Abstract: The invention relates to a state-variable feedback control system for monitoring and optimally controlling the operation of a microfluidic aspirate dispense-system. A steady state operating pressure is determined from the fluid, flow and/or operational characteristics of the system. Measurements from one or more pressure sensors are part of the control strategy to derive information for active feedback control and/or to achieve the desired operating pressure. Advantageously, the control system adds to the versatility of the aspirate-dispense system, for example, by permitting rapid dispensing of drops of different size. The control system also desirably facilitates efficient, repeatable and accurate performance and reduces wastage of valuable reagents or fluid.

Abstract: A method and apparatus for use in ablating hard and soft tissue and in particular, tooth, tooth enamel, tooth dentin, tooth cementum, bone, cartilage, skin, mucosa, gingiva and muscle, and preferably in the oral cavity, is disclosed. In operation, an electromagnetic energy source is applied to a target material producing thermo-elastic failure resulting in fracture or rupture of the material. When this point is reached, the energy source is stopped and immediately a fracturing fluid is applied to the lasing site with sufficient cooling power, solvating power, and momentum to not only cause further fracture or rupture of the material but also to remove debris from the site. The process is repeated until the desired ablation is effected.

Abstract: The invention relates to a state-variable feedback control system for monitoring and optimally controlling the operation of a microfluidic aspirate dispense-system. A steady state operating pressure is determined from the fluid, flow and/or operational characteristics of the system. Measurements from one or more pressure sensors are part of the control strategy to derive information for active feedback control and/or to achieve the desired operating pressure. Advantageously, the control system adds to the versatility of the aspirate-dispense system, for example, by permitting rapid dispensing of drops of different size. The control system also desirably facilitates efficient, repeatable and accurate performance and reduces wastage of valuable reagents or fluid.

Abstract: A reagent dispensing valve particularly adapted for dispensing precise microfluidic quantities of fluids. The valve includes a valve portion and a solenoid actuator that are in fluid isolation from one another. The valve portion includes a plunger and seat combination and the actuator is substantially decoupled from the fluid path through the valve. The fluid path through the valve is substantially non-tortuous, thereby minimizing localized fluid pressure drops, and hence undesirable gaseous bubble precipitation within the fluid. The valve is also configured to substantially prevent bubble accumulation. The valve can further include a bubble trap for trapping and removing bubbles.

Abstract: Recording methods, systems and media for recording and read-out with relatively low-power laser means to write digital data "bits" (as reflectance changes) for high density computer storage. One preferred medium comprises a disk support having an "anti-reflective" surface on which is laid a non-continuous "information layer" adapted to absorb recording radiation (from laser beam), and so "write" the bits, by "agglomerating" (coalescing).The information layer exhibits suprisingly high sensitivity, apt for low power recording, and extended archival stability; more suprising, it appears to be formed without any evidence of the usual ablation, "pit formation" or other deformation.

Abstract: An acoustic signal is transmitted into a flowing gas (10). The velocities of propagation of the signal in two predetermined directions are measured, and combined with sensed gas pressure and the frequency of the acoustic signal to compute the mass flow rate of the gas. The velocities are preferably measured as analogous phase differences between the transmitted signal, and the signal as incident upon receivers (18,20) spaced from the signal transmitter (16) by predetermined distances in the predetermined directions. The phase differences are preferably sensed using at least one phase locked loop (44) which adjusts the signal frequency so that a predetermined phase difference is maintained between the transmitted signal and one of the received signals or a derivative thereof. The flow rate computation includes obtaining the speed of the acoustic signal (speed of sound) in the material and the velocity of movement of the gas from the sensed phase differences.

Abstract: A novel optical media is provided for use in an optical recording and reproducing system. The optical media comprises a tuned multilayer optical structure employing an archival thin film absorber having a relatively high melting point, such as gold, along with an in-contact overcoat. The characteristics of the media are chosen so as to permit use of a specially chosen hole-forming data recording mechanism which permits recording optically detectable data in the media without requiring heating of the absorber material to its bulk melting point, and also without requiring ablation of the absorber material, whereby compatibility with the in-contact overcoat is also achieved.

