Abstract: An anchoring device and method for collapsible sun shelter so that the sun shelter can be used on a variety of terrains, the reusable anchoring device consists of a large corkscrew or other anchoring type post, that can be turned or driven into the ground, the anchoring device top being configured so that it can securely hold a rope, the anchoring device holds a mostly flat geometric shape greater than 36 square inches, the mostly geometric shape having a sewn compartment, or casing, to enclose a rope around the outside edge, with one corner of the mostly flat geometric shape casing open so that the rope can attach to a pole holding up the sun shape, and the opposite corner's reinforced casing open to allow the rope to be pulled out to attach to an anchoring post with an anchoring post stake, a separate anchoring device may be used for each post when setting up the sunshade.

Abstract: An optical encoder is provided. The encoder includes an optical disc mounted on a shaft, the optical disc containing pit and land markings; an optical pickup unit for an optical disc that receives light from the optical disc and supplies as an output an electrical signal representative of the received light, comprising: a reading head objective lens, and dynamic steering actuators that control the focus and tracking of the reading head objective lens; a processor that receives as an input the electrical signal from the optical pickup unit and reports motion of the substrate based on the received at least one electrical signal.

Abstract: An optical encoder is provided. The encoder includes an optical disc mounted on a shaft, the optical disc containing pit and land markings; an optical pickup unit for an optical disc that receives light from the optical disc and supplies as an output an electrical signal representative of the received light, comprising: a reading head objective lens, and dynamic steering actuators that control the focus and tracking of the reading head objective lens; a processor that receives as an input the electrical signal from the optical pickup unit and reports motion of the substrate based on the received at least one electrical signal.

Abstract: An improved optical encoder uses an optical pick-up unit that provides for degrees of freedom in the tracking and focus axes that are unavailable in conventional optical encoders thereby improving the encoders' performance. In an embodiment the encoder employs an optical disc marked with pits and lands which may be arranged in a spiral pattern. The optical disc is mounted on the shaft whose motion is to be monitored by the optical encoder. The encoder may be arranged to read the markings on the optical disc using the three-beam pickup method.

Abstract: An improved optical encoder uses an optical pick-up unit that provides for degrees of freedom in the tracking and focus axes that are unavailable in conventional optical encoders thereby improving the encoders' performance. In an embodiment the encoder employs an optical disc marked with pits and lands which may be arranged in a spiral pattern. The optical disc is mounted on the shaft whose motion is to be monitored by the optical encoder. The encoder may be arranged to read the markings on the optical disc using the three-beam pickup method.

Abstract: Apparatus and methods are provided for using a single multi-element detector and multi-channel signal conditioning circuitry to simultaneously read multiple tracks from either a CD disk or a DVD disk. The multi-element detector has a staggered arrangement and includes elongated detector elements, so that multiple reading beams reflected from multiple tracks of a CD disk are projected onto the detector, as are multiple reading beams reflected from multiple tracks of a DVD disk. The multi-channel signal conditioning circuitry conditions the signals produced by the multi-element detector, and produces signals for each of the tracks that is simultaneously read, as well as a tracking error signal, a focus error signal, a magnification error signal, and signals useful for reading DVD-RAM disks and for rapidly accessing tracks on an optical disk.

Abstract: A switchable liquid crystal diffractive element for use in an optical drive capable of reading multiple tracks of an optical disk simultaneously, and writing or erasing at least one track of the optical disk is disclosed. When the liquid crystal diffractive element is in an “on” state, it splits an incident beam into multiple beams suitable for simultaneously reading multiple tracks of an optical disk. When the liquid crystal diffractive element is in an “off” state, it permits an incident beam to pass through without being split, for writing to an optical disk. Embodiments are disclosed that use multiple electrodes to create switching and non-switching regions of a liquid crystal element to form a switchable phase grating, and that use a single switching liquid crystal element and a non-switching grating, or a birefringent non-switching grating, to form a switchable diffractive element.

Abstract: Methods and apparatus are provided for synchronously reading data from multiple tracks of an optical disk using multiple illumination beams. Circuitry is provided for use with a photodetector array to read and buffer data in parallel from the multiple adjacent tracks, while asynchronously providing processed data to a host processor. Circuitry is further provided for concurrently processing the signals read from the multiple data tracks to recover the data stored in the tracks.

Abstract: The present invention provides an optical system having a read mode, during which multiple tracks of an optical disk are simultaneously read, and a write mode, during which data is written to at least one track of the optical disk. The multiple light beams employed during read mode may be generated by a single laser diode operated at low power used in combination with a diffractive element, multiple laser diodes, or combinations thereof.

Abstract: A focus detection system for use in a multi-beam optical pickup assembly is provided that uses an optical element, either a holographic element or diffractive element, to split beams reflected off of a data-bearing surface of an optical disk into a plurality of data beams and a plurality of focus beams. The optical element also introduces astigmatism into the focus beams. The focus beams are projected onto focus detectors configured to account for overlap between adjacent focus beams to produce an accurate focus error signal.

Abstract: Methods and apparatus are provided for improving optical drive access times using a detector having multiple sensing elements to sense and count disk tracks. The detector may be oriented either radially or tangentially with respect to the disk radius, and either capable of sensing more than one disk location simultaneously or have a length greater than the maximum distance between detectable features of the disk.

Abstract: Focussing system methods and apparatus are provided for apparatus capable of simultaneously reading multiple tracks of an optical disk. Astigmatism introduced by a cylindrical lens disposed adjacent to the light source, or before the focus detectors arranged at the edge of a wide-area field of illumination, is used to compute an error signal corresponding to the degree of out-of-focus, which error signal is provided to a servo-system that moves the objective lens to correct the focus. An alternative embodiment employs a pair of focus detectors and a pair of micro-lenses having different focal lengths that directs the reflected light onto the focus detectors to generate a focus correction signal. Further alternative embodiments of employing the astigmatism method of focussing are described.

Abstract: Focussing system methods and apparatus are provided for apparatus capable of simultaneously reading multiple tracks of an optical disk. Astigmatism introduced by a cylindrical lens disposed adjacent to the light source, or before the focus detectors arranged at the edge of a wide-area field of illumination, is used to compute an error signal corresponding to the degree of out-of-focus, which error signal is provided to a servo-system that moves the objective lens to correct the focus. An alternative embodiment employs a pair of focus detectors and a pair of micro-lenses having different focal lengths that directs the reflected light onto the focus detectors to generate a focus correction signal. Further alternative embodiments of employing the astigmatism method of focussing are described.