Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage. Methods and systems of tape technology disclose optical tape media including: configurations, formulations, markings, and structure; optical tape manufacturing methods, systems, and apparatus methods and systems including: curing processes, coating methods, embossing, drums, testing, tracking alignment stamper strip; optical tape methods and systems including: pick up head adapted for the disclosed optical tape; and optical tape uses including optical storage media devices for multimedia applications.

Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage. Methods and systems of tape technology disclose optical tape media including: configurations, formulations, markings, and structure; optical tape manufacturing methods, systems, and apparatus methods and systems including: curing processes, coating methods, embossing, drums, testing, tracking alignment stamper strip; optical tape methods and systems including: pick up head adapted for the disclosed optical tape; and optical tape uses including optical storage media devices for multimedia applications.

Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage.

Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage.

Abstract: The systems, methods and products of the invention include systems and methods for manufacturing servo tracks on a magnetic tape. In one aspect, the invention includes systems for manufacturing magnetic tapes having servo tracks thereon wherein the servo tracks are optically detectable and are capable of being processed by a servo control system for maintaining alignment of a magnetic recording head with the data tracks on the recording side of the magnetic tape. In one practice, the manufacturing systems described herein engrave the servo tracks onto the non-recording side of a magnetic tape by directing a laser beam at the non- recording side of the magnetic tape. In another practice, the manufacturing systems described herein engrave the servo tracks onto the magnetic side of a magnetic tape by directing a laser beam at the magnetic side of the magnetic tape. Such engraved patterns can act as optical servo tracks for maintaining alignment of the recording head with the data tracks on the magnetic tape.

Abstract: The systems, methods and products of the invention include systems and methods for manufacturing servo tracks on a magnetic tape. In one aspect, the invention includes systems for manufacturing magnetic tapes having servo tracks thereon wherein the servo tracks are optically detectable and are capable of being processed by a servo control system for maintaining alignment of a magnetic recording head with the data tracks on the recording side of the magnetic tape. In one practice, the manufacturing systems described herein engrave the servo tracks onto the non-recording side of a magnetic tape by directing a laser beam at the non-recording side of the magnetic tape. In another practice, the manufacturing systems described herein engrave the servo tracks onto the magnetic side of a magnetic tape by directing a laser beam at the magnetic side of the magnetic tape. Such engraved patterns can act as optical servo tracks for maintaining alignment of the recording head with the data tracks on the magnetic tape.

Abstract: A method of generating a composite signal in a closed loop servo signal system of a data recording system used to drive a recording head to any given position within a dynamic range of a servo tracks includes an optical pickup system for generating optical spots focused on a recording medium, the spots separated by equal distances across a track, the optical pickup system receiving a set of reflectances from the spots, a media system for providing the servo tracks responsive to optical spot illumination, an electric system for generating a set of filtered signals from the reflectances and for generating a set of S-curves by pair wise subtraction of the filtered signals, a processing system to generate a composite servo position signal from the S-curves and filtered reflectances, and a servo system for driving the recording head to a desired position by comparing the desired position to a measured position from the composite servo position.

Abstract: An optical servo writer system including a laser subsystem to generate a multiplicity of light beams, a lens positioned to receive and focus the light beams and a spatial filter positioned in the system so as to allow a subset of the light beams to pass through the filter. The multiplicity of light beams includes the subset that contains the desired beams, or the servo beams, and also the undesired beams, called the ghost beams. The system further includes a digital linear tape positioned adjacent the spatial filter with the spatial filter allowing the subset of light beams to hit the digital linear tape and produce servo marks. The spatial filter includes openings positioned to allow the subset of light beams to pass through the filter. The openings may be staggered relative to the digital linear tape to prevent debris generated by the marking process from clogging the openings.

Abstract: An optical servo writer system including a laser subsystem to generate a multiplicity of light beams, a lens positioned to receive and focus the light beams and a spatial filter positioned in the system so as to allow a subset of the light beams to pass through the filter. The multiplicity of light beams includes the subset that contains the desired beams, or the servo beams, and also the undesired beams, called the ghost beams. The system further includes a digital linear tape positioned adjacent the spatial filter with the spatial filter allowing the subset of light beams to hit the digital linear tape and produce servo marks. The spatial filter includes openings positioned to allow the subset of light beams to pass through the filter. The openings may be staggered relative to the digital linear tape to prevent debris generated by the marking process from clogging the openings.

