Voice filter system for a video camera

• US 5,579,046 A
• Filed: 09/06/1994
• Issued: 11/26/1996
• Est. Priority Date: 07/26/1990
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Morita, Masaki, Mitsuhashi, Yasuo
• Primary Examiner(s): GARBER, WENDY RAE
• Application Number:
  US08/300,520
• Time in Patent Office: 812 Days
• Field of Search: 348/373, 348/375, 348/376, 348/207, 348/232, 381/92, 358/906
• US Class Current: 348/231.4
• CPC Class Codes: H04N 5/772 the recording apparatus and the television camera being placed in the same enclosure
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A one-piece type video camera comprises a device for taking the image of a subject, a device for collecting the voice and a device for magnetically recording the image and voice, all of which are built in the camera as one piece. The voice collecting device includes a microphone for collecting the voice incoming from the subject and another microphone for collecting the operator'"'"'s voice. The operator'"'"'s voice is subtracted from the voice incoming from the subject such that only the latter will be recorded. The operator'"'"'s voice is utilized in the voice recognition technique so as to control the entire system of the video camera. In a preferred embodiment, the microphones are directional microphones.

Claims

1. A video camera comprising:

a first microphone having a directivity toward a subject for collecting sounds incoming from the subject and also voice sounds from a camera operator, said first microphone converting the combined sounds into a first output voice signal;

a second directional microphone, spaced apart from said first microphone and located adjacent to the mouth of the camera operator, said second microphone having a narrow-beamed directivity toward an operator for collecting the voice sounds from the operator and to convert the operator voice sounds into a second output voice signal;

a delay element for delaying the second voice signal such that a difference between a time required to transmit the operator voice sounds between the operator and the first microphone and a time required to propagate the operator voice sounds between the operator and the second microphone will be compensated;

subtractor means for subtracting the delayed second output voice signal from the first output voice signal to form a differential output signal;

an optical system for collecting light representing the image of the subject; and

recording means for recording the differential signal and the image;

whereby the level of the operator'"'"'s voice sounds recorded are reduced in order to improve the clarity of the sounds from the subject.

5. The video camera of claim 1, wherein

said second microphone is adapted to collect sounds generated by mechanical vibrations created within an interior of the video camera.

2. The one-piece type video camera as defined in claim 9, wherein said subtractor means is an operational amplifier for receiving the first voice signal at a non-invert input terminal thereof and the second voice signal at an invert input terminal of said operational amplifier, said operational amplifier being adapted to form the differential output signal by amplifying a difference between the first and second voice signals.

3. The one-piece type video camera as defined in claim 9, further comprising:

switch means for selecting one of the differential signal and first voice signal to be supplied to said recording means.

4. The one-piece type video camera as defined in claim 9, further comprising:

a frequency filter for causing a frequency characteristic and level of the second voice signal to match a frequency characteristic and level of the first voice signal.