Abstract: A prism includes: a first portion made of a first material having a wavelength dependency in a refractive index; and a second portion adhered to the first portion, the second portion being made of a second material having a wavelength dependency in a refractive index which is different from the wavelength dependency in the refractive index of the first material. The first portion and the second portion have shapes such that the wavelength dependency in the refractive index of the first portion and the wavelength dependency in the refractive index of the second portion are substantially cancelled by each other.

Abstract: A reflector for improving the signal of spectrophotometer, the reflector comprising a truncated cone having a reflective inner surface and a conical axis, the truncated cone open at a larger axial end thereof, open at a smaller axial end thereof, and having an opening in the cone surface. The reflector returns specularly scattered light back to the surface of a sample, and therefore enhances the amount of collected light.

Abstract: A signal light including a housing is recessed into a traffic surface and projects minimally upwardly from the surface and wherein a light processing assembly is provided to receive light from a light source, intensify the light and direct the light toward a light outlet in a generally linear manner, the arrangement for processing light being mounted to the housing. For this purpose, the light source is designed in such a way that it sends an essentially linearly directed light beam onto the light processing assembly. The light is collected in the light processing assembly in such a way that, when it exits, it is still linearly extending in at least one direction but it has a higher intensity. For this purpose, the light processing assembly includes a cylindrical-convex lens entry surface and a cylindrical concave mirror surface for receiving and directing light.

Abstract: A see-through retroreflective structure includes a transparent polymeric film, an array of retroreflective elements attached to the polymeric film, and an array of apertures through the retroreflective structure within the array of retroreflective elements. In one embodiment, the retroreflective structure includes a metalized reflective layer formed on the transparent prism elements and a support layer, such as a fabric, is attached to the metalized reflective layer.The method includes providing a transparent polymeric film. An array of retroreflective elements is attached to the polymeric film. The array of retroreflective elements and the transparent polymeric film are perforated through the retroreflective structure to form an array of apertures, thereby forming a retroreflective structure. The apertures are of sufficient size and spacing to provide a see-through capability.

Abstract: The present invention relates to an optical element fixing device, and particularly to a prism mounting device for an optical device using light beam which passes through a prism or lens, a lens fixing device for aligning and fixing the center of a lens with a prescribed optical axis, and a device for fixing a reflecting mirror of an optical device. The invention can easily and securely position the prism to be press-contacted to the lens within a case, in which changes in the magnitude of press-contacting with the passage of time is very small. And, the lens can be securely fixed with its center accurately aligned with a prescribed optical axis. Besides, the reflecting mirror is fixed by a simple structure and a contact between the reflecting mirror and a plate spring is not limited to one point.

Abstract: An optical unit for projecting an image including first and second locating lines for substantially eliminating the introduction of visual parallax error. In one preferred form, the optical unit is incorporated into a machine for performing a forming operation on a workpiece and is operative to project an image of a portion of a scale to a position easily read by the user during machine operation. The optical unit includes a prism portion having a first side disposed adjacent the scale, a second side at an angle to the first side for reflecting the image and a third side through which the projected image may be viewed. The first locating line is disposed on the first side and the second locating line is disposed on the third side such that visual alignment eliminates the introduction of visual parallax error associated with reading a scale.

Abstract: An exterior rearview mirror for vehicles incorporates a forward vision improving system allowing improved visibility of the opposite roadway forward of the vehicle for safer passing. Preferably, the forward vision system includes a pair of prisms mounted in a mirror housing, one of which is directed at an angle of incidence past and to the left of a front, slower vehicle, the other of which receives the image from the first, and is positioned in the driver's line of sight. In one embodiment of the vision system, the front prism of the pair of prisms is replaced by a divergent lens.

Abstract: The present invention is a derotation assembly comprised of a plurality of dove prisms with multiple reflecting surfaces, each with a normal axis intersecting a common rotation axis aligned orthogonally to an optical device. The reflecting surfaces are parallel to each other and orthogonal to the common rotation axis.

Abstract: An optical polarization device includes a source of light emitting a non-polarised light beam. A polarization separator reflects one polarization component of the light beam and transmits the other polarization component. A reflection means receives the component reflected by the polarization separator, rotates its polarization plane through 90.degree., and returns it to the polarization separator. The polarization separator is a plane element. The reflection means is positioned on the source side of the separator and consists of a regular network of prisms, each partially covered with a reflective layer associated with a .lambda./4 plate.

