Ex Parte Marvin et al

Patent Trial and Appeal Board

Apr 24, 2017

13808920 (P.T.A.B. Apr. 24, 2017)

United States Patent and Trademark Office
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O.Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
13/808,920 01/08/2013 Daryl J. Marvin 60469-495PUS1 ;56789US 1 1864
64779 7590 04/26/2017
CARLSON GASKEY & OLDS
INTELLECTUAL PROPERTY DEPARTMENT
400 W MAPLE STE 350
BIRMINGHAM, MI 48009
EXAMINER
BERHANE, ADOLF D
ART UNIT PAPER NUMBER
2838
NOTIFICATION DATE DELIVERY MODE
04/26/2017 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
frederic .tenney@otis.com
ptodocket @ cgolaw. com
cgolaw@yahoo.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte DARYL J. MARVIN and STEVEN M. MILLETT
Appeal 2016-002847
Application 13/808,9201
Technology Center 2800
Before ADRIENE LEPIANE HANLON, CATHERINE Q. TIMM, and
JAMES C. HOUSEL, Administrative Patent Judges.
PER CURIAM
DECISION ON APPEAL
A. STATEMENT OF THE CASE
Appellants filed an appeal under 35 U.S.C. § 134(a) from the
Examiner’s decision finally rejecting claims 1—15.2 We have jurisdiction
under 35 U.S.C. § 6(b).3
1 According to Appellants, the real party in interest is Otis Elevator
Company, a business unit of United Technologies. Appeal Br. 1.
2 Claims 16 and 17 have been withdrawn from consideration. See Office
Action Summary of the Final Office Action mailed Mar. 13, 2015 (Final
Act.).
3 Our Decision refers to the Appellants’ Specification filed Jan. 8, 2013
(Spec.), the Appeal Brief filed Aug. 10, 2015 (Appeal Br.), the Examiner’s
Answer mailed Nov. 6, 2015 (Ans.), and the Reply Brief filed Jan. 5, 2016
(Reply Br.).
Appeal 2016-002847
Application 13/808,920
We REVERSE.
The subject matter on appeal relates to power supplies and methods of
controlling a power supply (see, e.g., claims 1 and 11). Appellants disclose
that bootstrap power supplies are known and used in consumer electronic
devices. According to Appellants, typical gate driver integrated circuits are
designed to function with a bootstrap supply. Spec. 11. Appellants’ Figure
1, which is reproduced below depicts a prior art bootstrap power supply.
Figure 1 depicts a prior art bootstrap power supply arrangement
A prior art bootstrap power supply arrangement 10 includes a voltage
source 14 for providing power to a load 12. Id. 12. A limiting resistor 16
and rectifier 18 are associated with the voltage source 14. Id. Appellants
state a low side insulated gate bipolar transistor (IGBT) 20 “switches on and
off in a known manner,” “[a] high side IGBT 22 is controlled by an upper
gate driver 24,” and “[a] bootstrap capacitor 26 powers the upper gate driver
24.” Id.
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Application 13/808,920
When the low side IGBT 20 is conducting, the voltage source 14
charges the bootstrap capacitor 26. Id. 13. When the low side IGBT 20 is
off, the bootstrap capacitor 26 is in a floating condition. Id. In this state, a
voltage drop across the low side IGBT 20 effectively changes the voltage
used to charge the bootstrap capacitor 26. Id. This causes the power supply
for the upper gate driver 24 to be unregulated, which is undesirable. Id.
Moreover, when high voltages are used, the voltage drop across the low side
IGBT 20 is significant in comparison to the voltage source 14, which causes
a large variation in the charging voltage for the bootstrap capacitor 26 and
difficulty in controlling the voltage for the upper gate driver 24 within a
desired range. Id. 14. In addition, the large voltage variation has a negative
effect upon the switching performance of the low side IGBT 20 and the high
side IGBT 22 and the rate for charging the bootstrap capacitor 26 is
relatively slow. Id. H 4, 5.
