Prosecution Insights
Last updated: April 19, 2026
Application No. 18/672,304

INDUCTION HEATING TYPE COOKTOP FOR HEATING VARIOUS OBJECTS

Non-Final OA §103
Filed
May 23, 2024
Examiner
CHEN, KUANGYUE
Art Unit
3761
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
LG Electronics Inc.
OA Round
3 (Non-Final)
63%
Grant Probability
Moderate
3-4
OA Rounds
3y 7m
To Grant
99%
With Interview

Examiner Intelligence

Grants 63% of resolved cases
63%
Career Allow Rate
354 granted / 560 resolved
-6.8% vs TC avg
Strong +45% interview lift
Without
With
+44.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
36 currently pending
Career history
596
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
46.6%
+6.6% vs TC avg
§102
20.4%
-19.6% vs TC avg
§112
31.4%
-8.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 560 resolved cases

Office Action

§103
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 . Continued Examination under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 02/04/2026 has been entered. Response to Amendment Applicant’s amendments to the claims filed on 02/04/2026 are acknowledged and entered. According to the Amendments to the claims, claims 1 and 11 has /have been amended, claims 3 and 9 were previously cancelled, claims 17-18 has /have been cancelled. Accordingly, claims 1-2, 4-8, 10-16 and 19-20 are pending in the application with claim 14 previously withdrawn. An action on the merits for claims 1-2, 4-8, 10-13, 15-16 and 19-20 are as follow. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1-8, 10-13 and 15-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bunuel (ES 2399733 A1) in view of Kataoka et al. (US 2005/0115957 A1) and Hirota et al. (US 2004/0245244 A1). Regarding Independent Claim 1, Bunuel discloses an induction cooktop comprising: an upper plate (a cooking plate 2, Abstract, Fig 1) configured to support an object (preparation containers, such as pans, pots, or the like, can be supported, [0026]); a working coil (an inductor 4, Abstract, Fig 1) configured to heat the object; and a thin film (electrically insulating layer 7, Abstract, Fig 1), wherein the induction cooktop further comprises a metal film (a metallic layer 8, Abstract, [0030], Fig 1), Bunuel discloses the invention as claimed and as discussed above; except does not disclose: the thin film (taught by Bunuel already) disposed on the upper plate, wherein the metal film (taught by Bunuel already) that forms an equivalent circuit with the thin film and the object and is configured to allow a current of the working coil to be induced into the object supported on the upper plate, wherein at least one of the object and the thin film is configured to be inductively heated by the working coil when an equivalent circuit component of the equivalent circuit is included in an induction heating region, and wherein the equivalent circuit component of the equivalent circuit comprises a resistance component of the equivalent circuit and an inductor component of the equivalent circuit, wherein the metal film includes at least one cutout portion that prevents the induced current from flowing, wherein a sum of a thickness of the thin film and a thickness of the metal film is less than a sum of a skin depth of the thin film and a skin depth of the metal film, and wherein an area of the metal film is less than or equal to a half of an area of the thin film Kataoka et al. teach an induction cooktop (induction heating apparatus, Title), and with a thin film (member 112 is made of … aluminum, [0105], Fig 1) disposed on the upper plate (112 disposed on top plate 118, [0003], Fig 1; “the upper plate” taught by Bunuel already); wherein the metal film (“the metal film” taught by Bunuel already) that forms an equivalent circuit with the thin film and the object (an object to be heated 110, [0003], Fig 1; “the object” taught by Bunuel already) and is configured to allow a current of the working coil (“the working coil” taught by Bunuel already) to be induced into the object supported on the upper plate (Clearly, “the metal film” is capable of “that forms an equivalent circuit with the thin film and the object and is configured to allow a current of the working coil to be induced into the object supported on the upper plate” as claimed), wherein at least one of the object and the thin film is configured to be inductively heated by the working coil (see Fig 1 of Bunuel) when an equivalent circuit component of the equivalent circuit is included in an induction heating region (Clearly, “an equivalent circuit