Light pipe optical coupling utilizing convex-shaped light pipe end

• US 7,215,863 B1
• Filed: 04/27/2006
• Issued: 05/08/2007
• Est. Priority Date: 04/27/2006
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: DeCusatis, Casimer M., Barringer, Dennis R., Qualters, Kevin R., Shadoff, Kenneth A., Arenella, Kenneth
• Primary Examiner(s): Pak; Sung
• Assistant Examiner(s): WONG, TINA MEI SENG
• Application Number:
  US11/412,765
• Time in Patent Office: 376 Days
• Field of Search: 385/133, 385/146
• US Class Current: 385/133
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers

Abstract

A light transmission device is provided including a light pipe having two ends, one end being an ellipsoidal-shaped end. A recess is configured within the ellipsoidal-shaped end for reception of a light source that transmits light into the light pipe. The recess includes an interior concave wall, and the light source is at least partially received in the recess to face the interior concave wall via which light is transmitted into the light pipe. The ellipsoidal-shaped end further includes a curved surface configured to facilitate collection of light into the light pipe when the light source is at least partially received in the recess in the ellipsoidal-shaped end. The ellipsoidal-shaped end includes a first focal point and a second focal point, wherein the recess in the ellipsoidal-shaped end intersects the first focal point, and the second focal point is disposed adjacent to or within the light pipe.

Claims

1. A light transmission device comprising:

a light pipe having two ends;

one of the ends comprising an ellipsoidal-shaped end comprising a first focal point and a second focal point and including a recess configured for reception of a light-emitting component that transmits light into the light pipe, the recess intersecting the first focal point and having an interior concave wall, with the light-emitting component to be at least partially received in the recess to face the interior concave wall via which light is transmitted into the light pipe; and

wherein the ellipsoidal-shaped end includes a curved surface configured to facilitate collection of light into the light pipe when the light-emitting component is at least partially received in the recess to face the interior concave call, and intersecting the first focal point.

2. The light transmission device of claim 1, wherein the light pipe comprises a longitudinal axis extending between the two ends thereof, and wherein the first focal point and the second focal point reside on the longitudinal axis.

3. The light transmission device of claim 2, wherein the light pipe comprises a longitudinally axially-extending light pipe, and the ellipsoidal-shaped end comprises an ellipsoidal-shaped extension at the one end of the longitudinally axially-extending light pipe.

4. The light transmission device of claim 3, wherein the longitudinally axially-extending light pipe includes a transverse diameter D, and wherein the ellipsoidal-shaped extension has an outer width W in a direction parallel to the transverse diameter D of the longitudinally axially-extending light pipe, wherein width W≧

diameter D.

5. The light transmission device of claim 3, wherein the ellipsoidal-shaped end and the light pipe are integrally formed of a common material.

6. The light transmission device of claim 5, wherein the common material is a plastic.

7. The light transmission device of claim 2, wherein the first focal point and the second focal point of the ellipsoidal-shaped end are conjugate focal points, and the ellipsoidal-shaped end comprises an elliptical surface which reflects light from the first focal point to the second focal point.

8. The light transmission device of claim 7, wherein with the light-emitting component received in the recess to face the interior concave wall, the first focal point is disposed in a center region of the light-emitting component.

9. The light transmission device of claim 7, wherein the second focal point of the ellipsoidal-shaped end is disposed adjacent to the light pipe with a majority of light passing therethrough being captured into the light pipe for propagation within the light pipe.

10. The light transmission device of claim 7, wherein the second focal point of the ellipsoidal-shaped end is disposed within the light pipe with light passing therethrough propagating within the light pipe.

11. The light transmission device of claim 2, wherein the light-emitting component comprises a visible light-emitting diode (LED), and wherein the recess in the ellipsoidal-shaped end defines a perimeter surface extending about the LED.

12. The light transmission device of claim 11, wherein the light transmission device is configured to reside on an electronics board, and wherein an opposite end of the light pipe from the ellipsoidal-shaped end is disposed near an edge of the electronics board when the light transmission device resides on the electronic board.

13. A light device comprising:

a light source;

a light pipe having two ends; and

one of the ends comprising an ellipsoidal-shaped end with the light source being at least partially disposed therein, the ellipsoidal-shaped end comprising a first focal point and a second focal point and including a curved surface configured to facilitate collection of light into the light pipe from the light source, wherein the light source is disposed to intersect the first focal point.

14. The light device of claim 13, wherein the light source is at least partially disposed within a recess formed in the ellipsoidal-shaped end of the light pipe, and the second focal point is within the light pipe.

15. The light device of claim 14, wherein the ellipsoidal-shaped end and the light pipe are integrally formed of a common material.

16. The light device of claim 15, wherein the ellipsoidal-shaped end and the light pipe are formed around the light source and in physical contact with the light source.

17. The light device of claim 13, wherein the light pipe comprises a longitudinal axis extending between the two ends thereof, and wherein the first focal point and the second focal point reside on the longitudinal axis, the first focal point and the second focal point being conjugate focal points, and the ellipsoidal-shaped end comprising an elliptical surface which reflects light from the first focal point to the second focal point.

18. The light device of claim 13, wherein the light source comprises a visible light-emitting diode (LED), the ellipsoidal-shaped end surrounding the LED, and wherein the ellipsoidal-shaped end and the light pipe are integrally formed of a common plastic material.

19. A method of coupling light from a light source on an electronics board to an edge of the electronics board, the method comprising:

providing a light transmission device comprising a light pipe having two ends, one end of the two ends comprising an ellipsoidal-shaped end, the ellipsoidal-shaped end including a first focal point and a second focal point, and including a curved surface configured to facilitate focusing of light into the light pipe, and wherein the ellipsoidal-shaped end further includes a recess configured to receive at least a portion of the light source, the recess intersecting the first focal point; and

positioning the light transmission device on the electronics board with the light source at least partially received within the recess in the ellipsoidal-shaped end of the light pipe to intersect the first focal point, and an opposite end of the light pipe disposed near an edge of the electronics board, wherein the second focal point is disposed within the light pipe with light passing therethrough continuing to propagate within the light pipe.

20. The method of claim 19, wherein the light pipe comprises a longitudinal axis extending between the two ends thereof, and wherein the first focal point and the second focal point reside on the longitudinal axis, the first focal point and the second focal point being conjugate focal points, and wherein the ellipsoidal-shaped end comprises an elliptical surface which reflects light from the first focal point to the second focal point.