Abstract: A support assembly for supporting a reflecting member of a focusing apparatus utilizes a flexure arrangement. The reflecting member can be in the form of a movable prism, and the flexure arrangement can include a pair of horizontal flexures in the form of sheets that support the moving prism of the focusing apparatus. The flexure arrangements permit the movement of the moving prism in a first direction relative to fixed prisms, fibers and lenses, while preventing or minimizing unwanted tipping, tilting or rotation of the movable prism. In one embodiment of the support assembly, the flexure arrangements can be symmetrically arranged on opposites sides of the movable prism, and in a further embodiment of the present invention, a further flexure arrangement can be arranged to provide for an increased range of motion of the movable prism.

Abstract: A compact optical imaging system that transmits light received from an object located at an image plane to an exit pupil to form an image comprises a first prism, a second prism, a converging reflective element, and a converging transmissive element. The first prism includes a first face, a second face, and a third face that faces the image plane. The included angle between the first face and the second face of the first prism is .alpha.. The second prism includes a first face facing the exit pupil and substantially parallel to the first face of the first prism, and a second face adjacent the second face of the first prism. The converging reflective element is adjacent the first face of the first prism. The converging transmissive element is on or adjacent the first face of the second prism. The included angle .alpha.

Abstract: An optical device for collecting light and selectively outputting or concentrating the light. A layer has an optical index of referaction n.sub.1, and top, bottom and side surfaces defining an angel of inclination .phi.. A back surface spans the top, bottom and side surface. A first layer is coupled to the bottom surface of the layer and has an index of refraction n.sub.2. The first layer index n.sub.2 causes light input through the back surface of the layer to be preferentially output into the first layer. A second layer is coupled to the bottom of the first layer and selectively causes output of light into ambient. Additional layers, such as alight polarization layer, a polarization converting layer and a post LCD diffuser layer can be used to make preferential use of polarized light of diffuse light having passed through the LCD layer to enhance viewing of the output light.

Abstract: Illuminated instruments in aircraft cockpits often create reflections from the canopy which interfere with the pilots vision. A wedge of optical material positioned adjacent the instrument retracts the light rays such that the canopy reflections are deflected away from the eyes of the pilot.

Abstract: Wavelength selection apparatus for use in various applications such as spectrometry, the demultiplexing/multiplexing of multiline laser beams, and so forth, includes an input prism and an output prism aligned along an optical axis, and at least one side mirror. A second side mirror spaced from the first side mirror on the opposite side of the optical axis may be provided, as well as end mirrors adjacent to the input and output prisms. An incoming beam incident upon the input prism is refracted so as to deflect and angularly disperse the various wavelengths present in the input beam, with the dispersing beam reflected from the first side mirror either directly to the output prism or with intermediate reflections from the second side mirror and the end mirrors before impinging upon the output prism. The output prism matches the input prism and deflects and recollimates the dispersed wavelengths to provide parallel output beams of different wavelengths spaced from one another.

Abstract: A prism-type objective lens is provided for use in the pickup head of an optical disc drive capable of driving two types of optical discs such as a CD and a DVD. The prism-type objective lens allows the pickup head to be made more compact in size with reduced structural complexity, and also allows the pickup head to read data from two different types of optical discs. The prism-type objective lens includes a prism having a cross section substantially in the shape of a right triangle, a front aspherical plano-convex lens, and a rear aspherical plano-convex lens, where the planar surface of each lens is attached to one or the other of the leg sides of the prism. The hypotenuse side of the prism can be formed with two aperture areas where different reflective layers are coated. Alternatively, the hypotenuse side of the prism can be formed with a reflective HOE layer that allows the laser beam incident on it and reflected from it to be diffracted into two beams which are focused at different points.

Abstract: A DMD illumination coupler, and a method of improving the wavefront quality of a transmitted illumination beam over the prior art using the invented DMD illumination coupler are disclosed. The invented DMD illumination coupler comprises an angularly selective reflective thin film. The invented DMD illumination coupler has the characteristics of high optical quality and cost effectiveness. The application of the invented DMD illumination coupler in holographic systems is also discussed.

Abstract: The present invention consists of two right angle prisms, one of which is coated with a wedged layer of low index of refraction transparent material such as magnesium fluoride. The coating varies in thickness, linearly, for example, from about 50 to 700 nanometers, for example. The prisms are cemented together forming a rectangular cube beamsplitter. The beamsplitter is then mounted onto a stage so that the plane of the cemented surfaces is parallel to the axis of translation. As one translates the cube along its axis, the ratio of reflectance to transmittance varies according to the thickness or other factors.

