Abstract: An anti-aliasing aperture and method of using the same is disclosed. In one embodiment, an anti-aliasing method includes passing light through an aperture stop, and diffracting the light passing through the aperture stop for spreading an image of a point object to cover more than a pixel on a detector array. The aperture stop includes two or more apertures. In another embodiment, an anti-aliasing apparatus includes an aperture stop having two or more apertures to diffract light passing therethrough and provide spreading of an image of a point object to cover more than one pixel on a detector array.

Abstract: An optical disk reader or read/write system for CD or DVD formats. First and second laser diodes operating at different wavelengths have their output beams collimated and directed at a single element objective lens, and are then reflected off the disk back through the lens to a photodetector. The single element objective lens has a central aperture zone and an outer aperture zone, the central zone being profiled to operate at a first numerical aperture at approximately 0.45 and the output beam of the first laser diode is confined to the central aperture zone. The outer aperture zone together with the central aperture zone are profiled to operate at a second numerical aperture, for example 0.60 wherein the output beam of the second laser diode has ray fans extending across the full aperture of the single element objective lens.

Abstract: A compact zoom lens system having four injection-molded singlet lens elements is described. In one embodiment, the compact zoom lens system includes a lens carrier and first and second lens elements coupled to the lens carrier. One surface of the first or second lens elements having a diffractive optical surface disposed thereon to correct chromatic aberrations of light passing therethrough. The lens carrier moves the first and second lens elements axially to change a focal length of the lens system. Third and fourth lens elements are fixed on either side of the first and second lens elements. The lens carrier includes an aperture stop placed proximate to the diffractive optical surface to correct chromatic aberrations over an entire range of focal lengths. The first lens element is made out of flint-like material while the other lens elements are made out of crown-like material. Moreover, the zoom lens system includes an anti-aliasing surface on one of the lens elements to control aliasing effects.

Abstract: There is disclosed a compact lens system having four injection-molded singlet lens elements with one of the singlet lens elements having a diffractive optical surface to control axial chromatic aberrations and another of the singlet lens elements having a flint-like plastic material to control lateral chromatic aberration. The lens system includes interdigitated flange features which provides interdigitated alignment between the lens elements. A plurality of light suppression elements are used to suppress stray light paths from reaching a detector array of the lens system. Moreover, the lens system includes an anti-aliasing surface on one of the lens elements for controlling aliasing effects.

Abstract: Several embodiment of an athermalizing apparatus is described. In one embodiment, the athermalizing apparatus includes a lens element and a support member coupled to the lens element. The support member has a sloped outer surface and a first coefficient of thermal expansion ("CTE"). The athermalizing apparatus further includes a rib member having a substantially complementary sloped surface that bears on the sloped outer surface of the support member. The rib member has a second CTE. The sloped outer surface of the support member forms a ramp angle with respect to an optical axis of the lens element. A radial expansion of the support and/or rib member causes an axial displacement of the support member as a function of the ramp angle.

Abstract: In one embodiment, an anti-aliasing apparatus is disclosed. The anti-aliasing apparatus includes an aperture stop including an array of apertures. Each of the apertures on the aperture stop diffracts light passing therethrough and provides spreading of an image of a point object in a controlled image irradiance distribution. In another embodiment, an optical system is disclosed. The optical system includes a detector array having an array of pixels and an aperture stop positioned between an object plane and the detector array. The aperture stop includes an array of apertures, each of which diffracts light passing therethrough and provides a controlled spreading of the light to cover more than one pixel of the detector array.

Abstract: An endoscope includes a disposable probe and a non-disposable focusing ocular. The probe includes a transfer module assembly including one or more relay modules, and an objective element including a distal glass window, a molded plastic prism and three molded plastic lenses. Each of the relay modules contains an entry glass rod, an intermediate glass rod, and an exit rod, each having flat end surfaces and two identical molded plastic doublets. The elements of the ocular are all of glass and include an axially movable focusing doublet and two non-movable doublets. The disposable probe introduces certain aberrations into the image. The non-disposable focusing ocular corrects these aberrations. A single curved surface is formed on the distal glass window of the probe; all other curved optical surfaces of the disposable probe are formed on molded plastic members, thereby reducing the cost of the probe sufficiently to be cost-effective for single patient, disposable use.

