DETAILED ACTION
This office action is in response to the amendment filed 04/02/2024.
Claim Objections
Claims 2, 12, and 14 are objected to because of the following informalities:
Re claim 2, it appears that “the plurality of converter stages” (line 12) should be “the plurality of resonant converter stages”.
Re claim 12, it appears that “the converter stages” (line 2) should be “the plurality of resonant converter stages”.
Re claim 14, it appears that “respective converter stage” (line 26-27) should be “respective resonant converter stage”.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 3-8, 10-13, and 18-23 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Re claim 3, it is unclear if “at least one output signal” (line 4) is the same or different as “the output signal” (lines 10-11) recited in claim 1.
Claims 4-8 inherit the same from claim 3.
Re claim 10, it is unclear if “a switching circuit” (line 4) is the same or different as “a switching circuit” (line 15) recited in claim 1. It is unclear if “a resonant circuit” (line 6) is the same or different as “a resonant circuit” (line 19) recited in claim 1.
Claims 11-13 inherit the same from claim 10.
Re claim 18, it is unclear if "a first resonant converter stage, a second resonant converter stage, a third resonant converter stage" is the same or different as "a respective resonant converter stage" recited in claim 1.
Claims 19-21 inherit the same from claim 18.
Re claim 22, it is unclear if "a first resonant converter stage, a second resonant converter stage, and a third resonant converter stage" is the same or different as "a respective resonant converter stage" recited in claim 1.
Claim 23 inherits the same as claim 22.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1, 10, 11, and 17-24, as best understood, is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Harrison (WO 2006/043837).
Re claim 1, Harrison teaches a power converter [Fig 16], comprising: a plurality of resonant converter stages [13, 14 , 15, 16 ,17, 18] each comprising a respective input [4, 6, 8] and a respective output [22, 24, 26]; a rectifier circuit [28]; and a control circuit [as described in page 7, ln 5-11] configured to control operation of the plurality of resonant converter stages, wherein the respective input of each of the plurality of converter stages is configured to receive a respective input voltage [from 1, 2, 3], wherein the rectifier circuit is configured to receive the outputs of the plurality of converter stages, the rectifier circuit further configured to provide an output signal [output to 29, 30] based on a cascaded voltage that is dependent on respective converter stage output voltages [as secondary voltages] received from the respective outputs of the plurality of resonant converter stages, and wherein each respective resonant converter stage of the plurality of resonant converter stages comprises: a respective switching circuit [16, 17, 18] coupled to the respective input of the respective resonant converter stage, the respective switching circuit configured to receive a respective first alternating voltage [from 1, 2, 3], and configured to generate a second respective alternating voltage [outputs of 16, 17, 18] based on the first respective alternating voltage; and a respective resonant circuit [capacitors in parallel to the transistors as well as the inductors in series with the primary windings] configured to receive the second respective alternating voltage and the respective resonant circuit coupled to the output of the respective resonant converter stage.
Re claim 10, Harrison teaches wherein each of the plurality of the resonant converter stages comprises: a switching circuit [16, 17, 18] connected to the input of the resonant converter stage; a resonant circuit [capacitors in parallel to the transistors as well as the inductors in series with the primary windings] connected to the switching circuit; and a transformer [19, 20, 21] comprising a primary winding [Fig 16] connected to the resonant circuit [connected in series to the inductor] and a secondary winding [Fig 16] inductively coupled with the primary winding and connected to the output [22, 24, 26] of the resonant converter stage.
Re claim 11, Harrison teaches wherein the operating frequency of each of the plurality of resonant converter stages is the operating frequency of the respective switching circuit [the switching frequency of the switches in 16, 17, 18 determines the operating frequency of each stage].
Re claim 17, Harrison teaches wherein the respective resonant circuit of each of the plurality of resonant converter stages comprises an LLC circuit including a respective capacitor [capacitor in parallel with transistors], a respective first inductor [inductor in series with the capacitor and transformer], and a respective second inductor [primary winding of transformers 19, 20, 21].
Re claim 18, Harrison teaches wherein the plurality of resonant converter stages includes a first resonant converter stage [10], a second resonant converter stage [11], and a third resonant converter stage [12]; and wherein the first resonant converter stage includes a first transformer winding [at 19]; wherein the second resonant converter stage includes a second transformer winding [at 20]; and wherein the third resonant converter stage includes a third transformer winding [at 21].
Re claim 19, Harrison teaches a series circuit path including the first transformer winding, the second transformer winding, and the third transformer winding connected in series [the windings are connected in series via nodes 22, 23, 24, 25, 26, 27].
Re claim 20, Harrison teaches wherein the first transformer winding is a first secondary winding [at 19, connected to nodes 22 and 23]; wherein the second transformer winding is a second secondary winding [at 20, connected to nodes 24 and 25]; and wherein the third transformer winding is a third secondary winding [at 21, connected to nodes 26 and 27].
Re claim 21, Harrison teaches wherein the series circuit path extends between a first node [22] and a second node [27]; and wherein the rectifier circuit is coupled to receive a differential voltage supplied by the first node and the second node [paragraph 57], the rectifier circuit operative to rectify the differential voltage into the output signal [output signal supplied to load 29, paragraph 57].
