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
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-6, 11-12, 14-18 and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nakamura et al (US 2019/0326899).
For claim 1, Nakamura teaches an apparatus for sensing current in a back-to-back MOSFET configuration (Figure 1), the apparatus comprising:
a first MOSFET (Q1) having a gate terminal, a drain terminal (top terminal), and a source terminal (bottom terminal);
a second MOSFET (Q2) having a source terminal coupled to the source terminal of the first MOSFET (top terminal, as understood by examination of Figure 1), a gate terminal, and a drain terminal (bottom terminal);
a gate driver circuit (9) including at least one gate drive output terminal (output of 91, output of 92) to output a gate drive signal to the gate terminals of the first and second MOSFETs (as understood by examination of Figure 1), and a return terminal (ground) coupled to the source terminals of the first and second MOSFETs (as understood by examination of Figure 1);
a shunt resistor (R12) coupled between the source terminals of the first and second MOSFETs (R12 is coupled between Q1 and Q2 in an overcurrent condition due to, e.g., incorrect wiring, [0031]-[0034], [0046]); and
a first MOSFET return resistor (R11) coupled between the source terminal of the first MOSFET and the return terminal of the gate driver circuit (ground);
Nakamura fails to distinctly disclose:
wherein a resistance of the first MOSFET return resistor is greater than a resistance of the shunt resistor.
It is noted that Nakamura teaches “respective resistance values of the resistors R11 to R14 are preferably set so that an electric current I1 flowing through the switch circuit 2 is equal to or less than each of the respective rated currents of the turned-on switch devices Q1 and Q2” ([0046]).
However, it would have been obvious to any person having ordinary skill in the art to select resistance values for Nakamura’s return resistor and shunt resistor such that the return resistor is greater than the shunt resistor because the resistance values can be set to any values desired as long as they that do not teach away from the principles of the invention. Thus, creating the claimed relationships would only involve routine "design optimization", which has been held to be within the ordinary capabilities of a person having ordinary skill in the art. Applicant should note In re Aller, 105 USPQ 233 (1955) where it was held that optimizing particular values is obvious to a person of ordinary skill in the art (who would easily be able to set different values within the range of possible values in order to arrive at the best value by simple experimentation). Note also that the Aller holding is consistent with the Supreme Court decision in KSR International v. Teleflex, Inc., 82 USPQ2d 1385 (2007) which also discussed the obviousness of "design optimization" where a reference is silent on such optimized values.
Note MPEP 2144.05-II-A and 2144.05-III-A which state:
In re Williams, 36 F.2d 436, 438 (CCPA 1929) (“It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.”).
Applicants can rebut a prima facie case of obviousness by showing the criticality of the range. “The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims... In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range.” In reWoodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) …
… In re Scherl, 156 F.2d 72, 74-75, 70 USPQ 204, 205 (CCPA 1946) (“Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies.”)
For claim 2, modified Nakamura teaches the limitations of claim 1 as cited above and further teaches:
a second MOSFET return resistor (R13) coupled between the source terminal of the second MOSFET and the return terminal of the gate driver circuit (as understood by examination of Figure 1);
Modified Nakamura fails to distinctly disclose:
wherein a resistance of the second MOSFET return resistor is greater than the resistance of the shunt resistor.
It is noted that Nakamura teaches “respective resistance values of the resistors R11 to R14 are preferably set so that an electric current I1 flowing through the switch circuit 2 is equal to or less than each of the respective rated currents of the turned-on switch devices Q1 and Q2” ([0046]).
However, it would have been obvious to any person having ordinary skill in the art to select resistance values for Nakamura’s second MOSFET return resistor and shunt resistor such that the second MOSFET return resistor is greater than the shunt resistor because the resistance values can be set to any values desired as long as they that do not teach away from the principles of the invention. Thus, creating the claimed relationships would only involve routine "design optimization", which has been held to be within the ordinary capabilities of a person having ordinary skill in the art. Applicant should note In re Aller, 105 USPQ 233 (1955) where it was held that optimizing particular values is obvious to a person of ordinary skill in the art (who would easily be able to set different values within the range of possible values in order to arrive at the best value by simple experimentation). Note also that the Aller holding is consistent with the Supreme Court decision in KSR International v. Teleflex, Inc., 82 USPQ2d 1385 (2007) which also discussed the obviousness of "design optimization" where a reference is silent on such optimized values.
