Invention Grant
- Patent Title: Laminated wave plate and optical pickup device using the same
- Patent Title (中): 层压波片和使用其的光学拾取装置
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Application No.: US11785528Application Date: 2007-04-18
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Publication No.: US07986608B2Publication Date: 2011-07-26
- Inventor: Masayuki Oto
- Applicant: Masayuki Oto
- Applicant Address: JP Tokyo
- Assignee: Epson Toyocom Corporation
- Current Assignee: Epson Toyocom Corporation
- Current Assignee Address: JP Tokyo
- Agency: Oliff & Berridge, PLC
- Priority: JP2006-114120 20060418; JP2007-106754 20070416
- Main IPC: G11B7/00
- IPC: G11B7/00

Abstract:
A laminated wave plate of the present invention includes a first wave plate having a phase difference of Γ1 and a second wave plate having a phase difference of Γ2 with respect to a wavelength λ, the first wave plate and the second wave plate being bonded together so that an optical axis of the first wave plate and an optical axis of the second wave plate intersect each other to function as a quarter-wave plate as a whole, the laminated wave plate comprising following equations from (1) to (6): Γ1=360×(n1+1) . . . (1); Γ2=90×(2×n2+1 . . . (2); ΔΓ1=(Γ12a−Γ11a)/(λ12−λ11) . . . (3); ΔΓ2=(Γ12b−Γ11b)/(λ12−λ11) . . . (4); cos 2θ1=1−(1−cos ΔΓ2)/{2×(1−cos Δθ1)}. . . (5); and θ2=45°±5°. . . (6), wherein θ1 is an optic axis orientation of the first wave plate, θ2 is an optic axis orientation of the second wave plate, and each of λ11≦λ≦λ12, n1, and n2 is a natural number starting from 1.
Public/Granted literature
- US20070247633A1 Laminated wave plate and optical pickup device using the same Public/Granted day:2007-10-25
Information query
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