Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V19/00—Fastening of light sources or lamp holders
  • F21V19/04—Fastening of light sources or lamp holders with provision for changing light source, e.g. turret
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
  • B60Q3/00—Arrangement of lighting devices for vehicle interiors; Lighting devices specially adapted for vehicle interiors
  • B60Q3/40—Arrangement of lighting devices for vehicle interiors; Lighting devices specially adapted for vehicle interiors specially adapted for specific vehicle types
  • B60Q3/41—Arrangement of lighting devices for vehicle interiors; Lighting devices specially adapted for vehicle interiors specially adapted for specific vehicle types for mass transit vehicles, e.g. buses
  • B60Q3/43—General lighting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
  • B60Q3/00—Arrangement of lighting devices for vehicle interiors; Lighting devices specially adapted for vehicle interiors
  • B60Q3/60—Arrangement of lighting devices for vehicle interiors; Lighting devices specially adapted for vehicle interiors characterised by optical aspects
  • B60Q3/62—Arrangement of lighting devices for vehicle interiors; Lighting devices specially adapted for vehicle interiors characterised by optical aspects using light guides
  • B60Q3/64—Arrangement of lighting devices for vehicle interiors; Lighting devices specially adapted for vehicle interiors characterised by optical aspects using light guides for a single lighting device
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
  • F21S10/00—Lighting devices or systems producing a varying lighting effect
  • F21S10/02—Lighting devices or systems producing a varying lighting effect changing colors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
  • F21V9/40—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters with provision for controlling spectral properties, e.g. colour, or intensity
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
  • G02B6/0096—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the lights guides being of the hollow type
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4298—Coupling light guides with opto-electronic elements coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F13/00—Illuminated signs; Luminous advertising
  • G09F13/02—Signs, boards, or panels, illuminated by artificial light sources positioned in front of the insignia
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21W—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO USES OR APPLICATIONS OF LIGHTING DEVICES OR SYSTEMS
  • F21W2131/00—Use or application of lighting devices or systems not provided for in codes F21W2102/00-F21W2121/00
  • F21W2131/40—Lighting for industrial, commercial, recreational or military use
  • F21W2131/405—Lighting for industrial, commercial, recreational or military use for shop-windows or displays

Definitions

• the present invention relates to an illuminating system, particularly useful for route and destination signs and for illuminating displays, such as for aircraft, buses or other vehicles.
• Readability of signs or displays is affected by day and night conditions, such as glare and external light. Readability can be improved by increasing contrast, since the greater the contrast, the greater will be legibility.
• illumination systems have been employed to improve readability, existing illumination systems do not provide a uniform or even distribution of light. Bright spots, darkened areas at the end of the sign or display, and a halo of light along the bottom of the display or sign may appear, depending upon the arrangement of the light source utilized for illumination.
• An optical film designed to convert point sources of light into an evenly dispersed area of light has been developed under the trade name 3M Brand Scotchlamp Film, and is shown in
• the film is made of transparent plastic in sheet form, which is smooth on one side and grooved on the other. Its thickness is about 20 mils (.02 inch). The grooves are actually tiny optical prisms with fragile corners and delicate faces.
• the film is flexible, and may be readily rolled or bent. It may be called a transreflective material.
• This film is used as a part of prism light guides which distribute sunlight received from a solar light tracking system to illuminate indoor office space evenly.
• This article suggests that colored light could be provided by fitting a luminaire with colored PAR lamps.
• the light could be controlled in three ways: electronic dimmers and a small microprocessor; rotating filter wheels with different colored gels; or solenoid-operated dichroic filters in front of white light sources.
• one aspect of the present invention resides in an arrangement for illuminating, comprising a source emitting light into a tube with a transparent portion.
• the light source may be arranged outside of the tube so as to emit light into the tube through an open end.
• a high reflectance or transreflective film covers a portion of the inner surface of the inner tube and distributes light along the length of the tube, which has a longitudinal area through which light is transmissible.
