Abstract: A glass ophthalmic lens which has been strengthened by thermal tempering or ion exchange treatment has increased impact resistance and durability, but such strengthening does not alter the appearance of the lens sufficiently to render the presence or absence of strengthening visually ascertainable even by one of high skill. It being necessary to inspect for the presence or absence of strengthening prior to dispensing lenses to the public, the present invention contemplates immersion of the lenses in a transparent liquid of approximately the same refractive index as the material of the lenses and projection of linearly polarized light through the fluid and lens. Viewing of the thus illuminated lens through a light polarizing analyzer reveals readily observable stress patterns in strengthened lenses and a lack of such patterns in non-strengthened lenses.

Abstract: An integral vacuum pump for producing ultra-high vacuums including, in combination, axial turbomolecular, centrifugal compressor and vortex diode pumping means.

Abstract: A laser rangefinder for clouds, fog, haze and precipitation including an erbium doped laser transmitter, a germanium photodiode monitor and a germanium avalanche photodiode detector. The germanium avalanche photodiode and an amplifier module is positioned at the focus of a parabolic reflector. The transmitter transmits light in a waveband with an optical center at 1.54 microns and is eye safe. A periscope system aligns the outgoing pulse with the returning light to reduce parallax.To reduce alignment problems when shifts in wavelengths occur, an optical circuit with only reflecting surfaces can be employed.To increase the efficiency of the laser transmitter, the clamps utilized to position the laser rod within the cavity are formed of the same material as the laser rod and the pump light reflector is a second surface mirror with a quartz substrate coated in succession with silver, copper and black paint.

Abstract: A general purpose ophthalmic lens series incorporating an aspheric, atoric design concept which allows the selection of lens base curves substantially independently of traditional field of view or marginal error performance criteria. Factors of sensitivity of field errors to fitting distance, shape magnification, geometric distortion, eyelash clearance, reflections, applicability to large spectacle frames and general cosmetic appearance are optimized by base curve selection and field corrections are attended to by aspherizing one or both surfaces of the lenses.

Abstract: A multi-wavelength optical filter, particularly useful for shielding against laser light, includes compounds incorporated into a glass base which produce Cu.sup.2.sup.+ ions, Er.sup.3.sup.+ ions, and Ce.sup.3.sup.+ ions, thereby providing a filter having desired optical densities at 488 nm, 515 nm, 530 nm, 671 nm, 694 nm, 1060 nm, 840-900 nm, 347 nm, and 337 nm.

Abstract: An optical filter includes glass doped with erbium (Er.sup.3.sup.+) ions for absorbing light at about 530 nm for protection against frequency doubled Nd-laser light; and to provide protection against Nd-laser light, ferrous (Fe.sup.2.sup.+) ions are included in the glass. The glass base may be changed to broaden the absorption band, increase the absorption coefficient, or to shift the absorption band towards longer wavelengths.

Abstract: In a field emission charged particle microscope having a housing defining a vacuum chamber, a field emission tip disposed in the chamber for generating charged particles, electrode means for establishing electrostatic focusing and accelerating field for forming a beam of charged particles, field electrode means in juxtaposition with the tip for developing an electrostatic field for extraction of charged particles generated by the tip and voltage means connected to the electrode means and the tip for supplying electrical potential thereto to establish the electrostatic fields, the inclusion of an apertured, conductive symmetrical glass resistor disposed intermediate the field electrode means and the electrode means for establishing the focusing and accelerating field, and in electrical contact therewith.

Abstract: Glass having an extremely high absorption coefficient for incident light in fiber optical image transfer devices and working compatibility with conventional light-conducting glasses used in the manufacture of such devices. The glass consists essentially of lanthanum trioxide, boron oxide, manganese dioxide, a colorant and glass forming, modifying and stabilizing ingredients.

Abstract: Laser glasses having high resistance to self-damage during operation are formed in all ceramic melting units, in the presence of a fining agent to eliminate the formation of metallic inclusions and semi-conductive inclusions and using base glass compositions with reduced tendency toward microphase separation and devitrification. The major ingredients of the glass batches include silicon dioxide, alkali and alkaline earth nitrates, carbonates and fluorides. The method involves introducing oxidizing compounds into the reaction mixture in a sufficient amount that during the reaction and fining phase, oxidizing conditions are maintained throughout the entire volume of the glass melt.

