Magnetic sheet for non-contact power receiving device, non-contact power receiving device, electronic apparatus, and non-contact charger

• US 9,443,648 B2
• Filed: 05/07/2014
• Issued: 09/13/2016
• Est. Priority Date: 11/08/2011
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Inventors: Nagasaki, Kiyoshi, Sawa, Takao, Yamada, Katsuhiko, Saito, Tadao
• Primary Examiner(s): WILLIAMS, ARUN C
• Application Number:
  US14/271,780
• Publication Number:
  US 20140239892A1
• Time in Patent Office: 860 Days
• Field of Search: 320/108
• US Class Current: 1/1
• CPC Class Codes: H01F 2017/0066 with a magnetic layer
• CPC Class Codes: H01F 27/245 made from sheets, e.g. grain-oriented H01F27/26 takes precedence
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/361 made of combinations of electrically conductive material and ferromagnetic material
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• CPC Class Codes: H01F 3/02 made from sheets
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01F 7/0247 Orientating, locating, transporting arrangements
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: Y10T 428/24314 Slit or elongated
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A magnetic sheet of an embodiment includes a laminate of a plurality of magnetic thin plates. The laminate constituting the magnetic sheet includes a first magnetic thin plate and a second magnetic thin plate different in kind from the first magnetic thin plate. The first magnetic thin plate has a magnetostriction constant exceeding 5 ppm in an absolute value, and the second magnetic thin plate has a magnetostriction constant of 5 ppm or less in an absolute value. Alternatively, the first magnetic thin plate has a thickness of from 50 to 300 μm, and the second magnetic thin plate has a thickness of from 10 to 30 μm.

Claims

1. A magnetic sheet for non-contact power receiving device, comprising:

a laminate including a first magnetic thin plate and a second magnetic thin plate laminated to the first magnetic thin plate via an adhesive layer portion,

wherein the first magnetic thin plate is made of a stainless steel, and has a thickness of from 50 μ

m to 300 μ

m,

wherein the second magnetic thin plate is made of a Co-based amorphous alloy or an Fe-based microcrystalline alloy having an average crystal grain diameter of from 5 nm to 30 nm, and has a thickness of from 10 μ

m to 30 μ

m, and

wherein the magnetic sheet is configured to be used for the non-contact power receiving device.

2. The magnetic sheet according to claim 1,

wherein the first magnetic thin plate has a magnetostriction constant exceeding 5 ppm in an absolute value and the second magnetic thin plate has a magnetostriction constant of 5 ppm or less in an absolute value.

3. The magnetic sheet according to claim 2,

wherein the first magnetic thin plate has the magnetostriction constant exceeding 5 ppm to 30 ppm or less in the absolute value, and

wherein the second magnetic thin plate has the magnetostriction constant of 2 ppm or less (including zero) in the absolute value.

4. The magnetic sheet according to claim 2,

wherein the laminate includes the one or more to four or less first magnetic thin plate(s) and the one or more to four or less second magnetic thin plate(s).

5. The magnetic sheet according to claim 2,

wherein the first magnetic thin plate has an electric resistance value of 80 μ

Ω

cm or more.

6. The magnetic sheet according to claim 2,

wherein the first magnetic thin plate has a saturation magnetic flux density of from 1 to 2.1 T.

7. The magnetic sheet according to claim 1,

wherein at least one of the first and second magnetic thin plates is provided with a incision portion with a width of 1 mm or less (including 0), and

wherein a ratio (B/A) of a total length B of the incision portion(s) in relation to a total outer peripheral length A of outer peripheral regions of the magnetic thin plate(s) disposed on the same plane is in a range of 2 to 25.

8. The magnetic sheet according to claim 7,

wherein the laminate has the two or more magnetic thin plates different in the ratio (B/A) of the total length B of the incision portion(s) in relation to the total outer peripheral length A of the magnetic thin plate.

9. A non-contact power receiving device, comprising:

a power receiving coil including a spiral coil;

a rectifier rectifying an alternating voltage generated in the power receiving coil;

a secondary battery to which a direct-current voltage rectified by the rectifier is charged; and

a magnetic sheet according to claim 1, disposed in at least one of places between the spiral coil and the secondary battery and between the spiral coil and the rectifier.

10. An electronic apparatus comprising:

a non-contact power receiving device comprising;

a power receiving coil including a spiral coil;

a rectifier rectifying an alternating voltage generated in the power receiving coil; and

a secondary battery to which a direct-current voltage rectified by the rectifier is charged;

an electronic apparatus main body comprising;

an electronic device operating when the direct-current voltage is supplied from the secondary battery; and

a circuit substrate on which the electronic device is mounted; and

a magnetic sheet according to claim 1, disposed at least one of places between the spiral coil and the secondary battery, between the spiral coil and the rectifier, between the spiral coil and the electronic device, and between the spiral coil and the circuit substrate.

11. A non-contact charger, comprising:

an electronic apparatus according to claim 10; and

a power feeding device comprising;

a power feeding coil disposed in non-contact with the power receiving coil of the electronic apparatus;

a power supply applying an alternating voltage to the power feeding coil; and

a magnet for positioning,

wherein the electronic apparatus is positioned by the magnet and a magnetic flux generated in the power feeding coil is transferred to the power receiving coil to transmit a power in a non-contact manner.

12. A non-contact charger comprising:

an electronic apparatus according to claim 10;

a power feeding device comprising;

a power feeding coil disposed in non-contact with the power receiving coil of the electronic apparatus; and

a power supply applying an alternating voltage to the power feeding coil,

wherein a magnetic flux generated in the power feeding coil is transferred to the power receiving coil to transmit a power in a non-contact manner.

13. The non-contact charger according to claim 12,

wherein the electronic apparatus is positioned by a movable coil disposed in a power feeding device side.