Abstract: Disclosed is an optical fingerprint acquisition apparatus capable of reducing an image distortion and a size of an optical system by deforming the shape of a prism. The prism according to the invention includes a fingerprint contacting surface to be touched by a fingerprint of a person, a totally reflecting surface facing the fingerprint contacting surface with an angle &thgr; for totally and inwardly reflecting the light scattered from the fingerprint in contact with the fingerprint contacting surface, a primarily projecting/re-incident surface linking the fingerprint contacting surface to the totally reflecting surface with an angle &phgr; for primarily projecting the light totally reflected from the totally reflecting surface so as to be re-incident from outside, and an ultimately projecting surface facing the primarily projecting/re-incident surface for ultimately projecting the light re-incident to the primarily projecting/re-incident surface toward outside.

Abstract: The invention concerns an apparatus for simultaneous zero-degree and oblique illumination for an optical viewing device, in particular a stereoscopic surgical microscope, which contains a shiftable prism combination (3) for deflecting a first illumination sub-beam a long distance from the optical axis (12) of the main objective in order to obtain an oblique illumination beam (9) (oblique illumination), and for deflecting a second illumination sub-beam (8) a short distance from the optical axis (12) of the main objective in order to obtain a zero-degree illumination (8).

Abstract: The present invention includes time delay devices and time delay systems. The invention also includes machines and instruments using those aspects of the invention. The invention may also be used to upgrade, repair, or retrofit existing machines or instruments, using methods and components known in the art. The present invention comprises a true time device that falls into the free-space category but uses a multiple-pass optical cell with refocusing mirrors that has the advantage of avoiding beam-spreading problems. This approach differs from previous free-space approaches in that it uses only one optical switch or spatial light modulator instead of one or more switches for each bit. In one approach, a microwave signal for each antenna element may be modulated onto an optical beam. After the individual optical beams are delayed by the desired amount of time through the system, the signals may then be down-converted to microwave signals for further processing.

Abstract: Novel optical devices, which are referred to as composite prisms in this document, have been designed, produced and tested. They have the potential to be useful for a number of vision related applications. For high prism diopter (15 prism diopters or more), composite prisms have resulted in thinner, lighter and lower aberration optical devices than the standard ophthalmic prisms currently in use. They also offer significantly better optical quality than the Fresnel press-on prisms which are also used to correct several ophthalmic disorders.

Abstract: An optical film for use in transparent displays, such as reflective LCDs. The optical film has three-dimensional, prismatic structures that reflect incoming light. The prismatic structures are elongate structures configured so that the reflecting facets orient the reflected light in desired reflective light pattern. The pattern shape and intensity can be controlled by the shape and dimensions of the various reflecting facets. In one embodiment, the height of the prismatic structure varies along the elongate structure.

Abstract: An improved lateral transfer retroreflector assembly is provided. The lateral transfer retroreflector assembly of the invention comprises a first segment comprising a mirror panel housing, a second segment comprising a roof mirror housing, and a third segment comprising an off-the-shelf connecting member between the two housings. The mirror panel housing will have mounted thereto a mirror panel. The roof mirror housing will have mounted thereto a roof mirror assembly, and the connecting member will be mounted between the mirror panel housing and the roof mirror housing. The off-the-shelf aspect of assembling the connecting allows the assembly to be built to customer specifications, thereby allowing for customized creation of lateral transfer retroreflectors, but at a time and cost savings to the customer.

Abstract: The object of the present invention is to provide a real image viewfinder optical system with high optical performance and compactness, whose dimension of a whole optical system including an image inverter optical system is small in the thickness direction, and whose dimension to an object side of an eyepiece lens system is small in the thickness direction. A real image viewfinder optical system comprises, in order from an object side, an objective lens system having a positive refractive power as a whole, an eyepiece lens system for observing a real image formed by the objective lens system and having a positive refractive power, and an image inverter optical system for erecting the image to be observed and arranged to an exit pupil side of a lens located to the most object side of the objective lens system and also to the object side of a lens located to the most exit pupil side of the eyepiece lens system. Conditional expressions are satisfied.

