JP4140113B2 - Display media - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present inventiondisplayIt relates to the medium.
[0002]
[Prior art]
  Conventionally, various methods using magnetic, light, static electricity, etc. have been devised as methods for recording digital data of characters and images, and these digital data can be easily recorded in other information processing apparatuses after they have been recorded. It can be transferred and played back. On the other hand, conversion from digital data to visualized analog data could be easily performed, such as a method of printing such digital data on a paper medium with a printer for visualization. Further, analog data printed on the paper medium can be converted again into digital data by using a scanner or the like.
[0003]
[Problems to be solved by the invention]
  However, if it is digital data, it is easy to exchange data, but if it is as it is, there is no visibility and the contents are not known at all. If it is desired to know the contents, it is necessary to read the data by some kind of information processing device and display it on a screen or the like to reproduce characters and images. Therefore, it is complicated to always provide an information processing apparatus that reproduces the digital data, and there is a problem that the contents cannot be understood at all if there is no information processing apparatus at hand.
[0004]
  On the other hand, in order to visualize the data, for example, if it is printed on a paper medium, it can be surely visualized, and if such a visualized recording medium is viewed as it is, the contents can be grasped in a list without an information processing device. Become. However, the characters and images printed on paper media and visualized here are analog data, and cannot be read, edited, saved, or transferred directly as digital data. There was also a problem that editing, saving, and forwarding would not be possible without it.
[0005]
  Furthermore, even if analog data printed on a paper medium is read by a scanner or the like, the original digital data cannot be completely reproduced, and the content deteriorates every time it is converted from analog data to digital data. there were.
[0006]
  The present invention solves the above-described problems and provides digital data.TheUsers can record and confirm the recorded contents with the naked eye.displayThe purpose is to provide a medium.
[0007]
[Means for Solving the Problems]
  In order to achieve this object, the invention according to claim 1displayIn the medium, depending on the direction of the applied electric field, the inside is polarized in the direction of the electric field and the polarization state is maintained, and the memory layer is laminated.Layered on the colored layer,Depending on the polarization stateFrom colored to colorlesscolorTheChangeMade of electrochromic materialAnd a visible layer.
[0008]
[0009]
[0010]
[0011]
[0012]
[0013]
[0014]
[0015]
[0016]
  According to this configurationdisplayIn the medium, the image can be displayed easily by an electric field generated from the polarization state of the memory layer. Further, if the electric field changes due to the change in the polarization polarity of the memory layer, the displayed image can be rewritten accordingly.
[0017]
[0018]
  further,According to this configurationdisplayIn the medium, it is possible to display an easy-to-see image with high contrast by greatly changing the color. In the transparent state, the color displayed on the display surface can be freely changed by changing the background color.Moreover, visibility can be improved by making a colored layer into a color with a high contrast with respect to the image of the color displayed on a visible layer.
[0019]
  Claim2Of the inventiondisplayIn the medium, the claim1Described indisplayIn addition to the configuration of the medium, the memory layer is made of a ferroelectric.
[0020]
[0021]
  In addition, the polarity of the spontaneous polarization can be converted again by reapplying an external electric field having a predetermined strength or higher. Accordingly, the image displayed in the visible layer can be rewritten accordingly.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
  FIG. 1 shows a recording medium 1(Display medium)It is a schematic cross section which shows the outline of a structure. First, an outline of the configuration of the recording medium 1 will be described with reference to FIG.
[0023]
  The recording medium 1 is formed in a rectangular thin plate shape by laminating a memory layer 2 made of a ferroelectric and a visible layer 3 made of an electrochromic material on the memory layer 2. For convenience, the surface having the right visible layer 3 in FIG. 1 is referred to as the front surface, and the surface having the left memory layer 2 is referred to as the back surface. The surface of the visible layer 3 is a surface on which an image is displayed, and is hereinafter referred to as a display surface.
[0024]
  The memory layer 2 is formed of a thin film made of a ferroelectric material such as polyvinylidene fluoride. Here, the term “ferroelectric material” refers to a substance in which the dielectric constant of a crystal increases with a decrease in temperature, diverges at a predetermined critical temperature (Curie temperature), undergoes a phase transition, and spontaneous dielectric polarization occurs in a low temperature phase. . There are many ferroelectrics whose spontaneous polarization can be reversed by an external electric field. With such a ferroelectric, the spontaneous polarization can be arbitrarily reversed. In particular, if the memory layer that is polarized in one direction can selectively reverse the polarization, the polarization corresponding to the pixel can be reversed. In this embodiment, digital data is stored in a state of spontaneous polarization by using a ferroelectric that can reverse spontaneous polarization by such an electric field.
