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:
Dec. 27, 2011
Filed:
Sep. 29, 2009
Osamu Hosokawa, Tokyo, JP;
Nobuyoshi Kobayashi, Kanagawa, JP;
Osamu Hosokawa, Tokyo, JP;
Nobuyoshi Kobayashi, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A DPD tracking error signal detection apparatus includes the following. Four differentiators remove DC components and differentiate four signal with varying differential phases. The signals are then sampled and quantized by four A/D converters, and output to a non-inverting unit and an inverting unit. A phase inverter/compositor then leaves as-is or phase-inverts the output signals, according to a control signal. The non-inverting and the inverting unit each include two Hilbert transformers that phase-shift the output from the A/D converters, two delay units that delay the output of the other A/D converters to match the delay of the Hilbert transformers, two cross-correlators that calculate the cross-correlation between pairs of Hilbert transformers and delay units, and an adding unit that combines the cross-correlator results and outputs the combined result to the phase inverter/compositor.