JP2006190042A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a miniaturized display device capable of saving power consumption. <P>SOLUTION: According to a card type display device 10, since current consumption in a signal transmitting circuit 20 is suppressed to save power consumption, a power transmitting coil 18 can be miniaturized. Consequently, the display device can be miniaturized. When the power consumption in the signal transmitting circuit 20 is large, increase in the number of turns of the power transmitting coil 18 is conceivable for obtaining a large driving power. However, this leads to enlargement of the power transmission coil 18, resulting in reduction in convenience of the card type display device 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device that displays characters and images based on input signals, and more particularly to a miniaturized display device that can save power consumption.

  2. Description of the Related Art Conventionally, an IC card that performs both power and data transmission by a contact type using a plurality of contacts is known and used for a credit card or the like. Furthermore, as disclosed in, for example, Japanese Patent Laid-Open No. 10-91736 (Patent Document 1), there is also known a method in which electric power and data are transmitted in a non-contact manner using a coil by using an electromagnetic induction action. Japanese Laid-Open Patent Publication No. 10-154215 (Patent Document 2) describes an IC card having a display panel capable of displaying information stored in the card and having a function as a display device. ing.

Such a display device (IC card) incorporates a CPU, and a CPU controls a display driver for driving the display panel, a communication circuit for transmitting data to and from an external device, and the like.
JP-A-10-91936 Japanese Patent Laid-Open No. 10-154215

  However, in general, in order to control the display driver, the CPU needs to output a control signal having a relatively large voltage (for example, 5 V). When a control signal having a voltage comparable to this is input from the CPU to the communication circuit, a large current flows through the communication circuit. Then, since the power consumption in the communication circuit increases, there is a problem that the display device may run out of power.

  In order to solve such a problem, it is conceivable to provide a battery having a large capacity in the display device or increase the number of turns of the coil for receiving power supply. The use of voltage-compatible components increases the size of the display device and impairs convenience.

  Further, when a large current flows through the communication circuit, there is a problem that the CPU that controls the communication circuit may be destroyed by the overcurrent.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a display device that can save power consumption and is miniaturized.

  The display device according to claim 1 displays a character or an image based on a communication means capable of transmitting input communication data and a display control signal inputted to a data processing means capable of receiving a signal wave. Display means, and the communication means and the control means capable of outputting the communication data and the display control signal to the display means, respectively, the voltage of the communication data input to the communication means And first voltage conversion means for lowering the voltage of the display control signal input to the display means.

  2. The display device according to claim 2, wherein the communication unit generates a signal wave modulated based on communication data whose voltage is lowered by the first voltage conversion unit. And an antenna for transmitting the signal wave generated by the modulation circuit to the data processing means.

  The display device according to claim 3 is the display device according to claim 2, wherein the modulation circuit converts the communication coil and communication data connected in parallel to the communication coil and reduced in voltage by the voltage conversion means. An inverting amplification circuit that is driven based on the inverting amplification circuit and that has capacitors connected to the input side and the output side of the inverting amplification circuit, wherein the antenna is a communication coil of the modulation circuit. The signal wave generated by the modulation circuit is transmitted to the data processing means by electromagnetic induction.

  According to a fourth aspect of the present invention, in the display device according to any one of the first to third aspects, the first voltage converting means is constituted by a resistor.

  The display device according to a fifth aspect is the display device according to any one of the first to third aspects, wherein the first voltage converting means is constituted by an operational amplifier.

  A display device according to a sixth aspect is the display device according to any one of the first to third aspects, wherein the first voltage conversion means is constituted by a regulator and a comparator.

  The display device according to claim 7 is the display device according to claim 1, wherein the data processing means is configured to be able to transmit and receive signal waves, and the communication means receives a signal wave transmitted from the data processing means. An antenna that is driven based on a power supply voltage input from the control means and that can amplify a signal wave received by the antenna, and a demodulation circuit that demodulates the signal wave amplified by the amplifier circuit And a second voltage conversion unit configured to lower the power supply voltage input to the amplifier circuit than a voltage of the display control signal input to the display unit.

  The display device according to an eighth aspect of the present invention is the display device according to the seventh aspect, wherein the second voltage converting means is formed of a diode.

  According to a ninth aspect of the present invention, in the display device according to the seventh aspect, the second voltage conversion means is composed of an operational amplifier.

  According to a tenth aspect of the present invention, in the display device according to the seventh aspect, the second voltage conversion means is constituted by a regulator.

  The display device according to an eleventh aspect is the display device according to any one of the seventh to tenth aspects, wherein the communication unit includes a signal wave shaping circuit that shapes the signal wave demodulated by the demodulation circuit.

  According to a twelfth aspect of the present invention, in the display device according to the eleventh aspect, the signal wave shaping circuit includes a comparator that binarizes the signal wave demodulated by the demodulation circuit.

  A display device according to a thirteenth aspect of the present invention includes the display device according to any one of the first to twelfth aspects, further comprising a power supply circuit that obtains a driving power source for the display device from an electromagnetic induction wave by a power feeding coil.

  The display device according to claim 14 is the display device according to claim 1, wherein the data processing means is configured to be able to transmit and receive signal waves, and the communication means transmits signals to and from the data processing means by electromagnetic induction. A communication coil capable of transmitting and receiving waves, an inverting amplifier circuit that is connected in parallel to the communication coil and driven based on the communication data reduced in voltage by the first voltage converting means, and that inverts and amplifies the input signal; A capacitor connected to the input side and the output side of the inverting amplifier circuit, connected to one end of the communication coil, driven based on a power supply voltage input from the control means, and received by the communication coil An amplification circuit capable of amplifying the signal wave, and a demodulation circuit for demodulating the signal wave amplified by the amplification circuit. A second voltage converting means for making the voltage lower than the voltage of the display control signal input to the display means; and the communication coil and the inverting amplifier circuit are electrically connected when transmitting a signal wave to the data processing means. And switching means for setting the other end of the communication coil to the ground potential when receiving a signal wave from the data processing means.

  The display device according to claim 15 is the display device according to claim 14, wherein the control means is configured such that the amplifier circuit is not driven when a signal wave is transmitted to the data processing means, and the signal from the data processing means is When receiving a wave, a power supply voltage is output so that the amplifier circuit is driven.

  A display device according to a sixteenth aspect is the display device according to the fourteenth or fifteenth aspect, further comprising a power supply circuit that obtains a driving power source for the display device from an electromagnetic induction wave by a feeding coil.

  According to a seventeenth aspect of the present invention, in the display device according to the sixteenth aspect, the demodulating circuit includes a low-pass filter that removes an electromagnetic wave induced by a carrier wave of the signal wave and a power supply coil of the power supply circuit.

