Liquid discharge head, liquid discharge recording apparatus, control method of liquid discharge head, control method of liquid discharge recording apparatus

Abstract

A liquid ejection head (4) includes a plurality of nozzles, a plurality of actuators corresponding to the plurality of nozzles, and a drive control section (51) that inputs a drive voltage to the actuators to drive the actuators, thereby enabling liquid to be ejected from the plurality of nozzles. The drive control section outputs, as the drive voltage, a first drive waveform that uses a potential difference between a first voltage and a second voltage different from the first voltage to cause liquid to be ejected, and a second drive waveform that uses a potential difference between the first voltage and a third voltage different from the first voltage and the second voltage to cause liquid to be ejected.

Description

Technical Field

[0001] This disclosure relates to a liquid ejector head, a liquid ejection recording device, a control method for the liquid ejector head, and a control method for the liquid ejection recording device. Background Technology

[0002] Liquid ejection recording devices such as inkjet printers include a liquid ejection head that ejects ink for image formation toward a recording medium. For example, the liquid ejection head includes a piezoelectric element such as a pressure-sensitive element, a liquid pressure chamber, and a liquid ejection orifice. The liquid ejection head pressurizes the liquid filling the liquid pressure chamber by displacing the piezoelectric element, and ejects it from the liquid ejection orifice. Known piezoelectric elements are those that displace in response to a drive signal representing a pulse-like voltage change.

[0003] Previously, techniques were known for ejecting various droplets, such as large, medium, and small droplets, based on voltage changes in the aforementioned drive signal, in order to form various images on a recording medium, corresponding to the pixel size of the image. In these conventional techniques, a portion of a drive waveform, consisting of a shape formed by interconnecting voltage changes corresponding to various ejection amounts, is extracted in relation to the desired ejection amount, and a drive voltage is input to the corresponding piezoelectric element. Summary of the Invention

[0004] The liquid ejector head of the first aspect of this disclosure includes: a plurality of nozzles; a plurality of actuators corresponding to the plurality of nozzles; and a drive control unit that inputs a drive voltage to the actuators to drive the actuators, thereby enabling liquid to be ejected from the plurality of nozzles. The drive control unit outputs, as the drive voltage, a first drive waveform that ejects liquid by utilizing a potential difference between a first voltage and a second voltage that is different from the first voltage, and a second drive waveform that ejects liquid by utilizing a potential difference between the first voltage and a third voltage that is different from both the first voltage and the second voltage.

[0005] The liquid ejection recording apparatus of the second aspect of this disclosure includes: a liquid ejection head having a plurality of nozzles and a plurality of actuators corresponding to the plurality of nozzles, and capable of ejecting liquid; a media support portion supporting a recording medium in a manner opposite to the liquid ejection head; and a drive control portion inputting a drive voltage to the actuators to drive the actuators, thereby enabling droplets to be ejected from the plurality of nozzles, wherein the drive control portion outputs, as the drive voltage, a first drive waveform that ejects liquid using a potential difference between a first voltage and a second voltage different from the first voltage, and a second drive waveform that ejects liquid using a potential difference between the first voltage and a third voltage different from both the first voltage and the second voltage.

[0006] The third aspect of this disclosure discloses a method for controlling a liquid ejector head, the liquid ejector head having a plurality of nozzles and a plurality of actuators corresponding to the plurality of nozzles, wherein the method for controlling the liquid ejector head includes: preparing a first drive waveform for ejecting liquid using a potential difference between a first voltage and a second voltage different from the first voltage, and a second drive waveform for ejecting liquid using a potential difference between the first voltage and a third voltage different from both the first voltage and the second voltage; and inputting the first drive waveform or the second drive waveform to the actuator to drive the actuator according to a desired volume of liquid ejected from the nozzles, thereby causing liquid to be ejected from the plurality of nozzles.

[0007] The fourth aspect of this disclosure discloses a control method for a liquid ejection recording apparatus, the liquid ejection recording apparatus comprising: a liquid ejection head having a plurality of nozzles and a plurality of actuators corresponding to the plurality of nozzles; and a media support portion supporting a recording medium opposite to the liquid ejection head, wherein the control method of the liquid ejection recording apparatus comprises: preparing a first drive waveform for ejecting liquid using a potential difference between a first voltage and a second voltage different from the first voltage, and a second drive waveform for ejecting liquid using a potential difference between the first voltage and a third voltage different from both the first voltage and the second voltage; and inputting the first drive waveform or the second drive waveform to the actuator to drive the actuator according to a desired volume of liquid ejected from the nozzles, thereby causing liquid to eject from the plurality of nozzles. Attached Figure Description

[0008] Figure 1 This is a perspective view showing the overall structure of an image forming apparatus according to an embodiment of the present disclosure.

[0009] Figure 2 yes Figure 1 A schematic cross-sectional view of line II-II.

[0010] Figure 3 This is a block diagram illustrating the electrical structure of an image forming apparatus according to an embodiment of the present disclosure.

[0011] Figure 4A It is a diagram used to illustrate the principle of liquid ejection based on a liquid ejection head.

[0012] Figure 4B It is a diagram used to illustrate the principle of liquid ejection based on a liquid ejection head.

[0013] Figure 4C It is a diagram used to illustrate the principle of liquid ejection based on a liquid ejection head.

[0014] Figure 5 This is a diagram showing the basic driving voltage applied to the piezoelectric element of the liquid ejector head.

[0015] Figure 6A It is a diagram showing the driving voltage applied to the piezoelectric element of the liquid nozzle, and it corresponds to large droplets, medium droplets, and small droplets.

[0016] Figure 6B It is a diagram showing the driving voltage applied to the piezoelectric element of the liquid nozzle, and it corresponds to large droplets, medium droplets, and small droplets.

[0017] Figure 6C It is a diagram showing the driving voltage applied to the piezoelectric element of the liquid nozzle, and it corresponds to large droplets, medium droplets, and small droplets.

[0018] Figure 7A It is a diagram showing the driving voltage applied to the piezoelectric element of the liquid nozzle, and a diagram showing the driving voltage selected corresponding to large droplets, medium droplets, and small droplets.

[0019] Figure 7B It is a diagram showing the driving voltage applied to the piezoelectric element of the liquid nozzle, and a diagram showing the driving voltage selected corresponding to large droplets, medium droplets, and small droplets.

[0020] Figure 8A This is a schematic diagram showing the ejection state of a droplet corresponding to the driving voltage.

[0021] Figure 8B This is a schematic diagram showing the ejection state of a droplet corresponding to the driving voltage.

[0022] Figure 9 This is a schematic diagram of a dual-liquid head that can spray two liquids from a single nozzle. Detailed Implementation

[0023] Hereinafter, a liquid ejector head, a liquid ejector recording apparatus, and a control method thereof according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. In the following embodiments, an inkjet printer equipped with an inkjet head that ejects ink for image formation onto a wide and elongated recording medium will be illustrated as a specific example of the liquid ejector recording apparatus. Inkjet printers are suitable for digital printing of text and images such as patterns onto recording media made of fabrics such as textiles and woven fabrics using inkjet printing. Of course, the liquid ejector recording apparatus of the present disclosure can also be used for printing various images onto recording media such as paper and resin sheets.

[0024] Figure 1 This is a perspective view showing the overall structure of the inkjet printer 1 according to this embodiment. Figure 2 yes Figure 1A schematic cross-sectional view along line II-II. The inkjet printer 1 is a printer that prints images onto a wide and elongated workpiece W (recording medium) using inkjet technology, and includes a device frame 10, a workpiece transport section 20 (transport section), and a carriage 3 assembled on the device frame 10. It should be noted that in this embodiment, the left-right direction is the main scanning direction for printing on the workpiece W, and the direction from rear to front is the secondary scanning direction (the direction intersecting the main scanning direction is the transport direction of the workpiece W).

[0025] The device frame 10 forms a skeleton for mounting the various components of the inkjet printer 1. The workpiece transport unit 20 is a mechanism that intermittently transports (transfers) the workpiece W in the printing area where inkjet printing is performed, in a transport direction from rear to front. In addition to the inkjet head 4, the carriage 3 also carries the pretreatment liquid head, posttreatment liquid head, and auxiliary tank 7 (described later), and reciprocates along the main scanning direction (left-right direction) during the inkjet printing process.

[0026] The device frame 10 includes a central frame 111, a right frame 112, and a left frame 113. The central frame 111 forms the skeleton for mounting various components of the inkjet printer 1 and has a left-right width corresponding to the workpiece transport section 20. The right frame 112 and the left frame 113 are respectively erected to the right and left of the central frame 111. Between the right frame 112 and the left frame 113 is the printing area 12 for performing printing processing on the workpiece W.

[0027] The right frame 112 forms a maintenance area 13. Maintenance area 13 is the area where the carriage 3 retracts when the printing process is not being performed. In maintenance area 13, cleaning and purging processes are performed on the inkjet head 4, the pre-treatment liquid head (described later), and the nozzles (ejection holes) of the post-treatment liquid head. Additionally, the cover is fitted. The left frame 113 forms a retraction area 14 for the carriage 3. Retraction area 14 is the area where the carriage 3, which has performed a main scan of the printing area 12 from right to left during the printing process, temporarily enters when performing a main scan in the opposite direction.

[0028] A carriage guide 15 for reciprocating movement of the carriage 3 in the left-right direction is assembled on the upper side of the device frame 10. The carriage guide 15 is a flat plate-shaped component that is longer in the left-right direction and is disposed above the workpiece transport section 20. A timing belt 16 is assembled to the carriage guide 15 in a manner that allows it to move around in the left-right direction (main scanning direction). The timing belt 16 is an annular belt that is driven to move around in the left or right direction.

[0029] A pair of upper and lower guide rails 17 are provided on the carriage guide 15, extending parallel to the left and right directions, to hold the carriage 3 in a state where it can reciprocate in the main scanning direction. The carriage 3 engages with the guide rails 17. In addition, the carriage 3 is fixed to the timing belt 16. While being guided by the guide rails 17 as the timing belt 16 moves around in the left or right direction, the carriage 3 moves to the left or right along the carriage guide 15.

[0030] Main reference Figure 2 The workpiece conveying unit 20 includes an annular belt 20H, a drive roller 21, and a driven roller 22. The drive roller 21 and the driven roller 22 tension the annular belt 20H. When the drive roller 21 rotates, the annular belt 20H wraps around in the direction of arrow H1, conveying the workpiece W by passing under the carriage 3.

[0031] With the carriage 3 cantilevered and supported on the guide rail 17, it reciprocates along the main scanning direction (or left-right direction in this embodiment) which is perpendicular to the transport direction (or orthogonal in this embodiment). The carriage 3 includes a carriage frame 30, and an inkjet head 4, a pre-treatment fluid head 5, a post-treatment fluid head 6, and a secondary tank 7 mounted on the carriage frame 30. The carriage frame 30 includes a head support frame 31 and a backrest frame 32.

[0032] The head support frame 31 is a horizontal plate that maintains the heads 4 to 6 as described above. The backrest frame 32 is a vertical plate extending upward from the rear end edge of the head support frame 31. The rear end of the head support frame 31 is cantilevered and supported by the backrest frame 32. As described above, the timing belt 16 is fixed to the backrest frame 32. In addition, the guide rail 17 engages with the backrest frame 32.

[0033] It should be noted that the cantilever state means that the guide rail 17 that holds the carriage 3 in the transport direction exists only on one side of the upstream or downstream side from the center of the carriage 3, and the opposite side of the side where the guide rail 17 exists is not held.

[0034] Each inkjet head 4 has multiple nozzles (ink ejection orifices) that eject ink droplets using methods such as pressure-sensitive methods using pressure-sensitive elements or thermal methods using heating elements, and ink passages that guide ink to these nozzles. As the ink, for example, an aqueous pigment ink containing a water-based solvent, pigment, and binder resin can be used. In this embodiment, the multiple inkjet heads 4 can each eject different inks. Each head is mounted on a head support frame 31 of the carriage 3.

[0035] The rows and columns of heads formed by the inkjet head 4 and each processing liquid head along the main scanning direction are called columns of heads, or simply columns. Conversely, the rows and columns of heads formed by the inkjet head 4 and each processing liquid head along the transport direction F are called rows of heads, or simply rows.

[0036] The ink ejected by the inkjet head 4 is not particularly limited, and inks utilizing pigments and dyes can be used. For example, inks containing pigments and water-based media can be used. The ink may also, as needed, contain at least one selected from the group consisting of surfactants, polyols, and binder resin particles. Examples of pigments include yellow, orange, red, blue, purple, and black pigments. The ink may also contain anionic pigments. In that case, the cationic polymer and anionic pigment contained in the post-processing liquid react and aggregate on the surface of the recording object, thus inhibiting the penetration of the binder resin (adhesive resin) contained in the ink into the recording medium. This reduces the penetration of the binder resin into the gaps between fibers and prevents the fibers from bonding together when the recording medium is fabric. Therefore, the texture (feel, etc.) of the fabric being printed can be improved.

[0037] As anionic pigments, specifically, anionic pigments having anionic groups such as carboxyl, sulfonic acid, phosphoric acid, phosphonic acid, benzenesulfonic acid, and phenylcarboxyl groups are preferred. The aqueous medium contained in the ink is a medium with water as its main component. The aqueous medium can function as both a solvent and a dispersant. Specific examples of aqueous media include water or a mixture of water and a polar solvent. Examples of polar solvents contained in the aqueous medium include methanol, ethanol, isopropanol, butanol, and methyl ethyl ketone. Furthermore, the ink contains surfactants, thereby improving the wettability of the ink on the recording object.

[0038] The binder resin particles contained in the ink exist in a dispersed state in an aqueous medium. These binder resin particles function as a binder, binding the printed material to the pigment. Therefore, the ink contains binder resin particles, resulting in printed products with excellent pigment fixing properties. Examples of resins contained in the binder resin particles include urethane resin, (meth)acrylic resin, styrene-(meth)acrylic resin, styrene-maleic anhydride copolymer, vinylnaphthalene-(meth)acrylic acid copolymer, and vinylnaphthalene-maleic anhydride copolymer. Uramel resin is preferred as the resin contained in the binder resin particles.

