JP2007006558A - Power transferring system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transferring system and a method for safely transferring power as a high-intensity light is propagated in an open space. <P>SOLUTION: A power receiving apparatus 40 as a portable device includes a light receiver 42, a corner cube reflector (CCR) 44 for a position measurement of the light receiver 42, and a secondary battery (48) charged by an electrical signal output from the light receiver 42. A scanning laser ranging apparatus 50 measures a distance and an angle between the light receiver (42) by a reflection from the CCR 44. A position calculator 54 calculates a position of the light receiver 42. A control circuit 24 in a power transferring apparatus 10 irradiates the light receiver 42 with a low-intensity light in accordance with position data from the position calculator 54. The low-intensity light is reflected by the CCR 44, and enters into a light receiver 22. The control circuit 24 makes a laser diode 12 output the high-intensity light when an output from the light receiver 22 is a predetermined level or more. The high-intensity light enters into the light receiver 42. The portable device is simply charged. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission system and method, and more particularly, to a system and method 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. It is sufficient if a laser can be used, but it is dangerous to propagate in space.

  An object of the present invention is to provide a power transmission system and method capable of safely transmitting power while propagating high-intensity light in an open space.

  The power transmission system according to the present invention includes a power receiving device, a measuring device, and a power transmitting device. The power receiving device includes a light receiver, a reflector for measuring the position of the light receiver, and a secondary battery charged by an output electric signal of the light receiver. The measuring device scans the existence range of the power receiving device with laser light, and measures the position of the light receiving device with the reflected light of the reflector. The power transmission device supplies power to the power receiving device by irradiating the light receiver of the power receiving device with high-intensity light according to the measurement result of the measuring device. Then, the power transmission device includes a light emitting element that can selectively output high-intensity light and low-intensity light, a second light receiver that receives reflected light from the reflector, a measurement result of the measurement device, and the first And a control circuit for controlling the output luminance of the light emitting element and the direction of light emitted from the power transmission device according to the output of the two light receivers. The control circuit causes the light emitting element to output low luminance light according to information indicating the position of the light receiver from the measurement device, and the output light level of the second light receiver with respect to the low luminance light is equal to or higher than a predetermined value. In this case, the high-intensity light is output to the light-emitting element.

  In the power transmission method according to the present invention, first, the position of a power receiving device including a light receiver, a reflector for measuring the position of the light receiver, and a secondary battery charged by an output electric signal of the light receiver is scanned. Measured with a type laser ranging device. In accordance with information indicating the position of the light receiver from the measurement device, the power transmission device irradiates the light receiver of the power reception device with low-intensity light. The power transmission apparatus receives the reflected light of the low-intensity light from the reflector. Then, when the light intensity of the received reflected light is equal to or higher than a predetermined level, the power transmission device irradiates the light receiver of the power reception device with high luminance light.

  ADVANTAGE OF THE INVENTION According to this invention, electric power can be easily supplied to a power receiving apparatus, without the effort of a cable connection. In addition, power can be transmitted safely and in a short time.

  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.

  The present embodiment includes a power transmission device 10, a power reception device 40, and a scanning laser distance measuring device 50 that measures a three-dimensional position of the power reception device 40.

  The power receiving device 40 is a mobile device, for example, a mobile phone. The power receiving device 40 includes a light receiver 42 composed of four-divided light receiving elements, a corner cube reflector (CCR) 44 disposed in the center of the light receiver 42, a secondary battery 48, and electrical energy output from the light receiver 42. And a charging circuit 46 for charging the secondary battery 48. The number of light receiving elements constituting the light receiver 42 is an example, and may be 5 or more or less than 3. Although details will be described later, the scanning laser distance measuring device 50 can three-dimensionally measure the position of the light receiving element 42 of the power receiving device 40 by the CCR 44. The power transmission device 10 can confirm that the power transmission laser light is incident on the light receiving element 42 by the CCR 44.

  The scanning laser distance measuring device 50 scans a laser beam in a plane like the scanning pattern 52 within a range where the power receiving device 40 is supposed to be placed, and reflects the reflected light (here, the power receiving device 40). This is a device that measures the distance L to CCR 44) and the angles θ and φ orthogonal to each other in polar coordinates with the scanning laser distance measuring device 50 as the center. Since the CCR 44 is arranged at the center of the light receiver 42 of the power receiving device 40, the three-dimensional position measurement of the power receiving device 40 by the scanning laser distance measuring device 50 is facilitated.

  In the present embodiment, when the user places the power receiving device 40 in the scanning range of the scanning laser distance measuring device 50, the output laser light of the scanning laser distance measuring device 50 is reflected by the CCR 44 of the power receiving device 40 and scanned. Return to the laser distance measuring device 50. The scanning laser distance measuring device 50 measures the distance L and the angles θ and φ from the reflected light to the CCR 44 of the power receiving device 40. The position calculating device 54 determines the three-dimensional position coordinates x, y, z of the CCR 44 of the power receiving device 40 from the distance data L and the angle data θ, φ from the scanning laser distance measuring device 50 according to a known coordinate conversion formula. Then, the three-dimensional position coordinates x, y, z are supplied to the control circuit 24 of the power transmission device 10.

