Abstract: A printer controller for an inkjet printer comprises a purpose-specific microprocessor; connections for linking the microprocessor to an external USB module, a printhead, a paper transport mechanism and a print media sensor; a memory module; a power source connection and an authentication chip. The microprocessor represents an integrated circuit fabricated on a single substrate. The integrated circuit includes a data bus and purpose-specific functional units connected to the data bus. The functional units include a JPEG decoder, a compressed bi-level expander, a halftoner, and a printhead interface. A general-purpose processor may also be connected to the data bus for controlling the functional units. The processor may be connected to run software that coordinates the functional units to receive, expand and print pages.

Abstract: A catadioptric projection objective for imaging an off-axis effective object field arranged in an object surface of the projection objective onto an off-axis effective image field arranged in an image surface of the projection objective has: an optical axis; an effective object field situated entirely outside the optical axis and having a length A in a first direction and a width B in a second direction perpendicular to the first direction such that a circular area of minimum size enclosing the effective object field defines a radius REOF of the effective object field according to: R EOF = ( A / 2 ) 2 + ( B / 2 ) 2 ; and a circular design object field centered around the optical axis having a design object field radius RDOF, where the projection objective is essentially corrected with respect to image aberrations in zones having radial coordinates smaller than RDOF and wherein the projection objective is not fully corrected in zones having radial coordinates larger than RDOF.

Abstract: In general, in a first aspect, the invention features a system that includes a microlithography projection optical system. The microlithography projection optical system includes a plurality of elements arranged so that during operation the plurality of elements image radiation at a wavelength ? from an object plane to an image plane. At least one of the elements is a reflective element that has a rotationally-asymmetric surface positioned in a path of the radiation. The rotationally-asymmetric surface deviates from a rotationally-symmetric reference surface by a distance of about ? or more at one or more locations of the rotationally-asymmetric surface.

Abstract: A device for depicting a linear optical marking (36, 38) in a room, including a housing (11) with a light source (16, 18) that emits the light along an optical axis (15, 17), as well as a lens (28, 30) that both reflects the light and allows it to pass through, that is arranged in front of the light source and through which the optical axis extends. In order to be able to illuminate an area of the room with simple design measures, i.e.

Abstract: A photolithographic reduction projection catadioptric objective includes a first optical group having an even number of at least four mirrors and having a positive overall magnifying power, and a second substantially refractive optical group more image forward than the first optical group having a number of lenses. The second optical group has a negative overall magnifying power for providing image reduction. The first optical group provides compensative aberrative correction for the second optical group. The objective forms an image with a numerical aperture of at least substantially 0.65, and preferably greater than 0.70 or still more preferably greater than 0.75.

Abstract: An exposure system for manufacturing flat panel displays (FPDs) includes a reticle stage adapted to support a reticle. A substrate stage is adapted to support a substrate. A reflective optical system is adapted adapted to image the reticle onto the substrate. The reflective optical system includes a primary mirror including a first mirror and a second mirror, and a secondary mirror. The reflective optical system has sufficient degrees of freedom for both alignment and correction of third order aberrations when projecting an image of the reticle onto the substrate by reflections off the first mirror, the secondary mirror, and the second mirror.

Abstract: A lens collimator according to the present invention includes a plurality of lens elements bonded together. The lens elements, preferably three, each include spherical surfaces and are generally concentrically disposed relative to each other. The lens elements are arranged to produce an increased quantity of reflections and refractions within a lens optical path. The reflections and refractions reduce aberrations and control signal intercept angles relative to an image plane, thereby enabling the lens to match the performance of an optical signal carrier utilized with the lens. The lens element arrangement basically serves to provide an optical path with a quantity of reflections similar to that achieved with a lens having a greater quantity of elements or surfaces. The reflections and refractions enable the lens to cancel out or remove undesired characteristics (e.g., aberrations, etc.) from the resulting optical signals.

Abstract: A projection optical system projects an image of an object onto an image plane, and includes a first imaging optical system for forming an image of the object, and a second imaging optical system for re-imaging the image upon the image plane, wherein the first and second imaging optical systems are disposed in an order from the object side and are disposed along a common straight optical axis. The first imaging optical system includes a first mirror for reflecting and collecting abaxial light from the object, wherein one of the first and second imaging optical systems includes a second mirror for reflecting light from the first mirror to the image plane side, and wherein, with the second mirror, the abaxial light is caused to pass an outside of an effective diameter of the first mirror.