[0039] The content of binder resin relative to the total weight of the ink can be either 1% by weight or more and 20% by weight or less, or 2% by weight or more and 10% by weight or less. When the content of binder resin particles is 1% by weight or more, a recording object with excellent pigment fixing can be obtained. On the other hand, when the content of binder resin particles is 20% by weight or less, ink can be stably ejected onto the recording object.

[0040] Processing heads 5 and 6 eject pretreatment fluid for performing prescribed pretreatment on workpiece W. The pretreatment fluid is ejected from the processing heads towards the position of workpiece W before ink is ejected from inkjet head 4. Additionally, processing heads eject posttreatment fluid for performing prescribed posttreatment on workpiece W that has been coated with ink. The posttreatment fluid is ejected from the processing heads towards the position of workpiece W after ink has been ejected from inkjet head 4.

[0041] Any pretreatment solution can be used. For example, a pretreatment solution that causes the ink pigments to aggregate, thereby improving color development and fixing properties, can be used. In addition, a pretreatment solution can also inhibit ink penetration into the recording medium, or conversely promote penetration, or print thicker to create a three-dimensional shape, or impart gloss, etc.

[0042] The pretreatment solution may contain, for example, a water-soluble cationic polymer, organic acid salts, and an aqueous medium. Under the action of this pretreatment solution, the pigments in the ink used for subsequent printing can react and aggregate, improving color development. Furthermore, wash fastness is improved, and the fabric texture is also enhanced. The content of the water-soluble cationic polymer relative to the total pretreatment solution can be 0.1% by weight or more and less than 10% by weight. Setting the content of the water-soluble cationic polymer to less than 10% by weight ensures sufficient wet rubbing fastness. The same aqueous medium as the ink can be used in the aqueous medium contained in the pretreatment solution.

[0043] Any post-processing solution can be used. For example, a post-processing solution that improves texture, as described later, can be used. The post-processing solution can also be used for coatings to protect printed ink, for creating a three-dimensional shape by printing thicker layers, or for imparting gloss. In addition, it can also be used for treatments that are not directly related to ink printing, such as imparting water repellency to the recording medium.

[0044] The post-treatment solution may contain, for example, emulsified particles of silicone oil, surfactants, and an aqueous medium. That is, the post-treatment solution is an emulsion in which emulsified particles are dispersed in an aqueous medium, more specifically, an oil-droplet (O / W) type emulsion in water. The silicone oil may also contain non-modified silicone oil. Examples of non-modified silicone oils include dimethylpolysiloxane, methylphenyl silicone oil, and methyl hydrogen silicone oil. Such a post-treatment solution can improve the texture.

[0045] As a surfactant, the surfactant may contain a first surfactant comprising an alkyl group having 12 to 14 carbon atoms, and a second surfactant comprising an alkyl group having 16 to 18 carbon atoms. Polyoxyethylene alkyl ethers may also be used.

[0046] The post-treatment solution contains an aqueous medium that can be used with the same aqueous medium as ink. The post-treatment solution is essentially a non-color-developing treatment solution that does not show color even when adhered to the workpiece W. It should be noted that the post-treatment solution is fundamentally different from the pre-treatment solution. Specifically, the components contained in the post-treatment solution and the pre-treatment solution are different.

[0047] The processing solutions are essentially non-color-developing solutions that do not show color even when adhered to the workpiece W. Here, "non-color-developing processing solution" means a solution that, when printed alone onto a recording medium, cannot be perceived as color-developing by the naked eye. This includes colors with a chroma of 0, such as black, white, and gray. Non-color-developing processing solutions are essentially transparent liquids; however, if one liter of the solution is observed as a liquid, it is not completely transparent, and sometimes a slight white tint may be visible. Such colors are very faint, and therefore, when printed alone onto a recording medium, they cannot be perceived as color-developing by the naked eye. It should be noted that, depending on the type of processing solution, when printed alone onto a recording medium, there may sometimes be changes such as gloss on the recording medium, but this is not considered color development.

[0048] In this embodiment, the pretreatment liquid and posttreatment liquid can be sprayed onto almost the entire surface of the workpiece W, and the pretreatment liquid and posttreatment liquid can also be selectively sprayed in accordance with the printed image, just like ink.

[0049] Here, the case of selectively spraying pretreatment and posttreatment solutions will be explained. As described above, the pretreatment solution, ink, and posttreatment solution are sprayed onto the workpiece W, the area to which the image is printed in color, in the order of pretreatment solution, ink, and posttreatment solution. In this case, the ink is one color or multiple colors. In the areas where no color is printed, i.e., the areas where no ink is sprayed, the pretreatment and posttreatment solutions are also basically not sprayed. It should be noted that, in order to adjust the image quality of the printed image, the texture of the workpiece W, etc., the selection of the spraying of the pretreatment and posttreatment solutions may differ from that of the ink. For example, the pretreatment and posttreatment solutions may be printed onto an area slightly larger than the area printed by the ink (e.g., a few pixels).

[0050] An opening is provided at the head mounting location of the head support frame 31. The inkjet head 4 and the liquid processing head are assembled to the head support frame 31 by being inserted into each opening. The nozzles located on the lower end face of each head protrude from each opening.

[0051] The auxiliary tank 7 is supported on the carriage 3 above each head via a concealed retaining frame. Each auxiliary tank 7 is correspondingly positioned to each head. Ink or processing fluid (sometimes referred to collectively as liquid) is supplied to each auxiliary tank 7 from a concealed container or main tank containing ink and processing fluid, and then supplied to each head. Each auxiliary tank 7 is connected to each head via concealed piping.

[0052] Each auxiliary tank 7 may also have a supply auxiliary tank and a recovery auxiliary tank. The supply auxiliary tank supplies liquid to the corresponding head. The recovery auxiliary tank recovers liquid that was not ejected from the corresponding head. The supply and recovery of liquid are performed, for example, by applying pressure to the liquid via gas (air) present above the liquid contained in the supply and recovery auxiliary tanks. The supply and recovery of liquid are performed using the pressure difference between the pressure applied to the supply auxiliary tank and the pressure applied to the recovery auxiliary tank. The applied pressure is controlled so that the pressure in the nozzle of each head is approximately 0 (zero, the same as atmospheric pressure) or slightly negative or positive. As a result, the nozzle can maintain a meniscus state and can maintain a state in which liquid can be ejected.

[0053] The transfer of liquid between the supply auxiliary tank, the recovery auxiliary tank, and the main tank can also be performed as follows: If the liquid level in the supply auxiliary tank decreases below a specified amount, the liquid in the recovery auxiliary tank is transferred to the supply auxiliary tank via a pump or the like. This allows the liquid to circulate among the supply auxiliary tank, the head tank, and the recovery auxiliary tank. If the liquid level in the recovery auxiliary tank decreases below a specified amount, the liquid in the main tank is supplied to the recovery auxiliary tank via a pump or the like.

[0054] If a liquid adjusted to a constant temperature is supplied to the head, the head's temperature can be stabilized. The liquid supplied to the head reaches a separate flow path equipped with nozzles via a common flow path (manifold) located within the head. Liquid recovery from the head may either not recover the liquid supplied to the separate flow path, or it may recover only the liquid that passed through the common flow path. Alternatively, liquid supply and recovery may be performed on the separate flow path equipped with nozzles, making it difficult for liquid to stagnate within and around the nozzles. In this case, the liquid recovered from the separate flow path may be recovered, for example, through the common flow path.

