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WO1987006997A1 - Phares de vehicules - Google Patents

Phares de vehicules Download PDF

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Publication number
WO1987006997A1
WO1987006997A1 PCT/US1987/001058 US8701058W WO8706997A1 WO 1987006997 A1 WO1987006997 A1 WO 1987006997A1 US 8701058 W US8701058 W US 8701058W WO 8706997 A1 WO8706997 A1 WO 8706997A1
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WO
WIPO (PCT)
Prior art keywords
reflector
light
section
lens
sections
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US1987/001058
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English (en)
Inventor
Nigel John Robert Dashwood
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Duracell Inc USA
Original Assignee
Duracell International Inc
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Filing date
Publication date
Application filed by Duracell International Inc filed Critical Duracell International Inc
Publication of WO1987006997A1 publication Critical patent/WO1987006997A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/30—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by reflectors
    • F21S41/32—Optical layout thereof
    • F21S41/33—Multi-surface reflectors, e.g. reflectors with facets or reflectors with portions of different curvature
    • F21S41/334—Multi-surface reflectors, e.g. reflectors with facets or reflectors with portions of different curvature the reflector consisting of patch like sectors
    • F21S41/336—Multi-surface reflectors, e.g. reflectors with facets or reflectors with portions of different curvature the reflector consisting of patch like sectors with discontinuity at the junction between adjacent areas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/20—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by refractors, transparent cover plates, light guides or filters
    • F21S41/28—Cover glass

