Abstract: An optical position sensor system is disclosed for determining the angular position of a rotary member having a longitudinal rotation axis that extends in an axial direction. The system includes a single light source aligned along the rotation axis. A collimating element is adjacent the light source a predetermined distance, the collimating element aligned along the rotation axis to collimate light from the light source along the rotation axis. A detection element is adjacent the collimating element a predetermined distance to receive collimated light from the collimating element and to provide a linear output. A light blocker is inserted between the collimating element and the detection element, the light blocker coupled to the rotary member to rotate therewith about the rotation axis to block portions of the collimated light from the light source and the collimating element from reaching the detection element in direct relationship to the rotary position of the light blocker.

Abstract: A gas supported bearing includes a first stationary bearing element having a longitudinal axis and a first bearing surface. A second rotating bearing element is coaxially aligned with respect to the first bearing element and includes a second bearing surface. A pneumatic load ramp is formed in one of the bearing surfaces to apply an asymmetric load to either bearing element to eliminate bearing whirl instability.

Abstract: A self-pressurizing gas supported bearing includes a cylindrical bearing sleeve having a longitudinal axis and a cylindrical inner surface forming a first bearing surface with a random surface texture having a first R.sub.a roughness profile. A cylindrical bearing shaft is positioned coaxially within the bearing sleeve and includes a cylindrical outer surface forming a second bearing surface with a random surface texture having a second R.sub.a roughness profile. The sum of the first and second R.sub.a roughness profiles falls within the range of from about eighteen to sixty. A drive system establishes a relative rotational velocity between the bearing sleeve and the bearing shaft, generating a bearing stiffness force which causes the overlapping bearing surfaces to lift off and break contact. The bearing sleeve and shaft are dimensioned to maintain a predetermined means spacing between the sleeve and shaft. The bearing may also take the form of a linear bearing or other cylindrical configurations.

Abstract: An optical input beam is split into first and second beams lying in first and second non-parallel planes. A polygon mirror scanner receives the first and second beams on a single facet and generates first and second angularly displaced, non-parallel synchronized scans. Redirecting means is positioned in the optical path between the scanner and a scanned plane for redirecting a portion of the first and second synchronized scans onto a timing plane to generate third and fourth non-coincident, synchronized scans. A beam position signal consisting of equally spaced, sequential pulses is generated in response to the travel of either the third or fourth synchronized scan along a second scanned line lying within a timing plane. The beam position signal is representative of the position of both the first and second synchronized scans along the first scanned line. The second section of the laser inspection apparatus reads information from a surface having an area illuminated by the dual beams of the optical scanner.

Abstract: A system is disclosed for transforming a collimated beam of light into a beam of light which repetitively scans a fixed path by utilizing first and second mirrors repetitively rotated through a predetermined angular displacement. The angle between each mirror facet and mirror axis of rotation varies and defines a facet to axis error which is eliminated by the present invention. A first mirror receives an upper input beam and repetitively generates a first scan. A second mirror receives a lower input beam and repetitively generates a second scan. First and second redirecting means such as first and second prisms form first and second redirected scans which are ultimately reflected from the mirrors to generate a plurality of first and second output scans. A lens converges the first and second output scans onto a fixed path such that the scanner optical output beam repetitively scans the fixed path and eliminates the effect of the facet to axis errors of the first and second mirrors.

Abstract: An optical beam pulse generator comprises segmented reflecting means aligned to receive an input light beam. The segmented and reflecting means includes a plurality of circumferentially spaced apart mirror facets having a centrally located, vertically oriented axis of rotation and mirror facet to axis errors. The segmented reflecting means is rotated to sequentially reflect the input beam to generate a pulsed beam. A prism or similar device redirects the pulse beam back onto the reflecting means to generate a redirected pulse beam vertically displaced from the pulse beam by a distance related to the mirror facet to axis error and laterally offset from the pulse beam by a distance related to the angle between the mirror facet and the input light beam. The redirected pulsed beam is reflected from each of the mirror facets to generate a pulsed reflected output beam.

Abstract: A system is disclosed for transforming a collimated beam of light, such as that generated by a laser, into a beam of light which repetitively scans a fixed path by utilizing a mirror which is repetitively rotated through a predetermined angular displacement. The angle between the mirror axis of rotation and the mirror position relative to the axis varies between subsequent mirror rotations and defines a scanning beam rotational axis error which is eliminated by the present invention. An input beam of collimated light is directed onto the rotating mirror along a first path to produce a first scanned reflected output beam for each rotation of the mirror. A second scanned reflected output beam is generated by redirecting the first scanned reflected output beam through a prism and back onto the mirror along a second path. The second path is vertically displaced from the first path by a distance related to the mirror rotational axis error.