Abstract: An imaging optical system includes sequentially from an object side a front group configured to include a positive lens disposed at a position nearest a diaphragm; the diaphragm; and a rear group configured to include a negative lens disposed at a position nearest the diaphragm. The imaging optical system satisfies a conditional expression (1) 0.27?|?3/?2|?1.80, where ?3 represents temperature-dependent variation of relative refractive index for d-line of the negative lens and ?2 represents temperature-dependent variation of relative refractive index for d-line of the positive lens.

Abstract: Projection optics for a lithographic projection system is provided that comprises a spatial light modulator (SLM) from which radiation is reflected and directed to a projection lens that projects the radiation to a substrate. The SLM is illuminated by non telecentric off axis illumination (e.g. from laser radiation that has a spectral bandwidth of the order of 1 picometer, and the projection optics is configured for significant reduction (e.g. at least 10× reduction, 20× reduction, or 50× reduction).

Abstract: A projection lens is a zoom lens and formed of a first group to an N-th group sequentially arranged from an image enlargement side (that is, screen side), where N is 6 or 7. The first group includes a first A group and a first B group sequentially arranged from the image enlargement side. The first A group is formed of two positive lenses, and the first B group is formed of a cemented lens formed of a positive lens and a negative lens. The second group includes at least two negative lenses. In magnification changing action, at least the first group and the N-th group are fixed, and at least the third group to the (N?1)-th group are moved along an optical axis. In focusing action, the first A group on the image enlargement side in the first group is solely moved along the optical axis.

Abstract: An optical system includes, in order from an enlargement conjugate side to a reduction conjugate side via a largest air gap, a front unit having a negative power, and a rear unit having positive power. The optical system satisfies 1.75<Ndn1<2.05, 0.02<?gFn1?(0.6438?0.001682×?dn1)<0.08, and 2.5<|fn1/F|<5.0, where fnl represents a focal length of a negative lens in the front unit, Ndnl represents a refractive index of a material of the negative lens, ?dn1 represents an Abbe number of the material of the negative lens, ?gFn1 represents a partial dispersion ratio of the material of the negative lens, and F represents a focal length of the optical system.

Abstract: A variable magnification projection optical system substantially consisting of two lens groups of a first lens group having a positive refractive power and is moved during magnification change, and a second lens group having a positive refractive power and is moved during magnification change, in which the variable magnification projection optical system is configured such that the reduction side is telecentric.

Abstract: A projector is associated with a head gear for a first participant of collaboration. The head gear does not obstruct the participant's eyes. The projector is configured to receive an image which was created with respect to a first participant's view point based on a dataset that represents an object. The projector is configured for projecting the received image onto a display surface. The first participant perceives the projected image by receiving at least a portion of diffused light associated with the projected image at the first participant's eye that is closest to the projector.

Abstract: A MEMS auto focus miniature camera module includes an image sensor and an optical train including at least one movable lens and one or more fixed lenses or fixed lens groups on either side of the movable lens. The movable lens provides an auto focus feature of the camera module. A MEMS actuator translates the movable lens through an auto focus range to adjust focus.

Abstract: An autostereoscopic apparatus for providing a 3D image to a viewer at a range of vertical eye locations. The apparatus includes a projection screen with a light receiving surface that is horizontally retroreflective and vertically diffusive. The apparatus includes a projector assembly including at least two projectors arranged side-by-side such that projection lenses of the projectors are horizontally aligned in a row. The apparatus includes a controller selectively operating the projectors to project at least two differing point-of-view images. The projection screen may take a number of useful embodiments to implement the autostereoscopic apparatus. For example, the projection screen may include a bottom layer including a retroreflective film that is retroreflective at least in the horizontal direction such as a brightness enhancement film and a top layer formed of a transparent sheet of lenticular material arranged for vertical diffusing.

Abstract: A super wide angle lens substantially consists of a positive first lens group in which a positive first lens, a negative second lens, a negative third lens, a negative fourth lens, a positive fifth lens, a sixth lens unit that is a cemented lens, a seventh lens, an aperture stop, and an eighth lens unit that is a cemented lens are arranged in this order from an object side, a second lens group in which a first lens unit that is a positive single lens or a cemented lens and a second lens unit that is a cemented lens are arranged in this order from the object side, and a third lens group including a positive lens. The super wide angle lens is structured in such a manner to satisfy conditional formula (1): 0.8<(T16+T17)/f<2.5.

