JPH1191083A - Ink jet mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink jet mechanism which can jet an ink constantly without requiring a variety of density of inks by injecting an ink and a solvent from respective inject ports and mixing them at a specified ratio before being jetted. SOLUTION: A solvent injecting section 3 is disposed contiguously to an ink injection member 1 and provided with heaters 5a-5d and 6a-6d constituting respective injecting members. The injecting members are operated selectively to inject an ink 2 and a solvent 4, respectively, from the injection ports 1a, 3a of the ink injection member 1 and the solvent injecting section 3. Furthermore, a mixing section 7 is provided below the injection ports 1a, 3a in order to mix the ink 2 and the solvent 4 injected from the injection ports 1a, 3a at a specified ratio. An ink jet port 8 is made at the end of tapers 7a, 7b below the mixing section 7 and a heater 9 is provided on the outer circumferential part of the mixing section 7 in order to heat up the mixed ink before being jetted. The ink jet port 8 and the heater 9 constitute a jet section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet mechanism, and more particularly, to an ink jet mechanism capable of performing gradation printing by changing the density of ejected ink droplets.

[0002]

2. Description of the Related Art Generally, as a method of forming a gradation image by an ink head in an ink jet printer, for example, there is a method described in Japanese Patent Application Laid-Open No. 56-16284. In the case of a stable region, the gradation is controlled by the size of the ink droplet, and in the case of the low gradation region, the number of ink droplets per unit area is adjusted. I try to improve the printing quality.

However, in this method, since the gradation of the stable area is controlled by the size of the ink droplet, the accuracy of the printing position (ejection accuracy) at which the dot diameter becomes smaller is obtained. In addition, when adjusting the number of ink droplets per unit area for the low gradation area, the dot spacing is widened when expressing light colors or halftones by increasing the dot spacing. When printed matter is viewed close up because dots of small diameter are scattered on the dots, the dots themselves are conspicuous, and the printing quality cannot be sufficiently improved.

[0004] To solve such a problem, there is, for example, one disclosed in Japanese Patent Application Laid-Open No. 59-15363 or Japanese Patent Application Laid-Open No. 8-258288. In this method, a plurality of types of inks having different densities for the same color are used, and a good gradation property is obtained by selecting an ink density.

[0005]

However, in such a conventional gradation printing method, since a plurality of types of inks having different densities for the same color are used, the installation space for the plurality of types of inks is limited. There is a problem that the size of the ink jet mechanism is increased due to the increase and the cost is increased.

In order to enhance the gradation, it is necessary to provide more inks of different densities.
There is a problem that the installation space for the ink is further increased and the cost is further increased. Therefore, the present invention is to adjust the concentration of the ink using a solvent, so that it is not necessary to prepare a large number of inks in advance, and it is possible to reduce the size and prevent the cost from increasing. It is another object of the present invention to provide an ink jet mechanism capable of improving the printing accuracy by ejecting certain ink droplets.

[0007]

According to the first aspect of the present invention,
In order to solve the above problems, in an ink jet mechanism for ejecting ink droplets of different concentrations, an ink ejecting member having an ejection port filled with ink and ejecting the ink, Provided,
A solvent ejecting member filled with a solvent and having an ejection port for ejecting the solvent, an ejection member for ejecting ink and solvent at a predetermined ratio from the ink ejection member and the ejection port of the solvent ejection member, and the ink ejection member And a mixing unit that mixes the ink and the solvent ejected from the ejection port of the solvent ejection member at a concentration corresponding to a predetermined ratio, and an ejection unit that ejects the ink droplets mixed at a predetermined ratio in the mixing unit. It is characterized by having.

In this case, the ink and the solvent are ejected from the ejection ports of the ink ejecting member and the solvent ejecting member at a predetermined ratio, and the ink and the solvent are mixed and ejected at a concentration corresponding to the predetermined ratio, so that the ink and the solvent are smoothly ejected. Printing can be performed with an appropriate color density. Further, since the ink can be ejected in a fixed amount, the ink droplet can be easily ejected to a target position, and the printing accuracy can be improved.