component of the equivalent circuit” is capable of “included in an induction heating region” as claimed), wherein the equivalent circuit component of the equivalent circuit comprises a resistance component of the equivalent circuit and an inductor component of the equivalent circuit (Clearly, “the equivalent circuit component of the equivalent circuit” is capable of “comprises a resistance component of the equivalent circuit and an inductor component of the equivalent circuit” as claimed), wherein a sum of a thickness of the thin film and a thickness of the metal film (“the metal film” taught by Bunuel already) is less than a sum of a skin depth of the thin film and a skin depth of the metal film (Clearly, “a sum of a thickness of the thin film and a thickness of the metal film is” capable of “less than a sum of a skin depth of the thin film and a skin depth of the metal film” as claimed), and Further, Hirota et al. teach an induction cooktop (induction heating apparatus, Abstract), and wherein the metal film includes at least one cutout portion (electrical conductor 27, [0101], clearance 27c (gap clearance), that is, a slit, of the electrical conductor 27, [0102]. Fig 1. Note: “the metal film” taught by Bunuel already) that prevents the induced current from flowing (because an induction current is induced in the electrical conductor 27, [0107]). wherein an area of the metal film (electrical conductor 27 including a clearance 27c, Fig 1) is less than or equal to a half of an area of the thin film (member 112 is made of … aluminum, [0105], Fig 1; taught by Kataoka et al. already); Bunuel in view of Kataoka et al. does not explicitly disclose that “wherein an area of the metal film is less than or equal to a half of an area of the thin film”; however, it would have been an obvious matter of design choice to one skilled person in the art at the time the invention was made to arrange an area of the metal film is less than or equal to a half of an area of the thin film; since such a configuration would have involved only a size/shape of components, and is generally recognized as being within the level of ordinary skill in the art. In re Rose, 105 USPQ 237; besides, applicant has not disclosed that this kind of design solves any stated problem or is for any particular purpose (see Spec. [0125]). Therefore, it would have been obvious before the effective filling date of the claimed invention to one of ordinary skill in the art to modify Bunuel with Kataoka et al.’s further teaching of wherein the metal film (taught by Bunuel already) that forms an equivalent circuit with the thin film and the object and is configured to allow a current of the working coil to be induced into the object supported on the upper plate, wherein at least one of the object and the thin film is configured to be inductively heated by the working coil when an equivalent circuit component of the equivalent circuit is included in an induction heating region, and wherein the equivalent circuit component of the equivalent circuit comprises a resistance component of the equivalent circuit and an inductor component of the equivalent circuit, wherein a sum of a thickness of the thin film and a thickness of the metal film is less than a sum of a skin depth of the thin film and a skin depth of the metal film; because Kataoka et al. teach, in Abstract, of providing a high safety induction heating apparatus in which leakage current is prevented from flowing to the human body during operation; and further modify Bunuel in view of Kataoka et al. with Hirota et al.’s further teaching of wherein the metal film includes at least one cutout portion that prevents the induced current from flowing; and wherein an area of the metal film is less than or equal to a half of an area of the thin film because Hirota et al. teach, in Para [0030], of providing an excellent induction heating apparatus to focus the magnetic field at the central portion in order to restricted the decrease of heating efficiency during the operation. Claim 2, wherein a thickness of the thin film (member 112 is made of … aluminum, [0105], Fig 1. Kataoka et al.) is smaller than a skin depth of the thin film (Clearly, “a thickness of the thin film is” capable of “smaller than a skin depth of the thin film” as claimed). Claim 4, wherein, while the object, which is made of aluminum, is positioned on a top of the upper plate (a cooking plate 2, Abstract, Fig 1, Bunuel), the equivalent circuit component formed by the metal film (electrically conduction layer 