Patent ID: 12257835

The accompanying drawings are intended to depict embodiments of the present invention and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views.

DETAILED DESCRIPTION

In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.

Referring now to the drawings, embodiments of the present disclosure are described below. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Embodiments of the present disclosure are described below with reference to the drawings. It is to be noted that the following embodiments are not limiting the present disclosure and any deletion, addition, modification, change, etc. can be made within a scope in which person skilled in the art can conceive including other embodiments, and any of which is included within the scope of the present disclosure as long as the effect and feature of the present disclosure are exhibited. In each of the drawings, the same reference codes are allocated to components and portions having the same structure or functions, and redundant descriptions thereof may be omitted.

Liquid Discharge Head

FIG.1is a schematic cross-sectional view of a liquid discharge head100according to embodiments of the present disclosure.FIG.2is a schematic plan view of the liquid discharge head100as viewed from a nozzle surface side (also referred to as a liquid discharge side from which liquid is discharged). That is, the liquid discharge head100illustrated inFIG.2is viewed in the direction indicated by arrow a inFIG.1, andFIG.1is the schematic cross-sectional view taken along line A-A inFIG.2. As illustrated inFIG.1, the liquid discharge head100according to the present embodiment includes a nozzle layer1, a liquid chamber substrate2, and a drive circuit92.

The nozzle layer1includes a diaphragm layer3, a piezoelectric actuator12as a piezoelectric layer, an electrode pad90, a first protective layer81, and a second protective layer82. The electrode pad90is an example of a circuit connection. The nozzle layer1has a nozzle4penetrating the nozzle layer1, and a liquid (for example, ink) is discharged from the nozzle4. The liquid chamber substrate2and a part of the nozzle layer1define a liquid chamber6, and the piezoelectric actuator12is driven by the drive circuit92to discharge the liquid in the liquid chamber6from the nozzle4.

The diaphragm layer3vibrates when the piezoelectric actuator12is driven. The material of the diaphragm layer3is not particularly limited, and for example, aluminum oxide (Al2O3), silicon nitride (SiN), silicon dioxide (SiO2), high temperature oxide (HTO), or a combination of some of these materials that are laminated one on another can be used.

The liquid chamber substrate2includes the liquid chamber6communicating with the nozzle4. A circuit protective layer17is disposed between the liquid chamber substrate2and the diaphragm layer3. The circuit protective layer17protects the drive circuit92and an inter-layer wiring layer95.

The material of the circuit protective layer17is not particularly limited, and examples thereof include a polytetrafluoroethylene (PTFE)-based resin. A position where the circuit protective layer17is formed is not particularly limited, and for example, the circuit protective layer17is formed so as to cover the drive circuit92and the inter-layer wiring layer95. The nozzle layer1may include the circuit protective layer17, or the liquid chamber substrate2may include the circuit protective layer17.

The piezoelectric actuator12includes a lower electrode21, a piezoelectric body22, and an upper electrode23. The lower electrode21may be a common electrode and the upper electrode23may be an individual electrode. Alternatively, the lower electrode21may be the individual electrode and the upper electrode23may be the common electrode.

The material of the piezoelectric body22is not particularly limited, and for example, lead zirconate titanate (PZT) can be used. The materials of the lower electrode21and the upper electrode23are not particularly limited, and known electrode materials can be used. For example, platinum (Pt) may be used.

The piezoelectric actuator12(the piezoelectric body22) is disposed adjacent to the nozzle4and over a side (first side) of the diaphragm layer3from which a liquid is discharged (i.e., the nozzle surface side). In the present embodiment, the piezoelectric actuator12is disposed on the diaphragm layer3. Since the piezoelectric actuator12is disposed at such a position, a diaphragm plate is unnecessary, which applies pressure to a liquid sucked and introduced into the liquid chamber6to discharge the liquid from the nozzle4.

The piezoelectric actuator12is connected to the drive circuit92to drive the piezoelectric actuator12, via connection electrodes94band94c. For example, the lower electrode21is connected to the drive circuit92via the connection electrode94b, and the upper electrode23is connected to the drive circuit92via the connection electrode94c.

