Patent Description:
Embodiments of the present invention are related to wireless power receivers and, specifically, to wireless powered digital locks.

Mobile devices, for example smart phones and tablets, are increasingly using wireless power charging systems. However, there are multiple different standards for wireless transfer of power, which utilize a variety of different transmission frequencies. Frequencies used can vary widely, for example from less than <NUM> to over <NUM>.

The more common standards for wireless transmission of power include the Alliance for Wireless Power (A4WP) standard and the Wireless Power Consortium standard, the Qi Standard. Under the A4WP standard, for example, up to <NUM> watts of power can be inductively transmitted to multiple charging devices in the vicinity of a coil at a power transmission frequency of around <NUM>. Under the Wireless Power Consortium, the Qi specification, an inductive coupling system is utilized to charge a single device at the resonance frequency of the device. In the Qi standard, the receiving device coil is placed in close proximity with the transmission coil while in the A4WP standard, the receiving device coil is placed near the transmitting coil, potentially along with other receiving coils that belong to other charging devices.

Devices that can utilize wireless power transmission incur the cost and the space limitations of power coils and circuitry associated with the wireless power. Therefore, there is a need to develop uses for the wireless power equipment.

[<NUM>] <CIT> discloses a key for selectively allowing access to an enclosure. The key is capable of building variable signals for transmission to a lock controller and interpreting signals received by the key from the lock controller. Signals are inductively transmitted wirelessly between the key and the lock controller. The key transmits power to the lock controller simultaneously with the transmission of data.

[<NUM>] <CIT> discloses an electromechanical lock comprising an electronic circuitry means for providing a wireless interface for a communication device to authenticate with a communication device and issue an open command if the authentication is successful. The lock further comprises an actuator means to receive the open command to set the lock in a mechanically openable state. The lock is configured to wirelessly receive power for the electronic circuitry means and the actuator means from the communication device.

[<NUM>] <CIT> discloses a lock system having a lock unit, a catch, and a memory, as well as a key unit having an aerial for receiving location determining signals. The lock and key units establish a communications link to release the catch only when the location is a location stored in the memory.

The invention relates to an electronic lock according to claim <NUM>; a method of operating an electronic lock according to claim <NUM>; a mobile device according to claim <NUM>; and a method of operating a mobile device according to claim <NUM>. In accordance with aspects of the presents, an electronic lock that interacts with a mobile device is presented. In accordance with the invention, an electronic lock includes a wireless power receiver configured to receiver power from a mobile device; a processor coupled to receive power from the wireless power receiver; a memory coupled to the processor and to receive power from the wireless power receiver; a communication unit coupled to the processor and to receive power from the wireless power receiver, the communication unit configured to communicate with the mobile device; and an actuator coupled to the processor and to receive power from the wireless power receiver. The processor executes instructions stored in a memory for authenticating the mobile device, and providing signals to the actuator according to instructions received from the mobile device once it is authenticated, wherein the communication unit transmits and receives data through the wireless power receiver by monitoring the wireless power for frequency modulation and by applying load modulation, wherein confirming that the device session key is valid includes convoluting the pseudo random number with a pairing key to generate a lock session key, and comparing the lock session key with the device session key.

According to the invention, authenticating the mobile device includes generating a pseudo random number; transmitting the pseudo random number to the mobile device; receiving a device session key from the mobile device; and confirming that the device session key is valid.

A mobile device according to the invention includes a wireless power receiver/transmitter; a power storage coupled to the wireless power receiver/transmitter; a processor coupled to the wireless power receiver/transmitter; a communications coupled to the processor; and a memory coupled to the processor, wherein the processor executes instructions stored in the memory for providing power to the electronic lock, receiving a pseudo-random number from the electronic lock, convoluting the pseudo-random number with a pairing key to generate a device session key, transmitting the device session key to the electronic lock, and providing instructions to the electronic lock to open or close a locking mechanism once the electronic lock validated the mobile device.

These and other embodiments are further discussed below with respect to the following figures.

In the following description, specific details are set forth describing some embodiments of the present invention. The specific embodiments disclosed herein are meant to be illustrative but not limiting.

This description and the accompanying drawings that illustrate inventive aspects and embodiments should not be taken as limiting--the claims define the protected invention. In some instances, well-known structures and techniques have not been shown or described in detail in order not to obscure the invention.

Elements and their associated aspects that are described in detail with reference to one embodiment may, whenever practical, be included in other embodiments in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may nevertheless be claimed as included in the second embodiment.

<FIG> illustrates a system <NUM> for wireless transfer of power. As illustrated in <FIG>, a wireless power transmitter <NUM> receives power from a power supply <NUM> into power transmitter <NUM> to drive a coil <NUM>, producing a magnetic field. Power supply <NUM> can be, for example, a battery based supply or may be powered by alternating current for example 120V at <NUM>. Wireless power transmitter <NUM> drives coil <NUM> at, typically, a range of frequencies, typically according to one of the wireless power standards.

