WO2025111209A1

WO2025111209A1 - Neck warmer with power density providing variable infrared heating

Info

Publication number: WO2025111209A1
Application number: PCT/US2024/056177
Authority: WO
Inventors: Kenneth Ryan TURNER; Chad Vincent PACILLI
Original assignee: Gentherm Inc
Current assignee: Gentherm Inc
Priority date: 2023-11-21
Filing date: 2024-11-15
Publication date: 2025-05-30
Anticipated expiration: 2026-05-21

Abstract

A seat includes a headrest that has an aesthetic covering configured to support an occupant head, and an infrared heater that is arranged in the headrest beneath the aesthetic covering. The infrared heater includes first and second regions respectively having first and second power densities, the first and second power densities different than one another.

Description

NECK WARMER WITH POWER DENSITY PROVIDING VARIABLE INFRARED HEATING

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to United States Provisional Patent Application No. 63/601 ,433 filed November 21 , 2023.

TECHNICAL FIELD

[0002] This disclosure relates to a seat that provides personalized thermal comfort using infrared heating.

BACKGROUND

[0003] Vehicles have become increasingly sophisticated, particularly in their use of personalized thermal conditioning for occupants. Vehicle seats have been a primary focal point for personalizing thermal comfort. Typically, simple conductive wire heating elements provide heat, and a thermoelectric device provides cooling through passages in the seat.

[0004] Extreme temperatures create a challenging environment to provide thermal comfort to the occupant. In extreme cold, it is desirable to bring seating surfaces and the environment immediately surrounding the occupant quickly up to a comfortable temperature. Infrared heaters have been proposed more recently for use in the seat headrest, but using infrared heating as proposed can result in hot spots on the back of the occupant’s head.

SUMMARY

[0005] In one exemplary embodiment, a seat includes a headrest that has an aesthetic covering configured to support an occupant head, and an infrared heater that is arranged in the headrest beneath the aesthetic covering. The infrared heater includes first and second regions respectively having first and second power densities, the first and second power densities different than one another. [0006] In a further embodiment of any of the above, the infrared heater is provided by at least one wire that includes first and second wire lengths. The first and second wire lengths respectively provide the first and second power densities.

[0007] In a further embodiment of any of the above, the first and second wire lengths respectively include first and second wire cross-sections. The first and second cross-sections are different than one another.

[0008] In a further embodiment of any of the above, the first and second wire lengths are different than one another.

[0009] In a further embodiment of any of the above, the seat includes at least one power supply that is connected to the first and second wire lengths. The at least one power supply is configured to provide a current to the infrared heater.

[0010] In a further embodiment of any of the above, the first and second wire lengths respectively include first and second currents, the first and second currents are different than one another.

[0011] In a further embodiment of any of the above, the first and second wire lengths are on a common circuit.

[0012] In a further embodiment of any of the above, the at least one power supply includes first and second power supplies that are respectively connected to the first and second wire lengths. The first and second power supplies respectively provide first and second currents, the first and second currents are different than one another.

[0013] In a further embodiment of any of the above, the seat includes an input in communication with a controller. The controller is in communication with the at least one power supply and configured to regulate an infrared heating that is provided by the infrared heater in response to the input.

[0014] In a further embodiment of any of the above, the first and second power densities are each at least 1 ,000 W/m².

[0015] In a further embodiment of any of the above, the first and second power densities are each in a range of 1000 W/m² to 4000 W/m².

[0016] In a further embodiment of any of the above, the first region is located centrally on the headrest and configured to support an occupant head, and the second region is adjacent the first region and configured to be adjacent the occupant head [0017] In a further embodiment of any of the above, the first power density is less than the second power density. The second region is below the first region and is configured to be arranged beneath an occupant neck.

[0018] In a further embodiment of any of the above, the second region is arranged laterally on either side of the first region and configured to be arranged next to an occupant face.

[0019] In another exemplary embodiment, a method of heating an occupant head includes providing a first infrared heat from a headrest to a first occupant zone using an infrared heater that has a first power density, and providing a second infrared heat from the headrest to a second occupant zone that is different than the first occupant zone. The second infrared heat is provided from the infrared heater that has a second power density that is different than the first power density.