Note MPEP 2144.05-II-A and 2144.05-III-A which state:
In re Williams, 36 F.2d 436, 438 (CCPA 1929) (“It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.”).
Applicants can rebut a prima facie case of obviousness by showing the criticality of the range. “The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims... In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range.” In reWoodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) …
… In re Scherl, 156 F.2d 72, 74-75, 70 USPQ 204, 205 (CCPA 1946) (“Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies.”)
For claim 3, modified Nakamura teaches the limitations of claim 2 as cited above but fails to teach the resistance of the first MOSFET return resistor and the resistance of the second MOSFET return resistor are substantially equal.
However, it would have been obvious to any person having ordinary skill in the art to select equal resistance values for Nakamura’s first MOSFET return resistor and second MOSFET return resistor since their resistance values can be set to any values desired as long as they that do not teach away from the principles of the invention. Thus, creating the claimed relationships would only involve routine "design optimization", which has been held to be within the ordinary capabilities of a person having ordinary skill in the art. Applicant should note In re Aller, 105 USPQ 233 (1955) where it was held that optimizing particular values is obvious to a person of ordinary skill in the art (who would easily be able to set different values within the range of possible values in order to arrive at the best value by simple experimentation). Note also that the Aller holding is consistent with the Supreme Court decision in KSR International v. Teleflex, Inc., 82 USPQ2d 1385 (2007) which also discussed the obviousness of "design optimization" where a reference is silent on such optimized values.
For claim 4, modified Nakamura teaches the limitations of claim 1 as cited above and further teaches:
the gate driver circuit includes an input terminal (right terminal of 91, right terminal of 92) to receive a control signal (from 6, as understood by examination of Figure 1); and
wherein the gate driver circuit is to output the gate drive signal based on the control signal (as understood by examination of Figure 1 and [0037]-[0038]).
For claim 5, modified Nakamura teaches the limitations of claim 1 as cited above and further teaches:
the drain terminal of the first MOSFET is to be coupled to a voltage source (8), and the drain terminal of the second MOSFET is to be coupled to a load (7, as understood by examination of Figure 1).
For claim 6, modified Nakamura teaches the limitations of claim 5 as cited above and further teaches:
the voltage source is an AC voltage source (as understood by examination of Figure 1).
For claim 11, Nakamura teaches an apparatus for sensing current in a back-to-back MOSFET configuration, the apparatus comprising:
a first MOSFET (Q1) having a gate terminal, a drain terminal (top terminal), and a source terminal (bottom terminal);
a second MOSFET (Q2) having a source terminal coupled to the source terminal of the first MOSFET (top terminal, as understood by examination of Figure 1), a gate terminal, and a drain terminal (bottom terminal);
a gate driver circuit (9) including at least one gate drive output terminal (output of 91, output of 92) to output a gate drive signal to the gate terminals of the first and second MOSFETs (as understood by examination of Figure 1), and a return terminal (ground) coupled to the source terminals of the first and second MOSFETs (as understood by examination of Figure 1);
a shunt resistor (R12) coupled between the source terminals of the first and second MOSFETs (R12 is coupled between Q1 and Q2 in an overcurrent condition due to, e.g., incorrect wiring, [0031]-[0034], [0046]); and
a second MOSFET return resistor (R13) coupled between the source terminal of the second MOSFET and the return terminal of the gate driver circuit (ground);
wherein the drain terminal of the first MOSFET is to be coupled to a voltage source (8), and the drain terminal of the second MOSFET is to be coupled to a load (7).
Nakamura fails to teach:
wherein a resistance of the second MOSFET return resistor is greater than a resistance of the shunt resistor.
It is noted that Nakamura teaches “respective resistance values of the resistors R11 to R14 are preferably set so that an electric current I1 flowing through the switch circuit 2 is equal to or less than each of the respective rated currents of the turned-on switch devices Q1 and Q2” ([0046]).
