JPS6122956A - Ink jet head - Google Patents

Abstract

PURPOSE:To eliminate the relative positional displacement of printing dots, and to conduct printing recording having high quality by forming nozzle holes with semicircular sections in a plurality of rows so that pitches thereof are alternated and disposing the nozzle holes so that the circular arc sides of the sections thereof are directed in the same direction. CONSTITUTION:Nozzles 21A in the nozzle surface 33 of the ink jet head are formed at regular pitches L, and nozzles 21B are arranged where alternate to the arrangement of the nozzles 21A at pitches L. Semicircular arc sections in the sections of the nozzles 21A and semicircular arc sections in the sections of the nozzles 21B are shaped so that the nozzle surfaces 33 are each directed in the same direction to the C direction that they are moved to recording paper. Printing dots 36A, 36B formed onto recording paper 34 by the nozzles 21A and the nozzles 21B are severally displaced only by distances l from prescribed positions and shaped on printing recording. The displaced distances are all directed to the same direction side, thus generating no relative positional displacement among the printing dots 36A and 36B.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to the structure of a multi-nozzle inkjet head, and in particular to a nozzle of an inkjet head in which dots formed by ink ejected from the nozzles are not misaligned. Regarding the arrangement structure.

A voltage is applied to the piezoelectric element installed above the pressure chamber containing the print recording ink to distort it based on the print information, and the pressure caused by this distortion is transmitted to the pressure chamber and communicated with the pressure chamber. An inkjet recording method is well known in which printing ink is ejected onto a recording paper from a nozzle provided at one end of the recording paper.

This inkjet head recording method is a non-impact recording method, which generates less noise when printing and recording.
In addition, since the printing quality is good and the device has a simple structure, it has recently become widely used as an output device for electronic computers.

When ink is ejected onto a recording paper from the nozzles of a multi-nozzle inkjet head in which a large number of such inkjet head nozzles are arranged to form -C printing dots, the relative ratio of ink ejected from each nozzle is determined. In order to realize highly reliable printing, it is required that the position does not shift.

[Conventional technology]

Regarding the conventional structure of such an inkjet head, the plan view in FIG. 5, the sectional view in FIG. 6 taken along line BB' in FIG. 5, and the cross-sectional view in FIG. This will be explained using the cross-sectional view of FIG. 7 taken along the line.

In FIG. 5, 1 is a nozzle for ejecting ink, 2 is a pressure chamber that accommodates ink and transmits pressure from a piezoelectric element 3, and 4 is an ink conductor that connects pressure chamber 2 and nozzle 1. 5 is a common ink chamber that temporarily stores ink; 6 is an ink supply path that connects the pressure chamber 2 and the common ink chamber 5;
Reference numeral 7 denotes an ink supply pipe for supplying ink to the common ink chamber 5 from an ink tank (not shown).

As shown in FIG. 7, ink passages such as the nozzle 1, ink conduction passage 4, pressure chamber 2, ink supply passage 6, and common ink chamber 5 are provided by an ink passage plate 8A made of a thin plate made of stainless steel; 8B, nozzle only ink channel plates 8A, 8B
The ink passages other than the nozzle are etched to approximately 1/2 the thickness, and the ink passages other than the nozzle are etched to form openings.
A piezoelectric element 3 is placed on the ink channel plates 8A and 8B.
Vibration plates 9^, 9B made of stainless steel thin plates that transmit pressure from the piezoelectric element 3 are joined by a soldering method or the like.

As shown in FIG. 6, the nozzle holes 1 of such an inkjet head are formed in a line at a predetermined pitch L in an ink flow path plate 88, and are formed in the ink flow path plate 8A.
Nozzles 1 are alternately formed on the ink flow path plate 8B corresponding to the nozzles 1 arranged on the ink flow path plate 8B, and the cross-sectional shapes of the nozzles formed on the ink flow path plate 8A and the ink flow path plate 8B are as follows. It has a semicircular structure obtained by cutting a circle with a straight line, and the arc parts of this semicircular cross section have corresponding structures.