Since the concentration of ink can be adjusted by using a solvent, the number of ink ejecting members can be reduced to reduce the installation space, and the size of the ink jet mechanism can be reduced. , The cost can be prevented from increasing. According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, the mixing section is provided at a position separated by a predetermined distance from an ejection port of an ink ejection member and a solvent ejection member. And

[0010] In this case, the ink mixed in the mixing section can be prevented from flowing back to the ejection port of the ink ejection member and the solvent ejection member, and the ink or solvent filled in the ink ejection member and the solvent ejection member can be prevented. It is possible to prevent the density from changing. Therefore, a desired ink density can be reliably obtained. According to a third aspect of the present invention, in order to solve the above problems, in the first or second aspect of the present invention, a plurality of the ink ejecting members are provided, and each of the ink ejecting members is filled with ink of a different color. It is characterized by:

In this case, since a plurality of primary colors can be mixed in the mixing section, printing with a smooth color tone can be performed. According to a fourth aspect of the present invention, in order to solve the above problems, in the first aspect of the present invention,
The ink jet unit has a moving unit for moving the inkjet mechanism so that the ejecting unit is located outside the printing region from the printing region, and the moving unit moves the inkjet mechanism to the non-printing region when printing is completed or when an error occurs. And operating the injection member to inject the solvent from the solvent injection member to the mixing section.

In this case, since the mixing section can be washed with the solvent at the end of printing or when an error occurs, clogging of the ejecting section can be prevented, and ink or other density ink or the like in the mixing section and the ejecting section can be provided. Adhesion of other color inks can be prevented, and printing can be performed immediately when new printing is performed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views showing an embodiment of an ink jet mechanism according to the present invention. First, the configuration will be described. In FIG. 1, reference numeral 1 denotes an ink ejecting member which is filled with ink 2 and has an ejection port 1a for ejecting the ink 2. The ink ejecting member 1 is designed to always supply a single color ink from a cartridge (not shown). It has become.

The ink ejection member 1 includes a solvent ejection member 3
The solvent injection member 3 is filled with the solvent 4 and has an injection port 3a for injecting the solvent 4, so that the solvent 4 is always supplied from a cartridge (not shown). . The ink ejecting member 1 and the solvent ejecting member 3 are provided with heaters 5a to 5d and 6a to 6d constituting the ejecting members, respectively. The heaters 5a to 5d and 6a to 6d are provided with the ink ejecting member 1 and the solvent ejecting member. 3 are provided at predetermined intervals in the longitudinal direction.

The heaters 5a to 5d and 6a to 6d are selectively operated so that the ink 2 and the solvent 4 are ejected from the ejection ports 1a and 3a of the ink ejection member 1 and the solvent ejection member 3, respectively. By using the heaters 5a and 6d, the heater 5b and the heater 6c, the heater 5c and the heater 6b, and the heater 6d and the heater 6a as a combination of the activated heaters, by generating air bubbles in a portion located at the heater, The ink 2 and the solvent 4 are ejected from the ejection ports 1a and 3a at a predetermined ratio.

A mixing section 7 is provided below the outlets 1a, 3a.
The ink 2 and the solvent 4 ejected from are mixed so as to have a concentration corresponding to a predetermined ratio. In addition, the mixing ratio of the ink 2 and the solvent 4 ejected from the ejection ports 1a and 3a becomes five ratios by adding the ink that ejects only the ink 2 as it is, and the ink density can be switched in five stages. The amount of the ink mixed in the mixing section 7 always becomes a constant amount.

