D/A conversion device, method, storage medium, electronic musical instrument, and information processing apparatus

Patent metadata

Field	Value
Publication number	US-11764803-B2
Application number	US-202217706012-A
Country	US
Kind code	B2
Filing date	Mar 28, 2022
Priority date	Jan 16, 2017
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

A digital-to-analog conversion device which performs integration processing for integrating a difference between an input signal and a first return signal generated based on the input signal, and outputting an integration result, first quantization processing for quantizing the integration result, and outputting a first quantization signal, first return signal output processing for outputting the first return signal by adding to the first quantization signal a correction value delay signal acquired by a correction value signal outputted based on the integration result being delayed, and output processing for outputting output signals including a signal whose pulse width is asymmetrical to center of a processing period, based on the first quantization signal, in which the correction value signal includes a signal indicating a correction value for correcting a difference between a center of the pulse width asymmetrical to the center of the processing period and the center of the processing period.

First claim

The invention claimed is:

1. A digital-to-analog conversion device comprising:
circuitry including:
an integrator that is configured to perform integration processing for integrating a difference between an input signal and a first return signal and a second return signal generated based on the input signal, to thereby generate an integration result;
a first quantizer that is configured to perform first quantization processing for quantizing the integration result generated by the integrator, to thereby generate a first quantization signal; and
an output section that is configured to perform output processing for outputting output signals including a Pulse Width Modulation (PWM) signal whose pulse width is asymmetrical to a center of a processing period, based on the first quantization signal generated by the quantization of the first quantization processing,

wherein the first return signal delays the first quantization signal,
wherein the second return signal delays a correction value signal outputted based on the integration result generated by the integrator, and
wherein the correction value signal includes a signal indicating a correction value for correcting a difference between (i) a center of the pulse width asymmetrical to the center of the processing period and (ii) the center of the processing period.

2. A digital-to-analog conversion method for a digital-to-analog conversion device comprising circuitry including an integrator, a first quantizer, and an output section, the method comprising:
performing, by the integrator, integration processing for integrating a difference between an input signal and a first return signal and a second return signal generated based on the input signal, to thereby generate an integration result;
performing, by the first quantizer, first quantization processing for quantizing the integration result generated by the integrator, to thereby generate a first quantization signal; and
performing, by the output section, output processing for outputting output signals including a Pulse Width Modulation (PWM) signal whose pulse width is asymmetrical to a center of a processing period, based on a first quantization signal generated by the quantization of the first quantization processing,
wherein the first return signal delays the first quantization signal,
wherein the second return signal delays a correction value signal outputted based on the integration result generated by the integrator, and
wherein the correction value signal includes a signal indicating a correction value for correcting a difference between (i) a center of the pulse width asymmetrical to the center of the processing period and (ii) the center of the processing period.

3. The digital-to-analog conversion device according to claim 1 ,
wherein the pulse width includes a first period that comes before a timing at the center of the processing period and a second period that comes after the timing at the center of the processing period, and
wherein the first period and the second period have different time lengths.

4. An electronic musical instrument comprising:
the digital-to-analog conversion device according to claim 1 ;
a keyboard; and
a sound emission section which emits a musical sound subjected to digital-to-analog conversion based on an output from the digital-to-analog conversion device.

5. An information processing apparatus comprising:
the digital-to-analog conversion device according to claim 1 ; and
a sound emission section which emits a musical sound subjected to digital-to-analog conversion based on an output from the digital-to-analog conversion device.

6. The digital-to-analog conversion device according to claim 1 , the circuitry further including:
a first subtractor that is configured to perform first subtraction processing for obtaining the difference between the input signal and the first return signal, to thereby generate a first subtraction processing result.

7. The digital-to-analog conversion device according to claim 6 , the circuitry further including:
a second subtractor that is configured to perform second subtraction processing for obtaining a difference between the first subtraction processing result and the second return signal, to thereby generate a second subtraction processing result.

8. The digital-to-analog conversion device according to claim 7 , the circuitry further including:
a first delay section that is configured to perform first delay processing for generating a correction value delay signal by delaying the correction value signal, and outputting the correction value delay signal; and
a second delay section that is configured to perform second delay processing for generating the first return signal by delaying the first quantization signal, and outputting the first return signal to the first subtractor.

9. The digital-to-analog conversion device according to claim 8 , the circuitry further including:
a third delay section that is configured to perform third delay processing for generating the second return signal by delaying the correction value delay signal output by the first delay section.

Assignees

• Casio Computer Co Ltd

Inventors

• Sakata Goro

Classifications

• H03M3/506 Primary

  the final digital/analogue converter being constituted by a pulse width modulator · CPC title

• H03M1/52 Primary

  Input signal integrated with linear return to datum · CPC title

• H03M3/02

  Delta modulation, i.e. one-bit differential modulation {(H03M3/30 takes precedence)} · CPC title

• G10H1/344

  Structural association with individual keys (electrically operated wind-actuated organs G10B3/22) · CPC title

• G10H7/08

  by calculating functions or polynomial approximations to evaluate amplitudes at successive sample points of a tone waveform · CPC title