Abstract: A projection tube featuring good accuracy in controlling a slant angle between a cathode ray tube and a projection lens, an excellent focusing performance, and further low production cost, and also a video projection systems which utilizes the foregoing projection tube. There are a spacing member to control the slant angle and according to the slant angle, both being built between a cathode ray tube and a radiator.

Abstract: An optical projection system capable of displaying an image of M.times.N pixels in various sizes, wherein M and N are integers, comprises an non-point light source, a collimating lens, a focussing lens, an optical baffle, an array of M.times.N actuated mirrors, and a varifocal projection system including a positive power lens and a negative powers lens separated by a distance, wherein the image in various sizes is provided by changing the distance between the positive and negative power lenses in the varifocal projection lens system.

Abstract: The projection-lens driving apparatus having a housing with a top and a bottom faces for use in a 3-beam projector includes an upper plate, an upper projection-lens holder, a pair of cross link, a pair of lower projection-lens holders, a guide bracket, a sliding plate, an upper guide member, a lower guide member, a timing belt, a driving means divided into a first driving means for driving the upper guide member and a second driving means for driving the lower guide member. The upper and the lower projection-lens holders is respectively fitted to the upper and the lower guide members mechanically and physically in such a way that they can be driven integrally using the driving means, thereby allowing the images to coincide on the screen accurately and, above all, simultaneously.

Abstract: In a projection type display apparatus for illuminating a projection original image with light from a projection light source, and projecting light transmitted through the illuminated original image using a projection lens, light reflected by a projection surface is extracted from a position at an original image side of the projection lens or in the projection lens, and the extracted light is received by a focus detection unit.

Abstract: The projection-lens driving apparatus for use in a 3-beam projector comprises an upper plate, an upper projection-lens holder, a pair of cross links, a pair of lower projection-lens holders, a guide member, and a driving means for driving the guide member. The upper and the lower projection-lens holders are fitted to the guide member in such a way that they can be driven integrally using the driving means, thereby allowing images to coincide on a screen simply, accurately and, above all, simultaneously.

Abstract: A projector is provided which is capable of performing projection and automatic focusing with one optical system and of being set in an arbitrary direction relative to the screen. The projector is provided with a projector lens, a liquid crystal panel, a light emitting device, a light receiving device, two prisms which direct a light beam from the liquid crystal panel and a light beam from the light emitting device to the projector lens and scan the light beams in two directions vertical to the optical axis of the projector lens. The image light beam from the liquid crystal panel and the light beam from the light emitting device are projected onto the screen through the projector lens. The light beam from the light emitting device reflected by the screen is received through the projector lens and the prisms. A position controller moves the projector lens forward and backward while scanning the light beam from the light emitting device by the prisms.

Abstract: A head-mounted display apparatus wherein an image displayed on an image display device is projected on an observer's eyeball, which is designed so that the displayed image can be observed at a desired angle of view and at a desired magnification by making the projection magnification changeable. The head-mounted image display apparatus includes an image display device (11) for displaying an image, and a projection optical system for projecting the image displayed on the image display device (11) onto an observer's eyeball. The projection optical system is composed of a first relay optical system (12), a second relay optical system (13), and an ocular optical system (14). The second relay optical system (13), which is an afocal optical system, is rotatable about an axis (16) perpendicular to the optical axis so that the projection magnification is changed in three steps by the rotation of the second relay optical system (13).

Abstract: A focusing lens 24 is held with a holder 27. A mounting plate 28, and a coupling plate 29 are provided between the holder 27 and the base member 26 of an optical system 10. In one of three combinations of the holder 27 and the mounting plate 28, the latter 28 and the coupling plate 29, and the latter 29 and the base member 26, those forming the combination are set in such a manner as to be movable relative to each other for adjustment of the length of an optical path of the focusing lens; in another of the three combinations, those forming the combination are set in such a manner that the components are movable relative to each other for adjustment of the optical axis of the focusing lens; and in the remaining combination, those forming the remaining combination are fixed in such a manner as to be movable relative to each other for adjustment of the resolving power balance of the focusing lens.