• the film is preferably formed with optical prisms for multiply reflecting the light inside the tube.
• a diffusing medium is arranged in the tube diametrical ⁇ ly opposite the light-transmissive longitudinal area so that, after the light strikes the diffusing medium, the light is scattered or diffused outwardly through the longitudinal area.
• a reflector may be placed at the opposite end of the inner tube from the light source to reflect light back into the tube.
• the outer tube is rotatable into a predetermined position by a motor drive to select a desired color for illumination.
• the outer tube is formed so that when in a predetermined position only one of its color portions is exposed to the light trans ⁇ mitted through the inner tube's light-transmissive longitudinal area.
• Fig. 1 is a schematic side longitudinal view of a light guide tube with light propagating through the tube from a light source, in accordance with the prior art.
• Fig. 2 is a schematic perspective view of the light guide tube of Fig. 1.
• Fig. 3 is a schematic transverse view of Fig. 2, in which light rays are shown, to illustrate total internal reflection off prism faces, with the encircled portion shown also enlarged.
• Fig. 4 is a schematic perspective view of a multicolor illumination arrangement in accordance with the present inven- tion, in place for illuminating a sign.
• Fig. 5 is a schematic exploded perspective view of the arrangement of Fig. 4.
• Fig. 6 is a schematic end elevation view of the arrangement of Fig,. 4, in which light rays are represented by arrows.
• Fig. 7 is a transverse sectional view of the light guide tube of Fig. 6 by itself.
• Fig. 8 is an enlarged fragmentary view of a portion of the tube of Fig. 7.
• Fig. 9 is a transverse sectional view of a light guide tube in accordance with a second embodiment of the invention.
• Fig. 10 is a perspective view of a destination sign, for buses or the like, utilizing three selectable-color light tubes similar to those of Figs. 1-8 and 9.
• Fig. 11 is a transverse sectional view of one of the light guide tubes of Fig. 10.
• Fig. 12 is a perspective view of a multiple-color outer tube useful in the preceding embodiments.
• Fig. 13 is a longitudinal view partly in section of a multi-color extended light source useful in preceding embodi ⁇ ments.
• Fig. 14 is. a fragmentary longitudinal section of an extended light source utilizing the principles of the inven ⁇ tion.
• Fig. 15 is a cross-sectional view of Fig. 14 viewed along line 14-14 thereof.
• Fig. 16 is a longitudinal view, partly broken away, of a modification of the device of Fig. 14.
• Fig. 17 is a cross-sectional view of the device of Fig. 16, viewed along line 17-17 thereof.
• a sign 1 is illuminated by evenly distributed colored light from a multi-colored illumination arrangement.
• This arrangement includes a light source 4 with reflector, an inner tube 2, an outer tube 3, reflectors 6, 11, a diffusing medium 12, a high reflectance light-distribution film 13, and a motor assembly 7.
• the reflector 6 is angled to reflect light emanating from the light source 4 into the inner tube 2.
• the reflector 6 is preferably made of 3M SILVERLUX material.
• the light then propagates inside the inner tube by reflecting off the high reflectance film or sheet 13, which is preferably 3M Scotchlamp film, whose properties are described below.
• Reflector 11 is arranged at the end of the inner tube 2 furthest from the light source 4 so as to reflect propagated light back into the inner tube 2.
• the diffusing medium 12 which may be a dull white colored strip or coating to cause diffusion or scattering of the light impinging thereon, extends along the length of the inner tube 2 near the bottom, as seen in Fig. 3.
• the diffusing medium 12 is substantially diametrically opposite a lon ⁇ gitudinally extending light-transmissive portion or opening 14 in the wall of the inner tube 2, which registers with a gap 14A in the film 13.
• the diffusing medium may be a dull white strip laid or coated on the inner surface of the film 13.
• the film 13 may have a longitudinal slot into which the diffusing medium is placed.
