Patent Description:
Linear lighting is a term that describes a broad range of lighting products in which LED light engines are arranged at a regular pitch on a long, thin printed circuit board (PCB). Linear lighting may be made in arbitrarily long lengths by joining shorter strips of PCB together, usually by soldering. The PCB is laid out electrically so that it can be cut at regularly-spaced cut points. In some cases, adhesive, such as pressure-sensitive adhesive, may be applied to the reverse of the PCB, so that the linear lighting can be physically adhered to a surface. Linear lighting with adhesive on the reverse is often referred to as "tape light.

In linear lighting, the PCB may be either rigid or flexible. "Flexible" PCB is usually flexible in a single plane. Bending in other planes may damage the PCB, as may bending the PCB too much even in the intended bending plane. Linear lighting with a PCB that can be flexed in multiple planes is known, e.g., as disclosed in <CIT>; however, PCB that is flexible in multiple planes usually has a reduced current carrying capacity relative to single-plane flexible lighting, which can result in shorter maximum lengths and less emitted light.

Flexible PCB is particularly common in linear lighting, mainly because it allows for easier installation - for example, an extremely long length of linear lighting may be wound around a spool, cut to a desired length in the field, and installed. While a flexible PCB can bend and conform to a surface, most conventional flexible linear lighting is installed in straight lines, with minimal or no bend in the final installation.

In the last few years, LED simulated neon has come onto the market. Simulated neon is a different form of linear lighting that usually includes a flexible PCB with LED light engines encased within an extrusion or other type of casing, such as a soft silicone or polyurethane extrusion. The casing is usually shaped, at least in part, to mimic the tubular shape of traditional neon. The LED light engines within the casing may be white-light emitting, colored-light emitting, RGB light engines that can emit a variety of colors, RGBW light engines that can emit a variety of colors and also have a dedicated white-light LED, or tunable white light engines that can emit a variety of color temperatures of white light. The extrusion or casing diffuses the light from the LED light engines, so that the product provides a light output similar to neon when lit.

LED simulated neon is intended to be bent when installed. Traditional neon lighting is a type of gas-discharge lamp made with flame-bent glass tubing, and simulated neon is intended to mimic the tight bends and intricately curved features that are possible with traditional neon. However, such tight bends can stress the PCB and cause failures, either during installation or over the life of the product. Document <CIT> discloses an elongated warning light comprising a shape-holding metal plate. Document <CIT> discloses a flexible elongated lighting system with an elongated plastic strip and a preferred plane of bending.

Scope of the present invention is to provide a linear lighting that overcomes the drawbacks mentioned above; this scope is achieved by the linear lighting according to one or more of the appended claims.

One aspect of the invention relates to LED simulated neon with a reinforcing member that provides strain relief to the linear lighting within the simulated neon. More specifically, the simulated neon has a flexible covering with a translucent upper portion and an opaque lower portion. At least the lower portion is filled with a transparent, flexible material. A channel is formed in the transparent, flexible material. Linear lighting is provided in the channel, along with a reinforcing member. The reinforcing member is shaped and oriented such that it can bend in the primary bending plane of the simulated neon but at least partially restricts or interferes with bending in other planes.

The reinforcing member has a rectangular cross-section, wider than it is thick. It may be made of plastic or, in an embodiment not covered by the claims, of metal, and its thickness may vary depending on the material of which it is made. If made of metal, the reinforcing member may be either resilient under the expected forces, or it may be malleable, retaining its shape when bent.

Other aspects not covered by the claims relate to reinforcing members of other shapes and configurations. For example, the reinforcing member may have the shape of a channel, with a bottom and sidewalls.

These and other aspects, features, and advantages of the invention will be set forth in the description that follows.

The invention will be described with respect to the following drawing figures, in which like numerals represent like features throughout the figures, and in which:.

<FIG> is a perspective view of a strip of side-bend LED simulated neon, generally indicated at <NUM>, according to one embodiment of the invention. As used here, the term "side bend" refers to the fact that the neon bends in a single plane that is perpendicular to a line normal to its top and bottom surfaces. <FIG> illustrates the linear lighting <NUM> bent in its bending plane. Aside from the bending plane, other planes are more rigid, and bending in other planes may damage the simulated neon <NUM>.

