Abstract: A method of extrusion molding a prism film and a prism film manufactured by the same, the method including providing a molten film, simultaneously forming a prism pattern and an embossed pattern on opposite surfaces of the molten film by passing the molten film through a gap between a prism roll and an emboss roll, and cooling the molten film having the prism pattern and the embossed pattern on opposite surfaces thereof.

Abstract: Disclosed are an optical sheet and a LCD apparatus having the same. The optical sheet receives a light emitted from a light guiding plate which is disposed under the optical sheet and emits the light substantially perpendicular to a liquid crystal panel. The optical sheet comprises a first prism pattern made of a material having a first refractive index and a second prism pattern made of a material having a second refractive index which is larger than the first refractive index. The viewing angle of the LCD apparatus having the optical sheet is extended and the brightness thereof is enhanced while a gray scale inversion is reduced.

Abstract: A light-condensing member includes a base plate, a main light-condensing pattern formed on the base plate, and a sub light-condensing pattern formed on the main light-condensing pattern. The main light-condensing pattern includes a plurality of main prisms extended in a first direction. A cross section of a main prism taken along a second direction substantially perpendicular to the first direction has a substantially triangular shape. The sub light-condensing pattern includes a plurality of sub prisms formed on the main prisms and extended in a second direction substantially perpendicular to the first direction. A cross section of a sub prism taken along the first direction has a substantially triangular shape. Since light is condensed simultaneously in both a horizontal direction and a vertical direction through one light-condensing member, manufacturing costs and the thickness of backlight assembly are reduced.

Abstract: A light converging sheet unit includes first and second light converging sheets stacked one on top of the other. The first light converging sheet has first light converging micro-prism structures with a first average peak-to-peak distance between adjacent ones of the first light converging micro-prism structures. The second light converging sheet has second light converging micro-prism structures with a second average peak-to-peak distance between adjacent ones of the second light converging micro-prism structures. At least one of the first and second average peak-to-peak distances is not larger than 35 ?m.

Abstract: The present invention provides a light redirecting article for redirecting light toward a target angle, the light redirecting article comprising: an input surface comprising a plurality of light redirecting structures. Each light redirecting structure has (i) a near surface having two slopes, sloping away from normal in one direction as defined by a first inclination base angle ?1, a second inclination angle ?2, and a first half apex angle ?2, for accepting incident illumination over a range of incident angles and (ii) a far surface sloping away from normal, in the opposite direction relative to the input surface, as defined by a second base angle ?1 and a second half apex angle ?1. In addition, light redirecting structures has (b) an output surface opposing to the input surface, wherein the near and far surfaces are opposed to each other at an angle (?1+?2), and the base angle ?1 is greater than or equal to 90 degrees.

Abstract: A prism sheet, capable of enhancing wet-out ability in a whole back light unit while maintaining center brightness, transmittance and haze in good condition, is disclosed. The prism sheet includes a base film made of a transparent material and having a flat first surface, and a light refracting part including a plurality of unit prisms unitarily formed with the base film on a second surface of the base film, opposite to the flat first surface. The unit prisms have a predetermined shape of a cross section, and are arranged with orientation. When an angle formed between a ridge of the unit prism of the light refracting part and a normal line of the flat first surface is defined as ?n, ?n and ?n+1 have different values from each other, and n is an integer more than 2.

Abstract: An optical sheet capable of enhancing contrast is provided. The optical sheet includes a layer configured to control light incident on the layer and then allow the light to exit towards the observer side. The optical sheet includes: an optical functional sheet layer (12) having multiple prisms (13, 13, . . . ) capable of transmitting light and multiple light-absorbing parts (14, 14, . . . ) capable of absorbing light, the multiple prisms and multiple light-absorbing parts being arranged alternately along a sheet plane of the optical sheet; and an electromagnetic-wave shield layer (12). The electromagnetic-wave shield layer (12) is positioned on a side opposite to the observer side relative to the optical functional sheet layer.

