Abstract: An operating voltage applied to a transmitter's power amplifier in a mobile wireless transceiver is dynamically controlled so as to improve the efficiency of the transmitter at all output power levels. In one embodiment, the bias current levels within the transmitter are also varied to optimize the efficiency of the transmitter at all output power levels. In a preferred embodiment, a highly efficient switching regulator is controlled by a control circuit to adjust the operating voltage and/or bias current for the power amplifier in the transmitter. The control circuit has as its input any of a variety of signals which reflect the actual output power of the transmitter, the desired output power, or the output voltage swing of the transmitter.

Abstract: A first laser light intensity detector is positioned within a stepper or scanner proximate to a reticle so that attenuation due to stepper optics has already occurred prior to the laser light impinging upon the light intensity detector. Preferably, the first light intensity detector is mounted as closed to the wafer as practical. A second light intensity detector is located at the output of the laser. The light intensity detected from the outputs of the first and second light intensity detectors, in conjunction, forms part of a feedback mechanism which adjusts the light output of the laser, during wafer fabrication, so that the light intensity detected by the first light intensity detector is an optimum value.

Abstract: In one embodiment of the invention, phosphor powder in a binder is deposited on a flat first side of a fused silica substrate. The UV output of a laser beam is reflected off an angled beam splitter so as to be incident upon a flat second side of the fused silica substrate. The phosphor is energized by the UV light transmitted through the fused silica and re-radiates a visible wavelength. The binder is selected to be opaque to UV wavelengths so that only a thin layer (10-20 microns) of the phosphor is energized by the incident UV beam. Since the energized phosphor layer against the first side of the substrate is extremely thin and flat, the energized phosphor produces a visible light which precisely corresponds to the incident UV light. The visible light may then be used to determine the characteristics of the UV beam.

Abstract: A wavelength shift correction system for a laser system is provided for correcting wavelength chirps. This wavelength shift correction system includes a learning algorithm that learns characteristics of a wavelength chirp from a laser and a computer system that executes the learning algorithm and provides wavelength correction control signals based on the learned characteristics to reduce the magnitude of the wavelength shift of the present wavelength chirp and subsequent wavelength chirps.

Abstract: An extra step for a conventional replica forming process for diffraction gratings used in lasers is described herein. Applicant has discovered that the deterioration of a replica diffraction grating, when used with intense laser light, is accelerated due to small quantities of the radiation leaking through minute fractures in the aluminum reflective coating. Applicant has identified the source of this problem as occurring during the removal of the replica from the master grating. Applicant's improvement to this conventional process is to deposit a thin reflective overcoat of aluminum on the surface of the replica after the replica has been removed from the master and cleaned. The overcoating is performed in a vacuum chamber by sputtering or evaporation. This overcoat is not subjected to any subsequent destructive forces and hence remains relatively opaque. A typical thickness of the overcoat is around 100 nm. An oxide layer is formed over the aluminum and a third layer of aluminum is formed over the oxide.

Abstract: The preferred embodiment of the invention uses known atomic or molecular absorptions as absolute wavelength standards for calibrating wavelength measurement instruments used in tunable lasers. Examples of atomic and molecular absorptions are carbon and molecular oxygen that have absorptions including 193.0905 nm and 193.2728 nm, respectively, for use with a tunable Argon Fluoride excimer laser at approximately 193 nm. A wavelength measuring device (e.g., a wavemeter) is equipped with a gas cell containing the absorption gas. During a calibration procedure, the wavelength measured by the wavemeter is compared to the atomic or molecular absorption. The wavemeter's calibration constants are then adjusted accordingly to match the wavemeter's output to the atomic or molecular absorption wavelength. Such calibration procedures, therefore, calibrate the wavemeter to absolute standards and correct for any drift in the wavemeter that may occur between calibrations.

Abstract: Disclosed are techniques and apparatus for flexibly mounting a mechanism. The embodiments describe a flexible mount that is at once tolerant of misalignment, shock resistant, insensitive to rotational orientation, compact, and failure resistant. A mechanism is rigidly attached to a retainer that interlocks with a stationary housing and confines and compresses annular resilient members. The methods may in particular apply to the mounting of hydraulic and pneumatic cylinders for actuation of a shutter assembly in an optical system. In addition the techniques can apply to the flexible mounting of other mechanisms incorporating movable members having axes of symmetry, including push rods and rotating shafts.

Abstract: The preferred embodiment of the invention measures the temperature increase of a light-transmitting optical component to determine the optical absorption of the optical component. Accurately determining the optical absorption of light-transmitting optical components advantageously allows for the accurate and efficient selection of light-transmitting optical components for use in an optical system. In one embodiment, an optical absorption tester holds multiple optical components and, for each optical component, the tester includes a temperature sensor placed in contact with the optical component and a reference temperature sensor placed in the vicinity of the optical component.

Abstract: An automatic gain control circuit in the feedback path for a laser wavelength control circuit is described herein. This gain control circuit automatically adjusts the amplification of the analog signals output from a photodetector array, where the array detects a fringe pattern created by a laser beam. Another feature of the preferred embodiment feedback circuit is the automatic setting of a DC offset voltage that compensates for errors in the feedback path and enables an accurate determination of a dark level signal in the fringe pattern signal. This dark level signal provides a reference for measuring the magnitude of the fringe pattern signal. Varying photodetector outputs may now be more accurately measured. The preferred embodiment feedback circuit also employs a very fast amplifier anti-saturation circuit using LED's connected in a clamp circuit.

