Abstract: A coupling device for detachably connecting an eyepiece of an endoscope optical system with a camera lens includes a receptacle for the eyepiece, attachment means for securing the eyepiece in the receptacle, and a manually activated handle arranged on the outside for releasing the attachment. The attachment means are controlled by the eyepiece so as to automatically attach the eyepiece in the receptacle while introducing the eyepiece into the receptacle.

Abstract: Optical qualities of a production lot of base material used in the fabrication of semi-finished lenses may be accurately determined by employing chipper plate samples produced from the base material in accordance with aspects of the present invention. In various implementations of the present invention, the chipper plates samples may be fabricated by subjecting base material to an extended cycle time and temperature profile using a mold having cavities of different thicknesses. The resulting chipper plates provide an improved indication of the color of semi-finished lenses molded from the production lot as well as an improved indication of resin stabilizer defects that may be utilized during a pelletizing process to control and enhance the quality of a production lot. Furthermore, the chipper plates may be provided by suppliers as samples of a production lot to enable customers to base purchasing decisions on a reliable and accurate measure of optical properties.

Abstract: An image display device may include an image generator, an ocular lens, an optical unit and a lens barrel. The optical unit may be disposed in an area between the image generator and the ocular lens. The optical unit may include at least one of an exit pupil expander and a mask in one or more arrangements. The lens barrel, when housing the ocular lens and the optical unit, may include an inner circumferential surface on which the ocular lens is supported to be rotatable around the optical axis thereof. The optical unit may, in some examples, be fixed to the ocular lens. A rotational position of the optical unit around the optical axis of the ocular lens is adjustable by rotating the ocular lens.

Abstract: The visual display apparatus of the invention has an image display device, a projection optical system for projection of an image displayed on the image display device, an eyepiece optical system of positive reflecting power that uses an image coming from afar as an image projected from the projection optical system, and a cylindrical or conical diffusing surface located near an image projected from the projection optical system. The image projected from the projection optical system is located in such a way as to draw a circular arc at any position in the plane orthogonal to the optical axis of the projection optical system.

Abstract: In the visual display device of the present invention, the first reflection plane 11 is so disposed as to face the eye point 4 in order of an optical path of reverse tracing that extends from the eye point 4 to the two-dimensional image displaying plane 3; the second reflection plane 21 is so disposed as to face the two-dimensional image displaying plane 3, and an optical axis connecting the first reflection plane 11 to the eye point 4 is so disposed as to cross an optical axis connecting the second reflection plane 21 to the two-dimensional image displaying plane 3; both the first and second reflection planes 11 and 21 have positive power; and diopter difference S of the position of a virtual image associated with diopter is substantially equal to that of the position of a virtual image associated with convergence.

Abstract: Providing a viewfinder optical system capable of obtaining given magnification and a given eyepoint, suitable for an SLR digital camera and an SLR camera, an optical apparatus equipped therewith, and a method for expanding observation. The viewfinder optical system M including an eyepiece optical system 15 for observing a real image of an object formed by an objective lens 11 through an erecting image forming member 14, the eyepiece optical system 15 consisting of, in order from the object along an optical axis, a double concave negative lens, a double convex positive lens, a lens, and a meniscus lens having a convex surface facing the object; an optical apparatus 10 equipped therewith; and a method for expanding observation.

Abstract: A diopter-adjustable eyepiece lens EL, comprising first through third lenses L1 through L3, satisfies the condition ?0.9<S1<?0.3, wherein first lens L1 shape factor S1 denotes a shape factor of the first lens L1, Re1 denotes the radius of curvature of a concave surface of the first lens L1 on an eyepoint EP side and Rs1 denotes the radius of curvature of a concave surface of the first lens L1 on the object side. The diopter adjustment satisfies also the condition 0.4<d2/?d<0.6 wherein d2 denotes an air gap along the optical axis between the first lens L1 and the second lens L2 when diopter adjustment is carried out so that diopter becomes maximum on the negative side, and Ed denotes an air gap along the optical axis between a concave surface of the first lens L1 on the eyepoint side and a concave surface of the third lens L3 on the object side when diopter adjustment is carried out so that diopter becomes maximum on the negative side.