• the high reflectance film 13 is a thin, flexible, clear transparent material, such as acrylic or polycarbonate polymer, with a smooth surface on one side and prismatic grooves on the other side, which form on the inner surface of inner tube 2 tiny optical prisms that extend longitudinally along tube 2.
• Fig. 1 schematically shows a light guide tube 35 and an external light source 33 with reflector.
• the light guide tube 35 is formed of Scotchlamp material, having a transparent wall with a grooved outer surface forming prismatic facets, which are efficient total internal reflection surfaces and prevent light which is travelling down the guide tube from escaping through the film 13.
• Each prismatic facet has two prism faces inclining outward towards each other and into contact with each other so as to have a V-like shape. These are more clearly shown in Figs. 2 and 3. Referring again to Fig. 1, it can be seen that a light ray 31, emitted from the external light source 33, strikes the interior of the transparent wall of a guide tube 35, through which the light refracts in accordance with Snell's law to pass through the body of the transparent wall.
• the ray strikes one prism face at any angle less than the critical angle for total internal reflection, it reflects by total internal reflection and heads for the other prism face of the same prismatic facet. If reflected by total internal reflection again, it returns to the interior of the tube for further propagation.
• a ray will be reflected if the angle it makes with the tube axis is less than about 27 degrees. The exact angular value is dependent upon the refractive index of the transparent material.
• the film 13 is formed to reflect the light and to minimize absorption and transmission. Absorption per bounce for a typical ray has been found to be as low as a 0.12% and residual transmission losses maybe about 1.2% for typical angles of incidence. Reflectance is thus about 98.7%.
• a white surface 15 may be added between the inner tube 2 and the high reflectance film 13 as shown in Fig. 7.
• light which may be transmitted through the film 13, which would otherwise be a residual transmission loss, is diffused or reflected back into the inner tube from the white surface 15 and is thereby retained to enhance efficiency.
• the outer tube 3 concentrically surrounds the inner tube 2.
• a motor assembly 7 is used to rotatably position the outer tube 3 relative to the inner tube 2 in any conventional manner.
• the outer tube 3 is formed of a number of longitudinal light-transmissive (transparent or translucent) colored filter sections (as seen in Fig. 6), any one section being positionable to be opposite the light-transmissive portion 14.
• the color filter segments of the outer tube 3 may be in the form of either transparent color inserts suitably held to the outer tube, as by projecting lips, or transparent color silk-screened onto the segments of the tube 3.
• the outer tube 3 is divided into color quadrants, each quadrant having a different color such as green G, red R, yellow Y, and blue or black B, each of which extends along substantially the full length of the outer tube 3. In this way the light then projects outwardly from the entire length of the sign 1 to effect illumination of the sign 1 with a single colored light.
• each color-transmitting section When used in a bus sign, for example, the colored light transmitted by the colored filter sections R, Y, G, B may not be highly visible in daylight, and such colored light-trans ⁇ mitting filter sections are usually poor light reflectors, leading to poor daylight visibility.
• This may be overcome by making each color-transmitting section partially efficiently light-transmissive and partially efficiently light-reflective.
• each section R, Y, G or B may be formed of alternate stripes 41 of color-filter material (shown stippled) and intervening stripes 43 of color-reflecting material.
• the color-filtering and color- reflecting materials are preferably chosen to have closely similar color as perceived either in daylight or night-time.
• a controller or a computer may be used to control the positioning of the outer tube 3 so that a desired color segment R, Y, G, or B will be exposed to filter the light passing through the light-transmissive portion of the inner tube 2 or to be reflected by ambient light.
• the light source 4 does not necessarily have to be arranged perpendicular to the axis of the inner tube 2. Any angular orientation can be used if accompanied by an ap ⁇ basementte position of the reflector 6 to reflect the light nearly axially into the inner tube 2. If the light source 4 and the inner tube 2 are substantially co-linearly arranged, no reflector 6 is needed.
