US5095496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital audio signal receiver
Assignee: QUESTOR ENGINEERING Inc
•
Filing: 1990-11-20
•
Granted: 1992-03-10
•
Expires: 2010-11-20
Abstract
Abstract There is disclosed a digital audio signal reciever for preventing the generation of modulation noise in a D/A converted analog signal by eliminating Jitter effect occurring during transmission of digital audio data beforehand. The digital audio signal receiver includes an input selection circuit for selecting one of external digital audio signal soures, a first waveform shaping circuit for removing noise components of digital audio signals selected by the input selection circuit and shaping waveforms thereof, a first low pass filter for integrating the shaped waveform generated from the first waveform shaping circuit and adjusting the duty rate thereof, a second waveform shaping circuit for removing a DC noise component of the output waveform with duty rate adjusted by the first low pass filter and shaping the waveform thereof, a second low pass filter for monitoring duty rate of the output waveform of the second waveform shaping circuit to be at 50%, a comparator for providing feedback to the input terminal of the second waveform shaping circuit by comparing the output waveform of the second low pass filter with a reference voltage, and a demodulator for demodulating the output waveform of the second waveform shaping circuit back to original PCM audio data.
Inventors
- 👤 Seong-Chul Jang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:46
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/12; H; H04; H04B; H04B14/00; H04B14/02; H04B14/04; H04B14/046
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
219 words
A digital audio circuit for a data audio appliance, comprising: an input selection circuit for selecting one digital audio signal from among multiple external digital audio signals; a first waveform shaping circuit for removing input noise components of said one digital audio signal selected by said input selection circuit and for providing a first shaped waveform by shaping the waveform of said one digital audio signal; a first low pass filter for providing an integrated waveform by integrating said first shaped waveform generated from said first waveform shaping circuit and adjusting the duty rate of said integrated waveform; a second waveform shaping circuit for removing direct current noise components of said integrated waveform with duty rate adjusted by said first low pass filter and for providing a second shaped waveform by shaping the waveform of said integrated waveform; a second low pass filter for providing an output waveform monitoring the duty rate of said second shaped waveform of said second waveform shaping circuit to be at 50%; a comparator for providing feedback to an input terminal of said second waveform shaping circuit by comparing the output waveform of said second low pass filter with a reference voltage; and a demodulator for demodulating the second shaped waveform of said second waveform shaping circuit back to pulse code modulated audio data.
Claim 2
Dependent Claim
219 words
A digital audio circuit for a data audio appliance, comprising: an input selection circuit for selecting one digital audio signal from among multiple external digital audio signals; a first waveform shaping circuit for removing input noise components of said one digital audio signal selected by said input selection circuit and for providing a first shaped waveform by shaping the waveform of said one digital audio signal; a first low pass filter for providing an integrated waveform by integrating said first shaped waveform generated from said first waveform shaping circuit and adjusting the duty rate of said integrated waveform; a second waveform shaping circuit for removing direct current noise components of said integrated waveform with duty rate adjusted by said first low pass filter and for providing a second shaped waveform by shaping the waveform of said integrated waveform; a second low pass filter for providing an output waveform monitoring the duty rate of said second shaped waveform of said second waveform shaping circuit to be at 50%; a comparator for providing feedback to an input terminal of said second waveform shaping circuit by comparing the output waveform of said second low pass filter with a reference voltage; and a demodulator for demodulating the second shaped waveform of said second waveform shaping circuit back to pulse code modulated audio data.
Claim 3
Dependent Claim
216 words
A digital audio circuit for a data audio appliance, comprising: an input selection circuit for selecting one digital audio signal from among multiple external digital audio signals; a first waveform shaping circuit for removing input noise components of said one digital audio signal selected by said input selection circuit and for providing a first shaped waveform by shaping the waveform of said one digital audio signal; a first low pass filter for providing an integrated waveform by integrating said first shaped waveform generated from said first waveform shaping circuit and adjusting the duty rate of said integrated waveform; a second waveform shaping circuit for removing direct current noise components of said integrated waveform with duty rate adjusted by said first low pass filter and for providing a second shaped waveform by shaping the waveform of said integrated waveform; a second low pass filter for providing an output waveform monitoring the duty rate of said second shaped waveform of said second waveform shaping circuit; a comparator for providing feedback to an input terminal of said second waveform shaping circuit by comparing the output waveform of said second low pass filter with a reference voltage; and a demodulator for demodulating the second shaped waveform of said second waveform shaping circuit back to provide pulse code modulated audio data.
Claim 4
Dependent Claim
216 words
A digital audio circuit for a data audio appliance, comprising: an input selection circuit for selecting one digital audio signal from among multiple external digital audio signals; a first waveform shaping circuit for removing input noise components of said one digital audio signal selected by said input selection circuit and for providing a first shaped waveform by shaping the waveform of said one digital audio signal; a first low pass filter for providing an integrated waveform by integrating said first shaped waveform generated from said first waveform shaping circuit and adjusting the duty rate of said integrated waveform; a second waveform shaping circuit for removing direct current noise components of said integrated waveform with duty rate adjusted by said first low pass filter and for providing a second shaped waveform by shaping the waveform of said integrated waveform; a second low pass filter for providing an output waveform monitoring the duty rate of said second shaped waveform of said second waveform shaping circuit; a comparator for providing feedback to an input terminal of said second waveform shaping circuit by comparing the output waveform of said second low pass filter with a reference voltage; and a demodulator for demodulating the second shaped waveform of said second waveform shaping circuit back to provide pulse code modulated audio data.
References Cited (Backward Citations)
US4307465A
Cited
US4469082A
Cited
US4516247A
Cited
US4701715A
Cited
US4910753A
Cited
US4873702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-10 | 1995-09-09 | 1996-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-10 | 1999-09-09 | 2000-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-10 | 2003-09-09 | 2004-03-10 | $7700.00 | Window Closed / Lapsed |