Abstract: An optical projection apparatus comprising, in this order, a radiation source (30), a liquid crystal display panel (33) and a projection lens (35). By arranging the axis of a projection lens portion (21 ) at an angle of substantially 90.degree. with the axis (L) of the remaining portion (29a), a compact apparatus is obtained, the projection axis of which can easily be set, by rotating the projection lens portion around an axis is parallel to the remaining portion axis.

Abstract: An autofocus device for still projection apparatus employing a light source and dual photoreceiver. A signal generator applies variable current pulses to the light source. A signal processing circuit converts output signals from the dual photoreceiver into digital signals from which direction and speed control signals are derived and applied to focus control means. Alternative signal processing circuits are disclosed for driving either an analog on digital stepper focus drive motor.

Abstract: An optical apparatus including an optical assembly having an image formation optical system and a device for receiving an image, said optical assembly including optical components disposed along an optical axis for projecting the image to a display surface, a detecting device for detecting each distance to a plurality of predetermined locations which are set apart from each other and for producing detection signals representing a non-orthogonal relationship between the display surface and the optical axis, and a controlling device for biasing at least one of the components included in the optical assembly in response to the detection signals thus obtained. Then, a part of such an optical assembly is driven in a direction perpendicular to the optical axis, thus making it possible to implement an optical apparatus capable of obtaining a projected image which is in focus all over the screen without distortion.

Abstract: An image projection device comprising at least one display panel (26, 27, 28), a projection lens system (C) and a focus-error detection system is described. The focus-error detection system comprises an auxiliary radiation source (50) delivering a focus measuring beam (b), an auxiliary lens (61) for capturing radiation (b.sub.r) diffusely reflected by a projection screen (D), and a detection unit (60) for measuring the size of a spot (S) formed on the screen by the beam (b).

Abstract: An image projection system for projecting an image obtained on an image field onto a screen through a projection lens comprises a plurality of spacers overlaid with each other and arranged between the image field and the lens, each of the spacers having first and second surfaces through which the image is projected and an angle defined by the first and second surfaces being a predetermined value, an adjusting device for each of the spacers for adjusting a rotational angle of the spacers on a rotational axis substantially parallel to an image projection direction, and a fixing device for fixing the plurality of spacers relative to the image field and the lens.

Abstract: An image projection device comprising at least one display panel (26, 27, 28), a projection lens system (C) and a focus error detection system (FS) is described. Since the radiation source (50) and the radiation-sensitive detector (51) of the focus error detection system are arranged in planes which effectively coincide with the plane of the display panel (28), and a focus measuring beam b traverses the projection lens system twice on its path to and from a projection screen (D), an accurate and reliable focus error signal (S.sub.f) is obtained.

Abstract: An apparatus comprises an image sensing optical system including an image pickup element for converting an image to an electrical signal and a projection lens for projecting an image onto a photo-sensing plane of the image pickup element. The image sensing optical system is driven along an optical axis thereof while maintaining a relative positional relationship between the projection lens and the image pickup element to adjust the focal position. An apparatus may also comprise an image sensing optical system including an image pickup element for scanning an image to convert it to an electrical signal and a projection lens for projecting an image onto a photo-sensing plane of the image pickup element, a focus adjusting device for adjusting a focal position of the image sensing optical system and a detector for detecting an in-focus position of the image sensing optical system to the object.

Abstract: A method of automatically focusing glass-mounted and glassless slides, permitting quick and reliable focusing as a function of the thickness of the glass mount. According to the invention, the multiple IR radiation images of a mask aperture reflected from glass-mounted slides are focused onto a CCD line sensor. Number and spacings of the images are subsequently electronically detected with respect to their sequence on the CCD line sensor, the second image detected being projected onto a predetermined cell of the line sensor by shifting an autofocusing device and projection lens carrier by means of an electromechanical adjusting apparatus, the cell corresponding to a focused projection image of a glassless slide. Simultaneously, a signal is electronically produced corresponding to the spacing between a first and a second aperture image and cause the projection lens to be shifted by the adjusting apparatus within the autofocusing device carrier by the spacing determined.

