Patent Application
20160365751
The present invention relates to a power source device for a portable device which is used as a power source device for a portable device and a charging device therefor.
There have traditionally been suggested, as a power source device for portable devices, a structure adopting a secondary battery capable of charging and discharging so that no frequent battery-exchanging work is required. For charging a secondary battery are adopted a wired charging system which supplies power through a mechanical contact as described in PTL 1, or a wireless charging system which supplies power by electromagnetic inductance as described in PTL 2 and 3.
PTL 1: Japanese Unexamined Patent Publication No. H09-50795
PTL 2: Japanese Unexamined Patent Publication No. 2014-7594
PTL 3: Japanese Unexamined Patent Publication No. 2010-207017
Since a portable device itself is preferred to be small in terms of light weight and portability, a charging device for such a portable device is also typically small to meet the size of the portable device. This condition for the charging device specific to portable devices is taken into account in various structures suggested. If there are other conditions that should be taken into account, suggestions of structures taking into account these conditions are desired.
An object of the present invention is to provide a power source device for a portable device, a portable device, and a charging device which contribute to downsizing of portable devices.
To achieve the above object, a first aspect of the present invention is a power source device for a portable device, including: a secondary battery; a circuit board on which a charging circuit is mounted, the charging circuit configured to charge the secondary battery with an input of external power; and a power-receiving module having a power-receiving resonance coil and a power-drawing coil, which are configured to receive power supplied from outside by a resonance phenomenon and output to the charging circuit as the external power, wherein at least one of the circuit board and the secondary battery is at least partially arranged on an inner circumference side of the power-receiving resonance coil and the power-drawing coil in the power-receiving module.
The above structure allows downsizing of a power source device for a portable device by arranging, at least partially, at least one of the circuit board and the secondary battery on an inner circumference side of the power-receiving resonance coil and the power-drawing coil in the power-receiving module. Thus, downsizing of the portable device is possible.
Further traditionally, regarding a power source devices for a portable device, the portable device is preferred to be small in terms of light weight and portability. Therefore, a charging device typically has a small size to fit with the size of the portable device. For a secondary battery in such a power source device for a portable device, an electromagnetic inductance charging system is adopted in general, which facilitates designing of a transmission distance to the order of several millimeters from the charging device and enables a high transmission efficiency at a short distance. Therefore, it has been out of the common practice of the technical field of the power source device to adopt, as the charging system for power source device for a portable device, a magnetic resonance charging system utilizing a resonance phenomenon, which system has been collecting attention, despite its lower transmission efficiency as compared with the electro magnetic inductance, for its ability to transmit power over a long transmission distance of the order of several meters.
However, as a result of various studies and experiments, the inventors of the present invention found that adopting the magnetic resonance system utilizing a resonance phenomenon brings about characteristics unattainable by the electromagnetic inductance system, and that these characteristics improves matters required in the power source devices for portable devices.
More specifically, the inventors have found that a resonance phenomenon forms a magnetic field space with a smaller magnetic field strength than the other, in a nearby position, on the inner circumference side or the outer circumferential side, of the power-receiving module. The power source device for a portable device enables formation of the magnetic field space in a position where the charging circuit and the like is arranged. Therefore, it is possible to make the power source device for a portable device smaller than that adopting the electromagnetic inductance.
Further, the inventors have found that the load fluctuation characteristic with respect to the charging time in a constant voltage charging is adjustable by adjusting the value of the coupling coefficient between the power-receiving module and a coil of a power-supplying module configured to supply an external power to the power-receiving module. This restrains input of excessive external power at the time of transition from the constant current charging to the constant voltage charging, without a need of separately providing an impedance matching box. As the impedance matching box is no longer needed, downsizing of the power source device for a portable device is possible.
The first aspect of the present invention may be adapted so that at least a part of the circuit board is arranged in a magnetic field space formed by the resonance phenomenon so as to have a smaller magnetic field strength than those of the other parts.
In the above structure, a space part having a small magnetic field is generated at around the power-receiving module, and this space part is effectively used as the arrangement location of at least a part of the circuit substrate. This allows an arrangement position for the charging circuit to be easily ensured in a power source device for a portable device, with limited space for arranging components, and further enables downsizing of the power source device for a portable device.
The first aspect of the present invention may be adapted so that the circuit board is a part of a support structure for components arranged inside the power source device for a portable device.
The above structure in which the circuit board substitutes for a part of the support structure allows further downsizing and weight reduction of the power source device for a portable device.
The first aspect of the present invention may be adapted so that the power-receiving module is configured to hold the secondary battery in a detachable manner.
The above structure enables use of the power-receiving module as a battery holder for the secondary battery, which further contributes to reduction of the number of the components.
