Patent Publication Number: US-2023157177-A1

Title: Actuator, liquid discharge head, liquid discharge device, and liquid discharge apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2021-186491, filed on Nov. 16, 2021, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein. 
     BACKGROUND 
     Technical Field 
     The present embodiment relates to an actuator, a liquid discharge head, a liquid discharge device, and a liquid discharge apparatus. 
     Related Art 
     A liquid discharge head that discharges liquid employs a damper including a Si-based membrane formed by a semiconductor process. 
     The liquid discharge head is provided with a damper including a deformable damper that forms a part of a wall surface of a common chamber. The damper is provided with a thick portion that increases in thickness toward an end part of the common chamber in a longitudinal direction. It is possible to improve the ability for discharging air bubbles from the common chamber. 
     An inkjet printhead employing a piezoelectric method includes an intermediate substrate formed with multiple dampers that penetrate the intermediate substrate at positions corresponding to the other end parts of multiple pressure chambers. It is possible to reduce crosstalk during the discharge of ink. The intermediate substrate is provided with a damping membrane that alleviates changes in the internal pressure of a manifold, and a cavity is formed below the damping membrane. The damping membrane is formed by thinning a part of a Si substrate that forms the intermediate substrate. 
     SUMMARY 
     An actuator includes: a frame having a recess; an actuator substrate including a common chamber; a damper between the frame and the actuator substrate, the damper defining a part of a wall of the common chamber of the actuator substrate. The damper includes multiple layers laminated in a lamination direction, and the multiple layers is symmetrical in the lamination direction with respect to a center of the damper in the lamination direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of embodiments of the present disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings, wherein: 
         FIG.  1    is an exploded perspective, schematic view for explaining an example of a damper and a liquid discharge head according to the present embodiment; 
         FIG.  2    is a schematic, cross-sectional view for explaining an example of the damper and the liquid discharge head according to the present embodiment; 
         FIG.  3    is a schematic, cross-sectional view for explaining an example of the damper and the liquid discharge head according to the present embodiment; 
         FIG.  4    is a schematic, cross-sectional view for explaining an example of a damper according to the present embodiment; 
         FIG.  5    is another schematic, cross-sectional view for explaining an example of the damper and the liquid discharge head according to the present embodiment; 
         FIGS.  6 A to  6 C  are schematic, cross-sectional views for explaining examples of an integrated damper according to the present embodiment; 
         FIG.  7    is a schematic view of an example of a liquid discharge apparatus; 
         FIG.  8    is a schematic view of another example of the liquid discharge apparatus; 
         FIG.  9    is a schematic view of an example of a liquid discharge device; and 
         FIG.  10    is a schematic view of another example of a liquid discharge device. 
     
    
    
     The accompanying drawings are intended to depict embodiments of the present disclosure 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. 
     A damper  103 , an actuator  106 , a liquid discharge head  404 , a liquid discharge device  440 , and a liquid discharge apparatus  500  according to the present embodiment are described below with reference to the drawings. The present embodiment is not limited to the embodiment indicated below, and changes such as other embodiments, additions, modifications, omissions, and the like are possible within the scope that is conceivable for a person skilled in the art. All of these changed configurations are also included in the scope of the present embodiment, as long as an action or an effect of the present embodiment is exhibited. 
     The damper of the present embodiment is a damper to be bonded to a frame having a recess and an actuator substrate including a common chamber. The damper includes a damper forming a part of a wall surface of the common chamber when the damper is bonded to the actuator substrate. The damper has a laminated structure including multiple layers and is symmetrical in a lamination direction, with respect to a center in the lamination direction. 
     The recess provided in the frame may be referred to as a cavity or the like. The damper may be referred to as a membrane or the like. 
     The liquid discharge head of the present embodiment includes the damper of the present embodiment, and additionally includes the frame, the actuator substrate, a nozzle substrate, and the like. In the present embodiment, the damper and the frame may form an integrated damper. 
       FIG.  1    illustrates a view for explaining the damper and the liquid discharge head  404  according to the present embodiment. 
       FIG.  1    is a view for schematically explaining an exploded perspective view of the liquid discharge head of the present embodiment. The liquid discharge head  404  of the present embodiment includes a nozzle substrate  101 , an actuator substrate  102 , a damper  103 , and a frame  104 . The actuator  106  includes the actuator substrate  102 , the damper  103 , and the frame  104 . The liquid discharge head  404  includes the actuator  106  and the nozzle substrate  101 . 
