Yu Chen

Patent Trials and Appeals Board

May 29, 2020

13651994 - (D) (P.T.A.B. May. 29, 2020)

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.
13/651,994 10/15/2012 Yu CHEN 424662058500 1012
25227 7590 05/29/2020
MORRISON & FOERSTER LLP
1650 TYSONS BOULEVARD
SUITE 300
MCLEAN, VA 22102
EXAMINER
JOSEPH, DEVON A
ART UNIT PAPER NUMBER
2846
NOTIFICATION DATE DELIVERY MODE
05/29/2020 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
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PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte YU CHEN
Appeal 2019-001675
Application 13/651,994
Technology Center 2800
Before CATHERINE Q. TIMM, JEFFREY B. ROBERTSON, and
GEORGE C. BEST, Administrative Patent Judges.
TIMM, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–11. See Final Act. 1. We have
jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies the real party in interest as Dyson
Technology Limited. Appeal Br. 2.
Appeal 2019-001675
Application 13/651,994
2
CLAIMED SUBJECT MATTER
The claims are directed to a method of starting a brushless motor (see,
e.g., claim 1) and a control system for starting a brushless motor (see, e.g.,
claim 10). Claim 1, reproduced below, is illustrative of the claimed subject
matter:
1. A method of starting a brushless motor, the motor
comprising a rotor, a stator having at least one phase winding,
and a rotor-position sensor, the method comprising:
exciting the winding;
sensing a signal output by the sensor;
determining whether an edge of the signal is sensed
during a first period:
in accordance with a determination that an edge of the
signal is sensed during the first period:
commutating the winding in response to the edge;
in accordance with a determination that an edge of the
signal is not sensed-during the first period:
commutating the winding at the end of the first period;
sensing the signal; and
commutating the winding in response to a second of two
edges of the signal sensed during a second period.
Appeal Br. 19 (Claims Appendix). Claim 10 is directed to a control
system that is configured to perform the steps of claim 1.
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Application 13/651,994
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REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Makaran US 5,744,921 Apr. 28, 1998
Wilkens US 2003/0090228 A1 May 15, 2003
REJECTIONS
The Examiner maintains the following rejections:
(1) The rejection of claims 1 and 4–11 under pre-AIA 35 U.S.C.
§ 102(b) as anticipated by Makaran; and
(2) The rejection of claims 2 and 3 under pre-AIA 35 U.S.C. § 103(a)
as obvious over Makaran in view of Wilkens.
The Examiner has withdrawn the rejection of claims 1–11 under 35
U.S.C. § 112 ¶ 2. Ans. 2.
OPINION
The Examiner finds that Makaran discloses a method of starting a
brushless motor that performs all of the steps recited in independent claims 1
and 10. Final Act. 3–6. In so finding, the Examiner relies on the algorithm of
Makaran’s Figure 5, steps 334, 336, 338, 340, and 342. Id.
Makaran describes a control circuit for a five-phase brushless motor
having five windings (phases A–E). Makaran col. 1, ll. 17–23; col. 8, ll. 18–
46. Makaran’s Figure 5 is a flow chart showing a portion of Makaran’s
controller algorithm for starting the motor. Makaran col. 3, ll. 46–48; col. 8,
ll. 27–31. Figure 6 shows further steps of the startup sequence. Makaran col.
8, ll. 27–54.
In the startup sequence of Figures 5 and 6, windings 114 are energized
in four steps. Makaran col. 8, ll. 27–54. First, in step 334, phase E is
Appeal 2019-001675
Application 13/651,994
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energized until a falling edge signal is detected by sensor E (sensor E is
shown in Fig. 12A). Id. Second, phase D is energized until a falling edge is
detected by sensor D (step 338). Id. Third, phase C is energized until a
falling edge is detected by sensor C (step 342). Id. Fourth, as shown in
Figure 6, the current is lowered (step 346) and phases C and D are energized
(step 348). Id. Commutating of the windings occurs in step 364. Makaran
col. 8, ll. 47–49; Fig. 6.
We agree with Appellant that the Examiner reversibly erred in
interpreting the claims and in finding Makaran teaches commutating the
winding based on the signal from a single sensor in the manner required by
the claims.
First, in the rejection, the Examiner does not identify what element is
relied on as the “rotor-position sensor” of claims 1 and 10. In response to
Appellant’s argument that the claims require a single sensor perform the
