JPS629429B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording device, and particularly to an inkjet recording device, in which ink ejected from a nozzle is made into particles, the ink particles are deflected based on a recording image signal, and the ink particles involved in recording are directed toward a recording medium. The present invention relates to the structure of a gutter in an inkjet recording apparatus in which ink particles are deposited on the surface of the ink jet to form a recorded image and the gutter collects ink particles not involved in recording.

FIG. 1 shows an outline of a charging deflection type inkjet recording apparatus. The nozzle 1 is excited by an electromechanical transducer 3 connected to a high frequency power source 2. When pressurized ink 4 is supplied to the nozzle 1 in this state and ejected, an ink column 5 is generated, and a periodic constriction is formed in this column, and this constriction develops under predetermined operating conditions, causing high frequency vibration and Ink particles 6 of uniform size can be periodically and regularly generated. At this time, a signal voltage from a recording signal source 8 synchronized with the excitation to the electromechanical transducer 3 is applied to the charging electrode 7 placed near the tip of the ink column 5.
The ink particles 6 are charged according to this voltage. Next, a DC high voltage source 10 applied to the deflection electrode 9
is deflected in accordance with the recording input signal voltage by an electrostatic field caused by the recording. In this way, the ink particles 6A necessary for forming a recorded image are transferred to the recording medium 12.
to form recording dots, while
Ink particles 6 that are not necessary to form a recorded image
B has a mechanism in which it is collected and recovered by a gutter 11.

FIGS. 2 and 3 are diagrams showing gutters used in conventional inkjet recording apparatuses. This gutter 11 is made by cutting a tubular body 13 whose opening has a circular cross-sectional shape into an appropriate length, bending it into a predetermined shape (in the figure, bending it into an approximately U-shape),
A flat portion 15 is formed by pressing the vicinity of one opening 14 from above. As shown in FIG. 3, the tube body 13 is arranged so that the flat portion 15 is slightly inclined with respect to the direction in which the ink particles 6B enter, and the holding member 16 is used for positioning.

Ink particles 6B that are not necessary for forming a recorded image enter through the opening 14 and impinge obliquely on the inner surface of the flat portion 15. And the inclined flat part 15
However, as shown in Fig. 3, the ink flow curves upward from the lowermost end of the flat portion 15 to the peripheral wall of the tube body 13 extending behind it, so the ink flow is as shown by the arrow. As shown, the flow changes its direction and flows down from both sides of the flat portion 15 along the peripheral wall below the flat portion.

The ink flowing down from the flat part 15 in this way is
Since the ink flows in a direction different from the direction in which the ink particles 16B enter, the ink does not flow smoothly;
In addition, the ink forms droplets at the end of the flat portion 15 and falls directly, creating splashes and scattering the ink. Therefore, normally, the ink collected in the gutter 11 is forcibly recovered by vacuum suction. However, in the case of vacuum suction, although the above-mentioned drawbacks are eliminated,
The loss of volatile components in the ink is large, causing a change in the composition of the ink, and the formation of air bubbles in the ink, which deteriorates the quality of the ink.Additionally, additional equipment such as a suction pump is required, leading to increased costs.

Further, since the conventional gutter 11 has a shape in which one opening 14 of the tube body 13 is directly used as an ink inlet, the direction in which ink particles are ejected is limited. That is, as shown in FIG. 1, when the ink particles 6 are ejected in the lateral direction to form a recorded image on the side surface of the recording medium 12, or when the ink particles 6 are ejected in the horizontal direction to form a recorded image on the top surface of the recording medium, the ink particles are When ejecting from the top to the bottom, the ink can be collected by directing the opening (ink inlet) 14 of the gutter 11 in the direction in which the ink particles enter. However, when ink particles are ejected from the bottom upward to form a recorded image on the bottom surface of the recording medium, the opening of the gutter 11 (ink inlet)
14 is directed downward, so that the ink adhering to the flat portion 15 flows down through the flat portion 15 and drips down as droplets from the opening edge. When ink particles are ejected from the bottom to the top in this manner, it is difficult to collect the ink, and it is necessary to separately provide an ink reservoir in the gutter for collection.

Furthermore, an inkjet recording apparatus as described in Japanese Utility Model Application Laid-Open No. 52-154245 has been proposed. This inkjet recording device has the 11th
It has a gutter as shown in the figure. That is, this gutter 50 has a slit-shaped opening 5 for collecting unnecessary ink along the axial direction of the peripheral wall of the pipe.
1, and the upper surface of the edge 52 of the opening 51 on the side facing the ink ejection nozzle (not shown) is made into a flat surface by cutting or the like to form an edge portion 53. This edge portion 53 is intended to prevent ink particles from colliding and scattering, and is inclined at approximately 20 degrees with respect to the flat portion.

