JPH0256219B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel non-impact recording device.

As non-impact recording apparatuses, a multi-on-demand type inkjet recording apparatus as shown in FIG. 1 and a multi-charge deflection type inkjet recording apparatus as shown in FIG. 2 have been proposed. However, the multi-on-demand type inkjet recording device shown in FIG. 1 requires a certain size for the vibrator 1 and the pump chamber 2, making it difficult to arrange the nozzles 3 at a high density. . In addition, in order to achieve high density, a configuration as shown in the figure has been considered, but it is necessary to bend the flow path 4 for guiding ink to the nozzle 3. In that case, the formation of the flow path 4 may be Although it can be easily processed by etching or the like, it is extremely difficult to eject uniform ink droplets from each nozzle because the fluid resistance of each channel is different. The multi-charge deflection type inkjet recording device shown in FIG.
However, it was necessary to arrange charging electrodes, deflection electrodes, etc. in front of the nozzle, and the structure was complicated.

The present invention has been made in view of the above-mentioned circumstances, and particularly aims to provide a new non-impact recording device that does not require electrodes on the front surface of the nozzle and can easily achieve high density recording. .

FIG. 3 is a diagram for explaining one embodiment of the non-impact recording device according to the present invention, in which a is a side sectional view of the main part, and b is a perspective view of the whole, in which 20 is an ink supply port, 21 is an A fluid diode, 22 is an electrostrictive vibrator for forming droplets, 23 is an ink supply channel, 24 is a nozzle plate, 25 is a nozzle hole, 26 is an ink discharge channel, 27 is an electrostrictive vibrator for preventing droplet formation, 28
is a fluid diode, 29 is an ink discharge port, to which ink is supplied at a certain pressure from the ink supply port 20,
The droplet forming electrostrictive vibrator 22 vibrates at a certain frequency. Therefore, the electrostrictive vibrator 27 for preventing droplet formation
is not operating, that is, when pressurized ink is not discharged from the ink discharge port 29, multiple (six in the illustrated example) ink droplets are ejected from the nozzle holes 25. Here, an image recording signal is supplied to the electrostrictive vibrator 27 for preventing droplet formation, and the electrostrictive vibrator 27 for preventing droplet formation is activated to remove ink droplets that are not used for recording before the ink droplets are formed. When the ink droplet is discharged from the ink discharge port 29, no ink droplet is ejected from the nozzle hole associated with the actuated droplet formation preventing electrostrictive vibrator, and the ink droplet is not ejected from the nozzle hole associated with the actuated droplet formation preventing electrostrictive vibrator. Since the ink droplets are ejected only from the nozzle holes associated with the child, only the ink droplets used for recording can be ejected from the nozzle holes according to the image recording signal, thereby allowing desired recording to be performed. Note that the ink discharged from the ink discharge port is recovered by an ink recovery system (not shown) and used again for printing.

Further, in the present invention, fluidic diodes 21 and/or 28 are provided in the ink flow path to prevent ink from flowing backward, thereby efficiently forming droplets and/or preventing droplet formation. . As the fluid diodes 21 and 28, for example, a cup-shaped pure fluid diode having no moving parts as shown in FIG. 4 is used. This cup-shaped pure fluid diode, as shown in Figure 4,
A substantially heart-shaped barrier 31 is formed in a substantially spade-shaped flow path 30. FIG. 4a shows the fluid flow in the forward direction, and FIG. 4b shows the fluid flow in the reverse direction. show. This cup type pure fluid diode is
It is known as a fluid diode that does not have a very large resistance ratio in the forward and reverse directions for a steady flow, but it has no suitable application and has rarely been used in the past. Various experiments were carried out using the diode as shown in FIG. 3, which showed a very good diode effect for the ink jet head. In other words, the response frequency can be improved to about 10 kHz, there is no mutual interference between nozzles, and even if the voltage of the driving pulse of the electrostrictive vibrator is lower than before, it can operate satisfactorily and improve efficiency. There was found. Furthermore, since the cup type pure fluid diode has a planar structure as mentioned above,
When forming channel grooves on a substrate, a groove for a cup-shaped pure fluid diode can be formed together with the grooves, and manufacturing costs are advantageously reduced. In the above embodiment, a cup type pure fluid diode was used as the fluid diode, but
The fluid diode used in the present invention is not limited to this. For example, even if a Stellar type pure fluid diode as shown in FIG. 5 is used,
Effects similar to those of the above embodiment can be achieved. However, in FIG. 5, a indicates a forward fluid flow, and b indicates a reverse fluid flow. Further, the fluid diode may be provided not only in one stage but also in multiple stages.

As is clear from the above description, according to the present invention, (1) unlike the conventional multi-on-demand type inkjet recording device shown in FIG. Since the desired number of ink droplets are formed at once using a common (single) ink supply vibrator, variations in the size, speed, etc. of the formed ink droplets are extremely small, and as a result, high-quality images can be produced. can be formed.

(2) The nozzle arrangement can be made denser.

(3) Even if each ink discharge channel is bent to increase the density of the nozzle array, the ink discharge channel only has to perform the function of discharging ink, so conventional multi-on-demand inkjet recording Unlike other devices, bending of the ink channels (because the shapes of the ink channels are different) does not interfere with the formation of ink droplets.

(4) Unlike the conventional multi-charge deflection type inkjet recording device shown in FIG. 2, an extremely simple non-impact recording device can be constructed without requiring complicated electrodes on the front surface of the nozzle.

(5) Since the fluidic diode is provided, ink droplet formation and/or formation prevention can be performed extremely efficiently and smoothly.

There are advantages such as

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining an example of a conventional multi-ink on-demand type inkjet recording device, in which a is a side sectional view of the main part, b is a front view, and FIG. 2 is a conventional multi-charge deflection type inkjet recording device. FIG. 3 is a side sectional view of a main part showing an example of a recording device. FIG. 4 and 5 are diagrams showing examples of fluidic diodes. 20... Ink supply port, 21... Fluid diode, 22... Electrostrictive vibrator for droplet formation, 23... Ink supply channel, 24... Nozzle plate, 25...
... Nozzle hole, 26 ... Ink discharge channel, 27 ...
Electrostrictive vibrator for preventing droplet formation, 28...Fluid diode, 29...Ink discharge port.

Claims (1)

[Claims] 1 a plurality of ink channels, a nozzle provided corresponding to each of the ink channels, and a first ink channel provided at one end of the ink channel for forming flying droplets from the nozzles; and a liquid pressure generating means for preventing the formation of the flying droplets from the nozzles, which are provided at the other end of the ink flow path and correspond to each of the ink flow paths. a second hydraulic pressure generating means for discharging ink from the other end of the flow path; and a fluid provided corresponding to at least one of the first hydraulic pressure generating means or the second hydraulic pressure generating means. a diode and a means for recovering the discharged ink, and the length of the portion of the ink flow path between the nozzle and the first hydraulic pressure generating means is all equal. Features a non-impact recording device.