8, Abstract, Fig 1, Bunuel), the thin film (member 112 is made of … aluminum, [0105], Fig 1, Kataoka et al.) and the object is included at least in part in the induction heating region (Clearly, “the equivalent circuit component formed by the metal film, the thin film and the object is” capable of “included at least in part in the induction heating region” as claimed). Claim 5, wherein the metal film (electrically conduction layer 8, Abstract, Fig 1, Bunuel) has a shape of at least one of the thin film (member 112 is made of … aluminum, [0105], Fig 1, Kataoka et al.) or the working coil (an inductor 4, Abstract, Fig 1, Bunuel). Bunuel in view of Kataoka et al. does not explicitly disclose that “the metal film has a shape of at least one of the thin film or the working coil”; however, it would have been an obvious matter of design choice to one skilled person in the art at the time the invention was made to arrange the metal film has a shape of at least one of the thin film or the working coil; since such a configuration would have involved only a size/shape of components, and is generally recognized as being within the level of ordinary skill in the art. In re Rose, 105 USPQ 237; besides, applicant has not disclosed that this kind of design solves any stated problem or is for any particular purpose (see Spec. [0134]). Claim 6, wherein the metal film (electrical conductor 27, [0101], Fig 1; “the metal film” taught by Bunuel already) comprises a plurality of metal film parts (see a plurality of round/square shapes on the circumference area of metal film 27, Fig 1), at least one of the plurality of metal film parts having a shape of the at least one of the thin film (member 112 is round shaped, [0105], Fig 2) and the working coil (induction heating coil 101 is round shaped, [0003], Figs 1 and 3, Hirota et al.) Claim 7, wherein at least two of the plurality of metal film parts are separated from each other (see two metal film parts with round shape located at both sides of 27c, Fig 1, Hirota et al.). Claim 8, wherein at least two of the plurality of metal film parts are disposed coaxially with respect to each other (see Fig 1, Hirota et al.). Claim 10, wherein the cutout portion of the metal film extends from an outer boundary of the metal film to or beyond a center of the metal film (clearance 27c (gap clearance) extends from an outer boundary of the metal film to or beyond a center of 27, [0102], Fig 1, Hirota et al.). Claim 11, wherein the metal film forms to have a ring shape with a hole at a center of the metal film (27 forms to have a ring shape with a hole at a center of the metal film, Fig 1, Hirota et al.). Claim 12, the thin film, metal film and the working coil arrange so as to overlap each other in a vertical direction (electrically insulating layer 7, electrically conduction layer 8, and inductor 4 overlap each other in a vertical direction, Fig 1, Bunuel). Claim 13, wherein the metal film is disposed between the thin film and the working coil in the vertical direction (electrically conduction layer 8 is disposed between electrically insulating layer 7 and inductor 4 in the vertical direction, Fig 1, Bunuel). Claim 15, wherein the metal film is positioned between the working coil and the upper plate (electrically conduction layer 8 is positioned between inductor 4 and cooking plate 2, Fig 1, Bunuel) so that the object placed on the upper plate is heated based on at least one of the induced current or a transferred heat from the thin film heated by the working coil (Fig 1, Bunuel). Claim 16, wherein the metal film is arranged on the top of the upper plate or a bottom of the upper plate (electrically conduction layer 8 is arranged on a bottom of the upper plate, Fig 1, Bunuel). Claim 19, further comprising an insulator disposed between the upper plate and the working coil (insulating layer 9 disposed between cooking plate 2 and inductor 4, Fig 1, Bunuel). Claim 20, wherein the thin film (member 112, [0105], Fig 1, Kataoka et al.) has a hole formed in a center of the thin film (has a hole formed in a center of 112, Fig 2, Kataoka et al.), wherein the metal film (electrical conductor 27, [0101], Fig 1, Hirota et al.) has a hole formed in a center of the metal film (opening portion 39 at the center of the electrical conductor 27. [0103], Fig 1, Hirota et al.), and wherein the hole of the thin film and the hole of the metal film overlap each other in a vertical direction (both holes are formed in a center of the cooktop, see Fig 1 of Kataoka et al. and Fig 3 of Hirota et