JP2016109774A - Information presentation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information presentation system that reduces driving electric power even with a small-sized liquid crystal displays.SOLUTION: A controller 100 controls a switching unit 200 so that electric charges stored in a display (liquid crystal display 300) will move to a capacitor (capacitor circuit 400) or electric charges stored in the capacitor (capacitor circuit 400) will move to the display (liquid crystal display 300) when changing the polarity of the display (liquid crystal display 300), and the display (liquid crystal display 300) includes a plurality of liquid crystal displays deposited on one another.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an information presentation system.

  Since the liquid crystal display has a relatively small driving power, it is particularly suitable for applications requiring low power consumption, such as a wristwatch display. If the driving power of the liquid crystal display can be further reduced, the driving time when using the same battery can be lengthened, or sufficient driving time can be secured even with a smaller battery, and the device can be downsized. .

  Several methods are known for reducing the driving power of a liquid crystal display. For example, power consumption can be reduced by lowering the drive frequency (see Non-Patent Document 1 below). In addition, it is conceivable to consider a liquid crystal display as a capacitor and use the resonance between the capacitor and an externally installed inductor to recover power and reduce power consumption. Such a method has already been shown to be able to reduce power consumption in a plasma display (see, for example, Non-Patent Document 2 below). Alternatively, the charge stored in the liquid crystal display can be recovered using an additional capacitor (see Patent Document 1 below).

Japanese Patent No. 3799308

Y. Asaoka, E. Satoh, K. Deguchi, T. Satoh, K. Minoura, I. Ihara, S. Fujiwara, A. Miyata, Y. Itoh, S. Gyoten, N. Matsuda and Y. Kubota, "29.1 : Polarizer-FreeReective LCD Combined with Ultra Low-Power Driving Technology, "SID SymposiumDigest of Technical Papers, Vol. 40, No. 1, pp. 395-398, (2009) H.B.Hsu, C.L.Chen, S.Y.Lin and K.M. Lee, "Regenerative powerelectronics driver for plasma display panel insustain-mode operation," IEEE Trans. Industrial Electronics, Vol. 47, No. 5, pp. 1118-1125, (2000)

  The existing method of reducing the drive frequency is limited in its effect when the liquid crystal display is quickly turned on and off. When an existing method using resonance with an inductor is applied to a liquid crystal display, a complicated circuit is required, and it is difficult to downsize the device. Further, since the driving voltage of the liquid crystal display is lower than the driving voltage of the plasma display, the power efficiency is lowered due to a voltage drop due to a diode or the like included in the resonance circuit. In addition, in the method of collecting charges using a capacitor, in a small liquid crystal display or the like that originally has low power consumption, the power consumption associated with the use of the capacitor (for example, the capacitor power) An increase in power consumption of circuits and devices added with use cannot be ignored, and the effect of reducing driving power is lost.

  If the driving power of the small liquid crystal display is further reduced, the liquid crystal display can be easily used not only for images and videos but also in an information presentation system that presents information in various modes.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an information presentation system capable of reducing drive power even with a small liquid crystal display.

  An information presentation system according to an aspect of the present invention is an information presentation system for presenting information, and includes a display driven by electric power, a switching device connected to the display, and the display via the switching device. And a control device for controlling the switching device such that when the polarity of the display is changed, the charge stored in the display moves to the capacitor or The switching device is controlled so that the electric charge stored in the capacitor moves to the display, and the display includes a plurality of stacked liquid crystal displays.

  According to the above information presentation system, the charge can be collected by moving the charge stored in the display to the capacitor. In addition, the charge can be reused by moving the charge stored in the capacitor to the display. Therefore, the driving power of the display can be reduced. In addition, the display includes a plurality of stacked liquid crystal displays. By reducing the thickness of each liquid crystal display, the voltage required for driving the liquid crystal display is also reduced, so that the possibility of further reducing the driving power is increased even with a small liquid crystal display.

