JPS62116154A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To eliminate interference between heads and record with high quality, by correcting the magnitude of a driving signal supplied to an ejecting energy generating means, according to the magnitude of a driving signal supplied to other ejecting energy generating means. CONSTITUTION:The pressure generated at the time of driving and the amount of an ink ejected are substantially proportional to each other, and an interference pressure delta appears directly as a variation in the amount of the ink ejected. When signals A-1-A-n for determining driving amounts for nozzles are supplied from driving signal sources in driving circuits for converting elements 3, a voltage corresponding to the interference pressure delta generated according to the driving amounts for adjacent ones of the nozzles is subtracted from a normal voltage by a subtracting circuit 9-1 to determine a peak value, and a driving pulse thus corrected in voltage is generated by a switching circuit 9-2. A driving voltage can be corrected by appropriately selecting resistors R-1-R-k according to a correction quantity, whereby the ink can be ejected in an appropriate amount.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an inkjet recording device, and particularly to an on-demand type inkjet recording device that integrates a plurality of inkjet heads.

[Prior Art] In order to process a large amount of information in a short time, there is a strong demand for faster recording devices. In order to achieve high-speed processing of information in an inkjet recording device that records by ejecting ink, it is necessary to improve the frequency characteristics of each head or to integrate multiple heads to perform recording over a wide range. However, since there is a natural limit to the frequency characteristics of the head, it is desirable to integrate a plurality of heads in order to achieve a significant increase in speed.

Conventionally, in this type of device, due to the structural limitation of integrating the head in a relatively small area, a so-called thyronics type device has been used, which has a plate-shaped piezo probe as an electro-mechanical transducer that applies ejection energy to the ink. Many types of heads are integrated.

[Problems to be Solved by the Invention] However, the same applies to this form or a form in which a so-called Gould type head having a cylindrical piezo element is integrated, but in such a device, the electrical
Since this method uses a mechanical transducer element to cause mechanical vibrations during ink ejection, when heads are integrated, mutual interference occurs between the heads due to the vibrations. In other words, for example, when adjacent heads are driven at the same time, more energy is applied than when they are driven alone, so the recorded dot diameter and droplet ejection speed are There are problems such as a change in the recording quality and a deterioration in recording quality. In particular, this problem becomes even more pronounced when the drive voltage is made variable to control the amount of ink ejection to express halftones.

[Means for Solving the Problems] An object of the present invention is to solve these problems and provide an inkjet recording device that can perform high-quality recording by eliminating mutual interference between heads. shall be.

In an inkjet recording apparatus comprising an ejection energy generating means disposed corresponding to each of the ejecting members and applying ejection energy of ink in response to supply of a drive signal, a method corresponding to each of the ejection energy generating means and the corresponding corresponding one is provided. The invention is characterized by comprising a correction means for correcting the magnitude of the drive signal supplied to the ejection energy generation means according to the magnitude of the drive signal supplied to the other ejection energy generation means. .

[Function] That is, according to the present invention, even when ejection energy interferes between ejection members, one ejection energy generation means is driven depending on the magnitude of a drive signal to another ejection energy generation means. Since the magnitude of the signal is corrected, an appropriate amount of drive signal is supplied to the ejection energy generating means.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the configuration of the main parts of an inkjet recording apparatus to which the present invention can be applied, and here a configuration in which n Gould type heads are integrated is shown. In the figure, 6 is an ink supply port, and ink supplied from this port is supplied from the common ink chamber 5 to the nozzles 1-1 to 1-n via a filter 7 for collecting foreign matter. In each head, a pressure chamber 4 is filled with ink, and when an electrical signal is applied to the electro-mechanical transducer 3, for example in the form of a panel, the element 3 deforms, and a pressure wave acts in the ink, almost simultaneously from the orifice 2. Ink droplets are ejected.

FIG. 2 shows the amount of pressure interference between adjacent heads. For example, when the element 3 corresponding to nozzle l-1 in FIG. This represents the magnitude of the observed pressure δ.

Figure 3 shows element 3 corresponding to nozzle 1-1 in Figure 1.
This figure shows the pressure δ generated in the pressure chamber in each nozzle when driven by a pulse signal with a constant wave height.

From FIGS. 2 and 3, it can be seen that the interference pressure δ can be expressed as . However, here, L is the distance between the electro-mechanical conversion element and the pressure measurement point when driven at the wave height V, and α and β are constants determined by the shape and material. Therefore, it can be seen that the interference pressure δ can be estimated at the stage when the shape and material are determined.

On the other hand, it is known that there is a substantially proportional relationship between the pressure generated during driving and the amount of ink discharged, and the interference pressure δ directly appears as a change in the amount of ink discharged.

FIG. 4 shows an example of the configuration of a drive circuit for the conversion element 3, and 8-1 in the figure is an amplifier for setting the pulse height using the input signal A. DI, Ql, and Q2 constitute a switch circuit when the output of the amplifier 8-1 is positive. Also, D2
．． Q3. Q4 constitutes a switch circuit when the output of amplifier 8-1 is negative. Both of these switch circuits are turned on by the timing pulse B, and at this time the element 3 is driven.