However, it would have been obvious to any person having ordinary skill in the art to select resistance values for Nakamura’s return resistor and shunt resistor such that the return resistor is greater than the shunt resistor because the resistance values can be set to any values desired as long as they that do not teach away from the principles of the invention. Thus, creating the claimed relationships would only involve routine "design optimization", which has been held to be within the ordinary capabilities of a person having ordinary skill in the art. Applicant should note In re Aller, 105 USPQ 233 (1955) where it was held that optimizing particular values is obvious to a person of ordinary skill in the art (who would easily be able to set different values within the range of possible values in order to arrive at the best value by simple experimentation). Note also that the Aller holding is consistent with the Supreme Court decision in KSR International v. Teleflex, Inc., 82 USPQ2d 1385 (2007) which also discussed the obviousness of "design optimization" where a reference is silent on such optimized values.
Note MPEP 2144.05-II-A and 2144.05-III-A which state:
In re Williams, 36 F.2d 436, 438 (CCPA 1929) (“It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.”).
Applicants can rebut a prima facie case of obviousness by showing the criticality of the range. “The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims... In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range.” In reWoodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) …
… In re Scherl, 156 F.2d 72, 74-75, 70 USPQ 204, 205 (CCPA 1946) (“Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies.”)
For claim 12, modified Nakamura teaches the limitations of claim 11 as cited above and further teaches:
the gate driver circuit includes an input terminal (right terminal of 91, right terminal of 92) to receive a control signal (from 6, as understood by examination of Figure 1); and
wherein the gate driver circuit is to output the gate drive signal based on the control signal (as understood by examination of Figure 1 and [0037]-[0038]).
For claim 14, modified Nakamura teaches the limitations of claim 11 as cited above and further teaches:
wherein the at least one gate drive output terminal includes a first output terminal (output of 91) and a second output terminal (output of 92); and
wherein the first output terminal is coupled to the second output terminal to output the gate drive signal to the gate terminals of the first and second MOSFETs (via D5 and D6, as understood by examination of Figure 1).
For claim 15, Nakamura teaches a method (Figure 1) of sensing current (I1) in a back-to-back MOSFET configuration, the method comprising:
generating, by a gate driver circuit (9), a gate drive signal (output of 91, output of 92) to drive a gate terminal of a first MOSFET and a gate terminal of a second MOSFET (as understood by examination of Figure 1);
forming a gate drive signal return path from a source terminal of the second MOSFET through a shunt resistor (R14) coupled between the source terminal of the second MOSFET to a return terminal of the gate driver circuit (ground) based on a resistance between the source terminal of the second MOSFET and the return terminal of the gate driver circuit (R13); and
detecting a voltage drop across the shunt resistor so as to detect current through the shunt resistor (via 120, [0031]-[0033]).
Nakamura fails to teach:
a resistance between the source terminal of the second MOSFET and the return terminal of the gate driver circuit that is greater than a resistance of the shunt resistor.
It is noted that Nakamura teaches “respective resistance values of the resistors R11 to R14 are preferably set so that an electric current I1 flowing through the switch circuit 2 is equal to or less than each of the respective rated currents of the turned-on switch devices Q1 and Q2” ([0046]).
However, it would have been obvious to any person having ordinary skill in the art to select resistance values for Nakamura’s R13 and R14 such that the resistance of R13 is greater than R14 because the resistance values can be set to any values desired as long as they that do not teach away from the principles of the invention. Thus, creating the claimed relationships would only involve routine "design optimization", which has been held to be within the ordinary capabilities of a person having ordinary skill in the art. Applicant should note In re Aller, 105 USPQ 233 (1955) where it was held that optimizing particular values is obvious to a person of ordinary skill in the art (who would easily be able to set different values within the range of possible values in order to arrive at the best value by simple experimentation). Note also that the Aller holding is consistent with the Supreme Court decision in KSR International v. Teleflex, Inc., 82 USPQ2d 1385 (2007) which also discussed the obviousness of "design optimization" where a reference is silent on such optimized values.
Note MPEP 2144.05-II-A and 2144.05-III-A which state:
In re Williams, 36 F.2d 436, 438 (CCPA 1929) (“It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.”).
Applicants can rebut a prima facie case of obviousness by showing the criticality of the range. “The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims... In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range.” In reWoodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) …
… In re Scherl, 156 F.2d 72, 74-75, 70 USPQ 204, 205 (CCPA 1946) (“Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies.”)
