JPS5840510B2 - ink jet multi head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording head in an inkjet recording apparatus.

In conventional inkjet recording devices, an electrostrictive vibrator is installed in a part of the pipe, etc., but in order to apply enough pressure to eject ink droplets in response to a data signal, the electrostrictive vibrator must be large. There was a limit to integration.

There are also devices that form ink droplets by installing two pressurizing parts, but since the jet flow is bottomed out from two directions (angles), ink droplets are caused by phase differences in pressure wave transmission and droplet ejection differences. It had the disadvantage of being unstable.

The present invention aims to eliminate the drawbacks of the conventional inkjet recording apparatus and provide a highly integrated pressurized inkjet head.Embodiments of the present invention will be described in detail below with reference to the drawings.

In the following, all the same parts are given the same number.

FIG. 1 is a schematic diagram of a multi-head block in an inkjet recording apparatus according to the present invention, in which 1 is an ink supply tube, 2 is an electrostrictive vibrator for bias, and 3 is a printed board that drives the electrostrictive vibrator for jetting, which will be described later. , 4 and 5 are connectors for bias electrostrictive vibrators, and 6 is a connector for the printed board 3.

FIG. 2 is a diagram showing each multi-head unit constituting the multi-head flock shown in FIG.
is an electrostrictive vibrator for injection, 11 is a multi-nozzle plate, 1
2 indicates an ink droplet.

FIG. 3 is a diagram showing the shape of the head, with reference numeral 13 indicating an ejection pressurizing chamber, 14 indicating a multi-head base, and arrow A indicating the flow of ink.

Figure 4 is an exploded view of the multi-head unit in Figure 2.
15 is a diaphragm driven by the injection vibrator 10, 16
is a nozzle.

FIG. 5, a shows a cross-sectional view along arrow A in FIG. 4, and a cross-sectional view along arrow B in FIG.

As shown in Figures 2 to 4, each multi-head unit has a plurality of injection pressurizing chambers connected to a bias pressurizing chamber provided at the top, arranged in a straight line of nozzle rows. On the other hand, they have a configuration in which they are arranged alternately on the left and right (this is called a "staggered" arrangement).

Bias pressurization chambers 9 are provided on both sides of the multi-head base 14.
A recess for the injection pressurizing chamber 13 is formed, and an injection diaphragm 15 having an injection electrostrictive vibrator 10 provided on both sides thereof is coupled, and the injection pressurization is performed by the recess and the injection diaphragm 15. Room 1
3 is formed.

When viewed from above, these injection pressurizing chambers 13 are arranged in a staggered manner in which injection diaphragms 15 are arranged alternately on the left and right sides of the nozzle row.

A multi-nozzle plate 11 having linearly arranged nozzles 16 is coupled to the lower part of the multi-head base 14.

A bias diaphragm 8 is connected to the upper part of the multi-head base 14 with a slight space therebetween, and this space communicates with each bias pressurizing chamber 9 provided in the multi-head base 14. It constitutes a common bias pressurization chamber.

One bias electrostrictive vibrator is attached to the bias diaphragm 8.

The operation of the multi-head described above will be explained with reference to FIGS. 6 and 7.

FIG. 7A shows a voltage waveform applied to the bias electrostrictive vibrator of FIG. 6, which is, for example, an alternating current with a constant amplitude of 2 KHz frequency.

This voltage drives the bias vibrator to vibrate the bias diaphragm to apply bias pressure.

The voltage for driving the bias vibrator has an amplitude such that even at the maximum value of the voltage, bias pressure is applied to the point just before forming an ink droplet.

That is, the bias diaphragm does not function to form and eject ink droplets, but only functions to generate pressure waves and meniscuses.

FIG. 7 shows an injection signal applied to the injection electrostrictive vibrator 10 of FIG. 6.

During the period (3) during which the bias signal increases, an injection signal having twice the frequency of the bias signal is added intermittently in synchronization with the bias signal in accordance with the data signal.

For example, in the case of the head /161, during the period (2) in which the bias signal increases, in the first period (2), the injection signal decreases, and therefore the injection pressure decreases, so that the pressures are canceled out.