Abstract: A zoom eyepiece lens system EL includes, in order from an eyepoint EP side: a first lens group G1 having positive refractive power; a second lens group G2 having positive refractive power; and a third lens group G3 having negative refractive power. Upon zooming from a low magnification end state to a high magnification end state, the second lens group G2 and the third lens group G3 move along an optical axis in opposite directions with each other. The second lens group G2 includes, in order from the eyepoint EP side, a first lens L3 having negative refractive power, a second lens L4 having positive refractive power, and a third lens L5 having positive refractive power. At least one aspherical surface is formed on the third lens L5.

Abstract: An eyepiece system has a lens group S1 in which a lens L1 having a negative refractive index and refractive power and a lens L2 having a positive refractive index and refractive power are joined, so that the lens group S1 as a whole has a positive refractive index and refractive power; and a multi-layer (stacked) diffraction optical element PF. In an optical system positioned between an image surface I and an eye point EP, the position of a diffraction plane on the optical axis is between EF in FIG. 1. In FIG. 1, EF is the range in which the value ra of the ratio between a distance (DH2) between the diffraction plane (C) and a principal point (H2) near the diffraction plane and a distance (DH1H2) between principal points is 0.5 or less in both directions from the principal points H1, H2.

Abstract: An object of the present invention is to provide a head mounted display capable of an accurate display of a surrounding situation always without affecting the display section even if a frame is deflected, and giving a comfortable mounting feeling as well as easy mounting. For this purpose, the head mounted display comprises: a support member including a pair of lateral frames contacting both of a user's head and a front frame in front of a user's face to contact a user's nose; an image display device for displaying an image; an eyepiece optical system provided in front of an eye of the user to lead the image displayed on the image display device to the user's eye; and a connection section which connects the eyepiece optical system with the front frame at a position corresponding to a center position in a lateral direction of the user's face.

Abstract: An optical scanner including a base body, a drive unit, a deflection status detector and a controller is provided. The base body has a non-linear frequency characteristic and has a first resonance frequency and a second resonance frequency. The controller includes a first upsweep unit which upsweeps a drive frequency from a frequency lower than the first resonance frequency; a dropping phenomenon detector which detects the dropping phenomenon; a target drive frequency determination unit which determines a frequency lower than a frequency at which the dropping phenomenon is detected, as a target drive frequency; a second upsweep unit which upsweeps the drive frequency toward the target drive frequency from a frequency lower than the first resonance frequency; and an adjustment unit which adjusts the drive frequency of the drive signal to keep the deflection status at the target drive frequency after the operation of the second upsweep unit.

Abstract: An eye piece (403) for use in a tunable chromatic dispersion compensator comprises a first strip (4031) made of a first metal, a second strip (4032) made of a second metal, a heater/cooler (4033), and a tunable positioning bar (4034). The second strip (4032) is attached to the first strip (4031), the heater/cooler (4033) is attached to the second strip (4032) for heating/cooling the first and second strips (4031, 4032), the tunable positioning bar (4034) is attached to the heater/cooler (4033) for keeping the position of the eye piece (403) in the tunable chromatic dispersion compensator, and the first metal and the second metal have different expanding coefficients from each other, so that in response to a change in temperature, the shape of the eye piece (403) is changed from a first shape to a second shape. A tunable chromatic dispersion compensator uses the eye piece (403).

Abstract: The light directed from a light source to a concave mirror and the light directed from a display device to an eyepiece optical system are intersected by each other in a layout. This allows the light source, the concave mirror, and the display device to be arranged in compactness adjacent to the eyepiece optical system without increasing the optical power of an illumination optical system. As the result, the apparatus can easily be minimized in the thickness or the overall size. A hologram optical element is provided where the relationship between the wavelength range ??1 at half of the diffraction efficiency of each of the three primary colors of the light in the hologram optical element and the wavelength range ??2 at half of the intensity of each of the three primary colors of the light emitted from the light source is defined by ??1<??2.

