JP2005094843A - Power feeding system and desk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power feeding system for orderly arrangement on the desk or around it, which omits wiring operation in a free address office, etc., and prevents failure to charge portable equipments. <P>SOLUTION: The power feeding system comprises: a desk 10 having a top plate 11 where a power transmission coil 20 is provided inside of it or on the rear surface; an electronic equipment 50 which incorporates a power receiving coil 60; and a voltage applying means for applying a prescribed power supply voltage to the power transmission coil 20. A power is supplied to the electronic equipment 50 through the power receiving coil 60 which is placed at the position corresponding to the power transmission coil 20 applied with power supply voltage by the voltage applying means on the top plate 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a power supply system and a desk for supplying power to an electronic device.

In recent years, personal computers (hereinafter also referred to as PCs) are widely used not only for business purposes but also for home use, as well as peripheral devices such as printers, scanners, digital cameras, and audio devices. In addition, with the development of information communication technology in recent years, portable devices such as notebook PCs and mobile phones are rapidly spreading.

Such an electronic device is often used while being placed on a desk, and is usually usable by being supplied with electric power from an outlet near the desk via a cable or an adapter. In addition, some electronic devices such as portable devices that require charging are charged by a charger or the like. Usually, such a charger is also placed on a desk in consideration of the usability of the electronic device. Often placed.

As a conventional charger, for example, there is a charger that supplies power to an electronic device by electromagnetic induction (for example, see Non-Patent Document 1). According to the charger described in Non-Patent Document 1, since a metal contact with an electronic device is not required, problems such as contact failure due to oxidation or electrostatic breakdown due to static electricity can be solved.
THE HOTLINE Vol. 22, [online], January 1997, TD Corporation, [searched on July 29, 2003], Internet <URL: www.tdk.co.jp/tjbce01/bce022_1.pdf>

By the way, in recent years, as described above, various electronic devices have been widely used, and along with this, a large number of cables, adapters, chargers, etc. are required for power supply, so the desk top and surroundings are cluttered. Therefore, there is a problem that the appearance is deteriorated and the work efficiency is lowered.

In particular, along with the introduction of wireless LAN, recently, an increasing number of companies have been promoting office free addressing for the purpose of space saving and cost reduction. If cables, adapters, chargers, etc. can not be omitted, the wiring work when changing seats will be complicated after all, and the problem of reduced layout freedom, aesthetics, and work efficiency will be solved. Therefore, there is a problem that it is not possible to fully enjoy the merits of free addressing.

In addition, with the spread of portable devices, for example, the number of portable devices used by one individual increases, such as one individual using a plurality of portable devices such as mobile phones, notebook PCs, and PDAs. When it comes, there is also a problem that it tends to forget to charge the portable device, and such a problem is one of the factors that hinder the improvement of work efficiency.

The present invention has been made in view of the above-described problems, and its purpose is to order the desk and the surroundings, and it is possible to omit wiring work in a free address office or the like. An object of the present invention is to provide a power supply system and a desk capable of preventing forgetting to charge a portable device.

In order to solve the above-described problems, the present invention provides the following.
(1) A desk having a top plate provided with a power transmission coil on the inside or the back surface thereof, an electronic device with a built-in power reception coil, and a voltage applying means for applying a predetermined power supply voltage to the power transmission coil,
A power supply system for supplying power via the power receiving coil to the electronic device placed at a position corresponding to the power transmitting coil to which a power supply voltage is applied by the voltage applying means on the top plate.

Furthermore, in the power supply system of the present invention, the following configuration can be adopted.
That is, the electronic device includes an IC tag,
The desk includes an IC reader / writer capable of transmitting / receiving data to / from the IC tag,
Electronic device identification means for identifying whether or not the electronic device is a power supply target based on an identifier read from the IC tag by the IC reader / writer,
The voltage applying unit applies a predetermined power supply voltage to the power transmission coil when the electronic device identifying unit identifies the electronic device as a power supply target.

Furthermore, in the power supply system of the present invention, the following configuration can be adopted.
That is, the desk includes a temperature sensor that senses the temperature of the power transmission coil and / or the top plate near the power transmission coil,
When the temperature sensor senses a temperature equal to or higher than a predetermined value, it includes power supply cutoff means for stopping application of a predetermined power supply voltage to the power transmission coil by the voltage application means.

Furthermore, in the power supply system of the present invention, the following configuration can be adopted.
That is, the electronic device includes voltage measuring means for measuring a voltage output to the electronic device,
Storage means for storing display data associated with the voltage;
And display means for reading out display data corresponding to the voltage measured by the voltage measuring means from the storage means and displaying it.

Furthermore, in the power supply system of the present invention, the following configuration can be adopted.
That is, the present invention is characterized in that power transmission coil moving means is provided that enables the power transmission coil to move within a predetermined range of the top plate or the back surface.

Furthermore, according to the power feeding system of the present invention, the following configuration can be adopted.
That is, the top plate is formed with alignment marks indicating positions where electronic devices are to be placed.

