JPS63206075A - Magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To realize a PinP function with a low cost by using one digital memory system for compressing a sub-video signal corresponding to the sub-screen at the time of recording and using it for decreasing the noise bar of a special reproduction at the time of reproducing. CONSTITUTION:Into input terminals 1 and 2, a sub-video signal and a sound signal are respectively inputted from a video source suck as a video camera and a VTR. A desired broadcasting channel is received at an antenna 3 and a receiving part 9 and a main video signal and the sound signal are sent to switches 10, 11, 15 and 16. The sub-video signal from a switch 10 is supplied through a switch 12 to an A/D converter 20 and written to a memory 21. The video signal read from the memory 21 is supplied to an adding circuit 23 as the sub-video signal compressed on the time axis. Into an adding circuit 23, the main video signal is supplied from the switch 11, the sub-video signal compressed to a part of the main video signal is inserted and a synthesizing video signal is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing apparatus which uses a nuclear digital memory system to reduce noise bars on a reproduction screen during special reproduction.

[Conventional technology]

During special playback such as slow, still, and search,
Noise bars appear on the playback screen because the scanning locus of the video head does not match the tracks on the magnetic tape.

Various methods have been proposed to reduce noise bars, one of which is known to use a digital memory system.

This extracts the playback video signal when tracking is the best during special playback, digitizes it and stores it in memory, and reads the video signal from this memory during periods when tracking is poor and outputs the playback signal. be.

According to this, if the playback video signal from the video head is used as the playback output as it is, the amplitude of the playback video signal will be sufficiently small or even zero in areas where tracking is poor, and noise bars will appear on the playback screen in these areas. However, by delaying the playback video signal when tracking is good in a digital memory system and using it during periods when the amplitude is sufficiently small, a playback output with almost constant amplitude can be obtained, and noise bars can be significantly reduced. .

[Problem that the invention seeks to solve]

By the way, according to the above-mentioned conventional technology, the digital memory system is used only for special playback and is expensive, while its use is limited to very busy people. Both are used to solve problems that can be solved using other methods. This makes it very expensive in terms of cost.

On the other hand, in recent years, digital memory systems have attracted increasing attention due to the multifunctionality of magnetic recording and reproducing devices.
A so-called PinP function is attracting attention, in which a sub-screen is compressed and displayed in a part of the main screen. However, in order to add such a function, it is necessary to add an expensive digital memory system, and a PinPin
Adding additional functionality would further increase costs.

The purpose of the present invention is to solve the above problems, suppress the increase in cost, and make it possible to realize multi-function magnetic recording and reproducing bag R.
is to provide.

[Means for solving problems]

In order to achieve the above object, the present invention uses one digital memory system to compress a sub-video signal for a sub-screen inserted into the main screen during recording, and to reduce noise bars during special playback during recording. It should be used for this purpose.

[Effect]

A single digital mesori system is used for recording and playback,
Moreover, they are designed to perform different functions in each use. Therefore, the use of digital memory system can be minimized, multifunctionality can be achieved, and cost reduction can be achieved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The figure is a block diagram showing an embodiment of a magnetic recording and reproducing device according to the present invention, in which 1 and 2 are input terminals, 3 is an antenna,
4.5 is an output terminal, 6 is a video head, 7 and 8 are audio heads, 9 is a receiving section, 10 to 19 are switches, 20
is an A/D converter, 21 is a memory, 22 is a D/A converter, 23 is an addition circuit, 24 is a recording processing circuit, 25 is an amplifier, 26 is a reproduction processing circuit, 27 is an output amplifier, 28
, 29 is a recording processing circuit, 30 is an output amplifier, 31,
32 is a reproduction processing circuit.

In the same figure, first, the operation during recording will be explained.

Input terminal 1.2 is connected to a video source such as a video camera or other magnetic recording/reproducing device, from which a video signal is input to input terminal 1, and an audio signal is input to input terminal 2. This video signal is supplied to the switch l0f) A side and the switch 110B side, and the audio signal is supplied to the switch 150
It is supplied to the A side of the B side switch 16. On the other hand, a desired broadcast channel is received by the antenna 3 and the receiver 9, the video signal of the channel is supplied to the B side of the switch 10 and the A side of the switch 11, and the audio signal is supplied to the switch 15.
and the B side of the switch 16. Switches 10 and 11 connect the video signal from the input terminal 1 to the receiving section 9.
This is used to set the main and sub-relationships of video signals from.

The video signal from the receiving section 9 is the main video signal, and the input terminal 1
When using the video signal from the auxiliary video signal as the sub video signal, the switch 10ik is closed to the A side and the switch 11 is closed to the B side. If the main and sub-relationships are to be reversed, the switches 10 and 11 may be closed to the opposite side. Further, the audio signal for the main video signal is selected by switch 15 as the main audio signal, and the audio signal for the sub video signal is selected by switch 16 as the sub audio signal. In the figure, receiving section 1
The main signal is received from the input terminals 1 and 2, and the secondary signals are input from input terminals 1 and 2.

The sub video signal from the switch 10 is supplied to the A/D converter 20 via the switch 12, which is closed to the R side during recording, and is converted into a digital signal.

This digital signal is written into the memory 21 and read out at a predetermined timing and at a faster speed than the writing speed. The read digital signal is sent to the D/A converter 2.
2, the signal is converted into an analog signal and supplied to the adder circuit 23 as a sub-video signal compressed on the time axis. The adder circuit 23 is supplied with the main video signal from the switch 11, and the compressed sub video signal is inserted into a part of the main video signal to obtain a composite video signal of the two video signals.