     The nozzle substrate  101  includes a nozzle  111  that discharges a liquid (for example, ink). 
     The actuator substrate  102  includes a common chamber  121  and is bonded to the nozzle substrate  101  and the damper  103 . The common chamber  121  is illustrated schematically in  FIG.  1   , and is not limited to the common chamber illustrated in  FIG.  1   . 
     The frame  104  includes a recess, which will be described later, and is bonded to the damper  103 . 
     The damper  103  is bonded to the frame  104  and the actuator substrate  102 . A bonding method may be appropriately selected, as described later. 
     The damper  103  includes a damper  131  that forms a part of a wall surface of the common chamber  121  when the damper  103  is bonded to the actuator substrate  102 . The shape of the damper  131  is illustrated schematically in  FIG.  1   , and is not limited to the illustrated shape. 
     Employing the damper  103  makes it possible to use vibration of the damper  131  to dampen vibration of the liquid. For example, employing the damper  103  makes it possible to dampen vibration of the liquid flowing through channel branches (channels) formed on the actuator substrate  102 . In addition, it is possible to reduce propagation of a vibration generated in one channel (a channel is defined as one nozzle unit) to another channel. 
     Next,  FIGS.  2  and  3    are views for explaining the damper of the present embodiment. 
       FIG.  2    is a schematic, cross-sectional view along a nozzle arrangement direction of the liquid discharge head of the present embodiment, and corresponds to a schematic, cross-sectional view taken along a line AA in  FIG.  1   . 
       FIG.  3    is a schematic, cross-sectional view in a direction perpendicular to the nozzle arrangement direction of the liquid discharge head of the present embodiment, and corresponds to a schematic, cross-sectional view along a line BB in  FIG.  1   . 
     As illustrated in the drawings, the frame  104  includes a recess  141 . By providing the recess  141 , the damper  131  can be prevented from contacting the frame  104 , when the damper  131  is deformed, for example. The recess  141  may also be referred to as a cavity, a damper region, a damper chamber, and the like. 
     In the examples illustrated in  FIGS.  2  and  3   , the frame  104  and the damper  103  are bonded by an adhesive  151 , but any other bonding methods may be used. 
     The actuator substrate  102  includes the common chamber  121 , and when the damper  103  is bonded to the actuator substrate  102 , the damper  131  forms a part of the wall surface of the common chamber  121 . For example, when the liquid in the common chamber  121  vibrates, the damper  131  can also vibrate to dampen the vibration of the liquid. It is possible to alleviate propagation of pressure to adjacent channels and fluctuations in the ink flow rate. For example, fluctuations of the pressure in the liquid chamber and the channels in the actuator substrate  102  can be alleviated. 
     For example, the damper  103  includes the damper  131  and a peripheral thick part  132 . The peripheral thick part  132  is a part to be bonded to the actuator substrate  102 . The peripheral thick part  132  is provided to improve a bonding performance between the damper  103  and the actuator substrate  102  or the frame  104 . However, the peripheral thick part  132  may not be provided. 
     In the illustrated example, only the common chamber  121  is illustrated in the actuator substrate  102 , but the actuator substrate  102  may also include individual chambers, a piezoelectric element, channels, and the like. For example, the individual chambers communicate with the nozzle  111  provided in the nozzle substrate  101 . The shape, the arrangement, and the number of the nozzles  111  are not limited to the shape, the arrangement, and the number of the nozzles illustrated in the figures, and can be appropriately selected. 
       FIG.  4    illustrates another view for explaining the damper of the present embodiment. 
       FIG.  4    is a schematic cross-sectional view for explaining the actuator substrate  102  of  FIG.  3   . 
     As illustrated in  FIG.  4   , the actuator substrate  102  includes, for example, a diaphragm  125  and a channel plate  127 . The actuator substrate  102  includes an individual chamber  122  communicating with the nozzle  111 , and also includes a liquid restrictor  123 , a piezoelectric element  124  (pressure generator), a channel  126 , and the like. In addition, an introduction channel is provided between the channel  126  and the liquid restrictor  123  to introduce a liquid from the channel  126  (common channel) to the liquid restrictor  123 . In the present example, the piezoelectric element  124  applies pressure to the liquid in the individual chamber  122  to discharge the liquid through the nozzle  111 . The liquid is supplied to the individual chambers  122  from the common chamber  121  via the channel  126 . 
