Abstract: The invention provides a zoom lens system having a zoom ratio as high as about 8 to 12 but is of wide field angle and small size, and is suitable for use on a video camera, said zoom lens system comprising a positive first lens unit L1 which is movable in an orbit, said orbit displaceable toward objet side at the telephoto end position rather than at the wide-angle end position, a negative second lens unit L2 which is movable in an orbit, said orbit displaceable toward the image side at the telephoto end position rather than at the wide-angle end position, a positive third lens unit L3 which is movable in an orbit, said orbit displaceable toward the object side at the telephoto end position rather than at the wide-angle end, and a positive or negative fourth lens unit L4 which is movable, and conforming to2.6<f.sub.l /(f.sub.W .multidot.f.sub.T).sup.1/2 <6 (1)-1.2<.beta..sub.2T <-0.7 (2)3.2<.beta..sub.2T /.beta..sub.2W <8 (3)where:f.sub.l is the focal length of the first lens unit,f.sub.

Abstract: A circumferentially cemented lens unit includes first and second lenses opposed to each other with a space therebetween on an optical axis thereof. The first lens has a concave surface, part of the second lens is a contact portion disposed radially inward from the periphery of the second lens and is in contact with a peripheral portion of the concave surface of the first lens. The first and second lenses are cemented to each other at a portion radially outward from the contact portion.

Abstract: An achromatic lens system includes in order, from the object side, a front lens group, a chromatic aberration correcting lens group, and a rear lens group. Aberrations, including spherical aberration, coma, astigmatism, curvature of image, as well as axial chromatic aberration of wavelengths from green to red, are substantially corrected by the front lens group and the rear lens group. The axial chromatic aberration of the wavelength blue, caused by the front lens group and the rear lens group, is corrected by the chromatic aberration correcting lens group.

Abstract: The light pulse generator includes a source for generating a light beam, an electroabsorbent modulator for modulating the light beam into light pulses, and means for applying voltage control to the modulator. The electroabsorbent modulator includes at least two doped layers and between them at least one intermediate layer that is made of a material that is not intentionally doped, and that has an electroabsorbent material included therein. The absorbent or transparent state of the intermediate layer is controlled by a voltage applied between two of the doped layers that have doping of the same sign, the transmissivity of the modulator as a function of the voltage controlling it being at a maximum in the vicinity of zero volts and being symmetrical thereabout.

Abstract: A fast lens system is provided which includes a front lens group having a negative power, a diaphragm, and a rear lens group having a positive power, arranged in this order from a side of an object of the lens system. The lens system satisfies the following conditions:-0.5<f/f,<-0.2; (1)1.0<.SIGMA.d.sub.F+S /f<3.0; (2)ana1.5<.SIGMA.d.sub.R /f<3.0, (3)wherein f represents a focal length of the entire lens system, f.sub.F represents a focal length of the front lens group, .SIGMA.d.sub.F+S represents a sum of the thickness of the front lens group and the distance between the front lens group and the rear lens group, and .SIGMA.d.sub.R represents a thickness of the rear lens group.

Abstract: A zoom lens system includes a first lens group having a positive refracting power, a second lens group having a negative refracting power, a third lens group having a positive refracting power and a fourth lens group having a positive refracting power. These lens groups are arranged in this order as viewed from an object. During zooming operation from the wide angle end to the telephoto end of the zoom lens system, the air space between the first and second lens groups increases and the air space between the third and fourth lens groups decreases. A focal length equal to the diagonal line of the effective image plane of the zoom lens system is included in the zooming range of the zoom lens system. The zoom lens system is formed so as to satisfy various conditions for making the zoom lens system small and giving a high zoom ratio.

