Pulse or digital communications – Pulse code modulation – Differential
Reexamination Certificate
2005-03-21
2008-11-11
Phu, Phuong (Department: 2611)
Pulse or digital communications
Pulse code modulation
Differential
C375S340000, C375S252000, C341S143000, C341S155000
Reexamination Certificate
active
07450648
ABSTRACT:
A signal processing device uses a ΔΣ modulator having varying effective orders to ensure an S/N ratio by selecting a high order when a 1-bit music signal is output via the ΔΣ modulator. The signal processing device prevents noise during switchover by shifting to a low order just before the ΔΣ modulator is bypassed if this occurs. The present invention provides a digital signal processing device which can switch between an original sound signal and a ΔΣ modulation signal and yield a sufficient S/N ratio for a reprocessed ΔΣ modulation signal. If any 1-bit original sound signal is input, little switching noise is generated.
REFERENCES:
patent: 5012244 (1991-04-01), Wellard et al.
patent: 5075679 (1991-12-01), Gazsi
patent: 5248971 (1993-09-01), Mandl
patent: 5248972 (1993-09-01), Karema et al.
patent: 5311181 (1994-05-01), Ferguson et al.
patent: 5621675 (1997-04-01), Linz et al.
patent: 5648779 (1997-07-01), Cabler
patent: 5742246 (1998-04-01), Kuo et al.
patent: 5757301 (1998-05-01), Kuo et al.
patent: 5805093 (1998-09-01), Heikkila et al.
patent: 6075820 (2000-06-01), Comino et al.
patent: 6600789 (2003-07-01), Lipasti et al.
patent: 0 512 687 (1992-11-01), None
patent: 0 783 207 (1997-07-01), None
“AD/DA Converter and Digital Filter”, Journal of Acoustical Society of Japan 46, No. 3 (1990).
EPO Search Report dated Aug. 21, 2003.
Kananen Ronald P.
Phu Phuong
Rader & Fishman & Grauer, PLLC
Sony Corporation
LandOfFree
Digital signal processing device, a method and a delta-sigma... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Digital signal processing device, a method and a delta-sigma..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digital signal processing device, a method and a delta-sigma... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4042921