JPH1120308A - Recording sheet and recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a repeatedly usable recording sheet having a display speed without interfering with practical use by multicolor expressing on a white background. SOLUTION: A resin color developing layer 3 formed by dispersing electrochromic particles 5 (rare earth metal diphthalocyanine) in a resin layer 4 in which electrolytic material for supplying cation or anion to electrochromic particle is solved to be solid is formed on a white sheet 1 having a transparent electrode 2 formed thereon. Thus, a coloring state of the particles 5 is selected by applying a voltage for realizing multicolor express on a white background, and response of color developing is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet structure capable of forming and erasing an image and being used repeatedly.
Further, the present invention relates to a recording apparatus for forming an image on the recording sheet.

[0002]

2. Description of the Related Art In recent years, computer-related equipment has been widely used as office equipment, and accordingly, a large amount of recording paper for printing output has been used. This paper consumption is increasing year by year, and is one of the important issues for the global environment. As a countermeasure, paper consumption is reduced by, for example, recycling paper, but the recovery rate by recycling is low, and is not sufficient as a countermeasure. Also, the amount of paper used on a global scale tends to increase further in the future.

[0003] Therefore, a recording sheet or film that replaces paper is required, and an attempt has been made to produce a recording sheet that can be used repeatedly by using a recording technique having a memory property such as a polymer liquid crystal.

For example, as a technique for performing color display on a recording sheet, a structure change material such as a phase change is used,
Although it is conceivable to use a polymer liquid crystal or an electrochromic material, it has not been put to practical use as a recording sheet because of its problems of low contrast, brightness, and color reproduction range.

[0005] That is, as a recording sheet using a structure-change material, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-62247, a crystal-amorphous or polycrystalline-single-crystal or phase-containing organic material is used. An image is recorded using the change in the refractive index and the change in the state of light scattering between the soluble and the immiscible. Most of these can be repeatedly used (recorded and erased) by selecting the state by heating and cooling. However, this recording sheet has a drawback that the contrast is low and it is very difficult to read. In addition, since a heating method is used for the recording method, power consumption increases, and two-dimensional writing is difficult, and high-speed image formation cannot be performed.

As a recording sheet using a polymer liquid crystal, for example, as shown in Japanese Patent Application Laid-Open No. Hei 6-33081, a polymer crystal is coated on a sheet on which a transparent electrode has been prepared in advance,
Further, a structure for forming a transparent electrode is generally known.
According to this structure, the orientation of the liquid crystal is changed by applying a voltage, and an image is recorded by an optical difference from a portion to which no voltage is applied. According to this recording sheet,
Since electric recording can be performed repeatedly without using a heating unit, power consumption is small. However, the polymer liquid crystal has a disadvantage that the contrast is low and it is very difficult to read.

As a recording sheet using an electrochromic material, for example, as shown in JP-A-5-224433, a sheet in which a transparent electrode is formed on a sheet and an electrochromic material is further formed thereon is disclosed. Proposed. Electrochromic materials are bright in color, have high contrast, and are easy to read. In particular, rare-earth diphthalocyanines can enable multicolor display such as red, blue, green, and violet, and when an electrolytic solution is used, the coloring time is as short as 50 ms. Attention has been paid.

[0008]

However, when a recording sheet is prepared using rare earth diphthalocyanine as an electrochromic material, a color forming layer (EC layer) composed of an electrochromic material, and a positive or negative ion It is necessary to solidify the entire electrolytic layer for supplying, and this causes a problem that the coloring speed is reduced. That is, for example, journal by M.STARKE et al.
of physica status solidi (a) K95 (1990) “A Solid
Electrochromic of Cell Using Erbium-diphthalocyani
As shown in “ne”, since the coloring time is several seconds, it is difficult to form a sheet as it is.

Further, since rare earth metal diphthalocyanine does not have a transmission mode, it is not possible to form a multicolor on a white background. For this reason, white expression only causes red, blue, and green colors to be close to each other, resulting in dark gray. When printed on this background (dark gray), it is difficult to obtain a clear display that is easy to read. . For this reason, it is difficult to perform multicolor display on a white background close to paper, and it has been applied only to segment display. Furthermore, for example, even in the case of printing red on a green background, the luminance is low because the reflectance of each color is low,
There was a problem that it was dark and difficult to read.

[0010] As disclosed in Japanese Patent Application Laid-Open No. 58-80625, there is an attempt to disperse an electrochromic material and an ion acceptor in a polymer resin. The film is uniformly colored, and a film is equivalently formed. As a result, the background color cannot be used.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is possible to provide a multi-color expression on a white background and a reusable recording sheet having a display speed that is practically acceptable. It is an object of the present invention to provide a recording device for performing recording.

