JPH0520758B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a display device for displaying images by fixing colored powder using electrical adsorption force. More specifically, it is intended to achieve high contrast, long life, and low environmental dependence, which are the basic performances of a display device. [Prior Art] Display devices, especially electrical display devices, include CRT displays, liquid crystal displays, light emitting diode displays,
Fluorescent displays, plasma displays, electrophoretic displays, electrochromic displays, etc. are well known.
They have various disadvantages, such as displaying on a large screen is difficult because it requires advanced technology, is extremely expensive, reduces the definition of the display, and causes severe visual fatigue because the display flickers. are doing. Several new display devices have been proposed to replace these display devices. A method of displaying images by using a photoconductive layer to electrically adsorb conductive colored derivatives at the same time as exposure. (Japanese Patent Application No. 56-197410, Japanese Patent Publication No. 03-064864)) An electric latent image is formed on a dielectric material using a pin electrode, etc.
A method of displaying an electrical latent image by electrically adsorbing an insulating colored differential material to the electrical latent image. (Utility Model Publication No. 57-55061) A method of displaying conductive colored fine powder by electrically adsorbing it on a dielectric material using a pin electrode, etc.
46707) A method of displaying colored magnetic differential materials by magnetic attraction using an easily magnetizable stylus. In principle, some of these display methods are capable of high-definition display, and can be easily and inexpensively displayed on a large screen, or because they are displayed using colored fine powder, the displayed image does not flicker and visual acuity is low. It is attracting attention because it causes relatively little fatigue. However, it has not been put to practical use because it is insufficient in terms of high contrast, long life, low environmental stability, high reliability, etc. required for display devices. [Problems to be Solved by the Invention] The present invention is based on an image forming method known as the so-called magnetic stylus, which is known from Japanese Patent Publication No. 51-46707, etc. In other words, conductive colored fine powder is formed on a dielectric material using a pin electrode or the like. The purpose of this method is to achieve high contrast and excellent recording or display characteristics in a method of displaying by electrically adsorbing. [Means for Solving the Problems] The present invention includes an image holding member and a plurality of divided electrodes, which are arranged so as to be separated and face each other with conductive colored fine powder interposed therebetween, and between the image holding member and the electrodes. In a recording or display method in which electrically conductive colored fine powder is electrically adhered to the surface of an image holding member by applying a voltage to the image holding member, the image holding member is at least on a conductive layer and is laminated on the layer, in a binder resin. The image holding member comprises a diffuse reflection layer in which fine particles are dispersed, and the reflection layer contains at least conductive fine particles. The present invention will be explained in detail below. The recording or display forming means used in the present invention employs a so-called magnetic stylus system known from Japanese Patent Publication No. 46707/1983.
That is, the principle is as shown in FIG. 1, a cylindrical magnet 2 is rotated within a non-magnetic cylinder 3, and a colored conductive colored magnetic fine powder 1 is conveyed over the non-magnetic cylinder 3. It passes over needle-shaped recording electrodes 4 that are densely arranged along the axial direction on the non-magnetic cylinder 3.
Thus, a voltage is applied between the recording electrode 4 and the conductive layer 7 of the image holding member 5, which is composed of the recording layer (diffuse reflection layer) 6 on the front side and the conductive layer 7 on the back side, according to the image information. , only the part to which the voltage is applied is the recording medium 5
