Abstract: The present invention discloses a light modulation element, having a first optical surface and a second optical surface receiving an incident light, the light modulation element comprising: at least a transparent diffusion unit, for scattering the incident light, each being placed on the first optical surface; and at least a transparent collimation unit, for collimating the incident light, each being formed on top of the diffusion unit.

Abstract: The optical system of the invention is comprised of a monolithic microlens array assembly that consists of two groups of microlenses sub-assemblies having different pitches between the adjacent lenses. A ratio between the pitches of sub-assemblies is determined by a predetermined relationship between the parameters of the optical system so that the microlenses of the first sub-assembly create a plurality of individual intermediate images arranged side-by-side in a common intermediate plane that are transferred by the microlenses of the second sub-assembly to the final image plane in the form of a plurality of identical and accurately registered images interposed onto each other. This is achieved due to the aforementioned ratio between the pitches.

Abstract: An optical sheet that accepts light transmitted at or within a specific entrance cone angle that then redirects and transmits the light within an exit cone that is substantially normal to the sheet's plane. The intensity of the light within the exit cone is substantially uniform for any light source entering the sheet within the sheet's acceptance angle. The optical sheet is made of transparent material with microlens arrays formed on its opposite front and back surfaces. The thickness of the optical sheet is sufficient so that the microlens on the opposite surfaces are separated a distance equal to the microlens focal length, with each microlens on the front and back surfaces having substantially similar size and shape, with centers transversely aligned. When used with one or more light sources located on one surface, the transmitted light through the optical sheet is uniform in intensity across a second surface.

Abstract: An optical surface substrate. The optical substrate features a three-dimensional surface. The optical substrate is defined by a first surface structure function modulated by a second surface structure function, the first surface structure function producing at least one specular component from a first input beam of light. The second surface structure function has a geometry with at least pseudo-random characteristics to modulate the first surface structure function such that the surface of the optical substrate produces specular and diffuse light from the first input beam of light. The optical substrate is suitable for use in a variety of applications, including brightness enhancement and projection devices.

Abstract: A laser beam optical system for an LCD device includes a laser light source, a variable attenuator for controlling an intensity of a laser light from the laser light source, a telescope lens for gathering the laser light having the controlled intensity from the variable attenuator in the length and width directions, a beam homogenizer including a filter for controlling a sectional profile of the laser light from the telescope lens vertical to the length direction, a condenser for focusing the laser light from the beam homogenizer, and a target to which the laser light is irradiated.

Abstract: An illumination method and system use a light source and illumination optics to illuminate a pattern generator. The illumination optics can include at least two devices. For example, if first and second diffractive and/or refractive devices are used, one can be a pupil defining element (PDE) and one can be a field defining element (FDE). In another example, a third diffractive or refractive element can be used to make light entering the illumination system uniform. When only two are used, the PDE forms one or more light beams having a defined profile. The FDE directs the one or more light beams having the defined profile, such that each directed beam substantially corresponds in size and shape to a desired illumination area(s) on the pattern generator. The directed beams are directed to impinge substantially only on the desired illumination area(s).

Abstract: An image display apparatus includes a display having an image display surface which displays a two-dimensional image of an object including a three-dimensional object, and an image transmitting panel spaced apart from the image display surface for creating an imaging plane displaying a real image of the two-dimensional image in a space opposite to the display. The image transmitting panel and the imaging plane are non-parallel with each other.

Abstract: The present invention is a head-mounted virtual display apparatus based on a non-cross-cavity optical configuration, in which a near-eye light deflecting element (LDE) is located in the peripheral field of view. Positioning of the near-eye LDE in the peripheral field of view provides the user with simultaneous access to an inset magnified image of a miniature display and an unobstructed forward field of view of at least 35 degrees. Active and passive alignment means, including articulating connections and image warping electronics, allows for correction of geometric distortion arising from folding of the optical train, and orthogonal alignment of the virtual image plane with the optical axis between the user's eye and the virtual image plane.

Abstract: An image display apparatus includes an indicating element which modulates or emits light as a pixel in accordance with image information. A displacement unit optically displaces a position of the pixel for each of two or more sub-fields constituting an image field corresponding to the image information. A projection unit enlarges the pixel and projects an enlarged pixel on a screen. A pixel-profile deformation unit changes an optical intensity profile of the pixel.

