`Hogrefe et al.
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 6,227,691 B1
`May 8, 2001
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`US006227691B1
`
`(54) HEADLIGHT ARRANGEMENT FOR MOTOR
`VEHICLE
`
`(75)
`
`Inventors: Henning Hogrefe, Walddorfhaeslach;
`Friedemann Schlienz, Tuebungen, both
`of (DE)
`
`(73) Assignee: Robert Bosch GmbH, Stuttgart (DE)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/348,589
`
`(22)
`
`Filed:
`
`Jul. 6, 1999
`
`(30)
`
`Foreign Application Priority Data
`
`Jul. 7, 1998
`
`(DE) ............................................ .. 198 30 298
`
`Int. Cl.7 ............................. .. F21V 14/08; B60Q 1/04
`(51)
`
`(52) U.S. Cl.
`362/539; 362/465; 362/514
`(58) Field of Search ................................... .. 362/276, 280,
`362/281, 282, 284, 322, 323, 324, 464,
`465, 467, 512, 513, 514, 539
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`1,305,498 *
`
`6/1919 Schroeder .
`
`1,834,542 * 12/1931 Karlebo.
`....................... .. 362/284
`4,987,521 *
`1/1991 Fratty etal.
`5,130,903 *
`7/1992 Fast et al.
`.......................... .. 362/284
`
`FOREIGN PATENT DOCUMENTS
`
`43 07 110 A1
`
`9/1994 (DE) .
`
`* cited by examiner
`
`Primary Examiner—Y. Quach
`(74) Attorney, Agent, or Firm—Michael J. Striker
`
`(57)
`
`ABSTRACT
`
`A headlight arrangement of a vehicle having a reflector
`subdivided into a plurality of reflector regions, a light source
`arranged in a region of an apex of the reflector so that a light
`emitted by the light source is reflected by the reflector onto
`a roadway in front of the vehicle, at least one screening
`device associated with at least one of the reflector regions,
`the screening device being adjustable between a position in
`which the light emitted by the light source can reach a
`selected one of the reflector regions, and a position in which
`a light emitted by the light source is at
`least partially
`screened from a selected one of the reflector regions, and a
`control unit which controls the screening device in depen-
`dence on vehicle sensor signals and adjusts the screening
`device so that in each vehicle situation an optimal light
`distribution is provided.
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`15 Claims, 3 Drawing Sheets
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`KOITO 1028
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`U.S. Patent
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`May 8, 2001
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`Sheet 1 013
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`US 6,227,691 B1
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`May 8, 2001
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`Sheet 3 013
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`US 6,227,691 B1
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`US 6,227,691 B1
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`1
`HEADLIGHT ARRANGEMENT FOR MOTOR
`VEHICLE
`
`BACKGROUND OF THE INVENTION
`
`The present invention relates to a headlight arrangement
`for a motor vehicle.
`
`More particularly, it relates to such a headlight arrange-
`ment which has a reflector subdivided into several reflector
`
`regions, a light source arranged in the region of the apex of
`the reflector, so that light which is emitted by the light source
`is reflected by the reflector on a roadway in front of the
`motor vehicle, and at least one screening device associated
`with at least one selected reflector region. The screening
`device is adjustable between a passage position in which the
`light emitted by the light source can reach the selected
`reflector region, and a screening position in which it screens
`the reflector region from the light emitted by the light
`source.
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`the reflector can be
`In such headlight arrangements,
`subdivided however into several desired functional reflector
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`regions. The subdivision must not be visible from outside,
`for example as steps between the reflector regions. Such
`headlight arrangement is disclosed for example in the Ger-
`man patent document DE 43 07 110 A1. The lateral reflector
`regions of the open headlight arrangement disclosed in this
`reference influence the side dispersion, the upper and lower
`reflector region influence the pre-field illumination.
`For switching of the known headlight arrangement from
`the right side traffic to the left side traffic and vice versa, the
`headlight arrangement is provided with at least one screen-
`ing device which screens the lateral reflector regions from
`the light source so that an asymetric illumination intensity
`distribution is produced with the bright-dark limit increasing
`toward the roadway edge at the road side itself (in other
`words right for the right side traffic and left for the left side
`traffic).
`While the screening devices in accordance with the prior
`art can be switched between the passage position and the
`screening position, an intermediate position is not provided
`in them. The screening device disclosed in the German
`patent document DE 43 07 110 A1 can be switched between
`the two positions for the right side traffic and left side traffic.
`The headlight arrangement has the same statistic light dis-
`tribution for the right side traffic and the left side traffic.