Abstract: A compressed data display system. There is disclosed a system for recording over extended periods of time EKG and other vital signs of a patient and for automatically displaying the waveforms in a compressed and readily interpretable manner. The EKG waveform is recorded on looped paper supported by and/or wrapped around rotatable drum or drums which may have cylindrical shape. The EKG is recorded in helical or spiral fashion by simultaneously rotating the drum and transversely moving a galvanometer pen in the direction of the axis of rotation of the drum or cylinder. After the paper is removed, if it is a continuous or closed loop, it can be slit and opened into a single sheet. The recorded EKG waveforms are thus displayed compressed in a line-over-line manner and provide the physician with a clear picture of the patient's heart activity for extended periods of time.

Abstract: A fixture for blocking lenses of various diametral sizes with cast blocks of corresponding diametral sizes using a single annular support of fixed diameter for all lenses as a reference relative to which pressure used in clamping of the lenses for blocking may be regulated to prevent lens distortion despite variations in their diametral sizes.

Abstract: Chemically stable, semiconducting glasses having a resistivity of from about 2 .times. 10.sup.7 to about 6 .times. 10.sup.8 ohm.sup.. cm contain 25 to 35 weight percent of vanadium pentoxide, 10 to 20 weight percent phosphorous pentoxide, and from 35 to 45 weight percent of molybdenum trioxide. These semiconducting glasses are melted readily, are castable into desired shapes, and offer good resistance to devitrification.

Abstract: An Oximeter Cuvette having a complimentary cover with a stirrer that extends into the cuvette cavity and which is rotated relative to the cuvette by the oximeter unit is particularly advantageous to permit a plurality of samples to be evaluated rapidly.

Abstract: Apparatus for evaluation a human subject's color vision response including light emmiting diodes providing luminance in the yellow and red and green color spectrums, means for controlling the individual luminescence of the red and green diodes in an inverse relationship and means for displaying the yellow and red-green luminescence for comparative viewing by the human subject.

Abstract: A field emission gun for use in an instrument such as an electron microscope including the field emission tip, an extraction electrode and focusing and accelerating anode means wherein there is disposed between the tip and the accelerating field of the anode means an electric field of a strength expressed in terms of electron voltage, at least equal to the lowest energy secondary electron sought to be prevented from entering the accelerating field.

Abstract: Spectacles having a face-formed readily separable two-section eyeglass frame front wherein a first forward section of the frame front supports a pair of fixed non-circular light-polarizing lenses and a rearward second section supports a rotatable light-polarizing lens in alignment with each forwardly disposed lens. A manually operable rear lens rotating mechanism is provided for selectively rotating the two rearward lenses in unison to simultaneously equally rotationally alter the orientation of axes of polarization of these lenses relative to axes of polarization of the fixed forwardly disposed lenses for correspondingly varying the intensity of light permitted to pass through each system of front and rear lenses of the spectacles.

Abstract: A cardiac defibrillator paddle in which the elctrode surface is provided with a removable cap. This permits the electrode to have its conductive paste pre-applied, with the cap readily removable for immediate use.

Abstract: A system for recording input electrical signals by positioning galvanometer pen styli relative to a chart paper device in accordance with the input signals. Each pen is mechanically linked to an optical mask. The optical mask in conjunction with an optical system provides a feedback light signal, which is converted to a feedback electrical signal for nulling the input signal. The ink application device includes structure for applying pressure directly to carbon paper, which in turn transfers the carbon or ink to the chart paper, thereby recording clear representations of the electrical signals.

Abstract: By using two or more masks in a microscope having an optical system with an intermediate image plane therein in combination with a camera, composite photomicrographs can be prepared with two or more images.

Abstract: Faraday rotation glasses exhibiting a high Verdet constant and a low susceptability toward devitrification are formed by introducing a high quantity of rare earth oxides into a borate glass base. The glasses can be melted under standard environmental conditions and may be made on a large scale.