CA1270036A - Motor vehicle headlight - Google Patents
Motor vehicle headlightInfo
- Publication number
- CA1270036A CA1270036A CA000529123A CA529123A CA1270036A CA 1270036 A CA1270036 A CA 1270036A CA 000529123 A CA000529123 A CA 000529123A CA 529123 A CA529123 A CA 529123A CA 1270036 A CA1270036 A CA 1270036A
- Authority
- CA
- Canada
- Prior art keywords
- reflector
- headlight according
- headlight
- filament
- capsule
- 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.)
- Expired - Lifetime
Links
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
- F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
- F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
- F21S41/162—Incandescent light sources, e.g. filament or halogen lamps
- F21S41/166—Incandescent light sources, e.g. filament or halogen lamps characterised by the shape of the filament
-
- 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
-
- 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
- F21S41/321—Optical layout thereof the reflector being a surface of revolution or a planar surface, e.g. truncated
-
- 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
- F21S41/331—Multi-surface reflectors, e.g. reflectors with facets or reflectors with portions of different curvature the reflector consisting of complete annular areas
- F21S41/333—Multi-surface reflectors, e.g. reflectors with facets or reflectors with portions of different curvature the reflector consisting of complete annular areas 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
- F21S41/30—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by reflectors
- F21S41/37—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by reflectors characterised by their material, surface treatment or coatings
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Non-Portable Lighting Devices Or Systems Thereof (AREA)
Abstract
TITLE: MOTOR VEHICLE HEADLIGHT
ABSTRACT
A motor vehicle headlight including a parabolic reflector a cover secured to the reflector and a lighting capsule located within the reflector. The capsule includes an envelope having A coiled filament located therein and including a substantially cylindrical configuration. Optimum light output is attained by providing the reflector with a short focal length (0.2 inch to about 0.5 inch) and by utilization of a coiled filament structure having a length to diameter ratio of less than about 2:1. The result is a headlight having an overall vertical height of only about two inches and a corresponding frontal area of extremely small size (between 3.0 and 7.5 square inches).
ABSTRACT
A motor vehicle headlight including a parabolic reflector a cover secured to the reflector and a lighting capsule located within the reflector. The capsule includes an envelope having A coiled filament located therein and including a substantially cylindrical configuration. Optimum light output is attained by providing the reflector with a short focal length (0.2 inch to about 0.5 inch) and by utilization of a coiled filament structure having a length to diameter ratio of less than about 2:1. The result is a headlight having an overall vertical height of only about two inches and a corresponding frontal area of extremely small size (between 3.0 and 7.5 square inches).
Description
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TITLE: MOTOR VEHICLE HEADLIGHT
TECHNICAL FIELD
~he present invention relates to headlights for use in motor vehicles (e.g., automobiles).
CROSS REFERENCE TO COPENDING APPLICATIONS
In U.S. Patent 4,545,001, entitled "Sealed Lens Member For Use In A Motor Vehicle Lighting System" (Inventors: ~. J.
English et al), there is defined a hollow, single piece lens member for use in a motor vehicle lighting system containing a plurality of individual lighting modules.
In U.S. Patent 4,646,207, entitled "Motor Vehicle Lighting System Including A Sealed Lens Member As Part Thereof" (Inventors: R. E. Levin et al), there is defined a motor vehicle lighting system including a light source and reflector means, a hollow, enclosed lens having a contoured front surface with a rear lensing surface, and a means for mounting the lens in a recess of said vehicle to assure adequate passage of light from the source through the lens.
In U.S. Patent D285,351, entitled "Lamp-Reflector Module For Use In A Motor Vehicle Headlighting System" (Inventors:
G. J. English et al), there is claimed the ornamental design for a lamp-reflector module for use in a motor vehicle lighting system.
In U.S. Patent D284,112, entitled "Lens Member For A
Motor Vehicle Headlighting System" (Inventors: G. J. English et al), there is claimed the ornamental design for a motor vehicle headlight lens member having a plurality of stepped lensing surfaces thereon and a slightly curved forward surface.
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127(:~03~i In U.S. Patent D283,362, entitled "Lens Component For A
Motor Vehicle Headlighting System" (Inventors: R. E. Levin et al), there is claimed the ornamental design for a motor vehicle headlight lens having a sloped, clear front surface, a pair of side walls, a bottom wall, and a stepped, rear lensing portion to in turn define a sealed, single piece component.
In U.S. Patent 4,569,002, entitled "Motor Vehicle Lighting System" (Inventors: G. J. English et al), there is defined a motor vehicle lighting system wherein each of the lighting modules includes a clear cover. The array of modules (e.g., four per side) is designed for use with a spaced, common lens component located a distance from the ''' modul~s.. ~
In Canadian Patent Application 478,615-7, filed April 9, 1985, entitled "Lighting Module For Motor Vehicle Lighting System" (Inventors: G. J. English et al), there is defined a lighting module for use as a part of a vehicle headlighting system wherein the module includes a reflector, a small tungsten halogen capsule sealed within the reflector, and a clear, front cover providing a seal for the module.
All of the above-identified U.S. Patent Applications were filed April 10, 1984, are assigned to the same assignee as the instant invention, and were sub~ect to an obligation to assign to said assignee or were so assigned at the time the instant invention was made.
BACKGROUND
Previous headlights as typically utilized in automobile headlighting systems have heretofore been relatively large in total frontal area. One factor which contributed significantly to this requirement was the overall vertical height of such headlights. As will be illustrated below, such headlights, 127~03`t~
whether of round or rectangular configuration, typically required a minimal height of at least four inches. In view of this requirement, the motor vehicle designed to accommodate such headlights in turn was required to possess a relatively large frontal area to serve as a housing for same. As a result, the vehicle exhibited relatively high aerodynamic drag which, as is known, constitutes the principal cause of energy consumption at normal highway speeds. Reducing the drag coefficient in such a motor vehicle in turn results in improved vehicle fuel consumption. The table below represents respective dimensional constraints for many previous headlight systems.
TABLE
Approx.
Approx. Total System Headlight Height area Type (Inches) (Sq. Inches) Sealed Beam Headlights
TITLE: MOTOR VEHICLE HEADLIGHT
TECHNICAL FIELD
~he present invention relates to headlights for use in motor vehicles (e.g., automobiles).
CROSS REFERENCE TO COPENDING APPLICATIONS
In U.S. Patent 4,545,001, entitled "Sealed Lens Member For Use In A Motor Vehicle Lighting System" (Inventors: ~. J.
English et al), there is defined a hollow, single piece lens member for use in a motor vehicle lighting system containing a plurality of individual lighting modules.
In U.S. Patent 4,646,207, entitled "Motor Vehicle Lighting System Including A Sealed Lens Member As Part Thereof" (Inventors: R. E. Levin et al), there is defined a motor vehicle lighting system including a light source and reflector means, a hollow, enclosed lens having a contoured front surface with a rear lensing surface, and a means for mounting the lens in a recess of said vehicle to assure adequate passage of light from the source through the lens.
