Title:
OPTICAL LOW-PASS FILTER AND DIGITAL CAMERA USING THE SAME
Document Type and Number:
Japanese Patent JP2007086106
Kind Code:
A
Abstract:
To provide an optical low-pass filter (OLPF) in which static electricity generated on the surface of the OLPF is reduced when lithium tantalate is used as a substrate material for the OLPF.
The OLPF 1, in which a birefringent plate comprising a crystal, etc. having birefringence is used, separates incident light rays L1 into a normal light ray L2 and an abnormal light ray L3. In the embodiment, lithium tantalate is used as a substrate material for the OLPF, wherein the direction of spontaneous polarization of lithium tantalate is made random. A separation distance d1 becomes larger as the difference between refractive index n0 of the normal light ray and refractive index ne of the abnormal light ray increases.
Inventors:
MATSUZAKI FUMITAKE
NAKASENDOU KAZUYUKI
KOMAI MAKOTO
SAKURAI MAKOTO
NAKASENDOU KAZUYUKI
KOMAI MAKOTO
SAKURAI MAKOTO
Application Number:
JP2005271361A
Publication Date:
April 05, 2007
Filing Date:
September 20, 2005
Export Citation:
Assignee:
EPSON TOYOCOM CORP
International Classes:
G02B5/30; G03B11/00; G03B17/02; H04N5/225