However, with such a gutter, the opening 5
Since the gutter 1 is slit-shaped, the installation direction of the gutter is limited, and it is not possible to sufficiently cope with diversification of printing directions. Further, as shown in FIG. 11, since the end of the opening 51 on the side where the flat part 52 is not formed remains as it is, ink particles are ejected from the bottom to the top as shown in the same figure. case,
The ink reservoir portion 54 formed by the peripheral wall is shallow. If the ink reservoir 54 is shallow in this way, the flow of ink will be poor when the amount of accumulated ink is small, and the ink will solidify or deteriorate during flow. Furthermore, by cutting a part of the peripheral wall, the edge portion 5
3, the sloped surface of the edge portion 53 cannot be sufficiently thick, and therefore, if the installation position of the gutter is even slightly shifted, there is a drawback that ink particles cannot be collected. .

SUMMARY OF THE INVENTION An object of the present invention is to provide an inkjet recording device that eliminates the drawbacks of the prior art described above and is equipped with a gutter that allows ink to be collected smoothly and that is sure to collect ink no matter which direction it is ejected from. There is something to do.

The present invention provides an ink entry gutter formed by providing a notch along the axial direction in the circumferential wall of a circular pipe and bending a portion of the circumferential wall in one direction adjacent to the notch toward the inside of the circular pipe. Ink enters from the opening edge of the ink inlet, which is formed by crushing the opening, the bent part that becomes a part of the ink reservoir formed by the bending, and the peripheral wall part on the other side adjacent to the notch. It is characterized by comprising a flat part extending on the rear circumferential wall of the mouth and inclined with respect to the ink entry direction, and having a shape in which the terminal end of the flat part and the rear circumferential wall of the ink entrance are overlapped. It is something.

Next, embodiments of the present invention will be described with reference to FIGS. 4 to 10.

A circular pipe 17 made of a material with good ink leakage properties such as stainless steel or the like is cut to a predetermined length, and a crescent-shaped ink inlet 19 is provided in the peripheral wall 18 of the circular pipe 17. form. This ink inlet port 19 is formed by cutting a part of the peripheral wall 18 along the axial direction of the circular pipe 17 and bending the peripheral wall portion on one side adjacent to this notch toward the inside of the circular pipe 17. It is formed by Further, the flat portion 20 is formed by pressing the peripheral wall portion on the other side adjacent to the notch.
will be established. This flat portion 20 corresponds to the ink inlet port 19.
The opening edge 21 extends toward the rear circumferential wall of the ink inlet 19 and is connected to the rear circumferential wall.

As shown in FIGS. 4 to 6, one opening of the circular pipe 17 is closed with a cap 22.
The other opening is fixed to the gutter body 23 and communicates with the gutter pipe 25 via the hollow part 24 (see FIG. 6) of the gutter body 23. A support shaft 26 is provided protruding from the opposite side of the gutter body 23 to the side on which the circular pipe 17 is fixed. The direction of the portion 20 is adjustable. Preferably, the flat portion 20 is inclined outwardly by about 20 degrees with respect to the direction of ink droplet ingress.

4 and 7 show the case where the ink droplets 6 are ejected laterally. Of the ink particles ejected from the nozzle 1, ink particles 6B that are not necessary for forming the image enter through the ink inlet 19 of the gutter 11 and obliquely hit the inner surface of the flat portion 20. Then, the ink flows down to the terminal end side of the inclined flat part 20, flows smoothly along the rear circumferential wall of the ink inlet 19 without changing its flow, and accumulates in the ink reservoir 28. Thereafter, as shown in FIG. 6, the ink passes through the hollow part 24 of the gutter body 23 from one opening of the circular pipe 17 and is collected from the gutter pipe 25.

FIG. 8 shows the arrangement of the gutter 11 and the ink entry state when the ink particles 6 are ejected from the top to the bottom, and FIG. 9 shows the arrangement of the gutter 11 and the ink entry state when the ink particles 6 are ejected from the bottom to the top. shows.

An ink inlet 19 is provided in the peripheral wall 18 of the circular pipe 17.
As a method for forming the ink inlet 19, there are two methods: cutting a part of the peripheral wall 18 as described above and bending the peripheral wall portion on one side adjacent to the cut inside the circular pipe 17, and forming the ink inlet port 19. There is a method of opening an ink inlet 19 in the peripheral wall 18 of the circular pipe 17 using a drill or the like. The present invention can be applied to any of these methods, but in the case of a usage mode in which ink particles are ejected from the bottom to the top,
It is preferable to form the ink inlet 19 using the former method. In the former method, as shown in FIG. 9, the peripheral wall portion 35 bent inward of the circular pipe 17 becomes a part of the ink reservoir 28, so the ink reservoir 28 is formed deep and the amount of accumulated ink is reduced. The flow is good even in small amounts.