  Since the object of the present embodiment is to supply power from the power transmission device 10 to the light receiver 42 of the power reception device 40 with a thin beam and high power laser light, the position calculation device 54 receives power received from the power transmission device 10. The direction or direction and distance of the device 40 may be supplied to the control circuit 24 of the power transmission device 10. Further, the three-dimensional position coordinates output from the position calculation device 54 are preferably relative values with respect to the power transmission device 10. This is because it is easy to determine the direction of laser irradiation from the power transmission device 10.

  The laser diode 12 of the power transmission device 10 can control the output power, and is driven by the drive circuit 14 to output low power or high power laser light. The output laser light from the laser diode 12 is converted into a parallel beam having a smaller beam diameter or a narrow beam by the lens 16, further reflected by the half mirror 18, and emitted to the outside of the power transmission device 10.

  When the laser beam output from the power transmission apparatus 10 enters the CCR 44, the reflected light of the CCR 44 enters the half mirror 18 of the power transmission apparatus 10 due to the characteristics of the CCR 44. The half mirror 18 partially transmits the reflected light from the CCR 44 of the power receiving device 40. The reflected light that has passed through the half mirror 18 enters the light receiver 22 through the lens 20. The light receiver 22 converts the reflected light into an electrical signal and applies the electrical signal to the control circuit 24.

  In the present embodiment, the laser diode 12, the lens 16, the half mirror 18, the lens 20, and the light receiver 22 are connected to a common base 30 (in order to direct the output laser light of the power transmitting device 10 to the power receiving device 40 whose three-dimensional position is measured. Fig. 2) fixed on top. Then, the optical axis deflecting device 26, in accordance with instructions from the control circuit 24, causes the table 30 to be driven in two directions orthogonal to each other (for example, two directions of pan in the horizontal plane and tilt in the vertical plane) by the motors 32a and 32b. Rotate the specified angle. Thereby, the laser beam can be deflected in a desired direction. Of course, the optical axis may be deflected in a desired direction by an optical mechanism.

  When the control circuit 24 receives the data indicating the three-dimensional position of the power receiving device 40 from the position calculating device 54, the control circuit 24 has a low power level from the laser diode 12 by the drive circuit 14, that is, a power level small enough to be harmless to human eyes. The laser beam is emitted and the optical axis deflecting device 26 is controlled to direct the output laser beam to the light receiver 42 of the power receiving device 40. The lens 16 is installed such that the beam diameter of the output laser beam is substantially the same size as the light receiver 42 within the assumed distance range to the power receiving device 40.

  The light receiver 42 converts the laser light from the power transmission device 10 into electrical energy, and the CCR 44 reflects the laser light from the power transmission device 10. However, the laser power at this stage is insufficient for charging. The reflected light of the CCR 44 passes through the half mirror 18 and the lens 20 and enters the light receiver 22 as described above. The light receiver 22 converts the reflected light into an electric signal and applies it to the control circuit 24.

  The control circuit 24 compares the output electric signal level of the light receiver 22 with a predetermined threshold value. When the output electric signal level of the light receiver 22 is less than the predetermined threshold value, the control circuit 24 continues to control the optical axis deflecting device 26 according to the three-dimensional position data from the position calculating device 54. That is, the search and tracking of the power receiving device 40 is continued.

  When the output electric signal level of the light receiver 22 is equal to or greater than a predetermined threshold, the control circuit 24 can determine that the output laser is substantially incident on the center of the light receiver 42 of the power receiving device 40. In this case, the control circuit 24 controls the drive circuit 14 to output laser light of high power, for example, several tens mW to several W from the laser diode 12. This high-power laser beam is reflected by the half mirror 18 and enters the light receiver 42 of the power receiving device 40. The light receiver 42 converts the laser light from the power transmission device 10 into electrical energy. At this time, the output electric energy of the light receiver 42 is sufficient for charging the secondary battery 48, and the charging circuit 46 charges the secondary battery 48 with the output electric energy of the light receiver 42.

  While outputting high-power laser light, the control circuit 24 controls the direction of the output laser beam by the optical axis deflecting device 26 according to the three-dimensional position data from the position calculating device 54. That is, in this embodiment, the laser beam emission direction from the power transmission device 10 is feedback controlled so as to track the power reception device 40.

  When a high-power laser beam is output for a certain period of time, the control circuit 24 lowers the output laser power of the laser diode 12 to a low level by the drive circuit 14, that is, a level that is harmless to human eyes, Alternatively, the laser output is stopped. This completes the temporary charging.

  If the output electrical level of the light receiver 22 becomes less than a predetermined threshold before the time for completion of charging has elapsed, for safety, the control circuit 24 temporarily outputs the output laser power of the laser diode 12 by the drive circuit 14. Is lowered to a low level, and the adjustment of the optical axis with reference to the three-dimensional position data from the position calculation device 54 is continued, and the output electric level of the light receiver 22 is waited for a predetermined threshold value or more. When the output electrical level of the light receiver 22 becomes equal to or higher than a predetermined threshold value, high-power laser output is resumed.

