JP4860305B2 - Display device and portable terminal - Google Patents

Description

  The present invention relates to a display device and a mobile terminal. Specifically, the present invention relates to a mobile terminal having a display device that displays a video by controlling a plurality of pixels arranged in a matrix. More specifically, the present invention relates to a portable terminal having a flat panel display device that displays an image using a plurality of thin film transistors provided over an insulating substrate.

In recent years, RFID (Radio Frequency Identification) tags have been researched and developed as a product identification and management technology that replaces barcodes in the distribution industry and as a new means of personal authentication. Attention is increasing as a basic technology for promoting computerization and automation (see Patent Document 1). The RFID tag is also called an RF chip, an RF tag, an IC (Integrated Circuit) chip, an IC tag, a wireless chip, a wireless tag, an electronic chip, an electronic tag, a wireless processor, a wireless memory, or the like.

  The RFID tag is characterized by the fact that an IC chip used for the tag is provided with an antenna, so that non-contact communication by a reader / writer is possible, and a typical barcode as a conventional authentication means is one by one. While direct reading by scanning with a reader is necessary, it is possible to perform authentication work on a plurality of objects at the same time.

  Further, the RFID tag itself does not have a power source, and a radio wave transmitted from the reader / writer is detected by the antenna portion, and direct current (hereinafter referred to as DC (Direct Current)) power is generated based on the detection. There is something that can work.

  Meanwhile, mobile terminals such as mobile phones and PDAs (Personal Digital Assistants) are required to be further reduced in weight and size for the convenience of portability. Therefore, it is necessary to further reduce the volume of the components that constitute each part of the mobile terminal. As a display device serving as an interface portion, a flat panel type display in which a circuit is configured by using a plurality of thin film transistors (TFTs) provided on an insulating substrate made of glass or plastic is mainly employed. .

Furthermore, since the range of things that can be carried in a portable state has increased due to the enhancement of the functions of the portable terminal itself, continuous driving for a longer time is required compared to the conventional case.
Japanese Examined Patent Publication No. 62-43238

  In order to improve the continuous driving time of the mobile terminal, there are reduction in power consumption of each component constituting the mobile terminal and realization of a large capacity of the battery. In the former, measures such as a reduction in drive voltage and software control to frequently set a standby mode to reduce power consumption have already been taken. However, in the latter case, if an attempt is made to increase the capacity of the battery, the volume of the battery increases, which is a trade-off between the above-described reduction in size and weight.

  In view of the above-described problems, an object of the present invention is to provide a portable terminal with improved continuous driving time. Another object of the present invention is to provide a portable terminal that improves the continuous driving time and that is reduced in size and weight.

  In the present invention, in the step of forming a TFT group constituting a driving circuit of a display device on an insulating substrate, the functional part of the RFID tag is also constituted by the TFT group. Here, the TFT group constituting the display device and the TFT group constituting the functional part of the RFID tag may be basically TFTs having the same structure, and the process can be simplified.

  When an RFID tag formed integrally with a display device is brought close to a reader / writer, an antenna in the RFID tag detects a signal from the reader / writer. The power supply circuit included in the functional part of the RFID tag generates DC power using a signal detected from the reader / writer. The display device is driven by the generated DC power.

  In addition, the power supply to the display device includes, for example, a method of supplying power from a household power source via an AC (Alternating Current) adapter, a method of supplying power from a built-in battery, and a power generated by an RFID tag. There are ways to supply. When the signal from the reader / writer is detected and the RFID tag becomes active, the RFID tag issues a power source switching signal, and the power supply to the display device is sent from the AC adapter (DC power source device) or battery by this switching signal. Switch to the RFID tag power circuit. When the signal from the reader / writer is not reached, the power supply is switched from the AC adapter or the battery again.

  Note that switching between the case where power is supplied from a household power source or the like via an AC adapter (DC power supply device) or the like and the case where power is supplied from a battery is performed in many portable terminals. The method is not described. Switching may be performed as appropriate according to a conventional method.

  A portable terminal of the present invention includes a resonance circuit having a coil and a capacitor connected in parallel, and a power supply circuit that rectifies AC power induced by bringing the resonance circuit into a resonance state to generate DC power, DC power obtained from the circuit is used as drive power.

