Patent ID: 6791913
Filing Date: 2004-09-14
Classification: B82Y,G11B

Abstract:
An optical recording apparatus comprising:first optical means for condensing light to be applied to an optical recording medium, said first optical means having a numerical aperture; second optical means interposed between the first optical means and the optical recording medium, for attaining a numerical aperture larger than the numerical aperture of the first optical means; main control means for maintaining a predetermined distance between the second optical means and the optical recording medium, by utilizing a linear characteristic of an amount of light reflected from the optical recording medium in a near-field region provided between an end of the second optical means and the optical recording medium; means for setting a threshold value corresponding to the amount of the light reflected from the optical recording medium and a control target value falling within the linear characteristic of the amount of light reflected; and a sub-control means for suppressing the influence of the amount of light reflected when the amount of light reflected is greater than the threshold value, and in which the main control means or the sub-control means, or both are used in accordance with a relation the amount of light reflected has with the threshold value or the control target value.