Abstract: A dry zeroing assembly is provided for zeroing a gun-sight implemented on a gun having a barrel.

Abstract: A lens distortion measurement system has a first grating of a first pitch on a transparent support such as a quartz reticle. The reticle is disposed between an illumination source and the lens system whose distortion is to be measured. An image sensor is provided within the image projection field of the lens system. A second grating of a second (different) pitch is provided on another transparent support, disposed between the lens system and the image sensor. Optionally, a relay lens is disposed between the second support and the image sensor. Illumination propagates from the illumination source through the first support, through the lens system, through the second support and is incident on the image sensor. The illumination forms a Moire fringe having a pitch orders of magnitude greater than the pitches of the first and second gratings.

Abstract: A method, and apparatus and lens sheet manufacturing process which utilize the method, of evaluating the quality of a lenticular lens sheet having a front side carrying a plurality of elongated parallel lens elements, and a back side. The method includes:(a) illuminating the sheet from one of the sides with a light source so that the light passes through the sheet and is then reflected from a reflector behind the other side to pass back through the sheet; and(b) comparing an observed feature of a pattern of the reflected light which has passed back through the sheet with a corresponding reference feature to provide an indication of the lenticular lens sheet quality.

Abstract: A lens meter is provided in which a beam of light from an illumination optical system (20) is made incident upon a lens (40) to be inspected, the light beam which has passed through the lens (40) is then received by a light receiving sensor (33b) through a lens platform (13) disposed on a lens receiving table (11) and a light receiving optical system (30), and the two-dimensional optical characteristics of the lens (40) are measured from a detection result of the light receiving sensor (33b). In the lens meter, the lens platform (13) is formed to have such an area as to guide light coming from the middle of the lens (40) and from a predetermined range around the middle to the light receiving sensor (33b), and projections (13b) are formed for determining a light reception distance (2) from the lens (40) to a relay lens (32) of the light receiving optical system (30).

Abstract: A focus evaluation technique for photolithography equipment is disclosed. This technique includes providing a substrate having a photoresist coating for treatment by the equipment. The equipment is activated to focus a first part of a image on a region of the surface and defocus a second part of the image relative to the region. The region is tilted relative to an image plane defined by the equipment. This activation is repeated for each of a number of spaced-apart regions along the surface. The substrate is processed to provide a pattern for each of the regions corresponding to the first and second parts. The equipment is characterized from the pattern for each of the regions. This characterization may result from inspection of the pattern relative to reference marks provided for each region. Focus information for the equipment which accounts for lens heating may be determined from this inspection.

Abstract: A method and apparatus of generating a test signal for broadcast to a plurality of locations for testing optical devices is disclosed. A tunable laser sweeps from a lower wavelength to a higher upper wavelength providing a test station with a variable input signal. A timing signal generated from the variable input signal is provided to the test station to determine the frequency of the variable input signal so that tests may be performed at several known wavelengths. Amplification is added to the system to provide sufficient power to the variable input signal and timing signal both split by a splitter to be provided to multiple test stations simultaneously.

Abstract: The present invention provides a measuring apparatus (10) for centering and determining wedge error of an optical element (12) under test. The measuring apparatus (10) preferably includes a lens holder (16) for supporting the optical element (12) to be tested. The lens holder (16) is rotatably supported on an air bearing (68) having an axis such that the lens holder (16) may be rotated about the axis. A first sensor (18) is located proximate the lens holder (16) for measuring the wedge characteristics of the optical element (12). The first sensor (18) is movable in a horizontal, vertical and rotatable direction such that the first sensor (18) may be positioned to a predetermined distance from the optical element (12) at a preselected angle. A second sensor (20) is located proximate the lens holder (16) for measuring centering characteristics of the optical element (12).

Abstract: The present invention discloses an optical system with multiple optical lens having capability of auto-focus calibration, instead of conventional scheme of manual operations. Furthermore, achieve purpose of obtaining more accuracy in sharpness and magnification calibration than the conventionally scheme, and of upgrading yield rate of the system. The optical system disclosed by the invention basically includes a lot of home-sensors and micro-sensors, lots of lens, an image sensor, an imaging control motor, a lens switch motor for switching the lens, and a base control motor for switching base of the optical system. By using the imaging control motor and the base control motor to control motions of the imaging device and the lens, auto sharpness and magnification calibration is easily achieved.

