JP2023020039A - Liquid discharge head and liquid discharging device - Google Patents

Abstract

To inhibit residual vibration generating in a nozzle formation layer after liquid discharge by a drive waveform.SOLUTION: A liquid discharging device comprises a nozzle formation layer having a piezoelectric layer, a nozzle penetrating the nozzle formation layer, a liquid chamber communicating with the nozzle, and a drive circuit impressing a driving waveform W1 to make the piezoelectric layer drive. When a natural oscillation period is set to Tc, the driving waveform W1 has a first waveform W11 impressing a drive voltage by which the liquid in the liquid chamber is discharged from the nozzle, and a second waveform W12 impressing a fall element of the voltage at a timing T12 of n×Tc (n is a positive integer) against the rise element U11 of the voltage.SELECTED DRAWING: Figure 3

Description

The present invention relates to a liquid ejection head and an apparatus for ejecting liquid.

2. Description of the Related Art In order to increase the density of nozzles in a liquid ejection head, a technique of driving a nozzle forming layer as an actuator to eject liquid has been devised and is already known.
However, there is a problem that residual vibration occurs in the nozzle forming layer after the liquid is ejected, and the speed at which the next liquid is ejected fluctuates, resulting in a problem that a normal image cannot be obtained.
For example, Patent Document 1 discloses a configuration in which a damper is arranged without providing a dedicated damper chamber for the purpose of suppressing vibration in the individual liquid chambers, but the above problem cannot be solved.

SUMMARY OF THE INVENTION An object of the present invention is to suppress residual vibration generated in a nozzle forming layer after ejection of a liquid by using a drive waveform.

In order to solve the above-described problems, the liquid ejection head of the present invention includes:
a nozzle forming layer having a piezoelectric layer;
a nozzle that penetrates the nozzle forming layer;
a liquid chamber communicating with the nozzle;
a drive circuit that applies a drive waveform to drive the piezoelectric layer,
Assuming that the natural vibration period is Tc,
The driving waveform is a first waveform for applying a driving voltage for ejecting the liquid in the liquid chamber from the nozzle, and a rising element of the driving voltage at a timing of n×Tc (n is a positive integer). , and a second waveform applying a voltage ramping component.

According to the present invention, it is possible to suppress the residual vibration generated in the nozzle forming layer after the liquid is ejected by using the drive waveform.

1 is a schematic cross-sectional view of a liquid ejection head according to an embodiment of the invention; FIG. 2 is a schematic plan view of the same liquid ejection head; FIG. 4A and 4B are diagrams illustrating examples of drive waveforms according to the first embodiment; FIG. FIG. 4 is a diagram for explaining the effect of the driving waveform of the first embodiment, in which (a) is an example of the driving waveform of the comparative example, (b) is an example of the driving waveform of the present embodiment, and (c) is the comparative example and the present embodiment. shows the meniscus displacement when a waveform of and is applied. FIG. 10 is a diagram illustrating an example of drive waveforms according to the second embodiment; FIG. 8A and 8B are diagrams for explaining the effect of the driving waveform of the second embodiment, in which (a) is an example of the driving waveform of the comparative example, (b) is an example of the driving waveform of the present embodiment, and (c) is the comparative example and the present embodiment. shows the meniscus displacement when a waveform of and is applied. FIG. 11 is a diagram for explaining an example of drive waveforms according to the third embodiment; 8A and 8B are diagrams for explaining the effect of the driving waveform of the third embodiment, in which (a) is an example of the driving waveform of the comparative example, (b) is an example of the driving waveform of the present embodiment, and (c) is the comparative example and the present embodiment. shows the meniscus displacement when a waveform of and is applied. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory plan view of an essential part of an example of a device for ejecting liquid according to the present invention; It is an explanatory side view of the main part of the device. FIG. 2 is an explanatory plan view of essential parts of an example of a liquid ejection unit according to the present invention; FIG. 5 is a front explanatory view of another example of the liquid ejection unit according to the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the present invention is not limited to the embodiments shown below, and can be changed within the scope of those skilled in the art, such as other embodiments, additions, modifications, deletions, etc. is also included in the scope of the present invention as long as the functions and effects of the present invention are exhibited. Further, in each drawing, constituent elements and corresponding portions having the same configuration or function are denoted by the same reference numerals, and descriptions thereof are omitted.

