Abstract: A scan engine is disclosed for use in a data collection device, as well as a method for producing a scan engine and an image sensor assembly. The scan engine includes a housing with an opening for receiving light from a scanned dataform, an image sensor which is located within the housing to sense light entering an aperture in the image sensor, and a prism located within the housing for receiving light from the opening along a first path and to provide at least a portion of the received light to the aperture along a second path.

Abstract: Radiation-induced damage to a lens material in a projection exposure system is reduced by selection of maximum design fluence values HD for lenses and at least one lens made of a material having a characteristic transition point TRC after exposure to a given amount of radiation, wherein, for instance, TRC<0.8. HD among other relationships and/or characteristics of the lenses.

Abstract: A beam splitter is constructed using one or more cholesteric layers. Each cholesteric layer reflects light of a given wavelength and polarization. The beam splitter is placed in a prism assembly. The cholesteric layers of the beam splitter are chosen such that portions of light entering the beam splitter are individually directed to a specific light path or to a processing face of the prism assembly. A microdisplay is mounted on each processing faces forms a kernel, and each microdisplay processes the light portions (light beams) directed toward them. Light beams reflected from the microdisplays have image content added to them from the microdisplays. The kernel is utilized in a light management system, such as that used in a video projection (e.g., projection television).

Abstract: A truncated triangular prism has an entrance and an exit face perpendicular to each other and a reflecting face inclined at an angle ? to the entrance face where ? is about 135°??B, and where ?B is the external Brewster angle for the material of the prism at the wavelength of radiation to be reflected by the prism. A beam of p-polarized radiation directed into the prism through the entrance face at the Brewster angle is totally internally reflected from the reflecting face and leaves the exit face at the Brewster angle and at an angle of ninety degrees to the direction at which the radiation enters the prism.

Abstract: An optical element (1) for reflecting and/or redirecting light rays (L1) entering therein and again emerging therefrom consists of a transparent base body (2) which is so structured and/or formed that, with the formation of reflection surfaces (8) bounding the base body (2), at least a part of the light rays (L1) impinging upon the reflection surfaces (8) upon emergence from the transparent base body (2) are totally reflected, and at least one cover body (9) arranged behind the reflection surfaces (8). The reflection surfaces (8), and the surfaces of the cover body or bodies (9) towards the reflection surfaces, are adapted to one another such that between them there remains a thin gap (10) or only point contacts exist.

Abstract: Disclosed is an optical component, which comprises a prism element adjacent to a lens element, where the two elements are separated by a small air gap. In disclosed embodiments, the elements have adjacent and parallel surfaces which are substantially planar and which, with the small air gap, operate through Total Internal Reflection (“TIR”) to direct light beams that strike the planar surfaces. Light beams that strike at less than the critical angle are internally reflected, while light beams which strike at greater than the critical angle pass through. The TIR surfaces thereby separate the desired optical signals from the spurious ones. The combined TIR prism lens operates as a single and integrated component which directs desired light beams to a reflective optical processing element such as a Spatial Light Modulator and which focuses the processed light beams as they leave the combined TIR prism lens.

Abstract: Embodiments of this invention include a system, method and apparatus for combining light paths of multiple colored light sources through a common integration tunnel.

Abstract: An integrated type optical pickup module apparently approximates a plurality of light-emitting points of semiconductor lasers. An optical element is interposed between first and second semiconductor lasers. The optical element has first and second reflecting surfaces perpendicular to each other. The first and second reflecting surfaces reflect laser beams projected from the first and second semiconductor lasers, respectively. The optical element further has a mounting surface perpendicular to both the first and second reflecting surfaces. The optical element is mounted, via the mounting surface of the optical element, to a submount having a top surface on which the first and second semiconductor lasers are mounted. Heterojunction surfaces of the first and second semiconductor lasers may be substantially perpendicular to the first and second reflecting surfaces, respectively.