`However, for an asymmetrical illumination intensity distri-
`bution the bright-dark limit at
`the roadway side raising
`toward the roadway edge can be switched for the right side
`traffic to the right and for the left side traffic to the left.
`It has been however recognized that there is no optimal
`statistic illumination which can be correct for all road and
`
`traffic situations. For example, during driving on a speedway
`with a high speed another optimal
`light distribution is
`required by governmental regulations that during driving
`with a lower speed. Therefore, a headlight arrangement
`would be desirable, in which the light distribution can be
`controlled adaptively, or in other words in correspondence
`with the road and traffic situations.
`
`A so-called curve headlight is known from the prior art
`and has turnable reflectors for variation of the dispersion
`width. With such a curve headlight
`the roadway edges
`during driving over curves can be illuminated wider.
`Moreover, free-standing individual headlights are known,
`which are arranged at the right side and the left side of the
`motor vehicle and provide illumination in the side regions.
`By turning on and turning off of the individual headlights,
`the side width of the vehicle can be illuminated as desired.
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`In the known curve headlights disclosed in the prior art,
`the construction is substantially large because of the adjust-
`ment mechanism and the turnable reflectors. Moreover they
`take into consideration only the steering angle as a single
`control value for the light distribution. Finally, the turnable
`reflectors are subjected to wear and must be maintained in
`regular time intervals. Due to the turnable reflectors and the
`broadly fluctuating environmental conditions (temperature,
`air moisture, dirt) in the headlights, the known curve head-
`light is especially sensitive.
`The lateral single headlights in accordance with the prior
`art has a disadvantage that they are fixedly mounted on the
`motor vehicle. They have no flexibility with regard to the
`light distribution. They are either turned on and illuminate
`the side regions or they are turned off and do not illuminate
`the side regions. Intermediate positions which can be desir-
`able for illumination of only predetermined parts of the side
`regions for illumination of side regions with variable
`intensity, are not provided. The known single headlights
`require a mounting space in the motor vehicle.
`
`SUMMARY OF THE INVENTION
`
`Accordingly, it is an object of the present invention to
`provide a headlight arrangement for a vehicle, which avoids
`the disadvantages of the prior art.
`More particularly, it is an object of present invention to
`provide a headlight arrangement for a vehicle, which makes
`possible an adaptive light distribution, has a simple
`construction, operates reliably and at
`the same time has
`small dimensions.
`
`In keeping with these objects and with others which will
`become apparent hereinafter, one feature of present inven-
`tion resides, briefly stated, in a headlight arrangement which
`it has a control unit controlling the screening device in
`dependence on vehicle sensor signals and the screening
`device is adjusted steplessly so that for each vehicle situa-
`tion an optimal light distribution is provided.
`Vehicle sensor signals which can be considered for use for
`the control unit to control the screening device include for
`example the vehicle speed,
`the motor rotary speed,
`the
`selected gear, the steering angle, the vehicle inclination, the
`yawing rate, the spring path, the adjustment of the gas pedal,
`the adjustment of the brakes, the outside temperature and/or
`the air moisture. In a particularly advantageous manner, as
`a vehicle sensor signal also a street traffic can be introduced,
`which is determined by a navigation system. Basically, all
`physical conditions which can have an influence on the
`vehicle condition can be determined by a sensor and sup-
`plied to the control unit. From the steering angle course in
`connection with the vehicle speed, for example the roadway
`course can be determined.
`In particular, curves can be
`recognized and the headlight arrangement can illuminate the
`curves correspondingly. From the spring path, for example
`the roadway quality can be determined and the light distri-
`bution can be correspondingly controlled.
`The control unit determines from the vehicle sensor
`
`signals the vehicle situation and correspondingly controls
`the screening device. For example low speeds mean fre-
`quently changing actuation of the gas pedal and the brake
`pedal and frequent curves during a city driving. High speeds
`over a long time interval with insignificant steering wheel
`action means the speedway driving, and corresponding
`greater steering wheel action means driving on a highway.
`Further vehicle situations include for example the vehicle
`inclination about the longitudinal axis during driving over
`curves, or the vehicle inclination about the transverse axis
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`US 6,227,691 B1
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`3
`during acceleration or braking. Moreover, the driving over
`curves is a vehicle situation which requires a special light
`distribution. Finally,
`the exterior conditions, weather and
`environmental conditions, produce a vehicle situation which
`requires a special light distribution. An optimal light distri-
`bution means that, depending on the corresponding vehicle
`situation, the prescribed and standard requirements are ful-
`filled on the one hand, but on the other hand with regard to
`the light distribution, they are completely satisfied.
