Drive circuit, liquid injection head, and liquid injection recording device

Abstract

To provide a driving circuit and the like which can improve convenience while improving image quality of a printed image.SOLUTION: A driving circuit according to one embodiment in the disclosure, which outputs a driving signal that is applied to a liquid jet head having a plurality of nozzles, comprises a signal generating part that generates driving signals for making the nozzles jet liquid, on the basis of image data which specifies drive waveforms. The signal generating part has a waveform storage part storing a plurality of drive waveforms. The plurality of nozzles is separated into a plurality of nozzle groups. The signal generating part generates a driving signal for each of the nozzle groups so that the liquid is discharged at different discharge timing for each of the nozzle groups, by performing timing adjustment for each of the nozzle groups to a predetermined drive waveform selected from the plurality of drive waveforms on the basis of the image data.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a drive circuit, a liquid ejection head, and a liquid ejection recording apparatus.

Background Art

[0002] Liquid ejection recording apparatuses equipped with liquid ejection heads are used in various fields, and various types of liquid ejection heads have been developed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such liquid ejection heads, generally, improving print image quality and improving convenience are required. It is desirable to provide a drive circuit, a liquid ejection head, and a liquid ejection recording apparatus capable of improving convenience while improving print image quality.

Means for Solving the Problems

[0005] According to an embodiment of the present disclosure FirstThe drive circuit is a circuit that outputs a drive signal to be applied to a liquid spray head having multiple nozzles, and includes a signal generation unit that generates a drive signal for spraying liquid from the nozzles based on image data that defines the drive waveform. This signal generation unit has a waveform storage unit that stores multiple drive waveforms. The multiple nozzles are distinguished into multiple nozzle groups. The signal generation unit generates a drive signal for each nozzle group by adjusting the timing of a predetermined drive waveform selected from the multiple drive waveforms based on the image data, on a nozzle group basis, so that the liquid is discharged at different discharge timings for each nozzle group. Furthermore, the signal generation unit includes one or more delay circuits that adjust the timing by delaying the discharge timing signal that defines the discharge timing on a nozzle group basis, and multiple signal generation circuits that generate drive signals for each nozzle group based on image data and the discharge timing signal, and at least a portion of which are connected in multiple stages. One or more of the above delay circuits are individually arranged between the preceding and succeeding circuits of the multiple signal generation circuits to output a delayed signal for the discharge timing signal to the succeeding circuit. A second drive circuit according to one embodiment of the present disclosure is a circuit that outputs a drive signal to be applied to a liquid spray head having a plurality of nozzles, and comprises a signal generation unit that generates a drive signal for spraying liquid from the nozzles based on image data defining a drive waveform. This signal generation unit has a waveform storage unit that stores a plurality of drive waveforms. The plurality of nozzles are distinguished into a plurality of nozzle groups. The signal generation unit generates a drive signal for each nozzle group so that liquid is discharged at different discharge timings for each nozzle group by performing timing adjustments on a nozzle group basis for a predetermined drive waveform selected from the plurality of drive waveforms based on the image data. The signal generation unit also comprises one or more delay circuits that perform timing adjustments by delaying a discharge timing signal that defines the discharge timing on a nozzle group basis, and a plurality of signal generation circuits that generate a drive signal for each nozzle group based on the image data and the discharge timing signal, and at least a portion of which are connected in multiple stages. In at least a portion between the preceding and succeeding circuits of the plurality of signal generation circuits, one or more of the delay circuits that output a delayed signal for the discharge timing signal to the succeeding circuit are arranged in multiple stages.

[0006] A liquid injection head according to one embodiment of the present disclosure is, according to the above embodiment of the present disclosure First or second drive circuit And this First or second drive circuit It comprises an injection unit having multiple nozzles that spray liquid based on a drive signal output from there.

[0007] A liquid injection recording device according to one embodiment of the present disclosure is equipped with a liquid injection head according to the above embodiment of the present disclosure. [Effects of the Invention]

[0008] One embodiment of the present disclosure The first and second Drive circuit, liquid injection head Furthermore Liquid jet recording devices make it possible to improve both print quality and convenience. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing a schematic configuration example of a liquid injection recording device according to one embodiment of the present disclosure. [Figure 2] Figure 1 is a schematic diagram illustrating an example of the configuration of various drive waveforms and the like stored in the waveform storage unit. [Figure 3] This is a block diagram schematically representing a detailed configuration example of the signal generation unit and other components shown in Figure 1. [Figure 4] It is a block diagram schematically showing a configuration example of a signal generation unit and the like in a liquid ejection head according to a comparative example. [Figure 5] It is a schematic diagram showing a configuration example of each drive waveform and the like stored in a waveform storage unit according to a comparative example. [Figure 6] It is a schematic diagram showing an example of the correspondence relationship among a printed image, the number of drops, and image data according to a comparative example. [Figure 7] It is a schematic diagram showing an example of the correspondence relationship among a printed image, the number of drops, and image data according to an embodiment. [Figure 8] It is a block diagram schematically showing a configuration example of a signal generation unit and the like in a liquid ejection head according to Modification 1. [Figure 9] It is a block diagram showing a detailed configuration example of a delay circuit and the like shown in FIG. 8. [Figure 10] It is a timing diagram showing an operation example of the delay circuit shown in FIG. 9. [Figure 11] It is a block diagram schematically showing a configuration example of a signal generation unit and the like in a liquid ejection head according to Modification 2. [Figure 12] It is a block diagram schematically showing a configuration example of a signal generation unit and the like in a liquid ejection head according to Modification 3. [Figure 13] It is a timing diagram showing an operation example of delay amount adjustment in a liquid ejection head according to Modification 4.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 1. Embodiment (Example in the case of providing a delay circuit that individually outputs a delay signal to each signal generation circuit) 2. Modifications Modification 1 (Example in the case of individually arranging delay circuits between all of the circuits of each signal generation circuit) Modification 2 (Example in the case of individually arranging delay circuits in a part between the circuits of each signal generation circuit) Modification 3 (Example in the case of arranging delay circuits in a multi-stage connection between the circuits of each signal generation circuit) Modification Example 4 (Example of adjusting the delay amount by changing the frequency of the basic clock signal) 3. Other Modification Examples

[0011] <1. Embodiment> [Schematic Configuration of Printer 5] FIG. 1 shows a schematic configuration example of a printer 5 as a liquid jet recording apparatus according to an embodiment of the present disclosure in a block diagram. In each drawing used in the description of this specification, the scale of each member is appropriately changed in order to make each member recognizable in size.

