Liquid injection head and liquid injection recording device

Abstract

To provide liquid spray heads and the like that can reduce costs while improving convenience. [Solution] A liquid spray head according to one embodiment of the present disclosure comprises a spray unit having a plurality of nozzles and a plurality of pressure chambers individually communicating with the plurality of nozzles, and one or more drive circuits that generate drive signals for spraying liquid from the nozzles based on image data defining a drive waveform and an additional signal. In at least one of the one or more drive circuits, drive signals having a plurality of types of drive waveforms defined by the additional signal are each generated based on the same image data and output to the spray unit.

Description

Technical Field

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

Background Art

[0002] Liquid ejection recording apparatuses provided 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, it is required to reduce costs and improve convenience. It is desirable to provide a liquid ejection head and a liquid ejection recording apparatus capable of improving convenience while reducing costs.

Means for Solving the Problems

[0005] A liquid ejection head according to an embodiment of the present disclosure includes an ejection unit having a plurality of nozzles and a plurality of pressure chambers individually communicating with the plurality of nozzles, and one or more drive circuits that generate drive signals for ejecting liquid from the nozzles based on image data defining a drive waveform and an additional signal. In at least one of the one or more drive circuits, drive signals having a plurality of types of drive waveforms defined by the additional signal are each generated based on the same image data and configured to be output to the ejection unit.

[0006] 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]

[0007] According to one embodiment of the liquid injection head and liquid injection recording device of this disclosure, it is possible to reduce costs while improving convenience. [Brief explanation of the drawing]

[0008] [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 block diagram showing a detailed configuration example of the drive board. [Figure 3] Figure 2 is a block diagram showing a detailed configuration example of the drive circuit. [Figure 4] Figure 3 shows a detailed example of the configuration of the additional signal. [Figure 5] Figures 1 to 3 are schematic diagrams illustrating examples of the configurations of various drive waveforms and the like stored in the waveform storage unit. [Figure 6] This is a schematic diagram showing an example of the configuration of each drive waveform, etc., stored in the waveform storage unit of the comparative example. [Figure 7] This is a schematic diagram illustrating an example of the correspondence between printed images, the number of drops, and image data related to a comparative example. [Figure 8] This is a schematic diagram illustrating an example of the correspondence between printed images, the number of drops, and image data related to the embodiment. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described in detail below with reference to the drawings. The description will be in the following order. 1. Embodiment (Example of generating drive signals for multiple types of drive waveforms from the same image data) 2. Variations

[0010] <1. Embodiment> [Schematic Configuration of Printer 5] FIG. 1 shows, in a block diagram, a schematic configuration example of a printer 5 as a liquid ejection recording apparatus according to an embodiment of the present disclosure. 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.

[0011] 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.

[0012] Note that the inkjet head 1 corresponds to a specific example of the "liquid ejection head" in the present disclosure, and the printer 5 corresponds to a specific example of the "liquid ejection recording apparatus" in the present disclosure. Also, the ink 9 corresponds to a specific example of the "liquid" in the present disclosure.

[0013] (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. 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 41 described later).

[0014] Note that this print control signal Sc includes, for example, image data Dp described later, a discharge timing signal, a power supply voltage (drive power supply) for operating the inkjet head 1, and the like.

[0015] (B. Inkjet Head 1) As shown by the dashed arrows in FIG. 1, the inkjet head 1 is a head that ejects (discharges) droplet-like ink 9 onto the recording paper P from a plurality of nozzle holes Hn described later to perform recording of images, characters, etc.

[0016] As shown in FIG. 1, this inkjet head 1 includes one ejection unit 11, one I / F (interface) substrate 12, and one drive substrate 13.

[0017] (B-1. Ejection unit 11) As shown in FIG. 1, the ejection unit 11 has a plurality of nozzle holes Hn, and is a part for ejecting the ink 9 from these nozzle holes Hn. Such ejection of the ink 9 is performed based on a drive signal Sd (drive voltage Vd) output from a drive circuit 41, which will be described later, on the drive substrate 13 (see FIG. 1).

