JP2000313128A - Ink jet recording apparatus - Google Patents

Abstract

(57) Abstract: Provided is an ink jet recording apparatus capable of stabilizing a droplet discharge direction. SOLUTION: A plurality of droplet discharge holes 2a, 3a, 4a, 5 are provided.
In the ink jet recording apparatus for performing printing by causing the droplet A to fly from the a to the same place 12 on the recording medium 11, the nozzle surface 1 of the plurality of droplet discharge holes 2a, 3a, 4a, 5a
The droplets a, 1b, 1c, and 1d are arranged so as to be perpendicular to the ejection direction B of the droplet A. Thereby, the droplet discharge holes 2
a, 3a, 4a, and 5a, the pressure applied inside and outside is equalized, and the droplet A is discharged from the droplet discharge holes 2a, 3a,
The droplets A are separated at the same time without being partially left from the wall surfaces of 4a and 5a, so that the ejection direction B of the droplet A is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for performing printing by flying droplets of ink or the like onto a recording medium.

[0002]

2. Description of the Related Art FIG. 7 shows a structure of a printer head of a conventional ink jet recording apparatus described in Japanese Patent Application Laid-Open No. 10-315511. As shown in FIG. 7, a plurality of ink chambers 52, 53, 54, 5
5, each of the ink chambers 52, 53, 54, and 55 has a heating element 52b, 53b, 54b, and 55b, and a plurality of liquids corresponding to the ink chambers 52, 53, 54, and 55. Drop ejection holes 52a, 53a, 54a, 55a
Are formed. The drive control circuit 60 and the ejection timing adjustment circuit 61 cause the droplet ejection holes 52a, 53a, 54a, and 55a to pass through the recording medium 62.
The printing is performed by causing the droplets 64 made of ink to fly at substantially the same location 63 at the same time.

The nozzle surface 51a of the recording head 51, on which the droplet discharge holes 52a, 53a, 54a, 55a are formed, is formed to be flat. 53a, 54a,
55a are formed in different inclined postures.

[0004]

However, in the above-described conventional ink jet recording apparatus, since the nozzle surface 51a is not perpendicular to the ejection direction, the droplet ejection holes 52a,
As shown in FIGS. 8 (a) to 8 (d), the way of applying pressure is different between the inside and the outside of 3a, 54a, 55a.
The droplet 64 is formed by the droplet discharge holes 52a, 53a, 54a, 55a.
8 (c), the ejection direction was not stable. As a result, there is a disadvantage that the droplets 64 do not stably mix at the same location on the recording medium 20 after ejection.

Further, since the flight distance of each droplet 64 is different,
In order to simultaneously print the droplets 64 at the same location 63 on the recording medium 62, an ejection timing adjustment circuit for delaying the ejection timing of the droplets 64 was required. In other words, the droplets 6 from the droplet ejection holes 53a and 54a arranged on the inner side
4 are the droplet discharge holes 52a, 55a arranged on the outer side
Since the flight distance is shorter than that of the droplet 64 from the outside, the ejection timing of the droplet 64 from the inner droplet ejection holes 53a and 54a is adjusted to the droplet 64 from the outer droplet ejection holes 52a and 55a.
It was necessary to delay the discharge timing of the nozzle according to the difference in the flight distance. As described above, the necessity of the ejection timing adjusting circuit 61 for adjusting the ejection timing complicates the circuit and causes an increase in manufacturing cost.

An object of the present invention is to provide an ink jet recording apparatus which can stabilize the ejection direction of droplets and can omit a circuit for adjusting the ejection timing. Things.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention relates to an ink jet recording apparatus which performs printing by causing droplets from a plurality of droplet ejection holes to fly to the same location on a recording medium. Is characterized in that the nozzle surface of the droplet discharge hole is perpendicular to the droplet discharge direction, and according to this configuration, the droplet discharge direction can be stabilized.

[0008]

According to the present invention, there is provided an ink jet recording apparatus which performs printing by causing droplets to fly from a plurality of droplet ejection holes to the same location on a recording medium. The nozzle surface of the hole is perpendicular to the discharge direction of the droplet. With this configuration, the pressure applied inside and outside the droplet discharge hole becomes equal,
The droplets are separated at the same time without leaving a state in which a part remains from the wall surface of the droplet ejection hole, so that the ejection direction of the droplet is stabilized, and the droplet is ejected at substantially the same location on the recording medium. The droplets mix with each other, and the mixed printing dots can be formed well on the recording medium.

