US3869708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speech compressor with gap filling
Assignee: VSC Co WESTPORT CT A OF LP
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Filing: 1974-01-14
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Granted: 1975-03-04
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Expires: 1994-01-14
Abstract
Abstract An improved speech compressor provides frequency transformation by passing speech signals through an analog shift register and controlling the shift rate of the register with a linearly varying periodicity with noise cancellation of the characteristic noise in the shift registers and the control of the sample period and output blanking to improve the signal output characteristic and minimize noise components therein. The system provides a single compression-expansion manual control which varies the record reproducer transport speed and the rate of change of the linearly varying pulse periodicity to provide a unitary control for selecting the corresponding compression ratio and automatically modifies the sample period to optimize the signal and discard intervals as the selected compression or expansion ratio is changed. Automatic initiation of reset in response to detection of a zero crossing of the audio output signal is provided and auxiliary fixed storage is used to fill blanking gaps in the output signal.
Inventors
- 👤 Murray M Schiffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:56
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/10; G; G10; G10L; G10L21/00; G10L21/04; G11; G11B; G11B21/00; G11B5/00; H03; H03H; H03H11/00; H03H11/02; H03H11/26; H03H11/265; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/50; H03K4/501; H03K4/502; H03K7/00; H03K7/08; H04B1/00; H04B1/66; H04B1/662
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
155 words
A sound reproducer for playing a sound record at playback speed different than its recorded speed comprising means for transporting said sound record at a selected playback speed relative to a transducer to obtain an electric signal having frequency components altered by the ratio of said playback speed to said recorded speed; means for frequency converting said electric signal with a repetitive varying time delay function having time delay variation adjusted in response to selection of said playback speed to be a function of C-1/C+1 where C is said ratio of said playback speed to recorded speed; means responsive to adjusting said delay variation for varying the repetitive interval of variation for said delay function approximately in direct relation to C+1/C-1 for all values of C; and utilization means for the portions of said electric signal which have been frequency converted by said varying time delay function operable to produce a substantially continuous output signal.
Claim 2
Dependent Claim
155 words
A sound reproducer for playing a sound record at playback speed different than its recorded speed comprising means for transporting said sound record at a selected playback speed relative to a transducer to obtain an electric signal having frequency components altered by the ratio of said playback speed to said recorded speed; means for frequency converting said electric signal with a repetitive varying time delay function having time delay variation adjusted in response to selection of said playback speed to be a function of C-1/C+1 where C is said ratio of said playback speed to recorded speed; means responsive to adjusting said delay variation for varying the repetitive interval of variation for said delay function approximately in direct relation to C+1/C-1 for all values of C; and utilization means for the portions of said electric signal which have been frequency converted by said varying time delay function operable to produce a substantially continuous output signal.
Claim 3
Dependent Claim
17 words
Apparatus according to claim 1 in which said repetitive interval of variation is approximately 10 C+1/C-1 milliseconds.
Claim 4
Dependent Claim
88 words
Apparatus according to claim 1 including: blanking means operable for blanking said output signal between successive signal portions of said repetitive interval; enabling means operative near the end of said repetitive interval for enabling said blanking means; zero crossing signal detector means for detecting zero crossings of said output signal; and circuit means responsive to a detected zero crossing during the period of said enabling for operating said blanking means for a predetermined interval between said successive signal portions and resetting said delay variation to an initial value.
Claim 5
Dependent Claim
57 words
Apparatus according to claim 3 and including auxiliary fixed delay means for storing a predetermined interval of said output signal and means for combining the stored signal of said auxiliary delay means with said output signal to supply a composite audio output that includes said stored signal during said predetermined interval when said output signal is blanked.
Claim 6
Dependent Claim
27 words
Apparatus according to claim 4 and including means for selecting said ratio of playback speed to recorded speed to cover the range C<1, C 1 and C>1.
Claim 7
Dependent Claim
180 words
In a speech compression-expansion system having variable delay line means repetitively varied to provide frequency transformation of signals passing through the line the combination comprising: means for sensing zero crossing points on the signals derived from the output of said line; enabling means for establishing an interval at the end of each repetitive variation; blanking means responsive to detection of a zero crossing within said interval and if no such zero crossing is detected responsive to the end of said interval for blanking said signals derived from the output of said line until after the start of the next repetitive variation of said line; fixed delay storage means coupled to the output of said variable delay line for supplying fixed further delay for signals which have been frequency transformed by said variable delay line; and means for combining the outputs of said variable delay line and said fixed delay storage means in accordance with operation of said blanking means to form a composite output signal having the blanking interval for said signals filled with signals having said fixed further delay.
Claim 8
Dependent Claim
180 words
In a speech compression-expansion system having variable delay line means repetitively varied to provide frequency transformation of signals passing through the line the combination comprising: means for sensing zero crossing points on the signals derived from the output of said line; enabling means for establishing an interval at the end of each repetitive variation; blanking means responsive to detection of a zero crossing within said interval and if no such zero crossing is detected responsive to the end of said interval for blanking said signals derived from the output of said line until after the start of the next repetitive variation of said line; fixed delay storage means coupled to the output of said variable delay line for supplying fixed further delay for signals which have been frequency transformed by said variable delay line; and means for combining the outputs of said variable delay line and said fixed delay storage means in accordance with operation of said blanking means to form a composite output signal having the blanking interval for said signals filled with signals having said fixed further delay.
References Cited (Backward Citations)
US2816175A
Cited
US3319013A
Cited
US3409743A
Cited
US3409736A
Cited
US3621150A
Cited
US3763328A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |