Vehicle headlamp system and dimming-type vehicle headlamp
First Claim
1. A vehicle headlamp system including a headlamp and configured to control illumination of lamp units in accordance with a driving condition, the headlamp comprising lamp units housed in a lamp chamber defined by a lamp body, and a front lens, and to emit a beam ahead of said vehicle in a light distribution pattern, the system comprising:
- a dimming unit that controls said illumination by adjusting an amount of power fed to a light source of at least one of the lamp units to adjust the quantity of light radiated from said lamp unit, wherein said dimming unit gradually decreases an effective value of a light source applied voltage to extinguish said lamp unit, and sets said effective value of said light source applied voltage to zero in one stroke when said effective value of said applied voltage has decreased to a threshold value.
1 Assignment
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Accused Products
Abstract
Lamp units for radiating a beam ahead of a vehicle in a light distribution pattern are housed in a lamp body. Illumination of the auxiliary lamp units is controlled based on driving conditions. Illumination control means extinguish light through dimming by gradually decreasing voltage applied to the light sources. When the applied voltage has dropped to a threshold value, the applied voltage is controlled to zero immediately. Compared to when the lamps remaining in an illuminated state are suddenly extinguished, a change in, quantity of light is mild, and no uncertainty arises. Below a threshold value where the applied voltage gradually drops to the threshold value and a change may arise in the filament crystalline structure due to annealing at a transition temperature, the applied voltage approaches zero. Hence, the filament does not pass from the transition temperature while being rapidly cooled, thus avoiding filament crystalline structure change.
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Citations
15 Claims
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1. A vehicle headlamp system including a headlamp and configured to control illumination of lamp units in accordance with a driving condition, the headlamp comprising lamp units housed in a lamp chamber defined by a lamp body, and a front lens, and to emit a beam ahead of said vehicle in a light distribution pattern, the system comprising:
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a dimming unit that controls said illumination by adjusting an amount of power fed to a light source of at least one of the lamp units to adjust the quantity of light radiated from said lamp unit, wherein said dimming unit gradually decreases an effective value of a light source applied voltage to extinguish said lamp unit, and sets said effective value of said light source applied voltage to zero in one stroke when said effective value of said applied voltage has decreased to a threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A vehicle headlamp system having a headlamp and an auxiliary lamp, and configured to control illumination of one of at least one lamp unit and said auxiliary lamp in accordance with a driving condition, the headlamp having at least one lamp unit housed in a lamp chamber defined by a lamp body, and a front lens, and to emit a beam ahead of said vehicle in a light distribution pattern, the system comprising:
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a dimming unit that controls said illumination by adjusting at least one of (a) an amount of power fed to a light source of at least one of the at least one lamp unit, and (b) an amount of power fed to a light source of said auxiliary lamp to adjust at least one of (a) a quantity of light radiated from said lamp unit and (b) a quantity of light radiated from said auxiliary lamp unit, both said lamp unit and said auxiliary lamp unit provided in said headlamp, wherein said dimming unit gradually decreases an effective value of a light source applied voltage to extinguish at least one of said lamp unit and said auxiliary lamp, and sets said effective value of said applied voltage to zero in one stroke when said effective value of said applied voltage has decreased to a threshold value. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A vehicle headlamp system configured to control illumination of one of a lamp unit and an auxiliary lamp disposed in a vicinity of said headlamp, in accordance with a driving condition and to emit a beam ahead of said vehicle in a light distribution pattern, comprising:
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the headlamp including at least one lamp unit housed in a lamp chamber defined by a lamp body, and a front lens; and
means for controlling said illumination by adjusting at least one of (a) power input to a light source of the lamp unit, and (b) power input to a light source of said auxiliary lamp, to respectively adjust at least one of (a) a quantity of light radiated from said lamp unit and (b) a quantity of light radiated from said auxiliary lamp unit, wherein said means for controlling gradually decreases an effective value of a light source applied voltage to extinguish said one of said lamp unit and said auxiliary lamp, and sets said effective value of said applied voltage to zero in one stroke when said effective value of said applied voltage has decreased to a threshold value.
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Specification