Abstract: An object of the invention is to achieve a small and thin irregular pattern reader comprising: a prism possessing a detection surface on which a subject to be detected having an irregular pattern is put and an incident plane having a first angle of inclination to the detection surface and emitting a light reflected on the detection surface corresponding to an incident light incident upon the incident plane; a first optical system possessing a light source and causing a light from the light source to be incident upon the incident plane of the prism with its optical axis substantially in parallel to the detection surface; and a second optical system for transmitting the emission light emitted from the prism to an image pick-up device.

Abstract: A light-projecting device comprises a superimpose-plate, which is put on a focusing glass. A hollow pentagonal mirror has a roof reflecting plane, reflecting a light beam passing through the focusing glass and the superimpose-plate, a third reflecting plane, reflecting the light beam reflected on the roof reflecting plane, and an emergent opening through which the light beam reflected on the third reflecting plane passes. An illumination light beam output from a light source of a light-projecting optical system is reflected on a light-projecting prism, and radiated from the emergent opening to the third reflecting plane. The illumination light beam is reflected on the third reflecting plane and the roof reflecting plane, and is approximately perpendicularly radiated on the superimpose-plate.

Abstract: An apparatus that reduces convergence and focus drift in imager prism assemblies includes at least one assembly having a first side and a second side. The first side communicates with a first isolator inner surface and a second side communicates with a second isolator inner surface. An outer surface of the first isolator communicates with a first member of a frame. An outer surface of the second isolator communicates with a top side of a damping member. A bottom side of the damping member communicates with a second member of the frame. There is at least one guide pin located through the first isolator and the first member. A first adhesive secures the first side to the first isolator inner surface and the first adhesive secures the second side to the second isolator inner surface. A second adhesive secures the first isolator outer surface to the first member and the second adhesive secures the second isolator outer surface with the top side.

Abstract: A color separation beam splitter for projectors is provided, which comprises a plurality of prisms connected with each other and three optical interference filters having different wavelength ranges respectively formed on side surfaces of the plurality of prisms. The three optical interference filters include a yellow color reflective dichroic mirror, a red color reflective dichroic mirror, and a blue color reflective dichroic mirror to filter out the yellow light and provide three primary color lights with high color purity. Moreover, by reflecting a light beam twice, the number of layers of dichroic mirror can be reduced. The color purity of the light is increased after reflected twice by the dichroic mirrors. Moreover, configuration of a liquid crystal projector by use of this prism assembly as color separation unit is also disclosed.

Abstract: The present invention relates generally to ladar and more particularly to a tilted primary clamshell lens laser scanner for transmitting a generally collimated beam of radiation at a first frequency such that the beam rotates about a central axis so as to form a conical scanning pattern suitable for lidar applications. In addition, the ladar includes a system for transmitting at least one additional collimated beam of radiation at a second frequency at a wider angle then the first collimated beam.

Abstract: A mounting bracket (40) for suspending a clear aperture of the base face of a prism (30) has a frame providing a horizontal support surface for allowing light to pass through the clear aperture of the suspended prism (30). First, second, and third support elements (44, 46) are spaced apart on the frame for supporting the base face of the prism (30), suspending the clear aperture. The second and third support elements (44) are peripheral to the clear aperture. The center of gravity of the prism (30), vertically projected, lies on or within the triangle formed by the first, second, and third support elements (44, 46).

Abstract: Systems and methods for adjusting optical path length of an optical path are provided. The systems and methods can be used to controllably adjust optical path length in an external cavity laser. A representative optical path having a first end and a second end comprises a first transparent refractive element located in the optical path between the first end and the second end. The transparent refractive element is adjustable to adjust the optical path length of the optical path without changing the physical distance between the first end and the second end. A representative method includes introducing a transparent refractive element into the optical path and adjusting the transparent refractive element to change the optical path length without changing the physical distance between the first end and the second end of the optical path.

