The present invention relates to a piezoelectric element, a piezoelectric actuator, a piezoelectric motor, a robot, an electronic component transporting apparatus, a printer, an ultrasonic transducer, and a method of manufacturing the piezoelectric element.
For example, JP-A-2008-47689 discloses a liquid droplet ejecting apparatus that ejects liquid droplets by vibrating a diaphragm using a piezoelectric element. In addition, as a method of forming the piezoelectric element on the diaphragm, JP-A-2008-47689 discloses a method of forming the piezoelectric element. First, films of a lower electrode, a piezoelectric body, and an upper electrode in order are formed on the diaphragm to obtain a laminate, and thereafter the laminate is patterned by dry etching.
However, when an upper electrode and a piezoelectric body are patterned by dry etching, a surface of the piezoelectric body is damaged by dry etching, and a damaged layer (altered layer such as an amorphous layer and a microcrystalline layer) is formed on the surface of the piezoelectric body. When such a damaged layer is formed, a mechanical strength of a piezoelectric element decreases and failure probability of a device increases.
An advantage of some aspects of the invention is to provide a piezoelectric element, a piezoelectric actuator, a piezoelectric motor, a robot, an electronic component transporting apparatus, a printer, an ultrasonic transducer, and a method of manufacturing the piezoelectric element which can reduce the failure probability.
The advantage can be achieved by the following configurations.
A piezoelectric element according to an aspect of the invention includes: a piezoelectric body; and a first electrode which is disposed on the piezoelectric body, and in which in a plan view viewed from a direction where the first electrode and the piezoelectric body are aligned, a region which is a surface of the piezoelectric body on which the first electrode is disposed, located at a vicinity of the first electrode, and within 10 μm from an outer edge of the first electrode has a crystal surface.
With this configuration, it is possible to suppress the occurrence of cracks, burnout, and the like, and the piezoelectric element which may improve the mechanical strength and reduce the failure probability of the apparatus may be obtained.
In the piezoelectric element according to the aspect of the invention, it is preferable that the piezoelectric element includes: a second electrode which is disposed on the surface of the piezoelectric body opposite to the surface on which the first electrode is disposed, and in which in the plan view viewed from the alignment direction, the second electrode has a portion overlapping with the crystal surface.
With this configuration, the occurrence of cracks, burnout, and the like may be more effectively suppressed.
In the piezoelectric element according to the aspect of the invention, it is preferable that in the plan view viewed from the alignment direction, when a portion overlapping with the first electrode of the piezoelectric body is set as a first portion and a portion located at the vicinity of the first electrode is set as a second portion, a length along the alignment direction of the second portion is shorter than a length along the alignment direction of the first portions.
With this configuration, the occurrence of cracks, burnout, and the like may be more effectively suppressed.
In the piezoelectric element according to the aspect of the invention, it is preferable that the piezoelectric body vibrates in a direction intersecting with the alignment direction.
With this configuration, for example, a piezoelectric actuator, a robot, an electronic component transporting apparatus, the printer, and the ultrasonic transducer using the piezoelectric element may be efficiently driven.
A piezoelectric actuator according to an aspect of the invention includes the piezoelectric element according to the aspect of the invention.
With this configuration, the effect of the piezoelectric element according to the aspect of the invention may be enjoyed, and the piezoelectric actuator with high reliability may be obtained.
A piezoelectric motor according to tan aspect of the invention includes the piezoelectric actuator according to the aspect of the invention.
With this configuration, the effect of the piezoelectric actuator (piezoelectric element) according to the aspect of the invention may be enjoyed, and the piezoelectric motor with high reliability may be obtained.
A robot according to an aspect of the invention includes the piezoelectric element according to the aspect of the invention.
With this configuration, the effect of the piezoelectric element according to the aspect of the invention may be enjoyed, and the robot with high reliability may be obtained.
An electronic component transporting apparatus according to an aspect of the invention includes the piezoelectric element according to the aspect of the invention.
With this configuration, the effect of the piezoelectric element according to the aspect of the invention may be enjoyed, and the electronic component transporting apparatus with high reliability may be obtained.
A printer according to an aspect of the invention includes the piezoelectric element according to the aspect of the invention.
With this configuration, the effect of the piezoelectric element according to the aspect of the invention may be enjoyed, and the printer with high reliability may be obtained.