A second aspect of the present invention is a portable device including any of the power source devices for a portable device, related to the first aspects.
The above structure enables downsizing of a portable device.
The second aspect of the present invention may be a human-wearable device including any of the above-described power source device for a portable device related to the first aspect.
The above structure enables downsizing of a human-wearable device as a portable device, and downsizing the power source device for a portable device improves the degree of freedom in the shape and size of the human-wearable device, which contributes to reduction of burdens in manufacturing such a device in a shape and size that fit to the physique and body shape of a user.
The second aspect of the present invention may be a hearing aid to be worn on an ear, including any of the above-described power source device for a portable device related to the first aspect.
The above structure enables downsizing of a hearing aid as a portable device, and downsizing the power source device for a portable device improves the degree of freedom in the shape and size of the hearing aid, which contributes to reduction of burdens in manufacturing the hearing aid in a shape that fits to the shape of the ear of a user.
Further, a third aspect of the present invention is a charging device which is attachable to the portable device of the second aspect, the charging device configured to supply external power to a power source device of the portable device attached, comprising: a power-supplying module configured to supply power to the power-receiving module by using a resonance phenomenon, the power-supplying module including a power-supplying resonance coil and a power-supplying coil; and a casing formed so that, while the portable device is attached, the power-supplying module and the power-receiving module are in a positional relation such that their coil axes match with each other.
In the above structure, the casing is formed so that, while the portable device is attached, the power-supplying module and the power-receiving module are in a positional relation such that their coil axes match with each other. This enables charging as intended in the design, with respect to the power source device for a portable device, simply by placing the portable device on the charging device. There is no need of warning the user regarding how the portable device should be placed on the casing; i.e., the tilt angle and the rotational angle of the tilt axis of the portable device with respect to a contact surface of the casing.
The present invention at least allows downsizing of portable devices.
(Overview of Power Source Device 10 for Portable Device)
As shown in
Specifically, as shown in
The power-receiving module 61 has a power-receiving resonance coil 611 and a power-drawing coil 612, which are configured to receive power supplied from outside by a resonance phenomenon and output to the charging circuit as an external power. At least one of the circuit board 63 and the secondary battery 3 is at least partially arranged on an inner circumference side of the power-receiving resonance coil 611 and the power-drawing coil 612 in the power-receiving module 61.
With this, a portable device-use power source device 10 is made smaller by arranging, at least partially, at least one of the circuit board 63 and the secondary battery 3 on an inner circumference side of the power-receiving module 61, as compared with a structure in which the circuit board 63 and the secondary battery 3 are arranged outer circumference side of the power-receiving module 61. As the result, the portable device-use power source device 10 enables downsizing of portable devices 6 such as an ear-hook hearing aid 9. It should be noted that the power-receiving module 61 may be used as a battery holder for the secondary battery 3. In other words, the power-receiving module 61 may be formed so as to hold the secondary battery 3 in a detachable manner. Further, as shown in
The portable device-use power source device 10, adopting the magnetic resonance system utilizing a resonance phenomenon, allows downsizing by utilizing characteristics that are not obtainable by an electromagnetic inductance system; i.e., a characteristic that a magnetic field space having a smaller magnetic field strength than those of the other parts are formed in a position nearby the inner circumference side or the outer circumference side of the power-receiving module 61; and a characteristic that enables adjustment of the load fluctuation characteristic with respect to the charging time in a constant voltage charging. The magnetic field space and the load fluctuation characteristic are detailed later.
(Portable Device-Use Power Source Device 10: Secondary Battery 3)
As the secondary battery 3, any type of batteries which are chargeable and rechargeable can be used. Examples of the secondary battery 3 include a lead storage battery, a valve-regulated lead storage battery, a lithium air battery, a lithium ion battery, a lithium ion polymer battery, a lithium iron phosphate ion battery, a lithium-sulfur battery, a lithium titanate battery, a nickel-cadmium storage battery, a nickel-hydrogen rechargeable battery, a nickel-iron battery, a nickel-lithium battery, a nickel-zinc battery, a rechargeable alkali battery, a sodium-sulfur battery, a redox flow battery, a zinc-bromine flow battery, a silicon battery, and a Silver-Zinc battery.
The nominal voltage of the nickel-metal hydride battery is 1.2V to 1.4V as in the case of the nominal voltage of an air cell which is a primary battery. By the term nominal voltage, it means a prescribed value used as a criterion of voltage between terminals, which is obtained when a battery is used in an ordinary circumstance. The voltage between terminals is higher than the nominal voltage, when the battery is fully charged, and is lower than the nominal voltage, when discharging from the battery has taken place, or when a large current is supplied to a load.