al.). Response to Arguments Applicant’s arguments filed 05/26/2025 with respect to Claims 1-2, 4-8, 10-13, 15-16 and 19-20 have been fully considered but they are not persuasive. The same prior art used under the Non-Final Rejection been able to cover all the limitations of the amended claims. A. The applicant's argument on Remarks, namely “Applicant respectfully disagrees and submits that Bunuel in view of Kataoka fails to render obvious the above-noted features of amended claim 1, at least for the following reasons. First, as acknowledged by the Office Action, "Bunuel in view of Kataoka et al. does not explicitly disclose that 'the predetermined area is a half of the area of the thin film"' and thus does not disclose that "the metal film has an area or equal to or smaller than [the] predetermined area [being the half of the area of the thin film]," as claimed. See id, p. 9. Second, a POSIT A would not have been led, absent impermissible hindsight gleaned from the present application, to somehow (i) modify Bunuel's "conduction layer 8" and Kataoka's "member 112" and (ii) combine Bunuel and Kataoka to arrive at the claimed features ("an area of the metal film is less than or equal to a half of an area of the thin film"). In particular, Bunuel and Kataoka say nothing about the area of the metal film relative to the thin film. By contrast, the present application clearly describes that limiting the area of the metal film relative to the thin film is important to maintaining heating efficiency for both aluminum objects and magnetic materials on an induction cooktop. See Present Application, ,-i,i [0122][0123]. For instance, the present application explains that "when the area of the additional metal film ML is larger than a predetermined area, the size of the magnetic field transmitted to the target heating object HO is reduced, thereby reducing heating efficiency," and thus the area of the metal film ML "may be equal to or less than a predetermined area [ e.g., half of an area of the thin film]" to ensure that a magnetic field capable of heating both an aluminum object and a magnetic material is transmitted to the thin film and the magnetic material. See id, iJ[0l23]. Accordingly, the claimed feature that "an area of the metal film is less than or equal to a half of an area of the thin film" reflects a purposeful structural feature tied to solving the problem of reduced heating efficiency for magnetic materials in an induction cooktop, rather than "obvious matter of design choice." The examiner’s response: The combination of Bunuel in view of Kataoka et al. and Hirota et al. teach exactly an induction cooktop in this office action as shown above. A. the purpose of bring in Kataoka et al. is to teach the induction cooktop (induction heating apparatus, see Title; taught by Bunuel already) with a thin film (member 112 is made of … aluminum, [0105], Fig 1) disposed on the upper plate (112 disposed on top plate 118, [0003], Fig 1; “the upper plate” taught by Bunuel already); wherein the metal film (“the metal film” taught by Bunuel already) that forms an equivalent circuit with the thin film and the object (an object to be heated 110, [0003], Fig 1; “the object” taught by Bunuel already) and is configured to allow a current of the working coil (“the working coil” taught by Bunuel already) to be induced into the object supported on the upper plate (Clearly, “the metal film” is capable of “that forms an equivalent circuit with the thin film and the object and is configured to allow a current of the working coil to be induced into the object supported on the upper plate” as claimed), wherein at least one of the object and the thin film is configured to be inductively heated by the working coil (see Fig 1 of Bunuel) when an equivalent circuit component of the equivalent circuit is included in an induction heating region (Clearly, “an equivalent circuit component of the equivalent circuit” is capable of “included in an induction heating region” as claimed), wherein the equivalent circuit component of the equivalent circuit comprises a resistance component of the equivalent circuit and an inductor component of the equivalent circuit (Clearly, “the equivalent circuit component of the equivalent circuit” is capable of “comprises a resistance component of the equivalent circuit and an inductor component of the equivalent circuit” as claimed), wherein a sum of a thickness of the thin film and a thickness of the metal film (“the metal film” taught by Bunuel already) is less than a sum of a skin depth