Patent ID: 6240054
Filing Date: 2001-05-29
Classification: G11B

Abstract:
In an information reproducing apparatus for reproducing information from a multiple layer disk, a method of preparing for reproducing the information from the multiple layer disk, the multiple layer disk comprising a plurality of layers including at least a first layer and a second layer, the information being recorded on each of the first layer and the second layer, the information reproducing apparatus comprising: a light emitting device that emits a light beam to the first layer or the second layer; an objective lens that focuses the light beam on the first layer or the second layer; a focus servo device that carries out a focus servo control for controlling a focal position of the light beam with respect to the first layer or the second layer; a tracking servo device that carries out a tracking servo control for controlling a position of the light beam in a radial direction of the multiple layer disk with respect to the first layer or the second layer; a reproducing device that reads the information recorded an the first layer or the second layer using the light beam and that reproduces the read information under the focus servo control and the tracking servo control; and a memory device, the method comprising the processes of:determining a first gain value to be used for the focus servo control with respect to the first layer, by detecting a focus error signal with respect to the first layer;determining a second gain value to be used for the focus servo control with respect to the second layer, by detecting a focus error signal with respect to the second layer; andstoring the first and second gain values into the memory device,wherein the processes of determining the first and second gain values and the process of storing the first and second gain values are carried out before a start of reproducing the information from the multiple layer disk.