DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Takabe et al. (# US 2008/0012911) in view of Ren et al. (# US 2022/0037584) and Kitada (# US 2018/0358540).
Takabe et al. discloses:
1. An actuator (see Abstract; see claim 1) comprising:
a vibration plate (element: 50, figure: 1-2);
a first electrode provided above the vibration plate (lower electrode; element: 60, [0027]);
a piezoelectric layer provided above the first electrode and containing a composite oxide having a perovskite structure (The piezoelectric layer 70 is provided between the first electrode 60 and the second electrode 80; [0033]); and
a second electrode provided above the piezoelectric layer (element: 80, figure: 2; [0032]-[0034]).
3. The actuator according to claim 1, wherein an increase rate of a displacement amount of the vibration plate when an electric field generated in the piezoelectric layer is increased by 10% from 210 kV/cm is 0.94 times or more a decrease rate of the displacement amount of the vibration plate when the electric field is decreased by 10% from 210 kV/cm (The stress of the vibration plate 50 according to this embodiment of the invention is such that a tensile stress from 300 MPa to 500 MPa, inclusive, generates in the piezoelectric element 300 in the state of being displaced when a voltage is applied to the piezoelectric element 300. In other words, a force acts on the piezoelectric element 300 in the state of being displaced by an application of a voltage, and the force makes the displaced piezoelectric element 300 return the original state with help of the vibration plate 50. Thanks to the forcer the piezoelectric element 300 restores the state substantially without displacement. For this reason, even when the piezoelectric element is repeatedly driven, the decrease in the amount of displacement of the piezoelectric element (the amount of displacement of the vibration plate) is prevented. When the tensile stress given to the piezoelectric element 300 by the vibration plate 50 is smaller than 300 MPa, the prevention of the decrease in the amount of displacement of the piezoelectric element 300 may sometimes fail. Meanwhile a tensile stress of more than 500 MPa may possibly cause a warpage or even a crack in the passage-forming substrate 10 ; [0029]; [0035]; [0039]).
4. The actuator according to claim 1, wherein a tensile stress of the piezoelectric layer is 261 MPa or more (300 to 500 Mpa; [0008]; see claim 1).
6. A liquid ejection head (figure: 1; [0025]), comprising: the actuator ([0025]; see Claim 1) according to claim 1;
a flow path (supply path; element: 14, figure: 1) forming substrate formed with a pressure generation chamber (element: 12, figure: 1; [0025]-[0026]) having a volume changed by the actuator ([0025]-[0027]); and
a nozzle plate (element: 20, figure: 1) provided with a nozzle hole (element: 21, figure: 1; [0038]) communicating with the pressure generation chamber ([0038]-[0043]).
7. A printer (see figure: 4) comprising:
the liquid ejection head (element: 1, figure: 2; [0040]) according to claim 6;
a conveyance mechanism configured to move a recording medium with respect to the liquid ejection head (figure: 4; [0040]); and
a control unit configured to control the liquid ejection head and the conveyance mechanism (figure: 4; [0040]-[0042]).
Takabe et al. explicitly did not discloses:
1. Wherein a residual polarization of the piezoelectric layer is 0.535 times or less a spontaneous polarization of the piezoelectric layer.
2. The actuator according to claim 1, wherein
the residual polarization is 12.2 μC/cm.sup.2 or less, and
the spontaneous polarization is 23.2 μC/cm.sup.2 or less.
5. The actuator according to claim 1, further comprising:
a seed layer provided between the first electrode and the piezoelectric layer, wherein a lattice constant in an in-plane direction of the piezoelectric layer is smaller than a lattice constant in an in-plane direction of the seed layer.
Ren et al. teaches to have the
1. Wherein a residual polarization of the piezoelectric layer is 0.535 times or less a spontaneous polarization of the piezoelectric layer (i.e. spontaneous polymerization is 22.5, and residual polymerization is 12, then 12/22.5=0.533; [0121]).
2. The actuator according to claim 1, wherein
the residual polarization is 12.2 μC/cm.sup.2 or less (the residual polarization maximum value Pr (17 μC/cm.sup.2), so less than 17; [0121]) and
the spontaneous polarization is 23.2 μC/cm.sup.2 or less (the spontaneous polarization maximum value Pm (24 μC/cm.sup.2), so less than 24; [0121]).
It would have been obvious to one of ordinary skill in the art before the effective filling date of the invention to modify the actuator of Takabe et al. by the aforementioned teaching of Ren et al. in order to have high quality lead free piezoelectric layer ([0002]).
Kitada teaches to have the piezoelectric layer with excellent leakage characteristics ([0007]).