Abstract: A projection optical apparatus comprises an illuminating device for illuminating an image, and a projecting device for projecting the image illuminated by the illuminating device onto a predetermined plane. In the projection optical apparatus, the projecting device has an NA on a side of the predetermined plane changed depending upon a projection magnification of the image onto the predetermined plane.

Abstract: A projector (100) including an liquid crystal display image source (120), a field lens (126), and a projection lens (128) projects a full-color image by projecting and converging images of multiple liquid crystal displays ("LCDs"). The image is properly positioned without keystoning by tilting the field lens and offsetting the center of the LCD image source from the optical axis (142) of the projection lens. Trapezoidal error is eliminated by maintaining the optical center (156) of the field lens on the optical axis of the projection lens. During focusing, a mounting apparatus (164) adjusts the offset (154) between the center of the LCD and the optical axis of the projection lens for proper convergence of the images and maintains the optical center of the field lens on the optical axis of the projection lens.

Abstract: A projection optical apparatus for projection an image of an object onto a workpiece, which is suitable for use, for example, as an exposure apparatus used in the manufacture of integrated circuits. The projection optical apparatus includes an image forming optical system whose optical characteristic is changed by the light energy supplied from the illuminated object. A change of the optical characteristic of the optical system is determined by the use of a predetermined parameter whereby when the distribution of the light energy on the pupil of the optical system is changed, the parameter is correct in such a manner that the change of the optical characteristic determined by the parameter is changed in correspondence to the change in the distribution of the light energy.

Abstract: An image combining and projecting apparatus having a plurality of light transmission type image panels through which light beams are transmitted, condenser lenses corresponding to the light transmission type image panels, a beam combining mechanism which combines beams transmitted through the image panels, and a projection lens through which beams are projected after being combined by the beam combining mechanism, wherein the condenser lenses are provided on the light outgoing side of the corresponding image panels. The apparatus further has a condenser lens adjusting mechanism for adjusting the positions of the condenser lenses.

Abstract: There is disclosed a video projector provided with automatic focusing function. An image is generated on a liquid crystal light valve according to the video signal, and this image is projected through a projection lens system. The aberration between the focal plane of the projection lens system and the projection surface, such as a screen, is detected, and the focal plane is shifted according to thus detected aberration, in such a manner that the focal plane coincides with the projection surface or screen.

Abstract: A relatively small liquid-crystal display (LCD) device located well above the fresnel stage of an overhead projector produces large, sharp images with full color and motion. A focus-correcting lens moves with the overhead projector's optical head to maintain proper projection-focus and magnification. Spectrally-selective filters are interposed between the LCD device and fresnel stage to avoid LCD deterioration. A fan-actuated shutter or electrically-actuated shutter optionally provide still further protection. Optical collimation methods are employed to attain a large depth-of-field and image brightness.

Abstract: An image projecting unit is shown which comprises a structure having a display surface on which a visual image is displayed, and a lens assembly movably arranged in front of the display surface of the structure. The lens assembly has a rearmost lens which faces the display surface. A bellows is disposed between the display surface and the rearmost lens to define therebetween a sealed space, and a liquid is contained in the sealed space to optically connect the display surface and the rearmost lens.

Abstract: An illumination system for use in an image projection apparatus, having a light source assembly which includes a lamp and a concave reflector for producing convergent light, and an illumination lens group which includes, in order from the light source assembly side, a first lens unit of a negative power movable along the optical axis, a second lens unit of a positive power and a third lens unit of a positive power. The illumination lens group fulfills the following equation,.phi.1+.phi.2<0where .phi.1 and .phi.2 represent the powers of said first and second lens units, respectively.

Abstract: Light beams containing image information from a plurality of liquid crystal panels are converged by condensing lenses. The converged light beams are combined by dichroic mirrors and projected onto a screen by a single projecting lens. The liquid crystal panels and condensing lenses are supported by an adjusting unit, and can be moved independently, in the direction of their respective optical axes.