Abstract: A prism includes a prism base member having first and second faces intersecting with each other and including calcium fluoride, an antireflection film for oblique incidence formed on the first face of the prism base member, and an antireflection film for 0° incidence formed on the second face of the prism base member. Each of the antireflection film for oblique incidence and the antireflection film for 0° incidence includes a high-refractive-index layer with a relatively high refractive index, and a low-refractive-index layer with a relatively low refractive index. The high-refractive-index layer includes thorium fluoride and the low-refractive-index layer includes aluminum fluoride.

Abstract: An optical device has a base body with a surface, a first optically effective, multilayer system in the base body, terminating at an intersection, and a second optically effective, multilayer system. The second system has a layer along the base body surface, spanning the intersection. The surface of the base body, including the intersection, are jointly treated by at least one of: milling, grinding, polishing, and lapping. A further base body with a further surface and a third optically effective system terminating at a further intersection area at the further surface also has a further layer between the second optically effective multilayer system and the further surface.

Abstract: There is disclosed an optical system for light beam amassment and concentration derived through intensification by cyclical accretion of light energy by passing a parallel light beam perpendicular to a 100% reflection double-faced conical optical glass prism repetitively cyclically via plural 100% reflective single-faced right-angle isosceles optical prisms arranged in a path surrounding said compound optical glass prism defining an endless recycled return path to and through said compound optical glass prism, the amassment occurring during the passage of said light beam through said compound conical prism to be reflected from the conical prism as an emergent amassed and concentrated light beam occasioned by each repeated pass to and from said conical portion of said compound prism and to and through a beam-splitting quadrivial prism to said return path to said compound prism and the conical prism portion thereof and emergence therefrom, an single-faced right-angle isosceles prism arranged to intercept said e

Abstract: A tunable spectral source includes an enclosure having first and second apertures; an optical dispersive element positioned in the enclosure; and multiple pixel source elements that are individually controllable for selectively directing one or more broadband light signals through the first aperture to irradiate the optical dispersive element. Each of the broadband light signals irradiates the optical dispersive element at a unique angle of incidence. The optical dispersive element disperses the broadband light signals into spectral component signals at dispersion angles that are dependent upon the angle of incidence of each broadband light signal that irradiates the optical dispersive element. The portions of the spectral component signals that are emitted through the second aperture are determined by selecting one or more particular pixel source elements to irradiate the optical dispersive element.

Abstract: An optical add/drop multiplexer to be tuned locally or remotely, to compensate for drift in operation, and to facilitate installation or replacement at remote terminals.

Abstract: A plurality of magnets is provided in an illumination prism carrier of a transmitted light refractometer and a corresponding plurality of magnets is provided in a sample prism housing of the refractometer to align a light exit surface of the illumination prism relative to a sample surface of the sample prism and urge the optical surfaces together in an even and uniform manner. The magnets replace mechanical biasing arrangements for positioning the optical surfaces and function to consistently reproduce a measurement optical path in the instrument for improved accuracy and repeatability of measurements.

Abstract: The invention relates to an arrangement (1) for the contactless transmission of data between a rotating component and a stationary component by means of light signals which are transmitted by a projector (2) and detected by a receiver (4). According to the invention, a ring-shaped light-conducting body (5) which consists of a transparent material and has integrated reflecting prisms is integrated between the projector (2) and the receiver (4). The exit surface (10) of the light-conducting body (5) opposite the receiver (4) is matt. The projector (2) is allocated to the stationary component and the receiver (4) is allocated to the rotating component This enables light signals to be permanently transmitted from the stationary component to the rotating component, with a high data rate at a high relative speed.

