Abstract: Disclosed is an environmental control apparatus for controlling a working environment in an exposure apparatus for effecting exposure using exposure light having a wavelength range in which oxygen absorbs the exposure light. The apparatus comprises an ozone removing filter for removing ozone in the air supplied to the exposure apparatus. By use of the environmental control apparatus of the present invention, ozone which is present in the air supplied to the exposure apparatus and absorbs the exposure light can be removed, so that a decrease in the amount of exposure light can be suppressed and hence, the amount of exposure light can be stabilized during exposure.

Abstract: An original reading lens for imaging the image information on the surface of an original on the surface of a sensor, includes an original reading lens having, in succession from the original side, a meniscus-shaped positive first lens having its convex surface facing the original side, a meniscus-shaped negative second lens having its convex surface facing the original side, a stop, a meniscus-shaped negative third lens having its convex surface facing the sensor side, and a meniscus-shaped positive fourth lens having its convex surface facing the sensor side, and the surface of a diffracting optical element disposed near the stop.

Abstract: The present invention provides a method for calculating the birefringence of an optical element and selecting the direction of minimum birefringence in the optical element. A material for manufacturing the optical element is a fluoride single crystal with a birefringence value that is reduced compared to conventional materials. The fluoride single crystal is cut from a fluoride single crystal ingot obtained by crystal growth so that the {111} crystal planes are two parallel planes, after which the optical performance is improved by subjecting this material to a heat treatment. The birefringence of the optical element is calculated by converting known piezo-optical constants in a specified three-dimensional orthogonal coordinate system for the optical material into piezo-optical constants in an arbitrary three-dimensional orthogonal coordinate system.

Abstract: A variable focal length lens barrel is constructed so that a complex lead thread and a cam groove can be provided in overlap on one barrel, and a crest of a helicoid thread meshing with the complex lead thread does not come off a root of the complex lead thread. For this construction, according to the present invention, an inner surface of a second driving barrel is formed with six streaks of complex lead threads and three streaks of cam grooves in overlap. In the complex lead threads, a root of a first lead thread having a first lead is connected via a bending portion to a root of a second lead thread having a second lead. The complex lead thread and the cam groove are disposed so at not to intersect each other at the bending portion.

Abstract: The present invention is an optical apparatus, e.g. an image display apparatus, which enables observation of a clear image at a wide field angle with substantially no reduction in the brightness of the observation image, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be fatigued. The optical apparatus has an image display device (6), and an ocular optical system (7) for leading an image of the image display device (6) to an observer's eyeball (1). The ocular optical system (7) includes, in order from the image side, a third surface (5) which forms an entrance surface, a first surface (3) which forms both a reflecting surface and an exit surface, and a second surface (4) which forms a reflecting surface. The first to third surfaces (3 to 5) are integrally formed with a medium put therebetween which has a refractive index larger than 1.

Abstract: The invention relates to a gas sensor (A) which is adapted for evaluating the contents of a gas sample enclosed in a cavity (2) or a gas cell (1). The gas sensor has the form of a block in which the wall or wall-parts of a gas cell or cavity have highly light-reflective properties, designated mirror surfaces (11A, 12A). The cavity (2) has an opening (2a) for incoming light rays which are reflected in the cavity a predetermined number of times such as to create an optical analysis path before being caused to pass through an opening (6) for outgoing light rays, such reflections being achieved with the aid of three opposing, concave light-reflecting wall-parts (11, 12, 13). A first of the light-reflecting wall-parts (11) has the shape of part of an ellipsoid. A second (12) and a third (13) of the light-reflecting wall-parts have a common shape conforming to part of an ellipsoid.

Abstract: Projection lens for use with pixelized panels are provided which consist of a first lens unit which has a negative power and a second lens unit which has a positive power. The V-values and Q-values of the lens elements of the first and second lens units are selected so that the projection lenses can simultaneously have: (1) a high level of lateral color correction, including correction of secondary lateral color; (2) low distortion; (3) a large field of view in the direction of the image (screen); (4) a telecentric entrance pupil; and (5) a relatively long back focal length.

Abstract: There are provided a circular transparent electrode provided on a first substrate at the center thereof, a plurality of annular transparent electrodes which are disposed outside the circular transparent electrode concentrically and narrowed in width and interval as they are directed outward, extension electrodes which extend crosswise outward from the center to an external terminal electrode, and an alignment layer on these electrodes. There are also provided a transparent electrode on an entire surface of a second substrate, and an alignment layer on the transparent electrode, wherein the first and second alignment layers are subjected to a parallel aligning treatment. The first substrate and the second substrate are bonded to each other while keeping a given internal by gap members disposed outside the annular transparent electrodes, and a nematic liquid crystal is sealed in a gap between the first substrate and the second substrate.

Abstract: An electrochromic medium for use in a normally operating electrochromic device comprising an anodic material and a cathodic material wherein both of the anodic and cathodic materials are electroactive and at least one of the anodic and cathodic materials is electrochromic, an additive, and means associated with the additive for maintaining a colorless or nearly colorless electrochromic medium while the electrochromic medium is in a high transmission state relative to an electrochromic medium without the additive.