Abstract: An imaging lens including the first˜fifth lens arranged in sequence from an object side to an image side is provided. The first lens has at least one aspheric surface. The second lens with negative optical power has at least one aspheric surface and a convex surface facing towards the object side. The third lens with positive optical power has at least one aspheric surface and a concave surface facing towards the object side. The fourth lens with negative optical power has at least one aspheric surface and a concave surface facing towards the image side. The fifth lens with positive optical power has at least one aspheric surface and a convex surface facing towards the object side. By the above arrangement, the imaging lens has a shorter optical total length and a larger aperture for enhancing the image quality.

Abstract: A projection objective for applications in microlithography, a microlithography projection exposure apparatus with a projection objective, a microlithographic manufacturing method for microstructured components, and a component manufactured using such a manufacturing method are disclosed. The projection objective includes an optical component configured so that, during use of the projection objective, the optical component generates a stray light component in the exposure field of the projection objective which adapts a parameter of the projection objective to a parameter of a second projection objective. The parameter is the stray light component at the exposure field of the projection objective and/or a variation of the stray light component at the exposure field of the projection objective.

Abstract: A projection lens for a projection device having a light valve is provided. The light valve provides an image light beam. The projection lens includes a first lens group, a second lens group and a reflecting lens group. The second lens group is disposed between the first lens group and the reflecting lens group. The first lens group has positive refractive power. The second lens group has positive refractive power and includes a plurality of lenses and an aperture stop located between the lenses. An angle of a field of view of the second lens group is less than 100 degrees. The reflecting lens has negative reflective power and has a curved reflecting surface to reflect the image light beam passed through the second lens group.

Abstract: The invention proposes a short-distance front projection system, that is to say with a wide angle, occupying a small volume and offering a possibility of focusing as well a zoom function. It makes it possible to obtain images with a diagonal greater than 2 meters, the whole of the optical system being at least 50 cm from the plane of the image. This projector is constructed on the basis of three optical elements: an ocular, an afocal lens system and a final group forming an objective intended to form the intermediate image in front of the mirror.

Abstract: A projection lens disposed between an enlarged side and a reduced side is provided. The projection lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, which are sequentially arranged from the enlarged side to the reduced side. Refractive powers of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are respectively negative, positive, positive, negative, positive and positive. A focal length of the third lens is greater than or equal to 20 mm and is less than or equal to 200 mm. An optical engine is also provided.

Abstract: In an optical system for projection that is telecentric on a reduction side, a correction lens group substantially consisting of a part of lens groups in the optical system for projection is configured to move in the direction of an optical axis to correct a shift in a focal position caused by a change in temperature, and predetermined conditional formulas are satisfied.

Abstract: Projection lens having improved properties such as a high throughput are described. In one embodiment, a projection lens is described comprising in sequential order from a screen side a first lens group, a second lens group of positive refractive power, and a third lens group of positive refractive power. At least one lens group has an aspheric surface. The ratio of the focal length of the projection lens (F) to the focal length of each of the lens groups (F1, F2, and F3) is such that |F1/F|>5, 0.5<|F2/F|<0.9, and 1<F3/F<8. In another embodiment, a projection lens is described comprising in sequential order from a screen side a first lens group, a second lens group of positive refractive power, and a third lens group of positive refractive power. At least one lens group has an aspheric surface. The ratio of the focal length of the projection lens (F) to the focal length of each of the lens groups (F1, F2, and F3) is such that |F1/F|>5, 0.5<|F2/F|<2.0, and 1.4<F3/F<8.

Abstract: The present invention uses the concave hybrid architecture to form a wide angle projection lens with large numerical aperture. The wide angle projection lens includes a refraction system and a reflection system, wherein the refraction system includes a first lenses group containing a plurality of spherical lenses and at least one spherical lenses, and a second lenses group containing at least two aspheric lenses and at least one spherical lens, and the at least one spherical lens is configured between any two of the at least two aspheric lenses. The present invention is beneficial in reducing the wide angle projection lens in size and is able to effectively overcome the problem in low geometric efficiency, and enable the ultra-short focus projector have compact and portable advantages.

