower glass substrate lb, and is closed by the upper glass substrate la of the ink flow path 1c. Electrodes 2 and 3 corresponding to the aforementioned electrodes 2.3 are provided on both sides of the groove 1c. The electrode 2 is connected to a positive DC power supply voltage (not shown) via a switch made of a semiconductor element (not shown), and the electrode 3 is grounded.

Further, a rectangular plate-shaped yoke 10 made of a high magnetic permeability material, like the yoke 9, is fixed to the upper glass substrate 1aJ-.

Such a laminated structure constitutes the head of this embodiment whose cross section is shown in FIG. 3, and the above-mentioned conductive ink 4 is supplied to the ink flow path 1c of the head.

With this structure, the magnetic flux generated from the magnet 8 flows through loops lla and llb shown by arrows, perpendicular to the ink flow path IC, and also perpendicular to the line connecting the electrodes 2 and 3.

Therefore, when a current is caused to flow from the electrode 2 through the conductive ink 4 to the electrode 3 by turning on the switch (not shown), the magnetic flux is orthogonal to this current, so that the conductive ink in the ink flow path IC is turned on as described above. An electromagnetic force acts on the ink 4 in the direction of jumping out from the paper surface toward the front, and the conductive ink 4 is ejected. The ejection of the conductive ink can be controlled by turning the switch on and off in the same manner as described above.

According to the configuration of this embodiment, the electromagnetic force described above acts directly on the conductive ink 4 in the ink flow path IC of the nozzle 1. Further, the direction of action of the electromagnetic force can be the direction along the ink flow path 1c, which is the direction in which the conductive ink 4 is ejected, or the opposite direction thereof, depending on the direction of the current.

Therefore, since there is no loss or time delay in transmitting the force for ejecting the conductive ink, a high ejection force can be efficiently obtained with respect to the applied current, and good frequency response characteristics can be obtained.

Shaving Accident 1 Incidentally, the head of the first embodiment described above was constructed as a single nozzle head, but a multi-nozzle type head can be constructed by the structure of the second embodiment of the present invention shown in FIG. You can also do that.

In the case of the structure shown in FIG. 4, the ink flow path IC is mounted on the glass substrate 1b.
are formed in parallel. A positive electrode 2 and a negative electrode 3 are provided on both sides of each ink channel IC, and in this case, the electrodes 2.3 are provided straddling the adjacent ink channels lc. Therefore, when a positive power supply voltage is applied to the electrode 2 by turning on a switch (not shown), the current flowing from the electrode 2 to the electrode 3 flows in the opposite direction in the adjacent ink flow path 1c as shown by the arrow. For this reason, in this embodiment, the magnet 8 is magnetized with opposite polarity at a pitch corresponding to the pitch of the ink flow path 1c, as indicated by polarity symbols N and S.

With such a structure, a multi-nozzle type head can be constructed at low cost with a small number of electrodes, that is, a small number of parts.

[Effect] As is clear from the above description, according to the liquid jet recording head according to the present invention, the liquid flow path of the nozzle to which the conductive recording liquid is supplied, and the liquid in the liquid flow path. On the other hand, it has means for passing a current in a direction substantially perpendicular to the liquid flow path, and means for generating a magnetic flux substantially perpendicular to the liquid flow path and the current, and the electromagnetic force generated between the magnetic flux and the current Since recording is performed by jetting the liquid from the liquid flow path, there is no loss or time delay in transmitting the force for jetting the recording liquid, and a high jetting force can be efficiently generated relative to the applied current. At the same time, good frequency response characteristics can be obtained.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the basic structure of the head of the present invention, Fig. 2 is an exploded perspective view showing the structure of the head according to the first embodiment of the invention, and Fig. 3 is the structure and magnetic flux of the head of the same embodiment. FIG. 4 is an explanatory diagram of the structure of the head according to the second embodiment. 1... Nozzle la, lb... Glass substrate IC... Ink channel 2, 3... Electrode 4... Conductive ink 5... Tube 7... Switch
8...Magnet 9.10...Yoke 2nd figure (8 sets of heads Maki ixzmu red/) Flow upstream θ word taU figure 3 Hera 1'Tomotsutsutsu's name 0 eyes figure 4

Claims (1)

[Claims] a liquid flow path of a nozzle to which a conductive recording liquid is supplied; a means for passing a current through the liquid in the liquid flow path in a direction substantially perpendicular to the liquid flow path; A liquid ejecting device characterized in that the liquid is ejected from the liquid flow path by means of an electromagnetic force generated between the magnetic flux and the current to perform recording. recording head.