[0012] The printer 5 is an inkjet printer that performs recording (printing) of images, characters, etc. on a recording medium (for example, the recording paper P shown in FIG. 1) using ink 9 described later. As shown in FIG. 1, this printer 5 mainly includes an inkjet head 1 and a print control unit 2.

[0013] Note that the inkjet head 1 corresponds to a specific example of the "liquid jet head" in the present disclosure, and the printer 5 corresponds to a specific example of the "liquid jet recording apparatus" in the present disclosure. Also, the ink 9 corresponds to a specific example of the "liquid" in the present disclosure.

[0014] (A. Print Control Unit 2) The print control unit 2 supplies various types of information (data) to the inkjet head 1. Specifically, as shown in FIG. FIG. 1, the print control unit 2 supplies a print control signal Sc to the inside of the inkjet head 1 (such as a drive circuit 4 described later).

[0015] Note that this print control signal Sc includes, for example, image data Dp and ejection timing signal St described later, and a power supply voltage (drive power supply) for operating the inkjet head 1.

[0016] (B. Inkjet Head 1) As shown by the dashed arrows in Figure 1, the inkjet head 1 is a head that records images, characters, etc., by ejecting droplet-shaped ink 9 onto the recording paper P from multiple nozzle holes Hn, which will be described later. As shown in Figure 1, this inkjet head 1 comprises one ejection unit 11, one I / F (interface) board 12, and one drive board 13.

[0017] (B-1. Injection part 11) As shown in Figure 1, the injection unit 11 has multiple nozzle holes Hn, and is the part that ejects ink 9 from these nozzle holes Hn. This ejection of ink 9 is performed based on a drive signal Sd (drive voltage Vd) output from a drive circuit 4, which will be described later, on the drive board 13 (see Figure 1).

[0018] As shown in Figure 1, the ejection unit 11 is composed of an actuator plate 111 and a nozzle plate 112. The ink 9 is supplied to this ejection unit 11 (actuator plate 111) from, for example, an ink tank (not shown in Figure 1) in the inkjet head 1 via an ink supply pipe.

[0019] (Nozzle plate 112) The nozzle plate 112 is a plate made of a film material such as polyimide or a metal material, and as shown in Figure 1, it has the above-mentioned plurality of nozzle holes Hn. These nozzle holes Hn are formed in a row at predetermined intervals and are, for example, circular in shape. Each of these plurality of nozzle holes Hn corresponds to one specific example of a "nozzle" in this disclosure.

[0020] (Actuator plate 111) The actuator plate 111 is a plate made of a piezoelectric material such as PZT (lead zirconate titanate). This actuator plate 111 is provided with a plurality of channels (pressure chambers). These channels are for applying pressure to the ink 9 and are arranged in a line parallel to each other at predetermined intervals. Each channel is defined by a drive wall (not shown) made of piezoelectric material, and in cross-sectional view it is a concave groove.

[0021] Such channels contain ejection channels for ejecting ink 9 and dummy channels (non-ejection channels) that do not eject ink 9. In other words, the ejection channels are filled with ink 9, while the dummy channels are not. The filling of each ejection channel with ink 9 is carried out, for example, through a common channel that communicates with all such ejection channels. Furthermore, each ejection channel communicates individually with a nozzle hole Hn in the nozzle plate 112, while each dummy channel does not communicate with a nozzle hole Hn. These ejection channels and dummy channels are arranged alternately along a predetermined direction.

[0022] Furthermore, drive electrodes are provided on the opposing inner surfaces of the drive wall described above. These drive electrodes include a common electrode (shared electrode) provided on the inner surface facing the discharge channel and an active electrode (individual electrode) provided on the inner surface facing the dummy channel. These drive electrodes are electrically connected to the drive circuit 4, which will be described later, via a drive substrate 13. As a result, the drive voltage Vd (drive signal Sd) described above is applied from the drive circuit 4 to each drive electrode via the drive substrate 13 (see Figure 1).

[0023] (B-2.I / F board 12) As shown in Figure 1, the I / F board 12 is a relay board (relay board) that connects the drive board 13 and the outside of the inkjet head 1 (print control unit 2). As a result, the print control signal Sc input from the print control unit 2 is supplied to the drive board 13 (drive circuit 4, etc.) via the I / F board 12.

[0024] (B-3. Drive board 13) As shown in Figure 1, the drive board 13 is a board that electrically connects the I / F board 12 and the injection unit 11, and has a drive circuit 4. This drive board 13 outputs the aforementioned drive signal Sd from the drive circuit 4, thereby individually controlling the ink injection operation of the nozzle plate 112.

[0025] The drive circuit 4 is a circuit that generates and outputs the above-described drive signal Sd (drive voltage Vd) for ejecting ink 9 from each nozzle hole Hn in the injection unit 11. As shown in Figure 1, this drive circuit 4 has a signal generation unit 42 that includes a waveform storage unit 41.

[0026] The waveform storage unit 41 is the part that stores multiple drive waveforms Wd associated with image data Dp (see Figure 1). As will be described in detail later (Figure 3), multiple waveform storage units 41 are provided within the signal generation unit 42 (one for each of the multiple signal generation circuits 521 to 524, which will be described later), but in Figure 1 they are shown together as one for convenience. The correspondence between the image data Dp and the multiple drive waveforms Wd will be described later (Figure 2).

[0027] The signal generation unit 42 generates the drive signal Sd (drive voltage Vd) described above based on the image data Dp that defines the drive waveform Wd described above. Specifically, although the details will be described later (Figure 3), the signal generation unit 42 generates the drive signal Sd for each of the multiple nozzle groups described later, and outputs the drive signals Sd1, Sd2, ..., Sd(n-1), Sdn (n: an integer of 2 or more) corresponding to each nozzle group as the drive signal Sd (see Figure 1).

[0028] [Detailed configuration of inkjet head 1] Next, with reference to Figures 2 and 3, a detailed example of the configuration of the drive circuit 4 and other components in the inkjet head 1 will be described.

[0029] Figure 2 schematically shows an example of the configuration of each drive waveform Wd, etc., stored in the waveform storage unit 41 within the drive circuit 4 shown in Figure 1. Specifically, Figure 2 shows an example of the correspondence between each drive waveform Wd stored in the waveform storage unit 41, image data Dp, waveform register Rw, and drop count. Figure 3 schematically represents a detailed example of the configuration of the signal generation unit 42, etc., within the drive circuit 4 shown in Figure 1, using a block diagram. Note that the example in Figure 3 is an example where there are four nozzle groups as described above, and the same applies to the other examples described later (Figures 4, 8, 9, 11, and 12).

