LED lamp

An LED lamp includes a housing having a base, a frame at a top end of the housing and a plurality of stanchions interconnecting the base and the frame. A heat sink is mounted on the frame. An LED module is received in the housing and attached on a bottom surface of the heat sink. A printed circuit board is arranged on the base of the housing, and a reflector is located on the printed circuit board. A transparent envelope is received in the housing and covers windows defined between the stanchions. A light generated by the LED module is reflected by the reflector to transmit outwardly through the envelope to illuminate a surrounding environment.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an LED lamp for a lighting purpose, and more particularly to an improved LED lamp having a novel structure for use in the outdoors.

2. Description of Related Art

An LED lamp is a type of solid-state lighting that utilizes light-emitting diodes (LEDs) as a source of illumination. An LED is a device for transferring electricity to light by using a theory that, if a current is made to flow in a forward direction through a junction region comprising two different semiconductors, electrons and holes are coupled at the junction region to generate a light beam. The LED has an advantage that it is resistant to shock, and has an almost eternal lifetime under a specific condition; thus, the LED lamp is intended to be a cost-effective yet high quality replacement for incandescent and fluorescent lamps.

Known implementations of LED modules in an LED lamp make use of a plurality of individual LEDs to generate light that is sufficient. The large number of LEDs leads to a more expensive module and one with greater power consumption. The greater power usage leads to greater heat output, which, if not adequately addressed at additional expense, impacts the LED lamp reliability. Therefore, various heat dissipation devices with complicated structures are exploited in the LED lamp, which increasing the difficulty and cost of the manufacturing of the LED lamp.

Besides, since a lighting angle of the LEDs is generally restricted in a narrow range, light of the LED lamp is of unsatisfactory spatial distribution, whereby a more larger illumination area can not be provided.

What is needed, therefore, is an improved LED lamp which has a simple and novel structure, whereby the LED lamp is suitable to mass-manufacture and has a satisfactory illumination area.

SUMMARY OF THE INVENTION

An LED lamp includes a housing, a heat sink, an LED module, a printed circuit board and a reflector. The housing has a base and a frame formed on a top end of the housing. The heat sink is located on the frame. The LED module is received in the housing and attached on a bottom surface of the heat sink. The printed circuit board is arranged on the base of the housing. The reflector is located on the printed circuit board to reflect light generated by the LED module towards an outside of the housing. The reflector has a cone-shaped configuration with a tip pointing toward the LED module.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 1-3, an LED lamp in accordance with a preferred embodiment is illustrated. The LED lamp comprises a housing10, a heat sink20disposed on the housing10, an LED module30attached on a bottom surface of the heat sink20, a reflector50and a printed circuit board60accommodated in the housing10. An envelope40is fitly received in the housing10. Light emitted by the LED module30is reflected by the reflector50to travel through the envelope40to illuminate a surrounding environment.

The housing10comprises a base12, a top frame16and four stanchions14interconnecting the base12and the top frame16. The base12is substantially rectangular. A through hole121is defined in a center of the base12and four fixing holes122are defined in the base12and adjacent to four side edges of the base12. Four stanchions14extend upwardly and outwardly from four corners of the base12. The top frame16has a rectangular shape and connects ends of the four stanchions14with four corners thereof. An area of the top frame16is larger than that of the base12. A plurality of first securing holes161is defined in the top frame16. The base12, the stanchions14and the top frame16corporately define a space (not labeled) for receiving the printed circuit board60, the reflector50, the envelope40and the LED module30therein. A window142is defined between every two adjacent stanchions14, through which the light emitted by the LED module30can project outside of the housing10. A connecting portion18extends downwardly from the base12for securing the LED lamp onto a supporting structure (not shown) such as a supporting post.

The heat sink20is mounted on the top frame16of the housing10and comprises a bottom plate21and a plurality of fins22arranged on the bottom plate21. Corresponding to the first securing holes161in the top frame16, a plurality of second securing holes211is defined in the bottom plate21for fixtures (not shown) to extend therethrough to engage in the first securing holes161thereby fixing the heat sink20to the housing10.

The LED module30is attached to a bottom surface of the bottom plate21of the heat sink20and comprises a plurality of LEDs32arrayed thereon in a matrix. The LED module30defines a plurality of screw holes (not labeled) therein for fixtures (not shown) to extend therethrough to engage in the bottom surface of the bottom plate21, thereby assembling the LED module30to the bottom surface of the bottom plate21.

The printed circuit board60is placed on the base12. The printed circuit board60is electrically connected to the LED module30via wires (not shown) for providing the LED module30with power, control signals, etc. The printed circuit board60can further get power from a power supply (not shown) via wires (not shown) through the through hole121in the base12.

The reflector50is located on and covering the printed circuit board60. In the present embodiment, the reflector50has a conical configuration, with a tip end thereof facing towards the LED module30and a bottom end thereof facing towards the printed circuit board60. Four legs51extend downwardly from an inner surface of a bottom portion of the reflector50. The four legs51are inserted into the fixing holes122and engage with the base12via fixtures (not labeled). Light generated by the LED module30is reflected towards an outside of the housing10by an outer surface of the reflector50. Understandably, the configuration of the reflector50can be various. For instance, the reflector50can be a polyhedron with lateral surfaces slantwise to the LED module30for reflecting light towards the envelope40omnidirectionally.

The envelope40has a substantially similar configuration with the housing10and is fitly received in the housing10, serving for protecting components received in the housing10such as the reflector50, the printed circuit board60, etc. The envelope40has four sidewalls, with each of the sidewalls extending over a corresponding one of the windows142of the housing10. Each of four corners of the envelope40connects every two adjacent sidewalls of the envelope40and fittingly abuts against one of the stanchions14. A bottom end of the envelope40abuts against the base12of the housing10, and a top end of the envelope40abuts against the bottom surface of the bottom plate21of the heat sink20. Specifically, receiving grooves124,214are respectively defined in the base12and the bottom surface of the bottom plate21for respectively receiving the bottom end and the top end of the envelope40therein. Furthermore, a waterproof cushion70can be received in each of the grooves124,214and sandwiched between the base12and the bottom end of the envelope40and the bottom plate21of the heat sink20and the top end of the envelope40. The waterproof cushion70can prevent rainwater from creeping into the housing10when the LED lamp is used in the outdoors.

The envelope40should be made of a transparent or semitransparent material such as glass, plastic, etc., for allowing the light emitted by the LED module30project therethrough to illuminate a surrounding environment. When the envelope40is made of a semitransparent material, the LED lamp in accordance with the present invention can generate a more soft and uniform light.

In assembly, the printed circuit board60is placed on the base12of the housing10. The reflector50is located on the printed circuit board60and engaged with the base12of the housing10. The envelope40is received in the housing10. The heat sink20assembled with the LED module30then is coupled onto the top frame16of the housing10.

In operation, referring toFIG. 3, the LED module30gets power from the printed circuit board60and generates light. Shown as arrows in theFIG. 3, a part of the light can directly project towards the outside of the housing10, and another part of the light projects to the reflector50. When reaching the outer surface of the reflector50, the light can be reflected out of the housing10. Since the outer surface of the reflector50is slantwise to the LED module30, the light emitted from the planar LED module30can be reflected in a multidirectional manner, which increases the illumination area of the LED lamp. The heat sink20can absorb heat generated by the LED module30and dissipate the heat into ambient air when the LED lamp is operated. Besides, the heat sink20located on the housing10can serve as a protective component for preventing rainwater, dust, etc. from entering into the LED lamp.