Abstract: A three element prism system and method for splitting/combining three different colors of light arranged such that the size of a selected one of the color prism, such as for example, the red prism and, consequently the clear aperture, are increased without a corresponding increase in the size of the other prisms (e.g., the blue and green prisms). This is accomplished by adjusting the air gap A2 of the selected light path (e.g., red) so that the effective total selected light path T, which includes the selected light air gap A2 and the selected light glass path G2 is the same as the total path length T of both the other light paths (e.g., green and blue) comprised of air gap A1 plus glass path G1.

Abstract: The present invention discloses a lighting apparatus including a light source, an optical member that is placed in front of the light source and provided with a reflecting surface for reflecting light from the light source or prism sections each made up of a refracting surface which receives the light incident from the light source and a reflecting surface for reflecting the light incident from this refracting surface. Here, in the optical member, there is a plurality of pairs of the reflecting surfaces or prism sections arranged in the direction perpendicular to the optical axis within a plane including the radial direction of the light source centered on the optical axis. The present invention can provide a low-profile lighting apparatus using light from the light source with high efficiency.

Abstract: A scan engine is disclosed for use in a data collection device, as well as a method for producing a scan engine and an image sensor assembly. The scan engine includes a housing with an opening for receiving light from a scanned dataform, an image sensor which is located within the housing to sense light entering an aperture in the image sensor, and a prism located within the housing for receiving light from the opening along a first path and to provide at least a portion of the received light to the aperture along a second path.

Abstract: Disclosed is an optical fingerprint acquisition apparatus capable of reducing an image distortion and a size of an optical system by deforming the shape of a prism. The prism according to the invention includes a fingerprint contacting surface to be touched by a fingerprint of a person, a totally reflecting surface facing the fingerprint contacting surface with an angle &thgr; for totally and inwardly reflecting the light scattered from the fingerprint in contact with the fingerprint contacting surface, a primarily projecting/re-incident surface linking the fingerprint contacting surface to the totally reflecting surface with an angle &phgr; for primarily projecting the light totally reflected from the totally reflecting surface so as to be re-incident from outside, and an ultimately projecting surface facing the primarily projecting/re-incident surface for ultimately projecting the light re-incident to the primarily projecting/re-incident surface toward outside.

Abstract: A dichroic prism 10 according to the present invention comprises first to fourth right angle prisms 12, 14, 16 and 18 respectively having first side faces 28, 34, 40 and 46, and second side faces 30, 36, 42 and 48, the side faces being arranged perpendicular to each other. A second bonded face 22 and a fourth bonded face 26, each having a dichroic film for a second color light, are arranged on the same plane. The first bonded face 20 and a third bonded face 26, each having the dichroic film for a first color light, are deviated by a predetermined distance. The distance of this deviation is adjusted so that an image formed by the light having reference image information corresponds to the image of the reference image information. The light is made incident on and reflected by the first bonded face and the third bonded face. Therefore, an appropriate image quality can be obtained without depending on a right angle precision.

Abstract: Disclosed is a color separation and color synthesis optical system provided between a light source portion and a projection optical system in a reflection type projection display apparatus, which color-separates a white color beam emitted from the light source portion into three primary color light beams of R (red), G (green) and B (blue), guides the three primary color light beams to a plurality of spatial light modulators corresponding to R, G and B, and color-synthesizes color light beams optically modulated by the respective spatial light modulators for the colors depending on video signals to emit a color-synthesized light beam, wherein at least one or more wavelength-selective polarization converting plates which rotate a plane of polarization of a specific color light beam by 90 degrees are located, and the wavelength-selective polarization converting plate is adhered to an incidence plane and/or an emission plane of a polarization beam splitter by adhesive with a slight gap.

Abstract: A light-conducting unit which can effectively balance the light-leaking effect and the light-propagation effect of the prismatic films forming the light-conducting space, and satisfy the requirements to reduce the weight of the unit is disclosed.