The exterior or covering <NUM> of the simulated neon <NUM> comprises an upper portion <NUM> that is at least translucent and a lower portion or base <NUM> that is opaque in the illustrated embodiment. The base <NUM> may be made opaque with a white or other light-reflective colorant. The upper portion <NUM> is at least semi-cylindrical in shape and, generally speaking, is shaped to resemble the small glass tube used in traditional neon. To facilitate mounting, the base <NUM> is squared-off and generally rectangular in cross-sectional shape, although it may have rounded corners and need not be rectangular in all embodiments.

Like many other forms of linear lighting, the simulated neon <NUM> is constructed and arranged to allow it to be cut to a desired length. Depending on the embodiment and the application, that cutting may occur in the field, it may occur in the factory, or it may occur on the premises of an authorized seller, reseller, or system integrator. As was described above, linear lighting is usually arranged electrically and mechanically so that it can be cut at specific cut points without compromising any circuits. For these reasons, in some embodiments, the simulated neon <NUM> may have exterior markings, such as tick marks, illustrating those cut points, i.e., where it can be cut without compromising any circuits. In other embodiments, these markings may be on a PCB within the covering <NUM>. For that reason, the covering <NUM> has a thin, transparent stripe <NUM> on one side that allows direct visualization of the underside of the PCB within the covering <NUM>. Markings on the PCB illustrate the cut points. Additionally, a pair of aligned grooves <NUM>, one on each side of the base <NUM> close to its bottom, allows for the use of mounting clips and other such mounting hardware.

The covering <NUM> itself is made of a flexible rubber, such as a soft silicone rubber or polyurethane rubber, that can comfortably bend to relatively tight radii. Depending on the embodiment, the same material may be used with different colorants or other additives to form the translucent upper portion <NUM>, the opaque base <NUM> and, if one is present, the transparent stripe <NUM>. The covering <NUM> and its various parts <NUM>, <NUM>, <NUM> may be extruded, either as a co-extrusion in a single stage or in multiple steps or stages. However, extrusion is not the only process that can be used to make the covering <NUM>. For example, the covering <NUM> may be made by casting a resin into a mold. For example, a two-part polyurethane resin could be cast in a series of steps into a silicone mold.

The simulated neon <NUM> may accept any type of power, either alternating current (AC) or direct current (DC) with any voltage or other characteristics. The operating voltage may be either high voltage or low voltage. (The definitions of "high voltage" and "low voltage" vary somewhat depending on the authority one consults, but for purposes of this description, "high voltage" should be defined as any voltage over about 50V. ) As those of skill in the art will understand, the length of the simulated neon <NUM> may be electrically limited by the inherent resistance of the conductors, the starting voltage, and other such factors. Regulatory limits may also limit the length of the simulated neon <NUM>, primarily by limiting the amount of power that a single strip of simulated neon <NUM> can draw. For example, to qualify as a "Class <NUM>" device under the electrical code of the United States-a designation that affects certain safety requirements-a device may draw no more than 60W with an operating voltage of 12V, or 96W with an operating voltage of 24V. A power connector <NUM> is shown attached to one end of the simulated neon <NUM>.

Generally speaking, the power and efficacy (i.e., light output per watt of input power) considerations for the simulated neon <NUM> are the same as for other forms of linear lighting. However, there are some additional considerations specific to simulated neon <NUM>. For example, while the covering <NUM>, and particularly its upper portion <NUM>, preferably provides an even, fully-diffused appearance to the emitted light, the material and thickness of the upper portion <NUM>, the distances between the LED light engines and the covering <NUM>, and other design factors should be selected so as not to unduly reduce the efficacy of the simulated neon <NUM>. In other words, the simulated neon <NUM> should be designed so that as much light is emitted as possible per watt of input power.

<FIG> is a cross-sectional view of the simulated neon, taken through Line <NUM>-<NUM> of <FIG>. As shown, the rounded upper portion <NUM> is hollow, leaving an air gap <NUM> between the upper portion <NUM> and the base <NUM>. The upper and lower portions <NUM>, <NUM> are connected. The opaque base <NUM> is at least partially filled with a transparent rubber <NUM>, which may be the same material of which the upper portion <NUM> and the base <NUM> are made without translucent or color additives. There is a break <NUM> in the mid-sidewall of the base <NUM>; the transparent rubber <NUM> fills the break to create the transparent stripe <NUM> that allows visibility into the interior of the base <NUM>.

