WO2020144249A1

WO2020144249A1 - Integrated electromagnetic and optical device for wireless transfer of power and data communication

Info

Publication number: WO2020144249A1
Application number: PCT/EP2020/050366
Authority: WO
Inventors: Suba ANANTHAN; Atheet RAJ; Ashwin BALARAM; Ramesh DAMODARAN
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2019-01-12
Filing date: 2020-01-09
Publication date: 2020-07-16
Anticipated expiration: 2021-07-12
Also published as: CN113302090B; CN113302090A

Abstract

An integrated electromagnetic and optical device for a wireless transfer of power and transmission of data, with a light emitter (111), a light receiver (112) and a magnetic flux directing member (108) are disposed on a base member (101). An electromagnetic inductive interface (107) is coupled to a magnetic flux amplifier (106) and disposed within the magnetic flux directing member (108). A sealing member (115) with optical apertures (116, 117) to expose the light emitter (111) and the light receiver (112) and to form a sealing enclosure. A pair of integrated electromagnetic and optical devices (200a, 200b) are disposed to be coupled electromagnetically and optically and to be configured for a wireless transfer of power and transmission of data between them. An occupant restraint system (300) for an automotive vehicle with a buckle assembly and a tongue assembly for a wireless transfer of transfer of power and transmission of data.

Description

INTEGRATED ELECTROMAGNETIC AND OPTICAL DEVICE FOR WIRELESS TRANSFER OF POWER AND DATA COMMUNICATION

Technical Field

[001] This invention relates to a wireless energy transfer and data communication, particularly to an integrated electromagnetic and optical device to enable a wireless transfer of power and transmission of data, across electromagnetically and optically coupled systems. The present invention also relates to an occupant restraint system for a vehicle that is equipped with the integrated electromagnetic and optical device of the present invention, for a wireless transfer of power and data communication between a buckle anda webbing of the occupant restraint system.

Background of the invention

[002] Energy or power may be transferred wirelesslyusing electromagnetic devices. Similarly, data and information can be communicated using optical networking technologies, such as Li-Fi, which use light-emitting diodes, which can be a visible light diode or infra-red diode for data transmission.

[003] However, the power transfer and data communication are performed, by means of adoption of independent structural arrangements viz., electromagnetic and optical networking devices, to transfer power and transmit data separately. Such separate arrangements may require independent hardware systems thereby increasing size of the devices and the complexity in configuration of the respective electromagnetic and optical components.

[004] In automobile safety systems, seat belt system plays a pivotal role in securing occupants, to their seats, particularly in the event of abnormal situations, due to an impact or otherwise, resulting in rapid displacement of the seated occupants from their normal positions.The seat belt system generally includes an arrangement of belt webbing reel that is stored in a retractor and connected to a sliding tongue. A buckle is attached to a structural component of vehicle like seat base and is positioned to receive and lock the sliding tongue, so that the seat belt webbing secures the occupants to their seats, in the event of an impact.

[005] The seatbelt systems are also provided with means to transfer power from a power source of a vehicle to the seat belt webbing through the buckle and tongue. There are also means available to transfer data from one part of a vehicle to the seat belt system, through the buckle and the tongue.

[006] US 2016/0355157 discloses a seat belt systemwhere an electromagnetic coupling between a primary and asecondary coil is used to transfer power/data from one conducting member (buckle as a transmission member) that is connected to the primary coil to another conducting member (tongue as a receiving member) that is connected to the secondary coil, when the primary and secondary coils are placed in proximity to each other and not physically connected. In this arrangement, the electromagnetic coils are arranged to be in close proximity to the locking zone of the buckle and tongue of the seat belt system and the electromagnetic coils are used for both power transfer and data communication.

Objects of the present invention

[007] A primary object of the present invention is to provide an integrated electromagnetic and optical device, to enable a wireless transfer of power and communication of data, across electromagnetically and optically coupled systems.

[008] An object of the present invention is to provide an integrated electromagnetic and optical device pair, which are coupled electromagnetically and optically, to enable a wireless transfer of power and communication of data, across electromagnetically and optically coupled systems.

[009] Another object of the present invention is to provide an occupant restraint system with the integrated electromagnetic and optical device pair of the present invention, for wireless transfer of power and communication of data, through an electromagnetic and optical coupling of a buckle and a tongue of the occupant restraint system.

[010] Yet another object of the present invention is to provide an occupant restraint system with the integrated electromagnetic and optical device pair of the present invention, for a wireless transfer of power and communication of data to a seat belt webbing, for actuating at least an alert member.

[011] It is also an object of the present invention is to provide an occupant restraint system with the integrated electromagnetic and optical device pair of the present invention, where electromagnetic interfaces and data transceivers are disposed in buckle and tongue extension housings and not in close proximity to the locking zones of the tongue and the buckle assemblies.

Brief description of the drawings

[012] FIG.l is an illustrated perspective view of the integrated electromagnetic and optical device, to enable a wireless transfer of power and communication of data, where the data transceivers are spaced apart.

[013] FIG.2 is an illustrated exploded view of the device as shown in FIG 1.

[014] FIG.3 is an illustrated top perspective view of the device of the device as shown in FIG 1.

[015] FIG.4 is an illustrated side perspective view of the device as shown in FIG 1.

[016] FIG.5 is an illustrated perspective view of the integrated electromagnetic and optical device for a wireless transfer of power and communication of data, where data transceivers are arranged in a close spatial configuration.

[017] FIG.6 is an illustrated exploded view of the device as shown in FIG 5.

[018] FIG.7 is an illustrated top perspective view of the device of the device as shown in FIG 5.

[019] FIG.8 is an illustrated side view of the device as shown in

FIG 5.

[020] FIG.9 is a schematic side view of paired integrated electromagnetic and optical device for a wireless power transfer and data transmission.

[021] FIG.10 is a side perspective illustrating magnetic flux lines from an electromagnetic interface, when the paired integrated electromagnetic and optical devices, as shown in FIG.9 are electromagnetically and optically coupled.

[022] FIG.11 is a side perspective illustrating magnetic flux lines from an electromagnetic interface and a magnetic flux amplifier, when the paired integrated electromagnetic and optical devices, as shown in FIG.9 are electromagnetically and optically coupled.

[023] FIG.12 is a side perspective illustrating magnetic flux lines from an electromagnetic interface and a magnetic flux amplifier, along with a magnetic flux directing member, when the paired integrated electromagnetic and optical devices, as shown in FIG.9 are electromagnetically and optically coupled.