FIG. 10 shows the state in which the gutter 11 is made using the former method. In order to process the circular pipe 17, the receiving molds 29A and 29B and the pressing mold 30 are used, and the receiving molds 29A and 29B are split molds, and have an outer diameter that is approximately the same as the inner diameter of the circular pipe 17. It has a cylindrical shape. An ink inlet 19 is provided in the circular pipe 17 on the circumferential surface of the joint between the receiving molds 29A and 29B.
A recessed portion 31 for forming the flat portion 20 and a flat portion 32 for forming the flat portion 20 are provided. On the other hand, a protrusion 34 having a semicircular front shape is provided at a predetermined position on the flat lower surface 33 of the press die 30.

By fitting the material for the circular pipe 17 into the receiving molds 29A and 29B and pressing the pressing mold 30 from above, the ink inlet 19 is formed in the circular pipe 17 by the recess 31 and the protrusion 34. Further, the flat portion 20 is easily formed on the circular pipe 17 by the flat portion 32 and the lower surface 33 in one step. Note that arrows placed near the receiving molds 29A, 29B and the pressing mold 30 indicate the retreat direction of the respective molds.

The present invention has the above-mentioned configuration, and by forming an ink inlet and a flat part on the peripheral wall of the circular pipe, the ink that has entered can be smoothly passed from the flat part without changing the flow. Since the ink can flow down along the rear peripheral wall, it becomes possible to collect the ink by its own weight without relying on vacuum suction, and the negative effects are eliminated by vacuum suction. In addition, since the other peripheral wall other than the ink entrance serves as an ink reservoir, ink can be reliably collected no matter what direction the ink is ejected. A part of the peripheral wall of the shaped pipe is bent inward, and the bent part becomes a part of the ink reservoir, so the width of the ink reservoir becomes narrow and deep. Therefore, even if the amount of accumulated ink is small, the flow is good, and there is no need to worry about the ink solidifying or deteriorating while flowing, which was the case with conventionally proposed systems. Furthermore, since the ink inlet is a substantially semicircular hole, unlike the previously proposed slit-shaped opening, there is no need for directionality in installation. Therefore, the same gutter can be used even if the printing direction is diverse, such as upward, downward, or horizontal, greatly contributing to the standardization of devices and reducing costs. Furthermore, since the flat portion is formed by crushing the peripheral wall portion, the inclination angle of the flat portion allows it to receive ink particles over a wider width than those proposed in the past. Therefore, it has the advantage that ink particles can be surely collected even if the gutter is installed in a slightly rough position.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a charging deflection type inkjet recording device, FIGS. 2 and 3 are a perspective view and a partially cutaway front view of a gutter used in a conventional inkjet recording device, and FIGS. 4 and 5. , FIG. 6 is a perspective view and a plan view of a gutter according to an embodiment of the present invention,
A side view, FIGS. 7, 8, and 9 are explanatory diagrams showing how the gutter is used, FIG. 10 is a perspective view showing the manufacturing state of the gutter, and FIG. 11 is a cross section of a conventionally proposed gutter. It is a diagram. 1... Nozzle, 6... Ink particles, 6A... Ink particles necessary to form a recorded image, 6B...
... Ink particles not necessary for forming a recorded image, 9 ... Deflection electrode, 11 ... Gutter, 12 ...
Recorded object, 17... Circular pipe, 18... Peripheral wall,
19... Ink inlet, 20... Flat portion, 21...
...Opening edge, 28...Ink reservoir portion, 35...Peripheral wall portion.

Claims (1)

[Claims] 1. Making ink ejected from a nozzle into particles, deflecting the ink particles based on a recorded image signal,
In the inkjet recording apparatus, in which ink particles necessary for forming a recorded image are attached to the surface of a recording medium to form recording dots, and ink particles not necessary for forming a recorded image are collected in a gutter, an ink inlet port formed in the gutter by providing a notch in the circumferential wall of a circular pipe along the axial direction and bending a portion of the circumferential wall on one side adjacent to the notch toward the inside of the circular pipe;
A bent portion that becomes a part of the ink reservoir formed by the bending, and a part formed by crushing the peripheral wall portion on the other side adjacent to the notch, from the opening edge of the ink inlet to the rear of the ink inlet. An inkjet recording device comprising a flat portion extending along a peripheral wall and inclined with respect to an ink entry direction, and having a shape in which a terminal end of the flat portion is connected to a rear peripheral wall of the ink entrance.