FIG. 5 shows an example of the configuration of a drive circuit for driving the head assembly shown in FIG. When signals A-1 to A-n for determining the drive amount of each nozzle are supplied from a drive signal source (not shown), interference occurs in the subtraction circuit 9-1 according to the drive amount of adjacent nozzles. A voltage corresponding to the pressure δ is subtracted to determine the peak value, and a voltage-corrected drive pulse is generated by the switching circuit 9-2, which is a collection of the switching circuits shown in FIG. Note that the amount of correction at this time can be set by appropriately selecting the resistors R-1-Rk.

In other words, it is possible to correct the driving voltage to correct the interference pressure component generated by driving adjacent nozzles so that a predetermined amount of ink is ejected, and therefore an appropriate amount of ink is ejected. . In particular, in this example, when controlling the amount of ink ejection by changing the drive voltage to express halftones, the drive of adjacent nozzles is different. Since the amount of correction is made in accordance with the IJ amount, appropriate correction will be made no matter what voltage the adjacent nozzle is driven with. Furthermore, since the input signal A is zero in a head that does not eject ink, the pulse applied to the element 3 becomes negative due to the correction signal, which also has the effect of suppressing unnecessary vibration of the meniscus due to the interference pressure δ. Furthermore, by arranging the nozzles as shown in Figure 1, just by correcting the interference pressure δ of the adjacent head, the propagation to the other side is eliminated, so it can be almost accurately corrected by the circuit shown in Figure 5. .

It goes without saying that the nozzle drive circuit can have various configurations.

FIG. 6 shows another configuration of the switching circuit for driving the element 3. In this example, compared to the example shown in FIG.
- The output of t is negative) - The arrow switch/switch circuit is omitted so that no correction is made when Ov is manually operated. This is originally effective when δ is small. That is, in the example shown in FIG. 4, the case where ejection is performed only with δ at the time of Ov input is also corrected, whereas this example is omitted because the δ value is small and there is no need for correction.

Further, in the two embodiments described above, analog correction calculations were performed, but it goes without saying that the correction calculations may be performed using digital signals. Furthermore, it is easy to use a microcomputer to perform correction calculations while referring to a look-up table provided in, for example, 110M during the processing process.

Furthermore, although the above embodiment deals with the case where the interference pressure is positive, if the interference pressure becomes negative depending on the structure of the head, a similar correction can be made by providing an adder in place of the subtractor 9-1. It becomes possible.

In addition, although the voltage value was used as the driving amount in the above-described embodiment, when controlling by pulse width or the like, for example, the same effect can be obtained by performing pulse width correction.

[Efficacy of invention! J, ] As described above, according to the present invention, it is possible to eliminate the adverse effects caused by the mutual interference of ejection energies between heads, thereby making it possible to perform high-quality image recording.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a configuration example of the main part of an inkjet recording apparatus to which the present invention can be applied, FIG. 2 is a diagram for explaining the amount of pressure interference between adjacent heads, and FIG. Figure 4 is a diagram for explaining the amount of pressure interference that propagates to other nozzle groups when an electro-mechanical conversion element as a discharge energy generating means arranged corresponding to one nozzle in Figure 1 is driven. A circuit diagram showing an example of a configuration of a switching circuit of an electro-mechanical conversion element, FIG. 5 is a circuit diagram showing an example of a configuration of a drive circuit for driving the main parts shown in FIG. 1, and FIG. FIG. 3 is a circuit diagram showing another configuration example of a switching circuit of a conversion element. 1-I N1-n...Nozzle, 3.3-1 to 3-n...Electro-mechanical conversion element, 4...
・Pressure chamber, 8-1...Amplifier, 9-1...Subtraction circuit, 9-2...Switching circuit, δ...Pressure interference amount. Figure 1 Figure 2/-27-31-4----1-n Figure 3 Figure 4

Claims (1)

[Claims] 1) A plurality of ejection members having ejection ports for ejecting ink, and a plurality of ejection members disposed corresponding to each of the plurality of ejection members and configured to emit ink ejection energy in response to supply of a drive signal. In an inkjet recording apparatus, the magnitude of the drive signal supplied to each of the ejection energy generating means is set to be different from that of the other ejection energy. An inkjet recording apparatus characterized by comprising a correction means for correcting according to the magnitude of a drive signal supplied to the generation means. 2) In the inkjet recording apparatus according to claim 1, the plurality of ejection members have the form of a stack stacked in parallel, and the correction means is disposed corresponding to adjacent ejection members. An inkjet recording apparatus characterized in that the correction is performed in accordance with the magnitude of a drive signal sent to an ejection energy generating means. 3) In the inkjet recording apparatus according to claim 1 or 2, the ejection energy generating means includes an electro-mechanical conversion element that applies mechanical energy to the ink in response to the supply of an electric signal. Features of inkjet recording device.