Title:
METHOD AND APPARATUS FOR MEASURING OPTICAL CHARACTERISTIC OF LIQUID CRYSTAL
Document Type and Number:
Japanese Patent JP3144125
Kind Code:
B2
Abstract:
PURPOSE: To measure a liquid-crystal retardation Δnd without the effects of the angle or torsion and the rubbing direction of the liquid crystal by setting the orientation of the liquid crystal cell so that the transmittance becomes the maximum value, changing the wavelength of emitted light, obtaining the extreme value of the transmittance, and computing the retardation Δnd of the liquid crystal based on the wavelength having the maximum value or the minimum value.
CONSTITUTION: A liquid crystal, cell 4 is rotated with a liquid-crystal-orientation setting means 32 so that the amount of the transmitted light becomes the maximum value. The output of a photoelectric converter 6 is made proportional with the transmittance. The wavelength λ of a wavelength selecting means 2 is changed with an operating means. The extreme value of the output of the photoelectric converter 6 is measured, and the liquid-crystal retardation Δnd is computed. Namely, the liquid-crystal retardation Δnd can be obtained by Δnd=λ√(m2-1/4) based on the wavelength having the minimum value and by Δnd=λ√(m2+m) based on the wavelength having the maximum value. In the expression, (m) indicates the integers of 1, 2, 3,....
Inventors:
Atsushi Fukui
Kanji Nishii
Kenji Takamoto
Masaya Ito
Kanji Nishii
Kenji Takamoto
Masaya Ito
Application Number:
JP4631493A
Publication Date:
March 12, 2001
Filing Date:
March 08, 1993
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
G01M11/00; G02F1/13; G02F1/1337; G09G3/18; (IPC1-7): G01M11/00; G02F1/13
Domestic Patent References:
| JP518859A |
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)