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:
Nov. 07, 2006
Filed:
Nov. 15, 2002
Takanori Okuda, Kashiba, JP;
Takashi Yokoyama, Kitakatsuragi-gun, JP;
Takanori Okuda, Kashiba, JP;
Takashi Yokoyama, Kitakatsuragi-gun, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A two-stage amplifier of a first-stage amplifierand second-stage amplifiersandis provided. A writing mode and reproducing modes are switched in the first-stage amplifierby switching a parallel circuit of a feedback capacitor Cfw and a feedback resistor Rfw and a parallel circuit of a feedback capacitor Cfr and a feedback resistor Rfr. The second-stage amplifieris provided with feedback resistors Rfand Rfthat are connected to each other in parallel. The feedback resistor Rfis connected in the feedback loop by a switch transistor QSW only when reproducing a high-reflective disk. This enables an amplifier gain to be suitably set for each of writing, low-reflective disk reproducing, and high-reflective disk reproducing. As a result, desirable reproducing characteristics can be obtained for the low-reflective disk while accommodating high-speed writing with a large laser power.