JP2006018132A - Display apparatus and information terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible display apparatus eliminating the need of an input/output terminal to be mechanically connected with a main body device or the like and enhancing the degree of freedom when transmitting and receiving information. <P>SOLUTION: The display apparatus comprises a display panel, a power source circuit, and a display signal receiving means provided at the periphery of the display panel. The power source circuit has a coil for generating electromotive force by electromagnetic induction. The image signal receiving means has an antenna for receiving electric waves transmitted from an external device, and a signal extracting circuit for extracting a signal for display out of the electric waves received by the antenna. Also, the image signal receiving means includes at least one light receiving means for receiving an optical signal supplied from the external device, and an optical signal extracting circuit for extracting the signal for display out of the optical signal received by the at least one light receiving means. The display panel of the display apparatus in this invention is an organic EL display panel. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device and an information terminal device, and more particularly to a flexible display device that can be bent and an information terminal device using the same.

In recent years, an electroluminescence display device using an organic electroluminescence element (hereinafter referred to as an OLED display device) has attracted attention as a next-generation flat display device that replaces a CRT or a liquid crystal display device.
This OLED display device is (1) a voltage required for light emission as low as 10 V or less, and can reduce power consumption, compared with a current flat display device such as a liquid crystal display device. No backlight needed (3) No vacuum structure like the same self-luminous plasma display device is needed, suitable for weight reduction and thinning, (4) Response time is as short as several microseconds, The viewing angle is as wide as 170 degrees or more.
In particular, a flexible display device is expected to be realized by making use of the characteristics of weight reduction and thinning (see Patent Document 1 below).

As prior art documents related to the invention of the present application, there are the following.
JP 2003-43955 A JP 2000-20665 A

In the display device described in Patent Document 1 described above, a flexible display is mechanically and electrically connected to a handle containing a power supply.
However, in the display device described in Patent Document 1 described above, the input / output terminals of the flexible display are mechanically connected to the handle. For example, the flexible display is rolled up and carried using the characteristics of the flexible display. In addition, there is a problem that the flexible display is easily broken at the input / output terminals.
As described above, assuming that the flexible display is rolled up and carried, protection of the input / output terminals of the flexible display is one problem, and without the input / output terminals, the reliability of the display device is dramatically improved. It is possible.
On the other hand, the wireless tag described in Patent Document 2 is known as one that does not require an input / output terminal.
In the wireless tag described in Patent Document 2, power is received and information is transmitted and received by an LSI (semiconductor integrated circuit) and an antenna formed on a flexible film.
However, the wireless tag described in Patent Document 2 has a problem that power and information are transmitted and received with one antenna, and the degree of freedom in transmitting and receiving information is lost.

The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to transmit and receive information without requiring an input / output terminal that is mechanically connected to a main unit or the like. An object of the present invention is to provide a flexible display device with improved flexibility.
Another object of the present invention is to provide an information terminal device using the main body device and the flexible display device described above.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
In order to achieve the above object, a display device of the present invention includes a display panel, a power supply circuit provided around the display panel, and display signal receiving means, and the power supply circuit generates an electromotive force by electromagnetic induction. The image signal receiving means includes an antenna that receives a radio wave transmitted from an external device, and a signal extraction circuit that extracts a display signal from the radio wave received by the antenna.
The image signal receiving means extracts at least one light receiving means for receiving an optical signal supplied from an external device, and light for extracting the display signal from the optical signals received by the at least one light receiving means. And a signal extraction circuit.
In the display device of the present invention, the display panel is an organic EL display panel.
Furthermore, the present invention is an information terminal device comprising the display device described above and a main device.

