Abstract: An objective lens system for use in a device for optically reading digital data on an optical disk is constituted by a single objective lens without use of a collimator lens element. A light source side aspherical surface of the objective lens element has a positive refractive power and a disk side surface thereof has a positive refractive power, too. The objective lens system is used with the projecting magnification .beta. which falls within the range -1/2<.beta.<-1/8.The objective lens system fulfills the following condition:0.9.ltoreq.(N.sub.1 -1)r.sub.1 /f.ltoreq.3.91.4.ltoreq.d.sub.1 r.sub.1 /f.sup.2 .ltoreq.4.01.4.ltoreq.d.sub.1.sup.2 /f.sup.2 (N.sub.1 -1).ltoreq.4.0wherein,f represents the focal length of the single lens element;r.sub.1 represents the paraxial radius of curvature of the light source side surface of the single lens component;N.sub.1 represents the refractive index of the single lens element; andd.sub.1 represents the axial thickness of the single lens element.

Abstract: A photographic control device for scanner and exposure control system calibration in a photographic printer includes a carrier disk to present an open scan aperture in the scan gate for normal printer operation, and selectively a plurality of control patches in the scan gate for calibration of the scanner at startup. The disk is driven by a stepping motor and timing belt, the disk position being controlled by a position sensor tied in with the drive motor. The disk is mounted by three rotatable bearings spaced around its periphery.

Abstract: A telephoto lens system is provided having a first lens group of a positive refractive power, a second lens group of a negative refractive power with a variable air space, and a third lens group of a positive refractive power with a variable air space. All of the lens groups are shiftable during a focusing operation with the second lens group air space increasing and the third lens group air space decreasing when focusing is effected from infinity to a short distance.

Abstract: A dynamically resonant system including a linearly movable element having a neutral position and a range of excursion centered on the neutral position, a spring-like element for urging the movable element toward the neutral position, the resonant system having a natural resonant frequency dependent on the spring characteristics of the spring-like element, the spring-like element having a temperature sensitive member that causes the spring characteristics to vary with temperature of the member.

Abstract: Retroreflective construction comprising a monolayer of microspheres with associated dielectric mirrors which are hemispherically surrounded by tangentially-oriented, preferably contour-conforming, reflective pigment nacreous flakes. The dielectric mirrors and reflective nacreous pigment flakes cooperate additively substantially without interfering with each other to provide a high brightness retroreflective sheet. The novel sheets retain much of their reflectivity after several launderings or drycleanings and, in some embodiments, can be made very flexible, making them well-suited for use as reflective fabrics.

Abstract: Progressive multifocal ophthalmic lenses are provided having a far vision viewing zone, a near vision viewing zone and an intermediate vision viewing zone therebetween. A central basic curve extends essentially vertically through the far, intermediate and near vision viewing zones. The sizes of the zones and configuration of the zones are set by predetermined conditions and equations. The construction provides improved lenses for use especially where intermediate and near vision viewing is required.

Abstract: An inspection device which can be used to enable a visitor on the outer side of a door (12) to be viewed from the inner side has a tube (1) extending through the door. At the end of the tube (1) on the inner side of the door there is a screen (36) and a lens system (5, 23) is provided to produce a viewable image of the visitor on the screen (36). The positioning of the screen (36) relative to the tube (1) can be adjusted e.g. with a rack and pinion mechanism (39, 40, 41) operated by a knob (42), and an image inverter such as a prism (43) is provided to give an upright image on the screen (36).

Abstract: A display apparatus for use with headgear, includes in combination visor means adapted to attach to the headgear and having a visor viewing area segment positioned in the line-of-sight of a wearer of the headgear. Optical display generating means are adapted to be attached to the headgear. Parabolic mirror means are interposed in the optical path from the optical display generating means to the visor viewing area segment. Fold mirror means, including at least one fold mirror positioned to receive the image from the parabolic mirror means for directing the image to the visor viewing area segment, is provided, whereby the size and curvature of the visor can be minimized without affecting transmission of the image.

Abstract: A reflector assembly for use on the road by a vehicle driver near his or her stopped vehicle comprising three reflective arms crossing and pivoted to each other at the middle, and bases pivotally connected to two of the arms at one end of each. When the assembly is erected, the crossing arms are spread apart angularly and the bases hold their respective arms extending up diagonally. Wing nuts at the pivots releasably clamp the arms and bases in this position. After loosening the wing nuts, the user can collapse the reflector assembly to a folded position in which the arms are aligned one behind the other.

Abstract: An improvement of an inverted telephoto type wide angle lens system having, from the object to the image side a front lens group of a negative refractive power which is left stationary upon focusing, and a rear lens group of a positive refractive power which is shiftable for the purpose of focusing is disclosed. The improvement is characterized in that the lens system fulfills the following condition:2.65<.vertline.f.sub.F .vertline./f.sub.R <7.5wherein f.sub.F represents the focal length of the front lens group, and f.sub.F represents the focal length of the rear lens group.

