Optical wireless power transfer system performing bidirectional communication
10727942 ยท 2020-07-28
Assignee
Inventors
Cpc classification
H04B10/808
ELECTRICITY
H02J50/80
ELECTRICITY
H04B10/807
ELECTRICITY
International classification
H04B10/80
ELECTRICITY
H02J50/80
ELECTRICITY
Abstract
An optical wireless power transfer system including a transmission module having a power light source configured to output power light; a communication light source configured to output communication light; a mirror disposed in a light path of the power light source and the communication light source and configured to pass the power light and reflect the communication light; and a transmitting processor configured to modulate the communication light to have a first modulation. The wireless power transfer system also includes a reception module having a photoelectric cell configured to receive the power light from the transmission module and generate power; a retro-reflector configured to retro-reflect the communication light back to the transmission module; and a receiving processor configured to control the retro-reflector to reflect the communication light to have a second modulation based on the power generated by the photoelectric cell.
Claims
1. An optical wireless power transfer system, comprising: a transmission module including: a power light source configured to output power light; a communication light source configured to output communication light; a mirror disposed in a light path of the power light source and the communication light source and configured to pass the power light and reflect the communication light; and a transmitting processor configured to modulate the communication light to have a first modulation; and a reception module including: a photoelectric cell configured to receive the power light from the transmission module and generate power; a retro-reflector configured to retro-reflect the communication light back to the transmission module; and a receiving processor configured to control the retro-reflector to reflect the communication light to have a second modulation based on the power generated by the photoelectric cell.
2. The optical wireless power transfer system of claim 1, wherein the transmission module further comprises: a beam splitter configured to reflect the communication light reflected by the mirror; a first photodiode configured to convert the communication light having the second modulation reflected by the beam splitter into an electrical signal, and wherein the transmitting processor is further configured to identify the communication light having the second modulation based on the converted electrical signal.
3. The optical wireless power transfer system of claim 2, wherein the reception module further comprises: a second photodiode configured to convert the communication light having the first modulation into an electrical signal, and wherein the receiving processor is further configured to identify the communication light having the first modulation based on the converted electrical signal.
4. The optical wireless power transfer system of claim 1, wherein the transmitting processor is further configured to: control the communication light source to output the communication light having a first predetermined intensity, and output, when an intensity of the communication light reflected by the retro-reflector is greater than or equal to a reference intensity, the power light and control the communication light to have the first modulation.
5. The optical wireless power transfer system of claim 1, wherein the transmitting processor is further configured to control the communication light source to gradually increase a magnitude of the power light until the communication light having the second modulation corresponds to a completion message received from the reception module, and wherein the receiving processor is further configured to generate the communication light having the second modulation to correspond to the completion message, when the power generated by the power light is greater than or equal to a required power.
6. The optical wireless power transfer system of claim 5, wherein the receiving processor is further configured to generate the communication light having the second modulation to correspond to a request message, when the power generated by the power light is less than the required power, and wherein the transmitting processor is further configured to gradually increase the magnitude of the power light when the request message is received.
7. The optical wireless power transfer system of claim 1, wherein the receiving processor is further configured to generate the communication light having the second modulation to correspond to a message of the received power during a reference period of time, when the power is generated based on the power light, and wherein the transmitting processor is further configured to prevent the power light from being output, when the message of the received power is not received during the reference period of time.
8. The optical wireless power transfer system of claim 7, wherein the transmitting processor is further configured to output the communication light having a predetermined intensity, when the message of the received power is not received during the reference period of time.
9. The optical wireless power transfer system of claim 1, wherein the transmitting processor is further configured to adjust an intensity of the communication light, and wherein the receiving processor is further configured to identify the communication signal having the first modulation based on the intensity of the communication light.
10. The optical wireless power transfer system of claim 1, wherein the receiving processor is further configured to generate the communication light having the first modulation using an on-off keying method.
11. The optical wireless power transfer system of claim 1, wherein the mirror includes a hole disposed in the light path of the power light source to pass the power light to the reception module without being reflected by the mirror.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given by illustration only, and thus are not limitative of the present invention, and wherein:
(2)
(3)
(4)
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DETAILED DESCRIPTION OF THE EMBODIMENTS
(8) The above-mentioned objects, features, and advantages of the present disclosure will be described in detail with reference to the accompanying drawings. Accordingly, the skilled person in the art to which the present disclosure pertains may easily implement the technical idea of the present disclosure. Preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings. In the drawings, same reference numerals are used to refer to same or similar components.
