US 7,623,420 B2 · Focus servo control method in optical disc device

Abstract

A focus servo control method for an optical disc device is provided which compensates for variations present on the disc while printing a label on a label surface of the disc. The label surface of the disc is radially divided into a plurality of areas arranged about the center of the disc, and a focus swing operation is performed for each of the radially divided areas to detect an RF signal. Respective center points of pulses in the detected RF signal are regarded as optimal focus points, and focus driving voltages corresponding respectively to the center points are detected and stored in association with the corresponding areas. When a label is printed on the label surface, feed-forward focus servo control is performed based on the stored focus driving voltages. Accordingly, feed-forward focus servo control can be performed while compensating for variations the disc, thereby improving the label printing operation and quality of the resulting label.

Claims20

Dependent claims

A method of printing on a LightScribe disc, comprising:

determining whether a recordable medium is a LightScribe disc based on a first pattern corresponding to spokes provided near an inner circumference of the recordable medium using a spoke detector;
determining whether a surface facing an optical pickup device corresponds to a data surface or a label surface based on whether reflection of optical light occurs on the surface or within the LightScribe disc;
detecting a second pattern corresponding to an index mark;
synchronizing with a spoke corresponding to position “0”, the spokes providing location information of an index mark, a saw teeth area, a media ID area, and controlling a speed of rotation of the LightScribe disc;
detecting media ID on the Lightscribe disc;
and
printing on the label surface of the LightScribe disc, wherein the label surface is divided radially into a plurality of areas, and a first focus point for the optical pickup device is determined for each of the plurality of areas, and the first focus point is used in its corresponding area of the label surface during printing.

4 more elements

A method of printing a label on recordable medium including a data surface configured to receive and store data on a first side thereof, and a label surface configured to receive a label printed thereon on a second side opposite the first side, the method comprising:

reading a first pattern from the recordable medium to determine if the recordable medium includes both a data surface on a first side thereof and a label surface on a second side opposite the first side thereof, wherein the first pattern is read by a spoke detector and comprises a plurality of spokes provided proximate an inner circumference of a recordable medium;
determining if a surface of the recordable medium facing an optical pickup device corresponds to the data surface or the label surface of the recordable medium based on a reflection of optical light from the surface of the recordable medium facing the optical pickup;
synchronizing operation of the optical pickup device with a reference position delineated by the first pattern if it is determined that the surface of the recordable medium facing the optical pickup device is the label surface;
dividing the label surface into a plurality of radial areas;
determining a plurality of first optimum focus points each corresponding to a respective area of the plurality of areas;
and
performing a label printing operation to print an image on the label surface of the recordable medium based on the plurality of first optimum focus points.

4 more elements

Dependencies are inferred from the claim text.

Focus servo control method in optical disc device

Life of this patent

Focus servo control method in optical disc device

Life of this patent

Abstract

Claims20