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 .
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, 6, 9 and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hirano et al. US 2023/0314764 (Example 3).
Regarding claim 1, Hirano teaches a fixed-focus lens (see at least Fig. 7 and para 0112) comprising: a first lens group; an aperture stop; and a second lens group sequentially arranged from an enlargement side toward a reduction side (Fig. 7 and para 112: first group G1 (31), aperture stop 41 and second group 32 are arranged from the screen to the display/image source 18), the first and second lens groups each having positive refractive power (see para 112: “As shown in FIG. 7, the projection system 3C includes a first lens group 31 having positive power, an aperture diaphragm 41, and a second lens group 32 having positive power sequentially from an enlargement side toward a reduction side”), wherein a lens (Fig. 7: L1) closest to the enlargement side or a lens second closest to the enlargement side in the first lens group is an aspherical lens (see para 115: “The lens L1 has aspheric shapes in both surfaces”), the reduction side of the fixed-focus lens is a telecentric system (se para 0123: “the reduction side of the lens L10 is telecentric.”), and the fixed-focus lens satisfies conditional expressions below,
ω > 45 (1) (see Table shown in para 0125: ω = 51.604)
0.15 < L1H/LL < 0.4 (2) (Table in para 125: reports YIM = 10.350 mm, and lens length 65 mm, and starting at that maximum image height, the chief ray is traced toward the enlargement side through the center of the aperture 41 using successive surface spacings and lens data from paras. 126-127, the ray intersects the curved enlargement side surface of L1 at height of approximately 13.8 mm from the optical axis. Thus calculated L1H/LL is ~ 13.8/65 = 0.213, satisfying claimed range)
2.5 < BF/F < 3.5 (3) (from para 132: BF/f = 29.125/8.308 = ~ 3.506). Therefore, Hirano does not expressly satisfy the claimed upper limit < 3.5. The difference is approximately 0.006, or 0.16% of the upper limit. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date to adjust the lens prescription and axial spacing slightly to obtain a ration between 3.5, while retaining sufficient back focus for the prism and a compact projection system. Given the small difference, a skilled person would reasonably expect such an adjustment to retain the system’s useful projection properties, absent evidence that the boundary at 3.5 produces a critical or unexpected result. In re Brandt, 886 F.3d 1171, 1177-78 (Fed. Cir. 2018); Titanium Metals Crop. V. Banner, 778 F.2d 775, 783 (Fed. Cir. 1985); MPEP 2144.05.
where ω: Largest half viewing angle of fixed-focus lens, L1H: Height of beam passing through top of maximum image height at lens surface of fixed-focus lens that is closest to enlargement side, LL: Length of fixed-focus lens BF: Back focal length in air, and F: Focal length of entire fixed-focus lens.
Regarding claim 6, Hirano teaches the fixed-focus lens according to claim 1, satisfying a conditional expression below,
3.0 < Fg1p/F < 25.0 (4) (From table in paras. 125-126: Example 3 identifies L3 lens closest to the reduction side in the first lens group 31, and it’s report f3 = Flp = 30.030 mm and F = 8.308, thus Fg1p/F = 30.03/8.308 = 3.615, within the claimed range)
where Fg1p: Focal length of lens closest to reduction side in first lens group.
Regarding claim 9, Hirano teaches the fixed-focus lens according to claim 1, satisfying a conditional expression below,
0.45 < LS/LL < 0.65 (7) (From Table 125: LL = 65 mm, and LS (From Table 126) = 31.146), thus LS/LL = 0.498, which falls within claimed range.
where LS: Distance from lens surface of fixed-focus lens that is closest to enlargement side to aperture stop.
Regarding claim 10, Hirano teaches a projector comprising: an image forming section including a light modulator configured to modulate light from a light source apparatus to form image light; and the fixed-focus lens according to claim 1, which projects the image light from the image forming section (Figs. 1 and 15 and paras. 27, 112: depicts projector system 1/3C having light source 10 and fixed lens shown in Fig. 7).
Claim(s) 1-5 and 8-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hirano et al. US 2023/0314763 Example 7, in view of the teachings of Example 6.
Regarding claim 1, Hirano teaches a fixed-focus lens (see at least Fig. 15 and para 0298) comprising: a first lens group; an aperture stop; and a second lens group sequentially arranged from an enlargement side toward a reduction side, the first and second lens groups each having positive refractive power (see para 298 and Fig. 15: “a projection system 3G according to Example 7. The projection system 3G includes a first lens group 31 having positive power, an aperture stop 41, and a second lens group 32 having positive power sequentially arranged from the enlargement side toward the reduction side, as shown in FIG. 15.”), the reduction side of the fixed-focus lens is a telecentric system (see para 309: “the portion at the reduction side of the lens L12 is a telecentric portion”), and the fixed-focus lens satisfies conditional expressions below,
ω > 45 (1) (see Table shown in para 310 and para 0316: ω = 44.287)
0.15 < L1H/LL < 0.4 (2) (Table in para 125: reports YIM = 10.350 mm, and lens length 61.243 mm, and starting at that maximum image height, the chief ray is traced toward the enlargement side through the center of the aperture 41 using successive surface spacings and lens data from paras. 0311-0312, the ray intersects the curved enlargement side surface of L1 at height of approximately 11.94 mm from the optical axis. Thus calculated L1H/LL is ~ 11.94/61.243 = 0.195, satisfying claimed range).