(9) The present disclosure relates to an optical wireless power transfer system capable of performing bidirectional communication wirelessly using light. Hereinafter, the optical wireless power transfer system of the present disclosure will be described in detail with reference to
(10) Referring to
(11) As shown in
(12) A method in which each module is arrayed and a method of determining, by the transmission module 10, a state in which modules are arrayed are described below. Further, the transmission module 10 can output power light and communication light including a first modulated signal, receive reflected light which is generated by reflecting the communication light, and process a second modulated signal included in the reflected light.
(13) In addition, the transmission module 10 may include a processor that processes a signal and two kinds of light sources that the output power light and the communication light, respectively. Further, the reception module 20 can process the first modulated signal included in the communication light output by the transmission module 10, reflect the communication light, and output the reflected light. Also, the reception module 20 can enable the second modulated signal to be included in the reflected light based on power generated by the power light output by the transmission module 10. Further, the reception module 20 may also include a processor that processes a signal, a reflector that reflects communication light, and an optical generator that generates power using the power light.
(14) The optical wireless power transfer system 1 according to an embodiment of the present disclosure is described below in more detail with reference to
(15) In addition, according to an embodiment of the present disclosure, the reception module 20 may include a photoelectric cell 21, a retro-reflector 22, a second photodiode 23, a receiving processor 24, and second magnetic bodies 25a, 25b, a regulator 26, and a decoder 27. The transmission module 10 and the reception module 20 shown in
(16) Hereinafter, a path of light output by the optical wireless power transfer system 1 according to an embodiment of the present disclosure is described below in detail with reference to
(17) In the present disclosure, the power light and the communication light can perform functions. More specifically, the power light can be output by the transmission module 10 to provide the reception module 20 with the power, and communication light can be output by the transmission module 10 to provide the reception module 20 with a specific signal.
(18) In addition, at least one of lens 11a, 12a may be further provided at an output end of the power light source 11 and an output end of the communication light source 12 to increase a light-transmission efficiency of each of the power light and the communication light, and the lenses 11a and 12a may be operated as a beam expander, a collimator, and the like. Further, the mirror 13 of the transmission module 10 passes the power light and reflects the communication light.
(19) More specifically, the mirror 13 can pass the power light output by the power light source 11 without change and can reflect the communication light output by the communication light source 12 toward the reception module 20. As shown in
(20) In addition, a portion of the communication light output by the communication light source 12 may pass through the hole provided in the mirror 13. Thus, the optical absorber 17 of the transmission module 10 can be placed on an extension line connecting the communication light source 12 and the hole to absorb the communication light that has passed through the hole provided in the mirror 13.
(21) Further, the transmitting processor Tx 16 of the transmission module 10 controls the communication light source 12 to enable the first modulated signal to be included in the communication light. In the present disclosure, the modulated signal (the first modulated signal and the second modulated signal) may refer to all kinds of signals transmitted and received between the transmission module 10 and the reception module 20. In addition, the transmitting processor 16 can control the first modulated signal to be included in the communication light through an on-off keying method, an intensity modulation (IM) method, and the like, and the method of generating the modulated signal is described below.
(22) Further, the photoelectric cell 21 of the reception module 20 receives the power light to generate the power. The photoelectric cell 21 may be any element through which a current flows when light is received and may include a solar cell. The photoelectric cell 21 can also receive the power light output by the power light source 11 to generate the power based on the intensity of the light. As the power light output by the power light source 11 goes straight through the hole of the mirror 13 described above, the power light source 11 and the photoelectric cell 21 can be placed in a straight line.
(23) As shown in
(24) Further, the second photodiode 23 of the reception module 20 can convert the communication light into an electric signal. Then, the receiving processor 24 can identify the first modulated signal based on the electrical signal converted by the second photodiode 23 and process the identified first modulated signal.
(25) In the present disclosure, the photodiodes (a first photodiode 15 and a second photodiode 23) may be any semiconductor diodes that convert light energy into electrical signals. Such a photodiode may be a single element, or may have an array form in which a plurality of elements are regularly arranged.
(26) In addition, the second photodiode 23 can convert the communication light output by the communication light source 12 into the electric signal based on the intensity of the light. The decoder 27 connected to the second photodiode 23 can then convert the electrical signal output by the photodiode into a digital signal and provide the receiving processor 24 with the converted digital signal.
