Abstract: The present invention provides a zoom lens system comprising, in order from the object side, a first lens unit G1 having a positive refracting power; a second lens unit G2 including a front subunit having at least one negative lens and a rear subunit having at least one negative lens and at least two positive lenses located more closely to the image side than said negative lens and having a positive refracting power as a whole, said front and rear subunits having a positive composite power; and a third lens unit G3 having a negative refracting power; said first, second and third lens units including gaps between them, which are variable for zooming from the wide to tele position.

Abstract: A lamp projecting a high-intensity optical beam of spectral radiation, with an IR-extracting (cooling) array including an IR-dissipating "black-box" arranged to receive IR and convert it to box-heat, plus an IR-diverting "hot-mirror" interposed along the beam to divert (only) the IR to this "black-box".

Abstract: A reflection type hologram scale, in which a hologram dry plate is bonded to a protecting base member in which a hologram grating formed on a scale base member forming the hologram dry plate and a reflecting film formed on a base member forming the protecting base member are opposed to each other. Therefore, the hologram grating and the reflecting film are both protected by the scale base member and the base member so that the hologram grating and the reflecting film are prevented from being exposed to the air, thereby preventing the hologram grating and the reflecting film from being smudged by fingermarks, dust and also from being scratched.

Abstract: An ophthalmic measurement method is provided to accurately measure the composition and concentration of protein components in the aqueous humor of the anterior chamber, even when the anterior chamber also contains blood cells. Prior to measuring the autocorrelation function of the intensity of the scattered light from protein components, the anterior chamber is scanned by a laser beam controlled by a control section and the scattered light intensity thereof is measured to determine the location of blood cells by differentiating between light scattered by protein components and light scattered by blood cells. Via an optical scanner, the laser beam is then projected at a position in the anterior chamber from which there has been scattered light from blood cells has not been detected, and the autocorrelation function is measured while the laser beam is stationary.

Abstract: A photosensitive element 46 absorbs at least a portion of an incident write beam 40, causing a spatially varying electric field to be applied across a layer of a ferroelectric liquid crystal (FLC) 48, thereby forming a pattern of local polarizations corresponding to the spatially varying electric field. In one embodiment, a signal beam is modulated with a phase variation characteristic of a particular aberrator. The signal beam is then combined with a substantially plane wave reference beam to form interference fringes. These interference fringes are directed as a write beam onto photosensitive layer 46, forming a hologram in FLC layer 48 which can be read optically. An incident beam of light can be diffracted by a hologram formed in the FLC layer, thereby modulating the incident beam of light with the phase variations comprising the hologram.

Abstract: A polarization diffraction element comprising two diffraction gratings formed on both faces of a substrate respectively. Both the diffraction gratings have grating lines which are arranged at the same grating pitch, and whose directions mutually form a predetermined minute angle. The grating lines may also be arranged parallel to each other. In this case, the relationship between grating pitches D.sub.1, D.sub.2 of the respective diffraction gratings and the wavelength .lambda. of an incident light is expressed as:0<.vertline..lambda.(1/D.sub.1 -1/D.sub.2)(1-(.lambda./2D.sub.1).sup.2).sup.-(1/2) .vertline..ltoreq.0.35; or0<.vertline..lambda.(1/D.sub.1 -1/D.sub.2)(1-(.lambda./D.sub.1 -.lambda./2D.sub.2).sup.2).sup.-(1/2) .vertline..ltoreq.0.35In a polarization detector employing this polarization diffraction element, a single converging lens of a small effective diameter separates one polarization from another polarization and converges them separately on different photodetectors.

Abstract: A zoom lens for the projector includes, in order from a screen, a first lens unit of positive refractive power, a second lens unit of negative refractive power and a third lens unit of positive refractive power, zooming from the wide-angle end to the telephoto end being performed by axially moving the second and third lens units in such a manner that the air separation between the first and second lens unit increases, while the air separation between the second and third lens units decreases, and the following conditions being satisfied:1<-.beta.3w<1.50.8<-.beta.2w<1.20.25<-f2/fw<0.450.7<e2w/fw<1.1where .beta.2w and .beta.3w are the image magnifications for an infinitely distant object of the second and third lens units in the wide-angle end, respectively, f2 is the focal length of the second lens unit, e2w is the interval between the principal points of the second and third lens units, and fw is the shortest focal length of the entire lens system.

Abstract: The invention provides an ultra-wide field eyepiece for microscopes, in which such off-axial aberrations as the curvature of field, astigmatism and coma are well-enough corrected at a field number as large, as 26.5, and in which the flatness of the image surface is degraded even when the entrance pupil position varies, and which comprises, in order from the entrance side, a first lens unit G1 of negative refracting power, a second lens unit G2 of positive refracting power, a third lens unit G3 of negative refracting power, a fourth lens unit G4 of positive refracting power and a fifth lens unit G5 of positive refracting power with the surface having a stronger curvature facing the entrance side, said third to fifth lens units being located in the rear of an intermediate image plane.

Abstract: A holographic laser beam scanning apparatus capable of removing astigmatism created by a hologram disc of the apparatus due to discordance of wave fronts of the laser beams, thereby allowing precise scanning to be effected. The apparatus includes a focusing lens for focusing a laser beam generated by a laser generator, and a hologram for converting the focused beam into a parallel beam, both the lens and hologram being disposed between the laser generator for generating the laser beam and the hologram disc for irradiating the parallel beam as a diffracted beam.

