Vehicular lamp

• US 20050117361A1
• Filed: 09/24/2004
• Published: 06/02/2005
• Est. Priority Date: 09/25/2003
• Status: Active Grant

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited, Nichia Corporation
• Inventors: Tokida, Tsukasa, Takeda, Hitoshi, Inoue, Takumi
• Granted Patent: US 7,168,834 B2
• Time in Patent Office: Days
• US Class Current: 362/509
• CPC Class Codes: B60Q 1/34 for indicating change of drive direction B60Q1/22 takes precedence
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 43/235 Light guides
• CPC Class Codes: F21S 43/255 Filters
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/52 Encapsulations

Abstract

A vehicular lamp that irradiates umber light includes: a light emitting diode operable to emit blue light; a long-wavelength phosphor operable to emit light of which a peak wavelength is substantially equal to or longer than a wavelength of the umber light based on the blue light emitting from the light emitting diode; and an optical filter operable to block the bulk of light emitting from the light emitting diode and also to transmit the bulk of light, which has a wavelength similar to the peak wavelength, among light emitting from the long-wavelength phosphor to generate the umber light depending to light emitting from the light emitting diode and the long-wavelength phosphor.

Claims

1. A vehicular lamp that irradiates umber light, comprising:

a light emitting diode emitting blue light;

a long-wavelength phosphor emitting light, of which a peak wavelength is substantially equal to or longer than a wavelength of the umber light according to the blue light emitting from said light emitting diode; and

an optical filter operable to block almost all light emitting from said light emitting diode and also to transmit almost all light, which has a wavelength similar to the peak wavelength, among light emitting from said long-wavelength phosphor to generate the umber light based on the light emitting from said light emitting diode and said long-wavelength phosphor.

4. A vehicular lamp as claimed in claim 1, wherein said long-wavelength phosphor comprises Y₃Al₅O₁₂:

Ce or Tb₃Al₅O₁₂;

Ce.

6. A vehicular lamp as claimed in claim 1, wherein said long-wavelength phosphor comprises M_xSi_yN_x:

Eu, where z=2x/3+4y/3, M is at least an element selected from a group consisting of alkaline earth metals.

2. A vehicular lamp that irradiates umber light, comprising:

a light emitting diode;

a long-wavelength phosphor emitting light, of which a peak wavelength is substantially equal to or longer than a wavelength of the umber light according to light emitting from said light emitting diode; and

an optical filter operable to block light having shorter wavelength than a transmission limit and transmit light having longer wavelength than the transmission limit,

wherein the transmission limit in said optical filter is located between a peak wavelength of light emitting from said light emitting diode and the peak wavelength of light emitting from said long-wavelength phosphor, and is located at longer wavelength side than that of a position of which light intensity is the lowest among light of continuous spectrum emitted from said light emitting diode and said long-wavelength phosphor and also located at shorter wavelength side than that of the peak of light emitting from said long-wavelength phosphor.

3. A vehicular lamp as claimed in claim 2, wherein the transmission limit in said optical filter is located at shorter wavelength side than that of 50% of the peak of light emitting from said long-wavelength phosphor.

5. A vehicular lamp as claimed in claim 2, wherein said long-wavelength phosphor comprises Y₃Al₅O₁₂:

Ce or Tb₃Al₅O₁₂;

Ce.

7. A vehicular lamp as claimed in claim 2, wherein said long-wavelength phosphor comprises M_xSi_yN_z:

Eu, where z=2x/3+4y/3, M is at least an element selected from a group consisting of alkaline earth metals.