     Next, a detailed example of the damper in the present embodiment will be described. 
     In the present embodiment, the damper has a laminated structure including multiple layers and is symmetrical in a lamination direction, with respect to the center in the lamination direction. 
     The damper having the laminated structure including the multiple layers makes it possible to easily control the physical properties of the damper. For example, the type (material) and thickness of each layer can be appropriately selected, and the number of layers can be appropriately selected. If the damper is formed by a single layer, it is not possible to change physical properties that are dependent on the type of film. On the other hand, in the damper having the laminated structure, the stress and the like may be unevenly distributed, and thus the damper may fail to function as a damper. Therefore, in the present embodiment, the damper has a laminated structure including multiple layers, and is symmetrical in the lamination direction, with respect to the center in the lamination direction. 
     Thus, an uneven distribution of the stress and the like can be reduced, while securing an advantage of increasing the degree of freedom in the physical properties of the damper. 
     Also, by designing the damper symmetrically with respect to the center in the lamination direction, it is easier to control a film stress and a center of rigidity of the damper. According to the present embodiment, the damper can be deformed with the same amount of deformation for both negative pressure and positive pressure in the vibration of the liquid, and can be deformed linearly, and thus vibration can be efficiently dampened. 
     An example of the laminated structure of the damper is illustrated in  FIG.  5   . 
       FIG.  5    is a schematic cross-sectional view of a circular portion indicated by a dashed line in  FIGS.  2  and  3   . 
     In the illustrated example, the laminated structure has a five-layer structure including a first layer  301  to a fifth layer  305  in this order from a lower side in the lamination direction. A dashed line in  FIG.  5    indicates the center in the lamination direction. 
     In the present example, the first layer  301  and the fifth layer  305  are made of SiO 2 , the second layer  302  and the fourth layer  304  are made of polysilicon (Poly-Si), and the third layer  303  is made of SiN. That is, the corresponding layers with respect to the center in the lamination direction are formed of the same material and components. 
     The thickness of each layer can be appropriately selected, but the corresponding layers with respect to the center in the lamination direction have the same thickness. For example, the first layer  301  and the fifth layer  305  have the same thickness, and the second layer  302  and the fourth layer  304  have the same thickness. 
     For example, when an upper portion of the laminated structure is referred to as an upper layer and a lower portion is referred to as a lower layer with respect to the center in the lamination direction, a thickness a of the upper layer and a thickness b of the lower layer are the same. It can also be said that the center in the lamination direction is a half point (½ point) of the total thickness of the damper  131 . 
     Thus, the damper  131  in the present embodiment is symmetrical in the lamination direction, with respect to the center in the lamination direction. 
     The material of each layer, the number of layers, and the like are not limited to the material, the number of layers, and the like described above, and can be appropriately changed. 
     For example, the illustrated example has a five-layer laminated structure, but the present embodiment is not limited thereto, and the number of layers may be three or another number. 
     The damper has the laminated structure including the multiple layers, and thus, it is possible to adjust the material of each layer, the thickness of each layer, and the like, and freely design the physical properties of the entire film. Thus, the degree of freedom in the physical properties of the film can be increased, and it is easier to choose a layer configuration that is optimal for the function of the damper. 
     The damper preferably has an elastic compliance of 7×10 −17  Pa −1  or more. To fully exhibit the function of the damper, it is preferable to adjust the elastic compliance to fall within a suitable range. If the elastic compliance of the damper is within the above-described range, it is easier to choose a layer configuration that is optimal for the function of the damper. 
     The elastic compliance of the damper is determined by the film thickness and the Young&#39;s modulus of the damper, when the dimensions of the channel branches through which the liquid flows are unchanged. The Young&#39;s modulus of the damper is not limited, but is preferably 3 GPa or more and 200 GPa or less. In this case, it is easier to obtain an elastic compliance of the damper that is within the above-described preferable range, and the propagation of vibrations in the liquid can be further reduced. 
     The damper preferably has a thickness of 2 μm or more and 10 μm or less. In this case, it is easier to obtain an elastic compliance of the damper that is within the above-described preferable range, and the propagation of vibrations in the liquid can be further reduced. 
     To fully exhibit the function of the damper, it is also preferable to adjust the film stress to fall within a suitable range. The damper preferably has a film stress of −200 MPa or more and 200 MPa or less. If the tensile stress is too strong, the damper may break, and if the compressive stress is too strong, the damper may buckle and form wrinkles. When the film stress is within the above-described range, the damper is prevented from breaking and it is possible to maintain the shape of the damper. Thus, the propagation of vibrations in the liquid can be further reduced. 