Abstract: A color display including a non-polarized light source, at least one polarizing beam-splitter receiving light from the non-polarized light source, at least one selectably actuable polarization rotating light valve having thereon impinging light from the polarizing beam splitter and operating in a reflective mode, the light valve having a plurality of separately controlled light valve regions which correspond to different colors, a display screen including a plurality of differently colored light impingement regions and imaging optics for directing light reflected from the at least one light valve via the at least one beam-splitter to the display screen such that light from individual ones of the plurality of separately controlled light valve regions which correspond to a given color impinges on correspondingly colored light impingement regions of the display screen.

Abstract: The present invention includes a structured optical film with variable pitch peaks and/or grooves to reduce the visibility of moire interference patterns and optical displays incorporating one or more layers of the film. The pitch variations can be over groups of adjacent peaks and/or valleys or between adjacent pairs of peaks and/or valleys.

Abstract: An assembly method of an air gap prism which has an air gap between a first glass member and a second glass member, the assembly method having steps of setting a first glass member on a positioning member, setting a sheet member on the positioning member so as to cover the first glass member, setting a second glass member on the first glass member covered with the sheet member so as to sandwich the sheet member between the first glass member and the second glass member, and cutting a portion of the sheet member protruding from the first glass member and the second glass member.

Abstract: Molded block optics system (10) writes and reads data from an optical storage medium and includes first molded optics block (12) for receiving reference beam (60) and original object beam (46) that contains a predetermined data set. First molded optics block (12) includes reflective surfaces (18, 20, 22, and 24) and spatial light modulator (50). Reflective surfaces (18, 20, and 24) include reference beam surfaces (24) and object beam surfaces (18, 20, and 22). Reference beam surfaces (24) direct reference beam (60) to optical storage medium (16) at predetermined location (54). Spatial light modulator (50) modulates object beam (46) and directs modulated object beam (46) to predetermined location (54). Reference beam (60) and object beam (46) form an interference pattern that writes data on optical storage medium (16). First molded optics block (12) also directs reference beam (60) to optical storage medium (16) for generating reconstructed object beam (64).

Abstract: A deflection mirror tower (DMT) of a multiple-disk array, optical storage system includes a plurality of prism members, each having an angular mirror surface, arranged along a vertical axis of the DMT and configured at a predetermined angular orientation to deflect a laser beam to a respective disk surface. The DMT is generally fabricated using a two-level partitioning process. Several prepared glass substrates, i.e., one for each mirror type, are initially sliced into bars having predetermined geometries. A bar from each substrate is sequentially aligned to a master reference and bonded to adjacent bars to form an intermediate bar stack. The stack is then segmented into a plurality of DMT components, each having a plurality of prism members.

Abstract: In an optical member coupling apparatus for coupling an exchangeable lens unit and an optical member such as a color-separating prism with each other, a supporting section for movably supporting the optical member in a plane perpendicular to the optical axis is provided, whereby even when the optical axes of the lens unit and optical member deviate from each other, they can be adjusted easily. A color-separating prism 2 is attached, together with a lens unit 1, to a panel 3 by means of first and second bases 7 and 8 which are respectively movable only along X and Y axes in a plane perpendicular to the optical axis. The first and second bases 7 and 8 respectively have elliptical holes 7G and 8G into which a joystick 16 can be inserted.

Abstract: A method of widening the directional range of view of a mirror device without enlarging the surface area of the device by suitably combining a number of partially-reflecting surfaces includes provision to avoid discontinuities and overlaps in the field of view. It also makes it possible for the viewer to visually identify an image with the particular reflector that generates the image seen in the image field and hence relate it to a zone of the field of visibility wherein the object is located. A device incorporating the method can be useful as a side-view mirror of an automobile.

Abstract: A deflection mirror tower (DMT) of a multiple-disk array, optical storage system includes a plurality of prism members, each having an angular mirror surface, arranged along a vertical axis of the DMT and configured at a predetermined angular orientation to deflect a laser beam to a respective disk surface. The DMT is generally fabricated using a two-level partitioning process. Several prepared glass substrates, i.e., one for each mirror type, are initially sliced into bars having predetermined geometries. A bar from each substrate is sequentially aligned to a master reference and bonded to adjacent bars to form an intermediate bar stack. The stack is then segmented into a plurality of DMT components, each having a plurality of prism members.

