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1. (WO1991018365) METHOD AND APPARATUS FOR GENERATING AN ANALOGUE SIGNAL FROM AN ENCODED DIGITAL SIGNAL
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1991/018365 International Application No.: PCT/GB1991/000767
Publication Date: 28.11.1991 International Filing Date: 16.05.1991
Chapter 2 Demand Filed: 03.12.1991
IPC:
G06J 1/00 (2006.01) ,G10H 7/02 (2006.01) ,G10H 7/08 (2006.01)
G PHYSICS
06
COMPUTING; CALCULATING; COUNTING
J
HYBRID COMPUTING ARRANGEMENTS
1
Hybrid computing arrangements
G PHYSICS
10
MUSICAL INSTRUMENTS; ACOUSTICS
H
ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
7
Instruments in which the tones are synthesised from a data store, e.g. computer organs
02
in which amplitudes at successive sample points of a tone waveform are stored in one or more memories
G PHYSICS
10
MUSICAL INSTRUMENTS; ACOUSTICS
H
ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
7
Instruments in which the tones are synthesised from a data store, e.g. computer organs
08
by calculating functions or polynomial approximations to evaluate amplitudes at successive sample points of a tone waveform
Applicants:
HI-MED INSTRUMENTS LIMITED [GB/GB]; Orbit House 64-66 St.Mary's Butts Reading RG1 2LL, GB (AllExceptUS)
HOWELL, Vernon, Thomas, Seymour [GB/GB]; GB (UsOnly)
Inventors:
HOWELL, Vernon, Thomas, Seymour; GB
Agent:
LLOYD, Patrick, Alexander, Desmond; Reddie & Grose 16 Theobalds Road London WC1X 8PL, GB
Priority Data:
9010970.316.05.1990GB
Title (EN) METHOD AND APPARATUS FOR GENERATING AN ANALOGUE SIGNAL FROM AN ENCODED DIGITAL SIGNAL
(FR) PROCEDE ET APPAREIL PRODUISANT DES SIGNAUX ANALOGIQUES A PARTIR DE SIGNAUX NUMERIQUES CODES
Abstract:
(EN) A digital audio signal generator (30) includes an EPROM memory (32) containing a digitally encoded audio signal sampled at a fixed rate. An address counter (48) retrieves the digital values sequentially from the memory, and the data is fed to a segment generator which generates a segment of a predetermined wavefuction. The audio signal is generated by joining together consecutive segments. The segment generator includes output DACs (66, 70) and reference DACs (60, 62) which control the output amplitudes of the output DACs. A summing amplifier (72) combines the outputs from the output DACs to produce the output audio signal. A counter (44) generates a sequence of values representing a straight line wave function, which values are fed to the output DACs.
(FR) Générateur de signaux sonores numériques (30) comprenant une mémoire morte programmable électriquement (32) qui contient un signal sonore codé numériquement, échantillonné à une fréquence fixée. Un compteur d'adresses (48) récupère les valeurs numériques de manière séquentielle dans la mémoire et les données sont transmises à un générateur de segments qui génère un segment d'une fonction d'ondes prédéterminée. Le signal sonore est généré en joignant des segments consécutifs. Ledit générateur de segments comprend des CNA de sortie (66, 70) et des CNA de référence (60, 62) qui contrôlent les amplitudes de sortie des CNA de sortie. Un amplificateur additionneur (72) combine les sorties des CNA de sortie pour produire le signal sonore de sortie. Un compteur (44) génère une séquence de valeurs représentant une fonction d'ondes en ligne droite, valeurs qui sont transmises aux CNA de sortie.
Designated States: AU, CA, GB, JP, US
European Patent Office (AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LU, NL, SE)
Publication Language: English (EN)
Filing Language: English (EN)
Also published as:
AU1991078661