JPH0787006B2 - Information signal recording device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an information signal recording apparatus, and more particularly to a circular track formed on a disk-shaped recording medium, the circular track having a plurality of circular diameters. The present invention relates to a device for recording a frequency multiplexed signal formed by frequency-multiplexing a first information signal located in one frequency band and a second information signal located in a lower frequency band than the first information signal.

<Description of Prior Art> In this type of apparatus, a large number of circular tracks are formed by rotating a sheet-shaped recording medium at a constant speed and moving a head in the radial direction of the sheet-shaped recording medium. ing.
Therefore, the relative velocity between the head and the medium differs depending on the diameter of the track. Since the gap width of the head is of course constant, the recording level varies depending on the diameter depending on the frequency of the information signal to be recorded even when the same recording current is used for recording. This is also related to the problem of interference between respective information, especially when recording a mixed signal in which two or more information signals are frequency-multiplexed.

As an apparatus of this kind, for example, a magnetic sheet is rotated to send a magnetic head in the radial direction thereof, a large number of circular tracks are formed, one track of a color video signal is recorded in each track, and each track is continuously recorded. A magnetic recording image reproducing device (hereinafter simply referred to as SV) that obtains a color still image signal by reproducing.
There is). In the present specification, this SV will be described as an example.

FIG. 1 is a diagram showing an example of a frequency spectrum of a recording signal in SV. In FIG. 1, 1 is an FM-modulated line-sequential color difference signal, and 2 is a frequency spectrum of an FM-modulated luminance signal. When recording such a recording signal on circular tracks having different diameters, particularly when recording on a track having a smaller diameter among these tracks, the recording level of the FM modulated luminance signal tends to be low. Therefore, the amount of interference of the line-sequential color-difference signal component with respect to the luminance signal component increases, and the beat appears on the screen when reproducing.

<Object of the Invention> The present invention has been made in view of the above problems, and is one circular track among a plurality of circular tracks having different diameters formed on a disc-shaped recording medium. Recording a frequency multiplexed signal formed by frequency-multiplexing a first information signal located in a first frequency band and a second information signal located in a lower frequency band than the first information signal It is an object of the present invention to provide an information signal recording device capable of optimal recording with a simple structure.

<Description of Examples> Hereinafter, the present invention will be described with reference to Examples. FIG. 2 is a diagram showing a simple configuration of the SV recording system according to the present invention.

In FIG. 2, 3 is a luminance signal (Y) input terminal, 4 and 5 are color difference signal (for example BY, RY) input terminals, 6 is a Y FM modulator, and 7 is a recording amplifier. , 8 is a line switch for line-sequencing two color difference signals, and 9 is for line-sequential color difference signals.
An FM modulator, 10 is a level adjusting circuit, 11 is a head, 12 is a magnetic sheet, 13 is a motor, 14 is a head feeding mechanism, and 15 is a system controller.

The luminance signal FM-modulated by the FM modulator 6 so as to take a relatively high band, and the line-sequential color difference signal FM-modulated by the FM modulator 9 at a relatively low band are frequency-multiplexed by the recording amplifier, and the head At 11 the recording is performed on the sheet 12 which is rotating at a constant speed by the motor 13. This mixed signal has a frequency spectrum as shown in FIG.

The system controller 15 moves the head to a track designated by an operation unit (not shown) via the head feed mechanism 14, and supplies a control signal related to the diameter of the track to the level adjusting circuit 10 to adjust the level. Control.
That is, when recording on a track with a small diameter, the level is reduced, and when recording on a track with a large diameter, the level is increased.

3 and 4 are diagrams showing an example of the configuration of the level adjusting circuit 10 shown in FIG. FIG. 3 shows the case where the gain K is recorded, for example, at T ₁ in response to the above-mentioned control signal for the track T n (where n is an integer, T ₁ is the smallest track, and T ₅₀ is the largest track). Is K = 0.42, K = 1 when recording at T ₃₀ , and K = 0.4 + 0.02 × n when recording at Tn.
In this way, it is a signal that determines K. As this circuit, for example, a well-known voltage control amplifier (VC
A) etc. should be used.

