Abstract: The present invention is directed to Optical Lithographic Systems which are particularly adapted, among many other possible uses, for use in effecting exposure of photoresist-coated semiconductor wafers, having a ring field projection system which includes at least one concave and one convex mirror arranged around an optical axis in face-to-face relationship with their centers of curvature being nearly concentric and falling on the axis, the convex mirror being smaller than and having a smaller radius of curvature than the concave mirror, an object location and a conjugate real image location, said convex mirror being positioned to reflect to the concave mirror light from the object location initially reflected from the concave mirror whereby light from the object location will be reflected at least twice at said concave mirror and at least once at the convex mirror before being focused at the image location, elements for limiting the image field to an annular zone centered about the optical axis, a first thi

Abstract: A telephoto lens system comprising, in the order from the object side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a fourth lens unit having negative or positive refractive power, the telephoto lens system being arranged to be focused by integrally moving the first through the third lens unit and arranged that the secondary spectrum is corrected extremely favorably, and the variation of aberrations to be caused is small when the lens units are moved for the purpose of focusing, the telephoto lens system being small in size and having high performance.

Abstract: A zoom lens in which fluctuation of lateral chromatic aberration is small has, in succession from the object side, a first group of positive refractive power including at least one positive lens, a second group of negative refractive power including at least one negative lens, and an aperture stop disposed closer to the image plane than the second group. Each of the groups is moved on the optic axis during magnification change so that the distance between the first group and the second group becomes greater and the distance between the second group and the aperture stop becomes smaller as the focal length of the entire system becomes longer. At least one of negative lenses constituting the second group is formed of a material which satisfies the following conditions:.nu.d+596.7.theta.>386.5.nu.d>55,where when the refractive indices of the lens material for wavelengths 436 nm (g-line), 486 nm (F-line), 588 nm (d-line) and 656 nm (c-line) are ng, nF, nd and nc, respectively, .nu.d and .theta.

Abstract: Three different embodiments are shown of a photographic objective comprising only six lens elements, which is made of three different optical glasses, and which is well-corrected for both monochromatic and chromatic aberrations and has only negligible secondary and higher-order spectra in a wavelength band extending from the visible to the near infrared regions of the electromagnetic spectrum. The photographic objective is also color-corrected at four widely separated wavelengths in that band. The first embodiment is optimized for a 200 mm focal length at a relative aperture of f/4 over a 12.degree. field of view. The second embodiment is optimized for a 200 mm focal length at a relative aperture of f/5 over a 20.degree. field of view. The third embodiment is optimized for a 200 mm focal length at a relative aperture of f/4 over a 12.degree. field of view.

Abstract: A method is described for selecting optical materials to use in designing color-corrected optical systems. Various dioptric, catadioptric and anamorphic optical systems are described, which use only two different types of optical materials to obtain precise axial color correction at three, four or five wavelengths (depending upon the particular optical materials), with only very small chromatic aberration occurring at wavelengths between the precisely color-corrected wavelengths. Examples of color-corrected lens systems comprising more than two glasses are also described.

Abstract: A field of vision enhancement device having a mounting on an article of headwear adjustable with respect to a straight ahead, normal line of sight including optics for displaying at least one field of optical information either normally occluded by the headwear article or not readily discernable with binocular vision whereby the field of vision is enhanced.

Abstract: The invention is directed to a device for generating an optical collimating beam. The device is so configured that it withstands extreme mechanical and thermal stresses and that the collimating beam is always at a precisely defined angle with respect to the base that supports the device. The device includes a single-lens objective having a first optical surface upon which the collimating mark is arranged which the objective images at infinity. The objective is made of transparent material having a linear temperature coefficient of expansion of less than 10.sup.-6 K.sup.-1. The objective is held in a metal housing in a form-tight manner and a thin layer surrounding the peripheral surface of the lens is disposed between the objective and the metal housing. This layer is made of an elastic material which is permanently elastic. The housing is connected form-tight and lock-tight with the base. The attachment is protected against shock and vibrational stress.

Abstract: A zoom lens having a component V which has at least one group of lens elements axially movable mainly for changing image magnification, a component C which has at least one group of lens elements axially movable for compensating for the image shift resulting from the change of image magnification to maintain the constant position of the image plane, and a compound component F positioned on the image side of either, or both, of said component V and said component C to be movable with zooming, and having a plurality of lens groups contributing to a small overall refractive power, whereby the focusing provision is made in at least one of the groups in said compound component F.

Abstract: A method is described for selecting optical materials to use in designing color-corrected optical systems. Various dioptric, catadioptric and anamorphic optical systems are described, which use only two different types of optical materials to obtain precise axial color correction at three, four or five wavelengths (depending upon the particular optical materials), with only very small chromatic aberration occurring at wavelengths between the precisely color-corrected wavelengths. Examples of color-corrected lens systems comprising more than two glasses are also described.