The mixing section 7 is set in a relatively large space, and this space is formed between the mixed ink and the ejection ports 1a, 3a so that the mixed ink does not flow back to the ejection ports 1a, 3a. Is required to be secured to the extent that a predetermined distance is formed. Tapers 7a and 7b are formed below the mixing section 7, and the taper 7a and 7b are formed.
An ink jetting hole 8 is formed at the end of each of a and b. Further, a heater 9 is provided on the outer peripheral portion of the mixing section 7, and the ink mixed in the mixing section 7 is heated by the heater 9 so that the ink is ejected from the ink ejection hole 8 to a recording paper or the like located in a printing area. The ink is jetted toward the ink jet head. In addition, the ink ejection hole 8 and the heater 9 are connected to the mixing section 7.
Constitutes an ejection unit that ejects ink droplets mixed at a predetermined ratio.

Further, the ink ejection member 1 and the solvent ejection member 3
The ink 2 and the solvent 4 ejected from the
In order to prevent direct ejection from the ink ejection member 8, the ink ejection member 8 and the ejection port 1a of the solvent ejection member 3
3a is not located on a straight line. on the other hand,
As shown in FIG. 2, the ink jet mechanism is built in an ink head 10, and the ink head 10 is movably connected to a holder 12 via a gear 11. The gear 11 is connected to a gear 14 via a belt 13. The gear 14 is driven by a motor 15 provided on the upper part of the holder 12, and by rotating the gear 11 via the belt 13, the position of the ink head 10 is indicated by a solid line and indicated by a broken line. It is designed to be moved between positions.

The holder 12 is provided with a magnet 16, and the magnet 16 is adapted to be attracted to a magnetic body 17 provided on the ink head 10. Further, a stopper 18 is provided on the holder 12, and the stopper 18 restricts the movement of the ink head 10 by contacting the ink head 10 when the ink head 10 moves to a position shown by a broken line. Has become.

The holder 12 is provided with a sponge 19, and the sponge 19 faces the ink ejection hole 8 at a predetermined distance when the ink head 10 contacts the stopper 18. . Further, when the ink head 10 is at the position shown by the solid line, it is located in the printing area where ink is ejected on recording paper or the like, and when it is at the position shown by the broken line, it is located outside the printing area. At the end of printing or when an error occurs, the ink head 10 is moved out of the printing area indicated by the broken line.

When the ink head 10 moves out of the printing area, the heaters 6a to 6d are operated so that only the solvent 4 is ejected to the mixing section 7. When the ink jet mechanism is provided in an ink jet printer, a copying machine, a facsimile machine or the like, the heaters 5a to 5d, 6a to 6d and the motor 15 are controlled by a controller provided in the ink jet printer, the copying machine, the facsimile machine or the like. It is controlled.

In the present embodiment, the gears 11, 14, the belt 13, the motor 15, and the controller constitute a moving means. Next, an ink discharging method will be described with reference to the flowchart of FIG. 3 and the operation explanatory diagrams of FIGS. Note that the flow in FIG. 3 is a program executed by the controller.

First, the ink ejection member 1 and the solvent ejection member 3 are filled with the ink 2 and the solvent 4 (step S).
1). Next, the heater is heated in order to set the density of the ink to a predetermined density. In the present embodiment, for example, the heaters 5a and 6d are operated to wait for a predetermined time (step S
2, S3). At this time, bubbles 20 and 21 are generated in the portions located at the heaters 5a and 6d, as shown in FIG.
As shown in (b), the ink is injected from the ejection ports 1a and 3a into the mixing section 7 at a predetermined ratio, mixed at the mixing section 7 at a predetermined ratio, and the ink 22 having a density corresponding to this ratio is obtained.

At this time, the heaters 5a and 6 are designed so that a pressure higher than the surface tension of the ink 22 is applied from the ink ejecting member 1 and the solvent ejecting member 3 to the mixing section 7 to prevent dripping.
The temperature of d is adjusted. Next, the heaters 5a and 6d
Is stopped, and after waiting for a predetermined time until the liquid levels of the ink ejection member 1 and the solvent ejection member 3 return to the steady state as shown in FIG. 5A (steps S4 and S5), the heater 9 is operated. Then, it waits for a predetermined time (steps S6 and S7). At this time, as shown in FIG.
The ink 22 is ejected from the ink ejection holes 8 with the force to evaporate the ink 22.

