Note: Descriptions are shown in the official language in which they were submitted.
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MAGNA REFLEX HdLDING GMBH
MAG 98/11 PCT
g~tPrior rear-view mirror with ~ighr ting arrangemen
The present invention relates to an exterior rear-view
mirror with a lighting arrangement for a vehicle,
especially a motor vehicle according to the preamble of
the main claim.
Exterior mirrors for motor vehicles have become known
in recent times (DE 297027~6~, which have an indicator
light in the mirror housing. The lighting arrangement
is here built into the front side of the housing
aligned in the direction of travel and can be
substantially recognised in the direction of travel
from the front, however it also radiates towards the
side. As the light source for such a lighting
arrangement, an incandescent lamp is used which,
however, generates considerable heat inside the mirror
housing and has a short service life. Therefore
attempts were made to use as light sources one or more
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light-emitting diodes which, however, do not supply
sufficient luminance of the radiating luminous field.
The problem underlying the invention, therefore, is to
create an exterior rear-view mirror with a lighting
arrangement for forming a luminous field in which the
luminous field has high luminance, the light source
being intended to groduce very little heat and the
lighting arrangement being simple and inexpensive to
manufacture.
This problem is solved according to the invention by
the characteristic features of the main claim in
conjunction with the features of the preamble.
As a light source, a high-voltage tubular lamp is used
elongated at least in partial regions, which lamp can
be bent particularly easily and deformed three-
dimensionally, producing very little heat and yielding
high luminance.
Preferably, the lighting arrangement is configured as
an indicator element or brake light element and
electrically connected to the remaining indicator
lights or brake lights of the motor vehicle.
The lighting arrangement according to the invention is
distinguished by the fact that it raaiates, m
accordance with legal requirements, light of a specific
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intensity or luminance, colour, radiation
characteristic and flashing frequency with high
efficiency, and can be manufactured inexpensively with
a long service life and good design potential. Here,
for example, thin fluorescent tubes with a fluorescent
layer applied on the interior are bent, corresponding
to the desired shape, into three-dimensional bodies,
the fluorescent tubes being triggered by an electronic
lamp ballast, which is provided with a so-called
inverter electronics system. Through the use of a
light-conducting body in conjunction with the at least
one fluorescent tube, luminous fields of high
homogeneity and high luminance are achieved.
Instead of using a light-conducting body, lens system
elements or a combination of light guides and lens
systems can be used. Likewise, light-scattering lens
system elements and/or prism elements and/or light-
conducting elements with a partial fully reflecting
coating and/or light-conducting elements with a
corresponding guiding of the refraction index can be
used and fitted as a unit in such a manner. Also any
combination of the above-mentioned elements are hereby
claimed as part of the invention.
The present invention has the advantage of making
available a lighting arrangement or a lamp element
which gives the greatest possible latitude to the
requirements of designing automobile parts or motor
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vehicle mirrors with a lamp element, Furthermore, the
lighting arrangement according to the invention or the
lamp element meets all technical and legal
requirements, especially in terms of radiated
brightness, radiated light colour, the characteristic
of the radiation direction and continuous radiation,
brightness-regulated radiation and/or flashing
radiation, and makes possible inexpensive manufacture
with easy assembly and easy dismantling taking into
account modern recycling strategies, as well as high
efficiency of the conversion of electrical energy into
light with a long service life of the whole system.
According to the invention, it was established that
fluorescent tubes, more especially cold cathode tubular
lamps can be very easily formed into three-dimensional
bodies, and that in addition fluorescent tubes of this
type can be produced with the desired layers of
fluorescent substance and the colour emission spectra
resulting therefrom, and that, with a corresponding
electronic triggering system in the form of so-called
CCFL~ inverters (cold cathode fluorescent lamp
inverters) or in the form of oscillating circuits with
corresponding transformers, the typical vehicle supply
voltage of 12 volts d.c, can be inverted into several
hundred volts a.c. with up to 120 kHz frequency and up
to lSOQ volts and in this way also a flashing operation
over typically 2000 hours can be realised without loss
of quality and with high efficiency. What is
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particularly suitable here is the low temperature
produced by the tubular lamps. Particularly this point
is, as opposed to conventional incandescent lamps
and/or I~EDs and/or halogen lamps, a significant aspect
5 for the design of the entire lighting arrangement or
the entire lamp element, especially in connection with
the light-conducting body, since where there is a low
temperature, small constructional heights and standard
thermoplastic plastics can be used, and the design
latitude becomes greater, and altogether an inexpensive
unit which is simple to fit can be designed.
