Abstract: A system includes a light pattern generator having light spots for illuminating front and back surfaces of a cornea with polarized light; one or more detectors for receiving one or more of first spot images from light reflected off the front surface, and second spot images from light reflected off the back surface, the light reflected off the front surface having a first polarization and the light reflected off the back surface having a second polarization; a polarization element in an optical path between the back surface and the one or more detectors, the polarization element being configured to attenuate an intensity of the light reflected off the front surface by an amount greater than an amount by which it attenuates the light reflected off the back surface; and a processor for determining a geometric characteristic of the cornea using at least the second plurality of spot images.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: Systems and methods for measuring a distance from a reference plane of an optical measurement instrument to a reference plane of an optical device under test are disclose. In one embodiment a system for measuring this distance includes an illumination system, an optical system, and optical sensor and a processor. The illumination system is configured or adapted to illuminate the object under test. The optical system is configured or adapted to receive light from the object under test and to produce an aberrated image. The optical sensor is configured or adapted to receive and sense the aberrated image. The processor determines the distance from the reference plane of the optical measurement instrument to the reference plane of the optical device based on an aspect of the aberrated image sensed by the optical sensor.

Abstract: A level-shifting amplifier is provided for level-shifting an input signal with a voltage magnitude that exceeds a supply voltage of the amplifier. In operation, the amplifier has an input impedance of greater than 100 MOhms.

Abstract: An ophthalmic error measurement system includes a projecting optical system delivering light onto a retina of an eye, a pre-correction system which compensates a light beam to be injected into the eye for aberrations in the eye, the pre-correction system being positioned in between the projecting optical system and the eye, an imaging system which collects light scattered by the retina, and a detector receiving light returned by the retina from the imaging system. Use of the pre-correction system allows the end-to-end aberrations of the ocular system to be analyzed. The use of a pre-correction system also allows use of a minimized spot size on the retina, and all of its attendant advantages.

Abstract: A system for mapping a three-dimensional structure includes a projecting optical system adapted to project light onto an object, a correction system adapted to compensate the light for at least one aberration in the object, an imaging system adapted to collect light scattered by the object and a wavefront sensor adapted to receive the light collected by the imaging system and to sense a wavefront of the received light. For highly aberrated structures, a number of wavefront measurements are made which are valid over different portions of the structure, and the valid wavefront data is stitched together to yield a characterization of the total structure.

Abstract: A level-shifting amplifier is provided for level-shifting an input signal with a voltage magnitude that exceeds a supply voltage of the amplifier. In operation, the amplifier has an input impedance of greater than 100 MOhms.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: A system and method of measuring the curvature of a surface of a object operate by illuminating the object surface with a light pattern having a known size to produce a virtual reflected image from the object surface; measuring a size of the virtual reflected image produced by the object surface from the light pattern; and calculating a curvature of the object surface from the known size of the light pattern and the size of the virtual reflected image.

Abstract: A system for determining a surface shape of a test object includes a pattern having a plurality of first elements dispose about a central axis and defining an aperture containing the central axis. The first elements includes a plurality of common elements having a common form and a reference element having a reference form that is different than the common form. The system further comprises a detector array and an optical system. The optical system is adapted to provide an image of the first elements when light reflects off a surface of a test object, passes through the aperture, and is received by the detector array. The reference form may be configured to facilitate an association between the common elements and the spot images of the common elements.

Abstract: A system for mapping a three-dimensional structure includes a projecting optical system adapted to project light onto an object, a correction system adapted to compensate the light for at least one aberration in the object, an imaging system adapted to collect light scattered by the object and a wavefront sensor adapted to receive the light collected by the imaging system and to sense a wavefront of the received light. For highly aberrated structures, a number of wavefront measurements are made which are valid over different portions of the structure, and the valid wavefront data is stitched together to yield a characterization of the total structure.

Abstract: A system for determining the shape of an object and/or a distance of the object from the system includes a first plurality of light source, a second plurality of light sources, and a detector or detector array. The first plurality of light sources are disposed about a central axis and are separated from the central axis by radial distances defining an aperture in the first plurality of light sources. The system also includes an optical system adapted to provide light from the second plurality of light sources through the aperture to the object. The system may further include a computer configured to determine the shape of the object and/or the distance of the object from the system using light from the first and second plurality of light sources that is reflected from the object and received by the detector.

Abstract: A level-shifting amplifier is provided for level-shifting an input signal with a voltage magnitude that exceeds a supply voltage of the amplifier. In operation, the amplifier has an input impedance of greater than 100 MOhms.

Abstract: A method and associated system improve accuracy in objective refraction measurements by including the measured distance between the photoreceptors of a subject's eye and the scattering location of light during the objective refraction measurements. Chromatic aberrations in the objective measurements are also compensated. The distance between the photoreceptors and the scattering location may be determined by adjusting a distance between a rotating speckled light pattern and an eye until the speckled light pattern appears to be stationary, or by employing a Scheiner disk.

Abstract: Systems and methods for measuring a distance from a reference plane of an optical measurement instrument to a reference plane of an optical device under test are disclose. In one embodiment a system for measuring this distance includes an illumination system, an optical system, and optical sensor and a processor. The illumination system is configured or adapted to illuminate the object under test. The optical system is configured or adapted to receive light from the object under test and to produce an aberrated image. The optical sensor is configured or adapted to receive and sense the aberrated image. The processor determines the distance from the reference plane of the optical measurement instrument to the reference plane of the optical device based on an aspect of the aberrated image sensed by the optical sensor.

Abstract: A system for mapping a three-dimensional structure includes a projecting optical system adapted to project light onto an object, a correction system adapted to compensate the light for at least one aberration in the object, an imaging system adapted to collect light scattered by the object and a wavefront sensor adapted to receive the light collected by the imaging system and to sense a wavefront of the received light. For highly aberrated structures, a number of wavefront measurements are made which are valid over different portions of the structure, and the valid wavefront data is stitched together to yield a characterization of the total structure.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: A level-shifting amplifier is provided for level-shifting an input signal with a voltage magnitude that exceeds a supply voltage of the amplifier. In operation, the amplifier has an input impedance of greater than 100 MOhms.

Abstract: A major aspect of the invention offers the subscriber the capacity to control one telephone connection from another, and/or from a television, including call diversion and transferring. Preferably this is done utilizing correlation and cross-linking between the various telephone and other devices connections. As in the preferred embodiment the cross-linking is performed primarily at the infrastructure level rather then at the device level, the subscriber enjoys unified telephony environment, as well as call control services from one connection to another.

Abstract: A level-shifting amplifier is provided for level-shifting an input signal with a voltage magnitude that exceeds a supply voltage of the amplifier. In operation, the amplifier has an input impedance of greater than 100M Ohms.