[024] FIG. 13 is a schematic front view, illustrating an occupant restrained by a seat belt with alert members, where a tongue plate and a buckle of the seat belt are shown in locked condition.

[025] FIG.14 is an illustrated perspective view of tongue plate and buckle assemblies of the occupant restraint system in Socked condition, depicting an arrangement of pair of integrated electromagnetic and optical devices of the present invention, for a wireless transfer of power and transmission of data.

[026] FIG.15 is a perspective view of the tongue assembly of the occupant restraint system, illustrating the arrangement of the integrated electromagnetic and optical device of the present invention.

[027] FIG.16 is a perspective view of the tongue assembly illustrating the arrangement of the integrated electromagnetic and optical device of the present invention, along with the alert member that is disposed in the seat belt webbing.

[028] FIG.17 is a partial magnified view of the integrated electromagnetic and optical device of the present invention as shown in FIG.16.

[029] FIG.18 is a perspective view of the buckle assembly illustrating the arrangement of the integrated electromagnetic and optical device of the present invention, along with the alert member that is disposed in the seat belt webbing.

[030] FIG.19 is a partial magnified view of the integrated electromagnetic and optical device of the present invention as shown in FIG.18.

[031] FIG.20 is a partial perspective view of the tongue and buckle assemblies of the occupant restraint system, shown in a latched condition, along with the arrangement of pair of integrated electromagnetic and optical devices.

[032] FIG.21 is a partial magnified view of FIG.20, illustrating the arrangement of paired integrated electromagnetic and optical devices.

[033] FIG.22 is a broad schematic drawing of the system with the integrated electromagnetic and optical devices of the present invention.

[034] FIG.23 is a perspective view of the tongue and buckle assemblies of the occupant restraint system, illustrating the arrangement of plurality of the integrated electromagnetic and optical devices.

[035] FIG.24 is a partial magnified view of FIG.23, illustrating the arrangement of the integrated electromagnetic and optical devices.

Summary of the present invention

[036] The present invention provides an integrated electromagnetic and optical device for a wireless transfer of power and transmission of data. The device is provided with a light emitter and a light receiver that are disposed on a base member. A magnetic flux directing member is mounted on the base member.An electromagnetic inductive interface that is coupled to a magnetic flux amplifier is disposed in the magnetic flux directing member and on an insulating substrate of the base member. A sealing member with optical apertures is connected to base member, to form a sealing enclosure. The light emitter and the light receiver are disposed to be configured for data communication and the electromagnetic inductive interface and the magnetic flux amplifier are disposed to be configured for power transfer. The present invention also provides a paired device and an occupant restraint system for an automotive vehicle with the paired device.

Detailed description of the invention

[037] This disclosure provides an integrated electromagnetic and optical device, to enable a wireless transfer of power and communication of data, across electromagnetically and optically coupled systems. In the present disclosure, one of the exemplary applications of the device is described in the form of an occupant restraint system of an automotive vehicle, where the power is transferred from a seat belt buckle assembly to a seat belt webbing, through a tongue assembly. Concurrently, data/information are transmitted from the seat belt buckle assembly to the seat belt webbing via tongue assembly. Further, data communication is also performed from the seat belt webbing to the seat belt assembly through the tongue assembly, as a feed back and other useful information which need to be communicated.

[038] It is therefore, to be understood here that the use device of the present invention is not restricted to particular exampIe(s)or application(s) as described and illustrated in this disclosure but may be used for driving a wide variety of applications, such asa heart rate monitor, a microphone and a heating system for a seat belt webbing of the occupant restraint system. The device of the present invention can also be used at various locations of a vehicle, for instance under a vehicle seat, where the corresponding seat electronics can be powered along with data communication. The device of the present invention can also find applications in power and data transmission at vehicle maintenance platforms or charging stations. The device of the present invention can also be used in domestic, commercial and industrial environments such as smart homes, offices and manufacturing establishments, wherever there is a need for a wireless transfer of power and communication of data between electromagnetically and optically coupled systems.

[039] Initially, the preferred embodiments of the integrated electromagnetic and optical device, to enable a wireless power transfer and data communication, across electromagnetically and optically coupled systems. In this disclosure, the term electromagnetically and optically coupled systems encompass contrivances, which are configured to receive and transfer power along with data transmission, where the data include set of instructions. The power and data are used to power and actuate the desired functional attributes of the electronic, mechanical and electro-mechanical elements of the contrivances.

[040] As shown initially shown in FIGs.1-4, the integrated electromagnetic and optical device 100 includes a base member 101, where the base member 101 is configured to act as a platform for the integration of other elements of the electromagnetic and optical elements of the device 100, to form a single unit. The formation of the single unit enables a concurrent or independent transfer of power and communication of data, across the electromagnetically and optically coupled systems. In this exemplary aspect, the base member 101 is shown as a rectangular structure, which is not limited to that particular configuration, since other suitable shapes such as square, circle etc., can also be suitably adapted for use as the base member 101. A flux directing member opening 109 is preferably arranged on the central portion of the base member 101. Base member openings 102, 103, 104 on the base member 101, which are positioned outside the flux directing member opening 109 and in the peripheral areas of the base member 101. A flux directing member opening 109 is provided on the base member 101. The base member 101 is preferably made of material that acts as a magnetic flux barrier, which can damp or attenuate the inductive magnetic flux that is generated in the device 100. Accordingly, materials such as acrylic, polystyrene, brass, copper, aluminum, steel, iron, paper, stainless steel etc.