[0025]
  Such ferroelectrics include barium titanate (BaTiO₃), Lead titanate (PbTiO₃), Lithium niobate (LiNbO)₃), Potassium tantalate (KTaO)₃), Sodium niobate (NaNb)₅O₁₅)and so on. For organic substances, in addition to polyvinylidene fluoride, copolymers of vinylidene fluoride and tetrafluoroethylene, copolymers of vinylidene fluoride and ethylene trifluoride, copolymers of vinylidene cyanide and vinyl alcohol, polyvinylidene chloride , Polyvinylideneaminad, and aliphatic polyamides such as, but not limited to, aliphatic polyamides such as odd-numbered nylons in which the molecular chain has a planar zigzag structure and the number of repeating units of the molecule is an odd number. A ferroelectric material having a thin film forming ability is desirable.
[0026]
  In addition, in the spontaneous dielectric polarization due to the electric field applied to the ferroelectric, a hysteresis characteristic is observed between the dielectric polarization similar to the magnetization curve of the ferromagnetic and the electric field, and a ferroelectric domain structure is generated in the crystal. Therefore, once spontaneous polarization is performed, the polarization state is maintained unless an external electric field exceeding the limit of the hysteresis characteristic is received, and a so-called memory effect is exhibited.
[0027]
  The visible layer 3 is formed from a thin film made of an electrochromic material such as tungsten oxide. Electrochromism is a phenomenon in which the color of a substance changes when an electric field is applied. It is found in the wavelength region such as the absorption edge of a semiconductor, the color center of an alkali halide, the absorption band of an organic molecule, and molybdenum or iron. In the case of tungsten oxide or strontium titanate with added, a clear reversible color change is a visible phenomenon. Note that the electrochromic material in a broad sense is understood to include liquid crystal, but in the present invention, liquid crystal is excluded. These color changes are anisotropic in the structure of liquid crystals, so that the color change is caused by the change of the light distribution by the electric field. For example, in tungsten oxide, it is reduced by the injection of electrons from the electrodes. The color density changes from colorless to blue, and the color density depends on the amount of injected electrons. If the color is sufficiently colored, a bright blue image with high contrast can be displayed on a white background, and an image like printed paper can be displayed. It is. There are also those that cause a color change when the ring structure is open or closed.
[0028]
  A material that exhibits an optical phenomenon such as a change in color tone and generates electrochromism by generating such a reversible electrochemical reaction is referred to as an electrochromic material in the present application. This electrochromic material includes tungsten oxide (WO₃In addition, inorganic compounds based on transition metal oxides such as molybdenum oxide, tantalate, and titanate, and organic substances such as polyviologen are known.
[0029]
  As for the changing color, color development and decoloration are based on an electrochemical redox reaction, and the color disappears due to oxidation. In the viologen system, a reduced color species is deposited on the electrode to form a colored film for display.
[0030]
  As a specific color, it is well known that the inorganic compound tungsten oxide changes from colorless to blue. For organic substances, the viologen derivative changes to colorless, blue, and purple. In addition, polyviologen, which is a conductive polymer obtained by electropolymerization, is blue and colorless, polypasophenanthrolin iron is red and colorless, polytetrathiafulvalene is yellow and green, red, and polyvinylcarbazole Colorless and green, blue and red for polythiophene, brown and blue for polypyrrole, yellow and blue for polyaniline, purple and yellow for polyparaphenylene, red and colorless for polyethylene terephthalate, colorless for polyisothianaphthene Each color changes to blue.
[0031]
  In the visible layer 3 of the present embodiment, tungsten oxide (WO₃), The electric field formed by the ferroelectric memory layer 2 is deprived and oxidized to become colorless, or injected and reduced to form a blue image. .
[0032]
  In addition, as a material for generating the memory layer 2, a material having flexibility is desirable in addition to polyvinylidene fluoride. In addition, it is desirable that the visible layer 3 also has flexibility. However, if the material is extremely thin, flexibility is caused by almost all materials other than tungsten oxide, so that the memory layer 2 and the visible layer 3 It is desirable to form a sufficiently thin film as long as it functions.
