US4219879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital to analog conversion system
Assignee: HP Inc
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Filing: 1978-09-07
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Granted: 1980-08-26
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Expires: 1998-09-07
Abstract
Abstract A digital signal is summed before application to a D/A converter, and a differentiator is inserted at some point between the signal input and output.
Inventors
- 👤 Neil H. K. Judell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:22
CPC Classifications
G; G06; G06J; G06J1/00; H; H03; H03M; H03M1/00; H03M1/06; H03M1/0617; H03M1/0626; H03M1/0631
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
56 words
A system for processing first analog signals comprising an analog-to-digital converter, a digital processor coupled to said converter, a digital summer coupled to receive the digital output of said processor, a digital-to-analog converter coupled to the outputof said summer for producing second analog signals, and means for differentiating one of said first and second analog signals.
Claim 2
Independent Claim
56 words
A system for processing first analog signals comprising an analog-to-digital converter, a digital processor coupled to said converter, a digital summer coupled to receive the digital output of said processor, a digital-to-analog converter coupled to the outputof said summer for producing second analog signals, and means for differentiating one of said first and second analog signals.
Claim 3
Independent Claim
57 words
A system for converting a digital signal to an analog signal comprising a summer to which the digital signal to be converted to analog form may be applied, a digital-to-analog converter coupled to the output of said summer, and a low pass filter and an analog differentiator coupled in series to the output of said digital-to-analog converter.
Claim 4
Independent Claim
57 words
A system for converting a digital signal to an analog signal comprising a summer to which the digital signal to be converted to analog form may be applied, a digital-to-analog converter coupled to the output of said summer, and a low pass filter and an analog differentiator coupled in series to the output of said digital-to-analog converter.
Claim 5
Independent Claim
122 words
A system for processing time-varying analog signals in digital form and producing the results in analog form, comprising a terminal to which an analog signal may be applied, an analog-to-digital converter having an input coupled to said terminal and having an output, a digital processor having an input coupled to the output of said analog-to-digital converter and having an output, a digital summer having an input coupled to the output of said digital processor, and having an output, a digital-to-analog converter having an input coupled to the output of said summer and having an output, a low pass filter coupled to the output of said digital-to-analog converter, and means for differentiating the signals in the system when they are in analog form.
Claim 6
Independent Claim
122 words
A system for processing time-varying analog signals in digital form and producing the results in analog form, comprising a terminal to which an analog signal may be applied, an analog-to-digital converter having an input coupled to said terminal and having an output, a digital processor having an input coupled to the output of said analog-to-digital converter and having an output, a digital summer having an input coupled to the output of said digital processor, and having an output, a digital-to-analog converter having an input coupled to the output of said summer and having an output, a low pass filter coupled to the output of said digital-to-analog converter, and means for differentiating the signals in the system when they are in analog form.
Claim 7
Dependent Claim
36 words
A system as set forth in claim 3 wherein said analog-to-digital converter and said digital-to-analog converter operate at a given sampling frequency and wherein said low pass filter attenuates frequencies above one-half of said sampling frequency.
Claim 8
Dependent Claim
30 words
A system as set forth in claim 3 wherein said processor is linear and said means for differentiating is coupled between said terminal and the input of said analog-to-digital converter.
Claim 9
Dependent Claim
29 words
A system as set forth in claim 3 wherein said means for differentiating is connected in series with said low pass filter to the output of said digital-to-analog converter.
References Cited (Backward Citations)
US4071827A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-26 | 1984-02-25 | 1984-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-26 | 1988-02-25 | 1988-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-26 | 1992-02-25 | 1992-08-26 | $7700.00 | Window Closed / Lapsed |