Abstract: An eyepiece system has a lens group S1 in which a lens L1 having a negative refractive index and refractive power and a lens L2 having a positive refractive index and refractive power are joined, so that the lens group S1 as a whole has a positive refractive index and refractive power; and a multi-layer (stacked) diffraction optical element PF. In an optical system positioned between an image surface I and an eye point EP, the position of a diffraction plane on the optical axis is between EF in FIG. 1. In FIG. 1, EF is the range in which the value ra of the ratio between a distance (DH2) between the diffraction plane (C) and a principal point (H2) near the diffraction plane and a distance (DH1H2) between principal points is 0.5 or less in both directions from the principal points H1, H2.

Abstract: A display platform orients a virtual image in alignment with a viewer's eye. A transmissive plate receives a light beam conveying the virtual image into the transmissive plate for propagation by internal reflection between inner and outer surfaces of the transmissive plate along the length of the transmissive plate. A plurality of reflective facets progressively interrupt the propagation of the light beam along the length of the transmissive plate for reflecting successive portions of the light beam in a direction for rendering the virtual image visible to the viewer.

Abstract: A lens system includes a first lens axially aligned with a second lens, where the first and second lenses are configured to be sequentially positioned from a pupil image of a viewer. The second lens is formed as a triplet having three cemented elements. The second lens includes a convex surface facing the first lens, and a flat surface opposing the convex surface of the second lens. The first lens includes a concave surface opposing a flat surface of the first lens; the second lens includes a concave surface and a convex surface; and the concave surface of the first lens and the concave and convex surfaces of the second lens have equal radii of curvatures.

Abstract: One embodiment of sighting optics according to the teachings provided herein may comprise a front sight and a rear sight positioned in spaced-apart relation. The rear sight includes optical element having a first focal length and a second focal length. The first focal length is selected so that it is about equal to a distance separating the optical element and said front sight and the second focal length is selected so that it is about equal to a target distance. The optical element thus brings into simultaneous focus for a user images of the front sight and the target.

Abstract: The present invention relates to optical instruments, in particular to magnification loupes, stereo-magnification loupes and magnification viewers, such as those worn by dentists and surgeons.

Abstract: The present invention relates to the optimization of human visual function by correcting and/or optimizing high-order optical aberrations in high performance optical devices. The optimization is particularly useful for high performance devices used under low light conditions such as binoculars, rifle scopes, telescopes, microscopes, night vision goggles and laser eye protection devices.

Abstract: An optical system includes an optical assembly frame having an input portion, an output portion, and an objective lens assembly disposed at the input portion of the optical assembly frame. The objective lens assembly has an objective lens central optical axis. An eyepiece lens assembly is disposed at the output portion of the frame. The eyepiece lens assembly has an eyepiece lens central optical axis parallel to the objective lens central optical axis and offset from the objective lens central optical axis by a distance. An inverting image intensifier is disposed between the objective lens assembly and the eyepiece lens assembly. The image intensifier has an image intensifier optical axis parallel to the objective lens central optical axis and parallel to the eyepiece lens central optical axis. The image intensifier optical axis is offset from both the objective lens central optical axis and the eyepiece lens central optical axis by about half the distance.

Abstract: An image display device projects lights emitted from each of two two-dimensionally light emitting type photoelectric devices onto first and second light diffusing bodies, and projects and images transmitted images of the light diffusing bodies onto the retina in the respective eyeballs of the user. The display device includes one light source, a first polarization beam splitter dividing light emitted from the light source into P-polarized light and S-polarized light, and an optical system which leads each of the P-polarized light and S-polarized lights respectively to the two photoelectric devices thereby illuminating the two photoelectric devices. The optical system leads polarized light to each of the two photoelectric devices via a second polarization beam splitter and a ?/4 plate, and leads reflected lights to the relay optical system via the ?/4 plate and the second polarization beam splitter.