(27) Further, the receiving processor 24 can identify the transmitted first modulated signal included in the communication light based on the digital signal provided by the second photodiode 23 and the decoder 27. The receiving processor 24 can then process the identified first modulated signal. More specifically, the receiving processor 24 can generate a control signal based on the first modulated signal or generate a response signal corresponding to the first modulated signal. Further, the receiving processor 24 can perform various kinds of operations to process a signal.
(28) In addition, the retro-reflector 22 of the reception module 20 can retro-reflect the communication light to output the reflected light. More specifically, the retro-reflector 22 can output the reflected light by reflecting the incident communication light in a direction opposite to an incident direction. As shown in
(29) Also, the receiving processor 24 can control the retro-reflector 22 to enable the second modulated signal to be included in the reflected light based on the power generated by the photoelectric cell 21. The receiving processor 24 can also control the second modulated signal to be reflected on the reflected light through the on-off keying method and the method of generating the modulated signal is described below.
(30) Further, the mirror 13 of the above-described transmission module 10 can reflect the reflected light. More specifically, as shown in
(31) The beam splitter 14 of the transmission module 10 can then reflect back the reflected light, which has been reflected by the mirror 13. As shown, the beam splitter 14 can be provided between the mirror 13 and the communication light source 12 to pass a portion of the incident light and reflect other portions of the incident light. Accordingly, the communication light incident on the mirror 13 can be output by the communication light source 12 and passes through the beam splitter 14.
(32) As shown in
(33) In addition, the transmitting processor 16 can identify the second modulated signal included in the reflected light based on the electrical signal provided through the first photodiode 15, and perform various kinds of operations to process the signal based on the identified second modulated signal.
(34) Hereinafter, a method of communicating, by the transmission module and the reception module 20 and a method of transmitting the power are described below in detail with reference to
(35) Referring to
(36) Further, the transmission module 10 can output communication light having the reference intensity, in a form of a continuous wave in the ping mode (S10). In this instance, when the transmission module 10 and the reception module 20 are not arrayed, the communication light is not reflected by the reception module 20 and thus the reflected light is not received at the transmission module 10. On the contrary, when the transmission module 10 and the reception module 20 are arrayed, the communication light can be reflected by the reception module 20 and thus the reflected light can be received at the transmission module 10.
(37) In addition, the transmission module 10 can determine that, when the intensity of the received reflected light is equal to or greater than a reference intensity, the reception module 20 is arrayed at the preset position, and can determine that, when the intensity of the received reflected light is less than the reference intensity, the reception module 20 is not arrayed at the preset position.
(38) For example, the transmission module 10 can determine whether the reception module 20 is arrayed based on comparison of the magnitude of voltage generated based on the reflected light with the reference voltage (S11). More specifically, when the optical wireless power transfer system 1 is provided as shown in
(39) The transmitting processor 16 can determine that, when the total of the voltages Vi converted by the first diode 15 is equal to or greater than the reference voltage V.sub.ref, the reception module 20 is arrayed at the preset position. On the contrary, the transmitting processor 16 determines that, when the total of voltages Vi converted by the first light diode 15 is less than the reference voltage Vref, the reception module 20 is not arrayed at the preset position.
(40) When the transmitting processor 16 determines the reception module 20 is arrayed at the preset position, the transmission module 10 can output the above-mentioned power light and enable the first modulated signal to be included in the communication light. In other words, in the ping mode S10, the transmission module 10 outputs only communication light having a reference intensity in a form of continuous wave without outputting the power light, and outputs the power light and communication light including the first modulated signal, when the transmitting processor 16 determines that the reception module 20 is arrayed at the preset position.
(41) In addition, the transmission module 10 and the reception module 20 may include first and second magnetic bodies 18a, 18b, and 25a, and 25b, respectively, to maintain the above-mentioned array state. In more detail, a plurality of first magnetic bodies 18a and 18b and a plurality of second magnetic bodies 25a and 25b may be provided, and an attraction can be generated between the first magnetic bodies 18a and 18b and the second magnetic bodies 25a and 25b.
(42) For example, as shown in
(43) In addition, the attraction enables the transmission module 10 and the reception module 20 to be fixed within a predetermined distance. For example, when a light transmitting material such as plastic or glass is provided between the transmission module 10 and the reception module 20, positions of the transmission module 10 and the reception module 20 can be fixed at both ends of the light transmitting material, respectively, based on the attraction generated between the first magnetic bodies 18 and 18b and the second magnetic bodies 25a and 25b.
