| 摘要 |
A recording/reproduced signal switching system for a 4-head type recording and reproducing apparatus, comprises a circuit for rotating a rotary body which has four heads mounted equally spaced apart so that adjacent heads are separated by 90 DEG , where a magnetic tape is wrapped around a peripheral surface of the rotary body over an angular range which is equal to or greater than 270 DEG but less than 360 DEG , a circuit for driving the tape to travel, four rotary transformers for performing transmission and reception of signals with respect to the four heads, four preamplifiers supplied with reproduced signals from the four heads, a first switch circuit for selectively and successively supplying a recording video signal to one of the four heads with a period which is approximately equal to a period in which the rotary body undergoes a 270 DEG -rotation, a second switch circuit for subjecting input terminals of three of the four preamplifiers to A.C. grounding, a third switch circuit for selectively and succesively passing one of the four reproduced signals which are obtained through the four preamplifiers, and a circuit for supplying switching signals to the first through third switch circuits. The switching signals are formed based on a rotation detection pulse which is in synchronism with the rotational speed of the rotary body.
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