Abstract: An image-formation optical system is disclosed which is an off-axial optical system configured using reflective surfaces, with which the performance deterioration with respect to manufacturing discrepancies is reduced, and which can be made sufficiently compact. The image-formation optical system comprises a reflective optical unit including a plurality of reflective surfaces. Each of the reflective surfaces has a curvature and a rotationally asymmetric shape. Moreover, L/{Er(S?1)} is smaller than 2.2 and L/{Eo (S?1)} is larger than 3.

Abstract: An optical scanning device is suitable for scanning a first information layer (23) of a first optical record carrier (21) with a first radiation beam (27) and a second information layer (47) of a second optical record carrier (45) with a second radiation beam (49). The device includes a radiation source (26) and a lens system (24). The radiation source (26) supplies the first and second radiation beams. The lens system has one optical axis (33) and operates: as a catadioptric system for the first radiation beam in order to transform this beam to a first focused radiation beam (35) having a first numerical aperture (NA1) so as to form a first scanning spot (36) in the position of the first information layer, and as a refractive system for the second radiation beam in order to transform this beam to a second focused radiation beam (52) having a second numerical aperture (NA2), different from the first numerical aperture, so as to form a second scanning spot (53) in the position of the second information layer.

Abstract: A catoptric projection optical system for projecting a pattern on an object surface onto an image surface and for serving as an imaging system that forms an intermediate image includes first, second, third and fourth mirrors serving substantially as a coaxial system so as to sequentially reflect light from an object side to an image side, and being arranged so that light from the object surface to the first mirror may intersect light from the second mirror to the third mirror.

Abstract: A method of operating a micromechanical scanning apparatus includes the steps of identifying a radius of curvature value for a micromechanical mirror and modifying a laser beam to compensate for the radius of curvature value. The identifying step includes the steps of measuring the far-field optical beam radius of a laser beam reflected from the micromechanical mirror. The measured far-field optical beam radius is then divided by a theoretical far-field optical beam radius reflected from an ideal mirror to yield a ratio value M. An analytical expression for M is curve-fitted to experimental data for M with the focal-length as a fitting parameter. The focal-length value determined by this procedure, resulting in a good fit between the analytical curve and the experimental data, is equal to half the radius of curvature of the micromechanical mirror.

Abstract: A recording and reproducing apparatus has an optical head that is provided with a laser light source for emitting light and a reflection converging optical system. The reflection converging optical system reflects light emitted from the laser light source, and converges the light on one point of a bottom surface of a solid immersion lens. Here, the reflection converging system has a first reflection surface for reflecting incident light; and a second reflection surface for further reflecting the light reflected by the first reflection surface and for converging the light onto the bottom the solid immersion lens.

Abstract: An all-reflective, relayed optical system is arranged along a beam path. The optical system includes a first mirror having positive optical power, and a second mirror having a negative optical power, wherein the second mirror receives the beam path reflected from the first mirror and wherein an intermediate image is formed after the beam path reflects from the second mirror. The optical system further includes a third mirror having positive optical power, wherein the intermediate image on the beam path is reflected from the third mirror; a fourth mirror having a negative optical power, wherein the beam path reflected by the third mirror is reflected by the fourth mirror, and a fifth mirror having positive optical power, wherein the beam path reflected by the fourth mirror is reflected by the fifth mirror to an image location.

Abstract: The invention relates to a small-format display optical system using a reflection type image device as an image display device and capable of displaying bright, high-resolution images. The display optical system comprises a reflection type display device 3 for displaying an image, an illumination light source 5 for illuminating the reflection type display device 3, an illumination optical system for guiding light from the illumination light source 5 to the reflection type disply device 3, a relay optical system 21 for projection of an image appearing on the reflection type display device 3 and an eyepiece optical system 22 acting to converge a light beam from the relay optical system 21 toward the eyeball of a viewer. An image projected through the relay optical system 21 is formed near the eyepiece optical system 22.

Abstract: An optical element formed from a transparent optical material includes two refraction surfaces, a first reflection surface group having a plurality of internal reflection surfaces arrayed in a predetermined direction, a second reflection surface group opposing the first reflection surface group and having at least one internal reflection surface and two side surfaces opposing each other in parallel to the predetermined direction. Light incident from one of the refraction surfaces is alternately reflected by the internal reflection surfaces of the first reflection surface group and the internal reflection surface of the second reflection surface group and guided to the other refraction surface.

