The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 13, 2001
Filed:
May. 28, 1999
Kabushiki Kaisha Toyota Chuo Kenkyusho, Aichi-gun, JP;
Abstract
A birefringent plate includes a transparent glass substrate, an antireflection coating formed on one of the surfaces of the glass substrate, an obliquely deposited film formed on the other one of the surfaces of the glass substrate by obliquely deposition of a dielectric material with respect to the normal of the glass substrate, and a protective film formed on the obliquely deposited film for holding the occluded water of the obliquely deposited film within the obliquely deposited film and reducing the light interference between the opposite surface of the glass substrate and the surface of the obliquely deposited film. The antireflection coating and the protective film inhibit the phase difference from fluctuating at different measurement positions when the phase difference is measured by using a light source, such as a laser beam. In addition, the protective film makes the birefringent plate less dependent on the temperature.