An ultrasonic transducer according to an aspect of the invention includes the piezoelectric element according to the aspect of the invention.
With this configuration, the effect of the piezoelectric element according to the aspect of the invention may be enjoyed, and the ultrasonic transducer with high reliability may be obtained.
A method of manufacturing a piezoelectric element according to an aspect of the invention includes: preparing a piezoelectric body on which a metal film is disposed; removing a portion of the metal film by dry etching or ion milling and patterning the metal film; and light etching a portion of the piezoelectric body which is exposed from the metal film.
With this configuration, it is possible to suppress the occurrence of cracks, burnout, and the like, and the piezoelectric element which may improve the mechanical strength and reduce the failure probability of the apparatus may be obtained.
It is preferable that the method of manufacturing a piezoelectric element according to the aspect of the invention further includes forming a mask on the metal film, which is performed before the process for patterning the metal film, and removing the mask, which is performed after the process for patterning the metal film and before the process for light etching.
With this configuration, it is possible to more accurately pattern the metal film.
It is preferable that the method of manufacturing a piezoelectric element according to the aspect of the invention further includes removing a portion of the piezoelectric body by dry etching or ion milling and patterning the piezoelectric body, which are performed after the process for patterning the metal film and before the process for light etching.
With this configuration, the patterning of the piezoelectric body may be completed before the light etching.
In the method of manufacturing a piezoelectric element according to the aspect of the invention, it is preferable that the piezoelectric body is formed using a solution method in the preparing process.
With this configuration, the piezoelectric body of a thin film may be easily formed.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, a piezoelectric element, a piezoelectric actuator, a piezoelectric motor, a robot, an electronic component transporting apparatus, and a printer, an ultrasonic transducer, and a method of manufacturing the piezoelectric element of the invention will be described in detail based on appropriate embodiments illustrated in the attached drawings.
First, the piezoelectric motor according to a first embodiment of the invention will be described.
A piezoelectric motor 100 (ultrasonic motor) illustrated in
The configuration of the piezoelectric motor 100 is not limited to the configuration of
As illustrated in
Next, the vibration units 10a and 10b will be described, since these two vibration units 10a and 10b are similar in configuration to each other, hereinafter, the vibration unit 10a will be described as a representative and the description of the vibration unit 10b is not repeated.
As illustrated in
In the embodiment, the vibration portion 21 has a substantially rectangular shape (longitudinal shape), the support portion 22 forms a U shape surrounding the base end side of the vibration portion 21, and the connection portion 23 is provided so as to support the vibration portion 21 at both ends thereof on both sides in the width direction of the vibration portion 21, but the shape and arrangement of each part is not particularly limited as long as each part can exhibit functions thereof.
The substrate 2 is not particularly limited, and a silicon substrate can be used, for example. The silicon substrate is used as the substrate 2, so that excellent processing accuracy (dimensional accuracy) can be exhibited. In addition, the semiconductor process can be used for manufacturing the piezoelectric actuator 1, and the piezoelectric actuator 1 can be manufactured efficiently. Although not illustrated, an insulating layer is provided on the surface (surface on the side of the piezoelectric element 3) of the substrate 2. The insulating layer is not particularly limited, and the insulating layer can be configured to include a laminate of, for example, a silicon oxide layer provided on the substrate 2 and a zirconium oxide layer provided on the silicon oxide layer.
As illustrated in
In addition, as illustrated in
The second electrode 33 is provided on the vibration portion 21. The second electrode 33 is a common electrode commonly provided for the piezoelectric elements 3a, 3b, 3c, 3d, and 3e. Such a second electrode 33 can be configured to include a lamination, for example, of a first titanium (Ti) layer provided on the vibration portion 21, an iridium (Ir) layer provided on the first titanium (Ti) layer, a platinum (Pt) layer provided on the iridium (Ir) layer, and a second titanium (Ti) layer provided on the platinum (Pt) layer. However, the configuration of the second electrode 33 is not limited to the above configuration and may be, for example, a metal material such as titanium (Ti), platinum (Pt), tantalum (Ta), iridium (Ir), strontium (Sr), indium (In), tin (Sn), gold (Au), aluminum (Al), iron (Fe), chromium (Cr), nickel (Ni), copper (Cu), a metal layer made of an alloy material or the like including these metal materials, or a mixture or a laminate of two or more of these.
