United States Patent (19)
`LOpez et al.
`
`54). APPARATUS FOR REGULATING THE
`ILLUMINATION FIELD OF A VEHICLE
`HEADLIGHT
`
`75 Inventors: Eladio Lopez, La Croix Sur Lutry;
`Dominique Marchal, Vallorbe;
`Philippe Schweizer, Lonay, all of
`Switzerland
`
`73 Assignee: Robert Bosch GmbH, Stuttgart,
`Germany
`This patent is subject to a terminal dis-
`laimer.
`CaC
`
`Notice:
`
`*
`
`21 Appl. No.: 09/020,009
`22 Filed:
`Feb. 6, 1998
`O
`O
`Foreign Application Priority Data
`30
`Feb. 6, 1997 DEI Germany ........................... 197 04 427
`7
`51 Int. Cl." ....................................................... B60Q 1/06
`52 U.S. Cl. ................................................. 315/82; 362/71
`58 Field of Search .................................. 315/82, 76, 77;
`362/66, 71
`
`56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`US006144159A
`Patent Number:
`11
`(45) Date of Patent:
`
`6,144,159
`*Nov. 7, 2000
`
`7/1987 Fukuda et al. .......................... 356/121
`4.679,935
`5,193,894 3/1993 Lietar et al. .............................. 362/66
`5,633,710 5/1997 Kumra et al. ...................... 356/139.08
`FOREIGN PATENT DOCUMENTS
`0 186571 7/1986 European Pat. Off..
`O 505 237 9/1992 European Pat. Off..
`43 41 409 6/1995 Germany.
`43 41 409 A1 6/1995 Germany.
`Primary Examiner David Vu
`Attorney, Agent, or Firm Michael J. Striker
`57
`ABSTRACT
`A headlight illumination field regulating apparatus includes
`an electromagnetic radiation emitter, a reflected radiation
`Sensor, an evaluation unit, and a unit for adjusting the
`alignment position of the headlights. The electromagnetic
`radiation emitter operates to radiate electromagnetic radia
`tion on the road to the front of the automobile and the
`reflected radiation Sensor Senses reflected radiation and
`creates a data point representative of the irradiated Spot. The
`evaluation unit evaluates the data points to establish the
`position of the detected Spot or area and thereafter compares
`the evaluated position with a predetermined desired position
`and Subsequently generate a correction Signal to control the
`regulation or adjustment of the headlights into a proper light
`projecting orientation which ensures a proper projection
`limit of the beam of the headlight.
`
`4,620,267 10/1986 Cibie ......................................... 362/71
`
`12 Claims, 6 Drawing Sheets
`
`
`
`
`
`VWGoA EX1010
`U.S. Patent No. 9,955,551
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`

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`U.S. Patent
`U.S. Patent
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`6,144,159
`6,144,159
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`Nov.7, 2000
`Nov. 7, 2000
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`Sheet 1 of6
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`U.S. Patent
`U.S. Patent
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`Nov.7, 2000
`Nov. 7, 2000
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`A/G 3
`FIG. 3
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`20 10
`2O 1 O
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`U.S. Patent
`U.S. Patent
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`6,144,159
`6,144,159
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`Nov.7, 2000
`Nov. 7, 2000
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`Sheet 3 of6
`Sheet 3 of 6
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`U.S. Patent
`U.S. Patent
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`Nov.7, 2000
`Nov. 7, 2000
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`Sheet 4 of6
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`6,144,159
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`U.S. Patent
`U.S. Patent
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`Nov.7, 2000
`Nov. 7, 2000
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`Sheet 5 of6
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`A/G.6A
`FIG. 66
`y e10 124
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`"| ©10 yo4
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`U.S. Patent
`U.S. Patent
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`Ae = eO - e1 O
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`Nov.7, 2000
`Nov. 7, 2000
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`Sheet 6 of6
`Sheet 6 of 6
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`A/G. 3A)
`FIG.8b
`y e10 124
`y
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`E10 194
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`1
`APPARATUS FOR REGULATING THE
`ILLUMINATION FELD OF A VEHICLE
`HEADLIGHT
`
`The present invention relates to an apparatus for regul
`lating the illumination field of a vehicle headlight.