Examples of a secondary battery 3 whose nominal voltage is higher than that of an air cell include: a lead storage battery, a valve-regulated lead storage battery, a lithium air battery, a lithium ion battery, a lithium polymer battery, a manganese dioxide lithium secondary battery, a titanium carbon lithium rechargeable battery, and the like.
Further, the nominal voltages of the lithium ion battery and the lithium polymer battery are 3.6V to 3.7V. Further, the nominal voltage of the manganese dioxide lithium secondary battery is 3.0V. Further, the nominal voltage of the titanium carbon lithium rechargeable battery is 1.5V. Further, a range from the “discharge cut off voltage” and the “charge termination voltage” of the lithium ion battery is 2.7V to 4.2V. By the discharge cut off voltage, it means the minimum value of voltage at which safe discharging is possible. By the charge termination voltage, it means the maximum value of voltage at which safe charging is possible.
The secondary battery 3 is preferably a lithium ion battery. The nominal voltage of the lithium ion battery which falls within a range of 3.6V to 3.7V is higher than the nominal voltages of 1.2V to 1.4V of the air cell or a nickel-hydrogen secondary battery. Although the lithium ion battery exhibits a discharge characteristic such that its battery voltage drops from approximately 4.2V to approximately 2.7V, the lithium ion battery is able to drive a device longer than the air cell or the nickel-hydrogen secondary battery, because the energy density of the lithium ion battery is higher than that of the air cell or the nickel-hydrogen secondary battery.
(Portable Device-Use Power Source Device 10: Power-Receiving Module 61)
The power-receiving module 61 has a power-receiving resonance coil 611 and a power-drawing coil 612. Example types of coils used as the power-receiving resonance coil 611 or the power-drawing coil 612 include: a spiral type, a solenoid type, and a loop type. For the power-receiving resonance coil 611 and the power-drawing coil 612, a copper wire material having an insulation coating is used.
(Portable Device-Use Power Source Device 10: Circuit Board 63)
As shown in
The circuit board 63 including the charge/discharge circuit 101 and the interface unit 631 is at least partially arranged in a magnetic field space formed by a resonance phenomenon, whose magnetic field strength is smaller than the magnetic field strengths of the other parts (surrounding area). This allows an arrangement position for the charging circuit 8 to be easily ensured in a portable device-use power source device 10 with limited space for arranging components, and further enables downsizing of the portable device-use power source device 10. This way, the portable device-use power source device 10 restrains occurrence of an eddy current attributed to a magnetic field of the circuit board 63, thus preventing malfunctions and generating of heat of a predetermined temperature or higher, and further enables downsizing.
It should be noted that at least a part of the secondary battery 3 or at least a part of the output unit 65 and the input unit 66 may be in that “magnetic field space”, in addition to or instead of the circuit board 63. Further, as shown in
(Portable Device-Use Power Source Device 10: Charge/Discharge Circuit 101)
As shown in
As the charging circuit, an IC for a constant current/constant voltage linear charger is adopted. The IC for the charging circuit has functions such as a function of notifying that the charging current has been reduced to a predetermined setting value, a function of ending the charging using a timer, a function of stabilizing the charging current by means of thermal feedback, and a function of limiting the chip temperature in a high-power mode or in high ambient temperatures. It should be noted that the process of charging the secondary battery 3 may be divided into a predetermined number of steps, and a plurality of charging circuits may be provided to enable the most efficient charging in each of the steps. This way a highly efficient charging is possible.
(Specific Structure of Portable Device-Use Power Source Device 10)
As shown in
(Arrangement of Components in Portable Device-Use Power Source Device 10)
Portable device-use power source device 10 is configurable in a plurality of ways with various combinations of the secondary battery 3, the circuit board 63, and the power-receiving module 61.
Specifically, as shown in
(Arrangement of Components in Portable Device-Use Power Source Device 10: First Group)
In the first mode, there is a positional relation such that the axis of the power-receiving module 61 perpendicularly crosses the terminal surface of the circuit board 63 while perpendicularly crossing the axis of the secondary battery 3. In such a positional relation, a part of the secondary battery 3 and a part of the circuit board 63 are arranged on the inner circumference side of the power-receiving module 61. The expression “parallel” and “perpendicular” in each mode encompass errors in mounting. It should be noted that the first mode may be such that at least one of the secondary battery 3 and the circuit board 63 is partially or entirely arranged on the inner circumference side of the power-receiving module 61.
In the arrangement of the first connection terminal 104a and the second connection terminal 104b in the first mode, the first connection terminal 104a and the second connection terminal 104b protrude from the terminal surface of the circuit board 63. This way, the first connection terminal 104a contacts the top surface of the secondary battery 3, and the second connection terminal 104b contacts the circumferential surface of the secondary battery 3.