[0018] As shown in FIG. 1, such an ejection unit 11 is configured to include an actuator plate 111 and a nozzle plate 112. The supply of the ink 9 to this ejection unit 11 (actuator plate 111) is performed, for example, from an ink tank (not shown in FIG. 1) in the inkjet head 1 through an ink supply tube.

[0019] (Nozzle plate 112) The nozzle plate 112 is a plate made of a film material such as polyimide or a metal material, and has the plurality of nozzle holes Hn as described above. These nozzle holes Hn are formed side by side at a predetermined interval and are, for example, circular in shape. Each of such a plurality of nozzle holes Hn corresponds to a specific example of the "nozzle" in the present disclosure.

[0020] (Actuator plate 111) The actuator plate 111 is a plate made of a piezoelectric material such as PZT (lead zirconate titanate). A plurality of channels C (pressure chambers) are provided in the actuator plate 111. These channels C are parts for applying pressure to the ink 9, and are arranged side by side so as to be parallel to each other at a predetermined interval. Each channel C is defined by a drive wall (not shown) made of a piezoelectric body and has a concave groove portion in a cross-sectional view.

[0021] Such a channel C contains 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 41, which will be described later, via a drive substrate 13. As a result, the drive voltage Vd (drive signal Sd) described above is applied to each drive electrode from the drive circuit 41 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 41, etc.) via the I / F board 12.

[0024] (B-3. Drive board 13) Figure 2 is a block diagram showing a detailed configuration example of the drive board 13 shown in Figure 1.

[0025] As shown in Figures 1 and 2, the drive board 13 is a board that electrically connects the I / F board 12 and the injection unit 11, and outputs the aforementioned drive signal Sd (and the drive signals Sda and Sdb described later) from the drive circuit 41, thereby individually controlling the ink injection operation of the nozzle plate 112. As shown in Figure 2, this drive board 13 comprises one drive circuit board 131 and two flexible wiring boards 132a and 132b.

[0026] The drive circuit board 131 has terminal sections T1, T2a, and T2b, and a drive circuit section 4 which includes one or more drive circuits 41 (in the example in Figure 2, five drive circuits 411 to 415). Terminal section T1 includes a terminal to which the aforementioned printing control signal Sc is input. Terminal section T2a is a terminal to which the drive signal Sda, as a drive signal Sd, is input from each drive circuit 411 to 413 toward the flexible wiring board 132a. On the other hand, terminal section T2b is a terminal to which the drive signal Sdb, as a drive signal Sd, is input from each drive circuit 413 to 415 toward the flexible wiring board 132b.

[0027] The drive circuits 41 (411-415) are circuits that generate and output the drive signals Sd (drive voltage Vd) described above for ejecting ink 9 from each nozzle hole Hn in the ejection unit 11. Each drive circuit 411-415 includes a waveform storage unit 51, which will be described later (see Figures 1 and 2). In the example shown in Figure 2, these multiple drive circuits 411-415 are cascaded together via a common group of signal lines (a group of signal lines such as image data Dp).

[0028] As shown in Figure 2, each of the drive circuits 411 to 413 generates the aforementioned drive signal Sda (drive voltage Vda as drive voltage Vd) and supplies it to the injection unit 11 via terminal T2a and flexible wiring board 132a. On the other hand, each of the drive circuits 413 to 415 generates the aforementioned drive signal Sdb (drive voltage Vdb as drive voltage Vd) and supplies it to the injection unit 11 via terminal T2b and flexible wiring board 132b. In other words, drive circuit 413 in particular supplies both drive signals Sda and Sdb (drive voltages Vda and Vdb) to the injection unit 11.