The piezoelectric body 32 is provided on the second electrode 33 and has a film shape. In addition, the piezoelectric body 32 vibrates (expands and contracts) in the direction along the longitudinal direction of the vibration portion 21 by applying an electric field in the direction along the thickness direction thereof (direction intersecting with the direction in which the first electrode 31 and the piezoelectric body 32 are aligned). As a result, the piezoelectric actuator 1 can be efficiently vibrated in the plane as described later, and furthermore, the rotor 110 can be rotated efficiently.
The thickness of the piezoelectric body 32 is not particularly limited, and the thickness is preferably 50 nm or more and 20 μm or less, more preferably 0.5 μm or more and 7 μm or less, for example. Accordingly, it can be said that the piezoelectric element 3 is the thin film piezoelectric element. When the thickness of the piezoelectric body 32 is smaller than 50 nm, the piezoelectric breakdown is likely to occur, so that the driving voltage cannot be increased and the output of the piezoelectric actuator 1 may be reduced accordingly in some cases. On the other hand, when the thickness of the piezoelectric body 32 is larger than 20 the possibility of cracking in the piezoelectric body 32 increases, which may increase the driving voltage in some cases.
In addition, the piezoelectric body 32 has an active portion 32a and a nonactive portion 32b. The active portion 32a is the portion interposed between the first electrode 31 and the second electrode 33, and actively drives (vibrates) by applying a driving voltage between the first electrode 31 and the second electrode 33. On the other hand, the nonactive portion 32b is the portion not interposed between the first electrode 31 and the second electrode 33 (that is, portion other than the active portion 32a), and is located at the vicinity of the active portion 32a.
In addition, a contact hole 321 penetrating to the second electrode 33 is provided in the nonactive portion 32b. A plurality of the contact holes 321 are provided at the vicinity of the first electrode 31.
The constituent material of the piezoelectric body is not particularly limited, and for example, a piezoelectric material of perovskite type oxide (oxide having a perovskite type crystal structure) can be used. Examples of such a piezoelectric material include lead zirconate titanate (PZT), lead zirconate titanate niobate (PZTN), barium titanate, potassium niobate, lithium niobate, lithium tantalate, and the like.
The first electrode 31 is provided on the piezoelectric body 32. The first electrode 31 is an individual electrode provided individually for each of the piezoelectric elements 3a, 3b, 3c, 3d, and 3e. The first electrode 31 may be, for example, a metal material such as titanium (Ti), platinum (Pt), tantalum (Ta), iridium (Ir), strontium (Sr), indium (In), tin (Sn), gold (Au), aluminum (Al), iron (Fe), chromium (Cr), nickel (Ni), copper (Cu), a metal layer made of an alloy material or the like including these metal materials, or a mixture or a laminate of two or more of these.
Hereinbefore, the configuration of the piezoelectric element 3 has briefly described. Next, the configuration of the piezoelectric element 3 will be described in more detail. Hereinafter, for the convenience of the description, the piezoelectric element 3e and its surrounding configuration will be described as a representative, and the piezoelectric elements 3a, 3b, 3c, 3d and surroundings thereof have the same configuration.
As described above, the piezoelectric element 3e has the piezoelectric body 32 and the first electrode 31 disposed in the piezoelectric body 32. As illustrated in
To explain this fact in more detail, as will be described in the method of manufacturing the piezoelectric element 3 to be described later, the piezoelectric element 3 is obtained by forming the second electrode 33, the piezoelectric body 32, and the first electrode 31 in order on the vibration portion 21 in a solid state, and thereafter patterning the first electrode 31 by dry etching (splitting for the piezoelectric elements 3a, 3b, 3c, 3d, and 3e), and subsequently patterning the piezoelectric body 32 by dry etching (forming contact hole 321). In such a manufacturing process, when the first electrode 31 is patterned by dry etching, the top surface 328 of the piezoelectric body 32 is slightly etched, and the top surface 328 of the piezoelectric body 32 is damaged by the plasma. Therefore, as illustrated in
Therefore, in the embodiment, the damaged layer D is removed and the top surface 328 of the nonactive portion 32b of the piezoelectric body 32 is configured to include the crystal surface (surface on which the crystal of the piezoelectric body 32 is normally maintained) as illustrated in
When the durability evaluation of the piezoelectric actuator was performed between a case where the light etching was performed and a case where the light etching was not performed, as illustrated in
The method of removing the damaged layer D is not particularly limited, but light etching using dry etching is preferable. The light etching is, for example, an etching having a low etching rate with respect to dry etching at the time of patterning the first electrode 31. In other words, the dry etching at the time of patterning the first electrode 31 increases the etching rate with emphasis on improving the throughput, whereas the light etching at the time of removing the damaged layer D decreases the etching rate with emphasis on reducing the charging damage over the processing rate. For light etching, for example, light etching can be easily performed by changing the type of gas, the gas ratio, the pressure in the chamber, RF power to be supplied into the chamber for the dry etching at the time of patterning the first electrode 31. By using such light etching, the damaged layer D can be removed while reducing damage to the piezoelectric body 32 (that is, while suppressing the formation of a new damaged layer D).
