JPH02273241A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To reduce a size, a density and a cost by employing a conductive material as the wall of a liquid chamber, supplying a current to the wall in a magnetic field to displace the wall, and varying the volume of the chamber. CONSTITUTION:A liquid chamber 9 is composed of conductive walls 1, 2 and insulating walls 3, 4. Leads are so attached to the walls 1, 2 as to supply a current in a direction of an ink passage, and connected to a pulse signal generator 8. The rear part 7 of the chamber is connected to an ink supply source, and magnets 5, 6 are so placed as to generate a magnetic field in parallel with the walls 1, 2. A current (1) is supplied in a direction for displacing the walls 1, 2 inward to reduce the volume of the chamber, and to discharge an ink droplet 10. When the current is stopped, the walls 1, 2 are returned to the original by its elastic force, and ink is supplied from a rear ink supply source.

Description

[Detailed description of the invention] Shōsara Komame The present invention relates to an inkjet recording device.

Yumei Gigon Special Publication No. 44-3888 (the former) discloses that the flow of conductive ink toward the recording medium is controlled by passing an electric current through the ink while the ink is maintained in a magnetic field. A method for recording by selectively depositing ink on a recording medium is disclosed. Also, r I
B M Technical Disclosure B
ulletinJ (vol, 18 No, 7゜1
975), P2195) (the latter) is a method of ejecting ink using electromagnetic force as in the above case, but instead of ink, a current is passed through mercury in a magnetic field to apply a displacement force, A method for ejecting ink in contact with mercury is disclosed.

In the former method of directly passing a current through the conductive ink, it is thought that electrolysis of the ink and electrode occurs. As a method of preventing this electrode plating, it has been proposed to periodically reverse the direction of current and magnetic flux.

Furthermore, in the latter method using mercury, the structure for supplying ink is complicated, and it is thought that it would be difficult to form a structure in which a certain amount of mercury is placed in a small chamber corresponding to each nozzle. It will be done.

■--The present invention was made in view of the above-mentioned circumstances.
The purpose of this invention is to provide an inkjet recording device that uses a method of applying a displacement force to a wall surface by passing an electric current through it.

To achieve the above object, the present invention provides an ink-on-demand head that electromechanically contracts and expands the volume of the liquid chamber of the head in response to signals used in inkjet recording. This device is characterized by using a conductive material for the wall surface and passing an electric current through the wall surface in a magnetic field to displace the wall surface and change the volume of the liquid chamber. Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a block diagram for explaining one embodiment of an inkjet recording apparatus according to the present invention. In FIG. 1, 1.2 is a conductive wall surface, 3.4 is an insulating wall surface, 5.6 is a magnet, and 7. 8 is a rear part of the liquid chamber, 8 is a pulse signal generator, and 9 is a liquid chamber.

The liquid chamber 9 is composed of conductive wall surfaces 1 and 2 and insulating wall surfaces 3 and 4. Lead wires are attached to the conductive wall surfaces 1 and 2 so that a current flows in the direction of the ink flow path, and are respectively connected to a pulse signal generator M8. The rear part 7 of the liquid chamber is connected to a source of ink. Magnets 5 and 6 are placed so that a magnetic field is generated parallel to the conductive walls 1 and 2.

FIG. 2 is a diagram for explaining how the liquid chamber operates when a current is passed through the conductive wall surface.

By flowing the current i in the direction in which the conductive walls 1 and 2 are displaced inward, the volume of the liquid chamber is reduced.

Ink/1Iio is ejected. When the current is turned off, the conductive wall surfaces 1 and 2 return to their original state due to elastic force, and at the same time, ink is supplied from the ink supply source at the rear.

If you use a material that is expected to undergo a sufficiently large deformation.

Current may be passed through either one of the conductive wall surfaces 1 and 2.

FIG. 3 is a diagram showing an embodiment in which the inkjet recording head according to the present invention is applied to a multi-head. Arrows indicate the direction of current flowing in accordance with signals. When ejecting from nozzles A and C, wall surfaces c and d After a predetermined delay time, current is applied to walls a and b. Since wall surfaces C and b are alternately displaced, no jet is ejected from nozzle B.

When discharging from nozzles A and B, a current is passed through walls a, b, and c. Walls a and b compress the volume of nozzle A.
Ejects more ink. At the same time, the walls S and C are displaced in a direction away from each other, and ink is supplied to the nozzle B. When the current is cut off and the walls S and C return to their original positions due to elastic force, the volume changes and ink is ejected from the nozzle B. Discharge is performed by the so-called pull-and-strike method.

In this way, ink can be ejected from each nozzle without changing the flow direction of the fa flow.

As is clear from the above description, according to the present invention, an inkjet recording device characterized in that the volume of the liquid chamber is changed by passing an electric current through the wall surface in a magnetic field has a simple structure. Therefore, it is possible to reduce the size, increase the density, and reduce the cost.

Generally, such electromagnetic force is small and difficult to put into practical use, but by changing the entire wall surface, as in the embodiment of the present invention, it is possible to change a large area while maintaining high density. , it is possible to obtain sufficient force for ejection.

Furthermore, it goes without saying that the ejection force can be further improved by utilizing the magnetic field generated by superconductivity.

In addition, since the method uses a method to apply a changing force by passing current through the wall surface, there is no need to worry about electrolysis.Therefore, since the direction of the magnetic flux is always constant and only switching is required, the electrical circuit becomes simple and low cost. It can be made smaller and smaller.

Furthermore, since the wall surface is used, the structure can be made into a very WM element, and therefore, further cost reduction, miniaturization, and higher density can be achieved.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of an inkjet recording apparatus according to the present invention, and FIG. 2 is a diagram for explaining how a liquid chamber operates when a current is passed through a conductive wall surface. FIG. 3 is a diagram when applied to a multi-head. 1.2... Conductive wall surface, 3, 4... Insulating wall surface, 5
゜6... Magnet, 7... Rear part of liquid chamber, 8... Pulse signal generator, 9... Liquid chamber.

Claims (1)

[Claims] 1. In an ink-on-demand head that electromechanically contracts and expands the volume of the liquid chamber in the head in response to signals used in inkjet recording, a conductive material is used on the wall of the liquid chamber, and the wall surface is heated in a magnetic field. By passing a current,
An inkjet recording device characterized by changing the volume of a liquid chamber by displacing a wall surface.