Abstract: A direct-type backlight unit for a flat panel liquid crystal display includesat least one lamp installed in a housing, a diffusion plate installed above the lamp, a reflection plate having a reflection surface and a back surface installed under the lamp for reflecting light generated by the lamp from the reflection surface to the diffusion plate, and the reflection plate having at least one aperture thereon, and a heat dissipating plate combined with the back surface of the reflection plate.

Abstract: A luminaire for ceilings, which permits improved packing density for warehousing and shipping. The reflector of the luminaire is designed to permit it to be shipped in a flattened or nested state. This increases the packing density and eliminates shipping and warehousing boxes whose volume is 95% air. An assembled luminaire comprises three or four parts: the reflector, a ballasted-socket, a lamp, and an optional diffuser or lens. The reflector, ballasted-socket, lamp, and optional lens are either shipped separately in bulk packs or shipped in kits containing the one or more sets of components to build the luminaire. When the luminaires are installed at the job site, a ballasted-socket is inserted into a mounting aperture in the reflector; a lamp is inserted into the ballasted-socket; the ballasted-socket is connected to a power source, and the assembly is placed into the ceiling opening.

Abstract: A lighting device has a light source and a light distributor comprising a lamella grid or, more precisely, a reflective lamella grid. This has two strips parallel to one another and a row of lamellae which are arranged between said strips and, together with the two strips, consist of a single sheet-metal piece. Each lamella has a web and one or two limbs associated with this. Each web is furthermore associated with the two strips. The light distributor furthermore has two lateral walls which serve as lateral reflectors and are formed either by lateral sections of the sheet-metal piece forming the reflective lamella grid or by two originally separate parts connected to the reflective lamella grid. The reflective lamella grid can be produced economically from an originally flat sheet-metal piece with little work.

Abstract: A light string includes light bulbs, an oval core having two power cord holes respectively defined to receive therein two secondary power cords, wire holes each defined to receive one of two wires extending from two adjacent light bulbs, apertures each defined between two wire holes, light bulb holes radially defined in the oval core to respectively receive therein one of the light bulbs and a circular cutout defined in a central portion of the oval core to allow extension of connection wires, each connection wire being connected between two wires from two alternately located light bulbs in the oval core and intersected with one another in one of the apertures, and a protrusion integrally formed on a side of the oval core and having a primary power cord hole defined to receive therein a primary power cord.

Abstract: A shutter drive mechanism for an outdoor floodlight is described herein. The shutter drive mechanism and outdoor floodlight has an outer housing which surrounds the light fixture and also which protects the light fixture and a drive mechanism from the elements. Extending outward from the housing is a drive vale which supports the drive mechanism for raising and lowering a rigid shutter which covers the lens of the light fixture so that the light may be doused readily without turning off the lamp. The planar shutter moves horizontally or vertically within rails through a first and second slide, the shutter moveable by a drive arm which is affixed to a runner retained within a runner guide and driven by a screw drive. The shutter is actuatable between an opened and closed position such that the light fixture is adequately doused while the lamp remains on.

Abstract: A light engine (9) for a projection display is provided which employs: 1) at least one light source (25), 2) at least one TIR prism assembly (13), and 3) at least one digital micromirror device (15), wherein: (a) the illumination path (55) between the light source (25) and the prism assembly (13) is unfolded, i.e., the illumination path is free of fold mirrors; and (b) the angle &ggr; between the illumination path (55) and the device's horizontal axis (53) is preferably less than or equal to about 20°.

Abstract: A luminaire has a brightness reduction cover element below and in proximity to the active light source of the luminaire to simulate a larger light source having a lower surface brightness which is exposed through the luminaire's down light opening. For example, where the luminaire has a high output T5 lamp, the brightness reduction cover element can be in the form of a substantially semi-cylindrical opal diffuser cover strip sized to simulate a T8 or T12 lamp. An opal diffuser cover strip having two side-by-side arcuate portions joined at opaque interior edges can be positioned under two side-by-side T5 lamps to simulate side-by-side T8 or T12 lamps.

Abstract: A controlled-luminance lighting device comprising a fluorescent light source of a linear type (5), which extends longitudinally between a reflector (1) that is formed by an elongated body having a curved surface, and a set of transverse fins (3), which are set at a distance apart from one another and which define a grill for directional control of the light emitted by the light source (5). The reflector (1) defines, together with the transverse fins (3), a plurality of elements (2) set alongside one another of a generally parabolic shape.