`BACKGROUND OF THE INVENTION
`German patent document DE 43 41 409 Al discloses a
`headlight illumination field regulating apparatus having an
`electromagnetic radiation emitter, a reflected radiation
`Sensor, an evaluation unit, and a unit for adjusting the
`alignment position of the headlights. The electromagnetic
`radiation emitter operates to radiate electromagnetic radia
`tion on the road to the front of the automobile and the
`reflected radiation Sensor Senses reflected radiation and
`creates a data point representative of the irradiated Spot.
`The evaluation unit evaluates the data points to establish
`the position of the detected Spot or area and thereafter
`compares the evaluated position with a predetermined
`desired position and Subsequently generate a correction
`Signal to control the regulation or adjustment of the head
`lights into a proper light projecting orientation which
`ensures a proper projection limit of the beam of the head
`light.
`In the event that the inclination of the vehicle in the fore
`and aft direction-namely, relative to its direction of travel
`changes, this disclosed regulating apparatus can accommo
`date Such inclinations and control the orientation of the
`headlights to maintain the proper projection limit of their
`beams. However, imprecision in the regulation of the head
`lights can arise from the circumstance that the projection
`limit of the headlight beam is influenced by changes in the
`height of the vehicle as well as by changes in its inclination.
`This imprecision is magnified the Smaller the projection
`limits of the headlight beam.
`SUMMARY OF THE INVENTION
`The present invention provides a headlight illumination
`field regulating apparatus which accommodates changes in
`the height of the vehicle as well as by changes in its
`inclination. According to one aspect of the present invention,
`there is provided an apparatus for regulating the illumination
`field of a running light of a vehicle, the running light being
`of the type for illuminating a region forward of the vehicle
`relative to the vehicle's direction of travel and the vehicle
`being of the type having an adjusting element for adjusting
`the orientation of the running light to thereby vary the
`position of the illumination field relative to the vehicle. The
`apparatus includes a member for irradiating an area on the
`road Surface with a radiation beam in a manner in which at
`least Some of the radiation beam is reflected. The apparatus
`also includes a Sensor for Sensing a characteristic of radia
`tion reflected from the irradiated area on the road Surface.
`The apparatus further includes a member for comparing a
`Sensed reflected radiation characteristic with a radiation
`characteristic representative of a predetermined position of
`the illumination field of the running light. The comparing
`member is operatively connected with the adjusting element
`for providing a Signal thereto in response to which the
`adjusting element can adjust the orientation of the running
`light on the vehicle and thereby reorient the running light
`into a position in which its illumination field is as desired.
`Also, the comparing member includes means for creating a
`data point which is representative of the Sensed reflected
`radiation characteristic and means for evaluating a charac
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`teristic of the data point with respect to a reference data point
`to determine the Signal provided to the adjusting element
`and the reference data point is representative of the position
`of the Sensor.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a perspective view of a vehicle having one
`embodiment of the headlight illumination field regulating
`apparatus of the present invention and Schematically show
`ing a coordinate reference System to facilitate an understand
`ing of the apparatus and its operation;
`FIG. 2 is a simplified Schematic view of a data processing
`unit of the apparatus shown in Figure and showing, in a
`Cartesian reference grid graphic, the output of the data
`processing unit;
`FIG. 3 is a side elevational view of a front portion of the
`vehicle shown in FIG. 1 and showing, in partial vertical
`Section, a Signal Sending unit of the apparatus and a head
`light to which the apparatus is operatively connected;
`FIG. 4 is a perspective view of a vehicle having another
`embodiment of the headlight illumination field regulating
`apparatus of the present invention and Schematically show
`ing a coordinate reference System to facilitate an understand
`ing of the apparatus and its operation;
`FIG. 5 is a simplified Schematic view of a data processing
`unit of the apparatus shown in FIG. 4 and showing, in a
`cartesian reference grid graphic, the output of the data
`processing unit;
`FIG. 6 is a perspective view of a vehicle having a further
`embodiment of the headlight illumination field regulating
`apparatus of the present invention and Schematically show
`ing a coordinate reference system to facilitate an understand
`ing of the apparatus and its operation;
`FIG. 7 is a simplified Schematic view of a data processing
`unit of the apparatus shown in FIG. 6 and showing, in a
`Cartesian reference grid graphic, the output of the data
`processing unit;
`FIG. 8 is a perspective view of a vehicle having an
`additional embodiment of the headlight illumination field
`regulating apparatus of the present invention and Schemati
`cally showing a coordinate reference System to facilitate an
`understanding of the apparatus and its operation; and
`FIG. 9 is a simplified schematic view of a data processing
`unit of the apparatus shown in FIG. 8 and showing, in a
`cartesian reference grid graphic, the output of the data
`processing unit.
