CN112082136A

CN112082136A - Lens heating system and method for LED lighting system

Info

Publication number: CN112082136A
Application number: CN201910517797.5A
Authority: CN
Inventors: E·迪灵
Original assignee: JW Speaker Corp
Current assignee: JW Speaker Corp
Priority date: 2019-06-14
Filing date: 2019-06-14
Publication date: 2020-12-15

Abstract

Systems and methods for illumination system lens heating are described. The systems and methods include a substantially transparent thermoplastic substrate; and a conductive ink or thin film circuit on the thermoplastic substrate.

Description

Lens heating system and method for LED lighting system

Technical Field

The present technology relates to an LED lighting system. More particularly, the present technology relates to systems and methods for providing an LED lighting system lens heater.

Background

Most vehicles include some form of vehicle headlights and taillights, as well as other lighting systems. For example, lighting systems using incandescent or HID bulbs may produce sufficient radiation, particularly in the invisible spectrum, so that in cooler conditions, moisture in the form of condensation, rain, ice, snow, or snow does not form ice on the lighting system that reduces the optical transmission of the lighting system lens. Some lamps using LED lighting do not produce enough radiation to melt snow and ice in the lens of the lighting system.

Thus, there is a need for improved systems and methods for heating an illumination system lens sufficiently to melt snow and ice to avoid reducing the optical transmission of the illumination system lens.

Disclosure of Invention

The present technology provides illumination system lens heating systems and methods.

In one form, the technique provides a system for heating a lens of an LED lighting system.

In another form, the technology provides a method of heating an LED lighting system.

In accordance with one embodiment of the present technique, a system for heating a lens of an illumination system is disclosed. The system includes a substantially transparent thermoplastic substrate; and a conductive ink or thin film circuit on the thermoplastic substrate.

In some embodiments, the heating system further comprises a lens heater circuit, and the lens heater controller is operably coupled to the lens heater circuit.

In some embodiments, the conductive ink circuit is screen printed on the thermoplastic substrate.

In some embodiments, the conductive ink circuit is a conductive silver trace.

In some embodiments, the conductive thin film circuit is a conductive silver trace.

In some embodiments, a Positive Temperature Coefficient (PTC) ink trace is used to adjust the heating output of the conductive ink circuit based on the temperature of the conductive ink circuit.

In some embodiments, the heating system further comprises a dielectric top coat on the conductive ink circuit.

In some embodiments, the conductive ink circuit has a resistance in a range of about 5 ohms to about 300 ohms.

In some embodiments, the conductive ink circuit includes traces of generally equal length.

In some embodiments, the traces are connected with the bus bars on the non-power connection side.

In some embodiments, the traces have a width in a range of about 0.05mm to about 1.0 mm.

In some embodiments, the conductive ink circuit produces about 1W/in ^2 (watts/inch)²)。

In some embodiments, the conductive ink circuit is a substantially transparent ink.

In some embodiments, the lens heater controller adjusts the conductive ink circuit voltage to increase or decrease the power dissipated by the conductive ink circuit.

In some embodiments, the heating system further comprises a lighting system lens, wherein the conductive ink circuit remains exposed on an inner side of the lighting system lens.

In accordance with another embodiment of the present technique, an LED lighting system assembly having a heated lens is disclosed. The assembly includes: a housing comprising a base and a lens having an inner lens side and an outer lens side; at least one LED positioned within the base to provide illumination through the lens; a lens heater controller; a lens heater circuit operatively coupled to the lens heater controller; a substantially transparent thermoplastic substrate on the inner lens side; and a conductive ink or film circuit on a thermoplastic substrate operatively coupled to the lens heater circuit.

In some embodiments, the conductive ink on the thermoplastic substrate is placed in a recess on the core of the injection molding tool, with the conductive ink side abutting the core and the conductive ink side remaining exposed on the final lighting system lens portion.

In some embodiments, the conductive ink on the thermoplastic substrate is placed against the cavity side of the injection molding tool, with the conductive ink side being encapsulated between the thermoplastic substrate and the final illumination system lens portion.

In some embodiments, the thermoplastic resin is then overmolded onto the thermoplastic substrate, adhering only to the non-printed side of the thermoplastic substrate.

In some embodiments, the injection molding tool uses a vacuum to recess and retain the thermoplastic substrate in the core.

In some embodiments, greater than 90 percent transmission in lumens and intensity is achieved.

In accordance with another embodiment of the present technique, a method for heating a lens of an illumination system is disclosed. The method may include applying a conductive ink or film circuit on a substantially transparent thermoplastic substrate; applying a conductive ink or thin film circuit on a substantially transparent thermoplastic substrate to at least one of the inner lens side and the outer lens side; and applying controlled power to the conductive ink or thin film circuit to heat the lens.

In some embodiments, the method further comprises applying a PTC trace near the conductive ink or thin film circuit; sensing the resistance of the PTC trace; and controlling power to the conductive ink or thin film circuit based on the sensed resistance of the PTC trace.

In accordance with another embodiment of the present technique, a lens heating system is disclosed. The lens heating system may include a substantially transparent thermoplastic substrate, and a conductive ink or film circuit on the thermoplastic substrate to heat the thermoplastic substrate. The lens heating system may further include a lens heater circuit including a lens heater and operatively coupled to the lens heater controller. The controller may be configured to determine a temperature associated with the outer lens surface and activate the lens heater in response to a result of the temperature being less than or equal to a threshold temperature. The lens heating system may further include a spring connector including a plurality of pins configured to couple to the conductive ink or thin film circuit, and the pins are also configured to provide an electrical connection between the pins and the conductive ink or thin film circuit.

In some embodiments, the controller may be coupled to a thermistor configured to determine a temperature associated with the outer lens surface.

In some embodiments, the thermistor may be a Negative Temperature Coefficient (NTC) thermistor.

In some embodiments, the spring connector may be positioned at least partially within a lens coupled to a substantially transparent thermoplastic substrate.

In some embodiments, the lens heater circuit may include a circuit board to which the spring connector is surface mounted.

In some embodiments, the system may further include a second spring connector coupled to a second bus bar of the conductive ink or film circuit, the spring connector coupled to the first bus bar of the conductive ink or film circuit.

In accordance with another embodiment of the present technique, a method for heating a lens of an illumination system is disclosed. The method may include applying a conductive ink or thin film circuit on a substantially transparent thermoplastic substrate and applying the conductive ink or thin film circuit on the substantially transparent thermoplastic substrate to at least one of the inner lens side and the outer lens side. The method may further include positioning a spring connector having a plurality of pins against the conductive ink or thin film circuit and establishing an electrical connection between the pins and the conductive ink or thin film circuit and applying controlled power to the conductive ink or thin film circuit to heat the lens.

In some embodiments, positioning may include moving the spring connector toward the conductive ink or film circuit until the pin is bent a predetermined amount corresponding to establishing the electrical connection.

In some embodiments, the method may further include receiving a value from the wireless module and providing power to the conductive ink or thin film circuit based on the value.

In some embodiments, the method may further include receiving a value from a velocity sensor, determining that the velocity value is above a predetermined threshold, and in response to determining that the velocity value is below the predetermined threshold, providing power to the conductive ink or the thin film circuit by a predetermined value.

In some embodiments, the method may further include receiving a value from the optical sensor, determining that the optical value is below a predetermined threshold, and in response to determining that the optical value is below the predetermined threshold, providing power to the conductive ink or the thin film circuit by a predetermined value.

In some embodiments, the method may further include positioning a spring connector at least partially within a lens coupled to the substantially transparent thermoplastic substrate.

In accordance with another embodiment of the present technique, a heated lighting system is provided. The system may include a substantially transparent thermoplastic substrate, a conductive ink or thin film circuit positioned on the thermoplastic substrate to heat the thermoplastic substrate, a lens in contact with the thermoplastic substrate, and an interconnect assembly including a plurality of spring connectors. The spring connector may be positioned in contact with the conductive ink or the thin film circuit, and the interconnect assembly may be positioned at least partially within the lens.

In some embodiments, the interconnect assembly may be configured to provide power to the conductive ink or thin film circuitry.

In some embodiments, the lens may be bonded to at least a portion of the interconnect assembly and at least a portion of the thermoplastic substrate.

In some embodiments, the conductive ink or thin film circuitry may be positioned on the outer surface of the lens.

In some embodiments, the lens may be composed of a thermoplastic polymer.

