Bulb-shaped lamp and lighting device

• US 9,080,757 B2
• Filed: 08/02/2012
• Issued: 07/14/2015
• Est. Priority Date: 02/04/2009
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Takahasi, Kenzi, Tomiyoshi, Yasushige, Uemoto, Takaari, Nagai, Hideo, Takeda, Mamoru, Manabe, Yoshio
• Primary Examiner(s): PAYNE, SHARON E
• Application Number:
  US13/565,652
• Publication Number:
  US 20120300448A1
• Time in Patent Office: 1,076 Days
• Field of Search: 362/294, 362/249.02, 362/311.02, 362/373, 257/712
• US Class Current: 1/1
• 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: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• 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 23/009 the casing being inside the housing of the lighting device
• CPC Class Codes: F21V 29/15 Thermal insulation
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 29/89 Metals
• 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: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A bulb-type lamp having both heat dissipation and size/weight reduction properties with a lower thermal load on a lighting circuit. An LED module is mounted in a case with a base member to allow dissipation of heat. An LED mount member closes another end of the case and allows conduction of heat to the case. A lighting circuit receives power via the base member. The lighting circuit is disposed inside a circuit holder. An air space exists between the circuit holder and both the case and the mount member. The lighting circuit is isolated from the air space by the circuit holder. A relationship 0.5≦S1/S2≦3.0, is satisfied where S1 denotes an area of a portion of the mount member in contact with the case and S2 denotes an area of the portion of the mount member in contact with a substrate of the LED module.

Claims

1. A lamp comprising:

a light emitting module including a substrate on which at least one light emitting element is mounted;

a cylindrically-shaped heat sink that allows dissipation of heat therefrom, the heat being generated by the at least one light emitting element emitting light;

a base member attached to one end portion of the heat sink; and

a mount member on a front surface of which the light emitting module is mounted, the mount member allowing conduction of the heat therefrom to the heat sink, wherein

the mount member allows conduction of the heat therefrom to the heat sink by being in contact with the other end portion of the heat sink, and

a fraction S1/S2 satisfies a relationship 0.5<

S1/S2 <

3.0, where S1 denotes an area of a portion of the mount member that is in contact with the heat sink, and S2 denotes an area of a portion of the mount member that is in contact with the substrate of the light emitting module.

2. The lamp of claim 1, wherein

the light emitting module is structured such that a plurality of LEDs are mounted on the substrate as light emitting elements, the plurality of LEDs being covered by a sealing member,

the substrate is made of a material having high thermal conductivity, and a wiring pattern is provided on a main surface of the substrate,

the wiring pattern includes (i) a connecting portion that electrically connects between the LEDs using a predetermined connection method, and (ii) a plurality of terminal portions connected to lead wires that connect to the circuit, and

the sealing member includes a transparent material and a conversion material that converts a wavelength of light emitted by the LEDs to a predetermined wavelength.

3. The lamp of claim 1, wherein

the substrate is made of ceramic.

4. The lamp of claim 1, wherein

one of thermal grease and resin containing a thermally-conductive filler is provided between the light emitting module and the mount member.

5. The lamp of claim 1, wherein

the heat sink has a thickness of 1 mm or smaller.

6. The lamp of claim 1, wherein

outer and inner diameters of the heat sink decrease from a tip of the other end portion toward a tip of the one end portion of the heat sink.

7. The lamp of claim 1, wherein

the other end portion of the heat sink is bent inward, and

a tip of the other end portion of the heat sink, which is bent inward, is positioned on or above the front surface of the mount member.

8. The lamp of claim 1, further comprising:

a globe covering the light emitting module, wherein

the mount member is made up of a small diameter portion that has a small outer diameter and a large diameter portion that has a greater outer diameter than the small diameter portion,

the light-emitting module is mounted on a front surface of the small diameter portion, and an outer circumferential surface of the large diameter portion is in contact with an inner surface of the heat sink, and

a tip of the globe at an opening of the globe is secured while being inserted between the inner surface of the heat sink and the small diameter portion of the mount member.

9. The lamp of claim 1, wherein

at least one stopper is provided on an inner surface of the other end portion of the heat sink, and

the mount member is inserted into the heat sink through an opening of the other end portion of the heat sink, and a position of the mount member is determined by the stopper.

10. The lamp of claim 9, wherein

the stopper is provided in a plurality, and

the stoppers are arranged at equal intervals along a direction of an inner circumference of the heat sink.

11. A lighting device comprising:

a lamp; and

a lighting fixture to/from which the lamp is attachable/detachable, wherein

the lamp is the lamp of claim 1.