In U.S. Patent D285,351, entitled "Lamp-Reflector Module For Use In A Motor Vehicle Headlighting System" (Inventors:
G. J. English et al), there is claimed the ornamental design for a lamp-reflector module for use in a motor vehicle lighting system.
In U.S. Patent D284,112, entitled "Lens Member For A
Motor Vehicle Headlighting System" (Inventors: G. J. English et al), there is claimed the ornamental design for a motor vehicle headlight lens member having a plurality of stepped lensing surfaces thereon and a slightly curved forward surface.
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'~ ~
'`' " ~.
127(:~03~i In U.S. Patent D283,362, entitled "Lens Component For A
Motor Vehicle Headlighting System" (Inventors: R. E. Levin et al), there is claimed the ornamental design for a motor vehicle headlight lens having a sloped, clear front surface, a pair of side walls, a bottom wall, and a stepped, rear lensing portion to in turn define a sealed, single piece component.
In U.S. Patent 4,569,002, entitled "Motor Vehicle Lighting System" (Inventors: G. J. English et al), there is defined a motor vehicle lighting system wherein each of the lighting modules includes a clear cover. The array of modules (e.g., four per side) is designed for use with a spaced, common lens component located a distance from the ''' modul~s.. ~
In Canadian Patent Application 478,615-7, filed April 9, 1985, entitled "Lighting Module For Motor Vehicle Lighting System" (Inventors: G. J. English et al), there is defined a lighting module for use as a part of a vehicle headlighting system wherein the module includes a reflector, a small tungsten halogen capsule sealed within the reflector, and a clear, front cover providing a seal for the module.
All of the above-identified U.S. Patent Applications were filed April 10, 1984, are assigned to the same assignee as the instant invention, and were sub~ect to an obligation to assign to said assignee or were so assigned at the time the instant invention was made.
BACKGROUND
Previous headlights as typically utilized in automobile headlighting systems have heretofore been relatively large in total frontal area. One factor which contributed significantly to this requirement was the overall vertical height of such headlights. As will be illustrated below, such headlights, 127~03`t~
whether of round or rectangular configuration, typically required a minimal height of at least four inches. In view of this requirement, the motor vehicle designed to accommodate such headlights in turn was required to possess a relatively large frontal area to serve as a housing for same. As a result, the vehicle exhibited relatively high aerodynamic drag which, as is known, constitutes the principal cause of energy consumption at normal highway speeds. Reducing the drag coefficient in such a motor vehicle in turn results in improved vehicle fuel consumption. The table below represents respective dimensional constraints for many previous headlight systems.
TABLE
Approx.
Approx. Total System Headlight Height area Type (Inches) (Sq. Inches) Sealed Beam Headlights
2 Lamp, Round 2D 7 77 4 Lamp, RoundIC/2C 5 3/4 102 2 Lamp, Rectangular 2B 5 1/4 79 4 Lamp, Rectangular lA/2A 4 1/4 111 Replaceable Capsule 2E 4 1/4 55 In the motor vehicle headlighting systems described and illustrated in the aforementioned copending Applications, particularly in U.S. Patent 4,569,002 and Canadian Patent Application 478,615-7, there is defined a headlighting system which utilizes a plurality of individual lighting modules ~headlights) which each possess a relatively short overall height (e.g., two inches). Accordingly, a motor vehicle utilizing such a system can in turn possess a relatively lower front portion to in turn assure improved aerodynamic characteristics.
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A6 vill be defined herein, the headlight of the instant invention al~o possesses a relatively short vertical height and i6 thu6 able to assure improved motor vehicle aerodynamics when utilized in ~uch a vehicle. As will be defined, the headlight of the in6tant invention i~ able to provide enhanced forward output using a reflector having a relatively small fcontal area and an internal light source (coiled filament) having a predetermined length to diameter ratio. The invention i~ ~hu6 adapted for use in a headlighting ~y6tem pos6essing additional, similar component6, or, alternatively, as part of the headlighting systems defined in the aforementioned copending applications.
It is believed that such a headlight (and a sy~tem utilizing same) would constitute a significant advancement in the art.
DISCLOSURE OF THE INVENTION
It is. therefore, a primary object of the instant invention to enhance the motor vehicle headlight art by providing a headlight which possesses a relatively ~mall frontal area and yet which assures enhanced forward illumination for the vehicle utilizing same.
It is another ob~ect of the instant invention to provide ~uch a headlight which can be ea~ily utilized with other heaalights as part of an overall headlighting system for a motor vehicle wherein the total frontal area required in the vehic~e to accommodate such a system is substantially reduced.
It is a still further object of the invention to provide a new headlight which can be produced in an expedient and facile manner.
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In accordance with one a~pect of the invention, there i6 provided a motor vehicle headlight comprising a reflector having a concave reflecting portion of sub~tantially parabolic configuration defining a forward opening, the reflector having a relatively short focal length, a cover secured to the reflector for providing a cover for the opening, and a lighting capsule located within the reflector and including an envelope ~ortlon having a coiled filament positioned therein and having a sub6tantially cylindrical configuration. The cap6ule i8 located within the réflector 6uch that the envelope portion is po~itioned within and 6ub6tantially surrounded by the concave reflecting portion and the coiled filament is 6ub6tantially centered at the focal point of the reflector. The coiled filament po6se6ses a length to diameter ratio of les6 than about 2:1.
BRIEP DESCRIPTION OF THE DRAWINGS
PIG. 1 i6 a 6ide elevational view, partly in 6ection, of a ~otor vehicle headlight in accordance with a prefecred embodiment of the invention:
PIG. 2 i6 an enlarged, partial view of one example of a coiled filament 6tructure for u6e in the headlight depicted in PIG l;
. PIG. 3 i~ an enlarged, partial view of the reflector and lighting capsule component6 of the headlight of FIG. 1, illu6tcating the focal length and focal point of the reflector and the relative po6ition of the coiled filament thereto;
PIC. 4 reprQsent6 a chart illu6trating the relative light ~ output ~between 0- and - 4.25 with re6pect to horizontal) in :~ comp~ri~on to the ratio of coil length to diameter for a coiled . 30 ril~mont ~ u6ed in the in6tant invention: and ,,~
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FIG. 5 represents a preferred embodiment of a coiled-coil filament structure for use in the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the above-described drawings.
With attention to the drawings, and particularly FIG. 1, there is shown a motor vehicle headlight 10 in accordance with a preferred embodiment of the invention. Headlight 10 includes a reflector 11 having a concave reflecting portion 13 of substantially parabolic configuration. Portion 13 is internally coated with a reflective coating material 15 (e.g., aluminum). Coating 15 is shown in FIG. 3. Concave reflecting portion 13 defines a forward opening 16, which, similar to the modules described in the aforementioned 20 copending applications U.S. Patent 4,569,002 and Canadian Patent Application 478,615-7, is of rectangular configuration. Another example of a motor vehicle headlight having an opening of substantially rectangular configuration is shown and described in U.S. Patent 4,545,001.