Abstract: A variable-magnification projection optical system substantially consists of a negative first lens group that is disposed at the most enlargement-side position and is fixed during magnification change, a positive last lens group that is disposed at the most reduction-side position and is fixed during magnification change, and a plurality of lens groups that are disposed between the first lens group and last lens group and are moved during magnification change. The lens groups that are moved during magnification change substantially consist of three lens groups, wherein the most enlargement-side lens group is a negative lens group. Predetermined conditional expressions relating to a back focus of the entire system on the reduction side at the wide-angle end, a focal length of the entire system at the wide-angle end, a focal length of the last lens group, and a focal length of the first lens group are satisfied.

Abstract: A variable-magnification projection optical system substantially consists of a negative first lens group that is disposed at the most enlargement-side position and is fixed during magnification change, a positive last lens group that is disposed at the most reduction-side position and is fixed during magnification change, and a plurality of lens groups that are disposed between the first lens group and last lens group and are moved during magnification change. The most enlargement-side lens group (the second lens group) of the lens groups that are moved during magnification change has a negative refractive power. Predetermined conditional expressions relating to a back focus of the entire system on the reduction side at the wide-angle end, a focal length of the entire system at the wide-angle end, a focal length of the second lens group and a focal length of the last lens group are satisfied.

Abstract: A projection objective lens system includes from an object plane to an image plane: a first lens group (S1) with a positive refractive power; a second lens group (S2) with a negative refractive power; a third lens group (S3) with a positive refractive power; a fourth lens group (S4) with a negative refractive power; and a fifth lens group (S5) with a positive refractive power being divided into two sub-lens groups. An aperture stop (AS) is provided between the two sub-lens groups. The following conditions are met: 0.12<|L/f|<0.4, and ?R/R<1%, wherein, f is an effective focal length of the system, L is a distance between the object and image planes, ?R represents a difference between radii at the aperture stop of a marginal field beam bundle and a central field beam bundle, and R represents a radius at the aperture stop of a central field beam bundle.

Abstract: A lithographic projection apparatus includes a projection system having a last element, by which an exposure light is projected onto an upper surface of a wafer through liquid locally covering a portion of the upper surface of the wafer. The last element has a lower surface from which the exposure light is emitted. The last element also has an outer surface which extends upwardly from an edge portion of the lower surface. The apparatus also includes a space along the outer surface of the last element, to which the liquid is supplied from above the lower surface of the last element. The space is defined by the outer surface of the last element and a surface opposing the outer surface of the last element.

Abstract: A projection lens that projects image information displayed on the reduction side conjugate position onto the magnification side conjugate position includes an aspherical lens having a positive refractive power that satisfies predetermined conditional expressions and, when the back focus of the entire system is taken as Bf, the focal length of the entire system is taken as f, the maximum effective image circle diameter on the reduction side is taken as Im?, and the distance from the reduction side conjugate position to the reduction side pupil position is taken as dexp, satisfies conditional expressions (6): Bf/f>2 and (7): 0.5<|Im?/dexp|<1.

Abstract: A catadioptric projection objective for imaging a pattern provided in an object plane of the projection objective onto an image plane of the projection objective has a first, refractive objective part for imaging the pattern provided in the object plane into a first intermediate image; a second objective part including at least one concave mirror for imaging the first Intermediate imaging into a second intermediate image; and a third, refractive objective part for imaging the second intermediate imaging onto the image plane; wherein the projection objective has a maximum lens diameter Dmax, a maximum image field height Y?, and an image side numerical aperture NA; wherein COMP1=Dmax/(Y?·NA2) and wherein the condition COMP1<10 holds.

Abstract: An image projection apparatus is provided, which includes an illumination unit which generates illumination light, a first prism which receives the illumination light from the illumination unit and performs total reflection of the illumination light, a reflection mirror which receives the illumination light from the first prism and reflects the illumination light, an image forming unit which forms an image from the illumination light that is reflected from the reflection mirror, and a second prism which performs total reflection of the image that is formed by the image forming unit toward a screen.

Abstract: A projection lens is provided having a positive refractive power as a whole and including a correction group consisting of a plurality of lens groups that corrects field curvature by moving in an optical axis direction and changing the distance between each lens group. The conjugation length of a combined optical system combining the most magnification side lens group constituting the correction group to the most reduction side lens group constituting the correction group in the projection lens is constant before and after the movement of the correction group for correcting field curvature. If the projection lens is variable in magnification or focusable by moving at least some of the lens groups, the movement of the correction group for correcting field curvature is allowed to be performed independently of the movement for either changing magnification or focusing.

