INDOOR SMD LED EQUIPPED FOR OUTDOOR USAGE

Abstract

An SMD LED that is designed for indoor use is equipped for outdoor use by encapsulation in a vacuum-forming and/or cover molding covering, which is placed over the indoor SMD LED and is formed thereon by evacuation. The thus-equipped indoor SMD LED is thereby usable in the same manner as a more expensive and ruggedly designed outdoor SMD LED.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to SMD (Surface Mount Device) LED (Light Emitting Diode) of the type originally designed for indoor usage, but specially equipped for outdoor usage.

BACKGROUND OF THE INVENTION

As is well known, a light emitting diode (LED) is a solid-state semiconductor component that, when supplied with an appropriate electric current, emits light. LEDs are well known to have a high efficiency and a long life, which has resulted in an increasingly large number of applications for LEDs wherein traditional incandescent bulbs were previously used.

SMD LEDs are composed of a large number of individual LEDs that are mounted on the surface of a circuit board. The circuit board is typically a printed circuit board, which is flat and is also used, in addition to mounting the LEDs, to appropriately electrically connect the LEDs. The printed circuit board may also have auxiliary components that are used to drive the LEDs, but it is also possible for the LED driving circuitry to be separately (remotely) mounted.

By contrast, traditionally mounted LEDs have wire leads that connect them to a circuit board. Typically, SMDs forego such wire leads, making the entire package compact.

SMD LEDs can be generally categorized into the categories of devices designed for indoor use and devices designed for outdoor use. A typical outdoor use for such devices is to serve as a video display. In order to withstand the environmental factors that can impair or damage the operation of such an outdoor device, outdoor SMD LEDs typically are designed with heavier and stronger components than an indoor SMD LED, which makes outdoor SMD LEDs more expensive. The outdoor environment that an outdoor SMD LED must be able to withstand can include water, UV, dust and other performance-degrading or material-degrading contaminants.

Attempts have been made to package or otherwise protect SMD LEDs design for indoor use so as to make such indoor SMD LEDs suitable for outdoor use, in order to take advantage of the lower cost of indoor SMD LEDs. Once such approach has been to provide a transparent cover over the entirety of an indoor SMD LED product. A disadvantage of this approach is that many crack or other opening in such a cover comprises the integrity of the entire device, by allowing water, for example, to reach the interior of the covering, and it is difficult to ensure that such cracks or openings will not develop in the covering much earlier than the expected usage life of the product. In other words, the duration that such a covering can be expected to remain intact is less that the usually-expected duration of use of the outdoor SMD LED product. Moreover, in view of the complete seal that is needed, heat that develops during usage of the SMD LED is difficult to release, and the continued use of the SMD LED in such an elevated temperature environment shortens the life of the SMD LED.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide improved outdoor SMD LEDs that overcome the aforementioned disadvantages of SMD LEDs.

In a first aspect, an outdoor SMD LED comprising an indoor SMD LED; and a covering held in place over said indoor SMD LED by evacuation between said covering and said SMD LED.

In a further aspect, said covering is a vacuum-forming covering or a cover molding covering.

In a further aspect, said covering is made of plastic or silicone.

In a second aspect, an outdoor SMD LED display, comprising a printed circuit board; a plurality of LEDs mounted to a same surface of said circuit board and forming, in combination with said circuit board, an indoor LED display; and a vacuum-forming and/or cover molding covering placed over said LEDs on said surface of said printed circuit board, and held in place over said LEDs on said printed circuit board by evacuation of a volume between said covering and said LEDs on said circuit board, thereby forming a protection for said indoor LED display allowing outdoor operation thereof.

In a further aspect, said vacuum-forming and/or cover molding covering is made of plastic or silicone.

In a third aspect, a method for equipping an indoor SMD LED for outdoor operation, comprising providing an indoor SMD LED; and vacuum-forming and/or cover molding a cover on said indoor SMD LED, thereby protecting said indoor SMD LED for outdoor operation.

In a further aspect, wherein said cover is made of plastic or silicone.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures are for illustration purposes only and are not necessarily drawn to scale. The invention itself, however, may best be understood by reference to the detailed description which follows when taken in conjunction with the accompanying drawings in which:

FIG. 1 shows an indoor SMD LED on a printed circuit board, in an embodiment forming a display.