Abstract: A lensmeter accessory is disclosed for supporting and positioning a corneal contact lens in a light path of a lensmeter. The accessory comprises a generally planer body with a tapered slot therein having a slot wall defining a recessed groove for receiving and removably holding a contact lens. The accessory may be placed on an adjustable lens platform of a lensmeter to position the contact lens in the lensmeter light path.

Abstract: A method and apparatus for evaluating optical elements which utilizes reflected images. The method allows determination of the optical effects contributed by individual surfaces of a single optical alone or in a multiple element optical system. The method is particularly useful for evaluating corneas after transplant, grafting and reshaping procedures.

Abstract: A lens inspection device has an objective lens composed by front and rear lenses, a two-dimensional image sensor and an image forming lens for forming a point image of light passing through the objective lens. A lens to be inspected is disposed between a light source and an object focal point of the objective lens. The light source projects a light beam through the lens to be inspected parallel to the optical axis of the objective lens, and the front lens of the objective lens is moved along the optical axis so as to shift the object focal point of the objective lens stepwise into a plurality of positions within a predetermined range including a normal focal point of the lens to be inspected. Brightness data of a point image formed on the two-dimensional image sensor is detected for each shifted position of the objective lens, and is used for judgment as to whether an actual focal point of the lens to be inspected is within a proper range.

Abstract: The present invention provides a lens meter capable of accurately measuring the optical characteristics of a lens including additive diopter and of providing highly reliable data representing the optical characteristics of the lens. The lens meter projects measuring light through a target mark on a lens, focuses an image of the target mark in a target image on a photo-detecting device, and determines the optical characteristics of the lens on the basis of a locus of the target image detected by the photo-detecting device.

Abstract: A device for pinpoint application of micro-quantities of a pharmacologically suitable composition to the outer hard coat of the eye, comprises a micro-container with a fixation element. The micro-container comprises a bore whose aperture is adapted to contact the eye surface, and the fixation element is adapted for reversibly adhering to the eye surface.

Abstract: An automatic lensmeter for automatically measuring a lens characteristic of a lens to be tested, comprises: a measuring unit including an optical system for detecting a refraction characteristic of the lens; a calculation unit for calculating a lens characteristic value in accordance with information from the measurement unit; a display unit for displaying the lens characteristic value calculated by the calculation unit; an actual eccentricity calculation unit for calculating an actual eccentricity based on the lens characteristic value calculated by the calculation unit; and an optical axis position determination unit for determining whether the actual eccentricity calculated by the actual eccentricity calculation unit is within a predetermined range or not to determine whether the measurement and/or the marking are permitted. The display unit displays the determination of the optical axis position determination unit.

Abstract: A method and apparatus for lens measurement that provide for a small error of measurement where a light source used for measurement emits a beam of light at a wavelength different from an operating wavelength of a lens to be measured. The spherical aberration of the lens being measured, which occurs at the nonoperating wavelength, is identified and measured. An auxiliary lens is then placed in the path of the light source emitting the beam of light with the nonoperating wavelength to suppress the spherical aberration. This method allows for performance measurements of the lens to be obtained at the nonoperating wavelength without the adverse effects of the spherical aberration which occurred at the nonoperating wavelength.

Abstract: Optical properties of a lens, including localized defects, are determined by analyzing the refracted image produced by transmitting a beam of light through an aperture and a lens to be tested. The image is reflected onto a light sensitive detecting surface. Information obtained from the light detecting surface is digitized and sent to an Image Processing Unit which calculates the optical properties of the lens. The aperture may consist of a single shaped opening or alternatively a plurality of concentric, annular rings. Correction lenses may be employed, either permanently or selectively, to alter the refracted beam before the beam intersects the detecting surface.

