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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 29 January 2026 has been entered.
Introduction
Any rejections and/or objections, made in the previous Office Action, and not repeated below, are hereby withdrawn.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim Objections
Claim 1 is objected to because of the following informalities:
Claim 1, in the amendment filed 29 January 2026, recites, “a stress profile at a depth of the glass ceramic of more than 10 µm….” This can be contrasted with the claim 1 submitted on 03 September 2025, which recites “a stress profile that has at least one inflection point at a depth of the glass ceramic of more than 10 µm.” The text marked with italics has been omitted from the January 2026 claims without bracketing or strikethrough to indicate deletion.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
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.
Claims 1-14, 25 and 26 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.
Newly added claim 26 depends from claim 1 and refers to second and third inflection points. Second and third inflection points imply a “first inflection point.” However, claim 1 does not refer to a first inflection point. Therefore, claim 1 is indefinite as to the presence or absence of a first inflection point. For purposes of examination, the examiner presumes claim 1 recites “a stress profile that has at least one inflection point at a depth of the glass ceramic of more than 10 µm.” Claims 2-14, 25 and 26 are rejected for failing to correct the deficiencies of claim 1.
Claim Rejections - 35 USC § 103
Claims 1-3, 5-6, 12-16 and 25-26 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 2020/0207660 A1).
Li et al. teaches glass ceramic that may be used as a cover glass. See the abstract and paragraph [0002].
The glass ceramic contains 58-70% by mass SiO2 and is therefore “silica based.” See paragraph [0017]. The glass ceramic forms a crystalline phase including β-spodumene (see the abstract) which is a species of keatite solid solution (as recited in claims 1, 4 and 15).
The glass ceramic has overlapping ranges of components with the glass ceramic recited in instant claims 1, 5 and 6 including amounts of SnO2, MgO and ZnO. See paragraph [0017], [0106] and [0110].
Li et al. teaches the glass ceramic has a haze of 1.0% or less. See paragraph [0066].
The stress profile may be as shown in Figure 1. See paragraph [0020]. Figure 1 has an inflection point at a point that transitions from the spike to the tail. The examiner calculates this inflection point is at approximately 14 µm.
The glass ceramic may have a thickness of 0.8 mm. See paragraph [0146].
Li et al. suggests the glass ceramic has a surface compressive stress of 600 MPa or more. See paragraph [0047].
Thus, Li et al. discloses a glass ceramic having overlapping ranges of properties and composition with the claimed glass ceramic and overlapping ranges have been held to establish prima facie obviousness. See MPEP 2144.05.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have selected from the overlapping ranges of components and properties suggested by Li et al. because overlapping ranges have been held to establish prima facie obviousness.
As to claims 2 and 3, the glass ceramic has a visible light transmittance of greater than 90%. See paragraph [0065].
The glass ceramic of Li et al. is presumed to have the property recited in claim 12 because the glass ceramic has an identical phase, overlapping ranges of composition and identical stress profile with instant claims 1-6.
As to claim 13, Example 1 is formed by a sodium and potassium strengthening process. See paragraphs [0161]-[0162].
As to claim 14, Li et al. does not disclose the presence of lithium metasilicate in the glass ceramics. See Tables 4 and 5.
Further as to claims 15-16, the glass ceramic of Li et al. is presumed to have the property recited in claim 12 because the glass ceramic has an identical phase, overlapping ranges of composition and identical stress profile with instant claims 1-6.
As to claim 25, Li et al. teaches lower the crystallite size reduces haze. See paragraph [0066]. However, if the crystallite size gets too small, the mechanical strength deteriorates. Id. Moreover, the average particle size of the crystallites is 100 nm or less. See paragraph [0077].
Therefore, it would have been obvious to one of ordinary skill in the art to have formed the crystallites of Li et al. to a size of less than 100 nm in order to balance transmittance, haze, and mechanical strength.
As to claim 26, Figure 2 of Li et al. shows a stress profile having three inflection points. Compare instant Figure 9 with Figure 2 of Li et al.
