Protective cover and protective cover set with wireless charging function

A protective cover cooperating with a wireless charging dock is provided. The protective cover includes a first cover and a second cover. An electronic device is disposed at the first cover and electrically connected thereto. The second cover is connected to the first cover and thus the second cover can cover the first cover. The second cover includes at least one folding line and at least one charging module, and the charging module receives the inducting power from the wireless charging dock. The second cover can be folded along the folding line to form a folding state. The charging module includes a state sensing module, a power compensating module and a control module. The charging module can adjust a power compensating value and transmit the power compensating value to the wireless charging dock.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of CN application serial No. 201310439939.3, filed on Sep. 24, 2013. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a protective cover and, more particularly, to a protective cover and a protective cover set with a wireless charging function.

Description of the Related Art

As wireless charging technology becomes popular, it is widely applied to electronic devices, such as a smart phone, a video player or a camera. The safety regulation and compatibility between different systems should be taken into consideration when a charging device provides stable and high power to the electronic device.

Conventional wireless charging system includes at least one transmitting end and one receiving end. Both the transmitting end and the receiving end include a coil. Alternative current is provided via the transmitting end, the receiving end collects the near-field inducting power, and a rectifier and a voltage adjusting circuit are used to convert the alternative current to direct current. In order to control the power transmission, the receiver should communicate with the transmitter continuously to inform the required power, electric quantity and a timing of stop power transmission.

Moreover, if a metal object exists between the transmitting end and the receiving end in the power transmission process, the metal object is heated by the electromagnetic waves from the transmitting end. Thus, the metal object may scorch the user or damage the electronic device. In order to solve the problem, a wireless charging system usually includes a foreign object detection (FOD) function. It can detect whether a metal object exists between the transmitting end and the receiving end by calculating the power loss between the transmitting end and the receiving end. If the power loss is larger than a predetermined value, it can be determined that a metal object exists between the transmitting end and the receiving end, and when the temperature of the metal object exceeds a predetermined temperature due to the power absorbed by the metal object, the transmitting end stops providing power.

Most electronic devices include metal components, but the metal components would cause power loss. In order to avoid the misjudgment due to those metal components, an FOD adjusting value is usually matched with a resistance to ground as a power compensation value to offset the power loss caused by the metal components of the electronic device. However, different electronic devices have different compensation values. That means, an electronic device with a wireless charging function can only charge itself, which is rather inconvenient.

BRIEF SUMMARY OF THE INVENTION

A protective cover with a wireless charging function is provided. An electronic device without a receiving end can cooperate with a wireless charging dock by disposing the receiving end at the protective cover of the electronic device. Moreover, even though a folding state of the protective cover is adjusted, an FOD function still runs normally.

The protective cover includes a first cover and a second cover. An electronic device is disposed at the first cover and electrically connected thereto. The second cover is connected to the first cover and can cover the first cover. The second cover includes at least one folding line and a charging module, and the second cover is folded along the folding line to form a folding state. The charging module receives inducting power from the wireless charging dock.

The charging module includes a state sensing module, a power compensating module, a control module and a charging module. The power compensating module is electrically connected to the state sensing module, and the control module is electrically connected to the power compensating module.

In detail, the state sensing module generates a state sensing signal according to the folding state of the second cover. The power compensating module generates a power compensating signal according to the state sensing signal. The control module adjusts a power compensating value according to the power compensating signal and transmits the power compensating value to the wireless charging dock.

A protective cover set with a wireless charging function is also provided. The protective cover set includes the protective cover and the wireless charging dock as stated above, and the charging module of the protective cover receives the inducting power from the wireless charging dock.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A protective cover and a protective cover set with a wireless charging function are illustrated with relating figures. The same symbols denote the same components, and in order to make the invention easy to understand, components which are not directly related are omitted.

Please refer toFIG. 1toFIG. 4A,FIG. 1andFIG. 2are schematic diagrams showing a protective cover in a first folding state and a second folding state in the first embodiment.FIG. 3is a partial enlarged view showing a charging module inFIG. 2.FIG. 4Ais a schematic diagram showing a circuit of a charging module in the first embodiment.