[0020] In a further embodiment of any of the above, the infrared heater is provided by first and second wire lengths respectively providing the first and second power densities. The first and second wire lengths have at least one of different lengths and different cross-sections than one another.

[0021] In a further embodiment of any of the above, the infrared heater is provided by first and second wire lengths respectively providing the first and second power densities. The first and second wire lengths are respectively connected to first and second power supplies in different circuits than one another.

[0022] In a further embodiment of any of the above, the first infrared heat providing step is directed at an occupant head from a head support region, and the second infrared heat providing step is directed adjacent the occupant head. The first infrared heat is less than the second infrared heat. The second infrared heat providing step is directed at an occupant neck and/or an occupant face.

[0023] In a further embodiment of any of the above, the first and second power densities are each at least 1 ,000 W/m².

[0024] In a further embodiment of any of the above, the first and second power densities are each in a range of 1000 W/m² to 4000 W/m². BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The disclosure can be further understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0026] Figures 1A and 1 B schematically illustrate example seats using an infrared (IR) heater in a headrest.

[0027] Figure 2 schematically illustrates a disclosed thermal conditioning system for the seat.

[0028] Figure 3 is a chart illustrating the effusivity of various materials and their surfaces by temperature range.

[0029] Figure 4 is a schematic of an example material stack in relation to an IR heater.

[0030] Figure 5 is a schematic of another example material stack in relation to the IR heater.

[0031] Figure 6 is a schematic view of one example headrest having first and second regions with power densities that are different than one another.

[0032] Figure 7 is a schematic view of another example headrest having different power densities than one another.

[0033] The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0034] Example seats 10, 110 are respectively illustrated in Figures 1 A and 1 B. For the seat 10, a seat back 14 is secured to a seat cushion 12. A non-integrated, adjustable headrest 16 is supported relative to the seat back 14 by one or more posts 18. The seat 110 illustrated in Figure 1 B has its headrest 16 integrated with the seat back 114, which is connected to the seat cushion 112. Both types of seats are referred to generally as “seat 10”.

[0035] Regardless of seating configuration, the headrest 16, 116 (generally, “headrest 16”) includes an infrared heater 20 that may be comprised of one or more IR heating elements. The disclosed IR heater 20, as contrasted with a typical conductive wire heater, has a much greater power density, for example, at least 1 ,000 W/m² or 1 ,800 W/m², and in one example, in a range of 1000 W/m² to 4000 W/m². In one example, a heater designed with 1000 W/m² in the perimeter and 500 W/m² in the center could be what is needed to maintain a 100 C/50 C surface temperature, but so could a 2000 W/m²/1000 W/m² heater config pulse width modulated to 50%. The advantage to higher power density is the fast time to temperature. The IR heater 20 is able to provide a heat flux configured to provide an occupant skin temperature target in a range of 33 C to 43 C, for example. This can be achieved by a variety of approaches, as the above examples illustrate. One suitable type of conductive wire heating element is provided by Gentherm’s Mechanical Structuring Process (MSP) technology, which allows a higher power density and may employ a foil element, if desired.

[0036] At least one material stack 22, 122 is arranged over the IR heater 20. The density, layering, and materials of the various material stacks provided in the headrest 16 can be varied tary the IR heating provided by different regions of the headrest 16 to different zones of the occupant (e.g., head (back and/or sides of head) and/or neck (back and/or sides of neck).

[0037] A simple system schematic is illustrated in Figure 2. The system includes a controller 24 that receives a signal from an input 26, which may be a switch, touchscreen, or other device typically found in a modern vehicle to control thermal conditioning. A power supply 28 is in communication with the controller 24 and the IR heater 20. The controller 24 is configured to energize the IR heater 20 via the power supply 28 in response to the signal from the input 26. That is, the signal may be used to initiate and/or terminate heating. A feedback sensor can also be used once heating has commenced. The feedback sensor can be accomplished with PTC materials (self- regulates as temperatures rise) and/or a thermostat in the IR heater 20. In one example, the controller 24 and the power supply 28 are provided in or on the seat 10. The input 26 is typically provided on the vehicle’s instrument panel, although the input 26 may be located elsewhere if desired.

