JPH02113401A - Rotating cylinder type magnetic recording and reproducing device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary cylinder type magnetic recording/reproducing device having a magnetic head switching means on a rotary cylinder.

2. Description of the Related Art In a conventional rotating cylinder type magnetic recording/reproducing device, such as a VH8 type VTR, two magnetic heads mounted on a rotating cylinder and having a positional relationship of approximately 180° from each other are switched every half rotation of the rotating cylinder. recording or playback. This switching every half rotation (hereinafter 180
° switching) is performed on the main body side. On the other hand, signal transmission between each head on the rotating cylinder and the circuit on the main body side is carried out via a transmission line formed by a rotary transformer provided for each head.

Problems to be Solved by the Invention However, with Hi-Vigilon VTRs and digital VTRs, the amount of information to be recorded is large, and when performing one-channel recording, the relative flux of the tape head increases, which reduces the lifespan of the head and cylinder bearing. This is disadvantageous because it requires multi-channel recording, and for professional VTRs that enable editing and simultaneous playback, advance playback heads and simultaneous playback heads are required, which further increases the number of magnetic heads and the transmission of rotary transformers. A problem arises in that a large number of passages are required and the configuration of the cylinder becomes complicated.

Therefore, the technical object of the present invention is to reduce the number of transmission lines between the main body side and the rotary cylinder side, thereby simplifying the configuration of the cylinder.

Means for Solving the Problems The present invention provides an electromagnetic transducer comprising at least two sets of magnetic heads, each pair of two magnetic heads mounted at symmetrical positions from the center on a rotating cylinder, and 180° switching means for switching the two magnetic heads of each set of the electromagnetic transducing means every 180°; and a 180° switching means provided as a signal transmission path between the main body side and the rotary cylinder to transfer the recording signal by the 180° switching means. a rotary transformer that transmits the obtained reproduction signal to the main body;
A serial transmission means for serially transmitting the switching timing signal of the 0° switching means from the main body side to the rotating cylinder, and an individual 180° switching signal corresponding to each set of magnetic heads on the rotating cylinder from the output signal of this serial transmission means. The invention is characterized by comprising a serial-to-parallel conversion means for creating the serial-to-parallel converter.

Operation As described above, the present invention uses the 180° switching means on the rotary cylinder to switch the two magnetic heads of each set of electromagnetic transducing means every 180° for recording or reproduction, so that the rotary cylinder side and the main body The transmission path for the recording signal or the reproduction signal to and from the magnetic head is only required by the number of sets of magnetic heads, each set consisting of two magnetic heads of the electromagnetic transducer. In addition, the switching timing signal for switching between the two porcelains of each set every 1800' is transmitted from the main body side to the rotating cylinder side through one transmission line by serial transmission means, and the electromagnetic conversion means is used by serial-parallel conversion means. It is used as a necessary 180' switching signal for each set.

Embodiment (1) The invention of claim 1 of the present application realizes a rotary cylinder type magnetic recording/reproducing device in which the number of digital transmission lines between the main body side and the rotary cylinder side is reduced, and the cylinder configuration is easy.

A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a block diagram showing the configuration of this embodiment, and FIG. 2 is a layout diagram showing the arrangement of a magnetic head, phototransistor, etc. on a rotating cylinder. In this embodiment, the effective tape winding angle is approximately I80, and the VRT uses four magnetic heads 8. 7. 8. 9 is arranged as shown in FIG.

Now, the input video signal applied from the input terminal O is given to the recording side signal processing section 1. The recording side signal processing unit 1 quantizes the input signal, performs shuffling, parity for error correction, addition of 5YNC, ID, etc., and modulation. During recording, the image signal is applied to the R E C180'SW unit 3, which is one of the 180° switching means on the rotary cylinder side, via one transmission path of the rotary transformer 2, and a synchronizing signal is also sent to the servo system control unit 14. is added. The servo·
The system controller 14 controls cylinders, capstans, etc. and the system of the VTR in the same manner as in conventional VTRs, and also generates a timing signal for switching the magnetic head 180' as shown in FIG. 4A. The signal is applied to an S/P converter 17, which is a serial-to-parallel converter, via an optical coupling unit 15, which is a transmission means. The optical coupling section 15 is composed of an LED 22 and a phototransistor 23 provided on the axis of a rotating cylinder 24 shown in FIG. 2(a). On the other hand, the rotating cylinder phase detection section 16 has an LED 25 on the main body side that is always lit and a phototransistor 26 on the rotating cylinder, as shown in FIG. 2(a). Each time the phototransistor 26 passes the position of the LED 25 due to the rotation of the rotating cylinder 24, a negative pulse such as waveform B in FIG. 4 is generated at the collector of the phototransistor 26.

