Vehicle lighting

Claim 1

A system for automatically reducing the intensity of light emitted from head lamps of a first vehicle in response to the intensity of light from an approaching second vehicle, each of said vehicles having a power supply across which said lamps are selectively connected, comprising, on each of said vehicles: a detector for deriving a signal indicative of the illumination intensity produced by the light from the approaching vehicle, signal level detection means responsive to said intensity indicating signal, said signal level detection means including means responding respectively to three predetermined levels: A, an intervention level at which the illumination received by the first vehicle becomes disagreeable for the driver of this vehicle; B, a glare level at which the headlight (upper beam) of the first vehicle must be cut off; C, a dark level at which the use of the headlight (upper beam) of the first vehicle is acceptable for the driver of the second vehicle, means responsive to the third level for connecting the head lamps to the power supply, means responsive to the second level for connecting the dimmed light (lower beam) to the power supply, means responsive to the first level for connecting different resistance means in series with said head lamps and control means responsive to said signal detection, means for selecting the value of said different resistance means to successively reduce the intensity of said head lamps as the two vehicles are approaching each other, said control means including: means for preventing an increase in illumination emitted by the head lamps as the vehicles are approaching each other while the first level is reached even though the light intensity from the approaching vehicle drops below the intervention level and means for reducing the emitted light intensity only when the detected illumination received from the approaching vehicle exceeds a predetermined value corresponding to the intervention level.

Claim 2

A system for automatically reducing the intensity of light emitted from head lamps of a first vehicle in response to the intensity of light from an approaching second vehicle, each of said vehicles having a power supply across which said lamps are selectively connected, comprising, on each of said vehicles: a detector for deriving a signal indicative of the illumination intensity produced by the light from the approaching vehicle, signal level detection means responsive to said intensity indicating signal, said signal level detection means including means responding respectively to three predetermined levels: A, an intervention level at which the illumination received by the first vehicle becomes disagreeable for the driver of this vehicle; B, a glare level at which the headlight (upper beam) of the first vehicle must be cut off; C, a dark level at which the use of the headlight (upper beam) of the first vehicle is acceptable for the driver of the second vehicle, means responsive to the third level for connecting the head lamps to the power supply, means responsive to the second level for connecting the dimmed light (lower beam) to the power supply, means responsive to the first level for connecting different resistance means in series with said head lamps and control means responsive to said signal detection, means for selecting the value of said different resistance means to successively reduce the intensity of said head lamps as the two vehicles are approaching each other, said control means including: means for preventing an increase in illumination emitted by the head lamps as the vehicles are approaching each other while the first level is reached even though the light intensity from the approaching vehicle drops below the intervention level and means for reducing the emitted light intensity only when the detected illumination received from the approaching vehicle exceeds a predetermined value corresponding to the intervention level.