Abstract: An arena light reflecting assembly includes an asymmetric parabolic shaped reflector having an exit aperture. The reflector surrounds a horizontally extending high intensity light source and has a focal axis that lies along an axis of an arc tube of the light source so that the reflector acts as a collimator redirecting light from the light source into essentially parallel rays from the exit aperture. A pan circumscribes the exit aperture and a louver assembly is disposed within the exit aperture behind a front surface of the pan.

Abstract: A light rope runs along the stringer of a stairway and is concealed by in-fill panels fitted into a groove on a frame rail running along the wall or stringer adjacent to the stairway. A light grille having a square frame and a patterned grille insert is seated along each tread adjacent to the next higher riser and is connected to the frame rail by a pair of adjustment arms. Translucent panels are mounted on the rear of the light grilles, allowing light to shine through them. Electrical circuitry turns the lights on when a user approaches the stairs and automatically turns the lights off after a predetermined time after the user has departed the area of the stairs.

Abstract: A display device having an indicator interposed between two light controlling elements. The light controlling elements act in cooperation to restrict the viewing angle of the display in at least two directions. Only one of the light collimating elements restricts the angle of ambient light entering the display.

Abstract: An illumination obscurement device for controlling the obscurement of illumination from a light source which is optimized for use with a rectangular, arrayed, selective reflection device. In a preferred embodiment, a rotatable shutter with three positions is placed between a light source and a DMD. The first position of the shutter is a mask, preferably an out of focus circle. This out of focus circle creates a circular mask and changes any unwanted dim reflection to a circular shape. The second position of the shutter is completely open, allowing substantially all the light to pass. The third position of the shutter is completely closed, blocking substantially all the light from passing. By controlling the penumbra illumination surrounding the desired illumination, DMDs can be used in illumination devices without creating undesirable rectangular penumbras.

Abstract: A lighting louver and process steps for forming at least portions of a louver are described in which the louver may include a “V” shaped louver body with opposed sides that diverge from a narrow end that include a vertex of the “V” shape, to a wide end. At least one integral hinge at the narrow end joins medial portions of the opposed sides along a singular fold line. The medial portions contact one another at a location adjacent to the singular fold line. At least one inward closure tab overlaps the wide end of the louver body.

Abstract: A motor vehicle headlight comprises a light source, a reflector and an occulting mask. The mask comprises a set of elements which in pairs define, respectively, mutually facing faces which define between them passages extending through the mask in directions passing away from the light source.

Abstract: A backlight 7 has light sources 2, a flat-plate-shaped light guide plate 3 for guiding the light emitted from the light sources 2 in a predetermined direction, a light shield louver 5, disposed so as to face the light guide plate 3, for shielding part of the light emerging from the light guide plate 3 according to angles of incidence, and a prism sheet 8 for converting the brightness distribution of the light incident on the light shield louver 5 into a predetermined brightness distribution. Owing to the prism sheet 8, the light incident on the light shield louver exhibits a brightness distribution such that brightness is at a minimum at an angle of incidence of 0°. Thus, the backlight 7, and a liquid crystal display device 1 employing it, permits light to emerge therefrom within a desired range of viewing angles while offering high brightness within that range, with reduced degradation of viewability.

Abstract: An electronic starter for fluorescent lamp has a preheating circuit for controlling the preheating of the fluorescent tube and a power switch and locking circuit for cutting off the current to the preheating circuit. The power switch and locking circuit makes use of the voltage level on the power input to determine the status of the fluorescent tube. A high voltage on the power input represents that the fluorescent tube has failed to turn on in the ignition operation, whereby the power switch and locking circuit thereupon cuts off the current to the preheat circuit, thereby eliminating flickering of the fluorescent tube and so preventing irritation to the eyes, and extending the service life of the lamp.

Abstract: A luminaire for an elongate lamp has longitudinal reflectors running parallel to the lamp and a multiplicity of spaced-apart transverse lamellae. The lamellae have a bottom, tapering region with a bottom edge that is curved. The cross-section of the bottom, tapering region is of the same shape over the width of the transverse lamellae. The edges of the bottom tapering region have the same curvature, with the lower edge coinciding with the bottom edge of the transverse lamellae.

