US3573364A
Expired / Lapsed
US
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Band-compressed signal transmission system
Assignee: NEC Corp
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Filing: 1969-08-05
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Granted: 1971-04-06
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Expires: 1989-08-05
Abstract
Abstract A band-compressed delta modulated signal communication system for transmitting an information signal admitting of abrupt variations in amplitude is disclosed in accordance with the teachings of the present invention wherein delta modulating means operable at a first frequency and at a first quantizing level generates a first pulse signal representative of gradual variations in the amplitude of said information signal and pulse modulating means responsive to said delta modulating means and operable at a second frequency and at a second quantizing level generates a second pulse signal representative of abrupt variations in the amplitude of said information signal. The first and second pulse signals are transmitted to a receiving station whereat said first and second pulse signals are demodulated to derive first and second analog signals which are combined to reproduce said information signal.
Inventors
- 👤 Tadao Shimamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:49
CPC Classifications
H; H04; H04N; H04N19/00; H04B; H04B14/00; H04B14/02; H04B14/06; H04B14/062
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
228 words
A band-compressed delta modulated signal communication system for transmitting an information signal admitting of abrupt changes of amplitude, comprising: delta modulating meAns for delta modulating said information signal, said delta modulating means including; first polarity discriminating means adapted to provide a first output pulse signal when an error signal applied to the input of said first polarity discriminating means admits of a first polarity, first integrating means coupled to said first polarity discriminating means for integrating said first output pulse signal to produce a first variable threshold level, and first subtracting means coupled to said first integrating means and adapted to be provided with said information signal, for comparing said information signal with said first variable threshold level to produce said error signal when said information signal exceeds said first variable threshold level, pulse modulating means coupled to said subtracting means for providing a pulse modulated signal representative of the amplitude of said error signal; transmitting means coupled to said first polarity discriminating means and said pulse modulating means for transmitting said first output pulse signal and said pulse modulated signal; receiving means coupled to said transmitting means for receiving said first output pulse signal and said pulse modulated signal; and reproducing means coupled to said receiving means for reproducing said information signal in response to said received first output pulse signal and said received pulse modulated signal.
Claim 2
Dependent Claim
228 words
A band-compressed delta modulated signal communication system for transmitting an information signal admitting of abrupt changes of amplitude, comprising: delta modulating meAns for delta modulating said information signal, said delta modulating means including; first polarity discriminating means adapted to provide a first output pulse signal when an error signal applied to the input of said first polarity discriminating means admits of a first polarity, first integrating means coupled to said first polarity discriminating means for integrating said first output pulse signal to produce a first variable threshold level, and first subtracting means coupled to said first integrating means and adapted to be provided with said information signal, for comparing said information signal with said first variable threshold level to produce said error signal when said information signal exceeds said first variable threshold level, pulse modulating means coupled to said subtracting means for providing a pulse modulated signal representative of the amplitude of said error signal; transmitting means coupled to said first polarity discriminating means and said pulse modulating means for transmitting said first output pulse signal and said pulse modulated signal; receiving means coupled to said transmitting means for receiving said first output pulse signal and said pulse modulated signal; and reproducing means coupled to said receiving means for reproducing said information signal in response to said received first output pulse signal and said received pulse modulated signal.
Claim 3
Dependent Claim
37 words
A band-compressed delta modulated signal communication system in accordance with claim 1 wherein said transmitting means comprises time-division multiplexing means for combining said first output pulse signal and said pulse modulated signal to form a multiplexed signal.
Claim 4
Dependent Claim
141 words
A band-compressed delta modulated signal communication system in accordance with claim 1 wherein said pulse modulating means comprises at least one additional delta modulating means including: second polarity discriminating means adapted to provide a second output pulse signal when a difference signal applied to the input of said second polarity discriminating means admits of a first polarity; second integrating means coupled to said second polarity discriminating means for integrating said second output pulse signal to produce a second variable threshold level, said second variable threshold level exceeding said first variable threshold level by a desired magnitude; and second subtracting means coupled to said second integrating means and adapted to be provided with said error signal for comparing said error signal with said second variable threshold level to produce said difference signal when said error signal exceeds said second variable threshold level.