Definitions

  • This invention is concerned with the design of reflectors f or vehic le lights , e specia lly but not exclusively cyc l e l i ght s .
  • I t is concern ed wi th th e efficient design of such lights in which the ref lector and lens are of non-circular profile and also with the problem of providing illumination in the far field at high angles from the optical axis.
  • cycle light are designed with a light- emitting area of rectangular cross-section and contain a circular section reflector which has been truncated to fit within the rectangular aperture of the light.
  • the reflector is generally of paraboloidal form. But in truncating the reflector optical efficiency is lost because some sections of the reflector are so severely curtailed that the degree of subtense of the lamp at the reflector is much reduced.
  • a parabaloidal reflector has been the norm because it is forgiving of poor manufacturing tolerances and ensures that al l parts of the reflector contribute to the forward going beam. But it provides a reflected beam of no angular spread except that imparted by filament size e spa a distribution heavily concentrated about the optical axis.
  • a preferable alternative, particularly for front cycle lights which traditionally are preferred with a simple front lens, is for the reflector to create, at least in part, an asymmetry in the light beam.
  • a further light loss mechanism occurs when cycle lights are mounted on the bicycle's wheel mounting forks, because the angular spread of light from the cycle lights is usually large enough to cause a significant portion of the light to be blocked by that portion of the wheel projecting beyond the forks.
  • a yet further problem in the design of a lens for a cycle front light is that the light source filament is sufficiently recessed in a light housing that direct light from the filament cannot supply, at large angles from the optical axis of the light, the ill umination required by the various international lighting standards.
  • Su ch standards require that cycle lights shall supply not only an int en se c entral l ight b eam b ut a l so a degree of illumination at large angles to the optical axis , defined by the centre of the central light beam.
  • the luminous intensity required at these angles is usually sufficiently low that it can be supplied as direct light from the filament.
  • cycle lights it is common for cycle lights to achieve the wide angle illumination by allowing direct light from the lamp fi la ment to be seen ei ther via a s lot i n th e reflector or via a truncated circu larly symm etric reflector. Redirection of the light beam, for example, to increase the angle of em ission from the cycle light, can be achieved by prismatic or lenticular structures in the front lens.
  • cycle rear lights it is common for cycle rear lights to employ such a reflector, together with a domed lens, in order to create the wide angle coverage. This is because a cycle rear light is required to illuminate a field of at least 180 degrees in the horizontal plane. Since the luminous intensity requirements of the central light beam are modest, it is not too important for the reflector to maintain a high optical efficiency in collecting light from the filament and delivering it to the central light beam. Cyc e ront l ght s , however , are re qu ired to provide a high luminous intensity central light beam and require the degree of light collection by the ref lector from the lamp fi lament to be high.
  • the need for a high degree of light collection by the reflector of a front light usually ensures that it subtends a large solid angle at the lamp, and this feature prevents direct light from the lamp illuminating a sufficiently wide angle field even though the d irect l i ght from the lamp fi la ment i s sufficient to provide the required level of illumination at the wider angle. It is a further consequence of the large ref lector subtense angle that the w ide angle illumination, via a truncated or s lotted reflector, is often not a viable compromise.
  • the invention provides a reflector for a lamp which reflector has a front opening of non-circular outline lying on one smooth unbroken surface, said outline defining generally orthogonal major and minor directions, the reflector comprising a plurality of nested sections each divided from an adjoining section by a step and each lying on a surface of revolution generated by a different curve extending rearwardly from the front opening, each said curve being generated from a common generating point in the vicinity of which an intended light source is to be held with an anterior section being defined by a region surrounding the aperture from which region opposed sectors with a broken posterior section being defined by a pair of sectors to opposed sides of the aperture extending to the front opening along the major direction, one of said sections being formed from an empirically determined non- conic curve which has a characteristic angularly unbroken reflected beam from a point source whi ch diverges in the far field but with a pattern of angular spread where
  • the outline of the reflector may lie on a surface defined by a plane normal to the optical axis or on a surface defined by a cylinder whose axis is normal to the optical axis or on a smooth unbroken concave or convex spherical surface or on a toroidal surface , but is preferably on a cylindrical surface.
  • a single reflector section is defined as consisting of one or more sub- sections or "regions ", these regions being parts of a single generated profi le exibiting 7 symmetry about its optical axis.