Abstract: A field-of-view controlling arrangement such as a privacy screen includes a single microprism or lenticular sheet having a plurality of sets of parallel surfaces that intersect to form prisms or lenticular structures, and in which field-of-view control is achieved by (i) for sheets made up of parallel “one-dimensional” microprism or lenticular structures having at least two intersecting sets of mutually parallel surfaces, altering at least two sets of the mutually parallel surfaces, and/or portions of the at least two sets of mutually parallel surfaces, by applying a light-attenuating treatment, (ii) for sheets made up of polyhedral lenticular structures having at least three intersecting sets of mutually parallel surfaces, or at least one set of curved surfaces extending in directions transverse to directions in which the field-of-view is to be limited, altering at least one set of the mutually parallel or curved surfaces by applying a light-attenuating treatment, or (iii) for any type of micropr

Abstract: A line narrowing unit for use within an excimer or molecular fluorine laser resonator includes a dispersive prism having antireflection coatings on entrance and exit surfaces. Entrance and exit angles and an apex angle are increased to enhance the dispersive power of the prism, while the antireflective coatings limit reflective losses. Preferably, a laser beam makes a non-symmetric pass through said prism. The apex angle is preferably greater than 65°, or even 75°, and the angle of incidence and the exit angle of the beam are each preferably greater than 65°. A beam expanding prism configured for enhanced beam expansion has an apex angle between within a range of 37.5° and 42.5°, and a beam incidence angle at the entrance surface of more than 65°, and an antireflection coating on preferably both the entrance and exit surfaces.

Abstract: The present invention 10 discloses an internal prism 20 for displaying a rainbow onto a surface by separating the spectrum of white light produced by a halogen lamp 44. The lighting device has a cylindrical housing 16 having external means for adjusting the intensity of the display in the form of a three way dimmer switch 18. The prism 20 is selectively held in place by threaded stud members 22 with finger nuts 24 positioned at each end thereof, whereby the prism can be selectively moved or rotated from one position to another. Also shown is a planar opaque element or light filter 26 having a slot 28 therein whereby the light is projected through the prism. Also shown are a lamp cover 30, vertical slots 32 for receiving and adjustment of the threaded studs 22 along with a power source 34 and air intake vents 36 on the bottom of the housing 16. Alternative embodiments disclose a rotatable base 66 and a rectangular housing.

Abstract: A beam deflector has first and second wedge prisms having refractive indices and geometries which are similar (in the case of the geometry to within arc minutes). The prisms are rotatable about an optical axis O defined by the direction of propagation of the incident light beam, to adjust the angle through which the incident beam is deflected. A third prism has a wedge angle which is greater than that of the first and second prisms by a factor of 2. When the directions in which the first and second prisms refract the beam away from the optical axis are aligned about the optical axis at notional angles of 0° and 90° respectively, and the third prism is aligned with its direction of refractive deviation at a notional angle of 225° about the optical axis, the light beam will pass undeviated through the deflecting device.

Abstract: The present invention relates to a compact and high-performance prism optical system having, in order in which light rays pass from the object side, a first transmitting surface (4), a first reflecting surface (5), a second reflecting surface (6), a third reflecting surface (7), and a second transmitting surface (8). When an axial principal ray (1) is projected onto a plane defined by three points at which the axial principal ray (1) impinges on the first transmitting surface (4), the first reflecting surface (5) and the second reflecting surface (6), the projected axial principal ray forms an optical path that bends at two consecutive reflecting surfaces (5, 6) in the same direction with respect to the direction of travel of the rays and bends at the other reflecting surface (7) in a direction different from the direction of bending at the two reflecting surfaces. At least one of the three reflecting surfaces is a rotationally asymmetric surface.

Abstract: An optical assembly (11) is formed by individually positioning a plurality of prisms (15) using mechanical reference surfaces (19) which are associated with the prism's diagonal (13) and are preferably formed by extensions of a first sub-prism (17A) beyond a second sub-prism (17B). The mechanical references surfaces and a first side of the prism engage fixed mechanical references (23) associated with a housing. A locking element (21) engages a second side of the prism and forces the mechanical reference surfaces and the first side of the prism against the fixed mechanical references to achieve accurate positioning of the prism's diagonal (13).