[0055] As described above, the inkjet printer 1 of this embodiment is an all-in-one printer in which the inkjet head 4, the processing liquid head 5, and 6 are mounted on a carriage 3. According to this inkjet printer 1, for example in the inkjet printing process of fabric in digital printing, the pretreatment liquid ejection process and the posttreatment liquid ejection process can be performed simultaneously. Therefore, the printing process can be simplified, and the printing apparatus can be made more compact.

[0056] Next, the printing method performed by the inkjet printer 1 of this embodiment will be described. The inkjet printer 1 prints the workpiece W in a serial printing manner. When the workpiece W has a wide size, it is not possible to print while continuously transporting the workpiece W. The serial printing method is a printing method that repeatedly moves the carriage 3 equipped with inkjet heads 4 of each color back and forth in the main scanning direction and intermittently transports the workpiece W in the transport direction.

[0057] The workpiece W, after printing using inkjet printer 1, can also be heated and dried by a heater (not shown) provided in inkjet printer 1. Alternatively, the printed portion of workpiece W can be transported to a dryer different from inkjet printer 1 instead of being wound onto a winding roller (not shown), and dried using that dryer. The heating temperature is, for example, 120°C or higher and 180°C or lower. The heating time is, for example, 1 minute or more and 10 minutes or less. Under heating, the volatile components contained in the ink and processing liquid dry, and the fixation of the ink and processing liquid to the workpiece W is promoted.

[0058] It should be noted that, in the above description, the pretreatment liquid is exemplified as one that primarily causes ink to condense on the workpiece W. However, the pretreatment liquid can also be a pretreatment liquid containing more resin components than ink and possessing the property of adhering the fabric to the pigment. In this case, the possibility of the pretreatment liquid clogging the ink nozzle or adhering to the nozzle surface becomes even higher, so a configuration of the head and nozzle area as described above is desirable.

[0059] It should be noted that the distances between the heads, the distances between the nozzle areas, and the distances between the heads and the nozzle areas are, for example, distances along the main scanning direction, and are the distances between the closest parts of each. In addition, the distance between the centroids of the areas occupied by each head in a top-down view along the main scanning direction can also be considered.

[0060] It should be noted that, unless otherwise specified, the spacing between adjacent heads in the main scanning direction (the spacing between the nearest portions of each head or the spacing between the centers of each head) is the same. Similarly, regarding the multi-column head configuration described later, the spacing between adjacent heads in the transport direction F (the spacing between the centers of each head) is the same.

[0061] [Liquid ejection principle based on liquid ejection head]

[0062] Next, the principle of liquid ejection based on the liquid ejection head will be explained. Figure 3 This is a block diagram illustrating the electrical structure of a liquid ejector head according to one embodiment of the present disclosure. Figure 4A , Figure 4B , Figure 4C It is a diagram used to illustrate the principle of liquid ejection based on a liquid ejection head. Figure 5 This is a diagram showing the basic driving voltage applied to the piezoelectric element of the liquid ejector head. In the following description, the liquid ejector heads of the aforementioned inkjet head 4, pre-processing liquid head 5, and post-processing liquid head 6 are collectively referred to as head 50.

[0063] Reference Figure 3Figure 4 shows a head 50 with a driver IC (integrated circuit) 51 (drive control unit) and multiple nozzle sections 80. The multiple nozzle sections 80 disposed in one head 50 are arranged along the main scanning direction and the sub-scanning direction. It should be noted that each figure in Figure 4 is an enlarged cross-sectional view of one nozzle section 80. Each nozzle section 80 has an ejection element 81 (actuator), such as a pressure-sensitive element, a liquid pressurization chamber 82 filled with liquid supplied from the auxiliary tank 7 via a pipe (not shown), and a nozzle 83 for ejecting liquid from the liquid pressurization chamber 82. The ejection element 81 is respectively disposed corresponding to the multiple nozzles 83, and is driven (displaced) by receiving a drive voltage input, causing liquid to be ejected from the corresponding nozzle 83. In this embodiment, the ejection element 81 is composed of a piezoelectric element. It should be noted that in... Figure 3 In the example map, three ejection elements 81 are shown.

[0064] The driver IC 51 generates a drive voltage corresponding to the image formed on the workpiece W, which is used to adjust the volume (size) of the liquid (ink, processing liquid) ejected from each ejection element 81, the ejection timing, etc., and inputs it to the ejection element 81. Specifically, the driver IC 51 has a head control unit 52 and a plurality of drive signal generation units 53 respectively provided corresponding to each ejection element 81. The driver IC 51 drives the ejection element 81 by inputting a drive voltage to the ejection element 81, thereby enabling liquid to be ejected from the plurality of nozzles 83.

[0065] The head control unit 52 determines the drive waveform of the drive voltage to be input to each ejection element 81 in accordance with the information of the image formed on the workpiece W, and inputs the information to the corresponding drive signal generation unit 53. In other words, the head control unit 52 has the function of controlling which drive waveform is generated for each ejection element 81. It should be noted that the drive waveform will be described in detail later.

[0066] The drive signal generation unit 53, in accordance with the drive waveform information (instructions) received from the head control unit 52, inputs a drive waveform (drive signal) to the corresponding ejection element 81. This drive waveform is generated once per ejection element 81 for each ejection. It should be noted that multiple droplets may be ejected in a single ejection. A single ejection essentially corresponds to one pixel of an image formed on the recording medium. In this embodiment, the driver IC 51, including the head control unit 52 and the multiple ejection elements 81, is constructed as a single substrate.

[0067] The drive signal of the first 50 is, for example, Figure 5 As shown, it is a pulse-shaped rectangular wave (drive waveform) that varies periodically with a specified ejection cycle (ejection interval). The amplitude of the drive signal of head 50 represents the voltage applied to the ejection element 81.

[0068] As an example, if the drive starts based on the first 50 of the drive signal, then the voltage "VH" applied to the ejection element 81 at the end of the previous ejection cycle is as follows: Figure 5 As shown in region (A), the force continues to be applied to the ejection element 81. Thus, as... Figure 4A As shown, the deformed state of the ejection element 81 is maintained for a certain period of time. Under this condition, the liquid inside the head 50, the pressure of the liquid inside the head 50, and the external atmospheric pressure correspondingly form a liquid meniscus in the nozzle 83.

[0069] Next, in Figure 5 During the period shown in region (B), the amplitude of the drive signal becomes VL (=0), and the application of voltage to the ejection element 81 stops (is cut off). Thus, as... Figure 4B As shown, the deformed state of the ejector element 81 is released, and the ejector element 81 begins to be parallel to the upper surface of the liquid pressurization chamber 82. As a result, the liquid in the liquid pressurization chamber 82 is depressurized, and a portion of the liquid in the nozzle 83 is introduced into the liquid pressurization chamber 82.

[0070] Moreover, in Figure 5 During the period shown in region (C), the voltage “VH” is applied again to the ejection element 81. Thus, as... Figure 4C As shown, the ejection element 81 deforms, and the liquid in the liquid pressurization chamber 82 is pressurized, resulting in the liquid in the liquid pressurization chamber 82 being ejected from the nozzle 83.