[0030] (Waveform storage unit 41) First, as shown in Figure 2, for example, in the waveform storage unit 41, multiple drive waveforms Wd associated with image data Dp are stored in a predetermined area (area A1) within the waveform register Rw.

[0031] Specifically, the drive waveform Wd for the "non-ejection" case, corresponding to the image data Dp with pixel value "0b0000", is stored in the waveform register Rw = "wave0" area (within area A1). Similarly, the drive waveform Wd for the "1 drop" case, corresponding to the image data Dp with pixel value "0b0001", is stored in the waveform register Rw = "wave1" area (within area A1). The drive waveform Wd for the "2 drop" case, corresponding to the image data Dp with pixel value "0b0010", is stored in the waveform register Rw = "wave2" area (within area A1). The drive waveform Wd for the "3 drop" case, corresponding to the image data Dp with pixel value "0b0011", is stored in the waveform register Rw = "wave3" area (within area A1).

[0032] Furthermore, in the example shown in Figure 2, the image data Dp for each pixel value "0b00100", "0b00101", and "0b00110" are as follows. That is, for the image data Dp for each of these pixel values, it is possible to assign waveforms other than the four types of drive waveforms Wd described above—"non-eject", "1 drop", "2 drop", and "3 drop"—to the waveform registers Rw = "wave4", "wave5", and "wave6", respectively.

[0033] (Signal generation unit 42) Furthermore, as shown in Figure 3, in the inkjet head 1 of this embodiment, the aforementioned multiple nozzle holes Hn are distinguished (grouped) into the multiple nozzle groups described above. Specifically, in the example in Figure 3, they are distinguished into four nozzle groups consisting of nozzle groups G1, G2, G3, and G4.

[0034] For convenience, these nozzle groups G1, G2, G3, and G4 will be collectively referred to as nozzle group G in the following explanation. An example of such nozzle group G is a row of nozzles extending along a predetermined direction within the nozzle plate 112. However, this is not the only example, and other grouping methods may be used to define the nozzle groups.

[0035] Furthermore, as shown in Figure 3, the signal generation unit 42 has one delay circuit 51 and multiple (four in this example) signal generation circuits 521 to 524.

[0036] The delay circuit 51 is a circuit that adjusts the timing by delaying the ejection timing signal St, which defines the ejection timing of the ink 9, in units of the nozzle group G described above. Specifically, the delay circuit 51 outputs delay signals St1 to St4 for the ejection timing signal St individually to each of the multiple signal generation circuits 521 to 524. In other words, the delay circuit 51 outputs delay signal St1 to signal generation circuit 521, delay signal St2 to signal generation circuit 522, delay signal St3 to signal generation circuit 523, and delay signal St4 to signal generation circuit 524.

[0037] Such a delay circuit 51 may include, for example, a programmable device such as an FPGA (Field Programmable Gate Array) or CPU (Central Processing Unit), a dedicated device such as an ASIC (Application Specific Integrated Circuit), or a general-purpose IC.

[0038] Each of the signal generation circuits 521 to 524 generates a drive signal Sd (Sd1 to Sd4) for each of the nozzle groups G (G1 to G4) based on image data Dp that defines the drive waveform Wd, delay signals St1 to St4 for the ejection timing signal St, and the basic clock signal SCLK. Each of these signal generation circuits 521 to 524 has the waveform storage unit 41 described above, as shown in Figure 3. Furthermore, these signal generation circuits 521 to 524 are connected in multiple stages via the signal line of the image data Dp. That is, as shown in Figure 3, signal generation circuit 522 is located downstream of signal generation circuit 521, signal generation circuit 523 is located downstream of signal generation circuit 522, and signal generation circuit 524 is located downstream of signal generation circuit 523.

[0039] With this configuration, the signal generation circuit 521 generates a drive signal Sd1 applied to nozzle group G1 based on image data Dp, delay signal St1, and basic clock signal SCLK, and outputs it to nozzle group G1 (see Figure 3). Similarly, the signal generation circuit 522 generates a drive signal Sd2 applied to nozzle group G2 based on image data Dp, delay signal St2, and basic clock signal SCLK, and outputs it to nozzle group G2. The signal generation circuit 523 generates a drive signal Sd3 applied to nozzle group G3 based on image data Dp, delay signal St3, and basic clock signal SCLK, and outputs it to nozzle group G3. The signal generation circuit 524 generates a drive signal Sd4 applied to nozzle group G4 based on image data Dp, delay signal St4, and basic clock signal SCLK, and outputs it to nozzle group G4.

[0040] In this way, the signal generation unit 42 generates a drive signal Sd for each nozzle group G by performing timing adjustment (delay processing) on ​​a nozzle group G basis for a predetermined drive waveform Wd selected from a plurality of drive waveforms Wd based on the image data Dp, so that ink 9 is ejected at different ejection timings for each nozzle group G.

[0041] [Action and function / effect] (A. Basic operation of Printer 5) In this printer 5, the recording operation (printing operation) of images, characters, etc., onto the recording medium (recording paper P, etc.) is performed using the ink ejection operation of ink 9 by the inkjet head 1 as described below. Specifically, the inkjet head 1 performs the ink ejection operation of ink 9 using the shear mode as follows.

[0042] First, the drive circuit 4 on the drive substrate 13 applies a drive voltage Vd (drive signal Sd) to the aforementioned drive electrodes (common electrode and active electrode) in the actuator plate 111 of the injection unit 11. Specifically, the drive circuit 4 applies a drive voltage Vd to each drive electrode located on the pair of drive walls that define the aforementioned discharge channel. As a result, these pair of drive walls deform so that they protrude toward the dummy channel adjacent to their discharge channel.

[0043] At this time, the drive wall bends in a V-shape around its midpoint in the depth direction. This bending deformation of the drive wall causes the ejection channel to deform as if it were expanding. In this way, the volume of the ejection channel increases due to the bending deformation caused by the piezoelectric thickness sliding effect of the pair of drive walls. As a result of this increase in the volume of the ejection channel, the ink 9 is guided into the ejection channel.

[0044] Next, the ink 9, which has been guided into the ejection channel in this manner, propagates inside the ejection channel as a pressure wave. At the moment when this pressure wave reaches (or near the moment) the nozzle hole Hn of the nozzle plate 112, the drive voltage Vd applied to the drive electrode becomes 0 V. As a result, the drive wall recovers from the bent deformation state described above, and the volume of the ejection channel, which had increased, returns to its original size.

