Patent Application
20240235676
Connectivity between electronic devices continues to grow at a rapid pace, particularly as the Internet of Things continues to evolve. Currently, wireless communication between electronic devices, both portable and stationary devices, depends primarily on radio communications.
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific examples in which the disclosure may be practiced. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims. It is to be understood that features of the various examples described herein may be combined, in part or whole, with each other, unless specifically noted otherwise.
Wireless communication between electronic devices, both portable and stationary electronic devices, depends primarily on radio communications (e.g., WiFi, Bluetooth). While effective, radio based communications lack the data bandwidth of wired communications and may create spectrum congestion leading to communication interference with nearby electronic devices (e.g., insufficient spacing between channels and band congestion as more devices operate in proximity to one another). Radio based communications are also susceptible to eavesdropping by malicious parties, thereby requiring very robust cryptographic security solutions to maintain privacy. Additionally, radio based communications may be adversely impacted by magnetic fields and, as result, require antennae to be disposed in areas free of metal interference. Such space is often limited, particularly in portable electronic devices, and may lead to sub-optimal antennae design, placement, and performance.
According to examples of the present disclosure, an optical communication system is described which provides wireless optical communication between electronic devices. In examples, the system employs an array of light cells providing controllable collimated light beams (e.g., vertical cavity surface emitting laser (VCSEL) diodes) disposed on a first device (e.g., a laptop), and an array of photosensitive cells (e.g., single photon avalanche diodes (SPAD)) disposed on a second device (e.g., a laptop, docking station). In examples, each light cell of the array is operable to output a collimated light beam which is separately controllable to represent encoded data, where the light beams of the array form an optical output signal encoded with data to transmit to the array of photosensitive cells of the second device. In examples, based on an overlap of the optical output signal with the array of photosensitive cells, a relative position between the optical output signal and the array of photosensitive cells is adjusted to achieve alignment there between.
In examples, an optical communication system, in accordance with the present disclosure, may be implemented in both single-duplex and full-duplex configurations, and may be operated in both single- and multi-channel configurations. Additionally, any number of suitable data encoding schemes may be employed, including temporal encoding (e.g., a binary bit stream), spatial encoding schemes (e.g., a QR code), and a combination of both, for example.
As will be described in greater detail herein, an optical communication system, in accordance with the present disclosure, provides higher-bandwidth and lower-latency communication relative to traditional wireless communication employing radio frequency communication (e.g., Bluetooth, WiFi). Because optical communication is more difficult to be eavesdropped by malicious parties, the optical communication system disclosed herein also provides enhanced privacy and security relative to radio frequency communication. Further, the optical communication system described herein is not disrupted by magnetic fields, as are RF communications and, thus, can be employed in the presence of metal components and enables implementation in a variety of environments and device form factors.
In one example, electronic device 20 includes a light cell array 24, a photocell array 26, and a controller 28. In examples, each light cell of light cell array 24 is individually operable, such as by controller 28, to output a controllable collimated light beam, where the light beams of light cell array 24 form an optical output signal 30 encoded with data (i.e., a data encoded optical output signal) to transmit to destination device 22. In examples, as will be described in greater detail below, light cell array 24 may be a one-dimensional array (a 1×m array) or a two-dimensional array (an m×n array) of any suitable dimension (where m and n are integer values greater than 1).
In examples, controller 28 encodes optical output signal 30 with data by selectively modulating and/or controlling any number of suitable characteristics of visible or non-visible light beams emitted by the cells of light cell array 24 such as an amplitude, frequency, color, pulse width, and duty cycle, for example. In one example, controller 28 may apply any suitable voltage or current waveform to each light cell of light cell array 24 to modulate and/or control a suitable characteristic of its emitted light beam, where the applied waveform represents data to be encoded in optical output signal 30 for communication to destination device 22. In examples, light cell array 24 and controller 28 together represent a transmitter module 32 for transmitting optically encoded data via optical output signal 30 to destination device 22.