[0071] It should be noted that the ejection cycle varies depending on the printhead's drive frequency. For example, the following cycle can be illustrated.

[0072] Drive frequency 30kHz = 1sec / 30000 times = drive cycle (ejection cycle) 33.3μsec

[0073] Drive frequency 5kHz = 1sec / 5000 times = drive cycle (ejection cycle) 200μsec

[0074] Furthermore, based on the determined ejection conditions (e.g., the amount of liquid ejected), the on-time, off-time, and number of on / off cycles of the drive signal can be adjusted within the ejection cycle (waveform adjustment).

[0075] In this embodiment, the system is in standby mode with a voltage "VH" applied before liquid ejection. A voltage "VL," lower than "VH," is applied to increase the volume of the liquid pressurization chamber 82. Then, a voltage "VH" is applied again to decrease the volume of the liquid pressurization chamber 82 (returning to standby mode). This relationship can also be reversed. That is, the voltage "VL" can be higher than the voltage "VH." In this case, a component whose volume increases with the voltage applied to the ejection element 81 is used.

[0076] Furthermore, in this embodiment, corresponding to the image formed on the workpiece W, the volume (amount) of the liquid ejected from each ejection element 81 is adjusted in three levels. In the following description, these levels, starting with the larger volume, are referred to as large droplets, medium droplets, and small droplets. It should be noted that these are also referred to as large dots, medium dots, and small dots. Figure 6A , Figure 6B , Figure 6C This is a diagram showing the driving voltage applied to the piezoelectric element of the liquid ejector head, and it corresponds to large, medium, and small droplets. These driving waveforms are different from each other and are delivered to the ejector element 81 within the range between ejection cycles.

[0077] like Figure 6A In this case, with two downward-convex pulses between the maximum and minimum values ​​of the driving voltage, two droplets can be ejected from the ejection element 81. The two droplets can also merge into one droplet (large droplet) during flight by making the later-ejected droplet faster. The two droplets can also land separately on the recording medium. In this case, the two droplets can expand and merge on the recording medium to form a pixel, or they can form a pixel separately on the recording medium. Alternatively, a single droplet (large droplet) can be ejected. Similarly, as... Figure 6B In this way, when there is a downward-convex pulse between the maximum and minimum values ​​of the driving voltage, a medium droplet can be ejected from the ejection element 81. In other words, the large droplet is ejected approximately as if two medium drops were ejected consecutively. Furthermore, as... Figure 6C In this way, when there is a short, downward-convex pulse between the maximum and minimum values ​​of the driving voltage, small droplets can be ejected from the ejection element 81. It should be noted that... Figures 6A to 6C In the entire process, the shorter pulse generated at the end of the drive waveform is used to remove the residual vibration generated by the ejection element 81.

[0078] Furthermore, in this embodiment, two drive waveforms are prepared in advance in the driver IC51. Figure 7A , Figure 7B It is a diagram showing the driving voltage applied to the piezoelectric element of the liquid nozzle, and also a diagram showing the driving waveform that can be selected to correspond to large droplets, medium droplets, and small droplets.

[0079] Figure 7A This is a driving waveform that uses the potential difference between the maximum and minimum values ​​of the driving voltage (VH and VL) to cause liquid to be ejected. The maximum value VH corresponds to the first voltage in this embodiment, and the minimum value VL corresponds to a second voltage different from the first voltage in this embodiment. Furthermore, [the following text is incomplete and requires further context: "will..."] Figure 7A The driving waveform that applies a voltage ranging from VL to VH, as shown, is called the first driving waveform. As an example, it can be set to VH = 26V and VL = 0V. That is, in the first driving waveform, the maximum potential difference of 26V is applied.

[0080] on the other hand, Figure 7B The liquid ejection is driven by the potential difference between the maximum and minimum values ​​of the driving voltage, VH and VM. The minimum value VM is larger than the aforementioned minimum value VL and smaller than the maximum value VH. The minimum value VM corresponds to the third voltage in this embodiment. This third voltage is different from the first and second voltages. Figure 7B The drive waveform that applies a voltage ranging from VM to VH, as shown, is called the second drive waveform. As an example, it can be set to VH = 26V and VL = 2V. That is, in the second drive waveform, the maximum potential difference is 24V.

[0081] It should be noted that the minimum value VM is not used in the first drive waveform. Similarly, the minimum value VL is not used in the second drive waveform. That is, the drive signal shifts between two voltages rather than three voltages in a single drive waveform. The first and second drive waveforms are obtained by shifting between two voltages and are different from each other.

[0082] In conventional techniques, a maximum and minimum value of the driving voltage is set corresponding to the large droplets that determine the maximum density of the image. Therefore, the waveforms of small and medium droplets are adjusted based on the set driving voltage. As a result, there is a problem that the adjustment range for the waveforms of small and medium droplets is relatively small.

[0083] On the other hand, in this embodiment, as described above, the driver IC51 outputs a first driving waveform that ejects liquid using a potential difference between a first voltage and a second voltage different from the first voltage, and a second driving waveform that ejects liquid using a potential difference between the first voltage and a third voltage different from both the first and second voltages. Therefore, compared to the case where multiple sizes of droplets are ejected using a single driving waveform, i.e., between a maximum and a minimum value, the adjustment amount for relatively small droplets can be suppressed. Consequently, the degree of freedom in adjusting the driving voltage for various droplets of different volumes can be improved.

[0084] At this time, the first voltage can also be a voltage that can be adjusted to change the volume of liquid ejected from the nozzle, and the third voltage is set to a fixed value. For example, when adjusting the concentration in the application of inkjet printer 1, the ejection volume of large droplets is sometimes made larger to ensure the maximum concentration. Therefore, assuming that large droplets are ejected using the first drive waveform and small droplets are ejected using the second drive waveform, by making the first voltage VH larger, the potential difference with the second voltage VL can be increased, thereby increasing the ejection volume of large droplets. On the other hand, according to the change of the first voltage VH, the potential difference of small droplets also increases, so the concentration increases from the low concentration region to the high concentration region, resulting in a uniform change in grayscale characteristics. Therefore, compared with the case where the concentration only increases in the high concentration region, the abrupt change in grayscale characteristics can be suppressed. It should be noted that the maximum concentration can also be adjusted using ejection volume other than that of large droplets. According to the above-described technique, for example, manufacturing deviations of the head can be corrected.

[0085] Furthermore, in the above-described case, by setting the third voltage VM to a fixed value that does not change, it is also possible to reduce secondary obstacles such as the influence of residual vibration.

[0086] Furthermore, even with two driving waveforms as described above, two potential differences can be prepared for the small droplet, thus expanding the width (degree of freedom) of the driving voltage for the small droplet, which is easier to adjust compared to the large droplet.

[0087] In addition, as mentioned above, the third voltage can be set to be greater than the second voltage and less than the first voltage.

[0088] It should be noted that, by Figure 3 The driver IC 51 shown in its entirety, and a portion thereof, may also be excluded from the head 50. They may be positioned either on the carriage 3 or on the outside of the carriage 3, on the side of the inkjet printer 1.

