Abstract: In a time chart plotter which uses a liquid ink supply (such as an ink jet plotter) the computer program in the plotter microcontroller is modified so that for any one increment of chart movement, each point in the other dimension (i.e., the signal axis) is plotted only once. This conserves ink and also prevents heavy buildup of ink on the chart.

Abstract: An acousto-optical device includes a solid state substrate having optical characteristics affected by an acoustic wave in the substrate, and a Z-cut lithium tantalate transducer coupled to the substrate for inducing the acoustic wave. Lithium tantalate provides the transducer with a coupling coefficient and acoustic impedance mismatch which generate a very high finesse acoustic standing wave within the substrate. The lithium tantalate also provides low shear wave components with relatively high manufacturing tolerances. The acousto-optical device with a lithium tantalate transducer is also utilized as a high Q modelocker in a laser capable of producing short pulses of laser light.

Abstract: A tunable solid state laser having a titanium:sapphire grain medium and a birefringent filter mounted within a resonant cavity is provided. The resonant cavity is longitudinally pumped. The cavity is enclosed in a casing which has a small window admitting the pump beam into the resonant cavity, and a small window with an anti-reflection coating allowing the laser output to exit the casing. The casing is maintained at a positive pressure of nitrogen gas during operation of the laser to purge the resonant cavity of air and water vapor.

Abstract: A device for detecting and displaying the relative position of a generally horizontal reference plane of light, even when partial shading of the device occurs, produces a linear response that is independent of spot size and energy distribution. The device includes a photodetector means having first and second interdigitated photodetector elements positioned adjacent each other on the device. The first and second interdigitated photodetector elements provide first and second detection signals, respectively. A circuit means, responsive to the photodetector means, determines the relative levels of the first and second detection signals such that the position of the reference plane of light with respect to the detector device is determined. A display means, responsive to the circuit means, provides an indication of the position of the reference plane of light with respect to the detector device.

Abstract: A wire, comprising a shape memory alloy, is shaped to define a perimeter of an aperture having an adjustable size. The wire is responsive to current flow through the wire to vary the length of the wire, and thereby the length of the perimeter of the aperture. A controllable power supply is coupled to the wire, for supplying a controllable current through the wire to adjust its length, and thereby to adjust the size of the aperture. The aperture is suited for controlling transverse modes in a laser by controlling diffraction losses in the laser resonant cavity. Also, the shape memory alloy aperture is suitable for mounting within a sealed cavity laser.

Abstract: An ion laser is constructed with means for generating a magnetic confinement field operating in the cathode transition region of the laser. The magnetic confinement field is preferably generated by first and second magnetic windings, each axially aligned with the laser volume, but disposed so as to generate first and second magnetic fields which are of opposite polarity. The first and second magnetic fields of opposite polarity combine to create a region of zero axial magnetic field, which in a preferred embodiment is located substantially within the cathode transition region of the laser. In an alternate embodiment, the first and second magnetic fields are of the same polarity, and therefore generate a region of minimized axial magnetic field, preferably located substantially within the cathode transition region of the laser.

Abstract: There is disclosed herein a modular, high power, flyback transformer based power supply with step up and step down capability. The power supply uses multiple flyback transformers having switching transistors which may be either connected to one terminal of the primary winding or which may be placed in the center of the primary winding. The switching transistors are driven by pulse trains which are out of phase with each other. This results in lowered RMS values for ripple current through the input and output capacitors. The flyback voltage transients may be used to step up or step down the input voltage by varying the pulse width of the pulses in the switching pulse trains. In embodiments where the switching transistors are placed in the middle of the primary windings, better suppression of radio frequency emissions and current in safety ground wires is achieved.

Abstract: An orthogonal light plane generator is associated with a primary light plane generator to convert a portion of a first light plane projected by the primary light plane generator into a second light plane substantially orthogonal to the first light plane. The orthogonal light plane generator comprises a diverter which defines three or more reflecting surfaces for receiving a portion of the first light plane and redirecting that portion as the second light plane. The three or more reflective surfaces are oriented relative to one another such that tilting of the orthogonal light plane generator is compensated to maintain the orthogonality between the two light planes. Tilting about one axis results in offset of the second light plane and tilting about a second axis orthogonal to the first results in a shifting of the sector within which the second light plane is projected, but tilting about either axis does not affect the orthogonality between the planes.

Abstract: A prism beam expander in which the incoming beam is essentially achromatically expanded by 100-500 times in one dimension with transmission through the prism beam expander exceeding 40%. In addition, the input beam is nearly collinear with the output beam. The prism beam expander includes 6 prisms in a preferred system, at least 2 of the apexes of which are oriented on the first side of the optical path while at least 2 of the apexes of the remaining prisms are oriented on the second side of the optical path. The achromatic, high-magnification collinear prism beam expander is used in a tunable laser achieving very narrow linewidths.

Abstract: Housing/mounting apparatus for a data gathering system inserted into a checkout counter and including a weighing scale and an optical scanner supported thereon for scanning bar code labels and defining an upper weighing surface of the scale comprises a base supported within the checkout counter for supporting the data gathering system with the scale being secured to the base. A perimeter enclosure is secured to the base and houses the optical scanner. The scale includes a spider load receiving plate supported within the perimeter enclosure through an aperture in its floor. Locator pins and corresponding holes stably position the optical scanner on the scale load receiving plate and the optical scanner thus positioned is sized such that clearance gaps required for proper operation of the weighing scale are defined between the optical scanner and the perimeter enclosure. Leveling and fastener or clamping devices are incorporated into the base to facilitate installation and maintenance of the system.

