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:
Jan. 19, 1999
Filed:
Apr. 25, 1997
Shinya Hasegawa, Kawasaki, JP;
Shigeo Kayashima, Kawasaki, JP;
Satoshi Maeda, Kawasaki, JP;
Shigetake Iwata, Kawasaki, JP;
Fumio Yamagishi, Kawasaki, JP;
Masato Nakashima, Kawasaki, JP;
Hirokazu Aritake, Kawasaki, JP;
Mamoru Hokari, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A high-resolution light-beam scanning apparatus including a rotatable hologram and a fixed plate which are diffraction gratings for minimizing either a sum total of values obtained by weighting (1): a square of an optical path length difference between a) an optical path of a light flux measured along a principal axis of a light beam incident on and diffracted by a first diffraction grating of the rotatable hologram, and incident on and diffracted by a second diffraction grating of the fixed plate so as to conduct a scanning and converging on an image formation surface scanning point, and b) an optical path of a light flux measured along a marginal ray distanced from the principal axis, or an absolute value of the optical path difference thereof; or (2) a square of a sum obtained by adding an amount of displacement of a light beam convergent on the scanning point, which displacement is measured along the marginal ray distanced from the principal axis of an incident reconstructing light flux with respect to the principal axis of a phase of the first diffraction grating, to an amount of displacement of the same light, which displacement is measured with respect to the principal axis of a phase recorded on the second diffraction grating, when the light flux is incident on the fixed plate, or by weighting an absolute value of the sum, each weighting being conducted at every scanning position covering an entire range of the image formation surface.