Abstract: The invention concerns a microlithographic reduction projection catadioptric objective having an even number greater than two of curved mirrors, being devoid of planar folding mirrors and featuring an unobscured aperture. The objective has a plurality of optical elements, and no more than two optical elements deviate substantially from disk form. The objective has an object side and an image side, and has in sequence from the object side to the image side a catadioptric group providing a real intermediate image, a catoptric or catadioptric group providing a virtual image, and a dioptric group providing a real image.

Abstract: There is provided a microlithography projection objective for short wavelengths, with an entrance pupil and an exit pupil for imaging an object field in an image field, which represents a segment of a ring field, in which the segment has an axis of symmetry and an extension perpendicular to the axis of symmetry and the extension is at least 20 mm. The objective comprises a first (S1), a second (S2), a third (S3), a fourth (S4), a fifth (S5) and a sixth mirror (S6) in centered arrangement relative to an optical axis. Each of these mirrors have an off-axis segment, in which the light beams traveling through the projection objective impinge. The diameter of the off-axis segment of the first, second, third, fourth, fifth and sixth mirrors as a function of the numerical aperture NA of the objective at the exit pupil is ?1200 mm * NA.

Abstract: Disclosed is a diffuse reflector comprising a reflective layer and a transparent polymeric film comprising a plurality of complex lenses on a surface thereof.

Abstract: A solid immersion mirror (SIM) type objective lens and an optical pickup employing the same. The objective lens has a first curved surface which condenses incident light and a second curved surface surrounding the first curved surface which diverges incident light. A second transmission surface disposed to face the first transmission surface has an area which transmits incident light and a first reflection surface surrounding the second transmission surface which reflects incident light. A second reflection surface which surrounds the second curved reflects incident light. The objective lens realizes an NA of 0.7 or more with a single lens; has a working distance enabling far field recording/reproducing; has a smaller blocking area than that of the conventional SIM; and generates a smaller amount of side lobe. Where the objective lens is adopted in an optical pickup device, generation of jitter during reproduction or cross erasure during recording is minimized.

Abstract: A zoom optical system comprises a plurality of optical elements. The plurality of optical elements include a first optical element having two refracting surfaces and a plurality of reflecting surfaces formed in a transparent body, being arranged such that a light beam enters an inside of the transparent body from one of the two refracting surfaces and, after being successively reflected from the plurality of reflecting surfaces, exits from the other of the two refracting surfaces, and/or a second optical element having a plurality of surface mirrors integrally formed and decentered relative to one another, being arranged such that an incident light beam exits therefrom after being successively reflected from reflecting surfaces of the plurality of surface mirrors, and a third optical element composed of a plurality of coaxial refracting surfaces.

Abstract: A method for performing optical adjustments of an exposure apparatus is based on an exposure apparatus having a light source for generating illumination light for exposure, and illumination optics for irradiating a mask with the illumination light generated from the exposure light source so as to imprint a mask pattern on a substrate base.

Abstract: An optical element formed from a transparent optical material includes two refraction surfaces, a first reflection surface group having a plurality of internal reflection surfaces arrayed in a predetermined direction, a second reflection surface group opposing the first reflection surface group and having at least one internal reflection surface and two side surfaces opposing each other in parallel to the predetermined direction. Light incident from one of the refraction surfaces is alternately reflected by the internal reflection surfaces of the first reflection surface group and the internal reflection surface of the second reflection surface group and guided to the other refraction surface.

Abstract: A photolithographic reduction projection catadioptric objective includes a first optical group having an even number of at least four mirrors and having a positive overall magnifying power, and a second substantially refractive optical group more image forward than the first optical group having a number of lenses. The second optical group has a negative overall magnifying power for providing image reduction. The first optical group provides compensative aberrative correction for the second optical group. The objective forms an image with a numerical aperture of at least substantially 0.65, and preferably greater than 0.70 or still more preferably greater than 0.75.

Abstract: An aspheric reduction objective has a catadioptric partial objective (L1), an intermediate image (IMI) and a refractive partial objective (L2). The catadioptric partial objective has an assembly centered to the optical axis and this assembly includes two mutually facing concave mirrors (M1, M2). The cutouts in the mirrors (B1, B2) lead to an aperture obscuration which can be held to be very small by utilizing lenses close to the mirrors and having a high negative refractive power and aspheric lens surfaces (27, 33). The position of the entry and exit pupils can be corrected with aspherical lens surfaces (12, 48, 53) in the field lens groups. The number of spherical lenses in the refractive partial objective can be reduced with aspherical lens surfaces (66, 78) arranged symmetrically to the diaphragm plane. Neighboring aspheric lens surfaces (172, 173) form additional correction possibilities.