Abstract: The present invention features a system for uniformly distributing luminance and a high degree of collimation from a back light module for flat-panel, liquid crystal displays (LCDs) simultaneously. A constant and uniform luminance output of the back light module in two directions is obtained through appropriate selection of lamps, geometry and optical components. An appropriate balance of lamps, lamp spacing, diffusers and light collimating optics are chosen to produce a high brightness back light module with very high intensity output over two very large surfaces. Variations in intensity over the illuminated area are minimized using light recycling in conjunction with the reflective diffusers and collimating optics. Precision collimators eliminate light beyond a defined angle, as required in tiled or monolithic flat-panel LCDs with predetermined display specifications.

Abstract: A lighting device has a light source and a light distributor comprising a lamella grid or, more precisely, a reflective lamella grid. This has two strips parallel to one another and a row of lamellae which are arranged between said strips and, together with the two strips, consist of a single sheet-metal piece. Each lamella has a web and one or two limbs associated with this. Each web is furthermore associated with the two strips. The light distributor furthermore has two lateral walls which serve as lateral reflectors and are formed either by lateral sections of the sheet-metal piece forming the reflective lamella grid or by two originally separate parts connected to the reflective lamella grid. The reflective lamella grid can be produced economically from an originally flat sheet-metal piece with little work.

Abstract: A curvilinear lighting louver is described in which first and second reflectors are formed in curvilinear configurations with respect to an axis, with parabolic reflector surfaces facing toward and away from the axis. Baffles connect the first and second reflectors between the first and second parabolic reflector surfaces. The baffles include third parabolic reflector surfaces extending substantially radially with respect to the axis.

Abstract: A night light having a base unit with a central cavity designed to house a light sensor, a printed circuit board, a light bulb, and a pair of electrical prongs. Attached to the front surface of the base unit is a fixed half-spherical lens. Disposed over the lens is a rotating, half-spherical cap having an approximately quarter-spherical sized opening that allows a portion of the lens to be exposed so that light from the light bulb located inside the lens may shine therethrough. Thus when the outer cap is selectively rotated around the base unit, the quarter-spherical sized opening is rotated therewith, and a dissipated broad beam of light may be selectively aimed in any 360 degree direction.

Abstract: A luminaire capable of providing up-lighting when suspended from above, or mounted from below, or wall lighting when mounted as a sconce, having a longitudinally extended tapered hollow shell body which is open in the direction of intended illumination, a lamp mounting assembly, a fixture mounting assembly, and a louver assembly which is positioned between a lamp mounted in the fixture and the surface to be illuminated. The louver assembly is an integral unit having a supporting member which carries longitudinally spaced light-transmissive louvers which project from the body opening toward the illuminated surface. Each louver is formed of a partial disk which may be arcuate (e.g. semi-circular or semi-elliptical) or polygonal, and may have a beveled peripheral surface.

Abstract: A transparent base panel has embedded therein a series of uniformly, sized, shaped and spaced louvers that extend outwardly from the base panel at an angle &bgr;, to optimize light flowing in a direction from an inner surface toward an outer surface while minimizing an amount of light flowing from the outer surface to the inner surface. This louvered screen has application in making outdoor illuminated signs more readable, in screening sunlight out of a compartment such as a room, and in deflecting and/or tinting light from a direct or indirect lighting source.

Abstract: An illumination obscurement device for controlling the obscurement of illumination from a light source which is optimized for use with a rectangular, arrayed, selective reflection device. In a preferred embodiment, a rotatable shutter with three positions is placed between a light source and a DMD. The first position of the shutter is a mask, preferably an out of focus circle. This out of focus circle creates a circular mask and changes any unwanted dim reflection to a circular shape. The second position of the shutter is completely open, allowing substantially all the light to pass. The third position of the shutter is completely closed, blocking substantially all the light from passing. By controlling the penumbra illumination surrounding the desired illumination, DMDs can be used in illumination devices without creating undesirable rectangular penumbras.

Abstract: A solid state light apparatus with a solar shielded heatsink ideally suited for traffic controls. The current state of the art solid state traffic signals utilize LED arrays encased in the existing plastic or metal traffic signal cases which were originally design for incandescent bulbs. Unlike LED's, incandescent bulbs are insensitive to high temperatures. As a result heat will build up on the LED die because of the limitations of the existing incandescent case design. The apparatus mounts the LED array directly to a louvered external heatsink in contact with the air outside of the traffic signal case facilitating the dissipation of heat generated from the LED die and from the sunlight shining on the case. For 25% of all signals (those facing west), during the late afternoon sunset the lensing system will focused the sunlight directly on the LED die raising the die temperature an additional 20 C.

