Sound collecting device minimizing electrical noise

• US 20050259837A1
• Filed: 05/12/2005
• Published: 11/24/2005
• Est. Priority Date: 10/05/1998
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kinoshita, Hidetoshi
• Granted Patent: US 7,317,804 B2
• Time in Patent Office: Days
• US Class Current: 381/163
• CPC Class Codes: G10H 2220/351 Environmental parameters, e.g. temperature, ambient light, atmospheric pressure, humidity, used as input for musical purposes
• CPC Class Codes: G10H 3/14 using mechanically actuated vibrators with pick-up means G10H3/24 takes precedence
• CPC Class Codes: H04R 1/086 Protective screens, e.g. all weather or wind screens

Abstract

A sound collecting device is provided which is designed to minimize adverse effects on an output caused by exposure of an electroacoustic transducer to the air. The device includes an electroacoustic transducer and a vibrating circuit. The transducer is exposed to the air and responsive to input of a sound wave to produce a corresponding acoustic signal. The vibrating circuit vibrates the transducer to shake foreign substances such as dust or drops of water from the transducer. In a modified form, an electromagnetic sensor is provided which measures an electromagnetic noise transmitted to the transducer and which removes the electromagnetic noise from an output of the transducer to produce a noiseless acoustic signal.

Claims

1. A sound collecting device comprising:

a transducer responsive to input of a sound wave to vibrate, producing a corresponding acoustic signal;

an amplifier amplifying the acoustic signal from said transducer;

an electromagnetic sensor responsive to input of an electromagnetic wave to produce a corresponding electromagnetic signal; and

an output circuit subtracting the electromagnetic signal produced by said electromagnetic sensor from an output from said amplifier to produce an acoustic signal from which an electromagnetic wave-caused noise is removed.

2. A sound collecting device as set forth in claim 1, further comprising a housing, a sound collecting unit disposed within said housing, and a sensor amplifier amplifying the electromagnetic signal outputted from said electromagnetic sensor, and wherein said transducer is installed in said sound collecting unit, and said electromagnetic sensor is installed in said housing adjacent said sound collecting unit.

3. A sound collecting device as set forth in claim 2, further comprising an opening formed in said housing for allowing the electromagnetic wave to enter said electromagnetic sensor from the same direction as that in which the sound wave enters said transducer.

4. A sound collecting device as set forth in claim 2, further comprising a first and a second peak hold circuit, the first peak hold circuit holding a peak of the output from said amplifier to provide a corresponding signal to said output circuit, the second peak hold circuit holding a peak of an output from said sensor amplifier to provide a corresponding signal to said output circuit.

5. A sound collecting device as set forth in claim 2, further comprising a transducer vibrating circuit connected to said transducer in parallel to said amplifier to vibrate said transducer and a sensor vibrating circuit connected to said electromagnetic sensor in parallel to said sensor amplifier to vibrate said electromagnetic sensor.

6. A sound collecting device as set forth in claim 5, further comprising a first and a second switch, the first switch selectively establishing and blocking communications between said transducer and said amplifier and between said transducer and said transducer vibrating circuit, the second switch selectively establishing and blocking communications between said electromagnetic sensor and said sensor amplifier and between said electromagnetic sensor and said sensor vibrating circuit.

7. A sound collecting device as set forth in claim 5, further comprising a controller which controls an operation of said transducer vibrating circuit.

8. A sound collecting device as set forth in claim 7, further comprising a controller which controls switching operations of said first and second switches.