Prosecution Insights
Last updated: April 19, 2026
Application No. 18/605,316

WAVELENGTH CONVERSION DEVICE, METHOD OF MANUFACTURING WAVELENGTH CONVERSION DEVICE, ILLUMINATION DEVICE, AND PROJECTOR

Final Rejection §103
Filed
Mar 14, 2024
Examiner
ENDO, JAMES M
Art Unit
2875
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Seiko Epson Corporation
OA Round
2 (Final)
65%
Grant Probability
Moderate
3-4
OA Rounds
2y 5m
To Grant
86%
With Interview

Examiner Intelligence

Grants 65% of resolved cases
65%
Career Allow Rate
250 granted / 385 resolved
-3.1% vs TC avg
Strong +21% interview lift
Without
With
+21.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
25 currently pending
Career history
410
Total Applications
across all art units

Statute-Specific Performance

§103
57.2%
+17.2% vs TC avg
§102
16.9%
-23.1% vs TC avg
§112
20.8%
-19.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 385 resolved cases

Office Action

§103
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Response to Amendment Applicant’s amendment filed on 11/20/2025 has been entered. Claims 1-8 are pending in this application. Claim Interpretation Claim 1, lines 3-9 recites the limitation “a wavelength conversion layer disposed on the substrate and including a plurality of phosphor particles and a bonding member configured to bond the plurality of phosphor particles and the substrate to each other; and a reflecting layer disposed between the substrate and the wavelength conversion layer”. The claim both recites the bonding member bonds the substrate, and a reflecting layer between the substrate and the wavelength conversion layer. The bonding member appears to bond to the reflecting layer because the reflecting layer is between the substrate and the wavelength. As a result, the limitation was interpreted as the bonding member bonds to the substrate by the reflecting layer. Claim 6 recites “removing a surplus particle which is included in the phosphor particle group, and which fails to be bonded to another phosphor particle via the bonding member on a surface of the wavelength conversion layer at an opposite side to the substrate”. The claim recites a surplus phosphor particle which fails to be bonded to another phosphor particle via the bonding member. In other words, a surplus phosphor particle is floating due to not being bonded by the bonding member. And because the surplus phosphor particle is floating, the surplus phosphor particle is removed. As a result, the limitation was interpreted as removing a surplus phosphor particle not bonded by the bonding member. 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. Claims 1-2, 4, and 7-8 are rejected under 35 U.S.C. 103 as being unpatentable over NAKATSU (US 2013/0163225), and in view of CHEN (US 2020/02333291), TSUMORI (US 2015/0354783), and OSHIO (US 2020/0109331). Regarding claim 1, NAKATSU discloses a wavelength conversion device comprising a substrate (10, Fig.1); a wavelength conversion layer (20, Fig.) disposed on the substrate and including a plurality of phosphor particles (30, Fig.1) and a bonding member (40, Fig.1) configured to bond the plurality of phosphor particles and the substrate to each other (as seen in Fig.1, the bonding member 40 and the substrate 10 was considered to be bonded to each other). NAKATSU fails to disclose a reflecting layer disposed between the substrate and the wavelength conversion layer and configured to reflect light emitted from the wavelength conversion layer, wherein a particle size distribution of the plurality of phosphor particles is no smaller than 40 μm and no larger than 200 μm, a center value of the particle size distribution is no smaller than 70 μm and no larger than 150 μm, some of the phosphor particles are thermally coupled to the reflecting layer, 50% or more of the phosphor particles are thermally coupled to each other through direct contact with adjacent phosphor particles of the plurality of phosphor particles, and a thickness of the bonding member is no smaller than 30% and no larger than 80% of a thickness of the wavelength conversion layer. However, CHEN discloses a reflecting layer (140, Fig.3) disposed between a substrate (110, Fig.3) and a wavelength conversion layer (120, Fig.3) and configured to reflect light emitted from a wavelength conversion layer, and some phosphor particles are coupled to the reflecting layer (as seen in Fig.2, some phosphor particles P were considered to be coupled to the reflecting layer 140). However, TSUMORI discloses a particle size distribution of the plurality of phosphor particles is 2 μm - 200 μm (para[0027]). However, OSHIO discloses phosphor particles (1, 2, Figs.3-4) are thermally coupled to each other through direct contact with adjacent phosphor particles (as seen in Fig.3 and para[0053], the phosphor particles 1, 2 can be coupled to each other by a heating reaction through direct contact between the phosphor particles 1, 2). Therefore, in view of CHEN, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a reflecting layer as taught by CHEN to the wavelength conversion device of NAKATSU in order to reflect light out of the wavelength conversion layer. Therefore, in view of TSUMORI, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a particle size distribution of the phosphor particles is 2 μm - 200 μm as taught by TSUMORI to the phosphor particles of