Abstract: In a method for producing a permanent mark in an optical element which consists essentially of a material that is transparent in the visible spectral region, a marking region of the optical element is irradiated with laser radiation in order to generate local, near-surface material changes in such a way that a mark of prescribed shape and size is generated. The laser radiation has an operating wavelength ? from the wavelength region between 1.1 ?m and 9.2 ?m. A thulium-doped fibre laser is preferably used as laser radiation source. The operating wavelength is selected in dependence from the material of the optical element such that the material exhibits a partial absorption with a transmittance between 60% and 98%. The method can be used, in particular, to provide spectacle lenses, contact lenses or intraocular lenses with marks.

Abstract: The present invention relates to the optimization of human visual function by correcting and/or optimizing high-order optical aberrations in high performance optical devices. The optimization is particularly useful for high performance devices used under low light conditions such as binoculars, rifle scopes, telescopes, microscopes, night vision goggles and laser eye protection devices.

Abstract: A lens arrangement suitable for looking through small holes is provided in which no conventional integral physical lens stop is required. The lens arrangement is relatively insensitive to its position, meaning that it may be set back behind the hole reducing the risk of detection and allowing rapid installation.

Abstract: The invention relates to a viewing optical system for viewing an object image formed on a focusing screen, and an imaging apparatus comprising the same. An image erection optical system comprises a prism having an internal reflective surface. An eyepiece optical system comprises, in order from a screen side to an exit pupil side, a first lens component having negative refracting power wherein its exit pupil-side surface has a paraxial-radius-of-curvature absolute value smaller than that of its screen-side surface, a second lens component in a double-convex shape and a third meniscus lens component in a meniscus shape concave on an exit pupil side. The total number of lens components included in the eyepiece optical system is 3, and the following conditions (1), (2) and (3) are satisfied. 1.55<ndp??(1) 0.35<fe/Dip<0.60??(2) 1.0<D3/(D1+D2)<1.

Abstract: The invention relates to an image pickup system comprising an electronic view finder suitable for achieving compactness and having a sufficient viewing angle of field and satisfactory optical performance. The image pickup system comprises an image pickup device, an image display device for displaying an image, a controller for converting image formation obtained from the image pickup device into a signal that enables the image information to be formed on the image display device, and a viewing optical system for guiding an image displayed on the display device to a viewer's eye. The viewing optical system comprises at least three lenses.

Abstract: The invention relates to an image pickup system comprising an electronic view finder suitable for achieving compactness and having a sufficient viewing angle of field and satisfactory optical performance. The image pickup system comprises an image pickup device, an image display device for displaying an image, a controller for converting image formation obtained from the image pickup device into a signal that enables the image information to be formed on the image display device, and a viewing optical system for guiding an image displayed on the display device to a viewer's eye. The viewing optical system comprises at least three lenses.

Abstract: A monolithic optical element for an eyepiece in a head mounted display system has a body, in which a first surface of the body receives light from a display device, the light passes through a second surface of the body to an eye of a user, and a reflective folding surface is located optically between the first surface and the second surface. The reflective folding surface folds an optical path between the first surface and the second surface. Finally, a diffractive optical element is provided on at least one of the first surface or the second surface. The use of the diffractive optical surface enables the eyepiece element to be constructed of a single optical substrate material, yet function over a broad color spectrum with superior resolution and minimal distortion over a large field of view.

Abstract: A lens module assembly and an imaging system are disclosed. The imaging system includes the lens module assembly and an image sensor received in the assembly. The lens module assembly includes a lens module, and a temperature regulator disposed on the lens module. The temperature regulator is configured for keeping temperature of the lens module within a predetermined range so as to ensure image quality of the lens module.

