Prosecution Insights
Last updated: April 19, 2026
Application No. 18/004,137

FILTER UNIT AND AIR PURIFIER HAVING SAME

Non-Final OA §103§112
Filed
Jan 03, 2023
Examiner
MCKENZIE, THOMAS B
Art Unit
1776
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Coway Co. Ltd.
OA Round
3 (Non-Final)
57%
Grant Probability
Moderate
3-4
OA Rounds
3y 3m
To Grant
80%
With Interview

Examiner Intelligence

Grants 57% of resolved cases
57%
Career Allow Rate
551 granted / 961 resolved
-7.7% vs TC avg
Strong +23% interview lift
Without
With
+22.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
91 currently pending
Career history
1052
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
46.5%
+6.5% vs TC avg
§102
17.6%
-22.4% vs TC avg
§112
27.5%
-12.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 961 resolved cases

Office Action

§103 §112
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 . Claim Rejections - 35 USC § 112(b) 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 1–3, 6–12 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 applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 1 recites: 1. A filter unit comprising: a frame having an outer shape surrounding an opening through which air flows and having a collection surface and an opposite surface opposite to the collection surface; and a filter member that is disposed in the opening and filters foreign substances included in the flowing air, and a fixing unit coupled to the frame and configured to fix relative positions of one part and another part of the frame divided based on the folding groove, wherein a folding groove is formed on the opposite surface of the frame, wherein the folding groove is formed at at least two points of the frame so that when an external force is applied from the opposite surface of the frame toward the collection surface, one of a part and another part of the frame divided based on the folding groove relatively rotates toward the other one, and the frame is folded in such a way that a portion of the collection surface approaches another portion of the collection surface, wherein the fixing unit includes: a holder formed on any one of the one part and the another part of the frame divided based on the folding groove; and a fixing protrusion formed to protrude on the other one, of the one part and the another part of the frame divided based on the folding groove, on which the holder is not formed, and configured to be fixed to the holder, and wherein the holder is extended from the any one of the one part and the another part of the frame so that a portion of the holder is disposed above the folding groove, wherein the frame includes a sliding portion formed along an outer peripheral surface thereof, and the sliding portion is disposed outward of the fixing unit in an extension direction of the folding groove, and is not overlapped with the fixing unit when viewed in the extension direction of the folding groove. Emphasis added. Claim 1 is indefinite because “the folding groove” lacks antecedent basis. Claim 1 is also indefinite because it is unclear if the recitation of “a folding groove” refers to “the folding groove” initially stated in the claim. Claim 1 is further indefinite because it is unclear if the recitation of “a part and another part of the frame divided based on the fold groove” refers to the “one part and another part of the frame divided based on the folding groove” initially introduced in the claim. To overcome the rejections, claim 1 could be amended to read: 1. A filter unit comprising: a frame having an outer shape surrounding an opening through which air flows and having a collection surface and an opposite surface opposite to the collection surface; and a filter member that is disposed in the opening and filters foreign substances included in the flowing air, and a fixing unit coupled to the frame and configured to fix relative positions of one part and another part of the frame divided based on [[the]] a folding groove, wherein [[a]] the folding groove is formed on the opposite surface of the frame, wherein the folding groove is formed at at least two points of the frame so that when an external force is applied from the opposite surface of the frame toward the collection surface, the one of [[a]] part and the another part of the frame divided based on the folding groove relatively rotates toward the other one, and the frame is folded in such a way that a portion of the collection surface approaches another portion of the collection surface, wherein the fixing unit includes: a holder formed on any one of the one part and the another part of the frame divided based on the folding groove; and a fixing protrusion formed to protrude on the other one, of the one part and the another part of the frame divided based on the folding groove, on which the holder is not formed, and configured to be fixed to the holder, and wherein the holder is extended from the any one of the one part and the another part of the frame so that a portion of the holder is disposed above the folding groove, wherein the frame includes a sliding portion formed along an outer peripheral surface thereof, and the sliding portion is disposed outward of the fixing unit in an extension direction of the folding groove, and is not overlapped with the fixing unit when viewed in the extension direction of the folding groove. Claims 2, 3 and 6–12 are indefinite because they depend from claim 1. 