(liquid ejection head)
FIG. 1 is a schematic cross-sectional view of a liquid ejection head according to an embodiment of the invention. FIG. 2 is a schematic plan view of the liquid ejection head, viewed from the nozzle surface side (also referred to as the liquid ejection side). 1 corresponds to FIG. 2, and FIG. 1 is a sectional view taken along line AA of FIG.
As shown in FIG. 1, the liquid ejection head of this embodiment includes a nozzle forming layer 1, a liquid chamber forming substrate 2, and a driving circuit 92. As shown in FIG.

The nozzle forming layer 1 has a vibration layer 3 , a piezoelectric actuator 12 that is a piezoelectric layer, an electrode pad 90 , a first protective layer 81 and a second protective layer 82 . The electrode pad 90 is an example of a circuit connecting portion.

The nozzle forming layer 1 has nozzles 4 from which liquid (for example, ink) is ejected. A liquid in a liquid chamber 6 formed by a part of the nozzle forming layer 1 and the liquid chamber forming substrate 2 is ejected from the nozzle 4 by driving the piezoelectric actuator 12 .

The vibration layer 3 vibrates by driving the piezoelectric actuator 12 . Although the material of the vibration layer 3 is not particularly limited, for example, Al ₂ O ₃ , SiN, SiO ₂ , HTO (High Temperature Oxide), or a structure in which several kinds of these materials are laminated can be used. .

The liquid chamber forming substrate 2 has a liquid chamber 6 communicating with the nozzle 4 . A circuit protection layer 17 is formed between the liquid chamber forming substrate 2 and the vibration layer 3 . The circuit protection layer 17 has a function of protecting the drive circuit 92 and the interlayer wiring layer 95 .

The material of the circuit protection layer 17 is not particularly limited, and examples thereof include PTFE (polytetrafluoroethylene) resin. Also, the location where the circuit protection layer 17 is formed is not particularly limited, and is formed so as to cover the drive circuit 92 and the interlayer wiring layer 95, for example. The nozzle forming layer 1 may have the circuit protective layer 17 , and the liquid chamber forming substrate 2 may have the circuit protective layer 17 .

The piezoelectric actuator 12 has a lower electrode 21 , a piezoelectric body 22 and an upper electrode 23 . The lower electrode 21 may be used as a common electrode and the upper electrode 23 may be used as an individual electrode, or the lower electrode 21 may be used as an individual electrode and the upper electrode 23 may be used as a common electrode.

The piezoelectric body 22 is not particularly limited, and for example, PZT (lead zirconate titanate) or the like can be used.
Moreover, the lower electrode 21 and the upper electrode 23 are not particularly limited, and known electrode materials can be used. For example, Pt etc. are mentioned.

The piezoelectric actuator 12 or the piezoelectric body 22 is formed in the vicinity of the nozzle 4 and on the side of the vibration layer 3 where the liquid is ejected (nozzle surface side). It may also be described that the piezoelectric actuator 12 is formed on the vibration layer 3 . By forming the piezoelectric actuator 12 at such a location, a vibrating plate for applying pressure to the liquid sucked and introduced into the liquid chamber 6 and ejecting the liquid from the nozzle 4 becomes unnecessary.

The piezoelectric actuator 12 is connected to the drive circuit 92 via connection electrodes 94b and 94c. Here, for example, the lower electrode 21 is connected to the drive circuit 92 via the connection electrode 94b, and the upper electrode 23 is connected to the drive circuit 92 via the connection electrode 94c.

As shown in FIG. 1, a piezoelectric actuator 12a that is not connected to the drive circuit 92 and does not contribute to liquid ejection may be provided. Such a piezoelectric actuator 12a can be used as a reference for the nozzle forming position when forming the nozzle 4, for example.

The drive circuit 92 is connected to the electrode pad 90, and is energized from the power source through the electrode pad 90 and the connection electrode 94a. The drive circuit 92 is formed on the side opposite to the electrode pad 90 with the vibration layer 3 interposed therebetween. The drive circuit 92 is preferably formed on the liquid chamber forming substrate 2, although this is not a limitation. In this case, there is an advantage that the driving circuit 92 can be easily manufactured.