Abstract: An optical element for deflecting light beams is formed form a plate-like core or element 1 of transparent material having tapered microprisms 2 one side, with furrows 7 formed between the microprisms, the furrows being covered with a reflective layer 12, and a foil 11 of transparent material arranged on a side of the reflective layer remote from the core or element 1.

Abstract: A lighting fixture for a heat generating light bulb which includes a pair of heat sinks to assist in dissipating heat and also an airflow path that extends through the lighting fixture that causes air to flow past the light bulb and the heat sinks with the heated air to pass through louvers and openings formed within the housing shell of the light fixture into the ambient.

Abstract: An adaptable landscape light designed to be used with ½ inch or 3-inch diameter poles. The light includes a light housing with a cylindrical-shaped lower base. Formed on the lower base is a downward extending cavity. Three downward extending tabs are radially and equally spaced apart around the lower base. Each tab includes a threaded bore through which a threaded connector may be selectively attached. Included with the light is a conical-shaped adaptor with a cylindrical-shaped upper section designed to fit into the downward extending cavity formed inside the lower base. Formed on the adaptor is a narrow, centrally aligned neck member with a longitudinally aligned threaded bore formed therein. Formed on the sidewalls of the upper cylindrical section are threaded bores which are aligned with the threaded bores formed on the tabs or sidewalls of the lower base.

Abstract: A controlled-luminance lighting device comprising a fluorescent light source of a linear type (5), which extends longitudinally between a reflector (1) that is formed by an elongated body having a curved surface, and a set of transverse fins (3), which are set at a distance apart from one another and which define a grill for directional control of the light emitted by the light source (5). The reflector (1) defines, together with the transverse fins (3), a plurality of elements (2) set alongside one another of a generally parabolic shape.

Abstract: A transparent base panel has embedded therein a series of uniformly, sized, shaped and spaced louvers that extend outwardly from the base panel at an angle &bgr;, to optimize light flowing in a direction from an inner surface toward an outer surface while minimizing an amount of light flowing from the outer surface to the inner surface. This louvered screen has application in making outdoor illuminated signs more readable, in screening sunlight out of a compartment such as a room, and in deflecting and/or tinting light from a direct or indirect lighting source.

Abstract: An air freshener dispenser is taught having plug-through capability as well as a night light. The dispenser is a plug-in diffuser for such active materials as fragrances and air fresheners, and eliminates the consumer problem of loss of an electrical outlet, by providing a receptacle into which another plug may be inserted. The dispenser uses replaceable cartridges of material to be dispensed, and provides a night light for those who desire such.

Abstract: A lighting device has a light source and a light distributor arranged under it. Said light distributor has a distributor element which preferably consists of sheet metal and has an extensive main section with an incidence side facing the light source and a number of holes for the passage of light which widen in the direction away from the incidence side, and a collar for each of said holes. Preferably, a diffuser is arranged above the distributor element and possibly a diaphragm, preferably consisting of sheet metal, is arranged above said diffuser. The light distributor deflects and distributes light radiated downward through it, in such a way that said light makes at least a desired angle of, for example, at least 25° with a horizontal plane. The light distributor can be produced with a small height and economically and has a good antidazzle effect.

Abstract: A low-profile fluorescent luminaire for attachment to a suspended ceiling and methods for retrofitting the luminaire to an existing lighting system. The low-profile fluorescent luminaire has lightweight “I”-shaped framework comprising a pair of transversely-extending end plates attached adjacent to opposed longitudinal ends of a longitudinally-extending spine. The spine and the end plates have a substantially coplanar arrangement to provide a low-profile structure that closely conforms to the ceiling. The “I”-shaped framework supports a reflector positioned below the spine and end plates when the luminaire is in a supported functional position. The low-profile luminaire can be retrofitted to a suspended ceiling to replace the existing light fixtures or to supplement the light output of an existing lighting system without modifying or removing the existing lighting fixtures.

Abstract: A luminaire has an inner annular housing separating an interior cavity of an outer annular housing of the luminaire into a central portion and an outer annular portion. The luminaire also has an annular support element detachably mounted to a bottom end of the inner annular housing and removably supporting an annular louver in the outer annular portion of the interior cavity outside of the inner annular housing and below an illumination lamp of the luminaire.