An image is formed by attaching conductive colored magnetic fine powder 1 to the surface of the magnetic field. It is also possible to provide a cleaning member to remove the surface image on the image carrier body 5. As the cleaning member, blade cleaning, fur cleaning, suction cleaning, magnetic brush cleaning, etc. used for removing fine powder can be used. A more effective cleaning method is to electrically remove the charges induced on the recording medium through a cleaning member so as to remove the charges induced on the surface of the recording medium. For example, there is a method in which a magnet is placed adjacent to the surface of the recording medium and conductive colored magnetic fine powder used for display is interposed therebetween and grounded. In such recording or display forming means, the image holding member conventionally has an uneven light reflecting surface to diffuse reflection in order to increase contrast. However, this is not desirable because the conductive colored magnetic fine particles are trapped in the recesses, resulting in a decrease in contrast. Also, a method using an anodic oxide film of aluminum as disclosed in Japanese Patent Publication No. 51-46707. In this method, voltage leaks are likely to occur due to cracks occurring during anodic oxidation, the surface becomes uneven and conductive colored magnetic fine powder is trapped in the recesses, which tends to reduce contrast, and the whiteness of the anodic oxide film is affected. It has disadvantages such as low voltage and insufficient contrast, and when the environment changes, a lot of voltage leaks occur, resulting in a decrease in recording or display density and insufficient contrast. In view of the above, the present invention significantly improves several conventional drawbacks by laminating a diffuse reflection layer in which fine particles are dispersed in a binder resin on at least the conductive layer as an image holding member. This is one of the important features of the present invention. That is, by configuring the diffuse reflection layer with a binding resin as a component, the surface uniformity is improved, and by removing internal cracks, etc., toner capture by the uneven surface is reduced and voltage leakage is prevented. , By dispersing fine particles in the binding resin, the whiteness is significantly increased due to interfacial reflection due to the difference in refractive index at the interface, and the contrast is improved. However, if the specific electrical resistance of the diffuse reflection layer is too high, the charges induced in the light diffusion reflection layer during recording will be difficult to attenuate, so excellent image quality can be obtained for one-time recording or display, but when reusing the light diffusion Charges induced in the reflective layer tend to remain, and the residual charges after cleaning cause the dielectric colored powder to be adsorbed again. Due to the so-called ghost phenomenon and charge remaining on the entire surface of the image holding unit,
Conductive colored powder is adsorbed all over the surface, which is called fog, resulting in deterioration of contrast due to a decrease in whiteness. In order to eliminate such drawbacks, one of the most important features of the present invention is that the electrical resistance of the diffuse reflection layer is adjusted so that charges are less likely to remain, and the charges are removed by natural discharge. have In order to obtain the desired effect of the present invention, the specific electrical resistance of the diffuse reflective layer is
10000 m every 60 seconds with an applied voltage of 40 V by the recording electrode.
60 of the dielectric charge in the diffuse reflection layer after repeating
FIG. 5 shows the ratio of the surface voltage of the diffuse reflection layer generated by the residual charge after a few seconds to the applied voltage and the recording or display characteristics. In the recording or display method of the present invention, the ratio of the surface potential of the diffuse reflection layer generated due to residual charge to the applied voltage must be 1% or less in order to prevent the occurrence of ghosts and decrease in contrast. In the recording or display method based on the invention, as a specific electrical resistance,
It can be seen that it is 10 ¹⁵ Ω·cm or less, and preferably 10 ¹⁴ Ω·cm or less. In addition, the diffuse reflection layer must be a layer with sufficiently high electrical resistance to function as an image holding member, and must not easily become conductive, or when electrically charged, generates a substantial potential and produces sufficient contrast. It is a layer that functions like this. Therefore, there are some factors that depend on the state in which it should function as an image holding member and the usage conditions, but if we aim to achieve high contrast, which is the gist of the present invention,
Since it is necessary to maintain 50% or more of the initial charging voltage for 100 msec or more, the specific electrical resistance of the diffuse reflection layer is
10 ¹² Ω・cm or more. To achieve higher contrast, it is necessary to maintain 90% or more of the potential after initial charging, so the specific electrical resistance of the diffuse reflection layer is 10 ¹³
