Abstract: Retroreflective sheet material is produced by forming sheet material with closely spaced retroreflective formations on one face and depositing on this face silver and copper atoms having high kinetic energy to provide a reflective metallic deposit comprising a base layer of metallic silver and an overlying layer of metallic copper. An organic protective coating is thereafter applied over the reflective metallic deposit. Light rays passing through the front face of the body enter the retroreflective formations, impinge upon the interface provided by the silver base layer and are retroreflected therefrom. As a result, the sheet material exhibits a bright white appearance in daylight as well as a bright white coloration at night when an incandescent beam impinges thereon.

Abstract: An optical low pass filter including a phase grating for obtaining useful picture image characteristics by provision of preferable low pass effects for each of wave form zones about the spatial frequency components beyond Nyquist limit which are required to be removed as the picture images are discretely sampled in nature in an optical system of a single tube color television camera having a color separating filter, a color video camera using solid state imaging elements, and so on, which is easier in construction to be constructed.

Abstract: In an ultraviolet polarizing device, a first piece of glass having a mating surface, a second piece of glass having a mating surface for mating with the mating surface of the first piece, a multilayer optical thin film coating disposed between the mating surface of the first and second pieces of glass, said mating surfaces and said thin film coating forming a physical bond therebetween without the use of a cement to thereby permit the polarizing device to be capable of withstanding high power laser energy.

Abstract: A stabilized imaging system in which the lens assembly is fixed, and an electro-optic imager element is moveable to compensate for three-dimensional movements of the surrounding structure. Preferably the optical train also includes a movable prism, which can rotate the field of view in one plane. Rotation of the imager compensates for the image rotation caused by rotation of the prism.

Abstract: A light deflecting device for use in a light scanner, comprises a deflector (4) and a dove prism (13) mounted together on a rotatable support (16). The support (16) rotates about a nominal axis (2) coaxial with an incident light beam direction (11). A beam is incident on the deflector (4) so as to be deflected through a fixed angle (.THETA.) relative to the nominal axis (2) independently of any angular movement of the support (16) about the nominal axis.

Abstract: A scanning optical system for preventing ghosting is provided wherein a laser beam emitted by a laser light source is first brought to an image in an auxiliary scanning plane, and reflected by a slit mirror provided in a prism block. The laser beam is incident on the scanning deflector along the optical axis of the scanning lens, and a screen is provided for obstructing ghosting in the vicinity of the scanning surface. Further, at least one side of the prism block on which the light is incident from which the light emerges is curved, or one side of the prism block is treated to prevent reflection. Further, the screen is disposed between the laser light source and the slit mirror so as to obstruct the part of the light beam incident on the mirror which is reflected by the mirror after being reflected by the scanning deflector.

Abstract: A display apparatus for a vehicle by which the brightness of a display image can be varied readily without using a dimming circuit and a display image of a high contrast can be assured. The display apparatus comprises a light emitting displaying element for emitting visible light therefrom, and a reflecting member for reflecting visible light from the light emitting displaying element toward a driver of the vehicle directly or indirectly by way of a component of the vehilce such as a windshield. The reflecting member is selectively moved between a first position at which the reflecting member totally reflects visible light from the light emitting displaying means and a second position at which the reflecting member reflects visible light from the light emitting displaying element but at a comparatively low reflecting rate.

Abstract: A display device of the reflection type for a vehicle wherein an analog meter can be used to effect analog display and which, while remote indication is effected making use of a reflecting face of a reflecting element, is compact in overall size and has a long distance for the remote indication. The display device comprises a display unit, a reflecting member having a spherical reflecting face directed to a display face of the display unit, and a light transmitting reflecting element disposed between the display unit and the reflecting member and having a reflecting face through which display light from the display unit is transmitted.

Abstract: The disclosed device is aimed at improving the light output of this type of device without impairing its homogeneity in colour and luminance while, at the same time, limiting the amount of space occupied. In such a device, three optical valves are placed before three faces of a recombiner cube. The means used to separate a beam of white light into three beams of coloured light consist of a divider cube. The intersections of the treated surfaces of the, two cubes are aligned, and these treated surfaces are in sets of two in one and the same plane. Furthermore, outside the cubes, the optical paths of the three beams are identical, so that the optical distances between the source of white light and the valves are themselves identical.

