JP4940594B2 - Display device - Google Patents

Description

This invention also relates to a display equipment.

  In recent years, electronic displays called electronic paper have been developed. Electronic paper is required to be as thin and light as paper and to be able to rewrite displayed information.

  When electronic paper is classified by display principle or display element, for example, a liquid crystal system using cholesteric liquid crystal, a flexible display using organic EL (Electro Luminescence), an electrophoretic system, and a twisted ball system are used in two different states. It is roughly classified into a switching method using an electric field or a magnetic field. A flexible display uses a film instead of glass as a substrate, thereby realizing a flexible, thin and lightweight electronic display.

  FIG. 15 schematically shows an electrophoretic display method. In the microcapsule 101, a plurality of white fine particles 102 that are negatively charged and a plurality of black fine particles 103 that are positively charged are enclosed.

  For example, as shown in FIG. 15A, when a positive voltage is applied to the electrode 104a and a negative voltage is applied to the electrode 104b, an electric field is applied to the microcapsule 101, and the negatively charged white fine particles 102 are moved toward the electrode 104a. The black fine particles 103 that are attracted and charged positively are attracted toward the electrode 104b. In the state of FIG. 15A, a white state is displayed for human eyes. Further, as shown in FIG. 15B, when a negative voltage is applied to the electrode 105a and a positive voltage is applied to the electrode 105b, the fine particles in the microcapsule 101 diffuse without being attracted to any electrode side, and the human eye Is displayed in gray. As shown in FIG. 15C, when a negative voltage is applied to the electrode 104a and a positive voltage is applied to the electrode 104b, the black fine particles 103 are attracted to the electrode 104a side, and the white fine particles 102 are attracted to the electrode 104b side. In this state, a black state is displayed for human eyes. In the electrophoretic method, for example, drive electrodes are arranged in a matrix and each electrode is driven, and characters and images are displayed by switching the states shown in FIGS. 15A to 15C.

  The following Patent Document 1 describes an invention related to a flexible display with a built-in speaker.

JP 2003-125315 A

  However, the conventional techniques described above have the following problems. For example, in the liquid crystal method, light incident on the liquid crystal layer is selectively reflected to display brightness and darkness, but the screen may become dark because reflected light that is part of the incident light is used. In addition, unlike flexible glass substrates, flexible displays have problems such as low thermal, chemical and optical stability, low heat resistance, poor surface accuracy, and high coefficient of thermal expansion. Cannot use flat panel display creation process with. In particular, a flexible display requires a fine processing technique for forming a thin-film organic EL layer in a barrier film, so that it is not easy to construct a new production process. In addition, a flexible display using a plastic substrate instead of a film substrate has been proposed, but it is difficult to achieve a hold feeling and bending feeling like paper.

  In addition, the method of applying an electric field in the above-described electrophoresis method is to apply an electric field to a predetermined pixel by, for example, arranging X electrodes and Y electrodes in a matrix and applying a voltage to each electrode. When the screen is enlarged, a voltage drop occurs at both ends of the screen, and there is a possibility that an appropriate electric field cannot be applied to the pixels existing at the end. In recent years, the number of pixels in the display has been increased, but there is a risk that an electric field applied to each pixel may also be applied to adjacent pixels, and the positioning of the pixels to which the electric field is applied is more accurate. There is a problem that must be done.

Accordingly, an object of the present invention has a complicated manufacturing process does not require a display unit, a character information and image information recorded on the display unit, provides a display equipment that can erase recorded information That is.

In order to solve the above-described problems, the present invention provides:
A first state in which the reflectance is intermediate, a second state in which the reflectance is lower than the reflectance in the first state, and a third in which the reflectance is higher than the reflectance in the first state. display device and a state being supported by the light-transmitting substrate filamentous, and tables radical 113 of light-transmitting substrate of a plurality of thread is formed woven into fabric-like,
Is applied to the display unit driving signal because the second or third state is changed to the first state, the erase head comprising a linear electrode,
Is applied to the display unit driving signal order is changed from the first state to the second and third one of the state of a display device and a recording head comprising a plurality of point electrodes.