The ejected ink 22 becomes an ink droplet 22 as shown in FIG. Next, it is determined whether or not any error has occurred (step S8). If no error has occurred, it is determined whether or not printing has been completed (step S9). If the printing has not been completed, the flow shifts to step S2 to execute the processing after step S2.

On the other hand, if an error has occurred in step S8 or S9, or if printing has been completed, the motor 15 is rotated in the forward direction (step S10). At this time, the ink head 10 moves from the state where the magnetic body 17 is attracted to the magnet 16 and is stably positioned in the print area to the outside of the print area indicated by the broken line. Then, when the ink head 10 comes into contact with the stopper 18, one of the heaters 6a to 6d is operated to stand by for a predetermined time (steps S11 and S12).

At this time, bubbles are generated in the solvent located in any of the heaters 6a to 6d, and the solvent 4 on the lower side of the bubbles is injected from the injection port 3a to the mixing section 7. Then
After stopping any one of the activated heaters 6a to 6d and waiting for a predetermined time until the liquid level of the solvent injection member 3 returns to a steady state (steps S13 and S14), the heater 9 is activated to wait for a predetermined time (step S13). S15, S16).

At this time, the solvent 4 is jetted from the ink jetting hole 8 toward the sponge 19 with a force to evaporate a part of the solvent 4 in the mixing section 7. Next, after the operation of the heater 9 is stopped (step S17), the motor 15 is rotated in the reverse direction (step S18), and the motor 15 is stopped when the magnet 17 is attracted to the magnetic body 17 (step S19). . As a result, the ink head 10 returns to the printing area.

As described above, in this embodiment, the ink 2 and the solvent 4 are ejected from the ejection ports 1a and 3a of the ink ejection member 1 and the solvent ejection member 3 at a predetermined ratio, and the ink 2 and the solvent 4 are mixed at a predetermined ratio. By jetting the ink 22 at a density suitable for the printing, printing can be performed with a smooth color density. Further, since the ink 22 can be ejected in a fixed amount, the ink 22 can be easily ejected to a target position, and the printing accuracy can be improved.

Since the concentration of the ink 22 can be adjusted by using the solvent 4, the number of the ink ejecting members 1 can be reduced to reduce the installation space, and the ink jet mechanism can be downsized. Can be done,
The cost can be prevented from increasing. In addition, the mixing unit 7 includes the ink ejection member 1 and the solvent ejection member 3.
Provided at a predetermined distance from the ejection ports 1a, 3a of the ink ejection member 1 and the solvent ejection member 3 can be prevented from flowing back to the ejection ports 1a, 3a of the solvent ejection member 3. Thus, it is possible to prevent the concentration of the ink 2 or the solvent 4 filled in the ink ejection member 1 and the solvent ejection member 3 from changing. For this reason,
A desired ink density can be reliably obtained.

When the printing is completed or when an error occurs, the ink head 10 is moved to the non-printing area, and the heaters 6a to 6d are operated to move the solvent injection member 3 to the mixing section 7 from the solvent injection member 3.
Since the solvent is ejected, the mixing unit 7 can be washed with the solvent 4 when printing is completed or when an error occurs. For this reason, clogging of the ink ejection holes 8 can be prevented, and ink of another concentration can be prevented from adhering to the mixing section 7 and the ink ejection holes 8. Printing can be performed immediately.

In this embodiment, the single color ink 2
Is provided, but a plurality of ink ejecting members are provided, and each of the ink ejecting members is filled with ink of a different color (for example, cyan, yellow, magenta, etc.). The concentration may be changed by mixing the solvent 4 with the color ink. In this case, since the colors of the plurality of primary colors can be mixed in the mixing section, printing with a smooth color tone can be performed.