The drive circuit 92 is not particularly limited, but may be, for example, a cmos circuit. Although not particularly limited, the drive circuit 92 is shown divided into a portion on the electrode pad 90 side and a portion on the piezoelectric actuator 12 side. ing. For example, a known electrode material can be used for the interlayer wiring layer 95 .

The electrode pad 90 (circuit connection portion) is formed on the liquid ejection side (nozzle surface side) of the vibration layer 3, and is connected to the drive circuit 92 via the connection electrode 94a. Although two connection electrodes 94a are illustrated here, the present invention is not limited to this. Two connection electrodes 94a are shown in consideration of two connection electrodes 94b and 94c corresponding to the lower electrode 21 and the upper electrode 23 in the piezoelectric actuator 12. FIG.

As illustrated, in the present embodiment, protective layers 81 and 82 are formed on the liquid ejection side (nozzle surface side). The first protective layer 81 is formed around the electrode pad 90 and forms an opening 85 of the electrode pad 90 . A second protective layer 82 is formed on the piezoelectric actuator 12 . By forming the first protective layer 81 and the second protective layer 82, for example, at least one of the piezoelectric actuator 12, the vibration layer 3, and the electrode pad 90 can be protected, and deterioration of the member can be prevented. can be achieved.

The liquid ejection head of this embodiment has a waterproof film 88 formed on the surfaces of the first protective layer 81 and the second protective layer 82 . By having the water-resistant film 88 , it is possible to further block the permeation of water, and it is possible to further suppress the problem that the performance of the piezoelectric actuator 12 is deteriorated due to the influence of water intruding through the protective layer.
2, illustration of the waterproof film 88 is omitted.

In this embodiment, the first protective layer 81 and the second protective layer 82 are not continuous. As shown, the first protective layer 81 and the second protective layer 82 are separated from each other by a separation groove 86 and are discontinuous. By doing so, in the liquid ejection head in which the piezoelectric actuator 12 and the electrode pad 90 (circuit connecting portion) are formed in the nozzle forming layer 1 , the piezoelectricity of the piezoelectric actuator 12 is increased by absorbing moisture from the opening 85 of the electrode pad 90 . A decrease in performance can be suppressed.

Note that the liquid ejection head of this embodiment is not limited to the configuration described above. The liquid ejection head of this embodiment includes a nozzle formation layer 1 having a piezoelectric layer, nozzles 4 penetrating the nozzle formation layer, liquid chambers 6 communicating with the nozzles 4, and driving waveforms applied to the piezoelectric layer. and a drive circuit 92 for driving the .

Next, driving waveforms used by the liquid ejection head of this embodiment will be described.
The present embodiment suppresses residual vibration generated in the nozzle forming layer by a drive waveform when suppressing residual vibration generated in the nozzle forming layer during ejection in a liquid ejection head having a structure that does not have individual liquid chambers.

The drive waveform applied to the piezoelectric layer by the drive circuit has a first waveform and a second waveform.
The first waveform is a waveform portion for applying a drive voltage to the piezoelectric layer to eject liquid from the nozzle.
The second waveform is a waveform portion for applying a suppression voltage for suppressing residual vibration generated in the nozzle forming layer.
The drive voltage should preferably have an amplitude greater than the suppression voltage.

The drive waveform of this embodiment is configured to apply the suppression voltage at a predetermined timing with respect to the rising element of the drive voltage. More specifically, the drive waveform is arranged such that the fall element or rise element of the suppression voltage is applied at a predetermined timing to the rise element of the drive voltage.
The predetermined timing is calculated using the timing of applying the rising element of the drive voltage and the natural vibration period. Here, the predetermined timing may be calculated each time a drive waveform is applied to the liquid ejection head, or may be calculated in advance at the time of manufacturing the liquid ejection head and stored in a memory or the like in the liquid ejection head. may be stored in Further, a driving waveform having a calculated predetermined timing may be stored in a memory or the like.
The natural vibration period is the primary natural vibration period of the piezoelectric layer when the liquid is filled in the liquid chamber and the nozzle. In the following description, the natural vibration period is referred to as "Tc" as appropriate.

By doing so, it is possible to suppress residual vibration generated in the nozzle forming layer due to the drive waveform without adding a new mechanical mechanism.
Details of the drive waveform will be described below in each embodiment.