[0045] In this way, as the volume of the ejection channel returns to its original state, the pressure inside the ejection channel increases, and the ink 9 inside the ejection channel is pressurized. As a result, droplet-shaped ink 9 is ejected to the outside (towards the recording paper P) through the nozzle hole Hn (see Figure 1). In this way, the ink ejection operation (discharge operation) of the ink 9 in the inkjet head 1 is performed, and as a result, the recording operation of images, characters, etc. is performed on the recording paper P.

[0046] (B. Operation of generating the drive signal Sd) Next, the signal generation operation (generation operation of the drive signal Sd) in the drive circuit 4 of this embodiment will be described in detail, in comparison with the comparative example.

[0047] First, in conventional inkjet heads, ink is generally ejected at the same (common) ejection timing in multiple nozzle rows. However, if ink is ejected at the same ejection timing in each nozzle group (all nozzle holes), there is a risk of deterioration in print quality (such as the occurrence of shading within the image) due to factors such as ink pulling between multiple nozzle holes (connected to the same liquid flow path).

[0048] Therefore, one possible approach is to prepare in advance multiple drive waveforms with staggered discharge timings (for example, multiple drive waveforms Wd with different discharge timings, corresponding to the aforementioned "1 drop"), as shown in the comparative example below.

[0049] (B-1. Comparative example) Figure 4 schematically shows a block diagram of an example configuration of the signal generation unit 102, etc., in a liquid jet head (inkjet head 101) related to this comparative example. Figure 5 schematically shows an example configuration of each drive waveform Wd, etc., stored in the waveform storage unit 104 (see Figure 4) related to this comparative example. Specifically, Figure 5 shows an example of the correspondence between each drive waveform Wd stored in the waveform storage unit 104 related to the comparative example, and the image data Dp, waveform register Rw, and drop count, similar to Figure 2 described above. Figure 6 schematically shows an example of the correspondence between the printed image (Figure 6(A)), drop count (drop count: Figure 6(B)), and image data Dp (Figure 6(C)) related to this comparative example.

[0050] In the comparative example inkjet head 101 shown in Figure 4, a signal generation unit 102 is provided instead of the signal generation unit 42 in the inkjet head 1 of this embodiment shown in Figure 3. Furthermore, within the signal generation circuits 521 to 524 in this signal generation unit 102, a waveform storage unit 104 according to the comparative example is provided instead of the waveform storage unit 41 described above. Moreover, the configuration of each drive waveform Wd etc. stored in the waveform storage unit 104 of this comparative example (see Figure 5) is different from the configuration of each drive waveform Wd etc. stored in the waveform storage unit 41 described above (see Figure 2), as will be explained below.

[0051] First, as shown in Figure 4, the signal generation unit 102 of this comparative example is the same as the signal generation unit of this embodiment (see Figure 3), but without the aforementioned delay circuit 51, and the other configurations are basically the same. Therefore, unlike the signal generation unit 42, the discharge timing signal St is input to each of the signal generation circuits 521 to 524 in common in this signal generation unit 102.

[0052] Furthermore, as shown in Figure 5, the configuration of each drive waveform Wd stored in the waveform storage unit 104 of the comparative example differs from that of the waveform storage unit 41 of this embodiment shown in Figure 2, and is as follows. That is, as indicated by the arrows P101, P102, and P103 in Figure 5, multiple (two in this example) drive waveforms Wd are prepared in advance to give different discharge timings for each number of drops.

[0053] Specifically, in the case of "1 drop," two drive waveforms Wd with different timings are stored in the waveform registers Rw = "wave1" and "wave2" respectively (see arrow P101 in Figure 5). Similarly, in the case of "2 drops," two drive waveforms Wd with different timings are stored in the waveform registers Rw = "wave3" and "wave4" respectively (see arrow P102 in Figure 5). Furthermore, in the case of "3 drops," two drive waveforms Wd with different timings are stored in the waveform registers Rw = "wave5" and "wave6" respectively (see arrow P103 in Figure 5).

[0054] In other words, in the comparative example shown in Figure 5, it is necessary to pre-store 7 (=1+3×2) types of drive waveforms Wd in the waveform storage unit 104 as drive waveforms Wd for the cases of "no discharge", "1 drop", "2 drops", and "3 drops". To put it another way, in the comparative example of Figure 5, unlike the embodiment shown in Figure 2 (where the region A1 of waveform register Rw = "wave0" to "wave3" is used), the region A101 of waveform register Rw = "wave0" to "wave6" is used as the drive waveforms Wd for the cases of "no discharge", "1 drop", "2 drops", and "3 drops".

[0055] Furthermore, with this configuration, in the comparative example inkjet head 101, when printing a print image in two regions A(G1) and A(G2) corresponding to nozzle groups G1 and G2, as shown in Figure 6(A), the following occurs. That is, even if the number of drops is the same ("3 drops") for pixels in region A(G1) and pixels in region A(G2), as shown by the dashed line in Figure 6(B), if the ejection timing is different for these regions A(G1) and A(G2), the image data value Dp (pixel value) will also be different. In other words, as shown by arrow P103 in Figure 5 and the dashed line in Figure 6(C), even if the number of drops is the same, different types of drive waveforms Wd must be applied to make the ejection timing different.

[0056] Thus, in the comparative example inkjet head 101, in order to suppress the above-mentioned degradation of print quality (such as the occurrence of variations in density within the image), when the ejection timing of the nozzle groups G is made different, it is necessary to pre-store multiple types of drive waveforms Wd corresponding to the different ejection timings in the waveform storage unit 104, as follows: In other words, the number of drive waveforms Wd that need to be prepared in advance to set different ejection timings for each nozzle group G (storage area of ​​waveform register Rw: area A101) increases. Therefore, in this comparative example, for example, there may be insufficient area (storage area of ​​waveform register Rw) to store other drive waveforms Wd, which may impair usability. In short, it can be said that it is difficult to improve usability while improving print quality with the inkjet head 101 of this comparative example.

[0057] (B-2. Embodiment) In contrast, in the inkjet head 1 of this embodiment, the signal generation unit 42 generates the drive signal Sd on a nozzle group G basis, as described below, unlike in the comparative example described above. Specifically, the signal generation unit 42 generates the drive signal Sd on a nozzle group G basis by adjusting the timing of a predetermined drive waveform Wd selected from a plurality of drive waveforms Wd based on the image data Dp, so that the ink 9 is ejected at different ejection timings for each nozzle group G.

[0058] Specifically, the delay circuit 51 in the signal generation unit 42 performs the timing adjustment described above by delaying the ejection timing signal St, which defines the ejection timing of the ink 9, in units of nozzle group G. More specifically, this delay circuit 51 outputs delay signals St1 to St4 for the ejection timing signal St, individually to each of the multiple signal generation circuits 521 to 524.