  According to the display device of claim 1, communication means capable of transmitting input communication data to a data processing means capable of receiving signal waves, and characters and images based on the input display control signal. Display means for displaying the communication means, and control means capable of outputting the communication data and the display control signal to the display means, respectively, by the first voltage conversion means to the communication means. Since the input communication data is made lower than the voltage of the display control signal input to the display means, current consumption in the communication means is suppressed, and power consumption can be saved.

  According to the display device of claim 2, in addition to the effect of the display device of claim 1, the communication unit is a signal modulated based on the communication data reduced in voltage by the first voltage conversion unit. Since the modulation circuit that generates the wave and the antenna that transmits the signal wave generated by the modulation circuit to the data processing unit are provided, current consumption in the modulation circuit is suppressed, and power consumption can be saved.

  According to the display device of the third aspect, in addition to the effect achieved by the display device of the second aspect, the modulation circuit is connected in parallel to the communication coil and the communication coil, and the first voltage conversion means. The modulation circuit includes communication data that is driven based on low-voltage communication data and that inverts and amplifies the input signal, and capacitors that are connected to the input side and output side of the inverting amplifier circuit, respectively. Is generated as a drive power source, and a signal wave modulated based on communication data is generated. And the signal wave produced | generated by the modulation circuit is transmitted to the said data processing means by electromagnetic induction using the coil for communication which comprises a modulation circuit. Here, since the modulation circuit uses the communication data whose voltage has been lowered by the voltage conversion means as the drive power supply, the current consumption in the modulation circuit is suppressed, and the power consumption can be saved.

  According to the display device of the fourth aspect, in addition to the effect produced by the display device according to any one of the first to third aspects, the first voltage conversion means is constituted by a resistor, so that communication is performed due to a decrease in voltage. There is an effect that curling of the waveform of the data is suppressed and occurrence of an error in the signal wave is suppressed. In addition, since the voltage can be reduced with a simple configuration, the display device can be reduced in size.

  According to the display device of the fifth aspect, in addition to the effect exhibited by the display device according to any one of the first to third aspects, the first voltage conversion means is constituted by an operational amplifier, and therefore depends on a connected load. There is an effect that the voltage can be output stably without being affected, and the response speed due to the change of the signal can be increased.

  According to the display device of the sixth aspect, in addition to the effect produced by the display device according to any one of the first to third aspects, the first voltage conversion means is composed of a regulator and a comparator, and therefore connected. The voltage can be output stably without being affected by the load, and the response speed can be increased by changing the signal.

  According to the display device of claim 7, in addition to the effect of the display device of claim 1, the data processing means is configured to be able to transmit and receive signal waves, and the communication means transmits from the data processing means. An antenna that receives the received signal wave, an amplification circuit that is driven based on a power supply voltage input from the control means and that can amplify the signal wave received by the antenna, and demodulates the signal wave amplified by the amplification circuit And a demodulating circuit that performs amplifying because the power supply voltage input to the amplifier circuit is made lower than the voltage of the display control signal input to the display means by the second voltage converting means. Current consumption in the circuit is suppressed, and power consumption can be saved. In addition, even if the voltage of the signal wave received by the antenna is low, the signal wave can be amplified and demodulated by the amplifier circuit.

  According to the display device of the eighth aspect, in addition to the effect exhibited by the display device of the seventh aspect, the second voltage conversion means is constituted by a diode, so that the power supply voltage output from the control means is stabilized. The output of the amplifier circuit can be stabilized.

  According to the display device of claim 9, in addition to the effect of the display device of claim 7, the second voltage conversion means is composed of an operational amplifier, so that the voltage can be reduced stably, There is an effect that the output of the amplifier circuit is stabilized.

  According to the display device of the tenth aspect, in addition to the effect exhibited by the display device according to the seventh aspect, since the second voltage conversion means is configured by a regulator, the voltage can be stably reduced. There is an effect that the output of the amplifier circuit is stabilized.

  According to the display device of the eleventh aspect, in addition to the effect exhibited by the display device according to any one of the seventh to tenth aspects, the communication means forms a signal wave that shapes the signal wave demodulated by the demodulation circuit. Since the circuit is included, there is an effect that it is possible to obtain a more smooth signal wave from the demodulated signal wave.

  According to the display device of claim 12, in addition to the effect produced by the display device of claim 11, the signal wave shaping circuit has a comparator that binarizes the signal wave demodulated by the demodulation circuit. A simple signal wave can be obtained with a simple configuration, and a stable output can be obtained even when the received signal is small.

  According to the display device of the thirteenth aspect, in addition to the effect produced by the display device according to any one of the first to twelfth aspects, the display can be performed from an electromagnetic induction wave by a power feeding coil provided separately from the communication coil. Since the power supply circuit for obtaining the drive power of the device is provided, the drive power can be supplied to the display device without being physically connected to the external device. In addition, since current consumption in the communication means is suppressed and power consumption is saved, the power supply coil and the power supply circuit can be reduced in size. As a result, the display device can be reduced in size.

  According to the display device of claim 14, in addition to the effect of the display device of claim 1, the data processing means is configured to be able to transmit and receive signal waves, and the communication means is configured to perform the data processing by electromagnetic induction. A communication coil capable of transmitting / receiving a signal wave to / from the means, and an inversion amplification of the input signal driven in accordance with the communication data connected in parallel to the communication coil and reduced in voltage by the first voltage converting means An inverting amplifier circuit, a capacitor connected to the input side and the output side of the inverting amplifier circuit, connected to one end of the communication coil, and driven based on a power supply voltage input from the control means An amplifier circuit capable of amplifying the signal wave received by the communication coil; and a demodulator circuit for demodulating the signal wave amplified by the amplifier circuit; The time of transmission of, by the switching means, the coil and the inverting amplifier circuit and is caused to conduct, the and upon receipt of a signal wave from said data processing means by the switching means, the other end of the coil at the ground potential. Therefore, when transmitting a signal wave to the data processing means, a circuit composed of a coil, the inverting amplifier circuit, and the capacitor oscillates using communication data as a drive power source, and a signal wave modulated based on the communication data is generated. Generate. The generated signal wave is transmitted to the data processing means by electromagnetic induction using the coil. On the other hand, when receiving the signal wave from the data processing means, the other end of the coil is set to the ground potential, so that the signal wave received by the coil is output to the amplification circuit and amplified, and the amplified signal wave is Demodulated. Accordingly, signal waves can be transmitted / received to / from the data processing means with a single coil, so that the display device can be reduced in size. Furthermore, since the power supply voltage input to the amplifier circuit is made lower by the second voltage conversion means than the voltage of the display control signal input to the display means, the amplifier circuit is based on the drive power supply whose voltage has been lowered. The modulation circuit is driven by using the communication data whose voltage is lowered by the first voltage conversion means as a driving power source. Therefore, current consumption in the communication means is suppressed, and power consumption can be saved.