Embodiment 1.
FIG. 3 is a diagram illustrating an example of drive waveforms according to the first embodiment. FIG. 3 and FIGS. 5 and 7, which will be described later, schematically show driving waveforms, where the vertical axis indicates voltage (volt) and the horizontal axis indicates time (microseconds).
In the driving waveform W1 of the first embodiment, the second waveform W12 causes the suppression voltage to rise at timing T12 of n×Tc (n is a positive integer) with respect to the driving voltage rising element U11 of the first waveform W11. It has a lowering element D12.

As shown in FIG. 3, among the plurality of waveform elements that the first waveform W11 has, the drive voltage rising element U11 that causes a voltage change at the rise of the drive voltage and the plurality of waveform elements that the second waveform W12 has Among them, the rising element U11 of the driving voltage and the falling element D12 of the suppression voltage that causes a different voltage change are separated by an interval of n×Tc.
FIG. 3 shows the interval (n×Tc) between the timing T11 at which the rising element U11 of the driving voltage starts and the timing T12 at which the falling element D12 of the suppression voltage starts. In addition, it is preferable that the fall element D12 of the suppression voltage is provided in the range from the start to the end of the rise element U11 of the drive voltage (slanted portion in the drawing).

The effect of the drive waveform of this embodiment will be described.
4A and 4B are diagrams for explaining the effect of the driving waveform of the first embodiment, in which (a) is an example of the driving waveform of the comparative example, (b) is an example of the driving waveform of the present embodiment, and (c) is the comparative example. and the waveforms of this embodiment are applied. In FIG. 4, the values of the comparative example are indicated by a solid line, and the values of the present embodiment are indicated by a dashed line.
In the case of the configuration of the liquid ejection head as shown in FIG. 1, residual vibration occurs in the nozzle formation layer after ejection.

When the drive waveform W1 shown in FIG. 3 is used, the drive circuit 92 applies the suppression voltage fall element D12 to the drive voltage rise element U11 at the timing T12 of n×Tc. As a result, the liquid ejection head can cancel the vibration generated by the ejection, and can suppress the residual vibration generated in the nozzle formation layer.
In this manner, the driving waveform W1 has a waveform configuration that can suppress the residual vibration generated in the nozzle formation layer.

Embodiment 2.
FIG. 5 is a diagram illustrating an example of drive waveforms according to the second embodiment.
In the driving waveform W2 of the second embodiment, the second waveform W22 is (m−0.5)×Tc (m is a positive integer) timing T22 with respect to the rising element U21 of the driving voltage of the first waveform W21. has a rise-up element U22 of the suppression voltage.

As shown in FIG. 5, a drive voltage rise element U21 that causes a voltage change in the rise of the drive voltage and a suppression voltage rise element U22 that causes the same voltage change as the drive voltage rise element U21 are ( m−0.5)×Tc apart.
FIG. 5 shows the interval ((m−0.5)×Tc) between the timing T21 at which the rising element U21 of the driving voltage starts and the timing T22 at which the rising element U22 of the suppression voltage starts. It is preferable that the suppression voltage rising element U22 is provided for the range from the start to the end of the drive voltage rising element U11.

The effect of the drive waveform of this embodiment will be described.
6A and 6B are diagrams for explaining the effect of the driving waveform of the second embodiment, in which (a) is an example of the driving waveform of the comparative example, (b) is an example of the driving waveform of the present embodiment, and (c) is the comparative example. and the waveforms of this embodiment are applied. In FIG. 6, the values of the comparative example are indicated by a solid line, and the values of the present embodiment are indicated by a broken line.

Using the drive waveform W2 shown in FIG. 5, the drive circuit 92 applies the suppression voltage rising element U22 to the driving voltage rising element U21 at the timing T22 of (m−0.5)×Tc. It will be. As a result, the liquid ejection head can cancel the vibration generated by the ejection, and can suppress the residual vibration generated in the nozzle formation layer.
In this manner, the driving waveform W2 has a waveform configuration that can suppress the residual vibration generated in the nozzle forming layer.

Embodiment 3.
FIG. 7 is a diagram illustrating an example of drive waveforms according to the third embodiment.
In the driving waveform W3 of the third embodiment, the second waveform W32 has a suppressing voltage falling element D32 at the timing T32 of n×Tc in contrast to the driving voltage rising element U31 of the first waveform W31, In addition, at timing T33 of (m−0.5)×Tc, there is a rising element U32 of the suppression voltage.

