According to some aspects, calibration techniques are provided that allow an optics module of an additive fabrication device to be installed and operated in a stereolithography device by a user. In particular, the calibration techniques enable the optics module to be calibrated in a way that only depends on the characteristics of the optics module, and not upon any other components of the stereolithography device. As a result, the techniques enable a user of a stereolithography device to remove one optics module and replace it with another, without it being necessary to repair or replace the whole device. In some cases, the calibration techniques may include directing light onto one or more fiducial targets within the stereolithography device and measuring light scattered from said targets.

The control system for a stage light fixture with photobiological safety includes a control unit connected to a motor assembly and a light source and configured to control the stage light fixture to operate, and a distance sensor connected to the control unit, and configured to acquire an instant distance from a living being to the stage light fixture. The control unit stores a light radiation hazard exposure radiance limit value and a light fixture irradiance value acquired in advance per unit of time and distance, and acquires a parameter of the living being entering an irradiation danger zone according to the instant distance, the light radiation hazard exposure radiance limit value, and the light fixture irradiance value. When a hazard condition reaches the parameter of the living being entering the irradiation danger zone, the control unit controls the stage light fixture to move to eliminate the hazard condition.

A method of measuring an axis angle of a toric contact lens including a posterior toric central zone having a cylindrical axis, and an anterior lens surface forming a ballast that has an axis of orientation offset from the cylindrical axis at a selected rotational angle is disclosed. The method involves (a) providing anterior and posterior mold sections including respective anterior and posterior mold cavity defining surfaces, wherein the posterior mold cavity defining surface includes a toric central zone and the anterior mold cavity defining surface is shaped to provide the ballast, the mold sections being alignable at multiple rotational positions; (b) providing a detectable feature on each of the anterior and posterior mold sections at a predetermined angular location with respect to the tonic and ballast axes thereof, respectively; (c) rotating the detectable feature of the posterior mold section relative to the detectable feature of the anterior mold section, wherein the detectable feature of the anterior mold section is a zero reference; and (d) measuring the axis angle between the detectable feature of the posterior mold section relative to the detectable feature of the anterior mold section after rotational displacement of the mold sections during toric contact lens formation.

A method and apparatus for a structured light measuring device, having a preferable VCSEL array in its previous illuminated cross plane, using the laser array to be projected through said device's objective and collect the reflected beams through the same objective lens. A motorized stage is attached to the objective focusing, enabling back and forth focusing on different external planes. A software algorithm running on a computer device will analyze the reflected laser beam and find its central point and further translate it to angular deviations, similar to Autocollimation principles. Furthermore, this could be displayed as a cross on the user GUI for better user interface. The focusing function has the capability to focus the laser array at various planes, and analyze if the reflected beam is at its best focal point or deviates. By moving the focal point back and forth, a 3-D reconstruction can be achieved, preferable for lenses and calculating the center location relative to the device's line of sight.

A method of determining a phase shift caused by reflection at, or transmission through, a dielectric coating as a function of wavenumber includes obtaining a nominal phase shift for the dielectric coating as a function of wavenumber, determining a first wavenumber and a second wavenumber for performing measurements of phase shift at these wavenumbers based on the nominal phase shift, determining a wavenumber shift based on a first measurement of phase shift at the first wavenumber, a second measurement of phase shift at the second wavenumber, and the nominal phase shift as a function of wavenumber, and determining the phase shift as a function of wavenumber based on the wavenumber shift and the nominal phase. Further described is a method of determining a layer design for a dielectric coating, wherein the dielectric coating comprises a plurality of stacked layers.

A method of determining a phase shift caused by reflection at, or transmission through, a dielectric coating as a function of wavenumber includes obtaining a nominal phase shift for the dielectric coating as a function of wavenumber, determining a first wavenumber and a second wavenumber for performing measurements of phase shift at these wavenumbers based on the nominal phase shift, determining a wavenumber shift based on a first measurement of phase shift at the first wavenumber, a second measurement of phase shift at the second wavenumber, and the nominal phase shift as a function of wavenumber, and determining the phase shift as a function of wavenumber based on the wavenumber shift and the nominal phase. Further described is a method of determining a layer design for a dielectric coating, wherein the dielectric coating comprises a plurality of stacked layers.

This invention discloses methods and apparatus for providing an ophthalmic lens of variable optical power. The variable optic insert may have surfaces within that have differing radii of curvature. The variable optic insert may also comprise polarizing elements. In some examples, an intermediate optic piece may be formed to comprise a UV absorbing dye, allowing differential processing of regions on either side of the intermediate optic piece. In some embodiments, an ophthalmic lens is cast-molded from a silicone hydrogel. The various ophthalmic lens entities may include electroactive liquid crystal layers to electrically control refractive characteristics.

A computer-implemented method for testing a modulation transfer function or spatial frequency response of an imaging system includes, on a computing device, generating a plurality of accumulation cells running along an accumulation line. A boundary delineation divides a first segment of a digital test image captured by the imaging system from a second segment, and the plurality of accumulation cells collectively comprise a one-dimensional accumulation array. For each of the accumulation cells, a projection ray is generated that extends through the accumulation cell and through the digital test image Each accumulation cell is loaded with an accumulated pixel value based on pixel values sampled from each of a plurality of sampling locations along the projection ray. The modulation transfer function or spatial frequency response of the imaging system is derived from the one-dimensional accumulation array.

The disclosure provides a device for detecting a wavefront error by modal-based optimization phase retrieval using an extended Nijboer-Zernike (ENZ) theory. The detection device includes a point light source (1), a half mirror (2), a lens (3) to be tested, a plane mirror (4) and an image sensor (5). The wavefront error of the component under test is characterized by using a Zernike polynomial, and a Zernike polynomial coefficient is solved based on an ENZ diffraction theory. The present disclosure realizes the one-time full-aperture measurement on the wavefront error of a large-aperture optical component, and can use a partially overexposed image to achieve accurate wavefront error retrieval. Meanwhile, the present disclosure overcomes the contradiction between underexposure and high signal-to-noise ratio (SNR) caused by a limited dynamic range when the image sensor (5) acquires an image. The detection device is simple and does not have high requirements for the experimental environment.

Method for detecting a defect in a zone of interest of an optical lens, the method including: an image reception step, during which a plurality of images is received, each image includes a view of the zone of interest in front of a plurality of specific patterns, each specific pattern including a bright area and a dark area, and at least one image received is saturated in light intensity; a sampling step, during which each image of the plurality of images are sampled based on a common sampling pattern; a recombination step, during which a recombined image of the zone of interest is determined based on the common sampling pattern; and a defect detection step, during which a defect is detected in the zone of interest of the optical lens based on an analysis of the recombined image.