  • a further object of the present invention is to overcome the problem of obtaining a sufficiently wide angle of illumination.
  • that problem is solved by using a ref lector that provides a beam of reflected light from a compact source , said beam having gaps in the near field beam profile, and said reflector being employed in combination with a front lens provided wi th diverting means su ch as lenticu l ar or prismatic structures located in the near field beam gaps to spread incident direct light to the far field at angles beyond those where the reflector cuts off direct light.
  • a light for generating a field of illumination the extremes of which are forme -by direct light from the lamp filament, and in which the reflector has a subtense at the lamp which is sufficient to reduce the angular field of direct light from the lamp to below the required angular field of illumination
  • said light comprising: a compact source of light; a re flector cons i s t ing of two or more curved sections, said sections either being edge-abutting or separated by one or more further sections which subtend a negligibly s ma ll angle at the lamp, said ref l ector producing a light beam from the compact source of light present in the near field light beam at least as far along the direction of the optical axis of said reflector as the reflector aperture rim; and a lens for spreading the light beam from the reflector, said lens containing at least one section which substantially overlays a deluminated portion of the light beam from the reflector,
  • Figure 1 is an exploded view of a cycle light according to the invention
  • Figure 2 is a cross-section of a conventional cycle light
  • Figure 3 is a front perspective view of a conventional reflector for a cycle light of rectangular front profile
  • Figure 4 is a front view of a first form of reflector according to the invention
  • Figures 5 and 6 are cross-sections of the reflector on the lines A-A and B-B of Figure 4 respectively;
  • Figure 7 is a diagrammatic section of the reflector of Figures 4 to 6 illustrating its differences from a conventional reflector
  • Figure 8 is a quartered front view of a reflector according to the invention showing its appearance with three sections, four sections and six sections;
  • Figure 9 is a front view of a reflector which to the right of the line A-A is the same as Figure 4 and to the left of the line A-A is of a further form;
  • Figure 10 is a diagrammatic section of a reflector of the further form of Figure 8;
  • Figure 11 is a diagrammatic section of a yet further form of the reflector;
  • Figure 12 is a ray diagram showing embodiments of er es before it diverges
  • Figures 13 and 14 are diagrammatic sections of further reflectors showing the formation of gaps in the pattern of reflected light
  • Figure 15 is a front view and Figure 16 is a fragmentary section of a lens having areas for deviating incident direct light in regions where there are gaps in the pattern of reflected light;
  • Figure 17 is a diagrammatic section of a reflector, lamp and lens showing the pattern of emergent light;
  • Figures 18-19 are respectively a section of the reflector of Figure 4 on the line B-B with a bulb in position and a diagrammatic front view of the bulb showing the filament and location details.
  • the general kind of light with which this invention is concerned is shown in Figure 1.
  • the light includes a compact light source 1 such as an electric lamp that is fitted in a reflector 2 that is generally rectangular in front view, and in plan has rearwardly curving upper and lower edges 7.
  • the reflector 2 is moulded in polystyrene or other suitable plastics material end is aluminised. It is covered by means of a convex part cylindrical lens assembly 3, of a suitable clear plastics material whose shape is complementary to that of the reflector 2 and which is a push fit thereon.
  • a cross-section of a conventional cycle light is shown in Figure 2.
  • the reflector 2 possesses a parabolic cross-section in a plane containing its optical axis 4 so that the light from reflector 2 travels essentially parallel to the optical axis 4, as indicated by rays 5.
  • Ref lector 2 may also consist of two or more sub-sections that are circularly symmetric about the optical axis 4 and have a common optical axis.
  • the lens 3 contains an array of lenticular or primsatic elements, typically as shown by convex lenses 6, which serve to spread the uni-directional beam from the reflector 2 into an output beam of the required light distribution and angular spread.
  • the reflector 2 'and lens 3 are of circular front profile so that the reflector is well-matched if its aperture diameter is equal to that of the lens and operates with an efficiency principally determined by the minimum and maximum subtense angles A and B of the source 1 at the reflector 2. But if the lens 3 is of rectangular front profile then either reflector 2 must have an aperture diameter which is no larger than the shorter side length of lens 3 or the reflector 2 must be truncated.
  • the former option requires that the reflector is other than paraboloidal or has a non-specular surface.
  • a truncated reflector is illustrated in Figure 3 , where the effect of the truncation is that the reflector loses surface in the two perpendicular sections C-C and D-D, and only remains fully in diagonal section E-E.
  • the maximum subtense angle of the light source 1 with respect to the optical axis 4 of the reflector is equal to the angle B, as also shown in Figure 1, the subtense angles at the side and end mid points of the reflector are reduced to F and G. Consequently, less light is collected from the source 1 and directed into the output light beam than would be the case for a corresponding circular reflector.