A channel <NUM> is formed within the center of the transparent rubber <NUM> that fills the base <NUM>. The channel <NUM> is offset from center, such that the channel <NUM> of the illustrated embodiment is closer to one sidewall of the base <NUM> than the other.

A strip of linear lighting <NUM> is mounted within the channel <NUM>. The linear lighting <NUM> is mounted on its side, such that the reverse of the PCB rests against the sidewall of the channel <NUM>. This mounting allows the bend-plane of the PCB to align with the desired bend-plane of the simulated neon <NUM>. The LED light engines <NUM> emit light toward the other sidewall of the base <NUM>. The opaque, reflective white sidewalls of the base <NUM> reflect the emitted light, and most of the emitted light ultimately travels upward, where it is released through the upper portion <NUM>. Notably, the channel <NUM> is wider than the linear lighting <NUM>, such that an air gap exists between the LED light engines <NUM> and the edge of the channel <NUM>. The air gap in the channel <NUM> and the air gap <NUM> between the upper and lower portions refract light as it moves through the interface between rubber and air, causing the light to diffuse. Other aspects of the design of the covering <NUM> also work to diffuse the light. If the base <NUM> is not white, reflective layers within the base <NUM> may be provided in order to reflect and direct the light emitted from the linear lighting <NUM>. The light engines <NUM> may be of any of the types described above.

The channel <NUM> of <FIG> is generally trapezoidal in overall shape, but there are no particular restrictions on its shape so long as it has sufficient width and height to accommodate the linear lighting <NUM> and other components that will be described below.

When the simulated neon <NUM> is installed, it may be subjected to significant bending, as was explained above. While the covering <NUM> may provide some strain relief, the linear lighting <NUM> within the simulated neon <NUM> will be subjected to at least some of the same bending stresses as the simulated neon <NUM>.

For that reason, the simulated neon <NUM> contains a reinforcing member <NUM>. In the illustrated embodiment, the reinforcing member <NUM> is located between the underside of the linear lighting <NUM> and the sidewall of the channel <NUM> against which the linear lighting <NUM> is mounted. However, other positions and arrangements are possible. The reinforcing member <NUM> is a wide, flat strip. It may be the same width as the linear lighting <NUM>, or it may be slightly wider than the linear lighting <NUM> itself, e.g., <NUM>-<NUM> wider than the linear lighting <NUM>. Generally speaking, the reinforcing member <NUM> is present to provide additional strain relief to the linear lighting <NUM>. In some cases, it may also prevent, restrict, or limit bending in planes other than the intended bending plane.

In most embodiments, the reinforcing member <NUM> will be between <NUM>-<NUM> in width and may be between about <NUM> and <NUM> in thickness, although thicknesses of at least <NUM> may be used in some embodiments. The reinforcing member <NUM> is preferably stiffer than the material of which the coating <NUM> is made, and may be as stiff or stiffer than the linear lighting <NUM> itself. "Stiffness," as the term is used here, is a function of at least the elastic or bending modulus of the reinforcing member <NUM>, as well as the cross-sectional shape and resulting moments of area of the reinforcing member <NUM>. In other words, the stiffness of the reinforcing member as a whole is a function of the inherent elasticity or rigidity of the material and how that material is distributed relative to the bending plane. Other factors may contribute to stiffness as well. Reinforcing members <NUM> that are more flexible may be thicker in section; reinforcing members <NUM> that are more rigid may be thinner.

Any number of different plastics may be used to form the reinforcing member <NUM> including polyesters, acrylonitrile-butadiene-styrene (ABS) plastics, polyamides, polyimides, polycarbonates, and polyvinylchloride (PVC), to name a few. As one example, polyethylene terephthalate (PET) may be a particularly suitable material for reinforcing member <NUM>, as it is widely available, easily processed, and has a relatively high elastic modulus for a plastic. According to the invention, the simulated neon <NUM> has a transparent slit <NUM> in its covering <NUM>, and the reinforcing member <NUM> is also transparent, so that the PCB of the linear lighting can be visualized. Alternatively, any necessary or desirable markings could be placed on the reinforcing member <NUM>.