[0012]

In order to achieve the above object, the recording sheet of the present invention has a resin coloring layer formed on a white sheet on which a transparent electrode is formed. This resin coloring layer is configured by dispersing particles of an electrochromic material in a resin layer in which an electrolytic material that supplies cations or negative ions to the electrochromic material is dissolved. The particles of the electrochromic material are rare earth metal diphthalocyanines whose coloring state can be selected by applying a voltage.

According to another aspect of the present invention, there is provided a recording apparatus which has a plurality of counter electrodes for the recording sheet according to claim 1 and forms an image on the recording sheet by applying a voltage between the electrode and the transparent electrode. It is characterized by including the following configuration. Cell selection means. The cell selecting means is for specifying an arbitrary position on the recording sheet. Voltage application means.
The voltage application means controls the color tone of the color-forming layer by applying desired positive and negative voltages to the cell selected by the cell selection means.

According to the recording sheet of the present invention, when the rare earth metal diphthalocyanine is used as the particles of the electrochromic material, the particles are dispersed in the resin coloring layer. By increasing the contact area with the solid-dissolved electrolytic material, the responsiveness of color development is improved, and a color development speed that can be practically used as a display sheet can be secured. In addition, since the coloring layer is formed by dispersing as electrochromic material particles and the background is formed of a white sheet, excellent white display can be performed, and voltage application of desired positive and negative values can be performed. Color expression.

According to the recording apparatus of the present invention, an electric field is applied from the counter electrode to a specific area of the recording sheet, and the color tone can be selectively controlled by applying positive and negative voltages.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a recording sheet according to the present invention will be described with reference to FIG.
The recording sheet 10 is manufactured by sequentially laminating the transparent electrode 2 and the resin coloring layer 3 on the sheet substrate 1. Resin coloring layer 3
Is a polymer material (electrolyte matrix) in which an electrolytic material is dissolved
In addition, a dispersed rare earth metal diphthalocyanine (electrochromic material particles 5) as an electrochromic material is dispersed therein. As the sheet substrate 1, a whitened white sheet obtained by mixing TiO ₂ particles in PMMA resin is used. External electrodes 6 of the recording apparatus can be arranged on the upper surface side of the recording sheet 10 so as to face the resin coloring layer 3.

The rare earth metal diphthalocyanine used as the electrochromic material is capable of multicolor expression. In particular, a lanthanoid metal is preferable because it can be multicolored in red, blue and green. As lanthanoid metals, lutetium (Lu), ytterbium (Yb), thulium (Tm), erbium (Er), holmium (H
o), dysprosium (Dy), terbium (Tb),
Gadolinium (Gd), Europium (Eu), Samarium (Sm), Premetium (Pm), Neodymium (N
d), praseodymium (Pr), cesium (Ce), lanthanum (La) can be used. The particle size of the particles is desirably about 0.05 to 1 μm in order to increase the contact area with the electrolytic material in the resin coloring layer 3 to be dispersed.

As an electrolytic material for supplying ions, for example, NaCl, H ₂ O, LiClO ₄ or KCl can be used. As the polymer material in which the electrochromic material particles and the electrolytic material are dispersed, a polyvinyl alcohol resin, a vinyl acetate resin, a xylene resin, a polycarbonate resin, or the like can be used.

According to the structure of the recording sheet 10 described above, the oxidation and reduction states of the rare earth metal diphthalocyanine (electrochromic particles) can be arbitrarily determined by the voltage applied between the electrodes (the transparent electrode 2 and the external electrode 6). , It is possible to cause the resin coloring layer 3 to develop a color corresponding to a plurality of positive and negative voltage values. The applied voltage is
For example, positive and negative voltage values for emitting red, blue, and green colors are set in advance in the recording apparatus described later.

By using the electrochromic material in the form of particles, the background color is white (white sheet).
In addition to the above, the contact area between the electrochromic material and the electrolytic material for supplying ions increases due to the formation of particles, so that high-speed response can be ensured even in the case of an all solid type.

In the recording sheet 10 described above, the sheet substrate 1 itself is whitened to form a white sheet, but a white layer may be laminated on the sheet substrate. Further, if a light control layer made of an electrochromic material such as WO ₃ is provided as a functional layer on the recording sheet, and the amount of light can be adjusted, a halftone can be expressed. Further, needless to say, a protective layer or the like for protecting the surface may be provided on the recording sheet.

