US3858040A - Motor vehicle headlamps - Google Patents

Motor vehicle headlamps Download PDF

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Publication number
US3858040A
US3858040A US00381555A US38155573A US3858040A US 3858040 A US3858040 A US 3858040A US 00381555 A US00381555 A US 00381555A US 38155573 A US38155573 A US 38155573A US 3858040 A US3858040 A US 3858040A
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United States
Prior art keywords
cut
headlamp
filament
horizontal
prismatic elements
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Expired - Lifetime
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US00381555A
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English (en)
Inventor
J Ricard
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Cibie Projecteurs SA
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Cibie Projecteurs SA
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    • 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

  • the present invention relates to the headlamps of motor vehicles.
  • the cut-out of the dipped beam is obtained by the choice of relative location of the dipped light filament in relation to the parabolic reflector together with the use of masking elements provided to serve as screen or shield between the filament and the reflector.
  • a substantially semicylindrical cup located below and all around the axial filament, the edges of the cup, parallel to the axis of the headlamp, defining the two half planes of cut-out (French standard N.F. R136 for a symmettis l qt tand-. 13: fqta a ym i out).
  • FIG. lb shows, with the same references how to obtain a symmetrical cut-out with a cup C having both its edges e in the same horizontal level (French norm R 136-02).
  • the present invention aims to obtain a new cut-out for a dipped beam for a car headlamp, which satisfies in a particularly effective manner the standards and regulations in force, and relates to an arrangement of means making it possible to obtain it in a simple and effective manner.
  • the new cut-out according to the invention is characterized by two horizontal half planes of cut-out connected by an inclined plane, namely a plane inclined at about 45 relative to the horizontal.
  • the horizontal half plane constituting the cut-out of the left-hand part of the beam is preferably slightly below the horizontal plane passing through the axis of the headlamp and its parabolic reflector.
  • the right-hand, horizontal half plane constituting for the main part of the masking limit of the right-hand part of the beam is, preferably, substantially in the horizontal plane passing through the axis of the headlamp.
  • the headlamp cut-out means known per se for effecting a horizontal cut-out along two symmetrical half planes of cut out.
  • a plurality of small prismatic, deflection elements there are provided in the path of the light rays of the dipped beam, in particular at the level of the headlamp glass, a plurality of small prismatic, deflection elements,-each of said prismatic elements intersecting a small part of said dipped beam just below said second half plane of cut-out, said small part of said beam projecting with respect to a reference screen a quadrangular image having an upper inside corner and an upper horizontal boundary
  • said plurality of prismatic elements including a series of stepped prismatic elements, each of said series of prismatic elements deflecting said part of said beam in a vertical direction and also in a transverse direction to translate said corner to coincide on said screen with an oblique segment, all of said prismatic elements intersecting and deflecting different parts of said dipped beam to create finally for said beam a central cut-out limit surface approximating step-by-step-wise on said screen said oblique segment and a lateral horizontal limit surface staggered in height relative to
  • the location of the prismatic deflection elements, their number, their geometric orientation, their dimensions, are chosen depending on the result to be obtained. These factors may vary in each particular case, but, however, following these general criteria in the case of an axial dipped filament, the location of the prismatic elements must be chosen on both sides of the horizontal plane of symmetry passing through the axis of the reflector in the case of a transverse, dipped filament, i.e., perpendicular to the axis of the headlamp, the location of the elements is chosen in the vicinity of the axial plane of symmetry of the headlamp in both cases, the number of prismatic elements is chosen to be sufficiently great in order that the plane of connection between the two horizontal half plane of cut-out is sufficiently clear In both cases also, the dimension of the prismatic elements depends on a certain maximum admissible tolerance, taking into account the variation of the aberration as one moves away from the axis of the headlamp.
