Light-guiding cover and illumination device having the same

• US 8,764,260 B2
• Filed: 12/28/2011
• Issued: 07/01/2014
• Est. Priority Date: 06/15/2011
• Status: Expired due to Fees

• Current Assignee: Lite-On Technology Corporation
• Original Assignee: Lite-On Technology Corporation
• Inventors: Liang, Chun-Wei
• Primary Examiner(s): Neils, Peggy
• Assistant Examiner(s): Kryukova, Erin
• Application Number:
  US13/339,228
• Publication Number:
  US 20120320580A1
• Time in Patent Office: 916 Days
• Field of Search: 362/555, 362/569, 362/249.02, 362/311.02, 36231106-3111, 362/311.13, 362/329, 362/310, 362/810
• US Class Current: 362/555
• CPC Class Codes: F21K 9/23 Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21W 2121/00 Use or application of lighting devices or systems for decorative purposes, not provided for in codes F21W2102/00 – F21W2107/00
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 19/0071 adapted to illuminate a complete hemisphere or a plane extending 360 degrees around the source

Abstract

The present invention relates to a light-guiding cover and an illumination device having the same. The light-guiding cover, for guiding light beams emitted by at least one light-emitting diode (LED), has a light-guiding portion and a light output portion. The light-guiding portion has a light input surface for transmitting light beams thereto and a connecting surface. The light output portion formed on one end of the light-guiding portion has an optical surface adjoining the connecting surface. The light-guiding cover is substantially symmetrical and defines a central axis. The light beams received by the light-guiding portion are guided by the light input surface for light reflection from one side to another side of the optical surface across the central axis to exit from the light-output portion. Thus, the illumination device having the light-guiding cover can illuminate in an omni-directional manner.

Claims

1. A light-guiding cover, integrally formed in solid one piece for guiding light beams emitted from at least one light-emitting diode (LED), comprising:

a light-guiding portion, wherein a light input surface is formed on one end of the light-guiding portion and orientated toward an LED, wherein the light input surface transmits light beams emanating from the LED into the light-guiding portion, wherein the light-guiding portion—

further has a connecting surface; and

a light output portion extending from another end of the light-guiding portion, wherein the light output portion has an optical surface extending from the connecting surface, wherein the overall profile shape of the light output portion is tapered away from the light-guiding portion to an upper end portion of the light output portion away from the LED;

wherein the light-guiding cover is substantially symmetrical around a central axis, each cross-section of the light output portion normal to the central axis is substantially circular, wherein the diameters of the cross-sections of the light output portion decrease in a direction away from the light-guiding portion, and the optical surface allows the light beams emanating from the LED to reflect or pass therethrough, and wherein the light beams emanating from the LED are refracted by the light input surface and enters the light-guiding portion for light reflection from one side to another side of the optical surface across the central axis to exit from the light-output portion, wherein at least one virtual LED is produced on the central axis in the upper end portion of the light output portion away from the LED by the light beams transmitted by the light input surface into the light-guiding portion.

2. The light-guiding cover of claim 1, wherein the light input surface has a central surface and an annular surface, and the annular surface is formed adjacent to the central surface, wherein the central surface and the annular surface cooperatively define an accommodating space for receiving the LED.

3. The light-guiding cover of claim 2, wherein the central surface is a free-form surface, a multi-segmented surface, a flat leveled surface, or a Fresnel lens-like surface, and the annular surface is a flat leveled surface, a parabolic surface, a free-form surface, or a multi-segmented surface, while the optical surface is a parabolic surface, a free-form surface, or a multi-segmented surface.

4. The light-guiding cover of claim 3, wherein the optical surface is a total internally reflective surface.

5. The light-guiding cover of claim 4, wherein the optical surface is a non-smooth surface.

6. The light-guiding cover of claim 2, wherein the light-guiding portion further has a reflecting surface, wherein the connecting surface adjoins the optical surface and the reflecting surface on opposite ends thereof, wherein the reflecting surface is formed extendingly from the connecting surface away from the optical surface, with the distance between the reflecting surface and the central axis gradually decreases in a direction away from the connecting surface, and wherein the reflecting surface reflects light beams transmitted by the annular surface to the optical surface.