Abstract: An imaging apparatus (10) to image wise expose desired microcapsules (38) within a photosensitive media (44) with an image exposure device (12) to harden the desired microcapsules applying pressure to the exposed photosensitive media rupturing the unexposed microcapsule (40), releasing the image-forming material (48) encapsulated within to form an image on the photosensitive media, the exposure device having a molded lenslet array (14) with a printed lens mask improving channel cross talk, aberrations, and reducing flair.

Abstract: Spherical convex micro-lenses are arranged between rectangular grooves adjacent to each other of a lens plate. The arrangement of convex micro-lenses is made to be in parallel with the short-side direction of the lens plate, namely, the direction of the rectangular grooves. Since stray light appears mainly on the convex micro-lenses arranged in the long-side direction of the lens plate, the stray light to appear in the long-side direction of the lens plate is removed by forming grooves at regular intervals in the long-side direction of the lens plate and forming a light absorbing film in each of the rectangular grooves. Or the stray light to appear in the long-side direction of the lens plate is removed by making the direction of arrangement of convex micro-lenses different from the long-side direction of the lens plate.

Abstract: A high contrast lenticular lens sheet that can improve the brightness of an image and the angle of visibility. When it is assumed that P represents the pitch of the lens element and H represents the width of the black stripe portion as viewed in a cross section perpendicular to the lens element, the difference F in height between the black stripe portion and the lens element is set to have a range that is expressed by the inequality: 0.098 P?F?(P?H)/2 tan(?/3). Simultaneously, the width B as measured from an apex portion of the black stripe portion in regard to a colored portion on a side wall of the black stripe portion is set to have a range that is expressed by the inequality: 0.30 F?B?0.89 F.

Abstract: An optical system including an array of micro-optic afocal optical subsystems capable of receiving electromagnetic radiation from a source and of transmitting at least a portion of the electromagnetic radiation received from the source, and an imaging subsystem capable of receiving electromagnetic radiation from the an array of micro-optic afocal optical subsystems and imaging at least a portion of the received electromagnetic radiation onto an image plane.

Abstract: The invention relates to an apparatus for shaping a light beam, having at least two optically functional boundary surfaces that are arranged one behind another in the propagation direction (z) of the light beam to be shaped, such that the light beam can pass through the at least two optically functional boundary surfaces one after another, and two groups of refractive or diffractive imaging elements that are arranged on at least one of the optically functional boundary surfaces, at least two of the imaging elements having different properties within at least one of the groups.

Abstract: A transparent screen includes a refraction/total reflection plate in a form of a Fresnel lens, the refraction/total reflection plate having a sawtooth surface upon which light is incident and another surface via which the light exits, and an image formation/display plate for forming a projection image from the light that exits from the refraction/total reflection plate. Refraction slating surface portions each for refracting incident light towards the other surface of the refraction/total reflection plate, transmission slating surface portions each for making incident light pass therethrough, and total reflection slating surface portions each for reflecting incident light passing through one transmission slating surface portion towards the other surface of the refraction/total reflection plate being formed concentrically on the sawtooth surface of the refraction/total reflection plate.

Abstract: A compact and efficient optical illumination system featuring planar multi-layered LED light source arrays concentrating their polarized or un-polarized output within a limited angular range. The optical system manipulates light emitted by a planar light emitters such as electrically-interconnected LED chips. Each light emitting region in the array is surrounded by reflecting sidewalls whose output is processed by elevated prismatic films, polarization converting films, or both. The optical interaction between light emitters, reflecting sidewalls, and the elevated prismatic films create overlapping virtual images between emitting regions that contribute to the greater optical uniformity. Practical illumination applications of such uniform light source arrays include compact LCD or DMD video image projectors, as well as general lighting, automotive lighting, and LCD backlighting.

Abstract: A semi-conductor based imager includes a microlens array having microlenses with modified focal characteristics. The microlenses are made of a microlens material, the melting properties of which are selectively modified to obtain different shapes after a reflow process. Selected microlenses, or portions of each microlens, are modified, by exposure to ultraviolet light, for example, to control the microlens shape produced by reflow melting. Controlling the microlens shape allows for modification of the focal characteristics of selected microlenses in the microlens array.

