Prosecution Insights
Last updated: April 19, 2026
Application No. 18/757,992

MAGNETIC DISK SUBSTRATE AND MAGNETIC DISK USING THE SAME

Non-Final OA §103
Filed
Jun 28, 2024
Examiner
CHAU, LISA N
Art Unit
1785
Tech Center
1700 — Chemical & Materials Engineering
Assignee
UACJ Corporation
OA Round
3 (Non-Final)
25%
Grant Probability
At Risk
3-4
OA Rounds
4y 10m
To Grant
39%
With Interview

Examiner Intelligence

Grants only 25% of cases
25%
Career Allow Rate
124 granted / 500 resolved
-40.2% vs TC avg
Moderate +14% lift
Without
With
+14.4%
Interview Lift
resolved cases with interview
Typical timeline
4y 10m
Avg Prosecution
57 currently pending
Career history
557
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
53.9%
+13.9% vs TC avg
§102
13.9%
-26.1% vs TC avg
§112
24.2%
-15.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 500 resolved cases

Office Action

§103
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 . 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 3/2/2026 has been entered. Response to Amendment Examiner acknowledges amended Claims 1, 2, and 4 and canceled Claims 2 and 5 in the response filed on 3/2/2026. Response to Arguments Applicant’s arguments with respect to Claims 1, 2, and 4 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. Claim Objections Claims 1, 2, and 4 are objected to because of the following informalities: In Claim 1: Line 6, please amend “a magnetic disk” to “the magnetic disk” and “a hard disk device” to “the hard disk device”. Appropriate correction is required. 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 and 2 are rejected under 35 U.S.C. 103 as being unpatentable over JP 07226044 (“Hino et al.”) in view of US Pub. No. 20200035268 (“Osakabe”). With regards to Claim 1, Hino et al. teaches a hard disk device having a magnetic disk, wherein the magnetic disk is prepared using a magnetic disk substrate having a pair of front and back principal surfaces comprising fixed portions that are in contact with fixing jigs when the magnetic disk substrate configured as a magnetic disk is incorporated in a hard disk device on the respective front and back principal surfaces (clamping area clamped on a disk table). Hino et al. further teaches that an average surface roughness of the fixed portions on the respective front and back principal surfaces (clamping area 3) is 0.5 μm or less. Example 1 discloses an average surface roughness Ra in the clamping region (3) is 0.05 μm (Fig. 1, [0010]-[0012], [0026], [0037], and [0040]). Hino et al. does not explicitly disclose the surface roughnesses in terms of a room mean square deviation Rq is 0.01 to 0.44 μm. Hino et al. is silent of the specific impact test parameters used to determine the claimed displacement properties, however, it is noted that USPTO does not have a laboratory to test out and experiment on Hino et al.’s invention. Hino et al. does not teach its hard disk device having a ramp, wherein a gap between the magnetic disk and the ramp is less than 171 μm. However, when the surface roughness distribution is a normal distribution, the values of the average surface roughness Ra and the root mean square deviation Rq of the surface roughness are Rq = (π/2)1/2⋅Ra = 1.25⋅Ra. Therefore, when the average surface roughness Ra of Hino et al. is converted into Rq, the root mean square deviation Rq of Example 1 is 0.06 μm, and thus would overlap within the claimed range of 0.01-0.44 μm. It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have a room mean square deviation Rq as claimed in order to obtain a magnetic disk substrate that is less susceptible to deformation over time or during chucking [0009]. Hino et al. further teaches that its magnetic disk substrate reduce the deformation during chucking by making the front and the back surface substantially parallel to each other and making the surface substantially smooth in the clamping region. If the amount of deformation at the time of chucking becomes large, the amount of runout becomes too large, or the magnetic head does not float stably [0011]. Therefore, in view of the instant teachings and Hino et al. teaching the claimed root mean square deviation Rq of surface roughnesses of the fixed portions on the front and back principal surfaces, the Examiner deems that it would have been obvious for Hino et al. to optimize its magnetic disk substrate to have the claimed maximum value H of the amount of displacement in the plate thickness direction of the outer circumferential end portion of the magnetic disk substrate be 165 μm or less, and the attenuation rate E of the amount of displacement is 17.7 μm/msec or more in order to obtain a stable and impact resistant magnetic disk substrate during use. Osakabe teaches a hard disk device comprising a ramp, wherein a gap between ramps that a magnetic disk enters has a length “the thickness of the magnetic disk+0.4 mm or less” ([0009], [0108], and [0113]). Therefore, a gap between the magnetic disk and a ramp is 0.2 mm or less, which overlaps the claimed range of less than 171 μm. It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to optimize a gap distance between Hino et al.’s ramp and magnetic disk to be 0.2 mm or less in order to suppress vibration during use [0113]. With regards to Claim 2, when the surface roughness distribution is a normal distribution, the root mean square deviation of Example 1 is 0.06 μm in Hino et al., as set forth above. In order to have substantially uniform properties in the front and back surfaces of the magnetic disk substrate, the Rq of the front and back principal surfaces would be substantially the same (i.e. about 0.06 μm in Example 1). Therefore, the absolute value of the difference ΔRq of Rq of the fixed portions of the front and back principal surfaces would substantially overlap with the claimed range of 0.01 to 0.11 μm. Thus, it would have been obvious to one of ordinary skill in the art to have Hino et al. optimize an absolute value of a difference ΔRq of Rq of the fixed portions of the front and back principal surfaces be from 0.01 to 0.11 μm in order to have a substantially uniform property/surface roughness in the clamping region/area of the magnetic disk substrate. Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over JP 07226044 (“Hino et al.”) in view of US Pub. No. 20200035268 (“Osakabe”) as applied to Claim 1 above, and further in view of WO 2022004826 (“Kitawaki et al.”). The Examiner notes that US Pub. No. 20230238027 is the English language equivalent to WO ‘826. See provided Derwent Abstract translation illustrating the equivalence of these two references. Hino et al. teaches a plate thickness of its disc-shaped magnetic disk substrate is 0.3-2.0 mm ([0015] and Claim 4). Hino et al. does not teach the claimed outer diameter and inner diameter values of the disc-shaped magnetic disk substrate. However, Kitawaki et al. teaches a magnetic disk substrate, which is a disc-shaped magnetic disk substrate having an outer diameter of 97 mm, an inner diameter of 25 mm, and a plate thickness of 0.5 mm ([0105] and [0108]). It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have Hino et al.’s disc-shaped magnetic disk conform to the size as claimed in view of design choice, increasing magnetic density/capacity, etc. Conclusion The prior art made of record and not relied upon is considered pertinent to Applicant's disclosure. US Pub. No. 20040038082 (“Tsumori”) discloses a magnetic disk substrate having a square mean roughness (Rms) of 1 to 1000 nm, wherein the square mean roughness (Rms) of the surface is the square root of the mean of the squares of deviation from the measurement average line to the measurement lines and can be measured by AFM (atomic force microscopy) [0035]. Yoon et al. “Operational Shock Analysis for 2.5-in Multi-Disk HDD Considering Ramp-Disk Gap Irregularity.” IEEE Transactions on Magnetics, Vol. 53, No. 3, 2017, pp. 1-4 (“Yoon et al.”). Yoon et al. teaches that the differences in the gap between the ramp and each disk should be decreased in order to improve the anti-shock performance of an HDD. As shown in Table 2, a gap between the magnetic disk and ramp less is than 60 μm (Abstract, Fig. 7, Table II, B. Ramp-Disk contact Effect With a Multi-Disk HDD section on Pages 3-4, and IV. Conclusion on Page 4). Any inquiry concerning this communication or earlier communications from the examiner should be directed to LISA CHAU whose telephone number is (571)270-5496. The examiner can normally be reached Monday-Friday 11 AM-730 PM. 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, Mark Ruthkosky can be reached at (571) 272-1291. 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. /LC/ Lisa Chau Art Unit 1785 /Holly Rickman/Primary Examiner, Art Unit 1785
Read full office action