Abstract: An objective lens system is provided and includes a spherical sapphire lens element, an aspheric first polymeric material lens element, and an aspheric second polymeric material lens element, all of which are axially aligned. The sapphire lens element is coupled to the first polymeric material lens element to form a meniscus shaped air lens element. When inserted as a component of an endoscope, the planar surface of the sapphire lens forms a robust outer distal window at the distal end of the endoscope and the flat surface of the second polymeric material lens element is attached to the relay lens system of the endoscope. The initial image of the observed area formed at the proximal end of the objective lens system is "buried" in a higher index medium than air thus allowing for easier coupling to a relay lens system leading to lower overall f/numbers.

Abstract: A projection lens apparatus has, in order from the side of a first conjugate point of a longer distance to the side of a second conjugate point of a shorter distance, a first lens group having a negative refracting power, a second lens group having a positive refracting power, and a third lens group having a positive refracting power. A focus change from a position of a short focus end to a long focus end is made by monotonously moving the first and second lens groups toward the first conjugate point.

Abstract: An eyepiece which has a simple lens group construction of a relatively small number of lenses and which is reduced in aberration and increased in field angle. The eyepiece includes, as arranged in the order from an eyepoint side, a first lens group of a positive refractive power composed of a cemented lens of a negative lens and a positive lens, and a second lens group of a positive refractive power composed of a single positive lens. With the positive lens of the second lens group, at least one of the lens surfaces is an aspherical surface. With f representing the focal length of the eyepiece, f.sub.1 the focal length of the first lens group, and D the spacing between the first and second lens groups, the eyepiece satisfies the following conditions.1.05 f.sub.1 /f<2.5D/f<0.

Abstract: A two-group zoom lens is provided which has a first lens group of negative power and a second lens group of positive power, located in this order from an object to be photographed. The first and second lens groups are moved relative to one another to provide various degrees of magnification. The first lens group includes a first lens of negative power, a second lens of negative power, and a third lens of positive power. The second lens group includes a fourth lens of positive power, a fifth lens of positive power, a sixth lens of negative power, and a seventh lens of positive power. The fifth lens is cemented to the sixth lens. The fifth and sixth lenses satisfy the following conditions: (a) 0.1<n.sub.N -n.sub.P <0.4; (b) -1.3<r.sub.c /f.sub.2 <-0.5; and (c) 0.6<d.sub.1-2 /f.sub.w <1.2; wherein, n.sub.P represents a refractive index of the fifth lens, n.sub.N represents a refractive index of the sixth lens, r.sub.

Abstract: A projection optical system for a liquid crystal projector having a plurality of lenses and projecting an image from liquid crystal display devices onto a screen including a front lens portion having a meniscus lens, a first concave lens, a convex lens and a second concave lens sequentially arranged from the furthermost of an image plane. A rear lens portion is also provided having two plano-convex lenses positioned between the front lens portion and image plane (display screen), with the flat surfaces thereof facing the image plane. The projection optical system for a liquid crystal projector having a compact size and capable of projecting focused images on the screen by adjusting the distance between the front and rear lens portions.

Abstract: A catadioptric optical reduction system for use in the photolithographic manufacture of semiconductors having a concave mirror operating near unit magnification, or close to a concentric condition. A lens group before the mirror provides only enough power to image the entrance pupil at infinity to the aperture stop at or near the concave mirror. A lens group after the mirror provides a larger proportion of reduction from object to image size, as well as projecting the aperture stop to an infinite exit pupil. An aspheric concave mirror is used to further reduce high order aberrations. The catadioptric optical reduction system provides a relatively high numerical aperture of 0.7 capable of patterning features smaller than 0.35 microns over a 26.times.5 millimeter field. The optical reduction system is thereby well adapted to a step and scan microlithographic exposure tool as used in semiconductor manufacturing.