In examples, the cells of light cell array 24 may be of any suitable light source, such as a light-emitting diode, a micro-scale light-emitting diode, an infrared band laser, and ultraviolet band laser, for example. In one example, light cell array 24 is an array of vertical cavity surface emitting lasers (VCSEL). In examples, each light cell may have corresponding structure(s) to collimate and/or focus the emitted light (e.g., beam collimators, micro-lenses, waveguides, reflectors, polarizers, etc.). For simplicity of description, light cell array 24 is referred to below as laser array 24 (e.g., a VCSEL array).
In examples, photocell array 26 is to receive an optical input signal 34 encoded with data (i.e., a data encoded optical input signal) from destination electronic device 22. In examples, each photocell of photocell array 26 provides an output signal representative of an amount of energy received from optical input signal 34. In examples, as will be described in greater detail below, photocell array 26 and optical input signal 32 are aligned as precisely as possible with one another to optimize communication between electronic device 20 and destination electronic device 22. In examples, based on the output signals of the photocells of photocell array 26, controller 28 determines an overlap of optical input signal 34 with photocell array 26. In one case, based on the determined overlap, controller 28 adjusts a position of photocell array 26 to achieve optimal alignment of photocell array 26 with optical input signal 34. In examples, photocell array 26 and controller 28 together represent a receiver module 36 for receiving optically encoded data, such as via optical input signal 32 from destination device 22.
In some examples, in it is noted that “optimal” alignment may not represent full alignment between photocell array 26 and optical input signal 34. In such cases, a mode of communication (e.g., direct or scanning mode) may be selected, such as by controller 28, to optimize communication based on a partial overlap between photocell array 26 and optical input signal 34 (such as when operating in a full-duplex arrangement, for example).
In one example, electronic device 20 includes a moveable carriage 38 on which photocell array 26 is arranged. In examples, based on a measured overlap between photocell array 26 and optical input signal 34, controller 28 adjusts a position of moveable carriage 38 (e.g., a 2-dimensional position along x- and y-axes) to optimally align photocell array 26 with optical input signal 34. In examples, moveable carriage 38 may be a microelectromechanical (MEMs) device supported by elastic elements which may be controllably moved from a center position (“home” position) via any suitable actuation mechanism (such as a piezoelectric actuator, magnetoresistive actuator, and electromagnetic actuator, for example). In some examples, as described in great detail below, mechanical alignment features or elements may be employed to ensure a degree of alignment (i.e., a coarse alignment) between electronic device 20 and destination electronic device 22, where such mechanical elements may be integral to the electronic devices (e.g., détentes, pins, keyed elements, etc.) and/or may be a separate alignment element to which the electronic devices 20 and 22 selectively attach.
In examples, the photocells of photocell array 26 include any suitable photosensitive element or combination of photosensitive elements such as charge-coupled devices, semiconductor photodiodes, semiconductor photodetectors, avalanche diodes, and single photon avalanche diodes (SPAD), for example. For simplicity of description, photocell array 26 is referred to below as SPAD array 26 (i.e., an array of single photon avalanche diodes).
As described in greater detail below, an optical communication system, in accordance with the present disclosure, may be implemented and operated in single-duplex and full-duplex configurations, and may be configured for single and multi-channel communication.
As described above with respect to
In some examples, first and second electronic devices 20 and 22 may include a number of mechanical alignment elements 40 (illustrated in dashed lines as 40a-40d) which engage one another to mechanically couple first electronic device 20 with second electronic device 22 and provide a coarse alignment and at least a partial overlap of optical output signal 30-1 of laser array 24-1 with SPAD array 26-1. Mechanical alignment elements 40 may be magnetic elements, detents, pins, or any suitable alignment and/or interlock elements. In some examples, a mechanical alignment device 42 separate from first and second electronic device 20 and 22 may be employed which mechanically receives and aligns first and second electronic device 20 and 22 with one another to ensure at least a partial overlap of optical output signal 30-1 of laser array 24-1 with SPAD array 26-1. In examples, after coarse alignment is achieved via mechanical elements 40 and/or mechanical alignment device 42, final alignment between laser array 24-1 and SPAD array 26-1 is optimized via positional adjustment of SPAD array 26-1 by controller 28-2 based on an overlap as indicated by output signals the photocells of SPAD array 26-1.