Next, in period ■', jet pressure is added to bias pressure, and when the sum of both becomes large enough to form and jet an ink drop, an ink drop is jetted as shown by the black circle. .

During the next period (■') in which the injection signal falls, the increase in bias pressure is offset by the decrease in injection pressure, and the pressure remains unchanged.

Next, during the period (2) (and I) in which the bias signal decreases, the injection signal is zero and the injection signal is in a so-called standby state, and the same process is repeated thereafter.

The same applies to /162 and /163. In this way, by performing bias pressure, the pressure amplitude for injection can be extremely small, so a small electrostrictive vibrator is sufficient. With a drive voltage of 200 volts, a sufficient ink droplet (approximately 0.1 mm in diameter) can be ejected even with a small drive voltage of 200 volts.

Therefore, in multiplication, the configuration of each head can be made smaller and higher integration per area can be achieved.

In order to achieve multi-head unit, the multi-head unit has a second
As shown in FIG. 4, it is constructed in the form of a strip, and the individual heads are integrated and wired using a printed board or the like.

Furthermore, the multi-head units are stacked to form a multi-head block as shown in FIG. 1, and each multi-head unit is provided with a connector.

Furthermore, for multi-purpose use, the multi-head base 14 is formed from a strip shape by machining by electric discharge machining or the like or by pressure molding (resin), and as shown in FIG. 5, by using both sides,
The pressurized chambers are arranged in a symmetrical staggered pattern to increase the degree of integration.

A diaphragm is brazed or glued to this multi-head base (Figures 4 and 5).

The electrostrictive vibrator and the multi-nozzle plate 11 are also
Seal and fix (glue) this.

As described above, according to the present invention, since bias pressure is applied, the electrostrictive vibrator for injection can be made small, the configuration of each head can be made small, and high integration per unit area is possible. Furthermore, since the injection pressurizing chambers are arranged in a staggered manner using both sides of the multi-head base, the degree of head integration can be increased.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a multi-head block in an inkjet recording apparatus according to the present invention, FIG. 2 is a diagram showing a multi-head unit, FIG. 3 is a diagram showing the shape of a head, and FIG. 4 is a diagram showing a multi-head unit. Exploded view of Figure 5a
is a sectional view in FIG. 4A, FIG. 5 is a sectional view in FIG. 4B, FIG. 6 is a diagram showing the action of the multi-head, and FIG. FIG. 2... Electrostrictive vibrator for bias, 3...
Printed board, 4, 5, 6... Connector, 8...
... Bias diaphragm, 9 ... Bias pressurization chamber, 10 ... Electrostrictive vibrator for injection, 11 ...
...Multi-nozzle plate, 13...Injection pressurization chamber, 14...Multi-head base, 15...
...Diaphragm, 16...Nozzle.

Claims (1)

[Scope of Claims] 1. A common bias pressurizing chamber; a plurality of ejection pressurizing chambers connected to the common bias pressurizing chamber and each having a nozzle; and a plurality of ejection pressurizing chambers connected to the common bias pressurizing chamber to form ink droplets. A common bias pressurization chamber driving element for performing bias pressurization with a front amplitude and a constant frequency, and a common bias pressurization chamber drive element coupled to each injection pressurization chamber and synchronized with the drive frequency of the common bias pressurization according to a data signal. and an ejection pressurization chamber drive element for performing pressurization drive to the extent that ink droplets are formed and ejected by combining with the bias pressurization, the inkjet multihead comprising: The nozzles of the chambers are arranged in an evenly spaced manner in one direction, and each of the plurality of injection pressurizing chambers has a nozzle row arranged in an evenly spaced manner to which a portion of the injection pressurizing chamber driving element is coupled. The common bias pressurizing chamber driving elements are arranged in a staggered manner so that they are arranged alternately on the left and right sides of the center, and the common bias pressurizing chamber driving elements are connected to the aligned surface of the nozzles and the injection pressurizing chamber driving elements. An inkjet multi-head characterized by being provided on one side different from the both sides on which the inkjet multi-head is arranged.