Ω・cm or more is desirable. In order to impart such specific electrical resistance to the diffuse reflection layer, the present invention is characterized in that conductive fine particles are used as the fine particles constituting the diffuse reflection layer. Examples of the conductive fine particles include conductive metal powder, conductive carbon, and metal oxides. However, conductive metal powder is difficult to use because it becomes oxidized and forms an oxide film on its surface when it is made into powder, resulting in loss of conductivity, poor reflectivity, and whiteness that does not reach the required whiteness of 60% or more. Alternatively, conductive carbon cannot be used because its whiteness is 0 and contrast cannot be obtained. In the present invention, tin oxide, zinc oxide, antimony oxide, indium oxide, etc. are excellent in providing a predetermined conductivity in terms of contrast as a recording or display device. For example, fine particles of tin oxide, metal oxides such as tin oxide and other titanium oxides, magnesium oxide, silicon oxide, aluminum oxide, barium oxide, metal sulfates such as barium sulfate, magnesium sulfate, calcium sulfate, or barium carbonate,
Fine particles made of metal carbonate such as magnesium carbonate and calcium carbonate are desirable. For example, fine particles of zinc oxide, metal oxides such as zinc oxide and other titanium oxides, magnesium oxide, silicon oxide, aluminum oxide, barium oxide, metal sulfates such as barium sulfate, magnesium sulfate, calcium sulfate, or barium carbonate, magnesium carbonate. , fine particles made of metal carbonate such as calcium carbonate, etc. are desirable. For example, fine particles of antimony oxide, antimony oxide and other titanium oxides, metal oxides such as magnesium oxide, silicon oxide, aluminum oxide, barium oxide, metal sulfates such as barium sulfate, magnesium sulfate, calcium sulfate, or barium carbonate, magnesium carbonate. , fine particles made of metal carbonate such as calcium carbonate, etc. are desirable. For example, fine particles of indium oxide, metal oxides such as indium oxide and other titanium oxides, magnesium oxide, silicon oxide, aluminum oxide, barium oxide, metal sulfates such as barium sulfate, magnesium sulfate, calcium sulfate, or barium carbonate, magnesium carbonate. , fine particles made of metal carbonate such as calcium carbonate, etc. are desirable. In addition to these conductive fine particles, reflective fine particles can be prepared by, for example, forming a film by mixing incompatible polymers, or dispersing insoluble fine particles in a binding resin. Insoluble fine particles include metal oxides such as titanium oxide, aluminum oxide, magnesium oxide, calcium oxide, and barium oxide, metal sulfates such as barium sulfate, magnesium sulfate, and calcium sulfate, barium carbonate, magnesium carbonate, and calcium carbonate. metal carbonate,
The use of a mixture of fine powder of thermoplastic resin or cured fine powder of curable resin had an excellent effect in further increasing the contrast. Note that the fine particles are not limited to these. In such a recording or display forming means, the diffuse reflection layer has a reflection property that forms a reflected light component other than specularly reflected light. The diffuse reflectivity of such a diffuse reflection layer is defined by the ratio of the intensity of the specularly reflected light component to the intensity of the non-specularly reflected light component, and the more the non-specularly reflected light component is, the better the diffuse reflectivity is. In a display device, it is desirable that the dependence of contrast on the viewing angle is small, so it is necessary to increase the non-specularly reflected light component. In other words, a material with excellent diffuse reflection properties is desired. The regulations for diffuse reflectance are:
Although there are several methods, in the present invention, due to its simplicity and practicality, the whiteness is defined based on the reflection density obtained with a Macbeth densitometer or a similar functional product based on the following. Whiteness = [(1.44 - Reflection density) / (1.44 + 0.04)] × 100 Whiteness 100: Reflection density 0.04 (Almost everyone described it as pure white in the panel test) Whiteness 0: Reflection density 1.44 (Almost 1.44 in the panel test) Based on this definition of whiteness, the contrast of recording or display is the difference between the whiteness of the image holding member and the whiteness of the recording or display unit, and Can be determined. Therefore, a decrease in the whiteness of the image holding member inevitably results in a decrease in contrast, resulting in insufficient recording or display. Conventionally, in such recording or display methods, the whiteness was insufficient and the contrast could not reach the required level, but in the present invention, a diffuse reflection layer in which fine particles are dispersed in a binding resin is laminated on at least the conductive layer. can achieve whiteness of 60% or more,