Abstract: An automatic lensmeter for measuring optical characteristics of a lens to be examined is disclosed. The automatic lensmeter includes a display for displaying thereon an alignment target, first and second calculation devices for converting a shift between the optical center of the lens to be examined and a measurement optical axis into a prism power and a deviation respectively, and device for forming the alignment target at a predetermined position, whereby highly accurate alignment can be attained and accurate marking can be readily obtained.

Abstract: An automatic lens meter includes a projection optical system for projecting light beams onto a lens to be tested. The lens is held at a predetermined position in the direction of an optical axis. The meter also includes a receiving optical system having a light position detector. The receiving optical system receives light beams transmitted through the lens to be tested on the light-position detector. The meter further includes a calculator for calculating a diopter value and an eccentricity of the lens to be tested from the position of the tranmitted light beams on the light-position detector, a timer for measuring the time during which the eccentricity is within a predetermined range, and a display device for displaying the diopter value of the lens to be tested when the time during which the eccentricity is within a predetermined range exceeds a predetermined time.

Abstract: Adaptions of lensmeter optical trains are disclosed for enabling the measurement of contact lenses without the interference of spherical aberration from the highly meniscus lens formats of contact lenses. A generic system of measurement of the contact lenses when off of the eye is introduced by having light incident to or passing from the suspect contact lenses at an approximate aplanatic condition of the contact lens. The approximate aplanatic condition is determined by taking the average power of the posterior and anterior surfaces of the contact lenses for the general population--approximately 8 mm, assuming an index of refraction of approximately 1.5--calculating the aplanatic condition for such a "surface," and having light incident on the lenses for the interrogation of the lenses approximate the aplanatic condition.

Abstract: A laser system for measuring dimensional aberrations across a target surface includes a laser diode for producing a diverging beam of laser emission. A mask spaced from the diode in the beam has an aperture therein and can be moved so as to translate the aperture to selected locations laterally with respect to the beam. The mask blocks emission from impinging on the target except for emission transitting the aperture. Emission reflected from a segment to the target returns through the aperture back into the laser diode. An AC current is added to the driver current to modulate the emission. A lock-in amplifier of a photodetector signal adds feedback current to the driver current to lock in phase angle, so that the feedback current is a measure of the aberrations.

Abstract: A method for measuring the power of a lens, comprising the following steps:(a) providing an unobstructed collimated beam of light to an opto-electronic transducer,(b) sampling the beam with said opto-electronic transducer to produce an output signal representing the intensity of light across the width of said collimated beam of light,(c) converting the transducer output signal to digital form and loading the resulting digital signal into a computer memory,(d) inserting a lens into the path of said collimated beam of light,(e) repeating steps (b) and (c) with the lens thus inserted into said beam for at least one separation distance, L, between said lens and said transducer, and(f) calculating the power of said lens from the digital signals stored in the computer memory.

Abstract: To determine the focal power of an ophthalmic lens, a plurality of light rays are passed through the lens and a photosensitive position sensor is disposed on the exit side of the lens to measure the coordinates of the points at which the light beams impinge on an analysis plane perpendicular to the lens axis. The light rays comprise three light rays on a circle and a light ray on the system axis.

Abstract: A device for measuring the radius of curvature of an optical element comprises a point light source or a pinhole, a beam splitter, an imaging optical system for forming a point image, an attaching member for a substance to be tested which is placed on an optical axis of the imaging optical system, a displacing mechanism for changing relative position on the optical axis of the point image, a light receiving element for detecting the point image, a prism for splitting the pupil by four comprising four wedge prisms having wholly different wedge directions and arranged between the light receiving element and the beam splitter, an image instrumentation section for detecting respective barycenter or center positions of four point images formed on the light receiving element and for calculating the displaced amount or the amount proportional to displacing differences of the point image from the reference image plane, and a display section for displaying the calculated result.