Abstract: Light output from a single-mode fiber is output as parallel light from a two-core collimator, and input to a deflection prism. The parallel light output from the deflection prism is vertically input to an area approximately half that of a plane side of a line focus lens, passes through approximately half of the areas of the line focus lens, a VIPA element, and a light-gathering lens, and is illuminated on a free-form surface mirror, so that its wavelength dispersion is compensated. The light then passes through the remaining areas of the light-gathering lens, the VIPA element, the line focus lens, and the deflection prism, through which the light from the single-mode fiber does not pass through, and is input to the two-core collimator as parallel light. The parallel light input to the two-core collimator is converged by a collimate lens, and input to another single-mode fiber.

Abstract: The object of the invention is to make a viewing unit of the image display compact so that it can be mounted on portable telephones or information terminals. The portable image display of the invention comprises a speaker portion, a microphone portion, an image display device 9 and a viewing optical system for forming an exit pupil to view an image displayed on the image display device and having a generally positive refracting power. The viewing optical system is constructed of at least one prism member 10 comprising an entrance surface through which a light beam emanating from the image display device 9 is entered into the prism, at least one reflecting surface at which the light beam is reflected within the prism and an exit surface through which the light beam leaves the prism. The at least one reflecting surface has a curved surface shape for imparting power to a light beam.

Abstract: An optical coupler includes a housing, and includes first and second optical terminals and a prism disposed in the housing. One terminal is moveable with respect to the other, and the prism maintains an optical alignment between the terminals. Because it includes a prism instead of a more complex and delicate optical assembly, such an optical coupler can often be less expensive and more rugged, and can often have a higher connection density, than prior optical couplers.

Abstract: A superimpose-plate is put on a focusing glass, on which a subject image obtained through tile photographing optical system is formed. The superimpose-plate and the focusing glass are provided in an incident opening of a hollow pentagonal mirror. The superimpose-plate comprises a plurality of micro-prisms that are formed on the superimpose-plate. Each of the micro-prisms shows a triangle in a cross-section. The vertical angle of the triangle is identical in each of the micro-prisms. A ridgeline of each of the micro-prisms is parallel to the right-left direction of the picture plane of the view finder.

Abstract: A scan engine is disclosed for use in a data collection device, as well as a method for producing a scan engine and an image sensor assembly. The scan engine includes a housing with an opening for receiving light from a scanned dataform, an image sensor which is located within the housing to sense light entering an aperture in the image sensor, and a prism located within the housing for receiving light from the opening along a first path and to provide at least a portion of the received light to the aperture along a second path.

Abstract: The invention relates to a two-dimensional optical scanner in which distortions upon scanning can be reduced in simplified construction and a compact, energy-saving image display system using the same. The two-dimensional optical scanner comprises a light source 10, a scanner unit of gimbal structure for scanning a light beam therefrom in a two-dimensional direction and a scanning optical system 20 comprising a non-rotationally symmetric surface having an action of correction of a distortion upon scanning of the scanned light beam. The scanning optical system 20 comprises a decentered prism comprising an entrance surface 24, a first reflecting surface 23, a second reflecting surface 22 and an exit surface 21. The respective surfaces of the prism are located such that in that prism, a light beam from the entrance surface 24 toward the first reflecting surface 23 crosses a light beam from the second reflecting surface 22 toward the exit surface 21.

Abstract: A system and method are provided for scanning all or part of a hand print for one or more hands positioned on a non-planar portion of a prism. The non-planar portion can be symmetrical about an axis of symmetry of the prism. Typically, a palm pocket, writer's palm, or the like, is hard to capture on a flat surface. In contrast, the non-planar portion of the prism according to embodiments of the present invention provides a form so that the palm pocket, writer's palm, or the like, can be captured. Hand and/or finger characteristic data can also be captured, for example hand geometry (e.g., finger lengths and spacing between fingers). The prism can also include a positioning device (e.g.