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the display device of the present invention, an input / output terminal that is mechanically connected to a main body device or the like is not required, and the degree of freedom in transmitting and receiving information can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanation thereof is omitted.
FIG. 1 is a diagram showing a schematic configuration of a display device according to an embodiment of the present invention.
The display device of this embodiment includes a display panel 11, a planar coil 12, a radio wave reception circuit 13, and a constant voltage circuit 16. Here, the planar coil 12, the radio wave reception circuit 13, and the constant voltage circuit 16 are provided around the display panel 11.
The display panel 11 includes a plurality of subpixels arranged in a matrix, and each subpixel includes an organic electroluminescence element (hereinafter simply referred to as an EL element) and a thin film transistor for driving the EL element. Have.
FIG. 2 is a circuit diagram showing an equivalent circuit of one representative pixel of the display panel 11 of the present embodiment.
In FIG. 2, OLED (m, n) is an EL element, Qd (m, n) is a driving thin film transistor (hereinafter referred to as EL driving TFT) for supplying current to the EL element, and Cst (m, n) Is connected to the gate electrode of the EL drive TFT (Qd (m, n)) and holds the video signal voltage, and Qs (m, n) applies the video signal voltage to the holding capacitor Cst (m, n). A thin film transistor for switching (hereinafter referred to as a switch TFT) for supply.
In the equivalent circuit shown in FIG. 2, when the scanning signal line G is sequentially scanned line by line and a high level scanning clock is applied to the gate electrode of the switch TFT (Qs (m, n)), the switch TFT ( Qs (m, n)) is turned on, whereby an analog video signal voltage is supplied from the video signal line Dn to the holding capacitor element Cst (m, n) via the switch TFT (Qs (m, n)). And held in the holding capacitor element Cst (m, n).
Based on the analog video signal voltage held in the storage capacitor element Cst (m, n), the current flowing through the EL drive TFT (Qd (m, n)) is controlled, that is, it corresponds to the analog video signal voltage. A current is supplied to the EL element OLED (m, n), whereby the EL element OLED (m, n) emits light and an image is displayed.

The EL drive TFT (Qd (m, n)) and the switch TFT (Qs (m, n)) are thin film transistors (hereinafter referred to as “polysilicon layers”) formed by a low-temperature process as semiconductor layers. It is called a polysilicon transistor).
Further, the planar coil 12 is formed using a wiring material used when the display panel 11 is formed.
The wireless radio wave receiving circuit 13 is formed using the above-described polysilicon transistor and a wiring material used when the display panel 11 is formed.
The radio wave receiving circuit 13 receives power, an image signal, a display device control signal, and the like transmitted wirelessly from the image signal transmission device (main device) 14 and displays an image.
The planar coil 12 is provided at a position corresponding to the coil 15 disposed in the vicinity of the display panel 11. When an alternating current is passed through the coil 15 in the image signal transmission device 14, the coil 15 generates an induced magnetic field, and an electromotive force is generated in the planar coil 12 by the induced magnetic field.
The electromotive force is converted into a DC voltage by a constant voltage circuit 16 formed on the display panel 11 and having an AC / DC converter, and then adjusted to a desired power and stabilized to drive the display panel 11. Create
The constant voltage circuit 16 is also composed of the aforementioned polysilicon transistor.

The image signal is transmitted wirelessly from the wireless transmission antenna 17 of the separately arranged image signal transmission device 14 and received by the wireless radio wave reception circuit 13 via the reception antenna 22 of the display panel 11.
The image signal transmission device 14 is formed with a slot 18 that can accommodate a wireless transmission antenna 17 and a media device, and further, a button such as a numeric keypad 19 is installed to enable switching of images. Further, a TV receiver or the like may be mounted, and the keypad 19 can be used for channel switching.
Thus, in this embodiment, there is no electrical contact between the display panel 11 and the image signal transmission device 14.
And electric power is transmitted to the display panel 11 from the image signal transmitter 14 using an induced electromotive force. By using the induced electromotive force, a considerable amount of power can be sent without contact.
The signal is transmitted wirelessly using radio waves or light. The radio wave receiver is composed of a polysilicon transistor, like an EL drive TFT (Qd (m, n)) for driving an OLED and a switch TFT (Qs (m, n)), and an EL drive TFT for driving an OLED. (Qd (m, n)) and the switch TFT (Qs (m, n)) can be formed integrally.