As shown in FIG. 7, the rising element U31 of the driving voltage and the falling element D32 of the suppression voltage that causes a voltage change different from that of the rising element U31 of the driving voltage are separated by an interval of n×Tc. Further, the rising element U31 of the drive voltage and the rising element U32 of the suppression voltage that causes the same voltage change as the rising element U31 of the drive voltage are separated by an interval of (m−0.5)×Tc.
In FIG. 7, the interval (n×Tc) between the timing T31 at which the rising element U31 of the driving voltage starts and the timing T32 at which the falling element D12 of the suppression voltage starts and the rising element U32 of the suppression voltage are The interval ((m−0.5)×Tc) from the start timing T32 is shown. It is preferable that the suppression voltage fall element D32 and the suppression voltage rise element U32 are provided for the range from the start to the end of the drive voltage rise element U11.

The effect of the drive waveform of this embodiment will be described.
8A and 8B are diagrams for explaining the effect of the driving waveform of the third embodiment, in which (a) is an example of the driving waveform of the comparative example, (b) is an example of the driving waveform of the present embodiment, and (c) is the comparative example. and the waveforms of this embodiment are applied. In FIG. 8, the values of the comparative example are indicated by a solid line, and the values of the present embodiment are indicated by a broken line.

Using the driving waveform W3 shown in FIG. 7, the driving circuit 92 applies the suppression voltage falling element D32 to the driving voltage rising element U21 at the timing T32 of n×Tc, and (m− 0.5)×Tc, the rising element U22 of the suppression voltage is applied at the timing T22. As a result, the liquid ejection head can cancel the vibration generated by the ejection, and can suppress the residual vibration generated in the nozzle formation layer.
In this manner, the driving waveform W3 has a waveform configuration that can suppress the residual vibration generated in the nozzle formation layer.

(Device for ejecting liquid and liquid ejection unit)
Next, an example of an apparatus for ejecting liquid according to the present invention will be described with reference to FIGS. 9 and 10. FIG. FIG. 9 is an explanatory plan view of the essential parts of the device, and FIG. 10 is an explanatory side view of the essential parts of the same device.

This apparatus is a serial type apparatus, and a main scanning movement mechanism 493 reciprocates the carriage 403 in the main scanning direction. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 is bridged between the left and right side plates 491A and 491B to movably hold the carriage 403 . A main scanning motor 405 reciprocates the carriage 403 in the main scanning direction via a timing belt 408 stretched between a drive pulley 406 and a driven pulley 407 .

The carriage 403 is equipped with a liquid ejection unit 440 in which a liquid ejection head 404 and a head tank 441 according to the present invention are integrated. The liquid ejection head 404 of the liquid ejection unit 440 ejects yellow (Y), cyan (C), magenta (M), and black (K) liquids, for example. Further, the liquid ejection head 404 is mounted with a nozzle row having a plurality of nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and the ejection direction facing downward.

The liquid stored in the liquid cartridge 450 is supplied to the head tank 441 by the supply mechanism 494 for supplying the liquid stored outside the liquid ejection head 404 to the liquid ejection head 404 .

The supply mechanism 494 is composed of a cartridge holder 451 which is a filling section for mounting the liquid cartridge 450, a tube 456, a liquid feeding unit 452 including a liquid feeding pump, and the like. Liquid cartridge 450 is detachably attached to cartridge holder 451 . The liquid is sent from the liquid cartridge 450 to the head tank 441 by the liquid sending unit 452 via the tube 456 .

This device has a transport mechanism 495 for transporting the paper 410 . The transport mechanism 495 includes a transport belt 412 as transport means and a sub-scanning motor 416 for driving the transport belt 412 .

The transport belt 412 attracts the paper 410 and transports it at a position facing the liquid ejection head 404 . The conveying belt 412 is an endless belt and stretched between a conveying roller 413 and a tension roller 414 . Adsorption can be performed by electrostatic adsorption, air suction, or the like.

The conveying belt 412 rotates in the sub-scanning direction when the conveying roller 413 is rotationally driven by the sub-scanning motor 416 via the timing belt 417 and the timing pulley 418 .

Further, on one side of the carriage 403 in the main scanning direction, a maintenance/recovery mechanism 420 for maintaining/recovering the liquid ejection head 404 is arranged on the side of the transport belt 412 .