Abstract: A two part data gathering system for use in a checkout counter to determine information relating to products to be purchased comprises a scale freely suspended within the checkout counter for determining weights of products, the scale including a scale load receiving plate located below the upper surface of the counter. An optical scanner is supported upon the scale load receiving plate for reading coded labels on the products. The optical scanner has an upper surface including an optical scanning window through which scanning light beams pass and is vertically positioned such that its upper surface is substantially aligned with the upper surface of the checkout counter when the optical scanner is supported upon the scale load receiving plate. The weight of the optical scanner is eliminated from the weight readings provided by the scale and the upper surface of the optical scanner becomes the scale weighing platter for receiving products to be weighed by the scale.

Abstract: A program installed in the microcontroller of an ink jet printer functions as a timer, to keep track of how much time has elapsed since the ink jet cartridge last printed. After a certain amount of time (such as one hour) has elapsed with no printing, the program directs all the nozzles of the cartridge to each print about twenty ink dots. This periodic priming of the nozzles during idle periods prevents viscous ink plugs from building up in and clogging the nozzles.

Abstract: A scanning method and scanning system according to the present invention determines the bar code data printed on a pair of concatenated, two-segment bar code labels, which labels have been scanned by repeatedly sweeping a beam in a succession of scanning passes to determine the left segment data and the right segment data of each of the pair of labels. The labels are of the type in which the left segment data and the right segment data are combinable to form a valid checksum. During scanning, it is noted if a left segment and a right segment were scanned during a single scanning pass across either or both of the pair of labels. Left segment data from a first left segment is combined with right segment data from a first right segment. If a valid first checksum results, the same left data is combined with right segment data from a second right segment. If a valid second checksum results, then left segment data from the second left segment is combined with right segment data from the first right segment.

Abstract: A mounting arrangement vertically mounts a scanner of the type which projects a laser light beam in a scan pattern to find a label on a package and read symbols thereon. The scanner has a housing, a window positioned on a first side of the scanner housing, power and communication cables emerging from a lateral side of the housing, and an optical system within the housing to project the beam through the window. The mounting arrangement includes a support plate for engaging a second side of the scanner housing opposite the first side. The support plate includes means for securing the plate to a horizontal surface. The mounting arrangement further includes a back cover for covering the side of the support plate on the side thereof opposite the scanner. Finally, the mounting arrangement includes a cable cover, securable to the support plate and to the back cover, for covering the cables emerging from the lateral side of the housing.

Abstract: A conveyor system for carrying skids supporting products to be assembled along an assembly line comprises straight sections of driven belt conveyors having skid positioning rails extending above the surface of the belt conveyors on either side with the rails being spaced to receive the skids therebetween to position the skids across the belt conveyors. Arcuate sections of driven roller conveyors are positioned between the straight sections of belt conveyors with the roller conveyors being wider than the belt conveyors to accommodate rotation of the skids as they are carried around the roller conveyors.

Abstract: A pushloop liquid sampling method is an improvement in the method of introducing liquid samples into test equipment (such as for liquid chromotography) via a six port valve. The method involves pulling the sample completely past the sample loop in the six port valve and then pushing the desired amount of sample back into the sample loop.

Abstract: A laser oscillator/amplifier system in which thermally induced birefringence in the gain media of the oscillator is compensated by thermally induced birefringence in the gain media of the amplifier. The system produces a quality output beam efficiently and with high power density in the preferred polarization. The oscillator cavity is characterized by a high reflector at one end and an output coupler at the second end with an oscillator gain medium exhibiting thermally induced birefringence in between. An amplifier exhibiting thermally induced birefringence which matches the thermally induced birefringence in the oscillator gain medium is mounted to receive the output of the oscillator cavity. A ninety degree rotator is mounted between the oscillator gain medium and the amplifier so that compensation for thermally induced birefringence in the oscillator gain medium is compensated by the matching thermally induced birefringence in the amplifier.

Abstract: An optical window is disclosed for association with a scanning face of a laser scanner wherein a laser beam is projected through the window to define a scanning pattern and the optical window is supported such that at least one surface of the window is angularly oriented relative to the scanning face to improve the incidence angles of the laser beam on the window and/or the refractive angles of the laser beam at the window. Preferably, the window comprises a composite block of optical material having sections corresponding to portions of the scanning pattern of the laser scanner and being formed and supported to define the angular orientations of upper and lower surfaces of the sections relative to the scanning face of the scanner in accordance with the corresponding portions of the scanning pattern. Portions of the window through which the laser beam is not transmitted may be used to support the window and preferably are matted to reduce ambient light sensitivity of the laser scanner.

Abstract: A switch cover arrangement for a push-botton electrical switch of the type having a switch actuation button, a switch body on which the button is mounted, and a pair of switch terminals mounted on the switch body protects the switch from its environment and prevents the application of excessive force to the switch actuation button. The switch cover arrangement includes a base plate to which the switch body is secured, and a housing to which the base plate is secured. The housing defines a central cavity for receiving the switch body and the switch button. The central cavity is closed at a first end by the base plate. The switch cover arrangement also includes a button cover mounted for sliding movement in the central cavity toward and away from the base plate. The button cover has a stop portion for contacting the base plate so as to limit sliding movement of the button cover in a direction toward the switch body.