  An information presentation system according to an aspect of the present invention is an information presentation system for presenting information, and includes a display driven by electric power, a switching device connected to the display, and the display via the switching device. And a control device for controlling the switching device such that when the polarity of the display is changed, the charge stored in the display moves to the capacitor or The switching device is controlled so that the electric charge stored in the capacitor moves to the display, and the display includes a one-pixel liquid crystal display and a retroreflecting material that reflects light that has passed through the one-pixel liquid crystal display. The device controls the state of the one-pixel liquid crystal display so that the light reflected by the retroreflector contains information That.

  Also with the information presentation system described above, the electric charge stored in the display can be recovered and reused, so that the driving power of the display can be reduced. In addition, in the above information presentation system, since the one-pixel liquid crystal display is controlled so that the light reflected by the retroreflecting material includes information (presented by the information presentation system) in the display, the information is stored in time. It is encoded in the direction, and the information can be read by an external camera, for example. In this way, it is possible to present information in a mode different from an image or video.

  The display may also include a plurality of stacked liquid crystal display displays. This increases the possibility of further reducing the display drive power.

  Each of the stacked liquid crystal displays has the same thickness, and the total thickness in the stacked state is a thickness that can obtain optical characteristics necessary for presentation of information by the information presentation system. Further, each of the stacked liquid crystal displays may be electrically connected in parallel as viewed from the switching device. Thereby, since it becomes easy to control a display by controlling each liquid crystal display similarly, the drive power of a display can be reduced easily.

  According to the present invention, it is possible to reduce driving power even in a small liquid crystal display.

  In addition, the present invention can be applied to a liquid crystal display that operates at high speed because power can be reduced regardless of the driving frequency. Furthermore, since the effect of reducing driving power in a small liquid crystal display can be realized with a simple circuit configuration, it can also be applied to a small device.

It is a figure which shows schematic structure of the information presentation system which concerns on embodiment. It is a flowchart for demonstrating an example of the process performed in an information presentation system. It is a figure which shows the connection state corresponding to each process of the flowchart of FIG. It is a figure which shows an example of a structure of a capacitor circuit. It is a figure which shows an example of the liquid crystal display of a laminated structure. It is a figure which shows schematic structure of the information presentation system which has a tag function.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

  FIG. 1 is a diagram illustrating a schematic configuration of an information presentation system according to an embodiment. As shown in FIG. 1, the information presentation system 1 includes a control device 100, a switching device 200, a liquid crystal display 300, and a capacitor circuit 400. In the example shown in FIG. 1, the terminals T1 to T6, T11 to T15, and T21 to T25 are described for convenience of explanation. However, these terminals are not necessarily components and are virtual. There may be.

  The control device 100 includes a power supply source 110 and a control unit 120. The power supply source 110 generates driving power (a constant voltage) for the liquid crystal display 300 and outputs it from the terminals T1 and T2. The control unit 120 controls, for example, the power supply source 110 to switch on / off the drive power generated by the power supply source 110, or to change the polarity of the voltage (drive power voltage) between the terminals T1 and T2. Can be switched. Furthermore, the control unit 120 can also switch the state (described later) of the switching device 200 by controlling the switching device 200. The control device 100 can be realized by a microcontroller, for example. In that case, since the function of generating a constant voltage of the power supply source 110 can be realized by the microcontroller, the control device 100 can include the power supply source 110 as shown in FIG. . For example, the power supply source 110 and the control device 100 may be provided separately.

  The switching device 200 switches the connection (connection state) of the power supply source 110, the liquid crystal display 300, and the capacitor circuit 400. The switching device 200 can be realized by a multiplexer (switch), for example.

  The liquid crystal display 300 is driven by electric power. The liquid crystal display 300 has a configuration in which electrodes are provided on both sides of a liquid crystal panel, for example. One electrode is connected to the terminal T3 and the other electrode is connected to the terminal T4. The liquid crystal display 300 operates when a voltage is applied. At this time, charges are accumulated in the liquid crystal panel. Further, in the present embodiment, as a driving method of the liquid crystal display 300, a driving method that is generally adopted and operates while changing (reversing) the polarity of the liquid crystal display 300 is adopted.

