JPH0351159Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a charge control type inkjet recording device, and more specifically to a gutter of a print head for color recording.

[Prior art]

FIG. 1 is a perspective view showing the schematic configuration of a conventional inkjet recording device, in which 1 is an ink supply system, 2 is a nozzle for ejecting an inkjet stream, and 3 is a nozzle for ejecting an inkjet stream.
4 is a piezoelectric vibrator that splits the ink jet stream into ink droplets; 4 is a charging electrode that charges the ink droplets; 5 is a charging electrode that charges the ink droplets;
8 is a phase detector; 6 and 7 are a pair of deflection electrode plates that generate an electric field that deflects the charged recording ink droplets in the feeding direction of the recording medium 12 (vertical direction in the figure);
are charged recording ink droplets, 9 and 10 are uncharged unnecessary ink droplets (9 is an ink droplet that is not charged due to recording information, and 10 is an ink droplet that is thinned out regardless of recording information), 11 12 is a recording medium such as paper, and these parts 1 to 11 constitute a print head. It is designed to be able to move in a direction intersecting the deflection direction (horizontal direction in the figure).

In this configuration, the ink supply system 1 pressurizes ink to a constant pressure and supplies it to the nozzle 2, from which the ink jet stream is constantly ejected at a constant speed.
At this time, a piezoelectric vibrator 3 that vibrates with ultrasonic waves applies vibration to the nozzle 2, causing a pressure amplitude in the ink, thereby splitting the ink jet stream into ink droplets having equal mass at equal intervals.

When recording, a pulse signal is input to the charging electrode 4 according to recording information to selectively charge ink droplets that contribute to recording, while ink droplets that do not contribute to recording are not charged. These ink droplets pass through a phase detector 5 for adjusting the charging timing, and then pass between deflection electrode plates 6 and 7. At this time, the recording ink droplets 8 charged as described above have their respective charges. It is deflected according to the amount, and then collides with the recording medium 12 to perform predetermined recording. On the other hand, unnecessary ink droplets 9 and 10 that have not been charged are removed from the deflection electrode plates 6 and 7.
After passing through, the ink is collected by the gutter 11 and returned to the ink supply system 1. In this manner, recording occurs as the print head advances.

Here, the unnecessary ink droplets 9 and 10 will be explained with reference to FIGS. 2 and 3. Generally, in a charge control type inkjet recording device, thinning droplets, which are unnecessary ink droplets that are not charged regardless of the recording information, are used as recording ink droplets 8a to 8e that are charged depending on the recording information, or unnecessary ink droplets that are not charged. Between the drops 9a and 9b, for example, 1 shown in FIG.
About half of the ink droplets actually produced are collected in the gutter 11 as unnecessary ink droplets 9 and 10.

When these unnecessary ink droplets 9 and 10 are collected in the gutter 11, the ink droplets are set at a point _H0 so as to hit the inner surface of the inclined plate 11A on the upper part of the gutter 11, as shown in FIG. Even if the flight direction of the ink changes and it points upwards, it will not exceed the height HG of the gutter 11, and the relationship between the recording ink droplets 8 and the gutter 11 is such that the recording range on the surface of the recording medium 12 is controlled. In H ₁ to _{H 2} , even if the flight direction of the recording ink droplet 8 that records the height of H ₁ , which has the lowest charge level, changes and is directed slightly downward, the gutter 11
The dimensions are such that it does not cover the inclined plate 11A.

By the way, in the conventional inkjet recording device for color recording, which is constructed by arranging the parts from the nozzle 2 to the gutter 11 in the same number as the number of inks of a plurality of colors, manufacturing variations in the gutter 11 are a problem. As a result, the height HG of each gutter 11 arranged adjacent to each other varies, so the above-mentioned H ₀ must be set according to each gutter 11. Therefore, the recording of each color ink droplet on the recording medium 12 This causes a positional shift, and therefore, in order to match the recording positions of each color ink droplet, there is a problem in that the charging voltage for each color ink must be adjusted over a wide adjustment range. Furthermore, since a plurality of color inks are used, there is a problem in that these color inks must be collected separately for each color instead of being mixed.

[Purpose of invention]

The present invention was developed in order to solve the problems of the prior art described above, and it is possible to reduce the adjustment range of the charging voltage to match the recording position of each color ink droplet, and to mix the colors of each color ink. It is an object of the present invention to realize an inkjet recording device that can reliably collect ink for each color without causing any problems.