Abstract: A DRDW differential phase tracking method including the steps of writing marks to a groove on an optical storage media utilizing a write beam; reading the trailing edge of each mark which is in the process of formation by the same write beam; detecting the diagonal signal components from a quadrature photodetector positioned in the path of the write beam reflected from the optical storage media; and forming a tracking error signal either as a function of the difference between the two diagonal signals out of the quadrant detector or as a function of the differential phase between the two diagonal signals out of the quadrant detector.

Abstract: An apparatus and method for filtering intersymbol interference from an information signal generated from a storage medium. This apparatus utilizes a delay line, gain devices, summing devices, and has specified transfer functions. Furthermore, this apparatus and method can make real time adjustments in order to maintain an optimal level of filtering.

Abstract: This invention pertains to an improved technique of introducing an added insulative layer between the thermoplastic layer and the photoconductive layer of the thermoplastic photoconductive holographic recording medium. The added layer (pure PVK) is electrically insulating at temperatures used for thermal development to prevent decaying charge contrast during hologram development.

Abstract: An optical system for creating the ambiguity function of a moving target is disclosed. The two signals which are to be used in the analysis are coded on spatial data masks as two-dimensional arrays of one-dimensional functions. The frequency scaling property of a post lens Fourier Transform is utilized to apply a variable scaling factor to at least one of the functions. This is accomplished by passing a beam of substantially coherent light through a cylindrical Fourier Transform lens before it passes through the data masks. At least one of the data masks is then set at an angle other than perpendicular to the beam path.

Abstract: An optical system which computes the ambiguity integral using one-dimensional spatial light modulators rather than the two-dimensional data masks or spatial light modulators used in the prior art is revealed. The coding is accomplished by compressing the light beam along one dimension, passing it through a one-dimensional spatial light modulator, and re-expanding the beam along the compressed dimension. The signal may be rotated to produce a linear dependence. In the preferred embodiment an acousto-optic cell commonly known as a Bragg cell is the one-dimensional spatial light modulator chosen.

Abstract: In a thermoplastic-photoconductor holographic recording medium in the form of several transparent layers over a transparent substrate, such as an optically transparent electrically conductive layer, then a photoconductor layer and a thermoplastic layer over such as glass or Mylar, a conventional material such as gold or platinum has been used as a transparent conductive layer. It is desired to use a less precious metal such as nickel-chromium (NiCr) as the conductive layer, however a limitation has been found in that an unwanted dark charge injection occurs from the NiCr to the photoconductive layer. This causes poor charge acceptance and therefore results in poor halogram formation. Herein a mono atom thick layer of the NiCr is treated and becomes on oxide layer which forms an effective charge blocking layer to dark charge injection.

Abstract: Charge leakage can occur at a photoconductor-conductor electrode interface of a thermoplastic photoconductive holographic recording medium. This reduces the charge contrast and causes poor performance of the thermoplastic-photoconductive device. In the present invention there is provided a blocking layer of polyvinyl alcohol or polyvinyl butyral between the conductive layer and the photoconductive layer.

Abstract: A nondestructive dynamic controller for thermoplastic development is disclosed. The dynamic controller monitors the development of a hologram, without altering the charge pattern on the recording medium that is required for the development. The dynamic controller determines when optimum deformation has occurred in the developing recording medium and provides a signal which is used to shut off the thermal input used in the development.

Abstract: An electro-optic smoke detector is described which has an improved smoke chamber and detector construction to enhance the detector sensitivity in general and its response to small smoke particles in particular.

Abstract: This invention pertains to an improved thermoplastic holographic recording medium having an added layer between the thermoplastic layer and the photoconductor layer. The added layer is electrically insulating at temperatures used for thermal development to prevent decaying charge contrast during hologram development.

Abstract: A holographic optical memory utilizes an optical heterodyne technique to significantly increase the signal-to-noise ratio during the readout stage of operation. A light source provides a coherent light beam which is split into a readout beam and a local oscillator beam. The readout beam is directed to one of the holograms stored in the memory medium and a portion of the readout beam is diffracted by the hologram to form a reconstructed image of the bit pattern stored in the hologram at the reconstructed image plane. The local oscillator beam is superimposed with the diffracted portion of the readout beam. An optical frequency translator is positioned in either the readout beam or the local oscillator beam to cause the beams to have different optical frequencies. Therefore, when the two beams are superimposed, a beat frequency signal is produced. An array of detectors is positioned at the reconstructed image plane to receive the superimposed beams.