JP2015087641A - Display device and power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose a display device suitable for wireless power transmission not to occupy a large space during charging.SOLUTION: A display device includes a display part that is formed into a rollable planar shape, and a coil forming part that is composed of a conductor and attached to an end of the display device, where the coil forming part is rolled to form a coil for receiving power transmitted from an external wireless power transmission device.

Description

  The present invention relates to a display device that can be rolled and a power transmission device.

  In recent years, display devices (also called flexible displays) that can be bent like paper have been developed. The flexible display does not use a glass substrate like a liquid crystal display device, but uses a thin film, and thus has an advantage of being light and resistant to impact. For this reason, it can be used rounded, and it is convenient when carrying or storing.

  On the other hand, such portable devices can use wireless power transmission technology. The wireless power transmission technology is a technology in which a power transmission device and a power reception device have coils facing each other and transmit power in a contactless manner. The resonance frequency is determined from the radius, length, and number of turns of the coil, and the power transmission efficiency is determined depending on the coincidence of the resonance frequencies of the opposing coils.

The resonance frequency F is obtained by the following equation (1).
F (Hz) = 1 / (2π√LC) (1)
Here, L represents the inductance of the coil, and C represents the capacitance of the capacitor.
L (inductance) is obtained by the following equation (2).
L = k × μ ₀ × π × a ² × n ² / b (2)
Here, k represents the Nagaoka coefficient, μ ₀ represents the vacuum magnetic permeability, a represents the coil radius, b represents the coil length, and n represents the number of turns of the coil.

  FIG. 12 is a diagram illustrating an example of the shape of the coil. In FIG. 12, a represents the radius of the coil, and b represents the length of the coil. Generally, a larger electric power can be transmitted as the radius a of the coil is larger. If wireless power transmission technology is used, charging can be performed without connecting or disconnecting the charging cable. A technique for performing wireless power transmission on such a flexible display is also disclosed (Patent Document 1).

JP 2007-260663 A

  However, the technique described in Patent Document 1 is intended for a small device such as a wristwatch, and the flexible display is bent and fixed in a predetermined shape. For this reason, it was possible to charge in the same shape without taking up a large space during charging. However, when wireless power transmission is applied to a device larger than a wristwatch (such as a tablet PC), there is a problem that a large space is taken up during charging.

In addition, in the case of a flexible display, if the coil is arranged in an unbent portion, the size of the coil is limited, charging efficiency is deteriorated, and charging time is increased.
Therefore, an object of the present invention is to avoid a large space during charging by proposing a display device suitable for wireless power transmission.

  The display device according to the present invention is a display device, and includes a display unit formed in a flat shape that can be rolled, and a coil forming unit that is formed of a conductor attached to an end of the display device, The coil forming unit is rounded to form a coil for receiving power transmitted from an external wireless power transmission device.

  According to the present invention, the space for charging the display device can be reduced, and the convenience for the user can be improved.

4 is a diagram for explaining an example of a configuration of a display device according to Embodiment 1. FIG. It is a figure for demonstrating the form which rounds the display apparatus which concerns on Embodiment 1, and performs wireless power transmission. 3 is a block diagram for explaining an example of components of the display device according to Embodiment 1. FIG. 4 is a diagram for explaining an example of where a coil formed by a coil forming unit is arranged in the display device 100. FIG. It is a figure for demonstrating an example of the circuit structure of the coil formed of a coil formation part. 6 is a diagram for explaining an example of a configuration of a display device according to Embodiment 2. FIG. It is a figure for demonstrating the form which rounds the display apparatus which concerns on Embodiment 2, and performs wireless power transmission. 6 is a block diagram for explaining an example of components of a power transmission device according to Embodiment 2. FIG. It is a figure for demonstrating the comparison of the magnitude | size of a display part. It is a figure for demonstrating that the winding number of a coil changes with the length of a coil formation part. It is a figure for demonstrating an example of the change of the resonant frequency with respect to the winding number of a coil. It is a figure which shows an example of the shape of a coil.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
FIG. 1 is a diagram for explaining an example of a configuration of a display device 100 that is a display device according to the first embodiment.
The display unit 101 is a part that displays image data, and is configured by printing a liquid crystal material on the surface of a thin film formed in a planar shape, and can be rounded.