NAKATSU modified by CHEN in order to provide a known range of particle sizes to the phosphor particles. Therefore, in view of OSHIO, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate phosphor particles thermally coupled to each other through direct contact with adjacent phosphor particles as taught by OSHIO to the phosphor particles of NAKATSU modified by CHEN and TSUMORI in order to provide an alternative bond to couple the phosphor particles to the wavelength conversion device. Regarding “a particle size distribution of the plurality of phosphor particles is no smaller than 40 μm and no larger than 200 μm”, TSUMORI discloses a particle size distribution of 2 μm - 200 μm for the phosphor particles. While TSUMORI discloses the upper limit, one of ordinary skill in the art would have recognized to select a range of sizes for the phosphor particles (including the lower limit of 40 μm) to balance between how the incident light interacts with the different sizes of phosphor particles. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a particle size distribution of the plurality of phosphor particles is no smaller than 40 μm and no larger than 200 μm to the phosphor particles of NAKATSU modified by CHEN, TSUMORI, and OSHIO in order to provide a range of phosphor particles depending on the desired properties of the output light. Regarding “a center value of the particle size distribution is no smaller than 70 μm and no larger than 150 μm”, TSUMORI discloses a particle size distribution of 2 μm - 200 μm for the phosphor particles. One of ordinary skill in the art would have recognized to select a narrower range of sizes for the phosphor particles (including the lower limit of 40 μm) to balance between how the incident light interacts with the different sizes of phosphor particles. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a center value of the particle size distribution is no smaller than 70 μm and no larger than 150 μm to the phosphor particles of NAKATSU modified by CHEN, TSUMORI, and OSHIO in order to provide a range of phosphor particles depending on the desired properties of the output light. Regarding “50% or more of the phosphor particles are thermally coupled to each other through direct contact with adjacent phosphor particles of the plurality of phosphor particles”, the phosphor particles of NAKATSU modified by CHEN, TSUMORI, and OSHIO was considered to be coupled to each other. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate 50% or more of the phosphor particles are thermally coupled to each other through direct contact with adjacent phosphor particles of NAKATSU modified by CHEN, TSUMORI, and OSHIO in order to bond the phosphor particles into the wavelength conversion layer. Regarding “a thickness of the bonding member is no smaller than 30% and no larger than 80% of a thickness of the wavelength conversion layer”, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the thickness of the bonding member no smaller than 30% and no larger than 80% of a thickness of the wavelength conversion layer to the bonding member of NAKATSU modified by CHEN, TSUMORI, and OSHIO in order to provide a desired thickness to contain a desired number of phosphor particles for a desired wavelength distribution. Regarding claim 2, NAKATSU further discloses wherein some of the phosphor particles are exposed from the bonding member at an opposite side to the substrate of the wavelength conversion layer (as seen in para[0018], some of the phosphor particles 30 protrude and exposed from the bonding member 40). Regarding claim 4, NAKATSU modified by CHEN, TSUMORI, and OSHIO fails to disclose wherein a phosphor particle which fails to be bonded to another phosphor particle via the bonding member is removed on a surface of the wavelength conversion layer at the opposite side to the substrate. Regarding “a phosphor particle which fails to be bonded to another phosphor particle via the bonding member is removed on a surface of the wavelength conversion layer at the opposite side to the substrate”, the recitation was considered to be referring to a process of making the wavelength conversion layer where unbonded phosphor particles are removed to form the final product. The applicant is advised that, even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” (See MPEP § 2113. See also In re Thorpe, 227 USPQ 964, (Fed. Cir. 1985)). Only the structure(s) necessarily present from the method is (are) given patentable weight. In the instant case, the resulting structure of the claim failed to distinguish from the structure of NAKATSU modified by CHEN, TSUMORI, and OSHIO. Regarding claim 7, NAKATSU further discloses an illumination device comprising a light source (201c, Fig.3) configured to emit excitation light. NAKATSU modified by CHEN, TSUMORI, and OSHIO discloses the wavelength conversion device according to claim 1 which the excitation light enters. Regarding claim 8, NAKATSU further discloses a projector comprising a light modulation device (226, 227, 228, 215, Fig.3) configured to modulate light emitted from the illumination device; and a projection optical device (229, Fig.3) configured to project the light modulated by the light modulation device. NAKATSU modified by CHEN, TSUMORI, and OSHIO discloses the illumination device according to claim 7. Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over NAKATSU (US 2013/0163225) modified by CHEN (US 2020/02333291), TSUMORI (US 2015/0354783), and OSHIO (US 2020/0109331), and in view of FURUYAMA (US 2018/0180975). Regarding claim 3, NAKATSU modified by CHEN, TSUMORI, and OSHIO fails to disclose wherein the thickness of the wavelength conversion layer is no smaller than 60 μm and no larger than 150 μm. However, FURUYAMA discloses a thickness of a wavelength conversion layer is no smaller than 50 μm and no larger than 200 μm. Therefore, in view of FURUYAMA, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a thickness of a wavelength conversion layer between 50 μm – 200 μm as taught by FURUYAMA to the wavelength conversion layer of NAKATSU modified by CHEN, TSUMORI, and OSHIO in order to select the properties of the wavelength conversion layer based on the thickness of the wavelength conversion layer. Regarding “no smaller than 60 μm and no larger than 150 μm”, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a thickness of a wavelength conversion layer between 60 μm – 150 μm to the wavelength conversion layer of NAKATSU modified by CHEN, TSUMORI, OSHIO, and FURUYAMA in order to select the properties of the wavelength conversion layer based on the thickness of the wavelength conversion layer. Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over NAKATSU (US 2013/0163225), and in view of CHEN (US 2020/02333291), TSUMORI (US 2015/0354783), OSHIO (US 2020/0109331), and MATSUDA (US 2011/0298004). Regarding claim 5, NAKATSU discloses a method of manufacturing a wavelength conversion device including a substrate (10, Fig.1), a wavelength conversion layer (20, Fig.1) which is disposed on the substrate, and in which a plurality of phosphor particles (30, Fig.1) and the substrate are bonded to each other with a bonding member (as seen in Fig.1, the bonding member 40 and the substrate 10 was considered to be bonded to each other). NAKATSU fails to disclose the phosphor particles having a particle size no smaller than 40 μm and no larger than 200 μm, and a center value of a particle size distribution no smaller than 70 μm and no larger than 150 μm, and a reflecting layer disposed between the substrate and the wavelength conversion layer and configured to reflect light emitted from the wavelength conversion layer, wherein a thickness of the bonding member is no smaller than 30% and no larger than 80% of a thickness of the wavelength conversion layer, the method comprising applying a coating film for the bonding member configured to form the bonding member on the reflecting layer disposed on the substrate; arranging a phosphor particle group including the plurality of phosphor particles to the coating film for the bonding member; pressing the phosphor particle group toward the reflecting layer with a pressing member such that 50% or more of the phosphor particles are thermally coupled to each other through direct contact with adjacent phosphor particles of the plurality of phosphor particles; and calcining the coating film for the bonding member together with the substrate and the phosphor particle group to form the bonding member. However, CHEN discloses a reflecting layer (140, Fig.3) disposed between a substrate (110, Fig.3) and a wavelength conversion layer (120, Fig.3) and configured to reflect light emitted from a wavelength conversion layer. However, TSUMORI discloses a particle size distribution of the plurality of phosphor particles is 2 μm - 200 μm (para[0027]). However, MATSUDA disclose applying a coating film (6, Fig.4; step 2) for a bonding member (3, Fig.4) configured to form the bonding member on a layer; pressing a phosphor particle group (2, Fig.4) toward the layer with a pressing member (1, Fig.4); and calcining (i.e. heating) the coating film (6, Fig.4) for a bonding member (3, Fig.4) together with the layer and the phosphor particle group to form the bonding member. However, OSHIO discloses phosphor particles (1, 2, Figs.3-4) are thermally coupled to each other through direct contact with adjacent phosphor particles (as seen in Fig.3 and para[0053], the phosphor particles 1, 2 can be coupled to each other by a heating reaction through direct contact between the phosphor particles 1, 2). Therefore, in view of CHEN, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a reflecting layer as taught by CHEN to the wavelength conversion device of NAKATSU in order to reflect light out of the wavelength conversion layer. Therefore, in view of TSUMORI, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a particle size distribution of the phosphor particles is 2 μm - 200 μm as taught by TSUMORI to the phosphor particles of NAKATSU modified by CHEN in order to provide a known range of particle sizes to the phosphor particles. However, in view of MATSUDA, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the step of pressing and calcining as taught by MATSUDA to the bonding member and the phosphor particles of NAKATSU modified by CHEN in order to make the wavelength conversion layer. Therefore, in view of OSHIO, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate phosphor particles thermally coupled to each other through direct contact with adjacent phosphor particles as taught by OSHIO to the phosphor particles of NAKATSU modified by CHEN, TSUMORI, and MATSUDA in order to provide an alternative bond to couple the phosphor particles to the wavelength conversion device. Regarding “a particle size distribution of the plurality of phosphor particles is no smaller than 40 μm and no larger than 200 μm”, TSUMORI discloses a particle size distribution of 2 μm - 200 μm for the phosphor particles. While TSUMORI discloses the upper limit, one of ordinary skill in the art would have recognized to select a range of sizes for the phosphor particles (including the lower limit of 40 μm) to balance between how the incident light interacts with the different sizes of phosphor particles. