Headlight anti-glare system

• US 6,515,425 B1
• Filed: 06/28/2000
• Issued: 02/04/2003
• Est. Priority Date: 06/28/2000
• Status: Expired due to Term

• Current Assignee: International Truck Intellectual Property Co. LLC (Volkswagen AG)
• Original Assignee: International Truck Intellectual Property Co. LLC (Volkswagen AG)
• Inventors: Bender, Burnell L.
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Tran, Chuc
• Application Number:
  US09/604,991
• Time in Patent Office: 951 Days
• Field of Search: 315/82, 315/83, 315/80, 315/77, 315/90, 315/84, 362/61, 362/80, 362/802, 307/10.8, 307/10.1, 307/29, 307/42, 340/469, 340/468
• US Class Current: 315/82
• CPC Class Codes: B60Q 1/1415 Dimming circuits

Abstract

An anti-glare system for motor vehicle headlights is effective to illuminate the headlights at reduced intensity when the vehicle is not in motion and the headlight switch is on thereby promoting better visibility for the driver of an oncoming vehicle. This system is believed particularly useful in service vehicles, such as pick-up and delivery trucks and school buses.

Claims

3. A motor vehicle headlight circuit that is energized from a voltage source and comprises:

a) at least one headlight providing illumination of a field of view frontally of the vehicle;

b) a headlight switch that is selectively operable to OFF and ON positions for selectively turning the at least one headlight off and on;

c) a main headlight circuit controlled by the headlight switch for operating the at least one headlight substantially at nominally rated operating voltage when the headlight switch is operated to ON position to illuminate the field of view at nominal illumination intensity;

d) a reduced illumination intensity circuit for operating the at least one headlight at less than nominally rated operating voltage to illuminate the field of view at less than nominal illumination intensity when the headlight switch is in OFF position; and

e) a signal source that is selectively operable to give a first signal for causing interruption of the main headlight circuit and the at least one headlight to operate at less than nominally rated operating voltage, and to give a second signal for causing no interruption of the main headlight circuit so that operation of the headlight switch to ON position is effective to operate the at least one headlight at nominally rated operating voltage;

in which the signal source comprises a signal switch that is selectively operable to a first position for giving the first signal and to a second position for giving the second signal;

the signal switch comprises a park brake switch for signaling application of a vehicle parking brake when in the first position and non-application of the vehicle parking brake when in the second position;

the reduced illumination intensity circuit comprises a daytime running light circuit to which the park brake switch is connected; and

including a selector switch through which the park brake switch is connected to the daytime running light circuit, wherein the selector switch is operable to a first position that provides continuity of the park brake switch to the daytime running light circuit and a second position that interrupts continuity of the park brake switch to the daytime running light circuit, and wherein the selector switch is effective, when in its second position, to prevent the park brake switch from interrupting the main headlight circuit.

4. A motor vehicle lighting system that includes an exterior light circuit and a headlight circuit that is energized from a voltage source and comprises:

a) at least one headlight providing illumination of a field of view frontally of the vehicle;

b) a headlight switch that is selectively operable to OFF and ON positions for selectively turning the at least one headlight off and on;

c) a main headlight circuit controlled by the headlight switch for operating the at least one headlight substantially at nominally rated operating voltage when the headlight switch is operated to ON position to illuminate the field of view at nominal illumination intensity;

d) a reduced illumination intensity circuit for operating the at least one headlight at less than nominally rated operating voltage to illuminate the field of view at less than nominal illumination intensity when the headlight switch is in OFF position;

e) a signal source that is selectively operable to give a first signal for causing interruption of the main headlight circuit and the at least one headlight to operate at less than nominally rated operating voltage, and to give a second signal for causing no interruption of the main headlight circuit so that operation of the headlight switch to ON position is effective to operate the at least one headlight at nominally rated operating voltage; and

f) at least one motor vehicle exterior light;

in which the signal source comprises a signal switch that is selectively operable to a first position for giving the first signal and to a second position for giving the second signal; and

the signal switch comprises a switch for also causing flashing of the at least one motor vehicle exterior light when in the first position.