According to a second aspect of the present invention, there is provided an ink jet recording apparatus for performing printing by causing droplets to fly from a plurality of droplet ejection holes to the same location on a recording medium, and to perform printing at one point on the recording medium. Characterized in that the plurality of droplet discharge holes are arranged side by side on a concentric circle centered at. With this configuration, the flight distance of each droplet from each droplet ejection hole to one printing location on the recording medium becomes equal, so that the recording time can be adjusted without adjusting the ejection timing from each droplet ejection hole. Each droplet reaches the print location on the medium at the same time, and a circuit for adjusting the ejection timing of the droplet is not required, so that the circuit is simplified.

According to a third aspect of the present invention, there is provided an ink jet recording apparatus for performing printing by causing droplets to fly onto a recording medium through droplet ejection holes provided in a plurality of recording heads. It is characterized in that a plurality of recording heads are arranged on a concentric circle centered on a printing position. With this configuration, the flight distance of each droplet from the droplet discharge hole of each recording head to one printing location on the recording medium becomes equal, so that it is not necessary to adjust the discharge timing from each droplet discharge hole. Each droplet simultaneously reaches a print location on the recording medium, and a circuit for adjusting the ejection timing of the droplet is not required, so that the circuit is simplified.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view schematically showing a recording head of an ink jet recording apparatus according to a first embodiment of the present invention. As shown in FIG. 1, the recording head 1 includes:
A plurality of ink chambers 2, 3, 4, 5 are provided, and each of the ink chambers 2, 3, 4, 5 has a heating element 2b, 3b, 4b, 5b,
The ink supply ports 2c, 3c, 4c, and 5c are provided correspondingly. The ink supply ports 2c, 3c, 4c, 5c are connected to the ink storage chambers 2t, 3t, 4t, 5t. Here, in the ink storage chambers 2t, 3t, 4t, and 5t, inks of cyan, yellow, magenta, black, and the like, in each of which a dye or a pigment of a predetermined color is dissolved in a solvent, are stored. These inks are stored in the liquid storage chamber 2t,
3t, 4t, 5t to ink supply ports 2c, 3c, 4c,
The ink is supplied to each of the ink chambers 2, 3, 4, and 5 through 5c.
For example, when printing is performed by ejecting cyan ink, a pulse signal is applied to the heating element 2b provided inside the ink chamber 2 corresponding to the cyan ink, thereby causing the heating element 2b to generate heat. Then, the cyan ink boils. The discharge electric pulse is generated by the heating elements 2b, 3b, 4b, 5b.
Is controlled by the drive control circuit 10. The ejection timing is adjusted by the ejection timing adjustment circuit 13 so that each droplet A reaches the print location 12 on the recording medium 11 at the same time.

Droplet discharge holes 2a, 3a, 4a, 5a are formed corresponding to the respective ink chambers 2, 3, 4, 5, and each of the droplet discharge holes 2a, 3a, 4a, 5a has a nozzle. Face 1
a, 1b, 1c, 1d are formed so as to be perpendicular to the ejection direction B of the droplet A. These droplet discharge holes 2a, 3a, 4a, and 5a are formed so that each ink flies to substantially the same location 12 on the recording medium 11 such as paper, OHP, or cloth.

With this configuration, each of the nozzle surfaces 1a, 1b,
Since 1c and 1d are perpendicular to the ejection direction B, the pressures applied inside and outside the droplet ejection holes 2a, 3a, 4a and 5a are equal, and are shown in FIGS. 2 (a) to 2 (d). As described above, since the droplets are separated at the same time without causing a problem that a part of the droplet remains from the wall surface of the droplet discharge hole unlike the related art, the discharge direction B of the droplet A is always stable. As a result, after the ejection, each droplet A is stably
1 at the same location 12 and good mixing quality can be obtained.

FIG. 3 is a sectional view schematically showing a recording head of an ink jet recording apparatus according to a second embodiment of the present invention. The components having the same functions as those of the ink jet recording apparatus according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIGS. 3 and 4, in the recording head 20, dyes or pigments of a predetermined color are dissolved in a solvent so that the droplets A 1 to A 4 fly to substantially the same location 12 of the recording medium 11. A plurality of droplet ejection holes 2a, 3a, 4a, 5a for ejecting color inks such as cyan, yellow, magenta, and black dissolved therein are arranged on a concentric circle centered on one printing portion 12 of the recording medium. Has been placed. Also in this embodiment, the nozzle surfaces 20a, 20b, 20c, and 20d are formed so as to be perpendicular to the ejection direction.

With this configuration, each of the droplet discharge holes 2a, 3
a, 4a, and 5a, one printing spot 1 on the recording medium 11
2, that is, the flight distances of the droplets A1 to A4 are equal, so that the droplet discharge holes 2a, 3a, 4a, 5a
5 (a) to 5 (a) without adjusting the ejection timing from
As shown in (d), the print location 12 on the recording medium 11
Droplets A1 to A4 arrive at the same time. Therefore, a circuit for adjusting the ejection timing of the droplets A1 to A4 becomes unnecessary, and the circuit is simplified, so that the manufacturing cost can be reduced. 4 and FIG.
d and 5d are ink bubbles formed by boiling.

