JP2885231B2 - Inkjet printer head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer, and more particularly to a thermal ink jet printer head.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a head of a thermal type ink jet printer includes a nozzle frame 12 provided with a nozzle 11 and a heating frame 14 provided with a heating element 13. As shown in FIG. The ink 15 is filled in the gap, and the heating element 13 is heated to generate the ink 1 in the vicinity.
5 is heated and vaporized, and the ink 15 is ejected from the nozzle 11 by the expanding force in the vaporization.

Further, Japanese Patent Application Laid-Open No. Hei 2-217250 proposes an ink jet recording system in which a blown transparent ink is passed through a dye vapor to color and print the ink.

[0004]

However, in the head of the above-mentioned conventional thermal type ink jet printer, there are various problems since the ink is directly heated and vaporized by the heating element. That is, since the ink is directly heated by the heating element, characteristics such as no deterioration due to the heating, and the ability to obtain a force for vaporizing the ink by the heat of the heating element and ejecting the ink are required. Therefore, the ink had to be selected within a range that satisfies these heating characteristics. As a result, the range for selecting the ink is narrow, and it is required that the ink does not spread on paper and that the ink has good color development. However, it was not possible to select an ink having such good characteristics.

In the ink jet recording system disclosed in Japanese Patent Application Laid-Open No. 2-217250, since the transparent ink must be colored, the transparent ink is required to have an affinity for dye vapor. Therefore, an ink can be selected only in a range having a good affinity for the dye vapor. In addition, by passing the ink through the dye vapor, the ink itself is more likely to scatter and the print quality is degraded. It was something that would be.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and does not directly heat the ink, but ejects the ink by heating a vaporizing liquid other than the ink. It is an object of the present invention to provide an ink jet printer head which can freely select a suitable one from among the above, and which has a good print quality and a simple structure.

[0007]

In order to achieve the above object, an ink jet printer head according to the present invention comprises a nozzle side frame, a heating element side frame, and a space between the nozzle side frame and the heating element side frame. And the nozzle, the separation layer holes and the heating element provided corresponding to the nozzle side frame, the heating element side frame and the separation layer, respectively, and the space between the nozzle side frame and the separation layer. And a vaporized liquid filled between the separation layer and the heating element side frame.

In the ink jet printer head of the present invention, the heating element to which the current is supplied according to the print data generates heat and heats the nearby vaporizing liquid. The heated vaporizing liquid reaches the boiling point and generates bubbles. Heating continues and the bubbles grow larger and penetrate into the ink through the separation holes to push the ink. The ink pushed by the bubbles is pushed out of the nozzle and goes out of the head. The outgoing ink is further pushed by air bubbles and ejected as ink droplets. The ejected ink droplets adhere to the paper and form one dot. Thereafter, this operation is repeated, and characters and figures are formed by dots.

Preferably, the vaporizing liquid is composed of a highly volatile substance. By using a highly volatile substance, the current supplied to the heating element can be reduced, which can contribute to energy saving.

[0010] The nozzle position is determined according to the resolution of the head, for example, 300 DPI (do
(t / Inch). The same number of heating elements and separation layer holes are arranged corresponding to the nozzles.

The vaporizing liquid can be freely selected without considering the affinity for the ink and the like, but a liquid having a low boiling point, high volatility and high jet pressure is preferable. As the liquid for vaporization, there is an alcohol-based liquid.

As the ink, an ink having good properties relating to printing, such as less bleeding on a printing medium (paper or the like) is selected. At this time, it is not necessary to consider the characteristics with respect to heating as in the related art.

The separation layer hole is a hole having a size such that the ink and the vaporizing liquid are not mixed in a liquid state and the vaporized liquid for the vapor passes through. The radius of this separation layer hole is 30 μm
The range is preferably from 80 to 80 μm, and more preferably from 30 to 50 μm.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an ink jet printer head according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of one dot of an embodiment of an ink-jet printer head, and FIGS. 2 to 4 are cross-sectional views of the ink-jet printer head during operation. In these figures, 1 is a nozzle side frame, 2 is a heating element side frame,
A separation layer 3 is disposed between the nozzle-side frame 1 and the heating element-side frame 2. A large number of nozzles 4 are formed at predetermined intervals in the nozzle side frame 1, and separation layer holes 5 are formed in the separation layer 3 so as to correspond to the nozzles 4, that is, to be on a straight line. In addition, a heating element 6 is arranged on the heating element side frame 2. The space between the nozzle frame 1 and the separation layer 3 is filled with ink 7, and the space between the separation layer 3 and the heating element frame 2 is filled with a vaporizing liquid 8.

Next, the operation will be described. When a current is applied to the heating element 6 according to the data to be printed in a state where the heating element 6 does not generate heat as shown in FIG. 1, the heating element 6 generates heat and the vaporizing liquid in the vicinity as shown in FIG. 8 is heated and vaporized to generate bubbles 9. When the generated bubble 9 reaches the separation layer hole 5, a part of the bubble 9 enters the ink 7 through the separation layer hole 5 as shown in FIG. The bubbles 9 that have entered the ink 7 press the ink 7, and the ink 7 is pushed out from the nozzle 4. Then, as shown in FIG. 4, when all of the generated bubbles 9 enter the ink 7 and reach the nozzle 4, the ink 7 is ejected from the nozzle 4 as an ink droplet 10. Thereafter, the bubbles 9 remaining in the ink 7
Is discharged from the nozzle 4 to the outside by the pressure of the ink 7, and returns to the original state shown in FIG.

[0016]

As described above, according to the ink jet print head of the present invention, the heating element heats the vaporizing liquid and the ink is ejected from the nozzles by vaporizing the vaporizing liquid. Does not come into direct contact with the ink. Therefore, it is not necessary to consider characteristics due to heating in selecting an ink, so that an ink can be selected from a wide range. As a result, an ink having good printing characteristics can be used.

[Brief description of the drawings]

FIG. 1 is a sectional view of one dot of an embodiment of an ink jet printer head of the present invention.

FIG. 2 is a cross-sectional view of an ink jet printer head according to an embodiment of the present invention in an operation state.

FIG. 3 is a cross-sectional view of the ink jet printer head according to the embodiment of the present invention in an operation state.

FIG. 4 is a cross-sectional view of an ink jet printer head according to an embodiment of the present invention during operation.

FIG. 5 is a sectional view of one dot of an example of a conventional inkjet printer head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle side frame 2 Heating element side frame 3 Separation layer 4 Nozzle 5 Separation layer hole 6 Heating element 7 Ink 8 Vaporization liquid 9 Bubbles 10 Ink droplet

Claims (5)

(57) [Claims] 1. A nozzle-side frame, a heating element-side frame, a separation layer disposed between the nozzle-side frame and the heating element-side frame, a nozzle-side frame, a heating element-side frame, and a separator. Nozzles, separation layer holes, and heating elements provided for the respective layers, ink filled between the nozzle side frame and the separation layer, and ink filled between the separation layer and the heating element side frame. An ink jet printer head comprising a liquid for vaporization. 2. The ink jet printer head according to claim 1, wherein said vaporizing liquid is a volatile substance. 3. The ink jet printer head according to claim 1, wherein said vaporizing liquid is a substance having a high injection pressure. 4. The ink jet printer head according to claim 2, wherein said volatile substance is an alcohol-based liquid. 5. The ink jet printer head according to claim 1, wherein the separation layer hole has a radius of 30 to 80 μm.