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. The factual inquiries 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. Claims 1, 2 and 6–10 are rejected under 35 U.S.C. 103 as being unpatentable over Knuckles, US 10,245,542 in view of Mountford, US 2004/0112019 A1 and in further view of Cavett, US 6,814,660 B1. Regarding claims 1 and 6, Knuckles teaches a foldable air filter 2, which reads on the claimed “filter unit.” See Knuckles Fig. 1, col. 4, l. 66–col. 5, l. 6. The air filter 2 comprises a frame 20 having an outer shape surrounding an opening through which air flows. See Knuckles Fig. 1, col. 5, ll. 1–6. The frame 20 reads on the “frame.” The frame 20 has an upper, dirty side 6 and a clean side 8. See Knuckles Figs. 2–3, col. 5, ll. 1–6. The dirty side 6 reads on the “collection surface” and the clean side 8 reads on the “opposite surface.” The air filter 2 further comprises a filter media panel 4 that is disposed in the opening and is used to filter foreign substances included in the flowing air. See Knuckles Fig. 1, col. 5, ll. 1–6. The filter media panel 4 reads on the “filter member.” The air filter 2 also comprises a hinge locking means 50 coupled to the frame 20, and configured to fix relative positions of the left-hand and right hand portions of side element 28 of the frame 20, from the perspective of Fig. 10, divided based on one of two hinge joints 40. See Knuckles Fig. 10, col. 6, ll. 28–41. The hinge locking means 50 reads on the “fixing unit.” The left and right-hand portions of side element 28 read on the “one part” and the “another part” of the “frame,” respectively. The hinge joints 40 reads on the “folding groove.” The hinge joints 40 are formed on the clean side 8 of the frame 20, as claimed. See Knuckles Fig. 5, col. 5, ll. 21–28. The hinge joints 40 are “formed at at least two points of the frame,” as claimed, because a hinge joint 40 is formed on two side elements 24, 28 of the frame 20. See Knuckles Fig. 5, col. 5, ll. 1–6. Also, when an external force is applied to opposite edge elements 22, 26 of the frame 20 toward the dirtied side 6, the left-hand portion of side element 28 relatively rotates toward the right-hand portion of side element 28, and the frame 20 is folded in such a way that a portion of the dirtied side 6 approaches another portion of the dirtied side 6 as seen in Fig. 5. This reads on “when an external force is applied from the opposite surface of the frame toward the collection surface, one of a part and another part of the frame divided based on the folding groove relatively rotates toward the other one, and the frame is folded in such a way that a portion of the collection surface approaches another portion of the collection surface.” The hinge locking means 50 includes a strap member (illustrated by the adhesive strap member 250 seen in Fig. 14; the strap member reads on the “holder”) formed on the left-hand portion of the side element 28. See Knuckles Fig. 14, col. 6, ll. 57–col. 7, ll. 3. This reads on “the fixing unit includes: a holder formed on any one of the one part and the another part of the frame divided based on the folding groove.” The strap member is extended from the left-hand portion of side element 28 so that a portion of the strap member is disposed above the cut 44 of the hinge joint 44, as seen by strap member 250 in Fig. 14. This reads on the “holder is extended from the any one of the one part and the another part of the frame so that a portion of the holder is disposed above the folding groove.” PNG media_image1.png 761 982 media_image1.png Greyscale Knuckles differs from claim 1 because it is silent as to the hinge locking means 50 (the “fixing unit”) including a fixing protrusion formed on the right-hand side of the side element 28 (the “another part of the frame…on which the holder is not formed”) and configured to be fixed to the strap member (the “holder”), as claimed. But the strap member can use a mechanical fastener, such as a rivet, to connect the left and right-hand sides of the side element 28 together. See