`DESCRIPTION OF PREFERRED
`EMBODIMENTS
`AS Seen in FIG. 1, a vehicle Schematically represented as
`an automobile is traveling on a road Surface road 14 and the
`automobile has a pair of headlights 10, 11 on its front end for
`illuminating a illumination field frontward of the automo
`bile. The headlights 10, 11 can be of the type for producing
`a blended light exclusively or, alternatively, of the type for
`producing both a blended light and a far distance illuminat
`ing beam. AS another alternative, the headlight 10, 11 can be
`of the type for producing light beams of the type considered
`Suitable for fog conditions.
`In the event that the headlights 10, 11 are of the type for
`producing a blended light beam, a light beam 12 is projected
`by each headlight 10, 11 capable of illuminating a region
`frontward of the automobile including at least the road 14.
`The light beam 12 is shown in FIG. 1 schematically by
`Several lines indicating a light beam having equal intensity
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`3
`acroSS its area of projection. To prevent a blinding of a
`perSon in an oncoming vehicle, the light beams 12 each have
`an upper bright-dark border which acts to limit the forward
`most distance of projection of the light beam 12 to a
`predetermined spacing or projection limit L from the auto
`mobile. The L represents thus the projection limit of the
`headlights 10, 11. In the event of changing load character
`istics of the automobile or in the event of road and travel
`related conditions Such as, for example, braking and accel
`erating of the automobile or unevenness of the road Surface,
`corresponding changes in the tilt or inclination of the
`automobile in a front and rear manner produce correspond
`ing changes in the projection limit of the headlights 10, 11
`and the position of the bright-dark border changes. AS a
`result, either the frontward illuminated area frontward of the
`automobile is not Sufficiently illuminated, if the projection
`limit is too small, or a blinding or an oncoming driver can
`occur, if the projection limit is too large. In accordance with
`the present invention, an illumination field regulating appa
`ratus is provided to maintain the projection limit L at a
`constant value independent of the tilt or inclination charac
`teristic of the vehicle. The headlight illumination field
`regulating apparatus can be operatively coupled to the
`assembly which controls the operation of the headlights 10,
`11 So that the headlight illumination field regulating appa
`ratus is operated in conjunction with the operation of the
`headlights 10, 11 or, alternatively, the headlight illumination
`field regulating apparatus can be continuously operated
`during vehicle operation. The headlight illumination field
`regulating apparatus includes an electromagnetic radiation
`emitter, a reflected radiation Sensor, an evaluation unit, and
`a unit for adjusting the alignment position of the headlights
`10, 11 in response to information evaluated by the headlight
`illumination field regulating apparatus. The electromagnetic
`radiation emitter operates to radiate electromagnetic radia
`tion on the road 14 to the front of the automobile during
`operation of the headlight illumination field regulating appa
`ratus whereby the radiation can be comprised of visible light
`and another type or frequency of light Such as, for example,
`infrared or ultraviolet light. The radiation beam is focused to
`the extent possible So that only a relatively Small area on the
`road 14 to the front of the automobile such as, for example,
`a spot, is irradiated. The radiation contacting the irradiated
`Spot is to Some degree reflected from the road 14 and the
`reflected radiation Sensor Senses this reflected radiation and
`Stores or otherwise creates a data point representative of the
`irradiated Spot or area from which the detected, back
`reflected radiation has been Sensed. The evaluation unit can
`thus evaluate the data points So created by the reflected
`radiation Sensor to establish the position of the detected Spot
`or area and can thereafter compare the evaluated position
`with a predetermined desired position and Subsequently
`generate a correction signal to control the regulation or
`adjustment of the headlights 10, 11 into a proper light
`projecting orientation which ensures a proper projection
`limit L.
