Vehicle headlamp and illuminating device

• US 8,569,942 B2
• Filed: 12/01/2010
• Issued: 10/29/2013
• Est. Priority Date: 12/17/2009
• Status: Active Grant

• Current Assignee: Sharp Fukuyama Laser Co., Ltd. (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kishimoto, Katsuhiko, Kawanishi, Hidenori
• Primary Examiner(s): Hanley, Britt D
• Application Number:
  US12/957,998
• Publication Number:
  US 20110148280A1
• Time in Patent Office: 1,063 Days
• Field of Search: None
• US Class Current: 313/483
• CPC Class Codes: F21S 41/00 Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps reversing lights F21S43/00
• CPC Class Codes: F21S 41/16 Laser light sources
• CPC Class Codes: F21S 41/176 Light sources where the light is generated by photoluminescent material spaced from a primary light generating element
• CPC Class Codes: F21S 41/24 Light guides
• CPC Class Codes: F21S 41/322 the reflector using total internal reflection
• CPC Class Codes: F21S 45/70 Prevention of harmful light leakage
• CPC Class Codes: F21W 2107/10 for land vehicles
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A headlamp 1 includes a laser diode 3 that emits a laser beam, a light emitting part 7 that emits light upon receiving the laser beam emitted from the laser diode 3, and a reflection mirror 8 that reflects the light emitted from the light emitting part 7. According to the headlamp 1, the light emitting part 7 has a luminance greater than 25 cd/mm², and an area size of an aperture plane 8a perpendicular to a direction in which an incoherent light travels outward from the headlamp 1 is less than 2000 mm².

Claims

1. A vehicle headlamp, comprising:

an excitation light source that emits excitation light;

a light emitting part that emits light upon receiving the excitation light emitted from the excitation light source; and

an optical system that distributes the light emitted from the light emitting part,

the light emitting part having a luminance greater than 75 cd/mm², and

an area size of the optical system, when viewed from a direction in which the light travels outward from the vehicle headlamp, being less than 1500 mm², and at least 100 times as large as an area size of a surface of the light-emitting part, which surface receives the excitation light.

2. The vehicle headlamp according to claim 1, wherein the area size of the optically system is greater than or equal to 100 mm².

3. The vehicle headlamp according to claim 1, wherein the excitation light emitted from the excitation light source has a peak wavelength falling within a range of not less than 400 nm but not more than 420 nm.

4. The vehicle headlamp according to claim 1, wherein the excitation light emitted from the excitation light source has a peak wavelength falling within a range of not less than 440 nm but not more than 490 nm.

5. The vehicle headlamp according to claim 1, which vehicle headlamp serves as a driving headlamp for an automobile.

6. A vehicle headlamp according to claim 1, wherein the excitation light source is provided outside the optical system, and the light-emitting part is provided inside the optical system.

7. An illuminating device, comprising:

an excitation light source that emits excitation light;

a light emitting part that emits light upon receiving the excitation light emitted from the excitation light source; and

an optical system that distributes the light emitted from the light emitting part,

the light emitting part having a luminance greater than 75 cd/mm², and

an area size of the optical system, when viewed from a direction in which the light travels outward from the illumination device being less than 1500 mm², and at least 100 times as large as an area size of a surface of the light-emitting part, which surface receives the excitation light.