Abstract: A projector optical system is provided, the system including an illumination unit including illumination lenses illuminating light downwards, a display device receiving light illuminated from the illumination lenses to enable to realize an image, projection lenses downwardly projecting light emitted from the display device to a screen, and a field lens changing an optical angle of the light illuminated from the illumination lenses and emitting the light to the display device, and changing an optical angle by receiving an image light of the display device and emitting the light to the projection lenses.

Abstract: An optical projection system for projecting an enlarged image on a projection surface is provided. The optical projection system includes an image forming element, a coaxial optical system and a concave mirror. The coaxial optical system and the concave mirror are arranged in this order on an optical path from the image forming element to the projection surface. The coaxial optical system includes lens groups and an aperture stop that share an optical axis. The lens groups include a first lens group and other lens groups. The first lens group has negative refractive power and independently moves in an optical axis direction for adjusting the focus of the optical projection system. The aperture stop is arranged at a position closer to the image forming element than the first lens group that is arranged closest to the concave mirror among the lens groups having the negative refractive power.

Abstract: A projection-type image display apparatus includes a display device and a projection optical system. The projection optical system includes a first lens group having a positive power as a whole, and a second lens group having a negative power as a whole. The second lens group includes a first lens and a second lens in an order from the display device side, both of which have negative powers. When the first lens is moved toward the display device and the second lens is moved away from the display device with reference to positions of the first lens and the second lens in a direction of an optical axis when an image surface is planar, a focal position of the peripheral light becomes closer to the projection optical system in the direction of the optical axis than a focal position of the on-axis light, and the image surface is made concave to the projection optical system side.

Abstract: The disclosure relates to an optical element configure to at least partial spatially resolve correction of a wavefront aberration of an optical system (e.g., a projection exposure apparatus for microlithography) to which optical radiation can be applied, as well as related systems and methods.

Abstract: The disclosure provides a microlithography projection objective which includes a plurality of optical elements along the optical axis of the projection objective. The plurality of optical elements includes a last optical element and a penultimate optical element. A distance between the last optical element and the penultimate optical element is variable. The disclosure also provides a microlithography projection exposure machine including such a projection objective, and a method of making semiconductor components using such a projection exposure machine.

Abstract: Some embodiments provide for a modular video projector system having a light engine module and an optical engine module. The light engine module can provide narrow-band laser light to the optical engine module which modulates the laser light according to video signals received from a video processing engine. Some embodiments provide for an optical engine module having a sub-pixel generator configured to display video or images at a resolution of at least four times greater than a resolution of modulating elements within the optical engine module. Systems and methods for reducing speckle are presented in conjunction with the modular video projector system.

Abstract: An illumination system of a microlithographic exposure apparatus comprises a condenser for transforming a pupil plane into a field plane. The condenser has a lens group that contains a plurality of consecutive lenses. These lenses are arranged such that a light bundle focused by the condenser on an on-axis field point converges within each lens of the lens group. At least one lens of the lens group has a concave surface. The illumination system may further comprise a field stop objective that at least partly corrects a residual pupil aberration of the condenser.

Abstract: Technology is described for a projection optical system which optically couples image light from an image source to a near-eye display (NED) of a wearable near-eye display device. The projection optical system and the image source make up a projection light engine. Light from the image source is directed to a birdbath reflective optical element which is immersed in high index glass. The image light is reflected and collimated by the birdbath element and travels outside a housing of the projection light engine forming an external exit pupil, meaning the exit pupil is external to the projection light engine. A waveguide optically couples the image light of the external exit pupil. An example of a waveguide which can be used is a surface relief grating waveguide.

Abstract: When a single lens which includes a surface having the smallest effective beam diameter or a cemented lens is designated as a reference lens, a system substantially consisting of lenses disposed closer to a magnification side than the reference lens is designated as a front group, and a system substantially consisting of lenses disposed closer to a reduction side than the reference lens is designated as a rear group, the projection lens satisfying conditional expressions (1) and (2) given below as well as conditional expressions (3) and (4): 75<2???(1) ?P<10??(2) |fM/fF|<2.0??(3), and |fM/fR|<2.0??(4).

