Abstract: An acoustic coupling plate extends from the bridge or vibrato to the neck of the instrument. It acoustically couples the strings, the neck, the instrument body, and either a bridge or a vibrato to alter the acoustic attenuation of the instrument and to reduce the amount of multipath distortion. When a different tonality is desired, this acoustic coupling plate can be divide into two plates and shaped to produce a desirable dampening versus frequency curve. One of these plates acoustically couples the instrument body to the bridge/vibrato and the second plate acoustically couples the neck to the instrument body. A vibrato assembly for stringed instruments makes slight and rapid changes in the pitch of the tone produced by stringed instrument. Previously known vibrato assemblies use knife-edge hinges or rolling ball bearings to produce these variations. The vibrato assemblies described herein use flexure bearings to produce variations in the tension of the strings and thereby the pitch of the tones.

Abstract: A vibrato assembly for stringed instruments makes slight and rapid changes in the pitch of the tone produced by stringed instrument. Previously known vibrato assemblies use knife-edge hinges or rolling ball bearings to produce these variations. The vibrato assemblies described herein use flexure bearings to produce variations in the tension of the strings and thereby the pitch of the tones. These flexure bearing vibrato assemblies have the advantages of high strength, zero operational noise and rumble, and virtually zero friction and hysteresis. Additionally, flexure bearing vibrato assemblies provide a robust path between the instrument and the strings resulting in improved tonal quality, range, and sustain.

Abstract: A drop detector having a piezoelectric membrane mounted to a substrate is presented. When a drop strikes the piezoelectric membrane, the membrane vibrates at a selected resonant frequency. The resonant frequency is selected to enhance the sensitivity of the drop detector and the signal-to-noise ratio of the output. The value of the selected resonant frequency depends on the type of material used for the piezoelectric membrane, the thickness of the membrane, the mounting of the membrane to the substrate, and other parameters such as the coating on the membrane. The vibrations of the membrane produce an output signal having a frequency equal to the selected resonant frequency. Since the frequency of the output signal is known, the output signal can be filtered with a bandpass filter to enhance the signal-to-noise ratio of the output signal. The resulting membrane drop detector is a high sensitivity, high signal-to-noise ratio drop detector.

Abstract: The invention is a method of packaging whole or large silicon wafers that provides support for the wafer, eliminates thermally or package-induced wafer strain, and allows selection of a mounting substrate material that provides optimal heat conduction.

Abstract: The trichromatic beamsplitter consists of composited dichroic beamsplitter plates that separate a projected image into its three color components with spacial as well as spectral precision. The three linear array photosensor comprises a monolithic sensor having three parallel photodiode arrays spaced precisely to accept the color component images of the trichromatic beamsplitter.

Abstract: An optical shaft encoder has a light detector configuration that includes the function of a phase plate. The light detectors are one-half the width of a code wheel transmissive section and are arranged in groups of four so that each group corresponds to one pitch of the code wheel. The light detectors are interdigitated such that they are adjacent to one another and receive information from two channels. One light beam illuminates the four light detectors producing four electrical signals. The physical layout of the light detectors causes the output signals to be phase shifted 90.degree. from each other. These signals are combined electronically in pairs forming quadrature push pull signals.

Abstract: A method is presented for accurately measuring an input signal's frequency components and the amplitude of those components. This is done by digitizing an input signal, passing it through a window, converting it into the frequency domain, and using the Fourier transform of the window to remove the effects of window from the input signal converted into the frequency domain.

Abstract: The capability of varying sizes of a dot in a printer is fully exploited to provide a gray scale image of superior quality. Errors in gray level are used to modulate the sizes of the dots in producing the image.

Abstract: A circuit tester and test technique are presented that compresses the amount of data stored in local test data RAMs for the implementation of a circuit test, thereby reducing the amount of data that must be downloaded to the local test data RAMs, thereby improving test throughput. Derivative data vectors are utilized in addition to raw data vectors as part of the data compression technique. Further compression results from storing only unique data vectors in the local test data RAMs and utilizing a sequencer to control the order in which the unique data vectors are utilized. The sequencer includes test program logic and logic capable of implementing on test pins indirect counters.

Abstract: A method and apparatus is presented for calibrating instruments for time interval measurements, pulse width measurements, and rise and fall time measurements. The preferred method comprises generating two coherent pulses using a linear passive device. The coherent pulses are simultaneously a.c. coupled to two channels of, for example, a time-interval measuring instrument. The time interval between the coherent pulses passing through the instrument is measured at identical voltages on each signal. Then the coherent pulses are exchanged between the channels and a further interval measurement is made. The results of each of the measurements are compared and used to calculate calibration constants to correct systematic errors present in the instrument.