  In the present embodiment, the liquid crystal display 300 is preferably a 1-pixel liquid crystal display. Further, the liquid crystal display 300 may be controlled (binary control) by switching to only two states of ON and OFF.

  The capacitor circuit 400 is a circuit for accumulating (collecting) the electric charge accumulated in the liquid crystal display 300 and re-supplying the accumulated electric charge to the liquid crystal display 300. In the example shown in FIG. 1, the capacitor circuit 400 can move charges between the liquid crystal display 300 and the switching device 200. When one end of the capacitor circuit 400 is a terminal T5 and the other end is a terminal T6, the capacitor circuit 400 has a capacitance between the terminals T5 and T6. Terminal T6 is connected to a ground (GND) having a reference potential (for example, 0V). For example, the capacitor circuit can be constituted by only one capacitor, or can be constituted by including two or more capacitors as will be described later with reference to FIG.

  Here, the switching device 200 will be further described. In the example shown in FIG. 1, eight terminals of terminals T11 to T14 and T21 to T24 are provided on one side of the switching device 200, and two terminals of terminals T15 and T25 are provided on the other side. . The switching device 200 switches to a state in which the terminal T15 is connected to any one of the terminals T11 to T14 and the terminal T25 is connected to any one of the terminals T21 to T24. The state of the switching device 200 can be switched by a control signal from the control unit 120, for example.

  Terminals T11 and T21 of switching device 200 are connected to terminals T1 and T2 of power supply source 110, respectively. Terminals T12 and T22 are connected to terminals T5 and T6 of capacitor circuit 400, respectively. Terminal T13 is connected to terminal T6 of capacitor circuit 400, and terminal T23 is connected to terminal T5 of capacitor circuit 400. Terminals T14 and T24 are connected to the ground. Terminals T15 and T25 are connected to terminals T3 and T4 of the liquid crystal display 300, respectively.

  In the information presentation system 1, various information can be presented by the liquid crystal display 300 while the polarity of the liquid crystal display 300 is changed by the control device 100 controlling the switching device 200. The various types of information are not limited to images and videos, for example, and may include tag information as will be described later with reference to FIG. Next, the point of changing the polarity of the liquid crystal display 300 will be described with reference to FIGS.

  FIG. 2 is a flowchart for explaining an example of processing executed in the information presentation system 1, and FIG. 3 is a diagram showing a connection state corresponding to each processing in the flowchart of FIG. 2 is executed by the control device 100.

  First, the control device 100 switches the connection so that the liquid crystal display 300 and the power supply source 110 are connected, and applies a constant voltage to the liquid crystal display 300 (step S1). Specifically, as shown in FIG. 3A, the terminal T1 and the terminal T2 of the power supply source 110 (FIG. 1) are connected to the liquid crystal display 300 via the terminals T11 and T15 and the terminals T21 and T25 of the switching device 200. Are connected to terminals T3 and T4, respectively. Further, when the voltage at the terminal T1 is set to a predetermined voltage (V) and the voltage at the terminal T2 is set to the ground potential, a constant voltage (+ V) is generated between the terminals T1 and T2. Thereby, a constant voltage is applied between the terminals T3 and T4 of the liquid crystal display 300.

  Next, the control device 100 switches the connection so that the liquid crystal display 300 and the capacitor are connected, and the liquid crystal display charges the capacitor (step S2). Specifically, as shown in FIG. 3B, the terminal T5 and the terminal T6 of the capacitor circuit 400 are connected to the terminal T3 and the terminal of the liquid crystal display 300 via the terminals T12 and T15 and the terminals T22 and T25 of the switching device 200, respectively. Each is connected to T4. Thereby, the electric charge stored in the liquid crystal display 300 moves to the capacitor of the capacitor circuit 400, and the capacitor is charged.