[041] Now, the preferred embodiments of the data transceiver assembly are now described. The data transceiver assembly includes a light emitter 111, that is arranged on the peripheral portion of the base member 101, through the base member opening 104 (as particularly shown in FIGs.l and 2). The light emitter 111 in this arrangement is advantageously a Li-Fi device, using a visible light spectrato act as data carrier for data communication. In the present exemplary embodiment, a light-emitting diode (LED), is the light emitter 111, that is configured to receive power from a source through a power cable 118 for generating light pulses or flashes. The light emitter 111 is equipped to connect with a suitable Li-Fi system having an integrated circuit package through light emitter cable 113with a data conversion module that is configured to convert data such as voice, text, video etc., into l"s and 0"s, so that they can be represented as digital signals. The digital signals are fed as input data to the light emitter 111 (LED) through the light emitter data cable 113, by the integrated circuit package. The Li-Fi system is preferably provided with an operating frequency in the range of 4X10¹⁴~8X 10¹⁴. The data processing unit is also provided with a transmitter module, which is configured to generate corresponding on-off patterns for the LED, using suitable Li- Fi techniques such as, single-carrier modulation schemes, for instance, an on-off keying (OOK), to transmit the digital signals in the form of light pulses or flashes of light, with time intervals between each bit. If preferred, a multi-carrier modulation scheme can also be suitably adapted for use for high-speed optical wireless communication. In this exemplary aspect, a single light emitter 111 is shown as an optical light emitter. However, it is understood here that an array of light emitters can also be suitably adapted for use. It is also within purview of this invention to use colour shift keying (CSK), where signals are encoded into colour intensities emitted by red, green and blue (RGB) LEDs. In the alternate, the light emitter 111 can also be a diode that emits infrared (IR) rays as data carrier. A digital camera can also used to view the emitted IR in order to verify the functioning of the device. Therefore, the light emitter 111, which is broadly based on Li-Fi system, the input data first get converted to binary through an ADC (digital signals) and the digital signals are then fed into a LED driver circuit, which is controlled by the integrated signal circuit. The LED driver works with On-Off Keying modulation at high speeds and transmits the data as optical pulses from the light emitter 111.

[042] A light or photo receiver 112, is arranged, in this exemplary aspect, on the peripheral portion of the base member 101, through the opening 102 (as shown in FIG.l). The light receiver 112 is configured to receive power from the source through a power cable 119. The light receiver 112 is positioned, advantageously, in a line- of-sight configuration with the light emitter 111 and is spatially separated, so as to prevent any possible optical interference between them. In this exemplary aspect, the light receiver 112 is a silicon photodiode ( p-i-n photodiodes), which is connected to an integrated circuit package, that is dedicated for the light receiver 112 through the light receiver data cable 114 and is configured to receive the optical pulses from the light emitter 111 that are incident on its surface. The light receiver 112 interprets the optical pulses into electrical signals, which are amplified by a transimpedance amplifier and then converted back to a binary data (digital signals) by using a comparator. In this exemplary aspect, a single light receiver 112 is shown. However, it is understood here that an array of light receivers can also be suitably adapted for use, in a reciprocal arrangement with an array of light emitters.

[043] In another aspect of the present invention, the light receiver 112 is also configured to receive data from the light emitter 111 (for instance from a light emitter of a paired data transceiver assembly), where the data can be in the form of a feed back or any other data and audio communications.

[044] Therefore, the arrangement of the light transmitter 111 and the light receiver 112, constitutes the data transceiver assembly, which can be configured to either transmit or receive data in a wireless mode.

[045] The data transceiver assembly (light emitter and receiver) of the present invention are in compliance with prevailing standards such as IrDA ("Infrared Data Association ) and IEEE 802.11, IEC, ANSI standards preferably those devices that render focused and narrow beam for data transmission. The data transceiver assembly of the present invention can also suitably adapted for a long range (greater than 10 m) data communications, by providing infrared links that are based on line-of-sight systems, to minimize the path loss.

[046] Hitherto, the constructional elements pertaining to optical transmission of data are described. Now, the preferred embodiments of the transfer of power, electromagnetically using the device 100 of the present invention are described, by referring to FIGs.1-4. A magnetic flux directing member 108 is connected to the base member 101, through the flux directing member opening 109 and is positioned in between the light emitter 111 and the light receiver 112, as particularly shown in FIG.2. In this exemplary aspect, the magnetic flux directing member 108 is provided with a hollow structural section and preferably with a cylindrical shape. Other suitable hollow structural sections, such as rectangular, square etc., can be suitably adapted for the magnetic flux directing member 108. The magnetic flux directing member 108 is configured to act as a magnetic flux guide or a magnetic flux concentrator, by directing the magnetic flux that is generated inductively by the device 100. The magnetic flux directing member 108 can also be constructed with different layers of suitable materials. In an exemplary aspect, the magnetic flux directing member 108 is preferably made of ferrite material containing predominantly oxides iron that are blended with other metals such as barium, strontium, manganese, nickel, zinc, lithium and cadmium.

[047] An insulating substrate 105 is adhered to the bottom portion of the magnetic flux directing member 108 and is made of an epoxy insulating resin or at least one material selected from materials such as acrylic polymer, phenol-based polymer, polyimide polymer or the like.

[048] An electromagnetic interface 107, which is capable of producing a desired electromagnetic field, on the application an electrical energy, is mounted on the insulating substrate 105. In this exemplary aspect, the electromagnetic interface 107 is an induction coil. The electromagnetic inductive interface 107 is coupled to the electrical source, to receive the electrical energy from a pre-designated power system, via a power supply transformer or any other suitable power conversion device. It is understood and appreciated, that the electromagnetic interface 107 may be large enough to power the connected devices. For instance, the electromagnetic interface 107 is a copper coil attached to a AC Signal generator circuit, which generates AC signals in the range of about 80-300 kHz. The copper coil then converts this alternating current into time-varying electromagnetic field.

[049] Inductive interface power cable 110, which are connected to the terminal ends of the the electromagnetic inductive interface 107 on one side are permitted to pass through the flux directing member opening 109 and through the base member opening 103, for establishing an electrical connection with the electrical source. The passage area of the flux directing member opening 109 that permits the inductive interface power cable 110, is sealed with a suitable material like adhesives, silicone sealants, rubber or polymer sealants etc., so as to prevent any possible leakage of magnetic flux through the flux directing member opening 109. The required strength of the magnetic field for the electromagnetic interface 107 is varied as a function of the amplitude of a drive current as obtained from the electrical source. In an exemplary aspect, the AC drive current that is provided to the electromagnetic inductive interface 105, is typically in the order of 10 to 2000(milli) amps at 5 to 12 volts, with a frequency in the range of 80to 300 kHz.

[050] A magnetic flux amplifier 106 is mounted on the insulating substrate 105 and arranged in central open area of the electromagnetic interface 107 as particularly shown in FIG.3. In this arrangement, the magnetic flux amplifier 106 is coupled electromagnetically to the electromagnetic interface 107. The magnetic flux amplifier 106, in the present embodiment is used to enhance the flux density of the electromagnetic interface 107, by directing, concentrating and focusing the flux generated by the electromagnetic interface 107. The magnetic flux amplifier 106 is advantageously a ferro or ferri magnet. Other exemplary magnetic flux focusing elements that can be suitably adapted for use, include Neodymium or Neo Rare Earth magnets (NdFeB), Samarium Cobalt (SmCo), Hard Ferrites or Ceramic magnets such as (SrFe203) Alnico magnets (Al-Ni-Co). The magnetic flux amplifier 106 thus generates a constant magnetic flux that is attributed to a permanent magnet.