Abstract: In a projection-type optical apparatus in which a projection optical system projects an image of an object upon a substrate, a position detecting sensor mechanically connected to the projection optical system detects the position of the projection optical system relative to the substrate along the optical axis of the projection optical system. A displacement measuring device measures relative displacement between the position detecting sensor and the projection optical system along the optical axis. The substrate is brought into coincidence with an optimum image forming plane of the projection optical system on the basis of the position detected by the position detecting sensor and the displacement measured by the displacement measuring device.

Abstract: A video projection system having a liquid crystal panel with a video image, a projection lamp with ON/OFF control, a zoom lens with a zoom control mechanism, a focusing lens with a focusing control mechanism, an audio system with a volume control, a projection-lamp light detector, a heat sensor, a variable-speed cooling fan, a control module having a microprocessor and a digital-to-analog converter, a display, a keypad, an alarm/annunciator, a power supply with ON/OFF control, and an infrared based remote control system able to control power ON/OFF, zoom, focus, picture, and sound volume.

Abstract: A magnifier apparatus for use with a hand-held video display apparatus which magnifier apparatus has a frame with a magnifier lens, the frame secured to a support, the support releasably adapted to be secured in a snap-in relationship to the sides of the housing of the video display apparatus in an upright, correct position, the frame with the magnifier lens adapted to move between an open, use position over the screen of the video display apparatus and a closed, non-use position nested within the support.

Abstract: An exposure method and apparatus in which a first member such as a reticle is illuminated with a light from a light source such as an excimer laser so that the image of a pattern carried by the first member is projected through a projecting optical system onto a second member such as a semiconductor wafer, thereby exposing the second member to the pattern. At least one of the first and the second members and the projecting optical system is adjusted along the optical axis of the projecting optical system and the focus condition of the pattern image on the second member is detected by a focus detecting device during the movement of the member. The exposure is effected in accordance with the output signal from the focus detecting device without requiring the movement of the member to be stopped.

Abstract: A projection exposure apparatus includes a projection optical system for projecting an image of a pattern of a first object to a second object, and an adjusting system for adjusting projection magnification and distortion of the projected image of the pattern, the adjusting system being operable to displace the first object and a lens element of the projection optical system in a direction of an optical axis of the projection optical system.

Abstract: A projection display apparatus, which projects a magnified image onto a screen, comprises an image forming system, such as a display panel, a projector including a plurality of lenses for projecting the image onto the screen, and a decentering mechanism for decentering some lenses in the projector with respect to the optical axis. Even if the image is distorted by arrangement of the screen and the optical axis and so on, the distortion is compensated by decentering the lenses and producing a decentering distortion.

Abstract: A drawing production aide is disclosed which is designed to be placed over a working surface where an artist, engineer or architect is drawing. The device includes a carrier for a drawing and a light and lens system designed to project the drawing on the working surface. In a further aspect, the inventive aide includes an adjustable grid device designed to be used to visualize a scene in terms of a plurality of subsections, to best facilitate drawing the scene.

Abstract: An illumination system for use in an image projection apparatus, having a light source assembly which includes a lamp and a concave reflector for producing convergent light, and an illumination lens group which includes, in order from the light source assembly side, a first lens unit of a negative power, a second lens unit of a positive power movable along the optical axis and a third lens unit of a positive power. The illumination lens group fulfills the following equation,1+2<0where 1 and 2 represent the powers of said first and second lens units, respectively.

Abstract: A three-tube color projection television. The outside projection optics are arranged so that a single part can be produced for use in projection televisions of diverse screen size. An image surface correcting lens is at a fixed angle with respect to the face of a projecting tube. The fixed angle corresponds to the Scheimpflug angle of one screen size. A focusing lens is at an adjustable angle with respect to the image surface correcting lens, thereby allowing overall angle adjustment and use of the part in projection televisions of diverse screen size.