`FIGS. 1-3 illustrate one embodiment of the headlight
`illumination field regulating apparatus of the present inven
`tion. The electromagnetic radiation emitter of the headlight
`illumination field regulating apparatus includes two spaced
`apart radiation SenderS 20, 22 which are disposed on the
`front end of the automobile in Spaced apart relationship to
`one another relative to a transverse of a vertical longitudinal
`plane 13 of the automobile. The radiation emitters 20, 22
`each are disposed at a Spacing e3 from the Vertical longitu
`dinal plane 13 as measured perpendicularly thereto. It can be
`provided that at least one or both of the radiation emitters 20,
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`22 are integrated into the headlights 10, 11. Alternatively, it
`can be provided that at least one or both of the radiation
`emitters 20, 22 are arranged at a spacing from the headlights
`10, 11. Preferably, the radiation emitters 20, 22 are disposed
`adjacent the Side edges of the automobile So that the maxi
`mum spacing e3 can be achieved and integration of the
`radiation emitters 20, 22 into the headlights 10, 11 is
`feasible. Each of the radiation emitters 20, 22 sends out or
`radiates two focused radiation beams. The radiation beam
`pairs of each radiation emitters 20, 22 act to irradiate two
`spots or areas to be Sensed on the road 14, the two Spots or
`areas each being at a different distance or spacing from the
`automobile as measured relative the direction of travel 9 of
`the automobile parallel to the Vertical longitudinal plane 13.
`The radiation emitter 20, which is on the right side of the
`automobile as viewed in the direction of travel 9, acts to
`irradiate a spot 24 at a spacing d1 from the front of the
`automobile and a spot 25 at a spacing d2 from the front of
`the automobile. The radiation emitter 22, which is on the left
`side of the automobile as viewed in the direction of travel 9,
`acts to irradiate a spot 26 at a spacing d1 from the front of
`the automobile and a spot 27 at a spacing d2 from the front
`of the automobile. The spots 24, 26 are preferably at
`generally the same spacing d1 from the automobile while the
`spots 25, 27 are preferably at generally the same Spacing d2
`from the automobile.
`The radiation beams sent out by the radiation emitter 20
`travel in a common vertical plane vertical plane 28 while the
`radiation beams Sent out by the radiation emitter 22 travel in
`a common vertical plane 29. The vertical plane vertical
`planes 28, 29 can be arranged parallel to one another,
`arranged to converge toward one another in the direction of
`travel 9, or arranged to diverge from one another in the
`direction of travel 9. In the disposition of the headlight
`illumination field regulating apparatus shown in FIG. 1, the
`vertical plane vertical planes 28, 29 are disposed parallel to
`one another. The spots 24, 26 are located on the road 14 each
`at a spacing e2 from the vertical longitudinal plane 13 as
`measured perpendicularly thereto. The spots 25, 27 are
`located on the road 14 each at a Spacing e1 from the vertical
`longitudinal plane 13 as measured perpendicularly thereto.
`Due the parallel arrangement of the Vertical plane vertical
`planes 28, 29, in which the radiation beams travel, the
`spacings spacing e1 and e2 are of generally the same
`magnitude and, in any event, are at least the same approxi
`mate magnitude as the Spacing e3 of the individual radiation
`emitters 20, 22 on the automobile. The sensor assembly 30
`of the headlight illumination field regulating apparatus is
`disposed between the two radiation emitters 20, 22 on the
`front of the automobile. The sensor assembly 30 is oriented
`toward the road 14 at the front of the automobile and
`includes a data point creation optic guide 31 and a plurality
`of plotters 32 for plotting graphically or in another manner
`the reflected radiation from the irradiated Spots on the road
`14. The optic guide 31 is operable to guide the reflected
`radiation to the plotters 32 so that the plotters 32 can then
`create data points representative of the spots 24-27. In
`FIGS. 1 and 2, an arrangement of the plotters 32 is shown
`in which the plotters 32 are arranged in a matrix. The Sensor
`assembly 30 is, for example, in the form of a camera,
`especially a Video camera, and the plotters 32 can be in the
`form of a so-called CCD-matrix or Charge-Coupled-Device
`matrix. Alternatively, the plotters 32 can be in the form of
`photocells or photo diodes. Instead of a matrix arrangement,
`the plotters 32 can be linearly arranged.
