Single card multi mode LCD backlight

• US 8,419,203 B1
• Filed: 09/03/2010
• Issued: 04/16/2013
• Est. Priority Date: 09/03/2010
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Mosier, Donald E, Walker, Brian W.
• Primary Examiner(s): Ward, John A
• Application Number:
  US12/875,707
• Time in Patent Office: 956 Days
• Field of Search: 362/97.1, 362/97.2, 362/97.3, 362/294, 362/373, 362/249.02, 362/243, 362/241, 362/247, 362/235
• US Class Current: 362/97.3
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133608 including particular frames or supporting means

Abstract

An light emitting diode (LED) assembly may include, but is not limited to: a printed circuit board comprising at least one aperture; a first LED mounted on a front surface of the printed circuit board; a second LED mounted on a rear surface of the printed circuit board; and a reflective surface configured to reflect light emitted by the second LED through the at least one aperture.

Claims

1. An light emitting diode (LED) assembly comprising:

a printed circuit board comprising at least one aperture;

a first LED mounted on a front surface of the printed circuit board;

a second LED mounted on a rear surface of the printed circuit board; and

a reflective surface configured to reflect light emitted by the second LED through the at least one aperture.

2. The LED assembly of claim 1, wherein the first LED and the second LED are oriented in substantially opposite directions.

3. The LED assembly of claim 1, further comprising:

a filter.

4. The LED assembly of claim 3, wherein the filter is disposed in a position to condition light emitted from the at least one aperture.

5. The LED assembly of claim 4, wherein the filter is configured to at least partially remove at least a very-long wavelength component of light emitted from the at least one aperture.

6. The LED assembly of claim 4, wherein the aperture comprises a reflective coating.

7. The LED assembly of claim 1, wherein the reflective surface comprises:

at least one indention in the reflective surface.

8. The LED assembly of claim 7, wherein the at least one indention comprises:

at least one of;

an at least partially concave indention;

an at least partially hemispherical indention;

an at least partially ovoidal indention;

an at least partially cubic indention;

an at least partially conical indention; and

an at least partially cylindrical indention.

9. The LED assembly of claim 7, wherein the at least one indention comprises at least one faceted surface.

10. The LED assembly of claim 7, wherein the at least one indention comprises a reflective coating.

11. The LED assembly of claim 1, wherein the reflective surface comprises:

at least one mechanism for sinking heat from the printed circuit board.

12. A display assembly comprising:

a transmissive imaging assembly; and

a light emitting diode (LED) assembly comprising;

a printed circuit board comprising at least one aperture;

a first LED mounted on a front surface of the printed circuit board;

a second LED mounted on a rear surface of the printed circuit board; and

a reflective surface configured to reflect light emitted by the second LED through the at least one aperture.

13. The display assembly of claim 12, further comprising:

a filter.

14. The display assembly of claim 13, wherein the filter is disposed in a position to condition light emitted from the at least one aperture.

15. The display assembly of claim 12, wherein the reflective surface comprises:

at least one indention in the reflective surface.

16. The display assembly of claim 12, wherein the reflective surface comprises:

at least one mechanism for sinking heat from the printed circuit board.

17. The display assembly of claim 12, further comprising:

a secondary filter disposed between the LED assembly and the transmissive imaging assembly.

18. A method of illuminating a display assembly comprising:

providing a transmissive display assembly;

providing a light emitting diode (LED) assembly comprising;

a printed circuit board comprising at least one aperture;

a first LED mounted on a front surface of the printed circuit board;

a second LED mounted on a rear surface of the printed circuit board; and

a reflective surface configured to reflect light emitted by the second LED through the at least one aperture;

operating the LED assembly in a first mode by powering the first LED to illuminate the transmissive display assembly; and

operating the LED assembly in a second mode by powering the second LED to illuminate the transmissive display assembly via light reflected from the reflective surface through the at least one aperture.