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Mobile Phone Patent Abstract
Disclosed is a charging device for mobile phone wherein the battery
can be charged by a secondary coil with current induced from a primary
coil in a charging stage. The inventive charging device use magnetic
induction, rather than metal contact, to transfer electrical energy
to battery, therefore, the poor-contact problem in prior art can
be prevented and the alignment tolerance between battery and charging
device can be enhanced.
Mobile Phone Patent Claims
What is claimed is:
1. A charging device for charging the battery of a mobile phone,
comprising
a charging stage having a primary iron core, a primary coil around
said primary iron core and functioned to convert electrical energy
into magnetic energy, a power supply connected to said primary coil
for providing the electrical energy for charging, and a controller
connected to said power supply to control the amount of electrical
power provided by said power supply;
an induced-type power supply having a secondary iron core, a secondary
coil around said secondary iron core and functioned to convert said
magnetic energy linked from said primary iron core to electrical
energy for charging the battery to be charged, a rectifying device
connected to the output of said secondary coil to function as power
supply to battery, a sensor connected to the output of said rectifying
device to detect a charging state of said battery;
an information transmitter functioned to transmit said charging
state detected by said sensor to said controller through said secondary
iron core, whereby said controller can control the electrical energy
provided by said power supply;
wherein said sensor comprises a current sensor in serial connection
with said rectifying device and said battery, and a voltage sensor
in parallel connection with said battery, and said information transmitter
generates a short-circuit signal by short-circuiting the periodic
signal sent from the said charging stage for a certain duration,
thus indicating the charging state to said charging stage.
2. The charging device for charging the battery of mobile phone
as in claim 1, wherein said primary iron core is of ringer-shape
or semi-circular shape with an outer opening.
3. The charging device for charging the battery of mobile phone
as in claim 1, wherein said voltage sensor is a voltage-divider
to sense the charging voltage of said battery.
4. The charging device for charging the battery of mobile phone
as in claim 1, wherein said current sensor is a current meter to
sense the charging current of said battery.
5. A charging device for charging the battery of a mobile phone,
comprising
a charging stage having a primary iron core, a primary coil around
said primary iron core and functioned to convert electrical energy
into magnetic energy, a power supply connected to said primary coil
for providing the electrical energy for charging, and a controller
connected to said power supply to control the amount of electrical
power provided by said power supply;
an induced-type power supply having a secondary iron core, a secondary
coil around said secondary iron core and functioned to convert said
magnetic energy linked from said primary iron core to electrical
energy for charging the battery to be charged, a rectifying device
connected to the output of said secondary coil to function as power
supply to battery, a sensor connected to the output of said rectifying
device to detect a charging state of said battery;
an information transmitter functioned to transmit said charging
state detected by said sensor to said controller through said secondary
iron core, whereby said controller can control the electrical energy
provided by said power supply;
wherein said sensor comprises a current sensor in serial connection
with said rectifying device and said battery;
further wherein said information transmitter generates a intermittent-type
signal formed by interrupting the periodic signal sent from said
charging stage, thus indicating the charging state to said charging
stage.
Mobile Phone Patent Description
FIELD OF THE INVENTION
The present invention relates to a charging device for use with
mobile phones, more particularly, to a contact-free type charging
device for use with mobile phones, which delivers electrical energy
to the mobile phone through magnetic induction.
BACKGROUND
The use of mobile phones has become more and more popular recently
for the provision of fast and convenient communication. The power
source of the mobile phone generally comes from a rechargeable battery,
therefore charging efficiency and the durability of the battery
are important issues. The conventional charging device generally
conveys electrical power to the battery of the mobile phone through
metal contact thereof and the mating metal contact of the battery
to be charged. More particularly, the metal contacts are generally
formed to have specific number and shape to delivers electrical
energy efficiently between the battery and charging device.
However, the metal contact of the charging device and the mating
metal contact may have poor contact therebetween if the battery
is not precisely aligned with the charging device. The charging
efficiency is degraded and the charging time is prolonged due to
the poor contact between those metal contacts.
The transmission of electrical energy by coil induction has been
adopted in the application of electric tooth-brush. More particularly,
the tooth-brush contains a barrel-shaped iron core to receive electrical
energy induced from a cylindrical iron core energized by a power
source. However, the alignment tolerance of above-mentioned induction-type
energy transmission method is not sufficient for the application
of mobile phone.
It is an object of the present invention to provide a charging
device for mobile phone which uses coil induction to convey electrical
energy, thus increasing the alignment tolerance between battery
and charging device, and enhancing the charging efficiency.
To achieve the above objects, the present invention provides a
charging device which has an induced-type power supply device and
a charging stage. The induced-type power supply device comprises
an induced iron core, a secondary coil around the surface of the
iron core, an induced-type power transmission device and a sensor
connected to the iron core. The charging stage comprises a primary
iron core of ringer-shape, a primary coil around the surface of
the primary iron core, a power source and a controller connected
to the coil. When the battery of the mobile phone is to be charged,
the power supply generates an intense magnetic field through sending
current to the primary coil around the primary iron core. The generated
magnetic field induces electric current on the secondary coil around
the induced iron core, which can charge the battery through the
induced-type power transmission device and the sensor.
The above-mentioned sensor is functioned to detect the charging
state of the battery, such as the charging voltage, the charging
current and the remaining charge. The sensor will send a warning
signal to the controller to reduce or turn off charging voltage
in case that the charging voltage or charging current is excessive.
Moreover, the sensor detects the remaining charge of the battery
and sends indication signal to the controller for displaying for
user.