Furthermore, in the power feeding system of the present invention in which the alignment mark is formed on the top plate, the following configuration can be adopted.
That is, the alignment mark is a recess formed on the top plate.

The present invention also provides the following.
(2) It has a top plate provided with a power transmission coil on the inside or the back surface thereof, and voltage application means for applying a predetermined power supply voltage to the power transmission coil,
Power is supplied through the power receiving coil to the electronic device that is mounted on the top plate at the corresponding position of the power transmitting coil to which the power supply voltage is applied by the voltage applying means and that has the power receiving coil incorporated therein. A desk characterized by.

Furthermore, the present invention provides the following.
(3) The desk according to (2) above,
An IC reader / writer capable of transmitting / receiving data to / from an IC tag included in the electronic device;
Electronic device identification means for identifying whether or not the electronic device is a power supply target based on an identifier read from the IC tag by the IC reader / writer,
The voltage applying unit applies a predetermined power supply voltage to the power transmission coil when the electronic device identifying unit identifies the electronic device as a power supply target.

Furthermore, the present invention provides the following.
(4) The desk according to (2) or (3) above,
A temperature sensor for sensing the temperature of the power transmission coil and / or the top plate near the power transmission coil;
When the temperature sensor senses a temperature equal to or higher than a predetermined value, it includes power supply cutoff means for stopping application of a predetermined power supply voltage to the power transmission coil by the voltage application means.

Furthermore, the present invention provides the following.
(5) The desk according to any one of (2) to (4) above,
The power transmission coil moving means is provided, which enables the power transmission coil to move within a predetermined range on the inside or the back surface of the top plate.

Furthermore, the present invention provides the following.
(6) The desk according to (2) to (5) above,
The top plate is formed with an alignment mark indicating a position where the electronic device is to be placed.

Furthermore, the present invention provides the following.
(7) The desk according to (6) above,
The alignment mark is a recess formed on the top plate.

According to the invention of (1), by placing an electronic device on a desk, power can be supplied to the electronic device, so that a cable and an adapter are not required, and the top and the periphery of the desk are neatly arranged. It is possible to improve layout flexibility and aesthetics. Further, wiring work in a free address office or the like can be omitted, and work efficiency can be improved. Furthermore, since it can be charged if the portable device is placed on a desk, it can be prevented from forgetting to charge, and from this point, work efficiency can be improved. .

In addition, when the electronic device includes the IC tag and the desk includes the IC reader / writer and the electronic device identification unit, power is supplied only to the electronic device that is identified as a power supply target. Since it can be supplied, the occurrence of an accident due to energization of a metal foreign object or the like placed on the top plate can be prevented in advance. In addition, power supply to unspecified electronic devices can be prevented, and power loss can be suppressed.

In addition, when the desk is configured to include the temperature sensor and the power supply cutoff sensor, when a metal foreign object or the like placed on the top plate is energized and heated, a predetermined power to the power transmission coil is obtained. Since the application of the power supply voltage is stopped, it is possible to prevent the occurrence of an accident such as a fire due to energization of a metal foreign object or the like.

Further, when the electronic device adopts a configuration including the voltage measuring unit, the storage unit, and the display unit, it is possible to visually recognize the voltage output to the electronic device. It is possible to take measures to efficiently receive power supply such as moving the electronic device to a position where a large voltage can be obtained.

In addition, if the desk adopts a configuration including the power transmission coil moving means, it is possible to arbitrarily change the position where the electronic device is placed, so the layout of the electronic device on the desk can be freely set, The aesthetics and work efficiency can be improved.

In addition, when the configuration in which the alignment mark is formed on the top plate of the desk is adopted, the electronic device is placed on the top plate based on the alignment mark, so that power can be efficiently received. It is possible to accurately place the electronic device.

Furthermore, when a configuration in which the alignment mark is a concave portion is employed, the electronic device can be more accurately placed at a position where power can be efficiently received.

According to the invention of (2), by placing the electronic device on the desk, it is possible to supply electric power to the electronic device, so that a cable and an adapter are not necessary, and the desk and the surroundings are neatly arranged. It is possible to improve layout flexibility and aesthetics. Further, wiring work in a free address office or the like can be omitted, and work efficiency can be improved. Furthermore, since it can be charged if the portable device is placed on a desk, it can be prevented from forgetting to charge, and from this point, work efficiency can be improved. .

According to the invention of (3), power can be supplied only to an electronic device that is identified as a power supply target, and therefore, by energizing a metal foreign object or the like placed on the top plate Accidents can be prevented from occurring. In addition, power supply to unspecified electronic devices can be prevented, and power loss can be suppressed.

According to the invention of (4), since application of a predetermined power supply voltage to the power transmission coil stops when electricity is applied to a metal foreign object or the like placed on the top board and heated, the metal Occurrence of an accident such as a fire due to energization of a manufactured foreign object or the like can be prevented.