Reflector 11 further includes a projecting neck portion 17 which extends from the rear, apex part of the reflector and which includes a relatively large aperture (recessed portion) 19 therein. Closure for neck portion 27 is provided by a rear wall 21 which may be secured to or which may form part of neck 17. Reflector 11 is a glass-filled thermoplastic, preferably one sold under the product name "Ryton" by Philips Petroleum, Inc., Bartlesville, Oklahoma.
An alternative plastic suitable for the reflector is a mineral-filled nylon.
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D-1~4-1-159 -7- PATENT
Secured to the front of reflector 11 and providing a cover for the forward opening thereof i6 a cover member 23. Cover 23, a6 illu6trated, i6 of planar configuration, 6imilar to the forward openin~ 16 defined by reflector 11. In a preferred embodiment cov~r 23 serve6 a6 a len~ member and thus include6 a plurality of lensing element6 25 located on an internal 6urface thereof facing the invention~s lighting cap6ule 27. The6e len6ing elem~nt6 are acranged in a pcedetermined pattern to proviae either the high or low beam functions for headlight 10. Cover 23 i6 preferably of gla66 material but alternatively may be of pla6tic (e.g., a polycarbonate). If gla6s, cover 23 i6 secured to reflector 11 u6ing a 6uitable adhesive known in the art. If of pla6tic, cover 23 may be 6imilarly attached or 6ecured to the reflector u6ing an alternative mean6 6uch a6 ultrasonic welding. A6 yet another alternative embodiment, cover 23 may be clear (tran6parent and devoid of len6ing element6) 6hould headlight 10 be utilized with a separate lensing member located immediately in front of cover 23. One example of such a len6ing member i6 de6cribed and illustrated in the aforementioned U.S. patent 4,545,001.
Prererably, however, cover 23 ~erve6 a6 a len6 number in the manner depicted in PIG. 1.
~ A6 stated, headlight 10 further include6 a lighting cap~ule ;~ 27 ~hich 6erve6 a6 the invention'6 light source. A6 6hown in ~5 FIG. 1, cap6ule 27 i~ located within reflector 11 and include6 an nvelope portion 29 having therein a coiled filament 31.
Under6tandably, filament 31 provide6 the light 60u~ce for headlight 10 upon electrical energization thereof. Capsule 27 is preferably a tung6ten halogen cap6ule wherein filament 31 i6 of tungsten material and the sealed envelope 29 include6 a ~' ~'' J
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i2'^~QO31Ei halogen gas therein. The halogen cycle is known in the lighting field and further explanation is thus not deemed necessary. One example of a tungsten halogen lamp is described in U.S. Patent 4,262,229. As further shown in FIG.
1, capsule 27 also includes a press sealed end portion 35 located adjacent the hollow envelope 29 and in which is positioned a pair of lead-in conductors 37 which are electrically coupled to filament 31. The preferred material for capsule 27 is glass (e.g., quartz) while that for the lead-in conductors is preferably nickel or molybdenum.
Conductors 37 are sealed within end 35 during formation thereof and may include an interconnecting molybdenum foil 39 as part thereof. Use of such a foil in tungsten halogen lamps as known. Understandably, each lead-in conductor provides a path for electrical current when coupled to an appropriate external connector or the like which forms part of the motor vehicle's electrical system. Each of the externally projecting ends of conductors 37 is rigid in construction and is firmly positioned and passes through the electrically insulative back wall 21 of reflector 11. This securement may be accomplished by ultrasonic welding or, alternatively, using a suitable adhesive. In either event, this form of retention serves to positively orient capsule 27 in the position depicted without the need for additional clamping member or the like about press sealed end 35.
In accordance with the teachings herein, capsule 27 is positioned within reflector 11 such that envelope portion 29 is located within and substantially surrounded by the parabolic, concave reflecting portion 13. In addition, coiled filament 31 is substantially centered at the focal point FP (FIG. 3) of the reflector. Further, in accordance with the teachings of the `~ 127~036 in6tant invention, coiled filament 31 iB of sub~tantially cylindrical configuration (FIG . 2 ) and po6se~ses a length to diameter (width) ratio of le66 than 2 :1. The length dimen6ion i6 repre6ented by the letter L in PIG. 2 while the diameter (or wiath) aimen6ion is depicted by the letter H in FIG. 2.
Purther, the length L of the coil must be 6mall in compari60n to the focal length PL of the nominally parabolic re~lector. Thi~ reguirement is necessary to a6sure that the bundle of rays reflected at each point on the reflective ~urface will have sufriciently 6mall aivergence 6uch that 6aid rerlected light i6 efficiently utilized in the u6ual automotive headlamp light di6tribution pattern; that i6, a di6tribution with greater angular divergence horizontally than vertically.
Por the 6mall aperture, 6hort focal length reflector de6cribed horein, the filament po66e66es a length that doe6 not exceed approximately 30 percent of the reflector focal length.
Utilization of a filament 6tructure po66e66ing the above dimen6ional requirement6 in combination with a parabolic -; reflector having a relatively 6hort focal length (FL in PIG. 3) ha~ re6ulted in a headlight po66e66ing enhanced forward liqht output. Specifically, u~e of 6uch a reflector enable6 greater flux collection efficiency for the light emitted from filament 31. In addition, utilization of a filament having the de~cribod length to diameter ratio insures that elemental beam 6prea~ leaving sUCh a reflector is never much greater in ~he vertical direction than in the horizontal direction. Exce66ive vertical 6pread represents wasted light from 6uch a headlight becau~e the reguired vertical 6preaa i6 6ignificantly le66 than the corre6ponding horizontal reguirement. In other term6, the forwar~ pro~ected light from each elemental beam contributes greater to the de~irea forward, 6ub~tantially horizontal patt~rn if it~ ~pread in both the vertical and horizontal ,, .~
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127(~03~
D-84-1-159 -lo- PATENT
direction6 i8 sub6tantially the same. Excessive vertical spread by ~uch a beam al60 increase~ the amount of glare from a headlight.
~oiled filament 31, which may also be of coiled-coil configuration (FIG. 5), is preferably located axially alonq the reflector's optical axis OA-OA (FIG. 3). Alternatively, filament 31 may lie orthogonal to the optical axis provided it i~ of course centered at focal 2oint PP.