[0059] Here, Figure 7 schematically represents an example of the correspondence between the printed image (Figure 7(A)), the number of drops (number of drops: Figure 7(B)), and the image data Dp (Figure 7(C)) according to an embodiment of this specification.

[0060] In the embodiment shown in Figure 7, unlike the comparative example shown in Figure 6, when printing a print image in two regions A(G1) and A(G2) corresponding to nozzle groups G1 and G2, as shown in Figure 7(A), the following occurs. That is, for example, as shown by the dashed line in Figure 7(B), when the number of drops is the same ("3 drops") for pixels in region A(G1) and pixels in region A(G2), even if the ejection timing is different for these regions A(G1) and A(G2), the image data value Dp (pixel value) will be the same. In other words, for example, as shown by the dashed line in Figure 2 and Figure 7(C) above, even when the number of drops is the same and the ejection timing is different, the same drive waveform Wd can be applied, unlike in the comparative example (see the dashed line in Figure 6(C)).

[0061] (B-3. Action / Effect) In this embodiment, timing adjustments are performed on a nozzle group G basis for a predetermined drive waveform Wd selected based on image data Dp, so that ink 9 is ejected at different ejection timings for each nozzle group G.

[0062] As a result, compared to, for example, the case where ink 9 is ejected at the same ejection timing in each nozzle group G (as in the conventional method described above), the deterioration of print quality (such as the occurrence of shading in the image) caused by the pulling of ink 9 between multiple nozzle holes Hn (connected to the same ink flow path) is suppressed. Furthermore, compared to, for example, the case of the comparative example above, where multiple types of drive waveforms Wd corresponding to different ejection timings are pre-stored in the waveform storage unit 104, the number of drive waveforms Wd (area A1 of the waveform register Rw) that need to be pre-prepared in the waveform storage unit 41 to set different ejection timings for each nozzle group G is reduced. Therefore, in this embodiment, compared to the case of the comparative example above, it is possible to improve convenience while improving print quality.

[0063] Furthermore, by varying (staggering) the ejection timing for each nozzle group G, it becomes possible to reduce the drive current during ink ejection, for example, and suppress electrical malfunctions (reduce noise). Moreover, as mentioned above, since the number of drive waveforms Wd that need to be prepared in advance to set different ejection timings for each nozzle group G is reduced, it becomes possible to reduce the load on the user side of the inkjet head 1 to generate image data Dp, for example.

[0064] Furthermore, in this embodiment, a delay circuit 51 is provided in the signal generation unit 42 to perform the timing adjustment described above by delaying the discharge timing signal St on a nozzle group G basis (performing delay adjustment), as follows: That is, timing adjustment on a nozzle group G basis for the predetermined drive waveform described above can be realized with a simple circuit configuration. As a result, convenience can be further improved.

[0065] In particular, in this embodiment, the delay signals St1 to St4 for the ejection timing signal St are output individually from the delay circuit 51 to each of the multiple signal generation circuits 521 to 524, as follows: That is, for example, it is possible to easily generate delay signals St1 to St4 for each of the multiple signal generation circuits 521 to 524 that correspond to various variations in delay amount. As a result, it becomes possible to further improve print quality.

[0066] <2. Variant> Next, modified examples (Modifications 1 to 4) of the above embodiment will be described. In the following, components identical to those in the embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0067] [Example 1] (composition) Figure 8 is a schematic block diagram showing an example of the configuration of the signal generation unit 42A, etc., in the liquid jet head (inkjet head 1A) according to Modification 1. Figure 9 is a block diagram showing a detailed example of the configuration of the delay circuit (delay circuits 511-513, described later) shown in Figure 8.

[0068] As shown in Figure 8, the inkjet head 1A of this modified example corresponds to the inkjet head 1 of the embodiment (see Figure 3) in which a signal generation unit 42A is provided instead of the signal generation unit 42, and the other configurations are basically the same. Furthermore, the signal generation unit 42A of this modified example corresponds to the signal generation unit 42 of the embodiment in which multiple (three in this example) delay circuits 511 to 513 are provided instead of one delay circuit 51, and the other configurations are basically the same.

[0069] This inkjet head 1A corresponds to one specific example of a "liquid jet head" as described in this disclosure.

[0070] As shown in Figure 8, delay circuits 511 to 513 are individually positioned between the preceding and succeeding circuits of the multiple signal generation circuits 521 to 524. Specifically, delay circuit 511 is positioned between signal generation circuits 521 and 522, delay circuit 512 is positioned between signal generation circuits 522 and 523, and delay circuit 513 is positioned between signal generation circuits 523 and 524. Each of these delay circuits 511 to 513 outputs a delayed signal (delay signals St2 to St4, described later) for the discharge timing signal St to the subsequent stage.

[0071] Each of these delay circuits 511 to 513 is configured to include flip-flop circuits (F / F circuits) 61 to 63, as shown in Figure 9, for example. Specifically, in the F / F circuit 61 that constitutes delay circuit 511, the discharge timing signal St is input to the D terminal, and the basic clock signal SCLK is input to the CLK terminal, and a delay signal St2 for the discharge timing signal St is output from the Q terminal. Similarly, in the F / F circuit 62 that constitutes delay circuit 512, the delay signal St2 is input to the D terminal, and the basic clock signal SCLK is input to the CLK terminal, and a delay signal St3 for the discharge timing signal St (a delay signal St3 for delay signal St2) is output from the Q terminal. Likewise, in the F / F circuit 63 that constitutes delay circuit 513, the delay signal St3 is input to the D terminal, and the basic clock signal SCLK is input to the CLK terminal, and a delay signal St4 for the discharge timing signal St (a delay signal St4 for delay signal St3) is output from the Q terminal. Furthermore, these discharge timing signals St and delay signals St2 to St4 are supplied individually to each signal generation circuit 521 to 524, as shown in Figure 9.

[0072] (Signal generation operation) With this configuration, in the signal generation unit 42A of the modified example 1, delay signals St2 to St4 for the discharge timing signal St are output from multiple delay circuits 511 to 513 to the subsequent signal generation circuits 522 to 524.

[0073] Figure 10 shows an example of the operation of the delay circuits 511-513 (F / F circuits 61-63) shown in Figure 9, represented as a timing diagram. Specifically, Figures 10(A) to 10(I) show the waveforms of the basic clock signal SCLK, the output timing signal St, the delay signals St2-St4, and the drive signals Sd1-Sd4, respectively. The horizontal axis in Figure 10 represents time t.