The drive circuit92is connected to the electrode pad90via a connection electrode94a, and is energized from a power supply unit via the electrode pad90and the connection electrode94a. The drive circuit92is disposed over a side (second side) opposite to the side (first side) where the electrode pad90is disposed across the diaphragm layer3. The drive circuit92is preferably disposed, but not limited to, on the liquid chamber substrate2. In such a case, the drive circuit92can be easily formed.

The drive circuit92is not particularly limited, but may be, for example, a complementary metal oxide semiconductor (CMOS) circuit. Although not particularly limited, the drive circuit92is divided into multiple portions connected to the electrode pad90and connected to the piezoelectric actuator12as illustrated inFIG.1, and the multiple portions are connected to each other via the inter-layer wiring layer95. As the material of the inter-layer wiring layer95, for example, a known electrode material can be used.

The electrode pad90(i.e., the circuit connection) is disposed over the liquid discharge side (nozzle surface side) of the diaphragm layer3, and is connected to the drive circuit92via the connection electrode94a. Here, two connection electrodes94aare illustrated inFIG.1, but the number of the connection electrodes94ais not limited to two. The two connection electrodes94band94cconnected to the lower electrode21and the upper electrode23of the piezoelectric actuator12correspond to the two connection electrodes94a, respectively.

As illustrated inFIG.1, in the present embodiment, the first and second protective layers81and82are disposed over the liquid discharge side (nozzle surface side) of the diaphragm layer3. The first protective layer81is disposed around the electrode pad90and defines an opening85above the electrode pad90. The second protective layer82is disposed over the piezoelectric actuator12. The first protective layer81and the second protective layer82can protect, for example, at least one of the piezoelectric actuator12or the diaphragm layer3, thereby preventing deterioration of these components.

The liquid discharge head100according to the present embodiment includes a water-resistant film88disposed over the surface of the first protective layer81and the surface of the second protective layer82. The water-resistant film88can prevent moisture from permeating into the first and second protective layers81and82. Therefore, the piezoelectric actuator12is prevented from deteriorating in performance due to the moisture permeating through the second protective layer82. The water-resistant film88is omitted inFIG.2for simplicity.

In the present embodiment, the first protective layer81and the second protective layer82are not continuous. As illustrated inFIG.1, the first protective layer81and the second protective layer82are separated from each other by a separation groove86. That is, the first protective layer81and the second protective layer82are discontinuous. With such a structure, in the liquid discharge head100in which the piezoelectric actuator12and the electrode pad90(circuit connection) are formed in the nozzle layer1, the piezoelectric actuator12is prevented from absorbing moisture from the opening85above the electrode pad90, thereby preventing the deterioration of piezoelectric performance of the piezoelectric actuator12.

The liquid discharge head100according to the present embodiment is not limited to the above-described configuration. The liquid discharge head100according to the present embodiment includes at least the nozzle layer1including the piezoelectric layer (the piezoelectric actuator12), the nozzle4penetrating the nozzle layer1, the liquid chamber6communicating with the nozzle4, and the drive circuit92that applies the drive waveform to the piezoelectric layer to drive the piezoelectric layer, and may not include other components described with reference toFIGS.1and2.

A drive waveform used by the liquid discharge head100according to the present embodiment is described below. When a liquid discharge head that does not includes an individual liquid chamber discharges a liquid and a residual vibration is generated in the nozzle layer1, a drive waveform according to the present embodiment reduces the residual vibration. If the residual vibration is generated in the nozzle layer1after the liquid is discharged, the speed of the liquid to be subsequently discharged may fluctuate, causing an abnormal image.

The drive waveform applied to the piezoelectric layer by the drive circuit92has a first waveform and a second waveform. The first waveform is a waveform portion of the drive waveform having a first voltage applied to the piezoelectric layer as a drive voltage to discharge a liquid from the nozzle4. The second waveform is a waveform portion of the drive waveform having a second voltage applied to the piezoelectric layer to reduce the residual vibration generated in the nozzle layer1. The first voltage is preferably has a larger amplitude than the second voltage.

In the drive waveform according to the present embodiment, the second voltage is applied at a predetermined timing with respect to a rising edge (positive edge) of the first voltage. More specifically, in the drive waveform, a falling edge (negative edge) or the rising edge of the second voltage is applied at a predetermined timing with respect to the rising edge of the first voltage.

