US3828361A — Speech compressor-expander

Claim 1

Independent Claim 332 words

A sound reproducer for playing recordings at different reproduction speeds comprising: a transport for moving said recording relative to a transducer for producing an electrical signal of the sound record on said recording with a frequency spectrum for said electrical signal related by a factor determined by the speed of said transport to the frequency spectrum of said sound recorded as said sound record; a controllable speed drive for said transport; analog shift register means having signal input and output terminals and a shift signal input; signal means for coupling said electrical signal from said transducer to said input terminal; a controllable pulse period square wave generator coupled to said shift signal input to shift signals through said analog shift register with the period of said generator; a ramp control signal generator having means for selecting the sign and slope value for an output ramp control signal to produce repetitive linear variation of said ramp control signal over a range of variation and for resetting to predetermined initial value at the end of said variation; means coupling said output ramp control signal to control said square wave generator for producing successive repetitive variation of the period of said square wave generator with selected sign and rate of change; output means coupled to said output terminal to receive the signals shifted through said analog shift register and operative for utilizing only successive signal portions shifted to said output terminal during said successive repetitive variation of said period of said square wave; manually operable control means for selecting said factor by selecting the speed of said transport to be greater than, equal to, or less than the transport speed at which said sound was recorded on said record; and means responsive to said manually operable control means for relating said selected sign and rate of change of said variation of said period to said factor to restore the frequency spectrum of said signal portions to that of said sound recorded on said sound record.

Claim 2

Dependent Claim 332 words

A sound reproducer for playing recordings at different reproduction speeds comprising: a transport for moving said recording relative to a transducer for producing an electrical signal of the sound record on said recording with a frequency spectrum for said electrical signal related by a factor determined by the speed of said transport to the frequency spectrum of said sound recorded as said sound record; a controllable speed drive for said transport; analog shift register means having signal input and output terminals and a shift signal input; signal means for coupling said electrical signal from said transducer to said input terminal; a controllable pulse period square wave generator coupled to said shift signal input to shift signals through said analog shift register with the period of said generator; a ramp control signal generator having means for selecting the sign and slope value for an output ramp control signal to produce repetitive linear variation of said ramp control signal over a range of variation and for resetting to predetermined initial value at the end of said variation; means coupling said output ramp control signal to control said square wave generator for producing successive repetitive variation of the period of said square wave generator with selected sign and rate of change; output means coupled to said output terminal to receive the signals shifted through said analog shift register and operative for utilizing only successive signal portions shifted to said output terminal during said successive repetitive variation of said period of said square wave; manually operable control means for selecting said factor by selecting the speed of said transport to be greater than, equal to, or less than the transport speed at which said sound was recorded on said record; and means responsive to said manually operable control means for relating said selected sign and rate of change of said variation of said period to said factor to restore the frequency spectrum of said signal portions to that of said sound recorded on said sound record.

Claim 3

Dependent Claim 38 words

Apparatus according to claim 1 and including means for decreasing the repetition interval for said repetitive variation directly as the speed of said transport is selected to be greater than the speed at which said sound was recorded.

Claim 4

Dependent Claim 73 words

Apparatus according to claim 1 in which said analog shift register means comprises two equal length analog shift registers, and said signal coupling means couples said electrical signal to the input of one of said analog shift registers inverted relative to the input to the other register and means for combining the outputs of said registers to add the signal components and cancel the noise characteristics of said registers in said output means.

Claim 5

Dependent Claim 90 words

Apparatus according to claim 1 in which said output means includes: blanking means operable for blanking the signal level between said successive signal portions; enabling means operative near the end of said repetitive linear variation of said ramp control signal for enabling said blanking means; zero crossing signal detector means for detecting zero crossings of signals coupled to said output means; 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.

Claim 6

Dependent Claim 31 words

Apparatus according to claim 4 including means operable for terminating said predetermined interval in response to detection of a zero crossing after resetting of said linear variation to said initial value.

Claim 7

Dependent Claim 133 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 proportional to (C - 1)/(C + 1) where C is said ratio of said playback speed to recorded speed; and 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 C > 1.

Claim 8

Dependent Claim 133 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 proportional to (C - 1)/(C + 1) where C is said ratio of said playback speed to recorded speed; and 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 C > 1.

Claim 9

Dependent Claim 21 words

Apparatus according to claim 6 in which said repetitive interval of variation is approximately 10 (C + 1)/(C - 1) milliseconds.

Claim 10

Dependent Claim 20 words

Apparatus according to claim 6 in which said repetitive interval of variation is maintained substantially constant for C < 1.

Claim 11

Dependent Claim 20 words

Apparatus according to claim 7 in which said repetitive interval of variation is maintained substantially constant for C < 1.

Claim 12

Dependent Claim 20 words

Apparatus according to claim 9 in which said repetitive interval of variation for C < 1 is approximately 50 milliseconds.

Claim 13

Dependent Claim 104 words

In speech signal processing in which frequency transformation of speech signals to restore their normal frequency spectrum is achieved by passing the signals through analog shift register means which is controlled with a repetitive variation of the shift period, the improvement which comprises providing said analog shift register means as at least two equal length registers, inverting the signal portion in one of said registers relative to the signal in the other register and combining the outputs from said two registers additively as to signals passed through said shift registers and subtractively as to characteristics imposed on said signals by operation of said registers.

Claim 14

Dependent Claim 104 words

In speech signal processing in which frequency transformation of speech signals to restore their normal frequency spectrum is achieved by passing the signals through analog shift register means which is controlled with a repetitive variation of the shift period, the improvement which comprises providing said analog shift register means as at least two equal length registers, inverting the signal portion in one of said registers relative to the signal in the other register and combining the outputs from said two registers additively as to signals passed through said shift registers and subtractively as to characteristics imposed on said signals by operation of said registers.

Claim 15

Dependent Claim 112 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; and 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 proportional to (C - 1)/(C + 1) where C is said ratio of playback speed to recorded speed and has a range of values includes: C<1, C 1 and C>1.

Claim 16

Dependent Claim 112 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; and 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 proportional to (C - 1)/(C + 1) where C is said ratio of playback speed to recorded speed and has a range of values includes: C<1, C 1 and C>1.

Claim 17

Dependent Claim 103 words

In a speed 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 said signal at the output of said line; enabling means for establishing an interval at the end of each repetitive variation; and 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 signals derived from the output of said line until after the start of the next repetitive variation of said line.

Claim 18

Dependent Claim 103 words

In a speed 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 said signal at the output of said line; enabling means for establishing an interval at the end of each repetitive variation; and 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 signals derived from the output of said line until after the start of the next repetitive variation of said line.

Claim 19

Dependent Claim 34 words

Apparatus according to claim 13 in which said blanking means is responsive to the detection of a zero crossing after the start of said next repetitive variation of said line for terminating said blanking.

Claim 20

Dependent Claim 54 words

Apparatus according to claim 14 in which said delay line means comprises an analog shift register with controlled shift period and including means for delaying said start of said next repetitive variation at least as long as it takes to shift said analog shift register to be filled from the input signals applied thereto.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-08-05	1978-02-04	1978-08-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-08-05	1982-02-04	1982-08-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-08-05	1986-02-04	1986-08-06	$7700.00	Window Closed / Lapsed

Speech compressor-expander

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