A~ stated, the reflector of the invention posses6es a relatively short focal length. As further stated, this results in a reflector possessing increasing optical efficiency. In most prior rectangular shaped headlamps wherein the forward opening is rectangular as is that of the instant invention, such as illustrated in U.S. Patent 4,210,841, the parabolic upper and lower reflecting surfaces are r0stricted by substantially horizontal planes to thus deprive the reflector of much of its parabolic reflecting regions. As a re~ult, flux incident on the6e horizontal planes is lost from the principal beam of the headlight. Utilization of a shorter focal length and minimal horizontal surface~ reduces the 601id angle of flux interception by these planar areas for a given forward open area of rectangular configuration. As shown in FIG. 1, reflector 11 utilizes minimal cut-off to the parabolic ; reflecting surfaces thereof while still maintaining the aforementioned extremely small vertical height (about two inches or less). In accordance with the teachings of the instant invention, reflector 11 possessed a focal length within the range of from about 0.2 inch to about 0.5 inch. Such a length is clearly extremely small, particularly when considering that reguired in the headlights utilized in the systQms listed in the aforementioned TABLE. Typically, such h~lights roguire a focal length in the range of from 1.0 to 1.5 inches.
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A6 ~tated, the overall vertical height (H in FIG. 1) for headlight 10 is very 6mall. In accordance of the teachings herein, the preferred vertical height H for headlight 10 i within the range of from about only l.S to about 2.5 inches.
The corre~ponding width dimension (in a direction toward and away from t~e viewer in FIG. 1) for the reflector'6 rectangular opening i8 preferably within the range of from about only 2.0 to about 3.0 i~che6. Accordingly, headlight 10 possesses a forward rectangular opening within the range of from only about
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A6 vill be defined herein, the headlight of the instant invention al~o possesses a relatively short vertical height and i6 thu6 able to assure improved motor vehicle aerodynamics when utilized in ~uch a vehicle. As will be defined, the headlight of the in6tant invention i~ able to provide enhanced forward output using a reflector having a relatively small fcontal area and an internal light source (coiled filament) having a predetermined length to diameter ratio. The invention i~ ~hu6 adapted for use in a headlighting ~y6tem pos6essing additional, similar component6, or, alternatively, as part of the headlighting systems defined in the aforementioned copending applications.
It is believed that such a headlight (and a sy~tem utilizing same) would constitute a significant advancement in the art.
DISCLOSURE OF THE INVENTION
It is. therefore, a primary object of the instant invention to enhance the motor vehicle headlight art by providing a headlight which possesses a relatively ~mall frontal area and yet which assures enhanced forward illumination for the vehicle utilizing same.
It is another ob~ect of the instant invention to provide ~uch a headlight which can be ea~ily utilized with other heaalights as part of an overall headlighting system for a motor vehicle wherein the total frontal area required in the vehic~e to accommodate such a system is substantially reduced.
It is a still further object of the invention to provide a new headlight which can be produced in an expedient and facile manner.
--" 12~003~
In accordance with one a~pect of the invention, there i6 provided a motor vehicle headlight comprising a reflector having a concave reflecting portion of sub~tantially parabolic configuration defining a forward opening, the reflector having a relatively short focal length, a cover secured to the reflector for providing a cover for the opening, and a lighting capsule located within the reflector and including an envelope ~ortlon having a coiled filament positioned therein and having a sub6tantially cylindrical configuration. The cap6ule i8 located within the réflector 6uch that the envelope portion is po~itioned within and 6ub6tantially surrounded by the concave reflecting portion and the coiled filament is 6ub6tantially centered at the focal point of the reflector. The coiled filament po6se6ses a length to diameter ratio of les6 than about 2:1.
BRIEP DESCRIPTION OF THE DRAWINGS
PIG. 1 i6 a 6ide elevational view, partly in 6ection, of a ~otor vehicle headlight in accordance with a prefecred embodiment of the invention:
PIG. 2 i6 an enlarged, partial view of one example of a coiled filament 6tructure for u6e in the headlight depicted in PIG l;
. PIG. 3 i~ an enlarged, partial view of the reflector and lighting capsule component6 of the headlight of FIG. 1, illu6tcating the focal length and focal point of the reflector and the relative po6ition of the coiled filament thereto;
PIC. 4 reprQsent6 a chart illu6trating the relative light ~ output ~between 0- and - 4.25 with re6pect to horizontal) in :~ comp~ri~on to the ratio of coil length to diameter for a coiled . 30 ril~mont ~ u6ed in the in6tant invention: and ,,~
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FIG. 5 represents a preferred embodiment of a coiled-coil filament structure for use in the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the above-described drawings.
With attention to the drawings, and particularly FIG. 1, there is shown a motor vehicle headlight 10 in accordance with a preferred embodiment of the invention. Headlight 10 includes a reflector 11 having a concave reflecting portion 13 of substantially parabolic configuration. Portion 13 is internally coated with a reflective coating material 15 (e.g., aluminum). Coating 15 is shown in FIG. 3. Concave reflecting portion 13 defines a forward opening 16, which, similar to the modules described in the aforementioned 20 copending applications U.S. Patent 4,569,002 and Canadian Patent Application 478,615-7, is of rectangular configuration. Another example of a motor vehicle headlight having an opening of substantially rectangular configuration is shown and described in U.S. Patent 4,545,001.
Reflector 11 further includes a projecting neck portion 17 which extends from the rear, apex part of the reflector and which includes a relatively large aperture (recessed portion) 19 therein. Closure for neck portion 27 is provided by a rear wall 21 which may be secured to or which may form part of neck 17. Reflector 11 is a glass-filled thermoplastic, preferably one sold under the product name "Ryton" by Philips Petroleum, Inc., Bartlesville, Oklahoma.
An alternative plastic suitable for the reflector is a mineral-filled nylon.
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- .. ~: ' -" 127~
D-1~4-1-159 -7- PATENT
Secured to the front of reflector 11 and providing a cover for the forward opening thereof i6 a cover member 23. Cover 23, a6 illu6trated, i6 of planar configuration, 6imilar to the forward openin~ 16 defined by reflector 11. In a preferred embodiment cov~r 23 serve6 a6 a len~ member and thus include6 a plurality of lensing element6 25 located on an internal 6urface thereof facing the invention~s lighting cap6ule 27. The6e len6ing elem~nt6 are acranged in a pcedetermined pattern to proviae either the high or low beam functions for headlight 10. Cover 23 i6 preferably of gla66 material but alternatively may be of pla6tic (e.g., a polycarbonate). If gla6s, cover 23 i6 secured to reflector 11 u6ing a 6uitable adhesive known in the art. If of pla6tic, cover 23 may be 6imilarly attached or 6ecured to the reflector u6ing an alternative mean6 6uch a6 ultrasonic welding. A6 yet another alternative embodiment, cover 23 may be clear (tran6parent and devoid of len6ing element6) 6hould headlight 10 be utilized with a separate lensing member located immediately in front of cover 23. One example of such a len6ing member i6 de6cribed and illustrated in the aforementioned U.S. patent 4,545,001.
Prererably, however, cover 23 ~erve6 a6 a len6 number in the manner depicted in PIG. 1.
~ A6 stated, headlight 10 further include6 a lighting cap~ule ;~ 27 ~hich 6erve6 a6 the invention'6 light source. A6 6hown in ~5 FIG. 1, cap6ule 27 i~ located within reflector 11 and include6 an nvelope portion 29 having therein a coiled filament 31.