[0074] First, in the circuit configuration of the signal generation unit 42A shown in Figure 9, one stage of F / F circuits 61 to 63 within delay circuits 511 to 513 is provided, leading from signal generation circuit 521 to signal generation circuit 524. Therefore, the delay signals St2 to St4 output from each F / F circuit 61 to 63 are delayed by one clock cycle of the basic clock signal SCLK relative to the input signal to each F / F circuit 61 to 63 (discharge timing signal St or delay signals St2, St3) (see Figures 10(A) to 10(E)). As a result, the drive signals Sd to Sd4 generated by each signal generation circuit 521 to 524 based on these discharge timing signals St and delay signals St2 to St4 have waveforms with sequentially shifted output timings by ((frequency of 1 / SCLK) × (number of stages passed through the F / F circuit)) (see Figures 10(F) to 10(I)).

[0075] (Effects / Actions) In this modified configuration 1, the same effects can be obtained through basically the same operation as in the embodiment.

[0076] Furthermore, in this modified example 1 in particular, the delay signals St2 to St4 for the discharge timing signal St are output from multiple delay circuits 511 to 513 to the subsequent signal generation circuits 522 to 524, as follows: That is, the generation of delay signals St2 to St4 for the subsequent signal generation circuits 522 to 524 is realized with a simple circuit configuration. As a result, convenience can be further improved in this modified example 1.

[0077] Furthermore, in this modified example 1, since multiple delay circuits 511 to 513 are individually arranged between all the preceding and succeeding circuits in the multiple signal generation circuits 521 to 524, a circuit configuration in which the delay amount differs for each signal generation circuit 522 to 524 can be easily realized. As a result, it becomes possible to further improve convenience.

[0078] In addition, in this modified example 1, since each of the delay circuits 511 to 513 includes an F / F circuit 61 to 63, the delay circuits 511 to 513 can be easily constructed using general-purpose circuits. As a result, manufacturing costs can be reduced.

[0079] [Differentiation 2] (composition) Figure 11 schematically shows a block diagram of an example configuration of the signal generation unit 42B and other components in the liquid jet head (inkjet head 1B) according to Modification 2.

[0080] As shown in Figure 11, the inkjet head 1B of this modified example 2 corresponds to the inkjet head 1A of modified example 1 (see Figure 8) in which the signal generation unit 42A is replaced with a signal generation unit 42B, and the other configurations are basically the same. Furthermore, the signal generation unit 42B of this modified example 2 corresponds to the signal generation unit 42A of modified example 1 in which only one of the delay circuits 511 is provided instead of the multiple (three) delay circuits 511 to 513, and the other configurations are basically the same.

[0081] In other words, unlike the signal generation unit 42A, the signal generation unit 42B places the delay circuit 511 only in some of the spaces between the preceding and succeeding circuits of the multiple signal generation circuits 521 to 524 (between signal generation circuits 521 and 522). Consequently, unlike the signal generation unit 42A, the signal generation circuit 523 receives the discharge timing signal St instead of the aforementioned delay signal St3, and the signal generation circuit 524 receives the delay signal St2 instead of the aforementioned delay signal St4 (see Figure 11).

[0082] In other words, the output timing signal St is input to the signal generation circuits 521 and 523 (the stage before the delay circuit 511), and the delay signal St2 output from the delay circuit 511 is input to the signal generation circuits 522 and 524 (the stage after the delay circuit 511). As a result, the signal generation circuits are grouped into two groups, for example, as shown in parentheses in Figure 11: the signal generation circuits 521 and 523 (output timing group A) and the signal generation circuits 522 and 524 (output timing group B), based on their output timing and delay amount.

[0083] This inkjet head 1B corresponds to one specific example of the "liquid jet head" in this disclosure.

[0084] (Effects / Actions) In this modified configuration 2, the same effect can be obtained through essentially the same mechanism as in modified configuration 1.

[0085] Furthermore, in this modified example 2, the delay circuit 511 is individually placed between some of the preceding and succeeding signal generation circuits in the multiple signal generation circuits 521 to 524 (between signal generation circuits 521 and 522 in the example in Figure 11), as follows: That is, the signal generation circuits can be grouped together as described above, between the preceding and succeeding signal generation circuits with respect to the delay circuit 511 (between signal generation circuits 521 and 523 and signal generation circuits 522 and 524 in the example in Figure 11). This makes it possible to broaden the variations in delay amounts with a simple circuit configuration, and as a result, further improvements in convenience can be achieved.

[0086] Regarding the number of delay circuits, there may be multiple (for example, two) as long as they are part of the circuitry between the preceding and succeeding stages described above. Also, the arrangement between the delay circuits and each signal generation circuit 521 to 524 may be in other configurations.

[0087] [Difference 3] (composition) Figure 12 schematically shows a block diagram of an example configuration of the signal generation unit 42C and other components in the liquid jet head (inkjet head 1C) according to Modification 3.

[0088] As shown in Figure 12, the inkjet head 1C of this modified example 3 corresponds to the inkjet head 1A of modified example 1 (see Figure 8) in which the signal generation unit 42C is provided instead of the signal generation unit 42A, and the other configurations are basically the same. Furthermore, the signal generation unit 42C of this modified example 3 corresponds to the signal generation unit 42A of modified example 1 in which three pairs of delay circuits 511a, 511b, 512a, 512b, 513a, and 513b are provided instead of the three delay circuits 511 to 513, and the other configurations are basically the same.

[0089] In other words, unlike the signal generation unit 42A, the signal generation unit 42B has multiple delay circuits connected in multiple stages between the preceding and succeeding circuits of the multiple signal generation circuits 521 to 524. Specifically, in the example in Figure 12, two (two-stage) delay circuits 511a and 511b are connected in multiple stages between the signal generation circuits 521 and 522, two (two-stage) delay circuits 512a and 512b are connected in multiple stages between the signal generation circuits 522 and 523, and two (two-stage) delay circuits 513a and 513b are connected in multiple stages between the signal generation circuits 523 and 524.

[0090] This inkjet head 1C corresponds to one specific example of the "liquid jet head" in this disclosure.

[0091] (Effects / Actions) In this modified configuration 3, the same effect can be obtained through essentially the same mechanism as in modified configuration 1.

[0092] In particular, in this Modification 3, at least a part (in the example of FIG. 12, between all the circuits) between the circuits on the front stage side and the circuits on the rear stage side in the plurality of signal generation circuits 521 to 524, as described above, delay circuits are connected in multiple stages (in the example of FIG. 12, two-stage connection), so the following is achieved. That is, according to the number of stages of the delay circuits connected in multiple stages, the delay amount for the signal generation circuits 522 to 524 on the rear stage side can be adjusted. As a result, the adjustment of the delay amount can be performed with a simple circuit configuration, and thus, it is possible to further improve convenience.

