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:
May. 16, 1989
Filed:
Jul. 12, 1988
Yoshifumi Nishimoto, Yokohama, JP;
Masahiko Okunuki, Tokyo, JP;
Takao Kariya, Akigawa, JP;
Yasuo Kawai, Shizuoka, JP;
Akio Atsuta, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A position detecting device for detecting the position of an object includes an illumination optical system for producing a light beam and for irradiating the object with the light beam, an optical system for focusing the light beam, a focus position controlling system operative to change the position at which the light beam is focused by the focusing optical system, a first detecting device for receiving the light beam reflected from the object to detect the state of incidence of the light beam on the object, and a second detecting device for detecting the position of the object on the basis of the detection of the state of incidence of the light beam on the object by the first detecting means.