FIG. 2 shows a vacuum-forming sheet used to cover the SMD LED display of FIG. 1, in accordance with the invention.

FIG. 3 shows the vacuum-forming sheet in the process of covering the device of FIG. 1.

FIG. 4 shows a corner of the device of FIG. 1, covered by the vacuum-forming sheet.

FIG. 5 is a view showing the device of FIG. 1 covered by a vacuum-forming sheet, in the process of evacuation, in accordance with the present invention.

FIG. 6 is a second view showing the device of FIG. 1 completely covered by a vacuum-forming sheet in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the invention, an SMD LED is encapsulated by a vacuum-forming and/or cover molding sheet that is held in place by evacuation over the printed circuit board (PCB) to which the LED is mounted. In the example shown in FIG. 1, the device, in this case is an LED display 1, is shown before being covered by the vacuum-forming and/or cover molding sheet. The device shown in FIG. 1 is designed as an indoor device, meaning that, by itself, it would not be capable of outdoor use because it is not capable of withstanding an outdoor environment. The LED display 1 has multiple LEDs 3 on a PCB 2.

The sheet can be made of plastic, such as polycarbonate plastic, silicon, or the like. The sheet can be transparent or translucent, can be in one or more colors, and/or can be embossed with one or more patterns that can help direct light. The sheet can have at least one anti-ultraviolet layer.

The sheet can be a vacuum-forming sheet, a cover molding sheet, or a vacuum-forming and cover molding sheet.

Although the device shown in FIG. 1 is, as noted, configured as a display, the present invention can be used to equip any SMD LED that is designed for indoor use, so as to make the indoor use SMD LED able to withstand an outdoor environment, and thus usable as an outdoor SMD LED.

FIG. 2 shows a vacuum-forming and/or cover molding transparent sheet 4 that is used to cover the device shown in FIG. 1, in accordance with the invention. As can be seem from FIG. 2, the sheet is formed with a number of recesses 5 that individually and respectively fit over each of the LEDs 3 on the PCB 2 in FIG. 1.

FIG. 3 shows the sheet 4 being pressed into place on the display 1 shown in FIG. 1. FIG. 4 shows the sheet completely covering the display shown in FIG. 1, but before evacuation.

FIG. 5 shows a view from above of the indoor SMD LED that is in the process of being equipped for outdoor use in accordance with the invention by evacuating the volume between the sheet 4 and the display. As can be seen in FIG. 5, the volume at the lower left corner still exists between the cover and the PCB with the LEDs as evacuation proceeds, in a known manner, so that the sheet 4 finally tightly covers and encloses the indoor SMD LED display 1, thereby completely protecting the indoor SMD LEDs from the attacking factors that are typical in an outdoor environment, and thereby producing a completed outdoor SMD LED display 5.

Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art.

Claims

1. An outdoor SMD LED comprising: an indoor SMD LED; anda covering held in place over said indoor SMD LED by evacuation between said covering and said SMD LED.

2. The outdoor SMD LED of claim 1, wherein said covering is a vacuum-forming covering or a cover molding covering.

3. The outdoor SMD LED of claim 2, where the covering is made of plastic or silicone.

4. An outdoor SMD LED display, comprising: a printed circuit board;a plurality of LEDs mounted to a same surface of said circuit board and forming, in combination with said circuit board, an indoor LED display; anda vacuum-forming and/or cover molding covering placed over said LEDs on said surface of said printed circuit board, and held in place over said LEDs on said printed circuit board by evacuation of a volume between said covering and said LEDs on said circuit board, thereby forming a protection for said indoor LED display allowing outdoor operation thereof.

5. The outdoor SMD LED display of claim 4, wherein said vacuum-forming and/or cover molding covering is made of plastic or silicone.

6. A method for equipping an indoor SMD LED for outdoor operation, comprising: providing an indoor SMD LED; andvacuum-forming and/or cover molding a cover on said indoor SMD LED, thereby protecting said indoor SMD LED for outdoor operation.

7. The method for equipping an indoor SMD LED for outdoor operation of claim 6, wherein said cover is made of plastic or silicone.