Next, a recording apparatus for forming an image on the recording sheet 10 will be described with reference to FIG. FIG. 2 is an equivalent circuit diagram in which the entire structure of the recording apparatus is simplified. The recording apparatus is formed so that the recording sheet 10 can be mounted thereon, and a plurality of opposing electrodes 20 (external electrodes in FIG. 1) are two-dimensionally arranged so as to face the transparent electrode 2 of the recording sheet 10 at the time of mounting. 6).
That is, the counter electrode 20 of the recording apparatus and the recording sheet 10
When the image is formed, the recording sheet 10 is mounted on the recording apparatus, and the opposing electrode 20 is adhered to the upper side of the recording sheet 10. In FIG. 2, recording sheet 1
Although the zero transparent electrode 2 is shown in a circuit configuration separated for each counter electrode 20, it is actually formed integrally (one-sided) as each layer of the recording sheet 10.

Each counter electrode 20 is connected to one drive line 22 via a TFT 21. The base electrode of each TFT 21 is connected to a plurality of data lines X for each column via a TFT 23, and the base electrode of each TFT 23 is connected to a plurality of data lines Y for each row, thereby forming a matrix composed of a plurality of cells. Make up. Therefore,
By selecting the data line X and the data line Y by the cell selection means (by applying a voltage for turning on the TFTs 21 and 23), the driving line 22 is transferred to a portion (pixel) of the recording sheet corresponding to an appropriate position in the matrix. Is applied. The drive line 22 is supplied with a drive voltage from a DC voltage application unit that controls a color tone by applying a desired positive or negative DC voltage to the coloring layer of the recording sheet.

[0024]

Next, more specific examples of the recording sheet of the present invention will be described. (Example 1) As a first example, a recording sheet was produced using a separable electrochromic material. First, a white sheet substrate 1 is prepared by dispersing TiO ₂ particles and utilizing light scattering. An ITO film having a thickness of 0.5 μm is deposited as a transparent conductive film on the sheet substrate 1 by RF sputtering to form a transparent electrode 2, and a 6 μm thick resin coloring layer 3 is formed on the transparent electrode 2. Produced.
The resin coloring layer 3 is obtained by mixing and dispersing electrochromic material particles 5 of Lu diphthalocyanine particles having a particle size of about 0.1 μm with an electrolyte matrix 4 made of polyvinyl alcohol resin in which LiClO ₃ as an electrolytic material is dissolved. It is configured.

At this time, the production of the Lu diphthalocyanine particles was performed by the following method. That is, a mixture obtained by mixing phthalonitrile, Lu acetate, DBU (1,8-diazabicyclo (5,4,0) -7-undecene) and 1-hexanol at 130 degrees was filtered and filtered on a filter paper. Washing the powder product with acetic anhydride, cooling the powder product with liquid nitrogen and washing with acetone, further washing the powder product with pentane, and then extracting the product with chloroform by Soxhlet, Obtained by drying over silica gel. The generation of the Lu diphthalocyanine particles is not limited to this method, and the particles generated by another method may be used.

The resin coloring layer 3 formed by mixing and dispersing Lu diphthalocyanine particles (electrochromic particles 5) in an electrolyte matrix 4 in which an electrolytic material (LiClO ₃ ) is dissolved,
It was prepared by the following procedure. That is, lithium perchlorate (LiC) is contained in an aqueous solution in which polyvinyl alcohol is dissolved.
lO ₃₎ dissolved, then prepare the mixed liquid of Lu di phthalocyanine particles, it was coated by spin coating on the sheet substrate 1 made transparent electrodes 2, dried in a drying furnace, the resin A recording sheet 10 on which the coloring layer 3 was formed was obtained.

The case of performing recording on the recording sheet 10 thus obtained will be described with reference to the drive circuit of FIG. The electrode on the earth side in FIG. 2 is the transparent electrode 2 of the recording sheet 10, and the TFT element is an external writing device. That is, selection of a necessary cell is performed by the data line X and the data line Y. When a certain position on the recording sheet is selected, the TFTs 21 and 23 of the selected cell are turned on, respectively, so that the coloring is controlled according to the applied voltage on the drive line. Color development can be obtained by controlling the DC voltage component. In this example, the pulse of the drive voltage running to the drive line is 30 ms, and an example of the pulse is shown in FIG. If the applied voltage is changed to -0.7, +0.7, 0, blue, yellow, and green can be developed correspondingly. The correspondence between the color to be developed and the drive voltage is as shown in Table 1, and purple can be produced at -1.2 V and red can be produced at +1.2 V.