The induced-type power transmission device is commonly used in
conventional charger and has constant-voltage/limiting current or
constant current/limiting voltage function.
Moreover, the inventive charging device can be applied to those
rechargeable battery such as nickel-cadmium (Ni--Cd), Ni-MH or lithium
ion battery.
The various objects and advantages of the present invention will
be more readily understood from the following detailed description
when read in conjunction with the appended drawings, in which:
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is the block diagram of the preferred embodiment according
to the present invention;
FIG. 2 is the detailed circuit of the block diagram in FIG. 1;
FIG. 3 is a perspective view showing the primary iron core and
the induced iron core in the preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is intended to provide a charging device
which conveys electrical power to the buttery of mobile phone by
the induced magnetic field rather than by the physical connection
with metal contacts such that the problem of poor contact in prior
art is prevented and the charging efficiency is enhanced.
FIG. 1 shows the block diagram of the preferred embodiment. The
inventive charging device comprises an induced-type power supply
10 and a charging stage 20. The induced-type power supply 10 is
generally arranged within the handset of the mobile phone. The other
component of mobile phone, such as communication circuit and display
circuit, are not related to the inventive charging device, therefore
the description thereof is omitted for clarity.
As shown in FIG. 1, the induced-type power supply 10 is provided
with an induced iron core 30 for receiving the induced magnetic
flux and secondary coil 31 around the iron core 30 to conduct the
induced current.
The output of the secondary coil 31 is connected to a rectifying
device 132. The type of the rectifying device can be full-wave type
or half-wave type, depending on the battery used.
The battery used can be, for example, Ni--Cd/Ni MH or lithium ion
type. Moreover, a sensor 12 is connected between the output of the
rectifying device 132 and the battery 11 to be charged. The sensor
12 is used to detect the charging condition of the battery 11, such
as charging voltage, charging current, or the remaining charge of
the battery.
With reference now to FIG. 2 the circuit related to the sensor
12 and the processing of signal thereof is described in more detail.
As shown in FIG. 2, the inventive charging device further comprises
an information transmitter 134 arranged between the sensor 12 and
the secondary coil 31 and for sending the detecting result of the
sensor 12 to the charging stage 20.
The information transmitter 134 can send the information, for example,
by short-circuit type signal 33, or intermittent-type signal 35,
as shown in FIG. 2. More particularly, the short-circuit type signal
33 is formed by short-circuiting the periodic signal sent from the
charging stage 20 to the induced-type power supply 10 for a certain
duration. The controller 22 in the charging stage 10 uses the duration
information sent by the information transmitter 134 to control the
amount of magnetic flux. As shown in FIG. 2, the section of signal
B marked by the dashed box denotes the short-circuit type signal
33.
The intermittent-type signal 35 is formed by interrupting the periodic
signal sent from the charging stage 20 to the induced-type power
supply 10 for a period of time per several periods. The controller
22 uses the interrupted period sent from the information transmitter
134 to control the amount of magnetic flux, thus controlling the
charging amount. As shown in FIG. 2, the section of signal A marked
by the lower dashed box represents the intermittent-type signal
35.
The sensor 12 further comprises a current sensor 122 in series
connection with the rectifying device 132 and the battery 11 to
detect the charging current, and a voltage sensor 124 in parallel
connection with the battery 11 to detect the charging voltage. Moreover,
the voltage sensor 124 can also be functioned to detect the charge
amount of the battery 11 and send indication to the charging stage
20 for controlling amount of charging. For example, the voltage
sensor 124 may comprises a voltage divider to detect the charging
voltage.
Moreover, the charging stage 20 comprises a primary iron core 40,
primary coil 41 around the iron core 40, a power supply 23 connected
to the primary coil 41, and a controller 22 connected to the power
supply 23. The power supply is functioned to provide electrical
energy to the charging device by supplying a magnetic flux over
the primary iron care 40 with coil 41. The magnetic flux on the
primary iron core 40 will induce current on the secondary coil 31
around the induced iron core 30, thus charging the battery 11.
Moreover, the controller 22 in the charging stage 20 controls the
power supply 23 according to the detection result sensed by the
sensor 12 and sent through the information transmitter 134. For
example, the controller will command the power supply to reduce
or even stop providing the charging voltage/charging current in
case that the charging voltage/current is harmfully high, thus prolonging
the lifetime of battery.
The inventive charging device is characterized in the shapes and
arrangements of the primary iron core 40 and the secondary iron
core. The primary iron core 40 is of ringer-shape with gap toward
the secondary iron core 30, as shown in FIG. 3. Moreover, the primary
iron core 40 can be of semi-circle shape. As also shown in FIG.
2, both the arms of the primary iron core 40 are two-layer iron
core 42, 43 with gap formed therebetween and toward the secondary
iron core 30. The primary coil 41 around the primary iron core 40
is functioned to convert the electrical energy of power source to
magnetic energy; and the secondary coil 31 around the secondary
iron core 40 is functioned to convert the magnetic energy induced
from the primary iron core 40 to electrical energy charging the
battery. Moreover, the shape and arrangement of the primary iron
core 40 are such that the magnetic flux thereof has efficient coupling
to the secondary iron core, thus increasing the alignment tolerance
of the
charging device.
Although the present invention has been described with reference
to the two preferred embodiments thereof, it will be understood
that the invention is not limited to the details thereof. Various
substitutions and modifications have suggested in the foregoing
description, and other will occur to those of ordinary skill in
the art. Therefore, all such substitutions and modifications are
intended to be embraced within the scope of the invention as defined
in the appended claims.
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