  The display device of the present invention displays a video by controlling a plurality of pixels arranged in a matrix. A resonance circuit having a coil and a capacitor connected in parallel, and a power supply circuit that rectifies AC power induced by bringing the resonance circuit into a resonance state to generate DC power. It is used as drive power for some or all of the circuits constituting the display device.

  The portable terminal of the present invention includes a display device (display unit) that displays a video by controlling a plurality of pixels arranged in a matrix, and a battery that supplies first DC power. A resonance circuit having a coil and a capacitor connected in parallel; a power supply circuit that rectifies AC power induced by bringing the resonance circuit into a resonance state to generate second DC power; Alternatively, the second DC power is used as driving power for a part or all of the circuits included in the display device.

  The portable terminal of the present invention has a first power source for supplying first DC power and a second power source for supplying second DC power. The second power source includes a coil and a capacitor connected in parallel. A resonance circuit having a power supply circuit that rectifies AC power induced by bringing the resonance circuit into a resonance state to generate second DC power, and drives the first DC power or the second DC power It is used as electric power. You may have the pixel part which controls the some pixel arrange | positioned at matrix form and displays an image | video.

  A display device according to the present invention includes a display unit that displays a video by controlling a plurality of pixels arranged in a matrix, a battery that supplies a first DC power, a resonance that includes a coil and a capacitor that are connected in parallel. And a power supply circuit that rectifies AC power induced by bringing the resonance circuit into a resonance state to generate second DC power, and displays the first DC power or the second DC power on the display unit. It is used as drive power for a part or all of the circuits constituting the circuit.

  A display device according to the present invention controls a plurality of pixels arranged in a matrix to display an image, a first power source that supplies first DC power, and second DC power A second power source that rectifies AC power induced by bringing the resonant circuit into a resonance state and rectifying AC power induced by bringing the resonant circuit into a resonant state. A power supply circuit that generates electric power is used, and the first DC power or the second DC power is used as driving power for a part or all of the circuits constituting the display portion.

  In the present invention having the above-described configuration, the display device includes a selection circuit that selects the first DC power or the second DC power. The selection circuit selects the first DC power when the resonance circuit is not in the resonance state, and selects the second DC power when the resonance circuit is in the resonance state. The first power supply may be an AC adapter (DC power supply device) or a battery, and the first DC current may be supplied from an AC adapter (DC power supply device) or a battery. Here, the power source does not indicate only a source that generates electric power, but includes one that serves as means for supplying electric power to the apparatus. That is, the AC adapter (DC power supply device) is a power source referred to in the present invention.

  In the present invention, the display device includes a source driver and a gate driver that control a plurality of pixels.

  In the present invention, the plurality of pixels, the resonance circuit, and the power supply circuit are formed over the same insulating substrate.

  In the present invention, the plurality of pixels, the resonance circuit, the power supply circuit, and the selection circuit are formed over the same insulating substrate.

  In the present invention, the plurality of pixels, the resonance circuit, the power supply circuit, the selection circuit, the source driver, and the gate driver are formed over the same insulating substrate.

  In the present invention, the plurality of pixels and the power supply circuit include a thin film transistor provided over an insulating substrate made of glass or plastic.

  In the present invention, each of the plurality of pixels, the power supply circuit, and the selection circuit includes a thin film transistor provided over an insulating substrate made of glass or plastic.

  In the present invention, each of the plurality of pixels, the power supply circuit, the selection circuit, the source driver, and the gate driver includes a thin film transistor provided over an insulating substrate made of glass or plastic.

  In the present invention, the plurality of pixels include a liquid crystal element or a self-luminous element.

  Conventionally, the power supply when carrying was dependent only on a battery with a limited capacity. However, according to the present invention, the RFID tag reader / writer signal can be detected at any location as long as it can be detected. It is possible to supply power, and as a result, improvement in driving time of portable terminals and display devices can be expected. In addition, by adopting a configuration in which a battery is not mounted, the mobile terminal can be greatly reduced in size.

  Further, the present invention focuses on supplying power to the portable terminal and the display device, switching operation, and the like. That is, in the case of a general RFID tag, it is used only by exchanging signals with a registered specific reader / writer. In the present invention, a signal output from an unspecified reader / writer is used. Since the power can be generated by detecting the signal, it can be used in various facilities. Of course, terminal authentication or the like may be performed in parallel with the application described in the present invention.

