Abstract: A beam directing device is provided which employs one or more mirrors mounted on a single rotatable shaft. The orientation of the shaft controls the rotational orientation of these directing mirror(s) to direct the beam toward any of a number of sample or reference cells. Behind each cell is a cube corner which reflects the beam back to the directing mirror(s) for reflection toward the detector. In one embodiment, a shaft encoded senses the orientation of the shaft, the encoder output being servoed against a position signal to coarsely rotate the shaft in order to direct the beam to a sample cell and thence to a spectrograph slit. A pair of slit diodes detect the beam overlap on each side of the slit and their output is used to accurately position the beam on the slit to within one second of arc and correct for deviations in beam direction.

Abstract: A semiconductor component and a method for manufacturing the semiconductor component with low electrical and thermal impedances is provided. The semiconductor component includes a thin semiconductor device with a plurality of layers of various conductivity types forming the active regions and semiconductor/metallic transition layers. The low electrical impedance of the component is achieved by the use of the thin semiconductor device, while the low thermal impedance is provided by a thick pedestal metalization on the semiconductor device.The method for manufacturing such a device includes the fabrication of at least one semiconductor device on one surface of a semiconductor substrate. The second surface of the semiconductor substrate is selectively etched by a controlled process to form a cavity of limited lateral extent adjacent to each of the semiconductor devices on the one surface.

Abstract: Apparatus and method are disclosed for deriving the maximum and minimum peaks of a wave representing blood pressure by comparing it with offsets that may be arbitrarily set or derived from the blood pressure signal, which offsets are alternatively added to and subtracted from the approximate mean of the blood pressure signal.

Abstract: A method and apparatus for converting a tri-state logic signal into a two-state logic signal accurately and repeatably for purposes of signal measurement. In particular, the method and apparatus deal with how the third, or high impedance state is translated into a high or a low state. This is accomplished by including a resistor of a selected value to form a voltage divider with the resistance of the path through which the stray capacitance of the circuit under test charges during these intervals. Thus, the level of the final voltage charge is limited to a selected voltage that is intermediate the high and low state threshold voltages of that circuit. The initially conditioned signal, now a true tri-stage signal, is next applied to two threshold detectors, whose outputs in turn are applied to a state machine. This combination generates a repeatable two-state signal by identifying each occurrence of the third state as the last previous high or low state, i.e.

Abstract: Signals having desired peaks and undesired peaks that may be due to noise are processed so as to identify the desired peaks by determining a first difference between the amplitude of every peak and a long-term average of the peak amplitudes and then obtaining a second difference between the first difference and the average of such first differences. If the second difference exceeds a predetermined amount, the peak is considered to be undesired; but if the second difference is less than the predetermined amount, the peak is considered to be desired. If the desirable peaks represent systolic or diastolic blood pressures, their respective averages are considered to be unreliable if the number of desired peaks occurring within a given time is less than an arbitrarily selected number; and if the ratio of undesirable to desirable peaks is less than a predetermined amount, the signal is considered to be of poor quality so that the averages attained are suspect.

Abstract: Analog to digital conversion is achieved with a reduction in digitization noise and anti-aliasing by coupling an integrating A/D converter to a digital filter having more than two sections and a gain greater than two.

Abstract: A digital signal is summed before application to a D/A converter, and a differentiator is inserted at some point between the signal input and output.

Abstract: A compact, DC-coupled Schmitt trigger circuit is disclosed for providing fast switching in response to differential current signals from an input source such as an amplifier. The circuit includes first and second matched pairs of transistors disposed for performing switching and feedback functions, respectively, and for producing a voltage at an input or base of the first pair equal to the sum (AND function) of the source voltage and the voltage at an emitter of the feedback pair. In response to the applied current signals, the transistors of the second matched pair are always in a conducting state (and requires no extra time to turn on) regardless of the conducting state of either of the transistors of the first matched pair.

Abstract: A paper alignment mechanism for a recorder in which the paper is moved by one or both rollers at the outer edges of the paper along the X axis in accordance with one variable and a stylus is moved across the paper along the Y axis in accordance with another variable, the alignment being achieved by determining the distance between two points on a line parallel to the Y axis and an orientation line on the paper, applying a pivot near one edge of the paper and a force near the other edge, the force being in such direction as to rotate the paper to an aligned position and the relative positions between the pivot and the point of application of the force being such that the paper between them is in tension.

