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:
Aug. 19, 2003
Filed:
Jun. 21, 1999
Toshiaki Oshima, Nagano, JP;
Chikashi Nakamura, Nagano, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
There are provided an image reading apparatus and a focus adjusting method thereof in which focusing can be accurately conducted by a simple moving mechanism. A condenser lens and line sensor can be moved being integrated with each other. When output values obtained when a document on AF line is read by a line sensor are represented by LS , LS , LS , . . . , and when a broken line graph is considered on which the horizontal axis represents a reading position in the horizontal scanning direction and the vertical axis represents an intensity of an output signal, it is judged that the larger the total distance LM +LM + . . . of the broken lines is, the more accurately the image is in focus. A square root of the sum of the square of a distance between the adjacent reading positions and the square of a difference of intensities of the signals which have been read, is calculated, and it is judged that the larger the sum is, the more accurately the focus is adjusted.