Abstract: An optical sheet has a large number of cylindrical lens elements provided successively on one of principal faces thereof. The cylindrical lens elements have a finite focal distance on the emission side of illumination light and have an aspheric face of a leftwardly and rightwardly symmetric sectional shape. Where a Z axis is taken in parallel to a normal line direction to the optical sheet and an X axis is taken in a direction of the row of the cylindrical lens elements, a cross sectional shape of the cylindrical lens elements satisfies Z=X2/(R+?{square root over ( )}(R2?(1+K)X2))+AX4+BX5+CX6+ . . . (where R is the radius of curvature of a distal end vertex, K is a conic constant, and A, B, C, . . . are aspheric coefficients).

Abstract: An electro-optic device includes a pair of substrates, and an electro-optic material held between the pair of substrates, wherein one of the pair of substrates includes a condensing unit provided on the electro-optic material-side surface of the substrate in order to condense light incident on the substrate, and a functional layer provided to overlap at least the condensing unit in a plan view.

Abstract: A security document including a substrate of transparent polymeric material, and opacifying layers provided on opposing sides of the substrate, the opacifying layers acting to guide light propagating within the substrate, wherein the substrate is formed with at least one micro-prism for diverting light propagating within or entering the substrate.

Abstract: An optical film and a backlight unit having the same are disclosed. The optical film includes a base film and a first prism disposed on the base film, the first prism having a first peak height and a second prism disposed on the base film, the second prism having a second peak height. A difference between the first peak height and the second peak height is substantially 1 ?m to 10 ?m.

Abstract: An illumination homogenizing optical element is disclosed that includes at least one optical surface having a plurality of refractive structures formed as either grooves or protrusions that, individually, are wider than the wavelength of light incident onto said illumination homogenizing optical element. At least part of the light incident onto the illumination homogenizing optical element is removed from the optical path by refraction of said light so as to provide even illumination on an illuminated surface. The illumination homogenizing optical element is advantageous over prior art illumination homogenizing optical elements in that it is easy and inexpensive to manufacture while providing sufficient optical performance.

Abstract: A composite lens structure is disclosed. The composite lens structure includes a diffusion plate and an optical structure formed on the diffusion plate. The optical structure includes a plurality of convex portions arranged in a 2-D matrix along a first direction and a second direction and a plurality of concave portions arranged in a 2-D matrix also along the first direction and the second direction. Each convex portion adjacent to a plurality of concave portions includes a low curvature portion and a high curvature portion higher than the low curvature portion. Each concave portion adjacent to a plurality of convex portions includes a low curvature portion and a high curvature portion lower than the low curvature portion. The convex portions, the concave portions and each junction of the convex portion and the concave portion have a curvature different from 0.

Abstract: The present invention relates to an optical film structure having improved properties and comprising at least one prism film and/or diffuser film as well as a multilayer optical film, wherein the multilayer optical film has at least one top film having an outer layer directed towards the prism film and/or diffuser film and made from a plastics composition containing a transparent thermoplastic and at least one quaternary ammonium salt of a perfluoroalkylsulfonic acid as lubricant additive. According to the invention the outer layer has at least one coefficient of sliding friction of <0.30 relative to the prism film and/or diffuser film measured in accordance with ASTM D 1894-06, with a roughness R3z of >5 ?m (R3z in accordance with ISO 4288). The invention also provides a backlight unit containing the improved film structure and the use of the optical film structure according to the invention for liquid crystal screens.

Abstract: Ellipsometry systems for imaging binding events between analytes in a sample and an array of ligands in an evanescent field generated by a beam of light reflected from the plane of the ligands is adapted to a multiwell plate structure in common use. In one example, a film of prism arrays is affixed to the underside of the plate with each prism array located in registry with a well and ligand arrays being immobilized on the (planar) bottom surface of the wells. The prism array may be formed in a film and juxtaposed with the bottom surface of the plate or a prism array can be made integral with the plate bottom of a multiwell plate.

Abstract: There is provided an optical apparatus that provides quick and precise TTL phase difference detection and pupil slicing focus detection. An optical apparatus includes a first optical element for splitting a first polarized light component contained in light that passes an exit pupil of a first optical system and directs to a photoelectric conversion element so that the first polarized light component direct to different light-receiving areas on the photoelectric conversion element. The optical apparatus may further include a second optical element for separating a second polarized light component contained in the light from said first optical element, from the first polarized light component.

Abstract: A display device includes a display panel on which a plurality of pixels are arranged in a matrix, and a lenticular sheet which is disposed above the display panel and includes a plurality of prism lenses disposed on the lenticular sheet. Each of the plurality of prism lenses includes a first surface, a second surface and a third surface. Each surface of the prism lens is disposed extending in a first direction substantially parallel to a longitudinal direction of the prism lenses, and arranged substantially parallel with each other.