[Summary of the idea]

To achieve this objective, the present invention ejects color ink droplets of different colors from multiple nozzles, and performs recording by charging and deflecting the color ink droplets used for recording and causing them to collide with the recording medium. In an inkjet recording device in which unnecessary color ink droplets not used for recording are collected by a gutter disposed between a deflection electrode plate and a recording medium, the gutter is made long enough to capture unnecessary color ink droplets of each color. one inclined plate, ink collection ports attached to the inclined plate in the same number as the ink colors of the colored inks, and each located in the vicinity of a region for capturing unnecessary color ink droplets for each ink color of the inclined plate. provided on the inclined plate so as to
an ink guide shaped to collect unnecessary color ink droplets captured in the area in one place and guide them to the corresponding ink recovery port; and an ink color mixing prevention device provided on the inclined plate between the ink guides. It is characterized by having a structure consisting of holes for.

By doing this, it is possible to eliminate variations in the height of the gutter, and to reduce the adjustment range of the charging voltage.Moreover, it is possible to dry unnecessary color ink droplets without mixing colors with a simple configuration. It becomes possible to collect each color separately.

〔Example〕

Examples will be described below with reference to the drawings.

Figure 4 is a perspective view of the gutter used in this invention.
Reference numeral 3 refers to the entire gutter, and this gutter 13 has holes 16a to 16c for preventing ink color mixing, and a sloped plate 14 having a length that can capture unnecessary color ink droplets of each color. The same number of ink guides 15a to 15c and the same number of ink recovery ports 17a to 17d are attached to form a completely integrated structure.

Here, set points for colliding unnecessary color ink droplets for each ink color are set at predetermined intervals on the front surface of the inclined plate 14, and the ink collection ports 17a to 17d are connected to the inclined plate 14 at predetermined intervals. They are attached to the lower part of the plate 14 at predetermined intervals.

The ink guides 15a to 15c are
Each of the unnecessary color ink droplets captured at each of the set points and the surrounding capturing area can be collected in one place and guided to the corresponding ink collection ports 17a to 17d, respectively, in a roughly Y-shape or V-shape as shown in the figure. and are attached to the inclined plate 14 so as to be located near each of the trapping areas, and holes 16a to 16c are formed to be located between each of the ink guides 15a to 15c. .

Incidentally, the ink guides 15a to 15c can also be formed integrally with the inclined plate 14 by stamping.

The inkjet recording apparatus for color recording according to the present invention has a plurality of sets of nozzles 2, piezoelectric vibrators 3, charging electrodes 4, phase detectors 5, and deflection electrode plates 6 and 7 arranged in parallel as shown in FIG. Deflection electrode plate 7
The above-mentioned gutter 13 is arranged between the recording medium 12 and the recording medium 12. Since the recording operation is the same as that of the conventional one, we will omit the explanation of the process of recording by charging and deflecting the recording ink droplets, and will only explain the operation of collecting unnecessary ink droplets using color ink below. Explain.

The inkjet flow of color ink ejected for each color from a plurality of nozzles is divided into a row of ink droplets, and the ink droplets that are not used for recording are unnecessary color ink droplets 18a and 1 as shown in FIG.
8b, 18c, and 18d, each reaches the gutter 13, collides with each setting point of the inclined plate 14 of this gutter 13, and the capture area around it, and is captured.
The unnecessary color ink droplets 18a to 18d thus captured are guided downward by ink guides 15a to 15d provided for each color, respectively, and collected into ink collection ports 17a to 17d according to color.

In addition, in this collection process, even if each unnecessary color ink droplet 18a to 18d deviates to the left or right during flight, or if it protrudes to the outside of the ink guides 15a to 15d after being captured by the inclined plate 14, each Since holes 16a to 16b are provided between the ink guides to prevent ink color mixing, ink of other colors will not be mixed into the ink collection ports 17a to 17d, and ink of each color can be reliably collected. I can do it. Therefore, the ink collected for each color can be pressurized and used again.

In the embodiment described above, the holes 16, 16a to 16c for preventing ink color mixing were provided in the inclined plate 14, but the fifth hole 16 for preventing ink color mixing was provided in place of the hole 16 for preventing ink color mixing.
Even if a wall 19 for preventing ink color mixing is provided as shown in the figure, ink color mixing can be similarly prevented.

Further, as shown in FIG. 6, if an ink color mixture prevention hole 16 is inserted from behind and protrudes forward from the ink color mixture prevention hole 16, a double ink color mixture prevention effect can be obtained.

