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:
Apr. 21, 1998
Filed:
Oct. 07, 1996
Kaoru Kumagai, Tokyo, JP;
Shinji Kawashima, Tokyo, JP;
Kiichi Furuya, Tokyo, JP;
Fumio Ohtomo, Tokyo, JP;
Kabushiki Kaisha TOPCON, Tokyo, JP;
Abstract
An electronic leveling apparatus and associated leveling staff are designed to form an image of scale patterns of the leveling staff on a photo-electric transducer by means of a telescopic optical system, convert the image into an electrical signal with the transducer and implement the Fourier transformation for the signal with a signal processor, thereby having functions of focusing control and abnormality detection. The leveling staff has an alignment of the first and second (and third) scale patterns aligned in order cyclically at a constant pitch along the length measuring direction, with the first and second patterns having their widths varied in different cyclic periods and the third pattern having a constant width.