`In the one embodiment of the headlight illumination field
`regulating apparatus as shown in FIG. 1, the Spots 24, 27 are
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`detected by the optic guide 31 and data points representative
`thereof are created by the plotters 32. The optical axis 33 of
`the sensor assembly 30 extends thus in a plane 34 which is
`at least generally parallel to the vertical planes 28, 29. The
`Spot 24 is represented as a data point in graphic form in the
`Sensor assembly 30 as a plotted point graphic data point 124,
`the Spot 25 is represented as a data point in graphic form in
`the sensor assembly 30 as a plotted point 125, the spot 26 is
`represented as a data point in graphic form in the Sensor
`assembly 30 as a plotted point data point 126, and the spot
`27 is represented as a data point in graphic form in the Sensor
`assembly 30 as a plotted data point 127. The matrix of the
`plotters 32 is comprised of a vertical axis Y and a horizontal
`axis X. The vertical axis Y represents thus the vertical axis
`of the automobile which lies in the vertical longitudinal
`plane 13 and the horizontal axis X represents a horizontal
`axis of the automobile which is perpendicular to the vertical
`longitudinal plane 13. A Spacing e20 extends between the
`graphic data point 124 and the data point 126 which repre
`Sent respectively the Spots 24, 26 and the Spacing e20 is
`representative of the Spacing e2 of the Spot spots 24, 25 on
`the road 14.
`A spacing e10 extends between the data points 125, 127
`which represent respectively the spots 25, 27 and spacing
`e10 is representative of the spacing e1 of the spots 25, 27 on
`the road 14. The Spacing e10 and Spacing e20 are parallel to
`an axis OX and are measured along that direction. If desired,
`the data point 126 can act as a reference position for the
`graphic data point 124, which lies at the Spacing e20 from
`this reference position. Conversely, the graphic data point
`124 can act as a reference position for the data point 126,
`which lies at the Spacing e20 from this reference position. In
`the same manner, the data point 127 can act as a reference
`position for the data point 125, which lies at the spacing e10
`from this reference position. Conversely, the data point 125
`can act as a reference position for the data point 127, which
`lies at the Spacing e10 from this reference position.
`AS Seen in FIG. 2, the headlight illumination field regul
`lating apparatus is shown in a simplified Schematic manner.
`The evaluation unit is designated as the evaluation unit 40.
`The radiation emitters 20, 22 are disposed in the headlights
`10, 11 and the sensor assembly 30 is disposed intermediate
`the radiation emitters 20, 22. The evaluation unit 40 is
`operatively connected to the sensor assembly 30 whereby
`the signal transceiver element 42 of the evaluation unit 40 is
`provided with Signals comprising information about the
`spacing e10 and the Spacing e20. The Signal transceiver
`element 42 receives a signal from the sensor assembly 30
`concerning the relationship between the Spacing e10 and the
`spacing e20, for example, in the form of a ratio q(spacing
`e10/spacing e20) which is the ratio of the magnitude of
`spacing e10 to the magnitude of spacing e20. The Signal
`transceiver element 42 in turn transmits a Signal represen
`tative of the ratio q to a comparator 43 which itself Stores a
`predetermined desired ratio qO or is provided with this
`desired ratio data from the Signal transceiver element 42.
`The comparator 43 compares the instantaneous ratio q with
`the ratio qO (spacing e10/spacing e20) and determines a
`difference q. The determined q is Sent as an output of the
`comparator 43 to a control element 44 and the headlight
`adjustment control element 44, if the q is not Zero, controls
`the headlight position adjuster 18 to accordingly adjust the
`orientation of the headlights 10, 11.
