Abstract: A microscope has a plural number of objective lenses switchable from one to another, a memory circuit for storing parfocality data for the individual objective lenses, and a correcting device for correcting imaging conditions on the basis of the parfocality data for an objective lens currently used and another objective lens to be selected for microscopy. The microscope is capable of always providing favorably focused condition even when the objective lenses are switched from one to another for changing observation magnification levels.

Abstract: An atomic force microscope comprises a probe having a sharply-pointed tip end. The probe is supported on the free end portion of a cantilever and is close to the surface of a specimen. When an interatomic force is produced, the cantilever is deformed, and the probe is displaced. The displacement of the probe is detected by an optical system. A light beam emitted from a light source is collimated by a lens, and reflected by a polarized beam-splitter, and also by a half-mirror. Then, the light beam passes through a quarter wavelength plate and an objective lens, such that the light is converged on the cantilever. The reflected light beam from the cantilever returns along the same optical path and passes through the splitter. The light beam is divided into two light beams at the splitter. These two light beams are reflected by respective prisms and are then incident on respective photodetectors. These photodetectors detect the displacement of the probe.

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 high reflection optical filter is described which comprises a film of a dielectric, inorganic or organic or other suitable material deposited on a suitable optically transparent substrate, the film having between a surface thereof exposed to incident radiation and an interface with the substrate a sinusoidal refractive index profile with selected number of periods and selected phase at the exposed surface in single band configurations, and superimposed multiple sinusoidal refractive index profiles with selected phase alignment of the superimposed profiles at the exposed surface in multi-band configurations.

Abstract: A spectacle frame includes a nose bar, a pair of eyewires each having one side connected to the ends of the nose bar and end pieces on their other side and a pair of temples pivotally connected to the end pieces of the eyewires. The nose bar and/or the pair of temples include at least three links having interengaged end portions. These links are fixedly connected, although some limited articulation may be provided. The spectacle frame desirably includes a unique hinge assembly for the temples and may also include inserts bonded to the eyewires to permit mechanical engagement with the nose bar. The spectacle frame may also include a brow bar which is threadably captured in bosses on the eyewires.

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: A visor apparatus for attachment to a pair of eyeglasses; the apparatus has two main parts, including a clip means which attaches to a pair of eyeglasses and a visor portion which is pivotally attached to the clip means. Preferably the visor portion and the clip means are manufactured from light weight and durable plastic. When the visor apparatus is attached to a pair of eyeglasses the visor portion may be locked into a functional position or a position which is substantially perpendicular to the wearer's forehead and an inoperative position or a position which is substantially parallel to the wearer's forehead.

Abstract: In an ophthalmologic apparatus comprises an illumination optical system for directing illumination light onto a prescribed point of an eye under examination, and an observation optical system for observing an image of the prescribed point of the eye under examination formed through an object lens. The object lens is movably supported along its optical axis between a first position at which the image point falls at its object point and a second position at which the prescribed point of the eye under examination falls at its image point. As a result, there is a change in the conjugate relationship so that a sharply focused image can be observed when the object lens is at either position thereby making it possible to observe sharply focused images of different magnifications simply by moving the object lens.

Abstract: A high efficiency integrating sphere that can be used in a large variety of scientific instruments. The sphere having an efficiency gain obtained by using a superconducting material, acting as a perfect reflector, on the inside hollow surface of the sphere. The sphere is operated with a delay between the incident and sensed light, heretofore not possible, and yielding substantial improvement in the signal-to noise ratio of the integrating sphere.

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 real image type variable magnification viewfinder optical system comprising, in order from the object side, an objective lens system having positive refractive power and an eyepiece lens system having positive refractive power. The objective lens system comprises, in order from the object side, a first lens unit having negative refractive power, a second lens unit having positive refractive power, a third lens unit having positive refractive power and a fourth lens unit having positive refractive power. The second lens unit and the third lens unit are moved, with the first lens unit kept fixed, for performing variation of magnification and adjustment of diopter. This viewfinder optical system can have a high magnification and a large field angle of emergence at a low magnification position thereof, a variable magnification ratio of 2 or higher and favorably corrected aberrations, and be manufactured at a low cost.

