Prosecution Insights
Last updated: April 19, 2026
Application No. 18/742,230

LIQUID EJECTION HEAD AND LIQUID EJECTION APPARATUS

Non-Final OA §103§112
Filed
Jun 13, 2024
Examiner
MCMILLION, TRACEY M
Art Unit
2853
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Canon Kabushiki Kaisha
OA Round
1 (Non-Final)
88%
Grant Probability
Favorable
1-2
OA Rounds
2y 2m
To Grant
90%
With Interview

Examiner Intelligence

Grants 88% — above average
88%
Career Allow Rate
545 granted / 623 resolved
+19.5% vs TC avg
Minimal +2% lift
Without
With
+2.4%
Interview Lift
resolved cases with interview
Fast prosecutor
2y 2m
Avg Prosecution
34 currently pending
Career history
657
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
56.2%
+16.2% vs TC avg
§102
25.9%
-14.1% vs TC avg
§112
14.7%
-25.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 623 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 . Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Claim Rejections - 35 USC § 112 Claim 8 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. It is unclear to the Examiner how “the liquid sending unit is the first pump” when independent claim 1 claims the liquid ejection head has both a first pump and a liquid sending unit. 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, and 9-12 are rejected under 35 U.S.C. 103 as being unpatentable over Kumagai (US 2019/0344580) and further in view of Katada (US 2009/0108879). With regard to claims 1, Kumagai discloses a liquid ejection head (12) [Para. 0023] comprising: an ejection unit (23) [nozzles; Para. 0023] capable of ejecting a liquid [Para. 0021]; a first pressure control unit (18) [Para. 0020] capable of regulating pressure in a supply channel (14) [supply flow path; Para. 0020] by supplying the liquid to the ejection unit via the supply channel [Fig. 8]; a second pressure control unit (19) [Fig. 8] capable of regulating pressure in a collection channel (15) [circulation flow path; Para. 0020] by collecting the liquid from the ejection unit via the collection channel [Fig. 8]; a first pump unit (17) [circulation pump; Para. 0020] which is provided between the second pressure control unit and the first pressure control unit [Fig. 8] and which is capable of sending the liquid from the second pressure control unit to the first pressure control unit [Fig. 8]; and a liquid sending unit (16) [supply pump; Fig. 8] which is provided outside a first channel for a flow from the supply channel to the collection channel via the ejection unit [Fig. 8], Kumagai does not discloses the liquid sending unit is capable of sending the liquid from the first pressure control unit to the second pressure control unit while bypassing the ejection unit. However, Katada teaches a liquid sending unit (V4) capable of sending the liquid from a first pressure control unit (P1) to a second pressure control unit (P2) while bypassing an ejection unit (50). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to configure the liquid sending unit of Kumagai to bypass the ejection unit as taught by Katada in order to control pressure of liquid outside of the ejection unit. With regard to claim 2, Kumagai’s modified ejection head discloses all the limitations of claim 1 and Kumagai also discloses wherein the liquid sending unit is a second pump [Fig. 8] provided in a second channel [Fig. 8] and Katada discloses a second channel (172) connects a first pressure control unit (P1) and a second pressure control unit (P2) and which is provided in parallel with the first pump unit [Fig. 11], the valve being capable of sending the liquid from the first pressure control unit to the second pressure control unit [Fig. 11]. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to configure the second channel of Kumagai parallel with the first pump unit in order to increase total flow rate of ink. With regard to claim 3, Kumagai’s modified liquid ejection head discloses all the limitations of claim 2, and Katada also discloses further comprising a pressure gauge (S2) capable of measuring pressure in the second pressure control unit [Para. 0088]. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to configure the ejection head of Kumagai with a pressure gauge in order to eject the liquid more reliably. With regard to claim 5, Kumagai’s modified liquid ejection head discloses all the limitations of clam 1, Kumagai also discloses wherein the liquid sending unit is a second channel (68) but does not disclose connecting the first pressure control unit and the second pressure control unit and which is provided in parallel with the first pump unit. However, Katada teaches a liquid sending unit (172) connecting the first pressure control unit (P1) and the second pressure control unit (P1) and which is provided in parallel with the first pump unit [Fig. 11]. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to configure the second liquid sending unit of Kumagai in parallel with the first pump unit in order to increase flow rate of liquid. With regard to claim 7, Kumagai’s modified liquid ejection head discloses all the limitations of claim 5, and Katada also discloses wherein the second channel includes a valve (V4) capable of opening and closing the second channel. [Fig .11] With regard to claim 9, Kumagai’s modified liquid ejection head discloses all the limitations of claim 1, and Katada also discloses wherein the ejection unit ejects the liquid by driving a heater resistor element [Para. 0079]. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to configure the ejection unit of Kumagai with a heater resistor element as taught by Katada in order to ejection ink from head by thermal method. With regard to claim 10, Kumagai discloses a liquid ejection apparatus (12) [Para. 0023] comprising: an ejection head (23) [nozzles; Para. 0023] capable of ejecting a liquid [Para. 0021]; a first pressure control unit (18) [Para. 0020] capable of regulating pressure in a supply channel (14) [supply flow path; Para. 0020] by supplying the liquid to the liquid ejection head via the supply channel [Fig. 8]; a second pressure control unit (19) [Fig. 8] capable of regulating pressure in a collection channel (15) [circulation flow path; Para. 0020] by collecting the liquid from the liquid ejection head via the collection channel [Fig. 8]; a first pump unit (17) [circulation pump; Para. 0020] which is provided between the second pressure control unit and the first pressure control unit [Fig. 8] and which is capable of sending the liquid from the second pressure control unit to the first pressure control unit [Fig. 8]; and a liquid sending unit (16) [supply pump; Fig. 8] which is provided outside a first channel for a flow from the supply channel to the collection channel via the liquid ejection head [Fig. 8]. Kumagai does not discloses the liquid sending unit is capable of sending the liquid from the first pressure control unit to the second pressure control unit while bypassing the liquid ejection head. However, Katada teaches a liquid sending unit (V4) capable of sending the liquid from a first pressure control unit (P1) to a second pressure control unit (P2) while bypassing a liquid ejection head (50). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to configure the liquid sending unit of Kumagai to bypass the ejection unit as taught by Katada in order to control pressure of liquid outside of the ejection unit. With regard to claim 11, Kumagai discloses a liquid ejection apparatus [Para. 0023] comprising: an ejection unit (23) [nozzles; Para. 0023] capable of ejecting a liquid [Para. 0021]; a first pressure control unit (18) [Para. 0020] capable of regulating pressure in a supply channel (14) [supply flow path; Para. 0020] by supplying the liquid to the ejection unit via the supply channel [Fig. 8]; a second pressure control unit (19) [Fig. 8] capable of regulating pressure in a collection channel (15) [circulation flow path; Para. 0020] by collecting the liquid from the ejection unit via the collection channel [Fig. 8]; a first pump unit (17) [circulation pump; Para. 0020] which is provided between the second pressure control unit and the first pressure control unit [Fig. 8] and which is capable of sending the liquid from the second pressure control unit to the first pressure control unit [Fig. 8]; and a liquid sending unit (16) [supply pump; Fig. 8] which is provided outside a first channel for a flow from the supply channel to the collection channel via the ejection unit [Fig. 8]. Kumagai does not discloses the liquid sending unit is capable of sending the liquid from the first pressure control unit to the second pressure control unit while bypassing the ejection unit. However, Katada teaches a liquid sending unit (V4) capable of sending the liquid from a first pressure control unit (P1) to a second pressure control unit (P2) while bypassing an ejection unit (50). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to configure the liquid sending unit of Kumagai to bypass the ejection unit as taught by Katada in order to control pressure of liquid outside of the ejection unit. With regard to claim 12, Kumagai’s modified ejection apparatus discloses all the limitations of claim 11 and Kumagai also discloses wherein the liquid sending unit is a second pump unit [Fig. 8] provided in a second channel [Fig. 8] and Katada discloses a second channel (172) which connects a first pressure control unit (P1) and a second pressure control unit (P2) and which is provided in parallel with the first pump unit [Fig. 11], a valve being capable of sending the liquid from the first pressure control unit to the second pressure control unit [Fig. 11]. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to configure the second channel of Kumagai in parallel with the first pump unit and configure the second channel of Kumagai to connect to the first control unit and the second control unit in order to increase flow rate of liquid. Claim(s) 4 is rejected under 35 U.S.C. 103 as being unpatentable over Kumagai (US 2019/0344580) in view of Katada (US 2009/0108879) as applied to claim 2 above, and further in view of Goto (US 2019/0092034). With regard to claim 4, Kumagai’s modified liquid ejection head discloses all the limitation sof claim 2 but does not disclose wherein the first pump unit and the second pump unit are piezoelectric diaphragm pumps. However, Goto teaches a liquid ejection head wherein first pump unit (33) [circulation pump; Para. 0044] and a second pump unit (53) [replenishing pump] are piezoelectric diaphragm pumps [Para. 0044]. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to substitute the first and second pump of Kumagai with piezoelectric diaphragm pumps in order to control volume changes through vibration by a voltage at a particular frequency. Allowable Subject Matter Claim 6 is 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. Claim 6 is objected to because the prior art does not teach or make obvious “wherein the second channel has flow resistance lower than flow resistance of the first channel.” Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to TRACEY M MCMILLION whose telephone number is (571)270-5193. The examiner can normally be reached Monday-Friday 6AM-2:30PM 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, the examiner’s supervisor, Ricardo Magallanes can be reached at 571-272-5960. 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. /TRACEY M MCMILLION/Examiner, Art Unit 2853 /RICARDO I MAGALLANES/Supervisor Patent Examiner, Art Unit 2853
Read full office action

Prosecution Timeline

Jun 13, 2024
Application Filed
Feb 04, 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

1-2
Expected OA Rounds
88%
Grant Probability
90%
With Interview (+2.4%)
2y 2m
Median Time to Grant
Low
PTA Risk
Based on 623 resolved cases by this examiner. Grant probability derived from career allow rate.

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