# US 8,786,252 B2 · Battery charger cradle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,252 B2 - Document ID: US8786252B2 - Status: Granted - Kind: B2 - Application number: 14/041,289 - Filed: 2013-09-30 - Published: 2014-01-30 - Granted: 2014-07-22 - Earliest claimed: 2007-12-18 - Assignees: Panasonic Corporation - Applicants: Panasonic Corporation - Inventors: Shoichi Toya; Yasunari Mizoguchi; Eiji Satsuma; Kyozo Terao - Web page: https://patentgrep.com/patent/US8786252B2 ## CPC - H02J 7/70: characterised by the mechanical construction - H02J 7/751: {concerning the insertion or the connection of the batteries} - H02J 50/10: using inductive coupling - H02J 50/12: of the resonant type - H02J 50/60: responsive to the presence of foreign objects, e.g. detection of living beings - H02J 50/80: involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices - H02J 50/90: involving detection or optimisation of position, e.g. alignment - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY ## Abstract In a battery charger cradle, a battery incorporated in a battery built-in device is charged by electric power induced to an induction coil. The cradle includes a primary coil for inducing electromotive force to the induction coil, a casing having a top plate atop of which the battery built-in device is placed, a movement mechanism for moving the primary coil along an inner surface of the top plate, and a position detection controller for detecting a position of the battery built-in device placed on the top plate and controlling the movement mechanism to bring the primary coil closer to the induction coil in the battery built-in device. When the battery built-in device is placed on the top plate, the position detection controller detects the position of the battery built-in device, and the movement mechanism moves the primary coil closer to the induction coil in the battery built-in device. ## Claims ### Claim 1 A battery charger cradle designed to be used with a battery built-in device having an induction coil and a battery rechargeable with power induced by the induction coil, the battery charger cradle comprising: a primary coil for inducing electromotive force to the induction coil; a movement mechanism for moving the primary coil; and a position detection controller for detecting a position of the induction coil and controlling the movement mechanism to bring the primary coil closer to the induction coil, wherein the position detection controller includes: a plurality of position detection coils; a pulsed power source for supplying a pulse signal to one of the position detection coils; a receiver circuit for receiving an echo signal outputted to the position detection coils from the induction coil which is excited by the pulse signal; and a discrimination decision circuit for detecting a level of the echo signal received by the receiver circuit and judging the position of the induction coil on the basis of the level of the echo signal. ### Claim 2 (depends on 1) The battery charger cradle according to claim 1, wherein the movement mechanism moves the primary coil in at least one of X axis and Y axis directions. ### Claim 3 (depends on 1) The battery charger cradle according to claim 1, wherein, when detecting a waveform other than a waveform of the echo signal, the discrimination decision circuit stops supplying power to the primary coil. ### Claim 4 (depends on 2) The battery charger cradle according to claim 2, wherein, when detecting a waveform other than a waveform of the echo signal, the discrimination decision circuit stops supplying power to the primary coil. ### Claim 5 (depends on 1) The battery charger cradle according to claim 1, wherein the plurality of position detection coils include a first group of detection coils, each detection coil of the first group of detection coils being of a loop elongated in a first direction. ### Claim 6 (depends on 5) The battery charger cradle according to claim 5, wherein the plurality of position detection coils further include a second group of detection coils, each detection coil of the second group of detection coils being of a loop elongated in a second direction orthogonal to the first direction. ### Claim 7 (depends on 5) The battery charger cradle according to claim 5, wherein a distance between adjacent position detection coils in the first group of detection coils is set to be smaller than an outer diameter of the induction coil. ### Claim 8 (depends on 6) The battery charger cradle according to claim 6, wherein a distance between adjacent position detection coils in the second group of detection coils is set to be smaller than an outer diameter of the induction coil. ### Claim 9 (depends on 1) The battery charger cradle according to claim 1, wherein the position detection controller further includes a switching circuit for switching each of the position detection coils to connect with the receiver circuit, wherein an input into the receiver circuit is switched one after another to be connected with the plurality of position detection coils. ### Claim 10 (depends on 1) The battery charger cradle according to claim 1, wherein the position detection controller further includes a switching circuit for switching and connecting an output side of the pulsed power source to one of the position detection coils, wherein the pulsed power source is switched to the one of position detection coils to output the pulse signal. ### Claim 11 (depends on 1) The battery charger cradle according to claim 1, wherein the position detection controller further includes a memory circuit for storing a level of the echo signal induced to each of the position detection coils with respect to the position of the induction coil, and compares the detected level of the echo signal with the level of the echo signal stored in the memory circuit. ### Claim 12 (depends on 1) The battery charger cradle according to claim 1, wherein the position detection controller further includes a memory circuit for storing a function specifying the position of the induction coil, and calculates the position of the induction coil on the basis of the detected level of the echo signal using the function.