In accordance with another embodiment of the present technique, a method for manufacturing a heated lighting system is disclosed. The method may include applying a conductive ink or thin film circuit on a substantially transparent thermoplastic substrate, positioning the thermoplastic substrate in a cavity of an injection molding tool, and positioning an interconnect assembly in a pocket of a core of the injection molding tool. The method may further include positioning the interconnect assembly against the thermoplastic substrate to establish an electrical connection between the interconnect assembly and the thermoplastic substrate, and injecting resin into the injection molding tool. The interconnect assembly may be configured to provide power to the conductive ink or thin film circuitry through the electrical connection.

In some embodiments, the interconnect assembly may include a plurality of pins, and positioning the interconnect assembly against the thermoplastic substrate may include bending the plurality of pins against the conductive ink or thin film circuitry.

In some embodiments, injecting resin into the injection molding tool may include overmolding at least a portion of the interconnect assembly and at least a portion of the conductive ink or thin-film circuit.

In some embodiments, positioning the thermoplastic substrate in the cavity may include positioning the conductive ink or thin film circuit away from the cavity.

These and other benefits will become clearer upon review and study of the following detailed description. Furthermore, while the embodiments discussed above may be listed as individual embodiments, it should be understood that the above-described embodiments, including all elements contained therein, may be combined in whole or in part.

Drawings

The present invention will be better understood and features, aspects and advantages other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such detailed description makes reference to the following drawings.

FIG. 1 is a perspective view of an illumination system having a lens heater according to an embodiment of the present invention;

FIG. 2 is a perspective view of the illumination system of FIG. 1 with the lens removed;

FIG. 3 is a perspective view of a portion of a lens heater assembly according to an embodiment of the invention;

FIG. 4 is a schematic diagram of a conductive ink or thin film circuit that may be used as a heating element according to an embodiment of the present invention;

FIG. 5 is a schematic view of the conductive ink or film of FIG. 4 attached to a lens of a lamp;

FIG. 6 is a table showing resistance repeatability data for various configurations;

FIG. 7 is a view showing a thermal image of a lighting system having an energized lens heater assembly according to an embodiment of the invention;

FIG. 8 is a view showing a lens-only thermal image of a lighting system having an energized lens heater assembly according to an embodiment of the present invention;

FIG. 9 is a perspective view of a lighting system with approximately 2mm ice accretion;

FIG. 10 is a perspective view of the lighting system of FIG. 9 with the lens heater circuit energized and with ice substantially removed from the optical zone;

FIG. 11 is a diagram showing an alternative embodiment of a lens heater circuit having traces with generally unequal trace lengths;

FIG. 12 is a diagram showing an alternative embodiment of a lens heater circuit having traces with generally equal trace lengths;

FIG. 13 is a graph showing key characteristics of PTC inks;

FIG. 14 is a schematic diagram showing an embodiment of a lens heater assembly layout (without a lens heater circuit) with PTC traces for temperature sensing;

fig. 15 is an enlarged view of the portion of fig. 14 showing the PTC trace;

FIG. 16 is a schematic diagram illustrating the positioning of ink and screen printed substrates in an injection molding tool to produce an illumination system lens with a lens heater according to an embodiment of the present invention;

FIG. 17 is an enlarged view of a portion of FIG. 16;

FIG. 18 is a schematic diagram illustrating an alternative positioning of ink and screen printed substrates in an injection molding tool to produce an illumination system lens with a lens heater according to an embodiment of the present invention;

FIG. 19 is an enlarged view of a portion of FIG. 18;

FIG. 20 is a table showing the optical effect of a lens heater trace on low beam illumination and high beam illumination; and

fig. 21 is an exploded perspective view of an alternative embodiment of an illumination system having a lens heater according to an embodiment of the present invention.

Fig. 22 is a perspective view of an alternative embodiment of an illumination system.

Fig. 23 is a front view of the lighting system of fig. 22.

Fig. 24 is an exploded view of the lighting system of fig. 22.

Fig. 25 is an exploded view of the lens, interconnect assembly, and thermoplastic substrate of the illumination system of fig. 22.

Fig. 26 is a perspective view of the interconnect assembly of fig. 22.

Fig. 27 is another perspective view of the interconnect assembly of fig. 22.

Fig. 28 is an exploded view of the interconnect assembly and thermoplastic substrate of the lighting system of fig. 22.

Fig. 29 is another view of the thermoplastic substrate and interconnect assembly of the lighting system of fig. 22 isolated from other components.

Fig. 30 is a cross-sectional view of a lens, interconnect assembly, and thermoplastic substrate of the illumination system of fig. 22.

Fig. 31 illustrates an exemplary process for manufacturing a lens bonded to at least a portion of a thermoplastic substrate and an interconnect assembly, in accordance with some embodiments.

Fig. 32 illustrates a circuit diagram of a driver circuit and a heater circuit according to some embodiments.

Fig. 33 illustrates an example block diagram of an example heater control system for a lighting system, according to some embodiments.

FIG. 34 is a perspective view of an alternative embodiment of a lighting system;

fig. 35 is a front view of the lighting system of fig. 34.

Fig. 36 is a perspective view of an alternative embodiment of an illumination system.

Fig. 37 is an exploded view of the lighting system of fig. 36.

Fig. 38 is a front view of the lighting system of fig. 36.

Fig. 39 is a view of the interconnect assembly, lens and thermoplastic substrate of the illumination system of fig. 36.

Fig. 40 is a perspective view of an alternative embodiment of a lighting system.

Fig. 41 is a front view of the lighting system of fig. 40.

Fig. 42 is a view of the interconnect assembly, lens and thermoplastic substrate of the illumination system of fig. 40.

Fig. 43 is a view of the interconnect assembly, lens and thermoplastic substrate of the lighting system of fig. 40.

Fig. 44 is a view of the interconnect assembly and thermoplastic substrate of fig. 40.

Fig. 45 is another view of the interconnect assembly and thermoplastic substrate of fig. 40.

Fig. 46 is yet another view of the interconnect assembly and thermoplastic substrate of fig. 40.

Fig. 47 is a perspective view of an alternative embodiment of an illumination system.

Fig. 48 is a front view of the lighting system of fig. 47.

Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.

Detailed Description

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Also, the use of "right," "left," "front," "back," "upper," "lower," "top," or "bottom" and variations thereof herein is for descriptive purposes and not to be construed as limiting. In this document, "comprising," "including," or "having" and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings.

The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to the embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is read with reference to the drawings, in which like elements in different drawings are numbered similarly. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Those skilled in the art will recognize that the embodiments provided herein have many useful alternatives and fall within the scope of embodiments of the invention.

High transmittance lens heaters are required to prevent certain LED lighting systems from freezing. Referring to fig. 1 and 2, in some embodiments, an overmolded screen printed conductive circuit may be used as a heating element for the illumination system 20. The lighting system 20 may include a housing 24 that includes a base 28 and a lens 32. The lens 32 has an inner lens side 36 and an outer lens side 40. At least one LED 44 may be positioned within the base 28 to provide illumination through the lens 32. The lens heater assembly 70 may include a lens heater controller 48, with the lens heater circuit 52 operatively coupled to the lens heater controller 48. In some embodiments, a substantially transparent thermoplastic substrate 60 may be positioned on the inner lens side 36 of the lens, and a conductive ink or thin film circuit 66 may be positioned on the thermoplastic substrate 66 and may be operatively coupled to the lens heater circuit 52. In some embodiments, a reflector 68 may be included to direct illumination from one or more LEDs 44.

In some embodiments, the heating output of the heating element can be adjusted based on the temperature of the heating element trace using Positive Temperature Coefficient (PTC) ink traces.

Fig. 3 illustrates an embodiment of a lens heater circuit 52. The lens heater circuit 52 may be coupled to the lens 32 or may be positioned within the base 28. As shown in fig. 3, when the lens heater circuit is coupled to the lens 32, a power cord 56 (see fig. 2) may extend from the base and couple to a connector 54 on the lens heater circuit. In some embodiments, the conductive element 58 may be used to provide power from the lens heater circuit 52 to the conductive ink circuit 66. For example, the conductive element may be a spring or a wire.

Fig. 4 and 5 illustrate an embodiment of a conductive ink or thin film circuit 66 that may be used as a heating element. It should be understood that the terms ink and film are used interchangeably herein. In some embodiments, the conductive film 66 is a conductive silver trace. It should be understood that other resistive elements may be used for the conductive film. Fig. 4 shows conductive silver traces that have been screen printed on a transparent base film 60. In some embodiments, the substrate 60 may be a thermoplastic polymer. In some embodiments, the substrate 60 may be a polycarbonate substrate. Also, other substrate materials may be used. Fig. 5 shows the conductive film 66 pre-attached to the base 60 of the illumination system lens 32 for testing. The substrate 60 can be any transparent or substantially transparent substrate film. Opaque substrates may also be used.

