FR2752206A1 - INSTALLATION OF PROJECTORS FOR VEHICLE - Google Patents

Abstract

Installation comprising low beam headlamps with a light source and high beam headlamps with a light source. In the high beam position, the low beam also works. However, at the moment (t1) of switching between the low beam position and the high beam position, the luminous flux (PHIt) emitted by the low beam headlamp is first reduced in relation to the flux (PHI1 ) that it emits normally. Then, after a while, its luminous flux is increased again.

Description

State of the art

  The invention relates to a projection installation

  vehicles for vehicles comprising at least one dipped beam headlamp with at least one light source and at least one high beam headlamp equipped with at least one light source, - in the low beam position, a light source of at least one less a headlamp headlamp operates and in the high beam position, both at least one light source of at least one dipped beam headlamp and at least one light source of at least one headlamp

  high beam headlight work.

  Such an installation is known according to the document

  DE-42 38 273-A1. This installation of projectors

  takes a headlamp for low beam, with a light source and a high beam headlamp with a light source. In low beam mode, only the

  light source of the dipped beam headlamp

  and in the high beam mode, both the light source and the

  both the low beam headlamps and the high beam headlamps The space available in the vehicle for the installation of projectors is often limited which

  not allow these facilities to be

  mension. The projectors, used most frequently for

  low beam, occupy most of the

  lume available, so that for the searchlight

  road, only a small fraction of the total

  lume; this makes it difficult to obtain a high beam

  ficient. Especially when switching from the position of

  low beam and high beam

  There is no improvement of the lighting in front of the vehicle for the driver, because his eyes remain focused on the area strongly illuminated by the light of the lights.

  crossing, near, in front of the vehicle.

  Advantages of the invention The present invention relates to a motor vehicle headlamp installation intended to overcome the drawbacks of known installations and characterized

  in that at the switching of the fire position cross-

  In the high beam position, the luminous flux emitted by at least one crossing light headlamp (10) is reduced relative to its flux for the low beam position and then this flux is increased again. The installation of projectors according to the invention offers the advantage that the temporary reduction of the luminous flux emitted by the dipped-beam headlamp makes the lighting of the zone remote by the headlamp of the headlamps.

  road, in front of the vehicle, is perceived by the driver,

  right after switching to high beam,

  subjective way as the most enlightened. This perception

  by the driver is directed as desired over the area

away from the front of the vehicle.

  According to other advantageous features of the invention: the luminous flux emitted by at least one dipped-beam headlamp is reduced so that at least the upstream zone near the vehicle is illuminated less intensely by the light beam emitted by less a headlamp headlamp than when it is in a position of

headlights.

  * to reduce and then increase again the luminous flux emitted by at least one dipped beam headlamp, it reduces the luminous flux emitted by the light source then

we increase it again.

  This allows, by simple means, first reduce and then increase again the luminous flux emitted by

the headlight of the dipped beam.

  According to other advantageous features of the invention: to reduce and then increase the luminous flux emitted by the

  light source of at least one light projector

  then, we decrease and then increase the electrical power

which is provided to him.

  * to reduce and then increase the electric power supplied to the source of at least one dipped beam headlamp,

  it decreases and then increases the electrical voltage again

  than applied to the light source.

  the luminous flux emitted by at least one dipped-beam headlamp is reduced to approximately 60% to 90% and preferably between approximately 70% and 80% of the luminous flux emitted by the dipped beam headlamp in the position of the lamps

crossing.

  the luminous flux emitted by at least one dipped beam headlamp is again increased in a range of

  the order of 0.1 to 10 seconds after its reduction.

  the luminous flux emitted by at least one dipped-beam headlamp is increased again at least substantially up to the level of the luminous flux emitted by this headlamp by

low beam position.

  * reduction of the luminous flux emitted by at least one projection

  headlamps are made simultaneously with the

  switching of the dipped beam position to the position

high beam.

  * The switching of the dipped beam position to the high beam position implements a device for

  timed switching which again controls the increase

  consecutive luminous flux emitted by at least one

low beam junction.

  Drawings An example of realization is represented in the

  drawings and will be described below in more detail.

So:

  * Figure 1 shows an installation of projectors for

  Figure 2 shows the chronological profile of the luminous flux emitted by a light source of a dipped beam headlamp and that of a high beam, * Figure 3 shows the lighting of a measurement screen placed

  before the installation of projectors, by the light beam

  issued by the installation of headlamps in the low beam

  * Figure 4 shows the measurement screen illuminated by the

  light emitted by the headlamp installation just after switching to the main beam operating mode, * figure 5 shows the measurement screen at the lighting by the headlamp installation in operating mode of

  high beam, some time after switching.