[0038] Referring to Figure 3, various materials and their effusivity is shown. A combination of different materials is used to create different, desired material stacks for different regions of the headrest 16. These different material stacks are used to vary the IR heat provided to different zones of the occupant as well as avoid hot spots to sensitive occupant areas. Effusivity is a heat penetration coefficient, which is the rate at which a material can absorb heat. Effusivity determines the contact temperature of two bodies that engage one another. As can be seen by Figure 3, metals have a much higher effusivity than thermally insulative materials, such as plastics. Effusivity is a function of thermal resistance and heat capacity. Thermal resistance relates to the temperature drop across the material. Materials with relatively high effusivity will have a relatively low temperature drop thermal resistance as the temperature is more easily communicated from one side of the material to the other. Heat capacity is the time it takes for a material to reach a given temperature. Materials with a high effusivity will have a low thermal capacitance, that is, the material will reach the equilibrium temperature relatively quickly.

[0039] Different materials and thicknesses of materials are used to provide different material stacks 22, 122 (Figs. 4 and 5) in the headrest 16 to vary the radiant heat to a particular zone of the occupant’s head or neck. Generally speaking, low effusivity materials can be used laterally on either side of an occupant’s head and/or near the neck to provide a relatively high radiant heat to those zones of the occupant, which do not contact the headrest support surface. Conversely, areas of the headrest 16 that are intended to provide a support surface for the occupant’s head will use relatively high effusivity materials to prevent hot spots or areas that are uncomfortably warm to the touch. Examples of this principle are illustrated in Figures 4 and 5.

[0040] The IR heater 20 can be used with the same materials, which have different material geometry and volumes in areas to deliver even sensation to occupant with variable IR power output across back of head and neck. The A-surface (exterior aesthetic covering) may include differing geometry/shapes to achieve variable temperature (perforations, thickness, etc.). The IR heater 20 itself may be constructed with different thickness and perforation to achieve power output variations (i.e. layered carrier material for heater wire to vary thermal resistance).

[0041] Referring to Figure 4, the material stack 22 in one region of the headrest includes an aesthetic covering 50, such as a fabric. The material stack has a relatively low effusivity, for example, in a range of 0 to 0.1 W/cm²/k/s⁰⁵. In one example, a fabric such as a mesh that may typically be used as a speaker cover in seating applications. A spacer material 52 (e.g., a three-dimensional woven spacer material or similar material providing low effusivity along with IR transparency, commonly used in the seating industry) is arranged between the aesthetic covering 50 and the IR heater 20. The spacer material 52, which may be an expanded, thick polymer material may be used to provide an air gap and some distance between the IR heater 20 and aesthetic covering 50.

[0042] Another material stack 122 is illustrated in Figure 5. In this example, the aesthetic covering 150 is different than the aesthetic covering 50, e.g., vinyl or leather. The material stack 122 has a relatively high effusivity, For example, if the material stack 122 has higher effusivity than skin and has potential to be in contact with the occupant, the temperature would be kept below 50 C. The aesthetic covering 150 is provided for supporting the occupant’s head in direct contact with the headrest 16. Thus, assuming an IR heater 20 has the same power density and heat flux behind both material stacks 22, 122, it is desirable to have less radiant heat for regions of the headrest 16 directly contacting the occupant. This is accomplished by providing a material stack 122 that overall provides more effusivity than the material stack 22. Protrusions 54 may extend from the surface of the aesthetic covering 150 to further space the occupant’s head from the IR heater 20 and minimize the surface area that the occupant contacts. The protrusions 54 may be provided as large raised dimples, ridges, or any aesthetically desirable pattern (e.g., vehicle manufacturer logo) to minimize contact between the occupant’s head and the aesthetic covering 150.