[051] Accordingly, the electromagnetic interface 107 along with the magnetic flux amplifier 106 is enclosed inside the magnetic flux directing member 108. Accordingly, on application of power the electromagnetic interface 107 generates a varying magnetic flux, inductively and whereas the magnetic flux amplifier 106 generates a substantially constant magnetic flux. Therefore, the generation of the magnetic flux by the magnetic flux amplifier 106, amplifies the varying magnetic flux that is generated by the electromagnetic interface 107, resulting in an efficient transfer of magnetic flux from the electromagnetic interface 107.

[052] In the arrangement as described above, where the magnetic flux lines that are generated from the electromagnetic interface 107 and the magnetic flux enhancer 106, take different loops around the electromagnetic interface 107 the magnetic flux enhancer 106 respectively. In this process, some of the magnetic flux lines depart from the stated path and broadcast into surroundings, thereby enhancing magnetic reluctance paths or magnetic resistance for the magnetic flux lines. The magnetic flux directing member 108 that is mounted on the base member 101, controls the departing magnetic flux lines by shielding and directing them so as to enhance paths of least resistance for the magnetic flux lines. Therefore, the preferred geometry of magnetic flux directing member 108 is selected so that it reduces, substantially the magnetic reluctance paths and prevents the broadcast of magnetic flux lines into undesired surroundings.

[053] Therefore, the combined arrangement of the electromagnetic interface 107, the magnetic flux enhancer 106 and the magnetic flux directing member 108, not only results in an enhanced flux density but also assists in directing the magnetic flux lines to have reduced magnetic reluctance paths and increase efficiency.

[054] A sealing member 115 is used to cover the base member 101 and the constituent elements of the device 100 of present invention. The shape of the sealing member 115 is reciprocal to the base member 101 and acts as a lid to contain and hermetically seal the constituent elements of the device 100 that are mounted on the base member 101. The upper portion of the sealing member 115 is also provided with optical apertures 116 and 117, to expose the terminal ends of the light emitter 111 and the light receiver 112, respectively.The material for the sealing member 115 is selected from materials that exhibit magnetic flux permeability. Accordingly, the sealing member 115, is made of suitable materials, that can permit the propagation of magnetic flux lines that are originating from the electromagnetic inductive interface 107 and the magnetic flux enhancer 106, through them, which include but are not limited to glass, teflon etc.

[055] In yet another aspect of the present invention, the magnetic flux directing member 108 can also be extended vertically to connected with the upper portion of the sealing member 115.

[056] Therefore, the integrated electromagnetic and optical device 100 to enable a wireless transfer of power and data communication, across electromagnetically and optically coupled systems, of the present invention, is an integrated combination of electromagnetic and optical elements that are arranged on a single base member 101. The integrated electromagnetic and optical device

100 can be configured not only to receive and transfer power but also to receive and transmit data.

[057] Accordingly, as shown in FIGs.1-4 the integrated electromagnetic and optical device 100 for a wireless transfer of power and transmission of data, is formed by an assembly where the light emitter 111 and the light receiver 112 constituting data transceivers, are optically coupled and disposed on the base member 101. The magnetic flux directing member 108 is mounted on the base member

101 and disposed in between the light emitter 111 and the light receiver 112. The electromagnetic inductive interface 107 that is coupled to the magnetic flux amplifier 106, is disposed in the magnetic flux directing member 108 and on the insulating substrate 105 of the base member 101. The sealing member 115 acting as lid and an enclosure for the constituent elements of the device 100. The sealing member 115 is also provided with optical apertures 116, 117, to expose the fight emitter 111 and the light receiver 112.

[058] In another aspect of the present invention, as shown in FIGs.5-8, the integrated electromagnetic and optical device 100, comprises a data transceiver assembly, with the light emitter 111 and the light receiver 112, which are arranged adjacent to each other on the magnetic flux amplifier 106, as particularly shown in FIG.5. This arrangement of the transceiver assembly can be used in applications where a compact integrated electromagnetic and optical devicelOO is preferred. The arrangement of the other constituent elements of the integrated electromagnetic and optical device 100, are as described above, while referring to FIGs.1-4. In view of the proximal arrangement of the light emitter 111 and the light receiver 112, a screen or a partition member that is made of suitable opaque material, can be placed in between the light emitter 111 and the light receiver 112, so as prevent optical interference between the light emitter 111 and the light receiver 112.

[059] In yet another aspect of present invention, the preferred embodiments of the electromagnetically and optically coupled device pair 200a, 200b, for power transfer and data transmission, are described by particularly referring to FIG.9. The electromagnetic and optical device pair 200a, 200b is constituted by an electromagnetic and optical coupling of the integrated electromagnetic and optical device 100 as described above. The coupled integrated electromagnetic and optical devices are designated as 200a, 200b, as shown in FIG.9. The integrated electromagnetic and optical device pair 200a, 200b for a wireless transfer of power and transmission of data, comprises the integrated electromagnetic and optical devices 200a, 200b that are configured to be coupled electromagnetically and optically, for wireless transfer of power and transmission of data, include light emitters and light receivers 211a, 211b, 212a, 212b respectively of the integrated electromagnetic and optical devices 200a, 200b, constituting data transceivers, which are optically coupled inter se and disposed on the peripheral ends of base members 201a, 201b. Magnetic flux directing members 208a, 208b with hollow structural sections are mounted on the respective base members 201a, 201b and positioned in between the light emitters and receivers 211a, 211b and 212a, 212b respectively. Electromagnetic inductive interfaces 207a, 207b that are coupled to magnetic flux amplifiers 206a, 206b are arranged in the magnetic flux directing members 208a, 208b and on insulating substrates 205a, 205b of the base members 201a, 201b. Sealing members 215a, 215b with optical apertures 216a, 217b to expose the light emitters and receivers 211a, 211b, 212a, 212b, are disposed on the base members 201a, 201b, respectively.