Furthermore, ink guides 15a to 15, which are separately manufactured in advance on the inclined plate 14 as in the embodiment described above, are provided.
Hole 16a for attaching d and preventing ink color mixing
Instead of drilling the ink guide 16c, a substantially V-shaped ink guide 2 is punched into the inclined plate 14 as shown in FIG.
1 and a wall 22 for preventing ink color mixture, the same ink recovery effect and ink color mixture prevention effect can be obtained, and in this case, there is also the advantage that the number of parts can be reduced.

[Effect of idea]

As explained above, the present invention has a gutter that collects unnecessary color ink droplets from among the color ink droplets of multiple colors ejected from multiple nozzles arranged in parallel. a single inclined plate with a predetermined height, ink collection ports as many as the ink colors of the colored inks attached to the inclined plate, and a region of the inclined plate in the vicinity of an area for capturing unnecessary color ink droplets for each ink color; Ink guides are provided on the inclined plate so as to be located at respective positions, and have a shape that collects unnecessary color ink droplets captured in the area in one place and guides them to the corresponding ink collection port, and the ink guides are located between each of the ink guides. The structure consists of holes provided in the inclined plate to prevent ink color mixing, and each unnecessary color ink droplet is captured by the same inclined plate, so it is possible to eliminate variations in the height of the gutter unlike in the conventional case. Since the dimensional accuracy can be easily improved, the adjustment range of the charging voltage for aligning the recording positions of the recording ink droplets of each color can be reduced. As a result, the maximum value of the charging voltage (printing position H ₂ ) can be lowered, which reduces electrical interaction when charging ink droplets, thereby improving printing quality and reducing the charging voltage. This has the effect of lowering the power supply capacity for.

Further, each unnecessary color ink droplet captured by the inclined plate is guided downward by an ink guide for each color,
In addition to collecting the ink at the ink collection port, holes are provided between the ink guides to prevent ink color mixing.
Another effect is that ink can be collected reliably without color mixing.

In addition, the present invention prevents ink color mixing through the holes provided in the inclined plate, and the ink guide can also be formed integrally with the inclined plate by stamping, so there is no need to add other parts. , and can be implemented without increasing the number of assembly steps, etc., and also has the effect of not causing an increase in cost.

Furthermore, the unwanted color ink droplets do not only impinge on the set point on the inclined plate, but also around the set point, and therefore impinge on an area rather than a single point on the inclined plate. In Although,
The present invention uses an ink guide to collect unnecessary color ink droplets trapped in this area in one place and then guides them to the ink collection port, thereby preventing the trapped unnecessary color ink droplets from drying out and ensuring that they reach the ink collection port more reliably. You can also get the effect of being able to lead.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a schematic configuration of a conventional inkjet recording device, Fig. 2 is an explanatory diagram of recording ink droplets and unnecessary ink droplets, and Fig. 3 shows the relationship between recording ink droplets, unnecessary ink droplets, and the gutter. Explanatory diagram showing, No. 4
The figure is a perspective view showing one embodiment of a gutter used in an inkjet recording device according to the present invention, FIG. 5 is a perspective view of a main part showing another embodiment of the gutter, and FIG. 6 is a perspective view showing another embodiment of the gutter. FIG. 7 is a perspective view of the main part showing another embodiment of the gutter. DESCRIPTION OF SYMBOLS 1... Ink supply system, 2... Nozzle, 4... Charge electrode, 6, 7... Deflection electrode plate, 12... Recording medium, 13... Gutter, 14... Inclined plate, 15a~
15d... Ink guide, 16a-16c... Holes for preventing ink color mixing, 17a-17d... Ink supply port, 18a-18d... Unnecessary color ink droplets, 19, 20, 22... Wall for preventing ink color mixing. , 21... Ink guide.

Claims (1)

[Claim for Utility Model Registration] Recording is performed by ejecting colored ink droplets of different colors from a plurality of nozzles arranged in parallel, charging and deflecting the color ink droplets used for recording, and colliding with a recording medium, In an inkjet recording device that collects unnecessary color ink droplets that are not used for recording with a gutter placed between a deflection electrode plate and a recording medium, the gutter is a single piece having a length that can capture unnecessary color ink droplets of each color. a slanted plate, a number of ink collection ports attached to the slanted plate equal to the number of ink colors of the colored inks, and ink collection ports each located near a region of the slanted plate that captures unnecessary color ink droplets for each ink color. an ink guide provided on the inclined plate and shaped to collect unnecessary color ink droplets captured in the area in one place and guide them to the corresponding ink collection port; and an ink guide disposed between the ink guides. An inkjet recording device characterized by comprising holes provided in a plate to prevent ink color mixing.