     The suitable range of the film stress of the damper can also be appropriately changed by selection of the type of material for each layer. For example, in the case of a laminated structure including SiO 2 , SiN, and polysilicon (Poly-Si), the damper breaks at 300 MPa, and at about −100 MPa, the damper can withstand practical use, but starts to buckle. Taking the above into consideration, it is preferable that the film stress of the damper is −200 MPa or more and 200 MPa or less, which is a range where breakage, buckling, and the like of the damper can be prevented. Even if a non-ductile, brittle material is used, the film stress of the damper is preferably −200 MPa or more and 200 MPa or less. 
     The material forming the layers can be appropriately selected, and examples thereof include Si, polysilicon (Poly-Si), SiN, SiO 2 , and Al 2 O 3 . By using the materials mentioned above, the elastic compliance, the film stress, and the Young&#39;s modulus can be easily set within the preferred ranges described above. In addition to the materials mentioned above, an organic material using vapor deposition or spin coating can also be used. 
     Next, the integrated damper of the present embodiment will be described. 
     The present embodiment provides an integrated damper including a frame and the damper according to the present embodiment, and in the integrated damper, the frame and the damper are bonded together. 
     Examples of the integrated damper of the present embodiment are illustrated in  FIGS.  6 A to  6 C . The integrated damper can be manufactured by employing a semiconductor process to form the damper and the frame as an integrated unit, for example. 
     In the integrated damper illustrated in  FIG.  6 A , the frame  104  and the damper  103  are bonded with the adhesive  151 . The integrated damper can be manufactured, for example, by attaching a wafer on which the damper  131  being a multilayer film is formed, to the frame  104  with an adhesive  151  and removing a substrate portion of the wafer. 
     The substrate portion may also be regarded as a portion other than a portion corresponding to the frame  104 , for example. In addition, if the damper  131  has the same area as the frame  104 , in other words, if the damper  131  is formed at the same location as the frame  104 , the substrate portion may also be regarded as a location other than the damper  131 . 
     In the integrated damper illustrated in  FIG.  6 B , the frame  104  and the damper  103  are directly bonded. The integrated damper can be manufactured, for example, by attaching a wafer on which the damper  131  being a multilayer film is formed, to the frame  104  by integral bonding and removing the substrate portion. 
     Two types of bonding that can be used are adhesive bonding and direct bonding. 
     The direct bonding includes bonding by pressurization and the like and bonding by film formation. 
     In  FIGS.  6 A and  6 B , the damper  103  and the frame  104  are manufactured separately and then bonded together. In this case, the method for forming the recess  141  of the frame  104  can be appropriately selected, and the recess  141  can be formed by a method such as etching using a sacrificial layer. 
     In the integrated damper illustrated in  FIG.  6 C , the frame  104  and the damper  103  are formed as an integrated unit. The integrated damper can be manufactured, for example, by forming, as an integrated unit, the frame  104  and a wafer on which the damper  131  being a multilayer film is formed, and then, removing a portion of the frame  104  to form the recess  141 . Thus, the integrated damper of the present embodiment can also be manufactured by directly forming a damper on a single wafer. 
     In the case of the integrated damper illustrated in  FIG.  6 C , a ceiling portion of the recess  141  is removed to form the recess  141 . Such a recess having no ceiling portion can also be referred to as the recess, but is preferably referred to as a damper region or the like. 
     (Liquid Discharge Apparatus and Liquid Discharge Device) 
     Next, an example of a liquid discharge apparatus  500  according to the present embodiment will be described with reference to  FIGS.  7  and  8   . 
       FIG.  7    is an explanatory plan view of main parts of the liquid discharge apparatus  500 . 
       FIG.  8    is an explanatory side view of main parts of the liquid discharge apparatus  500 . 
     The liquid discharge apparatus  500  is a serial type apparatus to discharge a liquid. The liquid discharge apparatus  500  includes a main scan movement mechanism  493  reciprocally moves a carriage  403  in a main scanning direction. The main scan movement mechanism  493  includes a guide member  401 , a main scan motor  405 , a timing belt  408 , and the like. The guide member  401  is bridged between a left-side plate  491 A and a right-side plate  491 B and moveably holds the carriage  403 . The main scan motor  405  reciprocally moves the carriage  403  in the main scanning direction via the timing belt  408  looped over a drive pulley  406  and a driven pulley  407 . 