Abstract: A system and method are disclosed for measuring medium range distances, of about 1-10 meters, to a target. A transmission signal is reflected off the target, with the phase difference between the transmitted and received signals taken as an indication of the target distance. The transmitter and receiver are part of a phase-locked loop, with a VCO adjusting the transmission frequency until a predetermined transmission-reception phase difference is reached. A coarse distance measurement is first obtained by comparing the transmitted signal with the received signal, followed by a fine distance measurement in which a multiple of the transmission signal frequency is compared with the received signal. The frequency multiplication in the preferred embodiment is obtained by dividing the VCO output frequency to obtain the transmission frequency. The transmission signal is initialy set at a low frequency prior to the coarse adjustment to avoid phase ambiguities.

Abstract: A bomblet within a cluster bomb is provided with an individually programmable detonation time delay, such that the bomblet can be programmed to detonate at a desired time after it has been dropped. Program signals are transmitted to the bomblet from a wire that runs through an opening in the bomblet, but is not mechanically attached to the bomblet. the bomblet has a secondary transformer winding to receive signals from the transmission wire, and is provided with a unique address code such that it responds to a timing program signal only when the signal is preceded by an appropriate address code. A series of timing program signals can be transmitted to a plurality of bomblets, with the bomblet addresses adjusted after each program signal so that only one bomblet (or more, if desired) responds to each successive program signal.

Abstract: Each bomblet within a cluster bomb is provided with an individually programmable detonation time delay, such that the bomblets can be programmed to detonate at desired intervals over a relatively long period of time. Program signals are transmitted to a number of bomblets at the same time from a wire that runs through openings in the bomblets, but is not mechanically attached to the bomblets. The wire is attached to the bomb canister at selected points and is severed inbetween the connection points when the canister is opened, thus permitting the wire sections to be pulled away without disrupting the bomblets' dispersion pattern. Each bomblet has a secondary transformer winding to receive signals from the transmission wire, and is provided with a unique address code such that it responds to a timing program signal only when the signal is preceded by an appropriate address code.

Abstract: A fiber optic switching system and method is described which is capable of rapidly switching among a number of closely spaced optical rods for optical connection with a communications channel, while alleviating alignment problems caused by vibration and similar environmental conditions. Focusing lenses are moved relative to stationary multirod cables, and brought into coarse alignment with desired rods in each cable in a programmed switching sequence. At each coarse lens position a fine alignment is achieved between the lens and rod by directing an optical alignment beam along the focal axis of the lens, reflecting the beam off the rod, and sensing the portion of the alignment beam which is reflected back through the lens as an indication of the misalignment. The misalignment detectors form part of a servomechanism that rapidly adjusts the lens position in response to detected misalignments to bring the lens into alignment with the desired rod.

Abstract: An optical storage system employing a laser beam which is directed and focused onto an optical disk for reading and/or writing data in a track of the disk. Positioning control is achieved by providing for track following and track seeking using a plurality of interactive servo-loops. Proper focusing is maintained using focusing control circuitry which produces a focus error signal that is applied to a focus motor. This focusing control circuitry is able to return the objective lens assembly to its in-focus position so long as the objective lens assembly remains within a predetermined capture range. In the event that the objective lens assembly is outside of this capture range, a waveform generator is enabled which produces a correction signal that causes the focus motor to move the objective lens assembly back within the capture range with a velocity and for a time period sufficient to permit the focusing control circuitry to regain control and return the objective lens assembly to its in-focus position.