  Next, the control device 100 switches the connection so that both terminals of the liquid crystal display 300 are connected, and discharges the charge stored in the liquid crystal display 300 (step S3). Specifically, as shown in FIG. 3C, the terminals T3 and T4 of the liquid crystal display 300 are all connected to the ground via the terminals T15 and T14 and the terminals T25 and T24 of the switching device 200. As a result, the charge remaining in the liquid crystal display 300 without being charged in the capacitor circuit 400 in step S2 is discharged to the ground.

  Next, the control device 100 switches the connection so that the liquid crystal display 300 and the capacitor are inverted and connected, and the capacitor charges the liquid crystal display 300 (step S4). Specifically, as shown in FIG. 3D, the terminal T5 and the terminal T6 of the capacitor circuit 400 are connected to the terminal T4 and the terminal T3 of the liquid crystal display 300 via the terminals T23, T25, T13, and T15 of the switching device 200, respectively. Connected to each. As a result, the charge stored in the capacitor of the capacitor circuit 400 moves to the liquid crystal display 300, and a voltage is applied across the liquid crystal display 300.

  Next, the control device 100 switches the connection so that the liquid crystal display 300 and the power supply source 110 are connected, and applies a constant voltage to the liquid crystal display 300 (step S5). Specifically, specifically, as shown in FIG. 3E, the terminal T1 and the terminal T2 of the power supply source 110 (FIG. 1) are connected via the terminals T11 and T15 and the terminals T21 and T25 of the switching device 200, respectively. The liquid crystal display 300 is connected to terminals T3 and T4, respectively. Here, when the voltage at the terminal T1 is set to the ground potential and the voltage at the terminal T2 is set to the predetermined voltage (V), a constant voltage (+ V) is generated between the terminals T2 and T1. Thereby, a constant voltage is applied between the terminals T4 and T3 of the liquid crystal display 300.

  Next, the control device 100 switches the connection so that the liquid crystal display 300 and the capacitor are inverted and connected, and the liquid crystal display 300 charges the capacitor (step S6). Specifically, as shown in FIG. 3F, the terminal T5 and the terminal T6 of the capacitor circuit 400 are connected to the terminal T4 and the terminal of the liquid crystal display 300 via the terminals T23 and T25 and the terminals T13 and T15 of the switching device 200, respectively. Each is connected to T3. Thereby, the electric charge stored in the liquid crystal display 300 moves to the capacitor of the capacitor circuit 400, and the capacitor is charged.

  Next, the control device 100 switches the connection so that both terminals of the liquid crystal display 300 are connected, and discharges the charge stored in the liquid crystal display 300 (step S7). Specifically, as shown in FIG. 3G, the terminals T3 and T4 of the liquid crystal display 300 are both connected to the ground via the terminals T15 and T14 and the terminals T25 and T24 of the switching device 200. As a result, the charge remaining in the liquid crystal display 300 without being charged in the capacitor circuit 400 in step S6 is discharged to the ground.

  Next, the connection is switched so that the liquid crystal display 300 and the capacitor are connected, and the capacitor charges the liquid crystal display 300 (step S8). Specifically, as shown in FIG. 3 (h), the terminal T5 and the terminal T6 of the capacitor circuit 400 are connected to the terminal T3 and the terminal of the liquid crystal display 300 via the terminals T12 and T15 and the terminals T22 and T25 of the switching device 200, respectively. Each is connected to T4. Thereby, the electric charge stored in the liquid crystal display 300 moves to the capacitor of the capacitor circuit 400, and the capacitor is charged.

  After the process of step S8 is completed, the process is returned to step S1 again. As a result, the processing of the flowchart is repeatedly executed, so that the liquid crystal display 300 can be always turned on. When the liquid crystal display 300 is temporarily turned off, the process may be temporarily stopped in step S3 or step S7. In that case, the liquid crystal display 300 can be turned on again only by starting the next step (step S4 or step S7).

