Title:
BROAD-BAND PHASE COMPENSATION POLARIZED LIGHT ELIMINATION PLATE AND BROAD-BAND PHASE COMPENSATION WAVELENGTH PLATE
Document Type and Number:
WIPO Patent Application WO/2006/041109
Kind Code:
A1
Abstract:
There is provided a wind-band phase compensation wavelength plate functioning as a quarter wavelength plate over a wide range for 400 nm to 785 nm which wavelength band is required for optical pickup corresponding to an optical disc such as CD and DVD and a blue laser disc. The broad-band phase compensation wavelength plate (4) includes a first wavelength plate (5), a second wavelength plate (6), and a third wavelength plate (7) which are superimposed on one another in a predetermined in-plane azimuth. As the substrate material of the wavelength plates, the first wavelength plate (5) and the second wavelength plate (6) uses quartz and the third wavelength plate (7) uses lithium niobate. Parameter of the broad-band phase compensation wavelength plate (4) are as follows: the first wavelength plate (5) has a phase difference &Ggr 1 = 180 deg (&lgr = 600 nm) and in-plain azimuth Ѳ1 = 11.5 deg; the second wavelength plate (6) has a phase difference &Ggr 2 = 195 deg (&lgr = 600 nm) and in-plain azimuth Ѳ2 = 56.1 deg; and the third wavelength plate (7) has a phase difference &Ggr 3 = 103 deg (&lgr = 600 nm) and in-plain azimuth Ѳ3 = -45.0 deg.
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Inventors:
OOTO MASAYUKI (JP)
Application Number:
PCT/JP2005/018821
Publication Date:
April 20, 2006
Filing Date:
October 12, 2005
Export Citation:
Assignee:
EPSON TOYOCOM CORP (JP)
OOTO MASAYUKI (JP)
OOTO MASAYUKI (JP)
International Classes:
G02B5/30; G11B7/135; G11B7/125
Foreign References:
| JPH05100114A | 1993-04-23 |
Attorney, Agent or Firm:
Suzuki, Hitoshi (6-5 Arai 2-chom, Nakano-ku Tokyo 26, JP)
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