Electrical audio signal processing systems and devices – Circuitry combined with specific type microphone or loudspeaker – With electrostatic microphone
Reexamination Certificate
2006-05-02
2006-05-02
Le, Huyen (Department: 2644)
Electrical audio signal processing systems and devices
Circuitry combined with specific type microphone or loudspeaker
With electrostatic microphone
C330S303000
Reexamination Certificate
active
07039202
ABSTRACT:
A microphone unit capable of suppressing the sensitivity reduction due to a parasitic capacitance that occurs depending on the structure of an electret capacitor, can be realized by the following manner. Specifically, an output signal (Vout) that is the inverted output of an input signal (Vin) is inputted to an operational amplifier (OP2) that is an inverting amplifier, such that the output signal (Vout) has the same phase as the input signal (Vin) and is amplified. With an output signal (Vfb) of the operational amplifier (OP2) connected to a first electrode of a parasitic capacitor (CX), the parasitic capacitor (CX) functions as a coupling capacitor, while a feedback is applied to an electret capacitor (EC). This allows for an increase in the voltage between both terminals of the electret capacitor (EC), and thus suppresses that the sensitivity of the microphone unit is lowered due to the parasitic capacitor.
REFERENCES:
patent: 3116366 (1963-12-01), Seligson
patent: 3810032 (1974-05-01), Van der Plaats
patent: 4079335 (1978-03-01), Doerig
patent: 4255716 (1981-03-01), Takada
patent: 4361735 (1982-11-01), Johnson et al.
patent: 4491972 (1985-01-01), Weber
patent: 4518829 (1985-05-01), Boeckmann
patent: 4731849 (1988-03-01), Bloomfield, III
patent: 4951174 (1990-08-01), Grantham et al.
patent: 5490220 (1996-02-01), Loeppert
patent: 5675296 (1997-10-01), Tomikawa
patent: 5767545 (1998-06-01), Takahashi
patent: 6084972 (2000-07-01), van Halteren et al.
patent: 6453048 (2002-09-01), Akino
patent: 6516069 (2003-02-01), Takeuchi et al.
patent: 6580797 (2003-06-01), Papadopoulos et al.
patent: 6681020 (2004-01-01), Papopoulos et al.
patent: 6978029 (2005-12-01), Ikeda
patent: 2003/0035558 (2003-02-01), Kawamura et al.
patent: 34 13 145 (1985-10-01), None
patent: 689 13 177 (1994-07-01), None
patent: 196 00 689 (1996-07-01), None
patent: 198 39 978 (1999-03-01), None
patent: 197 53 279 (1999-06-01), None
patent: 695 11 207 (2000-02-01), None
patent: WO 94/23547 (1994-10-01), None
Le Huyen
Lun-See Lao
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