[0089] Furthermore, in the inkjet printer 1 of this embodiment described above, the following control method is executed. One method is a control method for a liquid ejection recording device, the liquid ejection recording device including: a liquid ejection head having a plurality of nozzles and a plurality of actuators corresponding to the plurality of nozzles; and a media support portion supporting a recording medium in a manner opposite to the liquid ejection head. The method includes: preparing a first drive waveform for ejecting liquid using a potential difference between a first voltage and a second voltage different from the first voltage, and a second drive waveform for ejecting liquid using a potential difference between the first voltage and a third voltage different from both the first voltage and the second voltage, as a drive voltage for the actuator; and inputting the first drive waveform or the second drive waveform to the actuator to drive the actuator according to the required volume of liquid ejected from the nozzles, so that liquid is ejected from the plurality of nozzles.

[0090] Another method is a control method for a liquid ejection head having multiple nozzles and multiple actuators corresponding to the multiple nozzles. This method includes: preparing a first drive waveform for ejecting liquid using a potential difference between a first voltage and a second voltage different from the first voltage, and a second drive waveform for ejecting liquid using a potential difference between the first voltage and a third voltage different from both the first and second voltages; and inputting either the first drive waveform or the second drive waveform to the actuator to drive the actuator according to a desired volume of liquid ejected from the nozzles, thereby causing liquid to eject from the multiple nozzles.

[0091] The features of the aforementioned inkjet printer 1 can form part of the methods described above.

[0092] In conventional technology, a driving waveform is generated in each spray cycle of a liquid nozzle (or for the spraying of one color in a multi-color liquid nozzle). Furthermore, this driving waveform is used commonly in all spraying elements within the liquid nozzle. A temporal portion of the driving waveform is supplied as a driving voltage to each spraying element. For example, a driving waveform is formed by sequentially connecting voltage-changing patterns A, B, and C. Furthermore, portions of patterns A and C in the driving waveform are supplied as the driving voltage for large droplets to the spraying element. A portion of pattern A in the driving waveform is supplied as the driving voltage for medium droplets to the spraying element. A portion of pattern B in the driving waveform is supplied as the driving voltage for small droplets to the spraying element. In this conventional technology, in order to accommodate a spray waveform comprising multiple droplet volumes during a spray cycle, a waveform commonly used for multiple droplet volumes is provided in the driving waveform. In the example above, pattern A is used commonly for both large and medium droplets. When multiple droplet volumes are used together, a high degree of fineness in adjusting the drive waveform is required to achieve proper ejection at each droplet volume.

[0093] In order to adjust such a drive waveform, conventional techniques, for example, require setting four or more settable voltage values ​​to determine the drive waveform, or setting the transition time between set voltage values. More specifically, in the case of transitioning from one voltage to another, it is necessary to set not only the start of the transition but also the end of the transition, and the ratio of voltage change to time. The generation of such a drive waveform is, for example, performed by a driver IC, but generating such complex drive waveforms increases the size of the required integrated circuit.

[0094] In this embodiment, the drive waveform is generated for each ejection element 81. Therefore, it is unnecessary to provide a drive waveform like pattern A used for multiple droplet volumes as in the prior art described above. This reduces the need for fine adjustment of the generated drive waveform as in the prior art. Consequently, the size of the circuit for generating the drive waveform can be reduced. Furthermore, by generating the drive waveform with such a small circuit size, the same number of drive signal generation units 53 as the number of ejection elements 81 can be provided within the driver IC 51, and a drive waveform can be generated for each ejection element 81. Specifically, this allows the hundreds to thousands of ejection elements 81 contained in the head 50 to be driven.

[0095] Regarding the control of the ejector elements 81, if only the generated drive waveform is considered, a scheme that can generate a finely adjustable drive waveform for each ejector element 81 is preferable. However, if a drive signal generation unit 53 is provided that can finely adjust the drive waveform for hundreds to thousands of ejector elements 81, the circuit size of the driver IC 51 will become very large, and the cost will become very high. Furthermore, such a driver IC 51 will generate more heat, making it difficult to mount or place near the head 50. More specifically, the high temperature of the driver IC 51 can lead to malfunctions, or frequent stoppages in operation to prevent malfunctions. Alternatively, it may be difficult to mount or place a cooling device to prevent overheating near the head 50.

[0096] One method to reduce the circuit size of the drive signal generation unit 53 is as follows. For example, the number of settable voltages in the drive signal generation unit 53 can be reduced. Specifically, three settable voltages are set (VH, VM, VL).

[0097] For example, the voltage transition method between pre-defined voltages is set to be unconfigurable. Specifically, the voltage transition only sets the timing of the transition start; the time to reach the specified next voltage is determined by a time constant determined by the constructed circuit, or set to a fixed value. If it is determined by a time constant determined by the constructed loop, the circuit size can be further reduced. It should be noted that in this embodiment, the transition of the actual driving voltage applied to the ejection element 81 is sluggish under the time constant determined by the driving signal generation unit 53 and the electrical characteristics of the piezoelectric element, but... Figure 5 The sluggishness is not included, but is represented by a simplified rectangular wave.

[0098] For example, the number of settable voltages in a single drive waveform can be reduced. For instance, two settable voltages can be used. Firstly, the number of settable voltages is simply smaller, thus reducing the circuit size. Furthermore, with only two settable voltages, a circuit that switches between the two voltages is sufficient; that is, a circuit that sets one voltage as a reference voltage and switches between a state where that voltage is off and a state where the other voltage is on can be used, further reducing the circuit size.

[0099] For example, the drive signal generation unit 53 controls which of the two applied voltages (VH, VL) is turned on / off during the generation of a drive waveform. This allows the output of a drive waveform that alternates between VH and VL. Furthermore, if it is desired that the next drive waveform alternates between VH and VM, VL is changed to VM. In this way, the on / off control of which of the two applied voltages (VH, VM) is performed, thereby enabling the output of a drive waveform that alternates between VH and VM.

[0100] That is, if the drive signal generation unit 53 switches the voltage paired with VH to VM or VL at the boundary of two drive waveforms, it can output a drive waveform that migrates between VH and VL, and a drive waveform that migrates between VH and VM. In this way, although three voltages cannot be set during the output of one drive waveform, drive waveforms with different voltage differences can be generated with a smaller circuit size.

[0101] Next, the ejection control of large, medium, and small droplets using the two driving waveforms described above will be described in detail using examples.

[0102] <Example 1>

[0103] As an example, it is possible to utilize Figure 7A The first driving waveform ejects large droplets of liquid and utilizes Figure 7B The second driving waveform ejects medium and small droplets of liquid. More specifically, ejection can be achieved using a driving waveform as follows.

[0104] Large drop: Utilize Figure 6A The waveform pattern shown (the upper and lower voltage pattern) sets the voltage variation range as... Figure 7A (VL~VH).

[0105] Zhongdi: Utilizing Figure 6B The waveform pattern shown sets the voltage variation range as... Figure 7B (VM~VH).

[0106] Little Drop: Utilizing Figure 6C The waveform pattern shown sets the voltage variation range as... Figure 7B (VM~VH).