  • the prismatic elements are associated with the headlamp glass, being advantageously moulded with it.
  • the prismatic regions thus defined are theoretically defined on the glass by arcs of circles centred on the axis of the headlamp. However, in practice simpler shapes are satisfactory and the regions may be limited in the shape by small rectangles or small trapeziums with parallel vertical sides in the case of an axial filament and parallel horizontal sides in the case of a transverse filament.
  • FIGS. la and 1b have already been presented as prior art headlamp including cut-out means.
  • FIG. 1 is a representation on a reference screen of a dipped beam produced according to the present invention.
  • FIGS. 2 and 3 show in a similar illustration, the creation of the cut-out by the effect of prismatic zones in a headlamp according to the present invention.
  • FIG. 4 shows, in front view, a headlamp according to the present invention with an axial filament in which a cut-out is produced by means of prismatic zones.
  • FIG. 5 is a graph illustratingthe choice of prismatic zones for the headlamp of FIG. 4.
  • FIG. 6 is an illustration in projection, as in FIGS. 1 to 3 showing the production of the cut-out in the case of the headlamp of FIG. 4.
  • FIG. 7 is a front view of a headlamp according to the present invention with a transverse filament showing the location of these prismatic zones for producing the cut-out.
  • FIG. 8 is an illustration, on a screen, similar to that of FIGS. 1, 2, 3 and 6, showing the formation of the cut-out in the case of the headlight of FIG. 7.
  • FIG. 1 shows, on a vertical screen located at 25m from the headlamp, perpendicular to its axis, the new type of cut-out which it is desired to obtain.
  • the point H indicates the intersection of the screen and the central, horizontal axis of the headlamp.
  • the reference I corresponds to a length of 25 cm.
  • the new cut-out is constituted by a left-hand half plane AB located slightly below the axis of the headlamp, a half plane DC located substantially at the level of this axis, with an inclined connecting plane BD, preferably at an inclination of 45.
  • this zone gives an image such as G I J K on the screen (FIG. 2) in which the segment GI is on the righthand half plane Cd.
  • a point such as G may be moved to a point G' located on the segment BD previously defined.
  • the horizontal limit GI is given, in known manner, by a cup/masking element located around the filament this limitation is thus perfectly well defined.
  • the limit K] is a little significance for determining the cut-out. It depends on the height of the said region.
  • the basic limit for the formation of the cut-out is the limit GK.
  • the distance from the point G to the axis of the beam varies according to the distance from the corresponding area of the reflector to the axis of the reflector.
  • FIG. 4 shows a headlamp with a rectangular aperture provided with such a mirror.
  • A designates its glass, F its light filament, and C its cup constituting the symmetrical cut-out means.
  • the determination and the location of the prismatic regions 1, 2, 3 and 4 located on its glass will now be discussed.
  • the z-axis represents the variations in height, the y-axis, the variations in width, the x-axis the variations in depth, these variations being indicated in hundredths of a radian of angular separation.
  • the variation of the aberration as a function of the distance from the region to the axis of the reflector is shown in FIG. 5.
  • the tolerance T which can be allowed in the position of each point such as G, determines the width of the corresponding areas 1, 2, 3, 4 at the level of the glass.
  • areas 1, 2, 3, 4 are chosen as having the same tolerance T as seen on FIG. 5.
  • T 0.2 percent (in hundredths of a radian) the region 1 extends between the radii of aperture 56 and 62mm, the region 2 between the radii of aperture 62 and 68mm, the region 3 between the radii of aperture 68 and 76mm, the region 4 between the radii of aperture 76 and 85mm.
