Video display apparatus with vertical scan velocity modulation and video display method thereof

A video display apparatus comprising:

• a horizontal deflection circuit for deflecting an electron beam in the horizontal direction to form scanning lines in the horizontal direction on a screen;
• a vertical deflection circuit for deflecting said electron beam in the vertical direction;
• and
• a vertical velocity modulation circuit for modulating the scanning speed in the vertical direction of the electron bean such that a part of the scanning line having a luminance which is not less than a predetermined value in a luminance change portion in the vertical direction moves farther apart from a part of the adjacent scanning line having a lower luminance than said predetermined value, wherein
• said vertical velocity modulation circuit comprises:
• a movement control circuit for producing the movement control signal for controlling the movement in the vertical direction of the scanning lines on the basis of the luminance signal;
• a frequency domain emphasis circuit for emphasizing a predetermined portion of a frequency domain of said movement control signal produccd by said movement control circuit;
• and
• a vertical velocity modulation coil for generating a magnetic field for modulating the scanning speed in the vertical direction of the electron beam on the basis of said movement control signal emphasized by said frequency domain emphasis circuit, wherein
• said frequency domain emphasis circuit comprises:
• an extraction circuit for extracting said predetermined frequency domain of said movement control signal produced by said movement control circuit;
• an adjuster for adjusting the signal in said frequency domain extracted by said extraction circuit;
• and
• an adder for adding said movement control signal produced by said movement control circuit and the signal in said frequency domain adjusted by said adjuster together.

A vertical velocity modulation apparatus for modulating the scanning speed in the vertical direction of an electron beam for successively forming scanning lines in the horizontal direction on a screen, comprising:

• a movement control circuit for producing a movement control signal for controlling the movement in the vertical direction of the scanning lines such that a part of the scanning line having a luminance which is not less than a predetermined value in a luminance change portion in the vertical direction on the basis of a luminance signal moves farther apart from a part of the adjacent scanning line having a lower luminance than said predetermined value;
• and
• a vertical velocity modulation coil for generating a magnetic field for modulating the scanning speed in the vertical direction of the electron beam on the basis of the movement control signal produced by said movement control circuit;
• a parallel scanning circuit for outputting a parallel scanning signal for making forward and backward scanning lines formed on the screen by deflecting the electron beam back and forth parallel;
• and
• a synthesizing circuit for synthesizing the movement control signal produced by said movement control circuit and the parallel scanning signal outputted by said parallel scanning circuit,
• said vertical velocity modulation coil generating a magnetic field for modulating the scanning speed in the vertical direction of the electron beam on the basis of a signal synthesized by said synthesizing circuit.

A vertical velocity modulation apparatus for modulating the scanning speed in the vertical direction of an electron beam for successively forming scanning lines in the horizontal direction on a screen, comprising:

• a movement control circuit for producing a movement control signal for controlling the movement in the vertical direction of the scanning lines such that a part of the scanning line having a luminance which is not less than a predetermined value in a luminance change portion in the vertical direction on the basis of a luminance signal moves farther apart from a part of the adjacent scanning line having a lower luminance than said predetermined value;
• a vertical velocity modulation coil for generating a magnetic field for modulating the scanning speed in the vertical direction of the electron beam on the basis of the movement control signal produced by said movement control circuit;
• and
• a frequency domain emphasis circuit for emphasizing a predetermined portion of a frequency domain of said movement control signal produced by said movement control circuit, wherein
• said frequency domain emphasis circuit comprises:
• an extraction circuit for extracting said predetermined frequency domain of said movement control signal produced by said movement control circuit,
• an adjuster for adjusting the signal in-said frequency domain extracted by said extraction circuit;
• and
• an adder for adding said movement control signal produced by said movement control circuit and the signal in said frequency domain adjusted by said adjuster together.

A video display method comprising the steps of:

• deflecting an electron beam back and forth in the horizontal direction and the vertical direction, to successively form forward and backward scanning lines in the horizontal direction on a screen;
• and
• modulating the scanning speed in the vertical direction of the electron beam for successively forming scanning lines in the horizontal direction on a screen, wherein
• the step of modulating said scanning speed comprises the steps of:
• outputting a parallel scanning signal for making the forward and backward scanning lines parallel;
• producing a movement control signal for controlling the movement in the vertical direction of the scanning lines such that a part of the scanning line having a luminance which is not less than a predetermined value in a luminance change portion in the vertical direction on the basis of a luminance signal moves farther apart from a part of the adjacent scanning line having a lower luminance than said predetermined value;
• synthesizing said parallel scanning signal and said movement control signal;
• and
• generating a magnetic field for modulating the scanning speed in the vertical direction of the electron beam on the basis of a synthesized signal.

A video display method comprising the steps of:

• deflecting an electron beam in the horizontal direction and the vertical direction, to successively form scanning lines in the horizontal direction on a screen;
• and
• modulating the scanning speed in the vertical direction of the electron beam such that a part of the scanning line having a luminance which is not less than a predetermined value in a luminance change portion in the vertical direction moves farther apart from a part of the adjacent scanning line having a lower luminance than said predetermined value, wherein
• the step of modulating said scanning speed comprises the steps of:
• producing a movement control signal for controlling the movement in the vertical direction of the scanning lines on the basis of the luminance signal;
• emphasizing a predetermined portion of a frequency domain of said movement control signal;
• and
• generating a magnetic field for modulating the scanning speed in the vertical direction of the electron beam on the basis of said movement control signal, wherein
• said step of emphasizing includes the steps of:
• extracting said predetermined frequency domain of said produced movement control signal;
• adjusting the signal in said extracted frequency domain;
• and
• adding said produce movement control signal and the adjusted signal in said frequency domain together.