Abstract: An optical displacement sensor comprises a light source 2 coupled to an optical fiber 1 the end 5 of which is directed onto a reflector 3 the displacement of which is to be measured. A lens 4 of appropriate focal length is positioned between the end of the optical fiber and reflector 3 to focus the light emitted from fiber 1 onto reflector 3 so that the amount of light reflected back is a function of the position of reflector 3. A signal detector 6 is also coupled to fiber 1 to detect and measure the light reflected back from reflector 3. Additionally a further light source 8 optical fiber 7 and detector 10 are provided with the end 9 of fiber 7 positioned at the focus of lens 4 so that the light reflected back to detector 10 is independent of the position of reflector 3. The ratio of the measurements from the two detectors gives the position of the reflector 3 with compensation for the effects of the deterioration of its reflectance.

Abstract: A method of determining the displacement of a fiber optic sensor from a target in which a first lens is spaced from the target at a first distance an a second lens is spaced from said target at a second distance which provides the greatest intensity response at said first distance and thereafter spacing said first lens from said second lens to provide symmetrical slope values of response.

Abstract: A microtiter plate reader is disclosed which allows visual examination of the contents of the wells of a microtiter plate having an array of wells. The microtiter plate reader includes supporting means for supporting the microtiter plate with the wells opening generally upwardly and a light emitting surface is adapted to extend under a microtiter plate so held. Regions of reduced light emission on the light emitting surface are arranged in an array corresponding in relative position to a selected portion of the array of microtiter plate wells. Locator means are provided for locating the microtiter plate with respect to the array of regions of reduced light emission to allow selective alignment of the wells with the dark regions, providing a dark background to the bottom of the wells which are then illuminated indirectly. The wells can be illuminated directly when the dark regions are out of alignment with the wells.

Abstract: A photometrical apparatus has a first light receiving element, and a second light receiving element less sensitive to temperature and other environmental influences than said first light receiving element whereby a value Pm of measured quantity of light from the subject is calculated from the following formula ##EQU1## Pr designates a quantity of light from a standard light source, Dr and Dm designate outputs of the first light receiving element generated by the light from the standard light source and the subject, Dpo and Dpt designate outputs of the first light receiving element generated by the light from the reference light source and the subject, and Dso and Dst designate outputs of the second light receiving element generated by the light from the reference light source and the subject.

Abstract: An optical triangulation probe is provided for measuring the distance and inclination of a surface. A light source is utilized for projecting a beam toward the surface to form a light spot on the surface. The image of the light spot is reflected and formed on a light detector means which produces a signal representation of the image intensity distribution of the light spot image and the location of the image on the detector means. Estimating means utilizes the signal representation of the light spot image and a signal representation of a theoretical image to estimate the location of the light spot image on the detector means. The distance of the surface and its inclination as established upon making the estimation due to the known triangulation relationship between the location of the light spot image on the detector means and the location of the light spot on the surface.

Abstract: The present invention relates to viewing a three-dimensional internal structure of a specimen. According to the invention, it is possible to observe the internal structure of a particular cross section of a specimen as clearly differentiated from the other cross sections. The characteristic features of the invention lie in that a plurality of light beams passing through different portions inside the specimen are used, and a correlation among the measurements of transmittance of the plurality of light beams is determined.

Abstract: In an exposure apparatus for manufacturing semiconductor devices, a pattern on a photomask is aligned with a plurality of patterns formed on a wafer in a manner that detects and corrects misalignment, including, inter alia, rotational errors, not only between a photomask and a wafer, but also between a photomask and individual chips formed on the wafer, so that pattern matching is attained with very high accuracy. Apparatus for achieving this result employs different arrangements of alignment marks together with optical systems and positional adjustment devices.

Abstract: An index of refraction sensor utilizing a sensor face inclined at the nominal critical angle of an incident beam, refracts or reflects this incident radiation depending upon the wavelength of that radiation and the index of refraction external to it. The refraction sensor apparatus includes a broadband radiant energy source, a radiant energy guidance and collimating means, a prism sensing element interposed in the radiant energy guide, and a detector for continuously detecting the spectral intensities of the broadband radiant energy reflected by the prism sensing element. Advantageously, a single mode optical fiber may be used as the radiant energy guidance and collimating means for directing the broadband radiant energy to the prism and a multimode optical fiber may be used for returning the reflected radiant energy to the detector.

Abstract: As is known, the walls in cavity structures often become quiescent only after a prolonged period. In order to detect whether and to what extent rock displacements can occur, measuring instruments are installed at mutually opposite points (I, II) on walls (W1, W2). A pendulum (1) mounted on gimbals carries a light source (5) at the mounting point and a light receiver (3) at the pendulum mass (2). On the opposite wall (W2), a mirror (4) is arranged at an inclination .alpha. relative to the vertical. A displacement of the mirror by T.sub.x or by T.sub.Z leads to an indication T.sub.Z at the light receiver (3).

Abstract: This invention describes a length measuring device for measuring dimensions of (length and width) of labels which are for high speed application to bottles, cans and the like. A label to be checked is placed on a datum mounting plate, and a light source and photoelectric cell are arranged to sense the label edges as relative measurement in the direction of the label dimension to be measured and between the datum plate and light source takes place, thereby to obtain an indication of the label dimension.

Abstract: A method and apparatus for acoustic supervision of adjustment of a light bundle with respect to its intensity distribution in a reference plane which is at right angles to the optical axis of the light bundle. The reference plane is subdivided into surface elements. The intensity values corresponding to a rated intensity distribution are prescribed and stored for the individual surface elements of the reference plane. The intensity values for the individual surface elements respectively existing in the adjustment are successively measured in rapid cyclical succession. The intensity deviation from the prescribed intensity value is identified and stored for each surface element. The stored intensity values are read-out in slow cyclical succession and are made audible as measuring tones for the supervision of the adjustment.