Abstract: A reduction objective, a projection exposure apparatus with a reduction objective, and a method of use thereof are disclosed. The reduction objective has a first set of multilayer mirrors in centered arrangement with respect to a first optical axis, a second set of multilayer mirrors in centered arrangement with respect to a second optical axis, and an additional mirror disposed at grazing incidence, such that said additional mirror defines an angle between the first optical axis and said second optical axis. The reduction objective has an imaging reduction scale of approximately 4× for use in soft X-ray, i.e.

Abstract: A double mirror objective lens system uses a three optical surface refractor incorporating a convex mirror into a right surface thereof that reflects incident light to a concave mirror, which reflects the light back through the refractor and on toward a focal point of the system. This arrangement yields better resolution images with low spherical aberration, minimal chromatic aberration, and long working distance. A variation of the invention includes another refractor, a right surface of which carries the concave mirror to form a Mangin mirror. This variation on of the invention has even less aberration over increased wavelength range due to better corrected chromatic aberration.

Abstract: When n is taken as integers of 2 or more, n reflecting systems are constituted by providing reflecting mirrors on opposite (two) side surfaces in 2n side surfaces of a transparent body having the shape of a 2n-sided prism. The n reflecting systems are provided on each pair of opposite side surfaces, and images of an object are formed using each of the n reflecting systems.

Abstract: A zoom optical system comprises a plurality of optical elements. The plurality of optical elements include a first optical element having two refracting surfaces and a plurality of reflecting surfaces formed in a transparent body, being arranged such that a light beam enters an inside of the transparent body from one of the two refracting surfaces and, after being successively reflected from the plurality of reflecting surfaces, exits from the other of the two refracting surfaces, and/or a second optical element having a plurality of surface mirrors integrally formed and decentered relative to one another, being arranged such that an incident light beam exits therefrom after being successively reflected from reflecting surfaces of the plurality of surface mirrors, and a third optical element composed of a plurality of coaxial refracting surfaces.

Abstract: An aspheric reduction objective has a catadioptric partial objective (L1), an intermediate image (IMI) and a refractive partial objective (L2). The catadioptric partial objective has an assembly centered to the optical axis and this assembly includes two mutually facing concave mirrors (M1, M2). The cutouts in the mirrors (B1, B2) lead to an aperture obscuration which can be held to be very small by utilizing lenses close to the mirrors and having a high negative refractive power and aspheric lens surfaces (27, 33). The position of the entry and exit pupils can be corrected with aspherical lens surfaces (12, 48, 53) in the field lens groups. The number of spherical lenses in the refractive partial objective can be reduced with aspherical lens surfaces (66, 78) arranged symmetrically to the diaphragm plane. Neighboring aspheric lens surfaces (172, 173) form additional correction possibilities.

Abstract: An exposure apparatus is provided wherein an illumination beam emitted from a mask is projected onto a substrate, through a projection optical system having a reflecting optical element that includes a reflecting region for reflecting the illumination beam at a position spaced from an optical axis of the projection optical system, and a space portion that is provided on the side of the optical axis with respect to the reflecting region. The apparatus further includes a position detecting device for detecting position information of the substrate, at least part of which is located in the space of the reflecting optical element.

Abstract: A variable magnification optical system includes at least three optical units which are a first moving optical unit, a fixed optical unit and a second moving optical unit. The three optical units are arranged in that order in a propagation direction of light, and a variation of magnification is effected by a relative movement between the first moving optical unit and the second moving optical unit.

Abstract: The invention is directed to a directionally adjustable telescope arrangement (1) having a first arcuate mirror (3), a second arcuate mirror (9) and a planar deflecting mirror (13). A third arcuate mirror (17) is provided in the imaging beam path of the telescope arrangement (1). The mirror (17) coacts with the first arcuate mirror (3) and the second arcuate mirror (9) to effectively form images.