  According to the present invention, since the display element and the mechanism for recording and erasing information are separated, there is no problem in the process due to the characteristics of the film substrate, and a film display can be created by a simple method. In addition, since recording / erasing processing is performed using an external drive signal, information can be recorded and erased accurately without high-precision alignment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A shows an appearance of a display device 1 according to an embodiment of the present invention. The display device 1 includes a display sheet 11 that is a display unit, a head 12 that is an example of a recording unit, a cradle 13 that supplies power and data for driving the head 12, and a bar 14 that holds the display sheet 11. . The head 12 can slide up and down with the display sheet 11 in between. Moreover, the head 12 is comprised so that the display sheet 11 may be pinched | interposed by a pair of head which opposes so that it may mention later.

  The cradle 13 is connected to a power supply line 15 for supplying power from the outside and a data supply line 16 for supplying data to be written on the display sheet 11. The data supply line 16 is a LAN (Local Area Network) cable, for example, and is supplied with data from an external device such as a personal computer. Note that data may be supplied to the display device 1 not only by a wired connection but also by wireless communication.

  FIG. 1B shows an example of the usage state of the display device 1. The bar 14 is detachable from the cradle 13, and the display sheet 11 supported by the bar 14 is also detachable from the display device 1. Therefore, if the bar 14 is removed after the information is written on the display sheet 11, the information displayed on the display sheet 11 can be confirmed at a remote position.

  FIG. 2 shows a configuration of the display device 1 according to the embodiment of the present invention. The control unit 21 controls each unit of the display device 1 via the bus 41. For example, the recording process and the erasing process on the display sheet 11 are controlled by controlling the head 12. A program executed by the control unit 21 is stored in a ROM (Reed Only Memory) 22, and a RAM (Random Access Memory) 23 is used as a work area when the control unit 21 executes the program.

  The power control unit 24 controls the power supplied from the power supply line 15. For example, the display device 1 is turned on / off and the state of charge is switched under the control of the power supply control unit 24.

  The display information storage unit 25 stores display information displayed on the display sheet 11. For example, display information transmitted via the communication interface (I / F) 26 is stored in the display information storage unit 25. The display information may be supplied from a removable recording medium 27. The recording medium 27 is, for example, a magnetic tape, an optical disk, a semiconductor memory, or the like. Although not shown in FIG. 1, the display device 1 is provided with a mounting portion for the recording medium 27. When the recording medium 27 is loaded, display information is read from the recording medium 27 by the recording medium controller 28, and the read display information is supplied to the display information storage unit 25.

  The electrode control unit 29 controls switching of the polarity of the voltage applied to the electrode provided in the head 12. Although details of the head 12 will be described later, the head 12 is provided with an erasing head for erasing already written display information and a recording head for writing new display information. In this embodiment, the erasing head and the recording head are constituted by electrodes. The electrode control unit 29 controls switching of the polarity of the voltage applied to the erasing head and the recording head.

  The driver 30 drives the head feeding unit 31 based on a drive signal from the control unit 21. The head feeding unit 31 is driven by the driver 30, and the head 12 attached to the head feeding unit 31 is driven, and display information is recorded on and erased from the display sheet 11. At the time of recording, an erasing process by the preceding erasing head is performed, and then a recording process by the recording head is performed.

  Recording and erasing operations of the display device 1 will be described. Display information data supplied from the recording medium 27 or an external device via the communication I / F 26 is stored in the display information storage unit 25. The control unit 21 determines the polarity of the voltage applied to the recording head and the erasing head in the head 12 according to the display information data stored in the display information storage unit 25. The driver 30 controls the electrode control unit 29 while driving the head feeding unit 31 to perform recording and erasing processing on the display sheet 11.

  Next, an example of the display sheet 11 will be described. FIG. 3 shows the surface of the display sheet 11 in one embodiment of the present invention. As shown in FIG. 3A, display elements are uniformly applied to the surface of the display sheet 11 by a method such as coating.

