JPS62109656A - Liquid injection recorder - Google Patents

Abstract

PURPOSE:To maintain the state of excellent printing at all times by simple constitution by constituting an injection recording head so that a liquid is discharged from an orifice, inclining in the direction opposite to the main scanning direction of a carriage. CONSTITUTION:With a recording head 4, the quality of materials of members 21 and 24 in the periphery of an orifice 4B is composed of silicone and glass. Since wettability to ink of an silicon substrate 21 is the highest-that is, a contact angle is the smallest at that time, ink droplets 10 are discharged so as to be pulled in the direction of the silicon substrate 21 as shown in the direction of discharge 11. The direction of movement of a carriage is determined so that the main scanning direction of the carriage is directed toward the direction shown by the arrow 13 in this case. Accordingly, the state of excellent printing can be kept at all times by simple constitution.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a method of ejecting a recording liquid such as ink from an ejection port to form ink droplets, and making the ink droplets adhere to a recording material to perform recording. The present invention relates to a liquid jet recording apparatus that performs this, and more specifically, to a liquid jet recording apparatus that improves the accuracy of the impact point of droplets on a recording material.

[Prior Art] The liquid jet recording method, the so-called inkjet recording method, generates small droplets of recording liquid such as ink and attaches them to a recording material such as paper. It has attracted attention as a recording method that is extremely small to the extent that it can be ignored, is capable of high-speed recording, and can record on plain paper without the need for special processing such as fixing.Recently, various types of recording methods have become active. is being studied.

The recording head section of a recording device used in the inkjet recording method generally includes an orifice for ejecting ink, that is, a liquid ejection opening, and a part that communicates with the orifice and applies energy to the ink to eject the ink. The ink passage (liquid passage) has an ink passage (liquid passage) and an ink chamber for storing ink to be supplied to the ink passage.

During recording, the energy for ejecting ink is generated by a heating element disposed at a predetermined position in a part of the ink passage that applies ejection energy to the ink.
It can be generated by various types of energy generating elements, such as piezoelectric elements.

A method for manufacturing an inkjet recording head having such a configuration is, for example, to form fine grooves on a flat plate of glass, metal, etc. by cutting or etching, and then to attach another suitable plate to the flat plate with the grooves formed thereon. Alternatively, for example, a photosensitive resin layer deposited on a substrate on which an ejection energy generating element is arranged is cured according to the pattern of the ink passage using one step of photolithography. A method is known that includes the steps of forming groove walls by forming groove walls, and bonding the thus formed grooved plate with another flat plate as a cover to form ink passages (for example, Japanese Patent Application Laid-Open No. 1983-1999) 4387ft).

In these inkjet recording heads, when grooves are formed on the substrate by cutting or etching as in the former case, the material of the flat plate on which the fine grooves are formed is bonded to the flat plate on which the grooves are formed to form ink passages. Or, as in the latter method using photosensitive resin, the substrate on which the ejection energy generating element is arranged, the photosensitive resin, and the other flat plate as a cover are generally made of different materials. If they are different, the wettability (contact angle) of each material to the ink will be different, and the wettability of the parts around the orifice will be partially different. Therefore, when the ink is ejected, The ejected droplets receive a force that pulls them in the direction of the highly wettable member, and are ejected in a direction tilted with respect to the desired ejection direction.

Furthermore, droplets may be ejected obliquely depending on the shape of the orifice and the location of the energy generating element.

In this way, an inkjet recording head that ejects ink droplets away from the axial direction of the ink path is mounted on a carriage that slides on a guide bar extending in the main scanning direction, and the ink path is If the ink passage is arranged perpendicular to the scanning direction of the carriage and also perpendicular to the recording member, the carriage Depending on the moving direction of the ink droplet, the accuracy of the landing point of the ink droplet on the recording material differs due to the difference in the ejection speed of the ink droplet.
As a result, there has been a difference in print quality depending on the direction in which the carriage moves.

Furthermore, if ink droplets are ejected straight along the main axis direction of the ink path, there will be no difference in print quality depending on the direction of carriage movement, but there will be differences in print quality due to variations in carriage movement and ejection speed. , so-called print skew occurred.