Abstract: A luminaire for suspended ceilings, which permits improved packing density for warehousing and shipping. The reflector of the luminaire is designed to permit it to be shipped in a flattened state. This increases the packing density and eliminates shipping and warehousing boxes whose volume is 95% air. The reflector is typically a single sheet including a top plane with hinged side panels that snap together with interlocking tabs. An assembled luminaire comprises three or four parts: the reflector, a ballasted-socket, a lamp, and an optional diffuser or lens. The reflector, ballasted-socket, lamp, and optional diffuser or lens are either shipped separately in bulk packs or shipped in kits containing the one or more sets of components to build the luminaire.

Abstract: A troffer which can be shipped to the retailer or job site in several pieces and assembled on site. The reflector portion of the troffer is shaped, such that, one reflector can be shipped within another. This allows any number of reflectors to be nested together to increase the packing density for shipping and warehousing. Thus, a dozen troffers can be packaged together in a volume only slightly greater than a. single conventional troffer. The assembly of the troffer is accomplished by merely clipping one or more ballasted-sockets into the troffer's reflector and the inserting lamps into the ballasted-socket. The assembly is then set into the ceiling grid and connected to the power source. If a diffuser or lens is desired, it is merely placed into the ceiling grid prior to the rest of the troffer's reflector.

Abstract: A motor vehicle headlight has a light source, a reflector and a mask. The mask has one or more sets of masking elements, such as fins or annular rings, that face each other to form a passage. The passage extends through the mask in a direction away from the light source, thereby allowing heat to escape from the light source without optical leakage.

Abstract: Two or more single linear fluorescent lamp reflector housings are pivotably joined together so that at least one end of each single reflector housing overlaps an adjacent reflector housing. Provision is made for each reflector housing to be folded around or slid rectilinearly along the side of its adjacent reflector housing, thus adjusting the overall length of the fixture for installation. Shadowing effects caused by spaces between the ends of individual lamps are eliminated by the overlaps, and the fixtures may be folded for shipping or storage, requiring only a short packing length.

Abstract: A luminaire capable of providing desirably uniform up-lighting when suspended from above, or mounted from below, or similarly uniform wall lighting when mounted as a sconce, having a longitudinally extended tapered hollow shell body which is open in the direction of intended illumination, a lamp mounting assembly, a fixture mounting assembly, and a louver assembly which is positioned between a lamp mounted in the fixture and the surface to be illuminated. The louver assembly is an integral unit having a supporting member which carries longitudinally spaced light-transmissive louvers which project from the body opening toward the illuminated surface. Each louver is formed of a partial disk which may be arcuate (e.g. semi-circular or semi-elliptical) or polygonal, and may have a beveled peripheral surface. The louver assembly is designed to produce the desired uniform illumination.

Abstract: The invention provides in preferred aspects architectural lighting structures that comprise a plurality of tubular elements at least partially embedded into an at least substantially transparent lens structure of a lighting fixture. The lighting fixture is typically a device employed for interior use, particularly residential buildings or commercial buildings such as office buildings. By partially embedding the array or plurality of tubular elements into the transparent lens structure, the fixture can appear as if it is substantially a part of the surrounding surface when the lighting fixture is turned off. Nevertheless, when the light is turned on, light coming from the fixture can still be directed or modified in an appropriate manner, e.g. without detrimental light output reductions), and without the need of an expensive, sophisticated reflector or any necessity of the fixture extending beyond the surrounding surface as has been utilized in certain prior attempts to mask architectural lighting fixtures.

Abstract: A light diffusion preventing structure, suitable for use in vehicles, is provided on a structural member having a hole for passing light from a light source through the structural member and onto a target area. The hole has a three-dimensional shape that has a first opening located near the light source and a second opening located on the opposite side with an inner peripheral surface running between. Both the edge of the second opening and the inner peripheral surface are located completely outside a zone defined by projecting imaginary straight lines from the point light source through the first opening. A second set of imaginary straight lines running between the edge the first opening and the opposite edge of the second opening define at least one crossing angle, the measure of which should preferably not exceed 160 degrees.

