LED BULB AND LIGHTING APPARATUS

• US 20100289396A1
• Filed: 12/24/2008
• Published: 11/18/2010
• Est. Priority Date: 01/07/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Lighting & Technology Corporation (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Lighting & Technology Corporation (Toshiba Corporation)
• Inventors: Osawa, Shigeru, Morikawa, Kazuto, Tanaka, Toshiya, Hisayasu, Takeshi
• Granted Patent: US 8,450,915 B2
• Time in Patent Office: Days
• US Class Current: 313/46
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21S 8/026 intended to be recessed in a ceiling or like overhead structure, e.g. suspended ceiling
• CPC Class Codes: F21V 23/002 Arrangements of cables or conductors inside a lighting device, e.g. means for guiding along parts of the housing or in a pivoting arm
• CPC Class Codes: F21V 29/773 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An object of the present invention is to provide an LED bulb in which temperature of a lighting circuit is suppressed from rising during lighting of an LED so that life time of the lighting circuit is maintained without increasing manufacturing cost of components. According to the invention, an LED module 11 having multiple LEDs surface-mounted thereon is mounted in a heat dissipating unit 12. Heat generated by the LEDs is dissipated through multiple heat dissipating fins 18 of the heat dissipating unit 12. A glove 14, covering the LED module 11, radiates outward radiant light from the LEDs. A lighting circuit 17 for lighting the LEDs is incorporated in an inner hollow portion 23 of a cap 16 arranged on a side opposite to the glove 14 of the heat dissipating unit 12. Accordingly, the heat generated by the LEDs of the LED module 11 is mostly dissipated by the heat dissipating unit 12, thereby suppressing the temperature of the lighting circuit from rising.

Claims

1. An LED bulb comprising:

an LED module having a plurality of LEDs surface-mounted thereon;

a heat dissipating unit having the. LED module mounted thereon and dissipating heat generated by the LEDs through a plurality of heat dissipating fins;

a glove covering the LED module and externally radiating radiant light from the LEDs;

a cap arranged on a side opposite to a location side of the glove of the heat dissipating unit and having an inner hollow portion; and

a lighting circuit incorporated in the inner hollow portion of the cap so as to light the LEDs.

2. The LED bulb according to claim 1, wherein the LED module is disposed on a side of the glove of the heat dissipating unit in a manner of contacting a surface of the heat dissipating unit, and the heat dissipating unit is formed with a line-through-hole having a size sufficient for allowing at least a line extending from the LED module and connected to the lighting circuit to pass through the line-through-hole.

3. The LED bulb according to claim 1, wherein the heat dissipating fins are formed so as to extend outward in a radial pattern from a center of the heat dissipating unit, and the heat dissipating unit has a portion adjoining the heat dissipating fins and having a convex shape projecting, in the direction of the cap, toward the center of the heat dissipating unit.

4. The LED bulb according to claim 3, wherein an insulating unit having an inner hollow portion is arranged between the heat dissipating unit and the cap, and a groove, with which an end of the heat dissipating fin is engaged, is formed in a tip end of the insulating unit.

5. The LED bulb according to claim 1, wherein the tip end of the insulating unit is fitted into the heat dissipating unit, and a base end of the heat dissipating fin on the center axis side of the heat dissipating unit has a base end portion existing closer to the center axis side than a portion having a maximum outer diameter of the insulating unit.

6. The LED bulb according to claim 1, wherein a reflecting plate for reflecting, in a direction of the glove, light radiated from the glove in a direction of the heat dissipating unit is arranged in a junction portion between the heat dissipating unit and the glove.

7. The LED bulb according to claim 1, wherein a constricted portion is provided in a junction portion between the heat dissipating unit and the glove.

8. A lighting apparatus comprising:

the LED bulb according to claim 1; and

a lighting apparatus body having a socket to which the LED bulb is mounted.