In view of the above, Appellants disclose a power supply that
includes, among other things, an energy storage portion in parallel with a
bootstrap capacitor and a voltage regulator in parallel with the bootstrap
capacitor. 13, 16. Appellants state the energy storage portion adds
voltage to prevent the voltage of the bootstrap capacitor from dropping until
a voltage of the energy storage portion drops below the voltage of the
bootstrap capacitor, thus providing some control over whether the voltage of
the bootstrap capacitor drops. Id. 116. The energy storage portion also
promotes a faster, more effective charging of the bootstrap capacitor. Id. 1
17. The voltage regulator regulates the voltage of the bootstrap capacitor
and limits current to the bootstrap capacitor. Id. 118. Overall, the energy
storage portion and the voltage regulator dampen effects of a voltage drop
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Application 13/808,920
associated with a low side switch being off, protect the bootstrap capacitor
from experiencing a rapid increase in voltage, and facilitate charging the
bootstrap capacitor more rapidly. Id. 119.
Independent claim 1 is illustrative and is reproduced below from the
Claims Appendix of the Appeal Brief.4 The limitations at issue are
italicized.
1. A power supply, comprising:
a low side switch;
a high side switch;
a driver that controls operation of the high side switch;
a bootstrap capacitor that supplies power to the driver;
an energy storage portion in parallel with the bootstrap
capacitor, and
a voltage regulator in parallel with the bootstrap
capacitor for limiting current provided to the bootstrap
capacitor andfor regulating a voltage of the bootstrap capacitor.
The claims on appeal stand rejected as follows:
(1) claims 1—3 and 9—15 under 35 U.S.C. § 103(a) as unpatentable
over Applicants’ Admitted Prior Art in view of Kularatna;5
(2) claims 1—3 and 9—15 under 35 U.S.C. § 103(a) as unpatentable
over Chen6 in view of Applicants’ Admitted Prior Art;
(3) claims 4—8 under 35 U.S.C. § 103(a) as unpatentable over
Applicants’ Admitted Prior Art in view of Kularatna and further in view of
Vasquez;7 and
(4) claims 4—8 under 35 U.S.C. § 103(a) as unpatentable over Chen
4 Appeal Br., Claims Appendix 10.
5 Kularatna et al., US 7,907,430 B2, issued Mar. 15, 2011 (“Kularatna”).
6 Chen, US 8,138,731 B2, issued Mar. 20, 2012 (“Chen”).
7 Vasquez et al., US 2007/0114981 Al, published May 24, 2007
(“Vasquez”).
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Application 13/808,920
in view of Applicants’ Admitted Prior Art and further in view of Vasquez.
B. DISCUSSION
Rejection over Applicants ’ Admitted Prior Art and Kularatna
Claims 1—3 and 9—15 are rejected under 35 U.S.C. § 103(a) as
unpatentable over Applicants’ Admitted Prior Art in view of Kularatna. We
select claim 1 as representative for discussing the issues on appeal.
The Examiner finds Applicants’ Admitted Prior Art, particularly
Figure 1 of Appellants’ disclosure, discloses a low side switch 20, a high
side switch 22, a bootstrap capacitor 26, and a driver 24 but does not
disclose an energy storage capacitor and voltage regulator. Final Act. 3.
The Examiner finds Kularatna discloses an energy storage capacitor 54 and a
voltage regulator 50 for regulating an output voltage. Id. The Examiner
concludes that it would have been obvious to provide the energy storage
capacitor and voltage regulator of Kularatna in the arrangement of
Applicants’ Admitted Prior Art “in order to provide a stable and accurate
voltage to the driver in Applicants’ admitted prior art Fig. 1.” Id.
Appellants argue that “the claims include an energy storage portion
and a voltage regulator in parallel with the bootstrap capacitor A Appeal
Br. 4. Appellants argue the Examiner does not show a voltage regulator in
parallel with a bootstrap capacitor as claimed because the Examiner “admits
that Appellant’s Figure 1 does not show it and the Kularatna reference does
not have such a voltage regulator, either.” Appeal Br. 5.
In response, the Examiner finds that
voltage regulator (50) is connected in parallel to capacitor
(54).... [T]he regulator can be a shunt (parallel) or series
regulator. Shunt regulator is connected in parallel across a load
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Application 13/808,920
(60) and the capacitor (54) and when combined with
Appellant’s figure 1, the load in Appellant’s figure 1.. .will be
capacitor (26) [i.e., bootstrap capacitor (26)].
Ans. 6—7.