The predetermined timing is calculated based on the timing at which the rising edge of the first voltage is applied and a natural vibration period. The predetermined timing may be calculated each time the drive waveform is applied to the liquid discharge head100, or may be calculated in advance at the time of manufacturing the liquid discharge head100and stored in a memory or the like in the liquid discharge head100. Further, a drive waveform having the calculated predetermined timing may be stored in a memory or the like.

The natural vibration period is a natural period of vibration of the first (fundamental) mode of the piezoelectric layer when the liquid chamber6and the nozzle4are filled with the liquid. In the following description, the natural vibration period is referred to as “Tc” as appropriate.

Such a drive waveform can reduce the residual vibration generated in the nozzle layer1without new additional mechanical components. The drive waveform is described below in detail in each embodiment. A waveform has multiple elements such as a voltage to be applied, and the voltage has a leading edge (or slope), and a trailing edge (slope). The leading edge may be the rising edge in which the voltage rises (i.e., positively changes), and the trailing edge may be the falling edge in which the voltage falls (i.e., negatively changes). Alternatively, the leading edge may be the falling edge, and the trailing edge may be the rising edge.

First Embodiment

FIG.3is a graph illustrating an example of the drive waveform according to a first embodiment of the present disclosure.FIG.3schematically illustrates the drive waveform. The vertical axis represents voltage (V), and the horizontal axis represents time (μs).

The drive waveform W1has a first waveform W11having a first voltage and a second waveform W12having a second voltage. The first voltage has a first rising edge U11(trailing edge). The second voltage has a second rising edge U12(leading edge) at a timing T12delayed from the first rising edge U11by (m−0.5)×Tc, where m represents a positive integer.

Preferably, the second waveform W12has an amplitude of the second voltage smaller than an amplitude of the first voltage of the first waveform W11. Preferably, the direction of the amplitude of the second waveform W12is opposite to the direction of the amplitude of the first waveform W11. The second waveform W12is preferably applied next to the first waveform W11so that the second rising edge U12of the second waveform W12is delayed from the first rising edge U11of the first waveform W11.

When a PZT element is used for the piezoelectric body22as a drive element, the piezoelectric body22can be driven by a waveform having an amplitude within the range of voltages of the same polarity (for example, positive voltages). Alternatively, when the piezoelectric body22may be made of aluminum nitride, the piezoelectric body22can be driven by a waveform having an amplitude varying between the positive and negative voltages (opposite polarities).

As illustrated inFIG.3, the second rising edge U12of the second voltage is delayed from the first rising edge U11of the first voltage by an interval of (m−0.5)×Tc, where m represents a positive integer. The first rising edge U11, in which the voltage positively changes, is one of the multiple elements of the first waveform W11, and the second rising edge U12, in which the voltage also positively changes (i.e., the same voltage change as the first rising edge U11), is one of the multiple elements of the second waveform W12.

InFIG.3, the interval between a timing T11at which the first rising edge U11starts and the timing T12at which the second rising edge U12starts is (m−0.5)×Tc. Alternatively, in the drive waveform W1, the timing T12at which the second rising edge U12starts may be delayed from an arbitrary timing between the start and end of the first rising edge U12(within the slope of the first rising edge U11inFIG.3) by the interval of (m−0.5)×Tc.

Effects of the drive waveform according to the present embodiment is described.FIG.4Ais a graph of a drive waveform according to a comparative example.FIG.4Bis a graph of a drive waveform according to the first embodiment.FIG.4Cis a graph of meniscus displacement when the drive waveforms of the comparative example and the first embodiment are applied, illustrating an effect of the drive waveform of the first embodiment. InFIGS.4A to4C, values of the comparative example are indicated by solid lines, and values of the present embodiment are indicated by broken lines.

The meniscus displacement (i.e., a displacement of meniscus of the liquid in the nozzle4) corresponds to the residual vibration of the nozzle layer1. The residual vibration can be reduced by the drive waveform according to the present embodiment. In the liquid discharge head10illustrated inFIG.1, the residual vibration is generated in the nozzle layer1after the liquid is discharged from the nozzle4.

