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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
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.
Claim(s) 1-3, 5-7, 9, and 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over Lee (US 2014/0176032)(Lee 1) in view of Lee et al. (Lee 2)(US 2012/0038297) and Pramod et al. (US 2017/0250641).
Regarding claim 1,
Lee 1 discloses (Fig. 2):
A magnetic pole detection circuit (Fig. 2, all elements), comprising: a multi-phase voltage divider unit (140, one unit for each phase, the top and bottom resistors are a voltage divider for each phase), configured to detect a back electromotive force (EMF) signal of a multi-phase motor (¶0054);
They do not disclose:
a filter unit, configured to filter the back EMF signal to generate a filtered signal which has a phase lag; a DC level compensation unit, configured to compensate a DC level of the filtered signal to generate a compensation signal which has been compensated for the phase lag; wherein the DC level compensation unit is a digital-to-analog converter; an amplifying unit, configured to amplify the compensation signal to generate an amplified signal; and a hysteresis comparison unit, configured to generate a zero-crossing point signal according to the amplified signal and a reference signal, wherein the zero-crossing point signal is adapted to control an excitation mode of the multi-phase motor.
However, Lee 2 teaches (Fig. 6):
and a hysteresis comparison unit (Fig. 6, 614), configured to generate a zero-crossing point signal according to the amplified signal (from 613) and a reference signal (from 347, ), wherein the zero-crossing point signal is adapted to control an excitation mode of the multi-phase motor (BEMF signal, ¶0040).
Pramod teaches (fig. 4):
a filter unit (Fig. 4, 40), configured to filter the back EMF signal (Eα, Eβ) to generate a filtered signal which has a phase lag (¶0031-¶0032); a DC level compensation unit (52), configured to compensate a DC level of the filtered signal to generate a compensation signal which has been compensated for the phase lag (¶0032); wherein the DC level compensation unit is a digital-to-analog converter (¶0023); an amplifying unit (Fig. 6, 66), configured to amplify the compensation signal to generate an amplified signal (¶0036-¶0037);
Regarding claim 1, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to take the magnetic pole zero crossing detection circuit from Lee that uses a filter, and multiple amplifiers to read a Back electromotive force signal and condition its output in order to reliably control a motor (¶0096-0098) and connect the hysteresis comparator from Lee 2 to the output of the zero crossing unit from Lee 1 in order to filter more noise from the circuit as taught by Lee 2 in order to detect the back electromotive force and zero crossing of the motor (¶0040). This would enable the system to more accurately detect the back electromotive force and zero crossing in order have more accuracy when detecting the angle of the rotor in order to improve reliability and controllability of the motor.
It would have been further obvious to take the BEMF detection circuit from Pramod that filters and digitized the signal in order to provide a more reliable output of the BEMF crossing as taught by Pramod (¶0031-¶0032). This would enable the circuit to have more accuracy and be digitally controlled which would improve reliability.
Regarding claim 2,
Lee 1 discloses (Fig. 1):
further comprising: a motor controller (fig. 1, 100), configured to control the excitation mode of the multi-phase motor (160) according to the zero-crossing point signal (from 140, ¶0053-¶0058).
Regarding claim 3,
Lee 1 discloses (Fig. 2):
wherein the motor controller switches the excitation mode of the multi-phase motor when the zero-crossing point signal is detected, and maintains the excitation mode of the multi-phase motor when the zero-crossing point signal is not detected (¶0058, can change phase timing based on detected back EMF).
Regarding claim 5,
Lee 1 discloses (Fig. 2):
A motor control method (fig. 2, all elements), comprising: detecting a back EMF signal of a multi-phase motor (Fig. 2, via 140);
and generating a zero-crossing point signal according to the amplified signal (back electromotive force) and a reference signal (reference signal from 310, fig. 3, zero crossing signal output from 330), wherein the zero-crossing point signal is adapted to control an excitation mode of the multi-phase motor (¶0097-¶0098).