  • the limits of the regions at the level of the glass are theoretically arcs of circles concentric to the glass, but for reasons of simplifying the equipment, it is possible, as shown in FIG. 4 to provide the prismatic surfaces 1, 2, 3, 4 on the glass in the form of small rectangles having the previously defined width limits in the transverse plane passing through the axis of the headlamp.
  • lines GK are not straight vertical lines but curves which have the advantage of minimizing the stepped appearance of the inclined cutout.
  • the regions g g g g, of FIG. 6 are the useful parts of the initial regions G I J K In order that their heights are similar, one chooses initial regions 1, 2, 3, 4 of different heights.
  • the region 1 and 2 are mm above the axis of the regions 3 and 4 are 3mm above.
  • the displacements in width and in height are the following Lateral Vertical Displacement Displacement From G to G 0.5 1 From G to G 0.5 0.7 From G to G, 0.6 0.4 From G, to G, 0.6 0.2
  • the above displacements are made in hundredths of a radian of angular separation relative to the headlamp, more precisely relative to the plane of its glass.
  • FIG. 7 In order to obtain horizontal images from a transverse filament, there are used (FIG. 7) the regions 1, 2, 3, 4 which are substantially on the vertical axis of the headlamp.
  • the curves such as GK represent as previously, the limits of the regions l, 2, 3, 4 which are chosen so as to be as near as possible to a cut-out of 45.
  • FIGS. 9 and 10 sum up schematically the teachings of the invention, for headlamps P having known per se symmetrical cut-out means cooperating with an axial and a transverse filament, respectively.
  • the number of regions is not necessarily equal to 4 and that the shape of the cutout finally obtained is not necessarily constituted by two horizontal half planes connected by a segment inclined at 45, other inclinations being possible without departing from the scope of the invention.
  • the regions on the glass may have any desirable optical shape in order to achieve this or that particular cut-out effect, in particular for suppression or increasing the stepped effect.
  • the prismatic elements which have been described as preferably connected to certain regions of the glass could just as well be connected to homologous regions of the mirror, or to homologus regions of an intermediate transverse plane located between the reflector mirror and the glass, taking into account the correspondance which has been made explicit between a region of the mirror, a region of the glass and an image region, all three located in the same basic beam reflected by the reflector.
  • a motor vehicle headlamp comprising a parabolic reflector adapted to be mounted with a horizontal axis on a vehicle, a light filament for dipped lighting located in the vicinity of the focal point of said reflector, a front glass, cut-out means for effecting cut-out of the dipped light beam according to a left and a right horizontal half plane of cut-out on either side of the central axis of said reflector and of said headlamp, the improvement comprising a plurality of juxtaposed, prismatic elements, each of said prismatic elements inter secting a small part of said dipped beam just below said right half plane of cut-out, said small part of said beam projecting with respect to a reference screen a quadragular image having an upper inside corner and an upper horizontal boundary, each of said series of prismatic elements deflecting said part of said beam in a vertical direction and also in a transverse direction to translate said corner to coincide on said screen with an oblique segment, all of'said prismatic elements intersecting and deflecting different parts of
  • a headlamp according to claim 2 wherein the filament is located on the axis of the headlamp, the cut-out means comprise a masking cup with horizontal edges, and the prismatic elements are located on the side of the from glass.
  • a headlamp according to claim 2 wherein the dipped filament is located transversely relative to the axis of the headlamp and the prismatic elements are provided at the upper part of the glass in the vicinity of its vertical, axial plane.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Non-Portable Lighting Devices Or Systems Thereof (AREA)
  • Lighting Device Outwards From Vehicle And Optical Signal (AREA)
US00381555A 1970-05-14 1973-07-23 Motor vehicle headlamps Expired - Lifetime US3858040A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7017586A FR2087317A5 (ja) 1970-05-14 1970-05-14