Abstract: A stage light projector including an electronically controlled lens system capable of independently positioning two lenses of a triplet lens system to focus light from different selected back focal plane distances to project images having different selected sizes upon a screen or stage at a selected distance.

Abstract: A microfilm image reader apparatus for detecting an image on a microfilm strip and projecting the detected image onto a target plane, wherein a beam of light bearing an image detected from the microfilm strip is produced by illuminating the microfilm strip and is projected through a projection lens onto the target plane, and wherein an automatic mode of focus control is established through detection of a condition in which the image-bearing beam is focussed with respect to the target plane and, when it is detected that the automatic mode of focus control is inoperable, the projection lens is automatically moved to a position having its focal plane located on a predetermined plane with respect to the target plane and, after the projection lens is moved to such a position, the focal plane of the projection lens may be manually adjusted by the operator of the apparatus.

Abstract: A projection apparatus for projecting through an optical system a circuit pattern formed on a mask or reticle onto a wafer. Ambient or environment conditions of the apparatus, such as an atmospheric pressure, temperature and humidity are detected and, on the basis of the results of detection, any focus error and magnification error upon pattern projection on the wafer are corrected.

Abstract: An illumination device includes a light source; a secondary light source forming system for forming predetermined secondary light sources by use of light from the light source, the secondary light source forming system including a plurality of lens array units disposed in the direction of an optical axis and each having a plurality of lens elements distributed in a plane perpendicular to the optical axis; an optical system for directing light from the secondary light sources to a surface to be illuminated; and an actuating device for displacing at least one lens array unit in the direction of the optical axis to adjust the illuminance distribution on the surface being illuminated, while maintaining a substantially constant range of illumination on the surface being illuminated.

Abstract: An optical apparatus wherein an image is to be focused onto a generally rectangular projection surface through a projection lens and wherein a focal state at a particular location of the projection surface is to be detected to move the projection lens on the basis of the result of detection of the focal state, a method of automatically controlling the focal point of the projection lens, characterized in that, when it is found that the focal state of the particular location of the projection surface can not be detected, a focal state at another location of the projection surface is detected to move the projection lens with respect to the projection surface on the basis of the result of the detection at the other location.

Abstract: A projecting optical apparatus has a light source which is located above a document supporting plate to illuminate a document located on the document supporting plate. A projecting lens system is located above the document supporting plate to project an image of the document on a projection screen. A reflection mirror reflects the light transmitted through the projecting lens system toward the projection screen to make an image on the projection screen. The projecting lens system and the reflection mirror are incorporated in a projecting reflection unit, so that the projecting reflection unit is movable in directions substantially parallel with the plane of the document supporting plate.

Abstract: A projecting apparatus has a fixed mirror and two rotary mirrors whose rotary axes cross each other at a right angle are disposed on the projection side of a slide projector. An image is moved on a screen by controlling the angle of rotation of each of the rotary mirrors. With this arrangement, it is possible to impart motion to the image without need to perform projection while switching the slide projectors or to move the slide projectors themselves.

Abstract: A microfilm reader comprises a microfiche moving mechanism for sandwiching a microfiche film between an upper glass plate and a lower glass plate and moving the film in two-dimensional directions, and a projecting optical system for projecting images recorded on the film to a screen. The projecting optical system includes a projecting lens housed in a lens case placed on the upper glass plate of the microfiche moving mechanism. This lens case is raised away from the upper glass plate when the microfiche moving mechanism is in motion. The upper glass plate is raised only when the microfiche moving mechanism is in a home position for inserting and removing the microfiche film to/from a position between the upper and lower glass plates.

Abstract: A variable power reflectory type overhead projector for forming a projected luminous beam by lighting a reflecting mirror from the projecting lens side. A transparent film-to-be-projected support is provided between a regular position of the film to be projected and the projecting lens, and an auxiliary lens is included for focusing the projecting lens on the support.