In embodiments not covered by the claims, in addition to plastics, any number of metals could be used in a reinforcing member <NUM>. For example, the reinforcing member <NUM> may be a steel, aluminum, or copper ribbon. Because of their greater stiffnesses, metals would typically be used in thinner section than plastics. If a metal is used, the metal may be engineered so as to be either resilient or malleable. If the metal is malleable - i.e., it has a shape and other characteristics that allow it to deform plastically under manual pressure and remain in the position or shape that is imparted to it - that could be useful in helping to shape the simulated neon during installation. In that case, fewer mounting clips may be needed in order to keep the simulated neon <NUM> in the desired position.

The reinforcing member <NUM> may be attached to the linear lighting <NUM>, it may be attached to the interior of the covering <NUM>, it may be attached to both structures <NUM>, <NUM>, or it may be completely unattached. If the reinforcing member <NUM> is attached to any structure, it may be by means of a layer or layers of pressure-sensitive adhesive applied over the entire length of the reinforcing member <NUM>, or it may be by means of pressure-sensitive or other types of adhesive applied in particular spots.

The position of the reinforcing member <NUM> may also vary from embodiment to embodiment. In the embodiment of <FIG>, the reinforcing member <NUM> is located between the linear lighting <NUM> and the channel <NUM>. The reinforcing member <NUM> may alternatively be located along the opposite wall of the channel <NUM>. Generally speaking, the reinforcing member <NUM> can be located anywhere that allows it to bend in the bending plane of the simulated neon <NUM>.

One advantage of the position of the reinforcing member <NUM> that is shown in <FIG> is that the reinforcing member <NUM> can be inserted into the simulated neon <NUM> after the covering <NUM> is formed. In fact, if the reinforcing member <NUM> is made of a low-friction plastic, the presence of the reinforcing member <NUM> may make it easier to insert the linear lighting <NUM>. However, in some embodiments, a reinforcing member <NUM> could be embedded in the covering <NUM>, either in the sidewall, the bottom, or in the transparent rubber <NUM> that forms the channel <NUM>.

As those of skill in the art will appreciate, simulated neon with other intended bending planes may be made. <FIG> is a cross-sectional view similar to <FIG>, illustrating simulated neon, generally indicated at <NUM>, according to another embodiment of the invention. Like the embodiment described above, the simulated neon <NUM> has a covering <NUM> that is divided into an upper portion <NUM> and a lower portion <NUM> or base. The upper portion <NUM> is translucent and constructed to diffuse and to emit light. Like the upper portion <NUM>, the upper portion <NUM> is at least semi-cylindrical and is intended to mimic the thin tube of conventional neon. A transparent rubber <NUM> fills at least the lower portion of the simulated neon <NUM>, with a channel <NUM> formed within the transparent rubber <NUM>. The primary difference between the "side bend" simulated neon <NUM> and the "top bend" simulated neon <NUM> lies in the orientation of the channel <NUM>, and the linear lighting <NUM> within the channel <NUM>. The rear of the linear lighting <NUM> faces the bottom of the base <NUM>, rather than one of its sidewalls, such that the LED light engines <NUM> emit light directly at the upper portion <NUM>. A transparent slit <NUM> is formed in the bottom of the base <NUM>, filled with the transparent rubber <NUM>. The simulated neon <NUM> bends in a plane that is parallel to a line normal to the top and bottom surfaces of the simulated neon <NUM> and bisects the simulated neon <NUM> longitudinally. In other words, the simulated neon <NUM> bends up and down with respect to the coordinate system of <FIG>.

A reinforcing member <NUM> is interposed between the linear lighting <NUM> and the bottom of the base <NUM>. The reinforcing member <NUM> may be made of any of the materials described above, and may have any thickness or shape. For example, the reinforcing member <NUM> may be a <NUM> thick strip of PET.