Abstract: An optical lens composed of a transparent material, wherein one surface thereof on a light source side is a convex aspherical surface of rotation symmetry defined by a function relative to the radial distance from an optical axis. The aspherical surface is shaped to be a curved one without any stepped region with regard to the radial direction in the defined area, and has a portion where the derivatives of the function are discontinuous at a predetermined radial position. Although not equipped with an iris diaphragm, this optical lens is capable of eliminating an incident light beam outside the optical effective surface thereof without deteriorating the optical characteristics.

Abstract: A variable focus lens comprises first and second transparent, flexible membranes (2) which are tensioned and which define a cavity (30) in which a transparent, silicone oil (4) is sealed. Adjustment of the pressure or volume of the oil in the cavity changes the focal length of the lens. To fabricate the lens, the periphery of each membrane (2) is engaged between two rings (8, 10; 10, 12) of a set of three interengaging rings (8, 10, 12). The interengaged rings are crimped together to tension the membranes (2) and seal the cavity (30).

Abstract: An imaging system including a one-piece aluminum internal drum casting having reduced weight and increased stiffness. The internal drum is mounted to the frame structure of the imaging system using a plurality of mounts positioned in a plane substantially along the center of gravity of the internal drum. The mounts reduce the amount of sway of the internal drum within the frame structure.

Abstract: A zoom lens includes: a first lens group having positive refracting power; and a second lens group provided on an image side of the first lens group, having negative refracting power. The zoom lens has a variable power ratio of not less than 2.5 and a field angle of not less than 70° at a wide angle end, and a magnification of the zoom lens is changed by changing a distance between the first lens group and the second lens group, and further the following conditions are satisfied, 1.25≦Tw/Tt≦1.8 0.6≦fFc/fw≦0.9 where Tw represents a telephoto ratio at a wide angle end of the zoom lens, Tt represents a telephoto ratio at a telephoto end of the zoom lens, fw represents a focal length of the zoom lens at the wide angle end, and fFc represents a focal length of the first lens group.

Abstract: An optical head device capable of stably positioning an information head device even if a distance between the object point and the image point is reduced so as to miniaturize the device can be realized. The optical head device comprises a semiconductor laser emitting a light beam, a lens converging the light beam emitted from the semiconductor laser to a disk and a holding means maintaining the disk at a constant distance from the lens. The optical head device satisfies the following equations 24 and 25: L2=f×L1/(L1−f)  (equation 24) h<L2  (equation 25) wherein f denotes a focal length of the lens, L1 denotes a distance between the semiconductor laser and a first principal point located on the semiconductor laser side of the lens and h denotes a distance between a second principal point located on the disk side of the lens and the disk that is held by the holding means.

Abstract: A mechanical grating device for enhancing the reflective properties is presented. A mechanical grating has a plurality of parallel ribbon elements which are suspended above a channel. An incident light beam is modulated by the actuation of selected ribbon elements. The actuation of the ribbon elements, which changes the height of the ribbon elements relative to the substrate, is a result of an applied voltage that produces an electrostatic force. On the top surface of the ribbon elements is a coating of reflective metal upon which is an optical coating is provided. The optical coating is a stack of at least two different materials with different refractive indices. The thickness and the composition of the sequential layers in the stack are chosen to produce certain desired reflective properties. Embodiments are presented for reducing the mechanical effects of the dielectric optical coating.

Abstract: A calibration device which has at least two targets. Each target has at least one surface exhibiting areas of optical contrast, and each surface has a general plane of orientation. The targets are oriented such that a general plane of orientation of one target is inclined at an angle relative to the general plane of orientation of a surface of the second target which has areas of optical contrast.

Abstract: A diffracting beam splitter splits an optical beam. The resulting beams are swept over an object by a beam deflector. The beams are mechanically scanned transverse to the beam deflection direction. A position sensitive device receives light reflected from the incident beams and a three dimensional profile of the object is produced.

Abstract: A microscope objective that is achromatic, so that deviations in focus do not arise with visible light and ultraviolet light (particularly light in the vicinity of wavelength=266 nm), and which can satisfactorily observe a specimen. The microscope objective is made of at least three types of glass materials, of which one type is barium fluoride.

Abstract: A zoom lens system which includes a positive first lens group and a negative second lens group, in this order from the object side; wherein zooming is performed by moving the first lens group and the second lens group, and by varying the distance between the first lens group and the second lens group; wherein the zoom lens system satisfies the following condition: −7.0<fT/f2G<−5.1 . . .   (1) wherein: fT designates the focal length of the entire lens system at the long focal-length extremity and f2G designates the focal length of the second lens group.

Abstract: A laser irradiation device generates a linear laser beam extending in one direction, which is irradiated toward the substrate 20 to be processed. The length Lh of the emitted linear laser beam in the major axis direction is adjusted in accordance with a size of the substrate 20 to be processed or the area to be processed within the substrate 20. The adjustment of the length Lh is performed by altering the distance X between a pair of cylindrical lenses 43 and 5 of the optical system for adjusting the generated laser beam in the direction corresponding to the length Lh direction of the linear laser beam, in accordance with the required length Lh. The alteration of the distance X is performed by altering the position of one of the cylindrical lenses 43 and 5 within the optical path in forward and backward direction. The lens is, for example, one having more flexibility of layout in the optical system than the other.