  The hardware unit 102 is a part for collectively storing components that cannot be rounded when configuring the display device 100. As shown in FIG. 1, in the display device 100 according to the first embodiment, the display unit 101 is configured to be sufficiently larger than the hardware unit 102.

  The coil forming unit 103 is a part that forms a coil for receiving power, and is made of a conductor. By rounding the display unit 101, the coil forming unit 103 is also rounded together to form a coil for receiving power wirelessly, so that the power can be received wirelessly.

FIG. 2 is a diagram for explaining a mode in which the display device 100 is rolled to perform wireless power transmission. In FIG. 2, the same reference numerals are used for parts common to FIG.
As described above, the display unit 101 and the coil forming unit 103 are rounded into a shape as shown in FIG.

  The power transmission device 201 is formed in a cylindrical shape in which the rounded display device 100 can be disposed. The power transmission device 201 is a device that operates as a cradle, for example. In addition, the power transmission device 201 has a wireless power transmission coil 203 on the bottom surface of the cylindrical shape, and wirelessly transmits power to the display device 100 via the wireless power transmission coil 203. In this case, the power receiving coil formed by the coil forming unit 103 and the wireless power transmitting coil 203 formed in advance on the bottom of the power transmission device 201 are opposed to each other, so that wireless power transmission can be performed from the outside. Done. The outlet plug 202 is connected to an AC commercial power source and supplies AC power to the power transmission apparatus 201. In the first embodiment, the coil forming unit 103 is arranged at the lower end of the display unit 101 in order to make the coil formed by rounding the coil for wireless power transmission provided on the power transmission device 201 side. Has been placed.

FIG. 3 is a block diagram for explaining an example of components of the display device 100.
In FIG. 3, the display unit 101 and the coil forming unit 103 are the same as those described in FIGS.

The battery 301 is a part that stores the operating power of the display device 100. The power received by the coil forming unit 103 is stored in the battery 301 and used as the power source of the display device 100.
The power supply unit 302 is for supplying power to each component of the display device 100. The power supply unit 302 converts the power supplied from the battery 301 into a voltage value used by each component of the display device 100. Supply to component.

The application processing unit 303 is a part that stores and drives a software application. For example, it has an application that can be displayed on a display such as a calendar function or a calculator function.
The image processing unit 304 is for generating image data, and generates image data that can be displayed on the display unit 101 in accordance with an instruction from the application processing unit 303.

  The driver 305 is for driving the display unit 101, and determines a horizontal driving voltage and a vertical driving voltage of the display unit 101 in accordance with an instruction from the image processing unit 304. Here, the battery 301, the power supply unit 302, the application processing unit 303, the image processing unit 304, and the driver 305 are included in the hardware unit 102.

  However, the capacity of the battery 301 is limited by the size of the hardware unit 102. When the battery 301 is a large-capacity battery, a sheet-shaped large-capacity battery can be installed on the back surface of the display unit 101 without being included in the hardware unit 102.

  4 and 5 are diagrams for explaining an example of electrical connection of coils formed by the coil forming unit 103. FIG. FIG. 4 is a diagram for explaining an example of where the coil formed by the coil forming unit 103 is arranged on the display device 100. FIG. 5 is a diagram for explaining an example of a circuit configuration of a coil formed by the coil forming unit 103. 4 and 5, the same reference numerals are used for portions common to those in FIG.

  The electric wire 401 is a line that transmits the current flowing through the coil forming unit 103. The electric wire 401 is connected to both ends of the coil forming unit 103. The capacitor 402 is for storing electric power flowing in the electric wire 401, and both ends of the capacitor 402 are connected to the electric wire 401.

FIG. 4 shows a state where no coil is formed by the coil forming unit 103. FIG. 5 shows a state where a coil for receiving power is formed by the coil forming unit 103 by rounding the display unit 101.
Thus, in the first embodiment, an LC resonance circuit is formed from the coil configured by the coil forming unit 103 and the capacitor 402. As a result, electric power that vibrates at the resonance frequency can be stored.

  As described above, according to the first embodiment, a coil configured by the coil forming unit 103 is formed by rolling the display device 100 to form an LC resonance circuit, and wireless power transmission can be performed. Thereby, there is an effect that the battery 301 can be charged in a small space.

[Embodiment 2]
In the second embodiment, a method of efficiently transmitting power wirelessly when the resonance frequency of the coil changes depending on the number of turns and the length of the coil will be described.
FIG. 6 is a diagram for explaining an example of a configuration of a display device 600 that is a display device according to the second embodiment. In FIG. 6, the same reference numerals are used for portions common to FIG.
The non-contact communication unit 601 is a communication unit that can transmit information in a non-contact and power saving manner. The non-contact communication unit 601 stores information such as the coil length of the display device 600 according to the second embodiment, and is disposed at an end portion that is aligned horizontally with the coil forming unit 103.

FIG. 7 is a diagram for describing a mode in which the display device 600 is rolled to perform wireless power transmission. In FIG. 7, the same reference numerals are used for portions common to FIG. 1 and portions common to FIG. 6.
The non-contact communication unit 601 is provided at the same end as the coil forming unit 103.
The coil forming unit 103 and the non-contact communication unit 601 are disposed in the power transmission device 201. In this state, the coil forming unit 103 receives power transmission wirelessly from the power transmission device 201. The non-contact communication unit 601 transmits information on the display device 600 to the power transmission device 201.

FIG. 8 is a block diagram for explaining an example of components of the power transmission apparatus 201 according to the second embodiment.
The non-contact communication detecting unit 801 is for receiving and acquiring information from the non-contact communication unit 601 of the display device 600, and the acquired information is sent to the arrangement determining unit 802.

  The arrangement determination unit 802 determines the arrangement of the power receiving coil formed by the coil forming unit 103 from the received information. When the coil forming unit 103 is rolled and stored in the power transmission device 201, the number of turns of the coil varies depending on the length of the coil forming unit 103. When the number of turns of the coil changes, the resonance frequency of the wireless power transmission also changes. Therefore, the arrangement determination unit 802 determines the resonance frequency information changed according to the change of the number of turns of the coil and outputs it to the frequency adjustment unit 803.

The frequency adjustment unit 803 adjusts the variable capacitor 803a in the power transmission device 201 from the resonance frequency information sent from the arrangement determination unit 802 to change the transmission resonance frequency.
The power transmission unit 804 performs power transmission in order to perform wireless power transmission to the display device 600 housed in the power transmission device 201. The power transmitted from the power transmission unit 804 is transmitted to the coil forming unit 103 of the display device 600 shown in FIG.

9 and 10 are diagrams for explaining that the number of turns of the coil varies depending on the length of the coil forming portion 103. FIG.
FIGS. 9A and 10A show a display device 600 of model A, and FIGS. 9B and 10B show a display device 600 of model B. FIG.
9A and 9B are diagrams for explaining the comparison of the sizes of the display unit 101. FIG. FIG. 10A and FIG. 10B are for explaining a comparison of the number of turns of the coil forming unit 103 when the display device 600 is rolled up inside the cylindrical power transmission device 201. FIG.

As shown in FIGS. 9A and 9B, the display area of the model B display apparatus 600 is larger than that of the display apparatus 600 of the model A. If the aspect ratio is maintained, the length of the coil forming portion 103 becomes longer in proportion to the size of the display area.
Depending on the length of the coil forming portion 103, the number of turns of the formed coil also changes. In FIG. 10 (a), there is 1 turn, but in FIG. 10 (b), there are 2 turns.

  When the number of turns of the coil changes, the resonance frequency of wireless power transmission also changes. Therefore, by storing the length information of the coil forming unit 103 in the non-contact communication unit 601 and transmitting it to the power transmission device 201, the power transmission device 201 can calculate a resonance frequency suitable for the display device 600. It becomes.