[060] In this arrangement, the electromagnetic inductive interface 207a of the integrated electromagnetic and optical device 200b, acting as a power transfer cum data transmission device, is configured to receive power by from a desired electrical source to generatethe corresponding oscillating magnetic flux, which is amplified by the magnetic flux amplifier 206a. The generated oscillating magnetic flux is thus transferred to the electromagnetic inductive interface 207b, which converts this oscillating magnetic flux to a constant DC power, as particularly shown in FIG.9.

[061] The electromagnetically and optically coupled device pair 200a, 200b that is provided with magnetic flux directing members 208a and 208b, is as shown in FIG.10. The magnetic flux directing members 208a and 208b that are mounted on the base member 201a and 201b, control the departing magnetic flux lines by shielding and directing them so as to enhance paths of least resistance for the magnetic flux lines.

[062] The integrated electromagnetic and optical device 200a is also configured to receive and transmit data, through the data transceivers(light emitters and light receivers) 211a, 212a, where the light receiver 212a receives data (from a designated source) and the data are transmitted by the light emitter 211a, to the optically coupled light receiver 212b, in the form of light energy and received light energy is converted into the corresponding electrical signals and these electrical signals are amplified to generated the desired output. In other words, the data from the light emitter 211a is converted into an intermediate data representation i.e., byte format and then converted into light signals which are emitted by the light emitter 211a as shown in FIG.9. The light signals, which are received by the light receiver 211b, where the process is reversed to retrieve the data from the received light signals.

[063] The integrated electromagnetic and optical device pair 200a, 200b of the present invention, can be suitably adapted for use for transfer of power and data communication, in electromagnetically and optically connected systems.

[064] The electromagnetically and optically coupled device pair 200a, 200b of the present invention can be configured to be implemented in diverse systems, wherever there is a requirement of wireless transfer of power and data communication between the electromagnetically and optically coupled entities. The transfer of power and data communication between the electromagnetically and optically coupled device pair 200a, 200b can be performed by using suitable data processors and communication protocols.

[065] The preferred embodiments of the electromagnetically and optically coupled device pair 200a, 200b, to illustrate the functional aspects of the magnetic flux directing members 208a, 208b in regulating the flow of magnetic flux are described, by particularly referring to FIGs.10-12. The magnetic flux directing members 208a and 208b that are mounted on the base members 201a, 201b, control the departing magnetic flux lines by shielding and directing them so as to enhance paths of least resistance for the magnetic flux lines. In addition, the combined arrangement of the electromagnetic interfaces 207a, 207b, the magnetic flux enhancers 206a, 206b and the magnetic flux directing members 208a, 208b, not only results in an enhanced flux density but also assists in directing the magnetic flux lines to have reduced magnetic reluctance paths and so increasing the power transfer efficiency.

[066] In the present invention, as an exemplary embodiment, actuation of alert members, such as haptic actuators, which are arranged on the webbing of an occupant restraint system of an automotive vehicle, where the wireless transfer of power is performed from a buckle assembly to a tongue assembly for further onward transfer. Whereas, the data communication is also performed from the buckle assembly to the tongue assembly and vice versa, in a wireless mode. The transfer of power and data communication are used to actuate the actuators (visual and aural) including haptic actuators of seat belt webbing, based on the alerts that are generated by an electronic control unit (ECU), of the automotive vehicle, to the haptic actuators, through buckle and tongue assemblies. It is understood by a person of ordinary skill in the art that the power and data transfer using the integrated electromagnetic and optical devices of the present invention are not limited to transfer of power data communication in the occupant restraint system, as exemplarily shown here but the wireless transfer of power and transmission of data can be suitably implemented for other on-board systems of the automotive vehicle and also between the automotive vehicle and other external devices that can be wirelessly connected.

[067] Now, the preferred embodiments of the occupant restraint system 300 of the automotive vehicle, to demonstrate in an exemplary manner, the implementation of the integrated electromagnetic and optical devices of the present invention, particularly the paired integrated electromagnetic and optical devices, for a wireless transfer of power and communication of data, primarily, between the buckle and tongue assemblies and for actuating alert members (haptic actuators) that are provided in the seat belt webbing.

[068] The exemplary embodiments of the occupant restraint system 300 that is incorporated with the integrated electromagnetic and optical device pair of the present invention are described by particularly referring to FIGs.13-24. The coupled integrated electromagnetic and optical devices are designated as 300a for a buckle assembly and 300b for a tongue assembly of the occupant restraint system 300.

[069] The exemplary occupant restraint system 300,asillustrated in FIG.13, is used, during the course ofoperation of an automotive vehicle, by an occupant 325, who is positioned on a vehicle seat 326 and wears the seat belt 327 having a seat belt webbing 328. The seat belt webbing 328, when worn by the occupant 325, is arranged to extend about the occupant 325. One end of the seat belt webbing 328 is anchored to the vehicle body 329 through an anchor plate 330 that is located on one side of the vehicle seat 326 as shown in FIG.13. The other end of the seat belt webbing 328 is connected to a retractor(not shown in FIG.13), as fixed to the vehicle body 329 on the same side of the vehicle seat 326.

[070] The seat belt webbing 328 is also permitted to pass through a tongue assembly 331b, as shown in FIG.14 and the tongue assembly 331b is slidably mounted on the seat belt webbing 328. The seat belt webbing 328 is provided with the alert members (haptic actuators) 342, which in turn are connected to the integrate circuit package 341b of the tongue assembly 331b through the power and data cables 318b, 319b as shown in particularly shown in FIGs.15, 16.

[071] The tongue assembly 331b, as particularly shown in FIG.15 comprises a slidable tongue plate 332b that includes generally a narrower end portion with an opening 333b. The narrower end portion with an opening 333b is used to lock the tongue assembly 331b with a buckle assembly 337a as shown in FIG.11, when the seat belt 327 is worn by the occupant 325. Accordingly, the narrow portion of the slidable tongue plate 332b forms the locking zone of the tongue assembly 331b. The tongue assembly 331b also includes a tongue body 334b that is generally with a plastic overmold 335b having a webbing opening through which the tongue assembly 331b is slidably mounted on the seat belt webbing 328. A tongue extension housing 336T is formed, as a hollow member, by extending the plastic overmold 335b of the tongue body 334b. To engage the seat belt webbing 328, the tongue assembly 331b is held and pulled across the lap and torso of the occupant 325 sitting on the vehicle seat 326. As the tongue assembly 331b is pulled across the lap and torso of the occupant 325, the tongue assembly 331b moves along the seatbelt webbing 328 and the belt webbing 328 is unwound from the retractor, when the seatbelt webbing 328 is pulled across the torso and lap and of the occupant 325. The occupant 325 buckles the tongue assembly 331 into the buckle assembly 337a to make the seat belt 327 act as a restraint. When the seat belt webbing 328 is thus in buckled position, the length of seat belt webbing 328 extends over a torso portion of the vehicle occupant 325and a lap portion extends across the lap of the vehicle occupant 325. When the seatbelt 327 is not in use, the seat belt webbing 328 is wound on the retractor. The buckle assembly 337a is connected to the vehicle body 329 and is arranged on the side of the vehicle seat 326 opposite to the anchor plate 330.