Abstract: In order to provide a grism wherein even if the vertex angle of a prism increases, it does not exceed its critical angle, besides, which can elevate its efficiency, and mass-production of which is possible, whereby reduction in cost of which can be realized. The grism comprises a first prism having a high refractive index, a second prism having a high refractive index, and a volume phase grating used for a diffraction grating; and the vertex angle of the first prism being opposed to the vertex angle of the second prism so as to sandwich the volume phase grating between the first prism and the second prism.

Abstract: A compact image pickup optical system satisfactorily corrected for chromatic aberration as well as decentration aberrations and capable of providing a clear image with minimal distortion even at a wide field angle. The image pickup optical system includes an image pickup optical element and a diffractive optical element, which are decentered with respect to each other. The image pickup optical element has at least three optical surfaces adjacent to each other. At least one of the three optical surfaces is formed from a curved surface. At least two reflections take place between the optical surfaces.

Abstract: A diffuser is disclosed which transmits or reflects incident light into a specific range of angles. In a preferred embodiment, this light is uniformly scattered throughout a cone of angles. The diffuser consists of two parts. The first part diffracts or reflects light into a specific offset angle. The second part, in the preferred embodiment, uniformly scatters the light through a range of angles, which is centered on the offset angle. The diffusers have utility in applications such as screens for wrist watches, computers, calculators, and cell phones.

Abstract: A prism for a portable optical device is provided. The optical device is used for producing a wide-angle big-size virtual image of a picture from a mini-size high-resolution display and is usually used at an eye relief of only a few centimeters by wearing it on eyes or held closely to eyes with a hand. With the prism of the optical device, a magnified virtual image of the picture on the small display is projected onto a position beyond a distance of distinct vision of the user, so that the user could utilize a mini-size display and other video and audio instruments carried along the user to enjoy a picture on a wide-angle and big-size screen.

Abstract: An appartus, such as a binocular telescope, with an optical system which includes a long optical path. The binocular telescope includes a first objective lens, a second objective lens, a first prism, a second prism, and a group of eye piece lenses. A body of the second prism has an outer surface on which a film made of aluminum is deposited. A light which passes through the first objective lens is firstly reflected by an outer surface, or an exposed side, of the deposited film, and then reflected by an inner surface, or a side contacting the body of the second prism, of the film after the light passes through the second objective lens, the first prism and the second prism. The light reflected by the inner surface of the film is projected outside through the second prism and the eye piece lenses. The single deposited film serves as a pair of reflection elements within the optical system, so that the long optical path is secured therein.

Abstract: An article and method for controlling the sign (repulsion or attraction) and magnitude of dispersion forces, such as the Casimir force. In accordance with one embodiment of the present teachings, dispersion forces are controlled by selectively reflecting only those spectral components (i.e., frequencies) at which the random oscillations of the electromagnetic field contribute to the force behavior desired, while substantially suppressing all other spectral components. In one embodiment, the selected spectral components are omni-directionally reflected using photonic band gap materials.

Abstract: An apparatus for mechanical packaging of a piezo-actuator based add/drop module is disclosed. In one aspect of the invention, the combination of an assembly base and an optical add/drop module base provide the alignments for placing triangular prisms and a hexagonal prism. The assembly base has several sets of cylindrical pins where each set of cylindrical pins extends through the OADM base for positioning of a triangular prism or a hexagonal prism. In another aspect of the invention, a set of cylindrical pins extends through the OADM base for placement of a bimorph actuator.

