Abstract: Enhanced performance of an uneven surface image transfer apparatus is provided by using a well-defined convergent field of illumination that is nominally focussed at the stop of an imaging lens. An integrated optical system exhibiting such enhanced performance includes an aspheric illuminating lens that directs radiant energy onto a presentation platen from which fingerprint or bar code images are transferred to an external image sensing device, such as a charged coupled device chip. An evanescent wave image is totally internally reflected (TIR) off of the platen along an optical path including a plurality of TIR surfaces to achieve a predetermined optical path length. One or more of the TIR surfaces may be curved to reduce or eliminate astigmatism and geometric distortion. An aspheric imaging lens having a split-axis aperture stop transfers the image rays to the image sensing device. The split axis aperture stop has its stop axes on opposite sides of the nominal focal point of the aspheric illuminating lens.

Abstract: A portable visual display which enables observation of an image with minimal distortion includes a two-dimensional display device (7) for displaying an image for observation, and an ocular optical system (6) for projecting an image formed by the two-dimensional display device (7) or a real image thereof in the air as a magnified image and for deviating the optical axis. The ocular optical system (6) is comprised of a concave aspherical mirror. The concave mirror (6) is designed so that the curvature thereof in a direction (X direction) perpendicular to a plane (Y-Z plane) in which the optical axis conventionally increasingly deviates gradually increases in a direction (-Y direction) in which the optical axis is deviated as seen from the observer's eye (1).

Abstract: A concentric optical system usable as either an imaging optical system or an ocular optical system, which has an F-number of 1.5 to 3 and enables a flat and clear image to be photographed or observed at a view angle of up to 60.degree. or more with substantially no aberration. The concentric optical system includes at least two semitransparent reflecting surfaces (2) and (3) each having a center of curvature disposed in the vicinity of a pupil (1) and a concave surface directed toward the pupil. The semitransparent reflecting surfaces are disposed so that each semitransparent reflecting surface passes each particular bundle of light rays at least once and reflects them at least once, thereby providing a flat image surface (4).

Abstract: A visual display apparatus which enables observation of an image that is flat and clear as far as the edges of visual field at a view angle of 40.degree. or more and which ensures a large exit pupil diameter. The visual display apparatus has a two-dimensional image display device (14) for displaying an image for observation, a relay optical system (15) for projecting in the air a real image of the image display device (14), and an ocular concave reflecting optical system (3) for projecting the real image as an enlarged image in the air and for reflectively bending the optical axis. A decentered correcting optical system (8) which has surfaces decentered with respect to each other is disposed between the relay optical system (15) and the ocular concave reflecting optical system (3). The angle of reflective bending by the ocular concave reflecting optical system (3) is preferably 60.degree. or more.

Abstract: A broad band catadioptric optical reduction system using refractive elements made of different types of glass matched for color correction over a broad band width. A combination of fused silica and crown glass is used. An aspheric mirror is used for improved aberration correction. The optical system is adapted for use in lithography for semiconductor manufacturing in the I-line and is capable of 0.5 micron resolution at a wavelength of 365 nanometers.

Abstract: An optical pickup, installed in an optical or magneto-optical disc driver, for reproducing/recording optical information is disclosed. The optical pickup is of a subminiature united body type and very light weight, high speed seek, and is composed of an optical system including a hologram lens element. The hologram of the lens element is formed of a predetermined pattern which diffracts a spherical wave and focuses reflected light from the disc onto a detector offset from the light source. This optical pickup can reproduce optical information having no interference and detect focus and track errors without an optical element separating the incident light and reflected light by a hologram pattern. Accordingly, a very light, subminiature optical pickup composed of an optical system having one lens element is provided.

Abstract: An optical reimager (20) is formed by combining a two-element optical relay (24) with a single-element imager objective (22). The relay (24) comprises a refractive element (26) that is used twice and a mirror (28) that provides a real stop. The reimager can be made diffraction-limited by configuring the mirror with an aspheric surface to correct spherical aberration introduced by both the refractive element (26) and the objective (22), and configuring the objective with an aspheric surface to correct non-spherical aberrations (principally astigmatism and coma). The reimager (20) is described in connection with a thermal imaging application requiring telecentricity and a remote entrance pupil.

Abstract: A catadioptric zoom relay telescope whose refractive elements are made from only a single type of optical glass focuses all wavelengths in a broad infrared bandwidth onto a common focal plane with diffraction-limited imagery throughout a changing focal ratio (i.e., a zoom range) from less than f/1.5 to more than f/6.0.

Abstract: A catadioptric zoom relay telescope with an aspherical primary mirror and only three movable lens elements focuses all wavelengths in a broad infrared bandwidth onto a common focal plane with substantially diffraction-limited imagery throughout a changing focal ratio (i.e., a zoom range) from less than f/1.5 to more than f/6.0.

Abstract: A beam of light issued by a light source enters a catadioptric arrangement and initially travels therethrough along an axis. At least one lens is situated at the axis and is axially delimited by two curved major surfaces having respective centers of curvature. The beam of light is reflectively diverted from the axis and travels in a path which includes a path section that is directed at one of the major surfaces and has such a spatial orientation relative to the axis and the major surfaces that light traveling in this path section bypasses the centers of curvature and impinges all regions of the major surfaces at angle deviating from respective normals to the regions with attendant avoidance of specular retroreflection from such regions.

Abstract: An optical system for endoscopes so adapted as to be usable with video endoscopes, comprising an imaging lens system equipped with an aperture stop and a field lens component arranged on the image side thereof, and so designed as to prevent the color shading from being produced by selecting an adequate focal length for the field lens component.

Abstract: An optical element (12) has aspherical (14) and binary grating (16) optical surfaces. In the preferred embodiment, the optical element (12) is a positive meniscus optical element made of germanium having a useful spectral bandpass in the infrared wavelength region. A telescope (100) includes a first positive meniscus optical element (102), having a convex aspherical surface (104) and a concave binary grating surface (106). A first negative meniscus optical element (107) having a concave binary grating surface (108) and a concave aspherical surface (110) is employed. Next is a positive power lens (112), followed by a second negative meniscus lens (118). In the preferred embodiment, the first negative meniscus optical element (107) and the positive power lens (112) are affixed to a common housing (124), which is removable from the telescope system. Removal of the housing (124) converts the telescope (100) system from a wide-field-of-view telescope (100) to a narrow-field-of-view telescope (40).

Abstract: A single hybrid optical element combines reflective and refractive imaging. The optical unit utilizes a dual-reflector outer annulus zone and a refractive inner zone to achieve a high numerical aperture. This system is particularly suitable for, but not limited to, microscope objectives or for digital data storage applications.