[0093] In the example of FIG. 12, delay circuits are connected in multiple stages between all the circuits on the front stage side and the rear stage side as described above, but this is not limited to this example. For example, delay circuits may be connected in multiple stages in a part between the circuits on the front stage side and the rear stage side as described above. Also, the number of stages of such delay circuits is not limited to the two-stage example shown in FIG. 12, and for example, a multi-stage connection of three or more stages may be used.

[0094] [Modification 4] (Configuration) FIG. 13 shows an operation example of delay amount adjustment in a liquid ejection head (inkjet head) according to Modification 4 in a timing chart. Specifically, in FIGS. 13(A1) to 13(E1), the waveforms of the ejection timing signal St, the delay signal St2, and the drive signals Sd1 and Sd2 when the frequency of the basic clock signal SCLK described above is set to fs1 (see reference symbol P1 in FIG. 13) are shown respectively. On the other hand, in FIGS. 13(A2) to 13(E2), the waveforms of the ejection timing signal St, the delay signal St2, and the drive signals Sd1 and Sd2 when the frequency of the basic clock signal SCLK is set to fs2 (<f1) (see reference symbol P2 in FIG. 13) are shown respectively. In this FIG. 13, the horizontal axis represents time t.

[0095] In this modified example 4, the inkjet head is configured to allow arbitrary adjustment of the delay amount (delay amount by each of the aforementioned delay circuits: delay time) relative to the ejection timing signal St by changing the frequency of the basic clock signal SCLK (in the signal generation unit).

[0096] Specifically, in the example in Figure 13, the frequency of the basic clock signal SCLK is changed (towards a lower frequency) from fs1 (in the cases of Figures 13(A1) to 13(E1)) to fs2 (in the cases of Figures 13(A2) to 13(E2)), resulting in the following: First, when the frequency of the basic clock signal SCLK is fs1, the period of this basic clock signal SCLK is Ts1 (=1 / fs1). On the other hand, when the frequency of the basic clock signal SCLK is fs2, the period of this basic clock signal SCLK is Ts2 (=1 / fs1) (see symbols P1 and P2 in Figure 13). In other words, as the frequency of the basic clock signal SCLK is changed to a lower frequency from fs1 to fs2, the period of the basic clock signal SCLK is changed to a longer period from Ts1 to Ts2 (>Ts1). Consequently, as shown by the dashed arrow in Figure 13, for example, the delay amount (delay amount due to each delay circuit) relative to the discharge timing signal St will also increase from delay amount (delay time) Δd1 to delay amount Δd2 (>Δd1). Specifically, for example, if the frequency of the basic clock signal SCLK is halved (1 / 2 times), the delay amount (delay time) will double.

[0097] Furthermore, this modified example 4 of the inkjet head corresponds to one specific example of the "liquid jet head" in this disclosure.

[0098] (Effects / Actions) In this modified example 4, the delay amount relative to the discharge timing signal St can be arbitrarily adjusted by changing the frequency of the basic clock signal SCLK. As a result, various delay amounts can be set according to the adjustment of the basic clock signal SCLK frequency. Consequently, this modified example 4 offers even greater convenience.

[0099] <3. Other variations> Although this disclosure has been described above with reference to several embodiments and modifications, this disclosure is not limited to these embodiments, and various modifications are possible.

[0100] For example, in the above embodiments, specific configuration examples (shape, arrangement, connection method, type, number, etc.) of each component (drive circuit, nozzle group, various signal lines, etc.) in the printer and inkjet head were described. However, these configuration examples are not limited to those described in the above embodiments, and other shapes, arrangements, connection methods, types, numbers, etc., may also be used.

[0101] Specifically, for example, the configuration of the I / F board and the drive board is not limited to those described in the above embodiments, and other configurations are also possible. Also, although the above embodiments described an example in which one drive board is provided, for example, two or more drive boards may be provided. Furthermore, although the above embodiments described a case in which the I / F board as a relay board is provided inside the inkjet head, it is not limited to this case, and for example, such a relay board (I / F board) may not be provided inside the inkjet head. In addition, although the above embodiments mainly described an example in which the delay circuit is configured to include a flip-flop circuit (F / F circuit), it is not limited to this example, and for example, the delay circuit may be configured using other circuit configurations. Furthermore, although the above embodiments described an example in which all signal generation circuits arranged in the signal generation unit are connected in multiple stages by a single signal line (of image data Dp), it is not limited to this example. In other words, for example, some signal generation circuits (e.g., signal generation circuits 521, 522) may be connected in multiple stages using a single signal line, while other signal generation circuits (e.g., signal generation circuits 523, 524) may be connected in multiple stages using a different signal line.

[0102] Furthermore, in the above embodiments, the example of performing timing adjustment on a nozzle group basis by performing delay adjustment on a nozzle group basis with respect to a predetermined drive waveform was described, but the example is not limited to this case. That is, for example, timing adjustment on a nozzle group basis may be performed using methods other than delay adjustment.

[0103] Furthermore, various types of inkjet head structures can be applied. For example, a so-called side-chute type inkjet head may be used, which ejects ink 9 from the center of the extending direction of each ejection channel in the actuator plate 111. Alternatively, a so-called edge-chute type inkjet head may be used, which ejects ink 9 along the extending direction of each ejection channel. Moreover, the printer system is not limited to the systems described in the above embodiments, and various systems such as MEMS (Micro Electro Mechanical Systems) can be applied.

[0104] Furthermore, this disclosure can be applied to either a circulating inkjet head, which circulates the ink 9 between the ink tank and the inkjet head, or a non-circulating inkjet head, which does not circulate the ink 9.

[0105] Furthermore, the series of processes described in the above embodiments may be performed by hardware (circuits) or by software (programs). If performed by software, the software consists of a group of programs that cause the computer to execute each function. Each program may, for example, be pre-installed in the computer or installed on the computer from a network or recording medium.

[0106] Furthermore, while the above embodiments described a printer (inkjet printer) as a specific example of the "liquid jet recording device" in this disclosure, the invention is not limited to this example, and the disclosure can be applied to other devices besides inkjet printers. In other words, the "liquid jet head" (inkjet head) of this disclosure may be applied to other devices besides inkjet printers. Specifically, for example, the "liquid jet head" of this disclosure may be applied to devices such as facsimile machines and on-demand printing machines.

[0107] In addition, the various examples described so far may be applied in any combination.

[0108] Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also occur.

