Patent Description:
This invention generally relates to light heads (also called light modules or light engines) such as a Society of Automotive Engineers (SAE) J595 and J845 Class <NUM> type of directional flashing optical warning device for authorized emergency, maintenance, and service vehicles. In particular, this invention relates to light heads including flexible materials.

Rigid directional warning lights employ adapters and bulky bezels or brackets to conform to curved vehicle surfaces. Some other lighting devices include flexible materials. Such products, however, typically provide non-flashing (i.e. , steady or so-called steady burn) illumination modes. These modes can be achieved using electronics having a relatively small footprint that need not hinder bendability of the lighting device.

In contrast, electronics for controlling a flashing warning signal have a relatively large footprint that introduces rigidity hindering bendability. Vehicle warning lights also produce a relatively high amount of heat.

<CIT> describes a warning light device for attaching onto various portions of vehicles and includes a housing having a base plate and a cover secured together and having a bent portion for attaching onto curved portions of the vehicle. One or more circuit boards are received in the housing, and a number of light devices are attached to the circuit boards and facing forward and sidewise and rearward of the housing for generating lights to be seen from various directions of the vehicle. One or more panels are attached onto the circuit boards and have concentric circles for light diffusing purposes.

<CIT> describes an illuminating system of flexible shape and comprising at least one LED disposed on a flexible carrier material, an optic being provided that permits uniform, directed and/or glare-free light emission.

There is provided a flexible directional warning light as detailed in claim <NUM>. Advantageous features are in the dependent claims. Also provided is a method of assembling a flexible directional warning light as detailed in claim <NUM>, with advantageous features provided in the dependent claims thereto. In some embodiments, the warning light is designed so that each end is bendable along its longitudinal axis up to <NUM>° from the axis to conform to curved vehicle surfaces. Flexible components of the disclosed embodiments facilitate bending and include a bendable optic, bendable backing, bendable circuitry, and a segmented heatsink. Accordingly, the disclosed device is mountable onto a curved vehicle surface without cumbersome mechanical adapters. This allows the end user to use a single type of device for mounting on both flat and curved services of a vehicle in locations that previously would have necessitated specialized bezels or a combination of different light module shapes.

Additional aspects and advantages will be apparent from the following detailed description of embodiments, which proceeds with reference to the accompanying drawings.

<FIG> shows an overhead view of an outline of an emergency vehicle <NUM>. Vehicle <NUM> is equipped with lightbars and data and power wiring that are the subject of <CIT> by Code <NUM>, Inc. Louis, Missouri, which is an affiliate company of Electronic Controls Company (ECCO) of Boise, Idaho, the assignee of this patent application. In particular, <FIG> shows how light modules <NUM> are mounted about the periphery of vehicle <NUM>. The present inventors have recognized that, for some applications, it would be advantageous to employ a unitary type of light module that is mountable atop flat or curved surfaces of vehicle <NUM> without specialized curved bezels. For instance, <FIG> shows how light module <NUM> may be deployed as bumper light modules <NUM> mounted atop flat surfaces, mirror light modules <NUM> conforming to curved mirror-housing surfaces, and fender light modules <NUM> conforming to exterior surfaces of fender flares.

<FIG> show flexible light module <NUM>, respectively, with and without a removable flat-surface mounting bezel <NUM> and foam backing pad <NUM> for accommodating flat-surface mounting locations. Such optional components may be removed for mounting on curved surface, as shown in <FIG>.

<FIG> provide a comparison in which a prior art light module <NUM> (<FIG>) cannot be installed on a mirror housing without an additional bezel or bracket. In contrast, <FIG> shows light module <NUM> is bendable along its longitudinal axis <NUM> (<FIG>). Bending is facilitated by flexible components (described later with reference to <FIG> and <FIG>) and multiple light segments <NUM> (e.g., six) defining five flex joints <NUM> therebetween. Flex joints <NUM> are oriented such that they are transverse to longitudinal axis <NUM> to facilitate <NUM>° of bending per side (<NUM>° total) from axis <NUM>. Skilled persons will now appreciate, however, that some flex joints orientations and segment locations may be varied to establish different bend radiuses across different axes.

<FIG> and <FIG> show in detail components of light module <NUM>. Specifically, modules <NUM> include a flexible optic <NUM>. In some embodiments, optic <NUM> is a clear and flexible rubber, such as silicone, polyurethane, or other types of flexible material. A flexible backing <NUM> is matable with optic <NUM> to encase electrical components <NUM> and metal (e.g., aluminum) heatsink segments <NUM> (also referred to collectively as heatsink <NUM>). Heatsink segments <NUM> are discrete components, but in other embodiments they are formed a single segmented component (e.g., kerf bendable metal). A wiring harness <NUM> is also molded onto a rear side of backing <NUM> for receiving wires <NUM>. An optional double-sided adhesive panel <NUM> is also shown.

Electrical components <NUM> include circuitry for controlling LEDs. Specifically, a microcontroller <NUM> (<FIG>) and associated circuity control optical emission from six pairs of color LEDs <NUM>. Such circuitry is mounted atop a flexible electrical substrate, i.e., circuit board <NUM>. In some embodiments, flexible circuit board <NUM> is an aluminum-backed and copper clad printed circuit board (PCB) including pairs of opposing peripheral relief notches <NUM> (<FIG>) to facilitate flexing along flex joints. Similarly, backing <NUM> includes corresponding external notches <NUM> (<FIG>) and internal ribs <NUM> (<FIG>) that facilitate bending and segmentation of components of heatsink <NUM>. Alignment protrusions <NUM> on ribs <NUM> fit in corresponding apertures to aid in alignment of and heat dissipation from board <NUM>.

