Method and apparatus for data recording disc playback

A data recording disc playback apparatus capable of playback of a data recording disc with predetermined data which has been subjected to digital modulation processing recorded in a first area of said disc and a video signal which has been subjected to frequency modulation processing recorded with a predetermined digital signal superimposed thereon in a second area of said disc disposed peripherally outward from said first area, the apparatus comprising:

• an equalizer circuit for performing compensation of a frequency characteristic of a playback digital signal, and;
• means for detecting when a data detection point of a pickup of said apparatus reaches positions adjacent to respective boundaries of said first and second areas, and for producing a corresponding detection signal;
• wherein the improvement comprises:
• means for executing changeover of an equalizing chaacteristic of said equalizer circuit in accordance with indication of said first and second areas respectively by said detection signal.

A data recording disc playback apparatus capable of playback of a data recording disc with predetermined data which has been subjected to digital modulation processing recorded in a first area of said disc and a video signal which has been subjected to frequency modulation processing recorded with a predetermined digital signal superimposed thereon in a second area of said disc disposed peripherally outward from said first area, the apparatus comprising:

• an equalizer circuit for performing compensation of a frequency characteristic of a playback digital signal;
• an amplitude control circuit for controlling an amplitude of an said playback digital signal;
• means for detecting when said data detection point has reached positions adjacent to respective boundaries of said first and second areas, and for producing a corresponding detection signal;
• wherein the improvement comprises:
• means for executing changeover of an equalizing characteristic of said equalizer circuit and of a degree of control applied by said amplitude control circuit, respectively, in accordance with indication of said first and second areas respectively by said detection signal.

A data recording disc playback apparatus capable of playback of a data recording disc with predetermined data which has been subjected to digital modulation processing recorded in a first area of said disc and a video signal which has been subjected to frequency modulation processing recorded with a predetermined digital signal superimposed thereon in a second area of said disc disposed peripherally outward from said first area, the apparatus comprising:

• a pickup for directing a light beam onto a recording surface of said data recording disc for detecting recorded data of said disc by means of light reflected from said recording surface;
• focus servo means for controlling a position of a focal point of said light beam, to forma data detection ponit of said pickup on said recording surface;
• tracking servo means for controlling the position of said data detection point along a radial direction of said disc;
• carriage servo means for controlling the position of a carriage which supports said pickup, along a radial direction of said disc;
• spindle servo means for controlling a relative velocity of displacement of said data detection point with respect to said disc and;
• means for detecting when said data detection point has reached positions adjacent to respective boundaries of said first and second areas, and for producing a corresponding detection signal;
• wherein the improvement comprises:
• means for executing changeover of an equalizing characteristic of an equalizer circuit of at least one of said tracking servo means, said carriage servo means, and said spindle servo means, in accordance with indications of said first area and said second area respectively by said detection signal.

A data recording disc playback apparatus capable of playback of a data recording disc with predetermined data which has been subjected to digital modulation processing recorded in a first area of said disc and a video signal which has been subjected to frequency modulation processing recorded with a predetermined digital signal superimposed thereon in a second area of said disc disposed peripherally outward from said first area, the apparatus comprising:

• a pickup for directing a light beam onto a recording surface of said data recording disc for detecting recorded data of said disc by means of light reflected from said recording surface;
• focus servo means for controlling a position of a focal point of said light beam, to form a data detection point of said pickup on said recording surface;
• tracking servo means for controlling the position of said data detectio point along a radial direction of said disc;
• carriage servo means for controlling a position of a carriage which supports said pickup, along a radial direction of said disc;
• spindle servo means for controlling a relative velocity of displacement of said data detection point with respect to said disc and;
• means for detecting when said data detection point has reached positions adjacent to respective boundaries of said first and second areas, and for producing a corresponding detecting signal;
• wherein the improvement comprises:
• means for executing changeover of an equalizing characteristic of an equalizer circuit and the gain of a servo amplifier, respectively, of at least one of said tracking servo means, said carriage servo means, and said spindle servo means, in accordance with indications of said first area and said second area respectively by said detection signal.

A data recording disc playback apparatus capable of playback of a data recording disc with predetermined data which has been subjected to digital modulation processing recorded in a first area of said disc and a video signal which has been subjected to frequency modulation processing recorded with a predetermined digital signal superimposed thereon in a second area of said disc disposed peripherally outward from said first area, the apparatus comprising:

• a pickup for directing a light beam onto a recording surface of said data recording disc for detecting recorded data of said disc by means of light reflected from said recording surface;
• first means for biasing a data detection point of said pickup along a radial direction of said disc;
• second means for moving said pickup along a radial direction of said disc;
• means for applying drive pulses to said first means and second means in response to a track jump command and;
• means for detecting when said data detection point has reached positions adjacent to respective boundaries of said first and second areas, and for producing a corresponding detection signal;
• wherein the improvement comprises:
• means for changeover of at least one of the pulse width and the amplitude of said drive pulses, in accordance with indication by said detection signal of said first area and second area respectively.

A data recording disc playback apparatus capable of playback of a data recording disc with predetermined data which has been subjected to digital modulation processing recorded in a first area of said disc and a video signal which has been subjected to frequency modulation processing recorded with a predetermined digital signal superimposed thereon in a second area of said disc disposed peripherally outward from said first area, said disc further having television standard data expressing a color television standard recorded in a lead-in area thereof, the apparatus comprising means for controlling the speed of rotation of said disc in accordance with a phase difference between a playback clock signal contained in a playback digital signal and a reference clock signal;

• wherein the improvement comprises:
• means for judging the television standard of said disc, based on said television standard data, and for producing a non-correspondence signal in the event that said television standards of said disc and said apparatus are respectively different;
• means responsive to said non-correspondence signal for inhibiting a playback television signal from being produced as an output of said apparatus, and;
• means responsive to said non-correspondence siganl for producing an indication that the television standard of a disc being played by said apparatus and the television standard said apparatus are respectively different.

A data recording disc playback apparatus capable of playback of a data recording disc with predetermined data which has been subjected to digital modulation processing recorded in a first area of said disc and a video signal which has been subjected to frequency modulation processing recorded with a predetermined digital signal superimposed thereon in a second area of said disc disposed peripherally outward from said first area;

• wherein the improvement comprises:
• means for generating a first error signal in accordance with a phase difference between a playback clock signal contained in a playback digital signal and a reference clock signal;
• means for generaing a second error signal in accordance with a phase difference between a clock signal contained in a playback video signal and a reference clock signal, and;
• means for controlling the speed of rotation of said disc in accordance with said first error signal during playback of said first area and for controlling said speed of rotation in accordance with said second error signal during playback of said second area.