Abstract: An infrared device in accordance with the present invention includes an optical train for receiving incident radiation into the device, a focal plane array for receiving the incident radiation from the optical train, and an optical power limiter (OPL) that is positioned therebetween. To improve the overall optical gain for the device, the optical train initially focuses the incident radiation into an intermediate focal plane that is located within the OPL. With this configuration, however, the incident radiation begins to lose focus once it passes through the intermediate focal plane and exits the OPL. To prevent this, the infrared device includes a plurality of microlenses on the OPL surface that is facing the focal plane array. The plurality of microlenses re-focuses the incident radiation onto a final focal plane that is coincident with the focal plane array.

Abstract: A table type display device, in which a high resolution display with an unremarkable connection is realized at the time of large screen display by using a screen with a composition having few bending is described. In a table type display device comprising plural M of projectors 1L, 1R for projecting luminous flux to form an image, plural N of reflection mirrors 2L, 2R for bending optical paths of luminous fluxes projected from respective plural M of projectors 1L, 1R, screen 3 of horizontal installation type for projecting luminous fluxes for which optical path is bent, by the plurality N of reflection mirrors 2L,2R onto the predetermined region, respectively, the screen comprises a transparent base member 7 for reducing flexure of the screen, optical sheet 9 substantially for making luminous fluxes projected respectively from the plural M of projectors 1L,1R uniform, and a diffusing screen for imaging the image.

Abstract: An arrangement for optical beam transformation, having at least one light source which can emit at least one light beam, with the at least one light beam having a greater divergence in a first direction (Y) than in a second direction (X) at right angles to it, a collimation means, which can at least reduce the divergence of the at least one light beam in the first direction (Y), an apparatus for optical beam transformation, which is arranged downstream from the collimation means in the propagation direction (Z) of the at least one light beam, with the apparatus being such that the divergence of the at least one light beam passing through the apparatus in the first direction (Y) is interchanged with the divergence in the second direction (X) at right angles to it, and such that the cross-sectional area of the at least one light beam is reduced in the apparatus for optical beam transformation.

Abstract: An illumination method and system use a light source and illumination optics to illuminate a pattern generator. The illumination optics can include at least two devices. For example, if first and second diffractive and/or refractive devices are used, one can be a pupil defining element (PDE) and one can be a field defining element (FDE). In another example, a third diffractive or refractive element can be used to make light entering the illumination system uniform. When only two are used, the PDE forms one or more light beams having a defined profile. The FDE directs the one or more light beams having the defined profile, such that each directed beam substantially corresponds in size and shape to a desired illumination area(s) on the pattern generator. The directed beams are directed to impinge substantially only on the desired illumination area(s).

Abstract: A Modular Integral Magnifier that produces a uniformly magnified orthoscopic three-dimensional image of an original three-dimensional scene. The optical elements to achieve this effect are always maintained in relative alignment and registration regardless of movement and temperature deformations. The modules may be used together to construct a large composite high resolution viewing aperture or screen for large audiences to observe the magnified three-dimensional image. It may be used with photography, videography, or optical imaging of live scenes. It may be used for both still-life and animated three-dimensional images.

Abstract: A method of producing a microlens array includes a patterning step of forming a first optical resin layer having a first refractive index on a transparent substrate and forming a plurality of microlens planes arrayed in a two-dimensional pattern on the front surface of the first optical resin layer; a planarizing step of forming a planarized second optical resin layer; a joining step of providing a support layer on which a transparent protective film is previously formed; and a removing step of removing the support layer in such a manner that only the protective film remains on the second optical resin layer. The planarizing step is performed by filling irregularities of the microlens planes with a resin having a second refractive index and planarizing the front surface, opposed to the microlens planes, of the resin, to form the planarized second optical resin layer, and the joining step is performed by joining the support layer to the planarized second optical resin layer.

Abstract: An optical lens structure includes a substantially transparent substrate a lens array attached to the substrate with lenses of the lens array situated opposite the substrate and packaging material surrounding at least the periphery of the lens array, the packaging material including at least two alignment holes which are aligned with respect to positions of the lenses. In one example, the structure is fabricated by attaching a lens array to a substrate with lenses of the lens array situated opposite the substrate, surrounding a periphery of the lens array with a packaging material, the packaging material being attached to the substrate, planarizing the packaging material, and providing alignment holes through the packaging material.