[0033]
  Here, in the state where the visible layer 3 is transparent, the memory layer 2 is observed from the display surface through the visible layer 3, but the color of the memory layer 2 itself is reduced to the blue color of tungsten oxide that is colored by reduction. By coloring in a color that increases the contrast, for example, white, the contrast with the colored portion of the visible layer 3 can be increased, and an image with high visibility can be formed.
[0034]
  Next, the operation of the recording medium 1 having the above configuration will be described with reference to FIG. As described above, the memory layer 2 of the recording medium 1 is formed of a ferroelectric made of a polyvinylidene fluoride thin film.
[0035]
  First, as shown in the upper part of FIG. 1, the front and outer electrodes 87 that are anodes are brought into contact with the surface of the recording medium 1, and the back and outer electrodes 86 that are cathodes are brought into contact with the back side, and an external electric field is applied to the memory layer 2. If an external electric field is applied with an electrode in such a polarity, electrons are supplied from the cathode and electrons are taken away on the anode side, so that positive charges are present on the visible layer 3 side and negative charges on the back side. In this state, the dipole moment of the memory layer 2 is aligned in one direction. When an electric field is applied in this way, at this stage, the visible layer 3 is oxidized and becomes tungsten oxide because it is deprived of electrons, and becomes transparent and no image is formed. Layer 2 will be observed.
[0036]
  If this state is expressed by a chemical formula, tungsten oxide which is an electrochromic material of the visible layer 3 is WO₃+ XH⁺Expressed as + xe.
[0037]
  In this state, even if the application of the voltage from the electrode is stopped and the application of the electric field by the electrode is stopped, the polyvinylidene fluoride which is the ferroelectric of the memory layer 2 maintains the state of spontaneous polarization. An electric field in the same direction as the electric field remains, and the visible layer 3 is also affected by the electric field and maintains a state in which no electrons are supplied as in the state where the electric field is applied by the electrode. Accordingly, the visible layer 3 is kept transparent and does not form an image.
[0038]
  Next, as shown in the lower part of FIG. 1, an external electric field having a reverse polarity is applied so that the front external electrode 87 is a cathode and the back external electrode 86 is an anode. Then, the dipole in the portion of the pixel to which the electric field having the opposite polarity is applied by this external electric field is inverted, and electrons are injected into the electrochromic material of the visible layer 3, thereby reducing the tungsten oxide. Therefore, the visible layer 3 changes from transparent to blue, and an image is formed.
[0039]
  In this state, tungsten oxide which is the electrochromic material of the visible layer 3 is converted into HxWO.₃The state has changed.
[0040]
  And even if the application of the external electric field by the electrode is stopped here, the state of the spontaneous polarization is maintained and the electric field remains as in the reason described above, so that the visible layer 3 that has turned blue is also maintained in that state. The
[0041]
  An external electric field having a different polarity can be applied to each pixel by a large number of electrodes corresponding to each pixel arranged on the front and back of the recording medium 1, but this method will be dictated.
[0042]
  Since the recording medium 1 of the present embodiment has the above-described configuration, the following effects are obtained. That is, when an electron is taken from the visible layer 3 by applying an external electric field, the electrochromic material is oxidized and changes from blue to colorless, and when an electron is injected into the visible layer 3, the electrochromic material is reduced and colorless to blue. Therefore, a vivid blue image with high contrast is displayed against the background of the memory layer 2, and there is an effect that an image like a printing paper can be displayed.
[0043]
  In the image displayed on the visible layer 3, since the ferroelectric of the memory layer 2 is spontaneously polarized even after the application of the electric field is stopped, the electric field is continuously applied to the visible layer 3, There is an effect that the formed image is held. Since this state can be maintained for a long time, it can be used like a display board or a poster.
[0044]
  Furthermore, the recording medium 1 itself can be formed into a thin film from a flexible material, and can also be manufactured so that it can be folded or rolled. If it does so, the effect that the large screen can be rounded and made small and can be easily carried and stored is produced.
[0045]
  Further, the content displayed as an image is stored in the memory layer 2 as the direction of the dipole, and the direction of the dipole generated by this spontaneous polarization can be detected by a predetermined detection means. There is also an effect that it can be extracted as digital data without deterioration. In addition, since the direction to the dipole can be changed again by an external electric field, it is possible to edit the image read as digital data and rewrite the contents of the memory layer 2 recorded again.