According to the invention of (5), since the position where the electronic device is placed can be arbitrarily changed, the layout of the electronic device on the desk can be freely set, and the aesthetics and work efficiency can be improved. Can be planned.

According to the invention of (6), by placing the electronic device on the top plate based on the alignment mark, it is possible to accurately place the electronic device at a position where power can be efficiently received. become.

According to the invention of (7), the electronic device can be more accurately placed at a position where power can be efficiently received.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view schematically showing an example of a power feeding system of the present invention. Since the desk of the present invention is used in the power supply system of the present invention, the power supply system of the present invention will be described below and the desk of the present invention will also be described.

The power supply system according to the present invention includes a desk PC (electronic) having a desk 10 having a top plate 11 provided with a power transmission coil 20 (not shown) on the inside or the back surface, and a power receiving coil 60 (not shown). Device) 50 and a voltage applying means (not shown) for applying a predetermined power supply voltage to the power transmission coil 20, receiving an AC voltage input from an outlet (not shown) via the cable 12, 11, power can be supplied via the power receiving coil 60 to the notebook PC 50 placed at the corresponding position of the power transmitting coil 20 to which the power supply voltage is applied by the voltage applying means.
In the present invention, the electronic device is not particularly limited. For example, a notebook PC, a PDA, a mobile phone, a PHS, a portable audio device, a digital camera, and other portable devices, a shaver, a cordless phone, and the like are required to be charged. An electronic device etc. can be mentioned. An electronic device that does not require charging can also be used.
In the power supply system of the present invention, the electromagnetic induction method described below is adopted for power supply to the electronic device (notebook PC 50).

2A and 2B are explanatory diagrams for explaining the principle of the electromagnetic induction method used in the power feeding system of the present invention. In addition, the broken line in the figure has shown the magnetic flux.
The top plate 1 of the desk is provided with a power transmission coil 2, and an AC voltage E (V) can be input to the power transmission coil 2. In addition, on the top plate 1, an electronic device 5 with a built-in power receiving coil 6 is placed at a position immediately above the power transmitting coil 2. A load resistance R _L (Ω) is connected to the power receiving coil 6.

In the electromagnetic induction method used in the power feeding system of the present invention, an AC voltage E (V) is input to the power transmission coil 2, and an induced electromotive force is generated in the power reception coil 6 by interlinking magnetic fluxes according to Faraday's law. This is a method of receiving power by the load resistance _RL . At this time, an AC voltage is output to the load resistor _RL , but by providing a rectifier or the like in the electronic device 5 on the power receiving side, a DC voltage can be output to the electronic device 5, and as a result, Electric power can be supplied to the device 5.

In addition, as shown in FIG. 2A, in the electromagnetic induction method used in the power feeding system of the present invention, in addition to the magnetic flux (effective magnetic flux φ _R ) contributing to the active power component in the power receiving coil 6, it leaks to the outside. Thus, there is a magnetic flux (reactive magnetic flux φ _L ) that becomes a reactive component. For example, as shown in FIG. 2 (b), to be accurately placed at the predetermined position of the electronic device 5 is on the top plate 1 (the corresponding position of the power transmission coil 2), invalid magnetic flux phi _L is increased, the efficiency It is often impossible to supply power to the electronic device 5. Therefore, in the electromagnetic induction method used in the power feeding system of the present invention, how to reduce the reactive magnetic flux φL is a point for efficiently supplying power to the electronic device 5.
In the present invention, the top plate is preferably made of a material other than metal, such as resin or wood. This is for realizing efficient power supply by electromagnetic induction. Moreover, it is desirable that the thickness of the top plate is such that the distance between the power transmission coil and the power reception coil is about 4 to 6 mm. It is to reduce the reactive flux φ _L.

3 is a partially enlarged longitudinal sectional view of the power feeding system shown in FIG. In the drawing, the inside of the notebook PC 50 shows only the power receiving unit 53.
A notebook PC (electronic device) 50 is placed on the top plate 11 of the desk. On the top plate 11 of the desk, a concave portion 11a is formed as an alignment mark indicating the position where the notebook type PC 50 is to be placed. The convex portion 50a formed on the bottom surface of the notebook type PC 50 has a concave portion. It is mounted on the top plate 11 so as to fit into 11a. Thereby, the notebook PC 50 is accurately placed on the top plate 11 at a corresponding position of the power transmission coil 20 described later.

A power transmission unit 13 is provided on the back side of the top plate 11 so as to be partially embedded, and a cable 12 for power supply is connected to the power transmission unit 13. As shown in FIG. 1, the cable 12 is led out to the leg of the desk 10, and the power transmission unit 13 receives an AC voltage input at a commercial frequency by inserting a plug at the tip of the cable 12 into an outlet. It becomes possible.