  Further, by integrally forming the pixel portion for displaying an image and the RFID tag on the same substrate, the number of parts can be reduced, and the mobile terminal can be reduced in size and weight.

  One embodiment of the present invention will be described with reference to FIG. The mobile terminal 101 mainly includes a display device 102 and a battery 111. The display device 102 includes a display unit 103a and an RFID tag 103b. The RFID tag 103b has a power circuit 105, a functional portion 106 including a selection circuit, and an antenna formed of a resonance circuit having a coil 107 and a capacitor 108 connected in parallel. Here, the functional portion 106 refers to a memory in which authentication information is stored, a logic circuit that performs arithmetic processing such as generation of a signal output to the reader / writer antenna, and the like are formed. In addition, a switch 109 and a switch 110 that select a supply source of VDD and VSS (particularly, a potential is not specified; VSS is a ground potential, for example) as driving power for the display unit 103a from either the power supply circuit 105 or the battery 111 are provided. Have. The switches 109 and 110 are controlled by a selection circuit included in the functional part 106. The switches 109 and 110 select the supply source of the drive power VDD and VSS from either the power circuit 105 or the battery 111. Reference numeral 104 denotes an antenna provided on the reader / writer side.

  Here, the switch 109 and the switch 110 are not particularly limited in configuration, but have two input terminals, an output terminal, and a control terminal, and a signal from a selection circuit included in the functional portion 106 is input to the control terminal. By doing so, one of the two input terminals is selected and the output terminal is short-circuited.

  When the display device 102 having the RFID tag 103b enters a region 201 (a region indicated by hatching in FIG. 2A) in which the signal 120 of the antenna 104 on the reader / writer side can be detected, the display device 102 is connected in parallel. The parallel resonant circuit having the coil 107 and the capacitor 108 is in a resonance state, and AC power is induced between both ends of the parallel resonant circuit, that is, between the terminals at both ends where the coil 107 and the capacitor 108 are connected in parallel. Thereafter, the power supply circuit 105 having a rectifier circuit, a capacitor, and the like converts AC power induced in the resonance circuit into DC power and generates it.

  Subsequently, the functional part 106 of the RFID tag is driven based on the generated DC power. The selection circuit included in the functional part 106 controls the switch 109 and the switch 110 to supply the generated DC power to the display unit 103a. As long as the parallel resonant circuit is in the resonance state, the above state is maintained, and DC power is continuously generated, and the display device 102 is driven by the generated DC power.

  After that, when the display device 102 having the RFID tag 103b deviates from the region 201 where the signal 120 of the antenna 104 on the reader / writer side can be detected (the region indicated by the oblique lines in FIG. 2B), parallel display is performed. The resonance in the resonance circuit stops, and the power supply circuit 105 and the functional part 106 stop operating. At this time, the control terminals of the switches 109 and 110 controlled by the selection circuit included in the functional portion 106 can be in a floating state. After the RFID tag 103b stops functioning, it is necessary to ensure power supply from the battery 111. As a preferable example, the RFID tag 103b stops functioning, and the control terminals of the switch 109 and the switch 110, that is, the output terminal of the selection circuit included in the functional part 106 are fixed to the VSS side. It is preferable to provide it. Specifically, there is a method in which a high resistance is inserted between the output terminal of the selection circuit included in the functional portion 106 and the VSS potential. In addition, a method may be considered in which the VDD-side power supply unit used in the functional part 106 is set to the same potential as the VSS-side power supply when the power supply from the power supply circuit 105 is stopped. When the functional part 106 is operating, a signal for controlling the switch 109 and the switch 110 is output from the output terminal of the selection circuit, the operation of the functional part 106 is stopped, and the output terminal of the selection circuit is in a floating state. With the above-described configuration, the potential of the output terminal of the selection circuit included in the functional portion 106 is naturally fixed to the VSS side. What is necessary is just to comprise so that the power supply to the display part 103a may be performed from the battery 111 when it will be in this state.