According to this invention, it is now possible for the
first time, by means of a lighting arrangement which
can be simply integrated, or a corresponding lamp
element, to integrate lamp surfaces with a very even or
specifically chosen brightness distribution into
members located externally, such as an exterior rear-
view mirror of a motor vehicle, and thereby to achieve,
for example, light radiation sideways over an area e.g.
of 30 cm2 with a luminance of e.g, more than 500 cdlm2
and towards the front, i.e, in the direction of travel
via a lamp surface of only a few cm2 with a luminance
of e.g. more than 1000 cdlm~ with a very small angle of
light dispersion, or a light intensity in the region of
more than 0.6 to more than 0,9 cd.
In a preferred development, the fluorescent tube has a
fluorescent substance coating on the inside, which
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makes possible an emission in the orange light
spectrum, more especially in the wavelength range of
590 - 594 nm or a radiation temperature of 2856 kelvin
or with the colour co-ordinates (standard colour value
constituents) x - 0.595 - 0.564 and y - 0.398 - 0.429
and z =< 0.007. The fluorescent layer of the
fluorescent tube is thus formed according to the
required colour effects and, as well as the explicitly
mentioned orange colour emission, with corresponding
fluorescent substances practically any colour variant
from blue to green to yellow and red can also be
achieved and radiated.
In the desired colour emission, the three-dimensionally
formed light-conducting body also has to be taken into
account which has a light-radiating surface forming the
luminous field and at least one light entry surface,
the tubular lamp being disgosed in the immediate
proximity of the light entry surface. The light-
conducting body consists far example of a
thermoplastically deformed transparent and~or
translucent injection-moulded part made for example of
polymethyl methacrylate (P1~1A), polycarbonate (PC),
acrylonitrile-butadiene-styrene copolymer (ABS),
polyamides (PA), polystyrene (PS) and the like or of a
mixture of such thermoplastic plastics andlor of
traditional glass.
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The fluorescent tube is bent three-dimensionally in a
U-shape such that the two electrical connection
contacts come to lie adjacent to one another at the
open ends and thus the electrical contact can be
effected by means of a connector part with silicone
and/or polyurethane sealing elements.
A particularly advantageous flashing control of the
fluorescent tube consists in the fact that the inverter
regulates the brightness up and down by means of a
dimmer control system and there is no drop below the
firing voltage of the fluorescent tube. Moreover,
adaptation of the radiated brightness to the ambient
brightness can take place and it is furthermore also
possible to provide continuous radiation. This is true
especially if the lighting arrangement does not just
serve as an indicator light but also serves to
illuminate the entrance region into the motor vehicle.
In a preferred embodiment, the electrodes are pre-
heated by permanent discharge to make firing at low
temperature easier, such that electrodes and gas are
slightly heated up, by which means inter-connection at
high intensity is made possible.
The lighting arrangement forms on the visible outer
side of the light-conducting three-dimensional body a
luminous field, which in the non-luminous state shows
t the desired colour, such as white, grey, transparent or
a vehicle colour which shines through translucently,
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the luminous field also being able to be mirror-coated
semi-transparently and emits, only when the fluorescent
tube is switched on, a light emission with the desired
wavelength spectrum. The colour can be provided by an
additional coating on the front side of the lighting
arrangement, i.e. on the luminous field, which makes
the luminous field appear slightly tinted in the
switched-off state. This serves to heighten the
contrast, by which means the luminous field is better
visible in direct sunshine.
The three-dimensionally formed fluorescent tube is
attached in the light-conducting body with mounting
members in such a way, that good damping against
vibrations and impact-like load is guaranteed and yet
easy fitting and dismantling can be carried out. Here,
by preference, silicone rubber and/or polyurethane and
similar elements are used, in addition to which also
corresponding crimged ribs andlor spring members can be
used in the three-dimensionally formed light-conducting
body. In this way, a compact constructional unit is
formed which can be clipped, snapped or otherwise
fastened into corresponding cavities in the housing.