Abstract: The measurement of the scattering properties of very small particles by electro-optical means generally requires the use of an intense, though highly spatially inhomogeneous, light source such as a laser. Many instruments require, therefore, that the intersection of the particle stream with the illumination source be precisely regulated so that the flux incident on the particle be known accurately. A method and apparatus are described by which means the absolute intensity of the light incident on the particle need not be known. A special structure and measurement process are described by which means small particles are differentiated from larger particles grazing the illumination beam.

Abstract: A method and apparatus for acoustic supervision of adjustment of a light bundle composed of component beams with respect to its intensity distribution in an expanse of a reference plane situated in a beam path at right angles to an optical axis of the light bundle. Intensity values I of the component beams lying at a margin of the light wave are measured and the differential intensity values .DELTA.I are identified according to amount and operational sign. An oscillation is generated whose parameters are modified dependent on the amounts and operational signs of the respective differential intensity values. The modified oscillation is made audible as a distinguishable measuring tone for amounts and operational signs of the differential intensity values .DELTA.I.

Abstract: An optical refractometer for automatically determining the principal indices of a specimen receives an incident radiation beam which is reflected by a first rotatable mirror onto a reflecting surface of a first elliptical mirror wherein the axis of rotation of the first rotatable surface extends through a first focus of the first elliptical mirror. A hemicylinder has a center of curvature at a second focus of the first elliptical mirror and rotatably and translatably mounts a specimen about a first axis and along second and third axes, respectively, such that a portion of the specimen is located at the second focus to receive the reflected incident beam from the first rotatable surface. A second elliptical mirror has third and fourth foci and a second surface for reflecting the incident radiation beam from the second elliptical mirror with an axis of rotation extending through the fourth focus with the third focus being at the first axis coincident with the second focus for producing a reflected beam output.

Abstract: In an optical measuring device which comprises a polygonal rotary mirror for reflecting an incident light beam into a rotary scanning light beam, a collimator lens for converting the rotary scanning light beam into a parallel scanning light beam and a light receiving element for detecting bright and dark portions of the parallel scanning light beam, which has scanned a work to be measured, and a time duration of the dark portion or the bright portion is detected, which has been generated by the obstruction of a part of the parallel scanning light beam by the work, to thereby determine a dimension of the work, the collimator lens is made to be an f.theta. lens having such a spherical aberration that a light beam incident from the outlet side of the collimator lens toward the polygonal rotary mirror in parallel to the optical axis of the lens intersects the optical axis of the lens at a position shifted from a focal point on the inlet side to the outlet side by .DELTA.

Abstract: A support (56) is suitable for holding a substrate (10) horizontal, said substrate having a drop of liquid placed thereon. A source of light (74) associated with a collimator (78) forms a primary beam of parallel light which is directed perpendicularly (86) to the substrate. A receiver surface (126, 128) having a known geometry and placed in a known position relative to the substrate intercepts a secondary beam (124) produced by interaction between the primary beam and the drop and the substrate. The value of the contact angle between the drop and the substrate may be deduced from the illuminated zone on said receiver surface.

Abstract: A semiconductor laser beam scanning device includes a plurality of semiconductor lasers for emitting respective laser beams which are combined into a single laser beam to scan a desired surface. The amount of energy of the single laser beam is detected by a laser beam energy detector which applies a laser beam energy signal to a laser drive/control circuit. Alternatively, the laser beam energy signal is applied to a comparator which compares the laser beam energy signal with a reference signal and issues a difference signal to a control circuit connected to a laser drive circuit. The laser drive/control circuit or the control circuit is responsive to the applied signal for controllably energizing at least one of the semiconductor lasers to control the amount of energy of the laser beam emitted therefrom to thereby keep the amount of energy of the single laser beam at a constant level.

Abstract: A bore measuring system to optically measure the diameter of hole on thin boards, such as printed circuit boards. The bore measuring system of the invention is so contrived as to irradiate a hole to be measured, to project the light through the hole onto the receiving surface of the image sensor and to indicate the diameter of the hole by converting the output from the image sensor, corresponding to the size of the image, into a numerical figure. Unlike the conventional methods, measurement is possible simply by irradiating the hole to be measured without inserting any pin or measuring rod of a hole gauge into the hole, and without projecting the image to be measured onto a screen. Accordingly, the operation is quite simple and the measuring time can be shortened, yet measuring errors can be avoided. Moreover, the automatic display of hole diameter in a numerical value eliminates the reading errors which often occur with conventional methods.

Abstract: A soft contact lens measuring device. A cylindrical lens support defines a cavity and pedestal for immersing a soft contact lens in a saline solution. A piston engages the support and can be operated by the user to force air in controlled amounts through a narrow passageway extending up through the pedestal to the saline solution. A bubble forms and rises until it is trapped by the lens. The interface between the bubble and the lens makes a convenient surface for focusing a radiuscope to allow lens dimensions to be determined.

Abstract: An apparatus for measuring an optical axis direction in which an intensity of the light transmissive to a specimen to be measured disposed between two polarizers is measured by an orthogonal Nicol optical system which uniaxially comprises a light source, said two polarizers, and a light receptor thereby determining the optical axis direction of the specimen to be measured. The apparatus comprises a conveyor for continuously moving the specimen in an elongated form in the direction intersecting with the orthogonal Nicol optical system at a right angle. An intensity of the transmissive light is measured during the period of time when the specimen is fed from one side of a casing, and removed from the other side of the casing. The casing encases the optical system.