JPH01188184A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain the postrecording of a title by recording a character signal to a fly-back line erasing block, overlapping this character signal to a reproducing video signal and recording the character information of the title, etc. CONSTITUTION:The character signal to be based on data is time base-extended in a time base-extending circuit 22 during a vertical fly-back line erasing period, namely, between a vertical synchronizing pulse and the starting point of a video signal at a recordable degree. At a reproducing time, for the character signal, which is time base-compressed by a time base compressing circuit 25, a position matching with the reproducing video signal is executed in a position matching circuit 26. The position-matched character signal is added to the reproducing video signal in a character inserting circuit 27 and overlapped. When it is stopped adding this character signal to this reproducing video signal, the turning-on and off of title display can be executed. Thus, the postrecording of the title can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Field of Industrial Application) The present invention relates to a magnetic recording/reproducing device, and more particularly to a magnetic recording/reproducing device capable of recording and reproducing character information such as a title.

(Prior Art) Conventionally, when recording character information such as a title on a video tape recorder (VTR), a character signal based on this character information is superimposed on a video signal, and this superimposed signal is recorded in the same way as in general recording. 2. Description of the Related Art Magnetic recording and reproducing apparatuses that record and reproduce data using a method are known. This type of magnetic recording and reproducing apparatus consists of two systems, a recording system 1 and a reproducing system 2, as shown in FIG. First, during recording, character information input from the character input end is converted into data in the character data creation circuit 3, and a character signal based on this data is superimposed on the video signal input from the video signal end in the character insertion circuit 4. be done. The video signal on which this character signal is superimposed (hereinafter referred to as video signal) is separated into a luminance signal (Y signal) and a color signal (C signal) in the Y/C separation circuit 5, of which the Y signal is subjected to luminance signal processing. The signal is processed in the circuit 6, and then the VH3 signal is processed in the modulation circuit 7.
For system VTR, 3.4MH2 to 4.4MH
7 is FM modulated. On the other hand, the C signal is subjected to signal processing in a color signal processing circuit 8, and then converted to a low frequency signal in a frequency conversion circuit 9. The Y signal and C signal are mixed, amplified by a recording amplifier 10, and further sent to a video head 11 for video signals to be recorded on a magnetic tape. During playback, the video signal taken out from the video head 11 is amplified by a playback amplifier 12, and subjected to equalizer processing and AGC processing in an equalizer circuit 13 and an AGC circuit 14. Among the processed signals, the Y signal is demodulated in the demodulation circuit 15, and the C signal is extracted in the LPF1B. This low-frequency component signal is applied to any 3.581V signal in the color signal processing circuit 17.
Returned to IH2. Finally, the Y signal and C signal are mixed in a mixer 18 and outputted from the video signal output terminal as a video signal with character information inserted.

In a magnetic recording/reproducing apparatus having such a circuit configuration, a title must be inserted at the same time as recording, and it is not possible to insert a title (dub-recording) while viewing a reproduced image. Another disadvantage is that a title that has been recorded twice will always be played back.

FIG. 5 shows an example of a cylinder of a conventional magnetic recording/reproducing apparatus, and an A82 video head is sufficient to achieve the above-mentioned purpose of character insertion.

(Problems to be Solved by the Invention) In conventional magnetic recording and reproducing devices, the recording of a title must be performed simultaneously with the recording of a video signal, and a previously recorded title is always reproduced. have.

Therefore, the present invention was made in view of the above problems.
Titles can be recorded without deteriorating the reproduced image, and titles already recorded on magnetic tape can be displayed on the screen with 0N1.
It is an object of the present invention to provide a magnetic recording/reproducing device which can perform 0FF and can also perform post-recording of a title while viewing a reproduced image, that is, post-recording.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a character data creation circuit that converts character information such as a title into data, and a character signal based on this data that can be recorded in a vertical blanking interval. a time axis expansion circuit that expands the time axis; a recording position detection circuit that detects a predetermined position within the vertical blanking interval at which the time axis expanded character signal is to be recorded; A video head for video signals that records and plays back a character signal whose time axis has been expanded is a video head for characters with a reverse azimuth, and a time axis compression circuit that compresses the character signal extracted by the video head for characters. , a positioning circuit that matches the synchronization position in the time-axis compressed character signal with a synchronization position in the reproduced video signal, and a character insertion circuit that superimposes the aligned character signal on the reproduced video signal. It is composed of

(Function) A character signal is recorded in the blanking interval, and character information such as a title is recorded by superimposing this character signal on the reproduced video signal.
You can display the title on the screen in 0N10FF, and you can also dubbing the title.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3. FIG. 1 shows a block diagram of an embodiment of the magnetic recording and reproducing apparatus according to the present invention, in which 21 is a character data creation circuit that converts character information such as a title into data, and 22 is a character data creation circuit that converts character information such as a title into data. A time axis expansion circuit 23 extends the time axis to the extent that it can be recorded in the vertical blanking interval, and 23 is a recording position detection circuit that detects a predetermined position within the vertical blanking interval at which this time axis expanded character signal is to be recorded. A circuit 24 is a character video head 24 whose azimuth is opposite to that of the video signal video head 11 and is used to record and reproduce the time-axis expanded character signal at the detected recording position. 26 is a positioning circuit that matches the synchronization position in the time-base compressed character signal with the synchronization position in the reproduced video signal; 27 is a position adjustment circuit for time-base compression of the character signal extracted in . 28 is a cylinder servo circuit, 29 is a modulator, 30 is a recording amplifier, 31 is a reproduction amplifier, 32 is a pie path filter (HPF), 33 is determined by a demodulator.