Now I can get enough contrast. In the recording or display method based on the present invention, the display characteristics are proportional to the amount of charge generated in the diffuse reflection layer, and therefore are slightly related to the degree of coloring of the conductive colored magnetic fine powder forming the display, but in principle The thickness of the charged layer is V15 (V/μm)×t (μm) in order to obtain sufficient contrast, where V is the voltage applied when forming a display. In order to obtain further contrast, it is desirable to use V20 (V/μm)×t (μm). Considering the matching between the voltage applied during recording or display and the drive circuit, it is relatively easy to output a voltage of about 100 V or less, so the applied voltage
Considering 100V or less, the thickness of the charged layer is 7μ.
A practical value is 5 μm or less, preferably 5 μm or less. In order to prevent the conductive layer and the diffuse reflection layer from peeling off, an intermediate layer for increasing adhesiveness was provided between the layers, but the effects of the present invention were not reduced. In addition, the binding resin includes thermoplastic resins such as polyester, acrylic resin, polyolefin, polyacetal, polyamide, polystyrene, halogen-containing resin, silicone resin, polyether, polycarbonate, vinyl acetate resin, polystyrene resin, cellulose resin, and the like. Various copolymers, etc. or thermosetting resins such as phenolic resins, xylene resins, petroleum resins, urea resins, melamine resins, unsaturated polyesters, alkyd resins, epoxy resins, silicone resins, furan resins, etc. alone or copolymers. Mixtures etc. are used. Further, the conductive layer is a layer having a sufficiently low electrical resistance and is easily in a conductive state, or a layer that functions so as not to generate a substantial potential when electrically charged. Therefore, although there are some factors that depend on the state in which the conductive layer should function and the conditions of use, when aiming at high contrast, which is the gist of the present invention, the residual potential of the conductive layer is considered to be the cause of contrast reduction. Therefore, after charging
If the potential is attenuated to 1/100 or less of the initial charging potential in 100 msec or less, it can be said that there is sufficient conduction, and the specific electrical resistance of the conductive layer is 10 ¹¹ Ω·cm. 1m after charging for the purpose of faster image display
Since it is required to attenuate to 1/100 or less of the initial charging potential at sec or less, the specific electrical resistance of the conductive layer
10 ⁹ Ω・cm is desirable. The materials forming the conductive layer are aluminum, iron,
The conductive substance is contained in conductive metals such as gold, Sn, and Zn, conductive inorganic compounds such as carbon, tin oxide, indium oxide, and antimony oxide, or in binding resins such as polymers. It can be powdered and dispersed. In particular, in order to enhance the contrast in recording or display, it is desirable that the conductive layer has low light absorption and excellent light reflection. Although the conditions do not limit the present invention, the electrically conductive colored powder is mainly composed of a binder, electrically conductive powder, a magnetic material, and, if necessary, various dyes and pigments as a coloring agent. As a binder, thermoplastic resins such as polyester, acrylic resin, polyolefin, polyacetal, polyamide, polystyrene, halogen-containing resin, silicone resin, polyether, polycarbonate, vinyl acetate resin, polystyrene, cellulose resin, epoxy resin, and their Various copolymers, etc., and if necessary, thermosetting resins such as phenol resin, xylene resin, petroleum resin, urea resin, melamine resin, unsaturated polyester, alkyd resin, epoxy resin, silicone resin, furan resin, etc. alone or in combination. Use 15 to 60 wt% of polymer or mixture. As the conductive powder, 2 to 30 wt% of conductive carbon, fine particles of various conductive metals, conductive metal oxide powders such as zinc oxide, tin oxide, indium oxide, and antimony oxide are used. In addition, magnetic powders such as Fe ₂ and O ₄ are used as magnetic materials.
~80%wt% is used. If necessary, use various phthalocyanine, malagite green, etc. dyes as coloring agents.
Use 15-20wt% of pigment. These components are heated to about 100 to 300°C, mixed uniformly, and then cooled and ground into fine particles. If necessary, powder with unnecessary particle size is removed by classification or the like and used as a conductive colored powder. The average particle size is 5~
With a particle size of 20 μm, the specific electrical resistance is from 10 ³ Ω・cm at an applied voltage of 100 V or less in a conductive colored powder storage container.
It was ¹⁰⁹ Ω・cm. In addition, the process conditions for recording or displaying methods include rotating magnetic poles with a configuration of about 6 to 50 poles.
500 to 2000 Gauss intensity and 300 to 300 rotations.
It was used while rotating at about 7000 rpm. The non-magnetic cylinder is a molded product made of a non-magnetic metal such as aluminum or stainless steel, or a single or composite material such as plastic or various inorganic oxides. The non-magnetic cylinder may be used in a rotating or non-rotating state. Further, as recording electrodes, an electrode width of 0.1 to 1 mm, an inter-electrode width of 0.1 to 1 mm, and an applied voltage of 10 V to 100 V were used. Also, the moving speed of the recording medium is 50~
