Scan velocity modulation system with auxiliary vertical deflection towards bright side of video signal transitions

Apparatus for improving the sharpness of pictures, comprising:

• a picture tube with means for deflecting an electron beam (15) in a vertical direction and a horizontal direction for producing a raster scanned image;
• an interlace-progressive up-converter circuit (11);
• a vertical scan modulation unit (VSM) coupled to said picture tube and to said up-converter circuit, for generating a signal for additional deflection of said electron beam of said tube in said vertical direction in response to brightness transitions (FIG. 2b, FIG. 3b) of a video signal produced by said up-converter circuit, said video signal having at minimum a vertical component of lines (y(n-1), y(n), y(n+1)) passed from an output of said up-converter circuit to an input of said modulation unit;
• first means in said modulation unit for enabling said additional deflection solely for such lines (16,21,31,41,n) which are located in-between and are interpolated from original lines of a field and
• second circuit means in said modulation unit for changing the brightness of respective pixels (xi) of said interpolated lines in response to said brightness transitions.

Apparatus for improving sharpness of pictures displayed with a line structure on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said picture;
• means for providing auxiliary vertical deflection for vertically deflecting said scanning beam in response to brightness transitions having at least a vertical component of a video signal applied to said picture tube;
• means for enabling said auxiliary vertical deflection for said scanning beam only for lines which are located in-between and are interpolated from original lines of a field;
• and
• means for controlling said auxiliary vertical deflection such that at said brightness transitions of said vertical component said beam is deflected to the bright side of said brightness transitions of said video signal applied to said picture tube.

Apparatus for improving sharpness of pictures displayed with a line structure on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said pictures;
• means for providing auxiliary vertical deflection for vertically deflecting said scanning beam in response to brightness transitions having at least a vertical component of a video signal applied to said picture tube;
• means for enabling said auxiliary vertical deflection for said scanning beam only for lines which are located in-between and are interpolated from original lines of a field;
• means for controlling the amplitude of said auxiliary vertical deflection as a function of pixel difference values derived from at least one of:
• (i) the slope of said brightness transitions of said vertical component of said video signal applied to said picture tube;
• and
• (ii) the direction of said brightness transitions of said vertical component of said video signal applied to said picture tube.

Apparatus for improving sharpness of pictures displayed with a line structure on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said pictures;
• means for providing auxiliary vertical deflection for vertically deflecting said scanning beam in response to brightness transitions having at least a vertical component of a video signal applied to said picture tube;
• means for enabling said auxiliary vertical deflection for said scanning beam only for lines which are located in-between and are interpolated from original lines of a field;
• means for controlling the amplitude and the sign of said auxiliary vertical deflection in accordance with a staircase function relating to pixel difference values;
• and
• means for subjecting said auxiliary vertical deflection to an amplitude limitation.

Apparatus for improving sharpness of pictures displayed with a line structure on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said pictures;
• means for providing auxiliary vertical deflection for vertically deflecting said scanning beam in response to brightness transitions having at least a vertical component of a video signal applied to said picture tube;
• means for enabling said auxiliary vertical deflection for said scanning beam only for lines which are located in-between and are interpolated from original lines of a field;
• means for providing a control signal for at least one of (i) modifying the brightness of pixels of said interpolated lines, and (ii) modifying said auxiliary deflection of said beam;
• and
• means for averaging said control signal over a plurality of pixels.

Apparatus

• for improving sharpness of pictures displayed with a line structure on a picture tube having a scanning beam, comprising:
• means for scanning said picture tube with said scanning beam to produce said pictures;
• means for providing auxiliary vertical deflection for vertically deflecting said scanning beam in response to brightness transitions having at least a vertical component of a video signal applied to said picture tube;
• means for enabling said auxiliary vertical deflection for said scanning beam only for lines which are located in-between and are interpolated from original lines of a field;
• and
• means of providing a respective additional deflection for said scanning beam in a horizontal direction in response to brightness transitions having at least a horizontal component of said video signal applied to said picture tube.