The maintenance/recovery mechanism 420 includes, for example, a cap member 421 that caps the nozzle surface (surface on which nozzles are formed) of the liquid ejection head 404, a wiper member 422 that wipes the nozzle surface, and the like.

The main scanning movement mechanism 493, supply mechanism 494, maintenance/recovery mechanism 420, and transport mechanism 495 are attached to a housing including side plates 491A and 491B and a back plate 491C.

In this apparatus configured as described above, the paper 410 is fed onto the conveying belt 412 and attracted thereto, and the conveying belt 412 is rotated to convey the paper 410 in the sub-scanning direction.

Therefore, by driving the liquid ejection head 404 according to the image signal while moving the carriage 403 in the main scanning direction, the liquid is ejected onto the stationary paper 410 to form an image.

As described above, since this apparatus includes the liquid ejection head according to the present invention, it is possible to stably form a high-quality image.

Next, an example of the liquid ejection unit according to the invention will be described with reference to FIG. FIG. 11 is an explanatory plan view of the main part of the same unit.

Among the members constituting the apparatus for ejecting the liquid, the liquid ejection unit includes a housing portion composed of side plates 491A and 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, a liquid It is composed of an ejection head 404 .

A liquid ejection unit can also be constructed in which at least one of the maintenance/restoration mechanism 420 and the supply mechanism 494 is further attached to, for example, the side plate 491B of the liquid ejection unit.

Next, another example of the liquid ejection unit according to the present invention will be explained with reference to FIG. FIG. 12 is an explanatory front view of the same unit.

This liquid ejection unit comprises a liquid ejection head 404 to which a channel component 444 is attached, and a tube 456 connected to the channel component 444 .

Note that the channel component 444 is arranged inside the cover 442 . A head tank 441 can also be included in place of the channel component 444 . A connector 443 for electrical connection with the liquid ejection head 404 is provided above the channel component 444 .

In the present application, a "device that ejects liquid" is a device that includes a liquid ejection head or a liquid ejection unit, drives the liquid ejection head, and ejects liquid. Devices that eject liquid include not only devices that can eject liquid onto an object to which liquid can adhere, but also devices that eject liquid into air or liquid.

The "liquid ejecting device" can include means for feeding, transporting, and ejecting an object to which liquid can adhere, as well as a pre-processing device, a post-processing device, and the like.

For example, as a "device that ejects liquid", an image forming device that ejects ink to form an image on paper, and powder is formed in layers to form a three-dimensional object (three-dimensional object). There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that ejects a modeling liquid onto a formed powder layer.

Further, the "apparatus for ejecting liquid" is not limited to one that visualizes significant images such as characters and figures with the ejected liquid. For example, it includes those that form patterns that have no meaning per se, and those that form three-dimensional images.

The above-mentioned "substance to which a liquid can adhere" means a substance to which a liquid can adhere at least temporarily, such as a substance to which a liquid adheres and adheres, a substance which adheres and permeates, and the like. Specific examples include media such as recording media such as paper, recording paper, recording paper, film, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, and unless otherwise specified, includes anything that has liquid on it.

The materials of the above "things to which liquids can adhere" include paper, threads, fibers, fabrics, leather, metals, plastics, glass, wood, ceramics, building materials such as wallpaper and flooring, textiles for clothing, etc. However, it is sufficient if it can be attached.

The "liquid" also includes inks, treatment liquids, DNA samples, resists, pattern materials, binders, modeling liquids, and solutions and dispersions containing amino acids, proteins, and calcium.

Further, the ``device for ejecting liquid'' includes a device in which a liquid ejection head and an object to which liquid can be adhered move relatively, but is not limited to this. Specific examples include a serial type apparatus in which the liquid ejection head is moved and a line type apparatus in which the liquid ejection head is not moved.

In addition, as a "liquid ejecting device", there are other processing liquid coating devices that eject processing liquid onto the paper in order to apply the processing liquid to the surface of the paper for the purpose of modifying the surface of the paper, raw materials is dispersed in a solution, and sprays a composition liquid through a nozzle to granulate fine particles of the raw material.

A "liquid ejection unit" is a combination of functional parts and mechanisms integrated with a liquid ejection head, and is a collection of parts related to ejection of liquid. For example, the "liquid ejection unit" includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance/recovery mechanism, and a main scanning movement mechanism with a liquid ejection head.