(44) Accordingly, after the transmission module 10 and the reception module 20 are arrayed once, the array state can be maintained by the above-described magnetic bodies 18a, 18b, 25a, and 25b unless an external force having a predetermined magnitude or more is applied.
(45) Referring back to
(46) Referring to
(47) Further, the transmitting processor 16 can process the second modulated signal included in the reflected light to identify the completion message, and when the completion message is identified, the transmitting processor 16 can maintain a predetermined magnitude of the power light. On the contrary, when the magnitude of the generated power P.sub.out is less than the magnitude of the required power P.sub.req, the receiving processor 24 can generate the second modulated signal including the request message. Subsequently, the receiving processor 24 can control the retro-reflector 22 to enable the second modulated signal to be included in the reflected light, and the second modulated signal includes the request message. The output operation of the request message can be performed during a preset period of time.
(48) In addition, the transmitting processor 16 can gradually increase the magnitude of the power light every time the request message is received. More specifically, the transmitting processor 16 can process the second modulated signal included in the reflected light to identify the request message and gradually increase the magnitude of the power light every time the request message is identified.
(49) Referring back to
(50) As the operation of transmitting the power and the operation of transmitting and receiving the signal have been described with reference to
(51) Further, when the message of the received power M.sub.r is not received for a preset period of time, the transmission module 10 can block the output of power light (Laser Off) (S40). Referring to
(52) Subsequently, the receiving processor 24 can control the retro-reflector 22 to enable the second modulated signal to be included in the reflected light and the second modulated signal includes the message of the receiver power M.sub.r. As the message of the received power M.sub.r is generated during the reference period of time T.sub.m, the second modulated signal including the message of the received power M.sub.r can also be output through the reflected light during the reference period of time T.sub.m (S31).
(53) In addition, the transmitting processor 16 can identify the message of the received power M.sub.r by processing the second modulated signal included in the reflected light, and continuously output the power light and the communication light when the message of the received power M.sub.r is identified. When the transmission module 10 and the reception module 20 are arrayed, the transmission module 10 can receive the message of the received power M.sub.r during a predetermined period of time Tr for which the message of the received power is received.
(54) As the second modulated signal including the message of the received power M.sub.r is output during the reference period of time T.sub.m, the message of the received power M.sub.r can be received at the transmitting module 10 during the same period of time T.sub.r for which the message of the received power is received.
(55) Further, when a change occurs in the position of the transmission module 10 or the reception module 20 and the above-described array state may not be maintained, the power light may not be received at the photoelectric cell 21 of the reception module 20, and accordingly, the receiving processor 24 may not generate the second modulated signal including the message of the received power M.sub.r. Further, when the array state is not maintained, even if the second modulated signal is generated, the reflected light including the second modulated signal may not be received at the transmission module 10.
(56) In addition, the transmission module 10 can compare the period of time T.sub.r for which the message of the received power M.sub.r is received with a preset time T.sub.ref (S32), and as a result of comparison, the transmission module 10 can block, when the period of time T.sub.r for which the message of the received power M.sub.r is received exceeds a preset time T.sub.ref, the output of the power light.
(57) Further, the preset time T.sub.ref may be set longer than the aforementioned reference period of time T.sub.m. When the message of the received power M.sub.r is not received within a preset period of time, the transmission module 10 can operate in the ping mode S10 described above to output communication light having the reference intensity. As the operation process after the ping mode S10 has been described above, a detailed description thereof is omitted.
(58) As described above, when the transmission module 10 and the reception module 20 do not maintain the array state, operation of determining the array state thereof is automatically performed through operation of blocking the output (S40) and in the ping mode (S10), thereby saving the energy and improving reliability in communication.
(59) The modulated signals output by the transmission module 10 and the reception module 20 are described below with reference to
(60) However, as described above, the reception module 20 outputs the reflected light including the second modulated signal by reflecting the communication light. In addition, the communication light may have a continuous output. Accordingly, the first modulated signal is preferably included in the communication light through the IM method.
(61) Referring to
(62) As described above, the second photodiode 23 of the reception module 20 can generate an electrical signal based on the intensity of the communication light, and the receiving processor 24 can identify the first modulated signal included in the communication light as 101001 based on the magnitude of the electrical signal. In addition, the reception module 20 can reflect the communication light through the on-off keying method and output the reflected light including the second modulated signal.