Abstract: A mobile electronic device is disclosed. The mobile electronic device includes a processor and a communications bus coupled to the processor. The mobile electronic device also includes a light source. Further, the mobile electronic device includes a charge controlled mirror display. The charge controlled mirror display is coupled to the communications bus. The charge controlled mirror display includes an array of charge controlled mirrors. At least some of the charge controlled mirrors have a textured surface configured to cause reflective diffusion of light from the light source. The charge controlled mirrors have reflectance that is selectively controlled according to signals communicated along the communications bus.

Abstract: A compact binoculars utilizing roof mirrors is disclosed. Compactness of the binoculars is achieved by maintaining the optical axis in the same plane as the axes of movement of the focusing apparatus and eyewidth adjustment apparatus. A method of manufacturing the roof mirror is also disclosed. The method allows produces and inexpensive and precisely aligned roof mirror for use in the compact binoculars.

Abstract: An optical prism (1) for reflecting incident light from an incidence surface (2) suited for incidence of light from an LCD (20) or the like for at least twice before emitting the reflected light as emission light from a predetermined emission surface (4). The optical prism has side surfaces (6L and 6R) crossing the incidence and emission surfaces (2 and 4) and including receded surfaces 7L and 7R) formed such as not to impede an optical path of an effective size, the incident light being led along the optical path from the incidence surface to the emission surface.

Abstract: A counter-rotating anamorphic prism pair assembly with variable spacing allows the simultaneous adjustment of a prism pair using an adjustment member to circularize in cross section a range of elliptical laser beam cross sections. A first prism rotates and translates towards or away from an incident laser beam while a second prism simultaneously rotates towards or away from the laser beam in a fixed counter-rotating relationship with the first prism. The degree of rotation and translation is determined by a mechanical linkage connecting the two prisms.

Abstract: A low profile rearview mirror for a motor vehicle having a first refractor with a first refractive index and a first chromatic dispersive poser. The first refractor is disposed in a housing on the exterior of the vehicle A reflector mounted partially within the motor vehicle extends into the housing for the first refractor and the retractor is positioned to receive and reflect light from objects behind the vehicle passing through the first refractor. A second refractor having a second refractive index and a second chromatic dispersive power is mounted between the first refractor and the reflector and the first and second refractors have complementary properties of chromatic dispersion.

Abstract: An appartus, such as a binocular telescope, with an optical system which includes a long optical path. The binocular telescope includes a first objective lens, a second objective lens, a first prism, a second prism, and a group of eye piece lenses. A body of the second prism has an outer surface on which a film made of aluminum is deposited. A light which passes through the first objective lens is firstly reflected by an outer surface, or an exposed side, of the deposited film, and then reflected by an inner surface, or a side contacting the body of the second prism, of the film after the light passes through the second objective lens, the first prism and the second prism. The light reflected by the inner surface of the film is projected outside through the second prism and the eye piece lenses. The single deposited film serves as a pair of reflection elements within the optical system, so that the long optical path is secured therein.

Abstract: The invention concerns a microsystem module, in particular for use in microoptical systems, the module consisting of a body on the surface of which at least one functional area and support areas for attachment to adjacent microsystem components are provided. According to the invention, in order to provide a microsystem module of this type which can be connected to adjacent microstructure system components with an extremely good fit and in an exactly reproducible manner and preventing damage to the adjacent components and the sensitive functional areas of the microsystem module, the support areas are disposed in the region of outwardly projecting surface regions of the body which are set back relative to the support areas in the direction towards the interior of the body. The functional areas are disposed with very narrow tolerances in a dimensionally accurate manner relative to the support areas.

Abstract: An epifluorescent microscope (11) is constructed with a quick changing set of filters (13,20,21). A wheel (13) containing a plurality of dichroic beamsplitter mirrors (6165) mounted equidistance from a center axis (66) of the wheel is mounted at a 45° angle within the lightpath and provides a beamsplitter function. Light from an excitation source (12) is provided as monochromatic light, so that light from the excitation source (12) is reflected by a selected one of the dichroic mirrors (6165) to the specimen (15), and Stokes shifted light from the specimen (15) is transmitted through the dichroic mirror (6165). By separately mounting the dichroic mirrors (6165), the dichroic mirrors can be quickly moved and a quicker change of sensed fluorophores is achieved. An additional advantage is that excitation (20) and emission (21) filters can be quickly changed independently of the dichroic mirror element (13).