Abstract: A catadioptric anamorphic beam expanding telescope expands an optical beam in a first axis substantially perpendicular to the beam propagation axis, and deflects it in a plane substantially perpendicular to the first axis. The beam expanding telescope can include reflective, refractive, and combined reflective/refractive elements. An embodiment includes an off axis convex spheric reflector and an off axis combined reflective/reflective optical element, commonly known as a Mangin mirror, incorporating a refractive first surface and a reflective rear surface, which compensate for aberrations introduced by the off axis deflection of the beam. The telescope is particularly useful for deep ultraviolet (DUV) applications at wavelengths shorter than about 250 nm. In some applications, the telescope illuminates a diffraction grating or other wavelength dispersive element, aligned to retroreflect a preferential wavelength, thereby providing wavelength narrowing.

Abstract: The present invention relates to an omniramic wide angle optical system which is associated with a camera, projector, medical instrument, surveillance system, flight control system, or similar article. The optical system typically consists of a Cassegrain system having a strongly curved convex reflecting surface with a prolate aspheric figure, a secondary reflector surface, and a modular imaging and correcting lens system. The invention further relates to the distribution of still or motion picture image elements by optical or electronic means, whereby the entire image or any subset thereof is converted from a two dimensional annular image or a segment thereof to a viewable horizontal image or a subset thereof; or, from a horizontal format image or a subset thereof into an annular image or a segment thereof.

Abstract: A variable magnification optical system comprises at least three optical units which are a first moving optical unit, a fixed optical unit and a second moving optical unit. The three optical units are arranged in that order in a propagation direction of light, and a variation of magnification is effected by a relative movement between the first moving optical unit and the second moving optical unit.

Abstract: UV light and a fluid are used in a process for the decontamination of microlithographic projection exposure devices with optical elements or portions thereof, in particular of the surfaces of optical elements. A second UV light source is directed for decontamination, in intervals between exposures, toward at least a portion of the optical elements.

Abstract: An all-reflective optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first convex mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receives a chief ray at an incidence angle of less than substantially 9°, and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 14°. Four of the six reflecting surfaces have an aspheric departure of less than substantially 12 &mgr;m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 12 &mgr;m. Each of the six reflecting surfaces has an aspheric departure of less than substantially 16 &mgr;m.

Abstract: An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four reflective elements for projecting a mask image onto a substrate. The four optical elements are characterized in order from object to image as convex, concave, convex and concave mirrors. The optical system is particularly suited for step and scan lithography methods. The invention increases the slit dimensions associated with ringfield scanning optics, improves wafer throughput and allows higher semiconductor device density.

Abstract: The invention provides a real-image type finder optical system which is reduced in size in general and thickness in particular. In order from an object side of the system, the system comprises an objective optical subsystem having a positive refracting power, an image-inversion component for erecting a real image formed by the objective optical subsystem having only one image-formation action to an erect image and an ocular optical subsystem having a positive refracting power, with at least one of reflecting surfaces being defined by a roof surface. The objective optical subsystem comprises at least two reflecting surfaces of reflecting surfaces 12 to 14, each defined by a rotationally asymmetric surface with power imparted thereto.

Abstract: A reduction objective, a projection exposure apparatus with a reduction objective, and a method of use thereof are disclosed. The reduction objective comprises four (primary, secondary, tertiary, and quaternary) mirrors in centered arrangement with respect to an optical axis. The primary mirror is a convex mirror and the second mirror has a positive angular magnification. The reduction objective has an obscuration-free light path and is suitable for annular field scanning operation, such as is used in soft X-ray, i.e. and EUV and UV, lithography.

Abstract: An all-reflective optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first convex mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receive a chief ray at an incidence angle of less than substantially 9°, and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 14°. Four of the six reflecting surfaces have an aspheric departure of less than substantially 12 &mgr;m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 12 &mgr;m. Each of the six reflecting surfaces has an aspheric departure of less than substantially 16 &mgr;m.

Abstract: The invention is directed to a catadioptric microlithographic reduction objective having two concave mirrors (21, 23) facing toward each other. The concave mirrors have a symmetrical configuration and a central bore. Lenses (24 to 60) are mounted downstream of the mirrors (21, 23) on the light path toward the image plane (61). Preferably, lenses (15 to 20) are moved at the object end forward into the intermediate space between the mirrors (21, 23) in the region of the central bore. The light path between the concave mirrors can then preferably be free of lenses. The formation of an intermediate image (Z) downstream of the mirrors (21, 23) affords especially good correction possibilities.

