3868629 is referenced by 12 patents and cites 5 patents.

A vehicle safety device which gives a visual indication to a driver of one vehicle when the distance between his vehicle and another vehicle is safe, unsafe or where caution must be used for the speed at which he is driving. The device is positioned with respect to the other vehicle and includes a housing having an illumination source and a screen impervious to light. The screen contains a plurality of pairs of windows. The windows constituting a pair are separated from each other by a spacing which depends upon the resolving power of the eye. For a predetermined speed, the windows constituting a particular pair are separated such that at distances between the vehicles, up to a predetermined minimum safe stopping distance, the windows constituting that pair are seen as two windows indicating an unsafe condition; for distances between the vehicles which are greater than the minimum stopping distance by a fixed amount, the two windows appear as one, indicating a safe condition, and for distances therebetween a hazy indication is viewed which indicates that caution must be exercised at that speed for that distance between the vehicles.

Visual collision avoidance warning device
Application Number
Publication Number
Application Date
December 3, 1973
Publication Date
February 25, 1975
Caine Harold A
Helfgott Samson
B60q 01/00
G09F 13/04
G09F 13/06
B60Q 01/52
B60Q 01/50
G08G 01/16
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