A protective cover1with a wireless charging function cooperates with a wireless charging dock2. The protective cover1and the wireless charging dock2form a protective cover set, and the protective cover1receives the inducting power from the wireless charging dock2.

The protective cover1includes a first cover12and a second cover14. The electronic device3is disposed at the first cover12and is electrically connected to the protective cover1. The second cover14is connected to the first cover12to cover the first cover12. In the embodiment, the second cover14can be folded to cover a display screen of the electronic device3and protect the display screen.

The second cover14includes at least one folding line14A and at least one charging module14B. The second cover14can be folded along the folding line14A to form different folding states. In the embodiment, the second cover14is not folded to form a first folding state (as shown inFIG. 1), and it is folded along the folding line14A to form a second folding state (as shown inFIG. 2). The protective cover1receives the inducting power from the wireless charging dock2via the charging module14B.

Only one charging module14B is shown in the embodiment, and there also may be multiple charging modules14B connected to each other in series according to requirements. Moreover, the disposing position of the charging module14B is not limited.

Compared with the wireless charging module disposed in the electronic device, it is easier to calculate a power compensating value between a transmitting end and a receiving end when the charging module14B is disposed in the protective cover1, and the electronic device without a wireless charging module can cooperate with the wireless charging dock via the protective cover1.

Please refer toFIG. 3, the charging module14B includes a state sensing module141, a power compensating module142and a control module143. The power compensating module142is electrically connected to the state sensing module141and the control module143, respectively. An attaching element145(such as a metal sheet, a magnetic sheet or a plastic sheet) may be disposed between the charging module14B and the electronic device3to avoid affection on the electronic device when the charging module14B operates.FIG. 3only shows an inner connection of the charging module14B, the configuration of a practical product or a circuit may be any well known type of construction and further detailed reference thereto is omitted herein.

The charging module14B further includes at least one charging coil144, a rectifier (not shown) and a voltage adjusting circuit (not shown). The rectifier and the voltage adjusting circuit may be disposed in the control module143. The charging coil144receives and collects a magnetic field change and an electronic field change nearby to generate the inducting power, and provides the inducting power to the electronic device3via the rectifier and the voltage adjusting circuit. The inducting power may be provided via a transmission line (not shown). The transmission line is disposed in the second cover14and is electrically connected to the charging module14B, and provides the inducting power to the electronic device3. One end of the transmission line further includes a plug (such as a micro-USB plug), a magnetic probe joint and a connector for coupling the electronic device3.

Please refer toFIG. 2andFIG. 4A, the state sensing module141can generate a state sensing signal according to the folding state of the second cover14. In other words, different folding states generate different state sensing signals. The state sensing module141includes at least one sensing element141A. The first cover12further includes at least one auxiliary sensing element12A, and the auxiliary sensing element12A is disposed corresponding to the sensing element141A. The sensing element141A and the auxiliary sensing element12A may be metal sheets, magnetic elements or sensors. When the resistance, the magnetic field or the inducing signal between the sensing element141A and the auxiliary sensing element12A is changed, a state sensing signal is generated.

Then, the power compensating module142receives the state sensing signal and generates a power compensating signal accordingly. The control module143receives the power compensating signal and adjusts a power compensating value according to the power compensating signal and sends the power compensating value to the wireless charging dock2.

In the embodiment shown inFIG. 4A, the state sensing signal is generated when the sensing element141A is connected to the auxiliary sensing element12A. The power compensating signal is generated when a resistor R2is conducted.

In the embodiment, when the second cover14is flatly attached to the first cover12to form the first folding state (as shown inFIG. 1), the auxiliary sensing element12A at the first cover12does not attach to the sensing element141A, and thus the state sensing module141does not conduct the resistor R2. The power compensating value of the protective cover is set to the resistance of R1.

