Abstract: An improved zoom telescope which has a freely rotatable annular zoom ring connected through an interposition gear to a cam cylinder.

Abstract: A holographic display including a planar transparent light pipe (11) configured for rotation about a light pipe rotation axis that is orthogonal to the planar extent of the transparent light pipe and passes through a rotational center of the light, a multiple image hologram structure (13) having a plurality of holographic images attached to one side of the planar transparent light pipe, wherein the images are at different azimuthal angular positions on the light pipe about the light pipe rotation center, and a light source (17) for illuminating an input surface of the transparent light pipe such that an injected beam propagates within the light pipe to provide reconstruction illumination for a portion of the multiple image hologram structure.

Abstract: A lens-barrel optical system of the present invention is a lens-barrel optical system for guiding a beam emerging from an objective optical system in a focused state to an eyepiece optical system, which includes (i) a deflecting prism having three internal reflecting surfaces arranged in a triangular prism, the deflecting prism successively reflecting a beam incident in a first direction parallel to the optical axis of the objective optical system by the three reflecting surfaces to let the beam travel in a substantially M-shaped optical path, thereby letting the beam emerge in a second direction opposite to the first direction; and (ii) a reflector for reflecting the beam emerging from the deflecting prism to guide the beam to the eyepiece optical system.

Abstract: Columnar prisms 22 to 24, cross sections of which are parallelograms, are arranged symmetrically on both sides of a columnar prism 21 whose cross section is an isosceles right triangle. The prisms are bonded to their adjacent prisms at polarization separation films D1 to D3 which are dielectric multilayer films. A reflective films is applied on the outermost surface of the outside prism 24. The polarization separation films D1 and D3, which are located in odd-numbered order from the prism 21, transmit incident p-polarized light and reflect incident s-polarized light, the polarization separation film D2 located in even numbered order from the prism 21 transmits the incident s-polarized light and reflects the incident p-polarized light. In order to achieve uniform polarization at the emission surface of a polarization separation/conversion device 20, a 1/2 wave plate C2 is applied on to the emission surfaces of the prisms 22 and 23.

Abstract: A scanning (f.theta.) lens includes first, second, third, and fourth lenses, respectively having negative, positive, positive, and negative power in at least the main scanning directions. The lenses are arranged in order from a polygon mirror to a drawing surface. The Abbe number of the fourth lens is less than 40. In a further refinement, the Abbe number of the fourth lens subtracted from half the difference between the Abbe numbers of the second and third lenses is greater than 20. In another refinement, the scanned surface side surface of the first lens element is a cylindrical surface having negative power only in the auxiliary scanning direction, and the scanned surface side surface of one of the second or third lens elements is a toric surface having greater positive power in the auxiliary scanning direction than in the main scanning direction.

Abstract: An optical system for a beam scanning apparatus comprises a laser beam, a cylindrical first lens, a scanning mirror rotatable about an axis for deflecting and scanning the focused energy beam and a concave, toroidal mirror adapted to deflect the focused energy beam from the rotating mirror and collimate the beam. The toroidal mirror has a radius in a major axis equal to the focal length of the first lens and a radius in a minor axis equal to twice the focal length of the first lens, and is spaced from the first mirror a distance equal to the focal length of the first lens. Preferrably, the axis of rotation of the scanning mirror is non-orthogonal with respect to the direction of the beam from the first lens.

Abstract: In a method and apparatus for displaying a stereoscopic image, a plurality of 2-dimensional images having parallaxes in only horizontal directions are obtained and inputted when an object to be displayed is seen from different positions in the horizontal direction. The 2-dimensional image is divided in the vertical direction into 1-dimensional line images which are elongated in the horizontal direction. A phase distribution of a corresponding hologram segment is calculated from the pixels of the line image. The calculated phase distribution is displayed on a hologram forming surface of a phase displaying section using a display. A reproduction light is irradiated and converted into an optical wave front and is further enlarged in the vertical direction, thereby displaying a solid image. The 2-dimensional images are inputted by photographing the object by a plurality of cameras arranged in the horizontal direction.

Abstract: A scanning confocal microscope optical system overcomes the difficulties of previous devices and can be used in diagnostic applications that are inaccessible to previous devices. The optical system for forming an image of a subject illuminated by light from an illumination system includes a Nipkow disk that is perpendicular to a light propagation path and that has a surface upon which a plurality of pinholes are distributed substantially symmetrically about an axis perpendicular to the surface of the disk. The system further includes components for projecting an image of a first set of the pinholes onto a second set of the pinholes, the image being formed of light transmitted by the first set of the pinholes when the first set is illuminated by light that impinges on a first side of the disk. The system further includes a collective lens and a first objective lens for focussing light transmitted by the second set of the pinholes onto the subject and for collecting light reflected by the subject.

Abstract: The present invention relates to a positioning system for a rear view mirror. More specifically, the invention includes a first and second mirror joined together by an elongate resilient seam. Each of the mirrors is controllable by way of a positioning system. Each of the positioning systems includes a cam controlled by a cable.

Abstract: An adaptor detachably mounted on an ocular of night vision goggles for quly adjusting the objective lens focus to clearly view far and near objects. The adaptor includes a positive optical power or close-up lens mounted in a holder pivotally mounted between a stowed, inoperative position and an operative position locating the close-up lens in axial alignment with the objective lens of the ocular. The close-up lens has an effective diameter substantially smaller than the diameter of the objective lens to raise the F/number of the objective lens/close-up lens combination for increasing the depth of focus for enhanced near viewing. Auxiliary illumination is provided by a battery powered infra-red Light Emitting Diode (LED) mounted in the adaptor and energized by a switch as the lens holder moves toward its operative position.