5. A motor vehicle comprising:

a) a voltage source;

b) at least one headlight providing illumination of a field of view frontally of the vehicle;

c) a headlight control that is selectively operable to OFF and ON positions for selectively turning the at least one headlight off and on;

d) a main headlight circuit controlled by the headlight switch for causing substantially full voltage of the voltage source to be applied to the at least one headlight when the headlight control is operated to ON position to illuminate the field of view at a relatively full illumination intensity;

e) a reduced illumination intensity circuit for causing substantially less than full voltage of the voltage source to be applied to the at least one headlight so that the field of view is illuminated at substantially less than relatively full illumination intensity when the headlight switch is in OFF position; and

f) a signal source that is selectively operable to give a first signal that causes interruption of the main headlight circuit and substantially less than full voltage of the voltage source to be applied to the at least one headlight, and to give a second signal that causes no interruption of the main headlight circuit so that operation of the headlight switch to ON position is effective to cause substantially full voltage of the voltage source to be applied to the at least one headlight;

in which the signal switch comprises a park brake switch that is selectively operable to a first position for giving a first signal to indicate application of a parking brake of the vehicle and to a second position for giving a second signal to indicate non-application of the parking brake;

the reduced illumination intensity circuit comprises a daytime running light circuit to which the park brake switch is connected; and

including a selector switch through which the park brake switch is connected to the daytime running light circuit, wherein the selector switch is operable to a first position that provides continuity of the park brake switch to the daytime running light circuit and a second position that interrupts continuity of the park brake switch to the daytime running light circuit, and wherein the selector switch is effective, when in its second position, to prevent the park brake switch from interrupting the headlight circuit.

6. A motor vehicle comprising:

a) a voltage source;

b) at least one headlight providing illumination of a field of view frontally of the vehicle;

c) a headlight control that is selectively operable to OFF and ON positions for selectively turning the at least one headlight off and on;

d) a main headlight circuit controlled by the headlight switch for causing substantially full voltage of the voltage source to be applied to the at least one headlight when the headlight control is operated to ON position to illuminate the field of view at a relatively full illumination intensity;

e) a reduced illumination intensity circuit for causing substantially less than full voltage of the voltage source to be applied to the at least one headlight so that the field of view is illuminated at substantially less than relatively full illumination intensity when the headlight switch is in OFF position; and

f) a signal source that is selectively operable to give a first signal that causes interruption of the main headlight circuit and substantially less than full voltage of the voltage source to be applied to the at least one headlight, and to give a second signal that causes no interruption of the main headlight circuit so that operation of the headlight switch to ON position is effective to cause substantially full voltage of the voltage source to be applied to the at least one headlight;

in which the signal source comprises a signal switch that is selectively operable to a first position for giving the first signal and to a second position for giving the second signal; and

in which the vehicle comprises at least one exterior light, and the signal switch is effective to cause flashing of the at least one exterior light when operated to give the first signal.

1. A motor vehicle headlight circuit as set forth in claim 6 in which the signal switch comprises a park brake switch for signaling application of a vehicle parking brake when in the first position and non-application of the vehicle parking brake when in the second position.

2. A motor vehicle headlight circuit as set forth in claim 1 in which the reduced illumination intensity circuit comprises a headlight module to which the park brake witch is connected.

7. A motor vehicle as set forth in claim 6 in which the vehicle comprises a door that opens and closes to allow passenger ingress and egress, and the signal switch is associated with operation of the door to give the first signal when the door is open and the second signal when the door is closed.