Abstract: An optical system including a lens (30) which is an optical part without a reflecting surface, wherein an incident optical axis (1) and an outgoing optical axis (2) does not agree with each other. An optical axis (4) of the lens (30) is not parallel with nor perpendicular to a plane including an incident position (25) of an incident light, an outgoing position of an outgoing light (55), and the incident optical axis (1) or the outgoing optical axis (2).

Abstract: A confocal three dimensional inspection system, and process for use thereof, allows for inspecting of bumps and other three dimensional (3D) features on wafers and other semiconductor substrates. The sensor eliminates out of focus light using a confocal principal to improve depth response. This process and system creates multiple parallel confocal optical paths along a line. The out of focus light is eliminated by placing an aperture at a plane which is a conjugate focal plane to the surface of the sample. The result is that the sensor produces a signal only when the sample surface is in a narrow focal range.

Abstract: In order to achieve highly dispersive spectrometry in wide wavelength with the use of a single grism, but not a plurality of grisms, the grism is composed of a prism the vertex angle of which can be varied and a volume phase holographic (VPH) grating. More specifically, the grism comprises a prism the vertex angle of which can be varied; and a VPH grating being a diffraction grating and disposed substantially orthogonal with respect to a side including the vertex angle of the prism; the VPH grating being rotated around an axis being substantially orthogonal to the side of the prism, whereby a slope angle defined by the VPH grating and a predetermined plane is varied.

Abstract: A projection optical system includes a light source emitting light, a light valve with a surface in front of the light source, and a wedge prism disposed in the optical path from the light source to the light valve. By means of the wedge prism with different sectional thickness, the optical path and focus position of the light beam can be corrected. Therefore, the distortion produced by oblique incidence on to the light valve can be improved such that the light optical focus on the surface of the light valve to achieve the improvement of light spot on light valve and raise the uniformity, collection efficiency, and brightness.

Abstract: Systems and methods of the present invention are directed to an optical element that includes a diffraction grating, an inclined surface, good optical characteristics, and an optical element manufacturing metal die. The optical element manufacturing metal die is capable of injection molding of an optical element having a complex structure. Further, the optical element manufacturing metal die includes nestings that have a plurality of mirror surface forming portions. The pluralilty of mirror surface forming portions include a plurality adjoining pairs of mirror surfaces. The plurality of mirror surface forming portions are molded by two adjoining pairs of the plurality of adjoining pairs of mirror surface forming portions, which are formed on the same nesting. At least one of the plurality of mirror surface forming portions are formed by a mirror surface grinding method.

Abstract: Internal drum recording apparatus provided with a rotating deflecting element, comprising two (or more) beams of different wavelengths, which are simultaneously operatable, and optical elements for bringing the two or more beams to a common optical path before they reach the rotating deflecting element. The deflecting element may have dispersing properties such that beams of different wavelengths will leave it at slightly different angles. The beams of different wavelengths may be generated by laser diodes or tunable laser diodes. The apparatus may further comprise a beam combiner to combine the beams generated by the light sources.

Abstract: A projector device is provided which is capable of reducing its costs by making it possible to increase luminance of outgoing light from a rod integrator with an output from a light source being remained unchanged and by making it possible to achieve a compact illuminating optical system using a shortened total length of the rod integrator. Notches each having a predetermined angle or a convex portion is formed in a vicinity of a light incident face and in a vicinity of a light outgoing face of a rod integrator. A sloped line produced at an angle formed by one portion of each of the notches on the light incident side relative to a center line is approximately parallel to a light incident line produced at an angle formed by incident light relative to the center line.

Abstract: An air-gap optical structure is fabricated by depositing a metallic spacer structure on a first transmissive optical element, and then contacting a second transmissive optical element to the spacer structure so that the spacer structure lies between the first transmissive optical element and the second transmissive optical element and defines an air gap therebetween. A first layer of the spacer structure contacts the first transmissive optical element, and a second layer of the spacer structure contacts the first layer. The first layer is preferably deposited by vapor deposition and is relatively thin, and the second layer is preferably electroless deposited and is relatively thick. The total thickness of the spacer structure is typically from about 5 to about 15 micrometers.