[0029] Here, as shown in Figure 2, in this embodiment, the aforementioned multiple nozzle holes Hn are distinguished (grouped) into multiple nozzle groups (in this example, two nozzle groups Hna and Hnb). Similarly, the aforementioned multiple channels C are distinguished into multiple channel groups (in this example, two channel groups Ca and Cb). In the example in Figure 2, the nozzle group Ga and channel group Ca are shown as group Ga, and the nozzle group Gb and channel group Cb are shown as group Gb. The above-mentioned drive signal Sda (drive voltage Vda) is supplied to group Ga, and the above-mentioned drive signal Sdb (drive voltage Vdb) is supplied to group Gb. An example of such nozzle groups Hna and Hnb is a row of nozzles extending along a predetermined direction within the nozzle plate 112, and an example of channel groups Ca and Cb is a row of channels arranged in the actuator plate 111 corresponding to each row of nozzles. However, this example is not limited to this, and nozzle groups and channel groups may be set using other grouping methods.

[0030] [Detailed configuration of the drive circuit 41] Next, with reference to Figures 1, 2, and Figures 3 to 5, a detailed example of the drive circuit 41 in the inkjet head 1 will be described.

[0031] Figure 3 is a block diagram showing a detailed configuration example of the drive circuit 41 (particularly the drive circuit 413 described above) shown in Figure 2. Figure 4 shows a detailed configuration example of the additional signal Sa described later, shown in Figure 3. Figure 5 schematically shows an example of the configuration of each drive waveform Wd etc. stored in the waveform storage unit 51 shown in Figures 1 to 3. Specifically, Figure 5 shows an example of the correspondence between each drive waveform Wd stored in the waveform storage unit 41, the additional signal Sa described later, image data Dp, waveform register Rw, and drop count. Figure 5(A) shows an example of the correspondence between drive waveform Wda etc. used as drive waveform Wd when generating the drive signal Sda described above, and Figure 5(B) shows an example of the correspondence between drive waveform Wdb etc. used as drive waveform Wd when generating the drive signal Sdb described above.

[0032] As shown in Figure 3, the drive circuit 413 generates the aforementioned drive signals Sda and Sdb (drive voltages Vda and Vdb) based on image data Dp that defines the drive waveform Wd and an additional signal Sa, which will be described later. This drive circuit 413 includes a waveform storage unit 51 for storing multiple types of drive waveforms Wd, which will be described later, a waveform selection unit 52, and a signal generation unit 53.

[0033] (Waveform storage unit 51) In the waveform storage unit 51, as shown in Figures 5(A) and 5(B), for example, multiple types of drive waveforms Wd (Wda, Wdb) associated with image data Dp are stored in a predetermined area within the waveform register Rw.

[0034] Specifically, the drive waveform Wda used when creating the drive signal Sda shown in Figure 5(A) is as follows: That is, the drive waveform Wda=Wd0 in the case of "no output" corresponding to the image data Dp with pixel value "0b0000" is stored in the area of ​​waveform register Rw="wave0". Similarly, the drive waveform Wda=Wda1 in the case of "1 drop" corresponding to the image data Dp with pixel value "0b0001" is stored in the area of ​​waveform register Rw="wave1". The drive waveform Wda=Wda2 in the case of "2 drops" corresponding to the image data Dp with pixel value "0b0010" is stored in the area of ​​waveform register Rw="wave2". The drive waveform Wda=Wda3 in the case of "3 drops" corresponding to the image data Dp with pixel value "0b0011" is stored in the area of ​​waveform register Rw="wave3".

[0035] On the other hand, the drive waveform Wdb used when creating the drive signal Sdb, as shown in Figure 5(B), is as follows: Specifically, the drive waveform Wdb=Wd0 in the "non-eject" case, corresponding to the image data Dp with pixel value "0b0000", is stored in the waveform register Rw="wave0" area. Similarly, the drive waveform Wdb=Wdb1 in the "1 drop" case, corresponding to the image data Dp with pixel value "0b0001", is stored in the waveform register Rw="wave1" area. The drive waveform Wdb=Wdb2 in the "2 drop" case, corresponding to the image data Dp with pixel value "0b0010", is stored in the waveform register Rw="wave2" area. The drive waveform Wdb=Wdb3 in the "3 drop" case, corresponding to the image data Dp with pixel value "0b0011", is stored in the waveform register Rw="wave3" area.

