VEHICULAR LAMP

• US 20190376659A1
• Filed: 06/03/2019
• Published: 12/12/2019
• Est. Priority Date: 06/06/2018
• Status: Active Grant

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Kito, Masanori, Motohashi, Kazuya
• Granted Patent: US 10,641,457 B2
• Time in Patent Office: Days
• CPC Class Codes: B60Q 1/04 the devices being headlights
• CPC Class Codes: F21S 41/14 characterised by the type of light source
• CPC Class Codes: F21S 41/16 Laser light sources
• CPC Class Codes: F21S 41/25 Projection lenses
• CPC Class Codes: F21S 41/285 Refractors, transparent cover plates, light guides or filters not provided in groups F21S41/24 - F21S41/2805
• CPC Class Codes: F21S 41/321 the reflector being a surface of revolution or a planar surface, e.g. truncated
• CPC Class Codes: F21S 41/365 successively reflecting the light
• CPC Class Codes: F21S 41/43 characterised by the shape thereof
• CPC Class Codes: F21S 41/635 by moving refractors, filters or transparent cover plates
• CPC Class Codes: F21S 41/645 by electro-optic means, e.g. liquid crystal or electrochromic devices
• CPC Class Codes: F21S 41/663 by switching light sources by switching incandescent light sources F21S41/162
• CPC Class Codes: F21S 41/675 by moving reflectors
• CPC Class Codes: F21S 45/40 Cooling of lighting devices
• CPC Class Codes: F21S 45/435 circulating the gas within a closed system
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings

Abstract

A headlight includes light sources, and phase modulation elements that diffract lights incident from the light sources with changeable phase modulation patterns. The lights diffracted by the phase modulation elements are emitted with a low beam light distribution pattern that is a predetermined light distribution pattern based on the phase modulation patterns. A projection region on which zeroth order lights, that are emitted from the phase modulation elements without being diffracted by the phase modulation elements, among the lights incident on the phase modulation elements, are projected is located within a range where a driver'"'"'s view of a vehicle is obstructed by the vehicle.

Claims

1. A vehicular lamp comprising:

a light source; and

a phase modulator configured to diffract a light beam incident from the light source with a changeable phase modulation pattern,

wherein the light beam diffracted by the phase modulator is emitted with a predetermined light distribution pattern based on the phase modulation pattern, and

a projection region on which, in the light beam incident on the phase modulator, zeroth order light beam emitted from the phase modulator without being diffracted by the phase modulator is projected is located within a range where a driver'"'"'s view of a vehicle is obstructed by the vehicle.

2. The vehicular lamp according to claim 1, wherein the predetermined light distribution pattern has a light intensity distribution.

3. The vehicular lamp according to claim 1, further comprising:

a plurality of light-emitting optical systems each including one light source and one phase modulator; and

an optical synthesizer configured to synthesize light beams emitted from the light-emitting optical systems, respectively,

wherein light sources in the light-emitting optical systems emit light beams with mutually different predetermined wavelengths, respectively, and

phase modulators in the light-emitting optical systems diffract the light beams from the light sources, respectively, such that a light beam obtained through synthesis in the optical synthesizer has the predetermined light distribution pattern.

4. The vehicular lamp according to claim 3, wherein zeroth order light beams emitted from the phase modulators in the light-emitting optical systems, respectively, are synthesized in the synthesis optical system and projected on the projection region.

5. The vehicular lamp according to claim 2, further comprising:

a plurality of light-emitting optical systems each including one light source and one phase modulation element; and

an optical synthesizer configured to synthesize light beams emitted from the light-emitting optical systems, respectively,

wherein the light sources in the light-emitting optical systems emit light beams with mutually different predetermined wavelengths, respectively, and

the phase modulators in the light-emitting optical systems diffract the light beams from the light sources, respectively, such that a light beam obtained through synthesis in the optical synthesizer has the predetermined light distribution pattern.

6. The vehicular lamp according to claim 5, wherein zeroth order light beams emitted from the phase modulators in the light-emitting optical systems, respectively, are synthesized in the optical synthesizer and projected on the projection region.