1. Field of the Invention
The present invention relates to a cordless power transmission system, power transmission terminal and electrical appliance, which transfer power by electromagnetic waves.
2. Description of Related Art
As a conventional cordless power transmission system, there is known an LSI that is used for non-contact card or the like. It receives very feeble microwaves emitted into a communication space within a certain range, and operates by converting them into electric power. Such a system is applied to simple data transfer in ticket inspection at a ski lift, or in an intelligent transport system, for example.
Since the conventional cordless power transmission system supposes a single device within a narrow range, it cannot designate a specific device when there are multiple LSI cards within the range of the very feeble microwaves. Thus, the system can bring about erroneous operations in such a situation, presenting a problem of being unsuitable for large scale data communications or radio power transmission. Besides, the system is lacking in versatility with only limited applications.
The present invention is implemented to solve the foregoing problems. It is therefore an object of the present invention to provide a cordless power transmission system, power transmission terminal and electrical appliance suitable for large scale data communications and radio power transmission, and capable of transmitting and receiving electric power stably without any malfunctions even from separate places, thereby making all electrical appliances in a room wireless, for example.
According to a first aspect of the present invention, there is provided a cordless power transmission system comprising: at least one power transmission terminal connected to a network; at least one electrical appliance supplied with power from the power transmission terminal by electromagnetic waves; a network host connected to the network for managing the electrical appliance via the power transmission terminal; a default power transmitter installed in the power transmission terminal for transmitting default power to the electrical appliance by diffractive electromagnetic waves; a first data transceiver installed in the electrical appliance for receiving default power, and for transmitting unique data and required power intensity data to the power transmission terminal by diffractive electromagnetic waves; a second data transceiver installed in the power transmission terminal for receiving the unique data and required power intensity data from the electrical appliance, and for transmitting them to the network host; and a power transmitter installed in the power transmission terminal for transmitting ID data to be assigned to the electrical appliance and power with a required intensity to the electrical appliance by rectilinear electromagnetic waves, wherein the network host obtains the ID data to be assigned to the electrical appliance from the unique data of the electrical appliance, and obtains the required intensity of the power to be transmitted from the power transmission terminal from the required power intensity data sent from the electrical appliance.
Here, the first data transceiver may continuously transmit the ID data, which is assigned to the electrical appliance by the network host, to the power transmission terminal by the diffractive electromagnetic waves while the electrical appliance is in a normal operation mode, and the second data transceiver may notify the network host of the ID data received by the power transmission terminal.
The cordless power transmission system may further comprise a plurality of power transmission terminals, each of which includes a data collector for collecting intensity data of the electromagnetic waves arriving at the power transmission terminal from the electrical appliance, wherein the network host may obtain a 3-D position of the electrical appliance from the intensity data of the electromagnetic waves collected by the power transmission terminals, and assigns a part of the required intensity power to each of the power transmission terminals.
The cordless power transmission system may comprise at least two power transmission terminals, each of which includes a reflectance detector for detecting reflectance of the rectilinear electromagnetic waves while the power transmission terminals are transmitting required power by the rectilinear electromagnetic waves, and the second data transceiver of each of the power transmission terminals may notify the network host of the reflectance, wherein the network host has the power transmission terminals other than the power transmission terminal whose reflectance of the electromagnetic waves varies substantially, transmit the required power.
The network host may be installed in each room, and the network hosts may be interconnected by a cable to exchange data between the rooms.
The network hosts may be connected to an external communication circuit via a fire wall.
The diffractive electromagnetic waves may consist of radio waves; and the rectilinear electromagnetic waves may consist of light waves.
The power transmitter of the power transmission terminal may convert AC power into light power with the required intensity, transmit it to the electrical appliance by light waves, and carry out information communication with the electrical appliance by the light waves; the default power transmitter may convert the AC power into radio power, and transmit the default power to the electrical appliance by the radio waves; and the second data transceiver may carry out information communication with the electrical appliance by the radio waves.
The electrical appliance may further comprise: a light section for converting light power transmitted from the power transmission terminal into electric power, and for carrying out information communication with the power transmission terminal by light waves, wherein the first data transceiver may convert the radio power transmitted from the power transmission terminal into electric power, and carry out information communication with the power transmission terminal by the radio waves.
According to a second aspect of the present invention, there is provided a power transmission terminal that supplies power to an electrical appliance by electromagnetic waves in accordance with a command sent from a network host connected to a network, the power transmission terminal comprising: a default power transmitter for supplying the electrical appliance by diffractive electromagnetic waves; a data transceiver for receiving unique data and required power intensity data associated with the electrical appliance from the electrical appliance by diffractive electromagnetic waves, and notifies these data to the network host; and a power transmitter for transmitting ID data and power with a required intensity to the electrical appliance by rectilinear electromagnetic waves, the ID data and the required intensity of the power being assigned to the electrical appliance and to the power transmission terminal, respectively, by the network host.
According to a third aspect of the present invention, there is provided an electrical appliance that receives power by electromagnetic waves transmitted from a power transmission terminal connected to a network host through a network, the electrical appliance comprising: a default power receiver for receiving default power from the power transmission terminal by diffractive electromagnetic waves; a data transmitter for transmitting unique data and required power intensity data associated with the electrical appliance to the power transmission terminal by diffractive electromagnetic waves; and a power receiver for receiving ID data and power with a required intensity from the power transmission terminal by rectilinear electromagnetic waves, the ID data and the required intensity of the power being assigned to the electrical appliance and to the power transmission terminal, respectively, by the network host.