(63) Referring back to
(64) Accordingly, as shown in
(65) An optical wireless power transfer system 1 according to another embodiment of the present disclosure is described below in detail with reference to
(66) The transmission module 10 can output the main light including the first modulated signal and receive the reflected light generated by reflecting a portion of the main light, and process the second modulated signal included in the reflected light. Further, the transmission module 10 may include a processor that processes a signal and a single light source that outputs the main light.
(67) In addition, the reception module 20 can process the first modulated signal included in the main light and reflect a portion of the main light to output the reflected light, and may enable the second modulated signal to be included in the reflected light based on the power generated due to the main light. Further, the reception module 20 may include a processor that processes a signal, a reflector that reflects a portion of the main light, and an optical generator that generates power using the main light.
(68) Referring to
(69) The transmission module 10 and the reception module 20 shown in
(70) Basically, some of the components shown in
(71) However, as shown in
(72) In addition, each component included in the reception module 20 shown in
(73) Accordingly, light and paths of light different from those described in
(74) In the present disclosure, the main light may include both the power light and the communication light described with reference to
(75) The beam splitter 12 of the transmission module 10 can pass the main light. More specifically, the beam splitter 12 may be provided between the main light source 11 and the reception module 20 to pass a portion of incident light and reflect other portions of the incident light. Accordingly, the main light incident on the reception module 20 output by the main light source 11 passes through the beam splitter 12.
(76) Further, the transmitting processor 14 of the transmission module 10 can control the main light source 11 to enable the first modulated signal to be included in the main light. More specifically, the transmitting processor 14 can adjust the intensity of the main light and output the main light having the adjusted intensity to control the first modulated signal to be included in the main light.
(77) As a method of including the first modulated signal in the main light by adjusting the intensity of the light is the same as the method of including the first modulated signal in the communication light described with reference to
(78) Also, the regulator 26 can convert the power generated by the photoelectric cell 21 into a predetermined voltage and provide the receiving processor 24 with the predetermined voltage, and accordingly, the receiving processor 24 can receive the power based on the power generated by the photoelectric cell 21.
(79) In addition, the second photodiode 23 of the reception module 20 can convert a portion of the main light into an electrical signal. More specifically, the second photodiode 23 can receive a portion of the main light according to position thereof and convert the portion of the main light into the electrical signal. Then, the decoder 27 can convert the converted electrical signal into a digital signal and provide the receiving processor 24 with the converted digital signal.
(80) Further, the receiving processor 24 can identify the first modulated signal based on the electrical signal converted by the second photodiode 23 and process the identified first modulated signal. More specifically, the receiving processor 24 can identify the first modulated signal based on the intensity of the main light.
(81) As the method of identifying the first modulated signal based on intensity of the light has been described with reference to
(82) Also, the receiving processor 24 can control the retro-reflector 22 to enable the second modulated signal to be included in the reflected light based on the power generated by the photocell 21. As the method of including the second modulated signal in the reflected light is the same as the method described with reference to
(83) The beam splitter 12 of the above-described transmission module 10 can reflect the reflected light. More specifically, as shown in
(84) The first photodiode 13 can convert the reflected light reflected by the beam splitter 12 into the electrical signal based on the intensity of the light, and the converted electrical signal may be provided to the transmitting processor 14. The transmitting processor 14 can identify the second modulated signal included in the reflected light based on the electrical signal provided through the first photodiode 13 and can perform operation of processing various kinds of signals based on the identified second modulated signal.
(85) In addition, as shown in
(86) For example, referring to
(87) As described above, according to the present disclosure, wireless bidirectional communication is performed using the light, thereby increasing the possible distance to perform the communication between terminals. Further, according to the present disclosure, additional battery may not be mounted on the wireless terminal using the light as the power source, thereby reducing the volume and the weight of the terminal. Further, according to the present disclosure, the modulated signal may be transmitted and received through the light, thereby preventing the electromagnetic interference (EMI) generated by peripheral electronic devices.
(88) Various substitutions, modifications, and changes may be made within the scope that does not deviate from the technical idea of the present disclosure for the skilled person in the art to which the present disclosure pertains, the above-mentioned disclosure is not limited to the above-mentioned embodiment and the accompanying drawings.