Method and apparatus for recording and/or reproducing data on a disk formatted in accordance with a constant linear velocity (CLV) system

In an apparatus for recording information on a disk type recording medium and which comprises drive means for rotating the recording medium, head means movable in a radial direction relative to said disk type recording medium for scanning radially successive substantially circular tracks on the recording medium, and recording circuit means connected with said head means and operable in response to a clock signal for causing said head means to record information in tracks then scanned thereby:

• the combination of
• means for generating a total zone number signal representing a total number of virtual zones arranged successively in said radial direction and into which said disk type recording medium is virtually divided with each said virtual zone being comprised of a respective plurality of said tracks;
• means for generating a track number signal representing the radial position, counted in a radially outward direction, of a respective one of said tracks scanned by said head means for the recording of said information therein;
• means responsive to said track number signal and said total zone number signal for generating a zone number signal representing one of said virtual zones in which said one of the tracks is situated;
• means responsive to said track number signal, said zone number signal and said total zone number signal for generating a rotational speed reference signal representing a desired rotational speed of said disk type recording medium, said drive means being operative in response to said rotational speed reference signal to rotate said disk type recording medium at a predetermined angular velocity when said head means scans a track at the radially inner periphery of each of said virtual zones and to decrease said angular velocity progressively from said predetermined angular velocity at least so long as successive scanned tracks, considered in said radially outward direction, are within the same one of said virtual zones;
• and
• means responsive to said zone number signal and total zone number signal for generating said clock signal with the frequency thereof being increased stepwise for each of the successive zones considered in said radially outward direction and being maintained substantially constant at least as long as the tracks being scanned are within one of said zones.

In an apparatus for reproducing information recorded on a disk type recording medium formatted in accordance with a constant linear velocity system and which comprises drive means for rotating the recording medium, head means movable in a radial direction relative to said disk type recording medium for scanning radially successive substantially circular tracks on the recording medium, and reproducing circuit means connected with said head means and operable in response to a clock signal for reproducing information recorded in tracks then scanned by said head means:

• the combination of
• means for generating a total zone number signal representing a total number of virtual zones arranged successively in said radial direction and into which said disk type recording medium is virtually divided with each said virtual zone being comprised of a respective plurality of said tracks;
• means for generating a track number signal representing the radial position, considered in a radially outward direction, of one of said tracks scanned by said head means for reproducing of the information recorded therein;
• means responsive to said track number signal and said total zone number signal for generating a zone number signal representing one of said virtual zones in which said one of the tracks is situated;
• means responsive to said track number signal, said zone number signal and said total zone number signal for generating a rotational speed reference signal representing a desired rotational speed of said disk type recording medium, said drive means being operative in response to said rotational speed reference signal to rotate said disk type recording medium at a predetermined angular velocity when said head means scans a track at the radially inner periphery of each of said virtual zones and to decrease said angular velocity progressively from said predetermined angular velocity at least so long as successive scanned tracks, considered in said radially outward direction, are within the same one of said virtual zones;
• and
• means responsive to said zone number signal and total zone number signal for generating said clock signal with the frequency thereof being increased stepwise for each of the successive zones considered in said radially outward direction and being maintained substantially constant at least so long as the tracks being successively scanned are within the same one of said zones.

A method of processing data on a disk formatted in accordance with a constant linear velocity (CLV) system by means of apparatus having drive means for rotating said disk, head means movable in a radial direction relative to said disk for scanning radially successive substantially circular tracks on the disk, and circuit means connected with said head means and operable in response to a data transfer clock for causing said head means to selectively record or reproduce data in the tracks scanned thereby, said method comprising the steps of:

• dividing said disk into a plurality of virtual zones arranged successively in said radial direction and each comprised of a respective plurality of said tracks;
• determining the frequency of said data transfer clock during a recording or reproducing operation in dependence on the one of said virtual zones in which the tracks being scanned are situated at least during the initiation of said recording or reproducing operation, with said frequency determined at said initiation of the recording or reproducing operation being increased stepwise for each of the successive zones considered in the radially outward direction and being maintained substantially constant at least so long as the tracks being scanned are in the one of said zones at which said recording or reproducing operation was initiated;
• and
• establishing a predetermined angular velocity at which said drive means rotates said disk at said initiation of each said recording or reproducing operation and decreasing said angular velocity so long as successive tracks, considered in said radially outward direction, are scanned during said recording or reproducing operation in which said frequency of the data transfer clock is maintained substantially constant.

A method of recording information on a disk type recording medium by an apparatus having drive means for rotating the recording medium, head means movable in a radial direction relative to said disk type recording medium for scanning radially successive substantially circular tracks on the recording medium, and recording circuit means connected with said head means and operable in response to a clock signal for causing said head means to record information in tracks then scanned thereby:

• said method comprising the steps of
• generating a total zone number signal representing a total number of virtual zones arranged successively in said radial direction and into which said disk type recording medium is virtually divided with each said virtual zone being comprised of a respective plurality of said tracks;
• generating a track number signal representing the radial position, considered in a radially outward direction, of one of said tracks scanned by said head means for the recording of said information therein;
• generating, on the basis of said track number signal and said total zone number signal, a zone number signal representing one of said virtual zones in which said one of the tracks is situated;
• generating, on the basis of said track number signal, said zone number signal and said total zone number signal, a rotational speed reference signal representing a desired rotational speed of said disk type recording medium;
• controlling said drive means in response to said rotational speed reference signal so as to rotate said disk type recording medium at a predetermined angular velocity when said head means scans a track at the radially inner periphery of each of said virtual zones and to decrease said angular velocity progressively from said predetermined angular velocity at least so long as successive scanned tracks, considered in said radially outward direction, are within the same one of said virtual zones;
• and
• generating said clock signal in response to said zone number signal and said total zone number signal so that the frequency of said clock signal is increased stepwise for each of the successive zones considered in said radially outward direction and is maintained substantially constant at least as long as the tracks being successively scanned are within the same one of said zones.

A method of reproducing information recorded on a disk type recording medium formatted in accordance with a constant linear velocity system by means of an apparatus having drive means for rotating the recording medium, head means movable in a radial direction relative to said disk type recording medium for scanning radially successive substantially circular tracks on the recording medium, and reproducing circuit means connected with said head means and operable in response to a clock signal for reproducing information recorded in tracks then scanned by said head means:

• said method comprising the steps of
• generating a total zone number signal representing a total number of virtual zones arranged successively in said radial direction and into which said disk type recording medium is virtually divided with each said virtual zone being comprised of a respective plurality of said tracks;
• generating a track number signal representing the radial position, counted in a radially outward direction, of one of said tracks scanned by said head means for reproducing of the information recorded therein;
• generating, in response to said track number signal and said total zone number signal, a zone number signal representing one of said virtual zones in which said one of the tracks is situated;
• generating, in response to said track number signal, said zone number signal and said total zone number signal, a rotational speed reference signal representing a desired rotational speed of said disk type recording medium and which causes said drive means to rotate said disk type recording medium at a predetermined angular velocity when said head means scans a track at the radially inner periphery of each of said virtual zones and to decrease said angular velocity progressively from said predetermined angular velocity at least so long as successive scanned tracks, considered in said radially outward direction, are within the same one of said virtual zones;
• and
• generating said clock signal in response to said zone number signal and total zone number signal so that the frequency of said clock signal is increased stepwise for each of the successive zones considered in said radially outward direction and is maintained substantially constant at least so long as the tracks being successively scanned are within the same one of said zones.