Fig. 4 shows that when recording at T ₁ to _15, when recording at T ₁₆ to _{30 and} when recording at T _{31 to} T ₅₀ , the FM-modulated line sequential color difference signals are different from each other. It is a figure which shows the example of a concrete circuit structure of the level adjustment circuit for recording by a level. For example
When recording to T ₁ to ₁₅ , a high level input signal is applied only to the control signal input terminal 17 ′, and when recording to T ₁₆ to ₃₀ , a high level input signal is applied only to terminal 17 ″, T _{31 to} T
At the time of recording at ₅₀ , the output level of the level adjusting circuit 10 is changed in three stages by giving a low level signal to both terminals 17 'and 17 ".
16,16 'are input terminals, 18,18' are output terminals, 17,17 ', 17 "
Is a control signal input terminal.

According to the above configuration, the smaller the diameter of the track,
The mixing ratio of the FM modulation color difference signal to the FM modulation luminance signal becomes small. Therefore, when such a relative speed cannot be obtained, even if the level of the high frequency side of the FM modulated luminance signal decreases during playback, FM
It is possible to suppress the occurrence of beat components due to the modulation line-sequential color difference signal, and it is possible to prevent the occurrence of beat components on the playback screen.

A method of changing the mixing ratio is realized by changing the level in the FM modulation color difference signal transmission system in the above-mentioned embodiment, but the level is changed in the FM modulation luminance signal transmission system. Can also be realized by changing. It can also be realized by a combination of both.

Further, in the description of the above-mentioned embodiments, parts not directly related to the present invention, such as various amplifiers, various processing circuits for video signals, etc., are omitted in the drawing and description.

Further, although only the application of the present invention to the SV has been described as the embodiment, the present invention can be appropriately modified within the scope of the claims, and the information signal has a different diameter. It is very effective when applied to a device for recording on a circular track.

<Explanation of Effects> As described above, according to the present invention, the first information signal and the first information signal located in the first frequency band are used regardless of the diameter of the circular track to be recorded. A frequency-multiplexed signal formed by frequency-multiplexing a second information signal located in a low frequency band can always be recorded without a change in characteristics, and the first information signal and the second information signal can be recorded. It is possible to obtain an information signal recording device capable of suppressing the occurrence of interference with the information signal of No. 1 and preventing deterioration of the frequency-multiplexed signal recorded on a circular track having a small diameter with a simple configuration. Is.

[Brief description of drawings]

FIG. 1 is a diagram showing a frequency spectrum of a recording signal in SV, FIG. 2 is a diagram showing a configuration of a recording apparatus as one embodiment of the present invention, and FIGS. 3 and 4 are concrete examples of a level adjusting circuit. It is a figure which shows an example. 7 is a recording amplifier, 10 is a level adjusting circuit, 11 is a head, 12
Is a magnetic sheet, 14 is a head feeding mechanism, and 15 is a system controller.

Claims (1)

[Claims] 1. A first information signal located in a first frequency band on one circular track among a plurality of circular tracks having different diameters formed on a disk-shaped recording medium, and the first information signal. Is a device for recording a frequency-multiplexed signal formed by frequency-multiplexing a second information signal located in a frequency band lower than that of the information signal, the information generating information corresponding to the diameter of the circular track. Generating means, and the first information signal and the second information signal generated by the information generating means according to information corresponding to the diameter of the circular track.
After controlling the signal levels of the information signal and the frequency-multiplexed signal, the frequency-multiplexed signal forming means forms and outputs a frequency-multiplexed signal, and the frequency-multiplexed signal output from the frequency-multiplexed signal forming means. An information signal recording device, comprising: a recording unit for recording the data on the circular track on the disk-shaped recording medium.