Under6tandably, filament 31 provide6 the light 60u~ce for headlight 10 upon electrical energization thereof. Capsule 27 is preferably a tung6ten halogen cap6ule wherein filament 31 i6 of tungsten material and the sealed envelope 29 include6 a ~' ~'' J
,~
.
:
i2'^~QO31Ei halogen gas therein. The halogen cycle is known in the lighting field and further explanation is thus not deemed necessary. One example of a tungsten halogen lamp is described in U.S. Patent 4,262,229. As further shown in FIG.
1, capsule 27 also includes a press sealed end portion 35 located adjacent the hollow envelope 29 and in which is positioned a pair of lead-in conductors 37 which are electrically coupled to filament 31. The preferred material for capsule 27 is glass (e.g., quartz) while that for the lead-in conductors is preferably nickel or molybdenum.
Conductors 37 are sealed within end 35 during formation thereof and may include an interconnecting molybdenum foil 39 as part thereof. Use of such a foil in tungsten halogen lamps as known. Understandably, each lead-in conductor provides a path for electrical current when coupled to an appropriate external connector or the like which forms part of the motor vehicle's electrical system. Each of the externally projecting ends of conductors 37 is rigid in construction and is firmly positioned and passes through the electrically insulative back wall 21 of reflector 11. This securement may be accomplished by ultrasonic welding or, alternatively, using a suitable adhesive. In either event, this form of retention serves to positively orient capsule 27 in the position depicted without the need for additional clamping member or the like about press sealed end 35.
In accordance with the teachings herein, capsule 27 is positioned within reflector 11 such that envelope portion 29 is located within and substantially surrounded by the parabolic, concave reflecting portion 13. In addition, coiled filament 31 is substantially centered at the focal point FP (FIG. 3) of the reflector. Further, in accordance with the teachings of the `~ 127~036 in6tant invention, coiled filament 31 iB of sub~tantially cylindrical configuration (FIG . 2 ) and po6se~ses a length to diameter (width) ratio of le66 than 2 :1. The length dimen6ion i6 repre6ented by the letter L in PIG. 2 while the diameter (or wiath) aimen6ion is depicted by the letter H in FIG. 2.
Purther, the length L of the coil must be 6mall in compari60n to the focal length PL of the nominally parabolic re~lector. Thi~ reguirement is necessary to a6sure that the bundle of rays reflected at each point on the reflective ~urface will have sufriciently 6mall aivergence 6uch that 6aid rerlected light i6 efficiently utilized in the u6ual automotive headlamp light di6tribution pattern; that i6, a di6tribution with greater angular divergence horizontally than vertically.
Por the 6mall aperture, 6hort focal length reflector de6cribed horein, the filament po66e66es a length that doe6 not exceed approximately 30 percent of the reflector focal length.
Utilization of a filament 6tructure po66e66ing the above dimen6ional requirement6 in combination with a parabolic -; reflector having a relatively 6hort focal length (FL in PIG. 3) ha~ re6ulted in a headlight po66e66ing enhanced forward liqht output. Specifically, u~e of 6uch a reflector enable6 greater flux collection efficiency for the light emitted from filament 31. In addition, utilization of a filament having the de~cribod length to diameter ratio insures that elemental beam 6prea~ leaving sUCh a reflector is never much greater in ~he vertical direction than in the horizontal direction. Exce66ive vertical 6pread represents wasted light from 6uch a headlight becau~e the reguired vertical 6preaa i6 6ignificantly le66 than the corre6ponding horizontal reguirement. In other term6, the forwar~ pro~ected light from each elemental beam contributes greater to the de~irea forward, 6ub~tantially horizontal patt~rn if it~ ~pread in both the vertical and horizontal ,, .~
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127(~03~
D-84-1-159 -lo- PATENT
direction6 i8 sub6tantially the same. Excessive vertical spread by ~uch a beam al60 increase~ the amount of glare from a headlight.
~oiled filament 31, which may also be of coiled-coil configuration (FIG. 5), is preferably located axially alonq the reflector's optical axis OA-OA (FIG. 3). Alternatively, filament 31 may lie orthogonal to the optical axis provided it i~ of course centered at focal 2oint PP.
A~ stated, the reflector of the invention posses6es a relatively short focal length. As further stated, this results in a reflector possessing increasing optical efficiency. In most prior rectangular shaped headlamps wherein the forward opening is rectangular as is that of the instant invention, such as illustrated in U.S. Patent 4,210,841, the parabolic upper and lower reflecting surfaces are r0stricted by substantially horizontal planes to thus deprive the reflector of much of its parabolic reflecting regions. As a re~ult, flux incident on the6e horizontal planes is lost from the principal beam of the headlight. Utilization of a shorter focal length and minimal horizontal surface~ reduces the 601id angle of flux interception by these planar areas for a given forward open area of rectangular configuration. As shown in FIG. 1, reflector 11 utilizes minimal cut-off to the parabolic ; reflecting surfaces thereof while still maintaining the aforementioned extremely small vertical height (about two inches or less). In accordance with the teachings of the instant invention, reflector 11 possessed a focal length within the range of from about 0.2 inch to about 0.5 inch. Such a length is clearly extremely small, particularly when considering that reguired in the headlights utilized in the systQms listed in the aforementioned TABLE. Typically, such h~lights roguire a focal length in the range of from 1.0 to 1.5 inches.
!
, `` 127003`~
A6 ~tated, the overall vertical height (H in FIG. 1) for headlight 10 is very 6mall. In accordance of the teachings herein, the preferred vertical height H for headlight 10 i within the range of from about only l.S to about 2.5 inches.
The corre~ponding width dimension (in a direction toward and away from t~e viewer in FIG. 1) for the reflector'6 rectangular opening i8 preferably within the range of from about only 2.0 to about 3.0 i~che6. Accordingly, headlight 10 possesses a forward rectangular opening within the range of from only about
3.0 square inche6 to about 7.5 square inches. As a result, the ratio Or such a rectangular open area to the relatively short focal length of reflector 11 is within the range of from about 6:1 to about 37.5:1.
EXAMPLE
In one example of the invention, a headlight was made wherein the plastic reflector po66es6ed a rectangular opening having a height of about 2.0 inches and a correspondence width of 2.5 inches. The corresponding focal length was only about 0.30 inch and the filament's length to diameter ratio was an ideal 1:1. The coil po6sessed an outer diameter of about 0.065 inch. The capsule secured within the reflector, having an axially aligned coiled-coil tung~ten filament, was operational at a wattage of only about 20 watts. The planar cover which provided the closure for the reflector's rectangular openinq was of glas6 material and included the aforedescribed internal lensing elements.
;. ~: , ,: ', .