  FIG. 3B shows a display element according to an embodiment of the present invention. In this display device, a microcapsule 51 having a diameter of about 10 μm (micrometers) is dispersed with negatively charged white fine particles of about 0.5 μm and positively charged black fine particles of about 0.5 μm. The dispersion is sealed. As the black fine particles, for example, carbon or silica particles are used, and as the white fine particles, for example, titanium dioxide is used. In addition, charge adjustment can be performed by using a powder such as polyethylene and performing a surface treatment with a coupling agent or the like. As a method for microencapsulation, a polymerization phase separation method, a thermal phase separation method, a solvent evaporation phase separation method, or the like is used.

  The display element includes a first state in which the reflectivity is intermediate depending on the state of the internal fine particles, a second state in which the reflectivity is lower than the first reflectivity, and the reflectivity with respect to the first reflectivity. Has a high third state. For example, as shown in FIG. 4A, in the first state, the white fine particles and the black fine particles in the microcapsule 51 are dispersed, and, for example, gray is displayed with respect to the human viewing direction. As shown in FIG. 4B, the second state is a state in which the black fine particles are accumulated in the human viewing direction, and is in a black state in which the reflectance is lower than the reflectance in the first state. In the third state, as shown in FIG. 4C, the white fine particles are accumulated in the human viewing direction, and the white state has a higher reflectance than the reflectance in the first state.

  The microcapsules in which the white fine particles and black fine particles described above are encapsulated are uniformly dispersed in an ultraviolet curable resin, which is an example of a light-transmitting substrate, and uniformly applied to a film substrate. The microcapsules are dispersed in an ultraviolet curable resin by a paint shaker or the like. As shown in FIG. 5, for example, a doctor blade method is used to apply the ultraviolet curable resin 61 in which microcapsules are dispersed to the film substrate 62 using a doctor blade 63, as shown in FIG. . After the ultraviolet curable resin is applied to the film substrate 62, ultraviolet rays are irradiated to cure the ultraviolet curable resin, whereby the display sheet 11 is created.

  Another example of the display sheet will be described. First, microcapsules are dispersed in an ultraviolet curable resin. A pressure is applied to the ultraviolet curable resin containing the microcapsules to extrude from a small hole (nozzle), and ultraviolet rays are irradiated while being extruded. In this way, the ultraviolet curable resin containing the microcapsules can be processed into a thread shape. In the following description, an ultraviolet curable resin including microcapsules processed into a thread shape is referred to as a thread-shaped constituent material.

  In the above-described method, a technique for producing a yarn called a melt spinning method or the like is used. However, a yarn-shaped constituent material can be created by a method called another wet spinning method or a dry spinning method. These spinning methods are known techniques, and existing techniques can be used without the need to construct a new manufacturing process.

  Subsequently, the thread-like constituent material is woven as shown in FIG. That is, a plurality of thread-like constituent materials are regarded as warp and weft, and woven cloth-like display sheet 11 'is created by weaving them alternately while turning them upside down. The woven cloth-like display sheet 11 ′ thus produced is less likely to bend and has a touch and bending feeling closer to that of paper. Furthermore, the surface roughness is increased as compared with the case of using a film substrate, the surface scattering is increased, and a reflectance close to that of paper can be obtained.

  FIG. 7 schematically shows the display sheet 11 ′. For example, the thread-like constituent materials indicated by reference numerals 55, 56, 57, and 58 are woven alternately. Microcapsules are dispersed in each thread component.

  As shown in FIG. 8A, a plurality of microcapsules are supported on the thread-like component 55. When an electric field is applied to the thread-like constituent material 55 by applying a voltage to the external electrode, fine particles in the microcapsules supported by the thread-like constituent material 55 move. For example, when a negative voltage is applied to the external electrode 59a and a positive voltage is applied to the external electrode 59b as shown in FIG. 8B, the black fine particles in the microcapsule are attracted to the negative side, and the white fine particles are directed to the positive side. Be attracted. That is, even if the microcapsules are dispersed in the thread-like constituent material, the movement of the black fine particles and the white fine particles in the microcapsules can be controlled by applying an electric field from the outside.