Abstract: A viewing optical system for display devices or an image pickup optical system, which can be used with high efficiency at a plurality of wavelengths and enables bright images to be viewed with satisfactory color reproducibility and well-corrected aberrations. The optical system comprises a first prism, a second prism and a volume hologram element disposed between them and cemented to them. The hologram element comprises a first volume hologram optimized in such a way as to effect diffraction at least at a first wavelength and a second hologram optimized in such a way as to effect diffraction at a second wavelength different from the first wavelength. The first and second holograms are identical with each other in terms of the shape and spacing of interference fringes on their surfaces but different from each other in terms of the spacing and tilt of interference fringes in their hologram media.

Abstract: The optical system of a projection display apparatus comprises a light source, a prism, a light valve, and a projection lens. Wherein a light beam emitting from the light source impinges into the prism, and passes through the first surface of the prism directly to illuminate the light valve which is placed near the first surface and parallels the first surface. By the reflection of the light valve, the light beam impinges into the first surface again, and illuminates a total internal reflection surface with an incidental angle large than the critical total reflection angle, so as to reflect the light beam out of the second surface of the prism and impinge to projection lens to form an image. Therefore, the optical system can increase the transmission and decrease the components, and the volume of it will be more compact.

Abstract: The invention relates to a real image type finder optical system having an image inverting optical system, which is suitable for reducing the size and cost of cameras while maintaining satisfactory optical performance, and an imaging system comprising the same. The real image type finder optical system comprises an objective lens group 10 having positive refracting power and an eyepiece lens group 30 having positive refracting power. The objective lens group 10 comprises a first group G1 consisting of a negative lens, a second group G2 consisting of a positive lens, a third group G3 consisting of a positive lens, and a fourth group G4 having negative refracting power and forming a part of an image inverting optical system 20. Upon zooming from the wide-angle to the telephoto end, the first group G1 remains fixed, the second and third lens groups G2 and G3 move, and the fourth lens group G4 remains fixed.

Abstract: A four sided prism which provides the full scale front view and the full scale backside of one's own self. In addition, oblique front and rear views of one's own body, clothing or hair are available. Rigid frames allow for fast assembly without hand tools. The prism can be assembled as a fixed frame prism. The prism can be manufactured so as to allow for folding the frame into a thin cabinet for storage against a wall.

Abstract: The multi-beam scanning device includes first and second light emitting elements that emit first and second light beams, respectively, a polygon mirror that deflects the first and second light beams to simultaneously scan the first and second light beams across an object. A prism having a light entrance portion and a light exit portion is located between the light emitting elements and the polygon mirror such that the first light beam enters the first prism through the light entrance portion and exits from the first prism through the light exit portion toward the polygon mirror. The light exit portion is inserted into the optical path of the second light beam to prevent a part of the second light beam from proceeding toward the polygon mirror.

Abstract: A prism unit has transmitting/totally-reflecting surfaces which cross each other, formed using at least one prism. Light emanating from a light source falls on the prism unit. The light is transmitted or totally reflected from the surfaces according to an angle of incidence at which the light falls on the prism unit. Transmitted light is radiated forwards, while totally-reflected light is directed laterally. A reflecting member is located laterally in order to cover the prism unit, whereby light totally reflected laterally by the prism unit is reflected forwards. In order to constitute the transmitting/totally—reflecting surfaces, a first air layer and a second air layer are formed in the prism unit so to have a substantially uniform width and oppose each other with a plane, which contains a glowing member of the light source and extends forwards, between them.