As described above, the signal from the image signal transmission device 14 to the display panel 11 is transmitted wirelessly using radio waves or light.
Hereinafter, the configuration when using radio waves or light will be described.
FIG. 3 is a block diagram illustrating a configuration in the case where a signal is transmitted by radio waves from the image signal transmission device 14 to the display panel 11 in the present embodiment.
The signal created by the image signal transmission device 14 is transmitted as a radio wave from the transmission antenna 17. This radio wave can use generally used 13.56 MHz or 2.45 GHz frequency bands. When 2.45 GHz is used as the frequency band, the receiving antenna 22 can be as small as about 30 mm.
The reception antenna 22 is formed on one substrate (TFT substrate) 21 of the display panel simultaneously with the EL drive TFT (Qd (m, n)) for driving the OLED and the switch TFT (Qs (m, n)). Is done. The substrate 21 is a substrate on which the OLED driving EL driving TFT (Qd (m, n)) and the switch TFT (Qs (m, n)) are formed.
The signal received by the receiving antenna 22 is adjusted by the signal adjustment circuit 23 and then input to the display device driving circuit 25 to display an image on the display panel 11.

There are three types of signals transmitted from the image signal transmission device 14: an image signal, a display device control signal, and a synchronization signal.
These may be transmitted / received by providing respective antennas on one substrate 21 using different frequency bands, or may be transmitted / received as a single signal by multiplexing.
FIG. 4 shows the data flow when multiplexed.
The multiplexed signal 31 is received by the receiving antenna 32, and then amplified to a sufficient signal strength by the amplifier circuit 33. Then, the multiplexed signal 31 is separated into the three kinds of signals by the separation circuit 34 and controls the display device driving circuit 35. Then, an image is displayed on the display panel 11. The three types of signals may be partly multiplexed and the rest may be sent as separate radio waves.
Further, the synchronization signal may be generated by an alternating current for power transportation.
The data flow in this case is as shown in FIG. 5, and a frequency converter 41 is installed between the planar coil 12 for power reception and the constant voltage circuit 16 having an AC / DC converter to create a synchronization signal 42. .

FIG. 6 is a block diagram illustrating a configuration in the case where a signal is transmitted from the image signal transmission device 14 to the display panel 11 by light in the present embodiment.
A plurality of image signals, display device control signals, and synchronization signals created by the image signal transmission device 51 are converted into optical signals by a plurality of light emitting elements 52 as digital signals and formed on one substrate 53 of the display panel 11. Is received by the light receiving element 54. The substrate 53 is a substrate (TFT substrate) on which an OLED driving EL drive TFT (Qd (m, n)) and a switch TFT (Qs (m, n)) are formed. Further, it is sufficient that at least one light emitting element 52 and light receiving element 54 are provided.
The output of the signal converted into electricity by the light receiving element 54 is adjusted by an amplifier circuit and input to the display device driving circuit 25 to display an image on the display panel 11.
As the light emitting element 52, a light emitting diode (LED), an organic EL, an inorganic EL, a VFD (Vacuum Fluorescent Display), or the like can be used.
The positional relationship between the light emitting element 52 and the light receiving element 54 is arranged so that the light emitting element 52 and the light receiving element 54 face each other as shown in FIG.
In this case, in order to block light from the outside, a light shielding element 61 may be provided at the contact portion of the light emitting element 52 and the display panel 11. In order to improve utilization efficiency, a reflective film 62 may be provided.

The optical signal passes through one substrate (TFT substrate) 53 of the display panel 11 or the other substrate (sealing substrate) 63 of the display panel 11 and is disposed on the one substrate 53 so as to face the light emitting element 52. Received by the received light receiving element 54 and converted into an electrical signal by the light receiving element 54.
As the light receiving element 54, a photodiode made of amorphous silicon or polysilicon having a PN or PIN junction structure can be used. These are formed simultaneously on one substrate 53 when a thin film transistor is formed. Can do.
The light emitting element 52 does not need to be installed at a position facing the light receiving element 54. As shown in FIG. 8, the output of the light emitting element 72 is obtained by using an optical fiber 71 using quartz or the like for light transmission. You may make it guide to the opposing position of the light receiving element 73. FIG.
Further, in the case of the configuration shown in FIG. 8, as shown in FIG. 9, the end portion 81 on the light receiving element 73 side of the optical fiber 71 is cut obliquely, and a highly reflective film 82 such as AL is installed on the cut surface. The connecting portion between the optical fiber 71 and the display panel 11 can be made thin and flat.
Thereby, compared with the case where the light emitting element 52 is directly installed on the display panel 11, the connection portion can be made thinner.

