Invention Grant
- Patent Title: Retardation film
- Patent Title (中): 延迟膜
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Application No.: US12406737Application Date: 2009-03-18
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Publication No.: US08270076B2Publication Date: 2012-09-18
- Inventor: Taku Hatano , Shunsuke Yamanaka
- Applicant: Taku Hatano , Shunsuke Yamanaka
- Applicant Address: JP Tokyo
- Assignee: Zeon Corporation
- Current Assignee: Zeon Corporation
- Current Assignee Address: JP Tokyo
- Agency: Birch, Stewart, Kolasch & Birch, LLP
- Priority: JP2008-069540 20080318
- Main IPC: G02B5/30
- IPC: G02B5/30

Abstract:
A retardation film composed of a laminated film which comprises a layer A composed of a material having a positive intrinsic birefringence and a layer B composed of a material having a negative intrinsic birefringence; the retardation film has a stretching temperature Tα which causes delaying of a phase after the stretching to a phase before the stretching and a stretching temperature Tβ which causes hastening of a phase after the stretching to a phase before the stretching, in cases of uniaxially stretching in a direction of an X axis by draw ratio of 1.25, in which the phase is of linearly polarized light ΨX in relation to linearly polarized light ΨY, the X axis is an uniaxially stretching direction; and the retardation film satisfies 0.92 ≦R40/Re ≦1.08, wherein Re (nm) and R40 (nm) are retardation values of light having a wavelength of 550 nm.
Public/Granted literature
- US20090237790A1 RETARDATION FILM Public/Granted day:2009-09-24
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