US 6,204,989 B1 · Controlling a media master writing machine to produce curvilinear servo sector patterns

Abstract

Curvilinear servo sector patterns are produced on a master media by determining a series of offsets between a radially aligned reference and the desired curvilinear servo sector and expressing each offset as a delay that can be expressed in settings for controlling a master writer. Incorporation of the delay into the master writer allows a curvilinear servo sector pattern to be produced using data mapping that is ordinarily used for the radially aligned servo sector pattern. Thus, curvilinear servo sector patterns with a desired resolution are produced without increasing computational overhead or memory requirements, or decreasing throughput. The delay can be converted into control settings such as sector delay, clock cycle delay and residual fractional delay settings that each represent a portion of the delay. In certain embodiments, a piece-wise linear approximation of the curvilinear shape can be implemented to reduce the amount of required control data, and a master writer controller that generates pulses for multiple lasers can be implemented.

Claims20

Dependent claims

A method for determining settings for controlling a master writer to produce curvilinear servo sector patterns on a master disk, the method comprising:

determining a first offset from the distance between a reference axis and a curvilinear servo sector along a first track on the master disk;
determining a second offset from the distance between the reference axis and the curvilinear servo sector along a second track on the master disk, the second offset having a different value from the first offset;
using the first offset to determine a first set of master writer control settings for writing information to the curvilinear servo sector along the first track;
and
using the second offset to determine a second set of master writer control settings for writing information to the curvilinear servo sector along the second track.

2 more elements

An apparatus for determining parameters for controlling a master writer to produce curvilinear servo sector patterns on a master disk, the apparatus comprising:

a format parameters module, for providing a reference axis that is aligned with the radius of the master disk;
an offset determining module, in communication with the format parameters module, for determining a first offset between the reference axis and a curvilinear servo sector along a first track on the master disk, and determining a second offset between the reference axis and the curvilinear servo sector along a second track on the master disk, the second offset having a different value from the first offset;
and
a delay settings determining module, in communication with the offset determining module, for using the first offset to determine a first set of master writer control settings for writing information to the curvilinear servo sector along the first track, and using the second offset to determine a second set of master writer control settings for writing information to the curvilinear servo sector along the second track.

1 more element

Dependencies are inferred from the claim text.

Controlling a media master writing machine to produce curvilinear servo sector patterns

Life of this patent

Controlling a media master writing machine to produce curvilinear servo sector patterns

Life of this patent

Abstract

Claims20