Appellants argue that “the Examiner’s position that the load 60 in the
Kularatna reference corresponds to the bootstrap capacitor 26 of Appellant’s
Figure 1 demonstrates how strained the Examiner’s position is.” Reply Br.
2. Appellants argue:
The load 60 in the Kularatna reference is not a bootstrap
capacitor that supplies power to a driver that controls operation
of a switch.[8] The capacitor 54 in the Kularatna reference is
not a bootstrap capacitor that supplies power to a driver that
controls operation of a switch.[9] Therefore, it does not matter
whether the series LDO voltage regulator 50 of the Kularatna
reference is in a series or parallel relationship with the capacitor
54 or the load 60 of that reference. There still is nothing to
teach or suggest a voltage regulator situated in relationship with
a bootstrap capacitor as those elements are included in
Appellant’s claims.
Reply Br. 2.
Appellants’ arguments are persuasive of reversible error. As argued
by Appellants, the Examiner has engaged in impermissible hindsight in the
rejection of claim 1. “While the Supreme Court made clear that a mechanical
application of the teaching-suggestion-motivation test, requiring an explicit
teaching in the prior art, is inappropriate, ‘[w]e must still be careful not to
8 Appellants’ Figure 1 identifies load 12, and Appellants’ Figure 2 identifies
load 42.
9 In the rejection on appeal, the Examiner does not find that energy storage
capacitor 54 corresponds to the claimed bootstrap capacitor. Rather, the
Examiner finds energy storage capacitor 54 corresponds to the claimed
energy storage portion. See Ans. 3^4 (referring to energy storage portion 60
in Appellants’ Figure 2 as “energy storage capacitor (60)”).
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Application 13/808,920
allow hindsight reconstruction of references to reach the claimed invention
without any explanation as to how or why the references would be combined
to produce the claimed invention.’” Kinetic Concepts, Inc. v. Smith &
Nephew, Inc., 688 F.3d 1342, 1368 (Fed. Cir. 2012) (citing Innogenetics,
N.V. v. Abbott Labs., 512 F.3d 1363, 1374 n. 3 (Fed. Cir. 2008)).
The Examiner also finds Kularatna discloses voltage regulators as
being “well-known in the electrical engineering field” and used to “convert
and condition the battery output or mains current to a particular voltage
level.” Ans. 8. However, the Examiner’s finding does not explain why one
of ordinary skill in the art would have arranged such devices in a parallel
relationship with a bootstrap capacitor, as recited in claim 1. See Reply Br.
2-3.
Based on the foregoing, the § 103(a) rejection of independent claim 1
and dependent claims 2, 3, 9, and 10 based on the combination of
Applicants’ Admitted Prior Art and Kularatna is not sustained.
Independent claim 11 recites a method that includes “providing an
energy storage in parallel with the bootstrap capacitor” and “regulating the
voltage of the bootstrap capacitor using a linear regulator in parallel with the
bootstrap capacitor.” Appeal Br., Claims Appendix 11 (emphasis added).
The Examiner relies on the same factual findings and legal conclusions in
the rejection of claims 1 and 11. See Final Act. 3. Thus, for the reasons
discussed above with regard to claim 1, we do not sustain the rejection of
claim 11 and dependent claims 12—15 over the Admitted Prior Art in view of
Kularatna.
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Rejection of claims 4—8 over Applicants’ Admitted Prior Art,
Kularatna, and Vasquez
Claims 4—8 are rejected under 35 U.S.C. § 103(a) as unpatentable over
Applicants’ Admitted Prior Art in view of Kularatna and further in view of
Vasquez. Claims 4—8 depend from claim 1. The Examiner does not rely on
Vasquez to cure the deficiencies in the rejection of claim 1 identified above.
See Final Act. 5—6. Therefore, the § 103(a) rejection of claims 4—8 based on
the combination of Applicants’ Admitted Prior Art, Kularatna, and Vasquez
is not sustained for the same reasons we do not sustain the rejection of claim
1.
Rejection over Chen and Applicants ’ Admitted Prior Art
Claims 1—3 and 9—15 are rejected under 35 U.S.C. § 103(a) as
unpatentable over Chen in view of Applicants’ Admitted Prior Art. We
select claim 1 as representative for discussing the issues on appeal.
