JPS6219464A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To reduce the quantity of thermal energy required for heating and melting and shorten the heating time required for melting, by providing a passage filled with a solid ink (solid at normal temperature), a head comprising a conductive material at least at a part of the inner wall of the passage, and an electromagnetic wave oscillator in proximity to the head. CONSTITUTION:A heating element 20 consists of a thin film of chromium, which is provided as follows. After providing a groove part corresponding to the ink passage, chromium is vapor-deposited on the entire surface by sputtering before removing a photoresist remaining at parts other than the groove part. Then, the photoresist is removed to obtain a thin chromium film only at the groove part. Namely, the ink makes contact with the heating element 20 provided on the inner surface of the passage by vapor deposition. With this construction, the period of time and thermal energy required for melting a solid ink are less than those in a system wherein heating is conducted on the outside of the head substrate. To melt the solid ink by heating, the heating element 20 is heated through electromagnetic induction by the electromagnetic wave oscillator 21 fitted in proximity to a glass substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention mainly relates to an inkjet recording apparatus that uses hot melt type ink, and particularly to a head thereof.

[Conventional technology]

In recent years, inkjet recording devices, which are one of the non-impact recording methods, have been commercialized because of the requirements for high-speed printing, low noise, and the use of plain paper. However, while inkjet recording devices that directly spray ink onto plain paper do not require running costs, they have the fundamental problem that, since the recording medium is a liquid, it tends to dry after printing and is prone to smearing. It has disadvantages. If the drying is slow, it becomes difficult to increase the speed of recording, and a means such as forced drying is required to solve this problem, making the structure complicated and expensive.

When the print ht bleeds, it is not only difficult to improve the print quality, but also difficult from the viewpoint of improving the 1-resolution required for applications such as color image recording.

Therefore, we focused on the recording medium and improved it by using hot melt type ink, which is the inkjet recording method. In this method, ink that is in a solid state at room temperature is used for the recording medium, and when it is ejected from a nozzle, it is heated and melted to make it into a liquid state for printing.

[Problem that the invention seeks to solve]

In an inkjet recording device using a hard-melt type ink, it is required that the solid ink has a short melting time and that its heating means has a simple structure, especially in the multi-nozzle portion in the head.

The embodiment shown in Japanese Patent Application Laid-Open No. 59-7052 is as follows:
Since the system is mounted outside the shield and heated by a secondary heating element, it takes a long time for the solid ink to melt, which is undesirable. In the case of the melting means of the embodiments shown in JP-A-58-116162 and JP-A-58-208062, multi-nozzle formation is difficult.

Therefore, the solid ink can be melted in a short time, and.

In order to increase the efficiency of thermal energy used for melting, a heating element is provided directly on the inner wall of the ink flow path. It is most effective. This problem can be solved by applying electrical energy to a resistor attached to the inner wall of the channel. However, in this method, electrodes must be installed on the inner wall of the ink flow path, which must be as smooth as possible, in order to eliminate air bubbles remaining in the ink flow path, which is not preferable. Furthermore, the construction difficulties for installing electrodes increase with the number of nozzles, so for multi-nozzle heads,
This results in an inappropriate configuration.

An object of the present invention is to provide a means for heating and melting the solid ink in the head in an inkjet recording apparatus using hot melt type ink, which shortens the time bZ required for melting the solid ink and has a multi-nozzle head Kb. The objective is to provide a new mechanism with a simple structure, even if the structure is simple.

[Means for solving problems]

According to the present invention. An inkjet recording device consists of a flow path filled with solid ink that is in a solid state at room temperature, a head having a conductive material on at least a portion of the inner wall of the flow path, and an electromagnetic wave oscillator placed close to the head. This is an inkjet recording device characterized by the following.

[Effect]

With this configuration, an electromagnetic wave oscillator causes electromagnetic induction in the conductive member located on the inner wall of the ink flow path, and the Joule heat generated by the eddy current directly heats the solid ink filled in the flow path. , making it possible to melt 6.

〔Example〕

Hereinafter, it will be explained in detail using the drawings.

Figure ta1 shows an embodiment according to the invention. FIG. 2 is a plan view of a section of the inkjet recording apparatus. Figure WX2 is a sectional view taken at - in Figure 1.