In one example, second SPAD array 26-2 is disposed on a second moveable carriage 38-2. Similar to that described above by
In examples, first and second laser arrays 24-1 and 24-2 are respectively disposed on moveable carriages 44-1 and 44-2. In examples, when implements as a full duplex arrangement, first and second electronic devices 20 and 22 are able to provide feedback to one another regarding respective overlaps between respective optical input signals 34-2 and 34-1 and SPAD arrays 26-1 and 26-2. In examples, based on such feedback, controllers 28-1 and 28-2 adjust the respective positions of laser arrays 24-1 and 24-2 via movement of carriages 44-1 and 44-1 to achieve alignment of optical input signals 34-1 and 34-2 with SPAD arrays 26-1 and 26-2. In examples, alignment between laser arrays 24-1 and 24-2 with respective SPAD arrays 26-1 and 26-2 may be achieved via positional adjustment of SPAD arrays 26-1 and 26-2 via carriages 38-1 and 38-2, and/or positional adjustment of laser arrays 24-1 and 24-2 via carriages 44-1 and 44-2. Additionally, it is noted that full duplex optical communication system 50-2 may also employ mechanical alignment elements 40 and/or mechanical alignment device 42 as described above by
According to examples, an optical communication system, in accordance with the present disclosure, such as single- and full-duplex optical communication systems 50-1 and 50-2 of
In examples, laser and SPAD arrays 24-1 and 26-1 may be arrays having dimensions other than 4×4, and may be one-dimensional arrays (e.g., a single row or a single column of cells), or two-dimensional arrays (e.g., multiple rows and columns of cells). In examples, laser and SPAD arrays 24-1 and 26-1 may have different numbers of cells. In one case, SPAD array 26-1 may have larger dimensions than laser array 24-1 (i.e., more cells). For example, laser array 24-1 may be a 4×4 array while SPAD array 26-1 may be a 6×6 array so as to better ensure that at least a partial overlap is achieved between optical input signal 34-1 and SPAD array 26-1.
In a direct mode of operation, such as illustrated by direct mode 60-1, there is a one-to-one correspondence between laser cells L0 to L15 and photocells P0 to P15 of SPAD array 26-1 (i.e., the laser beam emitted by a given laser cell is received by a corresponding photocell). In the illustrated example, laser cell L0 corresponds to photocell P0, laser cells L1 corresponds to photocell P1, and so on. To transmit data from laser array 24-1 to SPAD array 26-1, controller 28-1 modulates and/or controls suitable characteristics (as described above) of light beam 50 of each laser cell L0 to L15 to encode data therein. The amount of energy received by a given photocell of SPAD array 26-1 via the laser beam 50 of the corresponding cell of laser array 24-1 is indicative of a bit of data represented by the received light beam 50.
In one example, each laser and photocell pair of laser array 24-1 and SPAD array 26-1 may represent a unique communication channel with each laser beam 50 transmitting a stream of data bits (e.g., a binary stream). In one example, each laser cell of laser array 24-1 may be controller to transmit a laser beam 50 at a different frequency, with the corresponding photocell tuned to receive light at the same frequency, such that laser cells L0 to L15 can simultaneously transmit data to their corresponding photocell (e.g., P0 to P15) without interference (“crosstalk”) there between.
In another example, the cells of laser array 24-1 combined may represent a single channel. In one example, when a channel is formed by multiple laser cells, the optical output of each channel may be spatially encoded with data (e.g., 2-dimensionally encoded), such as in the form of a quick response (QR) code, for instance, which represents a 2-dimensional spatial pattern. In one example, the power level of laser beam 50 of each light cell of laser array 24-1 may be controlled to represent binary data (i.e., a “0” or a “1”). In one example, the power level of laser beam 50 of each light cell of 24-1 may be modulated so that each laser beam 50 may be controlled to represent data on a scale between “0” and “1” and, thus, represent multi-bit data (i.e., more than simply binary data). In on other examples, data can be encoded as a sequence of QR code patterns (e.g., a sequence of 2 or more QR code patterns) to thereby transmit 3-dimensionally encoded data.