A method for improving sharpness of pictures displayed on a picture tube having a scanning beam, comprising:

• scanning said picture tube with said scanning beam to produce said pictures;
• providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original elements of a field;
• and
• controlling said auxiliary deflection such that at said brightness transitions said beam is deflected to the bright side of said brightness transitions having said component in said given direction of said video signal applied to said picture tube.

A method for improving sharpness of pictures displayed on a picture tube having a scanning beam, comprising:

• scanning said picture tube with said scanning beam to produce said pictures;
• providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• and
• controlling the amplitude of said auxiliary deflection as a function of pixel difference values derived from at least one of:
• (i) the slope of said brightness transitions;
• and
• (ii) the direction of said brightness transitions.

A method for improving sharpness of pictures displayed on a picture tube having a scanning beam, comprising:

• scanning said picture tube with said scanning beam to produce said pictures;
• providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• controlling the amplitude and the sign of said auxiliary deflection in accordance with a staircase function relating to pixel difference values;
• and
• subjecting said auxiliary deflection to an amplitude limitation.

A method for improving sharpness of pictures displayed on a picture tube having a scanning beam, comprising:

• scanning said picture tube with said scanning beam to produce said pictures;
• providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• and
• modifying the brightness of respective pixels of said interpolated lines according to pixel difference values derived from at least one of (i) the slope of said brightness transitions and (ii) the direction of said brightness transitions.

A method for improving sharpness of pictures displayed on a picture tube having a scanning beam, comprising:

• scanning said picture tube with said scanning beam to produce said pictures;
• providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• and
• providing a control signal for at least one of (i) modifying the brightness of pixels of said interpolated lines, and (ii) modifying said auxiliary deflection of said beam;
• and (iii) averaging said control signal over a plurality of pixels.

A method for improving sharpness of pictures displayed on a picture tube having a scanning beam, comprising:

• scanning said picture tube with said scanning beam to produce said pictures;
• providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• and
• providing an additional deflection for said scanning beam in a direction normal to said given direction for enhancing the edges of brightness transitions of said video signal in said direction normal to said given direction.

Apparatus for improving sharpness of images displayed on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said images;
• means for providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• means for enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• and
• means for controlling said auxiliary deflection such that at said brightness transitions said beam is deflected to the bright side of said brightness transitions having said component in said given direction of said video signal.

Apparatus for improving sharpness of images displayed on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said images;
• means for providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• means for enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• and
• means for controlling the amplitude of said auxiliary deflection as a function of pixel difference values derived from at lease one of:
• (i) the slope of said brightness transitions having said component in said given direction of said video signal;
• and
• (ii) the direction of said brightness transitions having said component in said given direction of said video signal.

Apparatus for improving sharpness of images displayed on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said images;
• means for providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• means for enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• means for controlling the amplitude and the sign of said auxiliary deflection in accordance with a staircase function relating to pixel difference values;
• and
• means for subjecting said auxiliary deflection to an amplitude limitation.

Apparatus for improving sharpness of images displayed on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said images;
• means for providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• means for enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• and
• means for modifying the brightness of respective pixels of said interpolated lines according to pixel difference values derived from at least one of (i) the slope of said brightness transitions and (ii) the direction of said brightness transitions.

Apparatus for improving sharpness of images displayed on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said images;
• means for providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• means for enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• and
• means for providing a control signal for at least one of (i) modifying the brightness of pixels of said interpolated lines, and (ii) modifying said auxiliary deflection of said beam;
• and (iii) averaging said control signal over a plurality of pixels.

Apparatus for improving sharpness of images displayed on a picture tube having a scanning beam, comprising:

• means for scanning said picture tube with said scanning beam to produce said images;
• means for providing auxiliary deflection in a given direction for deflecting said scanning beam in said given direction in response to brightness transitions having at least a component in said given direction of a video signal applied to said picture tube;
• means for enabling said auxiliary deflection for said scanning beam only for picture elements which are located in-between and are interpolated from original picture elements of a field;
• and
• means for providing an additional deflection for said scanning beam in a direction normal to said given direction for enhancing the edges of brightness transitions of said video signal in said direction normal to said given direction.