23. A motor vehicle as set forth in claim 6 in which the vehicle comprises a school bus for transporting students.

8. A motor vehicle comprising:

a) a voltage source;

b) at least one headlight providing illumination of a field of view frontally of the vehicle;

c) a headlight control that is selectively operable to OFF and ON positions for selectively turning the at least one headlight off and on;

d) a main headlight circuit controlled by the headlight switch for causing substantially full voltage of the voltage source to be applied to the at least one headlight when the headlight control is operated to ON position to illuminate the field of view at a relatively full illumination intensity;

e) a reduced illumination intensity circuit for causing substantially less than full voltage of the voltage source to be applied to the at least one headlight so that the field of view is illuminated at substantially less than relatively full illumination intensity when the headlight switch is in OFF position; and

f) a signal source that is selectively operable to give a first signal that causes interruption of the main headlight circuit and substantially less than full voltage of the voltage source to be applied to the at least one headlight, and to give a second signal that causes no interruption of the main headlight circuit so that operation of the headlight switch to ON position is effective to cause substantially full voltage of the voltage source to be applied to the at least one headlight;

in which the vehicle comprises a door that opens and closes to allow passenger ingress and egress, and the signal source is associated with operation of the door to give the first signal when the door is open and the second signal when the door is closed.

24. A motor vehicle as set forth in claim 8 in which the vehicle comprises a school bus for transporting students.

9. A motor vehicle comprising:

a) a voltage source;

b) at least one headlight providing illumination of a field of view frontally of the vehicle;

c) a headlight control that is selectively operable to OFF and ON positions for selectively turning the at least one headlight off and on;

d) a main headlight circuit controlled by the headlight switch for causing substantially full voltage of the voltage source to be applied to the at least one headlight when the headlight control is operated to ON position to illuminate the field of view at a relatively full illumination intensity;

e) a reduced illumination intensity circuit for causing substantially less than full voltage of the voltage source to be applied to the at least one headlight so that the field of view is illuminated at substantially less than relatively full illumination intensity when the headlight switch is in OFF position; and

f) a signal source that is selectively operable to give a first signal that causes interruption of the main headlight circuit and substantially less than full voltage of the voltage source to be applied to the at least one headlight, and to give a second signal that causes no interruption of the main headlight circuit so that operation of the headlight switch to ON position is effective to cause substantially full voltage of the voltage source to be applied to the at least one headlight;

in which the headlight control comprises a headlight switch, and further including a controlled conduction device having a controlled conduction path controlled by a controlling element is associated with the headlight control, the at least one headlight, and the signal source such that the controlled conduction path is connected in circuit between the headlight control and the at least one headlight, and the controlling element is connected between the headlight control and the signal source; and

in which the signal source comprises a signal switch, the controlled conduction device comprises a relay, the controlled conduction path comprises a normally closed contact of the relay, and the controlling element comprises a coil that when energized opens the normally closed contact.

10. A motor vehicle as set forth in claim 9 in which the signal source gives the first signal when a control of the vehicle indicates that the vehicle is not in motion and the second signal when the control indicates the vehicle is capable of motion.

11. A motor vehicle headlight circuit that is energized from a voltage source and comprises:

a) at least one headlight providing illumination of a field of view frontally of the vehicle;

b) a headlight switch that is selectively operable to OFF and ON positions for selectively turning the at least one headlight off and on;

c) a main headlight circuit controlled by the headlight switch for operating the at least one headlight substantially at nominally rated operating voltage when the headlight switch is operated to ON position to illuminate the field of view at nominal illumination intensity;

d) a reduced illumination intensity circuit for operating the at least one headlight at less than nominally rated operating voltage to illuminate the field of view at less than nominal illumination intensity when the headlight switch is in OFF position; and

e) a signal source that is selectively operable to give a first signal for causing interruption of the main headlight circuit and the reduced illumination intensity circuit to operate the at least one headlight at less than nominally rated operating voltage, and to give a second signal for causing no interruption of the main headlight circuit so that operation of the headlight switch to ON position is effective to operate the at least one headlight at nominally rated operating voltage;

in which the signal source indicates the status of a control of the vehicle that is selectively operable to respectively resist and not resist vehicle motion by giving the first signal when the control is operated to resist vehicle motion and by giving the second signal when the control is operated to not resist vehicle motion.

12. A motor vehicle headlight circuit as set forth in claim 11 in which the signal source comprises a signal switch that is selectively operable to a first position for giving the first signal when the control is operated to resist vehicle motion and to a second position for giving the second signal when the control is operated to not resist vehicle motion.

