Battery charger cradle

Patent metadata

Field	Value
Publication number	US-9312711-B2
Application number	US-201514807246-A
Country	US
Kind code	B2
Filing date	Jul 23, 2015
Priority date	Dec 18, 2007
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

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.

First claim

The invention claimed is:

1. A battery charger cradle for use with a battery built-in device having an induction coil and a battery that is rechargeable with power induced by the induction coil, the battery charger cradle comprising:
a top plate on which the battery built-in device can be placed;
a primary coil for inducing electromotive force to the induction coil of the battery built-in device placed on the top plate; and
a position detection controller for detecting a position of the induction coil and controlling the primary coil to emit an magnetic flux at a position corresponding to the detected position of the induction coil,
wherein the position detection controller includes:
a plurality of position detection coils arrayed along a surface of the top plate and covering substantially an entire region of the battery charger cradle on which the induction coil is to be placed;
a pulsed power source for supplying a pulse signal to one of the position detection coils;
a receiver circuit for receiving an echo signal output from the induction coil that 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.

2. The battery charger cradle according to claim 1 , wherein the position detection coils are arrayed in two directions along the surface of the plate.

3. The battery charger cradle according to claim 1 , wherein the position corresponding to the detected position of the induction coil is immediately under the position of the induction coil.

4. A battery charger cradle for use with a battery built-in device having an induction coil and a battery that is rechargeable with power induced by the induction coil, the battery charger cradle comprising:
a top plate on which the battery built-in device can beplaced;
a primary coil for inducing electromotive force to the induction coil of the battery built-in device placed on the toy plate; and
a position detection controller for detecting a position of the induction coil and controlling the primary coil to emit an magnetic flux at a position corresponding to the detected position of the induction coil,
wherein the position detection controller includes:
a plurality of position detection coils arrayed along a surface of the top plate;
a pulsed power source for supplying a pulse signal to one of the position detection coils;
a receiver circuit for receiving an echo signal output from the induction coil that is excited by the pulse signal;
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,

wherein the position detection coils are arrayed in two directions along the surface of the plate;
the battery charger cradle further comprising:
a full charge state detection circuit for detecting a full charge state of the battery, wherein:
the top plate is sized so as to allow a plurality of battery built-in devices to be placed thereon; and
when the full charge state detection circuit detects the full charge state of the battery contained in one of the battery built-in devices being subjected to a charging operation, a position of a non-charged battery built-in device incorporating a battery that is not fully charged is detected, and the primary coil is controlled to emit the magnetic flux at a position corresponding to the detected position of the non-charged battery built-in device for charging the battery contained in the non-charged battery built-in device.

5. The battery charger cradle according to claim 1 , further comprising an AC power source connected to the primary coil, the AC power source having a self-excited oscillation circuit, and the position detection controller detects the position of the induction coil on the basis of an oscillating frequency of the self-excited oscillation circuit to control the movement mechanism.

6. 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.

7. The battery charger cradle according to claim 2 , wherein the plurality of position detection coils include:
a first group of detection coils, each detection coil of the first group of detection coils forms a loop elongated in a first direction; and
a second group of detection coils, each detection coil of the second group of detection coils forms a loop elongated in a second direction that is orthogonal to the first direction.

8. The battery charger cradle according to claim 7 , 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.

9. The battery charger cradle according to claim 7 , 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.

10. 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.

11. 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.

12. 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.

13. 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 the position detection controller calculates the position of the induction coil on the basis of the detected level of the echo signal using the function.

Assignees

• Panasonic Corp

Inventors

• Toya Shoichi
• Mizoguchi Yasunari
• Satsuma Eiji
• Terao Kyozo

Classifications

• H02J7/751

  concerning the insertion or the connection of the batteries · CPC title

• H02J7/70 Primary

  characterised by the mechanical construction · CPC title

• H02J50/90

  involving detection or optimisation of position, e.g. alignment · CPC title

• H02J50/60

  responsive to the presence of foreign objects, e.g. detection of living beings · CPC title

• H02J50/12

  of the resonant type · CPC title