In <FIG> and <FIG>, the reinforcing member <NUM>, <NUM> has a thin, flat cross-sectional shape. However, that need not be the case in all embodiments. <FIG> illustrate other potential cross-sectional shapes for the reinforcing member, including the U- or C-shaped channel <NUM> of <FIG>, which corresponds to an embodiment not covered by the claims; the hollow member <NUM> of <FIG>; and the truss/girder members of <FIG>. When selecting a shape for a reinforcing member, relevant factors include the amount of space available within the simulated neon, the level of strain relief or bending resistance that is required, and the nature of the forces that are likely to be encountered. If the reinforcing member forms a channel, like the reinforcing member <NUM> of <FIG>, or the member is hollow, like the reinforcing member <NUM> of <FIG>, the linear lighting may be placed inside it.

The simulated neon <NUM>, <NUM> may be connected to power in any number of ways. One way of connecting the simulated neon <NUM>, <NUM> to power is to solder power connectors directly to the linear lighting <NUM>, <NUM>, usually to solder pads on the top of the PCB. Soldering is reliable, but requires equipment and practice; done incorrectly, it can damage the linear lighting <NUM>, <NUM>. For that reason, simulated neon <NUM>, <NUM> may be connected to power by a specialized, pronged connector that slides under the linear lighting <NUM>, <NUM> and makes electrical contact with conductive pads on the reverse of the PCB. The manner in which the simulated neon <NUM>, <NUM> is connected to power is not critical, but it may affect the positioning and other characteristics of the reinforcing member <NUM>, <NUM>. For example, if the reinforcing member <NUM>, <NUM> is under or behind the linear lighting <NUM>, <NUM>, it may be helpful if the reinforcing member <NUM>, <NUM> is not attached to the linear lighting <NUM>, <NUM>, or is only partially attached, so that a connector can be inserted between the linear lighting <NUM>, <NUM> and the reinforcing member <NUM>, <NUM>.

In the linear lighting <NUM>, <NUM> described above, the reinforcing member <NUM>, <NUM> is free-floating and can flex and move relative to the other components. That need not be the case in all embodiments. <FIG> is a cross-sectional view of a strip of simulated neon, generally indicated at <NUM>, that includes structure to fix or constrain the position of a reinforcing member. The overall structure of simulated neon <NUM> is very similar to structure of simulated neon <NUM> of <FIG>.

More specifically, the simulated neon <NUM> has a covering <NUM> that is divided into an upper portion <NUM> and a lower portion <NUM> or base. The upper portion <NUM> is translucent and constructed to diffuse and to emit light. The upper portion <NUM> is at least semi-cylindrical and is intended to mimic the thin tube of conventional neon. A transparent rubber <NUM> fills at least the lower portion of the simulated neon <NUM>, with a channel <NUM> formed within the transparent rubber <NUM>. The rear of the linear lighting <NUM> faces the bottom of the base <NUM>, rather than one of its sidewalls, such that the LED light engines <NUM> emit light directly at the upper portion <NUM>. A transparent slit <NUM> is formed in the bottom of the base <NUM>, filled with the transparent rubber <NUM>.

In the simulated neon <NUM>, a pair of projections <NUM> extend from opposite sidewalls of the channel <NUM>, forming slots <NUM> between the base of the channel <NUM> and the projections <NUM> on each side of the channel <NUM>. The slots <NUM> accommodate the reinforcing member <NUM>, such that the projections <NUM> hold the reinforcing member <NUM> in place or, at least, constrain its movement relative to the other components. <FIG> illustrates but one example of this principle; slots and the grooves or projections that create them may be positioned essentially anywhere. The reinforcing member <NUM> may move freely within the slots <NUM>, or it may be fixed in place within them. Moreover, while the slots <NUM> are defined by projections, in some cases, a continuous divider may be formed or provided in the channel <NUM>, forming a separate channel for the reinforcing member <NUM>. As those of skill in the art will appreciate, the principle of using a channel or other, similar features to constrain the movement of a reinforcing member is equally applicable to a side-bend configuration, like that of <FIG>.

As was described above, the simulated neon <NUM>, <NUM>, <NUM> described above has two air gaps, one in the base, between the linear lighting and the channel that contains it, and a second air gap between the base and the upper portion. While these air gaps may have some refractive effect and assist in diffusing the light, they are not necessary in all embodiments. Encapsulated linear lighting with fewer air gaps or no air gaps may be made with a reinforcing member, and that encapsulated linear lighting may or may not have the same cross-sectional shape as the simulated neon <NUM>, <NUM>, <NUM> described above.