[0107] In addition, as another example, it is possible to utilize Figure 7A The first driving waveform ejects large and medium-sized droplets of liquid, and utilizes... Figure 7B The second driving waveform ejects small droplets of liquid. That is, it is possible to utilize... Figure 6A The waveform pattern shown sets the voltage variation range as... Figure 7AThe driving waveform ejects large droplets to utilize Figure 6B The waveform pattern shown sets the voltage variation range as... Figure 7A The driving waveform ejects droplets to utilize Figure 6C The waveform pattern shown sets the voltage variation range as... Figure 7B The driving waveform ejects small droplets.

[0108] In this case, by applying the second driving waveform to the small droplets (medium droplets), the potential difference becomes smaller compared to when the first driving waveform is applied, thus suppressing the ejection amount compared to the case with the first driving waveform. Therefore, ejection can be performed with smaller droplets, thereby expanding the droplet size. As a result, the width of the grayscale representation of the image can be expanded.

[0109] <Example 2>

[0110] If the liquid ejected from multiple nozzles 83 lands on the workpiece W at the same timing, its image quality can be improved. Furthermore, the landing timing of the liquid ejected by each waveform can depend on the ejection speed. Generally, the ejection speed of the liquid based on each driving waveform follows the relationship of large droplets > medium droplets > small droplets. Moreover, small / medium droplets are more prone to deceleration due to air resistance; therefore, the greater the distance from ejection to landing (printing gap), the greater the deviation from this relationship. It should be noted that the ejection speed is proportional to the magnitude of the driving voltage (higher voltage and higher speed).

[0111] Based on the above viewpoint, it is possible to utilize Figure 7A The first driving waveform ejects medium and small droplets of liquid, and utilizes... Figure 7B The second driving waveform ejects large droplets of liquid. Additionally, as another example, it is possible to utilize... Figure 7A The first driving waveform ejects small droplets of liquid and utilizes... Figure 7B The second driving waveform ejects large and medium-sized droplets of liquid.

[0112] Figure 8A , Figure 8B This is a schematic diagram illustrating the ejection states of droplets corresponding to the driving voltage. It applies to large, medium, and small droplets. Figure 7A In the case of the first driving waveform, such as Figure 8A Therefore, because the larger droplets are ejected at higher speeds, the landing times of the three types of droplets on the workpiece W are inconsistent. On the other hand, as in this embodiment, when... Figure 8B The second driving waveform is applied to the case of large droplets, and by suppressing the ejection velocity of the large droplets, the landing timing of the three droplets can be made consistent.

[0113] As described above, in this embodiment 2, by applying the second driving waveform to the large droplet, the ejection velocity can be suppressed, synchronizing the landing timing with that of the small (medium) droplet. As a result, improved image quality can be achieved.

[0114] <Example 3>

[0115] Figure 9 This is a schematic diagram of a dual-liquid head capable of ejecting two liquids from a single head. For example, a head capable of ejecting two colors of ink from a single head will be described. In this case, as an example, a nozzle group ejecting black ink is arranged at one end of the carriage 3 in the main scanning direction, and a nozzle group ejecting yellow ink is arranged at the other end in the main scanning direction. In this case, a first drive waveform and a second drive waveform can be selectively applied in the voltage adjustment for each color.

[0116] For example, if the ink color is different, the physical properties of the ink also change, thus potentially altering the ejection state even with the same voltage setting. Even in this case, according to the structure described above, the drive waveform can be made different for each color, thereby allowing adjustment of the ejection performance corresponding to each ink and achieving stable ink ejection. It should be noted that, in this case, Figure 3 The drive signal generation unit 53 shown has two units on one head.

[0117] exist Figure 9 In the example, the first driving waveform can also be used in black ink and the second driving waveform in yellow ink. As a result, it is possible to set a potential difference between colors.

[0118] The inkjet printer 1 and its control method according to one embodiment of the present disclosure have been described above, but the present disclosure is not limited thereto, and for example, the following modified embodiments can be adopted.

[0119] The control unit of the inkjet printer 1 may be part or all of a personal computer or the like that that sends printing image information to the inkjet printer 1. The inkjet printer 1 is not limited to a structure capable of ejecting ink of multiple colors to the workpiece W; it may also be a structure that ejects monochrome ink. The inkjet printer 1 may also lack a pretreatment head 5 for ejecting pretreatment liquid and a posttreatment head 6 for ejecting posttreatment liquid, as well as related components.

[0120] It should be noted that in the examples above, three waveforms—large droplet, medium droplet, and small droplet—were used for illustration as shown in Figure 6. However, fine-tuning of the droplet can also be achieved by combining the first and second driving waveforms from a wider variety of waveforms. For example, the second driving waveform can be applied to extremely small droplets, the first driving waveform to small droplets, the second driving waveform to medium droplets, the second driving waveform to large droplets, and the first driving waveform to extra-large droplets.

[0121] An invention can be formed by combining the multiple structures disclosed in the above embodiments.

[0122] Furthermore, while the above description illustrates a configuration where one ejection element 81 (actuator) is configured corresponding to one nozzle, this disclosure is not limited to this. Alternatively, multiple ejection elements 81 may be configured corresponding to one nozzle.

[0123] <Summary of this Publication>

[0124] The liquid ejector head of the first embodiment of this disclosure includes: a plurality of nozzles; a plurality of actuators corresponding to the plurality of nozzles; and a drive control unit that inputs a drive voltage to the actuators to drive the actuators, thereby enabling liquid to be ejected from the plurality of nozzles. The drive control unit outputs, as the drive voltage, a first drive waveform that ejects liquid by utilizing a potential difference between a first voltage and a second voltage that is different from the first voltage, and a second drive waveform that ejects liquid by utilizing a potential difference between the first voltage and a third voltage that is different from both the first voltage and the second voltage.

[0125] The second embodiment of the liquid ejector head disclosed herein is based on the first embodiment, wherein the first voltage is adjustable to accommodate changes in the volume of liquid ejected from the nozzle.

[0126] The liquid ejector head of the third embodiment of this disclosure is based on the first or second embodiment, wherein the third voltage is greater than the second voltage and less than the first voltage.

[0127] The fourth embodiment of the liquid ejection recording apparatus disclosed herein includes: a liquid ejection head having a plurality of nozzles and a plurality of actuators corresponding to the plurality of nozzles, and capable of ejecting liquid; a media support portion supporting a recording medium in a manner opposite to the liquid ejection head; and a drive control portion inputting a drive voltage to the actuators to drive the actuators, thereby causing droplets to be ejected from the plurality of nozzles, wherein the drive control portion outputs, as the drive voltage, a first drive waveform that causes liquid ejection by a potential difference between a first voltage and a second voltage different from the first voltage, and a second drive waveform that causes liquid ejection by a potential difference between the first voltage and a third voltage different from both the first voltage and the second voltage.

[0128] The fifth embodiment of the liquid ejection recording device disclosed herein is based on the fourth embodiment, wherein the first voltage is an adjustable voltage that can be adjusted to cause changes in the volume of the liquid droplets ejected from the nozzle.

[0129] The liquid ejection recording device of the sixth embodiment of this disclosure is based on the fourth or fifth embodiment, wherein the third voltage is greater than the second voltage and less than the first voltage.

