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:
Jul. 18, 2000
Filed:
Jun. 22, 1998
Norio Matsuda, Kawagoe, JP;
Takashi Suzuki, Kawagoe, JP;
Kazushige Kawana, Kawagoe, JP;
Hitoshi Yamazaki, Kawagoe, JP;
Yuichi Kimikawa, Kawagoe, JP;
Masakazu Takahashi, Kawagoe, JP;
Kenichi Takahashi, Kawagoe, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
Disclosed is a focus control apparatus of the present invention capable of successfully performing an accurate focus jump operation without an erroneous operation of a focus actuator. The apparatus irradiates a light beam onto a recording medium, and generates a focus actuator drive signal for moving an optimized light convergence point of the light beam from one recording surface to the other, based on a focus error signal generated based on a returned light from the recording medium. The focus control apparatus comprises a detector for detecting that the focus error signal crosses a predetermined level as a specified level crossing; instruction means for generating a focus jump instruction; a drive signal generating means for generating the drive signal in response to the focus jump instruction and receiving a detection output from the detection circuit to recognize a timing of a specified level crossing of the focus error signal upon receipt of the detection output, thereby extinguishing the drive signal at the timing of the specified level crossing detection timing; and inhibiting means for inhibiting the recognition of the specified level crossing by the drive signal generating section for a predetermined period in response to the focus jump instruction.