  • a further problem in a conventional cycle light is that of obtaining a desired light distribution to wide angles from the optical axis.
  • the reflector 2 subtends a large useable semi- angle, typically up to 120-135 degrees at the source 1 so that an extreme ray 5a is correspondingly limited to an angle of from 45 to 60 degrees to the optical axis 4.
  • international lighting standards commonly require that illumination should extend to angles of up to 80° from the optical axis 4 and for a cycle rear light the angle is larger, at least 90°, and it is common for the reflector to be either truncated or slotted to let dirct light pass from the lamp filament to the required semi-angle.
  • a first form of a reflector according to the invention consists of four sections 10, 11, 12, 13 with a common optical axis 14 and a common focal point 15 at which a compact source 1 is sited.
  • Each section 10, 11 and 12 has a surface that is smoothly curved and that produces a far field diverging beam and the individual reflectors 10, 11 and 12 are so positioned as to fill as far as possible the rectangular aperture.
  • the section 10 occupies an anterior position, section 11 is at an intermediate position and section 12 is at a posterior position.
  • each section 10, 11 and 12 in a plane including the optical axis 14 is preferably an aspheric non-conic curve and can be generated numerically or by graphical means having regard to the reflectivity and texture of the surface, the size, shape and luminous output of source 16 and the required angular and intensity distribution of light in the far field.
  • the illumination produced by each section will be a bright central region of "spot” illumination merging into a peripheral region of fainter "flood” illumination, and the beam from the reflector will produce both spot and flood illumination that diverges in the far field even from a point source at its generating point whereas the beam from a parabola is parallel when a point source is at its focus.
  • the size of the "spot" illumination produced in the far field by the reflector can be adjusted as well as the divergence of the "flood" sections 10, 11 and 12 exhibit symmetry in a plane containing the optical axis 14.
  • Angular increments and distribution of light entering the reflector are correlated with required angular increments and required distribution of light in the far field as known in the art and the empirical curve needed to produce the required far field light distribution is derived from known principles of geometrical optics (see for an example "The Optical Design of Reflectors", William B. Elmer, John Wiley & Sons, New York, 1980 at page 226).
  • the reflector has a non-circular (in this case oval) outline bounded by relatively long sides 7 that are straight when viewed from the front and convex when viewed in top or underneath plan and relatively short arcuate ends 8.
  • the sides 7 and ends 8 lie .on a cylindrical surface having an axis perpendicular to the reflector optical axis.
  • the ends 8 are straight viewed from the front and from the side of the reflector.
  • the sides 7 and ends 8 of the reflector present a front opening having an aspect ratio of ⁇ about 1.5:1 for a beam- forming lens assembly 3 and there is a rear opening 9 for receiving the light source 16.
  • the middle or "vertical" reflector section 10 comprises a relatively small area central region 10a that surrounds the opening 9 and relatively large area upper and lower peripheral regions 10b defined by arcuate segments directed towards the reflector sides 7 and each of small angular extent with reference to the axis 14.
  • the reflector 10 serves to define a strong central beam of an appropriate vertical spread. Deluminated regions 10c bound lateral edges of the peripheral regions 10b and lead to intermediate or "diagonal" reflector 11 that is divided into four separated regions 11a each of relatively small azimuthal extent in the plane of Figure 4. Although the reflector 11, if complete, would be larger overall than the reflector 10, its curvature is similar to that of reflector 10 and it serves to collect additional light from the source 16 and direct it into the central beam.
  • the reflector 11 is bounded at its lateral edges opposite to the regions 10b of reflector 10 by deluminated regions lib that in turn lead to a pair of regions 12a of an outer or "horizontal" reflector 12 each of relatively large angular extent with reference to the axis 14 and each directed towards one of the refector ends 8.
  • the back section 13 which is deluminated is prefelably flat and serves to support the other three sections 10, 11 and 12 and hold them in registration with each other. It will be noted that although the central section 10 has the central region 10a continuous with the peripheral regions 10b, the sections 11 and 12 are present only as discontinuous front regions 11a, 12a, the rear portions being non-existent behind the deluminated back section 13.
  • the region 10a is forward of the plane of the deluminated back section 13 to enable the region 10a to act in the above way.
  • Section 13 is also illustrated in Figure 7, which is a simplified form of the section A-A shown in Figure 5. Irrespective of whether this section comprises a single flat surface, as shown at 13, or a multiplicity of surfaces, such as 17 (which may be used interchangeably), it preferably subtends an insignificantly small angle at the light source 16 and therefore remains substantially deluminated.
