FOG REAR LIGHT

• US 3,746,918 A
• Filed: 05/24/1971
• Issued: 07/17/1973
• Est. Priority Date: 05/23/1970
• Status: Expired due to Term

• Current Assignee: Gerhard Drucker, Reinhard Filsinger
• Original Assignee: Gerhard Drucker, Reinhard Filsinger
• Inventors: Drucker, Gerhard, Filsinger, Reinhard
• Primary Examiner(s): Kaufman, Nathan
• Application Number:
  US05/146,163
• Time in Patent Office: 785 Days
• Field of Search: 315/83,82,77,158,76,156,157,159
• US Class Current: 315/77
• CPC Class Codes: B60Q 1/0023 the element being a sensor, e.g. distance sensor, camera
• CPC Class Codes: B60Q 1/20 Fog lights
• CPC Class Codes: B60Q 1/2603 Attenuation of the light according to ambient luminiosity, e.g. for braking or direction indicating lamps
• CPC Class Codes: F21S 41/65 by acting on light sources
• CPC Class Codes: F21W 2107/10 for land vehicles

Abstract

A fog tail light, especially for motor vehicles, in which the operating voltage applied across the fog lamp is varied as a function of the light intensity produced by headlights of a following vehicle in such a manner that in case of a high light intensity of the following headlights, the operating voltage is reduced and vice versa.

Claims

1. A fog tail light, especially for motor vehicles, in which an operating voltage is applied across an incandescent lamp, comprising a housing, an incandescent lamp mounted in said housing, and control means connected to said incandescent lamp for varying the operating voltage applied thereto in dependence on the light intensity produced by the headlights of another vehicle on the fog tail light in such a manner that with a high light intensity of the headlights the operating voltage applied to the lamp is reduced, said control means including photodetector means mounted on said housing for detecting the level of light directed thereon, a transistor switching circuit including a control transistor responsive to said photo-detector means, and a resistor connected in series with said incandescent lamp and in parallel to the collector-emitter circuit of said control transistor.

2. A fog tail light as defined in claim 1 wherein said transistor switching circuit comprises a Schmitt trigger circuit with said photo-detector means being formed by a photo-transistor connected as one element of said Schmitt trigger, said control transistor being connected to the output of said Schmitt trigger.

3. A fog tail light with a housing according to claim 2, characterized in that the light-sensitive element is arranged at the end of a tubular member whose inlet cross section is disposed at least within the area of a glass window closing off the fog tail light housing.

4. A fog tail light according to claim 3, characterized in that the inlet cross section of said tubular member is arranged within the glass window closing off the fog tail light housing.

5. A fog tail light according to claim 4, characterized in that a transparent window is provided at the inlet of the tubular member.