The power transmission unit 13 includes a power transmission coil 20. A ferrite core 22 with less high-frequency loss is provided in the power transmission coil 20, and the electromagnetic induction effect can be increased. A primary printed circuit board 23 and a primary electrical component 24 are provided below the power transmission coil 20, and the primary printed circuit board 23 and the primary electrical component 24, and the power transmission coil 20, A parallel resonance circuit described later is configured. A circuit constituted by the primary side printed circuit board 23 and the primary side electric component 24 will be described later. The primary side printed circuit board 23 and the primary side electric component 24 supply a predetermined power source to the power transmission coil 20. It functions as a voltage applying means for applying a voltage.

The power transmission unit 13 includes a substrate type IC reader / writer module 30. The substrate type IC reader / writer module 30 includes an antenna 31, a reader / writer printed circuit board 32, and an electric component 33 for reader / writer, and can transmit and receive data to and from the IC tag 70 provided in the notebook PC 50. is there.
The IC reader / writer module 30 is an IC reader / writer capable of transmitting / receiving data to / from the IC tag 70 included in the notebook PC, and based on an identifier read from the IC tag 70, an electronic device (notebook). The mold PC 50) functions as an electronic device identifying means for identifying whether or not the power supply is an object.

When the electronic device (notebook PC 50) is identified as a power supply target, a command signal is transmitted from the IC reader / writer module 30 to the primary printed circuit board 23 and the primary electrical component 24. Based on the command signal, a later-described reed switch 44 (see FIG. 4) is turned on, and application of a predetermined power supply voltage to the power transmission coil 20 is started. At this time, the primary printed circuit board 23 and the primary electrical component 24 function as voltage application means, and the electronic device (notebook PC 50) is identified as a power supply target by the electronic device identification means. A predetermined power supply voltage is applied to the power transmission coil 20.

On the other hand, the notebook PC 50 includes a power receiving unit 53. The power receiving unit 53 includes an air-core power receiving coil 60, and includes two secondary batteries 61 on the top thereof. An electromagnetic shielding plate 62 made of, for example, composite ferrite is provided between the power receiving coil 60 and the secondary battery 61, and deterioration of the secondary battery 61 due to eddy current can be prevented. A secondary printed circuit board 63 and a secondary electrical component 64 are provided on the upper part of the secondary battery 61, and the secondary printed circuit board 63, the secondary electrical component 64, the power receiving coil 60, and the like. Constitutes a parallel resonant circuit to be described later.

The notebook type PC 50 includes an IC tag 70. The IC tag 70 includes an IC chip 71 including a memory and the like, and an antenna 72, and a unique identifier (ID) is stored in the memory of the IC chip 71.

FIG. 4 is a circuit diagram illustrating an example of a circuit configuration on the power transmission unit 13 side and the power reception unit 53 side. FIG. 4 shows only the circuit configuration related to power transmission on the power transmission unit 13 side and the circuit configuration related to power reception on the power reception unit 53 side.

The circuit on the power transmission unit 13 side includes a fuse 45, a reed switch 44, a full-wave rectifier circuit 43, a smoothing capacitor 28, an oscillation capacitor 26, a switching transistor 42, a starting resistor 27, a resonance capacitor 50, a power transmission coil 20, and feedback. It is comprised by the coil 41 grade | etc.,.

In the circuit on the power transmission unit 13 side, the circuit including the fuse 45, the reed switch 44, the full-wave rectifier circuit 43, and the smoothing capacitor 28 rectifies commercial-frequency alternating current and applies a DC voltage to the terminal of the smoothing capacitor 28. Is a circuit that generates

The circuit composed of the oscillation capacitor 26, the resonance capacitor 25, the starting resistor 27, the switching transistor 42, the power transmission coil 20, and the feedback coil 41 constitutes a collector-tuned self-excited oscillation circuit (high-frequency oscillation circuit). The power transmission coil 20 and the resonance capacitor 25 constitute a parallel resonance circuit. The collector-tuned self-oscillation circuit is configured to oscillate at the resonance frequency of the parallel resonance circuit.

The power transmission coil 20 is a coil wound around the ferrite core 22 (see FIG. 3), and functions as a primary winding of the transformer during charging. The feedback coil 41 is also a coil wound on the ferrite core, and functions as a feedback winding for the transformer during charging.

The reed switch 44 is turned on in the charged state and turned off in the non-charged state. When the reed switch 44 is turned off, the power supply circuit is cut off and the oscillation operation of the oscillation circuit described above is stopped.

The fuse 45 generates heat due to an excessive current and melts when the temperature reaches a predetermined value or more, interrupts the circuit, and stops energization of the power transmission coil 20.
The fuse 45 functions as a temperature sensor that senses the temperature of the power transmission coil 20 and / or the top plate 11 (see FIG. 3) in the vicinity of the power transmission coil 20, and when the temperature sensor senses a temperature equal to or higher than a predetermined value, It functions as a power supply interruption means for stopping application of a predetermined power supply voltage to the power transmission coil 20.
It should be noted that a breaker can be used in place of the temperature sensor and the fuse 45 that functions as a power supply interruption means. As the breaker, for example, a microbreaker having a contact made of a shape memory alloy formed so as to be turned off at a high temperature (for example, 70 ° C.) and turned on at a low temperature (for example, 20 ° C.) is used. Can do. In addition, a sensor capable of measuring the temperature of the power transmission coil 20 or the top plate 11 near the power transmission coil 20 is installed, and the reed switch 44 is turned off when a temperature equal to or higher than a predetermined value is measured by the sensor. May be.

