JPS62219306A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To vary a recording current by a recording current variable circuit while confirming a head output level of a PLAY head by a meter at the time of recording, so as to adjust it to an optimum value, by providing a circuit for detecting a reproducing output level by a head which can execute reproduction simultaneously at the time of recording, and the meter for displaying said output level. CONSTITUTION:At the time of recording, a video signal 4 is inputted from a terminal, modulated by a recording circuit 3, a recording current is controlled by a recording current variable circuit 5, and said signal passes through a switch 2 and recorded by an R/P head 1. Also, a signal level of the video input signal 4 is detected by a detector 12, and displayed by a meter 14 by switching a switch 13. A signal which has been reproduced simultaneously by a PLAY head 6 passes through a head amplifier 7, its output level is detected by a detector 8, and said signal passes through the switches 11, 13, and can be displayed by the meter 14. At the time of reproduction, a reproducing output level of the R/P head 1 is detected and the meter 14 is used as a tracking meter.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates to magnetic recording and reproducing apparatus such as broadcasting stations and professional video tape recorders.

Hereinafter, this device will be abbreviated as VTR.

Conventional technology An example of a conventional VTR is shown in the block diagram of FIG.

1 is an R/P head for recording and reproducing signals. Reference numeral 2 denotes a switch for switching between recording and reproduction, which connects the R/P head 1 to a recording circuit (described later) during recording, and connects it to a head amplifier (described later) during reproduction. 3 is a recording circuit which modulates the video input signal 4 into a signal that can be recorded by the R/P head 1; Reference numeral 5 denotes a recording radio wave variable circuit, which controls the recording current flowing from the recording circuit 3 to the R/P head 1. 6 is P for reproducing the signal
With the LAY head, simultaneous reproduction is possible when recording with the R/P head 1. 7 is a head amplifier of the PLAY head 6. 9 is a head amplifier of the R/P head 1. Reference numeral 15 denotes a switch for selecting and switching between the R/P head 1 and the PLAY head e during reproduction. 12 is a detector for detecting video input level 4;

A detector 1o is used to faithfully follow the recording track on the tape during reproduction and detects the reproduction output head of the R/P head 1. 16 is a switch for switching between a video input signal to be recorded and a signal reproduced by the R/P head 1 or the PLAY head 6; 13 is detector 1
This is a switch that switches between the video input level detected by the detector 12 and the playback output level detected by the meter 14.
to display the level. 17 is a reproducing circuit that demodulates the modulated signal, and 18 is a video output.

In the conventional VTR configured as described above, the input video signal level is obtained at the meter 14 during immediate recording, and the input video signal or the video signal during simultaneous playback is obtained at the video output 18. Also, during playback, the meter 14 is used as a tracking meter, and the video output 18 is connected to the R/P.
A video signal during playback by head 1 or PLAY head 6 is obtained.

Problems to be Solved by the Invention However, with the above configuration, it is difficult to adjust the recording current to the optimum recording current that makes the head amplifier output peak. However, there was a problem in that adjustment was not possible without the use of various jig threads.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a VTR that can easily adjust the recording current to an optimum value without requiring any special jig.

Means for Solving the Problems The present invention is a VTR equipped with a circuit for detecting the reproduction output level of a head capable of simultaneous reproduction at the time of recording, and a meter for displaying this output level.

Operation:-1 With the above-described configuration, the present invention can adjust the recording current to the optimum while checking the simultaneous reproduction output level with a meter during recording.

Embodiment FIG. 1 shows a block diagram of a VTR in an embodiment of the present invention. In FIG. 1, 1 is an R/↑ head for recording and reproducing signals. 2 is a switch for switching recording and reproducing. During recording, the R/P head 1 is connected to a recording circuit described later, and during playback, it is connected to a head amplifier described later. 3 is a recording circuit, and the video input signal No. 4 can be recorded by the R/P head 1. 6 is a recording current variable circuit, which controls the recording current flowing from the recording circuit 3 to the R/P head 1. 6 is a PLAY head that reproduces the signal. Simultaneous playback is possible. 7 is a head amplifier of the PLAY head 6. 8 is a detector that detects the output level of the head amplifier 7. 9
is the head amplifier of R/P head 1. 1o is a detector that detects the output level of the head amplifier 9. 11 and 13 are changeover switches, and the switch 11 switches the detector 1o.
and the output of detector 8, and switch 13 switches the output of detector 10.
Alternatively, the output of the detector 8 and the output of the detector 12 are switched. This is a meter that displays the output of the detectors 8, 10, and 12. A block diagram of the reproduction system from head amplifier 8.9 onwards will be omitted.

The operation of the VTR of this embodiment configured as described above will be explained below.

During recording, a video signal 4 enters from the terminal, is modulated by the recording circuit 3, and the recording current is controlled by the recording current variable circuit 6.
It is recorded by R/P head 1 via switch 2. Further, the signal level of the video input signal 4 is detected by a detector 12,
By switching the switch 13, it is displayed on the meter 14. Further, the signals simultaneously reproduced by the PLAY head 6 pass through the head amplifier 7, the output level of which is detected by the detector 8, passes through the switches 11 and 13, and can be displayed on the meter 14. During reproduction, the reproduction output level of the R/P head 1 is detected and the meter 14 is used as a tracking meter.

As described above, according to this embodiment, by providing the playback head output detector 8 and the changeover switch 11, the recording current variable circuit 6 can be used while checking the head output level of the PLAY head 6 with the meter 14 during recording. The recording current can be changed and adjusted to the optimum value.

As described in detail, according to the present invention, the optimum recording current can be easily adjusted without the need for a special jig, and the effect is significant.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a VTR according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. 1... R/P head, 2... Selector switch, 3... Recording circuit, 4... Video input, 6... Recording Variable current circuit, 6...
・PLAY head, 7...Head amplifier, 8.
...Detector, 9...Head amplifier, 10
...Detector, 11...Switch switch,
12...detector, 13...changeover switch, 14...meter, 16...changeover switch, 16...changeover switch, 17・・・・・・
...Reproduction circuit, 18...Video output. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
figure

Claims (1)

[Claims] Equipped with a head that can simultaneously reproduce data during recording, a circuit that detects the output level of the FM signal reproduced by this head, a meter that displays this output level, and a recording circuit that can change the recording current of the recording head. A magnetic recording/reproducing device characterized by: