Class 369/44.24 - Means to mask or shield a portion of the beam

Subclass of Class 369 - Dynamic information storage or retrieval
Definition: Subject matter wherein a modification is performed by masking
No. of patents: 243
Last issue date: 11/29/2011

Number	Title	Issue Date
3971002	Device for the optical read-out of a diffractive track belonging to a data carrier in the form of a disc or tape The present invention relates to the optical read-out of a diffractive track carried by a data carrier. The object of the invention is an optical read-out device in which concentrated illumination of the track is effected by at least two collateral read-o...	07/20/1976
3969575	Opto-electronic focus detection system In an opto-electronic focus detection system for determining a deviation between the plane of focussing of an objective and a radiation-reflecting surface the path of a focussing beam which is reflected by said surface includes an assembly of two radiatio...	07/13/1976
3969576	Apparatus for reading a record carrier with an optical information structure In an apparatus for reading a record carrier on which information is stored in an optically readable structure, the radiation which is supplied by the radiation source is split into a read beam and an auxiliary beam for determining the focussing of the re...	07/13/1976

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