Abstract: A neutralizing sheet for an autostereoscopic image viewing system. The image viewing system includes a lenticular sheet covering a display screen. The neutralizing sheet including a pliable portion and is movable between a first position and a second position. The pliable portion has a refractive index similar to the lenticular sheet. When pressed into the lenticular sheet to define the first position, the pliable portion deforms to assume the shape of the lenticular sheet. Thus, refraction through the lenticular sheet is neutralized and viewing of planar images is enabled. In the second position, the neutralizing sheet is separated from the lenticular sheet and viewing of stereoscopic images is enabled.

Abstract: A microelectrical mechanical out-of-plane thermal buckle-beam actuator is capable of providing transverse-plane movement of shutters. The actuator includes a pair of structural anchors secured to a substrate and one or more thermal buckle-beams secured at respective base ends to the anchors. Each buckle-beam extends substantially parallel to and spaced-apart from the substrate and is releasable from the substrate at points other than at the anchors. The thermal buckle-beam actuators are suitable for use in a microelectrical mechanical optical display system.

Abstract: There are disposed two homogenizers for controlling an irradiation energy density in the longitudinal direction of a laser light transformed into a linear one which is inputtted into the surface to be irradiated. Also, there is disposed one homogenizer for controlling an irradiation energy density in a width direction of the linear laser light. According to this, the uniformity of laser annealing can be improved by the minimum number of homogenizers.

Abstract: An improved optical imaging system includes a vertically stacked pixel array and a lenslet array for capturing images while minimizing the focal length. The vertically stacked pixel array is configured to operate as an image sensor. The lenslet array is configure to focus the image on the image sensor. Each lens of the lenslet array focuses an image on a sub-array of the image sensor. Each sub-array is shifted from one another so that additional data obtained for each equivalent pixel in each sub-array. An image is obtained by combining the data of each sub-array.

Abstract: Lenses 1, 2, and 4 as an optical element having a power are cemented together in an optical axis direction. An optical filter 3 is sandwiched between the lenses 2 and 4. Optical elements neighboring each other are cemented together such that a positioning section which is disposed on a side surface of the optical element disposes an appropriate space in an optical axis direction and optical axes of optical elements align in a direction orthogonal to the optical axis. The cemented optical element arrays are cemented together and cut at a line in a cutting operation. By doing this, it is possible to manufacture a small image pickup lens unit, which can be used in an image pickup device, by mass-production and at a low cost.

Abstract: An optical leveling module (1) includes a sensitive element (10) with a plurality of sensitive areas (11) thereon, and an optical leveling layer (20) mounted on the sensitive element and including a plurality of lenslets (21) wherein a refractive index of the lenslets progressively increases from a center of the optical leveling layer to a periphery of the optical leveling layer. The optical leveling module further includes an adjusting lens (30) and a filter (40) above the optical leveling layer. The intensity of image is essentially uniform after being adjusted by the optical leveling module. A method for manufacturing an optical leveling layer of the optical leveling module is provided. At first, enhance an optically resistant block's refractive index by doping. Second, cut it into slices. Third, each slice is etched to form a plurality of columns. Finally, each column is fused to form a lenslet.

Abstract: Compact systems with reduced insertion loss, and increased switch isolation and switching speed. The switching and/or routing devices utilize a separating sub-system, a switching and/or routing sub-system, and a recombining sub-system.

Abstract: A critical dimension measuring instrument includes a light source, a beam-shaping optical system, a condenser having a condenser pupil, a first microlens array arrangement, a first auxiliary optical element having positive refractive power, a second auxiliary optical element having positive refractive power, and a second microlens array arrangement. The first microlens array arrangement, the first auxiliary optical element, the second auxiliary optical element and the second microlens array arrangement are arranged in successive fashion between the beam-shaping optical system and the condenser.

Abstract: It is an object of the present invention to provide a stereoscopic image displaying method and a stereoscopic image displaying apparatus using the same, which are capable of excellently observing a stereoscopic image.

Abstract: In a method and system for imaging using multiple apertures, the present invention uses an array of lens elements to form the aperture for a high resolution imaging system. The light from each lens element is properly phased and reduced in volume to form a compact imaging system that captures images with higher resolution possible with each individual element, potentially the resolution will correspond to an aperture equivalent to the size of the lens array.

