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:
Oct. 27, 2009
Filed:
Dec. 03, 2008
Kun-jung Tsai, Taipei Hsien, TW;
Kun-Jung Tsai, Taipei Hsien, TW;
Hon Hai Precision Industry Co., Ltd., Tu-Cheng, Taipei Hsien, TW;
Abstract
A system for measuring a total track length of a telescopic lens includes a testing chart, a light source, a processor, a display screen and a range finder. The lens and an image sensor are received in a holder. The testing chart has a frame pattern and a plurality of line pair patterns. The testing chart faces and aligns with the image sensor for allowing the image sensor to capture an image of the testing chart. The processor analyzes the image generated by the image sensor, so as to obtain a modulation transfer function value representative of a precision focal position of the lens. The range finder measures a first distance between the image sensor and the range finder, a second distance between the lens and the range finder, and calculates a distance difference between the first and second distances to obtain the total track length of the lens.