  According to the display device of claim 15, in addition to the effect of the display device of claim 14, the control means is configured such that the amplifier circuit is not driven when a signal wave is transmitted to the data processing means. When receiving a signal wave from the data processing means, the power supply voltage is output so that the amplifier circuit is driven, so that an unnecessary current is prevented from flowing from the coil to the amplifier circuit when the signal wave is transmitted to the data processing means. Is done. Therefore, current consumption in the communication means is suppressed, and there is an effect that power consumption can be saved. In addition, there is an effect that an erroneous signal is output from the receiving circuit at the time of transmission to prevent the control means from malfunctioning.

  According to the display device of the sixteenth aspect, in addition to the effect produced by the display device of the fourteenth or fifteenth aspect, the display device is driven from an electromagnetic induction wave by a feeding coil provided separately from the communication coil. Since the power supply circuit for obtaining the power is provided, there is an effect that the power can be supplied to the display device without being physically connected to the external device. In addition, since current consumption in the communication means is suppressed and power consumption is saved, the power supply coil and the power supply circuit can be reduced in size. As a result, the display device can be reduced in size.

  According to the display device according to claim 17, in addition to the effect produced by the display device according to claim 16, the demodulator circuit is a low-pass filter that removes the electromagnetic wave induced by the signal wave carrier and the power supply coil of the power supply circuit. Since the filter is included, there is an effect that an electromagnetic induction wave that causes noise can be removed. Further, since the low-pass filter provided for removing the carrier wave is removed, there is an effect that the display device is reduced in size.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. 1A and 1B are diagrams illustrating a card-type display device 10 according to the present invention. FIG. 1A is a plan view of the card-type display device 10 and FIG. 1B is a cross-sectional view taken along line BB ′ of FIG. is there.

  The card type display device 10 of the present embodiment performs transmission / reception of signal waves and power supply (power supply) from the data processing device 30 to and from the data processing device 30 (see FIG. 2) wirelessly by electromagnetic induction, An image, characters, etc. are displayed based on the signal wave received from the data processing device.

  The card type display device 10 includes a substrate 11, a display unit 12 that displays images, characters, and the like, a module unit 13 that includes a main circuit group that controls the operation of the card type display device 10, and an outer periphery of the substrate 11. A surrounding outer frame 14.

  The substrate 11 is a substantially rectangular multilayer substrate in which a plurality of insulator layers are laminated, and includes an internal wiring layer 11a between the insulator layers. The circuits that are spaced apart from each other on the substrate 11 are electrically connected via the internal wiring layer 11a.

  The display unit 12 includes a display panel 15 and drive circuits 16 a and 16 b (see FIG. 2) that supply voltages to the display pixels of the display panel 15, and displays characters and images on the display panel 15. The display panel 15 includes a pixel electrode 15a, a common electrode 15b, a TFT transistor 15d (see FIG. 3), a frame 15e that surrounds the outer periphery of the display panel 15, and a glass substrate 15f that forms the surface of the display panel 15. And a known electrophoretic display device in which microcapsules 15c (see FIG. 3) having charged particles I are arranged between the pixel electrode 15a and the common electrode 15b. The configuration of the display unit 12 will be described in detail later with reference to FIG.

  The module unit 13 includes a data communication coil 17 that transmits and receives signal waves to and from the data processing device 30 by electromagnetic induction, a power transmission coil 18 that receives power from the data processing device 30 by electromagnetic induction, and a circuit group. Electronic component mounting areas 19a and 19b. In addition, each structure provided in the module part 13 is demonstrated in detail with reference to FIG.

  FIG. 2 is a block diagram illustrating an electrical configuration of the card-type display device 10 and the data processing device 30 that transmits and receives signals to and from the card-type display device 10. As shown in FIG. 2, the card-type display device 10 includes a display panel 15 and drive circuits 16a and 16b in the display unit 12, a signal transmission circuit 20 including a data communication coil 17 in the module unit 13, and power transmission. A power transmission circuit 21 including a coil 18, a rectifier circuit 22, a display drive power supply 23, and a system control circuit 24 are provided. Of the electronic components constituting these circuits provided in the module unit 13, other electronic components excluding the data communication coil 17 and the power transmission coil 18 are arranged in the electronic component mounting regions 19 a and 19 b. .

  The signal transmission circuit 20 performs communication with the data processing device 30 via the data communication coil 17, that is, transmission / reception of signal waves and modulation / demodulation of signals related to transmission / reception. The configuration of the signal transmission circuit 20 will be described in detail later with reference to FIG.

  The power transmission circuit 21 includes a power transmission coil 18. When an electromagnetic induction wave is generated in the power transmission coil 34a of the data processing device 30 described later, the power transmission coil 18 receives the electromagnetic induction wave and generates an electromotive force. The power transmission circuit 21 receives power from the data processing device 30 by taking out the electromotive force generated in the power transmission coil 18. The power supplied in the power transmission circuit 21 is used as a drive power source for the card type display device 10.

  The rectifier circuit 22 includes a transformer and a rectifier, and extracts a DC power source having a voltage (for example, 5 V) for controlling the system control circuit 24 from the AC power source fed by the power transmission circuit 21.

  The display drive power supply 23 transforms the rectangular wave from the system control circuit 24 into a high voltage HV, supplies a 50V DC voltage to the drive circuit 16a, and supplies a 25V DC voltage to the drive circuit 16b.

  The system control circuit 24 includes a CPU 24a, is connected to the drive circuits 16a and 16b, and the signal transmission circuit 20, and is driven by a 5V DC power source supplied from the rectifier circuit 22. The CPU 24a controls display on the display panel 15 by outputting display control signals to the drive circuits 16a and 16b, and controls communication in the signal transmission circuit 20 by supplying communication data and power supply voltage to the signal transmission circuit 20. To do. The configuration of the system control circuit 24 will be described later in detail with reference to FIG.

  The data processing device 30 includes a housing (not shown) configured to allow the card-type display device 10 to be placed at a predetermined position, a card detection circuit 32, a signal transmission circuit 33, and a power transmission circuit 34. With. The data processing device 30 transmits image data and various commands to the card-type display device 10 on the display panel 15 of the card-type display device 10 and displays an image on the display panel 15 of the card-type display device 10.

  The card detection circuit 32 includes an optical sensor, and detects by the optical sensor that the card type display device 10 is placed at a predetermined position of the casing (not shown) and removed from the predetermined position of the casing. Notify the control circuit 35. The system control circuit 35 controls the power transmission circuit 34 based on the card type display device 10 being placed at a predetermined position of the housing.

  The signal transmission circuit 33 should be transmitted by a data communication coil 33a capable of transmitting and receiving a signal wave by electromagnetic induction, a demodulation circuit (not shown) for demodulating the signal wave received by the data communication coil 33a, and the data communication coil 33a. It has a modulation circuit (not shown) for modulating data, and transmits / receives signal waves to / from the data communication coil 17 of the card type display device 10 via the data communication coil 33 by electromagnetic induction. The data communication coil 33 a is disposed at a position facing the data communication coil 17 of the card type display device 10 when the card type display device 10 is placed at a predetermined position of the housing of the data processing device 30.

  The power transmission circuit 34 has a power transmission coil 34a. The power transmission circuit 34 generates an electromagnetic induction wave in the power transmission coil 34 a and supplies power to the power transmission circuit 21 of the card type display device 10 via the power transmission coil 18. The power transmission coil 34 a is arranged at a position facing the power transmission coil 18 of the card type display device 10 when the card type display device 10 is placed at a predetermined position of the housing of the data processing device 30. .

  The system control circuit 35 includes a CPU 35 a and is connected to the card detection circuit 32, the signal transmission circuit 33, and the power transmission circuit 34. The CPU 35a controls various processes of the data processing device 30 according to a program stored in advance in a ROM (not shown) in the system control circuit 35. The processing control of the signal transmission circuit 33 and the power transmission circuit 34 by the CPU 35a will be described in detail later with reference to FIG.

  With reference to FIG. 3, the structure and display operation | movement of the display panel 15 of the card type display apparatus 10 are demonstrated. For ease of explanation, the pixel configuration of the display panel 15 is simplified to 10 × 10 pixels. In order to increase the number of pixels, this configuration may be expanded and applied.

  3A is a diagram showing the relationship between the arrangement of the pixel electrodes 15a provided on the substrate 11 side (see FIG. 1B) and the wiring, and FIG. 3B is the glass substrate 15f side. It is a figure which shows the relationship between arrangement | positioning of the common electrode 15b provided in (refer FIG.1 (b)), and wiring. The pixel electrode 15a is arranged for every 10 × 10 pixels.

  As shown in FIG. 3A, source lines S1 to S10 common to one row in the horizontal direction of the pixels are wired to each row in the pixel electrode 15a, and gate lines G1 to G10 common to one column in the vertical direction of the pixels. Are wired in each column. The source lines S1 to S10 and the gate lines G1 to G10 are driven by the drive circuit 16a, respectively. Among the source lines S1 to S10 and the gate lines G1 to G10, a potential is applied to the pixel electrode 15a of the pixel located at the intersection of the source line and the gate line which are both in an active state.

  As shown in FIG. 3B, the common electrode 15b is an electrode that is made of a light-transmitting material and is common to all pixels, and is supplied with a potential by the drive circuit 16b. As a result, the common electrode 15b is given a common potential (25V in this case) over all the pixels.

  As shown in FIG. 3C, one pixel of the display panel 15 is configured such that a microcapsule 15c constituting electronic ink is sandwiched between a pixel electrode 15a and a common electrode 15b. Note that in FIG. 3C, one pixel includes one microcapsule 15c, but one pixel may include a plurality of microcapsules 15c.

  The pixel electrode 15a is connected to the drain of the TFT transistor 15d. The TFT transistor 15d is configured in a matrix so as to correspond to each pixel, and a source is connected to the source lines S1 to S10 and a gate is connected to the gate lines G1 to G10.

  As can be understood from FIG. 3C, the potentials of the source lines S1 to S10 (0 V or +50 V in the figure) are applied to the pixel electrodes 15a connected to the drains of the TFT transistors 15d in which the gate lines G1 to G10 are active. Is given. The potential applied to the common electrode 15b is 25V, and the potential applied to the pixel electrode 15a is 0V for white display and + 50V for black display. That is, by setting the voltage difference between the pixel electrode 15a and the common electrode 15b to 25V, the charged particles I in the microcapsule 15c migrate to either the pixel electrode 15a or the common electrode 15b. This voltage difference depends on the characteristics of the display panel 15.

  Returning to FIG. 2, the operation of the display unit 12 will be described. When the image data is received from the data processing device 30, the CPU 24a outputs a display control signal to the drive circuits 16a and 16b based on the image data. The drive circuits 16a and 16b to which the display control signal is input control the drive of the display panel 15, that is, the movement of the charged particles I in the microcapsule 15c, according to the display control signal, and display characters and images on the display panel 15. .

  The configuration of the signal transmission circuit 20 and the system control circuit 24 will be described in more detail with reference to FIG. FIG. 4 is a circuit diagram of the signal transmission circuit 20 and the system control circuit 24 provided in the card type display device 10.

  As shown in FIG. 4, the signal transmission circuit 20 includes an oscillation circuit 25, an amplification circuit 26, a voltage doubler rectification circuit 27, a high frequency removal circuit 28, and a signal wave shaping circuit 29. The signal transmission circuit 20 is configured so that the data communication coil 17 can be used for both transmission and reception by appropriately switching the electrical conduction state of the data communication coil 17 included in the oscillation circuit 25. .

  The system control circuit 24 includes a CPU 24a, field effect transistors Q1, Q2, resistors R1, R2, and a diode array DA1. The CPU 24a performs various processes such as displaying an image on the display panel 15 and communicating with the data processing device 30 according to a program stored in advance in a ROM (not shown) provided in the system control circuit 24. Yes, 5V signal (voltage) can be output. The CPU 24a has a terminal P1 for outputting communication data to the oscillation circuit 25, a terminal P2 for outputting a voltage to the amplifier circuit 26, a terminal Vref for outputting a voltage for setting a threshold for the comparator CP1, and a signal. And a terminal RX to which a signal wave demodulated in the transmission circuit 20 is input. Note that the CPU 24a has another configuration for outputting a display control signal to the drive circuits 16a and 16b of the display unit 12, but the description thereof is omitted because it is a known configuration.

  The field effect transistor Q1 is for inverting and outputting the communication data output from the terminal P1 of the CPU 24a, and is composed of a P-MOS field effect transistor. The gate terminal is connected to the terminal P1 of the CPU 24a, the source terminal is connected to + VB (5V power source supplied from the rectifier circuit 22), and the drain terminal is connected to one end of the resistor R1. Therefore, the field effect transistor Q1 is switched on / off according to communication data (see FIG. 5A) output from the terminal P1 of the CPU 24a, and inverts and outputs the communication data (see FIG. 5B). .

  The resistor R1 is composed of, for example, a 1.2 kΩ resistor. One end of the resistor R1 is connected to the drain terminal of the field effect transistor Q1, and the other end is connected to the power supply terminal of the inverter U2 of the oscillation circuit 25. The resistor R1 lowers the voltage of communication data (see FIG. 5B) output from the drain terminal of the field effect transistor Q1 and outputs it (see FIG. 5C).

  Here, the communication data is data obtained by converting information to be transmitted from the card-type display device 10 to the data processing device 30 into a digital signal, and is a signal output from the terminal P1 of the CPU 24, by the field effect transistor Q1. It includes an inverted signal and a signal whose voltage value is lowered by the resistor R1.

