Vehicle lamp
A vehicle headlamp ( 1 ) includes: a light source ( 52 R, 52 G, 52 B) that emits light having a predetermined wavelength; a light distribution pattern forming optical system ( 56 R, 56 G, 56 B) that includes a collimator lens ( 53 R, 53 G, 53 B) and a diffraction grating ( 54 R, 54 G, 54 B) that change a traveling direction of at least some of pieces of light emitted from the light source ( 52 R, 52 G, 52 B), and emits light (L R , L G , L B ) having a predetermined light distribution pattern; and a vibration imparting unit ( 57 R, 57 G, 57 B) that relatively vibrates the light source ( 52 R, 52 G, 52 B) and the diffraction grating ( 54 R, 54 G, 54 B).
1. A vehicle lamp comprising:
a light source that emits light having a predetermined wavelength;
a light distribution pattern forming optical system that includes an optical element that changes a traveling direction of at least some of pieces of the light emitted from the light source, and emits light having a predetermined light distribution pattern; and
a vibration imparting unit that relatively vibrates the light source and the optical element;
wherein the vibration imparting unit is a vibrator which vibrates the light source or the optical element, and an amplitude of vibration imparted by the vibration imparting unit varies.
2. The vehicle lamp according to claim 1 ,
wherein the vibration imparting unit vibrates the optical element.
3. The vehicle lamp according to claim 2 ,
wherein the optical element is a diffraction grating.
4. The vehicle lamp according to claim 2 ,
wherein the vibration imparting unit imparts vibration to the optical element in two or more directions.
5. The vehicle lamp according to claim 2 ,
wherein a frequency of vibration imparted by the vibration imparting unit is 15 Hz or higher.
6. The vehicle lamp according to claim 1 ,
wherein the vibration imparting unit vibrates the light source.
7. The vehicle lamp according to claim 1 , wherein
the optical element is a set of a plurality of diffraction gratings, each of the plurality of diffraction gratings having a same diffraction grating pattern,
the vibration imparting unit vibrates the diffraction gratings, and
the amplitude of vibration imparted by the vibration imparting unit is larger than a length of a vibration direction of a region having the same diffraction grating pattern in each of the diffraction gratings.