  • Figure 7 illustrates why the multi-sectioned reflector of the invention is optically more efficient than a truncated circular aperture reflector. If the aspect ratio of the light emitting aperture is defined by the limit line J-J in one direction and the limit line K-K in the orthogonal direction then the truncation of the outer section 12 in the plane perpendicular to Figure 7 would reduce the subtense angle @f the reflector at the light source 16 from B to A. However, because the reflector profile in the plane perpendicular to Figure 7 is in fact the section 10 (shown to its full extent in this plane by the broken line extension) the actual angle subtended at the light source is L, which is greater than
  • the requirements for the output beam pattern from a front cycle light are described by lighting standards such as BS AU 155 and ISO 6742. Products which meet these standards or generally conform with their recommendations typically produce a centralised light beam pattern which, on a screen placed transverse to the optical axis, appears as a bright horizontal bar of light with about a 4:1 aspect ratio of horizontal to vertical width. Typically, the pattern has transverse beam widths of approximately 8 degrees by 2 degrees in order to conform with the above standards. There is generally an insignificant amount of light outside the central bar, beyond that generated as direct light from the filament itself and a degree of extended horizontal field side lighting.
  • the central beam pattern is spatially lengthened and thus reduced in terms of illumination in the direction of bicycle travel but remains substantially unaffected in the transverse direction. Even with this direction of travel is us ua lly very res tri ct ed and generally unsuitable for cycling on unlit roads.
  • the applicants consider that it is desirable for the area of light on the road to be significantly larger than the current centra l beam area , pa rti cular ly in the direction of travel, and, in common with almost all task lighting, should not exhibit an abrupt cut-off at its edges.
  • An aim of the present front light is to meet the recommendations of BS AU 155 and the ISO 6742 endurance tests with a large area light beam. M eeting the beam centre light output of ISO 6742 at the rated output of the lamp is considered a secondary goal.
  • N angle between reflected ray and the optical axis (a positive value for N denotes an initial convergence to the optical axis)
  • P distance from light centre to the specified point on the reflector
  • X distance of specified reflector point from the rearmost extent of reflector measured parallel to optical axis
  • Y distance of specified reflector point from optical axis.
  • M ⁇ and N 2 being values of the angle between the reflected r y and the optical axis corresponding to successive increments in M values.
  • the solid angle steps between successive M values is constant for each table.
  • the ratio for the vertical reflector 10 between 48 and 57.77 degrees, for which the output beam angle varies from 0 to 0.64 degrees is 2177
  • the ratio for the horizontal reflector 12 between 74.17 and 78.66 degrees, for which the output beam angle varies from 1.85 to 2.35 degrees is 238. Consequently, if the vertical and horizontal reflectors 10, 12 were to have continuous rotational symmetry about the optical axis, then the horizontal reflector 12 would produce a beam intensity in the interval 1.85-2.35 degrees 9.15 times less bright than the beam from the vertical reflector 10 over the interval 0-0.64 degrees.
  • the horizontal will be 238 cd and the vertical reflector beam intensity in the interval 0-0.64 degrees will be 2177 cd.
  • the effect of the light source fi lament size is al so to cause the beam at any angle N to emanate from an j extended area of the re f lector, so that a degree of 20 surface form error can be tolerated without significantly affecting the far field beam continuity.
  • the aggregate far field light beam pattern from the reflector 2 alone is characterised by a generally elongated beam with a non-uniform relative distribution of intensity in orthogonal directions transverse to the optical axis.
  • the re flector sections 12 produce a beam elongated in the direction H-H and having an intensity profile which is peaked in the centre
  • the reflector sections 10 produce a more compact beam of considerably greater relative central intensity
  • the reflector sections 11 produce an intensity profile between the two .
  • the l amp f i l am ent whi ch i s characteristically bow-shaped, is aligned to lie along the direction I-I.
  • the light from each of the reflector sections preferably generates a far field pattern which is in edge-abutment to the far field pattern from the other two reflector sections .
  • the lens 3 in front of the reflector 2 preferably spreads light only in the direction H-H.
  • the beam pattern in the direction H-H is primarily determined by the lens 3 and by the reflector sections 12 whilst the beam pattern in the direction I-I is primarily determined by re flector sections 10 and the di mension of the lamp filament in this direction.
  • the light from ref lector sections 11 primari ly rein forc e s the vertical beam pattern from reflector section 10.
  • the direction I-I should be comparable to the angular spread of light in the direction H-H, but that the relative intensity distribution should be more gradual in the direction H-H than the direction I-I.