of the thin film and a skin depth of the metal film (Clearly, “a sum of a thickness of the thin film and a thickness of the metal film is” capable of “less than a sum of a skin depth of the thin film and a skin depth of the metal film” as claimed); and providing a teach of a high safety induction heating apparatus in which leakage current is prevented from flowing to the human body during operation (see Abstract); and B. the purpose of bring in Hirota et al. is to teach the induction cooktop (induction heating device, see Title; taught by Bunuel already), and wherein the metal film includes at least one cutout portion (electrical conductor 27, [0101], clearance 27c (gap clearance), that is, a slit, of the electrical conductor 27, [0102]. Fig 1. Note: “the metal film” taught by Bunuel in view of Kataoka et al. already) that prevents the induced current from flowing (because an induction current is induced in the electrical conductor 27, [0107]); wherein an area of the metal film (electrical conductor 27 including a clearance 27c, Fig 1) is less than or equal to a half of an area of the thin film (member 112 is made of … aluminum, [0105], Fig 1; taught by Bunuel in view of Kataoka et al. already); Bunuel in view of Kataoka et al. and Hirota et al. does not explicitly disclose that “wherein an area of the metal film is less than or equal to a half of an area of the thin film”; however, it would have been an obvious matter of design choice to one skilled person in the art at the time the invention was made to arrange an area of the metal film is less than or equal to a half of an area of the thin film; since such a configuration would have involved only a size/shape of components, and is generally recognized as being within the level of ordinary skill in the art. In re Rose, 105 USPQ 237; besides, applicant has not disclosed that this kind of design solves any stated problem or is for any particular purpose (see Spec. [0125]); and providing a teach of an excellent induction heating apparatus to focus the magnetic field at the central portion in order to restricted the decrease of heating efficiency during the operation (Para [0030], Fig 1); which is exactly the same concern of “to maintaining heating efficiency for both aluminum objects and magnetic materials on an induction cooktop” as argued by the applicant shown above. Also, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). (See MPEP 2145 X. A.); During examination, a claim must be given its broadest reasonable interpretation consistent with the specification as it would be interpreted by one of ordinary skill in the art. Because the applicant has the opportunity to amend claims during prosecution, giving a claim its broadest reasonable interpretation will reduce the possibility that the claim, once issued, will be interpreted more broadly than is justified. In re Yamamoto, 740 F.2d 1569, 1571 (Fed. Cir. 1984); In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989)”. “Under a broadest reasonable interpretation, words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the time of the invention” (MPEP 2173.01(I)). Therefore, the examiner maintains the rejection. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Applicant is advised to refer to the Notice of References Cited for pertinent prior art. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KUANGYUE CHEN whose telephone number is 571/272-8224. The examiner can normally be reached on M-F 9:00-5:00 EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, supervisor Ibrahime Abraham can be reached on 571/270-5569, supervisor Kosanovic Helena can be reached on 571/272-9059, supervisor Steven Crabb can be reached on 571/270-5095, or supervisor Edward Landrum can be reached on 571/272-5567. The fax phone number for the organization where this application or proceeding is assigned is 571/273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866/217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800/786-9199 (IN USA OR CANADA) or 571/272-1000. /KUANGYUE CHEN/ Examiner, Art Unit 3761 /EDWARD F LANDRUM/Supervisory Patent Examiner, Art Unit 3761
Read full office action

Prosecution Timeline

May 23, 2024
Application Filed
Jul 02, 2025
Non-Final Rejection — §103
Oct 08, 2025
Response Filed
Oct 31, 2025
Final Rejection — §103
Jan 02, 2026
Response after Non-Final Action
Feb 04, 2026
Request for Continued Examination
Feb 25, 2026
Response after Non-Final Action
Mar 09, 2026
Non-Final Rejection — §103 (current)

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