JP2008245404A - Power transmitting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit power in space from transmission equipment to reception equipment. <P>SOLUTION: A laser diode (12) selectively outputs a low-power dummy beam for detection of reception equipment and a high-power laser beam for transmission. The output laser beam of the laser diode (12) is emitted out of the transmission equipment (10), with its beam spread adjusted by a lens (16). Four corner cube reflectors (CCR) (44-50) arranged around a light receiving element (42) reflect the dummy beams for detection of reception equipment from the transmission equipment (10). A controller (30) adjusts the focus of the lens (16), following the reflected beam from the reception equipment (40), and controls the direction of laser emission by an optical axis deflector (32). After these adjustment, the controller (30) outputs a laser beam for transmission from the laser diode. The receiving element (42) of the reception equipment (40) receives the laser beam for transmission from the transmission equipment (10) and converts it into electric energy. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power transmission method and system, and more specifically, to a method and system for transmitting power by light.

  Photoelectric conversion elements or light receiving elements such as solar cells are also elements that convert light energy into electrical energy. Various illumination devices such as the sun and fluorescent lamps, and light emitting elements such as lasers and light emitting diodes can be used as the light source.

In order to transmit a large amount of power in a short time, it is necessary to either increase the brightness of the output light of the light source or increase the light receiving area of the light receiving element. However, when using a high-luminance light source, it is necessary to ensure safety, so it is difficult to use in an open space. Usually, the shape and structure of the light receiving optical system are devised (Patent Document 1).
Japanese Patent Laid-Open No. 2004-165581

  When trying to transmit a large amount of power, it is inevitable to increase the output of the light source. A laser can be used, but it is dangerous to propagate in space.

  An object of this invention is to show the power transmission system which can transmit electric power safely, propagating high-intensity light in open space.

  A power transmission system according to the present invention is a power transmission system that spatially transmits power from a power transmission device to a power reception device, and the power transmission device includes a wide beam divergence and low power reception device detection dummy light and a narrow beam. A laser emitting device capable of selectively outputting a high-power laser beam for power transmission, an optical axis deflecting device capable of deflecting the emitting direction of the output laser beam of the laser emitting device, and the power receiving of the dummy light for detecting the power receiving device A control device for controlling the optical axis deflecting device according to the reflected light from the device, the power receiving device reflecting the power receiving device detection dummy light from the power transmitting device in the incident direction, and And a light receiver that photoelectrically converts the laser beam for power transmission from the power transmission device.

  According to the present invention, power can be spatially transmitted from a power transmitting device to a power receiving device with high efficiency by laser light.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic block diagram of an embodiment of the present invention, and FIG. 2 shows a perspective view of an optical system of this embodiment.

  In the present embodiment, the power transmission device 10 emits a low-power dummy light (power reception device detection dummy light) with a wide beam divergence angle in accordance with a predetermined operation of the user instructing the start of power supply. Check existence and direction. When the presence and direction of the power receiving device 40 can be confirmed, the power transmitting device 10 is directed toward the light receiving unit of the power receiving device 40 that has been confirmed with a high beam, for example, several tens of mW to a thin beam having an area of the light receiving unit. Several W of laser light (power transmission laser light) is emitted. Although details will be described later, the power transmission device 10 includes means for deflecting the emission direction of the power transmission laser light in two directions orthogonal to each other, for example, two directions in a horizontal plane and a vertical plane.

  The laser diode 12 can control the output power, and is driven by the drive device 14 to output a low-power receiving device detection dummy light or a high-power power transmission laser beam. The output laser beam of the laser diode 12 is adjusted in beam divergence by the lens 16, further reflected by the half mirror 18, and emitted outside the power transmission device 10. At this stage, the focus control device 20 adjusts the focus of the lens 16 so that the power transmission device 10 outputs the power receiving device detection dummy light 12a having a wide beam divergence angle to the outside. For example, the focus control device 20 controls the lens 16 to a defocused state.

  The power receiving device 40 is a mobile device, for example, a mobile phone, and receives a laser beam for power transmission from the power transmitting device 10 and converts it into electric energy, and four corners arranged around the light receiving device 42. Cubic reflectors (CCR) 44, 46, 48, 50 are provided. As is well known, the CCRs 44, 46, 48, and 50 are reflectors that reflect incident light as it is in the incident direction. In this embodiment, the CCRs 44, 46, 48, and 50 are installed to reflect power reception device detection dummy light from the power transmission device 10. The The light receiving element 42 and the four CCRs 44, 46, 48, 50 are arranged such that the light receiving element 42 is located at a position where a line connecting the CCR 44 and the CCR 48 intersects a line connecting the CCR 46 and the CCR 50. As will be described later, in the present embodiment, the position of the light receiving element 42, more specifically, the direction viewed from the power transmission device 10, is specified by the reflected light of the CCRs 44, 46, 48, 50, so the CCR 44 and the CCR 48 are connected. The line and the line connecting the CCR 46 and the CCR 50 are preferably orthogonal to each other.