Provision is made in a development for, instead of only
one three-dimensionally formed fluorescent tube, two or
a plurality of fluorescent tubes to be used. Here the
inner fluorescent coatings can be chosen to be
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different corresponding to the desired radiation colour
spectra or luminous colours.
Instead of the light-conducting body, a simple prism
cover can also be provided, behind which the
fluorescent tubes are located.
In order to increase the light efficiency, provision is
made for the three-dimensionally formed fluorescent
tube to have partially mirror-coated exterior sides,
and thus to emit light of the desired wavelength
distribution only in the direction of the light
coupling to the light-conducting body.
Furthermore, provision can be made for the three-
dimensionally formed light-conducting body to have
prism surfaces to deflect the light emitted by the
fluorescent tube or tubes towards the lamp surface, or
to be partially mirror-coated, i.e. on surfaces which
are not light entry surfaces and light-emitting
surfaces, and for it in this way to emit the coupled
light of the three-dimensionally formed fluorescent
tube in firmly prescribed surface regions with the
desired radiation characteristic and intensity
distribution. The light-conducting body can also,
together with the at least one fluorescent tube, be
covered by a cap provided with a mirror coating, which
is then a component of the unit.
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Embodiments of the invention, given by way of example,
are shown in the drawing and are explained in greater
detail in the following description. The features
disclosed in the drawings are to be included in the
5 disclosure of the invention. The figures show:
Fig. 1 a schematic representation of an exterior
rear-view mirror with a lighting arrangement
according to the invention, in plan view,
Fig. 2 the exterior rear-view mirror with the
10 lighting arrangement or the lamp element
according to Fig. 1 in front elevation, i.e.
seen towards the direction of travel,
Fig. 3 an embodiment, given by way of example, of a
part of the lighting arrangement according to
Fig. 1 and Fig. 2, in front elevation,
Fig. 4 a section through the lighting arrangement or
the lamp element,
Fig. 5 a section through the lighting arrangement or
the lamp element according to Fig. 4,
corresponding to section line ~,
Fig. 6 a section corresponding to Fig. 5 through a
further embodiment of a light-conducting body
used,
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Fig. 7 a plan view of the mounting location of the
exterior rear-view mirror with a lighting
arrangement on the right hand side of a
motor vehicle,
Fig. 8 a side view of the right-hand side of a motor
vehicle.
In Fig. 1 is shown the mounting location of a three-
dimensionally bent lamp element 4, which is part of a
lighting arrangement, in an exterior rear-view mirror
1. The rear-view mirror 1 has, in standard fashion, a
mirror side 2 orientated backwards, i.e. towards the
direction of travel, and in its front side 3, i.e. in
the side oriented in the direction of travel, is
incorporated the lamp element 4 which emits light in
arrow directions 7 forwards and to the side. The lamp
element forms a luminous field 5 visible from the
exterior and which in the non-luminous state can appear
for example white, transparent or translucent in the
colour of the motor vehicle.
In Fig. 2 the exterior rear-view mirror 1 is shown from
the front, it being possible to recognise that the
luminous field 5 extends approximately horizontally,
and approximately in a square shape with rounded edges,
beyond the exterior front face of the rear-view mirror
1 and is consequently also visible and radiates to the
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side. The lamp element 4 shown serves in the present
case as an indicator or brake light element.
Indicated in broken lines in Fig. 2 is the fact that a
further lamp element 6 can be present which is
installed in the underside of the rear-view mirror 1
and preferably radiates downwards. This lamp element
can be coupled in a light-conducting manner with the
first lamp element 4; however it can also be provided
completely separately from the first lamp element and
be used as an entry light. Here, as the vehicle is
entered, the base region is illuminated in front of the
door of the motor vehicle in the direction of arrow 8.