After the control module143adjusts the power compensating value, the charging module14B starts charging. If the calculated power loss is larger than a predetermined value (such as 250 mW) after the power compensating value at the first folding state is deducted, the wireless charging dock2determines that a metal object exists between the transmitting end and the receiving end. Thus, the control module143generates a stop signal, the wireless charging dock2stops supplying power, and the charging module14B stops charging.

When the second cover14is folded to form the second folding state (as shown inFIG. 2), the auxiliary sensing element12A of the first cover12is attached to the sensing element141A. The resistor R2is conducted, and the resistor R1and the resistor R2are connected in parallel to make the whole resistance decrease. The power compensating value of the protective cover is set from the resistance of R1to the value R1*R2/(R1+R2).

The power compensating value in the embodiment is a resistance value, but it may also be a current value or a voltage value, which is not limited herein.

After the control module143adjusts the power compensating value, the charging module14B starts charging. If the calculated power loss is larger than a predetermined value (such as 250 mW) after the power compensating value at the second folding state of the second cover14is deducted, the wireless charging dock2determines that a metal object exists between the transmitting end and the receiving end. Thus, the control module143generates a stop signal, the wireless charging dock2stops supplying power, and the charging module14B stops charging. The control module143may be a micro-processor or a micro-chip, which is not limited herein.

In the embodiment, two resistors are connected in parallel, but in other embodiments, a variable resistor may be used. In other words, the control module can change the resistance of a variable resistor according to the power compensating signal, so as to change the power compensating value and achieve similar effect.

FIG. 4Bis a schematic diagram showing a circuit of a charging module in the second embodiment.FIG. 4Cis a schematic diagram showing a circuit of a charging module in the second embodiment.

In the embodiment shown inFIG. 4B, the state sensing module241generates the state sensing signal according to the folding state of the second cover14. The control module243receives the state sensing signal and directly couples a specific resistor accordingly to make the power compensating module242generate the power compensating signal, so as to adjust the power compensating value. In other words, please refer toFIG. 1andFIG. 2, at the first folding state, the control module243couples the resistor R1, and at the second folding state, the control module243couples the resistor R2. Consequently, if the protective cover1has multiple folding ways, multiple groups of resistors are set to match with the folding states.

In the embodiment shown inFIG. 4C, the power compensating module242may be integrated to the control module343. In detail, the difference is that the power compensating value is adjusted via an interface conversion module345. The interface conversion module345receives the signals from the state sensing module341, and adjusts the power compensating value via software parameters to achieve similar effect, but not via a physical component.

Additionally, although the state sensing module, the power compensating module and the control module are shown as different and independent components in the previous embodiments, they can also be integrated to one single chip.

Please refer toFIG. 5toFIG. 7,FIG. 5is a schematic diagram showing a protective cover in the second embodiment.FIG. 6andFIG. 7are schematic diagrams showing a protective cover in a first folding state and a second folding state in the second embodiment.

Similarly, the protective cover4in the embodiment includes a first cover42and a second cover44. The electronic device6is disposed at the first cover42and is electrically connected to the protective cover4. The second cover44is connected to the first cover42to cover the first cover42. The protective cover4can cooperate with a wireless charging dock5.

The difference between the second embodiment and the first embodiment is that the second cover44includes multiple folding lines44A and44B, and the state sensing module441of the charging module44C includes multiple sensing elements441B. The first cover42further includes multiple auxiliary sensing elements42A.

The protective cover4can be folded in different ways to form different folding states. The folding states of the second cover44of the protective cover4can be transmitted via the sensing elements441B and the auxiliary sensing elements42A, and the state sensing signal is provided. The power compensating signal is generated according to the state sensing signal and is transmitted to the wireless charging dock5.

Other components and the application states of the state sensing module, the power compensating module and the control module are similar with those in the first embodiment, which is omitted herein.

In sum, the power compensating value is adjusted via the wireless charging module disposed in the protective cover and the state sensing module which senses the folding state of the protective cover, and the power compensating value is then transmitted to the wireless charging dock. Thus, the protective cover not only conforms to a security specification, but also can be applied by an electronic device without a wireless charging module.