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`SAE TECHNICAL
`PAPER SERIES
`
`970644
`
`Adaptive Light Pattern - A New Way
`to Improve Light Quality
`
`Henning Hogrefe and Rainer Neumann
`Robert Bosch Corp.
`
`Reprinted from: New Concepts in International Automotive Lighting Technology
`(SP-1249)
`
`~A II/!!! The Engineering Society
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`ISSN0148-7191
`ISSN0148-7191
`Copyright 1997 SocietyofAutomotiveEngineers, Inc.
`Copyright1997 Society of Automotive Engineers, Inc.
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`970644
`970644
`Adaptive Light Pattern - A New Way
`Adaptive Light Pattern - A New Way
`to Improve Light Quality
`to Improve Light Quality
`Henning Hogrefe and Rainer Neumann
`Henning Hogrefe and Rainer Neumann
`Robert Bosch Corp.
`Robert Bosch Corp.
`
`Copyright 1997 Society of Automotive Engineers, Inc
`Copyright 1997 Society of Automotive Engineers, inc
`
`ABSTRACT
`ABSTRACT
`
`In most cases of night
`time driving the low
`In most cases of night time driving the low
`beam light function is used for the road illumination
`beam light function is used for the road illumination
`in front of the car. This conventional
`low beam
`in front of the car. This conventional low beam
`function has a constant
`light pattern: no matter
`function has a constant light pattern: no matter
`whether the driver is actually driving on a straight
`whether the driver is actually driving on a straight
`or curvy road, whether the road is wet or dry,
`or curvy road, whether the road is wet or dry,
`always the same beam pattern is applied. Test
`always the same beam pattern is applied. Test
`experiences of
`the last years prove that a
`experiences of
`the
`last years prove
`that a
`headlamp with an adaptive light pattern" having
`headlamp with an ,,adaptive light pattern" having
`different optimum light pattern adapted to different
`different optimum light pattern adapted to different
`driving situations should give a better illumination
`driving situations should give a better illumination
`than the conventional constant
`low beam pattern
`than the conventional constant low beam pattern
`which can only be a compromise.
`which can only be a compromise.
`In this paper an outline of the basic idea of the
`In this paper an outline of the basic idea of the
` adaptive light pattern" is given. Different driving
`,,adaptive light pattern" is given. Different driving
`situations and their corresponding optimum light
`situations and their corresponding optimum light
`pattern, basic technical concepts and the legal
`pattern, basic technical concepts and the legal
`situation regarding homologation of
`such an
`situation
`regarding homologation of such an
`advanced lighting system will be discussed.
`advanced lighting system will be discussed.
`
`INTRODUCTION
`INTRODUCTION
`
`Automotive headlamps provide for each of
`the
`Automotive headlamps provide for each of the
`basic light functions (low beam, high beam and fog
`basic light functions (low beam, high beam and fog
`beam) a fixed static light pattern. Some thirty years
`beam) a fixed static light pattern. Some thirty years
`ago 200-300 lumen were a good total
`luminous
`ago 200-300 lumen were a good total luminous
`flux for a low beam headlamp. This amount of light
`flux for a low beam headlamp. This amount of light
`was at best enough to
`illuminate the most
`was at best enough
`to
`:i:::n:ir:ate
`the most
`important parts of the driver's night time viewing
`important parts of the driver's night time viewing
`zone.
`zone.
`All lighting regulations and techniques were set up
`All lighting regulations and techniques were set up
`to ensure a minimum light quality using available
`to ensure a minimum light quality using available
`light sources.
`light sources.
`
`The introduction of halogen bulbs around 1965
`The introduction of halogen bulbs around 1965
`greatly improved the light quality.
`In the eighties
`greatly improved the light quality. In the eighties
`two-reflector-headlamps for separate low and high
`two-reflector-headlamps for separate low and high
`beam and advanced reflector technologies further
`beam and advanced reflector technologies further
`increased the amount of
`light available for
`the
`increased the amount of light available for the
`street illumination.
`street illumination.