[0046]
  Further, there is an effect that only by rewriting the digital data stored in the recording medium 1, the image can be rewritten according to the contents.
[0047]
  Next, a recording medium 101 which is a first modification of the recording medium 1 of the present embodiment will be described. Here, FIG. 2 is a schematic cross-sectional view showing a configuration of a recording medium 101 which is a first modified example in which electrodes are provided on both the front and back surfaces of the recording medium 1. In the recording medium 1 of the present embodiment, the recording medium 1 itself is not provided with an electrode, but the recording medium 1 may be provided with an electrode in advance. As shown in FIG. 2, a surface electrode 14 a made of a transparent electrode is laminated on the surface side of the visible layer 3 so as to cover the entire recording medium 101. The transparent electrode is an electrode film in which a light-transmitting conductive film is attached to the inner surface of a light-transmitting resin substrate.ofIt may be such that the conductive layer is directly applied to the surface of the visible layer 3.
[0048]
  On the back surface of the recording medium 101, a back electrode 14 b is disposed on the surface of the memory layer 2. The back electrode 14b is arranged in a matrix corresponding to the pixels forming the image of the recording medium 101.
[0049]
  Here, FIG. 7 is a diagram showing the arrangement of the back electrodes 14b of the recording medium 101 of the present embodiment. The arrangement of the back electrodes 14b in the recording medium 101 shown in FIG. 7 is the same as the arrangement of the pixels of the recording medium 1, and the image is composed of pixels formed by electrodes arranged in an X and Y matrix. The back electrode 14b is formed by sticking or depositing a metal thin film.
[0050]
  The front electrode 14a and the back electrode 14b are preferably formed of thin films that are thin enough to have flexibility. If the electrodes 14a and 14b have flexibility as described above, the recording medium 101 having flexibility is combined with the memory layer 2 and the visible layer 3 formed to have flexibility. It can be.
[0051]
  Since the recording medium 101 configured as described above includes the electrodes 14a and 14b in close contact with the memory layer 2 and the visible layer 3, it is easy to apply an electric field at a position accurately corresponding to the pixel. In addition, an electric field without unevenness can be applied to the memory layer 2. Furthermore, since the front electrode 14a is a transparent electrode, it does not hinder the observation of the image formed on the visible layer 3.
[0052]
  The front electrode 14a may be configured to include a number of electrodes divided corresponding to the pixels. With this configuration, a clearer pixel can be formed.
[0053]
  Furthermore, when the visible layer 3 itself has conductivity, a configuration in which the visible layer 3 itself also serves as an electrode is possible.
[0054]
  FIG. 3 is a schematic diagram illustrating a configuration of a recording medium 201 that is a second modification of the present embodiment in which the visible layer 3 of the recording medium 101 is divided according to pixels. Hereinafter, the recording medium 201 will be described with reference to FIG. In the recording medium 201, the visible layer 3 is formed so as to be divided corresponding to the back electrode 14b. Therefore, the visible layer 3 is arranged in a matrix corresponding to the pixels. In this way, by arranging the visible layer 3 so as to correspond to the pixels, the edge portion of the image formed on the visible layer 3 becomes clear. Therefore, a sharp image can be formed on the visible layer 3.
[0055]
  FIG. 4 is a schematic diagram illustrating a configuration of a recording medium 301 that is a third modification of the present embodiment in which the coloring layer 16 is provided between the memory layer 2 and the visible layer 3 of the recording medium 101. Hereinafter, the recording medium 301 will be described with reference to FIG. The recording medium 301 includes a colored layer 16 laminated between the memory layer 2 and the visible layer 3 of a recording medium having the same configuration as that of the first modification 101. The colored layer 16 is formed by a thin film made of a white flexible resin, or is formed by applying a colored layer on the memory layer 2 or the visible layer 3. Visibility can be improved by making white with high contrast with respect to the blue image displayed on the visible layer 3. FIG. Of course, the color to be colored can be arbitrarily selected, and this configuration is particularly effective when it is desired to color a color that cannot be developed by coloring the material of the memory layer 2 itself.
