Turn-Key Solution Partner for Automotive Lighting Projects
Optonom assists you to realize your project related to Automotive Lighting. We can produce injection molded aspheric lenses and free-form lenses and Light guides for Automotive Lighting Applications. We provide turn-key solutions like "OPTICAL ENGINEERING + PROTOTYPING + PRECISE OPTICAL MOLDING + PLASTIC INJECTION PRODUCTION" with related international ECE standards.

---------- PHOTOMETRIC BASIS ----------

LIGHT INTENSITY
The intensity is the luminous energy from a lighting source in a specific direction:
- Symbol: I
- Unit: Candela (cd)
Light intensity varies depending on which direction the light source is being viewed from.
Some examples of Candela intensity on automotive lighting systems:
- A candle: 1 cd (reference)
- Parking lights: 2cd
- Position lights: 4 cd
- Direction lights: 50 cd
- Stop lights: 60 cd
- Reversing lights: 80 cd
- Fog lights: 150 cd
- Daytime Running Lights: 500 cd
- Low/High beams >1000 cd

LUMINOUS FLUX
The luminous flux is the complete light output radiated from a light source.
- Symbol: Ø
- Unit: Lumen (lm)
The Lumen unit is defined based on the human eye sensitivity curve

ILLUMINANCE
The luminous flux from a light source (lumens) falling on a unit of surface (m2) is called illuminance.
- Symbol: E
- Unit: Lumen/m2 also called Lux
The illumination level does not make allowance for the amount of light reflected off the surface.
The reflected light is called the luminance; this depends on the nature of the surface, including its colour.

LUMINANCE
The luminance measures the reflected light from a surface to a given direction; the surface can itself be light-emitting, transmitting or reflecting light from another source.
The luminance is the perceived brightness, it is used to categorise:
- Light sources (eg. lamps).
- Lighting systems (eg. headlights).
- Any surface that is bright (eg. road signs).
The luminance is related to a luminous intensity emitted per unit of area from a surface in a specific direction.
- Symbol: L
- Unit: Candela per m2

ECE Regulations for Lighting
European Commission regulations for lighting system are classified as follows:

ECE R37 => LIGHT SOURCES - FILAMENT LAMPS
ECE R99 => LIGHT SOURCES - HID LAMPS
ECE R112 => LOW AND HIGH BEAMS - FOR HALOGEN LAMPS AND LED SOURCES
ECE R98 => LOW AND HIGH BEAMS - HID LAMP SOURCES
ECE R19 => BEAMS - FRONT FOG LAMPS
ECE R87 => DAYTIME RUNNING LAMPS
ECE R48 => SETUP ON THE CAR
ECE R123 => AFS BEAMS - HALOGEN, XENON AND LED LIGHT SOURCES

Headlamp Lighting System

A good front lighting function provides maximum visibility with minimum inconvenience for other road users.
Headlight beams are standard patterns that set the light projection levels and limits on the road.
Several beams are defined:

- Low beam also called passing beam or dipped beam.
- High beam also called main-beam or full-beam.
- Fog beam.
Beam types

Beams can be defined according to their shape and performance:
- The “Width” area: where illuminance covers the whole road width in the driver’s near field of view.
- The “Comfort” area: which corresponds to the driver main vision zone.
- The “Range” area: where the maximum illuminance level occurs far on up to the road.

The cut-off Line

Depending on their type, projectors must include a system to produce a cut-off line.
The cut-off line defines a limit where light should not be projected, low beams and fog beams must comply with this but no legislative cut-off point is required for the high beams.
Low beam
- Must be orientated downwards.
- Must respect a cut-off line to avoid glazing the oncoming driver.
Daytime Running Light (DRL)

Daytime Running Lights belong to the signalling product family. DRLs are a perfect example of a high luminance application, they produce a huge intensity of light in a compact reflector.
The ECE R87 regulation specifies an apparent surface between 25 cm² and 200 cm², and an intensity level between 400 and 1200 cd.
The apparent surface and the intensity permit to calculate and see how huge can be the maximum luminance level on Daytime Running Lamps (480000 cd/m2).

As for lighting, the signalling devices have to comply with photometric specifications.
European Commission standard (ECE R.) set photometric limits and all measurement conditions. Minimum and maximum intensity values are defined in various directions of measurement, the minimum intensities are defined as a percentage of the minimum required in the axis for each lamp (100% in the direction H = 0° and V = 0°)