Abstract: A lighting device has a light source and a light distributor arranged under it. Said light distributor has a distributor element which preferably consists of sheet metal and has an extensive main section with an incidence side facing the light source and a number of holes for the passage of light which widen in the direction away from the incidence side, and a collar for each of said holes. Preferably, a diffuser is arranged above the distributor element and possibly a diaphragm, preferably consisting of sheet metal, is arranged above said diffuser. The light distributor deflects and distributes light radiated downward through it, in such a way that said light makes at least a desired angle of, for example, at least 25° with a horizontal plane. The light distributor can be produced with a small height and economically and has a good antidazzle effect.

Abstract: A display case lighting system having a lens positioned inside a display came adjacent a light source inside the case for directing light across a viewing plane within the case and reducing contrasting illumination of items displayed within the viewing plane.

Abstract: The luminaire comprises several flat, light-diffusing lamellae (10) between reflectors (1) which each comprise an edge (2) in a light emission window (3). Each lamella has lateral edges (100), an outer edge (12), an inner edge (11), and a relief (101). The relief (101) of the lamella (10) decreases in a direction towards the lateral edges (100), hence avoiding non-uniform light reflections (zebra patterns) of the lamellae (10) on the reflectors (1).

Abstract: A luminaire design for suspended ceilings, which permits improved packing density for the warehousing and shipping. The assembled luminaire comprises three or four parts: a reflector, a ballasted-socket, a lamp, and an optional diffuser or lens. The tapered design of the reflector allows the reflectors to be stored and transported with one reflector nested within another; therefore, a stack of a dozen luminaires take up only slightly more volume than one conventional luminaire. When the luminaires are installed at the job site, a ballasted-socket is clipped into a mounting hole in the reflector, a lamp is inserted into the socket of the ballasted-socket, this assembly is placed into the ceiling grid, and the ballasted-socket is connected to a power source. If a diffuser or lens is desired, it is merely placed in the ceiling grid before the rest of the assembly.

Abstract: A housing for a direct-indirect lighting fixture having a light baffle in the bottom opening of the fixture is fabricated from a unitary extruded part having a baffle plate integrally interconnecting sidewall portions and a central housing structure for the lighting fixture housing. The baffle plates are provided with a suitable aperture pattern by means of a punching process.

Abstract: A decorative lighting louver element is described in which a louver body includes opposed side surfaces. The louver body further includes a top end and a bottom end. A decorative member is sandwiched between the opposed surfaces and includes an edge that is visually exposed adjacent the bottom end of the louver body.

Abstract: A lighting fixture for reducing glare and darkspots on ceilings and walls. The lighting fixture includes a louver housing for supporting a plurality of fluorescent or high intensity discharge lamps. The lighting fixture further includes a first set of elongated, parallel, and spaced-apart reflectors; and a second set of elongated, parallel, and spaced-apart reflectors intersecting the first set of reflectors at a 90° degree angle for forming an open reflector grid therein. The open reflector grid includes four outer side walls. The open reflector grid is attached to the louver housing. The open parabolic reflector grid extends at least two inches (2″) below the ceiling level. The lighting fixture also includes a plurality of indirect reflectors connected to the four outer side walls of the open reflector grid for reducing glare and darkspots on ceiling and walls caused by the plurality of fluorescent lamps in the louver housing.

Abstract: A baffle mountable on the tube of a fluorescent lamp which in the absence of the baffle yields a harsh and glaring light. The baffle is formed of a long strip of fabric material having a row of holes therein through which the tube is threaded to cause the strip to assume the shape of an undulating shade which conceals the lamp. The felt strip is preferably constituted by a pressed, non-woven felt fabric whose fibers are reflective of light and absorbent of sound or a similar flexible absorptive material. Light rays emitted by the lamp are intercepted and dispersed by the shade, thereby diffusing the light and softening the illumination. Ambient sounds impinging on the undulating shade are absorbed thereby to reduce the noise in the room in which the lamp is installed.

Abstract: A collimator, in combination with a source of curing radiation and a working surface, for use in a process for curing a photosensitive resin disposed on the working surface having a machine direction and a cross-machine direction perpendicular to said machine direction, is disclosed. The collimator comprises a plurality of mutually parallel collimating elements spaced from one another in the cross-machine direction and disposed between the source of radiation and the resin. Each of the collimating elements is substantially perpendicular to the working surface, and every two of the mutually adjacent collimating elements have a machine-directional clearance and a cross-machine-directional clearance therebetween. The collimating elements and the machine direction form an acute angle therebetween such that the machine-directional clearance is greater than the cross-machine directional clearance.