`Now, a low beam light volume of 500 lumen and
`Now, a low beam light volume of 500 lumen and
`more can be achieved using halogen bulbs in
`more can be achieved using halogen bulbs in
`combination with advanced reflector techniques or
`combination with advanced reflector techniques or
`even 1000 lumen using gas discharge lamps
`even 1000 lumen using gas discharge lamps
`(HID). Having reached this
`state of
`lighting
`(HID). Having
`reached
`this state of
`lighting
`performance the question arises, in which direction
`performance the question arises, in which direction
`further development should be continued. Shall we
`further development should be continued. Shall we
`add, as in the past, more and more light
`-
`if
`add, as in the past, more and more light -
`if
`technically available - into the static light pattern
`technically available - into the static light pattern
`giving more and more intense illumination in the
`giving more and more intense illumination in the
`hot spot or broader side illumination? Recent HID
`hot spot or broader side illumination? Recent HID(cid:173)
`light pattern applications have shown very good
`light pattern applications have shown very good
`results on this way (Ref. 1, 2).
`results on this way (Ref. 1, 2).
`Another very promising alternative is to direct the
`Another very promising alternative is to direct the
`available light dynamically into the direction where
`available light dynamically into the direction where
`it is actually needed. Why illuminating the hot spot
`it is actually needed. Why illuminating the hot spot
`with full power while driving with low speed on a
`with full power while driving with low speed on a
`windy road? Why wasting many lumen on large
`windy road? Why wasting many lumen on large
`lateral side illumination while driving with high
`lateral side illumination while driving with high
`speed on a straight highway? Hence, the idea is to
`speed on a straight highway? Hence, the idea is to
`have a dynamic or Adaptive Light Pattern" (ALP)
`have a dynamic or ,,Adaptive Light Pattern" (ALP)
`which always supplies an adapted, optimal
`light
`which always supplies an adapted, optimal light
`performance for the actual driving situation.
`performance for the actual driving situation.
`The legal regulations are not yet completely ready
`The legal regulations are not yet completely ready
`for this innovative concept but the technique is
`for this innovative concept but the technique is
`now under full development. The ALP topic can
`now under full development. The ALP topic can
`cover a wide range of lighting aspects. We want to
`cover a wide range of lighting aspects. We want to
`concentrate here mostly on the main headlamp
`concentrate here mostly on the main headlamp
`functions, especially the low beam, because there
`functions, especially the low beam, because there
`seems to be the highest potential for improvement
`seems to be the highest potential for improvement
`of night time traffic safety.
`of night time traffic safety.
`
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`
`ALP - AN INNOVATIVE LIGHTING CONCEPT
`ALP - AN INNOVATIVE LIGHTING CONCEPT
`
`time driving the automotive
`During night
`time driving
`the automotive
`During night
`lighting equipment
`is responsible for illuminating
`lighting equipment is responsible for illuminating
`the driver's viewing field under many different
`the driver's viewing field under many different
`driving situations, street and traffic conditions. The
`driving situations, street and traffic conditions. The
`following parameters characterize most of these
`following parameters characterize most of these
`situations:
`situations:
`
`low - medium - high
`- Speed:
`dry -wet - slippery
`- Road condition:
`straight - curvy - intersection ...
`-Course of the road:
`flat - hilly
`- Road topography:
`highway -country - city ...
`- Road type:
`-Viewing conditions: clear - rain -fog -snow
`- Ambient illumination: dark - street lights ...
`- Traffic density:
`low - medium - high
`- Driver:
`age - driving skills ...
`- Other parameters:
`country, tunnel. ..
`
`At the same time the car must be visible to
`At the same time the car must be visible to
`other traffic members without causing glare or
`other traffic members without causing glare or
`other irritations. Regarding this complex task the
`other irritations. Regarding this complex task the
`conventional static headlamp light pattern can
`conventional static headlamp light pattern can
`only be a compromise. Usually most of the flux
`only be a compromise. Usually most of the flux
`available for static illumination is directed to the
`available for static illumination is directed to the
`central parts of the viewing zone including the
`central parts of the viewing zone including the
`range zone of the low or high beam (approx. ± 5"
`(approx. ± 5"
`range zone of the low or high beam
`hor./vert. of driving direction).
`In this zone we
`hor./vert. of driving direction). In this zone we
`certainly have the highest demand for good
`certainly have the highest demand for good
`illumination and therefore also the highest
`illumination and
`therefore also
`the highest
`requirements by current ECE and SAE standards.
`requirements by current ECE and SAE standards.
