Phase shifting device for vectorscope
AssigneeLeader Electronics Corporation
InventorsKenzo Ikuzawa, Yoshimichi Hika
Life of this patent
Estimating the term…
Abstract
A phase shifting device for a vectorscope is provided which enables a vector-displayed waveform to be instantaneously and accurately rotated to an arbitrary or variable predetermined target phase position, with an arbitrary or variable predetermined portion of the vector-displayed waveform being selected as a reference for phase shifting. The phase shifting device includes first and second phase shift input generators. The first generator produces a first phase shift input signal representative of an arbitrary amount of phase shifting. The second generator produces a second phase shift input signal representative of a predetermined amount of phase shifting for the instantaneous and accurate rotation of the vector-displayed waveform.
Claims11
A phase shifting device for shifting in phase a subcarrier regenerated from a video signal inputted to a vectorscope by a specified amount to control the phase of a vector-displayed waveform displayed on said vectorscope, comprising:
- a) phase shifting means having an input for receiving said regenerated subcarrier, an input for receiving a phase shift output signal, and an output for providing said regenerated subcarrier having a phase shifted by an amount represented by said phase shift output signal;
- b) first phase shift input generator means for producing a first phase shift input signal representative of an arbitrary amount of phase shifting;
- c) second phase shift input generator means for producing a second phase shift input signal representative of a predetermined amount of phase shifting;
- d) phase shift input selection command means for producing an input selection command signal for selecting one of said first and second phase shift input signals;
- and
- e) phase shift output generator means connected to said first and second phase shift input generator means and to said phase shift input selection command means for selecting one of said first and second phase shift input signals in response to said input selection command signal and for providing the selected one as said phase shift output signal.
A phase shifting device including phase shift means for controlling the phase of an entire vector-displayed waveform displayed on a vectorscope, characterized by including:
- predetermined phase shift input generator means for producing a predetermined phase shift input signal representative of a predetermined amount of phase shifting for application to said phase shift means.
A vectorscope comprising:
- A. an input terminal for receiving a color video signal;
- B. a subcarrier regenerator having an input connected to said input terminal and an output for providing a regenerated subcarrier;
- C. a phase shifting device having an input coupled to the output of said subcarrier regenerator, said device being operative to shift in phase said regenerated subcarrier by a specified amount, said phase shifting device including:
- a) phase shifting means having an input for receiving said regenerated subcarrier, an input for receiving a phase shift output signal, and an output for providing said regenerated subcarrier having a phase shifted by an amount represented by said phase shift output signal;
- b) first phase shift input generator means for producing a first phase shift input signal representative of an arbitrary amount of phase shifting;
- c) second phase shift input generator means for producing a second phase shift input signal representative of a predetermined amount of phase shifting;
- d) phase shift input selection command means for producing an input selection command signal for selecting one of said first and second phase shift input signals;
- and
- e) phase shift output generator means connected to said first and second phase shift input generator means and to said phase shift input selection command means for selecting one of said first and second phase shift input signals in response to said input selection command signal and for providing the selected one as said phase shift output signal;
- D. a demodulator circuit having a first input connected to said input terminal and a second input connected to an output of said phase shifting device, said demodulator circuit being operative to produce R-Y and B-Y signals;
- and
- E. a display coupled to receive said R-Y and B-Y signals.
Dependencies are inferred from the claim text.