Abstract: In one embodiment, the illumination system for a scanner incorporates an excimer laser whose square beam is incident upon a two-dimensional array of lenses. The light exiting the array is made incident on a long focal length lens for creating nearly parallel rays. The combination of the array and the long focal length lens causes the resulting square beam at the focal plane of the long focal length lens to have a substantially uniform intensity across its area. An array of cylindrical lenses receives these nearly parallel rays. The light output of the cylindrical lens array is then made incident on a first positive lens whose focal length is longer than the distance between the cylindrical lens array and the first positive lens. A second positive lens is located of the focal plane of the first positive lens. This results in all light rays from the cylindrical lenses which have the same angle to be focused at the same point on the second positive lens.

Abstract: A masking method for use in a silicide formation process is disclosed herein which prevents an oxide etching solution from tunneling under a photoresist masking layer and damaging oxide spacers not intended to be etched. This process may be used during the formation of a bipolar or MOS transistor formed in an isolated silicon island. A mask opening used to etch exposed oxide spacer portions is made to not expose any parasitic oxide spacers formed along an edge of the isolated silicon island. In this way, an oxide etch solution is prevented from tunneling along the parasitic oxide spacer and reaching any intersecting oxide spacers not intended to be etched. The desired oxide spacers will thus be intact to properly isolate silicide portions formed over exposed silicon and polysilicon surfaces.

Abstract: A high speed operational amplifier includes a differential amplifier input stage capable of producing a pair of complementary differential outputs. Complementary current mirrors receive the differential signals out of the first stage and combine them at a common output node for amplification by an output buffer. The circuit can be operated at low power and produces a high slew rate.

Abstract: A monolithic switching regulator on chip loop frequency compensation circuit is described. An op-amp is provided with a conventional small frequency compensation capacitor, which determines its unity gain frequency and an input resistor. The op-amp incorporates 100% negative feedback. When driven at a frequency that is below its unity gain frequency the noninverting input of the op-amp displays a capacitance having a value on the order of nanofarads, which value would ordinarily require an excessive chip area if fabricated as an actual capacitor. This capacitance value is useful in the on chip loop frequency compensation of a switching regulator where the switching frequency is operated at about 150 kHZ.

Abstract: An IBM PC compatible keyboard is provided which, on power-up, does not access the keyboard LEDs until receiving a command from the host computer. When the keyboard controller performs a Basic Assurance Test (BAT) on power-up before receiving a host command, the controller does not turn on the LEDs. Upon receiving a Reset command from the host, the controller: (1) turns on the LEDs and performs a BAT with LEDs on; and (2) flashes the LEDs a second time to be compatible with the IBM PCs. Another feature of the invention is a non-destructive test of the controller RAM during BATs. The RAM is tested non-destructively both for the "stuck-at-1" and the "stuck-at-0" conditions. Still another feature is that the controller determines the state of the keyboard LEDs without reading a hardware port. The controller keeps track of the LED state by flags in the controller memory, and the controller determines the LED state by reading the flags.

Abstract: An audiovisual subscription system includes means for aperiodically inverting the lines of a transmitted video signal on a frame-by-frame basis and for decrypting encrypted PCM audio information which is transmitted along with the aperiodically inverted video information.

Abstract: A switch device which is operated by movement of a knob coupled to a switch actuator. The knob comprises a projection from a center of an arc-like skirt, wherein the arc-like skirt has a rounded slope extending from the projection to a periphery of the arc-like skirt. A cover arranged over a switch element mounted on a printed substrate defines an opening and has projection walls formed at peripheral edges of the opening, wherein the opening acts to receive the switch actuator, and wherein the arc-like skirt co-acts with the projection walls for preventing water from entering the opening. Liquid contacting the knob flows down the arc-like skirt and is drained through a drain passage formed in the cover. Thus, the switch device is essentially made waterproof by the co-action of the arc-like skirt, the projection walls, and the drain passage.

Abstract: An audiovisual subscription system includes means for aperiodically inverting the lines of a transmitted video signal on a frame-by-frame basis and for decrypting encrypted PCM audio information which is transmitted along with the aperiodically inverted video information.

Abstract: An automatic sheet feed control system for a printer having an automatic sheet feeder for sequentially feeding a plurality of sheets set on a tray of the feeder to a printing position to print and output the sheets which comprises the steps of discharging the sheet upon detecting of the end of the sheet when receiving a page feed command or a sheet discharge command from an external controller and during the sheet feeding or after feeding the sheet, storing the sheet discharged, and then feeding next sheet to print from a predetermined position when the sheet is discharged at printing time, thereby preventing in advance a sheet from being wound on a platen for a long period by eliminating to allow the sheet wound on the platen to stand for a long period.

Abstract: A push button switch including a housing, an operating member slidably received in the housing, a contact switch section located under the operating member, an actuator rotatably supported to the housing for opening and closing the contact switch section, a spring retained between the actuator and the operating member, and a pusher pin extending downwardly from the operating member and adapted to push the actuator, wherein when the operating member is depressed to make the pusher pin abut against the actuator, the actuator starts to be rotated for generation of buckling of the spring. Accordingly, the switching time of the buckling of the spring can be made constant, thereby ensuring a constant on-timing of the switch.

Abstract: A printed circuit board has one or more conductor-deleted portions formed in the lands of a conductor pattern printed on an insulating substrate. The conductor-deleted portions may be one or more slits extending radially from a center hole of each land, one or more holes, or one or more notches. Preferably, the conductor-deleted portions are positioned to be in the direction of alignment of the lands. The conductor-deleted portions reduce the amount of solder adhering to the lands and prevent solder bridges between adjacent lands from forming.