Claim 5
Dependent Claim
56 words
A band-compressed delta modulated signal communication system in accordance with claim 3 wherein said first and second polarity discriminating means are connected to corresponding first and second means for applying first and second sampling signals, respectively thereto, and wherein the frequency of said first sampling signals is equal to the frequency of said second sampling signals.
Claim 6
Dependent Claim
58 words
A band-compressed delta modulated signal communication system in accordance with claim 3 wherein said transmitting means comprises multiplexing means for combining said first output pulse signal and said second output pulse signal; and wherein said receiving means comprises signal separating means for recovering said first output pulse signal and said second output pulse signal from said combined signal.
Claim 7
Dependent Claim
88 words
A band-compressed delta modulated signal communication system in accordance with claim 5 wherein said reproducing means comprises: first demodulating means for demodulating said first output pulse signal to derive a first analog signal corresponding to said first output pulse signal; second demodulating means for demodulating said second output pulse signal to derive a second analog signal corresponding to said second output pulse signal; and combining means coupled to said first and second demodulatIng means for combining said first and second analog signals whereby said information signal is reproduced.
Claim 8
Dependent Claim
208 words
A pulse communication system for transmitting an information signal admitting of abrupt amplitude variations, comprising: a transmitter including; first delta modulating means characterized by a first quantizing level, for modulating said information signal to produce a first output pulse signal in response to gradual variations of the amplitude of said information signal, second delta modulating means coupled to said first delta modulating means and characterized by a second quantizing level, for producing a second output pulse signal in response to abrupt variations of the amplitude of said information signal, said second quantizing level being larger than said first quantizing level, transmitting means coupled to said first and second delta modulating means for transmitting said first and second output pulse signals to a remote station, and a receiver including; receiving means for receiving said first and second output pulse signals, demodulating means coupled to said receiving means for demodulating said first and second output pulse signals whereby first and second analog signals representative of gradual variations in the amplitude of said information signal and abrupt variations in the amplitude of said information signal, respectively, are produced, and combining means coupled to said demodulating means for algebraically combining said first and second analog signals whereby said information signal is reproduced.
Claim 9
Dependent Claim
208 words
A pulse communication system for transmitting an information signal admitting of abrupt amplitude variations, comprising: a transmitter including; first delta modulating means characterized by a first quantizing level, for modulating said information signal to produce a first output pulse signal in response to gradual variations of the amplitude of said information signal, second delta modulating means coupled to said first delta modulating means and characterized by a second quantizing level, for producing a second output pulse signal in response to abrupt variations of the amplitude of said information signal, said second quantizing level being larger than said first quantizing level, transmitting means coupled to said first and second delta modulating means for transmitting said first and second output pulse signals to a remote station, and a receiver including; receiving means for receiving said first and second output pulse signals, demodulating means coupled to said receiving means for demodulating said first and second output pulse signals whereby first and second analog signals representative of gradual variations in the amplitude of said information signal and abrupt variations in the amplitude of said information signal, respectively, are produced, and combining means coupled to said demodulating means for algebraically combining said first and second analog signals whereby said information signal is reproduced.
Claim 10
Dependent Claim
197 words
A pulse communication system in accordance with claim 7 wherein each of said first and second delta modulating means comprises: 1-bit polarity coding means adapted to be provided with sampling pulses for generating an output pulse in response to a signal supplied thereto; integrating means coupled to said 1-bit polarity coding means for integrating said generated pulse, the magnitude of the output produced by said integrating means being increased by a predetermined increment in response to each generated pulse; whereby the predetermined increment associated with the integrating means of said first delta modulating means corresponds to said first quantizing level and the predetermined increment associated with the integrating means of said second delta modulating means corresponds to said second quantizing level such that the second predetermined increment exceeds the first predetermined increment by a desired amount; and subtracting means having a first input terminal, a second input terminal coupled to said integrating means and an output terminal coupled to said 1-bit polarity coding means for supplying a signal proportional to the difference between an input signal supplied to said first input terminal thereof and the output produced by said integrating means to said 1-bit polarity coding means.