  In the present invention, the DC power generated by the RFID tag 103b is used as the first power supply source, and the battery 111 is used as the second power supply source. However, the battery 111 is driven only by the first power supply source. You may be comprised so that. In this case, the selection circuit included in the functional portion 106 is not necessary, and the terminal can be used only in a region where the signal of the antenna 104 on the reader / writer side can be detected.

  Note that the power supply circuit 105 included in the RFID tag 103b generates power by detecting a signal from the reader / writer, but it is preferable that the power can supply power sufficient to drive the display device 102. In general, in an RFID tag using a 13.56 MHz band, the output of a power supply circuit is considered to take about several mW to several tens mW as drive power for a functional portion provided in the RFID tag. Therefore, in consideration of variations in TFT characteristics, conversion efficiency, and the like, it is preferable to use a reflective liquid crystal display device with low power consumption as the display device 102.

  In the case where a self-luminous display device using a transmissive liquid crystal display device, an EL (Electro Luminescence) element, or the like is used as the display device 102, power consumption in the backlight or the EL element is relatively large. Therefore, the power source generated by the above-described method may be used only for driving the driver portion of the display device 102, and a fixed power source or a battery may always be used to supply power to the backlight and the EL element. In that case, although not particularly illustrated, it is necessary to provide a separate power supply path without passing through the switch 109 and the switch 110 described above.

  In this embodiment mode, a method of using a battery as the second power supply source of the display device is illustrated in consideration of the fact that the power that can be generated by the power supply circuit provided in the RFID tag is not so large. It is also possible to use a similar technique for driving other functional components.

  A detailed configuration of the display device included in the portable terminal of the present invention will be described with reference to FIG. A pixel portion 302 in which pixels having a TFT and a display element such as a liquid crystal element or an EL element are arranged in a matrix is provided over an insulating substrate 301 made of glass, plastic, or the like. A source driver 303 and a gate driver 304 for driving each of the pixels are provided. The pixel portion 302, the source driver 303, and the gate driver 304 belong to the display portion 103a in FIG. Since the RFID tag 305 has a higher degree of freedom in circuit arrangement shape than the pixel portion 302, the source driver 303, and the gate driver 304, the RFID tag 305 may be provided in a blank area where the above-described circuit group is arranged. When inputting / outputting signals to / from these circuits and supplying power from an external power source such as a battery, for example, a flexible printed circuit (FPC) 306 may be used.

  Although not particularly illustrated here, a counter substrate for sealing a liquid crystal element or an EL element is attached to the insulating substrate 301. Regarding the counter substrate, although it depends on the elements constituting the display unit, a transparent substrate is necessary when it is necessary to extract light from the counter substrate side. Specifically, when light is not extracted from the counter substrate side, For example, when a bottom emission type EL element is used, a metal sealing can may be used.

  In addition, as to the structure of the coil and the capacitor constituting the antenna on the RFID tag side, as shown in FIG. 4A, a pixel portion 302, a source driver 303, a gate driver 304, an RFID tag 305, At the same time, the coil 401 and the capacitor (not shown) may be integrally formed. However, the size of the coil and capacitor varies depending on the resonance frequency. Further, when a capacitor is formed by forming a thin film on an insulating substrate, a considerable area is required to increase the capacity. This point is the same for the coil routing area, and therefore, when the increase in the substrate area due to the integral formation becomes a problem (specifically, for example, the casing of the electronic device to which the display device of the present invention is applied). 4), a coil 401, a capacitor 402, and the like are mounted on a separate substrate and connected to the RFID tag 305 through the FPC 306, as shown in FIG. 4B. You may make it do.

  An application example of the present invention will be described with reference to FIG. A reader / writer antenna 502 is built in a table 501 installed in a general facility, for example, inside the top plate. When the user places the portable terminal 503 on the table, the antenna in the portable terminal 503 detects the signal output from the reader / writer antenna 502 on the table 501 side, and the power supply circuit in the portable terminal 503 is detected. Becomes active. While the user is using the portable terminal 503 while seated, the display device in the portable terminal 503 can be driven by the DC power generated by the power supply circuit in the portable terminal 503.

  When considering such a use environment, when using a mobile terminal in an office, for example, using an authentication function that is an original function of an RFID tag, power is supplied as described above, and at the same time authentication by ID It is also possible to use this function. The authentication information has a variety of useful applications such as management of disk access authority of a computer in the office when a portable terminal is connected to a LAN, for example.