Abstract: A heads-up display unit provided with a display device serving as display image forming means which displays a display image. A hologram serves as a reflecting means, and reflects the display light emitted from the display device, causing reflection of the display image on the interior surface of a vehicle's windshield. A display image is formed outside the windshield towards the front of the vehicle. A concave mirror having a different focal length in different directions is recorded in the hologram serving as a reflecting means so as to offset distortion of the display image caused by curvatures of the windshield. This construction makes it possible to cause the windshield to display a display image free from distortion.

Abstract: An exterior rearview mirror for a motor vehicle has a base for connecting the rearview to the vehicle. A pivot axle is positioned in the base so as to extend vertically or at an acute angle to the vertical. A housing is connected to the base so as to be pivotable about the pivot axle for allowing a forced folding of the rearview mirror in a folding direction from a rest position into a folded position. The housing has an opening for receiving an adjustable mirror pane. A lever with a first and a second end is connected with the first end to the pivot axle. The lever extends in the longitudinal direction of the vehicle or at an acute angle to this direction. The housing has a housing section facing the base. The lever penetrates the housing section and extends into the interior of the housing. A spring rests at the second end of the lever for forcing the housing against the base.

Abstract: An information carrier is in the form of a composite laminate with a first, a second and a third layer having refractive indices n3, n4, n5 respectively. The second layer forms structures by only partially covering the first layer. The third layer covers over the second layer or the first layer in direct contact therewith. The surface on the first layer has surface elements with first and second diffraction structures which produce a visually verifiable authenticity feature or which serve for reading out the information contained in the structures formed by the second layer. The refractive indices n4 and n5 are substantially real in the visible range and therefore the second and third layers are transparent. The differences .vertline.n4-n3.vertline. and .vertline.n5-n3.vertline. are greater than 0.2 over large parts of the visible range so that the first diffraction structures produce visible diffraction effects independently of the structures formed by the second layer.

Abstract: An optical device, such as a position measuring instrument, having a source of light and a diffraction element for receiving the light, creating partial light beams which interfere with one another, and producing from the interfering partial light beams a first beam of light projecting along a first direction and producing a second beam of light projecting along a second direction. The optical device further includes a first optical projecting element positioned to receive the first beam of light and producing a first focused beam of light and a second optical projecting element positioned to receive the second beam of light and producing a second focused beam of light. Furthermore, the optical device has a first photodetector to receive and detect the first focused beam of light and a second photodetector to receive and detect the second focused beam of light.

Abstract: A rear-view mirror assembly is provided for motor vehicles, particularly commercial trucks. A housing defines an interior volume and at least one mirror glass assembly is removably attached to the open front side of the housing. A non-rotatable longitudinal support rod extends completely through the interior volume of the housing in a longitudinal vertical direction. Portions of the support rod extend from the housing at the top and bottom thereof for attaching the mirror to a support structure of the motor vehicle. The housing is manually or remotely rotatable relative to the longitudinal support rod.

Abstract: The invention provides a passive hand held target for use with a scanning light beam, particularly a laser beam, in which the beam impinged upon (i.e. input to) the target is divided and the resultant beams are directed to a viewing screen witha diffusing function, where an observer can discern equality or inequalities of their images as the target is moved to center its input window with respect to the scanning beam. Adjustment of the target then provides a reference for marking of a surface adjacent the target. The beam divider may include a mask which produces a pair of symmetrical easy to compare beam shapes. An alternative beam divider is an axicon. Holograms can be used as equivalent optical devices for the lens and axicon beam dividing function and for the diffusing viewing function, as well as to direct the beams at convenient angles.

Abstract: A display method for producing a plurality of different views of an object scene simultaneously is provided. A series of two-dimensional projections of an object is produced for the plane of a display device. Wavefront interference information, independent of the two-dimensional projections is produced for an intermediate plane. The two-dimensional projections and the wavefront interference information are combined to create a diffraction grating in the display device to provide a holographic image of the object scene from a number of positions relative to the display device.

Abstract: A head-mounted image display apparatus having an exit pupil that is enlarged without causing an increase in the size of a relay optical system or a reduction in the size of a projected image. The head-mounted image display apparatus has an image display device (1) having a display surface for displaying an image, a relay optical system (2) for transmitting the image displayed on the display surface of the image display device (1) to form an image of the display surface, and an ocular optical system (4) for projecting the image transmitted by the relay optical system inside an observer's eyeball as an enlarged image. A numerical aperture (NA) enlarging element is disposed at a position conjugated with the display surface with respect to the relay optical system (2). Thus, pupil alignment is facilitated without causing an increase in the size of the relay optical system (2) or a reduction in the size of the projected image.

Abstract: Security devices which are difficult to reproduce include a grid screen metallization pattern. The grid screen metallization pattern may be laid down over a hologram or diffraction grating formed as a surface relief pattern on a substrate, to form a visually identifiable, semi-transparent security device. Additionally, the metallization pattern may include resonant structures in which information about the security device is encoded. In some embodiments of these security devices, the metallization pattern is disposed in accurate registration with the underlying hologram or diffraction grating. These security devices are made by methods which include printing an oil pattern on the substrate. Areas on which oil is deposited do not receive metal during a metallization step. Since these methods do not use caustics, metallization patterns including features which would otherwise trap and hold caustics are possible.

Abstract: A mirror having a reflection coefficient that is spatially variable in amplitude and in phase includes at least two parallel spaced reflecting plates. One of the plates is displaced parallel to itself to vary the distance between the plates. At least one of the reflecting plates can be deformed transversely to its plane.