  In the conventional liquid crystal display driving method, the above-described four steps S1, S3, S5, and S7 or two steps S1 and S5 are repeated. The four-step process takes more time than the two-step process, but can reduce power consumption by half. In the present embodiment, the eight steps S1 to S8 are repeatedly executed, and further reduction of power consumption can be expected.

Here, what is important in the flowchart of FIG. 2 is that when the liquid crystal display 300 is changed from ON to OFF (polarity is changed), the charge stored in the liquid crystal display 300 is moved to the capacitor, and the liquid crystal display 300 is moved. When changing from OFF to ON (changing the polarity contrary to the above), the charge stored in the capacitor is moved to the liquid crystal display 300. As a result, the amount of electric power (power) that the power supply source 110 must supply to the liquid crystal display 300 is reduced. Specifically, in the configuration shown in the circuit of FIG. 1 (or Fig. 3), the liquid crystal display 300, and an ideal capacitor capacitance _{C LC, kC LC} capacitance of the capacitor circuit 400 (capacitor) using a constant k When the power consumption and leakage current of the control device 100 (for example, a microcontroller) are ignored, the amount of charge required to drive the liquid crystal display 300 is (1 + k) compared to the above-described conventional four-step procedure. / (1 + 2k) times. For this reason, when k is sufficiently large, the necessary charge amount can be reduced to ½. This reduction amount is an ideal value. In particular, the reduction amount approaches the ideal value as a sufficient number of polarity inversion cycles are performed and the power consumption of the control unit 120 is small.

  By the way, as described above, the capacitor circuit 400 may include a plurality of capacitors. Since the capacitor circuit 400 includes a plurality of capacitors, the amount of charge that the power supply source 110 must supply can be further reduced.

  FIG. 4 is a diagram illustrating an example of a configuration of a capacitor circuit including a plurality of capacitors. In the example illustrated in FIG. 4, the capacitor circuit 400 </ b> A includes three capacitors 410, 420, and 430. Both ends of the capacitors 410, 420, and 430 and the terminals T5 and T6 can be selectively connected, for example, by switching a switch circuit (not shown). Switching of the switch circuit can be controlled by a control signal from the control device 100, for example.

  4A shows a state where both ends of the capacitor 410 are connected to the terminals T5 and T6, and FIG. 4B shows a state where both ends of the capacitor 420 are connected to the terminals T5 and T6, respectively. (C) shows a state in which both ends of the capacitor 430 are connected to the terminals T5 and T6, respectively.

  When such a capacitor circuit 400A is used, the operations shown in FIGS. 4A, 4B, and 4C are executed in this order in steps S2 and S6 of FIG. Steps S2 and S6 in FIG. 2 are steps for charging the capacitor with the electric charge stored in the liquid crystal display 300. Therefore, the operations shown in FIGS. 4A, 4B, and 4C are executed in this order. As a result, charges are stored in the capacitors 410, 420, and 430, respectively. Therefore, more charges can be stored than when there is only one capacitor (for example, only the capacitor 410).

  In steps S4 and S8 in FIG. 2, the operations shown in FIGS. 4C, 4B, and 4A are executed in this order. Steps S4 and S8 in FIG. 2 are steps for moving the charge stored in the capacitor to the liquid crystal display 300. Therefore, the operations shown in FIGS. 4C, 4B, and 4A are executed in this order. Then, the electric charge stored in each of the capacitors 430, 420, and 410 moves to the liquid crystal display 300. Therefore, more charges can be supplied to the liquid crystal display 300 than when there is only one capacitor (for example, only the capacitor 410). The other steps (steps S1, S3, S5, and S7) in FIG. 2 are the same as those described above.

  By adopting the configuration shown in FIG. 4 in this way, more electric charge can be reused, and thus driving power can be further reduced. In the example illustrated in FIG. 4, the case where the number of capacitors included in the capacitor circuit 400 is three has been described. However, the number of capacitors included in the capacitor circuit 400 is not particularly limited.