This composite video signal is subjected to well-known processing such as FM modulation of the luminance signal and low frequency conversion of the chroma signal in the recording processing circuit 24, and then supplied to the video head 6 and recorded on a magnetic tape (not shown). Ru. Further, the composite video signal passes through the switch 13 which is closed to the R side during recording, is amplified by the amplifier 25, and is further amplified by the switch 14 which is closed to the N side during recording.
The signal is supplied to the output amplifier 27 via the output terminal 4, where it is amplified, and then supplied via the output terminal 4 to a monitor (not shown). This monitor displays a composite screen in which a sub-screen based on the sub-video signal is compressed and fitted into a part of the main screen based on the main video signal.

On the other hand, the main audio signal from the switch 15 is subjected to processing such as FM modulation in the recording processing circuit 28, and then processed by the audio head 7.
recorded. This audio head 7 is a rotating head mounted on the same rotating cylinder as the video head 6, and the main audio signal is recorded on a track parallel to the video track on the magnetic tape.

Further, the sub-audio signal from the switch 16 is transmitted to the recording processing circuit 2.
9, the signal is processed and supplied to the audio head 8, where it is recorded on a magnetic tape. This audio head 8 is a fixed head,
A sub-audio signal is recorded on a longitudinal track (linear track) K of the magnetic tape.

Further, either the main audio signal or the sub audio signal is selected by a switch 17, passes through a switch 18 which is closed to the R side during recording, is amplified by an output amplifier 30, and is supplied from an output terminal 5 to a monitor. Thereby, on the monitor, by operating the switch 17, either the main or sub audio can be heard.

Next, during playback, switch 12, 13, 1
8 is switched to the P side. The composite video signal reproduced by the video head 6 is subjected to processing such as amplification, FM demodulation of the luminance signal, and high frequency conversion of the chroma signal in the reproduction processing circuit 26, and then is amplified by the amplifier 25 via the switch 13. The switch 14 is closed to the N side during normal playback, and is closed to the B side during special playback such as slow, still, and search.

Therefore, during normal playback, the composite video signal is switched to switch 1.
4 and is amplified by the output amplifier 27, the output terminal 4
is supplied to the monitor from During special playback, the composite video signal is converted into a digital signal by the A/D converter 20, a portion with good tracking is extracted and stored in the memory 21, and this is repeatedly read out a predetermined number of times. This read digital signal is converted into an analog signal by the D/A converter 22, passes through the switch 14, is amplified by the output amplifier 27, and is then supplied from the output terminal 4 to the monitor. This results in a playback screen with fewer noise bars on the monitor.

On the other hand, the main audio signal reproduced by the audio head 7 is subjected to processing such as amplification and FM demodulation in the reproduction processing circuit 31, and then is supplied to the A side of the switch 19. Further, the sub-audio signal reproduced by the audio head 8 is subjected to processing such as amplification in the reproduction processing circuit 32, and then supplied to the B side of the switch 19. Either one of these main and sub audio signals is switched to the switch 19.
is selected by the output amplifier 3 and passes through the switch 18.
After being amplified by 0, the signal is supplied to the monitor from the output terminal 5. Therefore, by operating the switch 19, either the main or sub audio can be heard on the monitor.

Note that the above is the A/D converter 20. Memory 21.

The so-called PIN system uses a digital memory system consisting of a D/A converter 22 for recording and fits a sub-screen into the main screen.
Although the P function is activated, if you want to record and play back one of the video signals and display only that screen on the monitor, close the switch 12 to the P side and the switch 14 to the N side during recording. The digital memory system may be rendered inactive. In this case, if the switches 15 and 16 are for the same audio signal or stereo signal multiplexed signal, the right and left channel signals can be selected respectively, and the audio head can record and reproduce two channels. .

〔Effect of the invention〕

As explained above, according to the present invention, the digital memory system conventionally used for special playback can be used also for recording, and can be provided with new functions.
Multifunctionality can be achieved without complicating the circuit configuration or increasing costs.

[Brief explanation of the drawing]

The figure is a block diagram showing an embodiment of a magnetic recording/reproducing apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1... Video signal input terminal, 4... Video signal output terminal, 6... Video head, 9... Receiving section, 10,
11, 13, 14...switch, 20...A/
D converter, 21... Memo IJ, 22... D/A converter, 2
3... Addition circuit, 24... Recording processing circuit, 2
6... Reproduction processing circuit.

Claims (1)

[Claims] 1. Main and sub setting means for setting one of the two video signals as the main video signal and the other as the sub video signal, and a digital memory system that compresses the sub video signal during recording and supplies a reproduced video signal during special playback. , an adder circuit that inserts and synthesizes the sub video signal from the digital memory system into a part of the main video signal, a recording processing circuit that processes the composite video signal from the adder circuit for recording, and the recording processing circuit. A video head that records the output video signal of the circuit on a magnetic tape, a playback processing circuit that processes the video signal played back by the video head, and a playback processing circuit that selects the output video signal of the playback processing circuit during normal playback and selects the output video signal of the playback processing circuit during special playback. A magnetic recording/reproducing apparatus comprising: selecting means for selecting a reproduced video signal from the digital memory system.