`The ratio qO (spacing e10/spacing e20) applied by the
`comparator 43 is a ratio of the spacing e10 and the Spacing
`e20 in a correct adjustment position of the projection limit
`Lof the headlight 10. In the event that the spacing e1 and e2
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`of the spots 24-27 on the road 14 are represented as the
`spacing e10 and spacing e20 in the sensor assembly 30 and
`the ratio q (spacing e10/spacing e20) transmitted by the
`Signal transceiver element 42 to the comparator 43 is the
`Same as qO, the q in this event is Zero and no adjustment of
`the headlights 10, 11 need be undertaken by the headlight
`position adjuster 18. However, in the event that a change in
`the inclination of the automobile causes the actual position
`of the projection limit L to vary from its correct position, the
`spots 24-27 on the road 14 assume different positions on the
`road 14 than the Spacing d1 and spacing d2 of the correct
`position of the projection limit L. In this event, the Spots
`24-27 are represented differently in the sensor assembly 30
`than they are represented in a correct positioning of the
`projection limit L and, correspondingly, the graphic data
`point 124 and graphic data point 127 of the spots 24-27 in
`the sensor assembly 30 assume different positions as well
`and correspondingly different spacing e10 and spacing e20
`are produced. The Signal transceiver element 42 in this event
`creates a signal for the ratio q (spacing e10/spacing e20) and
`a signal is created in the comparator 43 representing the q
`which in this instance is a value other than Zero. In depen
`dence on this signal created by the comparator 43, the
`headlight adjustment control element 44 responds to control
`the headlight position adjuster 18 to So adjust the headlights
`10, 11 until the q achieves a value of Zero. In this event, the
`radiation emitters 20, 22 and, preferably, the Sensor assem
`bly 30 also, are synchronously adjusted with the adjustment
`of the headlights 10, 11 and this can be accomplished by an
`additional adjustment element or by the integration of the
`radiation emitters 20, 22 into the headlights 10, 11 whose
`adjustment is controlled by the headlight position adjuster
`18. The precision of the headlight illumination field regu
`lating apparatus is dependent among other things on the
`magnitude of the ratio q (spacing e10/spacing e20). It can be
`provided, for example, that qO is at a value of 0.5 in the
`correct position of the projection limit L whereby the
`spacing e20 is approximately double the value of the spacing
`e10 and correspondingly the spacing d2 of the spots 25, 27
`is approximately double the value of the Spacing d1 of the
`spots 24, 26. The Spacing d1 and Spacing d2 can amount to
`between several meters up to about 40 meters. For example,
`the Spacing d1 can range between about 2 meters and 5
`meters and the Spacing d2 can range between 4 meters and
`about 10 meters.
`AS seen in FIG. 3, the front end of the automobile is
`shown in a simplified Schematic view with a partial vertical
`sectional view to permit the headlight 10 and the radiation
`emitter 20 to be viewed. In the event of a change in the
`inclination of the automobile, an inclination angle t with
`respect to a horizontal axis H is created and, as well, a
`change h in the height h of the installed position of the
`headlight 10 and the radiation emitter 20 on the automobile
`is created. The h effects a change in the representative
`positions of the spots 24-27 in the sensor assembly 30
`although it is desired that this change not influence the
`projection limit L. Different spacing e10 and spacing e20 of
`the graphic data point 124 and graphic data point 127 are
`created in dependence on the existence and magnitude of the
`h. However, the creation of the ratio q (spacing e10/spacing
`e20) of the spacing e10 and the spacing e20 eliminates the
`undesired influence of the h So that the ratio q (spacing
`e10/spacing e20) is only dependent upon the change in the
`inclination angle t.
`In FIG. 4, an automobile is shown having another
`embodiment of the headlight illumination field regulating
`apparatus of the present invention. The same or Similar
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`components of the headlight illumination field regulating
`apparatus are provided on this embodiment as have been
`described with respect to the one embodiment shown in FIG.
`1 with several variations. Namely, the headlight illumination
`field regulating apparatus shown in FIG. 4 has only a single
`radiation emitter 20 which can be mounted, for example, in
`the headlight 10 which is on the right side of the automobile
`as viewed in the direction of travel 9. The radiation emitter
`20 radiates two radiation beams which irradiate the spot 24
`and 25 on the road 14. The sensor assembly 30 is installed
`in the headlight 11 on the left side of the automobile as
`viewed in the direction of travel 9 and the optical axis 33 of
`the sensor assembly 30 is in a plane 34 extending parallel to
`the Vertical longitudinal plane 13 and parallel to the vertical
`plane 28 in which the radiation beams radiated by the
`radiation emitter 20 travel. The spot 24 is at a spacing d1
`from the automobile and the Spot 25 is at a spacing d2. AS
`shown in FIGS. 4 and 5, the spot 24 is represented in the
`sensor assembly 30 as the graphic data point 124 and the
`spot 25 is represented as the data point 125.