Abstract: A method of making a micro magneto-controlled optical path-guiding platform comprises an optical path-guiding platform, couples of the optical routes, a micro magneto-flux prism located at the intersection of the optical route on the topside of the platform, and a magnetic field generator oppositely mounted under the location of the micro magneto-flux prism of the platform bottom side respectively. Therefore, the reflection ratio and refraction ratio to the incident optical signal traveling through this designed micro magneto-flux prism will be completely manipulated by adjusting the magnetic field intensity that is generated by the magnetic generator. Conclusively, this invention can be used to change the traveling orientation of the optical route or control the optical energy intensity as desired.

Abstract: A red-reflecting film and a blue-reflecting film are formed in a substantially X shape on joint surfaces defined by the respective side faces of four columnar prisms or right-angle prisms. The red-reflecting film is continuously formed without separating at an intersection of the two reflecting films. The blue-reflecting film is, on the other hand, divided into two pieces by the red-reflecting film and an adhesive. It is preferable that that four columnar prisms are obtained from one block of sheet glass. This arrangement ensures an improvement in properties of a resulting light-selective prism.

Abstract: A red-reflecting film and a blue-reflecting film are formed in a substantially X shape on joint surfaces defined by the respective side faces of four columnar prisms or right-angle prisms. The red-reflecting film is continuously formed without separating at an intersection of the two reflecting films. The blue-reflecting film is, on the other hand, divided into two pieces by the red-reflecting film and an adhesive. It is preferable that that four columnar prisms are obtained from one block of sheet glass. This arrangement ensures an improvement in properties of a resulting light-selective prism.

Abstract: A cross dichroic prism comprises four triangular prisms having isosceles right triangular cross sections identical in shape, opposing side faces thereof being bonded and secured together with rectangular portions thereof facing each other; and a dichroic film having an X-shaped cross section formed between the bonding faces of the triangular prisms; wherein, of the four triangular prisms, a given prism and at least one of the prisms adjacent thereto have a refractive index difference therebetween of 0.00005 or less, and the remaining two prisms opposed thereto have a refractive index difference therebetween of 0.00005 or less.

Abstract: An image display apparatus having a three-dimensionally decentered optical path to attain a reduction in overall size of the apparatus and to place constituent members effectively in a dead space, thereby permitting the apparatus to be designed in a variety of ways. The apparatus includes an image display device and a viewing optical system for leading an image formed by the image display device to a pupil. The viewing optical system has at least a first reflecting surface and a second reflecting surface positioned closer to the pupil than the first reflecting surface along the optical path. A first plane defined by the optical axis incident on the first reflecting surface and the optical axis reflected therefrom and a second plane defined by the optical axis incident on the second reflecting surface and the optical axis reflected therefrom intersect each other at an arbitrary angle, thereby forming a three-dimensionally decentered optical path.

Abstract: A projection display apparatus comprises a modulator, an analyzer, and projecting optical system. The modulator includes two-dimensionally arrayed pixel units and it modulates an incident light and emits the modulated light. The analyzer analyzes the emitted light from the modulator. The projection optical system projects the analyzed light from the analyzer. The analyzer includes a polarized beam splitter having a pair of prisms and an adhesive layer held between the pair of prisms. The difference in thickness between thin and thick portions of the adhesive layer is set equal to a predetermined value or less, based on a pixel pitch of the modulator.