In addition, parts other than the heave part are omitted, and the head part is formed by photo-etching the substrate 1, forming a groove corresponding to the ink flow path, and then fusing it with the substrate 2, which is made of a northern borosilicate glass plate. Ru. Ink is transferred from the ink tank to the common ink chamber 6.
1C is supplied, passes through each pressure chamber 5, and is ejected from the nozzle 4 in the upper right direction in FIG. 1 by an electrorecording signal applied to the piezoelectric element 3.

The ink material is, for example, a wax-based ink disclosed in JP-A-58-108271.

The 20 heating elements are made of chrome thin film and are formed through the steps described below. First of all, since I'm busy with photo etching,
After forming grooves corresponding to ink flow paths, chrome is sputter-deposited over the entire surface before removing the photoresist remaining outside the grooves. Thereafter, by removing the photoresist, a thin chrome film formed only in the groove can be obtained. Thick, 0.01~1.
It is 0 μm. Nanarichi ink is always in contact with the heating element 20 deposited on the inner wall of the flow path. With this configuration.

Compared to a method that heats the head substrate from the outside, it takes less time and less thermal energy to melt the solid ink.

The means for heating and melting the solid ink is provided in close proximity to the glass substrate, and then a heating element 20 is generated by an electromagnetic wave excavator 21.
by heating by electromagnetic induction. The oscillation conditions of the electromagnetic wave oscillator are a frequency of 1 to 100 KHz and a voltage of s to so.
It is ov.

The material of the substrate 1.2 may be any insulating material other than borosilicate glass, such as photosensitive glass or injection molded plastic.

The material of the heating element 20 may be copper, nickel, or other materials other than chrome.
Any material with conductivity, such as nichrome, titanium, or manganese, may be used.

The heating element 20 may be deposited on the inner wall of the flow path of the substrate 2 .

In addition, other means for attaching the heating element 20 to the inner wall of the flow path and [
Alternatively, a quick-drying metal solution may be applied and dried.

The heating principle used in the present invention is electromagnetic induction heating,
It does not require wiring such as electrodes.

This has structural advantages such as the fact that the heating element does not need to have continuous conductivity along the inner wall of the flow path. In other words, the heat generating resistors may be distributed in the form of islands on the inner wall surface of the channel. FIG. 3 is an explanatory view of the head configuration of an inkjet recording apparatus showing another embodiment of the present invention in which one heating element may be arranged in an island shape.

Please note that all but one channel corresponding to one nozzle button are omitted. Second, the configuration is the same as that in FIG. 1 except for the arrangement of the heating element 20. Formation of the heating element 20 requires an additional step of selectively etching the heating element by the 7-etching method in addition to the heating element forming step in the embodiment described above. In this embodiment, a common ink chamber 6 for 20 heating elements is connected to a nozzle 4.
The inner wall of the ink flow path leading to the ink flow path is formed in a striped pattern, and its distribution is such that the proportion of the heating element 20 increases as it approaches the nozzle portion. This configuration makes it possible to control the temperature gradient of the flow path, for example, by preferentially melting the solid ink within the nozzle portion.

In addition, the heating means in the present invention is not limited to a means for melting hot-melt type solid ink, but also a means for heating liquid ink in a general inkjet recording device, a puzzle jet method, that is, a means for generating air bubbles in an ink flow path, etc. It is also possible to use it as a heat generating means.

〔Effect of the invention〕

According to the present invention, for example, in an inkjet recording apparatus using hot melt type ink having a multi-nozzle head, the structure of the heat generating part for heating and melting the solid ink and the formation process h can be simplified, and the solid Since the ink is in direct contact with the first heat generating part, it has the advantage that the amount of thermal energy required for heating and melting is small and the heating time until melting is short.

[Brief explanation of drawings]

FIG. 1 is a plan view of a head section of an ink shed recording apparatus showing an embodiment of the present invention. FIG. 2 is a sectional view taken along the line -■ in FIG. 1. FIG. 3 is a plan view showing a local part of a head according to another embodiment of the present invention. 1... Board 2... Board 3...
... Piezoelectric element 4 ... Nozzle 5 ...
...Pressure chamber 6...Common ink 7...
...7ta 8...pipe 20...
... Heating element 21 ... Electromagnetic wave oscillator or more
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Claims (1)

[Claims] An inkjet recording characterized in that a flow path filled with solid ink that is in a solid state at room temperature has a head whose at least one wall surface is made of a conductive material, and an electromagnetic wave oscillator arranged close to the head. Device.