The Examiner finds “Chen discloses the claimed invention except for
[a] driver with an energy storage capacitor. Applicant’s admitted prior art
Fig. 1 teach the use of a driver with an energy storage capacitor for a power
supply.” Final Act. 3 (emphasis added). We understand the “energy storage
capacitor” referred to by the Examiner to be a bootstrap capacitor, not an
energy storage capacitor as found by the Examiner, because the only
capacitor identified in Applicants’ Admitted Prior Art Figure 1 is “bootstrap
capacitor 26” which “powers the upper gate driver 24.” Spec. 12.
The Examiner concludes that it would have been obvious to one of
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Application 13/808,920
ordinary skill in the art “to provide a driver [in Chen] to control the switches
as taught by Applicant’s admitted prior art in order to turn on and off the
switches.” Final Act. 4. The Examiner finds the modified Chen power
supply 200 comprises:
a low side switch (S2); a high side switch (S3); an energy
storage (Cbus) portion in parallel with the bootstrap capacitor
[26]; and a voltage regulator (202) in parallel with the bootstrap
capacitor [26]... for limiting current provided to the bootstrap
capacitor and for regulating a voltage of the bootstrap capacitor.
Final Act. 4.
Appellants argue “[t]here is nothing in the Chen reference that
suggests that the regulator 202 is in parallel with the bootstrap capacitor for
limiting current provided to the bootstrap capacitor and for regulating a
voltage of the bootstrap capacitor as suggested by the Examiner.” Appeal
Br. 7. Rather, Appellants argue that “the regulator 202 steps up the input
voltage to the bus voltage.” Appeal Br. 7 (citing Chen, col. 4,11. 54—56).
In response, the Examiner finds that Chen Figure 2A shows “the
voltage regulator (202) is connected in parallel to the [energy storage]
capacitor (Cbus).” Ans. 10. However, Appellants argue that “capacitor
[Cbus] ... is not a bootstrap capacitor that supplies power to a driver that
controls operation of a switch [as recited in claim 1].” Reply Br. 3.
On this record, the Examiner has failed to show, in the first instance,
that one of ordinary skill in the art, following the teachings of Chen and
Applicants’ Admitted Prior Art Figure 1, would have modified Chen’s
power supply 200 with bootstrap capacitor 26 (in Applicants’ Admitted
Prior Art Figure 1) as recited in claim 1, i.e., wherein Chen’s regulator 202
is “in parallel with the bootstrap capacitor [26] for limiting current provided
to the bootstrap capacitor and for regulating a voltage of the bootstrap
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Application 13/808,920
capacitor.” Appeal Br., Claims Appendix 10. For that reason, the § 103(a)
of independent claim 1 and dependent claims 2, 3, 9, and 10 based on the
combination of Chen and Applicants’ Admitted Prior Art is not sustained.
See In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992) (examiner bears the
initial burden of presenting a prima facie case of unpatentability).
Independent claim 11 recites a method that includes “providing an
energy storage in parallel with the bootstrap capacitor” and “regulating the
voltage of the bootstrap capacitor using a linear regulator in parallel with the
bootstrap capacitor.” Appeal Br., Claims Appendix 11 (emphasis added).
The Examiner relies on the same factual findings and legal conclusions in
the rejection of claims 1 and 11. See Final Act. 3^4. Thus, for the reasons
discussed above with regard to claim 1, we do not sustain the rejection of
claim 11 and dependent claims 12—15 over Chen in view of the Admitted
Prior Art.
Rejection of claims 4—8 over Chen, Applicants’ Admitted Prior Art,
and Vasquez
Claims 4—8 are rejected under 35 U.S.C. § 103(a) as unpatentable over
Chen in view of Applicants’ Admitted Prior Art and further in view of
Vasquez. Claims 4—8 depend from claim 1. The Examiner does not rely on
Vasquez to cure the deficiencies in the rejection of claim 1 identified above.
See Final Act. 6. Therefore, the § 103(a) rejection of claims 4—8 based on
the combination of Chen, Applicants’ Admitted Prior Art, and Vasquez is
not sustained for the same reasons we do not sustain the rejection of claim 1.
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Application 13/808,920
C. DECISION
The decision of the Examiner is reversed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1).
REVERSED
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