With the drive waveform W1illustrated inFIG.3, the drive circuit92applies the second rising edge U12to the piezoelectric actuator12at the timing T12delayed from the first rising edge U11by (m−0.5)×Tc. As a result, the liquid discharge head100cancels the vibration generated by discharging the liquid, thereby reducing the residual vibration generated in the nozzle layer1. Specifically, the nozzle layer1has the nozzle4from which the liquid is discharged and includes the piezoelectric actuator12, and the nozzle layer1around the nozzle4is driven (vibrated) together with the piezoelectric actuator12.

Accordingly, since the nozzle layer1is driven (vibrated) by the drive waveform W1according to the present embodiment, the liquid discharge head100can discharge the liquid with high accuracy. As described above, the drive waveform W1reduces the residual vibration generated in the nozzle layer1.

As illustrated inFIG.5, a drive waveform W2preferably has a falling edge D22of a second waveform W22at a timing T13delayed from the first rising edge U11of the first waveform W11by an interval of n×Tc, where n represents a positive integer. That is, the falling edge D22of the second voltage is delayed from the first rising edge U11of the first voltage by the interval of n×Tc. In the falling edge D22, the voltage negatively changes, which is different from the voltage change (i.e., positive change) in the first rising edge U11. The interval of n×Tc is larger than the interval of (m−0.5)×Tc, that is, n×Tc>(m−0.5)×Tc.

Second Embodiment

FIG.6is a graph illustrating an example of the drive waveform according to a second embodiment of the present disclosure. Similarly toFIG.3,FIG.6schematically illustrates the drive waveform. A drive waveform W3has a falling edge D32of a second waveform W32at a timing T32delayed from a first rising edge U31of a first waveform W31by the interval of n×Tc, where n represents a positive integer.

The voltage and direction (positive or negative) of the amplitude of the second waveform W32may be the same as those in the first embodiment. Similarly to the first embodiment, when the PZT element is used for the piezoelectric body22as a drive element, the piezoelectric body22can be driven by a waveform having an amplitude within the range of voltages of the same polarity, and when the aluminum nitride is used for the piezoelectric body22, the piezoelectric body22can be driven by a waveform having an amplitude varying between the positive and negative voltages.

As illustrated inFIG.6, the falling edge D32of the second voltage is delayed from the first rising edge U31of the first voltage by the interval of n×Tc. In the falling edge D32, the voltage negatively changes, which is different from the voltage change (i.e., positive change) in the first rising edge U31.

InFIG.6, the interval between a timing T31at which the first rising edge U31starts and the timing T32at which the falling edge D32starts is n×Tc. Alternatively, in the drive waveform W3, the timing T32at which the falling edge D32starts may be delayed from an arbitrary timing between the start and end of the first rising edge U31(within the slope of the first rising edge U31inFIG.6) by the interval of n×Tc.

Effects of the drive waveform according to the present embodiment is described.FIG.7Ais a graph of the drive waveform according to the comparative example.FIG.7Bis a graph of a drive waveform according to the second embodiment.FIG.7Cis a graph of meniscus displacement when the drive waveforms of the comparative example and the second embodiment are applied, illustrating an effect of the drive waveform of the second embodiment. InFIGS.7A to7C, values of the comparative example are indicated by solid lines, and values of the present embodiment are indicated by broken lines. In the liquid discharge head10illustrated inFIG.1, the residual vibration is generated in the nozzle layer1after the liquid is discharged from the nozzle4.

With the drive waveform W3illustrated inFIG.6, the drive circuit92applies the falling edge D32to the piezoelectric actuator12at the timing T32delayed from the first rising edge U31by n×Tc. As a result, the liquid discharge head100cancels the vibration generated by discharging the liquid, thereby reducing the residual vibration generated in the nozzle layer1. As described above, the drive waveform W3reduces the residual vibration generated in the nozzle layer1.

Other Embodiment

The second waveform in each of the above embodiments preferably has an amplitude of the second voltage equal to or less than, for example, 50% of an amplitude of the first voltage of the first waveform.

In each of the above-described embodiments, the drive waveform may have multiple second waveforms including the second waveform after the first waveform so that the second waveform is repeatedly applied. Each of the multiple second waveforms may have, for example, the same voltage.