[0036] Here, the drive waveforms Wda=Wd0,Wda1,Wda2,Wda3 for generating the drive signal Sda are defined by the image data Dp="0b0000", "0b0001", "0b0010", and "0b0011", respectively, when the additional signal Sa="0b00" is set (see Figure 5(A)). On the other hand, the drive waveforms Wdb=Wd0,Wdb1,Wdb2,Wdb3 for generating the drive signal Sdb are defined by the image data Dp="0b0000", "0b0001", "0b0010", and "0b0011", respectively, when the additional signal Sa="0b01" is set (see Figure 5(B)).

[0037] Furthermore, in the multiple types of drive waveforms Wda and Wdb defined by the additional signal Sa, the amplitude values ​​are different from each other in the examples shown in Figures 5(A) and 5(B). Specifically, the amplitude value Aa for drive waveforms Wda=Wda1, Wda2, Wda3 defined by the additional signal Sa="0b00" and the amplitude value Ab for drive waveforms Wdb=Wdb1, Wdb2, Wdb3 defined by the additional signal Sa="0b01" are different from each other (amplitude value Aa > amplitude value Ab). Note that the waveform widths W may also be different from each other in the multiple types of drive waveforms Wda and Wdb defined by the additional signal Sa.

[0038] (Waveform selection unit 52) As shown in Figure 3, the waveform selection unit 52 selects a drive waveform Wd from multiple types of drive waveforms Wd stored in the waveform storage unit 51 based on the image data Dp and the additional signal Sa described above. Specifically, the waveform selection unit 52 can select different types of drive waveforms Wd based on the same image data Dp by using the additional signal Sa, for example, as shown in Figures 5(A) and 5(B) described above.

[0039] In other words, based on the same image data Dp = "0b0001", if the additional signal Sa = "0b00", the above-described drive waveform Wda1 is selected, and if the additional signal Sa = "0b01", the above-described drive waveform Wdb1 is selected. Similarly, based on the same image data Dp = "0b0010", if the additional signal Sa = "0b00", the above-described drive waveform Wda2 is selected, and if the additional signal Sa = "0b01", the above-described drive waveform Wdb2 is selected. Also, based on the same image data Dp = "0b0011", if the additional signal Sa = "0b00", the above-described drive waveform Wda3 is selected, and if the additional signal Sa = "0b01", the above-described drive waveform Wdb3 is selected.

[0040] (Signal generation unit 53) As shown in Figure 3, the signal generation unit 53 generates a drive signal Sd based on the drive waveform Wd selected by the waveform selection unit 52. Specifically, when the drive waveform Wda (= Wd0, Wda1, Wda2, Wda3) is selected by the waveform selection unit 52, the signal generation unit 53 generates a drive signal Sda (drive voltage Vda) based on that drive waveform Wda. Also, when the drive waveform Wdb (= Wd0, Wdb1, Wdb2, Wdb3) is selected by the waveform selection unit 52, the signal generation unit 53 generates a drive signal Sdb (drive voltage Vdb) based on that drive waveform Wdb. The drive signals Sda and Sdb, each having multiple types of drive waveform Wd, are output separately for each of the aforementioned Ga and Gb groups (each of the channel groups Ca and Cb, and each of the nozzle groups Hna and Hnb) (see Figure 2).

[0041] In this embodiment, at least one of the drive circuits 41 (411 to 415), specifically drive circuit 413 (in the example shown in Figures 2 and 3), is configured as follows. Specifically, in this drive circuit 413, drive signals Sda and Sdb, each having multiple types of drive waveforms Wda and Wdb defined by the additional signal Sa, are generated based on the same image data Dp and output to the injection unit 11.