Abstract: A display producing virtual visible images of various virtual display products including visual glasses virtual display, head-mounted display, single eye virtual display and virtual 3D display. It consists of a display worn on eyes and mounted on a fixation rack; this display consists of the lens amplifying device and the micro-display; the foresaid lens amplifying device consists of a lens installation rack and the optical lens mounted on the lens installation rack; a micro-display is equipped at rear part of the lens installation rack; the foresaid micro-display displays images through the connection of drive circuit board with the video device, characterized in that: the foresaid optical lens is an aspherical lens; moreover, the above mentioned aspherical lens realizes optical amplification and achromatic function by single aspherical lens. By using this device, a clear amplified image can be seen in front of the eyes of people.

Abstract: An eyepiece includes, in order from the object side, a first lens with positive power, a second lens with positive power, and a third lens with negative power. The first lens is a positive meniscus lens with a convex surface facing the object side, and the eyepiece fails to have a fourth lens. The eyepiece satisfies the following conditions: 0.6<f1/f<1.2 ?2.0<f1-2/f3<?1.0 ?0.45<f3/f<?0.25 where f1 is the focal length of the first lens; f1-2 is a combined focal length of the first and second lenses and is a focal length where a diopter is ?1 m?1 when the focal length of the eyepiece is changed; f3 is the focal length of the third lens; and f is the focal length of the entire system of the eyepiece and is a focal length where a diopter is ?1 m?1 when the focal length of the eyepiece is changed.

Abstract: A laser riflescope includes a laser emitter, a laser receiver, an objective lens group (11) for collecting the visible light from the target to be measured, an eyepiece group (14) adapted for observation by the user of the distance information of the target and defining an optical axis with the objective lens group, a prism group (12) disposed between the objective lens group and the eyepiece group for light beam transmission, and a display element (13) for displaying the distance information of the target. The display element is an OLED having high transmittance to enhance the display brightness of the laser riflescope.

Abstract: A vision enhancing device for a person having macular degeneration of the retina, comprises a lens and a light diverging surface on the lens that symmetrically diverges away from the eye at an angle relative to an optic axis to redirect incident light away from the optic axis outwardly toward an un-diseased region of the retina. The light diverging surface can be a smooth surface, which can be a continuous curved surface, and can be a diverging conical surface. The lens can be an eyeglass lens, contact lens, intraocular lens, telescopic lens, correction lens, or magnification lens. A light diverging insert having a conical surface and, optionally, an end surface can be used in a lens for redirecting light to the un-diseased region of the retina.

Abstract: This invention discloses improved mold parts fashioned from a thermoplastic resin compounded with an additive to reduce the surface energy of the mold part. The mold parts can be used in manufacturing processes, such as, for example: continuous, in-line or batched processes of ophthalmic lens molds.

Abstract: An eyepiece includes, in order from the object side, a first lens with positive power, a second lens with positive power, and a third lens with negative power. The first lens is a positive meniscus lens with a convex surface facing the object side, and the eyepiece fails to have a fourth lens. The eyepiece satisfies the following conditions: 0.6<f1/f<1.2 ?2.0<f1-2/f3<?1.0 ?0.45<f3/f<?0.25 where f1 is the focal length of the first lens; f1-2 is a combined focal length of the first and second lenses and is a focal length where a diopter is ?1 m?1 when the focal length of the eyepiece is changed; f3 is the focal length of the third lens; and f is the focal length of the entire system of the eyepiece and is a focal length where a diopter is ?1 m?1 when the focal length of the eyepiece is changed.

Abstract: In an exemplary embodiment, an LCD screen hood is provided for use with digital cameras. The hood includes a hood tube that defines a light blocking sidewall having an open camera end and an opposite viewing end and enclosing a longitudinally extending viewpath therebetween. An eyepiece mounted on the viewing end includes an eyepiece lens for enlarging an image on an associated LCD screen disposed at the camera end of the hood tube. An eye cup is mounted on the eyepiece for shielding the eyepiece lens from ambient light. An objective tube fixed to the hood tube carries a three piece objective lens mounted between the eyepiece lens and the camera end of the hood tube. Magnification of the eyepiece lens varies as appropriate between 1× and 2.5×. Rotation of the eyepiece tube provides for diopter adjuxtment.