[0056]
  In the recording medium 1 according to the present embodiment and the recording media 101, 201, and 301 shown in the modification example, the front electrode 14a is laminated on the front side of the visible layer 3, but the front electrode 14a is disposed on the visible layer 3. Between the colored layer 16 and the memory layer 2, or when the colored layer 16 is laminated (not shown). The front electrode 14a may be configured to cover the entire recording medium, or may be an electrode that is divided corresponding to each pixel. This configuration is disadvantageous in terms of the effect of forming an electric field, but has the effect of eliminating the need to use a transparent electrode for the electrode 14a. However, when the conductivity of the visible layer 3 is low, it is necessary to separately wire the electrode 14a so that a voltage can be applied to the electrode 14a.
[0057]
  In order to apply an electric field to the recording medium 1 and the recording mediums 101, 201, and 301 (hereinafter referred to as the recording medium 1) of the modification and to detect the potential, the following detecting means are preferably used. It is done. That is, in the recording medium 1 or the like, an external electric field is applied to cause spontaneous polarization, digital data is stored according to the state of charge bias, and a potential difference due to spontaneous polarization and charge bias is detected. The stored contents are read out. The recording media 101, 201, and 301 include the electrodes 14a and 14b in the recording medium 1 of the present embodiment, and the principles of reading and writing digital data are the same. Therefore, the principle of reading and writing will be described using the recording medium 401 having a configuration in which the recording medium 1 includes the reading / writing device 80A.
[0058]
  Here, FIG. 5 is a schematic diagram showing a configuration of a recording medium 401 provided with a reading / writing device 80A as a charge detection means in the recording medium 1. As shown in FIG. 5, a reading / writing device 80 </ b> A is provided so as to sandwich a portion composed of the memory layer 2 and the visible layer 3 stacked on the front side.
[0059]
  Here, FIG. 6 is a schematic diagram for explaining in detail the structure of the recording medium 401 shown in FIG. In the recording medium 401, charges are biased due to spontaneous polarization in the memory layer 2 made of a ferroelectric material, but the back external electrode of the reading / writing device 80A disposed to face the back surface of the memory layer 2 86 is arranged corresponding to the pixel of the image, and the source S of the transfer gate transistor 81 made of nMOS FET is connected through the back external electrode 86. On the other hand, the drain D of the transfer gate transistor 81 is connected to the bit line 82. Further, the gate G of the transfer gate transistor 81 is connected to the word line 83, and further, one unit of memory cell is formed from the front external electrode 87 disposed on the front side of the visible layer 3. The bit line 82 and the word line 83 are connected to an address decoder and a computer (not shown). The external external electrode 87 constituting the reading / writing device 80A is connected to the ground wire 91 and connected to a computer (not shown).
[0060]
  Here, FIG. 7 is a diagram showing an array of pixels of the recording medium 1 of the present embodiment. The configuration of the pixels of the recording medium 401 is the same as that of the recording medium 1. Therefore, the arrangement of the back external electrodes 86 of the recording medium 401 is also configured as shown in FIG. As shown in FIG. 7, the back external electrodes 86 form rows in the Y direction in the drawing, number rows from the first row in the X direction, and columns in the X direction in the drawing, with the first in the Y direction. They are arranged in a matrix with column numbers from the rows. A unique address is given to each of the back external electrodes 86 by a combination of rows and columns. In this example, one pixel and the back external electrode 86 correspond one to one, and correspond to one memory cell. Accordingly, these memory cells are similarly arranged in a matrix arrangement to form a memory matrix. Each memory cell is controlled for each address by a row decoder (X) and a column decoder (Y) via a word line 83 arranged in the row and column directions.
[0061]
  First, data reading is determined by the potential difference due to the charge bias due to the polarity of the dipole of the memory layer 2. In the memory matrix, the control CPU of the computer (not shown) has a row decoder (X) and a column decoder. A predetermined address, for example, an address where X = 1 and Y = 1, is accessed by the address decoder consisting of (Y) to check whether or not there is a charge. Therefore, as shown in FIG. 6, a target address is selected by a word line 83 in a predetermined row and column, and electric charges are detected by the bit line 82. That is, a positive voltage is applied from the word line 83 of the transfer gate transistor 81 which is an nMOS FET to the gate G of the metal portion. Then, if a channel is formed by the electric field effect and electrons are stored in the electrode portion of the memory layer 2, the electrons move from the opposite back electrode 14b to the bit line 82, and negative electricity is output as an electric signal. Data will be detected.