Abstract: An exemplary prism sheet includes a transparent main body. The transparent main body includes a first surface and a second surface. The first surface and the second surface are on opposite sides of the transparent main body. The first surface defines a plurality of micro-depressions. Each micro-depression forms four inner sidewalls connected with each other. A transverse width of each inner sidewall progressively decreases with increasing distance from the first surface. The second surface defines a plurality of parallelogram microstructures. Each parallelogram microstructure defines four adjacent triangular pyramid depressions.

Abstract: An exemplary prism sheet includes a transparent main body. The transparent main body includes a first surface and a second surface. The first surface and the second surface are on opposite sides of the transparent main body. The first surface defines a plurality of a plurality of elongated arc-shaped grooves. The second surface defines a plurality of parallelogram microstructures. Each parallelogram microstructure defines four adjacent triangular pyramid depressions.

Abstract: The present invention provides: a lens optical system having a lens and a plastic block having two parallel planes, the plastic block being provided between the lens and a focal position of the lens to suppress a variation of a focal length due to a temperature change, and a photoelectric encoder including the lens optical system.

Abstract: A Fresnel lens having a curved surface and a large number of Fresnel lens steps with rectangular cross sections for enhancing the aesthetics while providing a diffuser appearance. The cylindrical Fresnel lens can be uniformly divided into rectangular sections across the lens axis. The rectangular sections are alternative and are offset from the curved surface by a distance, which produces a very parallel output beam. The front face of the cylindrical Fresnel lens provides a square like pattern, which results in an aesthetic appearance with the effective usage of light and reduced production costs.

Abstract: A prismatic lens and a reflector/refractor device having enhanced characteristics are provided for lighting fixtures. The prismatic lens and the reflector/refractor device are formed of a silicone material. A prismatic lens member includes a plurality of prisms on a surface thereof for refracting light. The reflector/refractor device includes a plurality of prisms on a surface thereof for reflecting and refracting light. The silicone material forming the prismatic lens and the reflector/refractor device is substantially transparent, and enables forming enhanced optical elements, for example, by injection molding technique. The silicone material is a selected one of dimethylsilicone, phenylmethlysilicone, or similar silicone material enabling enhanced optical performance for the prismatic lens and the reflector/refractor device.

Abstract: In one embodiment a film can comprises a surface comprising a plurality of prism structures. Each prism structure has a lateral modulation in the w direction of less than or equal to ±20% of an average pitch of the prism structures. The plurality of prism structures can have a variation in the w direction of prism peak height that is discrete and/or continuous. In one embodiment, a method for making a film can comprise forming a plurality of prism structures on a surface. The plurality of prism structures can have a lateral modulation in the w direction of less than or equal to ±20% of an average pitch of the prism structures, and wherein the plurality of prism structures have a variation in the w direction of prism peak height that is discrete and/or continuous.

Abstract: A lens sheet according to the invention includes a base film, a lenticular lens resin layer, a prism resin layer, and a filling resin layer. The lenticular lens resin layer includes a plurality of cylindrical lenses formed on one surface of the base film and arranged. The prism resin layer includes a plurality of prisms formed on the other surface of the base film and arranged, and has a lower refractive index than the refractive index of the base film. The filling resin layer is filled on a surface of the prism resin layer provided with the arranged prisms and has a higher refractive index than the refractive index of the prism resin layer. Therefore, the lens sheet according to the invention can restrain side lobe light emitted obliquely to the front surface.

Abstract: An illumination homogenizing optical element is disclosed that includes at least one optical surface having a plurality of refractive structures formed as either grooves or protrusions that, individually, are wider than the wavelength of light incident onto said illumination homogenizing optical element. At least part of the light incident onto the illumination homogenizing optical element is removed from the optical path by refraction of said light so as to provide even illumination on an illuminated surface. The illumination homogenizing optical element is advantageous over prior art illumination homogenizing optical elements in that it is easy and inexpensive to manufacture while providing sufficient optical performance.