Publications (1)

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US3858040A true US3858040A (en) 1974-12-31

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US00381555A Expired - Lifetime US3858040A (en) 1970-05-14 1973-07-23 Motor vehicle headlamps

Country Status (5)

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US (1) US3858040A (ja)
JP (1) JPS555201B1 (ja)
DE (1) DE2123844C3 (ja)
FR (1) FR2087317A5 (ja)
GB (1) GB1347357A (ja)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3970836A (en) * 1973-12-26 1976-07-20 Cibie Projecteurs Motor vehicle headlamps
US4173034A (en) * 1977-04-01 1979-10-30 Schemitz Sylvan R Lighting system with baffle
US4530042A (en) * 1982-11-19 1985-07-16 Cibie Projecteurs Dipped headlamp for automobiles
US4669032A (en) * 1985-08-31 1987-05-26 Robert Bosch Gmbh Low beam or fog headlamp for motor vehicles
AU579015B2 (en) * 1985-06-07 1988-11-10 Cibie Projecteurs A dipped headlamp for motor vehicles
US5651610A (en) * 1995-04-06 1997-07-29 Valeo Vision Motor vehicle headlamp for emitting a light beam delimited by a cut-off line in two half planes offset in height from each other

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2392322A1 (fr) * 1977-05-25 1978-12-22 Ducellier & Cie Procede d'obtention d'un nouveau faisceau de croisement
DE2810670C3 (de) * 1978-03-11 1981-08-20 Westfälische Metall Industrie KG Hueck & Co, 4780 Lippstadt Abgeblendeter Fahrzeugscheinwerfer
US4246631A (en) * 1978-05-23 1981-01-20 Lucas Industries Limited Vehicle headlamp
CS229071B1 (en) * 1981-10-28 1984-05-14 Milan Cejnek Headlight for motor vehicles
FR2528536A1 (fr) * 1982-06-09 1983-12-16 Cibie Projecteurs Perfectionnements aux projecteurs de croisement pour vehicules automobiles
JP2622564B2 (ja) * 1986-12-30 1997-06-18 ヴァレオ ヴイジョン カットオフによって限定されたビームを放射する、変形底部を有する自動車用前照灯
GB8927903D0 (en) * 1989-12-09 1990-02-14 Carello Lighting Plc Lamp assembly
DE19610904B4 (de) * 1996-03-20 2009-11-19 Automotive Lighting Reutlingen Gmbh Abblendlichtscheinwerfer für Fahrzeuge
GB2510652A (en) * 2013-02-07 2014-08-13 Paul Ivor Harper Method for fitting a vehicle headlamp converter

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1322776A (en) * 1919-11-25 And frederick p
US1430580A (en) * 1920-12-31 1922-10-03 Old James Harlan Lens
US1916514A (en) * 1931-05-09 1933-07-04 Guide Lamp Corp Auxiliary driving light
US1950978A (en) * 1932-12-07 1934-03-13 Gen Motors Corp Lens for head lamps
US2122465A (en) * 1934-03-20 1938-07-05 Graves Arnold Light-projection system particularly for vehicle lamps
US2142964A (en) * 1935-11-27 1939-01-03 United Lens Corp Head lamp and lens construction

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1322776A (en) * 1919-11-25 And frederick p
US1430580A (en) * 1920-12-31 1922-10-03 Old James Harlan Lens
US1916514A (en) * 1931-05-09 1933-07-04 Guide Lamp Corp Auxiliary driving light
US1950978A (en) * 1932-12-07 1934-03-13 Gen Motors Corp Lens for head lamps
US2122465A (en) * 1934-03-20 1938-07-05 Graves Arnold Light-projection system particularly for vehicle lamps
US2142964A (en) * 1935-11-27 1939-01-03 United Lens Corp Head lamp and lens construction

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3970836A (en) * 1973-12-26 1976-07-20 Cibie Projecteurs Motor vehicle headlamps
US4173034A (en) * 1977-04-01 1979-10-30 Schemitz Sylvan R Lighting system with baffle
US4530042A (en) * 1982-11-19 1985-07-16 Cibie Projecteurs Dipped headlamp for automobiles
AU579015B2 (en) * 1985-06-07 1988-11-10 Cibie Projecteurs A dipped headlamp for motor vehicles
US4797797A (en) * 1985-06-07 1989-01-10 Cibie Projecteurs Dipped headlamp for motor vehicles
US4669032A (en) * 1985-08-31 1987-05-26 Robert Bosch Gmbh Low beam or fog headlamp for motor vehicles
US5651610A (en) * 1995-04-06 1997-07-29 Valeo Vision Motor vehicle headlamp for emitting a light beam delimited by a cut-off line in two half planes offset in height from each other

Also Published As

Publication number Publication date
GB1347357A (en) 1974-02-27
FR2087317A5 (ja) 1971-12-31
DE2123844C3 (de) 1975-12-11
DE2123844A1 (de) 1971-11-18
JPS555201B1 (ja) 1980-02-05
DE2123844B2 (de) 1975-05-07

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