  When the power receiving device detection dummy light from the power transmission device 10 enters the CCR 44, 46, 48, 50, the CCR 44, 46, 48, 50 reflects the dummy light toward the power transmission device 10. A portion of the reflected dummy light passes through the half mirror 18 and enters the image sensor 24 via the lens 22.

  The image sensor 24 outputs an image signal including reflected light from the CCRs 44, 46, 48 and 50. The image display device 26 displays the image signal output from the image sensor 24 as an image. Further, the image processing / recognition device 28 detects the position and spot size of the reflected light from the CCR 44, 46, 48, 50 from the output image signal of the image sensor 24, and supplies the detection result to the control device 30. The control device 30 causes the focus control device 20 to adjust the focus of the lens 22 so that the spot size of the reflected light from the image processing / recognition device 28 is minimized, that is, so that the power receiving device 42 is in focus. By this adjustment, the positions of the CCRs 44, 46, 48, and 50 can be specified within the imaging field of the imaging device 24. The operator or user can confirm from the display image of the image display device 26 whether or not the power transmission device 10 appropriately irradiates the power reception device 40 with the power transmission laser light.

  The control device 30 changes the emission direction of the dummy light 12 a so that the centers of the four reflected spots of the CCRs 44, 46, 48 and 50 are located in the center in the imaging field of the imaging device 24. In order to adjust the optical axis, in this embodiment, the laser diode 12, the lens 16, the half mirror 18, the lens 22, and the image sensor 24 of the power transmission device 10 are installed on a common base 34 (FIG. 2). . The optical axis deflecting device 32 rotates the table 34 in two directions orthogonal to each other (for example, two directions of pan in a horizontal plane and tilt in a vertical plane) in accordance with an instruction from the control device 30. With this operation, the optical axis deflecting device 32 can direct the optical axis of the emitted laser light emitted from the power transmitting device 10 toward the light receiving element 42 of the power receiving device 40. As shown in FIG. 2, the optical axis deflecting device 32 includes a motor 34a for panning and a motor 34b for tilting. Of course, the optical axis may be deflected in a desired direction by an optical element.

  When the optical axis of the emitted laser light is aligned with the light receiving element 42 of the power receiving device 40, the control device 30 causes the power transmission device 10 to emit power transmission laser light having a narrow beam divergence angle and the focus control device. 20 is controlled. Specifically, the driving device 14 emits high-power laser light from the laser diode 12, and the focus control device 20 is such that the output laser light from the power transmission device 10 is incident on the light receiving element 42 of the power receiving device 40. For example, the focus of the lens 16 is controlled so as to focus on the light receiving element 42 of the power receiving device 10. As a result, a high-power thin beam of laser light is incident on the light receiving element 42, and the laser beam does not enter the eyes of the surrounding people.

  The light receiving element 42 converts the energy of the laser beam for power transmission from the power transmission device 10 into electric energy. The charging device 52 charges the secondary battery 54 with the output electric energy of the light receiving element 42.

  When the state of emitting power transmission laser light continues for a predetermined time, the control device 30 reduces the output power of the laser diode 12 and widens the divergence angle of the laser beam output to the outside. That is, the power supply to the power receiving device 40 is stopped. Of course, the power transmission device 10 may completely stop the output of the laser beam. In this case, according to the user's predetermined operation, the power transmission device 10 outputs the power reception device detection dummy light, searches for the power reception device 40, and if the power reception device 40 is found, as described above. A laser beam is emitted.

  The spreading of the power receiving device detection dummy light is preferably approximately the same as the field of view of the imaging element 24 at the assumed distance between the power transmitting device 10 and the power receiving device 40.