13. A motor vehicle headlight circuit as set forth in claim 12 in which the signal switch comprises a park brake switch for signaling application of a parking brake of the vehicle when in the first position and non-application of the parking brake when in the second position.

14. A motor vehicle headlight circuit as set forth in claim 13 in which the reduced illumination intensity circuit comprises a daytime running light circuit to which the park brake switch is connected.

15. A motor vehicle headlight circuit as set forth in claim 12 in which the reduced illumination intensity circuit comprises a daytime running light circuit to which the signal switch is connected, and further including a selector switch through which the signal switch is connected to the daytime running light circuit, wherein the selector switch is operable to a first position that provides continuity of the signal switch to the daytime running light circuit and a second position that interrupts continuity of the signal switch to the daytime running light circuit, and wherein the selector switch is effective, when in its second position, to prevent the signal switch from interrupting the main headlight circuit.

16. A motor vehicle comprising:

a) a voltage source;

b) at least one headlight providing illumination of a field of view frontally of the vehicle;

c) a headlight control that is selectively operable to OFF and ON positions for selectively turning the at least one headlight off and on;

d) a main headlight circuit controlled by the headlight control for causing substantially full voltage of the voltage source to be applied to the at least one headlight when the headlight control is operated to ON position to illuminate the field of view at a relatively full illumination intensity;

e) a control that is selectively operable to respectively resist and not resist vehicle motion;

f) a signal source that, when the control is resisting vehicle motion and the headlight control is in ON position, gives a signal for overriding the main headlight circuit by causing substantially less than full voltage of the voltage source to be applied to the at least one headlight so that the field of view is illuminated at substantially less than relatively full illumination intensity, and that, when the control is not resisting vehicle motion and the headlight control is in ON position, does not give the signal and hence does not override the main headlight circuit.

17. A motor vehicle as set forth in claim 16 in which the signal source comprises a signal switch that is selectively operable to a first position for giving the signal when the control is operated to resist vehicle motion and to a second position for that does not give the signal when the control is operated to not resist vehicle motion.

18. A motor vehicle as set forth in claim 17 in which the vehicle control comprises a parking brake that is selectively operable to respectively apply and release a vehicle parking brake, and the signal switch comprises a park brake switch for signaling application of a parking brake of the vehicle when in the first position and release of the parking brake when in the second position.

19. A motor vehicle as set forth in claim 17 in which the reduced illumination intensity circuit comprises a daytime running light circuit to which the park brake switch is connected.

20. A motor vehicle as set forth in claim 17 in which the reduced illumination intensity circuit comprises a daytime running light circuit to which the signal switch is connected, and further including a selector switch through which the signal switch is connected to the daytime running light circuit, wherein the selector switch is operable to a first position that provides continuity of the signal switch to the daytime running light circuit and a second position that interrupts continuity of the signal switch to the daytime running light circuit, and wherein the selector switch is effective, when in its second position, to prevent the signal switch from overriding the main headlight circuit.

21. A motor vehicle comprising:

a) a voltage source;

b) at least one headlight providing illumination of a field of view frontally of the vehicle;

c) a headlight control that is selectively operable to OFF and ON positions for selectively turning the at least one headlight off and on;

d) a main headlight circuit controlled by the headlight control for causing substantially full voltage of the voltage source to be applied to the at least one headlight when the headlight control is operated to ON position to illuminate the field of view at a relatively full illumination intensity;

e) exterior lights on the exterior of the vehicle that are visible to a driver of an on-coming vehicle;

f) a switch that is selectively operable to respectively flash and not flash the exterior lights, and that when operated to flash the exterior lights, overrides the main headlight circuit to cause substantially less than full voltage of the voltage source to be applied to the at least one headlight so that the field of view is illuminated at substantially less than relatively full illumination intensity while the exterior lights are flashing, and that, when operated to not flash the exterior lights while the headlight control is in ON position, does not override the main headlight circuit.

22. A motor vehicle as set forth in claim 21 in which the vehicle comprises a school bus for transporting students.