Although not particularly limited, when the etching rate of dry etching with respect to the piezoelectric body 32 at the time of patterning the first electrode 31 is set as A nm/min, and the etching rate of the light etch with respect to the piezoelectric body 32 at the time of removing the damaged layer D is set as B nm/min, A/B is preferably 10 or more and 50 or less, and more preferably 30 or more and 40 or less. By satisfying such conditions, it is possible to more effectively remove the damaged layer D while reducing damage to the piezoelectric body 32. In addition, it is possible to prevent excessive elongation of the processing time of the light etching.
In addition, as illustrated in
Here, as described above, in the embodiment, the second electrode 33 is a common electrode of the piezoelectric elements 3a, 3b, 3c, 3d, and 3e. Therefore, as illustrated in
Hereinbefore, the piezoelectric element 3 is described. As illustrated in
In addition, the first insulating layer 41 is provided with contact holes 411 and 412. The contact hole 411 is provided so as to penetrate the contact hole 321 to the second electrode 33. On the other hand, the contact hole 412 is provided so as to penetrate to the top surface of the first electrode 31.
On the top surface of the first insulating layer 41, a first conductive layer 42 is provided. The first conductive layer 42 may be configured to include, for example, a titanium tungsten (TiW) layer and a copper (Cu) layer provided on the titanium tungsten (TiW) layer. For example, the first conductive layer 42 is not limited to this configuration, and may further have a conductive adhesion layer provided between the titanium tungsten (TiW) layer and the first insulating layer 41.
In addition, the first conductive layer 42 has wiring layers 421 and 422. The wiring layer 421 is electrically connected to the second electrode 33 via the contact hole 411. On the other hand, the wiring layer 422 is electrically connected to the first electrode 31 via the contact hole 412.
On the top surface of the first conductive layer 42, a second insulating layer 43 is provided. The second insulating layer 43 has, for example, photosensitivity. Therefore, the second insulating layer 43 can be patterned by exposure, development, and baking (heat treatment) without using etching. The configuration material of the second insulating layer 43 is not particularly limited, and examples thereof include an epoxy resin, an acrylic resin, or the like.
In addition, the second insulating layer 43 is provided with a contact hole 431. The contact hole 431 is provided so as to penetrate to the top surface of the first conductive layer 42.
On the top surface of such a second insulating layer 43, a second conductive layer 44 is provided. In addition, the second conductive layer 44 has wiring layers 441 and 442. The wiring layer 441 is electrically connected to the wiring layer 421 via the contact hole 431. On the other hand, the wiring layer 442 is electrically connected to the wiring layer 422 via the contact hole 431. The configuration material of the second conductive layer 44 is not particularly limited, and may be the same as, for example, that of the first conductive layer 42 described above. Although not illustrated, the piezoelectric actuator 1 is electrically connected to the driving circuit via the second conductive layer 44 (wiring layers 441 and 442), and thus a driving voltage is applied to the piezoelectric element 3 via the second conductive layer 44.
On the top surface of the second conductive layer 44, a third insulating layer 45 is provided. The surface of the third insulating layer 45 is a bonding surface 451. Such a constituent material of the third insulating layer 45 is not particularly limited, and for example, the same material as that of the second insulating layer 43 can be used.
The wiring layer 4 is configured to include the first insulating layer 41, the first conductive layer 42, the second insulating layer 43, the second conductive layer 44, and the third insulating layer 45 as described above.