[0042] Furthermore, this additional signal Sa is set, for example, as shown in Example 1 or Example 2 in Figure 4. In other words, in Example 1, the additional signal Sa is pre-set for each channel C (for example, for each of the aforementioned groups Ga and Gb). On the other hand, in Example 2, the additional signal Sa is input along with the image data Dp as needed when data is transferred from outside the inkjet head 1 (print control unit 2).

[0043] [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.

[0044] First, the drive circuits 41 (411-415) on the drive board 13 apply 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 circuits 41 apply 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] (B. Operation of generating the drive signal Sd) Next, the signal generation operation (generation operation of the drive signal Sd) in the drive circuit 41 of this embodiment will be described in detail, in comparison with the comparative example.

[0049] First, in conventional inkjet heads, when a drive waveform is applied to the actuator, current flows during charging and discharging of the actuator, and most of this is lost as heat. Therefore, for example, when performing high-speed printing, it is desirable to reduce power consumption in order to reduce heat generation. One way to reduce power consumption is to lower the drive voltage. The power consumption of a capacitive load is calculated using the capacitance (C) and drive voltage (V), where (C × V) 2 Therefore, by reducing the drive voltage, power consumption decreases and heat generation can be suppressed.

[0050] However, simply lowering the drive voltage reduces the actuator's driving force. Therefore, one method involves using multiple types of power supplies to gradually increase the drive voltage. For example, if an intermediate potential (e.g., 5V if the upper limit is 10V) is set between the positive and negative drive power supplies, the power consumption is halved (1 / 2) when the voltage is increased stepwise (0V → 5V → 10V) compared to increasing it by 10V all at once. Furthermore, transitioning the drive waveform stepwise can improve print quality. In this way, when there is one or fewer positive and negative drive power supplies, the drive waveform can be determined by specifying only the waveform width as information about the drive waveform. However, as described above, when there are two or more positive and negative drive power supplies, it becomes necessary to specify not only the waveform width but also the amplitude value (potential) as information about the drive waveform, which complicates the drive waveform data.

[0051] On the other hand, actuators require changes in the drive voltage due to variations in piezoelectric element materials and manufacturing processes. For example, when stacking different actuator rows, the drive voltage differs for each row, requiring the drive voltage to be set for each row, thus requiring different drive waveform data to be set for each row. Also, when driving a long actuator, for example, multiple drive circuits (driver ICs) are implemented to drive the actuator. Therefore, the number of piezoelectric elements (number of nozzles) that can be driven by a drive circuit is determined by the number of drive circuits.

[0052] Furthermore, various actuator designs exist, but for example, in actuators using PZT (lead zirconate titanate), it is sometimes possible to cut and use wafers that serve as actuators from a bulk material. In this case, the actuator size in the nozzle row direction is determined by the original bulk size. While it is possible to change the bulk size for each product, this reduces the number of wafers needed for each size, increasing costs. Therefore, it is desirable to use the same bulk material for multiple products. Consequently, the maximum number of nozzles that can be formed per row is determined by the actuator wafer size and resolution. However, if this is not an integer multiple of the number of channels in the drive circuit, either the drive circuit channels or the nozzles will be left over. Since the price of an inkjet head is sometimes compared on a per-nozzle basis, having leftover drive circuit channels or nozzles increases the unit price, resulting in an unfavorable comparison.

[0053] Therefore, one method to solve these problems is to share (divide) the output of the drive circuit among multiple nozzle groups (nozzle rows, etc.), as in this embodiment. Specifically, for example, if the number of piezoelectric elements that can be formed on one row of actuators is equivalent to 2.5 in the drive circuit, then five drive circuits are placed on one substrate, and one of these drive circuits is used half each for two rows. In this way, the actuators can be used efficiently together with the drive circuits, making it possible to reduce the cost per nozzle.

[0054] However, in the above case, in order to ensure print quality, it is necessary to adjust the drive voltage for each actuator row, for example, due to manufacturing variations as shown above. If we consider the two actuator rows as row A and row B, and the drive waveform data includes amplitude value (potential) information, then it is necessary to set drive waveform data for the two actuator rows that have the same waveform width but different amplitude values.

