LED lamp with light guide

• US 20050152141A1
• Filed: 01/12/2005
• Published: 07/14/2005
• Est. Priority Date: 01/13/2004
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: Suzuki, Nobuyuki
• Granted Patent: US 7,134,768 B2
• Time in Patent Office: Days
• US Class Current: 362/241
• CPC Class Codes: B60Q 1/0052 concentric
• CPC Class Codes: B60Q 1/0058 Stacked, i.e. one lamp located behind the other in the optical axis direction
• CPC Class Codes: B60Q 1/2607 comprising at least two indicating lamps
• CPC Class Codes: F21L 4/027 the light sources being a LED
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 43/241 of complex shape
• CPC Class Codes: F21S 43/243 emitting light from one or more of its extremities
• CPC Class Codes: F21S 43/249 with two or more light sources being coupled into the light guide
• CPC Class Codes: F21S 43/315 using total internal reflection
• CPC Class Codes: F21S 43/40 characterised by the combination of reflectors and refractors
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21W 2111/02 for roads, paths or the like
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298

Abstract

Light emitted from a plurality of LED light sources can be introduced into a light guide and inwardly reflected (totally reflected) at a first reflective surface formed on the light guide to form a substantially collimated light. The substantially collimated light can then be inwardly reflected (totally reflected) at a second reflective surface and a third reflective surface. The light can then be led out of the light guide and emitted in a direction of illumination of the lamp. An increased amount of light provides a bright lamp. An arrangement of LEDs emitting different colored lights enables the different colored lights to be emitted at the same time or with time delays.

Claims

1. An LED lamp, comprising:

a plurality of LED light sources arranged to emit light;

a light guide located adjacent the LED light sources and having a primary reflective surface, a secondary reflective surface and a tertiary reflective surface; and

a reflector located adjacent the light guide, wherein the lamp has a direction of illumination and the light guide is configured such that light emitted from each of the LED light sources enters the light guide and is reflected and substantially collimated at the primary reflective surface, is reflected and substantially collimated at the secondary reflective surface, and is reflected at the tertiary reflective surface in turn and exits from the light guide toward the reflector as light guide exit light, the reflector being configured to reflect the light guide exit light substantially in the direction of illumination of the lamp.

2. The LED lamp according to claim 1, wherein the primary reflective surface is a paraboloidal curved surface having a focus substantially on at least one of the LED light sources, the secondary reflective surface is an oblique curved surface configured to receive the light reflected from the primary reflective surface and direct it toward the tertiary reflective surface, the tertiary reflective surface is an oblique curved surface configured to receive the light reflected from the secondary reflective surface and direct it toward the reflector, the reflector is provided about the tertiary reflective surface and configured as an oblique curved surface that receives the light reflected from the tertiary reflective surface and directs it substantially in the direction of illumination of the lamp.

3. The LED lamp according to claim 1, wherein the light emitted from the LED light sources includes light of at least two types.

4. The LED lamp according to claim 3, wherein the LED light sources are formed in groups of LEDs, wherein each group of LEDs emitting light of the same type can be individually power controlled.

5. The LED lamp according to claim 1, wherein the light guide includes a first light guide portion formed at an angle with respect to the direction of illumination of the lamp, and a second light guide portion formed substantially in parallel with the direction of illumination of the lamp,

the first light guide portion including the primary reflective surface,

the second light guide portion including the tertiary reflective surface and protruding toward a front of the lamp and in the direction of illumination relative to the first light guide portion.

6. The LED lamp according to claim 2, wherein the light emitted from the LED light sources includes light of at least two types.

7. The LED lamp according to claim 1, wherein the light emitted from the LED light sources is all the same type of light.

8. The LED lamp according to claim 2, wherein the light emitted from the LED light sources is all the same type of light.

9. The LED lamp according to claim 3, wherein the at least two types of light includes a first color light and a second color light that is different from the first color light.

10. The LED lamp according to claim 1 wherein the light guide includes a first light guide portion that is elongate in a direction substantially perpendicular to the direction of illumination of the lamp, and includes a second light guide portion that is elongate in a direction substantially parallel to the direction of illumination of the lamp.

11. The LED lamp according to claim 10 wherein the first light guide portion is configured in a substantially disc shape having a central axis extending along the direction of illumination of the lamp, and the second light guide portion extends along the central axis of the first light guide portion.

12. The LED lamp according to claim 11 wherein the LED light sources are located about a periphery of the disc shaped first light guide portion.

13. The LED lamp according to claim 1 wherein the light source guide is made from a transparent resin material.

20. The LED of claim 1, wherein the light emitted from the LED light sources is transmitted through the light guide along an optical path that traces a path from the primary reflective surface at which the light is substantially collimated and travels until it is reflected by the tertiary reflective surface.

14. An LED lamp having a direction of illumination, comprising:

a plurality of LED light sources;

a light guide located adjacent the LED light sources and having a first light guide portion that is elongate in a direction that is angled with respect to the direction of illumination of the lamp, and a second light guide portion that is elongate in a direction that is angled with respect to the elongate direction of the first light guide portion, the first light guide portion configured to receive light emitted from the plurality of LED light sources, to substantially collimate the received light into a first collimated light that travels in a first direction, and to change the direction of the first collimated light into a second different direction as second collimated light, the second light guide portion configured to receive the second collimated light and to change the direction of the second collimated light into a third different direction as third light; and

a reflector located adjacent to the light guide and configured to receive the third light and reflect the third light into another direction different from the third direction and substantially parallel to the illumination direction of the lamp.

15. The LED lamp of claim 14, wherein the light guide includes a primary reflective surface configured to collimate the light received from the LED light sources into the first direction, a secondary reflective surface configured to reflect the first collimated light into the second different direction, and a tertiary reflective surface configured to reflect the second collimated light into the third different direction.

16. The LED lamp of claim 14, wherein the first light guide portion is elongate in a direction substantially perpendicular to the illumination direction of the lamp, and the second light guide portion is elongate in a direction substantially parallel to the illumination direction of the lamp.

17. The LED lamp of claim 14, wherein the light reflected by the reflector is emitted from the lamp in the form of a geometric figure.

18. The LED lamp of claim 17, wherein the geometric figure is a circle.

19. The LED lamp of claim 17, wherein the geometric figure is a plurality if concentric circles.