`If an additional electromagnetic radiation emitter were to
`be installed in the headlight 11, the representative graphic
`data point 124 and 125 of the spots irradiated by this
`additional electromagnetic radiation emitter would be cre
`ated in the Sensor assembly 30 and these graphic data point
`124 and 125 would assume different positions along the
`vertical axis OY of the matrix of the 32 in correspondence
`with the respective spacings of the represented irradiated
`spots from the automobile. However, these graphic data
`point 124 and 125 would always maintain the same distance
`from the vertical axis OY as viewed with respect to the axis
`OX. The spots can be arranged to lie on the vertical axis OY
`by undertaking corresponding disposition of the Sensor
`assembly 30 such that its optical axis 33 lies in the plane in
`which the radiation beams of the additional electromagnetic
`radiation emitter travel. For this reason, the need for an
`additional electromagnetic radiation emitter in the headlight
`11 can be eliminated as, instead, as seen in FIG. 5, the
`graphic data point 124 and 125 representing the respective
`spacing e10 and spacing e20 of the spot 24 and 25 need only
`be evaluated with respect to the vertical axis OY in the
`direction of the horizontal axis OX. The spacing e10 and
`spacing e20 are thus representative of the Spacing e1 and e2
`of the spot 24 and 25 on the road 14 from the intersecting
`line 35 representing the trace of the optical axis 33 of the
`sensor assembly 30 on the road 14. The vertical axis OY thus
`forms a virtual reference position for the graphic data point
`124 and 125 which have the spacing e20 and spacing e10,
`respectively, from this reference position. The reference
`position in the form of the vertical axis OY for the graphic
`data point 124 and 125 is thus predetermined in the sensor
`assembly 30. In dependence upon the Spacing d1 and
`spacing d2, the Spot 24 and 25 are represented in the Sensor
`assembly 30 in differing positions and the spacing e20 and
`spacing e10 corresponding to these differing positions can
`55
`be evaluated with respect to the vertical axis OY as mea
`sured along the horizontal axis OX in the matrix of the 32.
`The signal transceiver element 42 of the evaluation unit 40,
`as Seen in FIG. 5, receives Signals concerning the Spacing
`e10 and spacing e20 and a signal for the ratio q (spacing
`e10/spacing e20) is created and transmitted to the compara
`tor 43. The comparator 43 compares the desired qO with the
`instantaneous q and transmits a Signal to the headlight
`adjustment control element 44 which, in turn, controls the
`headlight position adjuster 18 to adjust the headlights 10, 11
`in the q is not zero. The radiation emitter 20 and the sensor
`assembly 30 are preferably adjusted by this Same Sequence.
`
`8
`The another embodiment of the headlight illumination
`field regulating apparatus shown in FIG. 4 provides the ratio
`q (spacing e10/spacing e20); however, no information is
`provided concerning the adjustment of the headlight 11 in
`which the sensor assembly 30 is mounted. It can be assumed
`that the headlight 10 in which is mounted the radiation
`emitter 20 and the headlight 11 in which the sensor assembly
`30 is mounted are so adjusted that the headlights 10, 11
`project their light beams to the correct projection limit L.
`However, during the life of the automobile, the headlight 11
`may take on a different inclination than the headlight 10. In
`this event, the graphic data point 124 and 125 in the sensor
`assembly 30 have different positions in the vertical
`direction-that is, in the direction of vertical axis OY. The
`inclination angle change of the headlight 11 with respect to
`the headlight 10 is relatively small and can be approximated
`by the equation:
`
`in which Py is the extension of an element 32 of the sensor
`assembly 30 in the direction of vertical axis OY, DY is the
`change in the position of the graphic data point 124, 125 in
`the direction of vertical axis OY and f is the illumination
`width of the optic guide 31 of the sensor assembly 30. A
`change in the inclination angle in the Sense that the headlight
`11 is tilted relatively more severely downward results in the
`graphic data point 124,125 being plotted relatively higher in
`the direction of vertical axis OY, whereby the position shift
`or change DY is a negative value. Conversely, a change in
`the inclination angle in the Sense that the headlight 11 is
`tilted relatively less severely downward results in the
`graphic data point 124, 125 being plotted relatively lower in
`the direction of vertical axis OY, whereby the change DY is
`a positive value. The evaluation unit 40 is operable to
`transmit a signal concerning the change DY, whereby either
`continuously or intermittently a Synchronization of the
`adjusting of the inclination of the two headlights 10, 11 can
`be undertaken, with the value of the change DY being taken
`into account and the headlight position adjuster 18 of the
`headlight 11 So adjusting the position of the headlight 11 to
`reduce the value of the change DY to Zero.
`In FIG. 6, an automobile is shown having a further
`embodiment of the headlight illumination field regulating
`apparatus of the present invention. The same or Similar
`compone