FIG.8illustrates an example of a drive waveform W4in which multiple second waveforms W12are added to the drive waveform W1illustrated inFIG.3according to the first embodiment, and the second waveform W12is repeatedly applied after the first waveform W11. Similarly, multiple second waveforms W22or multiple second waveforms W32may be added to the drive waveform W2illustrated inFIG.5or the drive waveform W3illustrated inFIG.6so that the second waveform W22or W32is repeatedly applied after the first waveform W11or W31.

In each of the above-described embodiments, when the nozzle layer1having the nozzle4includes a vibration source (i.e., the piezoelectric actuator12), the residual vibration can be effectively reduced.

Liquid Discharge Apparatus and Liquid Discharge Device

Next, an example of a liquid discharge apparatus according to the present embodiment is described with reference toFIGS.9and10.FIG.9is a plan view of a portion of a liquid discharge apparatus1000.FIG.10is a side view of the portion of the liquid discharge apparatus1000inFIG.9.

The liquid discharge apparatus1000is a serial-type apparatus in which a main-scanning moving mechanism493reciprocates a carriage403in the main scanning directions indicated by arrow MSD inFIG.9. The main-scanning moving mechanism493includes a guide401, a main-scanning motor405, and a timing belt408. The guide401is bridged between left and right side plates491A and491B to moveably hold the carriage403. The main-scanning motor405reciprocates the carriage403in the main scanning direction via the timing belt408looped around a drive pulley406and a driven pulley407to move the liquid discharge head100relative to a sheet410.

The carriage403mounts a liquid discharge device440including the liquid discharge head100according to the above described embodiments of the present disclosure and a head tank441as a single integrated unit. The liquid discharge head100of the liquid discharge device440discharges color liquids of, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid discharge head100is mounted on the liquid discharge device440of the carriage403such that a nozzle row including a plurality of nozzles4is arranged in the sub-scanning direction perpendicular to the main scanning direction. The liquid discharge head100discharges the color liquid downward.

A supply mechanism494disposed outside the liquid discharge head100supplies a liquid stored in liquid cartridges450to the head tank441to supply the liquid to the liquid discharge head100. The supply mechanism494includes a cartridge holder451which is a filling part to mount the liquid cartridges450, a tube456, a liquid feed unit452including a liquid feed pump, and the like. The liquid cartridge450is detachably mounted on the cartridge holder451. The liquid feed unit452feeds the liquid from the liquid cartridge450to the head tank441via the tube456.

The liquid discharge apparatus1000further includes a conveyance mechanism495to convey the sheet410. The conveyance mechanism495includes a conveyance belt412as a conveyor and a sub-scanning motor416to drive the conveyance belt412. The conveyance belt412attracts the sheet410and conveys the sheet410to a position facing the liquid discharge head100. The conveyance belt412is an endless belt stretched between a conveyance roller413and a tension roller414as illustrated inFIG.10. The sheet410can be attracted to the conveyance belt412by electrostatic attraction, air suction, or the like. The conveyance belt412circumferentially moves in the sub-scanning direction indicated by arrow SSD inFIG.10as the conveyance roller413is rotationally driven by the sub-scanning motor416via a timing belt417and a timing pulley418.

On one side of the carriage403in the main scanning direction, a maintenance mechanism420that maintains and recovers the liquid discharge head100is disposed lateral to the conveyance belt412. The maintenance mechanism420includes, for example, a cap421to cap the nozzle surface (i.e., the surface on which the nozzles4are formed) of the liquid discharge head100and a wiper422to wipe the nozzle surface.

The main-scanning moving mechanism493, the supply mechanism494, the maintenance mechanism420, and the conveyance mechanism495are mounted onto a housing including the side plates491A and491B and a back plate491C. In the liquid discharge apparatus1000having the above-described configuration, the sheet410is fed and attracted onto the conveyance belt412and conveyed in the sub-scanning direction indicated by arrow SSD as the conveyance belt412circumferentially moves.

The liquid discharge head100is driven in response to an image signal while moving the carriage403in the main scanning direction to discharge liquid onto the sheet410not in motion, thereby forming an image. As described above, the liquid discharge apparatus1000includes the liquid discharge head100according to the above-described embodiments of the present disclosure, thus allowing stable formation of high-quality images.