Hereinbefore, the piezoelectric actuator 1 is described. Such a piezoelectric actuator 1 can be driven, for example, as follows. However, the method of driving the piezoelectric actuator 1 is not limited to the following method. For example, when a drive signal (alternating voltage) of a predetermined frequency is applied to each of the piezoelectric elements 3a, 3b, 3c, 3d, and 3e, so that the phase difference between the piezoelectric elements 3a, 3d and the piezoelectric elements 3b, 3c is 180°, and the phase difference between the piezoelectric elements 3a, 3d and the piezoelectric element 3e is 30°, as illustrated in
Hereinbefore, the piezoelectric element 3, the piezoelectric actuator 1 provided with the piezoelectric element 3, and the piezoelectric motor 100 provided with the piezoelectric actuator 1 have been described in detail. Since the piezoelectric actuator 1 and the piezoelectric motor 100 each have the piezoelectric element 3, and it is possible to enjoy the effect of the piezoelectric element 3 described above, excellent mechanical strength, low failure probability, and excellent reliability can be exhibited.
Next, the method of manufacturing the piezoelectric element 3 will be described. As illustrated in
First, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, the first electrode 31 is dry-etched via the mask M1, and the first electrode 31 is patterned. As a result, as illustrated in
Next, the mask M1 is removed by asking treatment. By removing the mask M1 at this stage, it is possible to prevent the mask M1 from obstructing the subsequent piezoelectric body patterning process.
Next, the mask M2 (that is, resist mask) having an opening corresponding to the contact hole 321 is formed on the piezoelectric body 32 and the first electrode 31. The mask M2 can be formed, for example, in the same manner as the mask M2. Next, as illustrated in
Next, the piezoelectric body 32 is light-etched to remove the damaged layer D from the piezoelectric body 32 as illustrated in
Accordingly, the piezoelectric element 3 in which the damaged layer D is removed, the occurrence of cracks, burnout, and the like can be suppressed, the mechanical strength is improved, and the failure probability can be reduced can be obtained.
In the manufacturing method described above, although patterning is performed by dry etching in the first electrode patterning process and the piezoelectric body patterning process, the method of patterning in these processes is not limited to dry etching, and ion milling or wet etching may be used. Even in a case where the ion milling or the wet etching is used, similar to the case where the dry etching is used, the piezoelectric element 3 in which the mechanical strength is improved, and the failure probability can be reduced can be obtained.
Next, a robot according to a second embodiment of the invention will be described.
The robot 1000 illustrated in
Such a robot 1000 is provided with the piezoelectric motor 100 (piezoelectric actuator 1 (piezoelectric element 3)). Therefore, the effect of the piezoelectric actuator 1 (piezoelectric element 3) described above is enjoyed and excellent reliability can be exhibited.
Next, an electronic component transporting apparatus according to a third embodiment of the invention will be described.
An electronic component transporting apparatus 2000 illustrated in
In addition, an Y stage 2210 which can move in the Y-axis direction with respect to the support table 2200 is provided on the support table 2200, an X stage 2220 which can move in an X-axis direction with respect to the Y stage 2210 is provided on the Y stage 2210, and an electronic component holding portion 2230 which can move in a Z-axis direction with respect to the X stage 2220 is provided on the X stage 2220. In addition, as illustrated in
Such an electronic component transporting apparatus 2000 is provided with the piezoelectric actuator 1 (piezoelectric element 3). Therefore, the effect of the piezoelectric element 3 described above is enjoyed and excellent reliability can be exhibited.
Next, a printer according to a fourth embodiment of the invention will be described.
The printer 3000 illustrated in
The printing mechanism 3020 includes a head unit 3021, a carriage motor 3022, and a reciprocating mechanism 3023 which reciprocates the head unit 3021 by the driving force of the carriage motor 3022. The head unit 3021 includes a head 4000 (liquid droplet ejecting head) which is an ink jet type recording head, an ink cartridge 3021b which supplies ink to the head 4000, and a carriage 3021c on which the head 4000 and the ink cartridge 3021b are mounted.
The reciprocating mechanism 3023 includes a carriage guide shaft 3023a which supports the carriage 3021c to be capable of reciprocating, and a timing belt 3023b which moves the carriage 3021c on the carriage guide shaft 3023a by the driving force of the carriage motor 3022. The paper supply mechanism 3030 includes a driven roller 3031 and a driving roller 3032 which are pressure-welded to each other, and the piezoelectric motor 100 which is a paper supply motor that drives the driving roller 3032. The control portion 3040 controls the printing mechanism 3020 or the paper supply mechanism 3030 based on printing data input from a host computer such as a personal computer.
