JPS62111582A - Video signal recording device - Google Patents

Abstract

PURPOSE:To prevent a recording wavelength from being varied by advancing or delaying the time base of a luminance signal by a prescribed variable extent by using a variable delay line in accordance with the rotational phase of a head at the time of recording. CONSTITUTION:To execute advancement/delay, 1H is delayed by a CCD 1H delay line 2. To advance time, voltage applied to a terminal 5 is changed so that the oscillation frequency of a VCO 4 is increased. To delay time, the voltage is changed so that the oscillation frequency is reduced. In a part looked as if the part is advanced or delayed at the time of reproducing, the luminance signal may be previously advanced or delayed prior to recording.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for recording video signals on a recording medium using a rotating head.

[Conventional technology]

This type of device is the video tape recorder (VTR).
However, in recent years, reflecting the market needs for multi-functionality in VTRs, in addition to the two standard recording/playback heads, special playback or long-time recording/playback heads have been installed on the rotating drum. The force of what we have is 8 (out lJ-, to A ζM
Soup 1 → person μIF Arrange the Ari small plate orthogonally, 4
This is a diagram showing the arrangement of the heads and the positional relationship between the tape and the heads when recording is performed using two heads selectively. In the figure, 10 is a rotating drum; 6, 7, 8.9 are Recording heads, tea, and 11b (hereinafter collectively referred to as 11) disposed perpendicularly to each other on this drum 10 are tape guide members, and 12 is a tape.

[Problem that the invention seeks to solve]

In the apparatus as described above, when the head 7 is currently recording, the direction of rotation of the drum and the direction of tape advancement are indicated by arrows in FIG. Then, the head 7 first comes into contact with the tape from the position A in the figure and starts recording. Then, when the head 6 reaches the opening position in the figure, the tape 12
begins to come into contact with At this time, the impact when the head 6 contacts the tape 12 causes a relative speed change between the tape and the head, and the recording wavelength changes. Next, when the head 7 comes to the position C in the same figure, the head 9 starts to come into contact with the tape 12, so that the recording wavelength changes as described above.

If another head comes into contact with or leaves the tape while recording, it will affect the recording head that is already running on the tape, making it difficult to record at a normal wavelength.

As mentioned above, in conventional devices, during recording, a head other than the recording head comes into contact with the tape or separates from the tape, and this impact causes a change in the speed of the drum or tape. , the recording wavelength changes, and when this recording tape is played back on another recording/playback deck, there is a problem in that an image distortion phenomenon called image blur occurs in a specific part of the reproduced image. Ta.

This invention solves these problems. The object of the present invention is to provide a video signal recording device that can prevent reproduced images from deteriorating due to fluctuations in relative speed between a recording head and a recording medium during recording.
- [Means for solving the problem] The video signal recording device according to the present invention advances or retreats the time axis of the luminance signal to be recorded by a predetermined amount using a variable delay line according to the rotational phase of the head. It is to be recorded.

[For production]

In this invention, during recording, the time axis of the luminance signal is advanced or retracted by a predetermined amount using a variable delay line according to the rotational phase of the head. It became possible to prevent this.

〔Example〕

FIG. 1 is a block diagram of a luminance signal recording system in a VTR according to an embodiment of the present invention. In the figure, 1 is a filter for separating luminance signals and color signals from an input television signal. , 2 is I consisting of a charge-coupled device (COD), etc.
H (horizontal scanning period) delay line, 6 is a brightness recording process circuit, 4 is a voltage controlled oscillator (VCO) that supplies a clock for driving the delay line 2, and 5 is a control terminal. Furthermore, FIG. 2 shows the waveforms at each point in FIG. 1, where a is the luminance signal before delay, b is the luminance signal after passing through the delay line, and C is the control signal input to terminal 5. .

In the conventional apparatus as described above, suppose that while the currently recording head is running over the tape, another head comes into contact with or leaves the tape.

At this time, if the relative speed between the tape and the head becomes slower, the recorded signal will have a shorter recording wavelength and become distorted.
When the recorded signal is played back, the time axis appears to be shorter. In reality, that part appears to have moved forward for a moment on the monitor screen, as shown in FIG. 4(a). Similarly, if the relative speed between the tape and the head increases, it will appear as if there is a momentary delay on the monitor, as shown in Figure 4 (bl).

Therefore, for parts that appear to have advanced during playback, it is sufficient to advance the luminance signal during recording by an appropriate amount of time before recording, and conversely, for parts that appear to have been delayed, advance the luminance signal by an appropriate amount of time before recording. It is sufficient to delay the luminance signal by an appropriate amount of time.

In this embodiment, the above-mentioned time advance and delay are actually c
The cDin delay line 2 is used to delay the signal by 1H. When it is desired to advance the time, the voltage applied to the terminal 5 is changed to increase the oscillation frequency of the VCO 4, that is, the clock frequency applied to the delay line 2, and the delay time is made shorter than usual. Moreover, if it is desired to delay the time, the voltage applied to the terminal 5 may be changed to lower the oscillation frequency of VC○4, contrary to the above.

In this embodiment, since the falsified portion, which is image distortion, is determined by the spatial positional relationship between the tape and the head, that is, the rotational phase of the head, it is easy to quantify the state of falsified image. .

Therefore, it is possible to make the voltage applied to the terminal 5 have a constant step waveform like the signal shown in FIG. 2, and it is possible to constantly apply this correction during recording.

FIG. 3 is a block diagram of main parts of a V'I'H recording system as another embodiment of the present invention, in which the same reference numerals as in FIG. 1 indicate the same or corresponding parts. In Figure 6, both the chrominance signal and the luminance signal are delayed and the luminance signal is separated, but is this the same effect as when the luminance signal is delayed after separation as in Figure 1?J C) ρ
,o.

Q: In the above embodiment, the CCDIH line is used as the variable delay line, but the delay time does not have to be limited to 1H, and if it is possible to vary the delay time from the outside, COD
Of course, this is not limited to delay lines. Further, although CO was used as the clock oscillator, it goes without saying that if the oscillation frequency is variable, it can be varied by switching the oscillator, etc., and therefore the signal corresponding to terminal 5 is also the same as in the above embodiment. Of course, there are no limitations.

〔Effect of the invention〕

As described above, the present invention provides a video signal recording device that can prevent deterioration of a reproduced image by applying time axis correction to a luminance signal recorded in advance during recording.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a luminance signal recording system of a video signal recording device according to an embodiment of the present invention, Fig. 2 is a timing chart showing waveforms of signals at various parts of Fig. 1, and Fig. 3 is a block diagram of a luminance signal recording system of a video signal recording device according to an embodiment of the present invention. FIG. 4 is a block diagram of the main part of the recording system of an apparatus according to another embodiment. FIG. 4 is a diagram for explaining image distortion in the conventional apparatus. FIG. It is a figure showing arrangement. In the figure, 1 is a filter, 2 is a delay line, 3 is a recording process, and 4 is a V COf6 line. Agent Patent Attorney 1) Haru Kitatake Figure 2 (a) (b)
Figure 4 Figure 5

Claims (1)

[Claims] A video signal recording device for recording a video signal using a rotating head, characterized in that the time axis of a luminance signal to be recorded using a variable delay line is advanced or retracted by a predetermined amount in advance according to the rotational phase of the head. Device.