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: 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: 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 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: 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.

Abstract: The two levels of programming complexity include a high level and an expert level. The command set on the high level includes a plurality of commands which comprise sequences of more detailed commands from the expert level. The expert level commands comprise single actions or operations, or small groups of operations, to be performed by the electromechanical devices, such as valve openings or closures. User access privileges are definable by a system manager to restrict different classes of users to one or more of the levels of complexity.

Abstract: A gas valve which is particularly useful in a laser gas fill system requiring repeated fillings includes a conduit positioned between high and low pressure gas regions. Within the conduit is a restriction, and this restriction is closed by a meltable solid material. When the valve is to be opened, heat is applied to the meltable solid material, either internally or externally, causing at least some of the material to flow and allow the passage of gas from the higher pressure region to the lower pressure region. When the pressure between the two regions has substantially equalized, or at least the pressure differential has greatly diminished, surface tension associated with the restriction in the conduit pulls the liquified material back into place to close and reseal the valve, at which point heat application is dicontinued so that the material again becomes solid.

Abstract: A switched resistor regulator is constructed whose duty cycle response is nonlinear with small changes in input control voltage. Specifically, the response of a pulse-width modulator is made to increase less than linearly with small changes in input control voltage. In a preferred embodiment, the pulse-width modulator is altered by comparing the input control voltage with a nonlinear reference signal, rather than the substantially linear reference signal which is used in prior art pulse-width modulators. Specifically, the nonlinear reference signal may be generated by a nonlinear reference voltage circuit, such as an RC charging circuit, or such as a D/A converter controlled by a clocked programmable microprocessor.

Abstract: A multi-faceted optical device for use in a laser scanner wherein the optical device is rotated about a central axis for rotational movement through a repetitive cycle to reflect and sweep a laser beam through a desired optical space comprises a body member formed by thermoplastic injection molding and shaped to be rotated about a central axis and to define multiple mirror receiving faces. Mirrors are shaped to be received upon the mirror receiving faces of the body member with three raised pads being formed on each of the mirror receiving faces for locating the corresponding mirrors received thereon in a defined orientation relative to the central axis. A fast setting, preferably ultraviolet curable adhesive, is applied to the three pads and the mirrors are forced against the pads and preferably released prior to curing the adhesive by means of the application of ultraviolet light or otherwise to form the optical device.

Abstract: A PbTe/PbEuSeTe buried heterostructure tunable diode laser and array and the method for making the same. The active region layer is buried between two lead salt semiconductor layers containing europium and selenium that are mutually of opposite conductivity type and have substantially the same lattice constant as the active region layer. In addition, the europium and selenium containing lead chalcogenide layers have an energy band gap greater than the active buried layer and an index of refraction less than the active layer. The buried structure enhances electrical and optical confinement, reduces threshold currents, and provides a stable single mode laser. Strontium, calcium or tin may be used in place of the europium. The buried laser and array are produced using a two-step molecular beam epitary method.

Abstract: A point of sale bar code scanner, such as a grocery store check-out label scanner, that is attendant-free and completely automated in providing a listing or a total pricing of a customer's selected items. At each automated check-out, the customer initiates the process, places items on a conveyor, which carries each item separately through a scanner. The scanner reads all sides of each package, including the bottom of the package, since the bar code label could be located on any surface. Serial conveyors are used, and gates preferably control the advancement of items onto a conveyor which will carry the item through the scanning area, such that only one item can be scanned at a time. The conveyor in the scanning area includes a series of belt strips through which an upwardly scanned beam can read the package bottom. Various methods and systems are disclosed for handling "no reads". The customer signifies termination of the process at the appropriate time.

Abstract: A bar code scanner which preferably generates an asterisk-like scan pattern has a scanner head at the end of a flexible mount enabling operator personnel to orient the scanner head in virtually any position and direction. The scan pattern generator is compact in size, utilizing a laser diode as a source, so that the scan head is easily manipulated to the desired position. In preferred embodiments the scanning mechanism generates the asterisk scan pattern with a rotating mirror or mirrors and a series of peripheral mirrors or lenses, one for each scan line, in an efficient and compact arrangement. The entire asterisk scan pattern may be constantly rotated at a relatively slow rate, so that bar code labels are more likely to be read without deliberate orientation by the operator, particularly in the case of bar codes of high aspect ratio.

Abstract: Self-normalization of laser spectrometers is provided by I"/I laser modulation and detection. A single tunable diode laser is frequency modulated by a high S/N ratio triangle wave, mechanically chopped, passed through an isothermal in-line gas and reference chamber absorption cell, and synchronously detected to provide the I" and I signals. The preferred embodiment discloses isotopic ratio measurements. The invention has application to quantitative trace gas measurements generally.

Abstract: A laser beam shaper which provides polarized output with a high spatial quality, utilizing induced stress birefringence. The laser beam shaper in which light resonates along a resonant path defined by reflective surfaces includes a solid state medium, such as a Nd:YAG rod which exhibits thermally induced stress birefringence that is of known, azimuthally independent distribution in planes perpendicular to the resonant path. On either side of the medium, quarter-wave retardation plates are provided which create essentially circular polarization of the resonant light within the medium. Sandwiching the quarter-wave plates and the medium are the first and second polarizing elements, both of which are aligned along the same preferred plane. By inducing stress birefringence in the medium, an output beam is produced. A shape defined by the distribution of the birefringence is provided. With media such as YAG, the shape of the beam is round with high quality.

Abstract: A two-phase fluid is injected into a volume upstream of the spark gap flow channel of a spark switch. The injected two-phase flow can be separated, causing the liquid component of the two-phase fluid to form a layer adjacent the wall of the flow channel and a predominately gas phase region near the spark switch electrodes. This distribution of liquid and gas phases can be achieved by tangential injection of the two-phase fluid. The resulting two-phase flow absorbs the thermal and radiant energy produced by the spark in the spark channel, as well as the energy of the shock wave systems produced by the spark in the spark channel, thereby reducing the temperature that the wall of the spark gap would attain without such two-phase fluid flow injection. Vaporization of the liquid due to this energy absorption generates a substantial gas flow which increases the purge flow and recovery rate of the spark gap switch.

Abstract: Glass laboratory vials are marked by grinding the surface of the vial with an abrasive wheel. The vial is moved relative to the wheel under control of a computer so as to automatically grind a desired bar code or alpha-numeric symbols into the surface. The ground portion of the surface of the vial scatters light while the unground portion of the surface transmits light.The process is automated and can be performed by a robot as part of an analyzing or processing system. The ground-in markings are more enduring than the prior art paper labels.

Abstract: A method and apparatus are disclosed for controlling the cross slope angle cut by the blade of an articulated frame motorgrader operated in the crabbed steering mode wherein the articulation angle of the motorgrader frame is sensed and used to calculate the blade angle relative to horizontal required to maintain a desired cross slope angle. The blade angle is sensed and controlled such that the sensed blade angle is maintained substantially equal to the calculated blade angle.