In the present embodiment, the heaters 5a to 5d and 6a to 6d are used as the injection members. However, the invention is not limited to this, and the injection members may be constituted by piezoelectric elements or the like.

[0034]

According to the first aspect of the present invention, the ink and the solvent are ejected from the ejection ports of the ink ejecting member and the solvent ejecting member at a predetermined ratio, and the ink and the solvent are made to have a density corresponding to the predetermined ratio. By mixing and jetting, printing can be performed with a smooth color density. Further, since the ink can be ejected in a fixed amount, the ink droplet can be easily ejected to a target position, and the printing accuracy can be improved.

Since the concentration of ink can be adjusted by using a solvent, the number of ink ejecting members can be reduced to reduce the installation space, and the ink jet mechanism can be downsized. , The cost can be prevented from increasing. According to the second aspect of the present invention, it is possible to prevent the ink mixed in the mixing section from flowing back to the ejection port of the ink ejection member and the solvent ejection member, and to fill the ink ejection member and the solvent ejection member. It is possible to prevent the concentration of the ink or the solvent from changing. Therefore, a desired ink density can be reliably obtained.

According to the third aspect of the present invention, since a plurality of primary colors can be mixed in the mixing section, printing with a smooth color tone can be performed. According to the fourth aspect of the invention, the mixing unit can be washed with the solvent at the end of printing or at the time of occurrence of an error, so that clogging of the ejection unit can be prevented. It is possible to prevent the ink of the density or the ink of another color from adhering, and it is possible to immediately perform printing when performing new printing.

[Brief description of the drawings]

FIG. 1 is a schematic view of an embodiment of an ink jet mechanism according to the present invention.

FIG. 2 is a diagram illustrating a print area and a mechanism that moves an ink jet mechanism to an outside of a print area according to an embodiment.

FIG. 3 is a flowchart illustrating an ink ejection procedure according to one embodiment.

FIG. 4 is a diagram illustrating an ink ejection procedure according to an embodiment.

FIG. 5 is a diagram illustrating an ink ejection procedure following FIG. 4 (b).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink ejection member 1a, 3a ejection opening 2 Ink 3 Solvent ejection member 4 Solvent 5a-5d, 6a-6d Heater (ejection member) 7 Mixing unit 8 Ink ejection hole (ejection unit) 9 Heater (ejection unit) 11, 14 Gear (Moving means) 13 Belt (Moving means) 15 Motor (Moving means) 22 Mixed ink

Claims (4)

[Claims] 1. An ink jet mechanism for ejecting ink droplets of different densities, comprising: an ink ejection member filled with ink and having an ejection port for ejecting the ink; and an ink ejection member provided in proximity to the ink ejection member; A solvent injection member filled with a solvent and having an ejection port for ejecting the solvent, an ejection member for ejecting ink and a solvent at a predetermined ratio from the ink ejection member and the ejection port of the solvent ejection member, and the ink ejection member A mixing unit that mixes the ink and the solvent ejected from the ejection port of the solvent ejection member at a concentration corresponding to a predetermined ratio, and an ejection unit that ejects ink droplets mixed at a predetermined ratio in the mixing unit. An ink jet mechanism, comprising: 2. An ink jet mechanism according to claim 1, wherein said mixing section is provided at a position separated by a predetermined distance from an ejection port of an ink ejection member and a solvent ejection member. 3. The ink jet mechanism according to claim 1, wherein a plurality of the ink ejection members are provided, and each of the ink ejection members is filled with ink of a different color. 4. A moving means for moving the ink jet mechanism so that the ejection unit is located outside a printing area from a printing area, and the moving means moves the ink jet mechanism out of the printing area when printing is completed or when an error occurs. Move to the area,
The inkjet mechanism according to any one of claims 1 to 3, wherein the solvent is injected from the solvent injection member to the mixing section by operating the injection member.