JPH0453375A - Video signal recorder - Google Patents

Abstract

PURPOSE:To correctly record a VITC signal with simple constitution by superimposing a vertical interval time code (VITC: Vertical Interval Time Code) signal recorded for a vertical synchronizing period onto a digital video signal before time axis compression (digital mixture). CONSTITUTION:A switch circuit SW 11 is provided to a Y output section 2A of a digital signal processing circuit 1 applying signal processing of a camera section, a digital Y signal is given to an input (a) of the SW 11 and a digital data corresponding to a white level at the input (b) and a VITC signal for standard format is fed to the SW 11. With the VITC signal set to a logical H, the SW 11 is thrown to the position of (b) and with the VITC signal set to a logical L, the SW 11 is thrown to the position of (a), the Y signal data and the white level data are selected in the timing of the VITC signal in the unit of words and the VITC signal is superimposed on the digital Y signal before compression. Thus, the VITC signal is correctly recorded with simple constitution.

Description

[Detailed Description of the Invention] [Industrial Application Field] Regarding a recording device that superimposes and records a so-called VITC time code on a video signal, in particular, it is possible to perform standard recording using a small-diameter head drum by compressing the time axis of the video signal. The present invention relates to a video recording device that can easily insert a VITC time code when recording in a format.

[Summary of the invention]

The present invention provides a method for superimposing a vertical period time code (VITC) on the digital video signal before time axis compression when recording the video signal in a standard recording format using a small diameter head drum by compressing the time axis. This is a video recording device that allows easy insertion of VITC.

[Conventional technology]

Conventionally, time codes are sometimes recorded along with video signals to facilitate editing of video tapes. The time code includes a longitudinal time code recorded in the longitudinal direction of the tape and a vertical time code (ITC: Vertical time code) recorded in the vertical synchronization period of the video signal.
Interval Time Code), all of which consist of data indicating hours, minutes, seconds, frames, user bit data, etc. Regarding these time code generators, there is, for example, Japanese Patent Laid-Open No. 61-242385 by the present applicant.

By the way, the video signal is processed by a video tape recorder (VTR).
When recording with etc., time axis compression may be necessary.
In order to record the VITC signal in such a case, the VIT
Since the C signal is also replaced on the time axis, a memory element such as a shift register and a circuit to control it are required, resulting in a complicated configuration.

A video tape recorder that compresses and records video signals in the time axis will be described below.

Fig. 5 is a diagram showing the configuration of a VTR's herad tram and the recording method on a record carrier. Fig. 5 (al) and (a2) show two recording heads arranged on a standard diameter head drum. This shows a standard format recording method in which each receiver has records rotated by 180°. Figures 5 (bl) and (b2) show that one recording head is arranged on a small-diameter head drum and records only 300° in one rotation, resulting in Figures 5 (al) and (a2). ) allows recording in the same standard format. No video signal is recorded during the 60° period when the tape is not wound, so if a normal video signal is recorded, the video will not be played back correctly (it will not be recorded in the standard format).

To solve this problem, we rotated the recording head at high speed and
Video signals for 360° are recorded in a period of 00°, so the video signal is also 300/360.
= 5/6 time axis compression is performed.

These techniques are disclosed in Japanese Patent Publication No. 60-51306 by the present applicant.
No., Special Publication No. 60-50105, Special Publication No. 60-5130
It is known as No. 7.

By applying these technologies, we have created a small V using a small diameter drum.
An example of a camera-integrated VTR in which a TR and a video camera employing digital signal processing are integrated is shown in FIGS. 3 and 4.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a video signal recording device that compresses and records a video signal in a time-axis manner, in which a VITC signal can be inserted with a simple configuration.

[Means to solve the problem]

In the present invention, in a recording device that compresses and records a video signal in the time axis, vertical 10
1 interval time code (VITC: Vertical In
The video signal recording device superimposes (digitally mixes) a terval time code signal) on the digital video signal before time axis compression.

The digital mixing includes, for example, a Sui-Sochi circuit that switches digital data corresponding to the white level potential of the video signal and a digital Y (luminance) signal in units of words (in units of samples during digital-to-analog conversion). Whether the switch circuit is connected to the VITC signal [I] (high level) or not.
(Low L/to 7+/) T: It can be configured to switch depending on whether it is present or not.

[Effect]

In the present invention, by inserting the VTTC signal into the digital video signal before time axis compression, the VI
There is no need for a separate circuit for converting the time axis of the TC signal and replacing it, and by providing only a standard format VITC signal generation circuit, the VITC signal can be recorded at the correct timing.

In particular, when the digital mixing is configured to switch between the Y signal and the white level in word units according to the level and timing of the VITC signal as described above, the white level inserted into the output signal of the switch circuit is By determining the level data, the timing and code content of the VITC signal can be accurately restored. Therefore, VITC signal insertion can be easily realized.

〔Example〕

Regarding the first embodiment of the present invention, while referring to a first example of a VTR (FIG. 3) and a second example of a VTR (FIG. 4) suitable for applying this, The explanation will be given according to the main circuit diagram.

First, the block diagram shown in FIG. 3 will be described.

CCD (Charge Coupled Device)
The three primary color signals of R and CB output from the image sensor such as e) enter a digital signal processing circuit including A/D (analog-to-digital) conversion, and undergo a series of signal processing such as gamma correction, black and white balance, and contour correction. Thereafter, the signal is outputted from the digital signal processing circuit 1 as, for example, an 8-bit or 10-bit digital Y (luminance) signal, color difference signal RY signal, and BY signal.