Abstract: The present invention provides an optical illumination device that permits an increase in the fill of a multiplicity of light sources that constitute a secondary source formed on an illuminated pupil plane. A fly's eye lens that forms a multiplicity of light sources from a light beam emitted by an optical integrator is disposed in the optical path between the optical integrator and an irradiation surface. The fly's eye lens comprises, in order from the light-source side, a first fly's eye member and a second fly's eye member. A cylindrical lens group arranged in a first direction is formed on each of the light source-side surface of a first fly's eye member and the light source-side surface of a second fly's eye member, and a cylindrical lens is group arranged in a second direction orthogonal to the first direction is formed on each of the irradiation surface side surface of the first fly's eye member and the irradiation surface side surface of the second fly's eye member.

Abstract: An adjustable compound optical microlens apparatus comprises first and second microlenses that are separated from one another along their optical axes. At least one of the microlenses is movable relative to the other. In a preferred embodiment, one microlens is stationary, the other movable. A MEMS controller electrically controls the position of the movable microlens relative to the stationary microlens, or the positions of at least two movable microlenses relative to one another. In accordance with one embodiment of our invention, an array of such microlens apparatuses is also contemplated, especially for applications such optical switches and routers. In accordance with another embodiment of our invention, the apparatus functions as an optical filter or dispersion compensator. Also described is method of compensating for variations in an optical parameter (e.g., effective focal length) of such an apparatus in an array.

Abstract: A multi-aperture beam integrator system/method for producing an polygon or other complex optical pattern on an image plane, which can be continuously varied in size, aspect ratio, or shape, is described. The integrator/method uses optical array elements having various phase functions, which can be combined to create optical patterns. Varying the location of the optical array elements with respect to each other and/or moving individual unit cells contained within the optical array elements can create continuously varying optical patterns at a desired location.

Abstract: The present invention provides an optical system that includes an array of opto-electronic devices, an array of micro lenses, and a fore optic. The array of opto-electronic devices lie substantially along a plane, but the fore optic has a non-planar focal field. To compensate for the non-planar focal field of the fore optic, each opto-electronic device has a corresponding micro lens. Each micro lens has a focal length and/or separation distance between it and it respective opto-electronic device, which compensates for the non-planar focal field of the fore optic. The focal lengths of these lenses may differ relative to one another. As a result, light that is provided by the fore optic is reconfigured by the micro lenses having various focal lengths to be substantially focused along the plane of the array of opto-electronic devices.

Abstract: An apparatus for displaying a stereoscopic two-dimensional picture includes a display unit having a flat image display screen for displaying a two-dimensional picture containing a stereoscopic image and an image transmitting panel placed parallel to and apart from the image display screen. The image transmitting panel has a microlens array of a plurality of lenses and an effective area larger than that of the stereoscopic image contained in the two-dimensional picture, and a lens frame area surrounding a perimeter of the effective area of the microlens array. The image transmitting panel generates an image-formation plane for displaying a real image of the two-dimensional picture in a space located on an opposite side to the display unit with respect to the microlens array. The apparatus also includes a stereoscopic frame for defining a space for accommodating the image-formation plane.

Abstract: A display apparatus has a lens sheet with a plurality of unit columnar lenses arranged so as to be parallel to one another, and is disposed on the observation side of a display panel, spaced therefrom by a layer of air. The direction of the ridge lines of the unit columnar lenses of the lens sheet, seen from the observation side, are non-parallel to the direction of an edge of the display panel.

Abstract: An optical surface substrate. The optical substrate features a three-dimensional surface having a correlation length of about 1 cm or less. The optical substrate is defined by a first surface structure function modulated by a second surface structure function, the first surface structure function producing at least one specular component from a first input beam of light. The optical substrate is suitable for use in a variety of applications, including brightness enhancement and projection devices.

Abstract: An image transfer device having: a lens array laminate 14 forming an erecting unit magnification optical system, the lens array laminate including a plurality of lens array sheets 12 of the same specification each of which has convex-convex lens elements 10 arranged in a plurality of rows and which are substantially closely laminated in a direction of each lens optical axis. Typically, two to four lens array sheets of the same specification each of which has convex-convex lens elements each having are fractive index of not lower than 1.45 and arranged in 3 to 9 rows are closely laminated on each other or one another in a direction of each lens optical axis. Each of the lens array sheets is preferably formed so that the lens thickness is in a range of from about 4 mm to about 0.5 mm and the number of lens rows is in a range of from 4 to 6.