[0062]
  Conversely, when data is written, if positive electricity is applied to the word line 83 of the memory cell at a predetermined address, it is possible to connect the current from the bit line 82 to the back electrode 14b and to pass a current. Therefore, if a voltage is applied with a predetermined polarity by the back electrode 14b through the bit line 82 and the front electrode 14a through the ground wire, the memory layer is formed by the back electrode 14b and the front electrode 14a connected to the ground wire 91. The direction of charge diversion is reversed by changing the direction of the two dipoles.
[0063]
  In the recording media 1, 101, 201, and 301, the read / write principle as described above is applied in the same manner. However, since the read / write device 80A is not provided, a separate read / write device is provided. There is a need. Here, FIG. 9 is a schematic diagram showing an example of a configuration of a reading / writing device 80B for reading or writing digital data of the recording medium 101 by an electrode layer in which a large number of electrodes are integrated. Although the recording media 1, 101, 201, and 301 have different configurations, the principle of data reading / writing is the same. Therefore, the reading / writing apparatus will be described below using the recording medium 101 as an example. As shown in FIG. 9, in the reading / writing device 80B, an electrode 87 is provided on a mounting table 88 on which the recording medium 1 or the like is mounted so that the electrode 87 can be connected to the surface electrode 14a mounted thereon. A lid 89 having a large number of electrodes 86 arranged in a matrix corresponding to the back electrode 14b of the recording medium 1 is swingably provided on the mounting base 88, and the electrodes 86 provided on the lid 89 are integrated. In this configuration, the back electrode 14b of the recording medium 1 mounted on the mounting table 88 is connected in pressure contact, and information is sequentially written or read collectively. Here, since the reading / writing method in the reading / writing device 80B is the same as that of the reading / writing device 80A, detailed description is omitted. By configuring the reading / writing device 80B in this manner, information can be written or read in a short time.
[0064]
  Next, FIG. 10 is a schematic diagram showing a configuration of a reading / writing device 80C for reading or writing digital data of the recording medium 101 by scanning with the scan head 90. As shown in FIG. 10, the recording medium 1 is mounted on the mounting table 88 and configured to move relative to the scan head 90. In other words, the recording medium 1 may be transported by a transport means (not shown), or conversely, the scan head 90 may be configured to move so as to scan the fixed recording medium 1. The head 90 is configured to move. The outer front electrode 87 provided on the mounting table 88 is disposed so as to come into contact with the front electrode 14 a of the recording medium 1 mounted on the mounting table 88. In the scan head 90, a back external electrode 86 of the recording medium is provided as an array electrode in a straight line corresponding to the back electrode 14b of the recording medium 101 in a direction perpendicular to the paper surface in FIG. The back surface of the medium 1 is slid. Then, a voltage is applied from the back external electrode 86 to the electrode 14b line by line while sliding, or the potential is read. The reading and writing methods here are the same as those described in the reading / writing device 80A except that reading and writing are performed for each row while scanning, and thus description thereof is omitted.
[0065]
  Next, FIG. 8 is a schematic diagram showing a configuration of a recording medium 501 that is a fifth modified example in which the recording medium 401 includes a connection terminal 85 that is a read / write pin. The recording medium 501 further includes an address decoder (not shown). Similar to the recording medium 401, the recording medium 501 includes a reading / writing device 80A and is provided integrally, so that a special reading / writing device that separately detects data for each pixel is not required. However, as shown in FIG. 8, for example, a connection terminal 85, which is a connection pin provided with a metal thin film on a substrate used in a well-known RAM (Random Access Memory) or the like, is provided on the recording medium 501. Thus, there is an effect that it is easy to connect the connector and the cord to other computers. Furthermore, the display surface is not obstructed when reading and writing information, and can be used as a simple display.
[0066]
  Although the present invention has been described based on one embodiment, the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the spirit of the present invention. This can be easily guessed.
[0067]
【The invention's effect】
  As is clear from the above description, the invention according to claim 1displayIn the medium, depending on the direction of the applied electric field, a memory layer that polarizes the inside in the direction of the electric field and maintains the polarization state, and the memory layer are stacked.Layered on the colored layer,Depending on the polarization stateFrom colored to colorlesscolorTheChangeMade of electrochromic materialBecause it is characterized by having a visible layer,The image data can be displayed on the visible layer as an image by the electric field generated by the spontaneous polarization of the memory layer. Therefore, the contents recorded on the display medium are visualized and the contents can be easily confirmed.