The speed was 700 mm/sec, and the distance to the electrode was set to 50 μm to 500 μm. Incidentally, FIG. 4 shows the structure of the image holding body 5. Figure 4-4-1 shows two of the conductive layer 7 and recording layer 6 (diffuse reflection layer).
Layer configuration, FIG. 4-2 shows a support 30, a conductive layer 7,
This is an example of a three-layer structure of the recording layer 6 (diffuse reflection layer). A recording/display apparatus to which the recording or display method according to the present invention is applied will be explained in detail with reference to FIG. 2. Reference numeral 5 denotes a recording medium composed of a conductive layer and a recording layer formed in the shape of an endless belt. 5 may be in the form of a belt that is not endless. The recording medium 5 is wound around a pair of rollers 11 and 11' arranged vertically opposite each other, and the recording medium 5 is placed on a back plate 16 in the display section 18.
It is movably supported in a planar manner by rollers 11 and 11'. This recording medium 5 is
It is driven in the direction of the arrow during image formation. At the lowest position of the circulation path of the recording medium 5, that is, at a position facing the roller 11', conductive colored magnetic fine powder 1 as a display substance is attached to the recording medium 5 according to the display information, and the display is displayed. Means 17 are provided for forming. Reference numeral 9 in the figure is a container for storing the conductive colored magnetic fine powder 1. Original reading device 1 based on the above-mentioned display forming means
The information obtained from 5 is applied as an electrical signal to the recording electrode 4 by the recording control unit 13 via the storage device 14. Incidentally, by adding a writing display function, a reading function, and a print function to this display device, a device as shown in FIG. 3 is also possible. Image information to be displayed is input from the document reading device 15 and sent to the recording electrode 4 via the encoding/decoding circuit section 28 and the storage device 14 or directly from the encoding/decoding circuit section 28 by the recording control section 13. Applied as an electrical signal. Further, on the outer circumferential side of the recording medium 1, a writing medium 20 is arranged, which is formed in the shape of an endless belt and is transparent and capable of being written on and erased with a felt pen or the like. 19′,
19" so that it can be circulated. Also,
This writing medium 20 is supported in a planar manner by rollers 19 and 19' in the display section 18. Further, a cleaning member is provided near the roller 11 to remove conductive colored magnetic fine particles adhering to the image on the recording medium 5 and the back surface of the writing medium 20. This cleaning member 1
Reference numerals 2 and 12' remove toner by moving toner spikes formed on the outer periphery of a cylindrical member by magnetic attraction in a rotating brush shape. Further, an erasing member 21 for erasing an image written on the writing medium 20 is provided below the roller 19'.
is installed. Further, on the back side of the recording medium 5, a means 22 for reading images on the recording medium 5 and the writing medium 20 is provided. That is, at the reading position that is the closest position between the recording medium 5 and the writing medium 20, there is a lamp 24 with a reflective shade 23 that illuminates the images on both the mediums 5 and 20, and a light image reflected from both the mediums 5 and 20. A mirror 27 is provided to make the light incident on the photoelectric conversion element 26 via the lens 25. The images on the recording medium 5 and the writing medium 20 are read by the photoelectric conversion element 26 and recorded by the printer 29 directly via the encoding/decoding circuit section 28 or via the storage device 14. These specific examples are merely embodiments of the present invention, and the present invention is not limited to these embodiments. [Example] The present invention will be further explained below with reference to Examples. Example 1 30 parts by weight of polyester resin, which is a condensation polymer of terephthalic acid and ethylene glycol, was added with an average particle size.
30 parts by weight of 0.5 μm titanium oxide powder, average particle size
30 parts by weight of 0.5μm tin oxide powder is melted and dispersed at 200℃ and extruded into a film through a T-shaped die.
A white film with a thickness of 5 μm was thermally laminated on one side of a 50 μm thick aluminum foil to serve as an image holding member. Based on the same procedure as in Example 1, the following composition ratios were used as Examples and Comparative Examples.