Prosecution Timeline

Jun 28, 2024
Application Filed
Mar 20, 2025
Non-Final Rejection — §103
Jul 25, 2025
Response Filed
Oct 31, 2025
Final Rejection — §103
Mar 02, 2026
Request for Continued Examination
Mar 06, 2026
Non-Final Rejection — §103
Mar 06, 2026
Response after Non-Final Action

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12555601
MAGNETIC RECORDING DISK WITH HIGH INTERNAL STRESS TO REDUCE DISK DEFLECTIONS FROM SHOCK FORCES AND METHODS FOR USE WITH THE DISK
2y 5m to grant Granted Feb 17, 2026
Patent 12475923
MAGNETIC RECORDING MEDIUM, MAGNETIC STORAGE APPARATUS, AND METHOD FOR MANUFACTURING MAGNETIC RECORDING MEDIUM
2y 5m to grant Granted Nov 18, 2025
Patent 12421400
MAGNETIC FLOOR SURFACE
2y 5m to grant Granted Sep 23, 2025
Patent 12394436
MAGNETIC RECORDING MEDIUM
2y 5m to grant Granted Aug 19, 2025
Patent 12313843
LIGHT SCANNING APPARATUS
2y 5m to grant Granted May 27, 2025
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
25%
Grant Probability
39%
With Interview (+14.4%)
4y 10m
Median Time to Grant
High
PTA Risk
Based on 500 resolved cases by this examiner. Grant probability derived from career allow rate.

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