JPS63213145A - Rotary head type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To eliminate the possibility of malfunction without changing a duty even when a conventional system to transmit a bit of control information by the change of the duty is used commonly, by recording the bit of control information by changing the leading gradient of a control signal. CONSTITUTION:A phase detecting pulse (a) is inputted to a pulse arranging circuit 6, and after being waveform-arranged to a control pulse (b) consisting of a rectangular wave formed in advance, it is inputted to a switching circuit 7. When a code set as program searching, etc., is attached, by generating a switching pulse (c) which rises in the period of the low level of the pulse (b) corresponding to the depression of a switch 11 and continues only for a prescribed time t0 from a switching pulse device 12, and inputting the pulse (c) to the switching circuit 7, a contact is switched to a contact 7b only for a time to seconds, and the pulse (b) from the pulse arranging circuit 6 is inputted to an integration circuit 13 and a gate circuit 14. A signal (d) having gradient parts in which the leading and trailing edges of the circuit 13 are inclined is inputted to an adder circuit 16. The output of the circuit is inputted to the circuit 14, and a signal (e) from which the gradient part of the trailing edge is eliminated can be obtained as a gate signal.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary head type magnetic recording and reproducing device that sequentially records and reproduces information signals as recording trajectories inclined with respect to the longitudinal direction of a magnetic tape using a rotary head. In particular, it is characterized by a control signal recorded to control the phase relationship between the rotational phase of the rotary head and the recording trajectory on the tape during reproduction.

Conventional technology Conventionally, in rotary head type magnetic recording and reproducing devices, signals related to the rotational phase of a rotary head during recording are sequentially recorded in the longitudinal direction of a magnetic tape as control signals, and during playback, these control signals are reproduced. This controls the phase relationship between the rotational phase of the rotary head and the recording trajectory on the magnetic tape.

In addition, in recent years, a part of the duty of this control signal is changed and recorded, and during playback, a signal B corresponding to the rising edge of the rectangular wave of the playback control signal is used as the control signal, and a signal B corresponding to the falling edge of the rectangular wave of the playback control signal is used as the control signal. Changes in time t from the signal signal are used as other control signals, such as a marker for a tape cue function that indicates the tape position during playback.

Problems to be Solved by the Invention However, in the above configuration, the times t from the signal are different from each other, and in addition to the first marker for cueing function during playback, the second marker is used as a cue signal for editing. If markers were also created, there was a risk of malfunction.

In view of the above problems, the present invention aims to transmit other information while having a function as a control signal using a method other than changing the duty.

Means for Solving the Problems The rotary head type magnetic recording/reproducing apparatus of the present invention records by changing the rising slope of a control signal during recording, and when reproducing, a pulse corresponding to the rising slope of the reproduction control signal is changed. The change in width is detected and used as control information.

Effects According to the above configuration, since the duty of the control signal is not changed, there is no possibility of erroneous detection even when used in combination with the conventional method of transmitting control information by changing the duty.

Embodiment Hereinafter, an embodiment of the rotary head magnetic recording/reproducing apparatus of the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, a magnetic head 2 records data as an inclined recording trajectory on a magnetic tape 1 running in the longitudinal direction.
A cylinder 3 having a cylinder 3 is rotated by a motor 4, and the rotational phase of the cylinder 3 is detected by a rotational phase detection device 6. A phase detection pulse a (shown in FIG. 2) obtained from the phase detection device 5 is input to a pulse shaping circuit 6. In the pulse shaping circuit 6, the phase detection pulse a is shaped into a control pulse b (shown in FIG. 2) consisting of a rectangular wave with a predetermined duty cycle (6:4 in this embodiment). The signal is input to the switch circuit 7. During normal recording, the switch circuit 7 is connected to the contact 7.
a, and the control pulse b is applied to the control head 10 via the adder 8 and the switch 9, which has been switched to the contact 9B and is in the recording mode,
It is recorded on the magnetic tape 1. Further, when a code is attached as a marker for cueing, etc., in response to the press of the switch 11, the control pulse b rises during the low level period of the control pulse b after being suppressed, and a predetermined time to (for example, 0.2
A switching pulse device 12 generates a switching pulse C that lasts for a duration of
is input to the switching circuit 7, the switching circuit 7 is switched to the contact point 7b for the time period to seconds, and the control pulse b shaped by the pulse shaping circuit 6 is sent to the integrating circuit 13 and the gate circuit 14, respectively. is input. A signal d obtained from the integrating circuit 13 and having a slope portion in which rising and falling edges are sloped.
, and the bias generated from the constant voltage source 15 are input to the adder circuit 16.