`The rest of the available static beam flux is more
`The rest of the available static beam flux is more
`or less scattered to the left and right sides of the
`or less scattered to the left and right sides of the
`viewing zone. This light pattern is a compromise in
`viewing zone. This light pattern is a compromise in
`the sense that it fairly covers the most important
`the sense that it fairly covers the most important
`viewing zones but only to some extent the special
`viewing zones but only to some extent the special
`zones needed for example for curve illumination,
`zones needed for example for curve illumination,
`fog conditions, etc. This compromise is only for
`fog conditions, etc. This compromise is only for
`those headlamps a very good overall solution that
`those headlamps a very good overall solution that
`have a total flux almost as high as in the case of
`have a total flux almost as high as in the case of
`HID headlamps. But the general idea - even for
`HID headlamps. But the general idea - even for
`high flux systems -
`is, that light (e.g. foreground
`high flux systems - is, that light (e.g. foreground
`illumination), which is beneficial in the static beam
`illumination), which is beneficial in the static beam
`pattern under normal driving conditions is most
`pattern under normal driving conditions is most
`likely undesirable in some other situations (e.g.
`likely undesirable in some other situations (e.g.
`wet roads).
`wet roads).
`These basic considerations about the static and
`These basic considerations about the static and
`dynamic light pattern seem to be obvious but they
`dynamic light pattern seem to be obvious but they
`have to be verified by scientific investigations.The
`have to be verified by scientific investigations. The
`
`goal
`is to evaluate the potential benefits of a
`goal is to evaluate the potential benefits of a
`dynamic or adaptive light pattern compared to the
`dynamic or adaptive light pattern compared to the
`conventional static light pattern.
`Independent
`conventional static
`light pattern.
`Independent
`from basic research, a few technical realizations
`from basic research, a few technical realizations
`using rotatable reflectors have been presented
`using rotatable reflectors have been presented
`years ago (e.g. Ref. 3, 4). First internal field tests
`years ago (e.g. Ref. 3, 4). First internal field tests
`and other investigations (Ref. 5, 6, 7) now prove
`and other investigations (Ref. 5, 6, 7) now prove
`that
`for most of
`the above mentioned driving
`that for most of the above mentioned driving
`situations different
`light pattern must be required
`situations different light pattern must be required
`to obtain an optimal illumination.
`to obtain an optimal illumination.
`The finding is,
`that no static light pattern, even
`The finding is, that no static light pattern, even
`the sum of all
`individual
`light pattern, can deliver
`the sum of all individual light pattern, can deliver
`the overall optimal headlamp beam pattern. The
`the overall optimal headlamp beam pattern. The
`philosophy of
` Adaptive Light Pattern"
`can
`philosophy of
`,,Adaptive Light Pattern" can
`achieve this goal by means of detection of the
`achieve this goal by means of detection of the
`actual driving condition and subsequent switching
`actual driving condition and subsequent switching
`to the well-adapted light pattern.
`to the well-adapted light pattern.
`The European ECE regulations do not yet allow
`The European ECE regulations do not yet allow
`the realization of
`the ALP concept. Both,
`the
`the realization of the ALP concept. Both, the
`application of multiple
`light sources
`in one
`application of multiple
`light sources
`in one
`headlamp and moving beams are considered as
`headlamp and moving beams are considered as
`important technical realization possibilities for ALP
`important technical realization possibilities for ALP
`as wili be pointed oui in ine nexi seciion. But it is
`as wili be pointed oui in ine nexi seciion. But it is
`neither permitted to use more than 1
`light source
`neither permitted to use more than 1 light source
`for the low beam function within one headlamp
`for the low beam function within one headlamp
`(and more than 2 light sources each for high beam
`(and more than 2 light sources each for high beam
`and fog beam) nor is it generally allowed to apply
`and fog beam) nor is it generally allowed to apply
`a movable or rotatable reflector.
`a movable or rotatable reflector.
`There is an exception of
`this practice:
`an
`There
`is an exception of
`this practice: an
`additional
`secondary
`high
`beam may
`be
`additional secondary high beam may be
`horizontally rotatable. Reflector parts may also be
`horizontally rotatable. Reflector parts may also be
`movable as long as their optical axis is not moved.
`movable as long as their optical axis is not moved.
`Also,
`it is not explicitly forbidden to have adaptive
`Also, it is not explicitly forbidden to have adaptive
`low, high or fog beam if the adapted light pattern
`low, high or fog beam if the adapted light pattern
`always fulfills the current regulation.