[0055] Therefore, as shown in the comparative example below, even if the number of drops is the same, the printer needs to set different image data for columns A and B. Normally, the print image would only need to be processed for each number of drops, but as described above, if the drive waveform data differs for columns A and B, image processing becomes necessary, making the process complicated.

[0056] (B-1. Comparative example) Here, Figure 6 schematically represents an example of the configuration of each drive waveform Wd, etc., stored in the waveform storage unit of the comparative example. Specifically, Figure 6 shows an example of the correspondence between each drive waveform Wd (Wda, Wdb) stored in the waveform storage unit of the comparative example, image data Dp, waveform register Rw, and drop count. Furthermore, Figure 7 schematically represents an example of the correspondence between the printed image (Figure 7(A)), drop count (drop count: Figure 7(B)), and image data Dp (Figure 7(C)) of this comparative example.

[0057] In the comparative example shown in Figure 6, unlike the embodiment described above (see Figure 5), the drive waveform Wd is selected from multiple types of drive waveforms Wd (Wda, Wdb) based only on the image data Dp, and both the aforementioned drive signals Sda and Sdb are generated.

[0058] Specifically, in the comparative example shown in Figure 6, the drive waveform Wda used when creating the drive signal Sda has the following relationship, similar to the embodiment shown in Figure 5(A). That is, the drive waveform Wda=Wd0 in the "non-eject" case, corresponding to the image data Dp with pixel value "0b0000", is stored in the area of ​​waveform register Rw="wave0". Similarly, the drive waveform Wda=Wda1 in the "1 drop" case, corresponding to the image data Dp with pixel value "0b0001", is stored in the area of ​​waveform register Rw="wave1". The drive waveform Wda=Wda2 in the "2 drop" case, corresponding to the image data Dp with pixel value "0b0010", is stored in the area of ​​waveform register Rw="wave2". The drive waveform Wda=Wda3 in the "3 drop" case, corresponding to the image data Dp with pixel value "0b0011", is stored in the area of ​​waveform register Rw="wave3".

[0059] On the other hand, in the comparative example shown in Figure 6, the relationship for the drive waveform Wdb used when creating the drive signal Sdb is different from that of the embodiment shown in Figure 5(B), as follows: Specifically, the drive waveform Wdb=Wdb1 in the case of "1 drop" corresponding to the image data Dp of pixel value "0b0100" is stored in the area of ​​waveform register Rw="wave4". The drive waveform Wdb=Wdb2 in the case of "2 drops" corresponding to the image data Dp of pixel value "0b0101" is stored in the area of ​​waveform register Rw="wave5". The drive waveform Wdb=Wdb3 in the case of "3 drops" corresponding to the image data Dp of pixel value "0b0110" is stored in the area of ​​waveform register Rw="wave6".

[0060] In this comparative example, as in this embodiment, if the drive waveform Wda is selected, the drive signal Sda (drive voltage Vda) is generated based on that drive waveform Wda. On the other hand, if the drive waveform Wdb is selected, the drive signal Sdb (drive voltage Vdb) is generated based on that drive waveform Wdb.

[0061] With this configuration, when printing an image in the comparative example inkjet head in the two regions A(Ga) and A(Gb) corresponding to the aforementioned groups Ga and Gb, as shown in Figure 7(A), the following occurs. That is, as shown by the dashed arrow in Figure 7(B), for example, even if the number of drops is the same for pixels in region A(Gb) as for pixels in region A(Ga), it becomes necessary to make the image data value Dp (pixel value) different.

[0062] Thus, in this comparative example, since it is necessary to define different image data Dp for each of the multiple types of drive waveforms Wd (Wda, Wdb), the drive circuit that outputs drive signals Sd (Sda, Sdb) with multiple types of drive waveforms Wd becomes complex in configuration. As a result, it can be said that it is difficult to improve convenience while reducing costs in this comparative example.

