Abstract: Projection lenses and projection lens systems are telecentric between an illumination subsystem and a set of imagers. The lenses and systems can exhibit color fringing correction, uniform imager illumination, athermalization, and component articulation for improved imaging. The lenses and systems may be employed in display apparatuses, such as folded display apparatuses that have decreased footprint size, but long effective projection lengths.

Abstract: Projection optical systems are provided for use in an exposure apparatus that have a numerical aperture greater than 0.63, a reduced field curvature of pupil at the aperture stop and are able to maintain imaging performance. Further, the present invention avoids degradation in the imaging performance when the numerical aperture is changed.

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: The present invention provides a projection lens for projecting light from a light source onto a screen to form a magnified image, including two joined lenses, each of which includes a negative lens and a positive lens. The difference in the refractive index and the Abbe number between the negative lens and the positive lens in each of the joined lenses and the partial dispersion ratio of the negative lens and the positive lens of the second joined lens are specified. Thus, a large angle of view and a long back focal length can be achieved while satisfying distortion aberrations, telecentric properties and magnification chromatic aberrations.

Abstract: An optical device for optically scanning an information plane includes a radiation source for supplying a scanning beam, and an objective system for focusing the scanning beam to a scanning spot on the information plane. The temperature dependence of the objective system can be compensated by a compensator which includes a planoconvex first element and a planoconcave second element arranged between the radiation source and the first element, the convex surface of the first element confronting the concave surface of the second element, and the refractive indices of the first and the second element being equal at the design temperature but having a different temperature dependence.

Abstract: A projection optical unit comprises a frame, a projection lens, a dichroic prism for synthesizing red image light, green image light and blue image light, and three liquid crystal display panels for red, green and blue. A lens mounting portion on which the projection lens is mounted, a prism mounting portion on which the dichroic prism is mounted, and three mounting surfaces on which the three liquid crystal display panels are respectively mounted are formed in the frame. The projection lens, the dichroic prism, and the three liquid crystal display panels are mounted on the frame. The three liquid crystal display panels are mounted through a focus adjusting mechanism comprising a belleville spring and a screw. The two liquid crystal display panels for red and blue are further subjected to CG adjustment (adjustment for matching pixels of the liquid crystal display panels for read and blue with pixels of the liquid crystal display panel for green) by an eccentric screw.

Abstract: Four groups of six lenses comprising a plastic lens having weak refracting power, three glass lenses of convex, concave, and convex yielding a major part a refracting power of the projection lens as a whole, a plastic lens having a weak refracting power, and a lens having a concave surface directed onto the screen side are successively disposed from the screen side, whereby the plastic lens with a temperature-correcting function is omitted, thus cutting down cost. Successively disposed from the screen side are G.sub.1 made of a plastic lens L.sub.1 having a weak refracting power and at least one aspheric surface, G.sub.2 made of three glass lenses of convex, concave, and convex L.sub.2 to L.sub.4 yielding a major part of the refracting power of the projection lens as a whole, G.sub.3 made of a plastic lens L.sub.5 having a weak refracting power and at least one aspheric surface, and G.sub.4 made of a lens L.sub.6 having at least one aspheric surface and a concave surface directed onto the screen side.

Abstract: An illumination system includes a light source and an optical system for projecting light from the light source to a surface to be illuminated, wherein the optical system includes an optical element having a paraxial power of substantially zero and having an aspherical surface, and the optical element is movable along an optical axis when an illuminance distribution on the surface to be illuminated is to be changed.

Abstract: A four element, athermalized projection lens for use in forming an enlarged color image of a LCD panel is disclosed. The powers of the elements from the screen to the LCD are negative/positive/negative/positive and the dispersions are low dispersion/low dispersion/high dispersion/low dispersion. The first three elements are composed of plastic and the last element is composed of glass. The projection lens exhibits a high level of aberration correction over magnifications ranging from about 5.times. to about 12.times.. The four element design comprises the minimum number of elements capable of achieving a relatively long back focal length, athermalization, and lateral color correction of less than about half a pixel.

Abstract: A projection optical system is provided which forms an image of a first object onto a second object and includes, in order from the first object side:a first positive lens group G1 with a subgroup G-1p having at least two positives lenses;a second negative lens group G2 with a subgroup G-2n having at least three negative lenses;a third lens group G3 with a subgroup G-3p having at least three positives lenses and one negative lens;a four negative lens group G4 with a subgroup G-4n having at least three negative lenses;a fifth positive lens group G5 with a subgroup G-5p having at least five positives lenses and having a positive lens G-5g arranged closer to the second object side than the subgroup G-5p and having a concave surface facing the second object side. The projection optical system provides an optimal range for the focal length and the preferable range of the radius of curvature for the concave surface R5g of the positive lens G-5g.

Abstract: Telecentric retrofocus lenses and projection systems comprising such lenses are disclosed. The lenses are compact and provide a wide field of view (>70.degree.) with effective distortion correction. The lenses comprise, in order from the image side, a first lens group G1, comprising an aspheric lens having a negative focal length, an aperture, and a second lens group having a positive focal length and having a lens that has maximum refractive power among the lenses of the second lens group. Conditions apply to the ratio of the focal lengths of the first and second lens groups and the distance between the aperture and the focal length of the lens within the second lens group having maximum refractive power. The conditions effectively provide compact, wide-field, low-aberration images. Projection systems using these lenses are also disclosed.