`The inventive headlight arrangement can control the light
`distribution correctly in accordance with the situation,
`depending on the street, driver, and vehicle situation, and
`therefore guarantees a substantial contribution to improve-
`ment of the street safety. At lower speeds, the side region of
`the vehicle and in some cases also the adjoining region in
`front of the vehicle are illuminated better, while during
`higher speeds the dispersion width comes back and therefore
`the visibility range along the roadway must be substantially
`increased. An amplified side light
`is also advantageous
`during deflecting processes on intersections as well as
`during driving over curved paths.
`The invention in particular deals with headlight
`arrangements, in which the light distribution is produced
`completely or at least substantially by the reflector. During
`this process the pre-field illumination is conventionally
`influenced by the reflector regions above and below the light
`source and the side dispersion by the reflector regions
`laterally of the light source. For reducing the side dispersion
`in the inventive headlight arrangement, the screening device
`screens the lateral reflector regions against the light pro-
`duced by the light source at least partially. For varying of the
`pre-field illumination, the screening device must be adjusted
`so that the upper and/or reflector regions are screened from
`the light emitted by the light source at least partially. The
`screening device can be adjusted so that only a part of the
`reflector region is screened from the light emitted by the
`light source. Thereby the side dispersion or the pre-field
`illumination can be varied in any desired way.
`The inventive headlight arrangement also provides a
`stepless adaptive light distribution.
`It has a simple
`construction, operates reliably and is of a particularly small
`size.
`
`In the practice, the side reflector regions are convention-
`ally not screened completely, since on the other regions the
`range maximum and the bright-dark limit are clearly jointly
`formed. However,
`it
`is desirable to have the utilization
`regions, in which the screening device preferably screens
`almost the whole selected reflector region.
`In accordance with a preferable further embodiment of the
`invention, the screening device can be formed as at least one
`light-impermeable shield. The shield is associated at least
`with a selected reflector region. It is steplessly adjustable
`between a position in which the light emitted by the light
`source reaches the selected reflector region, and a position in
`which the selected reflector region is screened from the light
`emitted by the light source.
`For adjusting the shield, preferably it is displaced parallel
`to the optical axis of the headlight arrangement.
`Alternatively, the shield can be turned about the optical axis
`of the headlight arrangement or turned about
`the axis
`parallel to it.
`In accordance with another advantageous further feature
`of the present invention, the contour of the shield can be
`shaped in correspondence with the geometry of the selected
`reflector region. Thereby the selected reflector region or only
`certain parts of the reflector region can be curved by the
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`shield. If for example the side dispersion of the inventive
`headlight arrangement must be reduced, then the shield must
`be formed so that only the lateral reflector regions which
`produce the side dispersion are covered. The upper and
`lower
`reflector regions which serve for pre-field
`illumination, must not be covered by the shield.
`In accordance with another advantageous further feature
`of present invention, the screening device is formed as at
`least one reflector element. In this way the light rays which
`are screened from the selected reflector region are not only
`absorbed but also reflected to the remaining reflector regions
`or reflected directly into a pre-selected direction on the
`roadway in front of the vehicle, and they can be used for the
`illumination of the roadway in front of the vehicle. The
`inventive headlight device with such design has an espe-
`cially high efficiency.
`Advantageously, the reflector element is turnable about
`the optical axis of the headlight arrangement or about an axis
`which is parallel to it. The reflector element is preferably
`arranged in front of a remaining reflector region in the
`passage position, in which the light emitted by the light
`source is supplied to the selected reflector region. In the
`screening position in which the reflector element screens the
`light of the light source from the selected reflector region,
`the reflector element is located in front of this reflector
`
`region. The light oriented to this reflector region is reflected
`by the reflector element for optimization of the light
`distribution, directly or indirectly over the remaining reflec-
`tor region onto the roadway in front of the vehicle.
`When the reflector is subdivided for example into four
`reflector regions, both lateral reflector regions influence the
`lateral dispersion, while the upper and lower reflector
`regions influence the pre-field illumination. In this construc-
`tion two reflector elements are located above and below the
`
`light source in front of the remaining reflector regions
`providing the pre-field illuminations. In this position the
`reflector elements have only insignificant little influence on
`the pre-field illumination and the side dispersion. The farther
`the reflector elements are turned however, in the horizontal
`position in front of the selected reflector region which are
`important for the side dispersion, the more they screen the
`width-dispersing lateral reflector regions of the reflector.