The output obtained from the adder circuit 16 is input to the gate circuit 14, and the control pulse b is used as a gate signal from the gate circuit 14 to obtain a signal e excluding the falling slope portion. The signal e is input to the adder 8, and the record control signal f is obtained from the adder 8. That is, during the period to when the switching pulse C exists, the signal e is obtained, and during the other periods, the control pulse b is obtained, followed by the control signal n. The recording control signal f is applied to the control head 1o and recorded on the magnetic tape 1.

When the recording control signal f recorded on the magnetic tape 1 is reproduced, the control head 10 obtains a reproduction control signal g obtained by differentiating the recording control signal f. The reproduction control signal g consists of narrow edge-shaped positive pulses i and negative pulses j that are in phase with the rising and falling edges of the rectangular wave of the control signal.
A positive pulse whose pulse width is widened only during the period of the rising slope part whose phase matches the rising slope part and the falling part of the waveform of the signal e, and an edge-shaped negative pulse whose pulse width is narrow. It consists of a signal consisting of β.

The control signal g is input to a control circuit 17 for performing conventionally known tracking control and a pulse width discrimination circuit 18 for discriminating pulse widths through the switch 9 which is switched to the contact 9b and is in the reproduction mode. be done.

The pulse width discriminating circuit 18 detects a plurality of wide positive pulses k that rises in synchronization with the rise of the first wide positive pulse and falls after the last wide positive pulse rises. Outputs control signals such as output.

As described above, in this embodiment, during recording, the rising slope of the control signal S is changed to record the recording control signal f with a slope section, and during reproduction, the reproduction signal f is reproduced in accordance with the recording control signal f. Since the positive pulse k whose pulse width has changed and corresponds to the gradient portion of the control signal g is detected and used as control information, the duty of the control signal g does not change. Therefore, there is no fear of malfunction even when used in combination with the conventional control method based on changes in duty.

Effects of the Invention As described above, the rotary head type magnetic recording and reproducing apparatus of the present invention records by changing the rising slope of a control signal during recording, and when reproducing a pulse corresponding to the rising slope of the reproduction control signal. Since the change in width is detected and used as control information, the duty of the control signal does not change, so there is no risk of false detection even when used in conjunction with the conventional control method based on changes in duty. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a rotary head type magnetic recording/reproducing device according to an embodiment of the present invention, and FIG. 2 is an operational waveform diagram of the same device. DESCRIPTION OF SYMBOLS 1... Magnetic tape, 2... Magnetic head, 5... Phase detection device, 6... Pulse shaping circuit, T... Switch Circuit, 8・°...
・Mixer, 1o...°°...Control signal head,
12...Switching pulse generation circuit, 13.
...Integrator circuit, 14...Gate circuit, 1
5... Constant voltage source, 16... Addition circuit,
18...Pulse width discrimination circuit.

Claims (1)

[Claims] During recording, when sequentially recording signals related to the rotational phase of the rotary head as control signals in the longitudinal direction of a magnetic tape, the rising slope of the control signal is changed and recorded, and during reproduction, the rising slope portion of the reproduction control signal is recorded. A rotary head type magnetic recording/reproducing device characterized in that a change in the width of a pulse corresponding to the change in width of a pulse is detected and used as control information.