In order to prevent such print curling, it is conceivable to increase the specific ejection speed of the ink, but there is a limit to this in terms of print quality, and it is not a perfect solution.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to devise a method to make ejected droplets of the type described in the conventional example fly, thereby making it possible to always maintain a good printing quality state. An object of the present invention is to provide a liquid jet recording device as described above.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides an orifice for ejecting a liquid to form a flying droplet, and an orifice for forming a flying droplet and a recording material. It is equipped with a liquid jet recording head in which an energy generating body that generates energy for flying toward the orifice is arranged upstream of the orifice, and a carriage that is mounted with the liquid jet recording head and is movable in the main scanning direction, The liquid jet recording head is arranged so that when the liquid jet recording head is in a stationary state, the liquid is ejected from the orifice at an angle perpendicular to the recording material in a direction opposite to the main scanning direction of the carriage. Features.

[Function] According to the present invention, for an inkjet recording head that ejects ink droplets at a certain angle due to differences in the materials around the orifice, the ink ejection direction is inclined due to differences in the wettability of the materials around the orifice. It is sufficient to set the direction opposite to the direction of carriage movement, for example,
A simple configuration that limits the installation direction of the inkjet recording head so that a member made of a material with high wettability is placed on the rear side in the direction of movement of the carriage in accordance with the main scanning direction of the carriage ensures good printing conditions at all times. It is possible to provide an inkjet recording device that can.

[Example] The present invention will be described in detail below with reference to the drawings.

First, when ink droplets are ejected obliquely, the mechanism by which print quality differs depending on the direction of carriage movement will be explained in detail, and then the present invention will be explained in detail.

FIG. 1 is a schematic diagram of the main parts of an inkjet recording apparatus to which the present invention is applied.

Here, two wooden guide shafts 28 and 2B are arranged parallel to the platen 1, and a carriage 3 is attached to these guide shafts 2A and 2B so as to be movable in the main scanning direction. It is being A recording head portion of the carriage 3 is equipped with a recording head 4 disposed facing the platen 1 and an ink container 5 positioned behind the recording head 4 .

A recording head 4, which is a recording means, and an ink container 5 are connected by an ink supply pipe 6, so that ink, which is a recording liquid, can be supplied to the recording head 4. Further, a flexible tube 7 is connected to the ink container 5 and forms an ink supply path with a main ink tank (not shown).

In this inkjet recording apparatus, by giving a control signal to the recording head 4 via the flexible circuit 8,
Ink is ejected from the recording head 4 according to a print pattern, and printing is performed using the ejected ink droplets on a printing paper 9, which is a recording material, which is guided along the platen 1.

FIG. 2 is a schematic diagram of the main parts of the inkjet recording apparatus shown in FIG. 1, viewed from above the apparatus.

Here, the droplets 10 are ejected in an ejection direction 11 that deviates from a direction perpendicular to the moving directions 12 and 13 of the carriage 3 (that is, the axial direction of the ink passage 4^ of the recording head 4 indicated by a dashed line in the figure). This shows the case where

Here, the main scanning direction of the carriage 3, that is, the moving direction 1
Ink droplet lO in each case of 2 and 13
The ejecting direction is shown in FIG. 3 and FIG. 4, respectively. That is, FIG. 3 shows the normal case in which the carriage 3 is moved in the direction 12, and FIG. 4 shows the case in the present invention in which the carriage 3 is moved in the direction 13.

In either case, the ink droplet 10 has a velocity component in the direction perpendicular to the recording surface of the recording material 9, that is, in the main axis direction toward the ink passage 4, and wettability due to the difference in the material around the orifice 4B. Due to the difference between the two, the liquid is discharged with a velocity component (2) that is pulled in a direction perpendicular to Vl. In addition, the velocity component ■3 due to the uniform motion of the carriage 3
As a result, the ink droplets 10 are ejected in the ejection direction 11 and adhere to the recording material 9 at the landing point 20 .