[0043] Multiple infrared heating regions are illustrated schematically in Figures 6 and 7. The number, size and configurations of the regions are exemplary and non-limiting. Referring to Figure 6, first, second, third and fourth regions 30, 32, 34, 36 are illustrated. The first region 30 corresponds to a head support region for supporting an occupant’s head (i.e, direct contact) on the headrest 16. Second and third regions 32, 34 are arranged laterally on either side of the occupant’s head to provide radiant heating to the sides of the occupant’s face. The fourth region 36 is arranged beneath the first region and in between the second and third regions 34, 36 to direct radiant heating at the occupant’s neck.

[0044] In the example illustrated in Figure 6, the multiple regions are provided by a single circuit 38 comprising an arrangement of wires in each of the four regions that are connected in series with one another to a single power supply 28. It is desirable to provide different IR heating to the occupant’s head, face and/or neck. As a result, the circuit 38 can be designed to provide different power densities to the different regions. In one example, the first region 30 has the least power density as is desirable to avoid overheating the occupant’s head, which is in direct contact with the headrest 16. The second, third and fourth regions 32, 34, 36 have a power density greater than the wires in the first region 30, and thus, include a higher density of wire in the regions.

[0045] The different power densities can be provided in any number of ways. In one example, a greater length of wire per unit area is provided in regions in which greater IR heating, and thus greater power density, is desired. For example, the first region 30 has a shorter wire length than the wire lengths in the other regions 32, 34, 36. In another example, thicker wire may be used to provide a different power density or volume of wire in a particular region. Variations of power density may also be achieved by providing different current to the wires in each region.

[0046] Referring to Figure 7, the differing power densities may be provided by multiple, discrete circuits, for example, first, second, third and fourth circuits 40, 42, 44, 46, respectively arranged in the first, second, third and fourth regions 30, 32, 34, 36. Each of these circuits may have its own power supply 28 in communication with the controller 24. This arrangement enables more finely tuned control of IR heating to the occupant in the different regions. The controller 24 is in communication with the multiple power supplies 28 and regulates an infrared heating provided by the infrared heater 20 in response to the input 26 (e.g., occupant request, time-based, etc.).

[0047] The controller 24 may be a hardware device for executing software, particularly software stored in memory. The controller 24 can be a custom made or commercially available processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the controller, a semiconductorbased microprocessor (in the form of a microchip or chip set) or generally any device for executing software instructions.

[0048] In terms of hardware architecture, such a computing device can include a processor, memory, and one or more input and/or output (I/O) device interface(s) that are communicatively coupled via a local interface. The local interface can include, for example but not limited to, one or more buses and/or other wired or wireless connections. The local interface may have additional elements, which are omitted for simplicity, such as controllers, buffers (caches), drivers, repeaters, and receivers to enable communications. Further, the local interface may include address, control, and/or data connections to enable appropriate communications among the aforementioned components.

[0049] The memory can include any one or combination of volatile memory elements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM, VRAM, etc.)) and/or nonvolatile memory elements (e.g., ROM, hard drive, tape, CD- ROM, etc.). Moreover, the memory may incorporate electronic, magnetic, optical, and/or other types of storage media. The memory can also have a distributed architecture, where various components are situated remotely from one another, but can be accessed by the processor.

[0050] The software in the memory may include one or more separate programs, each of which includes an ordered listing of executable instructions for implementing logical functions. A system component embodied as software may also be construed as a source program, executable program (object code), script, or any other entity comprising a set of instructions to be performed. When constructed as a source program, the program is translated via a compiler, assembler, interpreter, or the like, which may or may not be included within the memory. [0051] The disclosed input and output devices that may be coupled to system I/O interface(s) may include input devices, for example but not limited to, a keyboard, mouse, scanner, microphone, camera, mobile device, proximity device, etc. Further, the output devices, for example but not limited to, a printer, display, etc. Finally, the input and output devices may further include devices that communicate both as inputs and outputs, for instance but not limited to, a modulator/demodulator (modem; for accessing another device, system, or network), a radio frequency (RF) or other transceiver, a telephonic interface, a bridge, a router, etc.

[0052] When the controller 24 is in operation, the processor can be configured to execute software stored within the memory, to communicate data to and from the memory, and to generally control operations of the computing device pursuant to the software. Software in memory, in whole or in part, is read by the processor, perhaps buffered within the processor, and then executed.

