Prosecution Insights
Last updated: April 19, 2026
Application No. 18/624,016

PRINTING APPARATUS AND INK CIRCULATION METHOD

Final Rejection §103
Filed
Apr 01, 2024
Examiner
VALENCIA, ALEJANDRO
Art Unit
2853
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Canon Kabushiki Kaisha
OA Round
2 (Final)
42%
Grant Probability
Moderate
3-4
OA Rounds
2y 11m
To Grant
48%
With Interview

Examiner Intelligence

Grants 42% of resolved cases
42%
Career Allow Rate
567 granted / 1335 resolved
-25.5% vs TC avg
Moderate +6% lift
Without
With
+5.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
151 currently pending
Career history
1486
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
53.6%
+13.6% vs TC avg
§102
24.4%
-15.6% vs TC avg
§112
20.8%
-19.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1335 resolved cases

Office Action

§103
DETAILED ACTION 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) 1-17 are rejected under 35 U.S.C. 103 as being unpatentable over Hirosawa et al. (2012/0206524) in view of Oshio et al. (2007/0035592). Regarding claims 1 and 17, Hirosawa teaches a printing apparatus and method comprising: an ejection unit (fig. 1, item 14) that ejects an ink from an ejection port ([0027]); a circulation unit ([0048], fig. 8, item 71) that performs a circulation operation of regularly circulating the ink through a predetermined circulation channel (note that there is necessarily a circulation channel), wherein ink circulations and ink discharge operations are both executed periodically ([0048], [0053]). Hirosawa does not teach a setting a setting unit that sets a circulation time for which the circulation unit will perform a next circulation operation, wherein the setting unit sets the circulation time such that the circulation time in a case where an ink discharge operation of discharging the ink from the ejection port is performed between a last circulation operation and the next circulation operation is shorter than the circulation time in a case where the ink discharge operation is not performed between the last circulation operation and the next circulation operation. Oshio teaches setting a time period of circulation of a liquid in accordance with an amount of idle time the liquid to be circulated has remained undischarged (Oshio, see figs. 14, 15, [0106], [0107, Note that each shorter circulation times are prescribed for shorter amounts of elapsed idle times and longer circulation times are prescribed for longer periods of inactivity). It would have been obvious to one of ordinary skill in the art at the time of invention to apply the idle time/circulation time table disclosed by Oshio to the device disclosed by Hirosawa because doing so would allow for tailored periods of circulation times corresponding to exact amounts of elapsed times since previous activity. Upon application of Oshio’s technique to the device of Hirosawa, a time period from a last preliminary ejection of Hirosawa’s printhead would be obtained and time period for ink circulation would be assigned in accordance so that, if a preliminary ejection had been executed between two circulations, the second circulation would be shorter in duration, and if a preliminary ejection had not been executed, a second consecutive circulation would have the same duration as the previous circulation. That is, Hirosawa’s preliminary ejection is expressly stated as being executed to prevent a rise in viscosity of ink within the head. That said, reducing the viscosity of ink within the head between two circulations would necessarily mean that a circulation of less intensity would be needed after the preliminary ejection. (Examiner understands Oshio is directed to circulation of an application liquid to be applied by an application roller rather than an ink to be ejected by a printhead, as disclosed by Hirosawa. Nonetheless, Examiner maintains it would have been obvious to apply the idle time/circulation time scheme of Oshio to any device using such circulation methods). Regarding claim 2, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1, wherein the setting unit sets the circulation time by correcting a predetermined time according to an amount of the ink discharged per unit time from the ejection port in the ink discharge operation (Note that if unit time is the time between circulations, whether or not the preliminary discharge is executed would be an amount of ink, and thus the predetermined time is corrected according to whether the preliminary discharge is executed). Regarding claim 3, Hirosawa in view of Oshio teaches the printing apparatus according to claim 2, wherein the setting unit corrects the predetermined time in the next circulation operation according to a time for which the ink is ejected from the ejection port in the ink discharge operation (Note that if unit time is the time between circulations, whether or not the preliminary discharge is executed would be an amount of ink, and thus the predetermined time is corrected according to whether the preliminary discharge is executed). Regarding claim 4, Hirosawa in view of Oshio teaches the printing apparatus according to claim 3, wherein the setting unit corrects the predetermined time in the next circulation operation according to a time from the last circulation operation to the ink discharge operation (Note that if unit time is the time between circulations, whether or not the preliminary discharge is executed would be an amount of ink, and thus the predetermined time is corrected according to whether the preliminary discharge is executed. Note that if the predetermined time has been set according to a past preliminary ejection occurring, and then, in the next circulation cycle, no ejection is executed, the predetermined time would be corrected and set back to a longer predetermined time). Regarding claim 5, Hirosawa in view of Oshio teaches the printing apparatus according to claim 4, wherein the setting unit corrects the predetermined time in the next circulation operation according to a time from the ink discharge operation to the next circulation operation (see claim 1 rejection). Regarding claim 6, Hirosawa in view of Oshio teaches the printing apparatus according to claim 2, wherein the setting unit does not correct the predetermined time in a case where the amount of the ink discharged per unit time is less than a predetermined amount (Note that, when there is no preliminary ejection, i.e., when the amount