Abstract: Mode-index optical elements comprise an optical waveguide having a optical overlay of substantially uniform thickness. The contour of the overlay in the plane of the overlay controls the direction of propagation of radiation within the waveguide. According to the invention, mode-index optical elements are optimally achromatized (i.e., rendered as insensitive as possible to radiation wavelength changes) over a desired wavelength rqange by properly selecting the respective thicknesses and bulk refractive indices of the overlay and waveguide components. Specifically, such parameters are chosen so that, for a given waveguide substrate (e.g., quartz) and superstrate (e.g., air), the deviation of the ratio of the respective effective refractive indices of the waveguide element (N.sub.E) and waveguide material (N.sub.WG) from a mean or nominal value is minimized over the desired wavelength range of achromatization.

Abstract: A self-focusing optical head of the type used in magneto-optical and optical recording systems for directing a focused laser beam onto a moving recording surface uses a non-achromatized optical path between the laser and recording surface and the laser wavelength (mode) shifts induced by optically coupling reflected laser energy back to the laser cavity to automatically maintain the beam in sharp focus (i.e., self-focus) on the recording surface. A focus servo system including a photodetector positioned in the path of reflected laser energy serves to coarsely position a focusing lens relative to the recording surface. A field lens, used to concentrate reflected laser energy onto the photodetector, is achromatized to compensate for the chromatic aberration between laser and photodetector. Such achromatization allows the focus servo to operate independently of the wavelength (mode) shifts required to achieve self-focusing of the laser beam on the recording surface.

Abstract: To minimize the adverse effects of "flare" in reading-out stimulable phosphor recording elements, the light-collecting face of a photodetector is provided with a multiplicity of sharp, light-transparent, optical projections. By a combination of reflections and refractions, such optical projections serve to absorb substantially all incident photons thereby preventing phosphor-stimulating photons from being reflected by the photodetector's light-collecting face and exciting non-addressed regions of the recording element. Preferably, the optical projections take the form of a sawtooth array of optical wedges; however, pyramid-shaped and cone-shaped projections are also disclosed.

Abstract: A computer disk of the type having a central drive hub comprised at least in part of ferromagnetic metal to clamp the disk to a magnet spindle drive is provided with a ring-shaped amorphous ferromagnetic surveillance marker between the hub flange and the disk substrate. The hub metal has a high permeability, e.g. .gtoreq.2,000 to concentrate the drive magnet field in the hub, when the disk is in the disk drive, thereby to eliminate fringe fields that would magnetize the marker. This is to allow the use of a low magnetic field intensity sensor in the sensor to detect the presence of the marker to enable recording of data on the disk. The hub metal also has a coercivity between the coercivity of the marker and the intensity of the magnetic field employed in the interrogation zone of an area surveillance portal to eliminate the effect of any residual magnetism on the hub metal caused by the drive magnet thereby to enhance the detectability of the marker by the portal.

Abstract: Disclosed herein is a method for producing an amorphous aluminum nitride layer having a desired stoichiometry. Such method involves the steps of disposing a substrate in close proximity to an aluminum target in a low pressure atmosphere of nitrogen and an inert gas, and reactive sputtering an aluminum nitride layer onto the substrate at a certain minimum deposition rate while maintaining certain parameters (i.e. nitrogen-to-inert gas ratio, substrate temperature, sputtering power, nitrogen flow rate and sputtering pressure) within certain limits.

Abstract: The photoconductive layer of an electrophotographic plate, such as used to record radiographic patterns, is overcoated with a thin dielectric layer having luminescing (e.g., fluorescing or phosphorescing) properties. Upon being uniformly charged and imagewise exposed to actinic radiation (i.e. radiation to which the photoconductive layer responds), the resulting charge pattern is developed with toner. The toner-bearing surface of the electrophotographic plate is irradiated with radiation adapted to excite the luminescent overcoat. The toner image serves, in effect, to mask any luminescence by the underlying overcoat, thereby giving rise to a luminescent contrast image which may be recovered by laser scanning or CCD techniques, or photographed directly.

Abstract: A method and apparatus for anamorphically shaping a beam of radiation and for deflecting such beam by 90.degree.. The apparatus consists of a prism having at least four faces, two of such faces being parallel. The prism is arranged to receive a beam at the Brewster angle .THETA..sub.B, and is adapted to deflect the beam by 90.degree. by refraction and double internal reflection. The prism faces define four internal angles of .THETA..sub.B, 90.degree.+.THETA..sub.B, 90.degree.-.THETA..sub.B and 180.degree.-.THETA..sub.B.

Abstract: A passive infrared detection system includes a reflective optical system comprising a focusing element (e.g. an elliptical or parabolic reflector) having an apparent focal length dependent upon the displacement of incident rays from the optical axis of such element, and a plurality of planar reflectors arranged at different angles with respect to such optical axis to provide the detection system with a plurality of different zones of detection, each having a different maximum detection range associated with it. According to the invention, the planar reflectors are arranged with respect to the focusing element so that each planar reflector cooperates with a different portion of the focusing element to project onto an IR detector located at the focus of such focusing element a relatively constant size image of a given target located at the maximum detection range associated with that planar reflector.

Abstract: An infant carrier adapted to be worn about the waist of an adult for supporting and transporting an infant on the hip of the wearer. According to a preferred embodiment, such carrier comprises a shaped member having first and second contoured portions joined along an arcuate line approximating the waist line of the intended wearer. The first contoured portion is shaped to receive and support the buttocks and legs of an infant who is positioned to face the adult wearer with legs straddling the wearer's waist. The second contoured portion is shaped to the hip region of the wearer. The carrier may also include a belt for securing the shaped member to the wearer's waist. By virtue of its design, the weight of the infant is broadly distributed about the wearer's waist and hip region, thereby avoiding the neck and shoulder strain characteristic of heretofore proposed infant carriers.