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a particle size distribution of the plurality of phosphor particles is no smaller than 40 μm and no larger than 200 μm to the phosphor particles of NAKATSU modified by CHEN, TSUMORI, MATSUDA, and OSHIO in order to provide a range of phosphor particles depending on the desired properties of the output light. Regarding “a center value of the particle size distribution is no smaller than 70 μm and no larger than 150 μm”, TSUMORI discloses a particle size distribution of 2 μm - 200 μm for the phosphor particles. One of ordinary skill in the art would have recognized to select a narrower range of sizes for the phosphor particles (including the lower limit of 40 μm) to balance between how the incident light interacts with the different sizes of phosphor particles. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a center value of the particle size distribution is no smaller than 70 μm and no larger than 150 μm to the phosphor particles of NAKATSU modified by CHEN, TSUMORI, MATSUDA, and OSHIO in order to provide a range of phosphor particles depending on the desired properties of the output light. Regarding “50% or more of the phosphor particles are thermally coupled to each other through direct contact with adjacent phosphor particles of the plurality of phosphor particles”, the phosphor particles of NAKATSU modified by CHEN, TSUMORI, and OSHIO was considered to be coupled to each other. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate 50% or more of the phosphor particles are thermally coupled to each other through direct contact with adjacent phosphor particles of NAKATSU modified by CHEN, TSUMORI, and OSHIO in order to bond the phosphor particles into the wavelength conversion layer. Regarding “a thickness of the bonding member is no smaller than 30% and no larger than 80% of a thickness of the wavelength conversion layer”, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the thickness of the bonding member no smaller than 30% and no larger than 80% of a thickness of the wavelength conversion layer to the bonding member of NAKATSU modified by CHEN, TSUMORI, MATSUDA, and OSHIO in order to provide a desired thickness to contain a desired number of phosphor particles for a desired wavelength distribution. Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over NAKATSU (US 2013/0163225) modified by CHEN (US 2020/02333291), TSUMORI (US 2015/0354783), MATSUDA (US 2011/0298004), and OSHIO (US 2020/0109331), and in view of HAMADA (US 2021/0102117). Regarding claim 6, NAKATSU modified by CHEN, TSUMORI, MATSUDA, and OSHIO fails to disclose removing a surplus particle which is included in the phosphor particle group, and which fails to be bonded to another phosphor particle via the bonding member on a surface of the wavelength conversion layer at an opposite side to the substrate. However, HAMADA discloses removing a surplus particle which fails to be bonded to another phosphor particle via a bonding member (as seen in para[0092], excess phosphor particles 22 not bonded to another phosphor particle via a bonding member 21 is removed). Therefore, in view of HAMADA, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate removing a surplus particle as taught by HAMADA to the phosphor particle group of NAKATSU modified by CHEN, TSUMORI, MATSUDA, and OSHIO in order to remove excess phosphors. Response to Arguments Applicant’s arguments with respect to the presented claims have been considered but are moot because the arguments do not apply to all of the combination of references being used in the current rejection. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. The phosphor particles thermally coupled to each other through direct contact with adjacent phosphor particles has been further defined and amended in the claims. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 extension fee 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 date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAMES ENDO whose telephone number is (571)272-2782. The examiner can normally be reached Monday and Thursday 9AM-5PM. 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, JONG-SUK LEE can be reached at 571-272-7044. 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. /J.M.E/ Examiner, Art Unit 2875 /JONG-SUK (JAMES) LEE/Supervisory Patent Examiner, Art Unit 2875
Read full office action

Prosecution Timeline

Mar 14, 2024
Application Filed
Aug 19, 2025
Non-Final Rejection — §103
Nov 20, 2025
Response Filed
Feb 26, 2026
Final Rejection — §103 (current)

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Prosecution Projections

3-4
Expected OA Rounds
65%
Grant Probability
86%
With Interview (+21.4%)
2y 5m
Median Time to Grant
Moderate
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