  The diode array DA1 includes three diodes connected in series. The anode of the diode array DA1 is connected to the terminal P2 of the CPU 24a, and the cathode is connected to the gate terminal of the field effect transistor Q2 and the power supply terminal of the inverter U3 of the amplifier circuit 26. The diode array DA1 reduces and outputs the voltage (see FIG. 5E) output from the terminal P2 of the CPU 24a (see FIG. 5F).

  The field effect transistor Q2 is for switching the input state of the inverter U2 connected in parallel to the data communication coil 17 in the oscillation circuit 25, and is composed of an N-MOS field effect transistor. The gate terminal of the field effect transistor Q2 is connected to the cathode of the diode array DA1, the drain terminal is connected to one end of the data communication coil 17 of the oscillation circuit 25, and the source terminal is grounded. The field effect transistor Q2 is turned on when a voltage of 5V is output from the terminal P2 of the CPU 24, and the input of the inverter U2 connected in parallel to the data communication coil 17 by setting one end of the data communication coil 17 to the ground potential. Ground the side. On the other hand, when a voltage of 5 V is not output from the terminal P2 of the CPU 24, the field effect transistor Q2 is turned off, and the data communication coil 17, the inverter U2, and the capacitors C1 and C2 constitute an oscillation circuit.

  The resistor R2 is for preventing the field effect transistor Q2 from being turned on accidentally by the accumulated charge by releasing the charge accumulated between the gate terminal of the field effect transistor Q2 and the diode array DA1. For example, it is composed of a 1 MΩ resistor. One end of the resistor R2 is connected to the gate terminal of the field effect transistor Q2 together with the cathode of the diode array DA1, and the other end is set to the ground potential.

  The oscillation circuit 25 is for generating a high frequency modulated by communication data, and includes a data communication coil 17, an inverter U2, and capacitors C1 and C2.

  The data communication coil 17 is constituted by, for example, a coil having 27 turns and an inductance of 34 μH. One end of the data communication coil 17 is connected to the input terminal of the inverter U2 together with the drain terminal of the field effect transistor Q2, and the other end is connected to the output terminal of the inverter U2.

  The inverter U2 is for inverting the signal input from the input terminal, amplifying it to a voltage of about 3 V, and outputting it from the output terminal, thereby causing the oscillation circuit 25 to generate a high frequency, and in parallel with the data communication coil 17. And the other end of the resistor R1 of the system control circuit 24 is connected to the power supply terminal. A capacitor C1 is connected to the input terminal of the inverter U2 together with one end of the data communication coil 17, and a capacitor C2 is connected to the output terminal together with the other end of the data communication coil 17.

  The capacitors C1 and C2 are for setting the high frequency generated in the oscillation circuit 25 to a predetermined frequency. The capacitor C1 is composed of a coil having a capacity of 147 pF, for example, and the capacitor C2 is composed of a capacitor having a capacity of 45 pF, for example. Is done. One end of the capacitor C1 is connected to the input terminal of the inverter U2, and the other end is grounded. One end of the capacitor C2 is connected to the output terminal of the inverter U2, and the other end is grounded.

  The oscillation circuit 25 configured as described above is turned on because the voltage is supplied to the inverter U2 when the communication data input from the resistor R1 of the system control circuit 24 is 1 (high), so that the data communication coil A high frequency of a predetermined frequency (for example, 4.9 MHz) determined by the inductance of 17 and the capacitances of the capacitors C1 and C2 is oscillated. On the other hand, when the communication data input from the resistor R1 of the system control circuit 24 is 0 (low), no voltage is supplied to the inverter U2, so that it is turned off and the oscillation circuit 25 does not oscillate high frequency. Therefore, according to the oscillation circuit 25, on / off switching is performed on the basis of input communication data (see FIG. 5C), so that a high frequency having a predetermined frequency modulated according to the communication data (FIG. 5 ( D)) can be generated.

  Here, the operation of each circuit or element when transmitting a signal wave from the card type display device 10 to the data processing device 30 will be described with reference to FIG. The operation when the card-type display device 10 receives a signal wave from the data processing device 30 will be described in detail later together with the configuration of the amplifier circuit 26, the voltage doubler rectifier circuit 27, the high frequency removing circuit 28, and the signal wave shaping circuit 29. explain.

  FIG. 5 is a diagram showing the relationship of signal (voltage) waveforms in each circuit or element, (A) is a diagram showing the output signal waveform of the terminal P1 of the CPU 24a, and (B) is the drain of the field effect transistor Q1. It is a figure which shows the output signal waveform of a terminal, (C) is a figure which shows the output signal waveform of resistance R1, (D) is a figure which shows the voltage waveform concerning the data communication coil 17, (E) is CPU24a It is a figure which shows the output voltage waveform of the terminal P2.

  First, as shown in FIG. 5A, when a signal wave is transmitted from the card type display device 10 to the data processing device 30, communication data is output from the terminal P1 of the CPU 24a. Then, while communication data is being output from the terminal P1 of the CPU 24a, as shown in FIG. 5B, the terminal P2 of the CPU 24a does not output a voltage of 5V. Therefore, while the communication data is output from the terminal P1 of the CPU 24a, the field effect transistor Q2 (see FIG. 4) is turned off, so that the data communication coil 17 and the inverter U2 are electrically connected, and data communication is performed. The coil 17, the inverter U2, and the capacitors C1 and C2 constitute an oscillation circuit.

  As shown in FIG. 5A, the communication data output from the terminal P1 of the CPU 24a is inverted and output in the field effect transistor Q1 as shown in FIG. 5B. As shown in FIG. 5C, the inverted communication data is reduced in voltage to 3 V by the resistor R1 and supplied to the power supply terminal of the inverter U2 (see FIG. 4) of the oscillation circuit 25.

  As described above, the oscillation circuit 25 is switched on and off in accordance with the communication data illustrated in FIG. When a voltage is supplied to the inverter U2 (ie, 1 is input to the power supply terminal), the oscillation circuit 25 is turned on and oscillates, and no voltage is supplied to the inverter U2 (ie, 0 is input to the power supply terminal). Then, the oscillation circuit 25 is turned off and the oscillation is stopped. Therefore, a high frequency voltage modulated in accordance with communication data is applied to the data communication coil 17 constituting the oscillation circuit 25 as shown in FIG. The high frequency generated in the data communication coil 17 is transmitted as a signal wave to the signal transmission circuit 33 of the data processing device 30 by electromagnetic induction.

  According to the card type display device 10 of the present embodiment, since the oscillation circuit 25 is driven using the communication data set to 3 V by the resistor R1 as a driving power supply, current consumption in the oscillation circuit 25 is suppressed, and power consumption can be saved. .

