JPS63255891A - Vertical interval time code recording device - Google Patents

Abstract

PURPOSE:To improve the reliability of a VITC at the time of reproduction by inserting a vertical interval time code VITC at a prescribed horizontal period in the vertical blanking period of both a luminance signal and chrominance components and recording it into a magnetic tape. CONSTITUTION:The titled device is provided with a VITC generating circuit 3 to generate a VITC, a first VITC inserting circuit 4 to insert the output of the VITC generating circuit 3 at the prescribed horizontal period of the vertical blanking period of a luminance signal and a second VITC inserting circuit 5 to insert the output of the VITC generating circuit 3 at the prescribed horizontal period of the vertical blanking period of the chrominance components; and the output of the first VITC inserting circuit 4 and the output of the second VITC inserting circuit 5 are recorded to separate tracks. Thus, the VITC is inserted into the luminance signal only and recorded into the magnetic tape, and compared with the fact that the number of the VITC read is increased, and the reliability of the VITC read to a desired frame can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a recording device for a vertical interval time code (hereinafter referred to as VITC) inserted into a vertical blanking period of a video signal as tape position information in video tape editing or the like.

2. Description of the Related Art In editing a VTR, a time code signal has been conventionally recorded on a tape as tape position information in order to position the editing tape. This time code signal includes a longitudinal time code (hereinafter referred to as LTC) that is recorded in the longitudinal direction of the video tape, and a VITC that is inserted and recorded in the vertical blanking period of the video signal.
There is. VITC has the advantage that it can be read even during still playback or slow motion playback.

As shown in FIG. 4, VITC is a 90-bit data code format and is inserted into a predetermined horizontal period within the vertical blanking period of each field. As shown in Figure 4, VITC is 1 minute 9 seconds.

It indicates the frame number and also has user bits as free bits for users. The last 8 bits are filled with a periodic redundancy check code (CR) for error checking.
C code) is added.

This VITC is inserted into a plurality of horizontal periods, for example, 12H and 14H, in order to suppress dropouts and the effects of noise bands during steals.

By the way, there is a component recording type VTR in which a luminance signal and a chrominance signal are separated and recorded on separate tracks instead of recording the video signal on one track per field. Compared to the conventional FM direct method and low frequency conversion subcarrier method, this component recording method has a
/N ratio can be improved.

In the conventional component recording type VTR mentioned above, V
ITC was inserted and recorded only in the luminance signal.

FIG. 3 is a block diagram of a conventional VITC recording device.

2Q is an input terminal into which a luminance signal is input, 21 is an input terminal into which a color signal is input, and 23 is a VIT which generates VITC.
C generation circuit, 22 is a VITC insertion circuit that inserts VITC generated from the VITC generation circuit 23 into the horizontal periods of 12H and 14H of the vertical blanking period of the luminance signal input from the input terminal 20, and 24.25 is an output terminal. .

- The operation of the conventional VITC recording apparatus configured as described above will be explained below.

The luminance signal input from the input terminal 2o is input to the VITC insertion circuit 22, and the 12H of the vertical blanking period is input to the VITC insertion circuit 22.
VITC generated by the VITC generation circuit 23 is inserted into the horizontal period of 14H and outputted to the output terminal 24.

The color signal input through the input terminal 21 is output as is to the output terminal 26. The luminance signal and chrominance signal obtained at the output terminals 24 and 25 are recorded on separate tracks of the magnetic tape (not shown), so that the luminance signal track has VV.
ITC is recorded.

Problems to be Solved by the Invention However, in conventional VITC recording devices, the reliability of VITC during reproduction is still insufficient.

If the wrong VITC is read, there may be adverse effects such as the editing position on the tape going out of order or the editing device malfunctioning.

In view of the above points, it is an object of the present invention to provide a VITC recording device that can obtain VrTC data with higher reliability.

Means for Solving the Problems The present invention includes: a VITC generation circuit that generates VITC; a first VITC insertion circuit that inserts the output of the VITC generation circuit into a predetermined horizontal period of a vertical blanking period of a luminance signal; a second VITC for inserting the output of the VITC generation circuit into a predetermined horizontal period of the vertical blanking period of the color signal;
an output of the first VITC insertion circuit;
This VITC recording device records the output of the second VITC insertion circuit on separate tracks.

Function As described above, since the VITC is inserted in a predetermined horizontal period within the vertical blanking period of both the luminance signal and the chrominance signal and recorded on the magnetic tape, not only the luminance signal but also the chrominance signal is recorded on the magnetic tape. VITC can also be read out from the magnetic tape, and compared to recording on a magnetic tape by inserting VITC into only the luminance signal, the number of VITC to be read out can be increased and the reliability of VITC read out in a desired frame can be improved.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of essential parts of a VITC recording apparatus according to an embodiment of the present invention. 1 is an input terminal where a luminance signal is input, 2 is an input terminal where a color signal is input, 3 is a V
A VITC generating circuit 4 generates ITC, and 4 is a V generated by the VITC generating circuit 3 during the horizontal periods of 12H and 14H of the vertical blanking period of the luminance signal input to the input terminal 1.
A first VITC insertion circuit inserts ITC, 6 is an output terminal to which the output of the first VITC insertion circuit 4 is supplied, and 6 is a vertical blanking period 12H and 14H of the color signal input to the input terminal 2. a second VITC insertion circuit that inserts VITC generated from the VITC generation circuit 3 in the horizontal period;
γ is an output terminal to which the output of the second VITC insertion circuit 5 is supplied.

