Claims
- 1. A helical scan type magnetic playback apparatus for reproducing an image signal in which a frequency of color signals is changed in a frequency band lower than a luminance signal of which frequency is modulated, the color signal being reproduced from a magnetic recording medium which records the color signals in tracks as a low frequency color signal of which a phase shift is changed at every track, a phase of the color signals being shifted by a predetermined angle at each horizontal period in order not to overlap spectrums of the color signal between two adjacent tracks, the apparatus comprises:
- a plurality of magnetic heads;
- position signal generator means for generating a position signal indicative of each position of the plurality of magnetic heads;
- head switching control signal generation means for generating a head switching control signal responsive to said position signal;
- switching means responsive to said head switching control signal from said head switching control signal generation means to switch image signals reproduced by said plurality of magnetic heads;
- color signal processing means for separating the low frequency color signal from an output signal output from said switching means, for converting a frequency of the separated low frequency color signal, and for performing a phase shift which is substantially opposite to the phase at recording;
- sense means for sensing an error of the phase of said low frequency color signal produced at the time of reproduction by a shift between the switching point of a predetermined rule at the time of recording and the switching of a predetermined rule at the time of reproduction; and
- correction means for correcting the phase of said low frequency color signal at the time of reproduction on the basis of a sense signal of a phase error output from the sense means.
- 2. The helical scan type magnetic playback apparatus as set forth in claim 1, wherein said correction means comprises timing means for setting a fixed period related to the vertical synchronizing signal obtained from a reproduced image signal, and gate means for taking out said phase error sense signal only for a fixed period.
- 3. The helical scan type magnetic playback apparatus as set forth in claim 2,
- wherein said head switching control signal generation means generates a modified head switching control signal, by shifting up to a position at or after completion of said fixed period a state change point of said head switching control signal; and
- wherein said head switching means switches said image signals reproduced by said plurality of magnetic head responsive to said modified head switching control signal from said switching control signal generation means.
- 4. The helical scan type magnetic playback apparatus as set forth in claim 3, wherein:
- said gate means serves to take out only a first phase error within a fixed period, and said correction means serves to correct a reproduced color phase in accordance with a predetermined rule from the time when said error sense signal is produced to the time when said head switching control signal is produced.
Priority Claims (3)
Number |
Date |
Country |
Kind |
1-111074 |
Apr 1989 |
JPX |
|
2-9127 |
Jan 1990 |
JPX |
|
2-9128 |
Jan 1990 |
JPX |
|
Parent Case Info
This is a divisional of application Ser. No. 07/515,395 filed Apr. 27, 1990, now U.S. Pat. No. 5,223,941.
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0262320 |
Jul 1987 |
EPX |
3306791 |
Aug 1984 |
DEX |
3710740 |
Oct 1987 |
DEX |
3739283 |
Jun 1989 |
DEX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
515395 |
Apr 1990 |
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