  In the method described so far, many procedures are required as compared with the case of normal driving (when the liquid crystal display is driven without reusing charges), and the power consumption of the control device 100 can be increased. For this reason, it is necessary to reduce the amount of charge for driving the liquid crystal display 300 more than the increase in power consumption of the control device 100. In order to reduce the amount of charge required compared with that during normal driving at a constant ratio, the larger the amount of charge required during normal driving, the larger the absolute value of the amount of charge to be reduced.

  Here, PDLC (polymer dispersed liquid crystal) is considered as the liquid crystal display 300, and the distance between two electrodes (described later) is halved. Then, the required drive voltage is almost halved. However, the liquid crystal sealed inside is halved, and desired optical characteristics cannot be obtained as it is. Desired optical characteristics are optical characteristics necessary for presenting information by the information presentation system 1, and include, for example, parallel light transmittance and diffuse light transmittance at the time of ON and OFF. However, if two liquid crystal displays having a distance between electrodes (the thickness of the liquid crystal layer) are laminated, desired optical characteristics can be obtained. At this time, the two liquid crystal displays can be handled as if they were one liquid crystal display by being electrically connected in parallel. When driving a liquid crystal display in which these two liquid crystal displays are stacked, the driving voltage is halved and the flowing current or required charge is doubled (the total amount of energy applied does not change).

  FIG. 5 is a diagram illustrating an example of a liquid crystal display having a stacked structure. As shown in FIG. 5, the liquid crystal display 300 includes a plurality of stacked liquid crystal displays 310 and 320. Even with such a laminated structure, the liquid crystal display 300 can be a one-pixel liquid crystal display as a whole.

  An electrode 311 is provided on one side of the liquid crystal display 310 and an electrode 312 is provided on the other side. The liquid crystal display 310 is turned on and off by the potential difference between the electrode 311 and the electrode 312. Similarly, an electrode 321 is provided on one side of the liquid crystal display 320 and an electrode 322 is provided on the other side. The liquid crystal display 320 is turned on and off by the potential difference between the electrode 321 and the electrode 322.

  The electrode 311 of the liquid crystal display 310 and the electrode 321 of the liquid crystal display 320 are commonly connected to the terminal T3. The electrode 312 of the liquid crystal display 310 and the electrode 322 of the liquid crystal display 320 are commonly connected to the terminal T4. Therefore, each of the stacked liquid crystal displays 310 and 320 is electrically connected in parallel as viewed from the terminals T3 and T4 (from the switching device 200 in FIG. 1).

  Here, the desired thickness of the liquid crystal displays 310 and 320 can be obtained as a whole. The liquid crystal displays 310 and 320 preferably have the same thickness.

  According to the liquid crystal display 300 shown in FIG. 5, not only the amount of charge to be reduced is doubled but also the driving voltage can be lowered, so that it can be expected that the power consumption of the control device 100 can be reduced accordingly. Thereby, even in a small liquid crystal display or the like, the effect of reducing the driving power can be sufficiently obtained. The thickness of the liquid crystal layer can be appropriately changed (for example, increased) according to desired optical characteristics.

  When a plurality of liquid crystal displays 300 shown in FIG. 5 are arranged, they can be used as a segment type display device, and thus can be applied to a wristwatch or the like. Further, in the case of a liquid crystal display having a one-pixel configuration, for example, an electrically controlled frosted glass, a glass with a light control function, or the like can be considered. Furthermore, as another application example of the liquid crystal display having a one-pixel configuration, there is an application to an information presentation system having a tag function described below.

  FIG. 6 is a diagram showing a schematic configuration of an information presentation system having a tag function. As shown in FIG. 6, the information presentation system 1 </ b> A includes a liquid crystal display 300 </ b> A and other elements 500. The liquid crystal display 300 includes a liquid crystal display 330 and a retroreflecting material 350. The liquid crystal display 330 may be a single liquid crystal display, or may be a plurality of stacked liquid crystal displays like the liquid crystal displays 310 and 320 in FIG. Other elements 500 are, for example, control device 100, switching device 200, capacitor circuit 400, and the like shown in FIG.