`The lateral reflector regions are replaced, with increasing
`horizontal position of the reflector elements, by the reflector
`elements which provide concentrated dispersion. Thereby
`the light oriented on the selected lateral reflector element is
`screened by it and,
`in advantageous manner deviated to
`another light distribution. The screened light is available as
`before for illumination purposes.
`The light source of the inventive headlight arrangement is
`preferably formed as a gas discharge lamp. Due to the high
`light density of gas discharge lamps, the inventive headlight
`arrangement can be formed especially small, with the same
`remaining light intensity.
`The novel features which are considered as characteristic
`
`for the present invention are set forth in particular in the
`appended claims. The invention itself, however, both as to
`its construction and its method of operation, together with
`additional objects and advantages thereof, will be best
`understood from the following description of specific
`embodiments when read in connection with the accompa-
`nying drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a view showing an inventive headlight arrange-
`ment in accordance with a first embodiment in accordance,
`in a section;
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`US 6,227,691 B1
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`5
`FIG. 2 is a perspective view of the screening device of the
`inventive headlight arrangement of FIG. 1;
`FIG. 3 is a view showing an inventive headlight arrange-
`ment in accordance with a second embodiment, in a section;
`and
`
`FIG. 4 is a front view of the inventive headlight arrange-
`ment of FIG. 3.
`
`DESCRIPTION OF PREFERRED
`EMBODIMENTS
`
`A headlight arrangement for a motor vehicle shown in
`FIG. 1 is identified as a whole with reference numeral 1. It
`
`has a reflector 2 and a light source 3 which is arranged in the
`region of an apex of the reflector 2. The reflector 2 is
`subdivided into four reflector regions 2a, 2b, 2c, 2d.
`The lateral reflector regions 2a, 2b influence the lateral
`dispersion, while the upper and lower reflector regions 2c,
`2d influence the pre-field illumination. The light source 3 is
`formed as a gas discharge lamp. The light emitted by the
`light source 3 is reflected by the reflector 2 onto the roadway
`in front of the motor vehicle. A screening device 4 is
`arranged around the light source 3.
`The screening device is associated with the lateral reflec-
`tor regions 2a, 2b. The screening device is adjustable
`between a passage position in which the light emitted by the
`light source 3 reaches the lateral reflector regions 2a, 2b and
`a screening position in which it screens the light emitted by
`the light source 3 from the lateral reflector regions 2a, 2b.
`The adjustment
`is performed steplessly. The screening
`device has two individually adjustable, light-impermeable
`screens 4a, 4b. The screens 4a, 4b are displaceable parallel
`to the optical axis 5 of the headlight arrangement 1 and/or
`turnable about the optical axis 5. The screening device 4 is
`shown in FIG. 2 on an enlarged scale.
`The headlight arrangement 1 has a not shown control unit
`which controls the screening device 4 independently from
`the vehicle sensor signals. The control unit steplessly adjusts
`the screening device 4, so that in each vehicle situation an
`optimal light distribution is provided. The contour of the
`shields 4a, 4b is shaped in correspondence with the geom-
`etry of the lateral reflector regions 2a, 2b, so that the lateral
`reflector regions 2a, 2b or only certain parts of the reflector
`regions 2a, 2b are covered by the shields 4a, 4b.
`A headlight arrangement 1 in accordance with a second
`embodiment of the present invention is shown in FIG. 3. The
`screening device 4 has in this embodiment two reflector
`elements 4c, 4d. The reflector elements 4c, 4d are turnable
`about the optical axis 5 of the headlight arrangement 1. In
`the passage position in which the light emitted by the light
`source 3 can pass to the lateral reflector regions 2a, 2b, the
`reflector elements 4c, 4d are arranged in front of the upper
`and lower reflector regions 2c, 2d, as shown by broken lines
`for the reflector elements 4c‘, 4d‘ in FIG. 4. The light rays of
`the light source 3 in the passage position are reflected by the
`lateral reflector regions 2a, 2b as shown by broken lines in
`FIG. 3 for the course of the rays.
`In the screening position in which the reflector elements
`4c, 4d screen the light emitted by the light source 3 from the
`lateral reflector regions 2a, 2b, the reflector elements 4c, 4d
`are arranged in front of the reflector regions 2a, 2b. The
`shape of the reflector 2 of the headlight arrangement 1
`deviates from the shape of the reflector elements 4c, 4d so
`that the light rays of the light source 3 oriented to the
`reflector regions 2a, 2b are reflected in the screening device
`by the reflector elements 4c, 4d in another
`reflection
`direction, as shown in FIG. 3 by solid lines illustrating the
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`course of rays. The light rays in the screening position are
`reflected by the reflector elements 4c, 4d for optimization of
`the light distribution, directly or indirectly via the upper and
`lower reflector regions 2c, 2a’ in a predetermined direction
`onto the roadway in front of the vehicle.