[0028]

[Table 1]

The color retention on the recording sheet is as follows.
When the recording sheet 10 is detached from the counter electrode 20 (external electrode), the operation is performed by short-circuiting the drive circuit in FIG. This is done by resistance.

The white display on the recording sheet 10 is performed by displaying red, green, and blue adjacent to the resin coloring layer 3. Since the electrochromic element is in the form of particles and the background is white (whitened sheet substrate 1), a white reflectance of 40% or more is obtained, and the brightness of the entire recording sheet is improved to make it easier to read. became. In addition, the pulse application time required for color development can be set to 30 ms, and it was confirmed that the high-speed color development response of Lu diphthalocyanine could be all solidified without being deteriorated by the formation of particles. These could be repeatedly recorded / erased 100 times.

(Embodiment 2) The recording sheet of the second embodiment is composed of ytterbium Y as electrochromic particles.
The same as Example 1 except that b diphthalocyanine was used. Also in this case, white display was performed by displaying red, green, and blue adjacent to each other in the coloring layer. For the same reason as in Example 1, a white reflectance of 40% or more is obtained, and the pulse application time required for color development can be 30 ms as in Example 1, and ytterbium Yb diphthalocyanine It was confirmed that high-speed color development response was able to be solidified without deterioration due to particle formation. These could be repeatedly recorded / erased 100 times.

(Embodiment 3) The recording sheet of the third embodiment is composed of europium Eu as electrochromic particles.
The same as Example 1 except that diphthalocyanine was used. In this case, as in the first and second embodiments, a white reflectance of 40% or more can be obtained, and the pulse application time required for color development can be 30 ms.
0 recording / erasing was possible.

Example 4 The recording sheet of Example 4 is the same as Example 1 except that erbium Er diphthalocyanine was used as the electrochromic particles. Also in this case, as in the above-described embodiments, a white reflectance of 40% or more was obtained, the pulse application time required for coloring was 30 ms, and recording / erasing was repeated 100 times. .

Example 5 The recording sheet of the fourth example was the same as Example 1 except that dysprosium Dy diphthalocyanine was used as the electrochromic particles. Also in this case, as in the above-described embodiments, a white reflectance of 40% or more was obtained, the pulse application time required for coloring was 30 ms, and recording / erasing was repeated 100 times. .

(Comparative Example) As a comparative example, an electrochromic material was prepared in the same manner as in Example 1, a sheet-like coloring layer was formed, and 1 μm was formed thereon as an evaporation film.
Further, an electrolytic material layer was formed thereon by using polyvinyl alcohol in which lithium perchlorate was dissolved as a solid solution to form a recording sheet. In this case, the white reflectance was 20% or less, and it was difficult to use it as a reflective display sheet. That is, when the electrochromic particles are used as in Examples 1 to 5, the electrochromic material (color-forming layer) and the electrolytic material layer are each formed in a sheet shape (comparative example), The white reflectance can be improved.

[0036]

According to the present invention, a resin coloring layer in which dispersed rare earth metal diphthalocyanine (electrochromic material particles) is dispersed in a resin layer in which an electrolytic material is dissolved is prepared on a white sheet. Thus, a white background close to paper can be obtained, and high-speed and high-contrast multicolor display can be performed.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view of a recording sheet showing an example of an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram in which the entire structure of the recording apparatus is simplified.

FIG. 3 is a timing chart showing an application timing pattern when positive and negative DC voltages are applied to a recording sheet.

[Explanation of symbols]

1 ... sheet substrate, 2 ... transparent electrode, 3 ... resin coloring layer,
4: High polymer material (electrolyte matrix), 5: Electrochromic particles, 6: External electrode (counter electrode), 10: Recording sheet, 20: Counter electrode

Claims (2)

[Claims] 1. A resin formed by dispersing particles of an electrochromic material in a resin layer in which an electrolytic material for supplying cations or negative ions to an electrochromic material is solid-dissolved on a white sheet on which a transparent electrode is formed. A recording sheet, wherein a coloring layer is formed, and the particles of the electrochromic material are rare earth metal diphthalocyanines whose coloring state can be selected by applying a voltage. 2. A recording apparatus, comprising: a plurality of counter electrodes for the recording sheet according to claim 1, wherein a voltage is applied between the recording sheet and a transparent electrode to form an image on the recording sheet; Cell selecting means for specifying an arbitrary place of the above, and voltage applying means for controlling the color tone of the color forming layer by applying desired positive and negative voltages to the cell selected by the cell selecting means. Characteristic recording device.