Abstract: Apparatus for illuminating a spatial light modulator combines radiation from two or more multiple-emitter laser diode arrays. Brightness is conserved. The apparatus includes collecting optics which includes an array of microlenses. The microlenses steer beams of radiation which issue from individual emitters so that the beams overlap at a target plane to produce a desired beam profile.

Abstract: A conventional solid-state imaging device in which a sealing resin is applied onto a microlens has a low condensing efficiency. There are provided a photodiode 14 for receiving light, a microlens 4 made of a resin set on the photodiode 14 and having a refractive index of n3, a thin-film lens 3 formed on the microlens 4 and having a refractive index of n2, a sealing resin 2 formed on the thin-film lens 3 and having a refractive index of n1, and cover glass 1 formed on the sealing resin 2 to seal the sealing resin 2. The refractive index n2 of the thin-film lens 3 is set to a value smaller than n1 and n3. In this case, it is assumed that values of n1 and n3 are substantially equal to each other and the thin-film lens 3 is made of fluoride and/or oxide.

Abstract: A protected lenticular product includes a lenticular substrate having an index of refraction NL, the substrate having a lenticular surface with a plurality of peaks and valleys forming a plurality of respective lenticule lenses. An optical medium is provided on the lenticular surface, the medium having an index of refraction NC substantially less than NL.

Abstract: A display and method of displaying multidimensional images on an autostereoscopic display includes establishing a lenslet array to include a plurality of lens elements. There is an interlacing of a plurality of multiple images on the display with a fanning of the multiple images out into an angular array. The method establishes a plurality of views in a vertical and horizontal direction. A mapping of a plurality of views onto a plurality of pixels makes up the display and a three dimensional image is generated from the fanned out multiple images.

Abstract: The invention refers to the methods and means of conversion of electromagnetic radiation (mainly belonging to the optical range) with the purpose of forming of objects' images (mainly of spatially extended ones) within incoherent light. In an Optical System (OS) the following procedures are being performed: pre-defined distortion of optical motion of rays by means of Amplitude-Phase Mask (APM); optical-electronic conversion of distorted image of object 6 and deduction of the distortions inserted by the APM and by OS. Deduction of distortions is arranged by means of accorded spatial filtration of the distorted image. Distortion of optical motion of rays is accomplished in the direction that is close to the orthogonal one in regards to the distortions brought in by defocusing and by aberrations of the OS. In the meanwhile, the possibility to receive the function of distortions that possesses rotary symmetry is being secured.

Abstract: An exposing apparatus for a microlens array allows for easy alignment and attains high accuracy. An exposing method for a microlens array attains high accuracy and high light efficiency. The exposing apparatus for a microlens array includes a micro fly-eye lens for converting a light beam from a light source into a secondary point light source, a transmittance distribution mask for adjusting the luminance of the light of the secondary point light source, and a collimator lens for converting the light of adjusted luminance into a parallel light beam and for guiding the parallel light beam, via a first microlens array which is formed in advance, to a photosensitive resin layer to be a second microlens array. The light emitted from the light source is transmitted through the micro fly-eye lens, the transmittance distribution mask, and the collimator lens. The light is then adjusted to a desired luminance to expose the photosensitive resin of a microlens substrate.

Abstract: A lenticular lens sheet having (1) a light-transmitting lens sheet body with a lenticular lens group formed of multiple lenticular lenses placed on a surface of the body and a silver salt emulsion light-shielding layer laminated to the other surface of the light-transmitting lens sheet body. Light-transmitting areas in the light-shielding layer correspond to light-converging parts of the lenticular lenses on the body. The positions of the light-shielding areas correspond to non-light-converging parts of the lenticular lenses. The light-shielding characteristics result from the darkened silver dispersed in the silver salt emulsion. A method for making the lenticular lens sheet is disclosed also.

Abstract: A rear projection screen does not block the image light and provides a perfect complete image. The screen includes a Fresnel lens, and a cylindrical lens array consisting of a plurality of cylindrical lens elements. These elements are independent from each other and in parallel, and arranged closely between adjacent cylindrical lens element, so that there are no luminous flux loss therebetween. A strengthening area, which is provided with a rigid reinforced member connecting with cylindrical lens elements on two sides thereof, is formed on the are a being from their contact portion to the image-light exist-side surface between adjacent cylindrical lens elements. An ambient light absorbing portion is formed at the image-light exit side in the strengthening area.