[0063] (B-2. Embodiment) In contrast, the inkjet head 1 of this embodiment generates drive signals Sda and Sdb on a group Ga,Gb (channel group Ca,Cb, nozzle group Hna,Hnb) basis, as described below (see Figures 3 to 5). That is, in this embodiment, as described above, at least one drive circuit 41 (drive circuit 413) generates drive signals Sda and Sdb, each having multiple types of drive waveforms Wda and Wdb defined by the additional signal Sa, based on the same image data Dp.

[0064] Figure 8 schematically illustrates an example of the correspondence between the printed image (Figure 8(A)), the number of drops (number of drops: Figure 8(B)), and the image data Dp (Figure 8(C)) in the embodiments of this embodiment (Embodiments 1 and 2).

[0065] In the embodiment shown in Figure 8, unlike the comparative example shown in Figure 7, when printing a print image in two regions A(Ga) and A(Gb) corresponding to groups Ga and Gb, as shown in Figure 8(A), the following occurs. That is, by using the additional signal Sa mentioned above, as shown in Figures 8(B) and 8(C), if the number of drops is the same, the same image data value Dp (pixel value) can be applied to two different regions A(Ga) and A(Gb).

[0066] (B-3. Action / Effect) In this embodiment, at least one drive circuit 41 is configured to generate drive signals Sd having multiple types of drive waveforms Wd defined by the additional signal Sa, each based on the same image data Dp, and output to the injection unit 11. This eliminates the need to define different image data Dp for each of the multiple types of drive waveforms Wd, unlike the comparative example above, and allows drive signals Sd having multiple types of drive waveforms Wd to be output from at least one drive circuit 41 with a simple configuration. Furthermore, it becomes easier to appropriately set the relationship between the number of drive circuits 41 and the number of nozzle holes Hn, so in this embodiment, it is possible to improve convenience while reducing costs compared to the comparative example above.

[0067] Furthermore, in this embodiment, if the additional signal Sa is pre-set for each channel C (Example 1), it becomes possible to output drive signals Sd having multiple types of drive waveforms Wd with a simpler configuration. As a result, further cost reduction becomes possible.

[0068] Furthermore, in this embodiment, if the additional signal Sa is input from outside the inkjet head 1 along with the image data Dp as needed (Embodiment 2), the output settings of the drive signal Sd, which has multiple types of drive waveforms Wd, can be changed as needed (in a timely manner). As a result, convenience can be further improved.

[0069] <2. Variant> Although this disclosure has been described above with reference to several embodiments and examples, this disclosure is not limited to these embodiments, and various modifications are possible.

[0070] For example, in the above embodiments, specific configuration examples (shape, arrangement, connection method, type, number, etc.) of each component (drive circuit, group, channel group, 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.

[0071] Specifically, for example, the configuration of the I / F board and 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 an 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 described specific examples of the correspondence between various drive waveforms and image data, waveform registers, drop counts, and additional signals, these correspondences are not limited to the examples given in the above embodiments. Furthermore, although the above embodiments described an example in which multiple drive circuits are cascaded to each other via a common group of signal lines, it is not limited to this example.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] In addition, the various examples described so far may be applied in any combination.

[0077] Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also occur.