The lamg element 4 consists in the embodiment shown
substantially of a high-voltage discharge lamp, a so-
called tubular lamp, which in the present case is
provided with a coating of fluorescent substance on the
interior, and is thus configured as a fluorescent tube,
and of a light-conducting body which is represented
exactly in Figs. 3 - 5. The fluorescent tube 9 is bent
in a U-shape and fits, corresgonding to Fig. 3, the
contour of the housing of the exterior mirror 1 as a
complete " UJ'. It has here two tube portions lo, 11,
disposed at a distance from and parallel to one
another, which together with a curved tube portion 12
connecting these two portions form the U profile. Tube
portion 12 forms the front side of the lamp element 4
which runs approximately vertical on the side close to
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the motor vehicle, i.e. faces the motor vehicle. The
electrical connections of the fluorescent tube 9 which
are connected with an electronic triggering unit not
shown, the triggering electronic system forming
together with lamp element 4 the lighting arrangement,
are combined on a connection side 17 in order to
achieve simple mounting of the base.
In order to redirect the light generated by the
fluorescent tube 9, a light-conducting body is provided
which is disposed between tube portions to - 12 and is
configured in this embodiment in plate form and
consists of a plastics material. Here the front edges,
i.e. the narrow peripheral surfaces of the light-
conducting body, form the light entry surfaces,
opposite which the fluorescent tube 9 lies. The
luminous field 5 is formed by the light exit surface of
the light-conducting body 15, the surface lying
opposite the light exit surface being provided with a
substantially completely reflective coating, preferably
a mirror layer 14, which reflects the incident light
again completely into the interior of the light-
conducting body 15. The fluorescent tube is likewise
surrounded by a reflective layer 13 which reflects to
the light entry edge the light not emitted to the light
entry edge by the fluorescent tube 9. This reflective
layer 13 can be configured as a foil but also as the
cap surrounding the fluorescent tube, which forms
simultaneously a mounting for the whale arrangement.
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The fluorescent tube can also be partially coated self-
reflective.
In Fig. 5, the light-radiating surface of the light-
conducting body is provided with a coating 18 which can
be configured as a diffuser foil or forms a roughening,
lamination or texture. By means of the coating, it is
possible to make the distribution of light even, or it
serves to heighten the contrast.
As already explained above, the fluorescent tube 9 is
connected to the electronic triggering unit, not shown,
the triggering on the lamp element 4 being intermittent
corresponding to the flashing lamp. In a use
corresponding to lamp element ~, the corresponding
fluorescent tube is triggered in permanent operation,
i.e. continuously.
In Fig. 6 is shown a further embodiment of lamp element
4, the light-conducting body 15 being regresented as
prismatic. Depressions 26, here in rectangular shape,
are worked into the surface opposite the radiating
surface 5, into which depressions the fluorescent tube
is inserted. The fluorescent tube thus radiates in
each depression in three entry surfaces and, so that
the radiation radiating into the lateral light entry
surfaces is deflected to the light exit surface, the
surface lying opposite the luminous field, i.e. the
surface oriented towards the housing, is provided with
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slopes 27 which deflect the light to the light
radiating surface. The slopes 27 can in turn be
mirror-coated, however the light-conducting body can be
surrounded by a cag 28 which has an inner mirror
5 coating, through which only the luminous field 5
remains free. Here, too, a coating 29 which improves
the contrast is provided.
The light-conducting body can consist of a plastic
part, it can also be composed of a plurality of plastic
10 members. In this case, on the boundary surfaces
between the individual parts, additional mirror
coatings 30 can be provided which reflect the light and
deflect it in desired directions.
In Fig. 7 is shown the arrangement of a motor vehicle
15 mirror 1 on a car, the vehicle side edge being referred
to as 19. The light radiation is represented as 7 and
it can be recognised that, outside a sector 26 oriented
backwards, Light radiation also occurs towards the
rear. sector 23 is defined by an angle 22 of roughly
5° between a line 21 and a line which runs
approximately parallel to the longitudinal axis of the
vehicle, i.e. parallel to the side edge 19 of the
vehicle. Light radiation in arrow direction 7
therefore does not only occur in the direction of
travel 20 but also sideways therefrom.
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Fig. 8 shows a vehicle door 24 in plan view. As well
as the light radiation to the side, in the sense of
Fig. 7, light radiation obliquely upwards in the
direction of the arrow is also provided. In
conjunction with the additional lamp element 7, light
radiation downwards in arrow direction 8 can, according
to circumstances, also take place if the lamp element
6 is configured as an indicator element.
The light-conducting body 15 can also be configured as
a prismatic cover, it being possible to dispose a
plurality of fluorescent tubes or multiply-curved tube
portions behind the cover.