`always fulfills the current regulation.
`A European EUREKA project
`called AFS
`A European EUREKA project called AFS
`(Advanced Frontlighting Systems) with all major
`(Advanced Frontlighting Systems) with all major
`European
`bulb,
`headlamp
`and
`vehicle
`European
`bulb,
`and
`vehicle
`headlamp
`manufacturers participating (Ref. 8) has been
`manufacturers participating (Ref. 8) has been
`established to make studies and proposals for
`established to make studies and proposals for
`new regulations
`to
`overcome
`the
`current
`new
`regulations
`to overcome
`the current
`restrictive ECE homologation practice.
`In the
`restrictive ECE homologation practice.
`In the
`second phase the AFS working group is now
`second phase the AFS working group is now
`testing the basics and limits of adaptive lighting in
`testing the basics and limits of adaptive lighting in
`order to propose new regulations in the
`third
`order to propose new regulations in the
`third
`phase.
`phase.
`The US Federal Register, Part 571 (FMVSS 108),
`The US Federal Register, Part 571 (FMVSS 1 OB),
`for automotive lighting is not as restrictive as the
`for automotive lighting is not as restrictive as the
`European ECE regulation but the subject also is
`European ECE regulation but the subject also is
`not yet explicitly introduced.
`not yet explicitly introduced.
`Once we have realized the potential of adaptive
`Once we have realized the potential of adaptive
`lighting in general and supposed there will be
`lighting in general and supposed there will be
`some regulatory framework in a few years, what
`some regulatory framework in a few years, what
`
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`
`what kind of variations can be introduced by ALP?
`what kind of variations can be introduced by ALP?
`Various adaptation possibilities can be thought of:
`Various adaptation possibilities can be thought of:
`- Adaptation of low, high or fog beam pattern
`- Adaptation of low, high or fog beam pattern
`- Integration or combination of low, high and fog
`- Integration or combination of low, high and fog
`beam into one beam
`beam into one beam
`- Adaptation of a headlamp to different standards:
`- Adaptation of a headlamp to different standards:
`ECE left hand drive, ECE right hand drive,
`ECE left hand drive, EGE right hand drive,
`USA, Japan
`USA, Japan
`- Variation of shape of the cut-off of a low or
`- Variation of shape of the cut-off of a low or
`fog beam
`fog beam
`- Variation of beam inclination
`- Variation of beam inclination
`- Variation of the signal image of a headlamp
`- Variation of the signal image of a headlamp
`(the appearance to opposing traffic)
`(the appearance to opposing traffic)
`- Variation of brightness or colour
`- Variation of brightness or colour
`- On/off - automatic switching of beams
`- On/off - automatic switching of beams
`
`tests and investigations already
`The first
`The
`tests and
`investigations already
`first
`mentioned
`above
`allow some
`preliminary
`mentioned above allow some preliminary
`conclusions which help
`to select
`the most
`conclusions which help to select
`the most
`important variations and parameters for Adaptive
`important variations and parameters for ,,Adaptive
`Light Pattern" headlamps:
`Light Pattern" headlamps:
`
`components of a multi-segment headlamp - one
`components of a multi- segment headlamp - one
`realization technique for ALP - are indicated. The
`realization technique for ALP - are indicated. The
`most important control parameter, which is quite
`most important control parameter, which is quite
`easily accessible in a modern car,
`is the driving
`easily accessible in a modern car, is the driving
`speed. Driving with high speed requires the
`speed. Driving with high speed requires the
`attention of the driver to be directed to the far
`attention of the driver to be directed to the far
`field in the direction where
`the car is heading
`the car is heading
`field in the direction where
`instead
`of being distracted by the foreground
`instead
`of being distracted by the foreground
`scenery or the outer left and right sides of the
`scenery or the outer left and right sides of the
`total viewing zone.
`It
`is well known that
`the
`total viewing zone. It is well known that the
`driver's view is attracted by those parts of the
`driver's view is attracted by those parts of the
`scenery that have the highest luminance (Ref. 9).
`scenery that have the highest luminance (Ref. 9).
`Hence, the adaptive light pattern should support
`Hence, the adaptive light pattern should support
`to direct the concentration to the most important
`to direct the concentration to the most important
`zone for the current driving situation. Therefore,
`zone for the current driving situation. Therefore,
`at high speed, an additional
`far
`field spot
`at high speed, an additional
`far
`field spot
`illumination should be added, accompanied by
`illumination should be added, accompanied by
`reduced or normal side and foreground light.