The circuit on the power receiving unit 53 side includes a power receiving coil 60, a resonance capacitor 65, a smoothing capacitor 66, a rectifying diode 67, and a constant current element 68, and the secondary battery 61 can be charged by these circuits. It is configured to be able to. In the circuit on the power receiving unit 53 side, a resonance capacitor 65 is connected in parallel to the power reception coil 60, and the power reception coil 60 and the resonance capacitor 65 constitute a parallel resonance circuit. The power receiving coil 60 is electromagnetically coupled to the power transmitting coil 20 during charging to induce a voltage, and the parallel resonant circuit resonates due to the induced voltage.
In the present invention, the circuit on the power transmission unit 13 side and the circuit on the power reception unit 53 side are not limited to the example shown in FIG. For example, an AC voltage is directly input to the power transmission coil 20 without providing an oscillation circuit and a resonance circuit, and the AC voltage induced in the power reception coil 60 is converted into a DC voltage by a rectifier circuit and a smoothing circuit to recharge the secondary battery. 61 may be supplied.

Next, the operation of the power feeding system according to the present invention will be described with reference to FIGS.
In the following description, the power transmission unit 13 receives an AC voltage input via the cable 12, and the substrate type IC reader / writer module 30 is always placed on the top plate 11 via the antenna 31. It is assumed that an authentication signal for identifying whether or not the electronic device is an object of power supply is transmitted.

First, when the notebook PC 50 is placed on the top plate 11 of the desk 10, the authentication signal is supplied to the IC tag 70 provided in the notebook PC 50. When the IC chip 71 of the IC tag 70 receives the authentication signal via the antenna 72, the IC chip 71 transmits a response signal including an identifier unique to the IC tag 70. Since the IC tag 70 is activated by the current generated in the antenna 72 when the authentication signal (radio wave) transmitted from the notebook PC 50 is received by the coiled antenna 72, the IC tag 70 is connected to the secondary battery 61 of the notebook PC 50. Even when the battery is not charged at all, a response signal can be transmitted.

When the board-type IC reader / writer module 30 receives the response signal via the antenna 31, the board-type IC reader / writer module 30 determines whether or not the notebook PC 50 is a power supply target based on the identifier. This determination is performed, for example, by determining whether or not the identifier stored in advance in the memory of the substrate type IC reader / writer module 30 matches the identifier unique to the IC tag 70. At this time, the board-type IC reader / writer module 30 functions as an electronic device identification unit that identifies whether or not the notebook PC 50 is a power supply target based on the identifier read from the IC tag 70.

When the notebook PC 50 is identified as a power supply target, a command signal is transmitted from the IC reader / writer module 30 to the primary side printed circuit board 23 and the primary side electrical component 24.
The primary printed circuit board 23 and the primary electrical component 24 that have received the command signal turn on the reed switch 44, start energization of the power transmission coil 20, and enter a charged state. At this time, the primary side printed circuit board 23 and the primary side electrical component 24 function as voltage application means for applying a predetermined power supply voltage to the power transmission coil 20. On the other hand, when it is determined that the notebook PC 50 is not a power supply target, the command signal is not transmitted from the IC reader / writer module 30, and the reed switch 44 is not turned on.

When the reed switch 44 is turned on and application of a predetermined power supply voltage to the power transmission coil 20 is started and the charging state is established, the full-wave rectifier circuit 43 performs full-wave rectification, and the smoothing capacitor 28 smoothes the pulsating flow. By doing so, a smoothed DC voltage is generated at the terminal of the smoothing capacitor 48.

Next, in the collector-tuned self-excited oscillation circuit described above, when a current flows to the base of the switching transistor 42 through the starting resistor 27 and the feedback coil 41, the collector current of the switching transistor flows, and the power transmission coil Current also flows through 20. This current gradually increases.

For this reason, a voltage is generated in the feedback coil 41, and a current flows through the base of the oscillation capacitor 26, the feedback coil 53, and the switching transistor 42 due to the voltage generated in the feedback coil 41. With the increase, the collector current of the switching transistor 42 tends to increase further.

Thereafter, when the voltage of the feedback coil 41 is reversed, the switching transistor 42 is turned off. When the polarity of the voltage of the feedback coil 41 is reversed with the passage of time, the voltage flows again to the switching transistor 42 and operates as described above. As described above, the switching transistor 42 is repeatedly turned on / off according to the polarity of the voltage of the feedback coil 41. In this case, the parallel resonance circuit including the power transmission coil 20 and the resonance capacitor 25 has a predetermined frequency. Resonates at.