Abstract: A deflection mirror tower (DMT) of a multiple-disk array, optical storage system includes a plurality of prism members, each having an angular mirror surface, arranged along a vertical axis of the DMT and configured at a predetermined angular orientation to deflect a laser beam to a respective disk surface.

Abstract: The object of the present invention is to eliminate a double image of a display apparatus for automobiles in which an image of displayer is reflected by a transparent reflection plate toward a driver's seat so that the display image for displaying information on the condition of the vehicle such as vehicle speed can be seen as a virtual image. A display apparatus for automobiles according to the present invention comprising: a displayer for emitting display light; a reflection plate having a first surface on a driver's seat side and a second surface on a side opposite to the driver's seat, the display light diagonally falling on the first surface and being reflected on the first surface to be directed to an eye range, a display image of the displayer being recognized from the driver's seat side within a display range on the first surface, at least a portion of the second surface corresponding to the display range of the first surface being diagonally disposed in relation to the first surface.

Abstract: An antireflection surface having a predetermined roughness so as to keep the reflectivity of incident radiation low. A profile with projections having a height which is an integer multiple of the radiation wavelength can trap the radiation irrespective from its polarization and also at large angles of incident light.

Abstract: An image display apparatus which enables observation of a clear image at a wide field angle and which is extremely small in size and light in weight. The apparatus includes an image display device (6) for displaying an image, and an ocular optical system (7) for leading the image displayed by the image display device (6) to an observer's eyeball (1). The ocular optical system (7) has a first surface 3, a second surface 4, and a third surface 5. A space formed by the three surfaces is filled with a transparent medium having a refractive index larger than 1. Light rays emitted from the image display device (6) pass through the third surface (5) and are internally reflected by the first surface (3) and further internally reflected by the second surface (4), which is decentered and has positive power. The reflected light rays pass through the first surface (3) and are led to the observer's eyeball (1). The angle .theta..sub.

Abstract: A deflection mirror tower (DMT) of a multiple-disk array, optical storage system includes a plurality of prism members, each having an angular mirror surface, arranged along a vertical axis of the DMT and configured at a predetermined angular orientation to deflect a laser beam to a respective disk surface. The DMT is generally fabricated using a two-level partitioning process. Several prepared glass substrates, i.e., one for each mirror type, are initially sliced into bars having predetermined geometries. A bar from each substrate is sequentially aligned to a master reference and bonded to adjacent bars to form an intermediate bar stack. The stack is then segmented into a plurality of DMT components, each having a plurality of prism members.

Abstract: A hollow, cylindrical light conduit for transporting light generally longitudinally therethrough and distributing light therealong includes a cylindrical wall member of a transparent material. The wall member has an inner cylindrical smooth surface and an outer cylindrical structured surface having an array of isosceles prisms arranged side by side thereon. The faces of adjacent prisms extend longitudinally along the cylindrical wall member and are aligned at the same desired prism angle relative to one another. The light transporting performance of the light conduit, achieved by total internal reflection, and the light distributing performance of the light conduit, specifically relative to radially aligned, high incident angle longitudinal light rays in planes parallel or near parallel to the prisms, is optimized as a function of the desired prism angle between the faces of adjacent prisms.

Abstract: A beam shaper device for an optical read/write head on an optical disc drive is provided. This beam shaper device is particularly useful for shaping a laser beam originally emitted with an elliptical cross section, into having a substantially circular cross section. The beam shaper device includes only one prism and one plane mirror. The shape of the prism and the orientation of the plane mirror are specifically devised in such a way as to allow the output beam shaper device to have a circular cross section and to have its propagation axis orthogonal to that of the input laser beam.

Abstract: A multi-fold optical magnifier includes a prism with four reflecting surfaces positioned to direct light from an inlet to an outlet, and a lens positioned adjacent the prism outlet to receive light from the prism. An aspheric surface of the lens is in the light path for aberration correction and diffractive optical elements formed on the prism and lens are positioned in the light path to provide further aberration correction. The prism and lens angularly magnify an image source at the prism inlet by greater than ten. The total distance, orthogonal to the source plane, between the prism inlet and the lens outlet is 10 to 15 millimeters.