In such a printer 3000, the paper supply mechanism 3030 intermittently feeds the recording paper sheet P in the vicinity of a lower portion of the head unit 3021 one by one. At this time, the head unit 3021 reciprocates in a direction which is substantially orthogonal to a feeding direction of the recording paper sheet P, and the printing onto the recording paper sheet P is performed.
Next, the head 4000 will be described in detail. As illustrated in
In addition, the head 4000 is disposed on the diaphragm 4300 and has a plurality of the piezoelectric elements 4500 covered with the reservoir forming substrate 4400. In such a head 4000, the piezoelectric element 4500 vibrates the diaphragm 4300, thereby changing the pressure inside a pressure generating chamber 4210 formed in the flow path forming substrate 4200, and an ejection port 4110 formed in the nozzle substrate 4100 is configured to eject ink 4900 as liquid droplets. The pressure generating chamber 4210 is disposed in two rows in the lateral direction of
In addition, the plurality of the piezoelectric elements 4500 have a second electrode 4530 disposed on the diaphragm 4300, a piezoelectric body 4520 disposed on the second electrode 4530, and a first electrode 4510 disposed on the piezoelectric body 4520. In addition, the second electrode 4530 is drawn out to the outside of the reservoir forming substrate 4400 along the top surface of the diaphragm 4300. The first electrode 4510 is drawn out to the outside of the reservoir forming substrate 4400 via a lead wiring 4540.
In addition, as illustrated in
Such a printer 3000 is provided with the piezoelectric motor 100 and the piezoelectric element 3. Therefore, the effect of the piezoelectric element 3 described above is enjoyed and excellent reliability can be exhibited. In the embodiment, the piezoelectric motor 100 drives the driving roller 3032 for paper supplying, but in addition to this, for example, the timing belt 3023b may be driven.
Next, an ultrasonic transducer according to a fifth embodiment of the invention will be described.
As illustrated in
As illustrated in
In addition, each of the plurality of piezoelectric elements 5230 has a second electrode 5233 disposed on the flexible film 5240, a piezoelectric body 5232 disposed on the second electrode 5233, and a first electrode 5231 disposed on the top surface of the piezoelectric body 5232. The second electrode 5233 is a common electrode commonly provided for all the piezoelectric elements 5230. On the other hand, the first electrode 5231 is provided in common to the plurality of the piezoelectric elements 5230 aligned in the column direction (lateral direction). In such an element chip 5200, vibrations of the piezoelectric element 5230 causes the flexible film 5240 to vibrate, so that ultrasonic waves can be output, and conversely, vibration of the flexible film 5240 due to reflection of ultrasonic waves causes the piezoelectric element 5230 to be deformed, so that a detection signal can be obtained.
In addition, as illustrated in
In this manner, the ultrasonic wave probe 5000 as an example of the ultrasonic transducer is provided with the piezoelectric element 5230. Therefore, the effect of the piezoelectric element 5230 (the same effect as the piezoelectric element 3 described above) is enjoyed and excellent reliability can be exhibited.
Hereinbefore, the piezoelectric element, the piezoelectric actuator, the piezoelectric motor, the robot, the electronic component transporting apparatus, the printer, the ultrasonic transducer, and the method of manufacturing the piezoelectric element according to the invention are described based on the embodiments of the drawings, but the invention is not limited thereto, and the configuration of each portion can be changed to an arbitrary configuration having a similar function. In addition, other arbitrary configuration objects may be added to the invention. In addition, each of the embodiments may be appropriately combined with each other.
In addition, in the embodiment described above, the configuration in which the piezoelectric element is applied to the piezoelectric actuator, the piezoelectric motor, the robot, the electronic component transporting apparatus, the printer, and the ultrasonic transducer has been described, but the piezoelectric element can be applied to various electronic devices other than these.
The entire disclosure of Japanese Patent Application No. 2016-190782, filed Sep. 29, 2016 is expressly incorporated by reference herein.
Number | Date | Country | Kind |
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2016-190782 | Sep 2016 | JP | national |