  • the cycle light conforming with the luminous intensity recommendations of the above lighting standards, for which H-H lyirig horizontal is the preferred mounting (b) the light beam having a sufficiently high central intensity (preferably on the optical axis) with which to create a central localised pool of relatively high illumination, and (c) creating areas of light extending beyond and behind the central pool of light in the direction of travel by which to see a greater distance along an unlit road than is the case with other cycle lights and to be seen by oncoming vehicles.
  • Figure 8 illustrates the appearance of the aperture for 3, 4 and 6 reflector sections.
  • an additional reflector section 140 consisting of four isolated regions 140a is provided, the regions 140a occurring between the reflector regions 11a and 12a of each quadrant of the reflector.
  • the re ar e addit i ona l reflector s ect ions 141 -143 hav ing reg ions 141 a- 143 a located between the regions 10b and 12a.
  • the central reflector section 10 is continuous, all the remaining reflector sections 11 , 12 , 140 , 141 ,
  • FIG 9 illustrates another form of the reflector. To the right of the line H-H the reflector is the same as shown in Figure 4 whilst to the left of the line H-H it will be seen that the single flat deluminated section 13 of Figure 3 has been replaced by outer and inner flat
  • FIG. 10 shows a simplified section along the line I-I in Figure 9.
  • the reflector sections 10, 11 and 12 are all present along this section, as compared to the presence of 10 and 12 only in the similar view shown in Figure . ⁇
  • the sections 18 and 19 are sited such that they subtend a negligibly small amount of light from the source 20.
  • s ections 10 and 12 generate light beams from the light source which possess different angular light spreads and intensity distributions, whilst reflector section 11 possesses a similar output beam profile to section 10.
  • the profi le of reflector section 10 on either side of its optical axis is not a smooth monotonic curve but contains two or more edge-abutting sub-sections.
  • the reflector section consists of two sub- sections 21 and 22 which are edge-abutting at point 25. Both 21 and 22 have a common optical axis 23 and act so that light from the source 24 is converted into overlaid or separate output beams by the reflectors.
  • the ref l ector For most existing cy c le lights the ref l ector possesses a parabolic profile and therefore generally forms a highly colliraated light beam with a small degree of angular spread due in most part to the si ze of the light source filament.
  • the lens in front of the reflector then create s a diverg ence to thi s beam by mean s of lenticular or prismatic arrays. Should a cycle light with such a re flector and lens as sembly be si ted on the wheel mounting forks of a bicycle then a significant portion of the light will be blocked by that part of the wheel which protrudes beyond the cycle light. This effe ct becomes particularly noticeable with the small steering movements necessary to maintain the bicycle in motion.
  • At least one of the ref lector sections is designed so that the greater part of the light beam leaving it is initially convergent to points in the vicinity of the most forward- extending parts of the bicycle wheel and then starts to diverge to form its far field pattern.
  • Figure 12 illustrates one example of the convergence principle.
  • the light from a source 26 strikes reflector sections 27 and 28.
  • Three rays 29, 30 and 31 are shown leaving the outer reflector section 28.
  • the covergence or divergence properties which confine the light leaving it to within the light beam leaving region 28 until position Q-Q in Figure 12 and preferably the cycle light lens which is generally present in front of the reflector should not significantly affect the operation of the reflector as described with reference to Figure 12.
  • GAPS IN THE REFLECTED LIGHT Figure 13 shows more clearly the position of a typical deluminated section 13.
  • the rays 36 drawn from focus point 15 to the reflector sections 10 and 12 strike section 13 tangentially. Only the physical extent of the filament of lamp 16 in the direction of the optical axis 14 allows light from the filament to impinge upon section 13.
  • the reflector sections 10, 11 and 12 are preferably not parabolic, and the outer limits of a typical fan of rays reflected from the sections 10, 12 are shown as 37, 38, 39 and 40.
  • the presence of deluminated section 13 and the direction of the rays reflected by sections 10, 11 and 12 causes a gap in the overall reflected light beam profile to occur.
  • This gap is represented by 41 in Figure 13 and, dependin on the rate of convergence of the rays 37 to 40, this gap will extend for some distance beyond section 13.
  • the gap 41 extends at least to a line 42 drawn perpendicular to the optical axis 14 and touching the reflector at its rim. If the reflector were circularly symmetric about the optical axis
  • the gap 41 would have the form of an annular ring.
  • the reflector is of the form shown in Figures 4 to 6 and has only limited rotational symmetry about the optical axis 14. Consequently, the shape of the deluminated areas will be substantially the same as that of sections 13 as seen in Figure 4 and they will decrease in size at points further along the optical axis at a rate determined by the convergence and/or divergence of the light from reflector sections 10, 11 and 12.
  • Figure 14 illustrates another multi-section reflector that produces a light beam with a deluminated section in its profile.