Abstract: An insert is installed at a corner and two adjacent edges of an enclosure for electronic equipment so that a signal light, such as an LED, may be observed from two sides of the enclosure. The insert has a prism to refract light in both directions from an LED or similar signal light supported on the insert in a fixed position relative to the prism. The corner of the prism is rounded to function as a lens. The corner of the enclosure is cut away at the upper edges of the converging sides and the cut-away area filled with the lens. An apron depending from the insert may be welded or otherwise adhered to the interior of the enclosure.

Abstract: A method and device which is used to insert an implant in order for treating an eye with glaucoma in order to lower the intraocular pressure of the eye. The implant is an artificial meshwork. The implant is attached to a guide knife which is inserted into the anterior chamber of the eye. The knife is then removed leaving the implant in place. During the operation, a prismatic lens with c-shaped vacuum ring is used to help assist the surgeon in viewing the anterior chamber of the eye and stabilizing the eye.

Abstract: Endoscopic instrument having an elongated image guide adapted to be inserted through an opening in the human body. A prism is provided at one end of the image guide for directing images from a predetermined field of view through the image guide and means for. By tilting the prism relative to the image guide the field of view from which images are directed through the image guide is changed to provide continuous scanning for viewing and examining different features of internal cavities and hollow organs of the human body.

Abstract: An optical apparatus, for correcting deviations from straightness of an array of laser emitters in generally aligned positions along an array direction, includes a plurality of mirrors along the light beam paths and positioned to reflect its associated light beam along a folded light beam path. Individual mirrors are selectively displaced along its associated light beam path in a direction so as to align the reflected light beams from all of the plurality of mirrors along the folded light beam path, thereby to correct for any deviation of a laser emitter from the straight, array direction line of the laser emitters. According to a preferred embodiment, a plurality of lenslets having power in at least the array direction are positioned in the light beam paths between the laser emitters and the mirrors such that each lenslet receives the light from an associated laser emitter in the array.

Abstract: A rear view mirror unit of the type in which light from a region behind an observer is directed to the observer's eye by an optical system including a reflecting component and a refracting component in which the refracting component of the optical system includes a plurality of refracting interfaces inclined to one another and including first and second interfaces of an objective refractor, which converge towards a first side of the longitudinal median plane of the unit and third and fourth interfaces of an ocular refractor which converge towards a second side of the longitudinal median plane of the unit opposite the first. The ocular retractor is transversed twice by the light in its path to the observer's eye from the object, and the refractors may be formed as Fresnel prisms.

Abstract: An image projection system wherein light provided from a source passes through a prism and is then incident on an array of reflecting elements which are individually adjustable between a first and second position. Light reflected from each element re-enters the prism. Light from elements in the first position pass through the prism and into a lens. Light from elements in the second position travel through the prism, but do not enter the lens. The principal plane of the lens and the plane in which the elements are located are each parallel to the adjacent surface of the prism.

Abstract: A triangular prism mirror mounted adjacent a driver of a vehicle to enable the driver to view the blind spot area without any distortion of vision. The triangular prism mirror unit has three plane surfaces, the rear surface being blocked. By blocking the rear surface of the prism, the image entering one of the front surfaces will appear on the other front surface. Therefore the triangular prism mirror, when properly mounted, provides a clear vision for the driver of a vehicle giving access to the blind spot area.

Abstract: A device for deflection of a light beam formed of a light-permeable deflection prism extending in a direction of a rotational axis. The prism has a light entry face, a reflection face proceeding obliquely thereto and a light exit face, and is further formed of a carrier prism joined to the deflection prism at the reflection face. The carrier prism supplements the deflection prism to essentially form a cuboid unit that is seated rotatably around an optical axis that resides perpendicularly relative to the light entry face of the deflection prism. For producing a unit designed rotationally symmetrical relative to the optical axis at least in regions, the optically unused edges and corners of the cuboid unit are rounded. Spherical caps are attached to at least two of the unused outside surfaces of the unit, these spherical caps supplementing the unit to form a spherical outside contour at least in regions.

Abstract: A prism is provided for deflecting light through the tape information holes in the tape of a data cartridge. The prism includes a substantially hollow main prism body. The inside surface of the angled prism surface is formed in steps, so that light passing into the angled portion passes in the normal direction through a step, is reflected off of the angled surface, and then passes in the normal direction through the adjacent side of the step, or the adjacent side of the next step. In this fashion, minimal plastic material is required for the prism, while light reflection is restricted to only a single surface. An alternative embodiment provides steps on the internal surface of a mirror, instead of a prism.