Embodiments of the lens heater assembly 70 were tested using multiple types of inks with and without a dielectric top coat. The lens heater assembly 70 may also be tested at a variety of substrate thicknesses. Figure 6 shows resistance repeatability data for various configurations. In some embodiments, the lens heater circuit 52 may have a resistance in the range of about 5 ohms to about 300 ohms, depending on the application. Some 12-24V lighting system applications may be about 30 ohms, or more or less. Other voltages and resistances are also contemplated.

A version of the lens heater assembly 70 is affixed to the existing molded outer lens 32 and thermal testing is completed on the individual lens 32 and the lamp assembly. Fig. 7 and 8 show thermal images of the illumination system assembly 20 (fig. 7) and lens only (fig. 8) with the heater assembly energized. In the figure, the temperatures are represented by 72 hot, 74 warm, 76 cool, and 78 cool. It is contemplated that these descriptions of hot, warm, cool, and cold are relative terms, and are merely intended to show the gradient of the temperature range that may be produced by the lighting system 20.

Fig. 9 shows the lighting system 20 in a cooling chamber with an ice accretion 80 of about 2mm saturated at-20 ℃. Fig. 10 then shows the same lighting system 20 with the LEDs 44 energized (e.g., low and high beam) and the lens heater circuit 52 energized and dissipating approximately 18 watts. Ice 80 is substantially removed from optical zone 84 within a few minutes. The cooling chamber was maintained at-20 ℃ with considerable convective airflow.

FIG. 11 illustrates one embodiment having a lens heater circuit 52 comprised of traces 88 of unequal trace lengths. This arrangement creates non-uniform heating of the traces 88. Such an arrangement may be useful for certain applications. Slightly warmer heating can be seen at center 92 than at edge 96. Fig. 12 shows an additional embodiment having generally equal length traces 88. A more uniform heating can be seen. The traces may be connected to the bus bars 100 on the non-power connection terminals 104 to allow for the same trace length, which may also be useful in some applications. In the figure, the temperatures are indicated by 72 hot, 74 warm, 76 cool, and 78 cool. It is contemplated that these descriptions of hot, warm, cool, and cold are relative terms, and are merely intended to show the gradient of the temperature range that may be produced by the lighting system 20.

In some embodiments, silver-based screen-printing ink may be used as the lens heater traces 88. Silver allows for low resistance traces even when the traces are very thin. In some embodiments, the ink may be printed to a thickness of between about 5-15 millimeters (and may become more or less in other embodiments). Other conductive inks may be used so long as they meet the overall resistance requirements of various applications.

In some embodiments, the width of the lens heater trace used as a heating element may be about 0.35 mm. This may vary from about 0.05mm to about 1.0mm in various embodiments. The lens heater traces may be spaced about 8mm apart to provide uniform heating across the lens surface. This distance can be increased to about 15mm and still be effective, and can be reduced for other applications. It should be understood that other dimensions are possible.

In some embodiments, the total resistance of the lens heater circuit 52 may be about 30 ohms. In other embodiments, this may vary from about 5 ohms to about 300 ohms in various designs.

Through testing, it has been found that about 1W/in ^2 applied to the inner surface of the thermoplastic polymer outer lens 32 can be a sufficient amount of power per optical area of the LED lamp to effectively de-ice. In other embodiments, this may be increased to 2W/in ^2 or more in other designs. Some embodiments of the lighting system 20 may be designed to dissipate approximately 18 watts. It should be understood that other dissipations are possible.

In other embodiments, the lens heater portions may not necessarily need to be traces of opaque conductive ink. For example, the lens heater traces 88 may be substantially transparent ink (e.g., about 85 percent, or more or less transmittance) that may cover a portion or the entire surface of the heater substrate 60. This clear ink may also include a more conductive ink screen thereon to create bus bars and input power connection points. Non-limiting examples of transparent conductive inks include those based on carbon or graphite nanotechnology, silver micro-or nanostructures, and indium tin oxide, silver, or copper micro-foil grids.

As described above, the PTC ink traces 108 may also be incorporated into the lens heater circuit 52. Fig. 13 is a graph showing key characteristics of the PTC ink. The resistance of PTC inks increases with increasing temperature. At some predetermined temperature, the increase in resistance may become exponential. In some embodiments, the PTC trace 108 may be located near one or more of the lens heater traces 88. In some embodiments, the PTC trace resistance may reach infinity when the lens heater trace 88 approaches approximately 40-60 ℃. The lens heater controller 48 may identify this change in resistance and vary the voltage provided to the lens heater circuit 52 to maintain the lens heater trace 88 at or near about 40 ℃ during operation. In some embodiments, 40CPTC ink available from Henkel AG & Company, KGaA, Inc. may be used. PTC inks from DuPont (Dupont) and others may also be used.

Fig. 14 shows an embodiment of a lens heater assembly 70 layout (without lens heater circuit 52) with PTC traces 108 for temperature sensing. In the case of opposing bus bars 120, in some embodiments, most or all of the traces may be of substantially equal length and may heat evenly. There may be multiple connection points (each power bus bar 116 may have more than one connection to reduce current through a single point). Top connection point 128 and bottom connection point 132 support the electrical potential on lens heater trace 88. The top 128 and middle 136 connection points allow the resistance on the PTC trace 108 to be measured as a thermistor.

Fig. 15 shows an enlarged PTC trace 108. Since the PTC trace may extend along the side of the lens heater trace 88, it may have almost the same temperature as the lens heater trace. As the lens heater trace approaches 40 ℃, the resistance of the PTC trace may begin to increase exponentially. At some point on the exponential curve 144 (see fig. 13), the lens heater controller 48 may begin to adjust the lens heater voltage and thereby reduce the power dissipated by the lens heater circuit 52.

Fig. 16 shows the positioning of the ink 66 and screen printed substrate 60 in the injection molding tool 146 to produce an illumination system lens with lens heaters. Fig. 17 is a close-up view. A transparent substrate 60 with a pattern of screen printed conductive ink 66 may be placed in a recess on the core 148 with the ink side against the core. In such an arrangement, the exposed ink side may remain exposed on the final illumination system lens portion 32. The molten resin may then overmold the substrate 60, adhering only to the unprinted side of the transparent substrate 60. In some embodiments, various types of thermoplastic polymers (such as polycarbonate materials) may be used as the injection resin 152 for the lens 32. It should be understood that other component arrangements are contemplated in which the ink 66 side remains exposed on the final illumination system lens portion 32.

Fig. 18 shows an alternative arrangement for positioning the ink 66 and screen printed substrate 60 in an injection molding tool 146 to produce an illumination system lens with a lens heater. Fig. 19 is a close-up view. The ink 66 may be encapsulated and the transparent substrate 60 placed against the cavity side 156 of the tool.

Testing showed successful overmolding of the thermoplastic film substrate screen printed lens heater trace 88. Both of which are affixed to the core of the injection molding tool to prevent the material from pushing the label up against the cavity 156. The tool 146 may be modified to utilize a vacuum to recess the thermoplastic substrate 60 and conductive ink 66 into the core 148 and hold it there. In some embodiments, the conductive ink 66 may be exposed on the inner side 36 of the lens 32.

Fig. 20 is a table including the optical effect of lens heater trace 88 on low beam illumination and high beam illumination. The effect of the lens heater trace 88 on the illumination output is only minimal and may be imperceptible, and may be further reduced by a thinner lens heater trace. In some embodiments, greater than 90 percent transmission may be achieved in terms of lumen and intensity. This can be varied depending on the lighting system application by varying the thickness of the lens heater traces and the materials used for the conductive traces 66 and the substrate 60.

Fig. 21 shows an alternative embodiment of the lighting system 200. The illumination system 200 may include a base 204 and a lens 208. The lens 208 has an inner lens side 216 and an outer lens side 212. At least one LED220 may be positioned within the base 204 to provide illumination through the lens 208. The lens heater assembly 222 may include a lens heater controller 224, with a lens heater circuit 228 operatively coupled to the lens heater controller 224. In some embodiments, a substantially transparent thermoplastic substrate 232 may be positioned on the inner lens side 216 of the lens, and a conductive ink or thin film circuit 236 may be positioned on the thermoplastic substrate 232 and may be operatively coupled to the lens heater circuit 228. In some embodiments, a reflector 240 may be included to direct illumination from one or more LEDs 220. In some embodiments, the lens heater circuit 228 may include one or more contacts 248 to allow power transfer from the lens heater circuit 228 to the conductive ink circuit 236. Conductive elements 244 (e.g., springs or wires) may be positioned to electrically couple contacts 248 with contacts 252 on conductive ink circuit 236. In some embodiments, the conductive element 244 may pass through the mirror 240 to provide power from the lens heater circuit 228 to the conductive ink circuit 236.