Abstract: A driving device for a zoom lens barrel in a camera which includes a movable cylinder linearly guided in the optical axis direction, a linear groove formed on the movable cylinder, and a rotation cylinder engaging the movable cylinder. The driving device further includes a guide member which is supported on the rotation cylinder, which rotates in relation to the rotation cylinder, and which moves in the optical axis direction together with the rotation cylinder. An engaging member is formed on the guide member and engages the linear groove, a pinion is rotatably supported on the movable cylinder, and a shaft is driven to rotate by the pinion. One end of the shaft is supported on the movable cylinder and the other end of the shaft is supported on the guide member. At least one of the shaft ends is supported to be slidable in a direction parallel to the optical axis, and a second pinon for transmitting driving force to the rotation cylinder.

Abstract: A raster output scanning system is disclosed which utilizes a single light source, an electro-optical device and a beam-splitter to generate two partially overlapping light beams in order to scan one scan line in which the width of the scan line can be adjusted electronically. The two partially overlapping light beams in effect generate a resulting light beam. By changing the polarization factor of the electro-optical device, the intensities of the two light beams can be modified which in turn will change the width of the resulting light beam and as a result the spot size changes. By changing the spot size, the width of the scan line can be adjusted. Also, by changing the polarization factor, the position of the resulting light beam can be changed.

Abstract: An electro-optical device comprising a series of thin films with an electrically controllable optical state provided with a protective overlayer that has a high optical transmittance and high resistance to penetration by H.sub.2 O. The protective overlayer is a film of amorphous silicon oxycarbide (a-SiOC:H) having an O to C ratio such that the optical absorption edge of the a-SiOC:H is 3 eV or greater and the H.sub.2 O transport through a 500 nm thick film of a-SiOC:H is 10.sup.12 molecules/cm.sup.2 -s or less.

Abstract: A zoom lens has a first group of a positive refractive power and a second group of a negative refractive power in sequence as seen from an object. The first group of the positive refractive power comprises a front group of a positive refractive power arranged to face the object and in front of an aperture iris and a rear group of a positive refractive power arranged between the aperture iris and an image plane. The rear group includes displacement means to drive it across an optical axis for vibration correction.

Abstract: The saturation effects observed in an MQW electro-absorption modulator are reduced by modifying the composition of the MQW structure so that the barrier layers, that are interleaved with the quantum well layers, are in tension.

Abstract: A two-dimensional modulator array for modulating a plurality of light beams. The modulator array is comprised of a plurality of stacked wafer layers. Each of the wafer layers have a linear array of transversely driven Pockels modulators. The Pockels modulators are formed by placing a plurality of electrodes over a top surface of an optical material and extending the electrodes over a beveled edge of the optical material. A ground plane resides on the bottom surface of the optical material. Conductive end reflectors are associated with each of the modulator electrodes. These end reflectors reflect the light beams back through the wafer. Electrical attachments are connected to the ends of each electrode for controlling the modulation for each electrode. Thereby, separate light beams can be individually modulated.

Abstract: A semiconductor light intensity modulator utilizing the electric field absorbing effect, includes a light absorption layer which absorbs light due to the electric field absorption effect and a phase correcting semiconductor layer to which an electric field is applied independently from the light absorption layer, having a larger energy band gap than that of the light absorption layer disposed in the light waveguide path or in the vicinity thereof, of the semiconductor light intensity modulator.In this construction, by adjusting the refractive index of the phase correcting semiconductor layer and the length of the light waveguide path, the change in the refractive index in the light absorption layer can be cancelled, whereby a semiconductor light intensity modulator free of phase modulation is obtained.

Abstract: The present invention provides a general system and method for designing arbitrary lens systems with reduced chromatic aberration without the reliance on rigorous trial and error methods and/or approximations. The system and method selects optical materials for a color corrected optical system by generating both axial color terms and lateral color terms for a predetermined lens system. From the generated color terms, a plurality of glass terms are calculated from a plurality or linear algebraic formulas generated by a multiplication of two matrices using the generated axial and lateral color terms as coefficient values of one of the matrices or other computational method. From the calculations, the particular optical materials and the predetermined lens design for a color corrected optical system are identified. This information can be used to facilitate the manufacturing of a lens system. The present invention can also take into account the use of diffractive optical elements.