Here, integration means, for example, that the liquid ejection head and functional parts or mechanisms are fixed to each other by fastening, adhesion, or engagement, or that one is held movably with respect to the other. include. Also, the liquid ejection head, the functional parts, and the mechanism may be configured to be detachable from each other.

For example, as a liquid ejection unit, there is a liquid ejection head and a head tank integrated like a liquid ejection unit 440 shown in FIG. Also, there is a type in which a liquid ejection head and a head tank are integrated by being connected to each other by a tube or the like. Here, it is also possible to add a unit including a filter between the head tank and the liquid ejection head of these liquid ejection units.

Further, there is a liquid ejection unit in which a liquid ejection head and a carriage are integrated.

Further, as a liquid ejection unit, there is one in which the liquid ejection head is movably held by a guide member constituting a part of the scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated. Further, as shown in FIG. 7, there is a liquid ejection unit in which a liquid ejection head, a carriage, and a main scanning movement mechanism are integrated.

There is also a liquid ejection unit in which the liquid ejection head, the carriage, and the maintenance and recovery mechanism are integrated by fixing a cap member, which is a part of the maintenance and recovery mechanism, to a carriage to which the liquid ejection head is attached. .

Further, as a liquid ejection unit, as shown in FIG. 8, there is a unit in which the liquid ejection head and the supply mechanism are integrated by connecting a tube to a liquid ejection head to which a head tank or a flow path component is attached. .

It is assumed that the main scanning movement mechanism also includes a single guide member. Also, the supply mechanism includes a single tube and a single loading unit.

Also, the "liquid ejection head" is not limited to the pressure generating means to be used. For example, in addition to the piezoelectric actuator described in the above embodiment (which may use a laminated piezoelectric element), a thermal actuator using an electrothermal conversion element such as a heating resistor, and a vibration plate and a counter electrode may be used. An electrostatic actuator or the like may be used.

Further, the terms used in the present application, such as image formation, recording, printing, printing, printing, modeling, etc., are synonymous.

1 nozzle forming layer 4 nozzle 6 liquid chamber 92 drive circuit 404 liquid ejection heads D12, D32 suppression voltage fall elements U11, U21, U31 drive voltage rise elements U22, U32 drive voltage rise elements W1, W2, W3 Drive waveforms W11, W21, W31 First waveforms W12, W22, W32 Second waveforms

JP 2019-104152 A

Claims (5)

a nozzle forming layer having a piezoelectric layer;
a nozzle that penetrates the nozzle forming layer;
a liquid chamber communicating with the nozzle;
a drive circuit that applies a drive waveform to drive the piezoelectric layer,
Assuming that the natural vibration period is Tc,
The driving waveform is a first waveform for applying a driving voltage for ejecting the liquid in the liquid chamber from the nozzle, and a rising element of the driving voltage at a timing of n×Tc (n is a positive integer). , and a second waveform applying a voltage ramp-down component. a nozzle forming layer having a piezoelectric layer;
a nozzle that penetrates the nozzle forming layer;
a liquid chamber communicating with the nozzle;
a drive circuit that applies a drive waveform to drive the piezoelectric layer,
Assuming that the natural vibration period is Tc,
The driving waveform includes a first waveform for applying a driving voltage for ejecting the liquid in the liquid chamber from the nozzle, and (m−0.5)×Tc (m is positive) with respect to the rising element of the driving voltage. and a second waveform that applies the voltage rise element at a timing of (integer of ). a nozzle forming layer having a piezoelectric layer;
a nozzle that penetrates the nozzle forming layer;
a liquid chamber communicating with the nozzle;
a drive circuit that applies a drive waveform to drive the piezoelectric layer,
Assuming that the natural vibration period is Tc,
The driving waveform is a first waveform for applying a driving voltage for ejecting the liquid in the liquid chamber from the nozzle, and a rising element of the driving voltage at a timing of n×Tc (n is a positive integer). , a voltage falling element is applied, and a second waveform for applying a voltage rising element at a timing of (m−0.5)×Tc (m is a positive integer). 4. The liquid ejection head according to claim 1, wherein the amplitude of said drive voltage is greater than the voltage applied with said second waveform. An apparatus for ejecting liquid, comprising the liquid ejection head according to any one of claims 1 to 4.

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