Abstract: A hybrid refractive and diffractive achromatic lens suited for single-use or inexpensive single-lens cameras operating in visible spectral range. The lens comprises a body of optically transmissive material having an index of refraction at a wavelength approximately at the center of said range of at least 1.45. The lens body having a first and second surface on opposite sides thereof, at least one of said surfaces being curved to provide a refractive portion having power and introduces chromatic aberration, the lens having a diffractive portion having power which substantially achromatizes the lens for the chromatic aberration of the refraction portion over about 440 nm to about 650 nm range.

Abstract: A method of making gob preforms for the optical quality lens molding comprising: i) ejecting a measured gob molten glass through an exit in a stem of the container of a supply of molten glass; ii) allowing the gob to settle under gravity from the exit to a catching tool while heating the gob and the catching tool; and iii) continuing to heat the gob and tool until the gob is round.

Abstract: An optical magnifier, preferably having only two elements and including a rear negative surface associated with an object to be viewed, which is aspheric. The aspheric surface follows a formula having a sag which is positive to help effect correction for field curvature, astigmatism and distortion. Preferably the lens has at least one other aspheric surface and a diffractive surface. The diffractive surface is preferably on a curved surface to assist in improving the quality of the magnifier with a limited number of elements.

Abstract: A reverse telephoto lens includes a front negative group of lens components having a front component with greater than normal separation from a rear positive group of lens elements. Preferably, the front negative group also includes a rear positive component that is meniscus concave to the front.

Abstract: An optical system comprising two lens elements one of which is biaspheric, the optical system is suitable for use in photographic devices such as single-use cameras having curved image planes. This optical system can operate at low F-numbers while maintaining an excellent performance.

Abstract: An optical element assembly includes at least first and second optical elements. Each element has molded extensions to assist in the mounting. A pair of pins extend from the extensions on one element and fit into a pair of openings on the extensions of the other element. A clip having a hole in one leg to fit over the pin is positioned to urge each set of extensions together to prevent axial movement of one element with respect to the other.

Abstract: A reverse Galilean finder in which a front frame, preferably associated with a front element is projected away from the eye by the finder optics without separate frame projection optics to a position such that the distance between the apparent position of the frame to the eye and the rear vertex of the finder divided by the length of the finder is at least 2.2.

Abstract: A compact lens system has a predetermined focal length and comprises a plurality of lens elements and an internal aperture stop. The lens system is asymmetrical about the aperture stop. The plurality of lens elements define a field of view of at least 10 degrees. The plurality of lens elements include a front lens element, a rear lens element and at least one lens element located between the rear and the front lens elements. The rear lens element defines a rear vertex and a rear surface clear aperture with a predetermined diameter. The front lens element defines a front vertex and a front surface clear aperture with a predetermined diameter. The front and rear vertices are spaced apart less than 20% of the lens system's focal length. The front surface clear aperture diameter is within 10% of the rear surface clear aperture diameter.

Abstract: A method for interferometrically determining error continuously in the radius of curvature of a planetary polishing surface and for providing compensating correction of the surface shape while the polishing machine is in operation. A conditioner glass body disposed on the polishing surface for reshaping the surface is itself a Fizeau cavity having upper and lower partially-reflective surfaces which are parallel or slightly non-parallel for plano polishing and spherical polishing. The conditioner is illuminated by a plano, monochromatic, coherent light wavefront substantially perpendicular to the polishing surface, preferably over the entire upper surface of the conditioner. A portion of the incident wavefront is reflected from the upper surface as a reference wavefront, and another portion of the incident wavefront is reflected from the lower surface as a measurement wavefront.

Abstract: A variable aperture lens has a fixed aperture stop inside the lens and a variable aperture stop located outside the lens. When the lens is operated at its widest effective aperture, the effective aperture is defined by the fixed aperture stop. When it is operated at its narrowest effective aperture, the effective aperture is defined by the variable aperture stop. This permits highest corrections for the widest aperture but with a lens that is free of the cleaning and other difficulties of a variable interior aperture.

Abstract: A zoom lens having two units of lens components including from the object side a positive optical unit and a negative optical unit. The zoom lens satisfies the following relationship ##EQU1## where eW is the principal point separation of the zoom lens when said zoom lens operates at a wide angle position and eT is the principal point separation of the zoom lens when said zoom lens operates at the telephoto position.

Abstract: A printing apparatus includes an imaging system which focuses a plurality of different color LED sources on a photosensitive recording medium without use of any refractive optics. The imaging system comprises two concave mirrors having reflective surfaces, each of which is a conic section, and a baffle located between the mirrors. Each of the mirrors includes an aperture and the baffle is located between the apertures of the mirrors. A printing method utilizing the apparatus includes reflection of light generated by the LED sources between the mirrors following a series of zigzag turns, convergence of the light through an aperture in one of the mirrors, and formation of an image on a photosensitive recording medium without passing through refracting optics, wherein the baffle blocks light from propagating directly towards an imaging surface without reflecting in the imaging system.

Abstract: A method of manufacturing a diffractive surface comprising: rotating a surface to be cut at a rate W>1,500 RPM; translating a cutting tip at low speed V where V<1.2 mm/minute; and cutting the surface with the cutting tip.

Abstract: A scanner configured to provide a two-dimensional scan of a radiation beam moving along the path, including two deflectors and a scan lens located downstream in the path of the beam from the deflectors and separated from the farthest deflector by air equivalent distance at least equal to the focal length of the scan lens.

Abstract: Manufacturing of a desensitized lens system including: i) providing a starting point lens design having a plurality of aspheric surfaces; ii) decentering the design parameters of one of the aspheric surfaces; iii) optimizing the lens design with a decentered aspheric surface parameter by utilizing both positive and negative field rays to come up with optimum parameters for aspheric surfaces; iv) dropping the decenter out when the optimization is complete to obtain the nominal lens system parameters.

Abstract: Laser color printers include multiple laser sources formed of either diode lasers or laser diode arrays emitting light beams of different wavelengths, and an optical arrangement. The optical arrangement independently processes each of the light beams to provide a separate predetermined sized collimated light beam, and then focuses and scans the light beams over a printing media that prints separate colors for each different wavelength of light. Where different sized collimated light beams are required to match a printing media, a separate zoom lens is used is used in the optical arrangement to independently reshape each of two orthogonal cross-sectional directions of a separate one of the light beams before being properly sized at the output thereof.

Abstract: An optical system comprising two lens elements suitable for use in photographic devices such as single-use cameras having cylindrical image planes. This optical system can operate at F-numbers lower than F/11 while maintaining an excellent performance.

Abstract: A collector array for imaging comprises of a plurality of small concentrators having a hyperbolic cross section and a circular input and output aperture. Such an array is particularly suitable for use in conjunction with photoelectronic array-type detectors such as CCD's and with photographic film.

Abstract: A zoom lens having two units of lens components including from the object side a positive optical unit and a negative optical unit. The positive optical unit includes two lens components, a weak power lens component, and a second positive power lens component, while the negative optical unit provides most of the magnification change during zooming. The zoom lens has reduced aspheric decenter sensitivity.

Abstract: A compact objective lens with a diaphragm arranged behind the lens system suitable for use in very compact photographic cameras. The objective lens comprises a plurality of components arranged in a triplet or a triplet type configuration and is capable of covering at least a 55 degree field of view.