Abstract: A wide field-of-view optical element 12 suitable for use in a laser warning system including a frusto-conical block of optically transparent material having a first surface 14 and a second surface 16. The first surface 14 is parallel with the second surface 16 and coaxial therewith. The radius R.sub.1 of the first surface 14 is less than the radius R.sub.2 of the second surface such that the sides of the element 12 are slanted. Reflective material is coated on the interior 17 of the first surface 14 for directing incident optical energy toward a detector 20 mounted at the second surface 16. Similarly, a reflective material is coated on the interior 18 of the second surface 16 for directing incident optical energy to the detector 20 via the first surface 14. The second reflective coating on the second surface is disposed between the outer periphery thereof and a nonzero distance R.sub.3 from the center thereof to provide an aperture at which the detector 20 may be mounted.

Abstract: A device for projecting a rainbow-like spectral display including a housing provided with a projecting arrangement for projecting the rainbow-like spectral display onto a viewable surface. The projecting arrangement includes segments, each segment including a light emitting source for producing light rays, and a diffraction member such as a prism for effecting a spectral dispersion of the light rays for projecting same to produce the rainbow-like spectral display. Preferably, each segment also includes a convergent or convex lens disposed between the light emitting source and the diffraction member, and a reflector covering a rear portion of each light emitting source. The housing could be portable, battery operated, and in the form of a casing provided with a hinged cover.

Abstract: A rectangular prism includes an entrance surface for receiving light, an exit surface from which the light emerges, two reflecting surfaces orthogonal to each other for directing the light ray incident from the entrance surface to the exit surface, and a groove of V-shaped cross-section disposed in the boundary between the entrance surface and the exit surface.

Abstract: An optical device with an improved efficiency in the transmission of light through the device is disclosed. The device having an optical element in a block shape which is made up of a first plane on which incident light is presented at a predetermined incidence angle. The incident light is transmitted through the first plane and is reflected off of another plane which is oriented at a predetermined angle with respect to a plane perpendicular to the first plane. The reflected light is next totally transmitted through an exit plane situated parallel to the first plane. The incidence angle is predetermined so that the angle at which the light is finally transmitted with respect to the exit plane is a polarization angle satisfying Brewster's rule. Therefore, at the exit plane, the light is totally transmitted and thus none of the light is reflected, resulting in a greatly improved degree of efficiency in the transmission of light through the device.

Abstract: The prism reflector installed immediately above an indicator's display surface consists of a prism and a flange portion that is flush with one surface of the prism and which extends from the periphery of that surface. The surface of the prism and the flange portion form a reflecting surface. A reflector plate is arranged to face the reflecting surface of the prism reflector and has a concave surface, whose light axis is inclined with respect to the reflecting surface of the prism reflector toward the thicker side of the prism. Light from the indicator's display enters the prism, is refracted as it leaves the reflecting surface, and travels toward the reflector plate's concave surface, which reflects the incident light back toward the reflecting surface of the prism reflector, which then reflects it toward the driver's viewing point.

Abstract: A joined prism assembly having more than two prisms adhered to each other at joining surfaces is disclosed. The joined prism includes stepped portions between the end faces of the prisms adjacent to the joining surfaces for defining exposed positioning reference surfaces for when the prisms are adhered to each other.

Abstract: A transparent-scattering type optical device which includes a transparent-scattering type optical element having a layer of transparent-scattering mode optical material whose light scattering characteristics are changed in response to an external input; at least one prism having a bottom surface which is attached to an end portion of the transparent-scattering type optical element, and where the prism has a longitudinal cross section of a shape which is either triangular or triangular with a top portion cut away. A pair of angles formed by two opposite sides of the prism and the bottom surface are between 65.degree. and 90.degree. inclusive where one of the two angles is not equal to 90.degree.. A light absorbing face is formed from an area of the prism surface defined by portions of the two opposite sides of the prism nearest to the top.

Abstract: A real image mode finder optical system includes an objective lens, an image inverting optical member erecting an image of an object formed by the objective lens, and an eyepiece for observing the object image, in which the last reflecting surface of the image inverting optical member is constructed, as a prism, integral with the eyepiece. Whereby, the real image mode finder optical system has practically important advantages that the overall length can be reduced, with performance maintained, without any increase of the number of parts and the image inverting optical member can also be arranged at the rear end of the camera body.