Referring to fig. 22-29, components of a lighting system 256 are shown according to an embodiment of the present disclosure. The illumination system 256 may include a base 260 and a lens 264. As shown, the lens 264 has an inner lens side 268 and an outer lens side 272. According to one embodiment, at least one LED 276 may be positioned within the base 260 to provide illumination through the lens 264. The lighting assembly 280 (e.g., as shown in fig. 24) may include a controller and/or conditioning circuit coupled to the at least one LED 276 to control the power provided to the at least one LED 276. Additionally, the lighting assembly 280 may be coupled to an interconnect assembly 284 (e.g., as shown in fig. 25) to control the power provided to the interconnect assembly 284 and/or the communication between the lighting assembly 280 and the interconnect assembly 284. The interconnect assembly 284 may be used to provide heat to the thermoplastic substrate 288, as described below.

In some embodiments, the thermoplastic substrate 288 (e.g., as shown in fig. 25) may be made of certain materials, including substantially transparent thermoplastics. Conductive ink circuits 292 (which may also be referred to as conductive film circuits) may be positioned on the thermoplastic substrate 288 and coupled to the interconnect assembly 284, the details of which will be described below. In some embodiments, the conductive ink circuit 292 may comprise conductive silver deposited on the thermoplastic substrate 288 using known techniques such as screen printing. When the conductive ink circuit 292 is provided with the appropriate electrical power, the conductive ink circuit 292 can provide the heat.

In some embodiments, the conductive ink circuit 292 may be positioned on the inner thermoplastic substrate surface 296 (e.g., as shown in fig. 25). Additionally, an inner thermoplastic substrate surface 296 may be positioned above the lens 264. The outer thermoplastic substrate surface 300 may be exposed to the environment (including, for example, low temperatures) surrounding the illumination system 256. In some embodiments, the conductive ink circuit 292 may effectively prevent ice from forming on the lighting system 256 when the thermoplastic substrate 288 is positioned on top of (e.g., above) the lens 264 due to the relative thickness of the thermoplastic substrate 288 compared to the lens 264. The smaller thickness of the thermoplastic substrate may allow heat to be more efficiently transferred to the outermost surface of the illumination system 256 and may prevent ice from accumulating and possibly blocking illumination from the at least one LED 276.

In some embodiments, the interconnect assembly 284 may be coupled to the conductive ink circuit 292 to conduct the ink circuit 292 provide power. As shown in fig. 26, the interconnect assembly 284 may include a spring connector 304 coupled to a circuit board 308, and the circuit board 308 may be a printed circuit board. Portions of the conductive ink circuit 292 may act as bus bars to allow efficient power transfer from the spring connector 304 to the conductive ink circuit 292. In some embodiments, the spring connectors 304 may be included in the power and ground terminals of the conductive ink circuit 292. Each spring connector 304 may have a plurality of pins 312, such as two pins, three pins, four pins, or five pins. The additional pins may allow for higher current carrying capability due to the larger connection area on the conductive ink circuit 292. In some embodiments, the spring connector 304 may be a battery-type connector, such as a cable connector

9155-200 battery connectors are provided. The pins 312 may flex and/or depress when the interconnect assembly 284 is pressed against the thermoplastic substrate 288. When the interconnect assembly 284 is pressed against the thermoplastic substrate 288, the pins 312 may be configured to be biased to an outermost position and require progressively increasing force to be further bent and/or depressed. The pins 312 and the interconnect assembly 284 may then be held in place while injection molding around the interconnect assembly 284 to form the lens 264, as described below.

The bus bar 316 may be placed in contact with the spring connector 304 and coupled to the interconnect assembly 284, the details of which will be described below. The bus bars 316 may have a larger cross-sectional area along the length of the bus bars 316, and thus a reduced resistivity, as compared to other portions of the conductive ink circuit 292, which may utilize a higher resistivity to generate heat. The bus bars 316 may include a first bus bar 316A and a second bus bar 316B. Depending on the electrical configuration of the interconnect assembly 284, the first bus bar 316A may function as a power bus bar and the second bus bar 316B as a ground or neutral bus bar. Alternatively, the first bus bar 316A may function as a ground or neutral bus bar and the second bus bar 316B as a power bus bar.

A thermistor 320, which may be a Negative Temperature Coefficient (NTC) resistor, may be coupled to the circuit board 308 and placed in contact with the lens 264 during manufacture of the lens 264, as will be described in detail below. The thermistor 320 can be used to sense the temperature of the lens 264. Then, according to some embodiments, the power provided to the conductive ink circuit 292 may be controlled based on the temperature sensed by the thermistor 320.

In some embodiments, the pin connector 324 may be positioned on a circuit board and coupled to the thermistor 320 and/or the spring connector 304. The pin connector 324 may have any number of interfaces, such as pins for providing appropriate electrical connections to a circuit board. For example, four pins may be included to provide a power connection, a ground connection, a connection for a first terminal of the thermistor 320, and a connection for a second terminal of the thermistor 320, respectively. The power and ground connections may be used to directly power the conductive ink circuit 292 or the conditioning circuitry of the circuit board 308 to control the power supplied to the conductive ink circuit 292, as will be described below. The connection to the thermistor 320 can be used to provide a measurement of the resistance between the thermistor 320 and another circuit board and/or a controller. In some embodiments, additional pins may be provided for other electronic devices that may be coupled to the circuit board 308, such as optical sensors, additional conductive ink circuits, or additional thermistors.

In some embodiments, indicator light 327 may be coupled to circuit board 308 and configured to turn on when power is provided to conductive ink circuit 292. As an example, the indicator light 327 may be an LED coupled to the conductive ink circuit 292. In some embodiments, the indicator light 327 may be coupled to a dedicated indicator light pin included in the pin connector 324 and controlled by external circuitry and/or a controller coupled to the indicator light pin and configured to selectively provide power to the indicator light pin.

According to one non-limiting exemplary embodiment, the lighting system 256 is subjected to tests related to functionality and deicing capabilities for a range of temperatures. The test procedure involves placing the thermocouple centrally on the outer surface of the outer lens (in this case, the thermoplastic base 288). The lighting system 256 is then oriented to direct it within the vehicle (e.g., the lens 264 placed adjacent to the LED lights), as well as the thermoplastic substrate 288 and lens 264 visible through the viewing window. Thermocouple measurements and current measurements of the current supplied to the lighting system were recorded during the test. The sampling rate of the measurements is high enough to observe the temperature at which the heater is switched on. The lighting system 256 was placed in a 30 ℃ hot chamber and the high and low beams were powered at 13.5 VDC. The temperature in the chamber decreased from 30 ℃ to-30 ℃ over a period of 1 hour. The temperature in the chamber was then maintained at-30 ℃ for 1 hour. The illumination system 256 is then subjected to a temperature of-30 ℃ for 1 hour while a 2mm thick layer of ice is built up on the thermoplastic substrate 288 and/or the lens 264 by occasionally applying water to the thermoplastic substrate 288 and/or the lens 264. The 13.5VDC is then provided to the lighting system 256 via the high beam and low beam. Monitoring of ice is stopped when the ice on the lighting system 256 is in a steady state (defined as no change in 10 minutes) or when the lighting system 256 has been energized for one hour. The lighting system 256 is then evaluated to determine if functionality is maintained after testing, if all ice has been removed from the thermoplastic substrate 288 and/or the lens 264, and if the lighting system 256 has been subjected to any damage from the testing. Here, the function is maintained, the ice is removed, and the lighting system 256 is not subject to any damage. Thus, the lighting system 256 is considered to pass the test criteria.

Referring to fig. 22-30, cross-sectional views of the thermoplastic substrate 288 and the positioning of the interconnect assembly 284 within the lens 264 are shown. An injection molding process may be used to encapsulate the thermoplastic substrate 288 and the interconnect assembly 284 with a thermoplastic polymer, such as a polycarbonate material, to form the lens 264. An injection molding tool having a cavity and a core may be used to position the thermoplastic substrate 288 and the interconnect assembly 284. The thermoplastic substrate 288 may be positioned against the cavity with the conductive ink circuit 292 facing away from the cavity.