FIG. 8 shows the arrangement of nozzles obtained by moving FIG. 6 by 90 degrees along the direction of arrow B, and FIG.
1 is a plan view of a state in which printing is performed while ink is ejected from a nozzle facing 1.

In FIG. 9, the recording paper 11 moves in a direction perpendicular to this plan view, the nozzle surface 10 moves in the X direction, and the nozzle surface lO
After the nozzle row 12 injects ink to form printed dots, the nozzle row 13 forms printed dots by filling in the spaces between the printed dots formed by the nozzle dead weight 2.

[Problem that the invention seeks to solve]

By the way, when the cross-sectional shape of the nozzle 1 is enlarged, it becomes as shown in Fig. 10, and the cross-section of the nozzle 1 is vertically symmetrical with respect to the The shape is not symmetrical with respect to the y-axis. When a printing experiment is carried out by ejecting ink onto recording paper from such a nozzle, the ink tends to be displaced in the direction of the semicircular straight line of the cross section of nozzle 1 and fly, as shown in Figure 8. In the nozzle surface 10 where the arcuate portions of the nozzle 1 are arranged opposite each other, the flying direction of the ink is the direction of the angle θ, or the distance l, as shown in FIG. Each is displaced by the distance.

Therefore, when printing dots are formed on recording paper with an inkjet head having such a nozzle surface 10, the distance l of the positional deviation from the predetermined position of the printing dots 14 formed by the first nozzle row 12, 2nd row nozzle row 1
The distance l of the positional deviation from the predetermined position of the printed dots 15 formed in 3 overlaps, and these printed dots 14 and 1
The distance between the dots 5 and 5 is amplified to 21, and there is a problem in that if printing is performed using such printing dots, it is not possible to realize printing and recording as high as 'f4J'.

[Means for solving problems]

The problem described above is that in an inkjet head that ejects ink from a nozzle onto a recording paper, a nozzle row in which a large number of nozzle holes each having a semicircular cross section is arranged with a predetermined pinch spaced apart from each other is arranged. This problem is solved by the inkjet head of the present invention, in which a plurality of rows of nozzle holes are arranged so that the arcuate sides of the cross sections of the nozzle holes all face in the same direction.

[Effect]

That is, in the inkjet head of the present invention, a plurality of nozzle rows in which nozzle holes having a semicircular cross-sectional shape are arranged at a predetermined pitch are provided so that the pitches of the nozzle holes are staggered, and the nozzle holes are They are arranged so that the arcuate sides of the cross sections face the same direction, so that even if displacement occurs in the flying direction of the ink, the displacement is in the same direction with respect to the traveling direction of the inkjet head with respect to the recording paper. This eliminates variations in the distance between the printing dots formed by the second nozzle row and the printing dots formed by the second nozzle row.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of an inkjet head of the present invention.
Figure 2 is a cross-sectional view showing the structure of the nozzle taken along line A-A' in Figure 1, Figure 3 is a cross-sectional view of Figure 2 rotated 90 degrees in the direction of arrow B, and Figure 4 3 is a diagram showing a state in which a nozzle surface having the nozzle structure shown in FIG. 3 is arranged to face a recording paper to form printed dots. FIG.

As shown in FIGS. 1, 2, and 3, in the inkjet head of the present invention, only the nozzle holes 21 are half-etched to approximately 1/2 the thickness, and the pressure chambers 22, ink guide passages 23, and ink An ink passage plate 26 made of a thin stainless steel plate in which ink passages such as the supply passage 24 and a common ink chamber 25 are formed by etching, and a vibration plate 28 made of a thin stainless steel plate to which a piezoelectric element 27 is fixed. prepare. In addition, separately from this, the nozzle hole 21
Half-etching is performed for only one ink passage, and the other ink passages are formed using an ink passage plate 29 and a piezoelectric element 3 formed in the same manner as described above.
A diaphragm 31 made of a thin stainless steel plate to which 0 is fixed is prepared. Separately from this, a stainless steel bottom plate 32 in which the common ink chamber 25 is opened by etching is prepared.
3] and the bottom plate 32 are joined by soldering to form an inkjet head. As shown in FIGS. 2 and 3, the ink formed in this manner is 1! The first row of nozzles 21^ formed on the ink flow path plate 26 of the nozzle surface 33 are spaced apart by a predetermined pitch 5, and the second row of nozzles 21^ formed on the ink flow path plate 29 are spaced apart from each other by a predetermined pitch 5. The nozzles 21B are arranged at alternate positions with respect to the arrangement of the nozzles 21A in the first row with a pitch L between them. Also, the nozzle surface 33 moves relative to the recording paper in the semicircular arc section of the first row nozzle 21A and the semicircular arc section of the second row nozzle 21B. 3, that is, the direction of arrow C in FIG.