• a reflector may be used surrounding the light source or bulb, to focus the light rays to be substan ⁇ tially axial of or slightly converging along the tube, as indicated schematically in Fig. 6. However, a perpendicular orientation for the light source axis is preferred to obtain better accessibility to the light source bulb for replacement purposes, and to reduce the axial dimensions of the system.
• Fig. 7 shows a schematic sectional view of the inner tube alone, depicting the path of certain light rays.
• the only light emitted to the exterior is through the light-transmissive portion 14, derived from the diffusing medium 12.
• the film 13 on the inner -surface of tube 2 between diffusing medium 12 and the light-transmissive portion 14 serves primarily to dis ⁇ tribute the light uniformly along the length of the tube 2, without directly passing through the light-transmissive portion 14. After multiple reflections, the light ultimately hits the diffusing medium 12.
• Fig. 9 shows a view similar to Fig. 7 for a second embodiment.
• an opaque tube 2A which may be an aluminum extrusion, is used in the same way as inner tube 2.
• the opaque inner tube 2A also has a portion lined with the high reflectance film 13 except for an unlined portion or gap in the form of a longitudinal slit in which is placed a lens 8 which longitudinally extends along a length of the tube 2A.
• the inner surface of the tube 2A is made white or reflective so that light transmitting through the film diffuses or reflects back into the tube 2A and is thereby retained.
• the lens 8 may be designed in known manner to provide a more uniform illumination from the bottom to the top of a sign 1 (see Fig. 6) and to adjust for the shorter path length for light rays impinging on the lower portion of the sign 1.
• the lens 8 may be linear, prismatic, clear and illustratively is composed of polycarbonate material.
• a diffusing medium 5 is also arranged diametrically opposite the lens 8 and, for improved uniformity of light dis ⁇ tribution along the tube length, may be of a varying width. The diffusing medium 5 widens as it extends longitudinally away from the light source 4 in the embodiment of Fig. 5.
• the diffusing medium may have a width 5A of .43 inches nearest the light source, a width 5B of .58 inches about midway along the length of the inner tube 2, and a width 5C of .88 inches furthest from the light source 4 or nearest the end reflector 6.
• This varying width may be provided by bulging the diffusing material to provide a varying curved-surface width along the length of tube 2A. This may be provided, for example, by forming a uniform width groove or slot in the tube 2A, with edges to retain a strip of diffusing material of gradually varying width, providing gradually varying bulging of the strip along its length.
• the lens 8 which is preferable of a unitary piece construction, may have two or more transverse sections 8A and 8B. Such sections are useful to project the diffused light rays on either side of the centerline 16 of Fig. 9 to effect more uniform illumination over a sign such as sign 1.
• Each lens section 8A, 8B has a sloping surface relative to the centerline 16 so as to refract the light which is emitted from the curved surface of the diffusing medium 5, to distribute the light more uniformly over sign 1.
• each lens section may actually be a separate lens with its own refractive index different from that of the other.
• the light source 4 is preferably an incandescent halogen lamp which has advantages over a fluorescent lamp. For example where lower wattage is desired, one 20 watt incandes ⁇ cent halogen lamp can replace two 20 watt fluorescent lamps while providing an improved lighting effect.
• Such halogen lamps provide higher intensities, with a narrower beam, more uniform brightness (top to bottom of sigh), easy relamping through the back without opening the back cover, lower cost and fewer components (socket and lamp versus two lamps, two sockets, a ballast and wiring channel), and require less input power (e.g. 20 watts versus 43 watts).
• such lamps produce ultra-violet light which can be made to interact with fluorescent material on the illuminated surface to give enhanced brightness or special effects.
• the showing of darkened letters at each end of the sign or of a halo of light along the bottom of the sign is inhibited by the use of the present invention with halogen lamps.
• the electronic sign employs yellow dots or disks for the lettering, these dots or disks remain yellow in appearance in light from the halogen lamp rather than appearing yellow-green as would be common with light from fluorescent lamps.
