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:
Feb. 17, 2004
Filed:
Apr. 16, 2002
Norio Shoji, Kanagawa, JP;
Yuji Gendai, Kanagawa, JP;
Kimimasa Senba, Kanagawa, JP;
Nobuyoshi Kobayashi, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
To provide an asymmetry correcting circuit capable of canceling an asymmetry simultaneously with quantization in an ADC and utilizing the dynamic range of the ADC effectively, and also to provide an information reproducing apparatus using such a correcting circuit. An asymmetry correcting circuit includes a first envelope detection circuit for detecting the envelope of a positive peak of an input signal waveform; a second envelope detection circuit for detecting the envelope of a negative peak of the input signal waveform; an adding circuit for producing a sum voltage of the positive peak voltage and the negative peak voltage; a smoothing circuit for smoothing the sum voltage; a multiplying circuit for multiplying the smoothed sum voltage by a predetermined offset adjustment coefficient; and a quantization reference voltage control circuit for DC-wise shifting, in response to the output signal of the multiplying circuit, the median of the quantization reference voltage of the ADC in conformity with the offset derived from the asymmetry of the input signal, and controlling the upper limit and the lower limit of the quantization reference voltage to the values that correspond to the offset quantity.