Abstract: An image magnification apparatus, for use in a video display system that displays an image of an object, comprising a connecting module for connecting the image magnifying apparatus to a lens module of the video display system, and an objective lens system for forming an optical image of the object. The apparatus also includes a conversion optical system for magnifying the optical image formed by the objective lens system. The conversion optical system further includes a first biconvex lens unit having a positive refractive power, a second biconvex lens unit having a positive refractive power, and a third biconcave lens unit having a negative refractive power.

Abstract: A projection lens includes sequentially from a screen side a first lens group which has a negative power, a second lens group which has a weaker power than that of the first lens group, a third lens group which has a positive power, a fourth lens group which has a positive power, and at least one transparent prism, wherein the fourth lens group is placed on the third lens group side of the transparent prism so as to be close to or in contact with the transparent prism. In the projection lens, a back focus of the main lens group is much longer compared with a focal length. A projection display apparatus using this projection lens is composed of one main lens group, three auxiliary lenses, and three polarizer-beam splitters, and a color combining optical system for combining three primary color components of red, green, and blue into one light beam is placed between the main lens group and the auxiliary lens.

Abstract: Magnification correction for small field scanning of large blanks is provided by adding magnification adjusting elements (lenses) to a double pass Wynne-Dyson lens or other type of one-to-one projection lens. The magnification adjusting optical elements includes two pairs of low power lenses, one associated with each of the input and output prisms of a Wynne-Dyson lens. Movement of the magnification adjusting optics provides positive or negative magnification as needed to correct for any expansion or compaction of the blank relative to the reticle (mask) and hence maintain alignment. Further magnification correction is provided by a small velocity relative movement between the reticle and the blank by means of a secondary stage in the scan direction. This corrects for any alignment error in the scan direction and may be used independently of the optical correction technique with any type of projection lens.

Abstract: An improved projection lens capable of substantially and advantageously implementing a distinct picture by compensating for a chromatic aberration and a residue aberration, which includes a first lens group, including a lens element convex to a screen and having a relatively weak optical power, for eliminating a spherical surface aberration; a second lens group having positive optical power and cemented with a two side lens element having a positive optical element and a lens element having a negative optical element, which have a different dispersion from each other; a third lens group having a positive optical power on an optical axis and a radius code of a curvature surface toward an upper surface of which has the same radius code as the radius curvature surface of a cathode ray tube; and a fourth lens group having a high optical power toward an upper surface of the screen for compensating for a field dependent aberration.

Abstract: A projection lens assembly having an imaging lens group, including a first lens group having a positive refractive power, a second lens group having a positive refractive power, and a Fresnel lens group having a positive refractive power and at least one Fresnel lens surface, in this order from the enlargement side. The projection lens assembly satisfies the relationships 1.4<f.sub.1 /f<2.8, and 1.5<f.sub.2 /f<6.0. In these relationships, f represents the focal length of the whole lens system, f.sub.1 the focal length of the first lens group, and f.sub.2 the focal length of the second lens group.

Abstract: A projection lens unit using the principles of liquid-cooled, optical coupling is disclosed. In particular, the present invention automatically re-focusses a lens unit that is being exposed to high temperature operating conditions. The temperature rise of the optical coupling liquid changes the refractive index of the liquid, thereby changing the focussing distance of the projection lens. As a result, the picture projected onto the screen becomes unfocussed. The present invention provides a countermeasure for automatically re-focussing the picture projected on the screen. An optical coupling lens, which is one of the lens element group of the projection lens, is movably coupled to an OC housing to move along the optical axis. The volume expansion caused by the temperature rise of the optical coupling liquid is converted to a pressure change. The pressure change is used for controlling the movement of the optical coupling lens.

Abstract: A Dyson lens system includes a radiation source, a concave mirror, and a plano-convex lens. There is also incorporated in the system an additional lens that is spaced from the plano-convex lens a large part of the distance from the plano-convex lens to the mirror. A roof prism and a turning prism are provided to conduct radiation from the radiation source to the plano-convex lens and also from the plano-convex lens to an image plane. An image adjustor or compensator is provided between the prisms and either the image plane or an object plane--the latter being disposed between the radiation source and the prisms. An adjustment mechanism is provided to effect highly accurate adjustment of the location of the image, the adjustment mechanism including physical shifting to a slight degree of a portion of one or both prisms.

Abstract: A lens configuration integral with the output window of an enclosure at least partly surrounding a source of a beam is provided. In one embodiment, the beam is an anomorphic diverging beam, such as that produced by a diode laser, having differing angles of divergence along parallel and perpendicular axes, and the at least one lens is configured to at least partly equalize the angles of divergence along the perpendicular and parallel axes.