Next, another example of the liquid discharge device440according to the present embodiment is described with reference toFIG.11.FIG.11is a plan view of a part of the liquid discharge device440. The liquid discharge device440includes the housing, the main-scanning moving mechanism493, the carriage403, and the liquid discharge head100among components of the liquid discharge apparatus1000described above. The side plates491A and491B, and the back plate491C construct the housing. The liquid discharge device440may further include at least one of the maintenance mechanism420and the supply mechanism494, which may be attached to the side plate491B.

Next, another example of the liquid discharge device440according to the present embodiment is described with reference toFIG.12.FIG.12is a front view of the liquid discharge device440. The liquid discharge device440includes the liquid discharge head100to which a channel component444is attached and tubes456connected to the channel component444. The channel component444is disposed inside a cover442. In some embodiments, the liquid discharge device440may include the head tank441instead of the channel component444. A connector443for electrically connecting to the liquid discharge head100is provided on an upper portion of the channel component444.

In the above-described embodiments, the “liquid discharge apparatus” includes the liquid discharge head or the liquid discharge device and drives the liquid discharge head to discharge liquid. The liquid discharge apparatus may be, for example, an apparatus capable of discharging liquid to a material onto which liquid can adhere or an apparatus to discharge liquid toward gas or into liquid.

The “liquid discharge apparatus” may further include devices relating to feeding, conveying, and ejecting of the material onto which liquid can adhere and also include a pretreatment device and an aftertreatment device.

The “liquid discharge apparatus” may be, for example, an image forming apparatus to form an image on a sheet by discharging ink, or a three-dimensional fabrication apparatus to discharge fabrication liquid to a powder layer in which powder material is formed in layers so as to form a three-dimensional object.

The “liquid discharge apparatus” is not limited to an apparatus that discharges liquid to visualize meaningful images such as letters or figures. For example, the liquid discharge apparatus may be an apparatus that forms meaningless images such as meaningless patterns or an apparatus that fabricates three-dimensional images.

The above-described term “material onto which liquid can adhere” represents a material on which liquid is at least temporarily adhered, a material on which liquid is adhered and fixed, or a material into which liquid is adhered to permeate. Specific examples of the “material onto which liquid can adhere” include, but are not limited to, a recording medium such as a paper sheet, recording paper, a recording sheet of paper, a film, or cloth, an electronic component such as an electronic substrate or a piezoelectric element, and a medium such as layered powder, an organ model, or a testing cell. The “material onto which liquid can adhere” includes any material to which liquid adheres, unless particularly limited.

Examples of the “material onto which liquid can adhere” include any materials onto which liquid can adhered even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramic, construction materials (e.g., wall paper or floor material), and cloth textile.

Examples of the “liquid” include ink, treatment liquid, DNA sample, resist, pattern material, binder, fabrication liquid, and solution or liquid dispersion containing amino acid, protein, or calcium.

The liquid discharge apparatus may be an apparatus to relatively move the liquid discharge head and the material onto which liquid can adhere. However, the liquid discharge apparatus is not limited to such an apparatus. For example, the liquid discharge apparatus may be a serial head apparatus that moves the liquid discharge head or a line head apparatus that does not move the liquid discharge head.

Examples of the liquid discharge apparatus further include: a treatment liquid applying apparatus that discharges a treatment liquid onto a paper sheet to apply the treatment liquid to the surface of the paper sheet, for reforming the surface of the paper sheet; and an injection granulation apparatus that injects a composition liquid, in which a raw material is dispersed in a solution, through a nozzle to granulate fine particle of the raw material.

The “liquid discharge device” refers to a liquid discharge head integrated with functional components or mechanisms, i.e., an assembly of components related to liquid discharge. For example, the “liquid discharge device” includes a combination of the liquid discharge head with at least one of a head tank, a carriage, a supply mechanism, a maintenance mechanism, or a main-scanning moving mechanism.

Here, the integrated unit may be, for example, a combination in which the liquid discharge head and a functional part(s) are secured to each other through, e.g., fastening, bonding, or engaging, and a combination in which one of the liquid discharge head and a functional part(s) is movably held by another. The liquid discharge head may be detachably attached to the functional part(s) or unit(s) each other.