  • the reflector consists of two sections 43 and 44 in edge-abutment.
  • Light from a source 45 lying on the common optical axis 46 is reflected by sections 43 and 44 to form a light beam of which rays 47, 48, 49 and 50 are at the limits. Because there is a divergence between rays 48 and 49 a deluminated gap 51 will appear and persist at all points further along the optical axis 46 from light source 45 until either ray 47 meets ray 50 or ray 49 meets ray 48, whichever occurs sooner.
  • Figure 15 is a front view of the lens assembly 3 which s genera y s m lar to lenses used in most cycle front lights and mounted adjacent to the reflector.
  • the lens assembly 3 hereinafter referred to as the front lens, consists of a plurality of lenticular flutes 6 each typically containing a substantially flat, or long radius of curvature, face on the outside and a short radius of curvature convex face on the side facing the reflector 2.
  • a cycle rear light would normally contain a plurality of spherically symmetric lenses in place of the lenticular flutes 6.
  • a section 54 consisting of a pair of regions 54a is located within the front lens
  • the section 54 has the purposes of (a) steering direct light from the lamp into a wider divergence than the angle between the rays 5a in Figure 2 which is the maximum angle that direct light can emerge from the reflector, and (b) replacing the coverage lost by that part of the incident direct light that has been diverted to large angles from the axis 14 by extending the angular spread of a further portion of the direct light impinging on the section 54.
  • Figure 16 is an example of the profile of prismatic and lenticular elements used in the lens 3. It is preferable for these elements to be sited on the front lens face adjacent to the reflector. Lenses 6 are the elements common to most cycle front lights and serve to both spread the main l ight bea m ar ri ving from the reflector and smooth out any structure caused by the lamp filament. Lens element 56 and prismatic elements 57, 58,
  • the incl ination of faces 62 to 65 with respect to the optical - axis 68 of the ref lector is different for e-ach face, so that the beams of light deviated by each face leave the front lens at different angles.
  • the total beam leaving the front lens by way of faces 62 to 65 will consist of discrete sections incremented in angle.
  • the faces 62 , 63 , 64 and 65 are curved preferably with a shallow concave curvature, in order to create a small degree of divergence to each discrete section of the beam leaving the front lens.
  • the discrete sections will overlap and form a continuous beam.
  • Lens element 56 which preferably contains a convex general direction indicated by the arrow 61, causes incident direct light from the lamp filament to be diverged in the far field after leaving the front lens 3.
  • the divergence caused by the lens element 56 is sufficient to fill the range of angles not illuminated by direct light owing to the deviation by prismatic elements 57, 58, 59 and 60 whilst maintainng illumination in the direction defined by lens element 56 and the filament of source 16.
  • the other faces of prismatic elements 57, 58, 59 and 60 should be non- specular or frosted.
  • the prism elements 57, 58, 59, 60 and lens element 56 are arranged precisely as shown in Figure 16. There may be more or less prism elements . - and/or more lens elements, and they may be interspersed as desired. Conveniently the prism and lens elements 56-60 of Figure 16 are sited on the same pitch as lenses 53 in Figure 5, or a low multiple or sub-multiple thereof.
  • Figure 17 illustrates one arrangement of the reflector and lens that comprises the invention and the various light paths.
  • a large proportion of the light from the source 16 is collected by the reflector sections 10 and 12 and is formed into a beam defined by the limit rays 37, 38, 39 and 40. Without the presence of the lens assembly 3 the far field beam would be divergent and defined by the limit rays 37 and 39.
  • the effect of the lens elem ents 6 in thr front lens 3 is to provide a small degree of beam spreading and smoothing to the reflector light beam as indicated by arows 70.
  • Deluminated section 13 of the reflector subtends a negligible amount of light at the lamp 16 and therefore give ri se to delum inated sections in the re f l ec to r l ight be a m .
  • W i thin th e s e sections are sited prismatic elements 57-60 and lens element 56 of the front lens 3 , which receive only direct light f rom the lamp 16. Some of this direct light is deviated by the prismatic element 57-60 into discrete beams 71 which form the ex trem iti es of the required angular field from the cycle light and which overlap in the far field if the filament 16 has sufficient size in the plane of Figure 17 or if the incidence faces of prisms
  • FIG. 19 illustrate a typical cycle light lamp mounted in a reflector.
  • the light source is typified by Philips' lamps type PR2, PR6 and PR31, all of which have a P 13.5S prefocus mount and consists of a base 91 and glass bulb 92 which contains the filament 93 mounted between two supports posts 94. Electrical contact is made between
  • the flange 96 also contains a cut away section 101 which is in a prescribed orientation with respect to the length of the filament 93. The orientation of the flange 96, and hence the filament 93, with respect to the reflector 99 is determined by locating cut away 101 against a post 102 which is itself located in the reflector housing.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Non-Portable Lighting Devices Or Systems Thereof (AREA)