Spatially encoding data in such fashion increases a bandwidth relative to transmitting data in the form of serial bit streams. In examples, an optical communication system in accordance with the present application may be adapted to employ any number of protocols, such as Thunderbolt 3 or higher, and protocols such as USB and HDMI, for example.
In examples, a setup (or alignment) procedure may be performed to optimally align light beams 50 of laser array 24-1 with the photocells of SPAD array 26-1 prior to commencement of optical data transmission. According to one example, during such a setup procedure, controller 28-1 of first electronic device 20 causes each laser cell L0 to L15 of laser array 24-1 to output a light beam 50, which is received by SPAD array 26-1 as optical input signal 34-1. In one example, during a setup procedure, light beams 50 may non-modulated. In one example, based on the output signals from photocells P0 to P15 of SPAD array 26-1, controller 28-2 of second electronic device 22 determines and overlap of optical input signal 34-1 with SPAD array 26-1, and adjusts the position of receiver carriage 38-1 to optimally align SPAD array 26-1 with optical input signal 34-1. Upon completion of such setup procedure, controller 28-1 begins optically transmitting encoded date to second electronic device 22 via optical output signal 30-1.
As an illustrative example of such a setup procedure, assume upon startup that laser beams 50 of laser cells L0, L1, L4, and L5 of laser array 24-1 align with photocells P10, P11, P14 and P15 of SPAD array 26-1. In response, controller 28-2 adjusts the position receiver carriage 38-1 to move SPAD array 26-1 by the dimension of two cells in the positive x-direction and the dimension of two cells in the negative y-direction. In one example, controller 28-2 then “fine tunes” the position of SPAD array 26-1 by incrementally moving receiver carriage in the x- and y-directions until a signal strength from photocells P0 to P15 is optimized, thereby optimally aligning SPAD array 26-1 with optical input signal 34-1 (i.e., optical output signal 30-1 from laser array 24-1).
Using the same example as above, when implemented as a full duplex optical communication system, such as optical communication system 50-2 of
In other examples, when implemented as a full-duplex arrangement, the positions of both laser array 24-1 and SPAD array 26-1 may be adjusted to achieve optimal alignment there between. Adjusting the positions of both laser array 24-1 and SPAD array 26-1 enables larger misalignments between laser array 24-1 and SPAD array 26-1 to be corrected.
In some examples, initial misalignment between first and second electronic devices 20 and 22 may be large enough that, after the setup procedure, not all laser cells L0 to L15 are able to be aligned with a corresponding one of the photocells P0 to P15 of SPAD array 26-1 (i.e., full alignment is not achieved). In such case, according to one example, when implemented in a full-duplex arrangement, such as optical system 50-2, controller 28-2 of second electronic device 22 communicates to first electronic device 20 via optical output signal 30-2 (i.e., optical input signal 34-2) overlap data indicating which cells are overlapping between optical input signal 34-1 and SPAD array 26-1 (i.e. which represents the optimal alignment is such case). As an example, in one case, after the setup procedure is completed, optimal alignment may result in laser cells L0-L11 being respectively aligned with photocells P4 to P15 of SPAD array 26-1. In such case, based on the measured overlap with SPAD array 26-1, controller 28-2 optically transmits the optimal overlap information to first electronic device 20 via optical output signal 30-2. In one example, based on the optimal overlap information, controllers 28-1 and 28-2 adjust the transmission and/or encoding scheme employed so as to transmit information via only laser cells L0 to L11 and corresponding photocells P4 to P15 in the most efficient manner.
In one case, as illustrated, laser cells L0, L1, L4, and L6 are grouped with photocells P0, P1, P4, and P6 to form Channel 0, laser cells L2, L3, L6, and L7 are with photocells P2, P3, P6, and P7 to form Channel 1, laser cells L8, L9, L12, and L13 are grouped with photocells P8, P9, P12, and P13 to form Channel 2, and laser cells L10, L11, L14, and L15 are grouped with photocells P10, P11, P14, and P15 to form Channel 3. The illustration of
In one example, laser beams 50 of each channel may be controlled by controller 28-1 so as to be encoded with different data such that each channel may transmit data using a 2D (or 3D) encoding scheme. In other examples, laser beams 50 of each channel may be controlled by controller 28-1 so as to be encoded with the same data so as to increase a signal strength of each channel (i.e., a binary data stream). In one example, each laser beam 50 is controlled to transmit at a different frequency with the corresponding photocell tuned to same frequency so that laser cells L0 to L15 can simultaneously transmit data without “crosstalk” there between.