Abstract: An objective optical system according to the present invention is provided for use in an optical pickup apparatus for recording or reproducing information on an information recording surface of a first optical information recording medium using a first light flux emitted from a first light source, and the objective system includes: a first lens with a positive reflective power including plastic; and a second lens with a positive refractive power including plastic. Opposite optical surfaces of the first lens are convex surfaces, and a refractive power of the first lens and a power of a whole system of the objective optical system satisfy the predefined condition.

Abstract: In an exemplary embodiment, an LCD screen hood is provided for use with digital cameras. The hood includes a hood tube that defines a light blocking sidewall having an open camera end and an opposite viewing end and enclosing a longitudinally extending viewpath therebetween. An eyepiece mounted on the viewing end includes an eyepiece lens for enlarging an image on an associated LCD screen disposed at the camera end of the hood tube. An eye cup is mounted on the eyepiece for shielding the eyepiece lens from ambient light. An objective tube fixed to the hood tube carries a three piece objective lens mounted between the eyepiece lens and the camera end of the hood tube. Magnification of the eyepiece lens varies as appropriate between 1× and 2.5×. Rotation of the eyepiece tube provides for diopter adjuxtment.

Abstract: In a scanning display apparatus an image signal source produces an image signal. A light emitter is coupled to the image signal source and responsive to the image signal to emit light. A lensing system receives light from the light emitter and passes exiting light. A scanner scans the image light. A light sensor detects intensity of background light. A controller adjusts intensity of the image light in response to the detected background light intensity.

Abstract: The invention concerns a method which consists in irradiating at least one face of the article with UV radiation, causing the article to be photodegraded over a thickness of at least 1 ?m, and in contacting the irradiated face of the article with a colouring agent so as to diffuse the colouring agent in the entire thickness of the photodegraded surface layer of the article. The invention is useful for optical and ophthalmologic articles.

Abstract: An ocular or eyepiece lens assembly for a riflescope or spotting scope or other types of telescopic optical systems which may include a three element lens assembly comprised of materials of three different refractive indices, at least one of the lens elements composed of optical plastic material, for example, an acrylic polymer, and having at least one aspheric surface. In one configuration, the ocular includes a first lens component on the objective side which is a positive singlet lens element having at least one aspheric surface, and a second lens component on the eyepoint side (i.e. the side of the observer's eye), the second lens component being a doublet lens composed of a cemented lens pair. The singlet lens is configured to correct aberrations accumulated from the previous optics, such as for the objective lens assembly and the erector lens assembly of a riflescope, and also pre-correct the aberrations caused by the doublet lens located on the eyepoint side of the aspheric singlet lens.

Abstract: An optical device with five air-spaced optical elements. An optical device in the form of an eyepiece is disclosed with a center negative lens and two outer positive lenses on each side of the intermediate negative lens. The eyepiece transmits light from an object to an exit pupil along angles corresponding to the position of a focus point on an object. In a preferred embodiment the positive lenses are identical.

Abstract: An optical system for a laser riflescope includes, an objective lens group (1), an eyepiece lens element (3) defining an optical axis with the objective lens group, and an erector lens group (2) positioned between the objective lens group and the eyepiece lens element. The eyepiece lens element includes an aspheric element having a diffractive configuration (33). The aspheric element combines with a spherical lens so as to form a hybrid lens. Thus, the spherical aberration of the optical system is eliminated by the aspheric element and the chromatic aberration is eliminated by the diffractive configuration.

Abstract: An eyepiece lens includes first lens group G1 having a negative refracting power including a negative meniscus lens with a concave surface facing eyepoint E.P side, second lens group G2 having a positive refracting power including a lens with both convex surfaces on both ends, and third lens group G3 having a negative refracting power including a negative lens. The first–third lens groups are arranged in an order from eyepoint E.P side, and the eyepiece lens is capable of varying a diopter by moving the second lens group along an optical axis. The eyepiece lens is configured by aspherical surfaces to make the positive refracting power weak while at least one surface of the convex surfaces of the lens deviates from the optical axis. Further, conditions of a following formula are satisfied: 1.6<f1/f3<2.5 ?0.