  In addition, since the voltage of communication data output from the drain terminal of the field effect transistor Q1 is lowered by the resistor R1, the voltage can be lowered without causing a round in the waveform of the communication data, and an error may occur in the signal wave. Is suppressed from occurring. Since a signal wave is generated based on communication data in the oscillation circuit 25, if the waveform of the communication data is rounded, the error occurrence rate of the signal wave generated in the oscillation circuit 25 is increased.

  Returning to FIG. 4, the configuration of the amplifier circuit 26, the voltage doubler rectifier circuit 27, the high frequency removing circuit 28, and the signal wave shaping circuit 29 will be described. The voltage doubler rectifier circuit 27 and the high frequency elimination circuit 28 correspond to the demodulator circuit of the claims.

  The amplifier circuit 26 is for amplifying the signal wave received by the data communication coil 17, and includes a capacitor C7, an inverter U3, and a feedback resistor R5. One end of the capacitor C7 is connected to the other end of the data communication coil 17 whose one end is grounded via the field effect transistor Q2, and the other end of the capacitor C7 is connected to the input terminal of the inverter U3. The input terminal of the inverter U3 is connected to one end of the resistor R5 together with the other end of the capacitor C7, and the output terminal of the inverter U3 is connected to the other end of the resistor R5 and the input terminal of the voltage doubler rectifier circuit 27. The power supply terminal of the inverter U3 is connected to the cathode of the diode array DA1. The resistor R5 is a feedback circuit composed of, for example, a 300 kΩ resistor. Note that the capacitor C7 and the resistor R5 have a role of a high-pass filter, and cut frequency components of, for example, 500 Hz or less.

  According to the amplifier circuit 26 configured as described above, when a signal wave is received from the data processing device 30, the power supply voltage is output from the terminal P2 of the CPU 24a as shown on the right side of FIG. The voltage is supplied to the power supply terminal of the inverter U3 via the diode array DA1. When the power supply voltage is supplied to the inverter U3, the amplifier circuit 26 is turned on, and the signal wave (see FIG. 5D) received by the data communication coil 17 is amplified and output to the voltage doubler rectifier circuit 27 ( (See FIG. 5G).

  On the other hand, when a signal wave is transmitted to the data processing device 30, as shown on the left side of FIG. 5E, a power supply voltage of 5V is not output from the terminal P2 of the CPU 24, so that no voltage is supplied to the inverter U3 and amplification is performed. Since the circuit 26 is turned off, unnecessary current does not flow from the data communication coil 17 to the amplifier circuit 26, and power consumption can be saved. It is also possible to prevent the signal wave generated in the oscillation circuit 25 from flowing into the amplifier circuit 26 to amplify and demodulate the signal wave and flow into the terminal RX, which is the input terminal of the CPU 24a, and cause the CPU 24a to malfunction. .

  The voltage doubler rectifier circuit 27 has its input terminal connected to the output terminal of the inverter U3 that is the output terminal of the amplifier circuit 26, and its output terminal connected to the input terminal of the high frequency elimination circuit 28. The voltage wave rectified by the voltage doubler rectifier circuit 27 (see FIG. 5G) is rectified by cutting its DC component, and the voltage is amplified.

  The high frequency removing circuit 28 uses a low-pass filter, and its input terminal is connected to the output terminal of the voltage doubler rectifier circuit 27, and its output terminal is connected to the input terminal of the signal wave forming circuit 28. The high frequency removal circuit 28 removes the high frequency component from the signal wave from which the direct current is cut in the voltage doubler rectifier circuit 27, and the signal wave is smoothed (FIG. 5 (I)). In other words, the signal wave output from the amplifier circuit 26 is demodulated by the voltage doubler rectifier circuit 27 and the high frequency reject circuit 27.

  The high frequency removing circuit 28 is configured to cut the electromagnetic induction wave generated in the power transmission coil 34a of the data processing device 30 by a low-pass filter, so that noise generated due to the electromagnetic induction wave is also generated. Can be removed. For example, the signal wave received from the data processing device 30 is a high frequency of 4.9 MHz, the electromagnetic induction wave generated in the power supply coil 18 is 120 kHz, and the signal wave component to be demodulated and extracted by the high frequency removal circuit 28. Is 4.8 kHz, the high frequency removal circuit 28 may be configured to cut a high frequency of, for example, 20 kHz or more.

  The signal wave shaping circuit 29 is for shaping the waveform of the signal wave smoothed by the high frequency removal circuit 28, and uses the comparator CP1. When the output terminal of the high frequency elimination circuit 29 is connected to the inverting input terminal of the comparator and is larger than the reference voltage (for example, 1.25 V) input to the non-inverting input terminal of the comparator, a signal of 0 V, for example, is output from the output terminal. Output. On the other hand, when the signal wave input to the inverting input terminal is equal to or lower than the reference voltage value input to the non-inverting input terminal, a 5 V signal is output from the output terminal. As a result, the signal wave smoothed in the high frequency removing circuit 28 (see FIG. 5 (I)) is shaped into a signal wave waveform in the signal wave forming circuit, and the terminal RX of the CPU 24a is formed as a 5V signal wave with less rounding. (See FIG. 5J).

  With reference to FIG. 5, the operation of each circuit when the card-type display device 10 receives a signal wave from the data processing device 30 will be described in detail.

  5D is a diagram showing a voltage waveform applied to the data communication coil 17, FIG. 5E is a diagram showing an output voltage waveform of the terminal P2 of the CPU 24a, and FIG. 5F is a diagram showing an output voltage waveform of the diode array DA1. (G) is a diagram showing an output signal waveform of the amplifier circuit 26, (I) is a diagram showing an output voltage waveform after the voltage doubler rectifier circuit 27 and the high frequency removing circuit 28, and (J) These are figures which show the output voltage waveform of the signal wave shaping circuit 29. FIG.

  Except when transmitting a signal wave from the card type display device 10 to the data processing device 30, the terminal P2 of the CPU 24a outputs a power supply voltage of 5V as shown in FIG. 26 is turned on. That is, except when transmitting a signal wave to the data processing device 30, the card type display device 10 is put on standby in a state where the signal wave from the data processing device 30 can be received.

  In this state, when the data processing device 30 transmits a signal wave, the data communication coil 17 of the card type display device 10 has a frequency of 4.9 MHz, for example, by electromagnetic induction, as shown in FIG. A signal wave having an amplitude of 1V is received. At this time, since the field effect transistor Q2 is turned on, one end of the data communication coil 17 is set to the ground potential, the input terminal of the inverter U2 is also grounded, and the amplifier circuit 26 is turned on. Therefore, the signal wave received by the data communication coil 17 is input to the amplifier circuit 26.

  A signal wave having an amplitude of, for example, 1V input from the data communication coil 17 to the amplifier circuit 26 is applied with a DC voltage of 2V in the amplifier circuit 26 as shown in FIG. And output to the voltage doubler rectifier circuit 27.

