Headlight light distribution control device and method
First Claim
1. A headlight light distribution control device which is mounted on a vehicle and switches an irradiation direction of a headlight of the vehicle, the headlight light distribution control device comprising:
- a light source detector which detects a light source of a region ahead of the vehicle; and
a control device that controls the irradiation direction of the headlight, wherein the control device comprises;
a light source presence counter that acquires information on the presence of a light source of a region ahead of the vehicle per predetermined time interval from the light source detector and counts the number of times the light source of a region ahead of the vehicle changes from not present to present;
a threshold-reached judging section that judges whether or not the number of times counted by the light source presence counter has reached a predetermined threshold value within a predetermined amount of time (Tm); and
a beam maintaining section that keeps the headlight at low beam for a predetermined amount of time (Tp), based on the number of times counted by the light source presence counter and a speed of the vehicle detected by a speed detecting device, the beam maintaining section being configured to keep the headlight at low beam for the predetermined amount of time (Tp), on a condition that the counted number of times that the speed of the vehicle is high is larger than the counted number of times that the speed of the vehicle is low.
1 Assignment
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Accused Products
Abstract
Speed of a vehicle is acquired from a speed detecting device, and then a beam switching threshold, according to the acquired speed, of an irradiation direction of a headlight is initially set. When the number of appearance (i.e. frequency of appearance) of a light source in a predetermined time detected by a light source detection means have become the beam switching threshold or more, the headlight is switched to a low beam. When a predetermined time (beam switching prohibition time Tp) has been passed after the irradiation direction of a headlight was switched to the low beam, the irradiation direction of the headlight is switched to a high beam.
11 Citations
10 Claims
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1. A headlight light distribution control device which is mounted on a vehicle and switches an irradiation direction of a headlight of the vehicle, the headlight light distribution control device comprising:
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a light source detector which detects a light source of a region ahead of the vehicle; and a control device that controls the irradiation direction of the headlight, wherein the control device comprises; a light source presence counter that acquires information on the presence of a light source of a region ahead of the vehicle per predetermined time interval from the light source detector and counts the number of times the light source of a region ahead of the vehicle changes from not present to present; a threshold-reached judging section that judges whether or not the number of times counted by the light source presence counter has reached a predetermined threshold value within a predetermined amount of time (Tm); and a beam maintaining section that keeps the headlight at low beam for a predetermined amount of time (Tp), based on the number of times counted by the light source presence counter and a speed of the vehicle detected by a speed detecting device, the beam maintaining section being configured to keep the headlight at low beam for the predetermined amount of time (Tp), on a condition that the counted number of times that the speed of the vehicle is high is larger than the counted number of times that the speed of the vehicle is low. - View Dependent Claims (2, 3, 4, 5)
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6. A headlight light distribution control method for switching irradiation direction of the headlight of a vehicle, the headlight light distribution control method comprising:
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counting, by a light source presence counter, the number of times a light source of a region ahead of the vehicle changes from not present to present per predetermined time interval in a predetermined time; judging, by a threshold-reached judging section, whether or not the number of times has reached a predetermined threshold value within a predetermined amount of time (Tm); and keeping, by a beam maintaining section, the headlight at low beam for a predetermined amount of time (Tp), based on the number of times counted by the light source presence counter and a speed of the vehicle detected by a speed detecting device, wherein the keeping step keeps, by the beam maintaining section, the headlight at low beam for the predetermined amount of time (Tp), on a condition that the counted number of times that the speed of the vehicle is high is larger than the counted number of times that the speed of the vehicle is low. - View Dependent Claims (7, 8, 9, 10)
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Specification