Abstract: An optical storage system employing a laser beam which is directed and focused onto an optical disk for reading and/or writing data in a track of the disk. Proper focusing is maintained using focusing control circuitry which produces a focus error signal that is applied to a focus motor. This focusing control circuitry is able to return the objective lens assembly to its in-focus position so long as the objective lens assembly remains within a predetermined capture range. In the event that the objective lens assembly is outside of this capture range, a waveform generator is enabled which produces a correction signal that causes the focus motor to move the objective lens assembly back within the capture range with a velocity and for a time period sufficient to permit the focusing control circuitry to regain control and return the objective lens assembly to its in-focus position.

Abstract: A two-part head positioning system has a tracking motor for moving the head through relatively small distances so that it follows the track of a medium and moves between adjacent tracks and a seek motor for moving the tracking motor and head through relatively large distances between non-adjacent tracks. The system has been improved by mechanically isolating the seek motor from the tracking motor so that small movements from the tracking motor are not transmitted to or from the seek motor and the arm between that motor and the tracking motor. The tracking motor and the mechanical isolator are in one unit. A magnet is mounted on the head support, which extends from the tracking motor to the head. This magnet is positioned within an electromagnetic coil that is mounted within magnetic shielding and fixed to the arm extending to the seek motor. Selective energization of the electromagnetic coil moves the magnet and the head support laterally in the coil.

Abstract: Disclosed is a laser recording arrangement including a mirror for redirecting the laser beam in a controlled scan mode plus an associated electro-optical position monitor for monitoring mirror orientation, these being housed in a unitary casting.

Abstract: Disclosed is a laser recording arrangement including a pivoting mirror adapted for redirecting the laser beam in a controlled scan mode plus an associated electro-optical position monitor for monitoring mirror orientation, with a particular form of magnetic motor provided to activate mirror-pivoting.

Abstract: A three beam laser optical system comprising a writing beam and two reading beams all incident on the same track of a rotating disk optical recording medium. One of the reading beams is incident on the track ahead of the writing beam so as to serve as a read-before-write beam, while the other reading beam is incident on the track behind the recording beam so as to serve as a read-after-write beam. The read-before-write beam is used during the recording of data to provide an advance indication as to whether there is previously recorded data ahead of the writing beam, in which case the recording operation is interrupted to prevent an overwrite error. The read-after-write beam is used during recording to check the accuracy of the recording operation.

Abstract: A high density optical storage system employing a laser beam for reading data in a track on a rotating optical disk containing a large number of closely spaced concentric tracks. When a short seek operation is to be provided, track following is temporarily suspended for an appropriate time period during which specially shaped waveform is applied to the galvanometer-controlled mirror in the path of the beam. This specially shaped waveform is a doublet comprising a pulse of one polarity followed by a pulse of the opposite polarity. The duration and amplitude of these opposite polarity pulses are chosen based on the number of tracks that the beam is to be moved and the mechanical characteristics of the system so that the galvanometer mirror will accurately move the beam the requested number of tracks. After movement of the beam has been completed, operation automatically returns to track following.

Abstract: An optical data storage system employing a data-modulated writing laser beam and a non-erasing reading laser beam of predetermined wavelength along with an improved optical medium comprised of multiple layers whose optical characteristics and thicknesses are chosen in conjunction with the writing and reading laser beams to provide an anti-reflection condition for unrecorded portions of the medium and a relatively high reflectivity for recorded portions of the optical medium. A preferred optical medium includes a highly reflective aluminum layer, a fluorinated hydrocarbon polymer spacer layer overlaying the reflective layer, a nucleation layer overlaying the spacer layer and also serving as a heat insulator therefor, and a gold absorber layer overlaying the nucleation layer.

Abstract: An optical data storage system employing a data-modulated writing laser beam and a non-erasing reading laser beam of predetermined wavelength along with an improved optical medium comprised of multiple layers whose optical characteristics and thicknesses are chosen in conjunction with the writing and reading laser beams to provide an anti-reflection condition for unrecorded portions of the medium and a relatively high reflectivity for recorded portions of the optical medium. A preferred optical medium includes a highly reflective aluminum layer, a fluorinated hydrocarbon polymer spacer layer overlaying the reflective layer, and a gold absorber layer overlaying the spacer layer.