Abstract: A digital servo system is described in which the error signal is multiplied up to a given maximum before its application to a D/A converter that provides control voltage for the motor, as long as the motor has not reached its final position and its velocity is greater than a predetermined amount.

Abstract: A method and apparatus for obtaining an accurate measure of the frequency of an applied signal by generating a pair of independent frequency signals wherein one of the independent frequency signals has a frequency value which is indicative of the operating temperature of the counter. The counter has two modes of operation: a calibration mode and a measurement mode. In the calibration mode, an accurate signal having a preselected frequency value is applied to the counter. The frequency of this signal is measured with reference to the other of the pair of independent frequency signals and this measured value is then algebraically combined with a prestored value that is equivalent to the preselected frequency of the applied signals. The combined value represents the necessary normalized correction factor for any measured frequency when the counter is at the corresponding temperature.

Abstract: A digital servo system is described in which hunting that would be caused by restoring torque due to resilient coupling to a load is prevented by preventing the transfer of information from the error register to the D/A converter controlling the motor.

Abstract: Image forming means are described in which the discontinuities usually occurring in a raster scan display presentation of a waveform are smoothed by varying the width of the path pattern.

Abstract: The modular read-write and read-only memory, central processing, input-output control keyboard input and output printer units of the calculator described herein provide an adaptable programmable calculator that may be operated manually by the user from the keyboard input unit or automatically by a program stored in memory. Programs may be loaded directly into memory from the keyboard and either data or programs may be separately transferred bi-directionally between the memory unit and an external magnetic card. Programs stored in the memory unit may be edited and key-coded logs, program lists, labels, and messages may be printed by the output printer unit by specifying one of several modes of the calculator. In one of the modes, the printer will print a log comprising a listing of a key code for each key actuated, of nearly all programmable operations performed from the keyboard.

Abstract: In signal measurement circuits which are referred to a floating ground and which derive their input signals from electrodes attached to a patient's body, the effects of common mode potentials on the patient's body are minimized without requiring any patient electrodes other than those acting as signal sources, by using an operational amplifier to drive the floating ground toward the common mode potential on the patient's body.This process is accomplished without significantly degrading the isolation impedance between the measurement circuits and true ground.The patient is protected from hazardous electrical shock by incorporating a current limiting impedance in the amplifier circuit.

Abstract: An algebraic electronic calculator is provided having a keyboard input unit with digit keys for entering numbers into the calculator and control keys for entering add, subtract, multiply, divide, left parenthesis, right parenthesis, storage register designating, square root, equals, and other operators into the calculator. A record of each number and operator entered into the calculator is printed out by an output printer so that a mathematical problem may be continuously monitored as it is being entered into the calculator. Depression of the square root control key initiates computation of the square root of a number stored in the calculator and printout of the result. The calculator also includes provision for computation of another such unary function such as cube root if desired. Depression of the equals control key is accompanied by evaluation of all the previously entered numbers and operators and printout of the results.

Abstract: Each memory cell of an x-y addressable semiconductor memory includes a charge storage element serially connected with an I-O (bit) line through a pair of CCD-type transfer gates. One gate is responsive to x-addressing and the other gate to y-addressing.When an x-y address is selected only the charge storage element of the one selected memory cell communicates with the bit line.

Abstract: A heterodyne phase lock system is disclosed having a plurality of oscillator circuits, a similar plurality of heterodyne (mixer-filter) circuits representing an input circuit, and a similar plurality of heterodyne circuits representing a control circuit, at least one of the oscillator circuits being a voltage controlled oscillator (VCO) circuit. The heterodyne circuits of the input circuit are cascaded, i.e., linked each to the other, successively, and the heterodyne circuits of the control circuit are likewise cascaded. Each oscillator is linked to a pair of heterodyne circuits, i.e., to one heterodyne circuit in the input circuit and to one heterodyne circuit in the control circuit, and applies a common output signal to said pair of heterodyne circuits.

Abstract: An electronic calculator assembly is disclosed having a flexible printed circuit board bonded to a layer of resilient material mounted on a rigid backing plate. An integrated circuit package containing electronic calculator circuitry is held tightly against the flexible printed circuit board by a cradle assembly. Leads from the integrated circuit package make contact areas on the flexible printed circuit board and depress the flexible printed circuit board into the resilient layer. A keyboard assembly is mounted to the opposite side of the rigid member and the flexible printed circuit board is folded around the rigid member so that contact areas on the flexible printed circuit board also form fixed switch contacts for the keyboard.