In some embodiments, at least a portion of the interconnect assembly 284 may be placed with the spring connector 304 facing the thermoplastic substrate 288 in the pocket of the core. The portion of the interconnect assembly 284 that may be placed in the pocket of the core includes the heating connector 304 and the circuit board 308. The pocket may be sized to hold the interconnect assembly 284 in place before the resin has cooled and hardened around the interconnect assembly 284. Once the resin cools, the lens 264 may bond to at least a portion of the interconnect assembly 284 and at least a portion of the thermoplastic substrate 288 and hold the interconnect assembly 284 and the thermoplastic substrate 288 in place, forming the lens 264, the thermoplastic substrate 288, and the interconnect assembly 284 as a single piece structure (i.e., the lens 264 may resist removal of the thermoplastic substrate 288 and/or the interconnect assembly 284). In some embodiments, the interconnect assembly 284, the spring connector 304, and/or the pins 312 may be positioned at least partially within the lens 264.

Forming the lens 264, thermoplastic substrate 288, and interconnect assembly 284 as a single-piece construction may simplify repair of the lighting system 256, such as replacing LEDs. By way of example, a user may only need to remove the lens 264 and unplug the pin connector 324 from any attached cable without removing the interconnect assembly 284 and/or the thermoplastic substrate 288 from a position in which a suitable electrical connection is formed between the pins 312 of the interconnect assembly 284 and the conductive ink circuit 292 located on the thermoplastic substrate 288, thus removing the potentially complicated step of rearranging the interconnect assembly 284 on the conductive ink circuit 292 and/or the thermoplastic substrate 288 in order to recreate a suitable electrical connection, as will be explained below.

The core and interconnect assembly 284 may then be moved toward the cavity and thermoplastic base 288 until the pins 312 are slightly depressed, according to some embodiments. In some embodiments, the pins 312 may be pressed a predetermined amount so that an adequate electrical connection may be made. As an illustrative example, the pin 312 may be depressed approximately 10% -30% of the total range of motion of the pin 312 and into contact with the bus bar 316 and/or the conductive ink circuit 292. As described above, a thermoplastic polymer (e.g., a polycarbonate material) may be used as the injected resinous plastic material to form the lens 264. After depressing the pins 312, a resinous plastic material may then be injected into the tool. The plastic material and/or the lens 264 may overmold at least a portion of the conductive ink circuit 292. The plastic material and/or the lens 264 may insulate the portion of the conductive ink circuit 292 that is not in contact with the spring connector 304. Once the plastic material has hardened, the lens 264 may hold the spring connector 304 and the interconnect assembly 284 in place (i.e., with the pins 312 depressed) to ensure that the interconnect assembly 284 remains properly electrically coupled to the conductive ink circuit 292.

The interconnect assembly 284 (and more specifically the spring connector 304) may optionally be placed against the thermoplastic substrate 288 to ensure that the spring connector 304 remains in proper electrical connection with the conductive ink circuit 292. If the interconnect assembly 284 is positioned too inward toward the thermoplastic substrate 288, the pins 312 may exert excessive pressure on the conductive ink circuit 292 and may penetrate the conductive ink circuit 292. If the interconnect assembly 284 is positioned too far from the thermoplastic substrate 288, the pins 312 may not be depressed far enough and moved out of contact with the conductive ink circuit 292.

In some cases, if the pins 312 are not depressed far enough, the injected resin may move the pins 312 out of contact with the conductive ink circuit 292. As described above, when the interconnect assembly 284 is pressed against the thermoplastic substrate 288, the pins may be configured to require a gradually increasing force to be further bent and/or depressed. When displaced a relatively short distance, the pin 312 may require a relatively small force to be displaced further. After the interconnect assembly 284 is positioned against the thermoplastic substrate 288, resin may be injected into the injection mold. The injected resin may press against the pins 312 in a sufficient manner to further depress the pins 312 away from the thermoplastic substrate (and thus not in contact with the conductive ink circuit 292). This can occur if the pins are not depressed far enough and are biased outward if the force is not sufficient to resist further depression of the injected resin.

In some embodiments, a suitable electrical connection between the pin 312 and the conductive ink circuit 292 may be a low resistance connection. The resistance of the electrical connection is preferably close to zero ohms. In some embodiments, a suitable amount of resistance may be less than about 10% or less of the resistance of the conductive ink circuit 292.

To determine the proper location of the interconnect assembly 284 on the thermoplastic substrate 288, a thermal camera may be used to determine whether a proper electrical connection exists between the interconnect assembly 284 and the conductive ink circuit 292. A thermal camera may be used to detect heat around the area where the pins 312 are in contact with the conductive ink circuit 292. Power may be applied to the interconnect assembly 284 and the conductive ink circuit 292 and if excessive heat is spread around the area where the pins 312 contact the conductive ink circuit 292, the electrical connection between the interconnect assembly 284 and the conductive ink circuit 292 may not be efficient. The position of the interconnect assembly 284 relative to the thermoplastic substrate 288 may be adjusted until a threshold of maximum heat dissipation is met without the pins 312 penetrating the conductive ink.

The thermistor 320 may be overmolded by resin and positioned in contact with the lens 264. The thermistor 320 can then be used to sense the temperature of the lens 264, which can be indicative of the temperature of the outer lens side 272 of the lens 264. The temperature indicated by the resistance of the thermistor 320 may be lower than the ambient temperature due to the temperature caused by the thickness of the lens 264. For example, a resistance value representing 20 ℃ may correspond to a temperature of 5-15 ℃ at the outer lens side 272. The difference in temperature may be addressed by circuitry that powers the conductive ink circuit 292 such that the conductive ink circuit 292 provides heat when the temperature of the outer lens side 272 is low enough to potentially freeze the outer lens side 272.

Fig. 31 illustrates an exemplary process 328 for manufacturing a lens bonded to at least a portion of a thermoplastic substrate and an interconnect assembly. At process step 332, the conductive ink or film circuit may be positioned on the thermoplastic substrate using known techniques such as screen printing. In some embodiments, the conductive ink or film circuit may include silver traces. Once the conductive ink or thin film circuit is stable, the process 328 may proceed to step 336.

At process step 336, the thermoplastic substrate may be positioned in a cavity of an injection mold. In particular, the side of the thermoplastic substrate without the conductive ink or film circuitry may be placed against the wall of the cavity, with the conductive ink or film circuitry facing away from the cavity. The process may then proceed to step 340.

At process step 340, the interconnect assembly may be positioned in a pocket of a core of an injection mold. The interconnect assembly may have: one or more spring connectors, each spring connector having a plurality of pins; and a thermistor disposed on a side of the circuit board. The interconnect assembly may be positioned to face the spring connector of the cavity, more specifically the conductive ink or film circuit. The process may then proceed to step 344.

In process step 344, the interconnect assembly may be positioned against the thermoplastic substrate to establish a suitable electrical connection between the interconnect assembly and the thermoplastic substrate. In particular, the connection may be established at the conductive ink or film circuit while the injection mold is closed. As described above, placement of the interconnect assembly (more specifically, the spring connector) against the thermoplastic substrate 288 may be selected to ensure that the spring connector remains properly electrically connected with the conductive ink circuit. If the interconnect assembly is positioned too inward toward the thermoplastic substrate, the pins may exert excessive pressure on and potentially break down the conductive ink circuitry. If the interconnect assembly is positioned too far from the thermoplastic substrate, the pins may not be depressed far enough and moved out of contact with the conductive ink circuit during resin injection.

As described above, when the interconnect assembly is pressed against the thermoplastic substrate, the pins may be configured to require a gradually increasing force to be further bent and/or depressed. When displaced a relatively short distance, the pin may require a relatively small force to be displaced further. After the interconnect assembly is positioned against the thermoplastic substrate, resin may be injected into the injection mold. The injected resin may press against the pins in a sufficient manner to further depress the pins away from the thermoplastic substrate (and thus not into contact with the conductive ink circuit). This can occur if the pins are not depressed far enough and are biased outward if the force is not sufficient to resist further depression of the injected resin.

In some embodiments, a suitable electrical connection between the pin and the conductive ink circuit may have only a small percentage of the resistance of the conductive ink circuit. For example, if the conductive ink circuit has a resistance of 200 ohms, a suitable electrical connection may have a resistance of 10 ohms, or about 5% of the total resistance of the conductive ink circuit. In some embodiments, a suitable electrical connection may have a resistance of about one percent or less of the resistance of the conductive ink circuit, about two percent or less of the resistance of the conductive ink circuit, about five percent or less of the resistance of the conductive ink circuit, about eight percent or less of the resistance of the conductive ink circuit, about ten percent or less of the resistance of the conductive ink circuit 292. Once the appropriate electrical connection is obtained, the process may proceed to step 348.