Therefore, when the switching transistor 42 is turned on and the collector current increases, the collector current of the switching transistor 42 becomes a sine wave current determined by a fixed frequency by the parallel resonance circuit. As a result, the voltage generated in the feedback coil 41 also becomes a sine wave voltage having the above frequency, and the collector voltage of the switching transistor 42 also becomes a sine wave voltage.
On the other hand, when the switching transistor 42 is off, the parallel resonant circuit is in a resonant state, so that the collector voltage of the switching transistor 42 is a continuous sine wave voltage.

As described above, the parallel resonance circuit on the power transmission unit 13 side oscillates at a frequency determined by the inductance value of the power transmission coil 20 and the capacitance value of the resonance capacitor 25. The oscillation circuit oscillates at the resonance frequency of the parallel resonance circuit.

At this time, the power transmission coil 20 functions as a primary winding of the transformer, and the power receiving coil 60 functions as a secondary winding of the transformer and is electromagnetically coupled to each other. As a result, a voltage is induced in the power receiving coil 60, and a current flows through the power receiving coil 60. Then, the parallel resonance circuit constituted by the power receiving coil 60 and the resonance capacitor 65 is in a resonance state at a predetermined frequency, and a sine wave voltage is generated. This voltage causes a current to flow through the rectifier diode 67 to the smoothing capacitor 66, and a smoothed DC voltage is generated at the terminal of the smoothing capacitor 66.
Due to the DC voltage generated at the terminal of the smoothing capacitor 66, a current flows through the secondary battery 61 through the constant voltage element 68, and the secondary battery 61 can be charged.

Further, in the charged state, when the fuse 45 generates heat due to an excessive current and reaches a temperature equal to or higher than a predetermined value, the fuse 45 is melted to interrupt the circuit, and energization to the power transmission coil 20 is stopped. At this time, the fuse 45 functions as a temperature sensor that senses the temperature of the power transmission coil 20 and / or the top plate 11 in the vicinity of the power transmission coil 20, and when the temperature sensor senses a temperature that is equal to or higher than a predetermined value, the power transmission coil 20. It functions as power supply interruption means for stopping application of a predetermined power supply voltage to the power supply.

As described above, according to the present invention, power can be supplied to the notebook PC 50 by placing the notebook PC 50 at the corresponding position of the power transmission coil 20 on the top plate 11, so that a cable or an adapter can be used. Is not necessary, and the top plate 11 of the desk 10 and its periphery can be ordered, and the degree of freedom of layout and the improvement of aesthetics can be achieved. Further, wiring work in a free address office or the like can be omitted, and work efficiency can be improved. Furthermore, since it can be charged if the notebook PC 50 is placed on the top plate 11, it is possible to prevent the user from forgetting to charge, and from this point, work efficiency can be improved. it can.

Further, as described above, the desk of the present invention includes the IC reader / writer and the electronic device identification means, and the voltage application means is identified by the electronic device identification means that the electronic device is the target of power supply. Then, it is desirable to apply a predetermined power supply voltage to the power transmission coil.
Since power can be supplied only to electronic devices that are identified as power supply targets, it is possible to prevent accidents caused by energization of metal foreign objects placed on the top plate. Because you can. In addition, power supply to unspecified electronic devices can be prevented, and power loss can be suppressed.

In addition, as described above, the desk of the present invention preferably includes a temperature sensor and a power supply interruption unit.
Fire due to energization of metal foreign objects, etc., because application of a predetermined power supply voltage to the power transmission coil stops when power is applied to the metal foreign objects mounted on the top plate and heated. This is because the occurrence of accidents such as these can be prevented.

Next, an example of an electronic device according to the power feeding system of the present invention will be described.
FIG. 5 is a perspective view schematically showing a notebook PC 50 in the power supply system shown in FIG.
On the upper surface of the notebook PC 50, a small display unit 51 made of, for example, EL (Electro Luminescence), LCD (Liquid Crystal Display) or the like is provided. The display unit 51 displays display data corresponding to the voltage output to the notebook PC 50. This display data indicates the voltage output to the notebook PC 50 in a stepwise manner like a so-called level gauge.

FIG. 6 is a block diagram illustrating a portion related to display of display data on the display unit 51 in the internal configuration of the notebook PC 50. Note that this portion is independent of the portion of the notebook PC 50 itself, and can operate regardless of whether or not the notebook PC 50 is activated.

The CPU 55 in the control unit 54 reads out various control programs stored in the ROM 56 in accordance with an input signal from the voltage measurement unit 52 described later, develops it in the work memory of the RAM 58, and, for example, the display unit 51 in accordance with the control program. Controls the operation of each part, such as display control.

The voltage measurement unit 52 measures the voltage at the end of the secondary battery 61 (see FIG. 4) at a predetermined timing, and transmits the measurement result to the control unit 54. The power supply circuit 53 is connected to the control unit 54, and the control unit 54 can operate upon receiving power supply from the secondary battery 61 via the power supply circuit 53.

The RAM 58 has a work memory that temporarily stores programs, input data, output data, and the like that can be executed by the control unit 54 read from the ROM 56 in various processes controlled by the CPU 55.