Abstract: A spectacle lens right/left determination apparatus used in an optical characteristic measurement apparatus for checking and measuring optical characteristic of spectacle lenses, comprises a contact plate which has contact surfaces which are brought into contact with an eye-rim of one spectacle lens to be measured and an eye-rim of the other spectacle lens not to be measured when the spectacle lens to be measured, whose central portion is mounted on and fixed to the optical characteristic measurement apparatus, is inserted in a measurement optical path of the optical characteristic measurement apparatus; a first strain sensor, fixed to the contact plate, for, when a left-eye lens is present on the measurement optical path and the eye-rim of a right-eye lens is brought into contact with the contact surface, detecting a strain of the contact plate; a second strain sensor, fixed to the contact plate, for, when the right-eye lens is present on the measurement optical path and the eye-rim of the left-eye lens is b

Abstract: A focal point detecting optical apparatus has a focal point detecting optical system on an optical axis for reimaging a portion of a primary image formed in the vicinity of an optical axis through a taking lens on a row of light receiving elements linearly arranged by as a pair of images and detecting a focusing state in the vicinity of the optical axis; a focal point detecting optical system outside an optical axis for reimaging a portion of the primary image formed outside the optical axis on the row of light receiving elements and detecting a focusing state outside the optical axis; and light deflecting means disposed in the vicinity of an imaging surface on which the primary image is formed and deflecting beam of light outside the optical axis toward the optical axis side.

Abstract: A method for in vitro evaluation of focal length changes in a lens is disclosed, involving the steps of projecting parallel laser beams through the lens at at least two points, examining the convergence of the beams after exiting the lens to determine the focal length of the lens, and after a period of time, repeating these steps and comparing the focal length. Preferably, a scanning laser is used so that a number of beams pass through different spots on the lens, so that the spherical aberration of the lens may also be determined and compared over time. Apparatus is disclosed for carrying out the method, comprising a carousel plate having a number of spaced holes for receiving lens containers. A carousel drive servo motor rotates the carousel from lens container position to lens container position. A helium-neon laser is mounted horizontally on an X-Y table, and the laser beam is deflected upwardly through a lens held in a lens container.

Abstract: An autolensmeter for inspecting refracting power of optical systems is herein disclosed, which comprises a collimater lens for projecting light from a light source onto an optical system to be examined as a parallel luminous flux, a mask means having a mask pattern for selectively transmitting the luminous flux from the optical system and a photodetecting means for receiving the luminous flux partially transmitted through the mask pattern, disposed at a non-image forming position of the optical system, characterized in that an optical element is arranged in close vicinity of the mask pattern so that the light source and the photodetecting means are in an optical conjugate relationship with each other.

Abstract: A lens meter has a single point-like light source, a collimator lens for collimating the light from the point-like light source and causes it to enter a lens to be examined, a plural-aperature stop disposed immediately reawardly of the lens to be examined and having three or more apertures, a light-receiving optical system including a prism assembly for separating the light beams from the plural-aperture stop on the light-receiving surface thereof, and an array light-receiving element disposed at the focus position of the light-receiving optical system for measuring the refractive value of the lens to be examined by the mutual positional relation between the received light beams.

Abstract: This invention relates to a method and apparatus for measuring the optical power of soft contact lenses having a lens holding apparatus which is mountable on known prior art lensmeter structures. The lens holding apparatus includes a basic support housing means, a lens holder assembly mounted on the basic support housing means, and a lens conditioner means connected to the basic support housing means and operably engagable with the lens holder assembly. The lens holder assembly includes a contoured lens support member having a transparent lens support surface to substantially duplicate the outer contour and size of a person's eye. The lens conditioner means includes a lens wiper assembly operable through an actuator linkage assembly to move a wiper blade member over the contoured lens support member with a soft contact lens mounted thereon to provide a wetting action on both sides of the soft contact lens to duplicate the conditions when worn on the cornea of a person's eye.

