Abstract: A rotatable, bakeable vacuum sealed mount for an optical element, suitable for use on an endbell assembly for a gas discharge tube or as an integral part of a gas discharge tube for an ion laser comprises an elongated support member, having an axis and a passage along the axis of the support member. A first end of the support member is connected by a vacuum tight seal to the vacuum sealed chamber of the gas discharge tube, so that the passage has an opening toward the vacuum sealed chamber. A second end of the support member is connectable by vacuum tight seal to the optic, so that the second end of the passage has an opening toward the optic. A portion of the support member has a yield strength allowing adjustment by twisting of the support member about the axis for establishing a rotational alignment of the optic without breaking the vacuum of the vacuum sealed chamber.

Abstract: A syringe of relatively simple construction which is capable of both accurate and reproducible sample volume withdrawals, including volumes of 1.0 .mu.l or less, is provided. The syringe drive mechanism is preferably adapted for use in a liquid sampling apparatus and includes a threaded lead screw, a drive for rotating the screw, and a syringe having a plunger for withdrawing a liquid sample. The plunger is mechanically connected to the rotating lead screw by a nut threaded onto the screw and a slider mechanism associated with the nut which also is secured to the plunger. The nut is designed so that lateral misalignment of the drive screw does not affect the precise linear movement of the slider mechanism, and consequently, the plunger. This provides a mechanism which is less expensive to assemble and align properly, but which has a high degree of accuracy and reproducibility.

Abstract: A point of sale system involving a series of check stands with POS cash registers and bar code scanners includes a lottery ticket issuing and redemption system. A number pick stand in the store, apart from the checkout stands, enables the customer to choose numbers. Pick slips can be generated by the customer at this stand, and bear a bar coded transaction number which can be communicated to a lottery device at each check stand. The pick slip is readable at the check stand bar code reader along with a series of store-inventory items. The customer is automatically charged for the lottery ticket, and the ticket is printed at the check stand. At the time the ticket is issued, the lottery transaction is recorded via modem to the central lottery computer of the state or other controlling agency. In another embodiment the number pick stand may encode the actual picked numbers on the pick slip, in an extended field bar code.

Abstract: A handheld scanner including a housing with a top head portion and a bottom handle portion with a contoured hand rest portion therebetween. A scanner trigger is located on the top of the top head portion which can be actuated either by a thumb or finger. The angular scanner structure, the trigger location, and the transparent scanning window enables the user to intuitively aim the scanner where the user's finger is aimed. The trigger centerline mark to aid in aiming the scanner at bar codes. A "V"-shaped aiming mark on top of the scanner head also aids in aiming the scanner. The angular shape of the scanner allows it to rest comfortably in the user's hand when being held, or alternately permit it to lie securely on a table without rocking when not being held yet still allow it to be easily picked up by the user.

Abstract: A method and apparatus for automatically controlling the depth of earth grading for utilization with a grader or paver is disclosed. The method includes determination of time taken for an acoustic pulse to travel from a transducer to a reference surface and back, with this value being used to calibrate a microprocessor-controlled distance-measuring device. As the grader moves over a surface to be graded, the distance to the reference surface is constantly detected by a repeated emission and detection of such acoustic pulses. The timing of the echoed pulses is converted to addresses in a look-up table which contains control words symbolizing commands to be given to hydraulic rams carried by the grader. By implementing these commands, the depth of the blade relative to the reference surface is constantly updated, compensating for variations with the height of the reference surface. A thermistor is provided to automatically compensate for temperature variations as the grading takes place.

Abstract: A bar code scanner housing assembly for enclosing the components of a bar code scanner is provided. The bar code scanner housing assembly comprises a cartridge including an upper window which is removably mounted therein and a housing including a recess for receiving the cartridge, a lower window mounted within the recess and means for generating bar code scan lines. The cartridge is removably mounted within the recess such that the surface of the cartridge is substantially flush with the upper surface of the housing. The housing assembly may include a mask molded into the recess so as to minimize the amount of ambient light passing into the housing. The housing assembly may also comprise a groove surrounding the lower window which has a removable gasket disposed therein for sealing the space between the upper window and lower window. The housing assembly may comprise a window cartridge which eliminates the need for a separate upper window disposed within the cartridge of a bar code scanner housing assembly.