In one example, first controller 28-1 steers laser beam 70 in a zig-zag pattern 72 across SPAD array 26-1, such that laser beam may also be referred to as a scanning laser beam 70. Encoded data within scanning laser beam 70 is read by photocells P1 to P15 as scanning laser beam 70 travels along zig-zag scanning path 72. Although illustrated as being directed along a zig-zag scanning path 72, controllable scanning laser beam 70 may be directed by first controller 28-1 to follow any suitable path.
In examples, during an initial setup procedure, first controller 28-1 may operator laser array 24-1 in a direct mode, such as illustrated by
In another example, during an initial setup procedure, first controller 28-1 may steer scanning laser beam 70 along a predetermined “search” path until scanning laser beam 70 is detected by SPAD array 26-1. In one example, based on the photocell(s) P0 to P16 at which scanning laser beam 70 is detected, first controller 28-1 adjusts the phase offsets of the individual power signals to laser cells L0 to L15 to direct scanning laser beam 70 along a desired scanning path, such as scanning path 72 to optically transmit encoded data to SPAD array 26-1. In another example, based on the photocell(s) P0 to P16 at which scanning laser beam 70 is detected, controller 28-1 adjusts the position of SPAD array 26-1 via moveable carriage 38-1.
In one case, as illustrated, laser cells L0, L1, L4, and L6 are grouped to form Channel 0, laser cells L2, L3, L6, and L7 are grouped to form Channel 1, laser cells L8, L9, L12, and L13 are grouped to form Channel 2, and laser cells L10, L11, L14, and L15 are grouped to form Channel 3. According to scanning mode 62-2, controller 28-1 operates the laser cells of each channel as separate phased arrays such that laser beams 50 of the laser cells of each channel combine to form a corresponding scanning laser beam, such as illustrated by scanning laser beams 70-0 (corresponding to channel 0) and 70-3 (corresponding to channel 3).
In one example, as illustrated, the scanning laser beams of each channel, such as scanning laser beams 70-0 and 70-3 may be directed along a same scanning path, such as zig-zag canning path 72, but be temporally offset from one another to enable a readout of the output signals of photocells P0 to P15. Any number of scanning patterns may be employed.
In one example, as illustrated, laser cells L0 to L3 and corresponding photocells P0 to P3 form channel 0, laser cells L4 to L7 and corresponding photocells P4 to P7 form channel 1, laser cells L8 to L11 and corresponding photocells P8 to P11 form channel 2, and laser cells L12 to L15 and corresponding photocells P12 to P15 form channel 3.
According to scanning mode 62-3, controller 28-1 operates the laser cells of each channel as separate phased arrays such that laser beams 50 of the laser cells of each channel combine to form a corresponding scanning laser beam, such as illustrated by scanning laser beams 70-0 (corresponding to channel 0) and 70-3 (corresponding to channel 3). In examples, because each channel is formed using a 1-dimensional array of laser cells, controller 28-1 can control the phase sequence of the individual power signals to the laser cells of each channel so as to steer the corresponding scanning laser beam along a 1-dimensional path, such as steering scanning laser beam 70-0 of channel 0 along a repeating path 72-0 across photocells P0 to P3, and steering scanning laser beam 70-3 of channel 3 along a repeating path 72-3 across photocells P12 to P15.
As illustrated, according to one example, in a fashion similar to that illustrated and described by
It is noted that in both direct and scanning modes of operation, optical communication systems, in accordance with the present disclosure, may employ any suitable encoding scheme such as temporal encoding (e.g., a binary data stream), spatial encoding (e.g., 2- and 3-D encoding, such as QR codes, for instance), and a combination of both, for example. Additionally, in scanning modes of operation, a scanning rate may also be employed for encoding. Additionally, it is noted that, in some examples, the scanning mode employed may be selected such that a direct mode may be employed in one instance and a scanning mode may be employed in another instance (e.g., based on an optimal overlap). Further, in some examples, a channel configuration may be selectable (e.g., the laser and photocell arrays may be virtually portioned).
In examples, second electronic device 22 is a portable electronic device (e.g., laptop, tablet, cell phone, etc.) which, in addition to laser array 24-2, SPAD array 26-1, and controller 28-2, includes a battery 90, a charging circuit 92, an induction coil 94, and a housing 96 having a surface 98 including mechanical alignment elements 40b and 40d. In examples, as illustrated, mechanical alignment elements 40b and 40d are implemented as notches or recesses adapted to respectively receive mechanical alignment elements 40a and 40c of docking station 80.
To dock second electronic device 22 with docking station 80, surface 98 is disposed on surface 86 of docking station 80 such that mechanical alignments elements 40b and 40d respectively receive mechanical alignment elements 40a and 40c. Upon mechanical alignment elements 40b, 40d receiving mechanical alignment elements 40a and 40c, laser array 24-1 and SPAD array 26-2 of docking station 80 are respectively in coarse alignment with SPAD array 26-1 and laser array 24-2 of second electronic device 22. Final alignment between laser array 24-1 and SPAD array 26-1, and between laser array 24-2 and SPAD array 26-2 may then be established as described above (e.g., by adjustment of the laser and SPAD arrays via corresponding moveable carriages 38-1, 38-2, 44-1, and 44-2, and/or adjustment of the position of steerable laser beams 70 via adjustments to phase sequencing or control of corresponding MEMs devices). Once optimal alignment is achieved, optical data communication may commence between electronic device 22 and docking station 80.
Upon mechanical alignment elements 40b, 40d receiving mechanical alignment elements 40a and 40c, alignment is also achieved between induction coil 82 of docking station 80 and induction coil 94 of electronic device 22. A charging current induced by induction coil 82 in induction coil 94 is adapted and employed by charging circuitry 92 to charge battery 90.
In examples, docking station 80 (i.e., first electronic device 22) is arranged as a pad on which electronic device 22 is placed. Any number of suitable arrangement may be employed. By combining a wireless battery charging system with an optical communication system, in accordance with the present disclosure, docking station 80 provides a completely wireless docking solution for portable computing devices (e.g., laptops). Additionally, depending on the encoding scheme employed (e.g., 2D encoding), docking station 80 may have increased data transmission rates as compared to conventional wired docking stations. It is noted
At 104, the method includes receiving the optical output signal with a photocell array of a second electronic device, each light cell of the photocell array to provide an output signal indicative of an amount of energy received from the optical output signal, such as receiving optical output signal 30-1 from laser array 24-1 with SPAD array 26 of second electronic device 22, as illustrated
At 106, the method includes determining an overlap of the optical output signal with the photocell array based on the optical output signals of the photocell array, such as controller 28-2 of second electronic device 22 measuring an overlap of optical output signal 30-1 with SPAD array 26-1, as illustrated by
In summary, high frequency modulation of a light cell array (e.g., VCSEL array) and speed of light transmission enables an optical communication system, in accordance with the present disclosure, to provide higher bandwidth and lower latency communication relative to traditional wireless communication employing radio frequency communication (e.g., Bluetooth, WiFi). Also, an optical communication, as disclosed herein, is more difficult to eavesdrop by malicious parties, and thereby provides enhanced privacy and security relative to conventional radio frequency communications. Additionally, an optical communication system described herein is not disrupted by magnetic fields, as are RF communications and, thus, can be employed in the presence of metal components which enables implementation in a variety of environments and device form factors. Furthermore, an optical communication system, in accordance with the present disclosure, enables any number of encoding and protocol schemes to be employed, including high density spatial encoding schemes, and also enables simultaneous multi-channel data transmission which further increases bandwidth relative to radio communications systems and wired systems. Additionally, the transmission schemes (e.g., direct, scanning, multi-channels, etc.), and encoding and protocol schemes can be adapted to meet bandwidth requirements for a particular implementation.
Although specific examples have been illustrated and described herein, a variety of alternate and/or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/030345 | 4/30/2021 | WO |