Abstract: In an optical sheet 10 having a prism surface 16 formed by providing unit prisms 14 on the upper surface of a transparent base material 12, a coating layer 18 is provided on the reverse surface of the transparent base material opposite to the prism surface 16, spherical beads 20 are arranged projecting from the surface of the coating layer 18 by 1 to 10 &mgr;m in height, and the coating layer 18 is brought into contact with the flat and smooth surface 22A of the light-transmissive material 22 through the spherical beads 20 which are put between them. The spherical beads are 1 &mgr;m or less in half bandwidth of the distribution of particle diameters and are made uniform in height projecting from the coating layer 18.

Abstract: The invention concerns an illumination device having a stop (8) for a surgical microscope, whose stop (8) is capable of covering a partial light flux of the illumination system, the coverage not being accomplished completely as a result of the particular configuration of the stop.

Abstract: An optical element includes an optical body having a surface formed with a microstructure set which includes at least two microstructure relieves. At least one of the microstructure relieves has a configuration different from another one of the microstructure relieves. At least one of the microstructure relieves is defined by 3 to 5 faces.

Abstract: An observation system having a positive refracting power as a whole comprises a first unit G1 with a positive refracting power and a second unit G2 and forms an exit pupil for observation of an electronic image displayed on an image display element 5. The first unit G1 comprises a prism 4 with a positive refracting power and a transmission-type volume hologram 6 and has an action of imaging an observation image for obtaining a relay image. The second unit G2 is composed of a reflection-type volume hologram 3 and has an action of forming the exit pupil 1 so as to introduce the relay image to an observer. At least one of reflecting surfaces and an exit surface of the prism 4 is shaped as a rotationally asymmetric surface which exerts a power on bundles of rays, to compensate aberrations generated by decentering.

Abstract: A real image mode variable magnification finder has an objective optical system with positive refracting power, an image erecting optical system, and an ocular optical system with positive refracting power. The objective optical system has a first lens unit with negative refracting power, a second lens unit with negative refracting power, a third lens unit with positive refracting power, and a fourth lens unit with negative refracting power. When the magnification of the finder is changed, at least one lens unit, namely the third lens unit is moved. In this way, the total length of the objective optical system can be reduced, and thus a compact finder is obtained.

Abstract: A flow mark or residual stress occurring in the vicinity of a gate adversely affects the optical characteristics of a resin prism which is to be formed by injection molding. Thus, the molding conditions for the resin prism are strict, and accordingly the resin prism has poor moldability.

Abstract: An optical prism 100 for reflecting light incident on its light incidence surface 12 suited for incidence of light from an LCD 20 at least twice within itself and emitting the reflected light as emitted light from a light emission surface 14 to the outside. The optical prism is coupled in use with a display element support 30 adapted to suit it. The side surfaces of the optical prism crossing the light incidence surface 12 and light emission surface 14 have projections 90L and 90R for mounting the optical prism on the display element support.

Abstract: A TIR prism system for DMD and a projector adopting the same make a loss of incidence light be reduced, and having a small size and light weight. In a TIR prism system having the DMD and for total reflecting the incidence light to a certain direction in accordance with that the DMD is controlled, the TIR prism system of the present invention includes a first prism for receiving the incidence light on a surface set before, refracting the light, and outputting the refracted light, and a second prism coupled to the first prism for receiving the light outputted from the first prism, transmitting the light to the DMD, and outputting the transmitted light after being totally reflected in accordance with that the DMD is controlled, whereby a loss of light energy inside the system can be reduced.

Abstract: The object of the invention is to make a viewing unit of the image display compact so that it can be mounted on portable telephones or information terminals. The portable image display of the invention comprises a speaker portion, a microphone portion, an image display device 9 and a viewing optical system for forming an exit pupil to view an image displayed on the image display device and having a generally positive refracting power. The viewing optical system is constructed of at least one prism member 10 comprising an entrance surface through which a light beam emanating from the image display device 9 is entered into the prism, at least one reflecting surface at which the light beam is reflected within the prism and an exit surface through which the light beam leaves the prism. The at least one reflecting surface has a curved surface shape for imparting power to a light beam.