  Next, a recording process for writing display information to the display sheet 11 (the display sheet 11 ′ can be used in the same manner, the same applies hereinafter) and an erasing process for erasing will be described. FIG. 9 shows an outline of the recording process and the erasing process. The X direction and Y direction of the display sheet 11 are defined as shown in FIG. 9A. The head 12 performs recording and erasure processing by being sent in the Y direction by step feed for each line, for example. An erasing process is performed by an erasing head 73 and an erasing head 74 provided in advance in the head 12, and then a recording process is performed by the recording head 75. The erasing head 73 and the erasing head 74 are configured as linear electrodes parallel to the X direction of the head 12. The recording head 75 is configured as a plurality of point-like needle electrodes parallel to the X direction of the head 12. The number of needle-like electrodes of the recording head 75 corresponds to the number of pixels in one line. That is, it is not necessary to form a pixel array pattern on the display sheet 11.

  Further, the voltage applied to each head is applied in a pulse form as shown in FIG. 9B. For example, the voltage is turned off during the sheet feeding period in which the head 12 moves. When the sheet feeding is finished, the voltage is turned on. In this way, the voltage applied to each head is turned on / off.

  FIG. 10 schematically shows the display sheet 11 and the head 12. 1 and 9, the display sheet 11 is sent in the vertical direction. However, in FIGS. 10 to 12, the display sheet 11 is sent in the horizontal direction. Thus, in the present invention, the feeding direction of the display sheet 11 may be either the vertical direction or the horizontal direction.

  The head 12 includes a pair of heads 12a and 12b facing each other, and the display sheet 11 is fed in a state where the display sheet 11 is positioned in a gap between the heads 12a and 12b. On the surface of the head 12 a facing the display sheet 11, erase heads 73 a and 74 a for erasing display information displayed on the display sheet 11 indicated by broken lines, and a record for recording the display information on the display sheet 11. A head 75a is provided. Similarly, on the surface of the head 12 b facing the display sheet 11, erase heads 73 b and 74 b for erasing display information displayed on the display sheet 11 and a recording head for recording the display information on the cover sheet 11. 75b is provided. The erasing heads 73a and 73b are collectively referred to as the erasing head 73, the erasing heads 74a and 74b are collectively referred to as the erasing head 74, and the recording heads 75a and 75b are collectively referred to as the recording head 75 as appropriate.

  FIG. 11 shows a cross section of the head 12 with the display sheet 11 interposed therebetween. The head 12a includes sheet sandwiching portions 71a and 72a that sandwich the display sheet 11, erase heads 73a and 74a, a recording head 75a that is a needle-like electrode, and a sheet feeding unit 76a that transports the sheet in the horizontal direction. It is said.

  Similarly, the head 12b includes sheet sandwiching portions 71b and 72b that sandwich the display sheet 11, erase heads 73b and 74b, a recording head 75b that is a needle-like electrode, and a sheet feeding unit that transports the sheet in the horizontal direction. 76b is included.

  The sheet sandwiching portions 71a, 71b, 72a, 72b, which are examples of the support, have moderate friction for feeding the display sheet 11 while absorbing unevenness in the thickness of the display sheet 11. In addition, the electric field applied by each head is applied as perpendicular to the display sheet 11 as possible.

  The sheet feeding sections 76a and 76b are made of, for example, silicon rubber, and are rotationally driven so that display information is written at a correct position, thereby feeding the display sheet 11.

  An example of a process in which display information is written by the head 12 having the above-described configuration will be described with reference to FIG. In FIG. 12, the sheet sandwiching portions 71a, 71b, 72a and 72b and the sheet feeding portions 76a and 76b are not shown for easy understanding.

  As shown in FIG. 12, it is assumed that, for example, a certain microcapsule 81a dispersed in the display sheet 11 is in a black state. First, the display information already written is erased using the erase heads 73a and 73b and the erase heads 74a and 74b. To erase the display information, positive and negative voltages are alternately applied to the microcapsules. For example, if a positive voltage is applied to the erasing head 73a and a negative voltage is applied to the erasing head 73b, voltages having opposite polarities are applied to the erasing heads 74a and 74b. That is, a negative voltage is applied to the erasing head 74a, and a positive voltage is applied to the erasing head 74b.