Knuckles col. 6, l. 66–col. 7, l. 3. With this in mind, Mountford teaches a filter bag comprising a mechanical connection mechanism for attaching two sections of the filter bag together comprising a strip 701 with a female snap portion 703 that be snapped onto a male snap portion 704 of another strip 702. See Mountford Fig. 7, [0022]. The connection mechanism is beneficial because the two sections of the filter bag can be repeatedly attached and detached from each other due to the male and female snap combination. PNG media_image2.png 308 663 media_image2.png Greyscale It would have been obvious for the strap member of Knuckles to comprise a female snap portion that engages with a male snap portion on the right-hand side of side element 28 to provide a mechanical fastener that allows the strap member to be repeatedly attached and detached from the right-hand side of the side element 28. With this modification, the male snap portion reads on the “fixing protrusion formed to protrude on the other, of the one part and the another part of the frame divided based on the folding groove, on which the holder is not formed, and configure to be fixed to the holder” (claim 1). Also, the hole in the female snap portion reads on the “fixing hole in which the fixing protrusion is inserted” (claim 6). Knuckles also differs from claim 1 because it is silent as to the frame 20 including a sliding portion formed along an outer peripheral surface, where the sliding portion is disposed outward of the hinge locking means 50 in an extension direction of the hinge joints 40, where the sliding portion is not overlapped with the hinge locking means 50 when viewed in an extension direction of the hinge joints 40, as claimed. But the air filter 2 can be used in a heating and air conditioning system. See Knuckles col. 1, ll. 14–15. With this in mind, Cavett teaches a filter assembly 50 for an HVAC system comprising a filter support portion 52 (i.e., a frame) comprising a tab 62 formed along an outer peripheral surface of one side of the support 52, where the tab 62 is configured to be slidably received in a slot 60 of an assembly 20 of the HVAC system. See Cavett Figs. 1, 2, col. 3, ll. 49–63, col. 4, ll. 1–14. The tab 62 is beneficial because it acts as a key to inhibit placing the filter 50 within the frame in a backward position. Id. at col. 4, ll. 1–14. PNG media_image3.png 1005 1632 media_image3.png Greyscale It would have been obvious to provide the tab 62 of Cavett on the side element 28 at a location above the hinge locking means 50 of Knuckles (from the perspective of Fig. 10 of Knuckles) to provide a key mechanism to prevent the filter 2 of Knuckles from being installed backward (note that locating the tab 62 above the hinge locking means 50 would have been obvious because this is a convenient location for the tab 62, as seen in Fig. 10 of Knuckles). It also would have been obvious for the tab 62 of Cavett to extend outwardly past the hinge locking means 50 of Knuckles to ensure that there is enough material of the tab 62 to act as a key to engage with the HVAC system, with Fig. 2 of Cavett illustrating the tab 62 extending a substantial distance from the side of the frame 50. With this modification, the tab 62 reads on the “sliding portion formed along an outer peripheral surface” of the frame 20. The tab 62 would be disposed outward from the hinge locking means 50 of Knuckles (the “fixing unit”) in an extension direction of the hinge joints 40 (the “folding groove”), as claimed, because the tab 62 would extend out past the hinge locking means 50, as explained above. The tab 62 would not be overlapped with the hinge locking means 50 when viewed in the extension direction of the hinge joints 40, as claimed, because the tab 62 would be located above the hinge locking means 50, as explained above. Regarding claim 2, Knuckles teaches that the hinge joints 40 (the “folding grieve”) comprises a hinge joint 40 formed at each of one point of the frame 20 (the point on side element 24) and an opposite point of the frame 20 (the point on side element 28), as claimed, as seen in Fig. 5. In this way, the frame 20 is folded in half when an external force is applied from the clean side 8 (the “opposite surface of the frame”) toward the dirtied side 6 (the “collection surface”), as claimed, as seen in Fig. 5. Regarding claims 7 and 8, Knuckles as modified teaches that the hinge locking means 50 (the “fixing unit”) is configured to fix the frame 20 such that “one part and the another part of the frame divided based on the folding groove” (the two halves of the side elements 24, 28 split by the hinge joints 40) form a straight angle (claim 7) and are arranged side by side (claim 8), as seen in Fig. 10 of Knuckles. Regarding