VS - Lighting Systems - Lighting - 998542

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From Halogen to Xenon front lighting

As already discussed, the human eye perception depends on the light colour; today’s projectors are fitted with three types of light sources.

Light sources technologies differ in many points. l Light colour is different. l Luminous flux is different (lumens). l Intensity is different (candela). l Luminance is different (candela/m 2 ). All this leads to a huge light projection difference on the road, as illustrated by the following illuminance curves, so-called “isolux” curves.

l Incandescent lamps (Halogen). l Gas discharge lamps (Xenon). l LED lamps.

m

Halogen - Illuminance isolux curve

30

HALOGEN

H7

20

1500 lm 55W - 12v

10

1.0

2.0

0

2.0

2.0

100

5.0

2.0

-10

1.0

-20

m

-30

0

20

40

60

80

100

120

140

m

Xenon - Illuminance isolux curve

30

XENON

D2S

20

1.0

3200 lm 35W - 85v

2.0

10

5.0

0

100

2.0

1.0

-10

5.0

5.0

2.0

-20

1.0

1.0

m

-30

0

20

40

60

80

100

120

140

As Xenon lamps produce a larger light projection, the Xenon regulation (ECE-R98) defines more photometric points than the Halogen lamp regulation (ECE-R112) to characterize the system performances.

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