At process step 348, resin may be injected into the injection mold. The resin may be a thermoplastic polymer. A portion of the interconnect assembly, a portion of the thermistor, and/or a portion of the spring connector may be overmolded with resin. A portion of the interconnect assembly, a portion of the thermistor, and/or a portion of the spring connector may be partially contained within and/or bonded to the lens. A portion of the thermistor may then be placed in contact with a lens to be formed of resin. The thermistor can then be used to sense the temperature of the lens, which can be indicative of the temperature of the outer lens side of the lens. Once the resin hardens and the lens is formed, the interconnect assembly, thermoplastic substrate, and lens may form a single piece construction component. The process may then proceed to step 352. At process step 352, the one-piece component may be removed from the injection mold and placed or utilized in a heated lighting system.

Referring to fig. 32, a circuit diagram of a driver circuit 372 and a heater circuit 376 according to some embodiments is shown. The driver circuit 372 may include a temperature difference amplifier 380 and a driver amplifier 384. The temperature difference amplifier 380 may be coupled to a temperature set point voltage source 388 at a first input 392. The temperature set point voltage source 388 may provide a predetermined voltage that corresponds to a temperature threshold below which the drive circuit 372 will provide power to the heater element 396. The heater element 396 may include a conductive ink circuit arranged as described above. In some embodiments, the heater element 396 may be a conductive ink circuit. The power connections of the amplifiers are not shown for simplicity.

The temperature difference amplifier 380 may be coupled to the resistor 400 and the thermistor 404 at a second input 408. Resistor 400 may be coupled to a fixed voltage source 412. The fixed voltage source 412 can provide a predetermined voltage that is higher than the voltage provided by the temperature set point voltage source 388.

The thermistor 404 may be an NTC resistor as described above. The thermistor 404 may generally follow a predetermined resistance versus temperature curve, which may be provided by the manufacturer of the thermistor 404. The thermistor 404 may provide a greater resistance as the temperature decreases. The thermistor 404 may be configured to sense a temperature of a lens of the heating lighting system as described above, such as being arranged in contact with the overmolded lens. As described above, the temperature indicated by the thermistor 404 may be different from the external lens temperature. This temperature difference can be accounted for by selecting the appropriate voltages provided by the temperature set point voltage source 388 and the fixed voltage source 412.

The voltage at the second input 408 may vary as the thermistor 404 becomes more or less resistive based on temperature. As the temperature decreases and the thermistor 404 provides more and more resistance than the resistor 400, the smaller voltage from the fixed voltage source 412 drops across the resistor 400 as the thermistor 404 provides less resistance, and the voltage at the second input 408 is relatively higher than the voltage at the second input 408. If the voltage at the second input 408 is higher than the voltage at the first input 392 (i.e., the voltage provided by the temperature set point voltage source 388), the temperature difference amplifier 380 may provide a non-zero voltage to the driver amplifier 384. The driver amplifier 384 may then amplify the supplied voltage and supply power to the heater element 396. If the voltage at the second input 408 is lower than the voltage at the first input 392, the temperature difference amplifier 380 may provide a voltage of approximately zero to the driver amplifier 384. The driver amplifier 384 may then provide no power to the heater element 396.

Portions of the driver circuit 372 and the heater circuit 376 may be positioned at various locations within the lighting system. In some embodiments, both driver circuit 372 and heater circuit 376 may be included in an interconnect assembly (such as interconnect assembly 284) as described above in connection with fig. 22-30. For example, the driver circuit 372 and the heater circuit 376 may be included in a circuit board (such as circuit board 308) as described above in connection with fig. 22-30. In some embodiments, the heater circuit 376 may be included in the interconnect assembly, and the driver circuit may be located elsewhere in the lighting system. In some embodiments, the driver circuit 372 may be included in a lighting assembly configured to power LEDs of a lighting system.

In some embodiments, the fixed voltage source 412 may be coupled to a switch, such as an electrical switch or an electromechanical switch, to allow a user or a device, such as an electrical device or an electromechanical device, to control the power supplied to the heater element 396. If the fixed voltage source 412 is not providing a voltage to the second input 408, the driver circuit 372 may not power the heater element 396. The user or device may then effectively turn the heater on by closing the switch or effectively turn the heater off by opening the switch. When the switch is closed, power may be supplied to the heater element 396 based on the resistance of the thermistor 404 and thus based on the temperature of the lens of the lighting system. When the switch is open, power can be prevented from being supplied to the heater element 396.

Referring to fig. 33, a block diagram of a heater control circuit 416 for a lighting system is shown, in accordance with some embodiments. The heater control system 416 may include a controller 420 coupled to and in communication with a speed sensor 424, an optical sensor 428, and a temperature sensor 432. The controller 420 may also be coupled to the heater element 436 and configured to selectively supply power to the heater element. The controller 420 may be positioned within the housing of the lighting system. The heater element 436 may comprise a conductive ink circuit on a thermoplastic substrate of the illumination system as described above. The controller 420 may supply power to the heater element 436 based on signals received from the speed sensor 424, the optical sensor 428, and/or the temperature sensor 432, as will be described below.

The controller 420 may receive a temperature value from the temperature sensor 432. The temperature value may be a signal indicative of the temperature sensed by the temperature sensor 432. The temperature sensor 432 may be a thermistor included in the interconnect assembly, as described above. The controller 420 may supply power to the heater element 436 based on the temperature value. In some embodiments, the controller 420 may receive the temperature value, determine that the temperature value is below a predetermined threshold, and provide a predetermined amount of power to the heater element 436 corresponding to the temperature value in response to determining that the temperature value is below the predetermined threshold. The controller 420 may supply more power to the heater element 436 at lower temperature values. The controller 420 may have a plurality of predetermined amounts of power corresponding to a plurality of predetermined temperature value thresholds to better provide an appropriate amount of power for a given temperature. In some embodiments, the controller 420 may input the temperature value to a model configured to output an amount of power, receive the amount of power from the model, and supply power to the heater element 436 based on the amount of power. The model may include algorithms for determining the power supplied as a function of temperature values and may be determined based on field test data of the effectiveness of the lighting system at various temperatures and the amount of power supplied to the heater element 436.

The controller 420 may receive optical values from the light sensor 428. The optical value may be a signal indicative of light sensed by the light sensor 428. The light sensor 428 may be positioned in the illumination system to determine how much light is shining through the lens and/or thermoplastic substrate of the illumination system. A low optical value may indicate that the lighting system is at least partially frozen or otherwise obscured by rain, snow, ice, or the like. If the optical value is below a predetermined threshold, the controller 420 may supply power to the heater element 436. In some embodiments, the controller 420 may receive the optical value, determine that the optical value is below a predetermined threshold, and provide a predetermined amount of power to the heater element 436 corresponding to the optical value in response to determining that the optical value is below the predetermined threshold. The controller 420 may supply more power to the heater element 436 at lower optical values. The controller 420 may have a plurality of predetermined amounts of power corresponding to a plurality of predetermined optical value thresholds to better provide an appropriate amount of power for a given optical value. In some embodiments, the controller 420 may input the optical value to a model configured to output an amount of power, receive the amount of power from the model, and supply power to the heater element 436 based on the amount of power. The model may include algorithms for determining the power supplied as a function of the optical value, and may be determined based on field test data corresponding to the effectiveness of the lighting system at various levels of occlusion for the sensed optical value and the amount of power supplied to the heater element 436.

The controller 420 may receive a speed value from the speed sensor 424. In some embodiments, the speed sensor 424 may be a speedometer coupled to a vehicle to which the lighting system is coupled. The speed value may be a signal indicative of the speed sensed by the speed sensor 424. At speed values associated with relatively high speeds (e.g., highway speeds), more power may need to be provided to the heater element 436 due to rain, snow, and/or ice accumulating on the lighting system faster than at relatively low speeds. If the speed value is above a predetermined threshold, the controller 420 may supply power to the heater element 436. In some embodiments, the controller 420 may receive the speed value, determine that the speed value is below a predetermined threshold, and provide a predetermined amount of power to the heater element 436 corresponding to the speed value in response to determining that the speed value is below the predetermined threshold. The controller 420 may supply more power to the heater element 436 at higher speed values. The controller 420 may have a plurality of predetermined amounts of power corresponding to a plurality of predetermined speed value thresholds to better provide an appropriate amount of power for a given speed value. In some embodiments, the controller 420 may input the speed value to a model configured to output an amount of power, receive the amount of power from the model, and supply power to the heater element 436 based on the amount of power. The model may include algorithms for determining the power supplied as a function of the speed value, and may be determined based on field test data of the effectiveness of the lighting system at various speeds and the amount of power supplied to the heater element 436. In this way, an appropriate amount of power to be supplied at a given speed may be determined.