The storage unit 57 stores a plurality of types of display data indicating the voltage output to the notebook PC 50 in a stepwise manner like a so-called level gauge, and is output to the notebook PC (electronic device) 50. It functions as storage means for storing display data associated with voltages.

The VRAM 59 temporarily stores the display data to be displayed on the display unit 51 in accordance with a display instruction from the CPU 55. The display unit 51 is configured by an LCD, an EL, or the like, and displays display data stored in the VRAM 59.

Next, processing relating to display data display on the display unit 51 will be described.
FIG. 7 is a flowchart showing a subroutine for executing the voltage level display process.
First, the control unit 54 determines whether or not the notebook PC 50 is in a charged state (step S1). That is, for example, when the control unit 54 determines that an input signal from the voltage measurement unit 52 has been received, or when the board-type IC reader / writer module 30 determines that the notebook PC 50 is a power supply target ( For example, it is determined that the notebook PC 50 is in a charged state.

If it is determined that the notebook PC 50 is not in a charged state, the process returns to step S1.
On the other hand, when determining that the notebook PC 50 is in the charged state, the control unit 54 measures the voltage at the end of the secondary battery 61 by the voltage measurement unit 52 and receives the measurement result from the voltage measurement unit 52 (step). S2). At this time, the notebook PC 50 functions as voltage measuring means for measuring a voltage output to the notebook PC (electronic device) 50.

Next, the control unit 54 acquires display data corresponding to the measured voltage from the storage unit 57 based on the measurement result (step S3), expands it in the VRAM 59, and displays it on the display unit 51 (step S4). . As a result, display data corresponding to the notebook PC 50 is displayed on the display unit 51 of the notebook PC 50.
At this time, the notebook PC (electronic device) 50 functions as a display unit that reads display data corresponding to the voltage measured by the voltage measurement unit (voltage measurement unit) 52 from the storage unit (storage unit) 57 and displays the display data. To do.

In the power supply system of the present invention, as described above, the electronic device includes a voltage measuring unit that measures a voltage output to the electronic device, and a storage unit that stores display data associated with the voltage. It is preferable that the display device further comprises display means for reading out display data corresponding to the voltage measured by the voltage measuring means from the storage means and displaying it.
Since the voltage output to the electronic device can be visually recognized, for example, the electronic device can be efficiently supplied to a position where a larger voltage can be obtained. This is because it becomes possible to take measures to carry out.

In the above-described example, the case where display data is displayed on the display unit 51 of the notebook PC 50 has been described. However, for example, when the electronic device is a mobile phone, the mobile phone is a so-called antenna picture. It is possible to display display data corresponding to the voltage output to (electronic device).

As described above, the case where the power transmission coil is fixed to the top plate has been described. However, in the power feeding system of the present invention, the desk includes power transmission coil moving means that allows the power transmission coil to move within a predetermined range of the top plate or the back surface. It is desirable to have it. This is because the position where the electronic device is placed can be changed, so that the layout of the electronic device on the desk can be set freely, and the aesthetics and work efficiency can be improved.

Next, a desk according to the present invention provided with the power transmission coil moving means will be described.
FIG. 8A is a plan view schematically showing another example of the desk according to the present invention, and FIG. 8B is a bottom view of the top plate of the desk. In FIG. 8, components corresponding to those shown in FIGS. 1 and 3 are given the same reference numerals.

As shown in FIG. 8A, on the top plate 11 of the desk 10, eight alignment marks indicating positions where electronic devices are to be placed are formed at equal intervals. On two of these alignment marks, a notebook PC 50 and a mobile phone 50, which are electronic devices, are placed, respectively. These alignment marks are drawn on the top plate 11, and the surface of the top plate 11 is flat.

As shown in FIG. 8 (b), on the back side of the top plate 11 of the desk 10, a power transmission unit is attached in the vicinity of each alignment mark 13 so as to correspond to the eight alignment marks 13. A recess 14 is formed.
A power transmission unit 13 similar to that shown in FIG. 3 is attached to two of these power transmission unit attachment recesses 14. The power transmission unit 13 illustrated in FIG. 8 is unitized so as to be detachable from the power transmission unit mounting recess 14 described above.
Further, the length of the cable 12 for inputting the AC voltage to the power transmission unit 13 can be arbitrarily adjusted by the cable storage unit 15 capable of automatically winding the cable 12.

Therefore, the power transmission unit 13 can be attached to any of the eight power transmission unit attachment recesses 14. At this time, since the length of the cable 12 is adjusted to a necessary length by the cable storage portion 15, wiring work is not required when the power transmission unit 13 is moved. At this time, the power transmission unit 13, the power transmission unit mounting recess 14, the cable storage unit 15, and other components related to the movement of the power transmission unit 13 make the power transmission coil 20 movable within a predetermined range of the top plate 11. Functions as a means.