In the case of Fig. 3, ■2 and the moving direction 12 of the carriage 3
4 are in the same direction, and in the case of FIG. 4, 2 and the moving direction 13 of the carriage 3 are opposite directions.

■2 and V cause the inclination of the ink droplet 10 in the ejection direction.
3 is the sum of V2 and V3 in the case of FIG. 3, that is, when the carriage 3 moves in the direction 12, and in the case of FIG. 4, that is, when the carriage 3 moves in the direction 13.
When it moves to , it appears as a difference between ■2 and ■3.

By the way, in both cases of FIG. 3 and FIG. 4, if the velocity components V1, V2, and V3 are always constant, the ink droplet 10 is ejected obliquely as shown, but the inclination is Since it is always constant, printing can be performed while always maintaining a certain landing point deviation °C.

In such a case, when the moving direction of the carriage 3 is in one direction, that is, during unidirectional printing, no printing deviation or landing point deviation occurs at all, and even when printing in both directions,
By slightly shifting the ejection timing of the ink droplets 10 according to the moving direction of the carriage 3 and ejecting the ink droplets 10, it is possible to eliminate printing misalignment.

However, in general, the ink droplet ejection speed component (1) is not constant at all even when ejected from the orifice 27, but has a certain distribution.

In addition, in an inkjet recording head having a plurality of orifices, there are variations in the ejection velocity component V1 of each orifice, so in FIGS. 3 and 4,
1 changes, the discharge direction 11 changes,
As a result, the impact point shift I! , 0 will change, which causes the printing to be distorted.

By the way, in general, in inkjet recording devices, the direction of carriage movement during recording is either unidirectional printing or bidirectional printing, and if you want to increase the printing speed, bidirectional printing is performed, such as when recording a graphic pattern. Since data transfer requires a certain amount of time, unidirectional printing is performed when there is sufficient time to move the carriage or when high print quality is desired.

Therefore, in the present invention, when performing unidirectional printing in this way, the present invention moves the carriage 3 in the scanning direction of the printing in the opposite direction to the direction in which the ink droplets 10 deviate due to the difference in wettability. Using this direction, printing is performed in a direction in which print deviation due to variations in ejection speed is minimized.

That is, as shown in FIG. 4, unidirectional printing is performed only when the carriage 3 is moved in the opposite direction to the direction in which the ink ejection direction is inclined due to the difference in wettability of the materials around the orifice 4B.

In other words, in the present invention, when the materials around the orifice 4B are different, the direction in which the member having a large contact angle with the ink (for example, the glass member in the case of a silicon member and a glass member) is arranged with respect to the orifice 4B is Printing is performed by moving the carriage 3.

Furthermore, even when printing in both directions, printing is rarely done with exactly the same visibility in both directions, and printing occurs when main scanning is performed in one direction and then scanning is performed in the opposite direction before sub-scanning. The frequency is lower than the printing frequency during the previous main scanning in one direction, that is, the printing frequency is often biased toward a certain main scanning direction. Even in such a case, the moving direction of the inkjet recording head 4 may be determined so that one of the main scanning directions is the direction in which the member having a large contact angle with the ink is arranged with respect to the orifice 4B as described above. .

In order to set the direction in which the ink ejection direction is inclined due to the difference in wettability of the materials around the orifice 4B to be opposite to the moving direction of the carriage 3, for example, in an apparatus in which the moving direction of the carriage 3 is already determined, In accordance with the moving direction of the carriage 3, a member made of a material with higher wettability, such as a silicon substrate 21, is placed on the rear side in the moving direction of the carriage 3.
It is only necessary to determine the mounting direction of the inkjet recording head 4 so that a member made of a material with lower wettability, for example, the glass plate 24, is disposed on the front side in the traveling direction. That is, the configuration of the inkjet recording head 4 alone does not need to be changed in any way; it is only necessary to determine the direction in which the head is attached in accordance with the moving direction of the carriage 3.