7. The light-guiding cover of claim 1, wherein the light-guiding cover is a solid structure made from glass, acrylic glass, polyethylene (PE), poly(methyl acrylate), or any suitable combination thereof.

8. The light-guiding cover of claim 1, wherein the light-guiding cover is shaped like a candle flare or a chandelier bulb.

9. An illumination device, comprising:

a mounting seat;

at least one LED disposed on the mounting seat for emitting light beams; and

a light-guiding cover disposed on the mounting seat for guiding light beams emitted from the LED, wherein the light-guiding cover is integrally formed in solid one piece and comprises;

a light-guiding portion, wherein a light input surface is formed on one end of the light-guiding portion and orientated toward the LED, wherein the light input surface transmits light beams emanating from the LED into the light-guiding portion, wherein the light-guiding portion further has a connecting surface; and

a light output portion extending from another end of the light-guiding portion, wherein the light output portion has an optical surface extending from the connecting surface, wherein the overall profile shape of the light output portion is tapered away from the light-guiding portion to an upper end portion of the light output portion away from the LED;

wherein the light-guiding cover is substantially symmetrical around a central axis, each cross-section of the light output portion normal to the central axis is substantially circular, wherein the diameters of the cross-sections of the light output portion decrease in a direction away from the light-guiding portion, and the optical surface allows the light beams emanating from the LED to reflect or pass therethrough, and wherein the light beams emanating from the LED are refracted by the light input surface and enters the light-guiding portion for light reflection from one side to another side of the optical surface across the central axis to exit from the light-output portion, wherein at least one virtual LED is produced on the central axis in the upper end portion of the light output portion away from the LED by the light beams transmitted by the light input surface into the light-guiding portion.

10. The illumination device of claim 9, wherein the mounting seat includes a lamp cap and a heat sink, wherein the lamp cap and the LED are arranged on opposite ends of the heat sink, with the LED being electrically connected to the lamp cap.

11. The illumination device of claim 9, wherein the light input surface has a central surface and an annular surface, and the annular surface is formed adjacent to the central surface, wherein the central surface and the annular surface cooperatively define an accommodating space for receiving the LED.

12. The illumination device of claim 11, wherein the central surface is a free-form surface, a multi-segmented surface, a flat leveled surface, or a Fresnel lens-like surface, and the annular surface is a flat leveled surface, a parabolic surface, a free-form surface, or a multi-segmented surface, while the optical surface is a parabolic surface, a free-form surface, or a multi-segmented surface.

13. The illumination device of claim 12, wherein the optical surface is a non-smooth surface.

14. The illumination device of claim 12, wherein at least one virtual LED is produced on the central axis by the light beams transmitted by the light input surface into the light-guiding portion.

15. The illumination device of claim 11, wherein the light-guiding portion further has a reflecting surface, wherein the connecting surface adjoins the optical surface and the reflecting surface on opposite ends thereof, wherein the reflecting surface is formed extendingly from the connecting surface away from the optical surface, with the distance between the reflecting surface and the central axis gradually decreases in a direction away from the connecting surface, and wherein the reflecting surface reflects light beams transmitted by the annular surface to the optical surface.

16. The illumination device of claim 11, wherein the central surface is substantially in contact with a light emitting surface of the LED, and the annular surface is substantially in contact with side portions of the LED.

17. The illumination device of claim 12, wherein the optical surface is a total internally reflective surface.

18. The illumination device of claim 9, wherein the light-guiding cover is shaped like a candle flare or a chandelier bulb.

19. The illumination device of claim 9, wherein the light-guiding cover is a solid structure made from glass, acrylic glass, polyethylene (PE), poly(methyl acrylate), or any suitable combination thereof.