Next, the operation of this embodiment will be explained based on FIGS. 1 to 3. First, at the time of recording, character information such as a title input from a character input terminal is converted into data by a character data creation circuit 21, as shown in FIG. The character signal based on this data is processed by the time axis expansion circuit 22 during the vertical blanking period, that is, between the vertical synchronizing pulse and the start point of the video signal (under JX, the overlapping recording period m and ), the time axis is expanded to the extent that it can be recorded.

Here, time axis extension refers to converting a signal of a portion spanning time S into a signal spanning 25 degrees, for example. Memory is used as a means for this time axis expansion.

For example, write a signal to memory at a certain frequency f, 172
If the signal is read out at the frequency f, a signal whose time axis is doubled can be obtained. The time-axis expanded character signal is input from the cylinder servo circuit 28 to the recording position detection circuit 23, which serves as a video switch that operates based on video head position information. Therefore, the character signal whose time axis has been expanded is subjected to signal processing so that it fits within the above-mentioned overlapping recording period. The character signal output from this recording position detection circuit 23 is
The modulator 29 modulates the frequency (V
In the case of H3 system VTR, the frequency of the carrier wave is 6M82~7
The signal is FM-modulated to MH2 (appropriately), passes through a recording amplifier 30, and is superimposedly recorded by a character video head 24 running on the magnetic tape later than the video signal video head 11. In this case, the character video head 24 needs to be in opposite azimuth to the video signal video head 11 running on the same video track.

This is to prevent the already recorded video signal from being erased by overlapping recording of the character signal.

Next, during playback, the signal extracted by the character video head 24 passes through the playback amplifier 31 to the HPF 32.
Separated at The character signal obtained in this manner is demodulated by a demodulator 33. This character signal is compressed in the time axis to the original time axis in the time axis compression circuit 25. Here, time axis compression refers to, for example, converting a signal of a portion spanning time S into a signal spanning 1/2S. As one means for this time axis compression, a memory is used as in the case of time axis expansion described above. For example, if a signal is stored in a memory at a certain frequency f and then read out at a frequency of 2f, a signal whose time axis is compressed to 172 can be obtained. The time-base compressed character signal is aligned with the reproduced video signal in the alignment circuit 26. This is done, for example, by matching the horizontal synchronization position in the video signal with the horizontal synchronization position in the character signal. If this is not done, the title on the screen will be shifted, the title will not be located at the desired position, or the characters will be misaligned.

The aligned character signal is added to the reproduced video signal of the reproduced video signal in the character insertion circuit 27 and superimposed thereon. Further, by stopping adding this character signal to this reproduced video signal, it is possible to turn ON/OFF the title display.

FIG. 2 shows an example of a cylinder used in the magnetic recording/reproducing apparatus shown in FIG. (+), b: Azimuth (-)) are video heads for video signals (A: Azimuth (+)) that are mounted facing each other at 180 degrees.
, B: If they are on the same track with respect to azimuth (-)), they may be located at any position where Q'<θ<180°. Additionally, FIG. 3 shows the positional relationship between the switching point of the magnetic recording/reproducing device and the vertical synchronizing pulse of the video signal.

According to this embodiment, a new video head for characters is added in addition to the conventional video head for video signals, but it can also be used as a special playback head, or it can be used as a head for special playback. In some cases, it can also be used as a video head.

[Effects of the Invention] As described above, according to the magnetic recording and reproducing apparatus of the present invention,
Titles can be recorded without deteriorating the reproduced image, and titles already recorded on magnetic tape can be displayed on the screen with 0N1.
0FF, and it is also possible to post-record the title while viewing the reproduced image, that is, to perform post-recording.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the magnetic recording/reproducing device according to the present invention, FIG. 2 is a diagram showing an embodiment of a cylinder used in the device of FIG. 1, and FIG. FIG. 4 is a block diagram of a conventional magnetic recording/reproducing apparatus, and FIG. 5 is an explanatory diagram of a cylinder used in the conventional magnetic recording/reproducing apparatus. 21...Character data creation circuit 22...Time axis expansion circuit 23...Recording signal detection circuit 24...Character signal video head 25...Time axis compression circuit 26...Positioning circuit 27. ...Character insertion circuit agent Patent attorney Nori Chika Ken Yudo Uji HiroshiFigure 5

Claims (1)

[Claims] A character data creation circuit that converts character information such as a title into data, a time axis expansion circuit that expands the time axis to the extent that a character signal based on this data can be recorded in the vertical blanking interval, and this time axis expanded character signal. a recording position detection circuit for detecting a predetermined position within the vertical blanking interval at which the character signal is to be recorded; and a video signal video head for recording and reproducing the time-axis expanded character signal at the detected recording position. A character video head with reverse azimuth, a time axis compression circuit that compresses the character signal extracted by this character video head, and a synchronization position in this time axis compressed character signal and a reproduced video signal. 1. A magnetic recording and reproducing apparatus comprising: a positioning circuit that matches the synchronization position of the character signal; and a character insertion circuit that superimposes the aligned character signal on a reproduced video signal.