Abstract: A digital sine wave signal is read form a memory storage of a phase synchronizing apparatus and is converted into an analog signal through a digital to analog converter. This converted analog sine wave is phase compared to an input analog sine wave supplied to an input terminal of the synchronization apparatus. The phase of the digital sine wave is synchronized with that of the input analog sine wave by controlling a read address signal of the memory storage based upon a detected phase error signal between the input analog sine wave and the converted analog sine wave. Thus, a desired digital signal synchronized with the phase of an input signal can be generated by a simple arrangement by digital processing.

Abstract: When a continuous wave signal synchronized with a first color subcarrier signal is generated by a color subcarrier extracting circuit, a phase error detecting circuit, an A/D converting circuit, and a digital oscillating circuit from an analog video signal containing a first color sub carrier signal supplied to a first input terminal and a digital video signal containing a color signal component supplied to a second input terminal is converted by a digital video signal converting circuit into a composite video signal containing a carrier chrominance signal, a color signal component is converted into a carrier chrominance signal by using the continuous wave signal and a phase of a first color subcarrier signal contained in the analog video signal and a phase of a second color subcarrier signal of a composite video signal formed from the digital video signal are synchronized with each other.

Abstract: A video signal format converting circuit is disclosed, comprising a signal converting matrix circuit and a filter circuit that is constructed of a time delaying device for a video signal corresponding to a standard television format. When a digital video signal corresponding to a first video signal format is converted into a second video signal format that is different from the first video signal format and then output, the time delaying device of the filter circuit is used as a delaying circuit. The output signal of the delaying circuit or the video signal corresponding to the standard television signal format is selectively output. While or after the video signal corresponding to the first video signal format is converted into the video signal corresponding to the second signal format, the video signal is modified so as to protect it from being copied.

Abstract: A video signal format converting circuit is disclosed, comprising a signal converting matrix circuit and a filter circuit that is constructed of a time delaying device for a video signal corresponding to a standard television format. When a digital video signal corresponding to a first video signal format is converted into a second video signal format that is different from the first video signal format and then output, the time delaying device of the filter circuit is used as a delaying circuit. The output signal of the delaying circuit or the video signal corresponding to the standard television signal format is selectively output. While or after the video signal corresponding to the first video signal format is converted into the video signal corresponding to the second signal format, the video signal is modified so as to protect it from being copied.

Abstract: A video signal format converting circuit is disclosed, comprising a signal converting matrix circuit and a filter circuit that is constructed of a time delaying device for a video signal corresponding to a standard television format. When a digital video signal corresponding to a first video signal format is converted into a second video signal format that is different from the first video signal format and then output, the time delaying device of the filter circuit is used as a delaying circuit. The output signal of the delaying circuit or the video signal corresponding to the standard television signal format is selectively output. While or after the video signal corresponding to the first video signal format is converted into the video signal corresponding to the second signal format, the video signal is modified so as to protect it from being copied.

Abstract: A magnetic tape transport controller for a magnetic recording and reproducing apparatus in which a pilot signal for tracking control having four different frequencies is recorded on a magnetic tape by a rotary magnetic head and the magnetic tape is transported in a playback mode at a different tape speed than that in a recording mode. The tape transport controller has means for detecting an amplitude change of a specific one of signals derived by frequency-converting a reproduced pilot signal and controlling the tape speed such that the frequency of the amplitude change is maintained at a predetermined frequency. It also has a phase control loop to control the tape speed such that a phase of the specific signal coincides with a phase of a reference signal.