LED lighting system incorporating folded light sheets

Abstract

In accordance with certain embodiments, flexible light sheets are folded to define first and second portions of the light sheet divided by the fold, and the first and second portions of the light sheet may both feature light-emitting elements thereon.

Description

RELATED APPLICATION[0001]This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62 / 029,744, filed Jul. 28, 2014, the entire disclosure of which is hereby incorporated herein by reference.FIELD OF THE INVENTION[0002]In various embodiments, the present invention generally relates to electronic devices, and more specifically to array-based electronic devices.BACKGROUND[0003]Lighting design and the design of luminaires, fixtures and other lighting systems is often constrained by the limitations of the illumination source. In many applications, it is not easy or perhaps not possible to achieve a desired lighting effect with conventional illumination sources. For example, fluorescent tubes are available in a relatively small variety of fixed lengths. Incandescent and halogen lamps, e.g., A19 lamps, PAR lamps, and the like also generally have fixed sizes. Furthermore, these lamps are available in a relatively small number of light intensity ranges. S...

AI Technical Summary

Benefits of technology

The present invention provides a way to efficiently use a light sheet in a way that allows for better control over the direction and distribution of light. This is accomplished by folding the light sheet along one or more folds that separate a portion of the light sheet containing light-emitting elements from one or more additional portions of the light sheet having no light-emitting elements. The additional portions can be reflective and contain power conductors that supply power to the light-emitting elements. This allows for greater control over the light emitted by the light-emitting elements or enables the power conductors to extend beyond a planar area defined by the light-emitting element-containing portion of the light sheet. This results in lower resistance and improved performance.

Problems solved by technology

Lighting design and the design of luminaires, fixtures and other lighting systems is often constrained by the limitations of the illumination source.

In many applications, it is not easy or perhaps not possible to achieve a desired lighting effect with conventional illumination sources.

Solid-state illumination sources such as LEDs by themselves are relatively small, but are typically mounted on rigid printed circuit boards and may require significant heat-sinking and / or thermal management.

Thus, for solid-state lighting, while unique printed circuit boards may be designed and constructed, this is a time-consuming and costly process that prohibits cost-effective manufacture of a wide range of systems having different geometries.

Furthermore, all such illumination sources are rigid, precluding easy implementation in applications requiring curved or arbitrarily shape illumination sources.

For example, in systems made up of multiple conventional lamps, the large size of each light source (lamp or bulb) often results in non-uniform illumination, particularly in regions between lamps.

In addition, in systems having multiple in-line fluorescent tubes, the regions between lamps for the sockets may result in undesirable socket shadow.

The smaller size of solid-state emitters such as LEDs permits closer spacing; however, the large numbers of LEDs required to achieve high spatial uniformity have conventionally been limited to very expensive systems, because of the relatively high cost of the large number of LEDs.

Thus, higher uniformity may be possible, but it comes at the expense of size and rigidity—such systems are not amenable to small systems or free-form systems or systems requiring customization, for example signage, back illumination of custom panels or signs, channel lettering, or custom-length fixtures.

Piecing together a large number of custom circuit boards increases installation difficulty, and also increases cost and reduces reliability.

This is typically not possible with fluorescent lamps, because these are generally manufactured only in several fixed and unchangeable lengths.

Using a shorter circuit board permits finer adjustment of length, but requires a large number of circuit boards and interconnects between circuit boards, which increases the materials and assembly expense and reduces reliability.

Using a longer circuit board permits the use of a smaller number of circuit boards, but does not permit fine adjustment of the length.

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