Further, the arrangement of terminals in the first mode may be structured as shown in
Further, the arrangement of terminals in the first mode may be structured as shown in
In the second mode, there is a positional relation such that the axis of the power-receiving module 61 is parallel to the terminal surface of the circuit board 63 while perpendicularly crossing the axis of the secondary battery 3. In such a positional relation, the secondary battery 3 and the circuit board 63 are partially arranged on the inner circumferential surface of the power-receiving module 61. In the arrangement of the first connection terminal 104a and the second connection terminal 104b in the second mode, the first connection terminal 104a and the second connection terminal 104b protrude from the terminal surface of the circuit board 63. This way, the first connection terminal 104a contacts the top surface of the secondary battery 3, and the second connection terminal 104b contacts a portion on the circumferential surface of the secondary battery 3, which is not covered by the power-receiving module 61.
In the third mode, there is a positional relation such that the axis of the power-receiving module 61 is parallel to the terminal surface of the circuit board 63 while perpendicularly crossing the axis of the secondary battery 3. In such a positional relation, the secondary battery 3 is partially arranged on the inner circumferential surface of the power-receiving module 61, as shown in
It is even more preferable that the first connection terminal 104a contacts the top surface of the secondary battery 3 and the second connection terminal 104b contacts the lower surface of the secondary battery 3, without the whole 103a on the magnetic member 103. It should be noted that in a structure in which the second connection terminal 104b is brought into contact with the lower surface of the secondary battery 3, influences to the coil characteristics and influences from heat generation attributed to the magnetic field on the power-transmission end are concerned, because the second connection terminal 104b is a metal. However, no significant influence was confirmed in experiments, due to the size of the second connection terminal 104b. In a structure in which the second connection terminal 104b contacts the lower surface of the secondary battery 3, the first connection terminal 104a and the second connection terminal 104b at the top and bottom sandwiches the secondary battery 3. This structure may be modified as shown in
In the third mode, the secondary battery 3 may be embedded into the bottom portion of the ear-hook hearing aid 9, or alternatively, the casing of the ear-hook hearing aid 9 may be separable so that the battery is replaceable. For example, it is possible to structure as shown in
In the fourth mode, there is a positional relation such that the axis of the power-receiving module 61 is parallel to the terminal surface of the circuit board 63 while perpendicularly crossing the axis of the secondary battery 3. In such a positional relation, the secondary battery 3 and the circuit board 63 are arranged on the inner circumferential surface of the power-receiving module 61.
Further, the second group, in which the top surface of the secondary battery 3 and the terminal surface of the circuit board 63 abut each other, is further classified into a fifth mode and a sixth mode when the power-receiving module 61 is added.
In the fifth mode, there is a positional relation such that the axis of the power-receiving module 61 is parallel to the terminal surface of the circuit board 63 while perpendicularly crossing the axis of the secondary battery 3. In such a positional relation, the secondary battery 3 and the circuit board 63 are arranged on the inner circumferential surface of the power-receiving module 61.
In the sixth mode, there is a positional relation such that the axis of the power-receiving module 61 perpendicularly crosses the terminal surface of the circuit board 63 while being parallel to the axis of the secondary battery 3. In such a positional relation, the secondary battery 3 is arranged on the inner circumferential surface of the power-receiving module 61. In the arrangement of the first connection terminal 104a and the second connection terminal 104b in the sixth mode, the first connection terminal 104a is arranged in a planar manner on the terminal surface of the circuit board 63 while the second connection terminal 104b protrude from the terminal surface of the circuit board 63. This way, the first connection terminal 104a contacts the top surface of the secondary battery 3, and the second connection terminal 104b contacts the circumferential surface of the secondary battery 3. It should be noted that, in the arrangement of terminals in the sixth mode, the power-receiving module 61 may be separated from the circuit board 63 and the second connection terminal 104b may be brought into contact with a part of the circumferential surface of the secondary battery 3 in a gap between the power-receiving module 61 and the circuit board 63. Alternatively, in the arrangement of terminals in the sixth mode, the power-receiving module 61 may be abutted against the circuit board 63 and the second connection terminal 104b may be brought into contact with the circumferential surface of the secondary battery 3 which is on the other side of the circuit board 63.
In cases where an opening 103a with a size that covers the entire circumferential surface of the secondary battery 3 is provided on the inner circumferential surface of the power-receiving module 61, a notch is formed in a part of the magnetic member 103, and the second connection terminal 104b is brought into contact with the circumferential surface of the secondary battery 3 through this notch. It should be noted that the above structure with the opening 103a on the magnetic member 103 is preferable in actual implementation.