• tube 2 or 2A may be split longitudinally and at the diffusing medium 5, and thus formed in two nearly half-cylinder sections.
• the two halves may be joined, together with the lens 8 and diffusing medium 5, by an end ring or cylinder, which for example may carry a .gear to be driven by the motor drive assembly.
• the illumination arrangement of the present invention may be used to provide forward-facing selectable-color light bars.
• Multiple multi-color illumination arrangements of the invention may also be arranged end to end, as seen in Fig. 10. That figure illustrates use of the present invention in a bus destination sign display, having a section 51 displaying a bus route number, a section 53 displaying a bus destination, and three sections 54, 55, 56, each of which is a structure as described above which displays an elongated bar of a selectable color R, Y, G, B.
• 3-color codes up to 64 in number, may be displayed, which would be intelligible at a greater distance than letters or numbers may be legible.
• each segment may be an independent unit, with its own light source and motor drive.
• image enhancer plates 9 are shown on either side of the gap 14A, inclining inward from a housing assembly 10 towards the outer tube 3. These plates 9 are light-reflective and increase the apparent size of a colored segment of the color tube 3. These image enhancer plates 9 ideally extend longitudinally along the entire length of the outer tube 3 and may further extend transversely at the ends of the outer tube so as to incline outward along the entire periphery of the outer tube's color segment which is exposed to light from the inner tube 2 or 2A.
• the image enhancer plates 9 may incline outward from adjacent the periphery of the light- transmissive portion of the inner tube 2 or 2A. Such arrange ⁇ ments may also be used to enhance the light passing through the light-transmissible portion when no color-creating outer tube 3 is employed.
• the image enhancer plates 9 help to uniformly dis ⁇ tribute and enhance the illuminating effect of the light trans ⁇ mitting through the light-transmissible portion by reflecting light which would not have been directed at the object or sign to be illuminated and thus would have been lost.
• the enhancer plates thereby capture this otherwise lost light.
• Figs. 14-15 show an improved arrangement where color 15 change is not needed.
• the housing 61 contains a station ⁇ ary light guide arrangement 63 whose construction may be that of Fig. 7 or Fig. 9 without the outer tube or its drive.
• a light source assembly 65 is located at each end, comprising a light bulb 67 and reflector 69 for directing light along light guide 63.
• the assembly 65 is pivoted at 71 so that it may be extended beyond housing 61 though an opening 73, as seen in dashed line in Fig. 15, to permit easy replacement of bulb 67 when needed.
• Conventional latching means (not shown) usually retain each source 65 in operative position as shown in Fig. 14.
• Housing 61 is open along one side 75.
• Figs. 16 and 17 show a modified arrangement of the arrangement of Figs. 14 and 15.
• the housing 161 is formed of a clear transparent plastic having a light-transmitting face 162 and a back portion 163 where the clear transparent plastic is covered by an opaque coating, such as of black lacquer 164.
• Juxtaposed on the inner side of the clear housing face 162 is a flat plate or sheet 164 formed of the same transreflective material as the light guide arrangement described above with respect to Fig. 3.
• a curved sheet 166 of the same transreflective light guide material.
• Flat sheet 164 and curved sheet 166 together formed cylindrical light guide arrangement as above, but of non-circular cross section.
• At each end of the housing 163 is a light assembly 165.
• Each light assembly 165 is pivoted at 168 to the housing 163 so that, as shown in the left portion of Fig. 16, the light assembly 165 may be pivoted by 90° to make the light bulb 167 accessible for replacement purposes.
• the light assembly 165 is formed of a support 170 carrying a curved reflector 172 which may be of parabolic shape.
• a lamp socket (indicated generally at 174) into which a light bulb 167 may be plugged.
• the light bulb socket 174 has contacts (not shown) which engage the terminals of the light bulb 166 and are connected to terminals 165 for electrical connection to a suitable source of electrical power.
• the light bulb 167 extends generally axially of the housing 163 with its reflector 172 behind it, when the assembly is in the operative position shown at the right side of Fig. 16.