Abstract: Disclosed are image expanding lenses, display devices, and electronic devices incorporating the disclosed image expanding lenses. In accordance with a disclosed image expanding lens, the image viewed by the user is larger than the active area of the LCD panel underneath the lens, so that the border around, for example, the LCD display is hidden from viewing. The image expanding lenses may include a non-uniform transparent substrate, having for example, a wedge shape that may be the top surface of the display. The substrate in combination with prismatic films may bend the light output from an array of pixels so that the image hides the border of the display device. In this way, an electronic device can render an edgeless image to a viewer since the image of the electronic device is projected beyond an edge of the display device of the host electronic device.

Abstract: An image-displaying apparatus comprising a light-emitting diode, a relay lens, a secondary light source-forming prism arranged between the light-emitting lens and the relay lens, and a light valve, said secondary light source-forming prism having opposed first and second opposed rectangular planes and at least four polygonal planes, said first and second rectangular planes being positioned on sides of the light-emitting diode and the light valve, respectively, and an area of the first rectangular plane being greater than that of the second rectangular plane, wherein a light emitted from the light-emitting diode is illuminated upon the light valve through the relay lens and the secondary light source-forming prism.

Abstract: An optical film includes a supporting layer and a structured-surface layer having a plurality of prims juxtapositionally formed on the supporting layer, each prim including a lower prism element bonded with the supporting layer and at least one upper prism element integrally superimposed on the lower prism element to increase the prism height in order to pick up sideward refracted light to reduce light loss in order to enhance brightness of the optical film.

Abstract: A prism sheet includes a transparent base film with first and second surfaces and an optical refracting part with a plurality of prism units on the second surface, wherein the prism units are integral with the transparent base film, each prism unit having a predetermined height and extending along a first direction on the second surface of the transparent base film, wherein each prism unit includes a ridge extending along the first direction, a distance along a normal between the second surface of the transparent base film and the ridge defining the predetermined height of the prism unit, and wherein at least two prism units include ridges inclined at a predetermined angle other than zero with respect to the second surface of the transparent base film, the inclined ridges being unevenly distributed on the second surface of the transparent base film.

Abstract: In one embodiment a film can comprises a surface comprising a plurality of prism structures. Each prism structure has a lateral modulation in the w direction of less than or equal to ±20% of an average pitch of the prism structures. The plurality of prism structures can have a variation in the w direction of prism peak height that is discrete and/or continuous. In one embodiment, a method for making a film can comprise forming a plurality of prism structures on a surface. The plurality of prism structures can have a lateral modulation in the w direction of less than or equal to ±20% of an average pitch of the prism structures, and wherein the plurality of prism structures have a variation in the w direction of prism peak height that is discrete and/or continuous.

Abstract: An exemplary prism sheet includes a light input surface, a light output surface opposite to the light input surface, and a plurality of triangular pyramidal micro-elements and a plurality of hexagonal pyramidal micro-elements. The triangular pyramidal micro-elements and the hexagonal pyramidal micro-elements are formed on the light output surface. Each triangular pyramidal micro-element surrounded by three adjacent hexagonal pyramidal micro-elements. Bottom surfaces of each hexagonal pyramidal micro-element and each triangular pyramidal micro-element are coplanar with the light output surface. A liquid crystal display device using the prism sheet is also provided.

Abstract: A variable focus system that includes an electrovariable optic (EVO) and a controller operatively configured for changing the focal configuration of the EVO. The EVO includes a plurality of movable optical elements that may be moved substantially in unison with one another so as to change either the focal length of the EVO, the direction of the focal axis of the EVO, or both, depending upon the needs of a particular application. The variable focus system may be used in conjunction with an image source to construct a 3D floating image projector that projects a series of 2D image slices of a 3D image onto corresponding respective image planes in succession rapidly enough that a 3D floating image is perceived by a viewer.

Abstract: Providing a method and apparatus for efficiently irradiating a uniform laser light on an irradiation surface even when a laser light of high coherence or a large size substrate is used. The laser irradiation apparatus of the invention comprises a laser; means for dividing a laser light emitted from the laser into plural laser beams; means for synthesizing the laser beams on the irradiation surface or place in the vicinity thereof thereby forming a laser light having a periodical energy distribution; and means for moving the substrate relative to the laser light. Such a laser irradiation apparatus may be used to anneal the overall surface of a semiconductor film.