Next, in the case of V2-0, in which the ink droplet 10 is ejected along the main axis direction of the ink passage 4^, the trajectory of the ink droplet is affected by the movement of the carriage 3, and the trajectory changes between (1) and (2). It will be drawn in the direction of the composite component with 3. In such a case (2=0), in the present invention, the ink passage 4A
The main axis direction of the ink passage 4A is determined in advance so that the velocity component of the ink droplets 10 ejected from the carriage 3 is in the opposite direction to the velocity component (3) of the carriage 3. In other words,
With respect to the direction perpendicular to the recording surface of the recording material 9, the ink passage 4A is tilted so that the main axis direction of the ink passage 4A faces toward the start end of the main scan of the carriage 3. Inclining the ink passage 4A in this manner can be easily implemented by making it possible to appropriately adjust the direction in which the inkjet recording head 4 is attached to the carriage 3.

Next, an example of a more specific structure of the present invention is shown in FIGS. 5 and 6. FIG. 5 is a longitudinal cross-sectional view of the main part of the inkjet recording head 4, and FIG. 6 is a cross-sectional view of the vicinity of the orifice.

Here, 21 is a silicon substrate on which an ejection energy generating element is arranged, and 22 is a groove wall of the ink passage 4A formed from a photosensitive resin layer adhered on this substrate 21 according to the pattern of the ink passage 4A in one step of photolithography. be. A glass plate 24 with an ink chamber 23 formed therein is adhered onto the groove wall 22 to limit the ink passage 4A and the ink chamber 23 together with the groove wall 22. 25 is ink passage 4
The main axis direction of A is shown. Ink is supplied to the ink chamber 23 from the ink container 5 via the ink supply pipe 6.

The materials of the members 21 and 24 around the orifice 4B are as follows:
Since they are silicon and glass, respectively, in this example, silicon has the highest wettability to the ink, that is, the contact angle is the smallest, so the ink droplet 10 is directed in the ejection direction 11 as shown, that is, silicon Board 2
It is ejected as if being pulled towards 1. Therefore,
In this example, as in the case of FIG. 4, the moving direction of the carriage 3 is determined so that the main scanning direction of the carriage 3 is the direction indicated by the arrow 13.

Next, when the inkjet recording head 4 is configured in this manner, changes in the impact point deviation IO due to changes in the ejection speed component □ will be shown. In this example, the thickness of the silicon substrate 21 is 0.525 mm, and the thickness of the groove wall 22 is 0.05 mm5.
The thickness of the glass plate 24 was 1 mm. The width of the groove is 0.05
mm.

When we actually measured IV21 in this case, it was approximately 0.2
m/sec. IVl 1 was set to 5 m/sec and 10 m/sec, but the value of 1*21 was almost constant regardless of the size of *1. The moving speed of the carriage 3 was l V31 =0.3 m/sec.

Here, for the case of l V2 l = 0.2 m/sec and the case of jV2 I = O, lVl l=
Table 1 shows the results of measuring the impact point deviation Jlo at 5 m/sec and 10 m/sec. In this Table 1, when I V2 l =0.2 m/sec, not only the case of FIG. 4 (direction 13) but also the case of FIG. 3 (direction 12) are shown for comparison. When IV2+=O, carriage 3. Since the direction of movement is irrelevant, measurement in either direction is sufficient.

Table 1 Comparison of landing point deviation ILO Note that here, the landing point deviation XO is determined by the distance 11tjZ 1 between the orifice 4B and the recording material 9. In the example in Table 1, 11=1.2 mm.

As shown in Table 1, in the case of the movement direction 13 of the carriage 3, that is, in the case of the present invention in which the carriage 3 is moved in the opposite direction to the direction in which the ink droplets 10 deflect due to the difference in wettability, the movement is faster. It can be seen that the difference in landing deviation ILO due to variations in ink ejection speed is smaller than in the case of direction 12.

Note that in the case of 1V21=o, since the ink passage 4A is not tilted with respect to the carriage 3, the printing deviation is lower than that in the case of lV2+=o.
It can be seen that the case where the carriage 3 is moved in the direction 13 with l = 0.2 m/sec is smaller and better.

