Semiconductor device for the reproduction of acoustic signals
US4318188A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 21, 1979 |
| Grant date | Mar 2, 1982 |
| Priority date | — |
| Expiry date | May 21, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C27/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A microphone, for receiving an acoustic signal, is connected to a transducer which changes the analog signal delivered by the microphone into a sufficiently dense series of storable pulses in such a manner that the series contains the information necessary for the reproduction of the analog signal. The pulses delivered by the transducer can be pulse amplitude modulated (PAM) signals. The transducer must be connected to an analog memory. In the case where the signals are digital, such as pulse code modulated (PCM) signals, a digital memory is used. For reproduction, the pulses recalled from memory, in the first case, are fed via a low pass filter to an amplifier and a loud speaker. In the second case, the pulses are first converted into an analog form in a digital/analog converter. Stacked-gate injection metal-oxide-semiconductor (SIMOS) memories may be considered as the analog memories and, as digital memories, electrically alterable read-only memories (EAROM) may be utilized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.