Abstract: A day/night rearview mirror comprises an optical medium which is electrically driven between transmissive and opaque states. The mirror comprises a housing containing a circuit board assembly over which a mirrored reflecting surface is disposed. The mirrored reflecting surface is in turn overlaid by an optical transmission plate containing the optical medium. The transmission plate, mirror and circuit board are retained on the housing by means of a bezel. Electrical conductivity from the circuit board to the transmission plate is provided by helical coiled spring conductors which are conveniently supported in sleeves integrally formed with a retaining frame for the mirrored reflecting surface of the mirror. The circuit board contains a circuit for controlling the optical transmission plate and suitable controls which are accessible to the user to adjust certain operational characteristics of the mirror assembly.

Abstract: An apparatus projects luminous lines on an object by a laser beam and includes a laser beam generator wherein the laser beam has a width, a convex lens for limiting the width of the laser beam, and a reflector located at a position subsequent to the convex lens, wherein the reflector has a cylindrical reflecting surface adapted to allow the reflecting luminous lines to reflect unidirectionally at gradually decreasing angles with respect to the reflector. Thus, the laser beam is reflected at different points on the reflecting surface, at different angles, thereby forming sector-shaped continuous luminous lines on an object to be marked.

Abstract: An universal frame centering, holding and measuring device for use by an optician to transcribe and check a distance interpupillary distance a reading interpupillary distance, a segment height measured onto a customer, directly and precisely on a set of lenses mounted on a frame. The device comprises a base having a longitudinal axis, on which the frame may be positioned in flat position. A central pin supporting a vertical cylinder having such diameter as to fit within the bridge of the frame, projects from the base. A frame holder is slidably mounted onto the base. The frame holder is movable along the longitudinal axis of the base and comprises a vertical front wall extending perpendicularly to the longitudinal axis of the base.

Abstract: An eye fundus camera is provided with an illuminating system for illuminating an eye to be examined, a photographing system for photographing the fundus of the eye to be examined, eye fundus reflected light receiving portions disposed in a plane substantially conjugate with the fundus of the eye to be examined and at a plurality of locations with a spacing greater than the dimension corresponding to the nipple diameter, and a control unit for operation-processing the outputs of the eye fundus reflected light receiving portions and automatically controlling the quantity of photo-taking light.

Abstract: A zoom lens system having, from front to rear, a positive first component, a negative second component, a positive third component and a fourth component, in which to effect zooming, the first, second and third components are moved axially in A relation such that the movements of the first and second components are non-linear with respect to that of the third component, and that when in the telephoto end, the first and third components lie more toward the front and the second component lies more toward the rear than when in the wide angle end. By specifying the relation in which the first, second and third components move as zooming nears the wide angle end, a valuable decrease in the diameter of the front lens members is achieved to provide a compact zoom lens system.

Abstract: A binocular indirect ophthalmoscope is disclosed in which the optical observation axes from the examiner's pupils to the patient's pupil and the optical illumination axis from an illumination source to the patient's pupil are varied simultaneously by a single conveniently located lever. Mirrors reflecting the observation axes and the illumination axis are mounted on a common movable holder in fixed relationship to each other. The lever is coupled to the holder to move the holder in the observation plane upon actuation of the lever and thereby adjust both the observation axes and the illumination axis at the same time.

Abstract: Head-worn apparatus to which an optical device is adjustably coupled is disclosed. The apparatus comprises a headband, a support bow for the optical device rotatably coupled to the headband and a locking mechanism for automatically locking the bow in a viewing position of the optical device and in a rest position of the optical device while permitting the bow to be swivelled between the two positions. An articulated coupling adjustably connects the optical device to the central region of the bow. The locking mechanism always locks the bow in the same viewing position of the optical device so that once the articulated coupling has been adjusted with the optical device in its viewing position, the bow and with it the optical device can be swivelled back and forth between the rest and use positions without having to readjust the optical device.

Abstract: A photographic objective comprising six lens elements is well-corrected for both monochromatic and chromatic aberrations, and is color-corrected at four wavelengths in a band extending from the visible to the near infrared regions of the electromagnetic spectrum with only negligible secondary and high-order spectra at wavelength between those for which color correction is achieved. The design form for the objective has been optimized for a focal length of 200 mm at an aperture ratio of f/4 and a field of view of 12.degree. without vignetting.

Abstract: An objective lens comprising a front lens unit and a rear lens unit with the separation between the two lens units being varied to vary the focal length of the entire system, wherein the front lens unit has a positive refractive power and consists of a positive lens of strong convex curvature toward the front, a negative doublet lens of a negative lens and a positive lens cemented together in this order from the front, and a positive lens sub-unit, and the rear lens unit has a negative refractive power and comprises a positive lens and a negative lens. Particularly the double lens is so designed that the comatic aberration in the intermediate zone of the image frame is stabilized throughout the entire range of variation of the focal length, and the halo in the intermediate zone in the telephoto end is well corrected.

Abstract: An adjustable loupe frame is provided consisting of telescopic, spring-biased right and left bows and a loupe mounting bracket extending between and joined pivotably to the front ends of telescopic bows. The bows are adjustable to vary the distance between the loupe and the eyes of a viewer, so that an object to be viewed can be focused properly at any time.

Abstract: Sunglasses have a unitary transparent pane extending in a cylindrical plane. The sunglasses frame and nose-piece construction permits their ease of removal and replacement, as well as pane replacement.