<FIG> further shows a mobile device <NUM> that can be charged with wireless power transmitter <NUM>. The magnetic field produced by coil <NUM> induces a current in coil <NUM>, which results in power being received in a receiver <NUM>. Receiver <NUM> receives the power from coil <NUM> and provides power to the remainder of mobile device <NUM>. As shown in <FIG>, power receiver <NUM> may be coupled to charge storage device <NUM>, which in turn powers the remainder of mobile device <NUM>.

As is further illustrated in <FIG>, mobile device <NUM> may include a processor <NUM>, a user interface <NUM>, specific functional circuitry <NUM> (e.g. cell phone receivers or other functionality used by mobile device <NUM>), and memory <NUM>. Memory <NUM> can include both volatile and non-volatile memory in order store programming instructions executed by processor <NUM> and data.

Mobile device <NUM> also includes communications <NUM> coupled with processor <NUM>. In some embodiments, communications <NUM> is coupled to interface <NUM>, which provides communications with other devices. In some embodiments, interface <NUM> transmit and receive data using wireless transmission protocols, for example Bluetooth, Zigbee, WiFi or other radio links. According to the invention, communications <NUM> is coupled to power receiver <NUM> in order to transmit data through the wireless power coupling by modulating the load. In some embodiments, communications <NUM> may modulate the load of power receiver <NUM> with the same frequency as the transmitted power (in-band communications) or at a different frequency (out-of-band communications). As communications <NUM> is coupled to power receiver <NUM>, transmission of data can be achieved by modulating the load and receipt of data can be achieved through monitoring a frequency modulation of the wireless power received, for example.

In some embodiments, as shown in <FIG>, wireless power transmitter includes communications <NUM>, which allows wireless transmitter <NUM> to receive communications from a receiver through load modulation. Further, transmitter <NUM> may transmit data by, for example, frequency modulating the wireless power transmitted between coil <NUM> and coil <NUM>.

As shown in <FIG>, then, mobile device <NUM> can transmit and receive data through power receiver <NUM> and optionally through the wireless interface <NUM>. However, mobile device <NUM> can also utilize power receiver <NUM> as a power transmitter, thereby wirelessly transferring power from power storage <NUM> to another device.

<FIG> illustrates use of mobile device <NUM> with an electronic lock <NUM>. As illustrated in <FIG>, electronic lock <NUM> includes a power receiver <NUM> that wirelessly receives power from a coil <NUM>. Power receiver <NUM> provides power to processor <NUM>, memory <NUM>, actuator <NUM>, communications <NUM>, and interface <NUM>. As is illustrated, electronic lock <NUM> may have no internal power source and is powered completely from wireless power through power receiver <NUM>. As is further illustrated in <FIG>, power receiver <NUM> of mobile device <NUM> may function as a wireless power transmitter to transfer power stored in power storage <NUM> to electronic lock <NUM> when mobile device <NUM> is placed in proximity to electronic lock <NUM>.

Processor <NUM> is coupled to memory <NUM>, which includes both volatile and non-volatile memory to store programming instructions and data. Processor <NUM> is also coupled to actuator <NUM>. Actuator <NUM> receives an actuation signal from processor <NUM> and, in response, activates an electromechanical interface (for example an armature) to engage or disengage the locking mechanism <NUM> of lock <NUM>.

Processor <NUM> is further coupled to communications <NUM>. Communications <NUM> is coupled to power receiver <NUM> and optionally to interface <NUM>. According to the invention, communications <NUM> can transmit and receive data through wireless power receiver <NUM> by monitoring the wireless power for frequency modulation and by applying load modulation. In some embodiments, communications <NUM> can transmit and receive data through interface <NUM>, which may represent any wireless transmission such as, for example, Bluetooth, Zigbee, WiFi or other radio links.

Consequently, mobile device <NUM> provides power to operate electronic lock <NUM>. Once in operation, electronic lock <NUM> can authenticate mobile device <NUM> and can lock or unlock lock <NUM>. Electronic lock <NUM> is powered during the process by mobile device <NUM> through a wireless power transfer and therefore electronic lock <NUM> may not include an independent power source such as a separate battery. This prevents the problem that, when using a separate battery to power an electronic lock that fails or is discharged, there is no way to authenticate a user or to lock/unlock lock <NUM> electronically.