Abstract: An apparatus for measuring the optical characteristics of a lens disposed in a measuring optical system illuminated by the beams of a plurality of light sources, the apparatus includes photoelectric detecting means having a detecting surface disposed substantially orthogonal to the optical axis of the measuring optical system for detecting the positions of the light beams passed through the lens and producing a photelectric signal, optical characteristic calculating means responsive to the signal to calculate the spherical power, the cylindrical power and the principal meridians axis degree of the lens, deviation detecting means responsive to the signal to detect the amount of deviation of the central position of the light beams passed through the lens from the position of the optic axis of the measuring optical system, eccentricity calculating means for calculating the eccentricity of the optic axis of the lens from the optic axis of the measuring optical system in a two-dimensional coordinates system on the

Abstract: A reticle design is provided for step and repeat projection aligners which, when patterned on a wafer (10), allows quick macroscopic evaluation of best focus for used in fabricating integrated circuits. The reticle pattern consists of opaque lines and spaces of widths slightly above the resolution limit of the resist/aligner system. The macroscopic determination of best focus, being macroscopically visible, eliminates the need for microscopic determination, thereby providing a quick and easy method. The best focus determination is made by forming an array (22) of resist fields (14') on the wafer, subjecting each field to a different focus and exposure. Upon development, those fields away from the best focus and at the larger exposure doses will be removed, leaving a parabola (24) of fields whose apex (26) is at high exposure. Best focus is the focus setting used to print the row of fields (B) containing the apex.

Abstract: An apparatus (10) for measuring the magnification power of a magnifying aid (14) is disclosed. The apparatus (10) includes an optical system (12) having an objective lens (34) focused at infinity on a reticle. The reticle (20) is positioned in the line of sight of the optical system (12). The reticle (20) is precalibrated such that the magnification power of a magnifying aid (14) may be determined. Also, disclosed is a method of calibrating the optical system (12) and a method of measuring the magnification power of a magnifying aid (14).

Abstract: Lens meter and method of measurement of progressive multifocal lens using the same which is able to set the amount of movement of the lens and to simply position a far- or near-distance refraction characteristics-measuring portion of a progressive multifocal lens. In accordance with the method the optical center of a lens is first found from measurement employing the lens and using the optical center as point of origin, the lens is moved by a distance up to the far-distance refraction characteristics measuring portion and the near-distance refraction characteristics measuring portion of the lens mentioned by the lens manufacturer, so as to effect alignment with the measurement optical axis of the lens meter, thereby measuring the refraction characteristics of each measuring portion.

Abstract: An optical testing method and apparatus employing a non-interferometric technique, making use of axial intensity information, in which the intensity of the light pattern along the optical axis is calibrated to achieve improved measurement of spherical aberration.

Abstract: The power of an intraocular lens is verified under sterile operating room conditions prior to its insertion into a patient's eye. A testing apparatus amenable to single hand operation is utilized which is comprised of two slidably interengaged plates having two series of lenses adapted to be aligned upon optical axes perpendicular to the plates. The aligned lenses constitute adjustable minus power reference lenses. An intraocular lens to be tested is placed atop an appropriate minus power reference lens, and the surgeon views a stationary object through said lens system while moving the apparatus. By observing whether the stationary object appears to move in a direction with or against the lens movement following minor adjustments in the power of the reference lens, the power of the intraocular lens can be determined.

Abstract: A lens meter having a focusing indication system with divided-image registration focusing comprises a condenser lens, a target having a nondiffusing transmissive surface and a slit pattern thereon, an objective lens, a lens mount for supporting a lens to be examined, a projection lens, a screen, the arrangement being such that the distance of movement in unison of the condenser lens and the target in the direction of an optical axis is read to detect the degree of the lens supported on the lens mount, an aperture plate disposed in the vicinity of a front focal point of the condenser lens and movable with the condenser lens and the target in the direction of the optical axis, and at least two deflection prisms disposed in intimate contact with the slit pattern on the target and having bases extending across the slit pattern and substantially perpendicularly to each other.

Abstract: A portable measuring device for testing optical systems of an endoscope consisting of a base plate, a rail with a longitudinally extending V groove for receiving a portion of the endoscope being mounted to extend parallel to the plate on a carriage movable at right angles to the groove. The device includes a vertical shaft mounted on the plate and terminating at one end in a conical point and the shaft carries at least one extension arm which is mounted to pivot in a plane parallel to the base plate. Each arm adjustably supports a measuring disk which can have its height above the plate changed or its distance from the shaft changed.