Abstract: An epifluorescent microscope (11) is constructed with a quick changing set of filters (13,20,21). A wheel (13) containing a plurality of dichroic beamsplitter mirrors (6165) mounted equidistance from a center axis (66) of the wheel is mounted at a 45° angle within the lightpath and provides a beamsplitter function. Light from an excitation source (12) is provided as monochromatic light, so that light from the excitation source (12) is reflected by a selected one of the dichroic mirrors (6165) to the specimen (15), and Stokes shifted light from the specimen (15) is transmitted through the dichroic mirror (6165). By separately mounting the dichroic mirrors (6165), the dichroic mirrors can be quickly moved and a quicker change of sensed fluorophores is achieved. An additional advantage is that excitation (20) and emission (21) filters can be quickly changed independently of the dichroic mirror element (13).

Abstract: A method of making an array of corner cubes includes the steps of: preparing a substrate, at least a surface portion of which is made of a cubic crystalline material and which has a surface that is substantially parallel to {111} planes of the crystalline material; and patterning the surface of the substrate such that a plurality of solid shape elements defines a predetermined pattern on the surface of the substrate. Each of the solid shape elements is defined by a number of concave portions, a number of convex portions or a combination of concave and convex portions. The method further includes the step of supplying a first active species, including an element that is contained in the crystalline material, onto the substrate on which the solid shape elements have been formed.

Abstract: The present invention relates to an endoscope comprising a deflection system for a visual angle of up to 30 degrees which comprises reflective deflection elements. The inventive endoscope is characterized in that the beams which form the image are reflected more than twice. This enables visual angles of less than 30 degrees to be used, without any reduction in the image quality.

Abstract: The invention relates to a method for variably attenuating the intensity of the light beam, in the case of which method the light beam is directed onto at least one optical arrangement, that has at least one body transparent to the light beam, in such a way that the light beam enters the at least one body through a light incidence surface and emerges again from the at least one body through a light emergent surface, the at least one body being moved in position relative to the incident light beam, in order to change the intensity of the emergent light beam with reference to the intensity of the incident light beam.

Abstract: An optical device (29) for rotating the polarization of a linearly polarized, broadband input beam of light (3) comprises prism means (30, 37, 43). The input beam is incident normal to a first face (31) and exits normal to a second face (47) of the prism means. The prism means comprises a light transmitting material having a plurality of totally internally reflecting surfaces (32,33,34) and one or more interfaces, the totally internally reflecting surfaces are arranged such that the polarization of the exit beam is rotated by 90° relative to the input beam, each interface comprises a pair of parallel surfaces (35, 39) separated by a gap (36), the parallel surfaces are arranged substantially to satisfy the Brewster condition such that surface reflection losses are minimized and the input and exit beams are substantially collinear.

Abstract: A 4-prism color management device (600) comprised of first, second, third, and fourth prisms (610, 612, 614, 616). The first prism (610) is adjacent to the second prism (612) with an air gap (620) interposed therebetween, the second prism (612) is adjacent to the third prism (614) with an air gap (624) interposed therebetween, and the third (614) prism is adjacent to the fourth prism (616) with an air gap (626) interposed therebetween. The first prism (610) includes a first surface (630) for inputting and outputting a beam of light. The second prism (612) includes a first dichroic surface (642) mounted at a first angle (&bgr;) with respect to the first surface (630) for reflecting light of a first color and for transmitting light of a second color and light of a third color. The third prism (614) includes a second dichroic surface (644) mounted at a second angle (&khgr;) with respect to the first surface (630) for reflecting light of the second color and for transmitting light of the third color.

Abstract: The invention provides a numerical aperture limiter for an optical thermal imaging system, comprising at least one pair of wedge-like prisms made of a transparent material having a known index of refraction, the prisms of the pair being disposed in close mutual proximity and in opposite orientation with the narrow end of one prism adjacent to the wide end of the other prism, the prism surfaces facing one another of the pair of prisms being spaced apart from one another by a distance at least equal to the wavelength of the light used by the imaging system, with the vertex angle of each one of the prisms being a function of the desired numerical aperture and the index of refraction.