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US4633500A Expired / Lapsed US ⏱️ 0.0 years remaining

Speech synthesizer

Assignee: Mitsubishi Electric Corp
•
Filing: 1983-03-17
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Granted: 1986-12-30
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Expires: 2003-03-17
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Abstract

Abstract A speech synthesizer includes a lattice-type multi-stage digital filter modified in the next to last stage thereof by incorporating an increasing circuit for slightly effectively increasing the absolute value of a parameter K2 so as to reduce an attenuation factor. The device is useful for generating tones of a sustained quality, such as musical tones.

Inventors

  • 👤 Norimasa Yamada
  • 👤 Masahiro Hibino

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 16:18
CPC Classifications
G; G10; G10L; G10L19/00; G10L19/04; G10L19/16; G10H; G10H1/00; G10H1/02; G10H1/06; G10H1/12; G10H1/125; G10H5/00; G10H5/007; G10L13/00; G10L13/02; G10L13/04; G10H2250/00; G10H2250/055; G10H2250/061; G10H2250/065; G10H2250/471; G10H2250/511; G10H2250/535; G10L25/00; G10L25/03; G10L25/06

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 87 words
A partial auto correlation type speech synthesizer, comprising; a lattice-type multi-stage digital filter which comprises a digital tone source signal generating circuit, an adder/subtractor, a delay unit and a multiplier, for extracting a predetermined frequency spectrum component from a exciting signal, and an increasing circuit for slightly increasing the absolute value of a multiplication result for a coefficient K parameter multiplier in a predetermined state of said lattice-type multistage filter, for synthesizing and outputting a sustained sinusoidal waveform or a damped oscillation waveform of long attenuation time.
Claim 2
Dependent Claim 87 words
A partial auto correlation type speech synthesizer, comprising; a lattice-type multi-stage digital filter which comprises a digital tone source signal generating circuit, an adder/subtractor, a delay unit and a multiplier, for extracting a predetermined frequency spectrum component from a exciting signal, and an increasing circuit for slightly increasing the absolute value of a multiplication result for a coefficient K parameter multiplier in a predetermined state of said lattice-type multistage filter, for synthesizing and outputting a sustained sinusoidal waveform or a damped oscillation waveform of long attenuation time.
Claim 3
Dependent Claim 22 words
A speech synthesizer as claimed in claim 1, wherein said increasing circuit comprises a memory for storing increasing rates, and a multiplier.
Claim 4
Dependent Claim 15 words
A speech synthesizer as claimed in claim 1, wherein said increasing circuit comprises an adder.
Claim 5
Dependent Claim 72 words
A speech synthesizer as claimed in claim 1, wherein said increasing circuit comprises means for slightly increasing an absolute value of said multiplication result by setting at least one low-order bit of said multiplication result of a coefficient K 2 parameter multiplier in a next to the last stage of said lattice-type multistage filter to one logical level when said multiplication result is positive and to the other logical level when negative.
Claim 6
Dependent Claim 68 words
A speech synthesizer as claimed in claims 1, 2, or 3 wherein said increasing circuit slightly increases the absolute value of an addition result of a multiplication result of a coefficient K 2 parameter multiplier at a stage one stage before the last stage of said lattice-type multi-stage filter to a forward wave at a stage located two stages before the last stage of said lattice-type multi-stage filter.
Claim 7
Dependent Claim 51 words
A speech synthesizer as claimed in claims 1, 2, 3, or 4 further including switching means selectively selecting either an output of said increasing circuit or said multiplication result, and control circuit means for operating said switching means to select said increasing circuit output at least when synthesizing substantially sinusoidal waveforms.

References Cited (Backward Citations)

US4509188A Cited
US4542524A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-12-29 1990-06-30 1990-12-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-12-29 1994-06-30 1994-12-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-12-29 1998-06-30 1998-12-30 $7700.00 Window Closed / Lapsed

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