[072] Now the preferred embodiments of the integrated electromagnetic and optical device 300b, corresponding to the tongue assembly 331b are described. The integrated electromagnetic and optical device 300b is fitted inside the tongue extension housing 336b, as shown in FIG.15 and FIG.16. An integrated circuit package 341b for the tongue assembly 331b is arranged inside the plastic overmold 335b and is electrically connected to the integrated electromagnetic and optical device 300b of the tongue assembly 331b through a suitable wiring (for data and power) arrangement. The connectivity of the integrated circuit package 341b is further extended through the seat belt webbing 328 through the wiring arrangement. The extended wiring arrangement is connected to the haptic actuator sensor assemblies including, but not limited to assemblies of the haptic actuator 349. The integrated circuit package 341b is also connected to an electrical unit 348 of the and ECU 349 vehicle to receive data and instructions pertaining to sensing of an incident that requires triggering of an alert member (haptic actuator) 347 of the seat belt webbing 328. The haptic actuator 347b is arranged in the seat belt webbing 328 and connected to the integrated circuit package 341b, through the required data and power cables as shown in FIGs.15,16,17.

[073] The buckle assembly 337a, includes a buckle housing 338a in which a latch member (not shown in the figure) is arranged to lock the slidable tongue plate 332b of the tongue assembly 331b. Accordingly, the latch member of the buckle assembly 337b forms a latching zone of the buckle assembly 337a. The seat belt 327 can be taken off by pushing a release button 339 of the buckle assembly 337a. A buckle extension housing 340a is formed, as a hollow member, on the lateral side of the buckle housing 338. An integrated circuit package 344a is connected to the power source of the vehicle 347 and the electronic control unit (ECU) 348 of the vehicle to receive power and data pertaining to sensing of an incident that requires triggering of the haptic actuator 342.

[074] When the seat belt 327 is buckled by the occupant 325, through the latching of the tongue and buckle assemblies 331a, 337b, the latching zones physically mesh with each other to provide the locking arrangement. Such a locking arrangement is therefore, a frictional locking arrangement, that causes friction of the mating parts the tongue and buckle assemblies 331a, 337b, in the locking zone. Accordingly, any arrangement of electronic or electromagnetic components, in proximity to the locking zone are exposed to a possible risk of frictional wear and tear due to frequent buckling and unbuckling of the seat belt.

[075] Accordingly, the occupant restraint system 300 with the integrated electromagnetic and optical device pair 300a, 300b of the present invention, where the integrated electromagnetic and optical device pair 300a, 300b are disposed on the buckle and the tongue respectively and at locations that are not in proximity or nearer to the locking zone of the tongue with the buckle assemblies 331a, 337b, where frequent latching and de-latching of the seatbelt buckle does not interfere with the functioning of the integrated electromagnetic and optical device pair 300a, 300b. [076] Now, the arrangement of the shown in FIG.20 and FIG.16 the integrated electromagnetic and optical device 300 corresponding to the buckle assembly 331a, is arranged in the buckle extension housing 340a. An integrated circuit package 344a for the buckle assembly 331a is arranged inside the buckle extension housing 340a and is electrically connected to the integrated electromagnetic and optical device 300 of the buckle assembly 331a through a suitable wiring arrangement.

[077] Now the preferred embodiments of the system 300 of the present invention, when the buckle and tongue and assemblies 331a, 337b are in locked condition are described. In the locked condition, the tongue extension housing 336b and buckle extension housing 340a are arranged co-axial and close proximity to each other, as shown in FIG.21. The integrated electromagnetic and optical device 300b, corresponding to the tongue assembly 331b and the integrated electromagnetic and optical device 300a, corresponding to the buckle assembly 337a are also arranged co-axial to each other with an intervening gap between them as shown in FIG.21. In other words, when tongue and buckle assemblies 331a, 337b are in locked condition and in close proximity to each other, these assemblies are coupled electromagnetically, such that the wireless transfer of power transfer, through the generation and transfer of magnetic flux between the electromagnetic interfaces 307a, 307b can be performed from the buckle assembly 331a to the tongue assembly 337b. Concurrently, in the locked arrangement, an optical coupling is also established between the tongue and buckle assemblies 331a, 337b to perform data transmission between light emitters and light receivers 311a, 311b, 312a, 312b of the buckle and tongue assemblies 331a, 337b, in the form light pulses or flashes, as particularly shown in FIG.21.

[078] Now, the broad system architecture of the coupled devices, with a specific reference to their arrangement in an occupant restraint system, is now described by referring to FIG.24. While the present invention is described with respect to the system for the actuation of haptic actuators, the present invention may be adapted to be used in other control and communication systems or the like. In the following description, various operating parameters and components are described for one exemplary embodiment. Therefore, these specific parameters and components are included as examples and are not meant to be limiting.

[079] The system of the present invention is primarily composed ofthe following primary segments viz., a vehicle control and power segment 349, a buckle segment 350, a tongue segment 351 and a haptic actuator segment 352.

[080] The vehicle control and power segment 349 includes a vehicle power source 347 that caters to the power requirements of the on-board electrical, electronic and mechanical devices, of the vehicle. The vehicle power source 347, which is generally a unit comprising elements such as a battery, a starter, an alternator etc., provides a required DC power.

[081] The buckle segment 350 includes a power regulator 353, which is connected to vehicle power source 347, to regulate the input DC power and to protect the various components of the system. A power transmitter controller 354 is connected to the power regulator 353, t o control the amount of power that is to be transmitted to an electromagnetic interface driver 355 (buckle segment), depending on the required power. The electromagnetic interface driver 355 is provided with oscillators, AC/DC power converters, to generate an alternating current (AC) power corresponding to the input DC power. This alternating current power is then allowed to pass through an electromagnetic interface 307a, of the buckle segment 350, to generatethe corresponding time-varying magnetic flux.