Abstract: Apparatus for controlling the radial position of a transducer (e.g. an optical, magneto-optic, or magnetic write/read head) relative to a spinning disk (e.g. a data storage disk) comprises a transducer-supporting radial access arm which is mounted via a rotary bearing for pivotal movement about a spinning support shaft. The continuous rotary movement of the support shaft dramatically reduces stick-slip friction in the bearings separating the support shaft and the access arm, thereby reducing start-up torque and enabling more precise positioning of the transducer relative to the disk. Moreover, it prolongs the life of the rotary bearing in that it eliminates so-called Brinelling (wearing of the bearing balls or rollers due to small oscillations about the same point).

Abstract: A passive infrared detection system embodies a new three-element, single-channel, pyroelectric detector. For a given amount of motion by a target in a region under surveillance, the detector provides more complex signature information than conventional two-element detectors, thereby allowing the target to be more readily distinguished from spurious environmental or background sources. Owing to the geometry of the detector electrodes, the false-alarming effects produced by spurious stimuli common to all detector elements are reduced. The detector is particularly adapted for use in infrared detection systems of the type which use pulse-counting techniques to distinguish targets of interest from non-targets.

Abstract: Radial access apparatus for controlling the coarse and fine radial position of a read/write head relative to a data storage disk (e.g. optical, magneto-optical and magnetic disks) comprises a radial access arm supported for movement about a virtual pivot point by a pair of converging flexure members. An electromagnetic motor is provided for controlling the position of the arm to position a read/write head, supported by such arm, opposite a desired data track on the disk.

Abstract: Apparatus for sensing the instantaneous tracking position of a lens used in an optical read/write head for optically reading and/or writing information on an optical recording element (e.g. an optical disk). Such apparatus includes a variable inductance transducer which is positioned in close proximity to an electrically conductive, movably mounted lens support. As the lens is moved in a direction perpendicular to its optical axis, the lens support moves relative to the transducer, thereby varying the transducer's inductance. Circuit means responsive to the instantaneous transducer inductance provides a signal representative of the instantaneous lens position. Such signal is used to close a position feedback loop which maintains a fixed position of the lens axis relative to the optical axis of the head during sudden movements of the head (e.g. as occurs in during radial access in an optical disk recording system).

Abstract: A carrier for releasably retaining a data storage disk comprises a pair of crescent shaped frame members which cooperate to define a generally circular aperture for receiving a data storage disk. The frame members are preferably identical in shape and slidably coupled so as to vary the size of the aperture. The aperture-defining walls of the frame members define arcuate grooves adapted to support the peripheral region of the data storage disk, preferably over an arc length of at least 90.degree.. Spring means are provided for resiliently urging the frame members together so that the groove-defining surfaces of said frame members cooperate to support a data storage disk positioned in the aperture.

Abstract: A carrier for an optical disk or the like is provided with a pair of resilient buffer elements to isolate the relatively delicate disk assembly from impulse spikes to which the carrier may be subjected. The disk carrier comprises a pair of frame members having respective arcuate surfaces which cooperate to define a generally circular aperture for receiving a data storage disk. The resilient buffer elements are arranged along such arcuate surfaces, each element having a groove-defining surface which is adapted to support the periphery of an optical disk. The carrier frame members are slidably coupled so as to vary the size of the circular aperture defined by their respective arcuate surfaces, and means are providing for urging the carrier frame members together so that a disk positioned in the carrier's aperture is engaged and supported by the grooves formed in the buffer elements.

Abstract: A carrier for releasably retaining a data storage disk comprises a pair of frame members which cooperate to define a generally circular aperture for receiving a data storage disk. The frame members are slidably coupled so as to vary the size of the aperture. The aperture-defining walls of the frame members are provided with a disk-holding means adapted to engage and support the peripheral region of a data storage disk. The frame members are resiliently urged together so that they take a position in which the disk-holding means engage and support a data storage disk positioned in the aperture. A locking mechanism is provided for releasably locking the frame members in the aforesaid position.

Abstract: A write-protected data storage disk assembly comprises a disk carrier having a write-protect member movably mounted thereon for movement between two positions in which it enables and inhibits the writing/erase functions of a disk drive unit. During periods of non-use, the carrier is totally contained by a protective caddy. A write-protect indicator is movably mounted on the caddy, such indicator cooperating with the carrier's write-protect member to display the present write-protect status of the disk within.

Abstract: A protective cartridge for a data storage disk (e.g. an optical disk) includes a retainer mechanism for restricting longitudinal movement of a disk/carrier assembly within the cartridge interior. Such mechanism preferably comprises a flexible, cantilever-mounted leaf spring having a lip which is adapted to engage a trailing edge of a disk-carrier after such carrier has entered the cartridge through a pivotably mounted cartridge door. To allow extraction of a retained disk-carrier from the cartridge, the retainer is located so it is engaged and moved to a non-retaining position by the cartridge door as the latter moves from a closed to an open position.

Abstract: A disk-loading station for an automated disk library includes a "lazy-Susan" mechanism which enables disks to be loaded into the library from a direction perpendicular to the direction in which the disks are ultimately transported within the library. Such a loading station enables disks to be loaded through the front wall of the disk library, rather than through an end wall which would increase the space requirements for the library.

Abstract: Apparatus adapted for use in high vacuum, thin-film deposition system for controlling the temperature of moving substrate holder. Preferably, such temperature control apparatus comprises a fixed, temperature-controlled, thermally conductive member, and liquid heat transfer medium (preferably liquid gallium) for thermally coupling such member to the substrate holder as it moves through a vacuum chamber.