The operation of the VITC recording apparatus configured as described above will be explained below. The luminance signal input to the input terminal 1 is input to the first VITC insertion circuit 4, and VITC generated by the VITC generation circuit 3 is inserted into the horizontal period of 12H and 14H of the vertical blanking period, and the VITC is input to the output terminal 6.
and recorded on a magnetic tape (not shown). The color signal inputted to the input terminal 2 is inputted to the second VITC insertion circuit 6, and the chrominance signal inputted to the input terminal 2 is inputted to the second VITC insertion circuit 6.
V generated by the VITC generation circuit 3 during the horizontal period of 4H
The ITC is inserted, the signal is output to the output terminal 7, and the signal is recorded on a magnetic tape (not shown) on a separate track from the luminance signal.

VITC to read VITC recorded as above
An example of the configuration of the reading device is shown in the block diagram of FIG. 2, and will be described below. 1o is an input terminal to which a luminance signal reproduced from a magnetic tape (not shown) is input; 1 is an input terminal to which a color signal reproduced from a magnetic tape (not shown) is input; 12 is an input terminal 10 a first VITC extraction circuit for extracting VITC inserted in 12H and 14H of the vertical blanking period from a luminance signal inputted from the input luminance signal;
13 is a VIT inserted into 12H and 14H of the vertical blanking period from the color signal input from the input terminal 11.
a second VITC extraction circuit for extracting C; 14 is the first VITC extraction circuit;
The VITC extracted by the second VITC extraction circuit 12 and the second VITC extraction circuit 13 is supplied, and the VITC
VITC demodulation circuit that demodulates TC and obtains demodulated data, 1
5 compares the VITC demodulated data obtained by the VITC demodulation circuit 14 within one frame (or within one field),
A determination circuit 16 outputs the VITC demodulated data of the frame (or field) based on a majority decision, and 16 is an output terminal to which the output of the determination circuit 15 is supplied.

The operation of the VITC reader configured as described above will be described below. The luminance signal reproduced from the magnetic tape (not shown) is sent to the first VIT via the input terminal 1°.
VI supplied to the C sampling circuit 12 and inserted into the horizontal periods of 12H and 14H of the vertical blanking period.
The TC is extracted and supplied to the VITC demodulation circuit 14. Further, the color signal reproduced from the magnetic tape (not shown) is sent to the second VITC extraction circuit 13 via the input terminal 11.
12H and 14 of that vertical planking period.
The VITC inserted in the horizontal period of H is extracted,
The signal is supplied to the VITC demodulation circuit 14. The VITC demodulation circuit 14 demodulates the supplied VITC and supplies the demodulated data to the determination circuit 15. The determination circuit 15 determines whether the supplied V
By comparing the ITC demodulated data within one frame (or within one field) and taking a majority vote, erroneous data is removed, correct demodulated data is obtained, and correct demodulated data is output to the output terminal 18. Since the decision circuit 15 makes a majority decision among the VITC demodulated data obtained eight times per frame (four times per field), highly reliable VITC demodulated data can be obtained at the output terminal 18.

In this embodiment, the VITC is inserted in the horizontal section at the same position as the luminance signal and the color signal, but it may be inserted at a different position.

Effects of the Invention As described above, according to the present invention, highly reliable VITC demodulated data can be obtained with a simple configuration, and its practical effects are high.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing essential parts of an embodiment of a VITC recording device of the present invention, and FIG. 2 is a block diagram showing an embodiment of a VITC reading device that reads VITC recorded by the VITC recording device of the present invention. , Figure 3 shows the conventional VI
FIG. 4 is a block diagram showing the TC recording device, and is an explanatory diagram showing the code format of VITC. 3...VITC generation circuit, 4.A...1st V
ITC insertion circuit, 6... second VITC insertion circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3

Claims (1)

[Claims] a vertical interval time code generation circuit that generates a vertical interval time code; a first vertical interval time code insertion circuit that inserts an output of the vertical interval time code generation circuit into a predetermined horizontal period of a vertical blanking period of a luminance signal; a second vertical interval time code insertion circuit for inserting the output of the vertical interval time code generation circuit into a predetermined horizontal period of the vertical blanking period of the color signal; A vertical interval time code recording device characterized in that the outputs of two vertical interval time code insertion circuits are recorded on separate tracks of a magnetic tape.