[0109] Furthermore, this disclosure can also take the following form. (1) A circuit that outputs a drive signal for use with a liquid injection head having multiple nozzles, The system includes a signal generation unit that generates the drive signal for ejecting liquid from the nozzle based on image data defining the drive waveform, The signal generation unit has a waveform storage unit that stores a plurality of the drive waveforms, The aforementioned multiple nozzles are distinguished into multiple nozzle groups, The signal generation unit, Based on the image data, a predetermined drive waveform selected from a plurality of drive waveforms is adjusted for timing on a nozzle group basis, The drive signals are generated on a per-nozzle-group basis so that the liquid is discharged at different discharge timings for each of the nozzle groups. Drive circuit. (2) The signal generation unit, The system includes one or more delay circuits that perform timing adjustment by delaying the discharge timing signal that defines the discharge timing on a nozzle group basis. The drive circuit described in (1) above. (3) The signal generation unit has a plurality of signal generation circuits that generate the drive signals for each nozzle group based on the image data and the discharge timing signal. The delay circuit outputs a delay signal for the discharge timing signal individually for each of the multiple signal generation circuits. The drive circuit described in (2) above. (4) The signal generation unit generates the drive signal for each nozzle group based on the image data and the discharge timing signal, and has a plurality of signal generation circuits, at least a portion of which are connected in multiple stages. In the plurality of signal generation circuits, at least a portion of the circuitry between the preceding and succeeding stages is arranged one or more delay circuits that output a delayed signal for the discharge timing signal to the succeeding stage. The drive circuit described in (2) above. (5) The multiple delay circuits are individually positioned between all of the preceding and succeeding signal generation circuits. The drive circuit described in (4) above. (6) The one or more delay circuits are individually arranged in a portion of the space between the preceding and succeeding circuits in the plurality of signal generation circuits. The drive circuit described in (4) above. (7) In at least a portion of the preceding and succeeding circuits in the plurality of signal generation circuits, the delay circuit is connected in multiple stages. The drive circuit described in any of (4) to (6) above. (8) By changing the frequency of the basic clock signal in the signal generation unit, the delay amount for the discharge timing signal can be arbitrarily adjusted. The drive circuit described in any of (2) through (7) above. (9) The aforementioned delay circuit is configured to include a flip-flop circuit (F / F circuit). The drive circuit described in any of (2) through (8) above. (10) A drive circuit as described in any of (1) to (9) above, A spray unit having a plurality of nozzles that sprays the liquid based on the drive signal output from the drive circuit, A liquid spray head equipped with a liquid spray head. (11) Equipped with the liquid spray head described in (10) above Liquid injection recording device. [Explanation of Symbols]

[0110] 1,1A~1C...Inkjet head, 11...Jet unit, 111...Actuator plate, 112...Nozzle plate, 12...I / F board, 13...Drive board, 2...Print control unit, 4...Drive circuit, 41...Waveform storage unit, 42,42A~42C...Signal generation unit, 5...Printer, 51,511~513,511a,511b,512a,512b,513a,513b...Delay circuit, 521~524...Signal generation circuit, 61~63...F / F circuit, 9... Ink, P...recording paper, Hn...nozzle hole, Sc...print control signal, Sd, Sd1~Sdn...drive signals, Vd...drive voltage, G1~G4...nozzle group, Dp...image data, Rw...waveform register, Wd...drive waveform, SCLK...basic clock signal, St...ejection timing signal, St1~St4...delay signals, A1, A(G1), A(G2)...area, t...time, Ts1, Ts2...period, fs1, fs2...frequency, Δd1, Δd2...delay amount (delay time).

Claims

1. A circuit that outputs a drive signal for use with a liquid injection head having multiple nozzles, The system includes a signal generation unit that generates the drive signal for ejecting liquid from the nozzle based on image data defining the drive waveform, The signal generation unit has a waveform storage unit that stores a plurality of the drive waveforms, The aforementioned multiple nozzles are distinguished into multiple nozzle groups, The signal generation unit, Based on the image data, a predetermined drive waveform selected from a plurality of drive waveforms is adjusted for timing on a nozzle group basis, The drive signal is generated for each nozzle group so that the liquid is discharged at different discharge timings for each nozzle group. The signal generation unit, One or more delay circuits perform the timing adjustment by delaying the discharge timing signal that defines the discharge timing on a nozzle group basis, Based on the image data and the discharge timing signal, the drive signal for each nozzle group is generated, and at least a portion of the signal generation circuit is connected in multiple stages. It has, In the aforementioned plurality of signal generation circuits, one or more delay circuits are individually arranged between the preceding and succeeding circuits to output a delayed signal for the discharge timing signal to the succeeding circuit. Drive circuit.

2. A circuit that outputs a drive signal for application to a liquid spray head having a plurality of nozzles, The system includes a signal generation unit that generates the drive signal for ejecting liquid from the nozzle based on image data defining the drive waveform, The signal generation unit has a waveform storage unit that stores a plurality of the drive waveforms, The aforementioned multiple nozzles are distinguished into multiple nozzle groups, The signal generation unit, Based on the image data, a predetermined drive waveform selected from a plurality of drive waveforms is adjusted for timing on a nozzle group basis, The drive signal is generated for each nozzle group so that the liquid is discharged at different discharge timings for each nozzle group. The signal generation unit, One or more delay circuits perform the timing adjustment by delaying the discharge timing signal that defines the discharge timing on a nozzle group basis, Based on the image data and the discharge timing signal, the drive signal for each nozzle group is generated, and at least a portion of the signal generation circuit is connected in multiple stages. It has, In at least a portion of the preceding and succeeding circuits in the plurality of signal generation circuits, one or more delay circuits are arranged in a multi-stage connection, each delaying a delayed signal for the discharge timing signal to the succeeding circuit. Drive circuit.

3. The multiple delay circuits are individually positioned between all of the preceding and succeeding signal generation circuits. The drive circuit according to claim 2.

4. The one or more delay circuits are individually arranged in a portion of the space between the preceding and succeeding circuits in the plurality of signal generation circuits. The drive circuit according to claim 2.

5. By changing the frequency of the basic clock signal in the signal generation unit, the delay amount for the discharge timing signal can be arbitrarily adjusted. The drive circuit according to any one of claims 1 to 4.

6. The aforementioned delay circuit is configured to include a flip-flop circuit (F / F circuit). The drive circuit according to any one of claims 1 to 5.

7. A drive circuit according to any one of claims 1 to 6, A spray unit having a plurality of nozzles that sprays the liquid based on the drive signal output from the drive circuit, A liquid spray head equipped with a liquid spray head.

8. The liquid spray head is provided as described in claim 7. Liquid injection recording device.

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