`reduced or normal side and foreground light.
`When driving at low or medium speed usually
`When driving at low or medium speed usually
`the spot is not needed any more. In this case,
`the spot is not needed any more.
`In this case,
`the adapted optimum light pattern depends
`light pattern depends
`the adapted optimum
`on other parameters: When there
`is
`an
`on other parameters: When
`there
`is an
`intersection ahead, a curve or a broad street in
`intersection ahead, a curve or a broad street in
`an urban area then an enhanced lateral side
`an urban area then an enhanced lateral side
`illumination to the left and/or right is needed. In
`illumination to the left and/or right is needed. In
`
`Experimental Experiences:
`
`- Speed is a suitable control parameter
`
`- Distinction between city traffic, 25 Mph-zones,
`rural roads and highway is meaningful
`
`- Oncoming traffic on rural road:
`Enhanced SPOT is advantageous
`
`- Turns at intersections:
`Increased side illumination is very much
`welcomed
`
`- Driving in convoy: Spot illumination should be
`reduced in favour of large side illumination
`
`- Wet roads: Reduced foreground illumination
`helps to reduce glaring reflections to
`oncoming traffic
`
`- Switching between different light pattern
`components should be harmonic and not
`too abrupt
`
`Increased safety by:
`Curved road
`Improved lateral
`ilfuminance
`
`High speed
`Improved visibility
`
`City
`Large dispersion
`
`these
`Some
`of
`conclusions
`are
`nicely
`Some of
`these conclusions are nicely
`illustrated in
`Fig.
`showing schematically
`1
`illustrated
`in Fig. 1 showing schematically
`different driving situations from the bird eye's view
`different driving situations from the bird eye's view
`and their adapted light pattern.
`In
`the left
`and their adapted
`light pattern.
`In
`the
`left
`part
`of
`Fig.
`1
`the
`corresponding active
`part of Fig. 1
`the corresponding active
`
`Fig. 1: Three standard driving situations with adapted
`light pattern seen from the bird eye's view.
`
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`
`some cases, e.g.
`in a city,
`in a convoy or on wet
`some cases, e.g. in a city, in a convoy or on wet
`roads without oncoming traffic (supposed there
`roads without oncoming traffic (supposed there
`are means in the own car to detect oncoming
`are means in the own car to detect oncoming
`traffic), an enhanced foreground illumination may
`traffic), an enhanced foreground illumination may
`be beneficial. Vice versa, on wet
`roads with
`be beneficial. Vice versa, on wet roads with
`oncoming traffic a reduced foreground diminishes
`oncoming traffic a reduced foreground diminishes
`specular reflection by the wet road ahead and
`specular reflection by the wet road ahead and
`therefore also reduces glare to other
`traffic
`therefore also reduces glare to other traffic
`participants. The transition between different
`participants. The transition between different
`adapted light pattern should always be harmonic
`adapted light pattern should always be harmonic
`and not too abrupt in a manner that has to be
`and not too abrupt in a manner that has to be
`found out by detailed testing.
`found out by detailed testing.
`One important measure to assure safety and
`One important measure to assure safety and
`harmonic transitions is the idea to keep always a
`harmonic transitions is the idea to keep always a
` basic light pattern" component
`static
`and
`light pattern" component static and
`"basic
`switched on while the other beam pattern parts,
`switched on while the other beam pattern parts,
`e.g. spot, side illumination etc. will be adaptive.
`e.g. spot, side illumination etc. will be adaptive.
`ALP technique will be more complex than
`ALP technique wili be more complex than
`conventional headlamp technique is and it will be
`conventional headlamp technique is and it will be
`undoubtedly a challenge to incorporate it
`into
`undoubtedly a challenge to incorporate it into
`modern car bodies. On the other hand it can also
`modern car bodies. 0 n the other hand it can also
`offei new styling opportunities as it is shown for
`offei new styling opportunities as it is shown foi
`example in Fig. 2. Recently, some show cars with
`example in Fig. 2. Recently, some show cars with
`such stylish model headlamps could already be
`such stylish model headlamps could already be
`seen on automobile shows around the world.
`seen on automobile shows around the world.