Then, as a camera output that is directly output from the camera as a video signal, the Y signal is directly D/A (digital/analog) converted, and the color difference signal is digitally encoded and then D/A converted, and the above-mentioned D/A conversion is performed. It is mixed with the Y signal and output.

On the other hand, regarding the signal to be supplied to the VTR, the Y signal is compressed to 576 on the time axis while still being digital, and then
The signal is D/A converted, FM modulated, and sent to the recording head. The color difference signals are sent to CTDM circuits 4 (described later) for R-Y and B-Y respectively.
sent to. Therefore, RY is compressed to 172 on the time axis,
B-Y is compressed to 172 on the time axis and 0.5H (
H is a horizontal period) and is converted into a signal in which the 1/2 time axis compressed R-Y and B-Y are alternately arranged for each IH (CTDM in FIG. 3(b): Complete
ssed TimeDivision Multipl
ex signal processing method). Thereafter, the signal is further compressed to 576 on the time axis, subjected to I/A conversion, FM modulated, and sent to the recording head. The first example of the VTR shown in FIG. 3 performs analog component recording, and the recording head for recording the Y signal and the recording head for recording the CTDM-processed color difference signal are adjacent to each other and integrated. They are arranged to rotate and record on separate recording tracks.

In this embodiment, which is applied to the camera-integrated VTR with the above configuration, the Y output section 2A on the digital signal processing circuit is enlarged, and V r T C (Vertical Interv
FIG. 1 shows a circuit diagram of the main part including a circuit for superimposing the time code signal.

In the circuit shown in FIG. 1, for example, an 8-bit parallel switch circuit 5Wll is provided at the Y output section (a section that outputs a digital, for example, 8-bit parallel Y signal) on the digital signal processing circuit that processes the signal of the camera section. For example, S Wl
A digital Y signal is given to the input a side of 1, digital data corresponding to a white level potential is given to the input side, and a standard format time code signal (VITC signal) is supplied to the 5WII. Then, the time code signal is “H”′ (
If it is connected to the b side when it is "T-" (Low), and to the a side when it is "T-" (Low), the Y signal data and white level data are switched word by word at the timing of the time code signal. As a result, the time coat signal is superimposed on the digital Y signal before time axis compression.

As a result, when the digital Y signal is next time-axis compressed to 5/6, the time code signal is also time-axis compressed to 5/6 at the same time.

Next, a second example of the VTR shown in FIG. 4 will be explained. Fourth
In the circuit shown in the figure, the Y signal and color difference signals R-Y and B-Y output from the digital signal processing circuit 1 are the same as in the example shown in FIG. 3, but the signals sent to the VTR section are different.

The Y signal and the chroma signal encoded from the color difference signals R-Y and B-Y are each digitally divided into 5 pixels on the time axis.
76 and D/converted. After that, the Y signal is frequency modulated, the chroma signal is frequency converted and mixed with each other,
It is supplied to one recording head and multiplexed recording is performed on the tape.

In the circuit of Fig. 4, Y on the digital signal processing circuit is also
As for the output section 2A, the circuit of the first embodiment described in FIG. 1 can be applied.

Next, a second embodiment of the present invention will be described with reference to FIG.

Figure 2 shows an analog Y signal received from a video camera, etc., which performs video signal processing using an analog circuit, and an A/
This is an example in which the signal is D-converted and sent to the time-base compression circuit. In this example as well, the switch 5W12 is arranged for the digital Y signal before time axis compression, and the switch 5W12
Similarly to l, the switch SW1 is activated by the time code signal.
2 to open and close.

〔Effect of the invention〕

By implementing the present invention, it is possible to obtain a video signal recording device that digitally mixes a VTTC time code signal with a digital video signal before time-axis compression in a recording device that compresses and records a video signal on the time axis.

This eliminates the need for a memory element such as a shift register for exchanging VITC time code signals on the time axis, and a circuit to control it, allowing VTRs and other devices to record standard format recording on small-diameter drums that can record VTTC signals with a simple configuration. can get.

(a2) is a 2-head recording method, (b2) is a ±2.2A recording method, and (bl) is a 1-head 1-head recording method.

digital signal processing circuit Y output section Time axis compression circuit

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a main part of a first embodiment of the invention, and FIG. 2 is a circuit diagram of a main part of a second embodiment of the invention. FIG. 3 shows a first example of a VTR to which the present invention is applied;
The figure shows a second example of a VTR to which the present invention is applied. Fig. 5 is a diagram showing the head drum configuration of a VTR and the recording method on the record carrier, where (al) is a two-head system, drum (al) is a two-head system, and drum (al) is a two-head system; Pattern: Piece 1, 1 turn A, 6 heads alternately (2 records)
Go to Sodo A (7) Look and record (a2) Go to 2 Forward to Sodo (b2) 1-head recording method
(Record; 5 method Figure 5 VTR head drum configuration and portrait 6 article) Diagram showing the recording method on ice

Claims (1)

[Claims] A recording device that compresses and records a video signal on a time axis, characterized in that a vertical period time code recorded in a vertical synchronization period is superimposed on the digital video signal before time axis compression. Video signal recording device.