     The carriage  403  is mounted with a liquid discharge device  440  which is an integrated unit including a liquid discharge head  404  and a head tank  441  according to the present embodiment. The liquid discharge head  404  of the liquid discharge device  440  discharges liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). In the liquid discharge head  404 , a nozzle array including multiple nozzles is arranged in a sub-scanning direction perpendicular to the main scanning direction, and the liquid discharge head  404  is mounted so that the liquid is discharged downward. 
     A supply mechanism  494  which supplies the liquids stored outside the liquid discharge head  404  to the liquid discharge head  404  supplies the liquids stored in liquid cartridges  450  to the head tank  441 . 
     The supply mechanism  494  includes a cartridge holder  451  serving as a filling part to which the liquid cartridges  450  are mounted, a tube  456 , a liquid feed unit  452  including a liquid feed pump, and the like. The liquid cartridges  450  are detachably mounted to the cartridge holder  451 . The liquids are fed from the liquid cartridges  450  to the head tank  441  by the liquid feeding unit  452  via the tube  456 . 
     The liquid discharge apparatus  500  includes a conveyance mechanism  495  that conveys a sheet  410 . The conveyance mechanism  495  includes a conveyance belt  412  as a conveyor and a sub scan motor  416  that drives the conveyance belt  412 . 
     The conveyance belt  412  attracts the sheet  410  and conveys the sheet  410  to a position facing the liquid discharge head  404 . The conveyance belt  412  is an endless belt looped over a conveyance roller  413  and a tension roller  414 . The sheet  410  may be attracted to the conveyance belt  412  by electrostatic attraction, air suction, or the like. 
     The conveyance belt  412  moves circularly in the sub-scanning direction, as the conveyance roller  413  is rotationally driven by the sub scan motor  416  via a timing belt  417  and a timing pulley  418 . 
     At one side in the main scanning direction of the carriage  403 , a maintenance mechanism  420  that maintains the liquid discharge head  404  in good condition is disposed laterally to the conveyance belt  412 . 
     The maintenance mechanism  420  includes, for example, a cap member  421  that caps a nozzle surface (a surface where the nozzle is formed) of the liquid discharge head  404 , a wiper member  422  that wipes the nozzle surface, and the like. 
     The main scan movement mechanism  493 , the supply mechanism  494 , the maintenance mechanism  420 , and the conveyance mechanism  495  are attached to a housing that includes the left-side plate  491 A and the right-side plate  491 B, and a rear plate  491 C. 
     In the liquid discharge apparatus  500  thus configured, the sheet  410  is fed and attracted to the conveyance belt  412  and the sheet  410  is conveyed in the sub-scanning direction by the circular movement of the conveyance belt  412 . 
     While the carriage  403  moves in the main scanning direction, the liquid discharge head  404  is driven in response to an image signal to discharge the liquid to the sheet  410  being stopped to form an image on the sheet  410 . 
     As described above, the liquid discharge apparatus  500  including the liquid discharge head according to the present embodiment can stably form a high-quality image. 
     Next, another example of the liquid discharge device  440  according to the present embodiment will be described with reference to  FIG.  9   . 
       FIG.  9    is an explanatory plan view of main parts of the liquid discharge device  440 . 
     The liquid discharge device  440  includes a portion of housing, which includes the left-side plate  491 A and the right-side plate  491 B and the rear plate  491 C, the main scan movement mechanism  493 , the carriage  403 , and the liquid discharge head  404 , among members included in the liquid discharge apparatus  500 . 
     The liquid discharge device  440   440  may further include at least one of the above-described maintenance mechanism  420  and the supply mechanism  494 , which is attached to, for example, the right-side plate  491 B of the liquid discharge device  440 . 
     Next, still another example of the liquid discharge device  440  according to the present embodiment will be described with reference to  FIG.  10   . 
       FIG.  10    is a front view of the liquid discharge device  440 . 
     The liquid discharge device  440  includes the liquid discharge head  404  to which a channel component  444  is attached and the tube  456  connected to the channel component  444 . 
     The channel component  444  is arranged inside a cover  442 . Instead of the channel component  444 , the liquid discharge device  440  may include the head tank  441 . A connector  443  to be electrically connected to the liquid discharge head  404  is provided at an upper part of the channel component  444 . 