Abstract: The disclosure concerns the determination of the ophthalmic parameters of a thin astigmatic optical element without requiring initial location of its cylindrical axis. The effective optical power of the eye or other element is measured in three mutually spaced meridians that are selected without regard for the cylindrical axis. The ophthalmic parameters of the element, typically the spherical power, the cylindrical power and the cylindrical axis, are then derived from the measured powers and their selected meridian angles. The power of an astigmatic element in a selected meridian intermediate the principal meridians may be determined in generally conventional manner by adjusting a test optical system to produce a sharp image of a suitable target, preferably with limitation of the image-forming light to rays that traverse the element close to the selected meridian.

Abstract: Some of the conventional photographic printers are provided with plurality of lenses with different magifications. In order to change the size of enlargement (or magnification of enlargement), it is necessary for an operator to manually replace a lens or to select a suitable lens among the plural lenses on a revolving lens turret by pressing a selecting button. In this manipulation, the selection of lens and the correction of exposure for the selected lens are left to the operator's judgement. Replacement of lenses in accordance with the change in the size of enlargement involves much trouble in itself. The conventional printers are thus defective in that the printing process does not proceed smoothly.

Abstract: At least three light beams are applied to different positions on an optical element to be measured. The light beams coming via the optical element to be measured are received through a light-receiving lens by a two-dimensional light position detecting system provided at the rearward focus position of the light-receiving lens or at a position conjugate therewith or are received by two-dimensionally disposed light position detecting system. Three deviation vectors are detected and the refractive powers in three meridian directions are detected, or at least five light beams are applied to different positions on an optical element to be measured and from five deviated beam positions, a general elliptical curve coupling them is specified, whereby the degree of astigmatism, the direction of astigmatism and the refractive power are calculated.

Abstract: An apparatus for measuring the optical characteristics of an optical system includes a light source, collimator means for collimating a beam of light from the light source, a mask means, a means for holding the optical system to be tested between the collimator means and the mask means, a detector, a calculator, and first beam splitting means. The mask means includes at least one mask provided in each optical path following the first beamsplitter means, each having a linear band group consisting of at least two parallel linear bands, with each mask disposed to provide a different orientation for the linear bands.

Abstract: A projection type lensmeter in which the target image for measuring the refractive power of a lens is projected on a screen and the projected image is magnified and observed through a magnifying observation optical system including a collimator lens having a focal length f.sub.1 adapted to collimate light projected from the target image, and a projection lens having a focal length f.sub.2 adapted to project light from the target image to the screen. The magnifying observation optical system has an effective diameter .phi. and a magnification m.sub.2. The focal lengths f.sub.1 and f.sub.2, the effective diameter .phi., and the magnification m.sub.2 satisfy the following relations:25 mm.ltoreq.f.sub.1 .ltoreq.30 mm409 mm.ltoreq.f.sub.2 .ltoreq.600 mm60 mm.ltoreq..phi..ltoreq.70 mm1.25.ltoreq.m.sub.2 .ltoreq.1.83.The overall magnification of the lensmeter is 30 or greater.

Abstract: When a photographic film is to be printed, it is necessary to remove such defocused photographic images which are caused by improper focusing. In this invention, transmittivity or transmission density of an image recorded on photographic film is measured consecutively by scanning it with two photometric systems having different measuring areas, and a defocused photographic image is detected from the relation between the measured distribution of the difference between two measured values in the transmittivity and the contrast values which is obtained by totalling local contrasts measured all over the photographic film.

Abstract: An automatic lens meter includes a first positive lens system, a second positive lens system having its forward focal plane coincident with the rearward focal plane of the first positive lens system, a pin-hole plate disposed in the forward focal plane of the second positive lens system, the optical axis of the first and second positive lens systems passing through the pin-hole of the pin-hole plate, four spot light source means disposed on the forward focus side of the first positive lens system, the four spot light source means being provided in a plane orthogonal to the optical axis and made conjugate with a predetermined position on the rearward focus side of the second positive lens system by the first and second positive lens systems, a lens to be examined being disposed at said predetermined position, a third positive lens system provided on the side opposite to the second positive lens system with respect to said predetermined position, light-receiving means disposed on the opposite side of the second