For claim 16, modified Nakamura teaches the limitations of claim 15 as cited above and further teaches:
receiving a control signal (input to 91, input to 92);
wherein the gate drive signal is generated based on the control signal (as understood by examination of Figure 1).
For claim 17, modified Nakamura teaches the limitations of claim 15 as cited above and further teaches:
providing an input voltage to a drain terminal of the first MOSFET (8, as understood by examination of Figure 1); and
providing an output current to a load coupled to a drain terminal of the second MOSFET (7, as understood by examination of Figure 1).
For claim 18, modified Nakamura teaches the limitations of claim 15 as cited above and further teaches:
the input voltage is an AC voltage (8, as understood by examination of Figure 1), and wherein the gate drive signal causes the second MOSFET to turn on based on a polarity of the AC voltage (as understood by examination of Figure 1).
For claim 20, modified Nakamura teaches the limitations of claim 15 as cited above and further teaches:
turning on the second MOSFET before turning on the first MOSFET (capable of, as understood by examination of Figure 1).
Claim(s) 7, 13 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nakamura and Tang (WO 2021/114073).
For claims 7, 13 and 19, modified Nakamura teaches the limitations of claims 1 and 11 as cited above but fails to teach an operational amplifier as claimed.
However, Tang teaches substituting a thyristor (Q1, Figure 2) with an operational amplifier (U1B, R6).
Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to substitute Nakamura’s 120 with an equivalent operational amplifier design since the substitution of one known element for another would have yielded predictable results to one of ordinary skill in the art at the time of the invention, as evidenced by Tang.
The combination of Nakamura and Tang as cited above teaches:
an operational amplifier (in place of Nakamura’s 120) coupled to the shunt resistor to detect a voltage drop across the shunt resistor so as to detect current through the shunt resistor ([0031]-[0033]).
Claim(s) 8-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nakamura and Kamiya (US 2019/0260372).
For claims 8 and 9, modified Nakamura teaches the limitations of claim 1 as cited above and further teaches
the at least one gate drive output terminal includes a first output terminal (output of 91) and a second output terminal (output of 92);
Modified Nakamura fails to teach:
wherein the first output terminal is coupled to the second output terminal through respective gate driver output resistors to output the gate drive signal to the first and second gate terminals.
However, Kamiya teaches respective gate resistors (17, 18) connected between outputs of a driver circuit (3) and power MOSFET transistors (11, 12).
Before the effective filing date of the invention it would have been obvious to one of ordinary skill in the art to add resistors to the output of Nakamura’s 91 and 92, respectively, to adjust the signal level at the gates of Q1 and Q2.
Furthermore, the particular known technique was recognized as part of the ordinary capabilities of one skilled in the art, as evidenced by Kamiya.
For claim 10, the combination of Nakamura and Kamiya as cited above teaches the limitations of claim 9 but fails to teach the resistance values of the first gate resistor or the second gate resistor.
However, it would have been obvious to any person having ordinary skill in the art to select resistance values for Nakamura’s resistors such that the resistance of the first gate resistor is greater than the second gate resistor because the resistance values can be set to any values desired as long as they that do not teach away from the principles of the invention. Thus, creating the claimed relationships would only involve routine "design optimization", which has been held to be within the ordinary capabilities of a person having ordinary skill in the art. Applicant should note In re Aller, 105 USPQ 233 (1955) where it was held that optimizing particular values is obvious to a person of ordinary skill in the art (who would easily be able to set different values within the range of possible values in order to arrive at the best value by simple experimentation). Note also that the Aller holding is consistent with the Supreme Court decision in KSR International v. Teleflex, Inc., 82 USPQ2d 1385 (2007) which also discussed the obviousness of "design optimization" where a reference is silent on such optimized values.
Note MPEP 2144.05-II-A and 2144.05-III-A which state:
In re Williams, 36 F.2d 436, 438 (CCPA 1929) (“It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.”).
Applicants can rebut a prima facie case of obviousness by showing the criticality of the range. “The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims... In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range.” In reWoodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) …
… In re Scherl, 156 F.2d 72, 74-75, 70 USPQ 204, 205 (CCPA 1946) (“Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies.”)
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DANIEL CALRISSIAN PUENTES whose telephone number is (571)270-5070. The examiner can normally be reached M-F 9-6:30 (flex).
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/DANIEL C PUENTES/Primary Examiner, Art Unit 2849