  The liquid crystal display 300A is a one-pixel display, and when the control device 100 switches between ON and OFF, light (for example, infrared light IR1) emitted from the outside can be modulated so as to include tag ID information. it can. The modulated light is reflected by the retroreflecting material 350 and returns to the light irradiation source (for example, infrared light IR2). Therefore, an external reader including a light irradiator that can irradiate light (for example, infrared light IR1) and a light receiver that can receive light (for example, infrared light IR2) has a tag ID. It becomes possible to read the information. Since the liquid crystal display 300A can reduce the driving power in the same manner as the liquid crystal display 300 described above, the tag can be downsized.

  The operational effects of the information presentation system according to the present embodiment described above will be described. As shown in FIGS. 1 and 2, the information presentation system 1 is a system for presenting information, and includes a liquid crystal display 300 driven by electric power, a switching device 200 connected to the liquid crystal display 300, and a switching device 200. A capacitor circuit 400 capable of transferring charges to and from the liquid crystal display 300, and a control device 100 for controlling the switching device 200. The control device 100 changes the polarity of the liquid crystal display 300. The switching device 200 is controlled so that the charge stored in the liquid crystal display 300 moves to the capacitor circuit 400 or the charge stored in the capacitor circuit 400 moves to the liquid crystal display 300. As shown in FIG. 5, the liquid crystal display 300 includes a plurality of liquid crystal displays 310 and 320 that are stacked.

  According to the information presentation system 1, the charge can be collected by moving the charge stored in the liquid crystal display 300 to the capacitor circuit 400. Further, by moving the charge stored in the capacitor circuit 400 to the liquid crystal display 300, the charge can be reused. Since the electric power supplied from the power supply source 110 can be reduced by the amount of reuse of electric charges, the driving power of the liquid crystal display 300 can be reduced. In addition, since the liquid crystal display 300 includes a plurality of stacked liquid crystal displays 310 and 320, the thickness of each liquid crystal display can be made smaller than the thickness of the liquid crystal display 300. By reducing the thickness of the liquid crystal display 300, the voltage required for driving the liquid crystal display 300 is also reduced, so that the possibility of further reducing the driving power is increased even with a small liquid crystal display.

  As shown in FIG. 6, in the information presentation system 1 </ b> A according to another aspect, the liquid crystal display 300 </ b> A includes a 1-pixel liquid crystal display 330 and a retroreflection that reflects light that has passed through the 1-pixel liquid crystal display 330. The control device 100 (FIG. 1) controls the state of the one-pixel liquid crystal display 330 so that the light reflected by the retroreflecting material 350 includes information.

  Similarly to the information presentation system 1, the information presentation system 1A can reduce the driving power of the liquid crystal display 300 by collecting and reusing the charge stored in the display. In addition, in the information presentation system 1A, in the liquid crystal display 300, the one-pixel liquid crystal display 330 is controlled so that the light reflected by the retroreflecting material 350 includes information (presented by the information presentation system 1A). The information is encoded in the time direction, and the information can be read by an external camera, for example. In this way, information (in this case, tag information) in a mode different from an image or video can be presented.

  Also in the information presentation system 1A, the liquid crystal display 300 may be configured to include a plurality of stacked liquid crystal displays as shown in FIG. This increases the possibility that the driving power of the liquid crystal display 300 can be further reduced.

  Further, as shown in FIG. 5, the plurality of stacked liquid crystal displays 310 and 320 each have the same thickness, and the total thickness in the stacked state is the presentation of information by the information presentation system 1 and 1A. Further, the thickness may be sufficient to obtain the necessary optical characteristics, and each of the stacked liquid crystal displays 310 and 320 is electrically connected in parallel as viewed from the switching device 200 (FIG. 1). It may be. Accordingly, the liquid crystal displays 300 and 300A can be easily controlled by controlling the liquid crystal displays 310 and 320 in the same manner, so that the driving power of the liquid crystal displays 300 and 300A can be easily reduced.