In the example mentioned above, although the case where the two power transmission coils 20 (power transmission unit 13) were provided was demonstrated, in this invention, the number of the power transmission coils 20 is not specifically limited.

In the example described above, eight alignment marks are formed, but the number of alignment marks is not particularly limited, and the number of locations where the power transmission coil 20 is installed or the power transmission coil 20 is installed. The number of alignment marks can be set according to the number of possible locations.

Further, the alignment mark may be formed by drawing on the top plate 11 as shown in FIG. 8, and the recess 11a is formed on the surface of the top plate 11 as shown in FIG. Thus, a mark for alignment may be used. When the concave portion 11a is formed on the surface of the top plate 11, the electronic device can be more accurately placed at a position where power can be efficiently received.
Moreover, while forming a recessed part in the bottom face of an electronic device, the convex part which can be fitted in the said recessed part is formed on the top plate 11, and it is good also considering the said convex part as the mark for alignment. In addition, the pattern or shape of the alignment mark is not particularly limited as long as the position where the electronic device is to be placed can be recognized.

In the above-described example, the case where the electronic device (the notebook PC 50 or the mobile phone 90) is charged has been described. However, the power supply system or desk of the present invention directly supplies the power used by the electronic device without charging. It is good also as supplying.

It is a perspective view showing typically an example of an electric supply system of the present invention. (A), (b) is explanatory drawing for demonstrating the principle of the electromagnetic induction system used for the electric power feeding system of this invention. FIG. 2 is a partially enlarged longitudinal sectional view of the power feeding system shown in FIG. 1. It is a circuit diagram which shows an example of the circuit structure of the power transmission unit 13 side and the power receiving unit 53 side. It is a perspective view which shows typically notebook type PC50 in the electric power feeding system shown in FIG. 4 is a block diagram showing a portion related to display of display data on a display unit 51 in the internal configuration of the notebook PC 50. It is a flowchart which shows the subroutine for performing a voltage level display process. (A) is a top view which shows typically another example of the desk which concerns on this invention, (b) is a bottom view of the top plate of the said desk.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11 Top plate 2, 20 Power transmission coil 5 Electronic device 6 Power reception coil 10 Desk 11a Recessed part (Positioning mark)
12 Cable 13 Alignment mark 14 Power transmission unit mounting recess 15 Cable housing 22 Ferrite core 23 Primary side printed circuit board 24 Primary side electrical component 25, 65 Resonance capacitor 26 Oscillation capacitor 27 Start resistance 28, 66 For smoothing Capacitor 30 Substrate type reader / writer module 31, 71 Antenna 32 Reader / writer printed circuit board 33 Reader / writer electrical component 41 Feedback coil 42 Switching transistor 43 Full-wave rectifier circuit 44 Reed switch 45 Fuse 50 Notebook PC (electronic) machine)
50a Convex part 51 Display part 52 Voltage measurement part 53 Power supply circuit 54 Control part 55 CPU
56 ROM
57 Storage unit 58 RAM
59 VRAM
60 Receiving coil 61 Secondary battery 62 Electromagnetic shielding plate 63 Secondary printed circuit board 64 Secondary electrical component 67 Rectifier diode 68 Constant current element 70 IC tag 72 IC chip

Claims (7)

A desk having a top plate provided with a power transmission coil on the inside or the back surface, an electronic device with a built-in power reception coil, and a voltage application means for applying a predetermined power supply voltage to the power transmission coil,
A power supply system for supplying electric power to the electronic device placed at a position corresponding to the power transmission coil to which a power supply voltage is applied by the voltage application unit on the top plate, via the power reception coil. It has a top plate provided with a power transmission coil inside or on its back surface, and voltage application means for applying a predetermined power supply voltage to the power transmission coil,
Power is supplied via the power receiving coil to an electronic device that is mounted on the top plate at a corresponding position of the power transmitting coil to which a power supply voltage is applied by the voltage applying means and that has a power receiving coil built therein. A desk characterized by. An IC reader / writer capable of transmitting and receiving data to and from an IC tag included in the electronic device;
Electronic device identification means for identifying whether or not the electronic device is a power supply target based on an identifier read from the IC tag by the IC reader / writer,
3. The desk according to claim 2, wherein the voltage application unit applies a predetermined power supply voltage to the power transmission coil when the electronic device identification unit identifies the electronic device as a power supply target. A temperature sensor for sensing the temperature of the power transmission coil and / or the top plate near the power transmission coil;
The desk according to claim 2 or 3, further comprising: a power cut-off means for stopping application of a predetermined power supply voltage to the power transmission coil by the voltage application means when the temperature sensor senses a temperature equal to or higher than a predetermined value. The desk of any one of Claims 2-4 provided with the power transmission coil moving means which enables the said power transmission coil to move to the arbitrary positions of the inside of a top plate, or a back surface. The desk according to any one of claims 2 to 5, wherein an alignment mark indicating a position where an electronic device is to be placed is formed on the top board. The desk according to claim 6, wherein the alignment mark is a recess formed on the top plate.

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