Claim 11
Dependent Claim
61 words
A pulse communication system in accordance with claim 8 wherein said first input terminal of the subtracting means of said first delta modulating means is supplied with said information signal and said first input terminal of the subtracting means of said second delta modulating means is coupled to said output terminal of the subtracting means of said first delta modulating means.
Claim 12
Dependent Claim
107 words
A pulse communication system in accordance with claim 9 wherein said demodulating means comprises: first means for integrating said first output pulse signal to produce said first analog signal, the magnitude of said first analog signal being increased by a first given amount in response to each pulse of said received first output pulse signal; and second means for integrating said second output pulse signal to produce said second analog signal, the magnitude of said second analog signal being increased by a second given amount in response to each pulse of said received second output pulse signal, whereby said second given amount exceeds said first given amount.
Claim 13
Dependent Claim
17 words
A pulse communication system in accordance with claim 10 wherein said combining means comprises algebraic adding means.
Claim 14
Dependent Claim
224 words
A video signal communication system for transmitting a wide-band video signal representative of variations in light intensity, comprising: a first delta modulator operable at a first frequency and at a first quantizing level for producing a first output pulse signal in response to gradual variations in said light intensity that exceed an amount determined by said first quantizing level; a second delta modulator coupled to said first delta modulator, said second delta modulator being operable at a second frequency and at a second quantizing level for producing a second output pulse signal in response to abrupt variations in said light intensity that exceed an amount determined by said second quantizing level; whereby the sum of the product of said first frequency and said first quantizing level and the product of said second frequency and said second quantizing level is equal to the maximum slope of said video signal; means for supplying said video signal to said first delta modulator; transmitting means coupled to said first and second delta modulators to transmit said first and second output pulse signals; receiving means for receiving said first and second output pulse signals; demodulating means coupled to said receiving means for demodulating said first and second output pulse signals; and combining means coupled to said demodulating means for reproducing said video signal in accordance with the demodulated signals.
Claim 15
Dependent Claim
224 words
A video signal communication system for transmitting a wide-band video signal representative of variations in light intensity, comprising: a first delta modulator operable at a first frequency and at a first quantizing level for producing a first output pulse signal in response to gradual variations in said light intensity that exceed an amount determined by said first quantizing level; a second delta modulator coupled to said first delta modulator, said second delta modulator being operable at a second frequency and at a second quantizing level for producing a second output pulse signal in response to abrupt variations in said light intensity that exceed an amount determined by said second quantizing level; whereby the sum of the product of said first frequency and said first quantizing level and the product of said second frequency and said second quantizing level is equal to the maximum slope of said video signal; means for supplying said video signal to said first delta modulator; transmitting means coupled to said first and second delta modulators to transmit said first and second output pulse signals; receiving means for receiving said first and second output pulse signals; demodulating means coupled to said receiving means for demodulating said first and second output pulse signals; and combining means coupled to said demodulating means for reproducing said video signal in accordance with the demodulated signals.
Claim 16
Dependent Claim
160 words
A video signal communication system in accordance with claim 12 wherein each of said first and second delta modulators comprises: coding means adapted to be provided with sampling pulses for generating an output pulse in response to a signal applied thereto; integrating means coupled to said coding means for integrating said generated pulses to produce an integrated signal, the magnitude of said integrated signal being increased by a predetermined amount in response to each generated pulse; whereby the predetermined amount associated with the integrating means of said first delta modulator corresponds to said first quantizing level and the predetermined amount associated with the integrating means of said second delta modulator corresponds to said second quantizing level; subtracting means coupled to said integrating means and adapted to be supplied with an input signal for producing a difference signal proportional to the difference between said supplied signal and said integrated signal; and means for applying the difference signal to said coding means.
Claim 17
Dependent Claim
37 words
A video signal communication system in accordance with claim 13 further comprising means for supplying the difference signal produced by the subtracting means of said first delta modulator to the subtracting means of said second delta modulator.
Claim 18
Dependent Claim
65 words
A video signal communication system in accordance with claim 14 wherein the frequency of the sampling pulses provided to the coding means of said first delta modulator corresponds to said first frequency and the frequency of the sampling pulses provided to the coding means of said second delta modulator corresponds to said second frequency, and wherein said first frequency is equal to said second frequency.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |