Power receiving device and wireless power feed system

• US 9,496,743 B2
• Filed: 08/11/2011
• Issued: 11/15/2016
• Est. Priority Date: 09/13/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kamata, Koichiro
• Primary Examiner(s): Pelton, Nathaniel
• Application Number:
  US13/207,474
• Publication Number:
  US 20120062174A1
• Time in Patent Office: 1,923 Days
• Field of Search: 320/108, 455/41.1
• US Class Current: 1/1
• CPC Class Codes: H02J 50/05 using capacitive coupling
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/22 Capacitive coupling

Abstract

An electric field coupling type wireless power feed system including a power transmitting device and a power receiving device which is unlikely to be affected by a noise and which has a reduced size is provided. A capacitive coupling type wireless power feed system includes a power receiving device including a first electrode using an oxide semiconductor film, and a battery and a power transmitting device including a second electrode, wherein the battery is charged by a voltage generated based on an electric field generated between the first electrode and the second electrode. The charging of the battery may be stopped by applying a positive direct-current voltage from a charge control circuit to the first electrode.

Claims

1. A power receiving device comprising:

a first electrode consisting of an oxide semiconductor film;

a battery; and

a charge control circuit,

wherein the battery is charged by a voltage generated based on an electric field generated between the first electrode and a second electrode of a power transmitting device, and

wherein the charging of the battery is stopped by applying a positive direct-current voltage from the charge control circuit to the first electrode.

2. The power receiving device according to claim 1,

wherein the oxide semiconductor film has a sodium concentration of 5×

10¹⁶ atoms/cm³ or less.

3. The power receiving device according to claim 1,

wherein the oxide semiconductor film has a hydrogen concentration of 5×

10¹⁹ atoms/cm³ or less.

4. The power receiving device according to claim 1,

wherein the battery comprises a lithium battery, a nickel-metal-hydride battery, a nickel-cadmium battery, an organic radical battery, a lead-acid battery, an air secondary battery, a nickel-zinc battery, a silver-zinc battery, or a capacitor.

5. An electronic appliance comprising the power receiving device according to claim 1,

wherein the electronic appliance is a mobile phone, a portable information terminal, a camera, a computer, an image reproduction device, an IC card, or an IC tag.

6. A capacitive coupling type wireless power feed system comprising:

a power receiving device including a first electrode consisting of an oxide semiconductor film, a battery, and a charge control circuit; and

a power transmitting device including a second electrode,

wherein the battery is charged by a voltage generated based on an electric field generated between the first electrode and the second electrode, and

wherein the charging of the battery is stopped by applying a positive direct-current voltage from the charge control circuit to the first electrode.

7. The capacitive coupling type wireless power feed system according to claim 6,

wherein the oxide semiconductor film has a sodium concentration of 5×

10¹⁶ atoms/cm³ or less.

8. The capacitive coupling type wireless power feed system according to claim 6,

wherein the oxide semiconductor film has a hydrogen concentration of 5×

10¹⁹ atoms/cm³ or less.

9. The capacitive coupling type wireless power feed system according to claim 6,

wherein the battery comprises a lithium battery, a nickel-metal-hydride battery, a nickel-cadmium battery, an organic radical battery, a lead-acid battery, an air secondary battery, a nickel-zinc battery, a silver-zinc battery, or a capacitor.

10. The capacitive coupling type wireless power feed system according to claim 6,

wherein the power receiving device is provided for a mobile phone, a portable information terminal, a camera, a computer, an image reproduction device, an IC card, or an IC tag.

11. The capacitive coupling type wireless power feed system according to claim 6,

wherein the power transmitting device is provided for a charger sheet.