  The signal wave input to the voltage doubler rectifier circuit 27 and the high frequency removal circuit 28 is demodulated and smoothed by removing the high frequency as shown in FIG.

  The signal wave demodulated by the voltage doubler rectifier circuit 27 and the high-frequency rejection circuit 28 is input to the signal wave shaping circuit 29, where it is compared with the reference voltage value and binarized to either 0V or 5V ( (See FIG. 5J). Therefore, it is possible to output a signal wave without a round. Note that the signal wave output from the signal wave shaping circuit 29 is input to the terminal RX of the CPU 24a. The CPU 24a performs a predetermined operation according to the demodulated signal wave input from the terminal RX.

  According to the card type display device 10 of the present embodiment, since the amplifier circuit 26 is driven based on the power supply voltage lowered by the diode array DA1, the current consumption in the amplifier circuit 26 is suppressed, and the power consumption is reduced. Can save. Further, since the signal wave is amplified by the amplifier circuit 26 prior to demodulation, it can be demodulated even if the voltage of the signal wave received by the data communication coil 17 is low.

  Further, since the power supply voltage output from the terminal P2 of the CPU 24a is reduced by the diode array DA1, the power supply voltage can be stably reduced. Therefore, the output of the amplifier circuit 26 is stabilized.

  In addition, since it is possible to transmit and receive signal waves to and from the data processing device 30 using the data communication coil 17, there is no need to provide coils for transmission and reception, and the card-type display device 10 is provided. It can be downsized.

  The card type display device 10 of the present embodiment inverts communication data to be transmitted by the field effect transistor Q1 (see FIG. 5B), and also inverts the received signal wave by the comparator CP1 (see FIG. 5). 5 (J)), the signal wave is inverted and transmitted / received to / from the data processing device 30. According to the configuration of the CPU 24a and the data processing device 30, the signal wave is transmitted / received without being inverted. It may be.

  With reference to FIG. 6, the writing process executed in the CPU 35a of the data processing device 30 will be described. FIG. 6 is a flowchart showing the writing process. The writing process shown in FIG. 6 is a process executed according to a program stored in advance in a ROM (not shown) provided in the system control circuit 35, and is started after the data processor 30 is turned on. When the card type display device 10 is placed at a predetermined position of a housing (not shown) of the data processing device 30, the data associated with the card ID possessed by the data processing device 30 is transferred to the card type display device 10. It is displayed on the display panel 15.

  First, after the data processor 30 is powered on, it is determined whether or not the card detection circuit 32 (see FIG. 1) has notified that the card type display device 10 has been placed at a predetermined position of the housing (S1). .

  When the card detection circuit 32 is notified that the card type display device 10 is placed at a predetermined position of the housing (S1: Yes), the data processing device 30 starts supplying power to the card type display device. (S2). Specifically, an electromagnetic induction wave is generated in the power transmission coil 34 a by the power transmission circuit 34. The power transmission coil 34a is disposed at a position facing the power transmission coil 18 of the card type display device 10 when the card type display device 10 is placed at a predetermined position of the housing of the data processing device 30. An electromotive force is generated in the power transmission coil 18 by the electromagnetic induction wave generated in the power transmission coil 34 a, and power is supplied to the power transmission circuit 21 of the card type display device 10. The power supplied to the card type display circuit 21 is rectified in the rectifier circuit 22 (see FIG. 1), supplied to the CPU 24a of the card type display device 10, and activates the CPU 24a.

  Next, the unique ID stored in the card type display device 10 is inquired (S4). Specifically, a command (for example, “ID”) is modulated to the card type display device 10 by the signal transmission circuit 33 and transmitted to the card type display device 10 as a signal wave. The signal wave received by the data communication coil 17 of the card type display device 10 is demodulated by the signal transmission circuit 20 and input to the input terminal RX (see FIG. 4) of the CPU 24a.

  For example, when the command “ID” is input, the CPU 24a of the card-type display device 10 has its own characteristic stored in advance in, for example, a ROM (not shown) in the system control circuit 24 in accordance with a program stored in advance. Is modulated by the signal transmission circuit 20 and transmitted to the data processing device 30 as a signal wave.

  Next, the system control circuit 35 of the data processing device 30 waits until acquiring the unique ID of the card type display device 10 (S5). When the signal wave received from the card type display device 10 is demodulated in the signal transmission circuit 33 and input to the CPU 35a, the unique ID of the card type display device 10 is acquired (S5: Yes). A command (for example, “RFSH”) for refreshing the display panel of the type display device 10 is transmitted to the card type display device 10 (S6).

  When the command “RFSH” is input to the CPU 24 a of the card type display device 10, the CPU 24 a drives the drive circuits 16 a and 16 b of the display unit 12 in accordance with a program stored in advance in a ROM (not shown) in the system control circuit 24. And by applying voltages having different polarities alternately to the microcapsules 15c, refresh is performed to alternately switch the black display and the white display of the microcapsules 15c a plurality of times. This is because when the electrophoretic display panel 15 is left for a long period of time, the charged particles I in the microcapsule 15c may aggregate and become difficult to migrate. When the refresh in the card type display device 10 is completed, the card type display device 10 transmits a command (for example, “DONE + RFSE”) indicating the completion of the refresh.

  The CPU 35a of the data processing device 30 waits until the refresh is completed (S7), and receives the command “DONE + REFS” indicating the completion of the refresh from the card type display device 10 (S7: Yes), the uniqueness of the card type display device 10 Is transmitted to the display panel 15 of the card type display device 10 (for example, “WRF + display”) (S8). Here, “display” in the command is data representing whether all the pixels of the display panel 15 should be displayed in black or white.

  When the command “WRF + display” is input to the CPU 24 a of the card type display device 10, the CPU 24 a performs driving circuits 16 a and 16 b of the display unit 12 in accordance with a program stored in advance in a ROM (not shown) in the system control circuit 24. Then, a display control signal of 5V is output to display an image based on the data “display” on the display panel 15.

  Next, the CPU 35a of the data processing device 30 stands by until the card type display device 10 is removed from the data processing device 30 (S9). When the card detection circuit 32 detects that the card-type display device 10 has been removed from the data processing device 30 and notifies the CPU 35a (S9: Yes), the power transmission circuit 34 supplies power to the card-type display device 10. Supply is stopped (S10).

  According to the display device 10 of the present embodiment, power is supplied from the data processing device 30, so that power can be supplied to the card type display device 10 without being physically connected to an external device. In addition, since current consumption in the signal transmission circuit 20 is suppressed and power consumption is saved, the power transmission coil 18 can be reduced in size, and as a result, the display device is reduced in size. When the power consumption in the signal transmission circuit 20 is large, it is conceivable to increase the number of turns of the power transmission coil 18 in order to obtain a large driving power. The convenience of the card-type display device 10 is reduced because large parts that can handle high voltages must be used.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications and changes can be easily made without departing from the spirit of the present invention. Can be inferred.

  For example, in this embodiment, the resistor R1 and the diode array DA1 are used to reduce the voltage and output voltage of the communication data output from the CPU 24a, but an operational amplifier is used instead of the resistor R1 and the diode array DA1. Alternatively, a voltage conversion circuit including a regulator and a comparator may be used.

  In the present embodiment, the waveform forming circuit 29 is configured by the comparator CP1, but may be configured by a plurality of buffer circuits or a plurality of inverters instead of the comparator CP1.

  In the present embodiment, the card type display device 10 includes the power transmission circuit 21 and is supplied with driving power from the outside. For example, the card type display device 10 includes a solar battery or a storage battery and obtains driving power from the battery. It may be.

  In the present embodiment, both transmission and reception are performed by the data communication coil 17. However, instead of the data communication coil 17, a transmission coil constituting the oscillation circuit 25 and an input terminal of the amplifier circuit 26 are used. And a receiving coil connected to each other may be provided independently.

It is a figure explaining the card type display device of the present invention. It is a block diagram which shows the electrical structure of the data processing apparatus which transmits / receives a signal between a card type display apparatus and a card type display apparatus. (a) is a figure which shows the relationship between arrangement | positioning of a pixel electrode, and wiring, (b) is a figure which shows the relationship between arrangement | positioning of a common electrode, and wiring. It is a circuit diagram and a block diagram of a signal transmission circuit and a system control circuit provided in the card type display device. It is a figure which shows the relationship of the signal (voltage) waveform in each circuit or element, (A) is a figure which shows the output signal waveform of terminal P1 of CPU, (B) is the output signal of the drain terminal of field effect transistor Q1 It is a figure which shows a waveform, (C) is a figure which shows the output signal waveform of resistance R1, (D) is a figure which shows the voltage waveform concerning the data communication coil 17, (E) is the terminal P2 of CPU. It is a figure which shows an output voltage waveform, (F) is a figure which shows the output voltage waveform of diode row | line | column DA1, (G) is a figure which shows the output signal waveform of an amplifier circuit, (I) is a voltage doubler rectifier circuit And (J) is a diagram showing the output voltage waveform of the signal wave shaping circuit. It is a flowchart which shows a writing process.

Explanation of symbols

10 card type display device 15 display panel (display means)
17 Data communication coil (antenna, communication coil)
18 Electric power transmission coil (coil for feeding)
20 Signal transmission circuit (communication means)
24a CPU (control means)
26 Amplifier circuit (part of communication means)
27 Voltage doubler rectifier circuit (part of communication means, part of modulation circuit)
28 High frequency rejection circuit (part of communication means, part of modulation circuit, low-pass filter)
30 Data processor R1 Resistance (first voltage conversion means)
DA1 diode array (second voltage conversion means)
UA2 inverter (inverting amplifier circuit)
C1, C2 Capacitor Q2 Field effect transistor (switching means)

Claims (17)

Communication means capable of transmitting input communication data to data processing means capable of receiving signal waves, display means for displaying characters and images based on input display control signals, the communication means, In a display device comprising control means capable of outputting the communication data and the display control signal to the display means,
A display device comprising: first voltage conversion means for lowering a voltage of the communication data input to the communication means than a voltage of the display control signal input to the display means.   The communication means generates a signal wave modulated based on the communication data reduced in voltage by the first voltage conversion means, and transmits the signal wave generated by the modulation circuit to the data processing means. The display device according to claim 1, further comprising an antenna. The modulation circuit includes a communication coil, an inverting amplification circuit that is connected to the communication coil in parallel and is driven based on communication data that has been reduced in voltage by the first voltage conversion means, and that inverts and amplifies an input signal; A capacitor connected to each of the input side and the output side of the inverting amplifier circuit;
3. The display device according to claim 2, wherein the antenna is constituted by a communication coil of the modulation circuit, and transmits a signal wave generated by the modulation circuit to the data processing means by electromagnetic induction.   The display device according to claim 1, wherein the first voltage conversion unit includes a resistor.   The display device according to claim 1, wherein the first voltage conversion unit includes an operational amplifier.   The display device according to claim 1, wherein the first voltage conversion unit includes a regulator and a comparator. The data processing means is configured to transmit and receive signal waves,
The communication means includes an antenna that receives a signal wave transmitted from the data processing means, an amplifier circuit that is driven based on a power supply voltage input from the control means and that can amplify the signal wave received by the antenna; A demodulating circuit for demodulating the signal wave amplified by the amplifying circuit;
2. The display device according to claim 1, further comprising second voltage conversion means for making the power supply voltage input to the amplifier circuit lower than the voltage of the display control signal input to the display means.   The display device according to claim 7, wherein the second voltage conversion unit includes a diode.   The display device according to claim 7, wherein the second voltage conversion unit includes an operational amplifier.   The display device according to claim 7, wherein the second voltage conversion unit includes a regulator.   11. The display device according to claim 7, wherein the communication unit includes a signal wave shaping circuit that shapes the signal wave demodulated by the demodulation circuit.   12. The display device according to claim 11, wherein the signal wave shaping circuit includes a comparator that binarizes the signal wave demodulated by the demodulation circuit.   The display device according to claim 1, further comprising a power supply circuit that obtains a driving power source of the display device from an electromagnetic induction wave by a power feeding coil. The data processing means is configured to transmit and receive signal waves,
The communication means includes a communication coil capable of transmitting and receiving signal waves to and from the data processing means by electromagnetic induction, and a communication connected in parallel to the communication coil and having a low voltage by the first voltage conversion means. An inverting amplifier circuit driven based on data for inverting and amplifying an input signal, a capacitor connected to each of an input side and an output side of the inverting amplifier circuit, one end of the communication coil, and the control means An amplification circuit that is driven based on a power supply voltage input from the amplifier and can amplify the signal wave received by the communication coil, and a demodulation circuit that demodulates the signal wave amplified by the amplification circuit,
Second voltage conversion means for lowering the power supply voltage input to the amplifier circuit to be lower than the voltage of the display control signal input to the display means;
Switching means for electrically connecting the communication coil and the inverting amplifier circuit when transmitting the signal wave to the data processing means, and setting the other end of the communication coil to the ground potential when receiving the signal wave from the data processing means The display device according to claim 1, further comprising:   The control means outputs a power supply voltage so that the amplifier circuit is not driven when the signal wave is transmitted to the data processing means, and the amplifier circuit is driven when the signal wave is received from the data processing means. The display device according to claim 14, wherein the display device is a device.   16. The display device according to claim 14, further comprising a power supply circuit that obtains a driving power source for the display device from an electromagnetic induction wave by a power feeding coil. The display device according to claim 16, wherein the demodulation circuit includes a low-pass filter that removes an electromagnetic wave induced by a carrier wave of the signal wave and a power supply coil of the power supply circuit.

Images