They do not disclose:
filtering the back EMF signal to generate a filtered signal; compensating a DC level of the filtered signal to generate a compensation signal; amplifying the compensation signal to generate an amplified signal;
However, Pramod teaches (Fig. 4):
filtering (Fig. 4, 40) the back EMF signal (Eα, Eβ) to generate a filtered signal (¶0031-¶0032); compensating a DC level of the filtered signal (52) to generate a compensation signal (¶0032); amplifying the compensation signal to generate an amplified signal (Fig. 6, 66, ¶0036-¶0037);
Regarding claim 5, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to take the magnetic pole zero crossing detection circuit from Lee that uses a filter, and multiple amplifiers to read a Back electromotive force signal and condition its output in order to reliably control a motor (¶0096-0098) and connect the hysteresis comparator from Lee 2 to the output of the zero crossing unit from Lee 1 in order to filter more noise from the circuit as taught by Lee 2 in order to detect the back electromotive force and zero crossing of the motor (¶0040). This would enable the system to more accurately detect the back electromotive force and zero crossing in order have more accuracy when detecting the angle of the rotor in order to improve reliability and controllability of the motor.
It would have been further obvious to take the BEMF detection circuit from Pramod that filters and digitized the signal in order to provide a more reliable output of the BEMF crossing as taught by Pramod (¶0031-¶0032). This would enable the circuit to have more accuracy and be digitally controlled which would improve reliability.
Regarding claim 6,
Lee 1 discloses (Fig. 2):
further comprising: controlling the excitation mode of the multi-phase motor according to the zero-crossing point signal (fig. 1, ¶0053-¶0058, ¶0096-¶0097).
Regarding claim 7,
Lee 1 discloses (Fig. 2):
wherein the step of controlling the excitation mode of the multi-phase motor according to the zero-crossing point signal comprises: detecting the zero-crossing point signal (via Fig. 1, 140); switching the excitation mode of the multi-phase motor when the zero-crossing point signal is detected; and maintaining the excitation mode of the multi-phase motor when the zero-crossing point signal is not detected (¶0058, can change phase timing based on detected back EMF, ¶0096-¶0097).
Regarding claim 8,
Lee 1 discloses (Fig. 2):
wherein the step of compensating a DC level of the back EMF signal (Fig. 2, 210) to generate a compensation signal is dynamically compensating the DC level of the back EMF signal by a digital-to-analog converter (uses an OP-amp as DAC to shift voltage level, Fig. 2, 140, ¶0064-¶0066)
Regarding claim 9,
Lee 1 discloses (Fig. 2):
A magnetic pole detection circuit (fig. 2, all elements), comprising: a low-pass filter circuit (220), configured to receive a back EMF signal of a multi-phase motor (¶0064-¶0066) and to perform a low-pass filtering on switching noise on the back EMF signal (¶0066-¶0067, filters signal before amplifying to eliminate noise);
They do not disclose:
a digital-to-analog conversion circuit, configured to receive the back EMF signal which has been filtered and output by the low-pass filter circuit, and the digital-to-analog conversion circuit is configured to dynamically compensate a DC level of the back EMF signal to avoid a phase lag caused by the low-pass filter circuit: a back EMF amplifying circuit, configured to receive the back EMF signal which has been dynamically compensated for the phase lag and output by the digital-to-analog conversion circuit, and the back EMF amplifying circuit is configured to of a multi-phase motor and amplify an amplitude of the back EMF signal output from the digital-to-analog conversion circuit; and a hysteresis comparison circuit, configured to receive a reference signal and the amplified back EMF signal which has been amplified and output by the back EMF amplifying circuit, wherein the hysteresis comparison circuit is configured to perform a hysteresis comparison on the reference signal and the amplified back EMF signal, output from the back EMF amplifying circuit, to avoid signal bounce due to the switching noise, and the hysteresis comparison circuit is further configured to generate a zero-crossing point signal based on a result of the hysteresis comparison, wherein the zero-crossing point signal is adapted to control an excitation mode of the multi-phase motor.
However, Lee 2 teaches (Fig. 6):
and a hysteresis comparison circuit (Fig. 6, 614), configured to receive a reference signal and the back EMF signal which has been amplified and output by the back EMF amplifying circuit, wherein the hysteresis comparison circuit is configured to perform a hysteresis comparison on the reference signal (from 347) and the back EMF signal (613), output from the back EMF amplifying circuit, to avoid signal bounce due to the switching noise, and the hysteresis comparison circuit is further configured to generate a zero-crossing point signal based on a result of the hysteresis comparison, wherein the zero-crossing point signal is adapted to control an excitation mode of the multi-phase motor (BEMF signal, ¶0040.