As is illustrated in <FIG>, mobile device <NUM> can execute an application that operates power receiver <NUM> as a transmitter of wireless power and interfaces with electronic lock <NUM>. Instructions for the application can be stored in memory <NUM> and be executed by processor <NUM>. Executing these instructions, processor <NUM> can operate power receiver <NUM> as a transmitter of wireless power and communicate with electronic lock <NUM> through communications <NUM>. Similarly, memory <NUM> may include instructions to be executed by processor <NUM> so that when electronic lock <NUM> is powered by receiving wireless power in power receiver <NUM>, processor <NUM> can communicate with mobile device <NUM> through communication <NUM> and unlock and/or lock lock <NUM> through actuator <NUM>.

<FIG> illustrates an initiation process <NUM> executed by mobile device <NUM> and electronic lock <NUM> to initialize lock <NUM> with mobile device <NUM>. As shown in <FIG>, device <NUM> initiates by transmitting power in step <NUM>. The power is received in step <NUM>. In steps <NUM> and <NUM>, a key Key0 is negotiated between device <NUM> and lock <NUM>. In some embodiments, the initial pairing between device <NUM> and lock <NUM> can be accomplished by procedures similarly to that used in Bluetooth pairing of devices. In other communications standards, the negotiation between device <NUM> and lock <NUM> establishes that device <NUM> is an authorized user of lock <NUM> and assigns the key Key0 to device <NUM>. In step <NUM>, lock <NUM> stores Key0 in a non-volatile portion of memory <NUM>. In step <NUM>, device <NUM> stores Key0 in a non-volatile portion of memory <NUM>. Storage of Key0 in non-volatile memory insures that Key0 is not lost when electronic lock <NUM> is without power or if power storage <NUM> of device <NUM> becomes discharged. Key0 is the initial pairing key that is established privately when lock <NUM> is first paired with device <NUM>. Device <NUM> may store multiple ones of initial pairing keys that correspond with different ones of locks <NUM>. Similarly, lock <NUM> may include multiple ones of initial pair keys that correspond with different ones of devices <NUM>.

An example of subsequent interactions between device <NUM> and lock <NUM> are illustrated in <FIG>. Again, the interaction begins in step <NUM> when device <NUM> transmits power to lock <NUM> and power is received in step <NUM>. When powered, lock <NUM> in step <NUM> lock <NUM> can generate a pseudorandom number (PSN), which when convoluted with Key0 provides a session key KeyN. In step <NUM>, lock <NUM> transmits the PSN to step <NUM> in device <NUM>. According to the invention, PSN is encrypted during transmission. In step <NUM>, device <NUM> calculates the session key KeyN by convoluting the pairing key Key0 with the PSN. KeyN is the session key that device <NUM> must correctly provide to lock <NUM> in order to operate lock <NUM> (either open lock <NUM> or lock lock <NUM>). KeyN is the convolution of the decrypted PSN generated in step <NUM> and the previously established pairing key Key0 and therefore changes every session to thwart unauthorized use by EM filed interception.

In step <NUM>, device <NUM> transmits the session key KeyN to step <NUM> of lock <NUM>. In step <NUM> of lock <NUM>, lock <NUM> validates KeyN. If KeyN is not valid, then lock <NUM> proceeds to step <NUM> and stops. If KeyN is valid, then lock <NUM> proceeds to step <NUM> to receive instructions. In step <NUM>, device <NUM> transmits instructions to lock <NUM> to lock or unlock lock <NUM>. In step <NUM>, lock <NUM> executes the instructions by providing signals to actuator <NUM> to lock or unlock locking mechanism <NUM>.

Claim 1:
An electronic lock (<NUM>), comprising:
a wireless power receiver (<NUM>) configured to receive power from a mobile device (<NUM>);
a processor (<NUM>) coupled to receive power from the wireless power receiver (<NUM>);
a memory (<NUM>) coupled to the processor (<NUM>) and to receive power from the wireless power receiver (<NUM>);
a communication unit (<NUM>) coupled to the processor (<NUM>) and to receive power from the wireless power receiver (<NUM>), the communication unit (<NUM>) configured to communicate with the mobile device; and
an actuator (<NUM>) coupled to the processor (<NUM>) and to receive power from the wireless power receiver (<NUM>),
wherein the processor (<NUM>) executes instructions stored in the memory (<NUM>) for
authenticating the mobile device, wherein authenticating the mobile device includes generating a pseudo random number, transmitting the pseudo random number to the mobile device, receiving a device session key from the mobile device, and confirming that the device session key is valid; and
providing signals to the actuator (<NUM>) according to instructions received from the mobile device,
wherein the communication unit (<NUM>) transmits and receives data through the wireless power receiver (<NUM>) by monitoring the wireless power for frequency modulation and by applying load modulation,
wherein confirming that the device session key is valid includes convoluting the pseudo random number with a pairing key to generate a lock session key, and comparing the lock session key with the device session key
wherein transmitting the pseudo random number includes encrypting the pseudo random number.