Abstract: A method for operating a rotating reel type slot machine, or a video machine which depicts rotating reels, is described herein which allows a player to save in memory one or more symbols from one or more previous games and use those symbols in a current game to obtain a winning combination. In one embodiment, multiple sets of reels are employed, and saved symbols from a primary sets of reels may be used for any of said multiple sets of reels in subsequent games. In one embodiment, additional coins may be deposited to allow the use of saved symbols with additional reel sets. In another embodiment, a special symbol displayed by a first set of reels causes corresponding reels in second and third sets of reels to stop at the special symbol.

Abstract: An electrostatic discharge protection device for reducing electrostatic discharge spikes on a signal line is disclosed. The electrostatic discharge protection device includes first and second contact regions formed in a semiconductor material such as a compound semiconductor substrate. A first terminal is electrically coupled between the signal line and the first contact region. A second terminal is electrically coupled between the second contact region and a sink such as ground. An isolation region is formed in the semiconductor material between the first and second contact regions. The isolation region may be an implant-damaged region of the semiconductor material. The electrostatic discharge protection device provides protection against electrostatic discharges for integrated circuit components, while adding only a small amount of parasitic capacitance to I/O lines, which is particularly important in RF signal processing circuitry.

Abstract: A device with a low resistance zone having confinement, superior reproducibility, and a very high yield comprises a plurality of semiconductor layers, wherein layer resistivity is changed by annealing. The semiconductor layers include a resistance zone having a high activation coefficient of acceptor impurities and a resistance region having a low activation coefficient of acceptor impurities. The activation coefficient is controlled by irradiation with laser light. In addition, laser light is irradiated and absorbed into the semiconductor layers in one part of, or the entire, semiconductor layers, such that layer resistivity in the irradiated regions is changed by annealing resulting from such irradiation.

Abstract: The invention is an AlInGaN light-emitting device (LED) that includes a p-type contact made of highly-reflective material with closely-spaced openings that increase light extraction efficiency. The minimum dimension of the openings is ¼ of the wavelength of the emitted light and is preferably comparable to the distance current flows laterally in the p-layers of the device. The openings in the metal occupy 20-80% of the top surface of the contact and are finely spaced to achieve transparency and uniform light emission. An optional dielectric encapsulant may be deposited over the p-type contact to improve the contact's adhesion by tacking it down at regular intervals, and to improve light extraction. The surface of the epitaxial layers may be etched in the openings to scatter light in the semiconductor, increasing light extraction. A reflective layer may be applied to the bottom surface of the LED to increase the light extraction efficiency.

Abstract: An equipment loading plank that is detachably mounted on a machine tool table and used for easy and safe installation and removal of equipment on and off the machine tool work tables. The equipment loading plank includes a flat rectangular shaped body with an upper loading surface and a lower seating surface and a leg downwardly extending at an angle from one end of said loading plank. The leg is inserted into a T-slot in the machine tool table to detachably mount the loading plank to the machine tool table. The leg has a front face and a lower face that converge such that the leg can be wedged into the T-slot when the loading plank is seated on the machine tool table parallel to the upper surface of the machine tool table. The leg ends in a foot that prevents the leg from slipping from the T-slot whenever loads are placed on the loading plank.

Abstract: A differential pair includes a first and second transistors each having a control terminal coupled to a first input voltage, and a third and fourth transistors each having a control terminal coupled to a second input voltage. The first, second, third, and fourth transistors each has a first current handling terminal coupled to a reference voltage. The first and second transistors each has a second current handling terminal coupled to a first current mirror. The third and fourth transistors each has a second current handling terminal coupled to a second current mirror. A resistor is coupled between the second current handling terminals of the second and third transistors. The differential pair is capable of attaining a high slew rate and a possible common mode input voltage of ground while drawing only a small quiescent current.

Abstract: An RF power amplifier with variable bias current is disclosed. The RF amplifier includes a peak detector that detects the peak level of the amplifier input signal. The peak detector generates an output signal in response to the peak level of the amplifier input signal. A bias voltage level setting circuit coupled to the peak detector receives the peak detector output signal and generates a bias voltage in response to the peak detector output signal. An amplifier circuit coupled to the bias voltage level setting circuit receives the bias voltage and the amplifier input signal, and generates an output signal in response to the bias voltage and the amplifier input signal. The disclosed RF amplifier allows amplification of RF signals with high linearity and high efficiency at varying power levels, and extends the maximum power capability of the amplifier.

Abstract: The invention is a method for designing semiconductor light emitting devices such that the side surfaces (surfaces not parallel to the epitaxial layers) are formed at preferred angles relative to vertical (normal to the plane of the light-emitting active layer) to improve light extraction efficiency and increase total light output efficiency. Device designs are chosen to improve efficiency without resorting to excessive active area-yield loss due to shaping. As such, these designs are suitable for low-cost, high-volume manufacturing of semiconductor light-emitting devices with improved characteristics.

Abstract: A solderable light-emitting diode (LED) chip and a method of fabricating an LED lamp embodying the LED chip utilize a diffusion barrier that appreciably blocks molecular migration between two different layers of the LED chip during high temperature processes. In the preferred embodiment, the two different layers of the LED chip are a back reflector and a solder layer. The prevention of intermixing of the materials in the back reflector and the solder layer impedes degradation of the back reflector with respect to its ability to reflect light emitted by the LED. The LED chip includes a high power AlInGaP LED or other type of LED, a back reflector, a diffusion barrier and a solder layer. Preferably, the back reflector is composed of silver (Ag) or Ag alloy and the solder layer is made of indium (In), lead (Pb), gold (Au), tin (Sn), or their alloy and eutectics. In a first embodiment, the diffusion layer is made of nickel (Ni) or nickel-vanadium (NiV).

