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:
Jan. 13, 2004
Filed:
Feb. 28, 2001
Chong-sam Chung, Seongnam, KR;
Tae-kyung Kim, Suwon, KR;
Young-man Ahn, Suwon, KR;
Hea-jung Suh, Seongnam, KR;
Samsung Electronics Co., Ltd., Suwon, KR;
Abstract
An objective lens includes an aspherical lens facing a disk and having a predetermined first focal distance and a predetermined numerical aperture, and a holographic lens installed adjacent to the aspherical lens and having a second focal distance longer than that of the first focal distance and having a diffraction lattice to compensate for the chromatism due to a change in wavelength of laser light having a wavelength of 670 nm or less. Thus, during the shift between recoding and reproduction of a DVD or an HD-DVD, the change in wavelength due to the change in power of the laser light and chromatism according to the change can be effectively corrected. Also, since the objective lens is formed of one aspherical lens and one holographic lens, the material for each of the lenses can be easily selected and also the structure of the optical pickup using the objective lens according to the present invention can be simplified.