[0130] The seventh embodiment of this disclosure provides a method for controlling a liquid ejector head having multiple nozzles and multiple actuators corresponding to the multiple nozzles. The method includes: preparing a first drive waveform for ejecting liquid using a potential difference between a first voltage and a second voltage different from the first voltage, and a second drive waveform for ejecting liquid using a potential difference between the first voltage and a third voltage different from both the first and second voltages; and inputting either the first drive waveform or the second drive waveform to the actuator to drive the actuator according to the desired volume of liquid ejected from the nozzles, thereby causing liquid to eject from the multiple nozzles.

[0131] The eighth embodiment of the liquid ejection head control method disclosed herein is based on the seventh embodiment, wherein the first voltage is a voltage that can be adjusted to cause changes in the volume of liquid ejected from the nozzle.

[0132] The control method for the liquid ejector head in the ninth embodiment of this disclosure is based on the seventh or eighth embodiment, wherein the third voltage is greater than the second voltage and less than the first voltage.

[0133] The tenth aspect of this disclosure discloses a control method for a liquid ejection recording device. The liquid ejection recording device includes: a liquid ejection head having a plurality of nozzles and a plurality of actuators corresponding to the plurality of nozzles; and a media support portion supporting a recording medium opposite to the liquid ejection head. The control method includes: preparing a first drive waveform for ejecting liquid using a potential difference between a first voltage and a second voltage different from the first voltage, and a second drive waveform for ejecting liquid using a potential difference between the first voltage and a third voltage different from both the first and second voltages, as a drive voltage for the actuators; and inputting either the first drive waveform or the second drive waveform to the actuators to drive the actuators according to the desired volume of liquid ejected from the nozzles, thereby causing liquid to eject from the plurality of nozzles.

[0134] The control method of the liquid ejection recording device of the eleventh aspect of this disclosure is based on the tenth aspect, wherein the first voltage is a voltage that can be adjusted to cause changes in the volume of liquid ejected from the nozzle.

[0135] The control method of the liquid ejection recording device of the twelfth embodiment of this disclosure is based on the tenth or eleventh embodiment, wherein the third voltage is greater than the second voltage and less than the first voltage.

[0136] According to the above disclosures, compared to the case where multiple sizes of droplets are ejected using a single driving waveform, i.e., between a maximum and a minimum value, the adjustment amount for relatively small droplets can be suppressed. Therefore, the degree of freedom in adjusting the driving voltage relative to multiple droplets of different volumes can be improved.

[0137] In the above structure or method, the first voltage is an adjustable voltage that can cause a change in the volume of liquid ejected from the nozzle. The third voltage may also be a fixed value.

[0138] In the above structure or method, the third voltage may be larger than the second voltage and smaller than the first voltage.

[0139] Explanation of reference numerals in the attached figures

[0140] 1. Inkjet printer (liquid ejection recording device)

[0141] 3. Carriage

[0142] 4 inkjet heads

[0143] 5. Pretreatment liquid head

[0144] 6. Post-treatment liquid head

[0145] 20. Workpiece Handling Department

[0146] 21 Drive Rollers

[0147] 22 Driven Roller

[0148] 50 heads (liquid spray nozzles)

[0149] 51 Driver IC (Driver Control Unit)

[0150] 52-head control unit

[0151] 53 Drive Signal Generation Unit

[0152] 80 Nozzle section

[0153] 81 Ejection element (actuator)

[0154] 82 Liquid pressurization chamber

[0155] 83 Nozzle.

Claims

1. A liquid ejector head, wherein, The liquid ejector head includes: Multiple nozzles; Multiple actuators, corresponding to the multiple nozzles; and A drive control unit inputs a drive voltage to the actuator to drive the actuator, thereby enabling liquid to be ejected from the plurality of nozzles. The drive control unit outputs a first drive waveform that causes liquid to spray out using a potential difference between a first voltage and a second voltage that is different from the first voltage, and a second drive waveform that causes liquid to spray out using a potential difference between the first voltage and a third voltage that is different from both the first voltage and the second voltage.

2. The liquid ejector head according to claim 1, wherein, The first voltage is adjustable to accommodate changes in the volume of liquid ejected from the nozzle.

3. The liquid ejector head according to claim 1 or 2, wherein, The third voltage is greater than the second voltage and less than the first voltage.

4. A liquid ejection recording device, wherein, The liquid ejection recording device includes: A liquid ejector head having multiple nozzles and multiple actuators corresponding to the multiple nozzles, and capable of ejecting liquid; A media support portion that supports the recording medium in a manner opposite to the liquid ejection head; as well as A drive control unit inputs a drive voltage to the actuator to drive the actuator, thereby enabling droplets to be ejected from the plurality of nozzles. The drive control unit outputs a first drive waveform that causes liquid to spray out using a potential difference between a first voltage and a second voltage that is different from the first voltage, and a second drive waveform that causes liquid to spray out using a potential difference between the first voltage and a third voltage that is different from both the first voltage and the second voltage.

5. The liquid ejection recording device according to claim 4, wherein, The first voltage is a voltage that can be adjusted to cause changes in the volume of the droplets ejected from the nozzle.

6. The liquid ejection recording device according to claim 4 or 5, wherein, The third voltage is greater than the second voltage and less than the first voltage.

7. A method for controlling a liquid ejector head, the liquid ejector head having a plurality of nozzles and a plurality of actuators corresponding to the plurality of nozzles, wherein, The method for controlling the liquid ejector head includes: As a first driving waveform prepared for the driving voltage of the actuator, utilizing the potential difference between a first voltage and a second voltage different from the first voltage to cause liquid to be ejected, and a second driving waveform prepared for the same purpose, utilizing the potential difference between the first voltage and a third voltage different from both the first and second voltages to cause liquid to be ejected; and The actuator is driven by inputting either the first drive waveform or the second drive waveform into the actuator according to the required volume of liquid ejected from the nozzles, thereby causing the liquid to be ejected from the plurality of nozzles.

8. The method for controlling a liquid ejector head according to claim 7, wherein, The first voltage is a voltage that can be adjusted to cause changes in the volume of liquid ejected from the nozzle.

9. The method for controlling a liquid ejector head according to claim 7 or 8, wherein, The third voltage is greater than the second voltage and less than the first voltage.

10. A control method for a liquid ejection recording device, the liquid ejection recording device comprising: A liquid ejector head having multiple nozzles and multiple actuators corresponding to the multiple nozzles; and a media support portion that supports the recording medium in a manner opposite to the liquid ejection head, wherein, The control method for the liquid ejection recording device includes: As a first driving waveform prepared for the driving voltage of the actuator, utilizing the potential difference between a first voltage and a second voltage different from the first voltage to cause liquid to be ejected, and a second driving waveform prepared for the same purpose, utilizing the potential difference between the first voltage and a third voltage different from both the first and second voltages to cause liquid to be ejected; and The actuator is driven by inputting either the first drive waveform or the second drive waveform into the actuator according to the required volume of liquid ejected from the nozzles, thereby causing the liquid to be ejected from the plurality of nozzles.

11. The control method for the liquid ejection recording device according to claim 10, wherein, The first voltage is a voltage that can be adjusted to cause changes in the volume of liquid ejected from the nozzle.

12. The control method for the liquid ejection recording device according to claim 10 or 11, wherein, The third voltage is greater than the second voltage and less than the first voltage.

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