Example 7 reports a maximum half viewing angle ω = 44.287, rather than . 45 degree.
2.5 < BF/F < 3.5 (3) (from para 310/322: BF/f = 34.007/10.840 = ~ 3.137).
Hirano fails to expressly disclose: wherein a lens closest to the enlargement side or a lens second closest to the enlargement side in the first lens group is an aspherical lens.
However, Example 6 of Hirano teaches an aspherical L1 in a first group (see para 0260: “The lens L1 has aspherical surfaces at opposite sides.”) Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to provide Example 7’s L1 with an aspherical surface as taught by Example 6, to improve correction of image curvature while retaining Example’s 7 first group arrangement. Hirano identifies increasing the half viewing angle as a benefit of the negative enlargement side lens and demonstrates a half viewing angle of 48.888 degree in Example 6 (see para 276). Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date seeking a wider projected field would have a reason to adjust Example 7’s optical design to increase its 44.287-degree angle slightly above 45 degrees, using the aspherical front lens refractive power. Similarly, the reported angle lies close to the claimed boundary; the small numerical difference and considered under the principle of close ranges in MPEP 2144.05.
Regarding claim 2, Hirano teaches the fixed-focus lens according to claim 1, wherein the first lens group is configured with single lenses or cemented lenses having positive, positive, negative, negative, and negative refractive power and arranged from the reduction side (Fig. 15 and paras. 0299-0302: discloses: processing from the reduction side (right side) toward the enlargement side (left side), positive single lens L6, positive cemented lens L21 (para 301), negative single lens L3, negative single lens L2, and negative single lens L1).
Regarding claim 3, Hirano teaches the fixed-focus lens according to claim 1, wherein the second lens group is configured with single lenses or cemented lenses having negative, positive, positive, negative, and positive refractive power and arranged from the enlargement side (paras. 303-306: teaches L7 (-ve), L8 (+ve), L9 (+ve), L10 (-ve) and L11 (+ve)).
Regarding claim 4, Hirano teaches the fixed-focus lens according to claim 1, wherein the second lens group includes an aspherical lens having positive refractive power (paras. 303, 305 and Fig. 15: “The lens L9 has positive power. The lens L9 has convex surfaces both at the enlargement and reduction sides. The lens L9 has aspherical surfaces at opposite sides.”).
Regarding claim 5, Hirano teaches the fixed-focus lens according to claim 1, wherein the lens closest to the enlargement side in the second lens group is a negative cemented lens configured with a lens having positive refractive power and a lens having negative refractive power (From Fig. 15: L22, is cemented lens closest to enlargement side (left side), and para. 304: “The lenses L7 and L8 are bonded to each other into a cemented doublet L22. The lens L7 has negative power. The lens L7 has concave surfaces both at the enlargement and reduction sides. The lens L8 has positive power. The lens L8 has convex surfaces both at the enlargement and reduction sides. The cemented doublet L22 has negative power”).
Regarding claim 8, Hirano teaches the fixed-focus lens according to claim 1, satisfying a conditional expression below,
0.8 < |Fg2n1/ Fg2p3-| < 2.8 (6) (From Fig. 15 and para 304: L22 is negative power in the 2nd lens group, calculated value of L22 = ~ -23.86 mm, and L12 is positive lens closest to the reduction side on the 2nd lens group, and f1f = lens of L12 (see para 310) and its value is 28.771 mm, thus |Fg2n1/ Fg2p3-| = 0.829, which it is within the claimed range)
where Fg2n1: Focal length of negative single lens or negative cemented lens disposed at position closest to reduction side in second lens group, and Fg2p3−: Focal length of positive lens disposed at position closer to reduction side than negative single lens or negative cemented lens disposed at position closest to reduction side in second lens group.
Regarding claim 9, Hirano teaches the fixed-focus lens according to claim 1, satisfying a conditional expression below,
0.45 < LS/LL < 0.65 (7) (From Table 322: LL = 61.243 mm, and LS (From Table 311) = 30.504 mm), thus LS/LL = 0.479, which falls within claimed range.
where LS: Distance from lens surface of fixed-focus lens that is closest to enlargement side to aperture stop.
Regarding claim 10, Hirano teaches a projector comprising: an image forming section including a light modulator configured to modulate light from a light source apparatus to form image light; and the fixed-focus lens according to claim 1, which projects the image light from the image forming section (Figs. 1 and 15 and paras. 26, 298: depicts projector system 1/3G having light source 10 and fixed lens shown in Fig. 15).
Allowable Subject Matter
Claim 7 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Regarding claim 7, the fixed-focus lens according to claim 1, satisfying a conditional expression below,
0.2 < Fg2p1 /Fg2p2 < 1.2 (5)
where Fg2p1: Focal length of positive single lens or positive cemented lens disposed at position closest to enlargement side in second lens group, and Fg2p2: Focal length of positive single lens or positive cemented lens disposed at position second closest to enlargement side in second lens group.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 2023/0314777: teaches projection lens having a fixed lens majority of the limitation of claim 1.
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/EPHREM Z MEBRAHTU/Primary Examiner, Art Unit 2872