Abstract: A laser chamber with a circuitous gas return path dissipates shock waves. In one embodiment, the laser chamber includes a heat exchanger with a large surface area that defines an aerodynamic passage through which gas circulates in the laser chamber. The passage through which the gas circulates directs shock waves away from the discharge region so that the shock waves may dissipate elsewhere in the laser chamber. In addition, the large surface area of the heat exchanger efficiently cools the thermally energetic gas within the laser chamber. In another embodiment, ancillary chambers that are fluidically coupled to the main laser chamber are provided to permit shock waves to be directed away from the discharge area and to be dissipated within the ancillary chambers. Openings to the ancillary chambers are positioned such that shock waves generated by the electrode structure of the laser chamber may propagate directly into the ancillary chamber, where the shock waves then dissipate.

Abstract: A blower assembly for circulating gases in a laser chamber. The blower assembly includes a driving assembly operatively engaged to a drive side shaft for rotating a fan assembly. A first bearing assembly supports the drive side shaft. The blower assembly may further include an idle side shaft for supporting the fan assembly and a second bearing assembly circumscribing the idle side shaft. The driving assembly includes a motor disposed over a rotor. The fan assembly includes a pair of hubs supporting a plurality of blades. The first and second bearing assemblies comprise a ceramic compound, such as silicon nitride (Si3N4), and are lubricated with a synthetic oil, such as perfluoropolyalkylether (PFPE).

Abstract: An LED component is provided, with light emission in the green-to-near UV wavelength range. The light-emitting semiconductor die is encapsulated with one or more silicone compounds, including a hard outer shell, an interior gel or resilient layer, or both. The silicone material is stable over temperature and humidity ranges, and over exposure to ambient UV radiation. As a consequence, the LED component has an advantageously long lifetime, in which it is free of “yellowing” attenuation which would reduce the green-to-near UV light output.

Abstract: For AlGaAs LEDs the confining layers adjoining the active layer possess the highest Al composition. From failure analysis of non-passivated, WHTOL-aged, AlGaAs LEDs, it was discovered that corrosion occurs the fastest at the exposed surfaces of the high Al-content confining layers. By placing a high-quality native oxide at the exposed surfaces of the high Al-content confining layers which protect from the formation of the ‘poor’ oxide, it is possible for LEDs to retain essentially their same light output after 2,000 hours of WHTOL testing. Further, it is possible to improve carrier confinement, carrier injection, wave guiding, and other properties by increasing the Al-content of different layers.

Abstract: In the present invention, an interfacial layer is added to a light-emitting diode or laser diode structure to perform the role of strain engineering and impurity gettering. A layer of GaN or AlxInyGal1-x-yN (0≦x≦1, 0≦y≦1) doped with Mg, Zn, Cd can be used for this layer. Alternatively, when using AlxInyGa1-x-yN (x>0), the layer may be undoped. The interfacial layer is deposited directly on top of the buffer layer prior to the growth of the n-type (GaN:Si) layer and the remainder of the device structure. The thickness of the interfacial layer varies from 0.01-10.0 &mgr;m.

Abstract: A tangential fan, configured to recirculate a lasing gas mixture, has blade members, which are twisted in a substantially helical fashion about the rotation axis of the fan. The circumferential number of blade members can be constant variable between the end flanges. The circumferential position of blade members can shift monotonically or reversibly between the two ends. A tangential fan in accordance with the invention can be made using a conventional method of brazing together individually stamped and formed blade members and hub members. Finishing processes typically include post-machining, electropolishing, and electroless nickel coating.

Abstract: A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.

Abstract: Generally, and in one form of the invention, a method is disclosed for forming an ohmic contact on a GaAs surface 20 comprising the steps of depositing a layer of InGaAs 22 over the GaAs surface 20, and depositing a layer of TiW 24 on the layer of InGaAs 22, whereby a reliable and stable electrical contact is established to the GaAs surface 20 and whereby Ti does not generally react with the In.

Abstract: An apparatus for monitoring a thermal state of a system includes a thermal management integrated circuit (IC). The thermal management IC is coupled to receive a remote temperature signal. The remote temperature signal is indicative of a system temperature. The thermal management IC includes a software programmable temperature threshold setpoint, and a hardware programmable temperature critical threshold setpoint.

Abstract: A system of linked gaming machines has each of the linked gaming machines connected to a common controller. In a normal mode of play, each of the linked gaming machines operates like a conventional machine where the generation of certain combinations of symbols provide awards to the individual players whose machines generate such combinations. In addition to this normal mode of play, a bonus feature is added where the generation of combinations of bonus symbols is used by a central controller to build up a pooled bonus value based upon the values of the combinations of bonus symbols generated by all the linked gaming machines. When a player hits a combination which causes the accumulated bonus value to meet or exceed a predetermined value, a bonus award is given to the player which caused the threshold to be exceeded.

Abstract: A test fixture for a laser gas module offers automatic and manual testing for individual gas module components. Check or pressure relief valves are tested with an increasing pressure ramp caused by a metered gas flow into a ballast tank. Metering orifices are tested by measuring pressure change in a known volume tank as gas to or from the tank is directed through the orifice under test. The fixture includes capability to test valve logic and leakages. Test sequence and results are monitored on a computer display showing a schematic representation of both module and fixture. Manual control of module and fixture components is done via a computer graphic interface.