[0068]
[0069]
  Furthermore, since it can be formed into a thin film, it is easy to transport and store. In particular, if it is made of a flexible material, it can be displayed on a large screen that can display a large screen.displayThere is an effect that even a medium can be easily transported and stored.
[0070]
[0071]
[0072]
  Also,Since the visible layer is made of an electrochromic material, there is an effect that an image can be easily displayed by an electric field generated from the polarization state of the memory layer. Moreover, if the polarity of the polarization of the memory layer changes and the electric field changes, there is also an effect that the displayed image can be rewritten accordingly.
[0073]
  further,Since the electrochromic material is characterized in that it changes from colorless to colored according to the polarization state, there is an effect that it is possible to display a high-contrast and easy-to-view image by greatly changing the color. . In the transparent state, there is also an effect that the color displayed on the screen can be freely changed by changing the color of the background.Moreover, visibility can be improved by making a colored layer into a color with a high contrast with respect to the image of the color displayed on a visible layer.
[0074]
  Claim2Of the inventiondisplayIn the medium, the claim1Described indisplayIn addition to the effect of the medium, the memory layer is made of a ferroelectric material. Therefore, the polarity of the spontaneous polarization can be easily changed by applying an external electric field, and it has a memory property. Therefore, there is an effect that digital data can be held in a polarization state for a long time, and furthermore, since the polarization state can be stably maintained for a long time, the display of the visible layer can be stably maintained for a long time by the electric field generated by the polarization state. There is an effect that it can be held.
[0075]
  In addition, there is an effect that the polarity of the spontaneous polarization can be converted again by applying an electric field of a predetermined level or more again. Therefore, it is possible to rewrite the digital data in the memory layer and to rewrite the image displayed in the visible layer accordingly.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an outline of a configuration of a recording medium 1 according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view illustrating a configuration of a recording medium 101 that is Modification 1 in which electrodes are provided on both the front and back surfaces of the recording medium 1;
FIG. 3 is a schematic diagram illustrating a configuration of a recording medium 201 that is a second modification of the present embodiment in which the visible layer 3 of the recording medium 101 is divided according to pixels.
4 is a schematic diagram showing a configuration of a recording medium 301 that is a third modification of the present embodiment in which a colored layer 16 is provided between the memory layer 2 and the visible layer 3 of the recording medium 101. FIG.
FIG. 5 is a schematic diagram illustrating a configuration of a recording medium 401 provided with a reading / writing device 80A serving as a charge detection unit in the recording medium 1. FIG.
6 is a schematic diagram for explaining in detail the structure of the recording medium 401 shown in FIG. 5. FIG.
FIG. 7 is a diagram showing an arrangement of back electrodes 14b of the recording medium 101 according to the present embodiment.
FIG. 8 is a schematic diagram showing a configuration of a recording medium 501 as a fifth modified example in which the recording medium 401 includes a connection terminal 85 which is a read / write pin.
FIG. 9 is a schematic diagram showing an example of a configuration of a reading / writing device 80B for reading or writing digital data of a recording medium 101 by an electrode layer in which a large number of electrodes are integrated.
10 is a schematic diagram showing a configuration of a reading / writing device 80C for reading or writing digital data of a recording medium 101 by scanning with a scan head 90. FIG.
[Explanation of symbols]
1, 101, 201, 301, 401, 501 Recording medium
2 Memory layer
3 Visible layer
14a Front electrode
14b Back electrode
16 Colored layer
18 Protective layer
80A, 80B, 80C Reading / writing device
81 Transfer gate transistor
82 bit line
83 word lines
85 connection terminals
86 Back external electrode
87 External electrode
88 mounting table
90 scan head
91 Ground wire
G Gate
S source
D drain

Claims (2)

According to the direction of the electric field to be applied, the memory layer that polarizes the interior in the electric field direction and maintains the polarization state;
A colored layer laminated on the memory layer ;
A display medium comprising: a visible layer made of an electrochromic material that is laminated on the colored layer and changes color from colored to colorless according to the polarization state. The memory layer is
The display medium according to claim 1 , comprising a ferroelectric substance.

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