  Further, as shown in FIG. 5B, assuming applications such as an electronic book, a video viewer, and a music player, a function as a reader / writer is provided on the portable terminal 511 side such as an electronic book, a video viewer, and a music player. An RFID tag 513 is built in the receiver 512 side. If the receiver 512 can detect the signal 520 of the reader / writer antenna provided on the portable terminal 511 side such as an electronic book, a video viewer, or a music player, the receiver 512 is driven by the same method of the present invention. The power supply for generating can be generated in the RFID tag 513 portion.

  Furthermore, as shown in FIG. 5C, when a plurality of users each have a receiver 512 and play back data stored in a portable terminal 511 such as one electronic book, a video viewer, or a music player, When an individual ID is assigned to the RFID tag 513 provided in each receiver 512 and the ID is read by a reader / writer on the portable terminal 511 side such as an electronic book, a video viewer, or a music player, each user The set reproduction list or the like may be taken out, and the data reading order may be changed accordingly. Each user can use his / her favorite content from a portable terminal 511 such as one electronic book, video viewer, music player, or the like.

  Note that the RFID tag used in the present invention is not particularly limited in terms of frequency band standards. There are various standards for the frequency band of RFID, such as a long wave band (125 kHz, etc.), a short wave band (13.56 MHz, etc.), an ultra short wave band (around 900 MHz, etc.), and a microwave band (2.45 GHz, etc.). The essence of the present invention does not change even if the standard is met. Depending on the frequency band, there are advantages and disadvantages in the widespread fields, communication distance, directivity, etc., so it is sufficient to adopt a standard suitable for the application.

The figure which shows one Embodiment of this invention. The figure explaining the operation | movement in one Embodiment of this invention. The figure which shows the Example of this invention. The figure which shows the Example of this invention. The figure which shows the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Mobile terminal 102 Display apparatus 103a Display part 103b RFID tag 104 Antenna 105 Power supply circuit 106 Functional part 107 Coil 108 Capacitor 109 Switch 110 Switch 111 Battery 301 Insulating substrate 302 Pixel part 303 Source driver 304 Gate driver 305 RFID tag 401 Coil 402 Capacitor 502 Antenna 503 Portable terminal 511 Portable terminal 512 such as an electronic book, video viewer, music player, etc. Receiver 513 RFID tag

Claims (2)

And functional parts, including selected択回road,
First and second switches ;
A first power supply for supplying first DC power;
A second power source for supplying second DC power;
The first power supply includes a resonance circuit and a power supply circuit,
A portable terminal to which the first DC power or the second DC power is supplied as drive power,
(A) when the resonant circuit is in a resonant state;
The power supply circuit rectifies AC power induced in the resonance circuit to generate the first DC power,
The first DC power is supplied from the power supply circuit to the functional part to drive the functional part,
A signal is input from the output terminal of the selection circuit included in the functional part to the control terminal of the first and second switches,
The first DC power is supplied as the driving power from the power supply circuit via the first and second switches,
(B) When the resonance circuit is not in a resonance state, the second DC power is supplied as the drive power from the second power source via the first and second switches,
(C) when the resonant circuit is not in a resonance state, the portable terminal the potential of the output terminal of the selection circuit is characterized in that a VSS. A display unit;
And functional parts, including selected択回road,
First and second switches ;
A first power source for supplying first DC power to the display unit;
A second DC power have a, a second power supply to said display unit,
The first power supply is a display device having a resonance circuit and a power supply circuit ,
(A) when the resonant circuit is in a resonant state;
The power supply circuit rectifies AC power induced in the resonance circuit to generate the first DC power,
The first DC power is supplied from the power supply circuit to the functional part to drive the functional part,
A signal is input from the output terminal of the selection circuit included in the functional part to the control terminal of the first and second switches,
The first DC power is supplied from the power supply circuit to the display unit via the first and second switches,
(B) When the resonance circuit is not in a resonance state, the second DC power is supplied to the display unit from the second power source via the first and second switches,
(C) when the resonant circuit is not in a resonant state, a display device in which the potential of the output terminal of the selection circuit is characterized in that a VSS.

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