Next, as shown in FIG. 3, the S/P converter 17 inverts the output signal of the shift register 32 of the number of stages corresponding to the number of sets of heads (in this embodiment, two stages) and its final stage, and transfers the output signal to the shift register 32. It is composed of an inverter 33 that provides. The input terminal 30 of the shift register 32 is a terminal for inputting a timing signal such as the waveform A shown in FIG. This is a terminal for inputting a negative pulse signal such as a clear signal as a clear signal. Also, the output terminal 34
．． 35, as shown in the waveforms Q1 and Q2 in Figure 4, there are 2 waves with the same cycle and 90° different phase with a duty of 50%.
Two signals are output.

This signal is a terminal to which a 180' switching signal for each set of magnetic heads is output, and each! 80° switching means REC180' SWWB2 PB18G
' Added to the SW section 13. During recording, a recording signal is applied to the REC180' SWWB2 from the recording side signal processing section 1 via the rotary transformer 2.
G"SWWB2 The recording signal is switched by a switching signal such as the waveform Q1 in FIG. The recording signal is configured to be alternately recorded every half revolution of the rotation.

Next, on the playback side, playback head amplifiers 11 and 12 are always connected to the magnetic heads 8 and 8, and the PB is 180°.
In the SW section 13, a waveform like Q2 in FIG. 4 is generated! 80°
The effective one is selected from among the respective output signals of the reproduction head amplifiers 11 and 12 by the switching signal and transmitted to the reproduction side signal processing section 20 via the rotary transformer 2. The reproduction side signal processing section 20 performs various processes such as 5YNC and ID detection, error correction, deshuffling, and modification, and outputs a reproduced video signal to the output terminal 21. Note that the power supply section 18 and the rectification section 19 are for supplying electric power necessary for constructing an active circuit within the rotating cylinder.

As described above, in this embodiment, the signal transmission path for recording or reproduction between the main body side and the rotating cylinder side is reduced to half the number of heads, so the rotary transformer for signal transmission can be configured in a small size, and the cylinder configuration is easy. It has the effect of becoming In order to avoid complicating the explanation, this embodiment has been explained using a single-channel recording VTR. The effect of the present invention increases as the quantity increases.

Although optical coupling is used in the configuration of the serial transmission means in this embodiment, a slip ring or a rotary transformer may be used instead.

(2) The purpose of the present invention is to make the cylinder configuration easier than in the first embodiment by making the serial-to-parallel conversion means of the first embodiment unnecessary. There is.

The present invention uses the serial transmission means of the first embodiment to transmit a signal in which the 180° switching timing information of each set of magnetic heads and the cylinder rotation phase information are superimposed from the main body to the rotating cylinder. The conversion means includes a separator that separates the signal given from the serial transmission into cylinder rotation phase information and 180° switching timing information of each set of magnetic heads, and an N-stage shift register corresponding to the number of N sets of magnetic heads. It is replaced with a serial-to-parallel conversion means consisting of. Then, the cylinder rotation phase information of the separator output signal is used as a clear input signal to the N-stage shift register, and the 18
The configuration is such that the 0° switching timing information is used as a clock input signal, and the inverted output signal of the final stage is used as the input signal of the first stage.

The more specific structure and operation will be explained below. Note that in the block diagram of FIG. 1, the rotary cylinder rotation phase detection section 18 is not necessary, but the other components are the same, and the explanation will be given based on FIG. 1. Cylinder rotation phase information is for each set of magnetic heads.
80' It is added to the optical coupling section 15, which is a serial transmission means, from the servo system control section 14 together with the switching timing information.

The optical coupling section 15 expands the width of the pulse for selecting the magnetic head 9 indicated by the broken line in the 180° switching timing report by four times based on the cylinder rotation phase information as shown in FIG. Transmitting to the side. In this way, you can obtain approximate cylinder rotational phase information for each set of magnetic heads! The 80° switching timing information is superimposed and transmitted to the rotating cylinder 24. This signal is applied to the serial-to-parallel conversion means shown in FIG. The means is composed of a separator and a two-shot shift register 44. The separator is a monostable multivibrator (M
・M) 41 and a delay circuit (DL) with a certain delay time
42 and a gate 43 to which these outputs are applied. The monostable multi-bi break 41 outputs a signal with a constant width according to the rising edge of an input signal, and its output pulse width is set to twice the 180° switching timing information pulse width Th. The delay circuit 42 is set to twice the delay time Δt of the monostable multivibrator 41. The output of the monostable multivibrator 41 is given to the shift register 44 as a shift signal, and the output of the gate circuit 43 is given as a clear signal. The shift register 44 is a 2-pit shift register corresponding to the number N of head sets (in this embodiment, 2 sets) of the rotary cylinder, like the shift register 33 of the first embodiment described above, and its output is REC180'. SWWB2 and P8180
' Provided to the SW section 13. The inverted output terminal of the final output stage is provided to the input terminal of the shift register 44.