5. A seed layer provided between the first electrode and the piezoelectric layer (An orientation control layer (also referred to as a seed layer) for controlling an orientation of the piezoelectric layer 70 may be provided on the adhesive layer 56 or in a configuration in which the adhesive layer 56 is omitted.[0045]), wherein a lattice constant in an in-plane direction of the piezoelectric layer is smaller than a lattice constant in an in-plane direction of the seed layer ([0078]).
It would have been obvious to one of ordinary skill in the art before the effective filling date of the invention to modify the actuator of Takabe et al. by the aforementioned teaching of Kitada in order to have the piezoelectric layer with excellent leakage characteristics ([0007]).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
(1) Miwa (# US 2024/0316928) discloses the piezoelectric actuator comprises a substrate having an opening; a diaphragm having a first face on one face of the substrate, and facing the opening, and a lower electrode including a first lower electrode extending in a first direction, and multiple second lower electrodes each extending in the first direction and disposed on each of both sides of the first electrode in a second direction orthogonal to the first. The first electrode is interior of both ends of the body in the second direction. The second electrodes are separated from the first electrodes. The upper electrode covers an upper face and a side face of the piezoelectric body (see Abstract).
(2) Ohashi et al. (# US 2023/0301192) discloses the piezoelectric element comprises an adhesion layer that is formed at a substrate and, contains titanium, where a lower electrode is formed at the adhesion layer. A diffusion reduction layer is formed at the lower electrode, and contains iridium, where a seed layer is formed at the diffusion reduction layer, and contains bismuth. A piezoelectric layer is formed at the seed layer, and contains potassium, sodium and niobium. An upper electrode is formed at the piezoelectric layer. The seed layer is formed of iron, titanium and lead. The diffusion reduction layer is formed of iridium oxide (see Abstract).
(3) Morozumi et al. (# US 2011/0063377) discloses a piezoelectric element comprises a piezoelectric layer (30) disposed between a first conductive layer (10) and a second conductive layer (20), and comprising a compound oxide having at least lead, zirconium, titanium, and oxygen. The piezoelectric layer includes a first crystal layer (32) disposed on the first conductive layer side of the piezoelectric layer, and a second crystal layer (34) continued from the first crystal layer and disposed nearer to the second conductive layer side than the first crystal layer (see Abstract).
(4) Morozumi et al. (# US 2019/0288179) discloses a piezoelectric element includes a first electrode disposed over a substrate, an orientation control layer disposed over the first electrode and containing titanium, a piezoelectric layer disposed over the orientation control layer and having a perovskite crystal structure, and a second electrode disposed over the piezoelectric layer. The orientation control layer has a thickness in the range of 5.0 nm to 22.0 nm (see Abstract).
(5) Miyazawa et al. (# US 2011/0074890) discloses a droplet-ejecting head including a substrate including a pressure chamber communicating with a nozzle hole and also a piezoelectric element that includes a lower electrode, a piezoelectric layer which is formed above the lower electrode, and an upper electrode formed above the piezoelectric element and that causes a change in pressure in a liquid contained in the pressure chamber. The piezoelectric layer includes a first piezoelectric sub-layer located on the lower electrode and a second piezoelectric sub-layer located between the first piezoelectric sub-layer and the upper electrode. The first piezoelectric sub-layer has a polarization axis predominantly directed in an in-plane direction of the first piezoelectric sub-layer. The second piezoelectric sub-layer is predominantly (100)-oriented in the pseudocubic coordinate system (see Abstract).
(6) Kitada (# US 2018/0358540) discloses an actuator (see Abstract; [0039]) comprising: a vibration plate (element: 50, figure: 2); a first electrode provided above the vibration plate (element: 60, figure: 2); a piezoelectric layer provided above the first electrode and containing a composite oxide having a perovskite structure (The piezoelectric layer 70 is provided between the first electrode 60 and the second electrode 80; [0047]); and a second electrode provided above the piezoelectric layer (element: 80, figure: 2).
(7) Saya et al. (# US 2015/0280105) discloses the spontaneous polarization [C/m.sup.2] was measured to evaluate the piezoelectric properties. The spontaneous polarization was calculated from the product of the piezoelectric constant [C/N] and the stress [N/m.sup.2], so it was a method to maximize the spontaneous polarization so as to get a high piezoelectric constant. The spontaneous polarization was measured by using the Sawyer-Tower circuit. The spontaneous polarization was tested while an alternating current field of −50 MV/m to +50 MV/m was applied. Further, the maximal value Pm of polarization was measured as well as the residual polarization Pr. The ratio of Pr to Pm was compared to perform the evaluation on the piezoelectric properties. At that time, the input frequency of the circuit was 1 kHz ([0078]).
(8) Kubota et al. (# US 2012/0251820) discloses A residual polarization value +Pr indicated 20 .mu.C/cm.sup.2 after a voltage of 15 V was applied ([0074]).