Abstract: A catadioptric lens (10) comprising, along an optical axis (AX), a first lens group (L1) having an objectwise concave annular incident surface (SI) upon which light from an object is first incident, and a most imagewise lens surface (16). The catadioptric lens further includes an annular main mirror (MM) arranged imagewise of the first lens group and having an objectwise concave reflective surface (R1) that reflects light objectwise. A secondary mirror (MS) is located objectwise of the annular main mirror and has an imagewise convex reflective surface (R2) that reflects light imagewise. The first lens group has a glass optical path from the incident surface to the main mirror to the secondary mirror and to the most imagewise lens surface of the first lens group. The catadioptric lens may also include a second lens group L2 imagewise of the first lens group. The second lens group may include two or more lenses, and preferably includes a cemented doublet (L34, L35).

Abstract: A variable magnification optical system comprising four optical units each having a reflecting surface inclined with respect to a reference axis ray which is a ray passing from an aperture center of an aperture stop to a center of a final image plane, the variable magnification optical system being arranged to perform a magnification varying operation by moving at least two of the four optical units along the reference axis ray in such a manner as to vary an optical path length which extends along the reference axis ray from a predetermined position on an object side to the final image plane.

Abstract: The invention is directed to a four-mirror catoptric projection system for extreme ultraviolet (EUV) lithography to transfer a pattern from a reflective reticle to a wafer substrate. In order along the light path followed by light from the reticle to the wafer substrate, the system includes a dominantly hyperbolic convex mirror, a dominantly elliptical concave mirror, spherical convex mirror, and spherical concave mirror. The reticle and wafer substrate are positioned along the system's optical axis on opposite sides of the mirrors. The hyperbolic and elliptical mirrors are positioned on the same side of the system's optical axis as the reticle, and are relatively large in diameter as they are positioned on the high magnification side of the system. The hyperbolic and elliptical mirrors are relatively far off the optical axis and hence they have significant aspherical components in their curvatures.

Abstract: An imaging apparatus for sensing an image of a scene from a substantially single viewpoint, which includes a truncated, substantially paraboloid-shaped reflector positioned to orthographically reflect principal rays of electromagnetic radiation radiating from the scene, the paraboloid-shaped reflector having a focus coincident with the single viewpoint of the imaging apparatus, including the paraboloid-shaped reflector. The imaging apparatus also includes telecentric means, optically coupled to the paraboloid-shaped reflector, for substantially filtering out principal rays of electromagnetic radiation which are not orthographically reflected by the paraboloid-shaped reflector. The imaging apparatus also includes one or more image sensors positioned to receive the orthographically reflected principal rays of electromagnetic radiation from the paraboloid-shaped reflector, thereby sensing the image of the scene.

Abstract: A high-performance and low-cost image-forming optical system made compact and thin by folding an optical path using reflecting surfaces having power. The optical system has a plurality of reflecting surfaces having power. Among the reflecting surfaces, a reflecting surface (12) of negative power is placed closest to the object side, and a reflecting surface (22) of positive power is placed closer to the image side than the reflecting surface (12). At least one reflecting surface (13) is provided between the reflecting surface (12) and the reflecting surface (22). An axial principal ray (1) incident on the reflecting surface (13) satisfies the condition of 45.degree.<.vertline..theta..vertline., where .theta. is the angle formed between the axial principal ray and a line normal to the reflecting surface (13) in the decentration direction at a point where the axial principal ray (1) intersects the reflecting surface (13).

Abstract: A laser scanner includes an optical relay which reforms an image from a scan lens at a location that provides additional working distance. The optical relay contains primarily reflective elements which provide achromatic focusing for ultraviolet light. One embodiment of the optical relay has a magnifying power of about 1 and use spherical mirrors in a configuration where image distortion and aberrations cancels. A second optical relay provides a reduction in image size using aspherical mirrors such as parabolic and elliptical mirrors. An additional lens cancels distortion and aberration introduced in the second optical relay. The additional working distance allows insertion optical devices such as beamsplitters and chevron correction and autofocus optics in the optical path of the optical relay.

Abstract: 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 image, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be fatigued. The apparatus includes an image display device (6) and an ocular optical system (9) for leading an image of the display device (6) to an observer's eyeball (1). The ocular optical system (9) has a first optical element (7) and a second optical element (8). The first optical element (7) has three surfaces, and a space formed by the surfaces is filled with a medium having a refractive index larger than 1.