The maintenance of a light spot of a chosen dimension on the surface of a rotating disc for optical playback or optical recording of data is effectively accomplished by a hydrostatic bearing apparatus. The apparatus includes: a housing for a lens assembly, which is disposed in the housing with its axis aligned parallel to the path of an incident light beam; a movable frame mounted on a support for movement in a direction substantially parallel to the light path; a pair of leaf springs coupling the housing to the frame for maintaining the axis of the lens assembly parallel to the light path; adjustable means for fixing an operating location for the movable frame; and a pressurized gas source coupled to a hydrostatic pad affixed to the lower portion of the housing, for providing a lubricating film of gas between the housing and the disc of a chosen thickness. The apparatus maintains the dimensions of the light spot focused on successive regions of the surface of the rotating disc independent of variations, if any, in the height of the successive regions.
An automatic focusing device for microscopes comprising nozzles arranged around the individual objective lenses, a gas feed pipe attached to the arm or the similar member of the microscope, and a coupler arranged in or near the objective lens switching device and used for connecting said gas feed tube to said nozzle, said automatic focusing device being adapted in such a manner that when objective lenses are switched from one to another to be used for microscopy by rotating said objective lens switching device, the nozzle arranged around the objective lens to be used for microscopy is connected to said gas feed tube, whereby the gas supplied through said gas feed tube passes through said coupler and is injected from said nozzle for focusing the objective lens to be used for microscopy.
An optical sensor includes a vortex diffuser bearing for support of the optical elements thereof in a fixed, spaced apart and angular relationship relative to a subjacent surface. The sensors are readily adapted to be fabricated into matrices adapted for high volume scanning of surfaces, as for example to detect irregularities in the coatings thereof. The sensors are also adaptable for use in photogrammetry, microdensitometry, or other applications wherein precise, stable and repeatable positioning is required.
An improved optical system support and positioning device for use in an optical reading apparatus, for instance, an optical or audio disc reading apparatus, in which the tracking function of the optical system is improved. An electromagnetic positioning structure moves the optical system parallel and perpendicular to the direction of the optical axis of the optical system while the optical system is supported by a support element. The support element includes a pair of cantilevered flexible members, a pair of substantially parallel support members, and an intermediate section joining ends of the flexible members and support members. In accordance with the invention, the distance between fixed ends of the support members is greater than the distance between the free ends thereof.
A structure for focusing, collimating or diverging the light beam from a solid state laser diode comprises means non-symmetrically mounted between the structure for holding the lens system and the means for holding the laser diode thereby to allow the laser diode to be adjusted in position relative to the lens system along the optical axis of the lens system. Surprisingly, the non-symmetrical mounting of the adjusting means relative to the optical axis of the lens system does not cause any substantial transverse movement of the laser diode relative to the optical axis of the lens system. In one embodiment, the adjusting means comprises a screw rotatably mounted such that one end of the screw is rotatably screwed into with the structure holding the lens system and the other end of the screw is in rotatable contact the structure holding the laser diode. This other end is adapted to receive a turning instrument thereby to allow the screw to be rotated to thus adjust the position of the laser diode relative to the lens.
An optical disc reader is provided in which automatic focussing is achieved by movements of elements completely removed from the moving head which travels across the optical disc.