Abstract: An optical film and a backlight unit having the same are disclosed. The optical film includes a base film and a first prism disposed on the base film, the first prism having a first peak height and a second prism disposed on the base film, the second prism having a second peak height. A difference between the first peak height and the second peak height is substantially 1 ?m to 10 ?m.

Abstract: A space light modulating apparatus includes a modulating unit that modulates incident light based on an image signal including a plurality of pixels and a light-shielding part placed between the pixels, and a refracting unit that refracts modulated light including a group of prisms formed with a prism element that has at least a refracting surface. Light from the pixels is incident on at least a part of the prisms, and a direction of the refracting surface is such that a projection image of the pixels is guided onto a projection image of the light-shielding part on a projection surface at a predetermined distance. The refracting surface and a reference surface formed in a direction perpendicular to an optical axis make a predetermined angle.

Abstract: A multiple-axis imaging system having optical elements whose optimal image positions can be individually adjusted, comprising a plurality of optical array elements having respective optical axes and being individually disposed with respect to one another to image respective sections of an object; and a plurality of image position shifting devices corresponding to respective optical elements for separately establishing the image positions for a plurality of the optical array elements. The multi-axis imaging system preferably comprises a miniaturized microscope array. The shifting devices may comprise wavelength filters or optical-path-length-altering elements, such as a plane parallel plates. The devices may also comprise a pair of wedges that adjustably overlap one another, the wedges having apexes that point in opposite directions and respective corresponding planar surfaces that are parallel to one another.

Abstract: An optical film comprising: a transparent supporting (or base) layer; a prismatic layer consisting of a plurality of prisms integrally formed on the supporting layer; and a plurality of micro-lenses integrally formed on a plurality of prismatic faces of the prisms, whereby the incidence lights as refracted through the micro-lenses on the prisms will be refracted to be an outgoing light approximating the on-axes of the prisms, thereby increasing the on-axis brightness of the optical film.

Abstract: A compact rear projection image display apparatus in which the projection distance in a projection optical system is substantially reduced and no reflection mirror is used, thereby eliminating a major cause of image trapezoidal distortion. The rear projection image display apparatus has a projection lens system which includes a first lens group with positive refractive power and a second lens group which further enlarges an image enlarged by the first lens group. The projection lens system enlarges and projects an image displayed on an image display device, on a transmission screen. No reflection mirror is provided between the second lens group and the transmission screen and the image enlarged by the second lens group is directly projected on the transmission screen.

Abstract: An image decoder system includes a series of optically or digitally encoded images mounted on a series of flat surfaces. A decoding lens is positioned over the encoded images. The decoding produces simulated three-dimensional image, simulated motion images or other visible effects. The system includes a backing plate to which the images and one or more decoding lenses are hingedly attached, resulting in a variety of decoding methods. To improve image clarity, locking devices such as Velcro fasteners, snaps, locking tabs, etc. are used to hold the lens to the image surface. Special inks for the encoded images and selected material for lens manufacture are used to improve contact between the image and the lens. Alignment marks are encoded with the image and used to match to alignment marks on the lens to clarify the decoded image. Wide, narrow and special combination lenticular lenses are used for special decoding effects.

Abstract: A spatial light modulator has a modulating unit, a refracting part, and a flat part. The modulating unit includes a matrix of pixels, and a light-shielding portion between each of the pixels. The refracting part is a prism group composed of prism elements, each having at least a refracting surface. The modulated light from one of the pixels is incident on at least a portion of the prism group. The refracting surface is oriented to project an image of the pixel over an image of the light-shielding portion on a screen at a predetermined distance, making an apex with an angle with respect to a reference surface that is orthogonal to an optical axis at the apex. A distance d between the reference surface and the flat part satisfies d<0.95×?/(2×(n?1)) or d>1.05×?/(2×(n?1)), ? being a wavelength of the light, and n being a refractive index of the prism elements.

Abstract: A multiple-layer optical film comprises: a supporting layer; a printable intermediate thin layer formed on the supporting layer; and an upper structured-surface or upper prismatic layer formed on the printable intermediate layer. The intermediate thin layer is imprinted with a plurality of notches recessed in the intermediate thin layer to be respectively engaged with a plurality of lower protrusions protruding downwardly from the upper layer for firmly interlocking the upper layer with the intermediate layer which is formed on the supporting layer.

