1. Field of the Invention
The present invention generally relates to a recording apparatus for a mirror mother tape, and more particularly to a recording apparatus which is suitable for preparing a mirror mother tape for use in a contact type magnetic transfer printing apparatus in which a color video signal recorded on the mirror mother tape is copied onto copy tape.
2. Description of the Prior Art
In a contact type magnetic transfer apparatus, a mirror mother tape and a copy tape are contacted to each other, and a color video signal previously recorded on the mother tape is transferred to the copy tape by applying a magnetic field from a transfer bias head.
The mother tape is prepared using a recording circuit of a video tape recorder (VTR) for a mirror mother tape in a manner briefly described below. First, a luminance signal and a chrominance signal are separated from a color video signal to be recorded on the mirror mother tape. Then, the separated luminance signal is converted into a frequency-modulated signal by FM-modulation, while the separated chrominance signal is down converted into a down converted chrominance signal having a reduced frequency. Finally, these converted luminance and chrominance signals are combined or mixed and then applied to a magnetic head, so the composite signal, that is, the color video signal, can be recorded on the mirror mother tape in opposite polarity by the magnetic head, thereby preparing a so-called mirror mother tape.
A copy tape is produced by printing the color video signal thereon from the mirror mother tape using a contact type magnetic printing apparatus. The color video signal printed on the prepared copy tape is subjected to frequency demodulation and frequency conversion by a tape reproducing apparatus to be restored into the original color video signal and then an image of the converted color video signal is reproduced on a monitor, for example.
However, when an original video signal is reproduced by a tape reproducing apparatus from a copy tape which has been copied from a mirror mother tape prepared using a recording circuit of a conventional recording apparatus as described above, an unnecessary component, having a frequency fy.+-.2.times.fC, of the frequency converted chrominance signal is generated, where fy represents a frequency of the luminance signal and fC a frequency of the down-converted chrominance signal. The consequent problem is that a noise component having a mesh-like configuration appears in the image displayed on the monitor due to the secondary beat component, that is, the unnecessary frequency component having a frequency fy.+-.2.times.fC.
Further, it is difficult to record a down converted chrominance signal on a metal tape of relatively thin thickness, so that it is desirable to employ a large recording current for the down converted chrominance signal when recording it on a mother tape. In this case, however, the secondary beat component having a frequency fy.+-.2.times.fC becomes larger, and so it has been impossible to increase the level of the recording current.
USPTO Backgrounds
USPTO Backgrounds