-`~ 12~ 0~3~
D-84-1-159 -l2- PAT~NT
A6 illu~trated by the above example, the lighting cap6ule i8 operational at low wattage6. 8y low wattage i6 ~eant a wattage within the range of from about ten to about twenty-five watt~. In addition, headlight 10 i6 preferably utilized in combination with at lea6t three additional 6imilar comeonent6 to form an overall array of four 6uch component6. Two 6uch array6 are utilized per vehicle, with each array being po6itioned on one 6ide thereof. Even further, each of the6e headlight6 i6 preferably arranged in a horizontal, planar orientation 6uch a~ depicted in U.S. Patent 4,545,001. Thi6 i6 not meant to limit the invention, however, in that the6e array6 may be 6ucce66fully arranged in different orientation6 to thu6 accommodate the vehicle'6 forward 6hape.
Cap~ule 27 i6 oriented within reflector ll 6uch that the pre66 6ealed end 35 i6 located within (and 6urrounded by) the extending neck portion 17. Thi6 arrangement 6erve6 to 6ub6tantially prevent light 6catter from headlight 10 whicb in turn can contribute to the aforementioned glare problem. The pre66 6ealed end 35 of a cap6ule ~uch a6 depicted herein will adver6ely effect the cap6ule'6 light output. Accordingly, po61tioning of ~- thi6 part of the cap6ule within a rece66ed area of the reflector 6erve6 to prevent 6uch 6cattering, particularly it the internal 6urfaces of the neck portion 17 do not include a reflective coating thereon, It i6 6een in YIG.
3 that the de6cribed reflective coating lS does not extend into thi6 rece66ed area of the reflector. The above ~- 30 positioning relation6hip thu6 6erve6 to further a66ure ` opti~u- light output for the in6tant invention.
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With particular attention to FIG. 4, there i8 provided a chart which illustrates the relation~hip between relative light output in compari60n to the ratio of filament length to diameter for the low wattage coils.
Specifically, it i~ seen that a relatively high ratio of about 4:1 provide~ about twenty percent le~ relative ligbt in compari~on to an ideal ratio of l:l as taught herein. This light output i8 measured within a field of from 0 to a negative 4.25 with respect to horizontal.
The 0 coor~inate of the field is tha~ horizontal line which intersect6 the optical axis of the headlight when the headlight i~ faced in that direction. Accordingly, the negative 4.25 coordinate i6 that horizontal line at approximately 4.25 below the horizontal 0 line. This field understandably is located at a distance forward of the headlight.
In PIG. 5, there is 6hown a filament structure 31~ in accor~ance with a preferred embodiment of the invention.
Filament 31' i6 of coiled-coil con6truction and produced ; 20 from tungsten wire. Por~ation is achieved by winding thi6 - wire about a suitable mandrel (e.g., molybdenum rod) to form a single coiled member. This structure i8 then formed (coiled) to provide the shape depicted in FIG. 5.
A suitable high temperature wax is then applied to the end segments ot the structure and the ~tructure is then acid etched to remove the mandrel, excluding of course the - protected ena segments. Accordingly, the mandrel rod sections 41 remain in place and are surrounded by the respective internal ends of lead-in conductors 37'. The resulting coiled-coil filamentary material is axially orientoa along the optical axis OA-OA as shown, as well as boing ~ontorod at focal point PP. Uniguely, the m4n~rol-~ont4i~ing on~s are not activated (do not glow) `'' i.,~, .
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-- lZ70~3~;
D-Bq-1-159 -14- PATENT
upon filament energization due to the thermal ~quenching~
by tbe ~andrel material. Only the non-protected poction~
(defined cubctantially by tbe L and W dimen6ional arrows) will glow auring energization. This unique arrangement enable~ formation of a filament structure of coiled-coil configuration wherein the ideal 1:1 ratio of length to diameter i~ po~6ible, thu6 as6uring a 6ub~tantial point source of light for reflector 11.
Utilization of a plurality (e.g., four) of headlight6 of the type defined herein within each of two 6paced array6 for a motor vehicle provide6 ~everal advantages over many known prior art 6y6tems. Fir6t, the u~e of multiple 60urce6 Or the number mentioned provides desired re~undancy in that more than one 6ection of the overall sy6tem provide6 illumination to the 6ame region of space (forward pattern). Thu6, should one headliqht fail (e.g., burn out), a ma30r portion of t~e forward light pattern will not be totally 106t a6 i6 the 6ituation with many exi~ting headliqht sy6tems (typically including a total of only two or four headlights). In the instant invention, about ~eventy-five percent of the total coverage for any given forward component remain6 upon the failure of a singlo headlight in the system. Second, it is acknowledged that only certain parts of the headlight rerl~ctor provide beam element6 suitable for developing the ~igh inteQ6ity gradients required for the 6harp cut-off of the low beam pattern near the horizontal plane through the vehicle'~ light 60urce. A greater percentage of the net reflector area for developing high inten6ities near the horizontal with minimal glare in the upper left quadrant ttoward oncoming driver6) is possible utilizing a hoadlight a~ defined herein in view of the utilization of ~e~ral in~ ual reflector olement6. Thirdly, an :, : . , ,., ... i " ' .' ' ~
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12~ 0,3~
increase in the number of individual headlight unit~ in turn increases the 1eYibility of optimizing both high and low beam~. This is possible by switching (activating) selected headlight unit~ for either high or low beam or leaving other unit6 energized for both patterns. Pre~ent headlight 6y~tem6 in which two filament6 are activated in a 6ingle len6-reflector headlight unit do not typically pos~e~ ~uch flexibility. With the~e exi6ting ~y~tem6, the len6 element6 can be optimized for only one pattern and switching to a 6econd filament produce6 at best a compromised light distribution.
Pourthly, the small vertical aimension ana the freedom to configure variou6 arrangements of a plurality of small headlamp6 a6 taught herein enhance6 the ability to form - 15 aerodynamic front end6 for vehicle6 utilizing the ~ invention.
There ha6 thu6 been 6hown and de6cribed a motor vehicle headlight wherein the reflector po6~e~se6 a ~ relatively 6hort focal length and the coiled filament utilized in the headlight's lighting source (cap6ule) po6~e66es alreaay a preaetermined length to diameter ratio le~6 tban about 2:1) 80 a6 to provide optimum light output for the headlight ~uch that a fini6hed product having a ~mall vertical height (e.g., about two inches) can be produced. The above optimum light output is po~ible through the teaching6 herein wherein the hoadlight'6 reflector po66es6es a relatively small forward openinq in combination with the defined short focal length.
While there have been shown ana de6cribed what are at present con6iaered the preferred embodiment6 of the invention. it will be obviou6 to tho6e s~illed in the art that variou~ change6 ana modification~ may be made therein w~thout departing ~rom the 6cope of the invention as defined by the appended claim~.