Abstract: The object of the present invention is to provide an eyepiece lens having a large pupil diameter of 10 mm or more, securing higher magnification, equipped with a high quality diopter adjustment function at low cost. The eyepiece lens includes, in order from an eye point side EP, a negative meniscus lens L1 having a concave surface facing to the eye point side EP, a double convex lens L2, and a negative lens L3. Diopter of the eyepiece lens is adjusted by moving the double convex lens L2 along an optical axis. At least one surface of the double convex lens L2 has an aspherical surface having positive refractive power getting weaker in accordance with increase in a distance to the surface from the optical axis, and given conditional expressions are satisfied.

Abstract: An observation optical system of the present invention comprises an image erect optical system and an eyepiece optical system for observing an object image. The eyepiece optical system comprises a positive single lens having double convex surfaces and a negative meniscus lens having a concave surface directed toward eye point side, and the following condition is satisfied: 0<S<0.3 0.05<d1/f<0.15 where S=(r1?r2)/(r1+r2), r1 is a curvature radius of the object image side surface of the negative meniscus lens, r2 is a curvature radius of the eye point side surface of the negative meniscus lens, d1 is a distance of air space between the positive single lens and the negative meniscus lens, which represents a distance of air space when diopter of the observation optical system is adjusted to be ?0.8 (m?1) if the air space is changed, and f is a focal length of the eyepiece optical system.

Abstract: The invention relates to a display system wherein a Fresnel lens that forms an eyepiece optical system is curved to correct for decentration aberration, whereby a display screen can be wholly observed even in a decentered state. In the display system, an object image is projected via a relay optical system 2 near the eyepiece optical system 1 so that the exit pupil E1 of the relay optical system 2 is projected via the eyepiece optical system 1 onto an observer's pupil position E0. The eyepiece optical system comprises an optical element having a Fresnel surface. The eyepiece optical system 1 and relay optical system 2 are located such that an axial chief ray emerging from the relay optical system 2 is obliquely incident on the eyepiece optical system 1. The axial chief ray is defined by a light ray emerging from the center of the object, and passing through the relay optical system 2 and then through the center of the pupil E1 of the relay optical system 2.

Abstract: An optical system for use in a head-mounted display is provided which includes a microdisplay (4) and a magnifier (10) for producing a magnified image of the microdisplay for viewing by a human eye. The magnifier (10) includes a diffractive surface and has in order: a first element (1) having a first surface (S1) which is convex in the direction of the long conjugate, a block (3) of optical material, and a second element (2) having a second surface (S2) which is convex in the direction of the short conjugate. The first surface (S1) is preferably the diffractive surface. The magnifier provides a long eye relief, a large exit pupil, and a large field of view with a minimum of components.

Abstract: A finder optical system includes an eyepiece optical system with a positive refracting power. The eyepiece optical system includes an optical unit with a positive refracting power and a lens unit with a positive refracting power, In the eyepiece optical system, a refracting surface that is located most distant from an eyepoint of the eyepiece optical system has a positive refracting power and is configured as an aspherical surface with a negative refracting power on a periphery thereof.

Abstract: An observation optical system comprises an image display element 5 and an eyepiece optical system which introduces an image formed by the image display element 5 to a center of an eye of an observer without forming an intermediate image, so as to allow the observer to observe the image as a virtual image. The eyepiece optical system is constructed and arranged to bend the optical axis using reflecting surfaces so as to be compact. The optical axis lies in a plane, with respect to which the optical system is formed symmetric. The optical system includes a prism 3 having an entrance surface 33, a plurality of curved reflecting surfaces 31, 32 and an exit surface 31. The reflecting surface 32 is provided with a volume hologram (HOE) 4.