Abstract: A projection unit for a car head-up display comprises a display source, a curved mirror which provides the optical power of the projection unit and, in use, receives light from the display source, and a Fresnel mirror extending generally between the display source and the curved mirror and disposed to receive reflected light from the curved mirror and to reflect that light in a desired direction. The curved mirror and the Fresnel mirror may be disposed on a solid block of transparent material having one curved end coated to provide the curved mirror, the display source being located at an opposite end of the block, and the Fresnel mirror being formed in a block face extending from the opposite end of the block to the curved end of the block.

Abstract: A catadioptric reduction projection optical system is of a construction in which an on-axis light beam is used in a catadioptric system, and is designed such that resolving power is not deteriorated and a stop can be disposed.

Abstract: A concentrating lens has a receiving surface that is substantially spherical and a rear or reflecting surface that is substantially hyperbolic. The reflected radiation is directed to a focusing concavity in the receiving surface from which the resultant concentrated beam emerges, substantially in a direction that is opposite to the direction of the impinging radiation.

Abstract: An optical system for a night vision video camera having a pair of mirrors with an optical prescription providing f/2.8 speed and 50 line pairs per line millimeter resolution to an image intensifier located between the two mirrors on the common optic axis of the mirrors. The mirror first receiving the image to be viewed is an f/4 parabolic mirror and the second mirror is an f/10 spherical mirror with an external diameter of about forty percent of the diameter of the parabolic mirror (i.e., the obsuration ratio is about 0.40). The second mirror receives the reflected image of the object viewed by the night vision video camera from the first mirror and reflects the image to the image intensifier. The image may be viewed at a external view finder and can also be recorded.

Abstract: This invention intends to provide a catadioptric reduction projection optical system of a construction in which an on-axis light beam is used in a catadioptric system and resolving power is prevented from being deteriorated, and more particularly a catadioptric reduction projection optical system having a first lens unit G1 of negative refractive power for diffusing a light beam from a reticle 1, a semi-transparent mirror 5 for transmitting therethrough the light beam from the first lens unit G1, plane parallel plates 2, 3 and 4 disposed obliquely with respect to the optical axis between the first lens unit G1 and the semi-transparent mirror 5 for correcting aberrations attributable to the semi-transparent mirror 5, a concave reflecting mirror 7 for returning the light beam emerging from the semi-transparent mirror 5 to the semi-transparent mirror 5 while converging the light beam, and a second lens unit G3 of positive refractive power for converging the light beam returned to the semi-transparent mirror 5 an

Abstract: An optical system of a NX reduction catadioptric relay lens having sub-half micron resolution over the ultraviolet band width is described. A spherical mirror with a stop at the mirror is used to work at substantially the desired reduction ratio and the desired high numerical aperture sufficient to provide the desired high resolution. A beam splitting cube with appropriate coatings is used to form an accessible image of an object on an image plane. Refracting correctors in the path of the slow beam incident on the mirror and in the path of the fast beam reflected on the mirror are designed to fix the aberrations of the image formed by the mirror.

Abstract: In a cata-dioptric optical system having a combination of a reflection system and a refraction system for reduction-projecting an object on a first plane onto a second plane, a polarization beam splitter and a quarter wavelength plate are provided to split the incident light and the reflected light. The light beam directed to the polarization beam splitter is converted to a substantially collimated light beam by a first group of lenses. A second group of lenses are arranged between the polarization beam splitter and a concave reflection mirror to diverge the light beam. The light reflected by the concave reflection mirror is directed back to the polarization beam splitter with a substantially collimated state by the second group of lenses. The light beam from the second group of lenses transmitted through the polarization beam splitter is focused by a third group of lenses having a positive refraction power to form a reduced image.

Abstract: A broad band catadioptric optical reduction system using refractive elements made of different types of glass matched for color correction over a broad band width. A combination of fused silica and crown glass is used. An aspheric mirror is used for improved aberration correction. The optical system is adapted for use in lithography for semiconductor manufacturing in the I-line and is capable of 0.5 micron resolution at a wavelength of 365 nanometers.

Abstract: A parallax free sight which utilizes a concave-convex lens with a parabolic shaped optical surface attached to one end of a light channel, the concave side of the lens faces into the light channel, the perimeter dimensions of the lens is adapted to the rectangular shape and dimensions of the light channel, with the longer sides of the rectangular lens perimeter positioned in a horizontal plane when the sight is in use. A transparent body is attached to the other end of the light channel. A light emitting source is arranged at the focal point of the concave side of the lens, between the lens and the transparent body. The light source can be a light emitting material or an electrical light source, powered by a rechargeable battery or a solar cell, or both. A light reflective layer is attached to the concave side of the lens to only reflect light of the wavelengths corresponding to the light emitted by the light emitting source.