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EXAMPLE
In one example of the invention, a headlight was made wherein the plastic reflector po66es6ed a rectangular opening having a height of about 2.0 inches and a correspondence width of 2.5 inches. The corresponding focal length was only about 0.30 inch and the filament's length to diameter ratio was an ideal 1:1. The coil po6sessed an outer diameter of about 0.065 inch. The capsule secured within the reflector, having an axially aligned coiled-coil tung~ten filament, was operational at a wattage of only about 20 watts. The planar cover which provided the closure for the reflector's rectangular openinq was of glas6 material and included the aforedescribed internal lensing elements.
;. ~: , ,: ', .
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D-84-1-159 -l2- PAT~NT
A6 illu~trated by the above example, the lighting cap6ule i8 operational at low wattage6. 8y low wattage i6 ~eant a wattage within the range of from about ten to about twenty-five watt~. In addition, headlight 10 i6 preferably utilized in combination with at lea6t three additional 6imilar comeonent6 to form an overall array of four 6uch component6. Two 6uch array6 are utilized per vehicle, with each array being po6itioned on one 6ide thereof. Even further, each of the6e headlight6 i6 preferably arranged in a horizontal, planar orientation 6uch a~ depicted in U.S. Patent 4,545,001. Thi6 i6 not meant to limit the invention, however, in that the6e array6 may be 6ucce66fully arranged in different orientation6 to thu6 accommodate the vehicle'6 forward 6hape.
Cap~ule 27 i6 oriented within reflector ll 6uch that the pre66 6ealed end 35 i6 located within (and 6urrounded by) the extending neck portion 17. Thi6 arrangement 6erve6 to 6ub6tantially prevent light 6catter from headlight 10 whicb in turn can contribute to the aforementioned glare problem. The pre66 6ealed end 35 of a cap6ule ~uch a6 depicted herein will adver6ely effect the cap6ule'6 light output. Accordingly, po61tioning of ~- thi6 part of the cap6ule within a rece66ed area of the reflector 6erve6 to prevent 6uch 6cattering, particularly it the internal 6urfaces of the neck portion 17 do not include a reflective coating thereon, It i6 6een in YIG.
3 that the de6cribed reflective coating lS does not extend into thi6 rece66ed area of the reflector. The above ~- 30 positioning relation6hip thu6 6erve6 to further a66ure ` opti~u- light output for the in6tant invention.
,:
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With particular attention to FIG. 4, there i8 provided a chart which illustrates the relation~hip between relative light output in compari60n to the ratio of filament length to diameter for the low wattage coils.
Specifically, it i~ seen that a relatively high ratio of about 4:1 provide~ about twenty percent le~ relative ligbt in compari~on to an ideal ratio of l:l as taught herein. This light output i8 measured within a field of from 0 to a negative 4.25 with respect to horizontal.
The 0 coor~inate of the field is tha~ horizontal line which intersect6 the optical axis of the headlight when the headlight i~ faced in that direction. Accordingly, the negative 4.25 coordinate i6 that horizontal line at approximately 4.25 below the horizontal 0 line. This field understandably is located at a distance forward of the headlight.
In PIG. 5, there is 6hown a filament structure 31~ in accor~ance with a preferred embodiment of the invention.
Filament 31' i6 of coiled-coil con6truction and produced ; 20 from tungsten wire. Por~ation is achieved by winding thi6 - wire about a suitable mandrel (e.g., molybdenum rod) to form a single coiled member. This structure i8 then formed (coiled) to provide the shape depicted in FIG. 5.
A suitable high temperature wax is then applied to the end segments ot the structure and the ~tructure is then acid etched to remove the mandrel, excluding of course the - protected ena segments. Accordingly, the mandrel rod sections 41 remain in place and are surrounded by the respective internal ends of lead-in conductors 37'. The resulting coiled-coil filamentary material is axially orientoa along the optical axis OA-OA as shown, as well as boing ~ontorod at focal point PP. Uniguely, the m4n~rol-~ont4i~ing on~s are not activated (do not glow) `'' i.,~, .
~ ` , ~. .. .- . .
. , ' . - ', ''' .~: '` , ' :' .
~ - . ' . ' - -. - ........... ..
. .
-- lZ70~3~;
D-Bq-1-159 -14- PATENT
upon filament energization due to the thermal ~quenching~
by tbe ~andrel material. Only the non-protected poction~
(defined cubctantially by tbe L and W dimen6ional arrows) will glow auring energization. This unique arrangement enable~ formation of a filament structure of coiled-coil configuration wherein the ideal 1:1 ratio of length to diameter i~ po~6ible, thu6 as6uring a 6ub~tantial point source of light for reflector 11.
Utilization of a plurality (e.g., four) of headlight6 of the type defined herein within each of two 6paced array6 for a motor vehicle provide6 ~everal advantages over many known prior art 6y6tems. Fir6t, the u~e of multiple 60urce6 Or the number mentioned provides desired re~undancy in that more than one 6ection of the overall sy6tem provide6 illumination to the 6ame region of space (forward pattern). Thu6, should one headliqht fail (e.g., burn out), a ma30r portion of t~e forward light pattern will not be totally 106t a6 i6 the 6ituation with many exi~ting headliqht sy6tems (typically including a total of only two or four headlights). In the instant invention, about ~eventy-five percent of the total coverage for any given forward component remain6 upon the failure of a singlo headlight in the system. Second, it is acknowledged that only certain parts of the headlight rerl~ctor provide beam element6 suitable for developing the ~igh inteQ6ity gradients required for the 6harp cut-off of the low beam pattern near the horizontal plane through the vehicle'~ light 60urce. A greater percentage of the net reflector area for developing high inten6ities near the horizontal with minimal glare in the upper left quadrant ttoward oncoming driver6) is possible utilizing a hoadlight a~ defined herein in view of the utilization of ~e~ral in~ ual reflector olement6. Thirdly, an :, : . , ,., ... i " ' .' ' ~
. ~ ... ;* - . .
12~ 0,3~
increase in the number of individual headlight unit~ in turn increases the 1eYibility of optimizing both high and low beam~. This is possible by switching (activating) selected headlight unit~ for either high or low beam or leaving other unit6 energized for both patterns. Pre~ent headlight 6y~tem6 in which two filament6 are activated in a 6ingle len6-reflector headlight unit do not typically pos~e~ ~uch flexibility. With the~e exi6ting ~y~tem6, the len6 element6 can be optimized for only one pattern and switching to a 6econd filament produce6 at best a compromised light distribution.
Pourthly, the small vertical aimension ana the freedom to configure variou6 arrangements of a plurality of small headlamp6 a6 taught herein enhance6 the ability to form - 15 aerodynamic front end6 for vehicle6 utilizing the ~ invention.
There ha6 thu6 been 6hown and de6cribed a motor vehicle headlight wherein the reflector po6~e~se6 a ~ relatively 6hort focal length and the coiled filament utilized in the headlight's lighting source (cap6ule) po6~e66es alreaay a preaetermined length to diameter ratio le~6 tban about 2:1) 80 a6 to provide optimum light output for the headlight ~uch that a fini6hed product having a ~mall vertical height (e.g., about two inches) can be produced. The above optimum light output is po~ible through the teaching6 herein wherein the hoadlight'6 reflector po66es6es a relatively small forward openinq in combination with the defined short focal length.