Re claim 22, Harrison teaches wherein the respective converter stage output voltages include: i) a first converter stage output voltage [output of 19] outputted from a first resonant converter stage [10] of the plurality of resonant converter stages, ii) a second converter stage output voltage [output of 20] outputted from a second resonant converter stage [11] of the plurality of resonant converter stages, and iii) a third converter stage output voltage [output of 21] outputted from a third resonant converter stage [12] of the plurality of resonant converter stages.
Re claim 23, Harrison teaches wherein the rectifier circuit is operative to receive a differential voltage [received from nodes 22 and 27], the differential voltage being a summation of the first converter stage output voltage, the second converter stage output voltage and the third converter stage output voltage; and wherein the rectifier circuit is operative to rectify the received differential voltage to produce the output signal [paragraph 57].
Re claim 24, Harrison teaches wherein the respective resonant circuit of each of the respective resonant converter stages comprises an LLC circuit with a capacitor [capacitor in parallel with transistors], a first inductor [inductor in series with the capacitor and transformer], and a second inductor [primary winding of transformers 19, 20, 21].
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 of this title, 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) 12 and 13, as best understood, is/are rejected under 35 U.S.C. 103 as being unpatentable over Harrison in view of Deboy et al. (“Deboy”, US 2018/0278167).
Re claim 12, Harrison teaches the limitations as applied to the claim above but does not teach wherein the resonant circuit of each of the resonant converter stages comprises an LLC circuit with a capacitor, a first inductor, and a second inductor.
Deboy teaches a device [Fig 5A] wherein the resonant circuit of each of the resonant converter stages comprises an LLC circuit with a capacitor [223], a first inductor [221], and a second inductor [222]. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to have modified the device of Harrison to include the features of Deboy because it is known for enabling smaller designs with integrated power density, thus improving the utility of the device, which increases efficiency.
Re claim 13, Harrison teaches wherein the transformers of the plurality of resonant converter stages have the same winding ratio [as shown in Fig 16].
Allowable Subject Matter
Claims 2, 9, and 16 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claims 3-8 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
Claim 14 would be allowable if rewritten to overcome the objection set forth in this Office action.
The following is a statement of reasons for the indication of allowable subject matter: the prior art fails to teach or disclose:
Re claim 2 and its dependents thereof, the closet prior art (which has been made of record) fail to disclose (by themselves or in combination): “the control circuit is configured to: adjust an operating frequency of operating the plurality of resonant converter stages, operate each respective resonant converter stage of the plurality of resonant converter stages in a plurality of successive operating cycles at a same operating frequency, and individually adjust a corresponding power transfer duty cycle of each respective resonant converter stage of the plurality of resonant converter stages, wherein the power transfer duty cycle of each of the plurality of converter stages is a portion of each operating cycle of the respective resonant converter stage in which power is received by the respective resonant converter stage from the respective input” in combination with the additionally claimed features, as are claimed by Applicant.
Re claim 14, the closet prior art (which has been made of record) fail to disclose (by themselves or in combination): “the power conversion method comprises: adjusting an operating frequency of operating the plurality of resonant converter stages; operating each of the plurality of resonant converter stages in a plurality of successive operating cycles at the same adjusted operating frequency; and individually adjusting a power transfer duty cycle of each of the plurality of resonant converter stages, wherein the power transfer duty cycle of each of the plurality of resonant converter stages is a portion of each operating cycle of the respective converter stage in which power is received by the respective converter stage from the respective input” in combination with the additionally claimed features, as are claimed by Applicant.
Re claim 16, the closet prior art (which has been made of record) fail to disclose (by themselves or in combination): “the control circuit is configured to: adjust an operating frequency of operating the plurality of resonant converter stages, and individually adjust a corresponding power transfer duty cycle of each respective resonant converter stage of the plurality of resonant converter stages” in combination with the additionally claimed features, as are claimed by Applicant.
Response to Arguments
Applicant's arguments filed 04/15/2026 have been fully considered but they are not persuasive.
Applicant argues " Harrison indicates to implement bridge rectifiers 13, 14, and 15 as shown in FIG. 16. Such circuitry rectifies the received signals. However, in contrast to the cited prior art, the claimed invention recites that each of the resonant converter stage includes a respective switching circuit coupled to the respective input of the respective resonant converter stage, the respective switching circuit configured to receive a respective first alternating voltage, and the respective switching circuit configured to generate a second respective alternating voltage based on the respective first alternating voltage; and a respective resonant circuit configured to receive the respective second alternating voltage, and the respective resonant circuit coupled to the output. There is no mention of resonant circuits and Harrison".
The Examiner respectfully disagrees. It is known in the art that a series connection of an inductor and a capacitor produces a resonant circuit where the inductor and the capacitor work together to produce a resonant frequency. This is achieved in Harrison from the capacitors across the transistors and the inductors in converters 10, 11, and 12. Further, paragraph [0062] of Harrison recites "As active control is required for only a single stage, complexity and cost is reduced and resonant mode switching may be easily employed". As a result, it is implied that converters 10, 11, and 12 include resonant circuitry in order to employ resonant mode switching. Therefore, Harrison teaches the claimed limitation, and rejection is proper.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LAKAISHA JACKSON whose telephone number is (571)270-3111. The examiner can normally be reached on M-F 8:00-5:00.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, MONICA LEWIS can be reached on 571-272-1838. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/LaKaisha Jackson/
Primary Examiner, Art Unit 2838
Prosecution Insights