  When the three-dimensional position data indicating the position of the power receiving device 40 is not input from the position calculation device 54, the control circuit 24 stops the laser output.

  This embodiment is embodied as follows, for example. In other words, the power transmission device 10 and the scanning laser distance measuring device value 50 are arranged above the table on which the mobile phone serving as the power receiving device 40 is placed. The scanning laser distance measuring device value 50 is installed so as to search for the power receiving device 40 that will be placed on the table, and the scanning condition / range and the like are set. When the user places the power receiving device 40 on the table with the light receiver 42 facing upward, the power transmitting device 10 emits a high-power and narrow beam of laser light toward the light receiving element 42 of the power receiving device 40.

  In the present embodiment, in order for the user to charge the secondary battery of the power receiving device 40, it is only necessary to appropriately place the mobile phone serving as the power receiving device 40 within a certain range, and the user convenience 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.

  In the present embodiment, the scanning laser distance measuring device 50 measures the position of the power receiving device 40 three-dimensionally, but it is obvious that the measurement can be omitted for the obvious dimension. For example, when it is clear that the light receiver 42 is on a certain surface, the measurement of coordinate values related to that surface can be omitted.

  In the above-described embodiment, power is transmitted with high-power light that is narrowed down while the power receiving device is recognized, so that high power can be transmitted in a short time, and the safety of the surrounding human eyes is also achieved. Can do.

  For example, mobile phones having an electronic money function are generally available. By incorporating the function of the power receiving device 40 into such a portable device with an electronic money function, it is possible to charge the secondary battery of the portable device when depositing or paying the electronic money, increasing the convenience for the user. .

  Also, by providing the power transmission device of the present embodiment near the information box, the building entrance through which people pass, or the station ticket gate, the user can easily charge the secondary battery of the portable device. A store that has installed facilities can be expected to attract customers.

  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.

Explanation of symbols

10: Power transmission device 12: Laser diode 14: Drive circuit 16: Lens 18: Half mirror 20: Lens 22: Light receiver 24: Control circuit 30: Base 32a: Pan motor 32b: Tilt motor 40: Power reception device 42: Light receiver 44: Corner cube reflector (CCR)
46: charging circuit 48: secondary battery 50: scanning laser distance measuring device 52: scanning pattern or range 54: position calculating device

Claims (5)

A power receiving device including a light receiver (42), a reflector (44) for measuring the position of the light receiver (42), and a secondary battery (48) charged by an output electric signal of the light receiver (42). (40)
A measuring device (50, 54) that scans the existence range of the power receiving device (40) with a laser beam and measures the position of the light receiving device (42) by the reflected light of the reflector (44);
A power transmission device (10) that supplies power to the power receiving device by irradiating the light receiver (42) of the power receiving device (40) with high-intensity light according to the measurement result of the measuring device (50, 54).
A power transmission system comprising:
The power transmission device (10) includes a light emitting element (12) that can selectively output high-intensity light and low-intensity light, a second light receiver (22) that receives light reflected by the reflector, and the measurement. A control circuit (24) for controlling the output luminance of the light emitting element and the direction of light emitted from the power transmission device (10) according to the measurement result of the device (50, 54) and the output of the second light receiver (22). And
The control circuit (24) causes the light emitting element (12) to output low luminance light in accordance with information indicating the position of the light receiver (42) from the measuring device (50, 54), and to the low luminance light. The power transmission system, wherein when the output light level of the second light receiver is equal to or higher than a predetermined value, the light emitting element (12) outputs the high luminance light.   The power transmission device (10) outputs the output light of the light emitting element (12) to the outside, and the reflected light from the reflector (44) of the power reception device (40) is the second light receiver (22). The power transmission system according to claim 1, further comprising a half mirror (18) facing toward the center.   The power transmission system according to claim 1 or 2, wherein the power receiving device is a mobile phone.   The measuring device (50, 54) scans the existence range of the power receiving device (42) with laser light, and measures the distance to the reflector and the scanning angle by the reflected light of the reflector (44). 2. A laser beam distance measuring device (50), and a position calculation device (54) for calculating the position of the light receiver (42) from the measurement value of the scanning laser beam distance measuring device. 4. The power transmission system according to any one of items 1 to 3. A power receiving device including a light receiver (42), a reflector (44) for measuring the position of the light receiver (42), and a secondary battery (48) charged by an output electric signal of the light receiver (42). The position of the light receiver (42) of (40) is measured by the scanning laser distance measuring device (50),
In accordance with the information indicating the position of the light receiver (42) from the measurement device (50, 54), the power transmission device irradiates the light receiver (42) of the power reception device (40) with low luminance light,
The power transmission device receives the reflected light of the low-intensity light from the reflector,
A power transmission method, wherein when the light intensity of the received reflected light is equal to or higher than a predetermined level, the power transmission device irradiates the light receiver (42) of the power reception device (40) with high-intensity light.

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