ROM compensated microphone
US4631749A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1984 |
| Grant date | Dec 23, 1986 |
| Priority date | — |
| Expiry date | Jun 22, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R3/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A microphone is provided with a read only memory (ROM) which is programmed to compensate for the microphone's nonlinear frequency response characteristic during their integration into a single unit. The ROM is thus programmed to provide a frequency response complementary to that exhibited by the microphone. The microphone may have a relatively poor frequency response over the audio spectrum, i.e., 20 Hz-20 kHz, but with the ROM serving to calibrate the microphone, the combination exhibits a relatively flat frequency response over this frequency range. Intended for use in a portable, battery operated, microprocessor-controlled audio spectrum analyzer, the integrated microphone and ROM combination is coupled to a CMOS random access memory (RAM) in which the calibration contents of the ROM are stored. During normal operation, the microprocessor reads the microphone calibration data from the thus programmed RAM in order to conserve battery power, but may read this data from the ROM when necessary. This permits an inexpensive microphone to be used in a high performance audio spectrum analyzer resulting in a flat frequency response.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.