Abstract: In order to obtain an objective measurement of paint gloss on a flat or slightly curved surface, a distinctness of image instrument is provided having a light source for projecting a light beam onto the test surface, a detector responsive to reflected light from the surface, an aperture at the detector, a chopper near the light source and a lens for imaging the chopper blade on the plane of the aperture so that the sharpness of the image depends upon the reflective quality of the test surface. The rate of change of the detector output signal is large for a high glass surface while the rate of change is low for a low gloss surface. For use of the instrument on curved as well as flat surfaces the chopper is provided with a plurality of blades spaced at different distances from the light source.

Abstract: Apparatus and method for testing the optical throughput or efficiency of lens structures adapted to be used in pairs to make a connection between optical fibers by imaging one fiber end, serving as input, via the connector pair into the end of the other fiber end, serving as output. The apparatus comprises structure by which the output beam of a nominally perfect connector half is presented to a lens structure under test while a reflecting surface simulating a fiber end is positioned in the test structure under conditions of actual use. The simulating beam is focused by the test lens structure onto the reflecting surface after which it is reflected along a path travelling oppositely to its entering direction. Structure is provided for comparing the energy content of the beam emerging from the test structure with that presented to it whereby the optical efficiency of the lens structure is determined.

Abstract: An optic surface apparatus capable of handling aspheric surfaces uses dir measurement of the blur circle of the image created by the test surface. Direct measurement of the blur circle is obtained by providing a collimated light beam which includes the test surface in its optical path to an ultimate focal point. The focal point is occupied by an apertured screen with apertures of varying diameter. A light detector is placed behind the apertured screen to measure the intensity of light as a function of aperture size. The apertured screen and detector are mounted on a three-axis translator. For apertures less than the effective diameter of the blur circle, less than 100% light is received by the detector. For apertures equal to or greater than the effective diameter of the blur circle, 100% of the light reaches the light detector. A folding mirror is used in the optical path to permit the device to be physically compact.

Abstract: A contact lens holder for use in a lens meter comprises an upper cover and a casing which are hinged together and which have first and second axially aligned openings, respectively, for passage therethrough a beam of light from the lens meter. The casing has an annular wall defining the second opening and an annular projection surrounding the annular wall in spaced relation. A contact lens is placed on the annular wall with a concave side of the lens facing the second opening and a peripheral edge of the lens held against an inner peripheral surface of the annular projection. Thus, the contact lens is prevented from being wobbled laterally of the annular projection. The upper cover has a plurality of angularly spaced resilient tongues attached thereto as cantilevers and extending radially inwardly toward the center of the upper cover.

Abstract: A device for use with infrared lenses to determine the optimum focal plane. The device comprises an infrared energy source, a collimating lens and an energy sensor to determine the energy level from the energy source to provide a normalizing signal. An infrared energy detector may be moved toward and away from the lens which is to be calibrated in order to test various planes within the depth of focus of the lens. A knife edge shutter is stepped across the path of energy at each of the positions to determine specific read outs of energy at each position of the knife edge shutter. The energy which passe the knife edge shutter is then delivered to a computer where the signal has been normalized by the sensor previously described. The computer reads out the signals corresponding to energy level at successive steps of the knife edge shutter. The computer is programmed to step the detector to successive positions and then the shutter to successive positions across the focal plane.

Abstract: A method of measuring optical properties of a transparency uses a video camera for focusing and then refocusing an image of a point source of light transmitted through a test region when the transparency is first absent and then later present at the test region. The distance the camera needs to be moved together with the focal length of a focusing lens used in carrying out the method provide sufficient quantitative data to calculate the spherical optical power of the transparency. Also, the camera generates video images of the point source both before and after the transparency is present in the test region. These images are displayed on a screen containing a grid pattern which facilitates measurement of the displacement of the image from the center of the grid or from the optical axis due to the presence of prismatic deviation in the transparency. Given the earlier data and supplemented by the latter displacement quantity, the prismatic deviation of the transpareny can also be calculated.