Abstract: An air spaced reverse telephoto objective lens for use in a laser chemical vapor deposition system or the like having a quartz plate window. The objective lens includes a negative component having a first air-spaced doublet wherein each doublet element is made of crown glass and a negative meniscus crown glass element spaced from said first air-spaced doublet. The objective lens further includes an aperture stop, a positive component including second and third doublet components for effecting color correction, and a pair of bi-convex elements for effecting spherical aberration correction. The objective lens provides a common focal plane for both illuminating light and laser light passing through the objective lens and the quartz plate window.

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: This invention relates to a microscope stage assembly for use in combination with magnification apparatus. The stage assembly includes a support assembly, temperature control assembly and fluid control assembly. The stage assembly provides for continuous visual observation of an object being magnified while at the same time controlling the thermal and fluid environment of the object. Physical and chemical changes to an object can be viewed continuously.

Abstract: A broadband diffractive lens or imaging element produces a sharp focus and/or a high resolution image with broad bandwidth illuminating radiation. The diffractive lens is sectored or segmented into regions, each of which focuses or images a distinct narrowband of radiation but all of which have a common focal length. Alternatively, a serial stack of minus filters, each with a diffraction pattern which focuses or images a distinct narrowband of radiation but all of which have a common focal length, is used. The two approaches can be combined. Multifocal broadband diffractive elements can also be formed. Thin film embodiments are described.

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 laser beams which are conjugates of the reference beam into a single laser beam which is conjugate of the object beam. An optical device in the form of a prism has an entrance face with a diffusion surface, and an exit face with a light sensitive recording medium. An object beam incident on the diffusion surface is scattered over the recording medium, in interference with a reference beam simultaneously incident at an angle .theta. onto the same medium. Multiple beams, conjugate to the reference beam, incident at angles .theta..+-.4.degree. on the hologram thus created on the recording medium are diffracted by the hologram and caused to combine at the diffusion surface to form a signal output beam, conjugate to the original object beam and having an amplitude which is proportional to the sum of the separate amplitudes of the combined beams.

Abstract: A lens for an underwater camera is comprised of a first lens unit having no refractive power or having weak refractive power, a second lens unit comprising a forward unit having negative refractive power and a rearward unit having positive refractive power, and having weak refractive power, a third lens unit having positive refractive power, and a fourth lens unit having negative refractive power, the first lens unit being fixed relative to the image plane, the second lens unit and the third lens unit being axially moved together on the optical axis toward the object side relative to the fourth lens unit.

Abstract: A cam ring of a substantially annular shape for a lens barrel including at least one cam groove in which a guide pin provided on a lens group which is movable in an optical axis direction is placed and a gear which is provided on an outer periphery of the cam ring to rotate the cam ring, wherein at least a part of the cam groove is in the form of an inner cam groove with a closed bottom located on the outer surface thereof. The gear is integrally formed on the outer surface of the cam ring. The invention is also directed to a method for manufacturing such a cam ring.

Abstract: A stereo eye fundus camera has an illuminating optical system for illuminating the fundus of an eye to be tested through an objective lens, and a taking optical system for taking the eye fundus through the objective lens. The feature of the stereo eye fundus camera is that it has a mark projecting optical system for projecting at least three marks on the eye fundus such that the three marks are not on the same straight line.

Abstract: A projection lens system for a projection type television having a cathode-ray tube with a panel having a fluorescent inner surface for projecting an image onto a screen. The projection lens system includes a plurality of lens groups, the lens group positioned at a side nearest to the cathode-ray tube including, in successive order from a side toward the screen, a lens having a concave surface on the screenn side a transparent medium, and the cathode-ray tube panel having a fluorescent inner surface, the lens group attenuating at least a part of a wavelength region of the light emitted on the fluorescent surface so as to improve contrast while reducing observance of a ghost image due to multiple reflection without substantial impairment in at least one of brightness and luminance. More particularly, the attenuation is provided by the concave lens having at least one surface dyed in a predetermined color.