Abstract: A method and apparatus for mounting a compact optical scanner utilizes a one or two-piece mounting bracket to secure the scanner. A bevelled surface on the inside of the bracket cooperated with a conversely bevelled surface on the scanner to prevent removal of the scanner through the top surface of the bracket. Flexible extensions support the scanner and flex out of the way to allow insertion and removal of the scanner.

Abstract: A scanner including an oval-shaped handle and a round dome-shaped scanner head with a transparent scanning window above the trigger area of the dome. Markings on top of the scanner to aid with aiming, and a multi-color indicator light on top of the dome.

Abstract: A laser alignment apparatus is provided for use in positioning workpieces relative to one another and first and second spaced-apart substantially parallel reference planes. The laser alignment apparatus comprises a first projector for providing first and second reference beams of light disposed in a substantially orthogonal relationship with respect to one another. A second projector provides third and fourth reference beams of light disposed in a substantially orthogonal relationship with respect to one another. The first and second projectors are positioned relative to one another so that the first and third reference beams of light are substantially collinear with one another and the second and fourth reference beams of light are positioned substantially parallel to one another.

Abstract: A focus compensating lens structure wherein a lens means for collimating laser light produced by a source has an index of refraction which varies with temperature and wavelength to compensate for temperature effects on the wavelength of light produced by the laser source and the length of the mounting on which the source and lens are disposed.

Abstract: An electrophoresis instrument includes a capillary tube mounted in an air cooled cartridge. The cartridge also supports a spherical lens which is part of the optical detection apparatus. The cartridge rests in a manifold which includes the sample and buffer reservoirs. The temperature of the capillary tube is controlled by measuring the electrical resistance of the capillary tube during the electrophoresis process and then cooling or heating the cartridge by circulating temperature controlled air over the tube. The optical path associated with the instrument is a fiber optic bundle bifurcated close to dual detectors into a reference arm and a sample arm so as to provide similar reference and sample optical paths. The instrument may be used for temperature control for buffer gradient electro-phoresis and also, a neutral marker for determining electro-osmotic flow may be detected.

Abstract: A bar code scanning system which can be operated in two scanning categories: hendheld and fixed. The system incorporates a second scanning element having a fixedly mounted mirror and a dithering mirror disposed in relation to a hand-held scanner which is removably positioned in a holder means.

Abstract: A mode locked pulsed laser incorporates an intracavity element to compensate for the dispersion caused by other intracavity elements. This element reduces the tendency of the pulse to broaden in the cavity due to group velocity dispersion and results in very short pulses. In the laser of the present invention, mode locking is initiated by detecting the beat frequency between adjacent longitudinal modes using a high speed photodiode. This signal is amplified and then the frequency is divided by two. The signal is passed through an electronically adjustable phase shifter and then to a power amplifier. This signal is applied to the acousto-optic modelocker. If the cavity length drifts the beat frequency between the longitudinal modes changes. The rf signal applied to the modulator changes in exactly the right manner to track the drift in cavity length. Thus the modelocker is automatically synched to the round trip of the laser cavity.

Abstract: An optical system and method for data reading including a light source which generates an optical beam directed toward an object, a pivoting scan mirror which directs the optical beam over a scanning range on the object to be read, a stationary collection mirror for collecting light from the object, a fold mirror positioned behind the scan mirror for reflecting light collected by the collection mirror through an aperture in the collection to a photodetector.

Abstract: The scanner and scanning method of the present invention effect bar code scanning to determine the bar code data printed thereon by repeatedly sweeping a scanning beam in scan paths across the labels. The bar code labels bear bar codes of the type which include a primary code portion and which may also include an Add-On code portion. The method of the present invention includes the steps of sweeping a scanning beam across the label until the beam sweeps the entire primary code portion in a first scanning pass along a first scan path; immediately sweeping the scanning beam across the label in additional scanning passes along additional scan paths adjacent and parallel to the first scan path; and, if the beam sweeps the entire primary code portion in the additional scanning passes, and, if an Add-On code portion is not scanned in part during either the first or additional scanning passes, then the data scanned during the first and additional scanning passes is accepted as valid scan data.