In another embodiment (not shown), each segment of light module <NUM> includes a discrete PCB, and the discrete PCBs are electrically coupled via wires or flexible flat cables (FFCs). In other embodiments, one or more flexible printed circuits (FPC) are employed in lieu of or in addition to FFCs and PCBs. Skilled persons will appreciate that the choice of flexible circuit materials will depend on the size of the light module, the amount of desired bend and bend radius, the heat dissipation properties, and other design parameters.

During assembly, an adhesive, ultrasonic weld, or other technique is used to bond each metal segment of heatsink <NUM> to its corresponding confronting portion of electrical components <NUM>. Electrical components <NUM> and heatsink <NUM> are assembled into backing <NUM>, then optic <NUM> is bonded to backing <NUM> with adhesive to form a weather resistant flexible housing. In the present example, heat is conducted from the LEDs and electronics through PCB surface <NUM> (<FIG>), through aluminum heatsink <NUM>, and to backing <NUM>. A thermally conductive grease or adhesive is applied between heatsink <NUM> and backing <NUM> to further facilitate heat dissipation.

Optical elements acts upon the light passing through the clear (or colored) flexible optic <NUM>, and may comprise such as a lens, prism, or mirror. In some embodiments, an optical element provides for total internal reflection (TIR) maximizing light emission from LEDs. In the present example, <FIG> and <FIG> show in greater detail features of optical elements <NUM> that direct light from LEDs <NUM>. Each pair of LEDs <NUM> is centrally located in an aperture of a corresponding elliptic cylinder <NUM> defining an inner surface of an optical element. An outer wall <NUM> (shown in <FIG> and <FIG>) defining is generally frustoconical or otherwise tapered toward the LED-receiving aperture to define elliptic cylinder <NUM>. Such taper also facilitates bending by providing spatial displacement between optical elements <NUM> as they are bent inwards towards each other. Additional details of optic <NUM> are shown and described later with reference to <FIG>.

<FIG> also shows how each elliptic cylinder <NUM> is capped by a silicone membrane <NUM> extending between internal silicon sidewalls <NUM>. Flex joints <NUM> are formed by depressions in an exterior surface <NUM> of optic <NUM> between optical elements <NUM>. Accordingly, each segment <NUM> (<FIG>) includes a separate optic, pair of LEDs and associated circuitry, heatsink segment, and at least one flex joint.

<FIG> provides an overview of various features available in light module <NUM>. For instance, it is compatible with <NUM>- and <NUM>-volt (V) systems, supports various color options described in connection with <FIG>, and includes flash patterns that are configurable based on signals applied to wires in accordance with <FIG> and <FIG>.

Several color options are shown at the top of <FIG>, although skilled persons will now appreciate that many other options and combinations may be selected. For instance, at the bottom of <FIG> an example red and amber embodiment is shown. In this example, red and amber LEDs on a left-hand side are called, respectively, Color <NUM> and Color <NUM>. Similarly, red and amber LEDs on a right-hand side are called, respectively, Color <NUM> and Color <NUM>. These "Color" terms appear in connection with configuring flash pattern options described in connection with the "Function" shown in <FIG>.

<FIG> is a table describing wiring and electrical control functions for light module <NUM>, according to one embodiment. With reference to <FIG>, dual positive means positive can be applied to red alone, white alone, or both red and white. The sync function uses a signal from the microprocessor so if two lights are connected the timing of the flashes is synchronized. This allows multiple lights on the vehicle to either flash at exactly the same time or exactly opposite from each other if they are set to different phases. Finally, the term negative is DC ground.

<FIG> shows examples of various standard flash patterns available for light module <NUM>. The patterns are established by applying a voltage to one or both "Red" and "White" wires, and by sequentially grounding the "Blue" wire until the desired pattern is set. The patterns include options for different flash rates measured in flashes per minute (FPM), different synchronous color combinations (not shown), and different alternately flashing color combinations (not shown). Steady burn (i.e. , no appearance of flash) options are also supported.

<FIG> shows the directional light output <NUM> generated by optic <NUM>. A peripheral portion of light emitted from LEDs <NUM> passes through a solid inner wall <NUM> and reflects from an inside surface <NUM> of outer wall <NUM> and outward through optic <NUM>. Other light from LEDs <NUM> passes through the center of optic <NUM>.

<FIG> shows light module <NUM> emits SAE J845 Class <NUM> light output across a <NUM>-degree spread when it is mounted flat. At its maximum curvature, light module <NUM> provides <NUM>° of SAE J845 Class <NUM> light output. There is some reduction of light output at the center of light module <NUM> when it is mounted on a curved surface.

Claim 1:
A flexible directional warning light for mounting atop flat or curved vehicle surfaces when the light is in its respective unflexed or flexed positions, the light comprising:
a flexible optic (<NUM>) having multiple optical elements along a longitudinal axis (<NUM>) from which the light is configured to flex;
a flexible backing (<NUM>) matable with the flexible optic (<NUM>) to encase electrical components (<NUM>) of electrical circuitry and characterized in that the light further comprises a segmented heatsink (<NUM>),
the segmented heatsink (<NUM>) having multiple portions sized to fit in the flexible backing; and
the electrical circuitry is encompassed by the flexible optic and backing such that a first side of the circuitry confronts the segmented heatsink and a second side of the circuitry confronts the flexible optic.