Multi-channel pulse width modulation apparatus

Details Multi-channel pulse width modulation apparatus Multi-channel pulse width modulation apparatus

2003-07-29

2009-08-25

Chin, Vivian (Department: 2614)

Electrical audio signal processing systems and devices

Circuitry combined with specific type microphone or loudspeaker

C375S238000, C332S109000, C369S014000, C330S010000

Reexamination Certificate

active

07580532

ABSTRACT:
Disclosed are multi-channel PWM (Pulse Width Modulation) apparatuses and methods for modulating PCM-based multi-channel audio signals read from an optical medium into PWM-based multi-channel audio signals. A multi-channel PWM apparatus and method can reduce noise from amplifying PCM-based audio signals having adjacent signal processing paths. The multi-channel PWM apparatus and method selectively vary only gains of some channels in a plurality of channels in order to allow an audio signal applied to a pulse width modulator to have a different level in individual channels in a prescribed system condition (e.g., overload). The multi-channel PWM apparatus can selectively enable a subset among a plurality of pulse width modulators to reduce unnecessary driving and noise. Thus, preferred embodiments can reduce or prevent deterioration of output audio signals.

REFERENCES:
patent: 4173739 (1979-11-01), Yoshida
patent: 4641361 (1987-02-01), Rosback
patent: 5771301 (1998-06-01), Fuller et al.
patent: 5796359 (1998-08-01), Beard
patent: 5940021 (1999-08-01), Ahn
patent: 6107876 (2000-08-01), O'Brien
patent: 6429737 (2002-08-01), O'Brien
patent: 6473009 (2002-10-01), Grosso et al.
patent: 6538523 (2003-03-01), Sugita et al.
patent: 6567359 (2003-05-01), McPherson et al.
patent: 6683494 (2004-01-01), Stanley
patent: 7047325 (2006-05-01), Kondo et al.
patent: 1 028 524 (1999-02-01), None
patent: 1 028 524 (1999-02-01), None
patent: 1 178 388 (2000-08-01), None
patent: 1 178 388 (2002-02-01), None
patent: 10-1992-0006016 (1992-07-01), None
patent: 10-2000-0033481 (2000-06-01), None
patent: 10-0268476 (2000-07-01), None
patent: 10-2001-0023262 (2001-03-01), None
patent: 10-2001-0095927 (2001-11-01), None
patent: 20-0262157 (2002-01-01), None
Korean Office Action dated Jan. 25, 2005.
European Search Report dated Dec. 2, 2003.
Korean Office Action dated Apr. 23, 2009.

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