SIGNAL DETECTING APPARATUS FOR USE IN SOUND TRACK RERECORDING

• US 3,725,604 A
• Filed: 09/17/1971
• Issued: 04/03/1973
• Est. Priority Date: 09/17/1971
• Status: Expired due to Term

• Current Assignee: Ronald Crawford Alexander
• Original Assignee: Ronald Crawford Alexander
• Inventors: Alexander, Ronald Crawford
• Primary Examiner(s): Cardillo, Jr., Raymond F.
• Application Number:
  US05/181,470
• Time in Patent Office: 564 Days
• Field of Search: 179/1.1R,1.1VC,1.2B,1.2K,1.3P,1VC,1.4D
• US Class Current: 360/55
• CPC Class Codes: G11B 27/19 by using information detectable on the record carrier
• CPC Class Codes: Y10S 358/908 Pause control, i.e. "commercial killers"

Abstract

A signal detecting apparatus for use in sound track rerecording comprising a magnetic storage tape having voice frequency signals transcribed thereon. A first magnetic pickup head is adapted to sense the presence or absence of the voice frequency signals on the magnetic tape. A synchronizing circuit is connected to said first pickup head and to a visual indicator. A second magnetic pickup head is associated with the magnetic tape. The synchronizing circuit is operable by the presence of voice frequency signals at the first magnetic pickup head for producing signals indicative of the exact beginnings and ends of the voice frequency signals and any pauses the voice frequency signals being sensed by the second magnetic pickup head.

Claims

1. A signal detecting apparatus for use in sound track rerecording comprising:

1. magnetic storage means having voice frequency signals transcribed thereon, 2. first magnetic sensing means adapted to sense the presence or absence of said voice frequency signals on said magnetic storage means, 3. circuit means connected to said first magnetic sensing means and to a visual indicating means, 4. second magnetic sensing means associated with said magnetic storage means for sensing said voice frequency signals a predetermined time after they have been sensed by said first magnetic sensing means, 5. said circuit means being operable by the presence of voice frequency signals at said first magnetic sensing means for producing signals indicative of the exact beginnings and ends of said voice frequency signals and any pauses between said voice frequency signals being sensed by said second magnetic sensing means.

2. A signal detecting apparatus as claimed in claim 1 wherein said indicating means is operable in response to said indicating signals for visually indicating the approach of said beginnings and ends of said voice frequency signals and said pauses at said second magnetic sensing means.

3. A signal detecting apparatus as claimed in claim 1, wherein said visual indicator comprises a meter having a scale and a pointer, said scale having a first, second and third indicated position, said pointer being displaced to said second position at the precise instant when a voice frequency signal arrives at said second magnetic sensing means, said pointer being displaced to said third position when said voice frequency signal at said first magnetic sensing means is continuous, and said pointer being displaced to said first position at the instant the end of the voice frequency signal arrives at said second magnetic sensing means.

4. second magnetic sensing means associated with said magnetic storage means for sensing said voice frequency signals a predetermined time after they have been sensed by said first magnetic sensing means,

5. A signal detecting apparatus as claimed in claim 4 wherein said circuit means includes adjustable current means to adjust the rate of charge of said capacitor to synchronize said first and second magnetic sensing means with said voice frequency signal.

6. A signal detecting apparatus as claimed in claim 4 wherein said circuit means further includes a first, second and third timing circuit, said third timing circuit being activated when a pause in said voice frequency signal is detected by said first magnetic pickup head and causing said capacitor to discharge through said meter to displace said pointer on said scale from said third position to said first position, said second timing circuit being activated by said first magnetic pickup head when a voice frequency signal reappears before the full discharge of said capacitor and reconnecting said capacitor to a charging current from a silicon controlled rectifier circuit thereby causing said meter pointer to assume its third position, said first timing circuit being activated at the instance of absence of said voice frequency signal from said second magnetic pickup head to shunt said capacitor to discharge it rapidly thereby causing said meter pointer to return to its inoperative position.