Examples of the liquid discharge device include the liquid discharge device440in which a liquid discharge head and a head tank are integrated, as illustrated inFIG.10. Alternatively, the liquid discharge head and the head tank coupled (connected) to each other via a tube or the like may form the liquid discharge device as a single unit. Here, a unit including a filter may further be added to a portion between the head tank and the liquid discharge head of the liquid discharge device.

In another example, the liquid discharge device may be an integrated unit in which a liquid discharge head is integrated with a carriage.

As yet another example, the liquid discharge device is a unit in which the liquid discharge head and the main-scanning moving mechanism are combined into a single unit.

The liquid discharge head is movably held by a guide that is a part of the main-scanning moving mechanism. Like the liquid discharge device440illustrated inFIG.11, the liquid discharge head, the carriage, and the main-scanning moving mechanism may form the liquid discharge device as a single unit.

In another example, the cap that forms a part of the maintenance mechanism is secured to the carriage mounting the liquid discharge head so that the liquid discharge head, the carriage, and the maintenance mechanism are integrated as a single unit to form the liquid discharge device.

Further, in still another example, the liquid discharge device includes tubes connected to the liquid discharge head to which the head tank or the channel component is attached so that the liquid discharge head and the supply mechanism are integrated as a single unit, as illustrated inFIG.12.

The main-scanning moving mechanism may be a guide only. The supply mechanism may be a tube(s) only or a loading device only.

The liquid discharge head is not limited in the type of pressure generator used. For example, the above-described piezoelectric actuator (which may use a laminated piezoelectric element), a thermal actuator using a thermoelectric transducer such as a thermal resistor, and an electrostatic actuator including a diaphragm and a counter electrode can be used.

In the present specification, the terms “image formation,” “recording,” “printing,” “image printing,” and “fabricating” used herein may be used synonymously with each other.

Aspects of the present disclosure are, for example, as follows.

Aspect 1

A liquid discharge head includes a nozzle layer including a piezoelectric layer and having a nozzle penetrating through the nozzle layer, a liquid chamber communicating with the nozzle, and a drive circuit to apply a drive waveform to the piezoelectric layer to drive the piezoelectric layer. The drive waveform has a first waveform and a second waveform. The first waveform has a first voltage to discharge a liquid in the liquid chamber from the nozzle. The first voltage has a first rising edge from which the first voltage rises. The second waveform has a second voltage having a second rising edge from which the second voltage rises. The second rising edge is delayed from the first rising edge by (m−0.5)×Tc, where m represents a positive integer, and Tc represents a natural period of vibration of the piezoelectric layer.

Aspect 2

In Aspect 1, the second voltage of the second waveform further has a falling edge from which the second voltage falls. The falling edge is delayed from the first rising edge by n×Tc, where n represents a positive integer.

Aspect 3

A liquid discharge head includes a nozzle layer including a piezoelectric layer and having a nozzle penetrating through the nozzle layer, a liquid chamber communicating with the nozzle, and a drive circuit to apply a drive waveform to the piezoelectric layer to drive the piezoelectric layer. The drive waveform has a first waveform and a second waveform. The first waveform has a first voltage to discharge a liquid in the liquid chamber from the nozzle. The first voltage has a rising edge from which the first voltage rises. The second waveform has a second voltage having a falling edge from which the second voltage falls. The falling edge is delayed from the rising edge by n×Tc, where n represents a positive integer, and Tc represents a natural period of vibration of the piezoelectric layer.

Aspect 4

In any one of Aspects 1 to 3, the first voltage of the first waveform has a first amplitude. The second voltage of the second waveform has a second amplitude equal to or less than 50% of the first amplitude.

Aspect 5

In any one of Aspects 1 to 4, the drive waveform further has multiple second waveforms including the second waveform. The multiple second waveforms are repeatedly applied to the piezoelectric layer to drive the piezoelectric layer.

Aspect 6

A liquid discharge apparatus includes the liquid discharge head according to any one of Aspects 1 to 5, and a carriage mounting the liquid discharge head and configured to move the liquid discharge head.

As described above, according to the present disclosure, the drive waveform reduces the residual vibration generated in the nozzle layer after a liquid is discharged.

The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of the present invention.