(9) Kubota et al. (# US 2007/0262678) discloses a residual polarization value +Pr exhibited 14 .mu.C/cm.sup.2 after application of a 15-V voltage ([0069]).
(10) Ifuku et al. (# US 2004/0155559) discloses [0088] On thus obtained ferroelectric thin film element, a Pt pattern of a diameter of 100 .mu.m was formed by sputtering as an upper electrode, while a lower electrode was constituted of (La, St)TiO.sub.3 and a ferroelectric property of the ferroelectric tin film element was evaluated by a Sawyer-Tower circuit. As a result, there were obtained a spontaneous polarization Ps=100 .mu.C/cm.sup.2 and a residual polarization Pr=45 .mu.C/cm.sup.2 Also a fatigue characteristics test was conducted on 10 spots on the piezoelectric Pt pattern of the ferroelectric thin film element. The evaluation was conducted under conditions of an applied voltage of .+-.5 V, an evaluation temperature of 70.degree. C., a frequency of 1 kHz and a writing of 10.sup.7 times. As a result, a defective element was not found in any of all the evaluated 10 spots. The obtained results are summarized in Table 1. [0092] On thus obtained ferroelectric thin film element, a Pt pattern of a diameter of 100 .mu.m was formed by sputtering as an upper electrode, while a lower electrode was constituted of (La, St)TiO.sub.3 and a ferroelectric property of the ferroelectric tin film element was evaluated. As a result, there were obtained a spontaneous polarization Ps=90 .mu.C/cm.sup.2 and a residual polarization Pr=40 .mu.C/cm.sup.2. Also a fatigue characteristics test was conducted on 10 spots on the piezoelectric Pt pattern of the ferroelectric thin film element. As a result, a defective element was not found in any of all the evaluated 10 spots. The obtained results are summarized in Table 1. [0095] On thus obtained ferroelectric thin film element, a Pt pattern of a diameter of 100 .mu.m was formed by sputtering as an upper electrode, while a lower electrode was constituted of Pt and a ferroelectric property of the ferroelectric tin film element was evaluated by a Sawyer-Tower circuit. As a result, there were obtained a spontaneous polarization Ps=80 .mu.C/cm.sup.2 and a residual polarization Pr=35 .mu.C/cm.sup.2. Also a fatigue characteristics test was conducted on 10 spots on the piezoelectric Pt pattern of the ferroelectric thin film element. The evaluation was conducted under conditions of an applied voltage of .+-.5 V, an evaluation temperature of 70.degree. C., a frequency of 1 kHz and a writing of 10.sup.7 times. As a result, a defective element was not found in any of all the evaluated 10 spots. The obtained results are summarized in Table 1. [0097] Results shown in Table 1 indicate that, in all the ferroelectric thin film elements of the examples 1 to 3 of the present invention, the epitaxial ferroelectric thin film satisfied relations of z/z.sub.0>1.003 and 0.997.ltoreq.x/x.sub.0.ltoreq.1.003. Also the epitaxial ferroelectric thin film of the ferroelectric thin film elements of the examples had a crystal orientation degree of 90% or higher, a spontaneous polarization Ps of 80 .mu.C/cm.sup.2 or higher and a residual polarization Pr of 35 .mu.C/cm.sup.2. Also the ferroelectric thin film elements passed fatigue test of 10.sup.7 times. [0098] On the other hand, in the ferroelectric thin film element of the comparative example 1, the epitaxial ferroelectric thin film showed a relation z/z.sub.0.ltoreq.1.003, and this ferroelectric thin film element cleared the fatigue test of 10.sup.7 times but shows low ferroelectricity with a spontaneous polarization Ps of 70 .mu.C/cm.sup.2 and a residual polarization Pr of 28 .mu.C/cm.sup.2. In the ferroelectric thin film element of the comparative example 2, the epitaxial ferroelectric thin film showed a relation z/z.sub.0<0.997, and this ferroelectric thin film element, though showing a strong ferroelectricity, was unable to clear the fatigue test of 10.sup.7 times in some cases. Also in the ferroelectric thin film element of the comparative example 3, the epitaxial ferroelectric thin film showed a relation z/z.sub.0<0.997, a crystal orientation degree less than 90% and a low ferroelectricity with a spontaneous polarization Ps of 75 .mu.C/cm.sup.2 and a residual polarization Pr of 30 .mu.C/cm.sup.2, and was unable to clear the fatigue test of 10.sup.7 times in some cases.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MANISH S SHAH whose telephone number is (571)272-2152. The examiner can normally be reached 8:00am-4:00pm.
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MANISH S. SHAH
Primary Examiner
Art Unit 2853
/Manish S Shah/ Primary Examiner, Art Unit 2853
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