By transmitting a signal from the image signal transmission device 51 to the display panel 11 with light, the light emitting element 52 and the light receiving element 54 for transmission can be arranged in parallel, and parallel communication can be performed. It can be suppressed to the same level as the wired circuit.
Furthermore, by transmitting a signal from the image signal transmission device 51 to the display panel 11 with light, problems such as signal interference and malfunction of other devices do not occur even if parallel transmission is performed.
As described above, according to this embodiment, a truly flexible and lightweight display can be obtained by placing a power supply outside. In addition, since there is no input / output terminal, it is difficult to break and can be completely sealed, so that reliability can be improved.
Since the power supply device and the signal transmission device are separately provided, and the power transmission means and the information transmission means are separated, a flexible display device that improves the flexibility in transmitting and receiving information is provided. It is to provide.
As a result, it can be rolled and stored, and a large display can be easily stored. Furthermore, complete waterproofing can be achieved, and use outdoors or in water is also possible.
As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.

It is a figure which shows schematic structure of the display apparatus of the Example of this invention. It is a circuit diagram which shows the equivalent circuit of the typical 1 pixel of the display apparatus of the Example of this invention. In the Example of this invention, it is a block diagram which shows schematic structure in the case of transmitting a signal with an electromagnetic wave from an image signal transmission apparatus to a display panel. In the Example of this invention, it is a figure for demonstrating an example of the transmission method of the signal in the case of transmitting a signal with an electromagnetic wave from an image signal transmission apparatus to a display panel. In the Example of this invention, it is a figure for demonstrating the other example of the transmission method of the signal in the case of transmitting a signal with an electromagnetic wave from an image signal transmission apparatus to a display panel. In the Example of this invention, it is a block diagram which shows the structure in the case of transmitting a signal with light from an image signal transmission apparatus to a display panel. In the Example of this invention, it is a figure which shows an example of the positional relationship between the light emitting element and light receiving element in the case of transmitting a signal with light from an image signal transmission device to a display panel. In the Example of this invention, it is a figure which shows the other example of the positional relationship between the light emitting element in the case of transmitting a signal with light from an image signal transmission apparatus to a display panel. In the Example of this invention, it is a figure which shows the other example of the positional relationship between the light emitting element in the case of transmitting a signal with light from an image signal transmission apparatus to a display panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Display panel 12 Planar coil 13 Radio wave receiving circuit 14,51 Image signal transmitter 15 Coil 16 Constant voltage circuit 17 Radio transmitting antenna 18 Slot 19 Keypad 21, 53, 63 Substrate 22, 32 Receiving antenna 23 Signal adjustment circuit 25, 35 Display Device Driving Circuit 33 Amplifying Circuit 34 Separating Circuit 41 Frequency Converter 52, 72 Light Emitting Element 54, 73 Light Receiving Element 61 Light-shielding Power Bar 62 Reflecting Film 71 Optical Fiber 81 End 82 High Reflecting Film A Anode Current Supply Line D Video Signal Line G Scanning signal line K Gradation signal line Qs Thin film transistor for switching Qd Thin film transistor for driving Cst Retention capacitance element OLED Organic electroluminescence element

Claims (20)