  Further, as shown in FIG. 4, the capacitor circuit 400 may include a plurality of capacitors 410, 420, and 430. By using a plurality of capacitors 410, 420, and 430, more charge can be reused than when there is only one capacitor, and thus it is possible to further reduce the driving power of the liquid crystal displays 300 and 300A. .

  As described above, according to the present embodiment, it is possible to reduce driving power even in a small liquid crystal display. In addition, since the power can be reduced regardless of the driving frequency, the present embodiment can also be applied to a liquid crystal display that operates at high speed. Furthermore, since the effect of reducing driving power in a small liquid crystal display can be realized with a simple circuit configuration, it can also be applied to a small device.

  This embodiment differs from the technique described in Patent Document 1 at least in the following points. That is, while Patent Document 1 targets an active matrix type liquid crystal, this embodiment targets a one-pixel liquid crystal display, a segment type driving system, and the like. In this embodiment, sufficient power reduction is achieved even with a small display. In order to obtain the effect, a plurality of liquid crystal displays are stacked, and in this embodiment, it is used as an information communication tag using an external camera together.

  In the above, the information presentation system has been described as an example of the embodiment, but the embodiment of the present invention is not limited to this. For example, the display driving method can also be an embodiment of the present invention. In other words, the display driving method is a display driving method used in an information presentation system for presenting information. As shown in FIG. 2, the charge stored in the display is changed when the polarity of the display is changed. Is moved to the capacitor or the charge stored in the capacitor is moved to the display. The display may be a display including a plurality of stacked liquid crystal displays as shown in FIG. 5, and the light that has passed through the 1-pixel liquid crystal display and the 1-pixel liquid crystal display as shown in FIG. 6. A reflective retroreflecting material may be included. In the latter case, the state of the 1-pixel liquid crystal display may be controlled so that the light reflected by the retroreflecting material includes information.

  DESCRIPTION OF SYMBOLS 1,1A ... Information presentation system, 100 ... Control apparatus, 200 ... Switching apparatus, 300, 300A, 310, 320, 330 ... Liquid crystal display, 350 ... Retroreflective material, 400, 400A ... Capacitor circuit.

Claims (4)

An information presentation system for presenting information,
A display driven by electricity;
A switching device connected to the display;
A capacitor capable of transferring charge to and from the display via the switching device;
A control device for controlling the switching device;
With
When the control device changes the polarity of the display, the control device controls the switching device so that the electric charge stored in the display moves to the capacitor or the electric charge stored in the capacitor moves to the display. Control
The display includes a plurality of stacked liquid crystal displays,
Information presentation system. An information presentation system for presenting information,
A display driven by electricity;
A switching device connected to the display;
A capacitor capable of transferring charge to and from the display via the switching device;
A control device for controlling the switching device;
With
When the control device changes the polarity of the display, the control device controls the switching device so that the electric charge stored in the display moves to the capacitor or the electric charge stored in the capacitor moves to the display. Control
The display includes a one-pixel liquid crystal display and a retroreflector that reflects light that has passed through the one-pixel liquid crystal display;
The control device controls the state of the one-pixel liquid crystal display so that light reflected by the retroreflecting material includes the information.
Information presentation system.   The information display system according to claim 2, wherein the display includes a plurality of stacked liquid crystal displays. Each of the plurality of stacked liquid crystal displays has the same thickness, and the total thickness in the stacked state is a thickness capable of obtaining optical characteristics necessary for presentation of information by the information presentation system. ,
4. The information presentation system according to claim 1, wherein each of the plurality of stacked liquid crystal displays is electrically connected in parallel as viewed from the switching device.

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