〔result〕

The display functions of the display devices illustrated in FIG. 2 were compared. The conductive colored powder used was Pisphenol A.
30 parts of mold epoxy resin, 10 parts of conductive carbon,
It was composed of 60 parts of Fe ₃ O ₄ powder, had an average particle size of 10 μm, and had a specific electrical resistance of 10 ⁶ Ω·cm (100 V applied). In addition, the rotating magnetic pole has a 16-pole configuration of 900 gaum, and an outer diameter of
A 36φ one was used at a rotation speed of 2200 rpm in the opposite direction to the moving direction of the image holding body. The non-magnetic cylinder has a wall thickness of 1 mm and an outer diameter of 40 φ, and is made of a 200 μ thick polyimide film with electrodes etched at positions facing the image holding body with an electrode width of 0.5 mm and an inter-electrode width of 0.25 mm. was adhered to the outer surface of the non-magnetic cylinder. The voltage applied to the electrodes was 40V. Under these conditions, the image holding member was transported at a speed of 220 mm/sec. The results are shown in the table below.

[Table] Example 6 Aluminum was vapor-deposited to a film thickness of 800 Å on a 100 μm thick polyester surface, and a 4 μm thick film of the following composition was applied on the aluminum. Barium sulfate with an average particle diameter of 1.0 μm was used as an image holding member. 15 parts of powder, 15 parts of tin oxide powder with an average particle size of 0.5 μm, and 30 parts of thermosetting phenolic resin were dispersed with 810 parts of methyl ethyl ketone in a ball mill for 10 hours to obtain a dispersed average particle size of 0.8 μm.
Apply the mixture of m using a reverse roll coater.
Heated at 140°C for 5 minutes. Example 7 In Example 2, calcium carbonate having an average particle size of 0.8 μm was used instead of barium sulfate.

[Table] As seen in the above examples, excellent contrast can be obtained based on the present invention. Example 8 30 parts by weight of polyester resin, which is a condensation polymer of terephthalic acid and ethylene glycol, was added with an average particle size.
30 parts by weight of 0.5 μm titanium oxide powder, average particle size
30 parts by weight of 0.5μm zinc oxide powder is melted and dispersed at 200℃ and extruded into a film through a T-shaped die.
A white film with a thickness of 5 μm was thermally laminated on one side of a 50 μm thick aluminum foil to serve as an image holding member. Based on the same procedure as in Example 1, the following composition ratios were used as Examples and Comparative Examples.

〔result〕

The display functions of the display devices illustrated in FIG. 2 were compared. The conductive colored powder used was Pisphenol A.
30 parts of mold epoxy resin, 10 parts of conductive carbon,
It was composed of 60 parts of Fe ₃ O ₄ powder, had an average particle size of 10 μm, and had a specific electrical resistance of 10 ⁶ Ω·cm (1000 applied). In addition, the rotating magnetic pole has a 16-pole configuration, 900 Gaum, outer diameter
A 36φ one was used at a rotation speed of 2200 rpm in the opposite direction to the moving direction of the image holding body. The non-magnetic cylinder has a wall thickness of 1 mm and an outer diameter of 40 φ, and is made of a 200 μ thick polyimide film with electrodes etched at positions facing the image holding body with an electrode width of 0.5 mm and an inter-electrode width of 0.25 mm. was adhered to the outer surface of the non-magnetic cylinder. The voltage applied to the electrodes was 40V. Under these conditions, the image holding member was transported at a speed of 220 mm/sec. The results are shown in the table below.

