Three dimensional electro-optical retrieval system
AssigneeVideonics of Hawaii, Inc.
InventorsPeter G. Wohlmut, Frank D. Neu
Life of this patent
Estimating the term…
Abstract
A system for sensing information located in tracks in various layers or depths of a recording medium. The desired information is electro-optically tracked in three dimensions to provide sensing of the information contained in the multi-layered recording medium.
Claims19
An electro-optical retrieval system for retrieval of information from any one of a plurality of layers of a recording medium and of the type wherein relative motion is imparted between the recording medium and pick-up means for causing said information to be scanned for retrieval thereof, comprising
- means for receiving an information containing multi-layered recording medium, said recording medium having at least two adjacent layers each of which comprises an optically transparent substrate and optically readable data thereon in the form of a data track and a surrounding area, and
- electro-optical pick-up means for retrieving information selectively from any one of said layers, said electro-optical means including
- light source means exterior to said recording medium for flooding with light the general area of interest of at least two adjacent layers of said multi-layered recording medium,
- detector means and lens means for focusing an image of an area of a selected layer of said recording medium onto said detector means, the image so focused comprising a portion of the data track and surrounding area of the selected layer, said lens means having a short focal length providing a depth of field less than the thickness of two adjacent substrates to enable focusing of the data track between adjacent substrates of said recording medium, and
- control means for causing said focusing of the data track from a selected layer of said recording medium through said lens means onto said detector means.
An electro-optical retrieval system for retrieval of information from any one of a plurality of layers of a recording medium and of the type wherein relative motion is imparted between the recording medium and pick-up means for causing said information to be scanned for retrieval thereof, comprising
- means for receiving an information containing multilayered recording medium, said recording medium having at least two adjacent layers each of which comprises an optically transparent substrate and optically readable data thereon in the form of a data track and a surrounding area, and
- electro-optical pick-up means for retrieving information selectively from any one of said layers, said electro-optical means including
- light source means exterior to said recording medium for flooding with light the general area of interest of plural adjacent layers of said multi-layered recording medium, and
- detector means and lens means for focusing an image of an area of a selected layer of said recording medium onto said detector means, the image so focused comprising a portion of the data track and surrounding area of the selected layer, said lens means having a short focal length providing a depth of field less than the thickness of two adjacent substrates to enable focusing of the data track between adjacent substrates of said recording medium, said detector means deriving from said focused image information for tracking the data track of the selected layer and for retrieving data from the data track of the selected layer, and said lens means including positioning means responsive to said tracking information from said detector means for laterally positioning said lens means for tracking the selected data track, and including means for positioning said lens means in a direction normal to the plane of the recording medium for causing the focusing of the image of an area of the selected layer of said recording medium.
An electro-optical retrieval system for retrieval of information from any one of a plurality of layers of a recording medium and of the type wherein relative motion is imparted between the recording medium and pick-up means for causing said information to be scanned for retrieval thereof, comprising
- means for receiving an information containing recording medium, said recording medium having at least first, second and third adjacent layers each of which comprises an optically transparent substrate and optically readable data thereon in the form of a data track and a surrounding area, and
- electro-optical pick-up means for retrieving information selectively from any one of said layers, said electro-optical means including
- light source means exterior to said recording medium for flooding with light the general area of interest of adjacent layers of said multi-layered recording medium,
- detector means for receiving an image of an area of a selected layer of said recording medium and providing tracking information for tracking a selected data track and retrieving data from the selected data track,
- lens means for focusing the image onto said detector means, the image so focused comprising a portion of the data track and surrounding area of the selected layer, said lens means comprising a lens having a short focal length providing a depth of field less than the separation between data tracks of alternate layers of said recording medium, and
- control means responsive to said detector means, and including positioning means responsive to said tracking information from said detector means for laterally positioning said lens means for tracking the selected data track, and including means for positioning said lens means in a direction normal to the plane of the recording medium for causing the focusing of the image of an area of the selected layer of said recording medium.
Dependencies are inferred from the claim text.