Abstract: A prism sheet, a backlight assembly having the prism sheet, and an LCD device having the prism sheet, the prism sheet includes a first surface, a second surface and a reflecting member. A light is incident upon the first surface. The second surface includes a prism pattern. The incident light exits through the second surface. The reflecting member is provided on the first surface to partially reflect irradiated light that is received on the first surface.

Abstract: A highly adaptable system for creating colorful spectral displays or for achieving a prismatic effect using visible light. The invention includes a fixed-angle or monolithic prismatic element fabricated from plate glass mirror material. A compound version of this monolithic element wherein multiple single elements have been affixed to one another for the purpose of creating a more complex spectral display is also provided. The invention also includes a prism-like device that utilizes a standard mirror, mirrors, or other materials with highly reflective surfaces and water or a similar fluid that disperses light in a predictable manner at or on a specific target. Both the fixed prismatic elements and the adjustable light dispersing elements may be arranged into one or more arrays that may be used to create complex spectral displays on a variety of surfaces while utilizing one or more available light sources or a moving light source such as the sun.

Abstract: An optical system includes semiconductor lasers arranged in the direction of the slow axis of the laser beam, an optical means which makes parallel the collimated laser beams, an optical member which is provided with inlet and outlet faces which are positioned in perpendicular to the optical axis of laser beams and total reflection surfaces which are opposed to each other at a space where the component in the direction of the slow axis of the laser beam entering from the light inlet face repeats internal reflection, and emits from the light outlet face a slow axis uniform laser beam, and an imaging optical means which images the slow axis uniform laser beam on a surface as a linear line beam extending in the direction of the slow axis.

Abstract: The present invention relates to a rear projection type image display device comprising projection lenses (2, 3) for projecting an image displayed on an image display element onto a transmission type screen (6) on a larger scale, an optical path turn-back mirror (7) for turning back halfway a light beam projected from the projection lenses, and a drive circuit for displaying an image on the image display element, that are fixedly housed within a housing (5). When a diagonal size of the transmission type screen (6), the depth of the housing (5), and the length from a lower end of the screen (6) to a lower end of the housing (5), are assumed to be SS (inch), D (inch), and L (inch), respectively, the following conditions are satisfied: SS >40, D?SS/3.0, L?SS/10.9.

Abstract: A microreplicated article is disclosed. The article includes a web including first and second opposed surfaces. The first surface includes a first microreplicated structure having a plurality of first features. The second surface includes a second microreplicated structure having a plurality of second features. Corresponding opposed features cooperate to form a lens features.

Abstract: According to one aspect of the present invention, an apparatus for optically combining light beams is disclosed. The apparatus includes a set of prism shaped doorways configured to receive output beams from at least one optical device. Each of the plurality of doorways has a common refractive index. The apparatus also includes a set of spherical mirrors disposed substantially parallel to the plurality of doorways. Each mirror is associated with one of the plurality of doorways. The apparatus further includes a boundary layer disposed between the set of doorways and the set of mirrors. The boundary layer has a refractive index greater than the common refractive index of the plurality of doorways. The common refractive index of the set of doorways and the refractive index of the boundary layer are configured to change the angle of each of the received output beams to combine the set of received output beams into a single output beam.

Abstract: This invention discloses a reflective illumination system for supplying an optical radiation beam along a folded path for illuminating a planar object. The system includes a radiation source, and two facing parabolic dish-shaped arrays of parabolic or dished reflectors. Divergent light received from the light source incident on a first of the arrays is reflected as a larger collimated beam comprising plural separated sub-beams. Each of the reflectors or facets from the first array directs one of the sub-beams to a facet on the second array. The second array reflects the light it receives with a substantially uniform intensity onto a rectangular target location.

Abstract: A surface emitting device includes a light guiding plate, a light source, and a prism sheet. The light guiding plate is provided with prism portions each having a slight inclined plane and a steep inclined plane arranged closer to one edge than the slight inclined plane. A plurality of light refracting portions each having a refractive surface and a reflective surface are provided on an incident surface of the prism sheet. Light introduced into the light guiding plate from the light source is emitted from the slight inclined plane and is then incident on the light refracting portion. The light is introduced into the prism sheet by the refracting surface and is then reflected from the reflective surface to be emitted.

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.