Abstract: A projection lens that projects image information displayed on the reduction side conjugate position onto the magnification side conjugate position includes an aspherical lens having a positive refractive power that satisfies predetermined conditional expressions and, when the back focus of the entire system is taken as Bf, the focal length of the entire system is taken as f, the maximum effective image circle diameter on the reduction side is taken as Im?, and the distance from the reduction side conjugate position to the reduction side pupil position is taken as dexp, satisfies conditional expressions (6): Bf/f>2 and (7): 0.5<|Im?/dexp|<1.

Abstract: A projection lens for projecting image information displayed on a reduction side conjugate position to a magnification side conjugate position, including a negative first lens group, a positive second lens group, a positive third lens group, and a positive fourth lens group arranged in this order from the magnification side, which satisfies predetermined conditional expressions.

Abstract: A wide-angle lens comprising: an imaging lens system, including: a front lens group, an aperture, and a rear lens group, arranged in that order from an object side to an image side; wherein said front lens group comprises first and second lens elements, having negative power respectively, and a third lens that is a positive lens, arranged in that order from the object side to an aperture side; wherein said rear lens group comprises fourth and fifth lens elements, having positive power respectively, arranged in order from the aperture side to the image side; where an incident angle to an optical axis of the imaging lens system of a chief ray of a maximum angle of view passing through the aperture is ?I, the following Expression 1 is satisfied. 40° (degrees)<?I<60° (degrees)??Expression 1.

Abstract: A unit magnification Wynn-Dyson lens for microlithography has an image field sized to accommodate between four and six die of dimensions 26 mm×36 mm. The lens has a positive lens group that consists of either three or four refractive lens elements, with one of the lens elements being most mirror-wise and having a prism-wise concave aspheric surface. Protective windows respectively reside between object and image planes and the corresponding prism faces. The lens is corrected for at least the i-line LED wavelength spectrum or similar LED-generated wavelengths.

Abstract: A lithographic projection apparatus includes a projection system having a last element from which an exposure light is projected onto a wafer through liquid in a space under the last element. A light incident surface of the last element has a convex shape. A liquid retaining member is disposed adjacent to a surface of the last element through which the exposure light does not pass. The liquid retaining member has an undersurface under which liquid is retained. A gap is formed between the liquid retaining member and the surface of the last element, the gap being in fluidic communication with the space. The liquid is retained between the last element and the undersurface of the liquid retaining member on one side and an upper surface of the wafer on the other side. The liquid locally covers a portion of the upper surface of the wafer.

Abstract: A projection optical system which, when projecting an image of an optical modulator onto a projection surface on an enlarged scale, differs the aspect ratio of the image of the optical modulator and the aspect ratio of the image projected onto the projection surface, and includes, in order from the projection surface, a first group which is an enlargement optical system; a second group includes an adjustment optical component with a surface rotationally asymmetrical to an optical axis, when defining at least one direction of the vertical direction and the horizontal direction of the optical modulator as an adjustment direction in which conversion adjustment using compression or extension is performed, the adjustment optical component having at least one optical system which differs in power between the adjustment direction and another direction; and a third group which has a correction optical component with a surface rotationally symmetrical to the optical axis.

Abstract: An imaging system having reduced susceptibility to thermally-induced stress birefringence comprising relay optics and projection optics. One of either the relay optics or the projection optics is a reflective optical system that includes reflective optical elements, and the other is a refractive optical system having a negligible or low susceptibility to thermal stress birefringence. The refractive optical system includes: a first group of refractive lens elements located upstream from an aperture stop, and a second group of refractive lens elements located downstream from the aperture stop. The refractive lens elements in the first and second groups that are immediately adjacent to the aperture stop are fabricated using optical materials having a negligible susceptibility to thermal stress birefringence, and the other refractive lens elements in the first and second groups are fabricated using optical materials having at most a moderate susceptibility to thermal stress birefringence.

Abstract: A method for manufacturing a preferably asymmetrical lens element (5a) from a tempered blank (1) is characterized by: producing the lens element (5a) from a first partial volume (1a) of the tempered blank (1), whose thickness d is less than approximately 70%, preferably less than approximately 60%, particularly preferably less than approximately 50% of the thickness D of the tempered blank (1). Preferably, from a second partial volume (1b) of the tempered blank (1) at least a further lens element (5a?) is produced, wherein before the lens elements (5a, 5a?) are produced the tempered blank (1) is divided into the first and second partial volume (1a, 1b).

