Headlamp device and luminance control method therefor
First Claim
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1. A headlamp device for a vehicle that has LEDs as light sources, comprising:
- a situation detection portion detecting that a situation is a headlamp lighting situation in which headlamps should be on;
a headlamps control portion turning on the headlamps when the situation detection means detects that the situation is the headlamp lighting situation;
a luminance reduction portion reducing luminance of the headlamps by a prescribed amount;
an image acquiring portion that acquires image data on an area illuminated by the headlamps; and
a dimming control portion thatobserves a rate of decrease in brightness of the image data on the area illuminated by the headlamps when the luminance of the headlamps is reduced by the prescribed amount by the luminance reduction portion,compares the rate of decrease in brightness with a threshold value,reduces the luminance of the headlamps to a prescribed value that is greater than zero based on a determination that the rate of decrease in brightness is smaller than the threshold value, andmaintains the luminance of the headlamps based on a determination that the rate of decrease in brightness is equal to or larger than the threshold value.
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Abstract
To provide a headlamp device for a vehicle that has LEDs as light sources, the headlamp device including a situation detection part that detects a lighting status of headlamps; and a dimming control part that reduces the luminance of the headlamps to a prescribed value that is greater than zero based on the lighting status of the headlamps.
12 Citations
11 Claims
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1. A headlamp device for a vehicle that has LEDs as light sources, comprising:
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a situation detection portion detecting that a situation is a headlamp lighting situation in which headlamps should be on; a headlamps control portion turning on the headlamps when the situation detection means detects that the situation is the headlamp lighting situation; a luminance reduction portion reducing luminance of the headlamps by a prescribed amount; an image acquiring portion that acquires image data on an area illuminated by the headlamps; and a dimming control portion that observes a rate of decrease in brightness of the image data on the area illuminated by the headlamps when the luminance of the headlamps is reduced by the prescribed amount by the luminance reduction portion, compares the rate of decrease in brightness with a threshold value, reduces the luminance of the headlamps to a prescribed value that is greater than zero based on a determination that the rate of decrease in brightness is smaller than the threshold value, and maintains the luminance of the headlamps based on a determination that the rate of decrease in brightness is equal to or larger than the threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A luminance control method for a headlamp device for a vehicle having LEDs as light sources, comprising:
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detecting that a situation is a headlamp lighting situation in which the headlamps should be on by a situation detection portion; turning on the headlamps when the headlamp lighting situation has been detected by a headlamp control portion; reducing the luminance of the headlamps to a prescribed amount by a luminance reduction portion, acquiring image data on an area illuminated by the headlamps by an image acquiring portion, observing a rate of decrease in brightness of the image data on the area illuminated by the headlamps when the luminance of the headlamps is reduced by the prescribed amount by the luminance reduction portion, comparing the rate of decrease in brightness with a threshold value, reducing the luminance of the headlamps to a prescribed value that is greater than zero based on a determination that the rate of decrease in brightness is smaller than the threshold value, and maintaining the luminance of the headlamps based on a determination that the rate of decrease in brightness is equal to or larger than the threshold value.
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Specification