In the seventh mode, there is a positional relation such that the axis of the power-receiving module 61 is parallel to the terminal surface of the circuit board 63 and parallel to the axis of the secondary battery 3. In such a positional relation, the secondary battery 3 is arranged on the inner circumferential surface of the power-receiving module 61. In the arrangement of the first connection terminal 104a and the second connection terminal 104b in the seventh mode, the first connection terminal 104a is arranged in a planar manner on the terminal surface of the circuit board 63 while the second connection terminal 104b protrude from the terminal surface of the circuit board 63. This way, the first connection terminal 104a contacts the top surface of the secondary battery 3 which is not covered by the power-receiving module 61, and the second connection terminal 104b contacts the circumferential surface of the secondary battery 3 which is not covered by the power-receiving module 61.
It should be noted that the first connection terminal 104a and the second connection terminal 104b are used as electrodes to contact a coin-shaped secondary battery 3 in the present embodiment; however, the present invention is not limited to this. For example, an electrode may be welded to a coin-shaped secondary battery 3 and a lead wire may be drown out therefrom to be connected to the circuit board 63.
(Portable Device-Use Power Source Device 10: Space Portion with Weak Magnetic Field)
The following details a space portion with a weak magnetic field, which is a position for arranging the circuit board 63 and the like.
As shown in
For example, the portable device-use power source device 10 may be arranged such that, when power is supplied by the resonance phenomenon from the power-supplying resonance coil 711 of the power-supplying module 71 of the charging device 7 to the power-receiving resonance coil 611 of the power-receiving module 61, a magnetic field space having a magnetic field strength lower than the magnetic field strengths in parts other than the desired position is formed as the space portion, at a desired position between the power-supplying resonance coil 711 of the power-supplying module 71 and the power-receiving resonance coil 611 of the power-receiving module 61. In this case, the space portion is created in a position nearby the power-receiving module 61, closer to the charging device 7. Therefore, the leading end portion side of the outer wall member is ensured as the position for arranging the circuit board 63 and the like, by slightly shifting towards back side the position for arranging the power-receiving module 61 from the leading end portion of the outer wall member on the side of the charging device 7.
A method of forming the space portion will be detailed. When power is supplied from the power-supplying resonance coil 711 of the power-supplying module 71 of the charging device 7 to the power-receiving resonance coil 611 of the power-receiving module 61 by the resonance phenomenon, for example, the frequency of the power supplied to the power-supplying resonance coil 711 of the power-supplying module 71 is set in such a way that the direction of the current flowing in the power-supplying resonance coil 711 of the power-supplying module 71 is opposite to the direction of the current flowing in the power-receiving resonance coil 611 of the power-receiving module 61.
In the formation method above, when power transmission using the resonance phenomenon is performed, the coupling coefficient indicating the strength of the coupling between the power-supplying resonance coil 711 and the power-receiving resonance coil 611 is increased as the power-supplying resonance coil 711 of the power-supplying module 71 and the power-receiving resonance coil 611 of the power-receiving module 61 are disposed to be close to each other. When a transmission characteristic “S21” (which is an index of the power transmission efficiency in the power transmission from the power-supplying resonance coil 711 to the power-receiving resonance coil 611) is measured while the coupling coefficient is high as above, the analyzed waveform of the transmission characteristic “S21” has separate peaks; one on a low frequency side and another on a high frequency side. As the frequency of the power supplied to the power-supplying resonance coil 711 is set at a frequency around the peak on the high frequency side, the direction of the current flowing in the power-supplying resonance coil 711 is arranged to be opposite to the direction of the current flowing in the power-receiving resonance coil 611, and hence the magnetic field generated on the inner circumference side of the power-supplying resonance coil 711 and the magnetic field generated on the inner circumference side of the power-receiving resonance coil 611 cancel each other out, with the result that an influence of the magnetic field is reduced on the inner circumference sides of the power-supplying resonance coil 711 and the power-receiving resonance coil 611. With this, the magnetic field space having a magnetic field strength lower than the magnetic field strengths in parts other than the inner circumference sides of the power-supplying resonance coil 711 and the power-receiving resonance coil 611 is formed as the space portion.
In another method of forming the space portion, for example, when power is supplied from the power-supplying resonance coil 711 to the power-receiving resonance coil 611 by the resonance phenomenon, the frequency of the power supplied to the power-supplying resonance coil 711 is set so that the direction of the current flowing in the power-supplying resonance coil 711 is identical with the direction of the current flowing in the power-receiving resonance coil 611.
According to the method above, when power transmission using the resonance phenomenon is performed, the coupling coefficient indicating the strength of the coupling between the power-supplying resonance coil 711 and the power-receiving resonance coil 611 is increased as the power-supplying resonance coil 711 and the power-receiving resonance coil 611 are disposed to be close to each other. When the coupling coefficient is high in this manner, the measurement of the transmission characteristic shows that a measured waveform has two separated peaks on the low frequency side and the high frequency side, respectively. As the frequency of the power supplied to the power-supplying resonance coil 711 is set at a frequency around the peak on the low frequency side, the direction of the current flowing in the power-supplying resonance coil 711 is arranged to be identical with the direction of the current flowing in the power-receiving resonance coil 611, and hence the magnetic field generated on the outer circumference side of the power-supplying resonance coil 711 and the magnetic field generated on the outer circumference side of the power-receiving resonance coil 611 cancel each other out, with the result that an influence of the magnetic field is reduced on the outer circumference sides of the power-supplying resonance coil 711 and the power-receiving resonance coil 611. With this, a magnetic field space having a magnetic field strength lower than the magnetic field strengths in parts other than the outer circumference sides of the power-supplying resonance coil 711 and the power-receiving resonance coil 611 is formed as the space portion.
In addition to the above, the size of the space portion may be set based on the strength of the magnetic coupling between the power-supplying resonance coil 711 and the power-receiving resonance coil 611, by changing adjustment parameters regarding the power-supplying resonance coil 711 and the power-receiving resonance coil 611. For example, the size of the magnetic field space is increased by relatively weakening the magnetic coupling between the power-supplying resonance coil 711 and the power-receiving resonance coil 611. In the meanwhile, the size of the magnetic field space is decreased by relatively strengthening the magnetic coupling between the power-supplying resonance coil 711 and the power-receiving resonance coil 611. As such, a space portion optimum for the size of a portable device-use power source device 10 or portable device 6 to be mounted is formed.
Alternatively, the size of the magnetic field space may be changed in such a way that the arrangement relation of the power-supplying resonance coil 711 and the arrangement relation of the power-receiving resonance coil 611 are used as the adjustment parameters, and the adjustment parameters are changed to change the strength of the magnetic coupling between the power-supplying resonance coil 711 and the power-receiving resonance coil 611.
Furthermore, the shape of the space portion may be arranged to be a desired shape in such a way that the shapes of the power-supplying resonance coil 711 and the power-receiving resonance coil 611 are used as the adjustment parameters, and the shapes of these coils are changed in a desirable manner to change the strength of the magnetic coupling between and around the power-supplying resonance coil 711 and the power-receiving resonance coil 611. In this case, as the power-supplying resonance coil 711 and the power-receiving resonance coil 611 are arranged to have desired shapes, a magnetic field space having a relatively low magnetic field strength is formed with a desired shape corresponding to the shapes of the coils.
In addition to the above, the size of the space portion may be set in such a way that at least one of the first distance between the power-supplying resonance coil 711 and the power-supplying coil 712 and the second distance between the power-drawing coil 612 and the power-receiving resonance coil 611 is used as an adjustment parameter, and the size is set based on this adjustment parameter. For example, the size of the magnetic field space is increased in such a way that the first distance between the power-supplying resonance coil 711 and the power-supplying coil 712 and the second distance between the power-drawing coil 612 and the power-receiving resonance coil 611 are relatively shortened so that the magnetic coupling is relatively weakened. In the meanwhile, the size of the magnetic field space is decreased in such a way that the first distance between the power-supplying resonance coil 711 and the power-supplying coil 712 and the second distance between the power-drawing coil 612 and the power-receiving resonance coil 611 are relatively elongated so that the magnetic coupling is relatively strengthened.
In addition to the above, the magnetic field space may be formed as the space portion at a desired position with a magnetic field strength lower than the magnetic field strengths in parts other than the desired position, in such a manner that, the magnetic member 103 is provided to cover at least a part of the power-receiving resonance coil 611 and the power-supplying resonance coil 711 except the surfaces where these coils oppose each other, and power transmission is carried out by changing the magnetic field between the power-supplying resonance coil 711 and the power-receiving resonance coil 611. For example, the magnetic member 103 may be provided to cover the inner circumferential surface of the power-receiving resonance coil 611. In this case, by blocking the magnetic field generated on the inner circumference side of the power-receiving resonance coil 611, a magnetic field space having a relatively low magnetic field strength is formed as the space portion on the inner circumference side of the power-receiving resonance coil 611.
In addition to the above, the magnetic member 103 may be provided to cover the surfaces of the power-supplying resonance coil 711 and the power-receiving resonance coil 611, which surfaces are opposite to the surfaces where the coils oppose each other. In this case, by blocking the magnetic field generated at around the surface opposite to the opposing surface of the power-receiving resonance coil 611, a magnetic field space having a relatively low magnetic field strength is formed as the space portion at around the surface opposite to the opposing surface of the power-receiving resonance coil 611.