Abstract: A projection display having at least one light source and also regularly-disposed optical channels. The optical channels comprise at least one field lens, to which respectively one object structure to be imaged and also at least one projection lens are assigned. The distance of the projection lenses from the assigned object structures corresponds to the focal distance of the projection lenses while the distance of the object structures to be imaged from the assigned field lens is chosen such that a Köhler illumination of the assigned projection lens is made possible. Then the individual projections are superimposed to form the total image.

Abstract: In an optical system including a front lens unit having negative refractive power, a stop, and a rear lens unit having positive refractive power in order from an enlargement side to a reduction side, the front lens unit has a combination lens in which a negative lens and a positive lens are adjacently arranged in order from the enlargement side to the reduction side, and a focal length of the negative lens fN, an Abbe number ?N and relative partial dispersion ?N of a material of the negative lens, an Abbe number ?P and relative partial dispersion ?P of a material of the positive lens, and a focal length of the entire optical system fW are appropriately set.

Abstract: An endoscope apparatus includes an objective optical system mounted at a distal end portion of an endoscope, which is inserted into a tube cavity, and configured to form an image of an object in the tube cavity, the objective optical system including a focusing lens movable in an optical axis direction, a solid-state image pickup device for color image pickup configured to pick up the image formed by the objective optical system, a color separation filter being arranged for each pixel in the solid-state image pickup device, a focus adjusting mechanism configured to move the focusing lens and automatically adjust the objective optical system to a focus position in a focused state, a moving range switching section configured to perform switching of a moving range of the focusing lens, a moving range limiting section configured to limit the moving range in association with the switching by the moving range switching section, and the like.

Abstract: A projection zoom lens includes a front lens group, a rear lens group, and an aperture stop. The front lens group has negative refractive power and is disposed adjacent to an object side of the projection zoom lens. The front lens group includes a first lens group, a second lens group, and a third lens group. The rear lens group has positive refractive power and is disposed adjacent to an image side of the projection zoom lens. The rear lens group includes a fourth lens group, a fifth lens group, and a sixth lens group. The aperture stop is disposed between the front lens group and the rear lens group. The third lens group, the fourth lens group, and the fifth lens group move along an optical axis of the projection zoom lens to change an effective focal length of the projection zoom lens when the projection zoom lens zooms.

Abstract: An optical modulation device side lens group has different powers in the longitudinal direction and the lateral direction of a liquid crystal panel. Therefore, as the entire system of the optical projection system, the optical modulation device side lens group has different magnification in the longitudinal and lateral directions. Therefore, it is possible to make the aspect ratio of an image of the liquid crystal panel different from the aspect ratio of an image projected on a screen. That is, conversion can be performed on an aspect ratio. At this time, a distance p between each focus or a diaphragm and the screen SC side end surface of the optical modulation device side lens group satisfies the conditional expressions, so it is possible to achieve a predetermined or higher telecentricity in both states, that is, a first operating state and a second operating state.

Abstract: An optical projection system for projecting an enlarged image on a projection surface is provided. The optical projection system includes an image forming element, a coaxial optical system and a concave mirror. The coaxial optical system and the concave mirror are arranged in this order on an optical path from the image forming element to the projection surface. The coaxial optical system includes lens groups and an aperture stop that share an optical axis. The lens groups include a first lens group and other lens groups. The first lens group has negative refractive power and independently moves in an optical axis direction for adjusting the focus of the optical projection system. The aperture stop is arranged at a position closer to the image forming element than the first lens group that is arranged closest to the concave mirror among the lens groups having the negative refractive power.

Abstract: A catadioptric projection objective for imaging a pattern provided in an object plane of the projection objective onto an image plane of the projection objective has a first, refractive objective part for imaging the pattern provided in the object plane into a first intermediate image; a second objective part including at least one concave mirror for imaging the first intermediate imaging into a second intermediate image; and a third, refractive objective part for imaging the second intermediate imaging onto the image plane; wherein the projection objective has a maximum lens diameter Dmax, a maximum image field height Y?, and an image side numerical aperture NA; wherein COMP1=Dmax/(Y?·NA2) and wherein the condition COMP1<10 holds.

Abstract: In a projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source, the projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.