  In the state shown in the microcapsule 81b, the black fine particles are attracted to the positive electrode 73b, and the white fine particles are attracted to the electrode 73a side. Subsequently, in the state shown in the microcapsule 81c, the black fine particles are attracted to the electrode 74b side, and the white fine particles are attracted to the electrode 74a side. By this erasing process, it is possible to change from a low reflectance state to a state where the reflectance in which black fine particles and white fine particles in the microcapsules are appropriately dispersed is intermediate.

  In this embodiment, the erasing head is configured to provide two erasing heads, that is, the erasing head 73 and the erasing head 74, but may be configured to provide one or more erasing heads. However, in the state of the microcapsule 81a, the black and white fine particles are relatively firmly attached, and the microcapsule 81a may be in the white state. It is desirable to provide a plurality of erasing heads for reasons such as requiring a switching process.

  Note that the state of the microcapsule 81b and the microcapsule 81c is not necessarily a state in which the black fine particles and the white fine particles are uniformly dispersed, and is not attached to one of the vertical directions. Further, the magnitude of the voltage applied to the erasing heads 73a, 73b, 74a, 74b is appropriately determined to such an extent that black fine particles or white fine particles do not adhere to either the upper or lower side.

  Subsequently, a recording process for recording display information using the recording heads 75a and 75b is performed. In the recording process, the microcapsules whose reflectance is set to an intermediate level by the erasing process are changed to one of a high reflectance state and a low reflectance state. For example, when a negative voltage is applied to the recording head 75a and a positive voltage is applied to the recording head 75b by the control of the electrode control unit 29 described above, the black fine particles in the microcapsule 81 are attracted toward the recording head 75a. Then, the white fine particles are attracted toward the recording head 75b (the state of the microcapsule 81d). Then, the recording process is completed, and a black state is displayed with respect to the direction of human viewing as indicated by the microcapsule 81e. The magnitude of the voltage applied to the recording head 75a and the recording head 75b in the recording process is such a magnitude that black or white fine particles adhere to the end, for example, about 50 to 100 volts.

  In FIG. 12, for the sake of easy understanding, the description has been made using one microcapsule in the display sheet 11. However, as described above, a large number of microcapsules are dispersed in the display sheet 11. For example, an electric field is formed by applying a voltage to the recording heads 75a and 75b, and the microcapsules to which the electric field is applied change to a state where the reflectance is high or the reflectance is low depending on the polarity of the voltage. In this way, by applying an electric field using the recording heads 75a and 75b composed of a plurality of needle-like electrodes from the outside, a pixel array is formed on the display side as in the prior art, and each pixel is accurately positioned. There is no need to control.

  FIG. 13 shows an example in which the present invention is applied to a twisting ball system in which spherical fine particles are rotated by an electric field. In the display sheet 11, spherical fine particles may be dispersed instead of the above-described microcapsules. The spherical fine particles 82 shown in FIG. 13 are covered with an insulating resin such as oil, the hemisphere is color-coded in black and white, and the charging characteristics are different. Here, it is assumed that the black side has a negative charging characteristic and the white side has a positive charging characteristic.

  When a positive voltage is applied to the erasing head 73a and a negative voltage is applied to the erasing head 73b when the spherical fine particles 82 are in the state 82a, the negatively charged black side is directed toward the erasing head 73a. Start spinning. At this time, some of the spherical fine particles do not rotate immediately due to sticking caused by friction with the side walls of the particles. Therefore, a reverse voltage is applied to the erasing head 74 alternately with the erasing head 73. That is, a negative voltage is applied to the erasing head 74a, and a positive voltage is applied to the erasing head 74b. Then, the spherical fine particles 82 are in a state 82c, and the black side tends to rotate toward the erasing head 74b. In this way, by alternately applying a reverse voltage to the erasing head 73 and the erasing head 74, it is possible to make the spherical fine particles 82 easy to move.

  Then, a recording process is performed using the recording heads 75a and 75b. In the recording process, a voltage required for recording is applied to the spherical fine particles 82, and the spherical fine particles 82 are changed to either a state where the reflectance is high or a state where the reflectance is low. For example, when a positive voltage is applied to the recording head 75a and a negative voltage is applied to the recording head 75b under the control of the electrode control unit 29, the black side of the spherical fine particles 82 rotates toward the recording head 75a. The white side rotates toward the recording head 75b (state of spherical fine particles 82d). When the recording process is completed, the spherical fine particles 82 are in a state 82e, and a black state is displayed for human eyes.