Abstract: A projecting lens for projecting the image of an object onto a screen comprising, in the order from the screen side, a first lens group of a positive refractive power; a cemented second lens group of a positive refractive power; a third lens group of a negative refractive power; and a fourth lens group of a positive refractive power with a concave surface at the screen side; wherein each of the first and third lens group has at least an aspherical face, and the focal length f of the projecting lens, the focal length f1 of the first lens group and the focal length f3 of the third lens group satisfy conditions: 0<f/f1<0.25 and -0.1<f/f3<0.

Abstract: This invention relates to a projection lens system used for transferring circuit or other patterns from masks, etc. on which the circuit patterns are drawn onto semiconductor wafers by projection photolithography, and provides a projection lens system which makes high resolving power of the order of a few micrometers and wide exposure coverages compatible with each other.This projection lens system includes at least two sets of lens groups, each built up of lenses having concave surfaces located opposite to each other, and includes at least one lens surface of positive refractive power between said two sets of lens groups, said two sets of lens groups all satisfying the following conditions:1/L<.vertline..phi..sub.1 <20/L (1)1/L<.vertline..phi..sub.2 <20/L (2)wherein .phi..sub.1 and .phi..sub.2 stand for the respective negative refractive powers of said oppositely located concave surfaces, and L is the distance between object and image.

Abstract: The present invention relates to a projection lens system for use in a rear type projection television. The projection lens system includes a plurality of lenses which are sequentially arranged along an optical axis perpendicular to a CRT screen. The system includes: a first lens unit including at least one lens of meniscus form and having a weak positive or weak negative optical power; a second lens unit including one lens with a strong positive optical power and a bi-convex form; a third lens unit including at least one lens having a weak positive or negative optical power, and a further lens having a strong positive optical power; a fourth lens unit having a strong negative optical power and including a meniscus lens that is convex toward the CRT screen and that has a strong negative optical power, the fourth lens unit further including a coolant for cooling a fluorescent surface of the CRT. The optical power of the whole system is largely divided between the second and third lens units.

Abstract: A projection TV lens (60) includes first (64), second (66), third (70), and fourth (72) element-groups counted in numerical order and arranged on a common optical axis (62). The first, third, and fourth groups each include at least one lens element. The first and third group has positive power and the fourth group has negative power. The second group includes a first lens element (67) having negative power and having a graded refractive index.

Abstract: An optical system of a projection display apparatus includes a projection lens assembly having a first lens group having a negative power, a second lens group having a negative power and a third lens group having a positive power, all arranged in this order from a side of a screen. An air space is provided between the first and second lens groups and also between the second and third lens groups. Each air space is longer than the entire length of the second lens group as taken along the optical axis of the assembly.

Abstract: A projection lens system for a video projector for projecting a color image which is generated by combining red, green and blue images from an image source on a large screen. One lens element of a four lens optical lens system is disposed between an image-generating surface (or CRT) and an image combining unit for combining the images, and an oil chamber is provided by sealing the edges of the lens element and the image-generating surface. The flattening of the CRT's image-generating surface and a large aperture are attained by allowing the one lens to correct field curvature aberration and the other lenses to correct coma aberration. Separate cooling for respective CRTs enhances cooling devices efficiency and facilitates CRT movement adjustment for correcting chromatic aberration.

Abstract: A projection lens system includes a first lens group for correcting spherical aberration and coma aberration, a second lens group for correcting chromatic aberration, a third lens group for providing the main optical power for the whole system, and a fourth lens group for correcting petzval aberration. The first, second and third lens groups are sequentially disposed forward of a screen in front of a dichromatic mirror, and the fourth lens group is disposed between the CRTs and dichromatic mirror. Further, the fourth lens group and CRTs form an enclosure and are filled with transparent cooling oil, thereby accomplishing a high-resolution color image having no chromatic aberration and using a reduced number of lenses.

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.

Abstract: In one embodiment, a three-element biocular eyepiece system 40 having a first optical element 42 with at least one diffractive surface 44, a second optical element 48 having a refracting convex surface 50 and a refracting concave surface b 52 is provided. A third optical element 54 having a refracting convex surface 56 and a refracting convex surface 58 is also employed. In another embodiment, a four-element biocular system 60 is disclosed as having an optical element 62 having a refracting concave surface 64 and a refracting convex surface 66, a refractive-diffractive hybrid optical element 68 having a diffractive surface 70 and a refracting convex surface 72, an optical element 74 having a refracting convex surface 76 and a refracting concave surface 78, and an optical element 80 having a refracting concave surface 82 and a refracting convex surface 84. The diffractive surfaces 44 and 70 have a kinoform profile 102 a-d or approximated kinoform profiles 112a-d and 122a-d.

Abstract: A projection lens in which a lens unit which may comprise one or two elements is closely coupled at the object end of the lens to a cathode ray tube. At the image end is a lens unit of overall weak optical power which comprises from the image end a first positive element followed by a closely spaced negative element of substantially higher dispersion. Intermediate the object side lens unit and the image side lens unit is a lens unit of substantial optical power supplying substantially all of the positive optical power of the lens. Closely spaced to this power lens unit on the object side is a negative lens element of high dispersion. This negative lens element may be considered to be part of the power lens unit.