A display panel;
A power supply circuit and a display signal receiving means provided around the display panel;
The power supply circuit has a coil that generates an electromotive force by electromagnetic induction,
The image signal receiving means includes an antenna for receiving radio waves transmitted from an external device,
And a signal extraction circuit for extracting a display signal from the radio wave received by the antenna. The display signal includes an image signal, a synchronization signal, and a display device control signal,
The display device according to claim 1, wherein the image signal, the synchronization signal, and the display device control signal are transmitted from the external device using radio waves of different frequency bands. The display signal includes an image signal, a synchronization signal, and a display device control signal,
The display device according to claim 1, wherein the image signal, the synchronization signal, and the display device control signal are multiplexed into one radio wave and transmitted from the external device. The display signal includes an image signal, a synchronization signal, and a display device control signal,
Two of the image signal, the synchronization signal, and the display device control signal are multiplexed into one radio wave and transmitted from the external device,
The display device according to claim 1, wherein the remaining one is transmitted from the external device using a radio wave having a frequency band different from that of the one radio wave.   The display device according to claim 2, wherein the synchronization signal is generated by the power supply circuit instead of being transmitted by radio waves from the external device. A display panel;
A power supply circuit and a display signal receiving means provided around the display panel;
The power supply circuit has a coil that generates an electromotive force by electromagnetic induction,
The image signal receiving means includes at least one light receiving means for receiving an optical signal supplied from an external device;
A display device comprising: an optical signal extraction circuit for extracting the display signal from an optical signal received by the at least one light receiving means. The display signal includes an image signal, a synchronization signal, and a display device control signal,
The display device according to claim 6, wherein the image signal, the synchronization signal, and the display device control signal are digital signals.   The display device according to claim 1, wherein the display panel is an organic EL display panel. A main unit,
An information terminal device comprising a display device connected in a non-contact manner with the main body device,
The main device includes a first coil that generates an induction magnetic field;
An antenna for transmitting radio waves modulated with a display signal,
The display device includes a display panel,
A power supply circuit and display signal receiving means provided around the display panel;
The power supply circuit includes a second coil that generates an electromotive force by an induced magnetic field generated by the first coil,
The image signal receiving means includes an antenna for receiving radio waves transmitted from the main body device,
An information terminal device comprising: a signal extraction circuit that extracts a display signal from radio waves received by the antenna. The display signal includes an image signal, a synchronization signal, and a display device control signal,
The information terminal device according to claim 9, wherein the main body device transmits the image signal, the synchronization signal, and the display device control signal using radio waves in different frequency bands. The display signal includes an image signal, a synchronization signal, and a display device control signal,
The information terminal device according to claim 9, wherein the main body device multiplexes the image signal, the synchronization signal, and the display device control signal into one radio wave and transmits the multiplexed signal. The display signal includes an image signal, a synchronization signal, and a display device control signal,
The main body device multiplexes and transmits two of the image signal, the synchronization signal, and the display device control signal into one radio wave,
The information terminal apparatus according to claim 9, wherein the remaining one transmits a radio wave having a frequency band different from that of the one radio wave.   The information terminal device according to claim 10 or 11, wherein the synchronization signal is generated by the power supply circuit instead of being transmitted by radio waves from the main body device. A main unit,
An information terminal device comprising a display device connected in a non-contact manner with the main body device,
The main device includes a first coil that generates an induction magnetic field;
Having at least one light emitting element that converts a display signal into an optical signal and sends it to the display device,
The display device includes a display panel,
A power supply circuit and display signal receiving means provided around the display panel;
The power supply circuit includes a second coil that generates an electromotive force by an induced magnetic field generated by the first coil,
The image signal receiving means includes at least one light receiving means for receiving an optical signal supplied from the main body device;
An information terminal apparatus comprising: an optical signal extraction circuit that extracts the display signal from an optical signal received by the at least one light receiving means. The display signal includes an image signal, a synchronization signal, and a display device control signal,
15. The information terminal device according to claim 14, wherein the image signal, the synchronization signal, and the display device control signal are digital signals.   The information terminal device according to claim 14, further comprising a cover that blocks external light at a contact portion between the at least one light emitting element and the display device.   The information terminal device according to claim 16, wherein the cover has a reflective film therein.   16. The information terminal device according to claim 14, further comprising an optical transmission path for propagating light emitted from the at least one light emitting element to the at least one light receiving element. The optical transmission line is obliquely cut at an end on the side of the at least one light receiving element,
The information terminal device according to claim 18, wherein a reflective film is formed on the cut surface.   The information display device according to any one of claims 9 to 19, wherein the display panel is an organic EL display panel.

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