`The control unit processes vehicle sensor signals, deter-
`mines from them the vehicle situation, and controls the
`screening device 4 correspondingly. By adjusting the screen-
`ing device 4, the side dissipation or the pre-field dispersion
`can be steplessly varied.
`While the invention has been illustrated and described as
`
`embodied in headlight arrangement for motor vehicle, it is
`not intended to be limited to the details shown, since various
`modifications and structural changes may be made without
`departing in any way from the spirit of the present invention.
`Without further analysis, the foregoing will so fully reveal
`the gist of the present invention that others can, by applying
`current knowledge, readily adapt it for various applications
`without omitting features that, from the standpoint of prior
`art, fairly constitute essential characteristics of the generic or
`specific aspects of this invention.
`What is claimed as new and desired to be protected by
`Letters Patent is set forth in the appended claims.
`What is claimed is:
`
`1. A headlight arrangement of a vehicle, comprising a
`reflector subdivided into a plurality of reflector regions; a
`light source arranged in a region of an apex of said reflector
`so that a light emitted by a light source is reflected by said
`reflector onto a roadway in front of the vehicle; at least one
`screening device associated with at least one of said reflector
`regions, said screening device being adjustable between a
`pass-through position in which the light emitted by said light
`source can reach a selected one of said reflector regions, and
`a screening position in which a light emitted by said light
`source is at
`least partially screened from reaching the
`selected one of said reflector regions; and a control unit
`which controls said screening device in dependence on
`vehicle sensor signals and adjusts said screening device
`between said pass-through position and said screening posi-
`tion in any vehicle situation with in a given lighting function
`to provide an optimal light distribution.
`2. A headlight arrangement of a vehicle as defined in
`claim 1, wherein said screening device is formed so that in
`its screening-position it screens substantially the whole
`selected reflector region.
`3. A headlight arrangement of a vehicle as defined in
`claim 1, wherein said screening device is formed as at least
`one substantially light-impermeable screens.
`4. A headlight arrangement of a vehicle as defined in
`claim 3, wherein said screens is displaceable parallel to an
`optical axis of the headlight arrangement.
`5. A headlight arrangement of a vehicle as defined in
`claim 3, wherein said screen is turnable about an optical axis
`of the headlight arrangement.
`6. A headlight arrangement of a vehicle as defined in
`claim 3, wherein said screen is turnable about an axis
`extending parallel to an optical axis of the headlight arrange-
`ment.
`
`7. A headlight arrangement of a vehicle as defined in
`claim 3, wherein said screen has a contour corresponding to
`a geometry of the selected reflector region, so that at least a
`certain part of the selected reflector region is covered by said
`screen in its screening position.
`8. A headlight arrangement of a vehicle as defined in
`claim 7, wherein the whole selected reflector region is
`substantially covered by said screen in its screening posi-
`tion.
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`7
`9. A headlight arrangement of a Vehicle as defined in
`claim 1, wherein said screening device is formed as at least
`one reflecting reflector element.
`10. A headlight arrangement of a Vehicle as defined in
`claim 9, wherein said reflector element is turnable about an
`optical axis of the headlight arrangement.
`11. A headlight arrangement of a Vehicle as defined in
`claim 9, wherein said reflector element is tumable about an
`axis extending parallel to an optical axis of the headlight
`arrangement.
`12. A headlight arrangement of a Vehicle as defined in
`claim 11, wherein said reflector element in its pass-through
`position is arranged if front of at least one further reflector
`region, said reflector element being also formed so that in its
`screening position it is arranged in a direction of light rays
`emitted by said light source in front of said selected reflector
`region, and light rays oriented to said selected reflector
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`8
`region for optimization of a light distribution on the roadway
`in front of the Vehicle are reflected by the at least one further
`reflector region onto the roadway in front of the Vehicle.
`13. A headlight arrangement of a Vehicle as defined in
`claim 12, wherein said reflector element is formed so that the
`light oriented on said selected reflector region is directly
`reflected onto the roadway in front of the Vehicle.
`14. A headlight arrangement of a Vehicle as defined in
`claim 12, wherein said reflector element is formed so that the
`light oriented on said selected reflector region is indirectly
`reflected by the at least one further reflector region on the
`roadway in front of the Vehicle.
`15. A headlight arrangement of a Vehicle as defined in
`claim 1, wherein said light source is formed as a gas
`discharge lamp.
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