  Description of the exemplary embodiment

  The installation of projectors according to FIG. 1 for a vehicle, notably a motor vehicle, comprises a headlamp 10 for the low beam headlamps and a headlamp

  12 for high beam. The two projectors 10, 12 can

  They must be housed in a common housing 14 by which they are fixed to the bodywork of the vehicle as is known. Alternatively, the two projectors 10, 12 can also be integrated separately from one another in the body and be attached thereto. Usually, at the front of a vehicle there are two installations of projectors symmetrical with respect to the median plane of the vehicle. The headlight 10 of the dipped beam

  comprises a reflector 16 housing at least one light source

  such as an incandescent lamp or a lamp

gas discharge.

  The headlight 12 for high beams includes

  also a reflector 20 housing at least one light source

  such as an incandescent lamp or a lamp

gas discharge.

  The two reflectors 16, 20 can be realized

  in one piece or as a separate piece placed in the box.

  tier 14. The light outlet orifice of the housing 14 is covered with a transparent glass cover window 24

or plastic.

  When the projector installation is in mode

  of low beam, only the light source 18 of the

  jector 10 is connected. The light source 18 emits

  light reflected by the reflector 16; this light travels

  the cover glass 24 is poured and forms a beam of light rays of dipped beam with a light cutoff (between the illuminated area and the unlit area)

  The shape of the reflector 16 can be defined so that it reflects

  chisse the light source 18 to form at least primarily the light beam of the dipped beam that can cross virtually without being influenced, the cover glass 24; this window can be practically smooth. Alternatively, the reflector 16 may also have a

  simple form to define, for example a form of paraboloid.

  The cover glass 24 may comprise optical elements

  which deflect the light reflected by the reflector 16, as they pass through the cover glass 24 to generate the

beam of low beam.

  The light beam emitted by the headlamp 10 of the dipped beam headlamps, in dipped beam mode, illuminates a measurement screen 50 shown in FIG.

  located at a certain distance in front of the installation of

  spotlights; lighting gives a zone 52. The median plane hoses

  ricefront of the measurement screen 50 bears the reference HH; its vertical median plane bears the reference WVV. The horizontal median plane HH and the vertical median plane VV intersect at the

  point HV crossed by the line connecting the installation of pro-

  jets and the measuring screen 50. The lighting cut, which

  borders the upper part of zone 52, present on the

  té corresponding to the traffic coming in opposite direction (in the case of the exemplary embodiment shown, it is, for the right-hand traffic, the left-hand portion of the vertical median plane WVV) a horizontal segment 54; this

  segment is substantially below the median mid-plane

  rice HH. On the vehicle traffic side, (this is

  for the traffic on the right, as shown, the right of the vertical median plane WVV) the lighting cutoff

  presents a growing segment 56 from the horizontal segment

  tal 54 towards the right edge of the measurement screen 50 which rises above the horizontal median plane HH. The angle of inclination

  segment 56 is of the order of 150.

  When the installation of projectors is used

  for left-hand traffic, it is necessary to reverse the

  54, 56 of the lighting cutoff relative to the vertical median plane W. In an alternative embodiment, the cut-off

  lighting may include, as described above, a seg-

  horizontal direction 54 for the traffic side in the opposite direction and a segment 58 also horizontal on the side of the vehicle traffic as shown in the line

  interrupted in FIG. 3, this last segment 58 is located

  significantly higher than the horizontal median plane HH. Enjoyed-

  even lines of the same illumination intensity 54 still

  called Isolux lines are drawn in zone 52. The

  their highest illuminance levels are found

  substantially below point HV and the lighting intensity di-

  strongly towards the edges of Zone 52.

  In the operating position corresponding to the low beam, the light source 18 of the projector 10 receives the nominal electrical power corresponding to the dipped beam as this source is set to the nominal voltage. The light source 18 thus emits its nominal luminous flux ON. FIG. 2 shows the curve of the ratio of the luminous flux θt emitted by the light source 18 of the headlight headlamp with respect to the nominal luminous flux ON,

  as a percentage of time t.

  In the corresponding operating position

  at low beam, before time tl, the light source

  neuse 18 emits a nominal luminous flux ON, constant so

  that the ratio is then equal to 100%.