Abstract: The described three-dimensional image viewing apparatus offers the possibility to perceive spatial objects which are reproduced through a pair of stereoscopic images as three-dimensional images, without the necessity to provide auxiliary optical means in the vicinity of the eye during viewing. For this purpose, an optical image forming system according to the basic principle of a microscope is provided between the two images (1a, 1b) of the pair of stereoscopic images and the two exit pupils (11a, 11b) for the eyes of the viewer, consisting of two fields lenses (2a, 2b) located immediately in front of the light-emitting images, two objectives (5a, 5b) a positive optical system on the eye side (9, 10) and of mirrors (3a, 3b, 4a, 4b, 8) for folding the ray paths located between the images (1a, 1b) and the positive optical system (9, 10). With such a viewing apparatus, unusually large exit pupils (11a, 11b) can be achieved, so that the viewer can move around considerably, without loosing contact with the image.

Abstract: An optical beam scanning system which is employed as an optical scanning means for writing or reading information with a laser beam includes a lens disposed in front of a light deflector with respect to the path of travel of the laser beam. The lens has an optical axis normal to the axis of rotation or angular movement of the light deflector. The lens is arranged such that the laser beam will be applied thereto parallel to the optial axis thereof and at a suitable lens height thereon. The laser beam that has reached the light deflector through the lens is reflected as a scanning light beam as the light deflector rotates or is angularly moved.

Abstract: A scanning optical system includes a light source, first and second focusing optical systems, and a light deflector. The second focusing optical system serves to focus a light beam deflected by the light deflector onto a medium to be scanned. The second focusing optical system comprises a single anamorphic lens, a single spherical lens having positive refracting power, and a single lens having a toric surface, successively arranged in order from the light deflector toward the medium.

Abstract: A visor for mounting on a helmet adapted to be worn by an individual, includes a substantially transparent visor having an inner concave surface, and, with reference to an orthogonal, right-handed xyz Cartesian coordinate system of spatial reference having its origin located on the inner concave surface and its z-axis parallel to the line of sight of the individual wearing the helmet, the inner concave surface being defined by a cross-section of the visor in the x-axis of reference, which is symmetrical about both the origin and the y-z plane of reference, having one-half of the cross-section of the visor in the x-axis of reference being a first circular segment containing the origin at one end and connected to its opposite end to one end of a first paraboloid segment which is connected at its opposite end to one end of an elliptic segment whose opposite end forms a side boundary of the visor, and by a cross-section of the visor in the y-axis of reference having a second circular segment, one end of which for

Abstract: A projection lens for a cathode ray tube consisting from the image end of a first lens unit including an element of overall meniscus shape and of positive power at the optical axis, the first lens unit has an object side surface convex to the aperture stop, a second lens unit which consists of a biconvex element and supplies the majority of the positive optical power of the lens, the biconvex element beng of glass and having spheric surfaces, a third lens unit adjacent the cathode ray tube having a strongly concave image side surface and serving as a field flattener, the axial spacing between the first lens unit and said second lens unit also contributing to correction of field curvature, and a corrector lens unit having image side surface convex toward the aperture stop. The surfaces of the first lens unit and the corrector lens unit which are both convex to the aperture stop contribute to correction of sagittal oblique spherical aberration.

Abstract: An optical system for projection television apparatus has three projection cathode-ray tubes for producing red, green and blue monochrome images, respectively. Three projection lens systems are disposed in front of faceplates of the projection cathode-ray tubes, respectively for producing the red, green and blue screen, each of the projection lens systems having a rear lens element having a negative power and disposed in front of a corresponding one of the cathode-ray tubes and a front group having a positive power and disposed in front of the rear lens element, the rear lens element having a concave surface facing the front group. In each of at least two of the three projection lens systems, the optical axis of the front group is tilted to that of the rear lens element, and the optical axis of the rear lens element is in parallel with or aligned with that of the corresponding one of the projection cathode-ray tubes.

Abstract: A micromanipulator for an inverted design microscope comprises a needle carrier disposed between a stage and a condenser lens of the microscope for carrying a glass needle in the direction of an optical axis. It also includes a centering mechanism which causes a displacement of the glass needle in a plane orthogonal to the optical axis, a hydraulic drive mechanism disposed on the upper surface of the stage for supporting the needle carrier to cause a vertical movement of the glass needle carried by the carrier along the optical axis, and a hydraulic operator connected to the hydraulic drive mechanism through a hydraulic transmission tube.

Abstract: A scanning device is described which comprises a rotationally symmetrical rotating reflecting facet disc (3) in which a scanning beam (2, 2') is focussed on a face (5, 6) of the facet elements (4). The sensitivity of the device to surface defects or dust particles on the faces of the facet elements can be reduced by means of a first astigmatic element (20) which widens the beam (2') issuing from the detector (10) at the location of the facet disc in a direction transverse to the scanning direction (18), while a second astigmatic element (21) cancels the astigmatism of the first element.

Abstract: A microscope wherein, in order that the observing position may be variable over a wide range of a sample to be observed without requiring a large objective, the objective optical system is so formed as to be movable in parallel with the sample surface and the light path length between the objective optical system and eyepiece optical system is made variable by moving the objective optical system.

Abstract: A device for exchanging the display information to be given to an electrostatic display apparatus constituted with many electrostatic display units arranged to form a matrix. The present device comprises a RAM and a backup battery, both mounted on a base plate detachable from the main circuit of the device. This device makes it possible to partially change the display information data without interrupting the display in proceeding.