Abstract: A portable missile launcher has an optical system with a single lens (22) for receiving visible and near infrared light energy from a target (14) directing it to a prism (24) where the light is split into a part transmitted to an eyepiece (28) and a further part (30) to infrared tracking equipment (18). The objective lens (22) is a doublet having a front lens (32) and a rear lens (41) which cooperate to provide sufficiently small chormatic aberration to enable image quality correction for both visual examination and near infrared tracking.

Abstract: The invention is an inverted microscope with a housing having multiple integrated ray paths leading from the specimen being examined to (a) the viewer/operator and (b) one or more auxiliary ports used for image recording and/or measurement by accessories such as cameras and video recorders. The microscope lens is positioned below the specimen stage; and, positioned below the lens is a simple reflector which deflects the combined rays from the lens diagonally upward toward the viewer at exactly the same angle at which the viewer looks into the microscope's binocular eyepieces. The position of this simple reflector is the lowest point in the unit's paths of rays, thereby significantly lowering the lens turret and, therefore, the specimen stage to a relatively low, ergonomically-appropriate position. The optical arrangement is simple and compact, minimizing the number of deflections in the path of the viewing rays.

Abstract: An apparatus for optically scanning a reflective object includes a first reflector having a frustoconical reflecting surface with a central opening. A second reflector has a flat reflecting surface which faces the frustoconical surface and is inclined with respect to the axis thereof. To the side of the flat surface is an optoelectronic sensor which is connected to a processing unit. Between the sensor and the flat surface is a focusing system which functions to focus light reflected from such surface onto the sensor. In operation, an object to be scanned is moved through the central opening of the frustoconical surface along the axis of the latter. As the object moves, a light source illuminates successive, circumferentially complete bands of the object at a predetermined location within the space surrounded by the frustoconical surface. Light from the source impinges upon the object from laterally thereof and at an angle to the axis of the frustoconical surface.

Abstract: An arrangement for turning an image projected on an image screen has an image screen, a trapezoidal prism for image turning, and an optical system for image producing. The prism has an entry surface, a base surface and an exit surface. The entry surface of the prism encloses with the base surface an angle which is different from an angle enclosed by the exit surface of the base surface. A light beam extending on an optical axis of the optical system for image producing is offset on the exit surface relative to the optical axis and encloses an angle with the optical axis which is not equal to zero, and a transmission filter is located between the prism and the image screen.

Abstract: A beam shaping optical system has an optical prism; a gap layer stacked on a reflecting face of the optical prism and having a refractive index lower than that of the optical prism; and a waveguide layer stacked on the gap layer and having a refractive index lower than that of the optical prism and higher than the refractive index of the gap layer, the optical prism, the gap layer and the waveguide layer constituting a prism coupler. The prism coupler is adapted to reflect a collimated light beam made incident to the prism coupler on a stacking face of the optical prism such that the diameter of the incident light beam in a direction parallel to an incident face of the prism coupler is changed to shape the incident light beam, the gap layer and the waveguide layer being stacked on the stacking face. The waveguide layer may be stacked on a transparent substrate and the refractive index of the waveguide layer may be higher than that of the transparent substrate.

Abstract: An improved real-time confocal scanning microscope, and an improved perforated disk for use in such microscope. A preferred embodiment of the inventive microscope includes a polarizing beamsplitting cube and a rotatable Nipkow disk perforted with a hexagonal hole pattern. The disk is preferably mounted so that the scan lines produced as the disk rotates will cross both the sample feature to be imaged and the sensor array in the system's video camera at an angle substantially equal to 45 degrees. This disk orientation ensures that brightness variations caused by a non-uniform scan will not affect the measurements. Rotation of the disk is preferably synchronized with the camera frame rate to prevent any scan errors from causing random (frame to frame) variations in the camera output. The polarizing beamsplitting cube consists of two triangular prisms connected (i.e., cemented) together by a dielectric film.

Abstract: A color separation optical system includes a set of prisms which separate incident light into components having different wavelengths. Image pickup devices may be exposed to the separated light components. An arrangement prevents or reduces the influence of a temperature variation upon color separation characteristics. The color separation optical system may be manufactured in a new way.