     As used herein, the term “liquid discharge apparatus” means an apparatus which includes the liquid discharge head or the liquid discharge device and drives the liquid discharge head to discharge a liquid. 
     The liquid discharge apparatus may not be limited to an apparatus to discharge a liquid onto an object onto which liquid can adhere but also an apparatus to discharge a liquid toward gas or into a liquid. 
     The “liquid discharge apparatus” may include units that feeds, conveys, and ejects the object onto which liquid can adhere, and may further include a pretreatment apparatus and a post-treatment apparatus. 
     For example, the “liquid discharge apparatus” may be an image forming apparatus that discharges ink to form an image on a sheet, or a stereoscopic fabrication apparatus (three-dimensional fabrication apparatus) that discharges a fabrication liquid onto a powder layer in which powder material is formed in layers to form a stereoscopic fabricated object (three-dimensional fabricated object). 
     The “liquid discharge apparatus” is not limited to a liquid discharge apparatus to visualize meaningful images, such as letters or figures. For example, the liquid discharge apparatus also includes an apparatus for forming arbitrary patterns and images, or an apparatus for fabricating three-dimensional images. 
     The term “object onto which liquid can adhere” means an object onto which liquid can adhere at least temporarily, and includes an object onto which liquid is adhered and fixed, and an object onto which liquid is adhered and into which the liquid permeates. Specific examples of the “object onto which liquid can adhere” include recording media such as a paper sheet, a recording paper, a recording sheet, a film, and a cloth, electronic components such as an electronic substrate and a piezoelectric element, and media such as a powder layer (powder material layer), an organ model, and a testing cell. The “object onto which liquid can adhere” includes any object onto which liquid can adhere, unless particularly limited. 
     Examples of the material of the “object onto which liquid can adhere” include any materials onto which liquid can adhere even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramic, construction materials such as wallpaper and floor material, and textiles for clothing. 
     Examples of the “liquid” include ink, treatment liquid, DNA samples, resists, pattern material, binders, fabrication liquid, and solutions or liquid dispersions containing amino acid, proteins, or calcium. 
     The “liquid discharge apparatus” may be an apparatus in which the liquid discharge head and the object onto which liquid can adhere are relatively moved. However, the liquid discharge apparatus is not limited to such an apparatus. More specifically, the liquid discharge apparatus may be a serial type apparatus that moves the liquid discharge head or a line type apparatus that does not move the liquid discharge head. 
     Examples of the “liquid discharge apparatus” further include a treatment liquid coating apparatus that discharges a treatment liquid onto a sheet to coat a surface of the sheet with the treatment liquid with the aim of reforming the surface of the sheet, and an injection granulation apparatus that discharges a composition liquid obtained by dispersing a raw material in a solution, from a nozzle to produce fine particles of the raw material. 
     The “liquid discharge device” is an integrated unit including the liquid discharge head and a functional component or a mechanism, and is an assembly of components relating 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, and a main scan movement mechanism. 
     Here, the term “integrated” means, for example, securing the liquid discharge head and the functional component or the mechanism to each other by, e.g., fastening, bonding, or engaging, and holding one of the liquid discharge head and the functional component or the mechanism movably to the other. The liquid discharge head and the functional component or the mechanism may be detachably attached to each other. 
     For example, the liquid discharge device may be a unit in which the liquid discharge head and the head tank are integrated, as in the liquid discharge device  440  illustrated in  FIG.  8   . Alternatively, the liquid discharge device may be a unit in which the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. A unit including a filter may be added at a position between the head tank and the liquid discharge head of the liquid discharge device. 
     In another example, the liquid discharge device may be a unit in which the liquid discharge head and the carriage are integrated. 
     In still another example, the liquid discharge device may be a unit in which the liquid discharge head and the main scan movement mechanism are integrated, and the liquid discharge head is movably held by a guide member that forms a part of the main scan movement mechanism. In still another example, as illustrated in  FIG.  9   , the liquid discharge device may be a unit in which the liquid discharge head, the carriage, and the main scan movement mechanism are integrated. 
     In still another example, the liquid discharge device may be a unit in which the liquid discharge head, the carriage, and the maintenance mechanism are integrated, and a cap member that forms a part of the maintenance mechanism is secured to the carriage to which the liquid discharge head is attached. 
     In still another example, as illustrated in  FIG.  10   , the liquid discharge device may be a unit in which the liquid discharge head and the supply mechanism are integrated, and the tube is connected to the liquid discharge head to which the head tank or the channel component is attached. 