  When the installation of projectors is in

  of high beam operation, the light source

  The projector 12 is operated for the main beam and the light source 12 of the headlamp 10 for the low beam also operates. The light emitted by the light source 22 is reflected by the reflector 20 and passes through the cover glass 24 to form a distant light beam, concentrated, which has a very large range and illuminates at least the remote area to

  the front of the vehicle. The shape of the reflector 20 may be

  for it to already reflect the light emitted by the light source 22 to at least substantially form the beam of high beam and can cross the window of

  overlap 24 without substantially being influenced; this

can be smooth.

  Alternatively the reflector 20 may also have

  a simple form to define, for example that of a para-

  Loide; under these conditions, the cover glass 24 is provided with optical elements that deflect the light reflected by the reflector 20 to the passage of the window 24 to generate

  the distant beam of light, necessary.

  The beam of light emitted by the high beam headlight 12 illuminates the measurement screen 50 as is

  represented in FIGS. 4 and 5 according to an area carrying the

  Zone 62 is, at least in part, above area 52, and as shown, this area may partially combine with area 52; alternatively, it can

  only be provided above Area 52 adjacent to that area.

  this. Several Isolux lines 64 have been drawn in zone 62; the highest intensity of illumination is at the point HV and the illumination intensity decreases towards the edges of the zone 62. The two zones 52, 62 are illuminated for the

  operating position of high beams. The light source

  The main beam headlamp 12 emits high beam headlamps in the operating position from time t1 as shown by a dashed line curve in FIG. 2, a constant nominal luminous flux ON; the

  ratio Ot / N is then constant, equal to 100%.

  According to the invention, when switching the installation of headlamps from the position of road lights to the dipped beam position, the luminous flux

  emitted by the dipped beam headlamp 10 is reduced.

  For this, we can simultaneously reduce switching,

  moment tl, the luminous flux Ot supplied by the light source

  18 of the dipped beam headlamp 10 as shown in Figure 2, compared to the nominal luminous flux ON supplied in the dipped beam position. It is possible to reduce the luminous flux Ot between approximately 60% up to 90% and preferably of the order of 70% to 80% of the luminous flux.

  nominal ON. The reduced luminous flux provided by the light source

  loom 18 causes the area 52 of the measurement screen 50 to be

  illuminated with less light intensity and its

  and its development will be as shown in Figure 4,

  lower than in the case of the cross-beam position

  3. The reduction of the luminous flux emitted by the light source 18 is preferably made at the same time t1, that is to say simultaneously at the instant t1 at which the light source 22 of the headlight 12 of the main beam headlamps. is connected. The luminous flux α emitted by the light source 18 of the low beam headlamp 10 will then be increased again substantially to the nominal flux ON. increasing

  of the luminous flux Ot can be done for example in an inter-

  A time range from about 0.1 to 10 seconds

  and at time t2, the luminous flux emitted by the source 18 will again be equal to ON. The increase in the luminous flux Ot can be preferably continuous, at least

  substantially linear way as shown in Figure 2.

  It is possible to reduce the luminous flux O emitted by the light source 18 of the dipped beam headlamp 10 by decreasing the electric power supplied to

  light source 18. This can also be done by

  of the voltage applied to the light source 18. A switching of the headlamp system from the low beam position to the

  route is usually made using a 40-way switch

  by the driver of the vehicle. The switch 40 can

  several switching positions 41, 42. A first

  first switch position 41 is associated with the position of the dipped beam; the second switching position 42 corresponds to the position of the high beam. The reduction of the voltage applied to the light source 18 is preferably done by switching the switch 40 from its first position 41 to its second position 42.

  for example a time switch installation

  44 which again increases the voltage in the time interval At. The timed switching installation 44 can

  be constituted by a timed relay or microproces-

  sor. The reduction of the luminous flux Dt emitted by the

  light source 18 of the projector 10 for the crossing lights

  As stated above, this consists in decreasing the intensity and the spreading of the light beam emitted by the dipped-beam headlamp 10 to illuminate the zone.

  52. In particular, the area in front of and close to the vehicle

  it is lit less intensely than for the posi-

  dipped beam. The driver thus perceives the illumination of the remote area at the front of the vehicle by the high beam headlamp 12 as being more intense than

  where, in addition to the start of the light source,

  In addition, the light source 22 of the high beam headlamp 12 is connected to the low beam headlamp 10 illuminating with the total luminous flux. The driver's attention is thus directed, as desired, after switching to dipped beam position on the

  remote area at the front of the vehicle. The subsequent increase

  the luminous flux Dt emitted by the light source 18

  will not interfere with the attention of the

tor.