In some embodiments, the controller 420 may supply power to the heater element 436 based on a combination of received speed, optical, and/or temperature values. For example, controller 420 may have a stored lookup table of power values, each corresponding to a predetermined speed value, optical value, and/or temperature value. Using a combination of received speed, optical, and/or temperature values to determine the power output may allow the controller 420 to provide a more appropriate power level to the heater element 436 than if a single value was used.

The controller 420 may be coupled to a switch 440. The controller 420 may receive wired input values from the switch 440, which may allow a user or a device such as an electrical or mechanical device to input commands to the controller 420. The wired input value may be used to determine how much power to supply to the heater element 436. The wired input value may have a series of values based on the configuration of the switch 440. For example, if the switch is a two-position selector switch or relay, the switch 440 may supply an "on" value and an "off" value. Alternatively, if the switch is a three-position selector switch, the switch 440 may provide an "off" value, a first position value, and a position level value. Furthermore, if the switch is a potentiometer, a continuous range of values may be provided. Other ranges of values corresponding to a range of power values may be provided to heater element 436. The controller 420 may supply a predetermined amount of power corresponding to the position of the switch 440, i.e., an amount for the "on" value, the first position value, and/or the second position value. If the switch 440 can provide a continuous range of values, the controller 420 may receive the wired input value, determine that the wired input value is indicative of a switch position value (such as an "on" value, a first position value, or a second position value), and provide a predetermined amount of power to the heater element 436 corresponding to the switch position value.

In some embodiments, controller 420 may be coupled to wireless module 444 and in communication with wireless module 444. The controller 420 may receive wireless input values from a wireless module 444, and the wireless module 444 may be a transceiver capable of one-way or two-way communication using one or more wireless protocols, including but not limited to bluetooth, WiFi, Zigbee, or other suitable wireless communication protocol. The wireless input values may be transmitted from an electronic device (e.g., a smartphone or a control FOB) that may be external to the lighting system. The smartphone may be configured to run an application capable of receiving user input from the interface and sending appropriate wireless input values based on the user input. In some embodiments, wireless module 444 may be included in controller 420. The controller 420 may receive the wireless input value, determine that the wireless input value indicates a power level to be provided to the heater element 436 (such as an "on" value or one of a series of power values (such as the first power value and/or the second power value) corresponding to a fixed predetermined power level), and provide a predetermined amount of power corresponding to the power level to the heater element 436.

Referring to fig. 34 and 35, an additional embodiment of an illumination system 448 is shown. The illumination system 448 may include a base 452 and a lens 462. At least one LED 456 may be positioned within the base 452 to provide illumination through a lens 462. The conductive ink or film circuit 460 may be positioned on the inside of the thermoplastic substrate 466. The thermoplastic substrate 466 can be positioned on the outside of the lens 462 with the conductive ink circuit 460 facing the lens 462. As described above, the interconnect assembly 468 may be at least partially overmolded by the lens 462, and the interconnect assembly 468 may be electrically coupled to the conductive ink circuit 460. The lens 462 may be bonded to at least a portion of the thermoplastic substrate 466 and the interconnect assembly 468. In some embodiments, the lens 462, the thermoplastic substrate 466, and the interconnect assembly 468 may form a single-piece structure. The interconnect assembly 468 may have spring connectors as described above for contacting the conductive ink circuit 460 and providing appropriate electrical connections for powering the conductive ink circuit 460 and thus heating the lens 462 the interconnect assembly may include and/or be coupled to portions of a drive circuit as described above and a heater circuit as described above, or to a controller configured to selectively power the conductive ink circuit 460 as described above.

The bus bar 464 may be placed in contact with the spring connector and coupled to the interconnect assembly 468. The bus bars 464 may have a larger cross-sectional area along the length of the bus bars 464, and thus a reduced resistivity, as compared to other portions of the conductive ink circuit 460 that may utilize a higher resistivity to generate heat. The bus bars 464 may include a first bus bar 464a and a second bus bar 464 b. Depending on the electrical configuration of the interconnect assembly 468, the first bus bar 464a may function as a power bus bar and the second bus bar 464b as a ground or neutral bus bar. Alternatively, the first bus bar 464a may function as a ground or neutral bus bar and the second bus bar 464b as a power bus bar.

Referring to fig. 36-39, various components of another embodiment of an illumination system 472 are shown. Illumination system 472 can include base 476 and lens 500. At least one LED 497 may be positioned within the base 476 to provide illumination through the lens 500. The conductive ink or film circuit 480 may be positioned on the inside of the thermoplastic substrate 496. The thermoplastic substrate 496 is positioned on the outside of the lens 500 with the conductive ink circuit 480 facing the lens 500. The conductive ink circuit 480 may include a plurality of bus bars 484, each of the plurality of bus bars 484 may be a power bus or a neutral or ground bus. As described above, the interconnect assembly 488 can be at least partially overmolded by the lens 500, and the interconnect assembly 488 can be electrically coupled to the conductive ink circuit 480. The lens 500 may be joined to at least a portion of the thermoplastic substrate 496 and the interconnect assembly 488, and the lens 500, the thermoplastic substrate 496, and the interconnect assembly 488 may form a single piece structure. The interconnect assembly 488 can have spring connectors as described above for contacting the conductive ink circuit 480 and providing appropriate electrical connections for powering the conductive ink circuit 480 and thus heating the lens 500. the interconnect assembly can include and/or be coupled to portions of the drive circuit and the heater circuit as described above, or to a controller configured to selectively power the conductive ink circuit 480 as described above. The lighting system 472 may supply power to the conductive ink circuit 480 at a rate of approximately 2 watts per square inch, which may allow the lighting system 472 to be used for relatively high speed applications, such as being mounted on a snow plow operating at highway speeds.

According to one non-limiting exemplary embodiment, lighting system 472 is subjected to tests for functionality over a range of temperatures and deicing capabilities. The test procedure includes placing the thermocouple centrally on the outer surface of the outer lens, in this case the thermoplastic base 496. The lighting system 472 is then oriented to be oriented within a vehicle (e.g., a lens 500 placed adjacent to an LED), and wherein the thermoplastic substrate 496 and lens 500 are visible through the viewing window. Thermocouple measurements and current measurements of the current supplied to the lighting system were recorded during the test. The sampling rate of the measurements is high enough to observe the temperature at which the heater is switched on. The lighting system 472 was placed in a hot chamber at 30 ℃ and powered at 13.5VDC for high and low beams. The room temperature rose from 30 ℃ to-30 ℃ over a period of 1 hour. The temperature in the chamber was then maintained at-30 ℃ for 1 hour. The illumination system 472 is then subjected to a temperature of-30 ℃ for 1 hour while a 2mm thick layer of ice is accumulated on the thermoplastic substrate 496 and/or lens 500 by occasionally applying water to the thermoplastic substrate 496 and/or lens 500. And then provides 13.5VDC to the lighting system 472 with high beam and low beam turned on. Monitoring of ice is stopped when ice on the lighting system 472 assumes a steady state (defined as no change in 10 minutes) or when the lighting system 472 has been energized for a hour. Illumination system 472 is then evaluated to determine if it remains functional after testing, if all ice has been removed from thermoplastic substrate 496 and/or lens 500, and if illumination system 472 has been subjected to any damage from the test. Here, the function is maintained, the ice is removed, and the lighting system 472 does not suffer any damage. Thus, the lighting system 472 is considered to pass the test criteria.

