Title:
FILTER POLARIZING LIGHT IN SPECIFIC WAVELENGTH RANGE
Document Type and Number:
Japanese Patent JP3402122
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide the polarizing filter which can polarize light of large irradiation area in a specific wavelength range, has high heat resistance, and does not vary in transmissivity with heat.
SOLUTION: The filter which polarizes light in the specific wavelength range is formed by alternately layering a film which has optical anisotropy of optical thickness 1/4 as large as desired wavelength to be polarized and a film which has isotropy. This multi-layered film 3 has no difference in refractive index between the layers to light whose electric field vibrates in an (x) direction and operates as a single-layer film having a specific refractive index and also operates as a multi-layered film having different-refractive-index films laminated by turns to light whose electric field vibrates in a (y) direction orthogonal to the (x) direction. Therefore, when light of the specific wavelength to be polarized (light having wavelength 1/4 as large as the optics thickness of the film) is made incident on this multi-layered film 3, the light whose electric field vibrates in the (x) direction is transmitted and the light whose electric field vibrates in the (y) direction has mutual interference between reflected lights on the border surfaces of the respective layers, so that transmitted light is reduced.
Inventors:
Osamu Mizuno
Hiroyuki Kameda
Hiroyuki Kameda
Application Number:
JP14131797A
Publication Date:
April 28, 2003
Filing Date:
May 30, 1997
Export Citation:
Assignee:
Ushio, Inc.
International Classes:
G02B5/30; G02B5/28; G02F1/1337; (IPC1-7): G02B5/30; G02B5/28
Domestic Patent References:
| JP949924A | ||||
| JP8227014A | ||||
| JP1081955A | ||||
| JP9166710A | ||||
| JP5997105A | ||||
| JP57179807A | ||||
| JP63132203A |
Other References:
【文献】米国特許3610729(US,A)
Attorney, Agent or Firm:
Shunichiro Nagasawa