JPS61227247A - Video tape recording device - Google Patents

Abstract

PURPOSE:To know the information of the tape replacing operation beforehand by providing a detecting circuit to detect the detecting signal from the head for the detecting signal, a switch circuit, a switch control circuit and a forcible control circuit. CONSTITUTION:A detecting exclusive-use signal 3a which is already recorded on the tape by a signal head 7 for detection is detected by a detecting circuit 12, and the detecting output is sent to the forcible control circuit 13. The forcible control circuit 13 does not pass a reproducing/picture recording control 14 connected from an external operation reproducing switch 15 and a picture recording switch 16, connects forcibly a video signal change-over switch 11 connected to a head 9 for the video signal directly to a reproducing side 11a and simultaneously, a total erasing head change-over switch 10 is also changed over to a reproducing side 10a. Thus, the picture recording condition up to the present is changed over to the reproducing condition, a tape picture-recorded comment video signal 5 is reproduced, the contents of the comment are pictured on the camera monitor or a television screen and an operator can acknowledge the information.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a VTR, and particularly to a videotape recording device (VTR) K that can automatically switch playback/recording/mode operations based on signals recorded on the tape. related.

[Conventional technology]

Conventionally, the playback/recording mode switch of a VTR was operated by the operator himself by pressing each switch provided on the VTR set.When in playback mode, he pressed the playback switch, and when in recording mode, he pressed the record switch and playback switch. It works by pressing both or only the recording switch.

[Problem that the invention seeks to solve]

Since the playback/recording operations in conventional VTRs are performed by the operator through an external switch, there is a drawback that when recording on the fF, the remaining amount of tape must be constantly monitored while recording. Considering the work involved in replacing tapes, etc., it is very difficult to know in advance when a replacement tape will be needed, so there is a drawback that the desired content may be missed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a VTR that eliminates these drawbacks and allows information on tape switching operations to be known in advance.

[Means for solving problems]

The configuration of the VTR of the present invention includes a detection signal head for extracting a detection signal from a comment video signal of a pre-recorded videotape and a detection signal for detecting the start and end of the comment, and a detection circuit that detects a detection signal; a switch circuit that switches the video head and erase head between recording mode and playback mode; a switch control circuit that switches this switch circuit according to an operation switch; and a forced control circuit for temporarily switching the switch circuit to a playback mode even if the switch circuit is in a recording mode when the switch circuit outputs the video tape, so that comment information on the videotape can be monitored. .

According to the configuration of the present invention, when a detection signal is detected even in recording mode, the VTR itself is automatically switched to playback mode, comment information such as TA tape amount is monitored, and a comment screen is displayed. After being projected for a certain period of time, the camera can automatically return to the original recording mode when a second detection signal is received.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
FIG. 3 is a plan view of an example of an image reproduced according to the illustrated embodiment, and FIG. 3 is a signal arrangement diagram on the tape of this embodiment. In the figure,
l is a normal recording/playback control signal, 2 is a tape recording source control signal, Laassb is a start and stop tape recording detection signal, 4 is a normal recording/playback video signal, and 5 is a tape recording method comment video signal. . Further, 6 is an all erase head, 7 is a head for control/detection signals, 8 is a head for control signals, 9 is a head for video signals, 10 is an all erase head signal changeover switch, 10a is a body symbol during reproduction, 10b indicates the position at the time of recording. In addition, 11 is a video head signal changeover switch, 11m is the positive position during playback, and 11b is the positive position during recording.
Indicates the

Reference numeral 12 indicates a signal detection circuit for detecting that the tape has been imaged, 13 indicates a compulsory control circuit for all erase head signals and video head signal changeover switch, 14 indicates a playback/recording control circuit, 15 indicates a playback switch, 16 indicates a recording switch, and 17 indicates a video switch. Signal regeneration circuit.