steps recited in the claims (Appeal Br. 16–17), the Examiner finds that
“Makaran is using only sensor 106 in conjunction with the controller to
sense the rotor position” and, thus, “[o]nly one sensor is [used] to
[accommodate] each winding” (Ans. 10).
Appellant has identified a reversible error in the Examiner’s finding
that Makaran’s sensing circuit 106 is a “rotor-position sensor” within the
meaning of the claims. See claims 1 and 10; Reply Br. 4–5. Interpreting the
“rotor-position sensor” in a manner consistent with the Specification, we
determine the “rotor-position sensor” of claims 1 and 10 is a sensor that
detects rotor-position and encompasses sensors such as the Hall sensor
described in Appellant’s Specification. See Spec. 6:5–9 (describing a Hall-
effect sensor 5 that outputs a digital signal, HALL, that differs depending on
the direction of the magnetic flux through the sensor 5), 7:18–22 (describing
Appeal 2019-001675
Application 13/651,994
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Hall-effect sensor 5 as a sensor that senses the polarity of the rotor poles A
or B when parked in position P of Figure 5). Makaran’s sensing circuit 106
is not a “rotor-position sensor.” Makaran’s sensing circuitry 106 is circuitry.
Makaran col. 5, ll. 36–38; Fig. 12A. Although sensing circuitry 106 includes
sensors (sensors A–E in Figure 12A), which may be optical, magnetic, or
Hall sensors; it is the sensors that do the sensing and it is the sensors that are
“rotor-position sensors,” not the sensing circuit. Makaran col. 5, ll. 45–48;
col. 8, ll. 31–35.
Second, we agree with Appellant that “the signal” as recited
throughout the claims refers to “a signal output by the sensor” (emphasis
added) and “the sensor” is the “rotor-position sensor” recited in the preamble
of the claims. Thus, “the signal” recited throughout claims 1 and 10 must be
output from a single sensor. Reply Br. 2.
Claim 1 recites a step of determining whether an edge of “the signal,”
i.e., the signal from the rotor-position sensor recited in the preamble, is
sensed during a first period. Based on this determination, one of two actions
is taken. When the edge is sensed during the first period, the winding is
commutated in response to the edge (first “in accordance” clause of claim 1).
When the edge is not sensed during the first period, commutating does not
take place until the end of the first period (second “in accordance” clause).
The Examiner finds that Makaran’s step 338 performs commutation in
the manner required by both “in accordance” clauses. Final Act. 3–4.
Appellant contends that Makaran’s step 338 “does not disclose commutating
(i.e., reversing the direction of current) of the winding.” Appeal Br. 15. The
Examiner does not dispute that commutating is a step of reversing the
direction of current in the winding. Ans. 7–9.
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Application 13/651,994
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A preponderance of the evidence supports Appellant’s argument that
the Examiner reversibly erred in finding that commutating occurs at
Makaran’s step 338. In step 338, Makaran energizes another winding (phase
D) in response to a signal from a sensor (sensor E; Fig. 12A). Makaran Fig.
5; col. 8, ll. 32–35. The Examiner fails to provide any convincing evidence
that energizing phase D involves commutating the winding previously
excited, i.e., reversing the direction of current in winding E. Ans. 7–9. Thus,
we cannot say that the Examiner has supported the finding that commutating
winding E in response to either the edge or at the end of the first period
occurs when phase D is energized in step 338. Nor does the Examiner
support the finding that when the signal is not sensed during the first time
period, commutating takes place at a different time, i.e., not until the end of
the first period.
Appellant has identified a reversible error in the Examiner’s claim
interpretation and in the findings regarding the commutating steps of the
claims.
The Examiner does not apply Wilkens in a manner that remedies the
deficiencies discussed above. Thus, we do not sustain either rejection.
CONCLUSION
The Examiner’s decision to reject claims 1–11 is REVERSED.
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Application 13/651,994
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DECISION SUMMARY
Claim(s) 35 U.S.C. § Basis/Reference(s) Affirmed Reversed
1, 4–11 102(b) Makaran 1, 4–11
2, 3 103(a) Makaran, Wilkens 2, 3
Overall
Outcome
1–11

REVERSED