Referring to fig. 40-46, components of yet another embodiment of an illumination system 504 are shown. The illumination system 504 may include a base 508 and a lens 532. At least one LED 529 can be positioned within the base 508 to provide illumination through the lens 532. The illumination assembly 520 may be configured to provide power to the at least one LED 529 the conductive ink or film circuit 516 may be positioned on the inside of the thermoplastic substrate 528. The thermoplastic substrate 528 may be positioned on the outside of the lens 532 with the conductive ink circuit 516 facing the lens 532 the conductive ink circuit 516 may include a plurality of bus bars 544, each bus bar of the plurality of bus bars 484 may be a power bus bar or a neutral or ground bus bar. As described above, the interconnect assembly 524 may be at least partially overmolded by the lens 532, and the interconnect assembly 524 may be electrically coupled to the conductive ink circuit 516. The interconnect assembly 524 may include a spring connector 536 having one or more pins 540. Each spring connector 536 may be positioned to contact one of the bus bars 544. The lens 532 may be bonded to at least a portion of the thermoplastic substrate 528 and the interconnect assembly 524. In some embodiments, the lens 532, the thermoplastic substrate 528, and the interconnect assembly 524 may form a single piece construction. The interconnect assembly 524 may have spring connectors as described above for contacting the conductive ink circuit 516 and providing appropriate electrical connections for powering the conductive ink circuit 516 and thus heating the lens 532. The interconnect assembly may include and/or be coupled to portions of the driver circuit and the heater circuit as described above, or to a controller configured to selectively power the conductive ink circuit 516 as described above.

According to one non-limiting example embodiment, the lighting system 504 is subjected to tests with respect to functionality over a temperature range and deicing capability. The testing procedure includes placing the thermocouple centrally on the outer surface of the outer lens, in this case the thermoplastic substrate 528. The lighting system 504 is then oriented to direct it within the vehicle (e.g., the lens 532 placed near the LED lights) and the thermoplastic substrate 528 and lens 532 are visible through the viewing window. Thermocouple measurements and current measurements of the current supplied to the lighting system were recorded during the test. The sampling rate of the measurements is high enough to observe the temperature at which the heater is switched on. The lighting system 504 was placed in a 30 ℃ hot chamber and the high and low beams were powered at 13.5 VDC. The temperature in the chamber decreased from 30 ℃ to-30 ℃ over a period of 1 hour. The temperature in the chamber was then maintained at-30 ℃ for 1 hour. The illumination system 504 was then subjected to a temperature of-30 ℃ for 1 hour while a 2mm thick layer of ice was accumulated on the thermoplastic substrate 528 and/or the lens 532 by occasionally applying water to the thermoplastic substrate 528 and/or the lens 532. The 13.5VDC is then provided to the lighting system 504 via the high beam and the low beam. Monitoring of ice is stopped when the ice on the lighting system 504 is in a steady state (defined as no change in 10 minutes) or when the lighting system 504 has been energized for a hour. The lighting system 504 is then evaluated to determine if it remains functional after the test, if all of the ice has been removed from the thermoplastic substrate 528 and/or the lens 532, and if the lighting system 504 has been subjected to any damage from the test. Here, the function is maintained, the ice is removed, and the lighting system 504 is not subject to any damage. Thus, the lighting system 504 is considered to pass the test criteria.

Referring to fig. 47-48, various components of another embodiment of an illumination system 548 are shown. Illumination system 548 may include a base 552 and a lens 553. At least one LED 556 can be positioned within base 552 to provide illumination through lens 553. The conductive ink or film circuit 560 can be positioned on the inside of the thermoplastic substrate. The thermoplastic substrate is positioned on the outside of the lens 553 with the conductive ink circuit 560 facing the lens 500. the conductive ink circuit 560 may include a plurality of bus bars 564. Bus bars 564B and 564C may be a power bus or a neutral or ground bus, respectively. Bus bar 564C may be a bridging bus bar configured to provide a low resistance electrical connection between

bus bars

564B and 564C. As described above, the interconnect assembly 568 may be at least partially overmolded by the lens 553, and the interconnect assembly 568 may be electrically coupled to the conductive ink circuit 560. The lens 553 can be bonded to at least a portion of the thermoplastic base and interconnect assembly 568, and the lens 500, thermoplastic base and interconnect assembly 568 can form a single-piece structure. The interconnect assembly 568 may have spring connectors as described above for contacting the conductive ink circuit 560 and providing appropriate electrical connections for powering the conductive ink circuit 560 and thus heating the lens 553. The interconnect assembly may include and/or be coupled to portions of the driver circuit and the heater circuit as described above, or to a controller configured to selectively power the conductive ink circuit 560 as described above.

It should be understood that the heated lighting assemblies presented in this disclosure may be used in a variety of applications, where the heated lighting assemblies may perform better than non-heated lighting assemblies, such as applications for vehicles operating at cryogenic temperatures (e.g., snow plows, helicopters, snowmobiles, semi-trucks, freight and passenger trains, airplanes, ice repair machines, etc.), applications for refrigeration systems requiring illumination (e.g., industrial freezers, warehouses, laboratory equipment, etc.), applications for outdoor lighting in cold environments (e.g., construction sites, oil drilling platforms, various water containers, street lights, heavy duty flashlights, etc.), and other lens applications related to cryogenic environments.

The present disclosure describes embodiments with reference to the drawings, wherein like numerals represent the same or similar elements. Reference throughout this specification to "one embodiment" or "an embodiment" or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment.

The described features, structures, or characteristics of the embodiments may be combined in any suitable manner in one or more embodiments. In the previous description, numerous specific details were set forth to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. Accordingly, the scope of the present technology should be determined from the following claims and not limited by the above disclosure.

Claims

1. A lens heating system, comprising:

a substantially transparent thermoplastic substrate;

a conductive ink or thin film circuit positioned on the thermoplastic substrate to heat the thermoplastic substrate;

a lens heater circuit comprising a lens heater and operably coupled to a lens heater controller, the controller configured to receive a value from a wireless module and activate the lens heater in response to the value from the wireless module; and

a spring connector comprising a plurality of pins configured to couple to the conductive ink or thin film circuitry, the pins further configured to provide an electrical connection between the pins and the conductive ink or thin film circuitry.

2. The system of claim 1, wherein the controller is coupled to a thermistor configured to determine a temperature associated with an outer lens surface.

3. The system of claim 2, wherein the thermistor is a Negative Temperature Coefficient (NTC) thermistor.

4. The system of claim 1, wherein the spring connector is positioned at least partially within a lens coupled to the substantially transparent thermoplastic substrate.

5. The system of claim 1, wherein the lens heater circuit comprises a circuit board, the spring connector being surface mounted to the circuit board.

6. The system of claim 1, further comprising a second spring connector coupled to a second bus bar of the conductive ink or film circuit, and wherein the spring connector is coupled to a first bus bar of the conductive ink or film circuit.

7. The system of claim 1, wherein the value from the wireless module is a speed value corresponding to a speed sensor, the controller further configured to:

determining that the speed value is above a predetermined threshold; and is

Activating a predetermined amount of power provided to the conductive ink or thin film circuit by the lens heater in response to determining that the velocity value is above the predetermined threshold.

8. The system of claim 1, wherein the value from the wireless module is an optical value corresponding to an optical sensor, the controller further configured to:

determining that the optical value is below a predetermined threshold; and is

Activating a predetermined amount of power provided to the conductive ink or thin film circuit by the lens heater in response to determining that the optical value is below the predetermined threshold.

9. A method for heating a lens of an illumination system, the method comprising:

applying a conductive ink or film circuit on a substantially transparent thermoplastic substrate;

applying the conductive ink or thin film circuit on the substantially transparent thermoplastic substrate to at least one of an inner lens side and an outer lens side;

positioning a spring connector comprising a plurality of pins against the conductive ink or thin film circuit and establishing an electrical connection between the pins and the conductive ink or thin film circuit;

receiving a value from a wireless module; and

based on the value, applying controlled power to the conductive ink or thin film circuit to heat the lens.

10. The method of claim 7, wherein the positioning comprises:

moving the spring connector toward the conductive ink or film circuit until the pin is bent a predetermined amount corresponding to establishing the electrical connection.

11. The method of claim 7, wherein receiving the value from the wireless module comprises receiving a speed value from a speed sensor, the method further comprising:

determining that the speed value is above a predetermined threshold; and is

Applying a predetermined amount of power to the conductive ink or thin film circuit in response to determining that the velocity value is above the predetermined threshold.

12. The method of claim 7, wherein receiving the value from the wireless module comprises receiving an optical value from an optical sensor, the method further comprising:

determining that the optical value is below a predetermined threshold; and is

Applying a predetermined amount of power to the conductive ink or thin film circuit in response to determining that the optical value is below the predetermined threshold.

13. The method of claim 7, wherein receiving the value from the wireless module comprises receiving an input value from a user device, the method further comprising:

applying a predetermined amount of power to the conductive ink or thin film circuit in response to the input value.

14. The method of claim 7, further comprising:

positioning the spring connector at least partially within the lens coupled to the substantially transparent thermoplastic substrate.