Audio signal amplification device

Patent metadata

Field	Value
Publication number	US-9848264-B2
Application number	US-201615206274-A
Country	US
Kind code	B2
Filing date	Jul 10, 2016
Priority date	Feb 18, 2014
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

An audio signal amplification device of the disclosure includes: a delta-sigma modulation part configured to resample an input digital audio signal with a quantization number smaller than a quantization number of the digital audio signal; a pulse-width modulation part configured to convert an output signal from the delta-sigma modulation part into a pulse-width modulation signal which sets a gradation of the output signal in an amplitude direction at a gradation of a pulse width; a power amplification part configured to perform power amplification on an output signal from the pulse-width modulation part; a low-pass filter configured to diminish a component higher than a predetermined cutoff frequency, in an output signal from the power amplification part, and to output the resultant signal; and a correction processing part configured to generate a correction signal for correcting the digital audio signal. The correction processing part includes a switch configured to control coupling of the correction processing part to the low-pass filter. When the switch is on, the correction processing part couples a loudspeaker to the low-pass filter, and generates the correction signal.

First claim

What is claimed is:

1. An audio signal amplification device comprising:
a delta-sigma modulation part configured to resample an input digital audio signal with a quantization number smaller than a quantization number of the digital audio signal;
a pulse-width modulation part configured to convert an output signal from the delta-sigma modulation part into a pulse-width modulation signal which sets a gradation of the output signal in an amplitude direction at a gradation of a pulse width;
a power amplification part configured to perform power amplification on an output signal from the pulse-width modulation part;
a low-pass filter configured to diminish a component higher than a predetermined cutoff frequency, in an output signal from the power amplification part, and to output the resultant signal; and
a correction processing part configured to generate a correction signal for correcting the digital audio signal by utilizing octave band analysis,
wherein
the correction processing part includes a switch configured to control coupling of the correction processing part to the low-pass filter, and
when the switch is on, the correction processing part couples to the low-pass filter, and generates the correction signal.

2. The audio signal amplification device according to claim 1 ,
wherein
the correction processing part includes:
a response signal measurement part configured to measure an output signal from the low-pass filter;
a correction part configured to generate the correction signal, based on a result of the measurement by the response signal measurement part; and
a synthesis part configured to synthesize the correction signal with the digital audio signal.

3. The audio signal amplification device according to claim 1 ,
wherein
when the switch is on, the delta-sigma modulation part receives a measurement signal having an impulse characteristic, and
the correction part generates one of a correction signal for a frequency-amplitude characteristic and a correction signal for a frequency-phase characteristic, from the result of the measurement by the response signal measurement part.

4. The audio signal amplification device according to claim 1 , wherein the switch is a manual switch.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Iwata Kazuya

Classifications

• H04R3/04 Primary

  for correcting frequency response · CPC title

• H03F3/183

  with semiconductor devices only · CPC title

• H03F1/34

  Negative-feedback-circuit arrangements with or without positive feedback (H03F1/02 - H03F1/30, H03F1/38 - H03F1/50, H03F3/50 take precedence {; for rejection of common mode signals H03F3/45479}) · CPC title

• H03F2200/331

  Sigma delta modulation being used in an amplifying circuit · CPC title

• H03F3/2175

  using analogue-digital or digital-analogue conversion (H03F3/2173 takes precedence) · CPC title