The invention relates to a method for correcting a telecentricity error of an imaging device for semiconductor lithography having an illumination unit, an imaging optical unit, and a filter for correcting the telecentricity error, having the following method steps: determining the telecentricity error of the imaging device, designing a filter for correcting the telecentricity error, arranging the filter in the pupil plane of the illumination unit, determining the telecentricity error again, and repeating the method steps one to four until the telecentricity error falls below a specified telecentricity error.

The invention furthermore relates to an imaging device for semiconductor lithography, which is configured for carrying out the method.

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.

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.

A method of measuring a surface of an optical element and an interferometric measuring device for measuring a surface or profile of the optical element. The optical element having a first surface and a second surface opposite the first surface. The method includes defining at least a first measurement point, a second measurement point and a third measurement point on a measurement surface of the optical element being one of the first surface and the second surface, measuring a first position of the first measurement point by directing a measurement beam from a measurement head onto the first measurement point and by detecting a measurement beam portion reflected at the first measurement point, subsequently measuring at least a second position of the second measurement point and a third position of the third measurement point by directing the measurement beam onto the second measurement point and onto the third measurement point and by detecting a measurement beam portion reflected at the second measurement point and the third measurement point, respectively, and determining at least one of a decenter and a tilt of the measurement surface relative to a reference axis on the basis of at least the first position, the second position and the third position.

The present invention provides an apparatus and method for optical centering of lenses, potentially to be used for automatic accurate alignment and bonding of said lenses into an imaging system. The non-rotating lens centering device includes a motorized focusing autocollimator, one or two aiming lasers coupled to the motorized focusing autocollimator, and an optical laser redirector such as retro-reflectors or beam splitters and mirrors. The system may comprise an imaging device for alignment and beam profiling, a computer device and algorithms for data analysis to provide information related to centering offsets to be corrected. Motorized correcting system will realign and eliminate the unwanted decentering and adjustment of the lens.

The present disclosure provides a distance determination method, apparatus and system, relating to the technical field of image processing. The method includes the following steps: acquiring a master visual image photographed by a master camera and an original auxiliary visual image photographed by an auxiliary camera; acquiring an initial matching point pair between the master visual image and the original auxiliary visual image through feature extraction and feature matching; correcting the original auxiliary visual image sequentially, based on the initial matching point pair and different constraints, so as to obtain a target auxiliary visual image, wherein the different constraints includes: a constraint of a minimum rotation angle and a constraint of a minimum parallax; and determining a focusing distance according to the master visual image and the target auxiliary visual image. The focusing distance can be determined more accurately.

The present invention discloses an aspheric lens eccentricity detecting device based on wavefront technology and a detecting method thereof. The device comprises: an upper optical fiber light source, an upper collimating objective lens, an upper light source spectroscope, an upper beam-contracting front lens, an upper beam-contracting rear lens, an upper imaging detector, an upper imaging spectroscope, an upper wavefront sensor, a lens-under-detection clamping mechanism, a lower light source spectroscope, a lower beam-contracting front lens, a lower beam-contracting rear lens, a lower imaging spectroscope, a lower wavefront sensor, a lower imaging detector, a lower collimating objective lens and a lower optical fiber light source. The present invention achieves non-contact detection, with no risk of damaging the lens, and there is no moving part in the device, so the system reliability and stability are high; and in the present invention, various eccentricity errors in the effective aperture of the aspheric lens can be detected at a time, thereby avoiding errors caused by splicing detection, and also greatly reducing the detection time, thus being applicable to online detection on an assembly line.

Disclosed is a method and apparatus for determining information about an alignment of one or more optical components of a multi-component assembly involving: detecting an optical interference pattern produced from a combination of at least three optical wave fronts including at least two optical wave fronts caused by reflections from at least two surfaces of the one or more optical components; and computationally processing information derived from the detected optical interference pattern with at least one simulated optical wave front derived from a model of at least one selected optical surface of the at least two surfaces to computationally isolate information corresponding to an alignment of the selected optical surface.

This method for retrieving at least one optical parameter of an ophthalmic lens comprises: obtaining an image of a first and second patterns by using an image capture device located at a first position; from that image, obtaining a first set of data from at least a part of the first pattern that is seen through the lens by the image capture device and obtaining a second set of data from at least a part of the second pattern that is seen directly i.e. outside the lens by the image capture device; retrieving the at least one optical parameter by using the first and second sets of data and taking account of relative positions of the image capture device, the lens and the first and second patterns.