Abstract

Phare destiné principalement à être utilisé dans un véhicule tel qu'une bicyclette, comprenant un réflecteur (2) formant un faisceau de lumière réfléchie à partir d'une source (1). Le faisceau présente des vides, tels que les vides (41), dans son profil. Le réflecteur (2) est utilisé en combinaison avec une lentille avant (3) pourvue d'un organe divergent (6) qui diffuse la lumière directe incidente dirigée au loin selon des angles situés au-delà de ceux où le réflecteur (2) coupe la lumière directe.
PCT/US1987/001058 1986-05-09 1987-05-07 Phares de vehicules Ceased WO1987006997A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8611327A GB2190479B (en) 1986-05-09 1986-05-09 Improvements in lights for vehicles
GB8611327 1986-05-09

Publications (1)

Publication Number Publication Date
WO1987006997A1 true WO1987006997A1 (fr) 1987-11-19

Family

ID=10597577

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1987/001058 Ceased WO1987006997A1 (fr) 1986-05-09 1987-05-07 Phares de vehicules

Country Status (4)

Country Link
EP (1) EP0267268A4 (fr)
CA (1) CA1288130C (fr)
GB (1) GB2190479B (fr)
WO (1) WO1987006997A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2053304A1 (fr) 2007-10-25 2009-04-29 Stanley Electric Co., Ltd. Phare de véhicule
EP2605268A3 (fr) * 2011-12-15 2014-06-18 General Electric Company Source de lumière incandescente anisotrope

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2517368B2 (ja) * 1988-09-27 1996-07-24 株式会社小糸製作所 自動車用前照灯及び自動車用前照灯装置
JP3017195B1 (ja) * 1998-12-10 2000-03-06 スタンレー電気株式会社 灯 具
TWM429057U (en) * 2011-12-01 2012-05-11 Shou Meng Entpr Co Ltd Bicycle lighting
CN107960117B (zh) * 2015-05-22 2021-01-12 三菱电机株式会社 前照灯模块及前照灯装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4180849A (en) * 1976-08-18 1979-12-25 The Ever Ready Company (Great Britain) Limited Pedal cycle headlamp
US4208704A (en) * 1977-06-17 1980-06-17 Lucas Industries Limited Lamp reflector for a motor vehicle
US4213171A (en) * 1976-06-24 1980-07-15 Sassmannshausen Knut Lighting fixture with side escape window
DE3035005A1 (de) * 1980-09-17 1982-04-29 Ulo-Werk Moritz Ullmann Gmbh & Co Kg, 7340 Geislingen Leuchte, insbesondere signalleuchte fuer zweiradfahrzeuge

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2174937A (en) * 1936-12-21 1939-10-03 Dietz Gustav Reflector
GB2184824A (en) * 1985-12-19 1987-07-01 Duracell Int Improvements in rear lights for bicycles and other vehicles

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4213171A (en) * 1976-06-24 1980-07-15 Sassmannshausen Knut Lighting fixture with side escape window
US4180849A (en) * 1976-08-18 1979-12-25 The Ever Ready Company (Great Britain) Limited Pedal cycle headlamp
US4208704A (en) * 1977-06-17 1980-06-17 Lucas Industries Limited Lamp reflector for a motor vehicle
DE3035005A1 (de) * 1980-09-17 1982-04-29 Ulo-Werk Moritz Ullmann Gmbh & Co Kg, 7340 Geislingen Leuchte, insbesondere signalleuchte fuer zweiradfahrzeuge

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0267268A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2053304A1 (fr) 2007-10-25 2009-04-29 Stanley Electric Co., Ltd. Phare de véhicule
EP2605268A3 (fr) * 2011-12-15 2014-06-18 General Electric Company Source de lumière incandescente anisotrope

Also Published As

Publication number Publication date
CA1288130C (fr) 1991-08-27
GB2190479B (en) 1991-01-09
GB2190479A (en) 1987-11-18
GB8611327D0 (en) 1986-06-18
EP0267268A1 (fr) 1988-05-18
EP0267268A4 (fr) 1989-10-12

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