As shown in FIG. 4, the nozzle surface 33 of the inkjet head of the present invention having such nozzles is placed facing the recording paper 34, and the nozzle surface 33 is moved in the direction of the arrow When printing is performed while moving in a direction perpendicular to this drawing, ink 358 is ejected onto the recording paper 34 from the nozzle 21A and the nozzle 21B.
35B is displaced by an angle θ from a predetermined position and flies toward the side cut by the semicircular straight section of the cross section of nozzle 218 and nozzle 21B.

Therefore, nozzle 218 and nozzle 2 are placed on the recording paper 34.
The printed dots 368 and 36B formed in B are respectively formed by being displaced by a distance l from the predetermined position, but since both of these displaced distances are displaced toward the same direction, the first column There is no relative positional shift between the print dot 368 formed by the nozzle 218 in the first row and the print dot 36B formed by the second row nozzle 21B.

Therefore, if print recording is performed using the ink side end head having the nozzle surface of the present invention, the relative position between the print dots printed by each nozzle row will not be displaced, so high quality print recording can be achieved. There is.

Further, in this embodiment, the case where there are two nozzle rows has been described, but the unpaid nozzle rows may be two or more rows.

〔Effect of the invention〕

As mentioned above, if printing is performed using an inkjet head having a nozzle surface with the nozzle array structure of the present invention, there will be no relative positional deviation of printed dots.
This has the effect of allowing high-quality printing and recording.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the real male side of the inkjet head of the present invention, Fig. 2 is a plan view of the nozzle surface of the inkjet head of the invention, and Fig. 3 is a plane rotation of Fig. 2 by 90 degrees in the direction of arrow B. FIG. 4 is a schematic diagram showing the state when printing is performed on recording paper using the inkjet head of the present invention; FIG. 5 is a plan view showing the structure of a conventional inkjet head; Figure 6 is a cross-sectional view of Figure 5 taken along line B-B'', Figure 7 is a cross-sectional view of Figure 5 taken along line D-D', and Figure 8 is a cross-sectional view of a conventional inkjet head. A plan view of the nozzle surface, FIG. 9 is a schematic diagram showing the state of printing and recording using a conventional inkjet head, and FIG. 10 is an enlarged view of the ρ nozzle hole of the conventional inkjet head. 21A and 21B are nozzles, 22 is a pressure chamber, 23 is an ink conduction path, 24 is an ink supply path, 25 is a common inductor chamber, 26.29 is an ink channel plate, 27.30 is a piezoelectric element, 'tg, sx are 32 is a diaphragm, 32 is a bottom plate, 33 is a nozzle surface, 34 is a recording paper, 35A and 35B are ink, 3
68, 36B are printed dots, B is an arrow indicating the direction of rotation of the nozzle surface, C is an arrow indicating the moving direction of the nozzle, L is the pitch between nozzles, and l is the displacement distance of the printed dots. Figure 1 Figure 4 Figure 5

Claims (1)

[Claims] In an inkjet head that ejects ink onto a recording paper from a nozzle for recording, a nozzle row in which a large number of nozzle holes having a semicircular cross section are arranged at a predetermined pitch is arranged such that each nozzle is staggered. An inkjet head characterized in that a plurality of rows of nozzle holes are provided, and the arc sides of the cross sections of the nozzle holes all face the same direction.