Abstract: A rotatable polygon mirror comprising a transparent regular polygonal cylinder having the sides of a regular polygon. The sides are rotationally symmetrical with one another relative to a rotating axis of the transparent regular polygonal cylinder. The transparent regular polygonal cylinder has inner surfaces in the body of the transparent regular polygonal cylinder which correspond to the respective sides of the regular polygon, where the inner surfaces consist of total internal reflection surfaces.

Abstract: Disclosed is a projection system wherein light provided from a source passes through a prism and is then incident on an array of reflecting elements which are individually adjustable between a first and second position. Light reflected from each element re-enters the prism. Light from elements in the first position pass through the prism and into a lens. Light from elements in the second position travel through the prism, but do not enter the lens. The principal plane of the lens and the plane in which the elements are located are each parallel to the adjacent surface of the prism.

Abstract: A deflection mirror tower (DMT) of a multiple-disk array, optical storage system includes a plurality of prism members, each having an angular mirror surface, arranged along a vertical axis of the DMT and configured at a predetermined angular orientation to deflect a laser beam to a respective disk surface. The DMT is generally fabricated using a two-level partitioning process. Several prepared glass substrates, i.e., one for each mirror type, are initially sliced into bars having predetermined geometries. A bar from each substrate is sequentially aligned to a master reference and bonded to adjacent bars to form an intermediate bar stack. The stack is then segmented into a plurality of DMT components, each having a plurality of prism members.

Abstract: A device for lighting a medical treatment field is disclosed and includes an optical member for focusing a plurality of light rays. The device also includes a prism assembly formed of a plurality of sectors of prisms. Each prism has an entry face and an exit face. The vertices of the sectors are substantially located in the center of the prism assembly. The sectors of prisms are configured and dimensioned so that the optical focusing member can focus the plurality of light rays generally onto the entry faces of the prisms. In addition, the device includes a mechanism for displacing at least a predetermined number of sectors such that the exit faces of the prisms of the predetermined sectors can be selectively positioned in one of a generally planar or a non-planar configuration. In an alternative embodiment, the device includes an optical focusing member and a prism assembly wherein the exit faces of the prisms are generally arc shaped along the length of the sector.

Abstract: An optical system of an optical disc apparatus is disclosed for converging and projecting a bundle of rays emitted from a light source onto an optical disc. The optical system includes a collimating lens which collimates the bundle of rays emitted from the light source, two anamorphic prisms for shaping the cross section of the collimated bundle of rays transmitted through the collimating lens, and an objective lens which converges the bundle of rays shaped by the anamorphic prisms onto the optical disc. At least one of the anamorphic prisms is detachably mounted to an immovable body portion of the optical system.

Abstract: An all-directional optical sensor apparatus 8 includes an all-directional prism 20 which has a cylindrical-shaped body with a hollow-out cone section formed in its top surface 22. The surface 28 of the cone works as a reflector 30 for rays received through side surfaces 24 of the cylindrical-shaped body. An optical sensing element is disposed adjacent to a bottom surface 26 of the prism 20. A roof plate 40 having a dimension larger than the top surface 22 of the prism is arranged for shielding the entry of any light other than an input signal into an upper portion of the prism 20.

Abstract: In a color projection display system employing display devices operating in the reflective mode, the optical path lengths are considerably reduced by employing prism illuminators immediately adjacent the display devices to illuminate the reflective display surface and to spatially separate the incident and reflected illumination. Such color projection systems are easier to arrange and offer sufficient brightness to be useful in both home and commercial applications, such as movie theaters.

Abstract: A surveyor's retro-reflective device, such as a corner cube prism, is striped along the reflective surfaces to provide an internal visual center target. The precise center of the prism is identified by the visual target which allows the prism to be used both for distance measuring purposes as well as visual alignment for the one step setting of surveying points or locations. The corner cube prism has the ridges of the intersecting reflective surfaces on the back of the prism striped or lined either with a stripe having equal thickness or tapered towards the center apex of the prism. The stripes are formed with a highly visible paint, ink, tape, or sheet material. This arrangement produces a highly visible visual center target. The prism target can be mounted in an enclosed case and the case can be rigidly mounted or tiltably mounted on a horizontal axis to tilt the prism in a vertical direction for use in mountainous terrain.