Abstract: A mode locked pulsed laser incorporates an intracavity element to compensate for the dispersion caused by other intracavity elements. This element reduces the tendency of the pulse to broaden in the cavity due to group velocity dispersion and results in very short pulses. In the laser of the present invention, mode locking is initiated by detecting the beat frequency between adjacent longitudinal modes using a high speed photodiode. This signal is amplified and then the frequency is divided by two. The signal is passed through an electronically adjustable phase shifter and then to a power amplifier. This signal is applied to the acousto-optic modelocker. If the cavity length drifts the beat frequency between the longitudinal modes changes. The rf signal applied to the modulator changes in exactly the right manner to track the drift in cavity length. Thus the modelocker is automatically synched to the round trip of the laser cavity.

Abstract: An automatic plumb, level, pointing and distance measuring tool uses a visible laser diode to project a beam in any of several different modes through a beam exit window. The tool, approximately the size and shape of a tape measure, can be placed on one edge to project a tilt-compensated vertical beam. Placed on another edge 90.degree.-rotated, the tool projects through the same exit window a tilt-compensated horizontal beam. When laid on either of its larger flat sides, the tilt compensation becomes inoperative and the tool projects a beam which is fixed relative to the housing. Acoustic distance measurement is facilitated using a second component or target side device which is activated to send an acoustic signal across a space to be measured, toward the laser tool. A receiver in the laser tool detects arrival of the acoustic signal and causes the laser to project a characteristically modulated or pulsed beam, received at a photodetector on the target side device.

Abstract: Methods and apparatus for effective vacuum degassing of a liquid are provided for liquid chromatography. The bottles with the liquid are mounted above the vacuum degassing unit to provide a head pressure to the LC pump and physical stability to the bottles. The liquid is heated in the vacuum chamber by a radiator of electromagnetic energy (in one embodiment, infra-red light). Alternatively the liquid is heated before it enters the vacuum chamber. The liquid is in an agitated state in the vacuum chamber. In one variation, the liquid is conducted through the vacuum chamber through tubes wound around bobbins so as to expose a greater portion of the surface area of the tubes to vacuum. Circuitry stops the vacuum pump for a duration of a chromatographic run. The circuitry controls the LC pump and the vacuum pump so as to optimize the chromatographic conditions in the liquid chromatography analytical system.

Abstract: A method and apparatus for automatically controlling the depth of earth grading for utilization with a grader or paver is disclosed. The method includes determination of time taken for an acoustic pulse to travel from a transducer to a reference surface and back, with this value being used to calibrate a microprocessor-controlled distance-measuring device. As the grader moves over a surface to be graded, the distance to the reference surface is constantly detected by a repeated emission and detection of such acoustic pulses. The timing of the echoed pulses is converted to addresses in a look-up table which contains control words symbolizing commands to be given to hydraulic rams carried by the grader. By implementing these commands, the depth of the blade relative to the reference surface is constantly updated, compensating for variations with the height of the reference surface. A thermistor is provided to automatically compensate for temperature variations as the grading takes place.

Abstract: A miniaturized Q-switch is added to the resonant cavity of a compact laser diode pumped solid state laser to produce short high peak power pulses. Q-switching the compact diode pumped solid state lasers takes advantage of the relatively high gain and short cavity length to provide a desirable combination of pulsewidth and pulse energy. Nd:YAG or Nd:YLF are useful solid state laser materials for Q-switching, or other longer lifetime rare earth ions such as erbium or holmium for greater energy storage. The Q-switch is formed of a material such as TeO.sub.2, SF.sub.10, or LiNbO.sub.3 with an acoustooptic figure of merit substantially greater than fused silica. Pulsewidths of 10-50 ns are achieved at pulse energies of 10-20 microjoules. TEMOO output is easily produced by the compact laser pumped solid state resonator. Applications include materials processing, link blowing in semiconductor memories, marking and scribing, and optical time domain reflectometry.