FIG. 11 is a diagram for explaining an example of a change in the resonance frequency with respect to the number of turns of the coil.
Since the radius of the coil is the same depending on the cylindrical shape of the power transmission device 201, only the number of turns of the coil changes depending on the size of the display device 600.

  FIG. 11 shows an example in which the number of coil turns is one in model A and the number of coil turns is two in model B. When other conditions such as the length of the coil and the capacitor capacity are the same, the resonance frequency also changes as the number of turns of the coil changes.

  In this manner, in the second embodiment, the wireless power transmission system is configured by the display device 600 and the power transmission device 201. Accordingly, even when the display device 600 has a plurality of models and the resonance frequency of the coil formed by the coil forming unit 103 changes, the power is efficiently and wirelessly transmitted using the common power transmission device 201. can do.

  As described above, according to the second embodiment, the resonance frequency can be determined based on the size of the display device 600 and the inner diameter of the cylindrical shape of the power transmission device 201, so that efficient wireless power transmission is performed. It becomes possible.

[Embodiment 3]
At least one of the various functions, processes, and methods described in the first and second embodiments can be realized using a program. Hereinafter, in the third embodiment, a program for realizing at least one of the various functions, processes, and methods described in the first and second embodiments is referred to as “program X”. In the third embodiment, a computer for executing the program X is referred to as “computer Y”. A personal computer, a microcomputer, a CPU (Central Processing Unit), etc. are examples of the computer Y.

  At least one of the various functions, processes, and methods described in the first and second embodiments can be realized by the computer Y executing the program X. In this case, the program X is supplied to the computer Y via a computer-readable storage medium. The computer-readable storage medium according to the third embodiment includes at least one of a hard disk device, an optical disk, a CD-ROM, a CD-R, a memory card, a ROM, and a RAM. Further, the computer-readable storage medium according to the third embodiment is a non-transitory storage medium.

DESCRIPTION OF SYMBOLS 101 Display part 102 Hardware part 103 Coil formation part 201 Power transmission apparatus 202 Outlet plug 301 Battery 302 Power supply part 303 Application process part 304 Image processing part 305 Driver 401 Electric wire 402 Capacitor 601 Non-contact communication part 801 Non-contact communication detection part 802 Arrangement determination unit 803 Frequency adjustment unit 804 Power transmission unit

Claims (10)

A display device,
A display unit formed in a planar shape that can be rounded;
A coil forming portion made of a conductor attached to an end of the display device;
The display device according to claim 1, wherein the coil forming unit is rounded to form a coil for receiving power transmitted from an external wireless power transmission device.   The display device according to claim 1, wherein the display unit is configured by printing a liquid crystal material on a surface of a thin film and configured to be roundable. Having a hardware part attached to the end of the display device;
The display device according to claim 1, wherein the hardware unit includes an image processing unit that generates image data that can be displayed on the display unit, and a driver that drives the display unit. .   The display device according to claim 1, wherein the coil forming portion is disposed at a lower end portion of the display device.   The display device according to claim 1, further comprising a non-contact communication unit that transmits information in a non-contact manner with the outside.   The non-contact communication unit stores information on the display device and is disposed at an end of the coil forming unit, and communicates with the wireless power transmission device. 5. The display device according to 5.   The display device according to claim 5, wherein the information transmitted from the non-contact communication unit to the wireless power transmission device is information related to a length of the coil forming unit. A power transmission device,
Wireless power transmission means for transmitting power to the coil formed by rounding the coil forming portion of the display device;
The wireless power transmission means is disposed on the bottom surface of the power transmission device formed in a cylindrical shape,
The wireless power transmission unit is configured to wirelessly transmit power to the display device via the coil when the display device is rounded and disposed on the bottom surface. Non-contact communication detecting means for communicating with a non-contact communication unit disposed in the display device,
The power transmission device according to claim 8, wherein the non-contact communication detecting unit acquires information on the length of the coil by performing communication with the non-contact communication unit.   The power transmission device according to claim 9, further comprising a determining unit that determines a resonance frequency based on information on the length of the coil and a cylindrical inner diameter of the power transmission device.

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