Abstract: The present invention relates to an optical element and catadioptric optical systems using the optical element. The optical element has a spherical surface with a reflective layer formed on at least a portion of the surface, and is formed of a radiant energy transmitting material having a radial gradient index of refraction. The catadioptric optical systems include at least two optical elements at least one of which is refractive, and at least one of which has a gradient index therein. One optical system includes first and second optical elements disposed sequentially along a longitudinal axis of the system. The second optical element is the optical element with the gradient index. The first optical element is formed of a homogeneous light transmitting material and includes a spherical surface, and a reflective layer formed on a central portion of one of the spherical surface.

Abstract: The position of an object including a retroreflector is determined by scanning first and second optical beams toward an axis on a planar surface from spaced sites on opposite sides of the axis. The scanned beams are incident on and reflected from the retroreflector along coincident first and second paths between the sites and the retroreflector. Indications are derived of first and second angles between a baseline between the sites and the first and second paths extending between the sites and the retroreflector. In response to the known distance between the sites and the derived indications of the first and second angles a two-coordinate direction indication of the retroreflector position is derived. The retroreflector refracts and reflects the scanned optical beams incident thereon and refracts the beams reflected thereby.

Abstract: A device for the generation of basic electrical signals which are supplied to a computerized processing complex for the operation of industrial robots. The system includes a stereo mirror arrangement for the projection of views from opposite sides of a visible indicia formed on a workpiece. The views are projected onto independent halves of the retina of a single camera. The camera retina is of the CCD (charge-coupled-device) type and is therefore capable of providing signals in response to the image projected thereupon. These signals are then processed for control of industrial robots or similar devices.

Abstract: An optical system of a NX reduction catadioptric relay lens having sub-half micron resolution over the utlraviolet band width is described. A spherical mirror with a stop at the mirror is used to work at substantially the desired reduction ratio and the desired high numerical aperture sufficient to provide the desired high resolution. A beam splitting cube with appropriate coatings is used to form an accessible image of an object on an image plane. Refracting correctors in the path of the slow beam incident on the mirror and in the path of the fast beam reflected on the mirror are designed to fix the aberrations of the image formed by the mirror.

Abstract: A lens system is characterized by a back focal length that substantially exceeds its front focal length. An input lens having a relatively short focal length is arranged to receive an image. The back of the input lens is a mirrored concave surface that is inclined in such a way as to direct the reflected image to a concave mirror. The concave mirror and a Mangin mirror having a convex mirrored back surface form a relay lens system for redirecting the image reflected from the concave mirror to a second point on that mirror from which the image is reflected to a predetermined focal point. The Mangin mirror is arranged to remove chromatic and spherical aberrations from the virtual image. The lenses and mirrors of the system are arranged so that the optical distance from the concave mirror to the predetermined focus is at least three times the focal length of the first lens.

Abstract: A wavefront correction system is provided which uses an achromatic null lens to correct various aberrations introduced in a spherical wavefront when the wavefront is reflected off a non-spherical surface, particularly a parabola. Chromatic aberration, including spherochromatism, is corrected over a relatively wide bandwidth. When used in conjunction with an interferometer and a variable wavelength source, the wavefront correction system provides adequate means for determining relative position errors of the segments of a segmented mirror. The derivative of the phase error is obtained with wavelength by measuring interference for different wavelengths of light. This allows position errors of greater than one half wavelength to be accurately measured.

Abstract: A beam of light issued by a light source enters a catadioptric arrangement and initially travels therethrough along an axis. At least one lens is situated at the axis and is axially delimited by two curved major surfaces having respective centers of curvature. The beam of light is reflectively diverted from the axis and travels in a path which includes a path section that is directed at one of the major surfaces and has such a spatial orientation relative to the axis and the major surfaces that light traveling in this path section bypasses the centers of curvature and impinges all regions of the major surfaces at angle deviating from respective normals to the regions with attendant avoidance of specular retroreflection from such regions.

Abstract: A single hybrid optical element combines reflective and refractive imaging. The optical unit utilizes a dual-reflector outer annulus zone and a refractive inner zone to achieve a high numerical aperture. This system is particularly suitable for, but not limited to, microscope objectives or for digital data storage applications.

Abstract: An optical projection system has been provided which is particularly suited for use in microlithography and includes a source of exposure energy for generating a beam of energy. A primary lens and mirror are located in the path of the beam for receiving the beam and passing only a portion of the beam therethrough. A refractive lens group is located in the path of the portion of the beam for receiving and transmitting that portion. A recticle element is located in the path of the portion of the beam and has a uniform thickness having a pattern on one surface thereof and an unpatterned portion adjacent thereto. The reticle element is positioned for permitting the portion of the beam to pass through its thickness and for reflecting the portion of the beam back through its thickness and the refractive lens group to the primary lens and mirror.