US 4,868,720 A · Road surface-sensitive beam pattern leveling system for a vehicle headlamp

Abstract

A motorcycle headlamp capable of emitting a light beam with a beam pattern calculated to provide optimum forward illumination. In order to maintain the beam pattern in a level position about the lamp axis despite the lateral tipping of the motorcycle, at least one road sensor is employed for detecting the lateral angular position of the vehicle with respect to the road surface by transmitting radiation such as an ultrasonic wave or infrared rays toward the road surface and receiving its reflection from the road surface. Electric signals representative of lateral vehicle inclinationare fed to a central processor unit, which then causes energization of a reversible electric motor built into the headlamp unit for leveling the beam pattern by revolving the bulb and control lens of the headlamp unit relative to the lamp housing. Thus, as the lateral angular position of the vehicle is detected in reference to the road surface, instead of to the perpendicular, the beam pattern can be maintained in the level position with respect to the road surface regardless of whether the road is banked or unbanked. Several different methods of detecting lateral vehicle inclination are disclosed.

Claims17

Dependent claims

A beam pattern leveling headlamp system for use on a motorcycle or like vehicle that is subject to lateral tipping as when taking a curve, the headlamp system comprising:

(a) a headlamp unit on a vehicle for throwing a light beam having a prescribed beam pattern, the headlamp unit having a lamp axis and being capable of angularly displacing the beam pattern about the lamp axis;
(b) beam pattern leveling means acting on the headlamp unit for causing the same to angularly displace the beam pattern about the lamp axis;
(c) vehicle inclination detector means sensitive to a road surface on which the vehicle is traveling, for detecting the degree of lateral tipping of the vehicle with respect to the road surface;
(d) control means responsive to the vehicle inclination detector means for actuating the beam pattern leveling means so as to cause the head lamp unit to angularly displace the beam pattern about the lamp axis to an extent necessary for leveling the beam pattern with respect to the road surface in the face of the lateral tipping of the vehicle thereon;
(e) whereby the beam can always be maintained in the level position with respect to the road surface regardless of whether the road is banked or unbanked.

2 more elements

A beam pattern leveling headlamp system for use on a motorcycle or like vehicle that is subject to lateral tipping as when taking a curve, the headlamp system comprising:

(a) lamp housing means;
(b) a reflector within the lamp housing means and centered about a lamp axis;
(c) a light source coaxially positioned within the reflector for rotation relative to the lamp housing means about the lamp axis;
(d) a control lens positioned within the lamp housing means and coupled to the light source for joint rotation therewith;
(e) the reflector and the light source and the control lens coacting to emit a light beam having a prescribed beam pattern which is angularly displaceable about the lamp axis by the joint rotation of the light source and the control lens about the lamp axis;
(f) beam pattern leveling means for bidirectionally revolving the light source and the control lens relative to the lamp housing means in order to cause angular displacement of the beam pattern about the lamp axis;
(g) beam pattern angle detector means responsive to the rotation of the light source and the control lens for detecting the actual angle of the beam pattern about the lamp axis;
(h) vehicle inclination detector means including at least one road sensor for detecting the direction and angle of lateral tipping of the vehicle with respect to a road surface on which the vehicle is traveling, the road sensor being capable of transmitting radiation toward the road surface and receiving the reflection of the radiation from the road surface;
and
(i) control means responsive to the beam pattern angle detector means and to the vehicle inclination detector means and to the vehicle inclination detector means for actuating the beam pattern leveling means so as to cause the same to revolve the light source and the control lens in such a direction, and through such an angle, that the beam pattern remains level with respect to the road surface in the face of the lateral tipping of the vehicle regardless of whether the road is banked or unbanked.

7 more elements

Dependencies are inferred from the claim text.

Road surface-sensitive beam pattern leveling system for a vehicle headlamp

Life of this patent

Road surface-sensitive beam pattern leveling system for a vehicle headlamp

Life of this patent

Abstract

Claims17