However, the deviation io of the impact point is better than in the case of the direction 12 in FIG. 3, but as is clear from the above explanation, in the case of the movement direction 12, This is because the composite component with Jl acts in the direction of increasing the deviation Jl.

Furthermore, as shown in FIG. 4, when the moving direction of the carriage 3 is selected so that (2) and (3) are opposite directions,
By selecting the carriage speed and/or the combination of materials around the orifice 4B so that 1V31 and 1V31 are equal, the impact point deviation io can always be made zero, as seen from equation (1). This results in
Printing deviation due to variations in the ejection speed IV11 can be almost completely eliminated.

Note that when printing in both directions, the size of the print skew differs depending on the scanning direction of the print, but when the print skew is large, for example in direction 13 in Fig. 3, the moving speed of the carriage 3 (2) By reducing 3, the print deviation can be reduced. In this case, the moving speed of the carriage 3 is reduced during the backward main scan.

In addition, on the upper side, there are two cases in which the direction of arrangement of the recording head is determined by considering the relationship between the moving direction of the carriage 3 and the wettability of the material around the orifice 4B, and the main axis direction toward the ink passage 4 is determined by the direction of carriage movement. Although the case where the impact point is tilted in the opposite direction is shown, it goes without saying that both of these configurations may be used in combination to minimize the landing point deviation fl, o.

[Effects of the Invention] As explained above, according to the present invention, for an inkjet recording head that ejects ink droplets at a certain angle due to the difference in the material around the orifice, the wettability of the material around the orifice is It is sufficient to set the direction in which the ink ejection direction is inclined due to the difference between It is possible to provide an inkjet recording apparatus that can always maintain a good printing condition by a simple configuration in which the mounting direction of the inkjet recording head is limited so that the members are arranged.

Furthermore, even in the case of an inkjet recording head in which ink droplets are ejected straight along the main axis of the ink passage, the ink passage can be installed with the ink passage inclined relative to the carriage, or the inclination angle can be adjusted.
It is possible to suppress printing deviation due to variations in ejection speed.

As described above, according to the present invention, it is possible to exhibit the effect of improving printing quality without increasing the ejection speed.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the main parts of an example of an inkjet recording device to which the present invention is applied, FIG. 2 is a schematic diagram of the device viewed from above, and FIGS. 3 and 4 are examples of conventional examples, respectively. and a schematic diagram comparing and showing the difference in the deviation of the landing point of ink droplets according to the moving direction of the carriage in the present invention. FIG. FIG. 6 is a longitudinal cross-sectional view showing an example of the orifice. FIG. 6 is a cross-sectional view showing the vicinity of the orifice. 1... Platen, 2A, 2B... Guide shaft, 3... Carriage, 4... Recording head, 4A... Ink passage, 4B... Orifice, 5... Ink container, 6... ...Ink supply tube, 7.Flexible tube, 8.Flexible circuit, 9.Recording material, 10.Ink droplet, 11.Discharge direction, 12.13.Carriage movement. Direction 5. 20... Impact point, 21... Silicon substrate, 22... Groove wall, 23... Ink liquid chamber, 24... Glass plate, 25... Ink passage main axis direction. 0 layer ζ
``To the side of di-1j15Figure 6

Claims (1)

[Scope of Claims] 1) An orifice that ejects liquid to form flying droplets, and an energy generator that generates energy for forming the flying droplets and making them fly toward a recording material. ,
a liquid jet recording head placed upstream of the orifice;
a carriage on which the liquid jet recording head is mounted and movable in a main scanning direction, and when the liquid jet recording head is in a stationary state, a direction perpendicular to the recording material is opposite to the main scanning direction of the carriage. A liquid jet recording apparatus characterized in that the liquid jet recording head is arranged so that the liquid is ejected from the orifice at an angle. 2) In the liquid jet recording apparatus according to claim 1, the moving speed of the carriage when moving the carriage in a direction opposite to the main scanning direction is the moving speed of the carrier in the main scanning direction. A liquid jet recording device characterized by lowering the height.