`
`TECHNICAL REALIZATION ASPECTS
`TECHNICAL REALIZATION ASPECTS
`
`The design of a headlamp with Adaptive Light
`The design of a headlamp with ,,Adaptive Light
`Pattern"
`has
`to
`fulfill
`the
`same
`general
`fulfill
`the same general
`Pattern" has
`to
`requirements
`as
`the
`conventional
`lighting
`requirements as
`the conventional
`lighting
`equipment: cost effectiveness,
`limited space,
`equipment: cost effectiveness,
`limited space,
`stability,
`life time etc. and it has to deal with the
`stability, life time etc. and it has to deal with the
`trend to more exotic vehicle front shapes, inclined
`trend to more exotic vehicle front shapes, inclined
`lenses and low profile reflectors. Additionally,
`it
`lenses and low profile reflectors. Additionally, it
`has to incorporate the ALP-functions.
`has to incorporate the ALP-functions.
`
`Rg. 2: Example for styling opportunities of ALP
`headlamps
`
`Once the available space of an ALP headlamp
`Once the available space of an ALP headlamp
`and the cost frame is known it can be decided
`and the cost frame is known it can be decided
`which technique will be used to make the light
`which technique will be used to make the light
`pattern adaptive. There is no feasible concept yet
`pattern adaptive. There is no feasible concept yet
`known which allows to realize arbitrary light
`known which allows to realize arbitrary
`light
`pattern in a single headlamp.
`In reality, a few
`pattern in a single headlamp. In reality, a few
`major light pattern states, e.g. curve illumination,
`major light pattern states, e.g. curve illumination,
`together with
`the
`corresponding adaptation
`together with
`the corresponding adaptation
`technique have to be selected to realize a
`technique have to be selected to realize a
`powerful ALP headlamp.
`powerful ALP headlamp.
`There are several
`techniques to realize an
`There are several techniques to realize an
`adaptive beam:
`adaptive beam:
`- Changes of the light source(s) only
`- Changes of the light source(s) only
`e.g. moving the bulb inside the reflector, dimming
`e.g. moving the bulb inside the reflector, dimming
`- Adaptive reflectors
`- Adaptive reflectors
`e.g. moving the reflector (and bulb), moving or
`e.g. moving the reflector (and bulb), moving or
`deforming parts of the reflector, inserting new
`deforming parts of the reflector, inserting new
`reflective surfaces, blocking parts of the beam...
`reflective surfaces, blocking parts of the beam ...
`- Adaptive Lenses
`- Adaptive Lenses
`e.g. moving lenses, inserting new lens parts or
`e.g. moving lenses, inserting new lens parts or
`other optical elements, blocking parts of the lens
`other optical elements, blocking parts of the lens
`- Changes on the whole bulb-reflector-lens
`- Changes on the whole bulb-reflector-lens
`system e.g. moving the system, superposition
`system e.g. moving the system, superposition
`of single beams
`of single beams
`- Combinations of the described methods
`- Combinations of the described methods
`
`A lot of patent applications and patents about
`A lot of patent applications and patents about
`all of these different methods can be found and it
`all of these different methods can be found and it
`would go beyond the scope of
`this paper to
`would go beyond the scope of this paper to
`comment on all of them.
`comment on all of them.
`Generally, motorized moving parts should be
`Generally, motorized moving parts should be
`avoided in a headlamp or should be as simple as
`avoided in a headlamp or should be as simple as
`possible because complex motorized motions are
`possible because complex motorized motions are
`expensive, need much space and are potentially
`expensive, need much space and are potentially
`unreliable. Often a simple movement of the bulb or
`unreliable. Often a simple movement of the bulb or
`a rotation of a reflector is not sufficient to achieve
`a rotation of a reflector is not sufficient to achieve
`a well-adapted light pattern.
`a well-adapted light pattern.
`On the other hand continuous movements have
`On the other hand continuous movements have
`the advantage that a beam pattern can be
`the advantage
`that a beam pattern can be
`continuously changed to another beam pattern
`continuously changed to another beam pattern
`whereas other solutions often do not allow the
`whereas other solutions often do not allow the
`realization of
`transition states between light
`realization of
`transition states between
`light
`pattern.
`pattern.
`It has to be found out whether motorized motions
`It has to be found out whether motorized motions
`of headlamp parts can be done in cost-effective
`of headlamp parts can be done in cost-effect