As such, the portable device-use power source device 10 is arranged such that, based on one or more combination of at least one of the above-described methods of forming the space portion, a magnetic field space having a low magnetic field strength can be intentionally formed at will as the space portion at and around the inner side of the power-receiving module 61, and the size and shape of the space portion can be arbitrarily set. In other words, in the portable device-use power source device 10, a desired space portion can be formed by adjusting the layout of the power-receiving module 61.
(Portable Device-Use Power Source Device 10: Load Fluctuation Characteristic)
The following details a load fluctuation characteristic of the portable device-use power source device 10. A load fluctuation characteristic is variation in the input impedance to the portable device-use power source device 10 with respect to a charging time of the constant voltage charging.
Any of coupling coefficients of the power-supplying module 71 and the power-receiving module 61 in the portable device-use power source device 10 is preferably set so that the input impedance related to the load fluctuation characteristic rises when power is supplied, by varying a magnetic field, from the power-supplying module 71 to the power-receiving module 61 of the portable device-use power source device 10 including a secondary battery 3 chargeable by a constant current/constant voltage charging system. This structure automatically restrains an input of an excessive external power at a time of transition from the constant current charging to the constant voltage charging, without a need of separately providing an impedance matching box. As the result, for example, downsizing by the amount of eliminating the impedance matching box becomes possible. Alternatively, it is possible to double-restrain the external power: a forced restraint of the external power by the impedance matching box, and an automatic restraint of the external power by the load fluctuation characteristic.
The part of the above description reading “any of coupling coefficients of the power-supplying module 71 and the power-receiving module 61” means at least one of the following coupling coefficients: a coupling coefficient between the power-supplying coil 712 and the power-supplying resonance coil 711; a coupling coefficient between the power-supplying resonance coil 711 and the power-receiving resonance coil 611; and a coupling coefficient between the power-receiving resonance coil 611 and the power-drawing coil 612.
It should be noted that values of the coupling coefficient between the power-supplying coil 712 and the power-supplying resonance coil 711, the coupling coefficient between the power-supplying resonance coil 711 and the power-receiving resonance coil 611, and the coupling coefficient between the power-receiving resonance coil 611 and the power-drawing coil 612 may be adjusted by varying the distance between the power-supplying coil 712 and the power-supplying resonance coil 711, the distance between the power-supplying resonance coil 711 and the power-receiving resonance coil 611, and the distance between the power-receiving resonance coil 611 and the power-drawing coil 612, respectively. This allows adjustment of the load fluctuation characteristic by a simple work of adjusting a distance between coils as a parameter.
Further, the “any of coupling coefficients of the power-supplying module 71 and the power-receiving module 61” may be set by adjusting a drive frequency, in cases where the power-supplying module 71 and the power-receiving module 61 are set so that a value of transmission characteristic with respect to a drive frequency of the power supplied to the power-supplying module 71 has a double-hump characteristic having a peak in a lower drive frequency band than a resonance frequency in the power-supplying module 71 and the power-receiving module 61, and a peak in a higher drive frequency band than the resonance frequency.
Specifically, the drive frequency of the power supplied to the power-supplying module 71 is set to a band corresponding to a peak value of the transmission characteristic, which occurs in a drive frequency band lower than the resonance frequency of the power-supplying module 71 and the power-receiving module 61 or a band corresponding to a peak value of the transmission characteristic, which occurs in a drive frequency band higher than the resonance frequency of the power-supplying module 71 and the power-receiving module 61, so that the input impedance of the portable device-use power source device 10 in the constant voltage charging tends to increase.
(Example Application of Portable Device-Use Power Source Device 10: Portable Device 6)
The following specifically describes an example application of the portable device-use power source device 10 to a portable device 6.
As shown in
A human-wearable device with a portable device-use power source device 10 built therein enables downsizing of a human-wearable device as a portable device 6, and downsizing the portable device-use power source device 10 improves the degree of freedom in the shape and size of the human-wearable device, which contributes to reduction of burdens in manufacturing such a device in a shape and size that fit to the physique and body shape of a user.
(Example Application of Portable Device-Use Power Source Device 10: Ear-Hook Hearing Aid 9)
The following details a case where the portable device 6 is a hearing aid, with an example of an ear-hook hearing aid 9. A hearing aid with a portable device-use power source device 10 built therein enables downsizing of a human-wearable device as a portable device 6, and downsizing the portable device-use power source device 10 improves the degree of freedom in the shape and size of the hearing aid, which contributes to reduction of burdens in manufacturing the hearing aid in a shape that fits to the shape of the ear of a user.