18 is a video signal recording circuit, 19 is a control signal generation circuit, and 20 is an index and servo circuit. Further, 23 is a video signal head switching forced control signal line, 24 is a playback/recording control circuit 14 forced control tQ2, 25 is a playback/recording control output signal line, and 26 is a control signal line.

This embodiment operates as follows.

A detection circuit 12 detects a detection exclusive signal 3a already recorded on the tape by a detection signal head 7, and sends this detection output to a forced control circuit 13. This forced control circuit 3 is an externally operated regeneration switch 15.
, the video signal changeover switch 11 directly connected to the video signal head 9 is forcibly connected to the playback side 11a without passing through the conventionally operated playback/recording control 14 connected from the recording switch 16, and at the same time, the all-erase head changeover switch is 10 is also switched to the reproduction side 103. Therefore, the current recording state is switched to the playback state, the tape recording method comment video signal 5 is played back, and the comment content is displayed on the camera monitor or television screen so that the operator can recognize the information.

Next, when the comment that has been projected for a certain period of time is finished, a detection signal 3b is input which can be distinguished from the detection signal 33 by having a different frequency and a different degree of υ modulation, and is similarly detected by the detection circuit 12. Now, the forced control circuit 13
through the video signal changeover switch 11 and all erase changeover switch 10 to the previous recording state side (llb, 10b).
). Therefore, the VTR automatically returns to the previous mode, and during this time the operator can see the image receiving screen and know the comment information.

FIGS. 2 and 3 are diagrams showing the positional relationship between the image displayed on the monitor or television screen and the tape when such an operation is performed.

First, at time T1, a normal recording screen (FIG. 2) appears due to the video signal 4 (FIG. 3) controlled by the normal recording/playback control signal 1. Next time T! So,
Since it is controlled by the recording method control signal 2 and there is a recording method detection signal 3a at the start, nothing appears on the screen. At time T, the comment video signal 5 (FIG. 3) is supplied, so that a comment such as "5 minutes remaining on the tape!" (FIG. 2) appears on the screen.

At the next time T4, nothing appears on the screen again because of the stop detection signal 3b, but the end of this detection signal 3b is detected and the normal recording screen (FIG. 2) returns at time Tb.

〔Effect of the invention〕

As explained above, according to the present invention, during VTR recording, you can check the monitor or TV screen in advance to record the VTR.
Since it is possible to convey various information to the operator, such as the setting status of the machine, it is expected that operations and advance preparations will proceed smoothly.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG.
The figure is a front view of the image side to be reproduced according to this embodiment and a signal arrangement diagram on the tape corresponding to this image example.
...Tape recording control circuit s 3as
3b... Signal for detecting tape recording (start and stop), 4... Recording/playback video signal, 5... Song tape recorded comment video signal, 6... All song erasing head , 7... Control self-detection signal head, 8... Control signal head,
9...Video signal head, lO...
All erase head signal changeover switch, 11...Video head signal changeover switch, 12...Tape recording method, detection signal detection circuit, 13...All erase head signal and Compulsory control of video head signal changeover switch jl, 14... Playback, recording control circuit, 15... Playback switch, 16...
. . . Recording switch, 17 . . . Video signal reproducing circuit, 18 . . . Video signal recording circuit, 19.
...Control signal generation circuit, 20...
・Index, servo circuit, 23... Video signal head switching forced control signal line, 24...
····reproduction. A forced control signal line to the recording control circuit, 25...playback and recording control output signal line, and 26...control signal line. 1. ′

Claims (1)

[Claims] A detection signal head that extracts a detection signal from a comment video signal of a pre-recorded videotape and a detection signal that detects the start and end of this comment, and a detection circuit that detects the detection signal from this detection signal head. a switch circuit that switches the video head and erase head between recording mode and playback mode; a switch control circuit that switches the switch circuit according to an operation switch; and when the detection circuit outputs a detection signal, the switch circuit is in the recording mode. 1. A videotape recording device comprising: a forced control circuit for temporarily switching this switch circuit to a playback mode, if any, so that comment information on the videotape can be monitored.