  FIG. 14 shows an example of use of the display device in one embodiment of the present invention. FIG. 14A shows an example of use as an electronic newspaper. Even today, when networks such as the Internet are widespread, the transmission of information using paper media such as newspapers and magazines is widely performed. If used as an electronic newspaper, paper resources can be saved. In addition, operability and the point of being able to pay attention to some articles after seeing the entire article are excellent points that other electronic displays do not have.

  FIG. 14B shows an example in which the display in this embodiment is used for a signboard. In the example of FIG. 14B, the signboard displays the content of entry prohibition, but can be freely changed to other contents such as an advertisement signboard or a signboard displaying a store advertisement. In other words, one display device can be used according to the application, and resource saving can be achieved.

  The present invention can be variously modified and applied without departing from the gist of the present invention, and is not limited to the above-described embodiment. In the above-described embodiment, the head is configured as an electrode, and a recording and erasing process is performed on the display sheet 11 by applying a voltage as a drive signal. However, the head is configured as a magnetic head and a magnetic field is used as the drive signal. You may make it apply. The present invention can also be applied to a display method for switching display by chemically changing electrochromic, electrodeposition, photochromic, leuco dye, thermochromic, or the like.

  Further, the display information may be recorded and erased on the display sheet 11 by scanning the head 12 for each line by using the head 12 as a dot configuration.

  The processing described above may be realized by hardware, or may be processed by software using a program.

It is an external view of the display apparatus in one Embodiment of this invention. It is a block diagram which shows the structure of the display apparatus in one Embodiment of this invention. It is a basic diagram for demonstrating the display element which comprises the display sheet in one Embodiment of this invention. It is a basic diagram for demonstrating the difference in the reflectance of the display element in one Embodiment of this invention. It is a basic diagram which shows an example of the preparation method of the display sheet in one Embodiment of this invention. It is a basic diagram which shows the other example of the preparation method of the display sheet in one Embodiment of this invention. It is a basic diagram which shows the display sheet in one Embodiment of this invention. It is a basic diagram for demonstrating a state when an electric field is applied to the thread-shaped structural material in one Embodiment of this invention. It is a basic diagram for demonstrating the outline of the recording and the erasure | elimination process of the information in one Embodiment of this invention. It is a basic diagram for demonstrating the positional relationship of the head and display sheet in one Embodiment of this invention. It is sectional drawing of the head in one Embodiment of this invention. It is a basic diagram for demonstrating the erasure | elimination process and recording process in one Embodiment of this invention. It is a basic diagram for demonstrating the other example of the erasure | elimination process and recording process in one Embodiment of this invention. It is a basic diagram which shows the example of application of this invention. It is a basic diagram for demonstrating the display method by an electrophoresis system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display apparatus 11 Display sheet 12 Head 21 Control part 29 Electrode control part 73, 74 Erase head 75 Recording head

Claims (5)

Reflectivity is high compared to the first state in which the reflectance is intermediate, the second state in which the reflectance is lower than the reflectance in the first state, and the reflectance in the first state. and Table radical 113 to display device and a third state is supported by the light-transmitting substrate filamentous, light-transmitting substrate of a plurality of said thread-like is formed woven into fabric-like,
The driving signal because the upper Symbol second or the third state is changed to the first state is applied to the display unit, and the erase head comprising a linear electrode,
A drive signal of order is changed to the first above the state the second and upper Symbol third one states is applied to the display unit, and a recording head comprising a plurality of point electrodes Display device. A cradle on which the erasing head and the recording head are slidably mounted;
A bar supported by the cradle;
With
The display device according to claim 1, wherein the display unit is held by the bar, and the erasing head and the recording head slide to apply the driving signal to the held display unit. The display device according to claim 2, wherein the bar is detachable from the cradle. 4. The display device according to claim 2, wherein data to be displayed on the display unit and electric power for driving the erasing head and the recording head are supplied via the cradle. A plurality of the erasing heads are provided,
The display device according to claim 1, wherein drive signals having different polarities are alternately applied by the plurality of erasing heads.

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