As shown in
The ear-hook hearing aid 9 further includes an ear mold 92 to be worn at or nearby an ear hole opening, a connecting member 93 connecting the hearing aid main body 91 and the ear mold 92, a circuit board 63, and the output unit 65 and the input unit 66 shown in
The hearing aid main body 91 has a hexahedral housing (outer wall member) which is curved from the top portion to the bottom portion so as to fit the root of the pinna. That is, the housing of the hearing aid main body 91 includes: a top surface portion 911d positioned in the top portion; a bottom surface portion 911c positioned in the bottom portion; a head-contacting surface portion 911a to contact the head; a pinna-contacting surface portion 911e opposing the head-contacting surface portion 911a, which contacts the pinna; an inside contacting surface portion 911b which contacts the root of the pinna in a surface-to-surface manner; an outside surface portion 911f on the opposite side of the inside contacting surface portion 911b. Further, the hearing aid main body 91 can be divided into two at the head-contacting surface portion 911a and the pinna-contacting surface portion. This way, the head-contacting surface portion 911a serves as a cap, and the pinna-contacting surface portion is an accommodated body.
To the top surface portion of the hearing aid main body 91 is connected an end portion of the connecting member 93. The connecting member 93 is formed as a tubular manner. The other end of the connecting member 93 is connected to the other end portion the ear mold 92. With the above described ear-hook hearing aid 9, the sounds collected and amplified by the hearing aid main body 91 is output from the speaker 651 to the ear mold 92 via the connecting member 93, thereby making the sounds clearly audible to the user of the ear-hanging hearing aid 9.
(Charging Device 7 of Portable Device-Use Power Source Device 10)
The ear-hook hearing aid 9 is attachable and detachable to/from the charging device 7. As shown in
Inside the charging device 7 is provided a power-supplying module 71 configured to supply power, by a resonance phenomenon, to the ear-hook hearing aid 9 placed on the charging pedestal. The power-supplying module 71 is set so its axis matches with that of the power-receiving module 61. The power-supplying module 71 includes a power-supplying resonance coil 711 and a power-supplying coil 712. Example types of coils used as the power-supplying resonance coil 711 or the power-supplying coil 712 include: a spiral type, a solenoid type, and a loop type. The charging device 7 includes a power source unit 72 supplying AC power to the power-supplying module 71 and a controlling unit 73 controlling the power source unit 72.
The charging device 7, as is the case with portable device-use power source device 10 of the ear-hook hearing aid 9, may have a structure which creates a space portion with a weak magnetic field in an inner side position of or a position nearby the power-supplying module 71, when power is supplied by utilizing a resonance phenomenon. This space portion may be used as a position for arranging the power source unit 72 and the controlling unit 73. This allows downsizing of the charging device 7 in addition to the ear-hook hearing aid 9.
As described, the charging device 7 allows an ear-hook hearing aid 9 to be placed thereon, and is configured to supply external power to the portable device-use power source device 10 of the ear-hook hearing aid 9. Such a charging device 7 includes a power-supplying module 71 including a power-supplying resonance coil 711 and a power-supplying coil 712, which is configured to supply power by a resonance phenomenon to the power-receiving module 61, and a casing 75 formed so that, while the ear-hook hearing aid 9 is attached, the power-supplying module 71 and the power-receiving module 61 are in a positional relation such that their coil axes matches with each other. It should be noted that the ear-hook hearing aid 9 is no more than an example and the same may apply to any given portable device 6.
The casing 75 is formed so that, when the ear-hook hearing aid 9 is attached, the power-supplying module 71 and the power-receiving module 61 are in a positional relation such that their coil axes match with each other. This enables charging as intended in the design, with respect to the portable device-use power source device 10, simply by placing the ear-hook hearing aid 9 on the charging device 7. There is no need of warning the user regarding how the ear-hook hearing aid 9 should be placed on the casing 75; i.e., the tilt angle and the rotational angle of the tilt axis of the ear-hook hearing aid 9 with respect to the surface of the support 75b (contact surface) of the casing 75.
(Example Application of Portable Device-Use Power Source Device 10: Ear Hole Fitting Hearing Aid A5)
As shown in
As shown in
Although the above descriptions have been provided with regard to the characteristic parts so as to understand the invention more easily, the invention is not limited to the embodiment as described above and can be applied to the other embodiments and the applicable scope should be construed as broadly as possible. Furthermore, the terms and phraseology used in the specification have been used to correctly illustrate the present invention, not to limit it. In addition, it will be understood by those skilled in the art that the other structures, systems, methods and the like included in the spirit of the present invention can be easily derived from the spirit of the invention described in the specification. Accordingly, it should be considered that the present invention covers equivalent structures thereof without departing from the spirit and scope of the invention as defined in the following claims. In addition, it is required to sufficiently refer to the documents that have been already disclosed, so as to fully understand the objects and effects of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-033094 | Feb 2014 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/055180 | 2/24/2015 | WO | 00 |