[0053] According to the disclosed system, a method of heating an occupant head includes providing a first infrared heat from the headrest 16 (e.g., head support region) to a first occupant zone (e.g., back of occupant head contacting the headrest 16) using the IR heater 20. The IR heater in this first region 30 has a first power density. The method also provides a second infrared heat from the headrest 16 (e.g., second, third and/or fourth regions 32, 34, 36) to a second occupant zone (e.g., an occupant neck and/or an occupant face) that is different than the first occupant zone. The second infrared heat provided from the IR heater 20 having a second power density that is different (e.g., higher) than the first power density. This approach creates a more homogeneous neck and head heating by using variable temperature surfaces based upon geometry of human head and skin exposure.

[0054] It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom. Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present invention.

[0055] Although the different examples have specific components shown in the illustrations, embodiments of this invention are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples.

[0056] Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For that reason, the following claims should be studied to determine their true scope and content.

Claims

CLAIMS What is claimed is:

1. A seat comprising: a headrest having an aesthetic covering configured to support an occupant head; and an infrared heater arranged in the headrest beneath the aesthetic covering, the infrared heater including first and second regions respectively having first and second power densities, the first and second power densities different than one another.

2. The seat of claim 1 , wherein the infrared heater is provided by at least one wire including first and second wire lengths, the first and second wire lengths respectively providing the first and second power densities.

3. The seat of claim 2, wherein the first and second wire lengths respectively including first and second wire cross-sections, the first and second crosssections are different than one another.

4. The seat of claim 2, wherein the first and second wire lengths are different than one another.

5. The seat of claim 2, comprising at least one power supply connected to the first and second wire lengths, the at least one power supply configured to provide a current to the infrared heater.

6. The seat of claim 5, wherein the first and second wire lengths respectively include first and second currents, the first and second currents are different than one another.

7. The seat of claim 5, wherein the first and second wire lengths are on a common circuit.

8. The seat of claim 5, wherein the at least one power supply includes first and second power supplies that are respectively connected to the first and second wire lengths, wherein the first and second power supplies respectively provide first and second currents, the first and second currents are different than one another.

9. The seat of claim 5, comprising an input in communication with a controller, the controller in communication with the at least one power supply and configured to regulate an infrared heating provided by the infrared heater in response to the input.

10. The seat of claim 1 , wherein the first and second power densities are each at least 1 ,000 W/m².

11. The seat of claim 9, wherein the first and second power densities are each in a range of 1000 W/m² to 4000 W/m².

12. The seat of claim 1 , wherein the first region is located centrally on the headrest and configured to support an occupant head, and the second region is adjacent the first region and configured to be adjacent the occupant head.

13. The seat of claim 12, wherein the first power density is less than the second power density, wherein the second region is below the first region and configured to be arranged beneath an occupant neck.

14. The seat of claim 12, wherein the second region is arranged laterally on either side of the first region and configured to be arranged next to an occupant face.

15. A method of heating an occupant head, comprising: providing a first infrared heat from a headrest to a first occupant zone using an infrared heater having a first power density; and providing a second infrared heat from the headrest to a second occupant zone that is different than the first occupant zone, the second infrared heat provided from the infrared heater having a second power density that is different than the first power density.

16. The method of claim 15, wherein the infrared heater is provided by first and second wire lengths respectively providing the first and second power densities, the first and second wire lengths having at least one of different lengths and different cross-sections than one another.

17. The method of claim 15, wherein the infrared heater is provided by first and second wire lengths respectively providing the first and second power densities, the first and second wire lengths are respectively connected to first and second power supplies in different circuits than one another.

18. The method of claim 15, wherein the first infrared heat providing step is directed at an occupant head from a head support region, and the second infrared heat providing step is directed adjacent the occupant head, wherein the first infrared heat is less than the second infrared heat, wherein the second infrared heat providing step is directed at an occupant neck and/or an occupant face.

19. The method of claim 1 , wherein the first and second power densities are each at least 1 ,000 W/m².

20. The method of claim 19, wherein the first and second power densities are each in a range of 1000 W/m² to 4000 W/m².