[082] Whereas, the tongue segment 351 includes an electromagnetic interface 307b, which is configured to receive the magnetic flux from the electromagnetic interface 307a and convert the magnetic flux into a corresponding power. An electromagnetic interface driver (tongue) 356 is connected to the electromagnetic interface 307b and includes rectifiers, AC/DC power converters, to convert the provided AC source to required DC power. This DC power is then allowed to pass through a power receiver controller 357 to control or modulate the amount of power considering the end use requirements. For instance, in the present case, the power that is required to actuate the haptic actuators of the seat belt webbing. A power regulator 358 is connected to the power receiver controller 357 of the tongue segment 351, so that a constant DC power is supplied to the other components, including integrated circuit package of the tongue segment 351and to the alert members 342 of the seat belt webbing. The power receiver controller also communicates its power requirement and amount of power received to the power transmitter controller, by using the existing optical communication system. This helps the power transmitter to take required actions to increase power efficiency, by doing so unwanted system heating and interference due to metal objects can be avoided.

[083] The vehicle control and power segment 349 further includes an electronic control unit (ECU) 348. The term ECU as indicated here shall also mean to include a group of ECU's catering to various functionalities of the vehicle. Accordingly, the ECU 348 can be any embedded systems in automotive electronics, which control one or more of the electrical and electronic systems, subsystems in a vehicle. For instance, automotive ECUs that are connected to devices such as image processing modules, sensors and camera, support a number of advanced driver assistance systems (ADAS) like adaptive cruise control, driver drowsiness detection, lane departure warning, forward collision alert, pedestrian detection and more, based on which suitable actions and alerts are prompted and executed in the vehicle, either automatically or through the occupants of the vehicle. The ECU 348 includes a microprocessor, an application specific integrated circuit (ASIC) or any other custom designed device, with a required memory slots. The ECU is generally embedded with a firm ware corresponding to various functionalities of the automotive vehicle. The ECUs are also provided with ADC's, DAC's, capabilities to generate high-level digital outputs, signal conditioners, communication chips to implement in-car communication standards such as controller-area networking (CAN). The ECU 348 may be the central computer for the vehicle and, therefore, be capable of controlling the operations of other vehicle components and accessories. The ECU 348, in the present exemplary embodiment is configured to execute, inter alia, routines for receiving alerts from advanced driver assistance systems (ADAS), in conjunction with on-board event capturing members (devices/sensors), such as charge-coupled devices (CCDs), Radar, Lidar, infrared sensors, oxygen sensors, image capturing and processing devices, wheel speed sensor, etc. The alerts that are received by the ECU 348 are processed and communicated to an integrated circuit package 344a, which isarranged in the buckle segment 350, through communication protocols such as CAN, FlexRay or Ethernet.

[084] The integrated circuit package 344a of the buckle segment is advantageously a PCB with a central processor, input/output and memory controllers, interface connectors, memory and other components integrated for the required purpose and applications. The subsystems of the PCB are configured touse communication protocols such as serial peripheral interface (SPI), inter-integrated circuit (I2C) for internal communication. The integrated circuit package 344a processes the received information from the ECU 348 into a compatible format for transmission to a driver 359 of the light emitter of the buckle segment 350. For instance, in the present case, the processed information relates to the actuation of the haptic actuators of the seat belt webbing. The driver 359 is configured to convert the information received from the integrated circuit package 344a, into pulsed voltage signals of desired pulse width and frequency, which are sent to the light emitter 311a. The light emitter 311a, which is a Li-Fi device, uses a visible light spectra to act as data carrier for data communication. In the present exemplary embodiment, the light emitter 311a that is connected to the integrated circuit package 344a of the buckle segment 350 is provided with a data conversion module or a routine that is configured to convert data such as voice, text, video etc., into l"s and 0"s, so that they can be represented as digital signals. These digital signals are fed as input data to the light emitter 311a. The Li- Fi device is preferably configured to operate with an operating frequency in the range of 4X10¹⁴~8X 10¹⁴. The integrated circuit package 344a is also provided with a transmitter module or a routine, which is configured to generate corresponding on-off patterns for the light emitter 311a, using suitable Li-Fi techniques such as, singlecarrier modulation schemes, for instance, an on-off keying (OOK), to transmit the digital signals in the form of light pulses or flashes of light, with time intervals between each bit. If preferred, a multi-carrier modulation scheme can also be suitably adapted for use for high-speed optical wireless communication. It is also within purview of this invention to use colour shift keying (CSK), where signals are encoded into colour intensities emitted by red, green and blue (RGB) LEDs. In the alternate, the light emitter can also be a diode that emits infrared (IR) rays as data carrier. A digital camera can also used to view the emitted IR in order to verify the functioning of the device. Therefore, the light emitter 311a, which is broadly based on Li-Fi system, firstly, the input data get converted to through an ADC (to obtain digital signals) and the digital signals are then fed into a LED driver circuit (light emitter), which is controlled by a signal processor. The LED driver works with On-Off Keying modulation at high speeds and transmits the data and/or processed information, as optical pulses from the light emitter 311a.

[085] The tongue segment 351, which is coupled optically and electromagnetically to the buckle segment 350, is provided with light receiver 312b is optically coupled to the light emitter 311a to receive the pulsed optical signals carrying the data through wireless mode. A driver 360 (tongue) is connected to the light receiver 312b of the tongue segment 351 and is configured to convert the pulsed signals into a suitable format, for further processing by an integrated circuit package 341b of the tongue segment 351. The configuration of integrated circuit package 341b is similar to the integrated circuit package 344a. The integrated circuit package 341b is configured to communicate with alert members 542 of the seat belt webbing are coupled to integrated circuit package 341b for actuation. Accordingly, the system of the present invention, facilitates a wireless transfer of power and data communication between the buckle and tongue assemblies and to the end use devices such as haptic actuators.

[086] In the arrangement of the system of the present invention, the integrated circuit package 341b is also connected to the driver 360 and the light emitter 312b of the tongue segment 351, to provide a feedback once the tongue and buckle assemblies are coupled. The feedback is communicated from the light emitter 312b to the light receiver 312a of the buckle segment 350, which is turn is communicated to the integrated package circuit 343a through the driver 362. The feedback information channel can be used to determine events such as the optical and electromagnetic coupling of the paired devices, transmission errors etc.