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Claims 7-11 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 2020/0207660 A1) as applied to claim 1 and further in view of Amin et al. (US 2014/0134397 A1).
As to claim 7 and 8, Li et al. renders obvious claim 1 for the reasons recited above. The glass composition of Li et al. has overlapping ranges of components with the glass recited in claim 7 with the exception of 0.0001-0.1 wt% Fe2O3.
Amin et al. teaches glass ceramics, including β-spodumene, which are used as a cover glass of an electronic device. See the title and paragraph [0010]. Amin et al. further teaches:
[0030] … it is known that the presence of Fe2O3 alone (no TiO2) up to contents of the order of 300 ppm in a glass-ceramic is generally not a concern as regards coloration. However, the joint presence of Fe2O3 and TiO2 generates a characteristic yellowish tint. A number of commercial products which are otherwise known for their high transparency retain this yellowish tint, in particular those sold by the Applicant under the trade name KERALITE® (described in European patent application EP 0 437 228), those sold by Schott AG under the trade name ROBAX® and those sold by Nippon Electric Glass under the trade name NEOCERAM® N--O, because of the joint presence in their compositions of TiO2 and Fe2O3. Treating the raw materials used to reduce the Fe2O3 content to below 150 ppm in particular is an expensive operation (an option mentioned in Japanese patent application JP 2001-348250) and it is seen above that TiO2 is the best performing nucleating agent, allowing ceramming to occur on reasonable time scales. To overcome the technical problem mentioned above--obtaining transparent β-quartz glass-ceramic materials with no yellowish coloration.about.one possible approach seems to be to dispense with the presence of TiO2 during manufacture.
300 ppm by weight of Fe2O3 corresponds to 0.03 wt% and 150 weight ppm corresponds to 0.015 wt%.
Therefore, it would have been obvious to one of ordinary skill in the art to permit up to 300 ppm Fe2O3 in Glass No. 1 of Li et al. as suggested by Amin et al. because it is expensive to reduce the amount of Fe2O3 below 150 ppm and 300 ppm Fe2O3 is not detrimental to the color.
As to claims 9-11, the general glass composition of Li et al. has amounts of components that overlap the amounts of components recited in instant claims 9-11 with the exception of Fe2O3. See paragraph [0067].
As noted above, Amin et al. teaches glass ceramics, including β-spodumene, which are used for a cover glass of an electronic device and may include up to 300 ppm Fe2O3.
Therefore, it would have been obvious to one of ordinary skill in the art to permit up to 300 ppm Fe2O3 in the glass ceramic composition of Li et al. as suggested by Amin et al. because it is expensive to reduce the amount of Fe2O3 below 150 ppm and 300 ppm Fe2O3 is not detrimental to the color.
Li et al. does not teach the specific ratios recited in claims 9 and 10. However, the general amounts SnO2, TiO2 and ZrO2 of Li et al. overlap the claim 7 amounts and it would have been obvious to have operated within these ranges including amounts both inside and outside the specific ratios recited in claims 9 and 10, lacking unexpected results associated with the claimed ratios.
Response to Arguments
Applicant's arguments filed 29 January 2026 have been fully considered but they are not persuasive.
Applicants submitted a declaration asserting unexpected results associated with the presence of MgO, ZnO, and SnO2 in the glass ceramic in the claimed amounts. Allegations of unexpected results must be commensurate in scope with the claims. See MPEP 716.02(d). The data provided is not commensurate in scope with the present claims for at least the following reasons:
The claims are generic to high quartz solid solution or keatite solid solution, but the showing only presents evidence related to keatite solid solution. No evidence was submitted related to high quartz solid solution.
Claims 1 and 15 are generic to any silica-based composition, however, evidence has only been provided related to lithium aluminosilicate glass compositions.
Allowable Subject Matter
Claim 4 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims. Applicants have established unexpected results associate with a glass ceramic having the scope recited in claim 4.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to David Sample whose telephone number is (571)272-1376. The examiner can normally be reached Monday to Friday 7AM to 3:30 PM.
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/David Sample/Primary Examiner, Art Unit 1784