[0078] Furthermore, this disclosure can also take the following form. (1) An injection unit having multiple nozzles and multiple pressure chambers that communicate individually with the multiple nozzles, One or more drive circuits generate a drive signal for ejecting liquid from the nozzle based on image data defining a drive waveform and additional signals. Equipped with, In at least one of the one or more drive circuits, The drive signals, each having one of the multiple drive waveforms defined by the aforementioned additional signal, are each generated based on the same image data and output to the injection unit. Liquid spray head. (2) The aforementioned drive circuit is A waveform storage unit for storing multiple types of the aforementioned drive waveforms, A waveform selection unit selects the drive waveform based on the image data and the additional signal, A signal generation unit generates the drive signal based on the drive waveform selected by the waveform selection unit. It has, The waveform selection unit is capable of selecting different types of drive waveforms based on the same image data by using the additional signal. The liquid spray head described in (1) above. (3) The aforementioned additional signals are set in advance for each pressure chamber. The liquid spray head described in (1) or (2) above. (4) The aforementioned additional signal is input from outside the liquid injection head, along with the image data, as needed. The liquid spray head described in (1) or (2) above. (5) In the multiple types of drive waveforms defined by the aforementioned additional signal, the amplitude values ​​or waveform widths are different from each other. A liquid spray head as described in any of (1) through (4) above. (6) The aforementioned multiple nozzles are distinguished into multiple nozzle groups, The drive signals, each having one of the multiple drive waveforms, are configured to be output for each of the nozzle groups. A liquid spray head as described in any of (1) through (5) above. (7) Multiple drive circuits are provided, Multiple of the aforementioned drive circuits are cascaded to each other via a common set of signal lines. A liquid spray head as described in any of (1) through (6) above. (8) Equipped with a liquid spray head as described in any of (1) to (7) above Liquid injection recording device. [Explanation of symbols]

[0079] 1...Inkjet head, 11...Jet unit, 111...Actuator plate, 112...Nozzle plate, 12...I / F board, 13...Drive board, 131...Drive circuit board, 132a,132b...Flexible wiring board, 2...Print control unit, 4...Drive circuit unit, 41,411~415...Drive circuit, 5...Printer, 51...Waveform storage unit, 52...Waveform selection unit, 53...Signal generation unit, 9...Ink, P...Recording paper, C...Channel (pressure chamber), Ca,Cb... Channel group, Hn...nozzle hole, Hna, Hnb...nozzle group, Ga~Gb...group, Sc...print control signal, Sa...additional signal, Sd, Sda, Sdb...drive signal, Vd, Vda, Vdb...drive voltage, Dp...image data, Rw...waveform register, Wd, Wd0, Wda, Wda1~Wda3, Wdb, Wdb1~Wdb3...drive waveform, Aa, Ab...amplitude value, W...waveform width, A(Ga), A(Gb)...region, T1, T2a, T2b...terminal section.

Claims

1. An injection unit having multiple nozzles and multiple pressure chambers that communicate individually with the multiple nozzles, One or more drive circuits generate a drive signal for ejecting liquid from the nozzle based on image data defining a drive waveform and additional signals. Equipped with, In at least one of the one or more drive circuits, The drive signals, each having one of the multiple drive waveforms defined by the aforementioned additional signal, are each generated based on the same image data and output to the injection unit. Liquid spray head.

2. The aforementioned drive circuit is A waveform storage unit for storing multiple types of the aforementioned drive waveforms, A waveform selection unit selects the drive waveform based on the image data and the additional signal, A signal generation unit generates the drive signal based on the drive waveform selected by the waveform selection unit. It has, The waveform selection unit is capable of selecting different types of drive waveforms based on the same image data by using the additional signal. The liquid spray head according to claim 1.

3. The aforementioned additional signals are set in advance for each pressure chamber. A liquid spray head according to claim 1 or claim 2.

4. The aforementioned additional signal is input from outside the liquid injection head, along with the image data, as needed. A liquid spray head according to claim 1 or claim 2.

5. In the multiple types of drive waveforms defined by the aforementioned additional signal, the amplitude values ​​or waveform widths are different from each other. A liquid spray head according to claim 1 or claim 2.

6. The aforementioned multiple nozzles are distinguished into multiple nozzle groups, The drive signals, each having one of the multiple drive waveforms, are configured to be output for each of the nozzle groups. A liquid spray head according to claim 1 or claim 2.

7. Multiple drive circuits are provided, Multiple of the aforementioned drive circuits are cascaded to each other via a common set of signal lines. A liquid spray head according to claim 1 or claim 2.

8. The liquid injection head is provided according to claim 1 or claim 2. Liquid injection recording device.

Images