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 .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claim(s) 1-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kobayashi (US 10890698) in view of Nakai (US 20020012170)
Regarding Claim 1,
Kobayashi discloses (Fig. 1 to Fig. 5) a diffractive optical element comprising: a first diffraction grating (8) made of a first material; a second diffraction grating (9) made of a second material; and a thin film layer (10), wherein grating slopes of the first diffraction grating (8) and the second diffraction grating (9) are in contact with each other via the thin film layer (10), wherein the diffractive optical element includes a plurality of annular areas each including annuli arrayed in a radial direction (column 3, lines 10-20) and array pitches of the annuli of each annular area are different from each other (column 17, lines 35-55), refractive indices N1 and N2 of the first diffraction grating and the second diffraction grating, respectively, for a design wavelength, as well as refractive index Nf of the thin film layer.
Kobayashi does not disclose wherein the following inequalities are satisfied:
0.4 < |N1-N2|×P < 6.0
0 ≤ |N1+N2-2×Nf|×df < 40
Nakai discloses selecting refractive index differences, pitch, and thin film thickness to control phase characteristic, and it would have been obvious to one of ordinary skill in the art to select values falling within the claimed ranges as a matter of routine optimization. Thus, Nakai discloses wherein the following inequalities are satisfied:
0.4 < |N1-N2|×P < 6.0
0 ≤ |N1+N2-2×Nf|×df < 40
It would have been obvious to one of ordinary skill in the art to modify Kobayashi to include Nakai’s selecting refractive index differences, pitch, and thin film thickness to control phase characteristics. Combining these teachings merely involves applying known optimization techniques to known structure to achieve predictable results.
Regarding Claim 2,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) wherein the thin film layer includes an inorganic material ( Al.sub.2O.sub.3 and ZrO.sub.2 are inorganic (column 11, lines 45-55).
Regarding Claim 3,
In addition to Kobayashi and Nakai, Nakai discloses teaching of selecting materials based on Abbe number differences to control wavelength dependency wherein the following inequality is satisfied: 1.0 < (N1-N2)/(1/ν2-1/ν1) < 20.0 where ν1 and ν2 are Abbe numbers of the first diffraction grating and the second diffraction grating based on d-line, respectively.
Regarding Claim 4,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) array pitch values that vary radially and are selected based on diffraction efficiency and manufacturability. The claimed pitch range falls within conventional DOE pitch ranges taught in the art, therefore wherein the following inequality is satisfied: 10 < P < 80. (column 11, lines 45-55)
Regarding Claim 5,
In addition to Kobayashi and Nakai, Nakai discloses wherein the second material is a thermoplastic resin ([0014] PMMA is thermoplastic).
Regarding Claim 6,
In addition to Kobayashi and Nakai, Nakai discloses wherein the first material is an ultraviolet curable resin [0083].
Regarding Claim 7,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) integrating diffraction gratings with refractive lenses of varying thickness ratios to optimize optical performance. Selecting thickness ratios within the claimed range would have bene an obvious design choice. Therefore, Kobayashi discloses wherein the following inequality is satisfied: 5 < L2/L1 < 200 where L1 is a thickness on an optical axis of a first lens made of the same material as that of the first diffraction grating, and L2 is a thickness on the optical axis of a second lens made of the same material as that of the second diffraction grating.
Regarding Claim 8,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) wherein the following inequality is satisfied: 0.001 < |N1+N2-2×Nf| < 0.600. Selecting refractive indices of the gratings and thin film to achieve desired phase relationships. The claimed numerical range represents routine optimization and would have been obvious.
Regarding Claim 9,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) wherein the following inequality is satisfied: 0.02 < N1-N2 < 0.15. Kobayashi teaches selecting different refractive indices between the first and second gratings to achieve phase correction. The claimed range falls within commonly used refractive index differences and would have been obvious.
Regarding Claim 10,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) wherein the following inequality is satisfied:3 < df < 200. Kobayashi discloses thin film layer thicknesses selected to balance adhesion and optical performance. The claimed thickness range represents routine selection and would have been obvious.
Regarding Claim 11,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) discloses wherein the thin film layer includes a portion where a thickness changes at valley portions on the grating slopes (column 3, lines 30-40).
Regarding Claim 12,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) wherein the following inequality is satisfied: 0.10 < dfmn/df < 0.95 where dfmm is a minimum value of the thickness of the thin film layer on the grating slopes. Kobayashi teaches selecting different refractive indices between the first and second gratings to achieve phase correction. The claimed range falls within commonly used refractive index differences and would have been obvious.
Regarding Claim 13,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) wherein the following inequality is satisfied: 0.2 < |dfs×(N1+N2-2×Nf)| < 30.0 where dfs is a difference between the maximum value and the minimum value of the thickness of the thin film layer on the grating slopes. Kobayashi teaches selecting different refractive indices between the first and second gratings to achieve phase correction. The claimed range falls within commonly used refractive index differences and would have been obvious.
Regarding Claim 14,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) wherein the following inequality is satisfied in an annular area having a minimum array pitch: 0.002 < w/(P×d) < 0.100 where w (μm) is a width of the portion in an array direction of the annular sections, and d (μm) is a grating height. Kobayashi teaches selecting different refractive indices between the first and second gratings to achieve phase correction. The claimed range falls within commonly used refractive index differences and would have been obvious.
Regarding Claim 15,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) wherein grating wall surfaces of the first diffraction grating (8) and the second diffraction grating (9) are in close contact with each other via the thin film layer (10), and the thin film layer on the grating wall surfaces is thinner than the thin film layer on the grating slopes (as shown in the figures).
Regarding Claim 16,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) further comprising a lens (column 3, lines 10-20) made of the first material, wherein the following inequality is satisfied in an effective area of the diffractive optical element: 2 < Ah < 50 where Ah (deg) is an angle formed between each grating wall surface of the second diffraction grating and an optical axis of the lens in a section including the optical axis. Kobayashi discloses integrating diffractive structures with refractive lenses and selecting wall angles to balance diffraction efficiency and manufacturability. The claimed angular range would have been obvious.
Regarding Claim 17,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) An optical system comprising the diffractive optical element according to claim 1. (ABSTRACT)
Regarding Claim 18,
In addition to Kobayashi and Nakai, Kobayashi discloses (Fig. 1 to Fig. 5) the optical system according to claim 17; and an image sensor configured to receive an optical image formed by the optical system. (column 16, lines 35-50)
Regarding Claim 19,
In addition to Kobayashi and Nakai, Nakai discloses a display element configured to display an image; and the optical system according to claim 17 configured to guide light from the display element. Nakai teaches guiding light form display elements using diffractive optics. Applying the optical system of Kobayashi to a display apparatus would have been obvious.
Conclusion
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/LUCY P CHIEN/Primary Examiner, Art Unit 2871