摘要 |
<p>A record carrier for, for example, video and/or audio information, which information is recorded in an optical structure, and an apparatus for reading the record carrier are described. By means of an additional electrically conducting plate which together with an electrically conducting highly reflecting coating of the optical structure forms a capacitive element the distance by which the image-forming objective system and the optical structure are spaced from one another can be measured.</p> |