• the light bulb 167 therefore projects its light along the interior of the housing longitudinally of the cylindrical light guide formed by 164,166.
• the properties of the light guide are as described above, so that light rays impinging at a shallow angle on the interior of the light guide are reflected inwardly. Those rays that travel the length of the housing 163 will then be reflected by the reflector 172 at the opposite end. Ac ⁇ ording- ly, the light rays travel back and forth within the light guide.
• Certain of the rays impinging on the sheets 164, 166 may be refracted by the material of the light guide and exit from the light guide.
• the interior of the housing 163 which surrounds the curved light guide sheet 166 is coated or painted white, so that any light which may exit from the light guide is in turn reflected or diffracted back into the light guide.
• the transparent housing may be coated white on its exterior, beneath any black or opaque outer coating.
• a central portion of the curved light guide sheet 166 may (but need not) have a diffusing strip 176 extending along its length diametrically opposite from the clear face 162 of the housing 161.
• the flat sheet 164 preferab ⁇ ly has a length greater than that of the curved sheet 166 so that the curved light guide sheet 166 covers only the central part of the length of the housing 161.
• the curved sheet 166 backs up only a portion of the flat sheet 164, leaving end portions 162A of the flat sheet 162 unbacked by the curved sheet 166, but backed by the white surface 178 of the interior of the housing 161.
• the white sections 178 at each end of the housing serve as diffusing areas from which light rays are directed nearly perpendicularly or at other angles to sheet 164. These light rays may pass through sheet 164 and provide illumination.
• the flat or front face of the housing may extend to a region 181 at the top edge of the housing 163 at an angle to the front face. Therefore, par ⁇ ticularly in the regions to which the curved light guide sheet 166 does not extend, light rays may exit directly through the clear area 181 of the housing 161 for further regulation of the distribution of the light emitted from this arrangement.
• the housing 161 may have a flattened corner shown at 177, which forms a surface for mounting the housing under a shelf or light shield.
• the clear region 181 thus illuminate generally forwardly while the front face 162 would illuminate generally at a downward angle, and provides a diffused light source essentially without glare. This is particularly useful for illuminating instrument panels of an aircraft, beneath a glare shield under which the arrangement may be mounted.
• sheet 164 and areas 178 may be suitably colored if desired.
• a stationary single-color outer tube may be used in place of the rotatable outer tube, or the outer tube may be dispensed with entirety.
• the diffusing strip 12 may be appropriately colored, when desired to provide a non-white illumination, such as for photographic dark rooms or night illumination of instrument panels.
• an extended-length source of infra-red or ultra-violet light may be provided by the present arrange ⁇ ment by placing an appropriate infra-red or ultra-violet filter between light source 4 or 65 and the light guide, or otherwise inputting only infra-red or ultra-violet light to the light guide.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Spectroscopy & Molecular Physics (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Optics & Photonics (AREA)
• Theoretical Computer Science (AREA)
• Illuminated Signs And Luminous Advertising (AREA)

Applications Claiming Priority (4)

Publications (2)

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Family Applications (1)

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Citations (3)

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• 1989
  • 1989-09-11 EP EP19890911483 patent/EP0411065A4/en not_active Withdrawn
  • 1989-09-11 WO PCT/US1989/003920 patent/WO1990004132A1/en not_active Application Discontinuation
  • 1989-09-11 AU AU43477/89A patent/AU4347789A/en not_active Abandoned
  • 1989-09-11 JP JP1510646A patent/JPH03504290A/ja active Pending
  • 1989-09-29 CA CA000614653A patent/CA1331980C/en not_active Expired - Fee Related
  • 1989-10-06 ES ES8903361A patent/ES2016508A6/es not_active Expired - Lifetime
  • 1989-10-07 CN CN89107696A patent/CN1042779A/zh active Pending

Patent Citations (3)

Non-Patent Citations (1)

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