     The main scan movement mechanism may include a guide member only. The supply mechanism may include a tube or a loading unit only. 
     The pressure generator used in the “liquid discharge head” is not limited to a particular type of pressure generator. The pressure generator is not limited to the piezoelectric actuator (or a laminated-type piezoelectric element) described in the above-described embodiment, and may be, for example, a thermal actuator that employs a thermoelectric transducer element such as a heating resistor, or an electrostatic actuator including a diaphragm and opposed electrodes. 
     The terms “image formation”, “recording”, “character printing”, “image printing”, “printing”, and “fabrication” used herein may be used synonymously with each other. 
     [Aspect 1] 
     An actuator ( 106 ) includes: a frame ( 104 ) having a recess ( 141 ); an actuator substrate ( 102 ) including a common chamber ( 121 ); a damper ( 103 ) between the frame ( 104 ) and the actuator substrate ( 102 ), the damper ( 103 ) defining a part of a wall of the common chamber ( 121 ) of the actuator substrate ( 102 ), wherein the damper ( 131 ) includes multiple layers laminated in a lamination direction, and the multiple layers is symmetrical in the lamination direction with respect to a center of the damper ( 131 ) in the lamination direction. 
     [Aspect 2] 
     In the actuator ( 106 ) according to Aspect 1, the damper ( 131 ) has an elastic compliance of 7×10 −17  Pa −1  or more. 
     [Aspect 3] 
     In the actuator ( 106 ) according to Aspect 1, the damper ( 131 ) has a Young&#39;s modulus of 3 GPa or more and 200 GPa or less. 
     [Aspect 4] 
     In the actuator ( 106 ) according to Aspect 1, the damper ( 131 ) has a film stress of −200 MPa or more and 200 MPa or less. 
     [Aspect 5] 
     In the actuator ( 106 ) according to Aspect 1, the damper ( 131 ) has a thickness of 2 μm or more and 10 μm or less. 
     [Aspect 6] 
     In the actuator ( 106 ) according to Aspect 1, materials of the multiple layers of the damper ( 131 ) are selected from Si, Poly-Si, SiN, SiO 2 , and Al 2 O 3 . 
     [Aspect 7] 
     In the actuator ( 106 ) according to Aspect 1, the frame ( 104 ) and the damper ( 103 ) are bonded together. 
     [Aspect 8] 
     In the actuator ( 106 ) according to Aspect 1, corresponding layers of the multiple layers with respect to the center in the lamination direction are formed of the same material and components. 
     [Aspect 9] 
     In the actuator ( 106 ) according to Aspect 1, corresponding layers of the multiple layers with respect to the center in the lamination direction have the same thickness. 
     [Aspect 9] 
     In the actuator ( 106 ) according to Aspect 1, a first thickness of an upper layer of the multiple layers is the same as a second thickness of a lower layer of the multiple layers, where the upper layer is an upper portion of the multiple layers with respect to the center in the lamination direction, and the lower layer is a lower portion of the multiple layers with respect to the center in the lamination direction. 
     [Aspect 10] 
     A liquid discharge head ( 404 ) includes the actuator according to Aspect 1; and a nozzle substrate ( 101 ) bonded to the actuator substrate ( 102 ), the nozzle substrate ( 101 ) including a nozzle ( 111 ), and the actuator substrate ( 102 ) includes an individual chamber ( 122 ) communicating with the nozzle ( 111 ) and the common chamber ( 121 ). 
     [Aspect 12] 
     A liquid discharge device ( 440 ) includes the liquid discharge head ( 404 ) according to Aspect 11. 
     [Aspect 13] 
     In the liquid discharge device ( 440 ) according to Aspect 12, further includes at least one of: a head tank ( 441 ) storing a liquid to be supplied to the liquid discharge head ( 404 ); a carriage ( 403 ) on which the liquid discharge head ( 404 ) is mounted; a supply mechanism ( 494 ) configured to supply the liquid to the liquid discharge head ( 404 ); a maintenance mechanism ( 420 ) configured to maintain the liquid discharge head ( 404 ); or a main scanning movement mechanism ( 493 ) configured to move the liquid discharge head ( 404 ) in a main scanning direction, combined together with the liquid discharge head ( 404 ) to form a single body. 
     [Aspect 14] 
     A liquid discharge apparatus ( 404 ) includes the liquid discharge device ( 440 ) according to Aspect 12. 
     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.