<FIG> is a cross-sectional view of "top bend" encapsulated linear lighting, generally indicated at <NUM>, according to a further embodiment of the invention. As those of skill in the art will understand, the distinction between simulated neon and the more general category of encapsulated linear lighting is sometimes not a firm one. For purposes of this description, all simulated neon is a type of encapsulated linear lighting, in that the raw linear lighting is contained within a covering. Whether a piece of encapsulated linear lighting is simulated neon depends, at least in part, on its shape, especially of the uppermost portion; the type of LED light engines used within it; and the use to which it is put.

Encapsulated linear lighting <NUM> has an encapsulation or covering <NUM> with an upper portion <NUM> and a lower portion or base <NUM>. The covering <NUM> is typically flexible, but may be either more or less flexible than the simulated neon <NUM>, <NUM>, <NUM> described above. In the encapsulated linear lighting <NUM>, there is no air gap between the upper portion <NUM> and the base <NUM>. The upper portion <NUM> of <FIG> is a rounded portion that lies directly overtop the base <NUM>. The base <NUM> comprises a sidewall and bottom that are typically made in a reflective white. The base <NUM> may be filled with a layer or layers of transparent or translucent plastic or rubber <NUM>, leaving no air gap between the rubber <NUM> and the linear lighting <NUM> that is disposed at the bottom of the base <NUM>. A reinforcing member <NUM> is disposed under the linear lighting <NUM>. Either the top portion <NUM> or a layer of the rubber <NUM> within the base may be made with a translucent additive in order to assist in light diffusion. A transparent strip <NUM> in the bottom of the base <NUM> allows visualization of the underside of the linear lighting <NUM>, in order to allow visualization of markings indicating cut points.

Typically, the encapsulated linear lighting <NUM> would be made by forming the outer shell of the base <NUM>, installing the reinforcing member <NUM> and the linear lighting <NUM> in the base <NUM>, and then filling the base <NUM>. That filling may be done in a single dose or layer, or it may be done in multiple doses or layers. As was described briefly above, layers of transparent material may be interposed between a layer or layers of translucent material. The upper portion <NUM> may simply comprise the meniscus that occurs when the base <NUM> is filled, or steps may be taken to shape it as shown in <FIG>. (The upper portion <NUM> of <FIG> is rounded but not hemispherical. ) As was noted briefly above, the resins that are used in the process may single-part or two-part polyurethanes or silicones.

The reinforcing member <NUM> may have the same properties and be made of the same materials as the reinforcing members <NUM>, <NUM>, <NUM> described above. The only potential additional consideration in encapsulated linear lighting <NUM> is whether the material of which the reinforcing member <NUM> is made is compatible with the resins that are used, since the reinforcing member <NUM> will be encapsulated in the resins.

The encapsulated linear lighting <NUM> of <FIG> is "top bend. " However, "side bend" linear lighting could be made in accordance with the principles described above.

Claim 1:
A linear lighting (<NUM>), comprising:
a flexible covering (<NUM>) having a translucent upper portion (<NUM>) and an opaque lower portion (<NUM>);
a transparent filling disposed within the lower portion;
a channel (<NUM>) within the transparent filling;
a strip of flexible linear lighting disposed within the channel (<NUM>), the strip of flexible linear lighting having at least one bending plane and at least one non-bending plane;
a reinforcing member (<NUM>) disposed within the channel (<NUM>), the reinforcing member (<NUM>) being constructed and arranged to bend in the at least one bending plane and to restrict bending in the at least one non-bending plane,
wherein the linear lighting is more rigid in the non-bending plane than in the bending plane, wherein the reinforcing member (<NUM>) is resilient and extends in parallel with the strip of flexible linear lighting, the reinforcing member (<NUM>) having a rectangular cross-section, wider than it is thick, and characterized in that the linear lighting further comprises a transparent strip (<NUM>) in a side or bottom face of the opaque lower portion of the covering (<NUM>), the strip of flexible linear lighting arranged in the channel (<NUM>) so that an underside of the strip of flexible linear lighting is visible through the transparent stripe (<NUM>),
wherein the reinforcing member (<NUM>) is transparent and is positioned in the channel between the underside of the strip of flexible linear lighting and the transparent stripe (<NUM>).