Abstract: Illumination for the platen of a finger receiving imaging prism is provided from a source mounted below the prism and reflected to the platen surface at an angle greater than the critical angle, through a beam folding input prism that is positioned primarily below and behind a front edge of the platen. Transmitting and scanning optics of the system are positioned behind and below the imaging prism, and an output prism is bonded to the imaging prism to receive light reflected from the platen, to shift the path of this reflected light downwardly and to direct it rearwardly toward system optics. The beam from the output prism is fed through an F-Theta scanning lens to a scanning mirror mounted on a scanning galvanometer that causes the fingerprint image to precisely scan across a linear array of print camera sensors that are repetitively sampled to provide a readout of the entire surface of the prism platen for reading a slap print.

Abstract: An endoscope includes a disposable probe and a non-disposable focusing ocular. The probe includes a transfer module assembly including one or more relay modules, and an objective element including a distal glass window, a molded plastic prism and three molded plastic lenses. Each of the relay modules contains an entry glass rod, an intermediate glass rod, and an exit rod, each having flat end surfaces and two identical molded plastic doublets. The elements of the ocular are all of glass and include an axially movable focusing doublet and two non-movable doublets. The disposable probe introduces certain aberrations into the image. The non-disposable focusing ocular corrects these aberrations. A single curved surface is formed on the distal glass window of the probe; all other curved optical surfaces of the disposable probe are formed on molded plastic members, thereby reducing the cost of the probe sufficiently to be cost-effective for single patient, disposable use.

Abstract: A collapsible terrestrial telescope having a lens system which includes an objective lens and a terrestrial eyepiece, wherein the eyepiece includes an erecting lens group, and an eyepiece lens. The objective lens and the erecting lens group each include an aspheric surface. The objective lens may be one of an optically interchangeable doublet including a positive element having the aspheric surface and a negative element, or a singlet having the aspheric surface and a diffractive surface.

Abstract: An endoscope includes a disposable probe and a non-disposable focusing ocular. The probe includes a transfer module assembly including one or more relay modules, and an objective element including a distal glass window, a molded plastic prism and three molded plastic lenses. Each of the relay modules contains an entry glass rod, an intermediate glass rod, and an exit rod, each having flat end surfaces and two identical molded plastic doublets. The elements of the ocular are all of glass and include an axially movable focusing doublet and two non-movable doublets. The disposable probe introduces certain aberrations into the image. The non-disposable focusing ocular corrects these aberrations. A single curved surface is formed on the distal glass window of the probe; all other curved optical surfaces of the disposable probe are formed on molded plastic members, thereby reducing the cost of the probe sufficiently to be cost-effective for single patient, disposable use.

Abstract: An endoscope including a disposable probe and a non-disposable focusing ocular. The probe comprises negative and positive gradient index of refraction objective elements and a transfer module.

Abstract: A double-pass scanning monochromator for use in an optical spectrum analyzer includes an input optical fiber for emitting an input light beam, a diffraction grating for diffracting the input light beam to produce a spatially dispersed light beam, a slit for passing a selected portion of the dispersed light beam, a motor for rotating the diffraction grating, a shaft angle encoder for sensing grating position, and an output optical fiber. The light that passes through the slit is directed to the diffraction grating and is recombined by the diffraction grating to produce an output light beam. The light beam to be analyzed is incident on the diffraction grating during first and second passes. A polarization rotation device rotates the polarization components of the light beam by 90.degree. between the first and second passes so that the output of the monochromator is independent of the polarization of the input light beam.