of ink is less than a positive amount of ink, the predetermined time is not corrected because the predetermined time remains the same from one circulation to the next). Regarding claim 7, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1. Hirosawa in view of Oshio does not expressly teach wherein the ink discharge operation is a printing operation of performing printing by ejecting the ink from the ejection port. However, Hirosawa teaches wherein ink is discharged from the nozzles in a preliminary ejection in the exact same manner as it would be ejected during printing. Examiner takes official notice that one of skill in the art would have found it obvious that ejecting ink for printing and ejecting ink during a preliminary ejection would work as obvious alternatives to prevent increase in viscosity given the disclosure of Hirosawa, [0053]. Regarding claim 8, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1, wherein the ink discharge operation is a recovery operation of recovering an ejection condition of the ejection unit by performing at least one of a suction operation of sucking the ink from the ejection port or a preliminary ejection operation of preliminarily ejecting the ink from the ejection port ([0053]). Regarding claim 9, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1, wherein the ink is a pigment ink ([0027], Note that the inks are necessarily pigment inks as dye inks do not increase in viscosity when they settle). Regarding claim 10, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1. Hirosawa in view of Oshio does not teach wherein the ink is a white ink. Examiner takes official notice that one of ordinary skill in the art at the time of invention would have found it obvious to use any color of ink with the prior art device. Regarding claim 11, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1, wherein the ejection unit is capable of ejecting a first ink and a second ink different from the first ink, and the circulation unit is capable of circulating the first ink and does not circulate the second ink ([0027], Note that every ink is circulated separately and independently). Regarding claim 12, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1, wherein the ejection unit is capable of ejecting a first ink and a second ink different from the first ink, and the circulation unit circulates the first ink and the second ink ([0027], Note that every ink is circulated separately and independently. Thus, it is possible for any or all inks to be circulated at the same time or different times). Regarding claim 13, Hirosawa in view of Oshio teaches the printing apparatus according to claim 12, wherein a circulation time for which the circulation unit circulates the first ink in the circulation operation is different from a circulation time for which the circulation unit circulates the second ink in the circulation operation (Note that, because all colors are ejected independently, corrected predetermined times for circulations vary across colors). Regarding claim 14, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1, wherein the ejection unit is capable of ejecting a first ink and a second ink different from the first ink, and the ejection unit is a print head having the ejection port for ejecting the first ink and the ejection port for ejecting the second ink (Hirosawa, fig. 1). Regarding claim 15, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1, wherein the ejection unit is capable of ejecting a first ink and a second ink different from the first ink, and the ejection unit includes a first print head having the ejection port for ejecting the first ink, and a second print head having the ejection port for ejecting the second ink (Hirosawa, fig. 1). Regarding claim 16, Hirosawa in view of Oshio teaches the printing apparatus according to claim 1, wherein the ejection unit performs printing by ejecting the ink while being mounted on and moving with a carriage (Hirosawa, see fig. 1). Response to Arguments Applicant's arguments filed 1/14/2026 have been fully considered but they are not persuasive. Applicant argues Oshio does not teach liquid ejection, but this argument attacks the secondary reference alone when the liquid ejection is taught by the primary reference Hirosawa. Hirsosawa teaches periodic liquid ejection and liquid circulation. Hirosawa is silent as to what criteria it uses to determine a need for or intensity of a circulation operation. Because Hirosawa’s liquid ejection itself serves to circulate liquid, dedicated circulation of liquid is only required when a substantial amount of time after a liquid ejection has been performed has elapsed. Thus, a dedicated circulation is performed. Only the basic teaching of Oshio’s corresponding idle time and circulation duration is being applied to Hirosawa. As detailed, it is maintained that this relation would have been applicable to any number of devices that employ such circulation techniques. The combination of references is maintained as proper. The standing prior art rejection is maintained. 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 ALEJANDRO VALENCIA whose telephone number is (571)270-5473. The examiner can normally be reached M-F. 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, DOUGLAS X. RODRIGUEZ can be reached at 571-431-0716. 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. /ALEJANDRO VALENCIA/Primary Examiner, Art Unit 2853
Read full office action

Prosecution Timeline

Apr 01, 2024
Application Filed
Oct 08, 2025
Non-Final Rejection — §103
Jan 14, 2026
Response Filed
Jan 21, 2026
Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12600127
INKJET ASSEMBLY, INKJET PRINTING APPARATUS AND INKJET PRINTING METHOD FOR USE IN PREPARATION OF DISPLAY COMPONENT
2y 5m to grant Granted Apr 14, 2026
Patent 12583238
PAPER SUPPLY CONTROL DEVICE
2y 5m to grant Granted Mar 24, 2026
Patent 12576644
RECORDING DEVICE AND METHOD OF CONTROLLING RECORDING DEVICE
2y 5m to grant Granted Mar 17, 2026
Patent 12570101
RECORDING DEVICE
2y 5m to grant Granted Mar 10, 2026
Patent 12558904
DROP-ON-DEMAND INK DELIVERY SYSTEMS AND METHODS WITH TANKLESS RECIRCULATION FOR CARD PROCESSING SYSTEMS
2y 5m to grant Granted Feb 24, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

3-4
Expected OA Rounds
42%
Grant Probability
48%
With Interview (+5.9%)
2y 11m
Median Time to Grant
Moderate
PTA Risk
Based on 1335 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month