FIG. 6 is a sectional view schematically showing a recording head of an ink jet recording apparatus according to a third embodiment of the present invention. This inkjet recording device 30
In this example, recording heads 31, 32, 33, and 34 for ejecting color inks such as cyan, yellow, magenta, and black are provided individually, and the recording heads 31, 32, and
33, 34 are the one print spots 12 on the recording medium 11
Are arranged on a concentric circle centered at the center. Note that 31
a, 32a, 33a, and 34a are recording heads 31, 3
Droplet ejection holes provided in 2, 33 and 34, respectively.

According to this configuration, each recording head 31,
Droplet ejection holes 31a, 32 provided in 32, 33, 34
Since the distances from a, 33a, and 34a to one printing point 12 on the recording medium 11, that is, the flying distances of the droplets A1 to A4 are equal, the same as the inkjet recording apparatus according to the second embodiment described above. The operation and effect can be obtained.

In the ink jet recording apparatus according to the second embodiment, one recording head 20 has a plurality of droplet discharge holes 2a, 3a, 4a, 5a of cyan, yellow, magenta, black and the like. In this manner, a single recording head 20 has a plurality of droplet ejection holes 2.
It is not easy to create a, 3a, 4a, 5a. On the other hand, it is relatively easy to arrange the recording heads 31, 32, 33, and 34 each having one droplet discharge hole as shown in FIG. The above-described effects can be obtained by simply changing the head arrangement while using an ink jet printer head.

[0019]

As described above, according to the present invention, by disposing the nozzle surfaces of the plurality of droplet discharge holes so as to be perpendicular to the droplet discharge direction, the droplet discharge direction can be changed. As a result, inks such as cyan, yellow, magenta, and black can be stably mixed with each other at the same location on the recording medium, and high-resolution printing can be performed.

Further, a plurality of droplet ejection holes may be arranged on a concentric circle centered on one printing point on the recording medium, or a plurality of droplet ejection holes may be arranged on a concentric circle centering on one printing point on the recording medium. By arranging the recording heads side by side, the flight distances of the droplets of ink and the like become the same, and a circuit for adjusting the ejection timing is not required, so that the circuit can be simplified and the manufacturing cost can be reduced. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a recording head of an ink jet recording apparatus according to a first embodiment of the present invention.

2 (a) to 2 (d) are views each showing a state of discharge of a droplet by the ink jet recording apparatus.

FIG. 3 is a sectional view schematically showing a recording head of an ink jet recording apparatus according to a second embodiment of the present invention.

FIGS. 4A to 4C are diagrams showing states in which droplets are discharged from respective droplet discharge holes by the same inkjet recording apparatus.

FIGS. 5A to 5D are diagrams showing states in which each droplet is ejected from the inkjet recording apparatus.

FIG. 6 is a sectional view schematically showing a recording head of an ink jet recording apparatus according to a third embodiment of the present invention.

FIG. 7 is a sectional view schematically showing a recording head of a conventional ink jet recording apparatus.

8 (a) to 8 (d) are views showing the discharge state of droplets by the conventional inkjet recording apparatus, respectively.

[Explanation of symbols]

A, A1 to A4 Droplet B Discharge direction 1, 20 Recording head 1a, 1b, 1c, 1d Nozzle surface 2, 3, 4, 5 Ink chamber 2a, 3a, 4a, 5a Droplet discharge hole 11 Recording medium 20a, 20b, 20c, 20d Nozzle surface 30 Inkjet recording device 31, 32, 33, 34 Recording head 31a, 32a, 33a, 34a Droplet ejection hole

Claims (3)

[Claims] In an ink jet recording apparatus that performs printing by causing droplets to fly from a plurality of droplet discharge holes to the same location on a recording medium, the nozzle surfaces of the plurality of droplet discharge holes are directed in the direction of droplet discharge. An ink jet recording apparatus characterized by being perpendicular to the recording medium. 2. An ink jet recording apparatus which performs printing by causing droplets to fly from a plurality of droplet discharge holes to the same location on a recording medium, and to form a concentric circle centered on one printing location on the recording medium. An ink jet recording apparatus, wherein the plurality of droplet discharge holes are arranged. 3. An ink jet recording apparatus which performs printing by causing droplets to fly onto a recording medium from droplet ejection holes provided on a plurality of recording heads, with one printing point on the recording medium as a center. An ink jet recording apparatus comprising a plurality of recording heads arranged side by side on a concentric circle.