Abstract: An endoscope includes a disposable probe and a non-disposable focusing ocular. The probe includes a transfer module assembly including one or more relay modules, and an objective element including a distal glass window, a molded plastic prism and three molded plastic lenses. Each of the relay modules contains an entry glass rod, an intermediate glass rod, and an exit rod, each having flat end surfaces and two identical molded plastic doublets. The elements of the ocular are all of glass and include an axially movable focusing doublet and two non-movable doublets. The disposable probe introduces certain aberrations into the image. The non-disposable focusing ocular corrects these aberrations. A single curved surface is formed on the distal glass window of the probe; all other curved optical surfaces of the disposable probe are formed on molded plastic members, thereby reducing the cost of the probe sufficiently to be cost-effective for single patient, disposable use.

Abstract: A double pass scanning monochromator for use in an optical spectrum analyzer includes an input optical fiber for emitting an input light beam, a diffraction grating for diffracting the input light beam to produce a spatially dispersed light beam, a slit for passing a selected portion of the dispersed light beam, a motor for rotating the diffraction grating, a shaft angle encoder for sensing grating position, and an output optical fiber. The light that passes through the slit is directed to the diffraction grating and is recombined by the diffraction grating to produce an output light beam. The light beam to be analyzed is incident on the diffraction grating during first and second passes. A polarization rotation device rotates the polarization components of the light beam by 90.degree. between the first and second passes so that the output of the monochromator is independent of the polarization of the input light beam.

Abstract: An autofocusing system for a microscope is disclosed. An autofocus target is placed between a colliminating lens and a relay lens of the microscope. The autofocus target contains a pattern of dark areas which are projected onto a specimen and reflected into a CCD camera array. The focus of the microscope is adjusted such that the variation in intensity of light through the pattern is maximized.

Abstract: Apparatus is described for exposing a layer of photosensitive material to form an image thereon, by passing the photosensitive layer under a row of closely spaced light shutter apertures which are selectively opened and closed. The total light falling on each pixel area at the photosensitive layer is increased by using apertures which are long and thin, and concentrating the light passing therethrough onto a pixel at the photosensitive layer. Two rows of staggered apertures are used. The photosensitive layer is on a transparent substrate, and a reflector lies on a side of the substrate opposite the light apertures, so light passing through the photosensitive layer and substrate is reflected back through the layer to pass twice therethrough. The entire sheet is pre-exposed to light of a level less than a threshold, with the light subsequently passing through each light aperture being sufficient to raise the total exposure beyond the threshold.

Abstract: An improved keratometer instrument capable of measuring keratometric values of an eye is provided. An optical reference of a predetermined dimensional value is directed at the cornea of the eye and an optical sensor measures the same at different meridians. A computer circuit can determine whether the instrument is de-centered or de-focused relative to the eye and can derive measurements of keratometric values. The axis of astigmatism can be visually displayed to the surgeon during an operation.

Abstract: An improved infrared detector system includes a pair of thin film thermopile sensing elements that receives reflected energy from aspheric reflectors that are designed to provide optimum energy resolution. An absorbing coating can be placed above the sensors and extending beyond the periphery to improve the signal to noise ratio. A high gain low noise D.C. amplifier is coupled to the output of the infrared sensing elements while a high pass amplifier and low pass amplifier are designed to pass an amplified signal in the frequency range from approximately 0.2 Hz to 15 Hz. Finally, a combined peak detector and time dependent integrator summing amplifier circuit provides an enabling predetermined threshhold detection gate that requires either a predetermined large signal level or a multiple of small electrical signals within a preselected interval to produce an alarm enabling signal.

Abstract: A pocket-sized microform reader is realized by employing a unique lenticular (screen) assembly and a projection lens assembly, the latter permitting a fold in the middle of an optical path allowing the size requirements of such a reader to be met. The cooperation between the lenticular screen and the projection lens assemblies permits sufficient brightness to be obtained and the lenticular screen assembly defines a non wasteful exit pupil of limited dimensions consistent with a pocket-sized reader.