Abstract: A microfilm image processing apparatus in which a plurality of zoom lenses having different ranges of magnification are provided for selective use and in which each of the zoom lenses has an associated zoom control gear coaxially disposed aroung the lens to be capable of driving the associated zoom lens for axial movement to vary the effective magnificatio ratio to be achieved by the lens, wherein an angular position detector of, for example, the stroboscopic pickup type is provided in conjunction with the zoom control gear on at least one of the zoom lenses to detect the angular position of each of the zoom lenses and thereby determine the magnification ratios achievable by the individual zoom lenses, and an integral magnification ratio detector is provided in association with the zoom control gear on each of the zoom lenses to detect a particular angular position of the associated zoom control gear, the particular angular position of each zoom lens being such that the zoom lens associated with the gear prov

Abstract: A magnified image projector apparatus such as a microfilm strip reader or a microfilm strip printer apparatus having an automatic focus control system and a tiltable reflector mirror by means of which the image-carrying beam passed through an image projection lens may be directed to advance along one path of light toward the viewing screen to along another path of light to a photodetector unit of the focus control system which comprises a focusing lens located in the path of light between the tiltable reflector mirror and the photodetector unit so that the image-carrying beam passed through the projection lens may be incident on the photodetector unit to a reduced scale. This arrangement of the focussing lens allows significant reduction in the effective light receiving area of the photodetector unit used in the apparatus while enabling the photodetector unit to accurately detect the location at which the beam is focussed by the projection lens.

Abstract: An apparatus for transferring images of a pattern of a reticle onto a semiconductor wafer, by projection exposure through a projection lens system having a plurality of lens components. In the apparatus, environmental conditions such as temperature, pressure, humidity, etc. are sensed and a focus error and a magnification error of the projection lens system related to the changes in the environmental conditions are calculated. On the basis of the thus calculated focus error, the interval between the projection lens system and the semiconductor wafer in the direction of an optical axis of the projection lens system is adjusted, while, on the basis of the calculated magnification error, at least one of the lens components of the projection lens system is displaced in the direction of the optical axis of the projection lens system. By this, a satisfactory imaging performance of the projection lens system is stably assured, regardless of the changes in the environmental conditions.

Abstract: Multi-lens slide projection apparatus for displaying transparent fingerprint records in side-by-side and juxtaposed relation to one another. Each lens system is independently mounted on a gimbaled platform having externally accessible tilt and rotation control mechanisms for one or both platforms for varying the relative positions of each platform to the other to orient the projected images without skewing or paralax.

Abstract: A multiple lens image rotation system includes an elongated base fixedly mounted to a microfilm reader apparatus having a plurality of projection lenses with different magnification levels on a carrier movably mounted with respect to the base. The carrier is adapted to move along an axis generally parallel to the longitudinal axis of the base defining a first position wherein one projection lens is aligned with an image projection path and a second position and subsequent positions wherein other projection lenses are aligned with the image projection path. A single image rotation prism is rotatably mounted in the image projection path for use with the plurality of projection lenses one at a time. The image rotation prism is adapted to rotate about an axis generally coaxial with the image projection path.

Abstract: A overhead projector including a projection lens and a deflection mirror for directing the light projected from the lens toward a screen, both the lens and the mirror being individually pivotally movable about horizontal axes parallel to each other and to the original support surface of a stage. The lens is pivotally movable in accordance with variations in the angle of inclination of the mirror and is also pivotally movable with the focusing operation of the lens by an interlocking mechanism. The lens is brought to a proper pivotally moved position by the mechanism according to the angle of elevation and to the focusing operation to project images free of trapezoidal distortion and less of focus.

Abstract: An overhead projector which has a stage for supporting an original thereon comprises an optical system for collecting light to the entrance pupil of a projection lens and a movable mirror for directing light from an illumination light source to an optical system.The movable mirror is movable with the movement of the projection lens parallel to the plane of the stage for placing an original thereon so that trapezoidal distortion and loss of focus which occur when the projection lens projects an image at an oblique angle are avoided. The position for the collection of the illumination light by the optical system is changed according to the movement of the projection lens, and illumination light is always collected at the position of the entrance pupil of the projection lens.