claim 9, Knuckles in view of Mountford and Cavett teaches that the hinge locking means 50 of Knuckles (the “fixing unit”) includes the female snap portion of Mountford (the “fixing hole”) formed on the strap member of Knuckles formed on the left-hand portion of side element 28 (“formed on the any one of the one part and the another part of the frame divided based on the folding groove”), as explained in the rejection of claim 1 above. Regarding claim 10, Knuckles teaches that the frame 20 includes a “handle portion” formed at an upper portion of the frame, which is the edge element 22, as seen in Fig. 1. The edge element 22 is a “handle portion” because it is capable of being gripped. See MPEP 2114(IV) (Functional claim language that is not limited to a specific structure covers all devices that are capable of performing the recited function). Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Knuckles, US 10,245,542 in view of Mountford, US 2004/0112019 A1 in view of Cavett, US 6,814,660 B1 and in further view of Barry et al., WO 2020/076751 A11. Regarding claim 3, Knuckles as modified teaches the limitations of claim 1, as explained above. Knuckles differs from claim 3 because it is silent as the frame 20 comprising a reinforcing rib having both ends connected to the frame 20 to partition the opening. But Barry teaches a collapsible filter assembly 100 comprising a sub-frame area 134 comprising a diagonally extending stringers 136 with both ends of each stringer 136 connected to the sub-frame area 134, and with each stringer 136 partitioning an opening in the middle of the sub-frame area 134. See Barry Fig. 7, [0055]. The stringers 136 are rib-shaped elements. Id. The stringers 136 are beneficial because they stiffen the filter assembly 100. Id. PNG media_image4.png 788 723 media_image4.png Greyscale It would have been obvious for the frame 20 of Knuckles to include the stringers 136 of Barry in order to stiffen the foldable air filter. Claims 11 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Knuckles, US 10,245,542 in view of Mountford, US 2004/0112019 A1 in view of Cavett, US 6,814,660 B1 and in further view of Marshall, III, US 2019/0021272 A1. Regarding claim 11, Knuckles teaches an air conditioning system, which reads on the claimed “air purifier.” See Knuckles col. 1, ll. 19–28. The air conditioning system comprises the air filter 2 (the “filter unit according to claim 1”). Id. Knuckles differs from claim 11 because it is silent as to the air conditioning system comprising a blower for providing blowing force to allow outside air to pass through the filter 2. But Knight teaches an HVAC unit 12 comprising a filter 38 and a blower assembly 34 for providing blowing force for allowing air from outside of the filter 38 to pass through it. See Knight Fig. 2, [0028]. It would have been obvious for the air conditioning system of Knuckles to include a blower assembly in order to provide motive force for moving air through the air filter 2. Regarding claim 12, Knuckles teaches that filter 2 is disposed such that air flows through the dirtied side 6 (the “collection surface”) and the clean side 8 (the “opposite surface”) in this order, because the dirtied side 6 is upstream of the clean side 8 as the dirtied side 6 gets dirtied. See Knuckles col. 5, ll. 1–6. Response to Arguments 35 U.S.C. 112(b) Rejections The claim amendments are sufficient to overcome the previous 35 U.S.C. 112(b) rejections. However, the claims remain rejected for being indefinite for the reasons stated above. 35 U.S.C. 103 Rejections Applicant’s arguments with respect to claims 1–3 and 6–12 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to T. BENNETT MCKENZIE whose telephone number is (571)270-5327. The examiner can normally be reached Mon-Thurs 7:30AM-6:00PM. 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, the examiner’s supervisor, Jennifer Dieterle can be reached at 571-270-7872. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. T. BENNETT MCKENZIE Primary Examiner Art Unit 1776 /T. BENNETT MCKENZIE/Primary Examiner, Art Unit 1776 1 Barry is in the record as the 28-page Foreign Reference filed April 24, 2024.
Read full office action

Prosecution Timeline

Jan 03, 2023
Application Filed
Mar 27, 2025
Non-Final Rejection — §103, §112
Jul 01, 2025
Response Filed
Jul 07, 2025
Final Rejection — §103, §112
Oct 09, 2025
Request for Continued Examination
Oct 14, 2025
Response after Non-Final Action
Jan 14, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
57%
Grant Probability
80%
With Interview (+22.9%)
3y 3m
Median Time to Grant
High
PTA Risk
Based on 961 resolved cases by this examiner. Grant probability derived from career allow rate.

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