  The CCR position and number may be set so that the center of the light receiving element can be determined from the CCR position. Examples of CCR arrangement are shown in FIGS. FIG. 3 shows an example in which one CCR 44 a is arranged at the center of the light receiving element 42. FIG. 4 shows an example in which one CCR 44b and 46b are arranged on the left and right of the light receiving element 42, respectively. FIG. 5 shows an example in which three CCRs 44 c, 46 c, and 48 c are arranged at equal angles around the light receiving element 42. FIG. 6 shows an example in which four CCRs 44d, 46d, 48d, and 50d are arranged at an equal angle around the light receiving element. FIG. 7 shows an example in which a CCR 50 e is arranged at the center of the light receiving element 42 in addition to the configuration shown in FIG. 6.

  Although the embodiment in which the single light receiving element 42 is used for power reception has been described, a plurality of light receiving elements may be juxtaposed. 8 to 11 show examples of a configuration in which a plurality of light receiving elements are juxtaposed. FIG. 8 shows a configuration example in which two light receiving elements 42a and 42a are arranged side by side. FIG. 9 shows a configuration example in which three light receiving elements 42b, 42b, and 42b are arranged side by side. FIG. 10 shows a configuration example in which four light receiving elements 42c, 42c, 42c, and 42c are arranged in a 2 × 2 matrix. FIG. 11 shows a configuration example in which a large number of light receiving elements 42d are arranged in a matrix.

  The above-described embodiment is embodied as follows, for example. In other words, the power transmission device 10 is disposed above a table on which a mobile phone serving as the power receiving device 40 is placed. When the user places the power receiving device 40 on the table with the light receiving element 42 facing upward, the power transmitting device 10 automatically recognizes the position of the power receiving device 40, and transmits the laser beam for power transmission to the light receiving element 42 of the power receiving device 40. Irradiate correctly. The user only needs to appropriately place the mobile phone serving as the power receiving device 40 within a certain range, and the usability of the user is improved.

  Although the embodiment using the laser diode as the light source has been described, a high-intensity light emitting diode may be used.

  Although the invention has been described with reference to specific illustrative embodiments, various modifications and alterations may be made to the above-described embodiments without departing from the scope of the invention as defined in the claims. This is obvious to an engineer in the field to which the present invention belongs, and such changes and modifications are also included in the technical scope of the present invention.

It is a schematic block diagram of the first embodiment of the present invention. It is a schematic block diagram of the optical system of the Example shown in FIG. It is an example of arrangement | positioning of CCR. It is an example of arrangement | positioning of CCR. It is an example of arrangement | positioning of CCR. It is an example of arrangement | positioning of CCR. It is an example of arrangement | positioning of CCR. It is the example of arrangement | positioning of the light receiving element in the case of using a some light receiving element. It is the example of arrangement | positioning of the light receiving element in the case of using a some light receiving element. It is the example of arrangement | positioning of the light receiving element in the case of using a some light receiving element. It is the example of arrangement | positioning of the light receiving element in the case of using a some light receiving element.

Explanation of symbols

10: Power transmission device 12: Laser diode 12a: Dummy light for detecting power reception device 14: Drive device 16: Lens 18: Half mirror 20: Focus control device 22: Lens 24: Image sensor 26: Image display device 28: Image processing / recognition Device 30: Control device 32: Optical axis deflection device 34: Stand 34a: Pan motor 34b: Tilt motor 40: Power receiving device 42: Light receiving elements 44, 46, 48, 50: Corner cube reflector (CCR)
52: Charging device 54: Secondary battery

Claims (4)

A power transmission system for spatially transmitting power from a power transmission device to a power reception device,
The power transmission device
A laser emitting device (12, 16) capable of selectively outputting a power receiving device detection dummy light with a wide beam divergence angle and a high power power transmission laser light with a narrow beam;
An optical axis deflecting device (32) capable of deflecting the emitting direction of the output laser beam of the laser emitting device;
A control device (30) for controlling the optical axis deflecting device according to the reflected light from the power receiving device of the power receiving device detection dummy light
And
The power receiving device is
A reflector (44, 46, 48, 50) for reflecting the power receiving device detection dummy light from the power transmitting device in the incident direction;
Photoreceiver (42) that photoelectrically converts the laser beam for power transmission from the power transmission device
An electric power transmission system comprising:   The laser emitting device includes a laser generator (12) capable of selecting an output power and a beam adjusting device (16, 20) for adjusting the beam spread of the output laser light of the laser generator. Power transmission system.   The said power receiving apparatus is further equipped with the secondary battery (54) and the power receiving apparatus 52 which charges the said secondary battery according to the output electric signal of the said light receiver (42), The characterized by the above-mentioned. The power transmission system described in 1. The power transmission system according to any one of claims 1 to 3, wherein the reflector includes one or more corner cube reflectors (44, 46, 48, 50).

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