Pramod teaches (fig. 4):
a digital-to-analog conversion circuit, configured to receive the back EMF signal which has been filtered and output by the low-pass filter circuit (¶0023, Fig. 4, 40, Eα, Eβ, ¶0031-¶0032), and the digital-to-analog conversion circuit is configured to dynamically compensate a DC level of the back EMF signal to avoid a phase lag caused by the low-pass filter circuit (¶0032):a back EMF amplifying circuit (fig. 6, 66), configured to receive the back EMF signal which has been dynamically compensated for the phase lag and output by the digital-to-analog conversion circuit, and the back EMF amplifying circuit is configured to of a multi-phase motor and amplify an amplitude of the back EMF signal output from the digital-to-analog conversion circuit (¶0036-¶0037);
Regarding claim 9, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to take the magnetic pole zero crossing detection circuit from Lee that uses a filter, and multiple amplifiers to read a Back electromotive force signal and condition its output in order to reliably control a motor (¶0096-0098) and connect the hysteresis comparator from Lee 2 to the output of the zero crossing unit from Lee 1 in order to filter more noise from the circuit as taught by Lee 2 in order to detect the back electromotive force and zero crossing of the motor (¶0040). This would enable the system to more accurately detect the back electromotive force and zero crossing in order have more accuracy when detecting the angle of the rotor in order to improve reliability and controllability of the motor.
It would have been further obvious to take the BEMF detection circuit from Pramod that filters and digitized the signal in order to provide a more reliable output of the BEMF crossing as taught by Pramod (¶0031-¶0032). This would enable the circuit to have more accuracy and be digitally controlled which would improve reliability.
Regarding claim 12,
Lee 1 discloses (Fig. 2):
further comprising: a multi-phase voltage divider circuit (Fig. 2, 140), coupled to the multi-phase motor (to each line of 160), wherein the multi-phase voltage divider circuit (140) is configured to detect the multi-phase motor to generate the back EMF signal (¶0064), and perform voltage division and filtering (220) on the switching noise on the back EMF signal (¶0064-¶0067), wherein the back EMF signal received by the low-pass filter circuit (220) is the back EMF signal output after the voltage division (from voltage divider resistors) and filtering by the multi-phase voltage divider circuit (140, 220, ¶0064-¶0067).
Regarding claim 13,
Lee 1 discloses (Fig. 2):
further comprising: a motor controller (fig. 1, 100), configured to control the excitation mode of the multi-phase motor (160) according to the zero-crossing point signal (from 140, ¶0053-¶0058).
Regarding claim 14,
Lee 1 discloses (Fig. 2):
wherein the motor controller switches the excitation mode of the multi-phase motor when the zero-crossing point signal is detected, and maintains the excitation mode of the multi-phase motor when the zero-crossing point signal is not detected (¶0058, can change phase timing based on detected back EMF).
Response to Arguments
Applicant's arguments filed 6/27/25 have been fully considered but they are not persuasive.
Regarding claims 1-3, 5-7, 9, and 12-14 applicant argues that Pramod uses a flux estimation module that is implemented digitally which does not teach a digital to analog converter, however, in ¶0023 Pramod teaches how this can be implemented digitally, this would meant that a digital to analog converter would be inherent because the digital signals would eventually have to be converted to analog signals to be outputted to the motor. Furthermore, applicant argues that Pramod does not teach processing the phase compensation using analog circuitry, however, ¶0058 from Pramod teaches how circuitry could be used to perform this task. Applicant also argues that, Pramod does not teach analog circuitry for performing compensation and amplification of the back EMF signal at the signal level, ¶0036-¶0037, however, the signal processing is implemented with a filter as taught in ¶0031 and could be circuitry from ¶0058. Furthermore, since the this is said how it could be implemented in software or hardware, would be capable of being circuitry or a logic circuit as taught in ¶0058 from Pramod.
As such, examiner is maintaining the rejections of claims 1-3, 5-7, 9, and 12-14.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/C.S.L./Examiner, Art Unit 2846 /KAWING CHAN/Primary Examiner, Art Unit 2846