Next, the operation of this serial-parallel conversion means will be explained with reference to FIG. When a signal such as waveform C in FIG. 6 is applied to the input terminal 40, the output shown in FIG. 6A is obtained from the monostable multivibrator 41. gate 43
When the monostable multivibrator output is low level and the output of the delay circuit 42 is high level, it outputs a low level as shown in waveform B in FIG. 6 to clear the shift register 44.

Since the inverted output terminal of the final stage of the shift register 44 is given as an input to the first stage, the output terminals 45 and 46 have the first
Similarly to the embodiment shown in FIG. 6, the waveform Ql.

A 180° switching signal such as Q2 for each set of magnetic heads is output.

As described above, according to this embodiment, each set of magnetic heads has 180
“By superimposing the approximate cylinder rotational phase on the switching timing information using pulse width modulation and serially transmitting it on one channel, it is possible to accurately detect each set of magnetic heads without having to install a rotational cylinder rotational phase detection section on the rotational cylinder. This has the effect that a 180° switching signal can be created and the cylinder configuration becomes easier.

Effects of the Invention As described above, according to the inventions of Claims 1 and 2 of the present application, the number of transmission paths between the main body side and the rotating cylinder side can be reduced, so that the cylinder structure is easy. This has the effect that the device can be realized. Moreover, the effect increases as the number of heads mounted on the rotating cylinder increases.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of this embodiment, Fig. 2(a) is a side view of the cylinder showing the arrangement of the magnetic head and the arrangement of phototransistors and light emitting diodes on the rotating cylinder in the first embodiment. (b) is a top view thereof, FIG. 3 is a concrete block diagram of the S/P converter 17 of the first embodiment, FIG. 4 is a waveform diagram for explaining the first embodiment, and FIG. 5 6 is a concrete block diagram of the serial-to-parallel conversion means of the second embodiment, and FIG. 6 is a waveform diagram for explaining the second embodiment. 1... Recording side signal processing section, 2...
Rotary transformer, 3...RE C18
0° SW section, 4, 5... Recording amplifier, 6
, 7... recording head, 8°9 playback head,
10...Tape, 11,12...Playback head amplifier, 13PB180' SW section, 14
... Servo system control section, 15 ...
- Optical coupling unit, 16...Rotating cylinder phase detection unit, 17...S/P conversion unit, 18...
... Power supply section, 19 ... Rectification section, 20
...Playback side signal processing section, 22.25...
・LEDl 23,2B...Phototransistor, 24...Rotating cylinder, 32°44
...Shift register, 41 ... Monostable multivibrator, 42 ... Delay circuit. Name of agent: Patent attorney Shigetaka Awano

Claims (2)

[Claims] (1) An electromagnetic transducer consisting of at least two sets of magnetic heads, each pair being a pair of two magnetic heads mounted symmetrically from the center of the rotating cylinder, and an electromagnetic converting means provided on the rotating cylinder. A 180° switching means for switching the two magnetic heads of each set every 180°, and a signal transmission path between the main body side and the rotary cylinder, which transmits the recording signal and the reproduction signal obtained by the 180° switching means to the main body. a rotary transformer, and serial transmission means for serially transmitting a switching timing signal of the 180° switching means from the main body side to the rotating cylinder;
A rotary cylinder type magnetic recording and reproducing apparatus comprising serial-to-parallel conversion means for creating individual 180° switching signals corresponding to each set of magnetic heads on the rotary cylinder from the output signal of the serial transmission means. (2) The serial transmission means includes 180 serial transmission means for each set of magnetic heads.
゜A signal in which switching timing information and cylinder rotational phase information are superimposed is transmitted from the main body side to the rotating cylinder, and the serial-to-parallel conversion means converts the cylinder rotational phase information and magnetism from the signal given from the serial transmission means. The N-stage shift register includes a separator that separates the 108° switching timing information of each set of heads and an N-stage shift register corresponding to the number N of sets of magnetic heads, and the N-stage shift register separates the cylinder rotation phase information obtained from the separator. Clear input signal, one for each set of magnetic heads obtained from the separator.
2. The rotating cylinder type magnetic recording and reproducing apparatus according to claim 1, wherein the 80° switching timing information is used as a clock input signal, and the inverted output signal of the final stage is used as the input signal of the first stage.