While there have been shown ana de6cribed what are at present con6iaered the preferred embodiment6 of the invention. it will be obviou6 to tho6e s~illed in the art that variou~ change6 ana modification~ may be made therein w~thout departing ~rom the 6cope of the invention as defined by the appended claim~.
', , ,~ ~ ..... .
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Claims (14)
1. A motor vehicle headlight comprising:
a reflector having a concave reflecting portion of substantially parabolic configuration defining a forward opening, said reflector having a focal length within the range of 0.2 inch to 0.5 inch;
a cover secured to said reflector for providing a cover for said opening; and a lighting capsule located within said reflector and including an envelope portion having a coiled filament positioned therein and having a substantially cylindrical configuration, said capsule being located within said reflector such that said envelope portion is positioned within and substantially surrounded by said concave reflecting portion and said coiled filament is substantially centered at the focal point of said reflector, said coiled filament having a length to diameter ratio of less than 2:1.
a reflector having a concave reflecting portion of substantially parabolic configuration defining a forward opening, said reflector having a focal length within the range of 0.2 inch to 0.5 inch;
a cover secured to said reflector for providing a cover for said opening; and a lighting capsule located within said reflector and including an envelope portion having a coiled filament positioned therein and having a substantially cylindrical configuration, said capsule being located within said reflector such that said envelope portion is positioned within and substantially surrounded by said concave reflecting portion and said coiled filament is substantially centered at the focal point of said reflector, said coiled filament having a length to diameter ratio of less than 2:1.
2. The headlight according to claim 1 wherein said forward opening is substantially planar and of a rectangular configuration, the ratio of the area of said rectangular opening to said focal length of said reflector being within the range of 6.0:1 to 37.5:1.
3. The headlight according to claim 2 wherein said area of said rectangular opening is within the range of 3.0 square inches to 7.5 square inches.
4. The headlight according to claim 1 wherein said length to diameter ratio of said coiled filament is 1:1.
5. The headlight according to claim 1 wherein the length of said filament is no greater than thirty percent of said focal length of said reflector.
6. The headlight according to claim 2 wherein said reflector includes a neck portion projecting from the rear of said reflector and including an aperture therein, said capsule further including a sealed end portion adjacent said envelope portion and positioned within said aperture to substantially prevent light scattering.
7. The headlight according to claim 6 wherein said capsule is a tungsten halogen capsule and said sealed end is a press sealed end.
8. The headlight according to claim 7 wherein said capsule further includes a pair of lead-in conductors electrically coupled to said coiled filament and being positioned substantially within said press sealed end and projecting therefrom.
9. The headlight according to claim 8 wherein said neck portion of said reflector includes a rear wall, each of the projecting portions of said lead-in conductors being positioned within and passing through said rear wall.
10. The headlight according to claim 1 wherein said cover secured to said forward opening of said reflector is a lens cover.
11. The headlight according to Claim 10 wherein said lens cover includes a plurality of lensing elements located on an internal surface of said lens cover facing said lighting capsule.
12. The headlight according to Claim 10 wherein said reflector is plastic and said lens cover is glass.
13. The headlight according to Claim 1 wherein said filament is of coiled-coil construction and includes a pair of end segments each having therein a quantity of material for thermally quenching said end segments to prevent activation thereof during energization of said filament.
14. The headlight according to Claim 13 wherein said lighting capsule further includes a pair of lead-in conductors. each of said conductors coupled to a respective one of said end segments of said filament.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US82652686A | 1986-02-06 | 1986-02-06 | |
| US826,526 | 1986-02-06 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA1270036A true CA1270036A (en) | 1990-06-05 |
| CA1270036C CA1270036C (en) | 1990-06-05 |
Family
ID=25246781
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA529123A Expired CA1270036C (en) | 1986-02-06 | 1987-02-05 | Motor vehicle headlight |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0232843B1 (en) |
| JP (1) | JPH0821370B2 (en) |
| CA (1) | CA1270036C (en) |
| DE (1) | DE3786931T2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01164661U (en) * | 1988-05-10 | 1989-11-16 | ||
| JP2003501793A (en) * | 1999-06-03 | 2003-01-14 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | Lamp / reflector unit |
| DE10035401B4 (en) * | 2000-07-19 | 2006-01-26 | Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH | Halogen bulb for motor vehicle headlights |
| WO2007061956A2 (en) | 2005-11-21 | 2007-05-31 | Entegris, Inc. | System and method for a pump with reduced form factor |
| US8083498B2 (en) | 2005-12-02 | 2011-12-27 | Entegris, Inc. | System and method for position control of a mechanical piston in a pump |
| JP4991834B2 (en) * | 2009-12-17 | 2012-08-01 | シャープ株式会社 | Vehicle headlamp |
| JP5232815B2 (en) | 2010-02-10 | 2013-07-10 | シャープ株式会社 | Vehicle headlamp |
| US9816677B2 (en) | 2010-10-29 | 2017-11-14 | Sharp Kabushiki Kaisha | Light emitting device, vehicle headlamp, illumination device, and laser element |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH108619A (en) * | 1924-02-25 | 1925-02-02 | Lilienfeld Julius Edgar Prof D | Automobile headlights. |
| CH310970A (en) * | 1952-11-17 | 1955-11-15 | Siemens Ag Albis | Headlights. |
| JPS4427113Y1 (en) * | 1967-07-05 | 1969-11-12 | ||
| JPS5439151Y2 (en) * | 1975-07-23 | 1979-11-20 | ||
| HU178521B (en) * | 1979-03-07 | 1982-05-28 | Egyesuelt Izzolampa | Electric reflector unit,in particular fullglass headlamp |
| EP0158328B1 (en) * | 1984-04-10 | 1991-02-06 | GTE Products Corporation | Lighting module for motor vehicle lighting system |
-
1987
- 1987-02-04 EP EP87101484A patent/EP0232843B1/en not_active Expired - Lifetime
- 1987-02-04 DE DE87101484T patent/DE3786931T2/en not_active Expired - Fee Related
- 1987-02-05 CA CA529123A patent/CA1270036C/en not_active Expired
- 1987-02-06 JP JP62024924A patent/JPH0821370B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE3786931D1 (en) | 1993-09-16 |
| DE3786931T2 (en) | 1994-02-24 |
| EP0232843A2 (en) | 1987-08-19 |
| EP0232843A3 (en) | 1989-06-07 |
| CA1270036C (en) | 1990-06-05 |
| JPS62254355A (en) | 1987-11-06 |
| EP0232843B1 (en) | 1993-08-11 |
| JPH0821370B2 (en) | 1996-03-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed | ||
| MKLA | Lapsed |
Effective date: 20000605 |