[087] In yet another aspect of the present invention, as shown in FIGs.23 and 24, an occupant restraint system 400 with a plurality of the integrated electromagnetic and optical devices 400al, 400bl, 400a2, 400b2 are arranged on either side of respective buckle 437a, and tongue assemblies 431b and inside the buckle extension housings 440a1, 440a2 and tongue extension housings 436bl, 436b2, where an electromagnetic and optical coupling is established between the tongue and buckle assemblies 400a1, 400bl, 400a2, 400b2.

Claims

We claim;

1. An integrated electromagnetic and optical device 100 for a wireless transfer of power and transmission of data, comprising: a Sight emitter 111 and a Sight receiver 112 constituting data transceivers are disposed on a base member 101,

a magnetic flux directing member 108 is mounted on the base member 101 and disposed in between the light emitter 111 and the light receiver 112; an electromagnetic inductive interface 107 that is coupled to a magnetic flux amplifier 106 is disposed in the magnetic flux directing member 108 and on an insulating substrate 105 of the base member 101;

a sealing member 115 with optical apertures 116, 117 to expose the light emitter 111 and the light receiver 112, is connected to base member 101 and to form a sealing enclosure; and the light emitter 111 and the light receiver 112 are disposed to be configured for data communication and the electromagnetic inductive interface 107 and the magnetic flux amplifier 106 are disposed to be configured for power transfer.

2. The integrated electromagnetic and optical device 100 as claimed in claim 1, wherein a pair of the integrated electromagnetic and optical devices 200a, 200b are disposed to be coupled electromagnetically and optically and to be configured for a wireless transfer of power and transmission of data between them.

3. The integrated electromagnetic and optical device 100 as claimed in claim 1, wherein the electromagnetic inductive interface 107 is an electromagnetic coil.

4. The integrated electromagnetic and optical device 100 as claimed in claim 1, wherein the material for magnetic flux directing member 108 is a ferrite material.

5. The integrated electromagnetic and optical device 100 as claimed in claim 1, wherein the magnetic flux directing member 108 is connected to upper portion of the sealing member 115.

6. The integrated electromagnetic and optical device 100 as claimed in claim 1, wherein the light emitter 111 and the light receiver 112 are disposed on the peripheral ends of adjacent to each other or on the magnetic flux amplifier 106.

7. The integrated electromagnetic and optical device 100 as claimed in claim 1, whereinan array of light emitters and the light receiversare disposed on the base member (101).

8. The integrated electromagnetic and optical device 100 as claimed in claim 1, wherein the light emitter 111 is a white LED or an IR light-emitting diode and the light receiver 112 is a silicon photodiode.

9. The integrated electromagnetic and optical device 100 as claimed in claim 7, wherein the array of light emitters are white LEDs, red, green and blue (RGB) LEDs or IR light-emitting diodes and the array of light receivers are silicon photodiodes.

10. An occupant restraint system of a vehicle with a buckle assembly and a tongue assembly for wireless transfer of power and data communication between the buckle and tongue assemblies, when the tongue assembly is latched with the buckle assembly, comprising: a webbing 328 of a seat belt 327 with at least an alert member 342, is slidably connected to the tongue assembly 331b and fastened to an occupant 325, a vehicle power source 347 and an ECU 348 of the vehicle are connected to the buckle assembly 337a; characterized in that

integrated electromagnetic and optical devices 300a, 300b are disposed in buckle and tongue extension housings 336a, 340b and are configured to be coupled electromagnetically and optically, for wireless transfer of power and transmission of data, the integrated electromagnetic and optical devices 300a, 300 include

light emitters 311a, 311b and light receivers 312a, 312b constituting data transceivers, are disposed on the base members 301a, 301b;

magnetic flux directing members 308a, 308b, are mounted on the base members 301a, 301b and disposed in between thelight emitters 311a, 311b and the light receivers 312a, 312b;

electromagnetic inductive interfaces 307a, 307b that are coupled to magnetic flux amplifiers 306a, 306b of the buckle and tongue assemblies 337a, 331b, are disposed in the magnetic flux directing members 308a, 308b and on insulating substrates 305a, 305b of the base members 301a, 301b; sealing members 315a, 315b with optical apertures 316a, 317b, to expose the light emitters 311a, 311b and the light receivers 312a, 312b, are connected to the base members 301a, 301b and to form sealing enclosures; and

integrated circuit packages 343a, 341b are disposed in the buckle and tongue assembles 337a, 331b and are operably connected to vehicle power source 347, the ECU 348, and the integrated electromagnetic and optical devices 300a, 300b to transfer power of the vehicle source 347 as magnetic flux from the electromagnetic inductive interface 307a to the electromagnetic inductive interface 307b, and to supply power to the alert member 342 from the electromagnetic inductive interface 307b; and

the integrated circuit packages 343a, 341b and the ECU 348 are also configured to perform data communication from the ECU 348 to the alert member 342, through the data transceivers 311a, 311b.

11. The occupant restraint system as claimed in claim 10, wherein a pair of the integrated electromagnetic and optical devices 300a, 300b are disposed to be coupled electromagnetically and optically for a wireless transfer of power and transmission of data.

12. The occupant restraint system as claimed in claim 10, wherein the electromagnetic inductive interfaces 307a, 307b are electromagnetic coils.

13. The occupant restraint system as claimed in claim 10, wherein the material for magnetic flux directing members 308a, 308b is a ferrite material.

14. The occupant restraint system as claimed in claim 10, wherein the magnetic flux directing members 308a, 308b are connected to upper portions of the sealing members 315a, 315b.

15. The occupant restraint system as claimed in claim 10, wherein light emitters 311a, 311b and light receivers 312a, 312b are disposed on the peripheral ends of adjacent to each other or on the magnetic flux amplifiers 306a, 306b.

16. The occupant restraint system as claimed in claim 10, wherein an array of light emitters and the light receivers are disposed on the base members 301a, 310b.

17. The occupant restraint system as claimed in claim 10, wherein the light emitters 311a, 311b are white LEDs or IR light- emitting diodes and the light receivers 312a, 312b are silicon photodiodes.

18. The occupant restraint system as claimed in claim 16, wherein the array of light emitters are white LEDs, red, green and blue (RGB) LEDs or IR light-emitting diodes and the array of light receivers are silicon photodiodes.