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.

Date of Patent:
Dec. 07, 2004

Filed:

Dec. 10, 2002
Applicant:
Inventors:

Hideo Yoshida, Saitama, JP;

Yoshikazu Mihara, Saitama, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B 1/336 ;
U.S. Cl.
CPC ...
G03B 1/336 ;
Abstract

In the distance measuring apparatus which uses a passive AF sensor and determines the subject distance by carrying out correlation value calculation according to AF data obtained from a pair of line sensors of the AF sensor to detect the smallest minimum value of the correlation value, if the difference between the smallest minimum value and the second smallest minimum value of the correlation values is smaller than a predetermined value, it is determined that distance measurement is impossible, and the predetermined value is changed in accordance with the magnitude of the smallest minimum value, thus making it possible to appropriately determine whether distance measurement is possible or impossible according to the aspect of AF data. Therefore, problems such that it is determined that distance measurement is impossible more than necessary, or erroneous distance measurement occurs can be prevented. Also, if the distance object is located at a distance shorter than the closest distance at which distance measurement is possible, it is determined that distance measurement is impossible, and/or a short distance warning is given, so as to prevent erroneous distance measurement.


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