Abstract: A holographic recording of the interference between an object laser beam and a reference laser beam is used to combine the amplitudes of multiple input laser beams which are conjugates of the reference beam, into a single output laser beam which is a conjugate of the object beam. An optical device in the form of a trapezoidal prism has an entrance top face with a diffusion surface, and an exit base face with a holographic recording made on a light sensitive recording medium of an interference pattern of an object beam incident on the diffusion surface and scattered over the recording medium, in interference with a reference beam simultaneously incident to a side of the prism onto the same medium.

Abstract: Reflective, metalized plastic films for use in lighting fixture reflectors have improved performance when the plastic film upon which the metalization layer is deposited contains ultraviolet absorber.

Abstract: In a fly-eye lens device according to the present invention, a fly-eye lens supported by supporting means is formed by two-dimensionally arranging plural types of fly-eye constituent lenses of unequal size. In the arrangement, the plural types of the fly-eye constituent lenses are disposed in order of ascending size from the center of the fly-eye lens toward the periphery thereof. A lighting system according to the present invention is equipped with the fly-eye constituent lenses. In the lighting system, light emanating from a light source passes through first optical means and impinges on the fly-eye constituent lenses. The light, after passing through a stop, is directed through second optical means to an object to be illuminated. The present invention can ensure the predetermined number of fly-eye constituent lenses which contribute to uniformity of illumination, and achieve uniform illumination at low cost.

Abstract: An automatically controlled rear view mirror for a truck tractor-trailer rig is disclosed which utilizes an stranded metal cable running from an encoder box, mounted on the back center of a tractor to the front center of a trailer; whereby as the trailer turns, the angle between the tractor and trailer changes so as to change the length of the stranded metal cable; thereby triggering the encoder box to send digital signals to a control panel which controls the stepper motor located on the mirror assembly, thereby turning the mirror in response to the tractor being turned at an angle relative to the trailer.

Abstract: The improved reading zoom lens system includes, in order from the object side, a front group that has a positive power and that is of a four-unit-six-element composition and a rear group that has a positive power and that is composed of two elements, which lens system is capable of zooming by changing the distance between the front and rear groups and satisfies the following conditions (a) to (c):(a) 0.90<fL/fF<1.10(b) 0.09<fF/fR<0.35(c) 3.0<(dL-dS)/(fL-fS)<9.5where fL: the focal length of the overall system at the highest magnification;fS: the focal length of the overall system at the lowest magnification;fF: the focal length of the front group;fR: the focal length of the rear group;dL: the variable distance at the highest magnification; anddS: the variable distance at the lowest magnification.

Abstract: An optical interconnect network has four stages (S.sub.4 to S.sub.7) each formed from two-dimensional perfect shuffle interconnect stage (6) and a two-dimensional array of processing modules (8) each of which has a two-dimensional array of inputs and outputs. The use of two-dimensional modules provides an increase in optical channels which can be processed compared to the equivalent one-dimensional modules. The modules can perform switching functions.

Abstract: A projection-type display device having a single light source which produces light. A first dichroic mirror group receives the light and separates it into colored light. A transmissive light valve system modulates the colored light and a second dichroic mirror group synthesizes the modulated colored light. A projection system projects the synthesized colored light onto a screen.

Abstract: A system for collecting solar energy includes a space station which receives and concentrates solar light and produces a plurality of collimated beams each diverging toward a common axis and toward a target area on the surface of the earth. On reaching the target area on the earth, each of the collimated beams is superimposed on the other.

Abstract: An electrochromic window/glazing assembly disclosed which reduces the transmission of near-infrared and ultraviolet radiation while protecting against risk of laceration or chemical contact if broken/damaged, against ultraviolet (UV) radiation degradation, and against fogging or misting in high humidity conditions. The window assembly may include a pair of glass or other elements confining an electrochromic medium therebetween for varying the light transmittance through the assembly. Transmission of near-infrared radiation is reduced by a reflector incorporating at least one semitransparent, elemental, thin metal film. Preferably, the thin metal film has a physical thickness of between about 80 angstroms to about 300 angstroms and of sheet electrical resistance of no greater than about 8 ohms/square, and is sandwiched between optically transparent thin metal compound films to form a thin film stack.

Abstract: An apparatus for enhancing signal to noise ratio in the detection of electromagnetic radiation traversing a capillary tube includes a ball lens and a holding element for holding the ball lens and the capillary tube, the holding element having an aperture so that the aperature and the lens together define an optic axis. The holding element is configured to hold the capillary tube such that the center of the capillary tube traverses the optic axis. The lens has a focal length and is held at such a position relative to that focal length by the holding element such that electromagnetic radiation incident on the aperature is focussed to pass radially through the capillary tube. Thus, the effective path length is 100% of the inside diameter of the capillary tube.

Abstract: A zoom lens comprises sequentially from a side of an object: a fixed first lens group constituted by a convex lens, a double convex lens and a meniscus convex lens; a movable second lens group constituted by a meniscus convex lens, a double concave lens and a convex lens; a fixed third lens group constituted by a single lens having at least one aspherical surface; and a movable fourth lens group constituted by a concave lens and two convex lenses at least one of which has at least one aspherical surface.