  As a variant of the embodiment of the installation of projectors described above, it is also possible to reduce the luminous flux emitted by the dipped beam headlamp 10 as indicated in broken lines at the

  FIG. 1, by a diaphragm 46 at least partially trans-

  parent which is placed in the path of the light beam emitted by the projector 10. The diaphragm 46 may for example be placed in the dipped beam projector 10, between the reflector 16 and the cover glass 24 or on the cover glass 24. It is possible to control the movement of the diaphragm 46 by a displacement device 48 and by switching from the low beam position to the

  high beam position, this diaphragm is placed in the

  wise of the light beam; after the period At it is again extracted. In the low beam position, the

  diaphragm 46 is outside the path of the light rays

nous.

  As a variant, the diaphragm 46 can also be mounted in a fixed manner and have a variable transparency.

  corn; this transparency can for example be modified by the action of an electric voltage applied by the control installation 49 to the diaphragm 46. In the dipped beam position, the diaphragm 46 is transparent and when switching on the high beam position, decreases the transparency of the diaphragm 46 and then increases it again

in the time interval At.

  One can provide a diaphragm 46 occupying the entire path of the light beams of the projector 10 or only a portion of the light rays. In particular, it may be provided

  that the diaphragm 46 in principle occupies only a fraction

  the light beam path of the corresponding headlamp

  the illumination of the upstream field near the vehicle so that this portion of the light rays is intentionally attenuated when switched to the position of

  Redlights. The moving device 48 or the device

  control 49 are preferably operated by the

  40 from its first position 41 to its second position 42 and a timed switching installation 44 returns the diaphragm 46 to its position which does not influence the

passage of light rays.

Claims (8)

R E V E N D I C A T IONS   1) Installation of vehicle headlamps comprising at least one low beam headlamp (10) with at least one light source (18) and at least one high beam headlamp (12) equipped with at least one light source (22) ), - in the low beam position, a light source (18) of at least one dipped-beam headlamp (10) operates and in the high-beam position, at least one light source (18) at least one dipped beam headlamp (10) and at least one light source   (22) at least one high beam headlamp (12)   characterized in that at switching of the dipped beam position to the high beam position, the luminous flux emitted by at least one dipped beam headlamp (10) is reduced in relation to its flow for the position of low beam then this flow is increased again.   2) Installation of projectors according to claim 1, characterized in that the luminous flux emitted by at least one dipped beam headlamp (10) is reduced so that at least the upstream zone near the vehicle is illuminated less intensely by the light beam emitted by at least one dipped-beam headlamp (10) only when it is in a position of fire crossing.   3) Installation of projectors according to any one of preceding claims,   characterized in that to reduce and then increase again the luminous flux emitted   by at least one dipped beam headlamp (10), it shall be   the luminous flux emitted by the light source (18) then we increase it again.   4) Installation of projectors according to claim 3, characterized in that to reduce and then increase the luminous flux emitted by the   light source (18) of at least one dipped beam headlamp (10), it decreases and increases the electric power supplied to it.    ) Installation of projectors according to claim 4, characterized in that to reduce and then increase the electrical power supplied to the source (18) of at least one dipped beam headlamp   (10), it decreases and then again increases the voltage elec-   applied to the light source (18).   6) Installation of projectors according to any one of preceding claims,   characterized in that the luminous flux emitted by at least one dipped beam headlamp (10) is reduced to about 60% to 90% and preferably between about 70% and 80% of the luminous flux emitted by the headlamp. low beam (10) in position headlights.   7) Installation of projectors according to any one of preceding claims,   characterized in that the luminous flux emitted by at least one dipped beam headlamp (10) is again increased in a range of   the order of 0.1 to 10 seconds after its reduction.   8) Installation of projectors according to any one of preceding claims,   characterized in that the luminous flux emitted by at least one dipped-beam headlamp (10) is increased again at least substantially to the level of the luminous flux emitted by this headlamp. low beam position.   9) Installation of projectors according to any one of preceding claims, characterized in that -   the reduction of the luminous flux emitted by at least one dipped beam headlamp (10) is effected simultaneously with the switching of the dipped beam position to the high beam position (5).    Projector installation according to one of the preceding claims,   characterized in that the switching of the dipped beam position to the po-   high beam set-up implements a communication device   time delay (44) which again controls the consequent increase in the luminous flux emitted by at least one projector of low beam (10).