[Table] Example 13 Aluminum was vapor-deposited to a film thickness of 800 Å on a 100 μ-thick polyester surface, and a 4 μ-thick coating of the following composition was applied on the aluminum. Barium sulfate with an average particle diameter of 1.0 μm was used as an image holding member. 15 parts of powder, 15 parts of zinc oxide powder with an average particle size of 0.5 μm, and 30 parts of thermosetting phenolic resin were dispersed in a ball mill for 10 hours with 810 parts of methyl ethyl ketone to obtain a dispersed average particle size of 0.8 μm.
Apply the mixture of m with a reverse roll coater,
Heated at 140°C for 5 minutes. Example 14 In Example 2, calcium carbonate having an average particle size of 0.8 μm was used instead of barium sulfate.

[Table] As seen in the above examples, excellent contrast can be obtained based on the present invention. Example 15 30 parts by weight of polyester resin, which is a condensation polymer of terephthalic acid and ethylene glycol, had an average particle size.
30 parts by weight of 0.5 μm titanium oxide powder, average particle size
30 parts by weight of 0.5 μm indium oxide powder was melted and dispersed at 200°C, extruded into a film through a T-shaped die, heat laminated on one side of a 50 μm thick aluminum foil, and a white film with a thickness of 5 μm was provided as an image holding member. And so. Based on the same procedure as in Example 1, the following composition ratios were used as Examples and Comparative Examples.

〔result〕

The display functions of the display devices illustrated in FIG. 2 were compared. The conductive colored powder used was Pisphenol A.
30 parts of mold epoxy resin, 10 parts of conductive carbon,
It was composed of 60 parts of Fe ₃ O ₄ powder, had an average particle size of 10 μm, and had a specific electrical resistance of 10 ⁶ Ω·cm (100 V applied). In addition, the rotating magnetic pole has a 16-pole configuration, 900 Gaum, outer diameter
A 36φ one was used at a rotation speed of 2200 rpm in the opposite direction to the moving direction of the image holding body. The non-magnetic cylinder has a wall thickness of 1 mm and an outer diameter of 40 φ, and is made of a 200 μ thick polyimide film with electrodes etched at positions facing the image holding body with an electrode width of 0.5 mm and an inter-electrode width of 0.25 mm. was adhered to the outer surface of the non-magnetic cylinder. The voltage applied to the electrodes was 40V. Under these conditions, the image holding member was transported at a speed of 220 mm/sec. The results are shown in the table below.

[Table] Example 20 Aluminum was vapor-deposited to a film thickness of 800 Å on a 100 μm thick polyester surface, and a 4 μm thick film of the following composition was applied on the aluminum. Barium sulfate with an average particle diameter of 1.0 μm was used as an image holding member. 15 parts of powder, 15 parts of indium oxide powder with an average particle size of 0.5 μm, and 30 parts of thermosetting phenol resin were dispersed with 810 parts of methyl ethyl ketone in a ball mill for 10 hours to obtain a dispersed average particle size.
A 0.8 µm mixture was applied using a reverse roll coater and heated at 140°C for 5 minutes. Example 21 In Example 2, calcium carbonate having an average particle size of 0.8 μm was used instead of barium sulfate.

[Table] As seen in the above examples, excellent contrast can be obtained based on the present invention. Example 22 30 parts by weight of polyester resin, which is a condensation polymer of terephthalic acid and ethylene glycol, had an average particle size.
30 parts by weight of 0.5 μm titanium oxide powder, average particle size
30 parts by weight of 0.5 μm antimony oxide powder was melted and dispersed at 200°C, extruded into a film through a T-shaped die, heat laminated on one side of a 50 μm thick aluminum foil, and a white film with a thickness of 5 μm was provided as an image holding member. And so. Based on the same procedure as in Example 1, the following composition ratios were used as Examples and Comparative Examples.

〔result〕

The display functions of the display devices illustrated in Figure 2 were compared. The conductive colored powder used was Pisphenol A.
30 parts of mold epoxy resin, 10 parts of conductive carbon,
It was composed of 60 parts of Fe ₃ O ₄ powder, had an average particle size of 10 μm, and had a specific electrical resistance of 10 ⁶ Ω·cm (100 V applied). In addition, the rotating magnetic pole has a 16-pole configuration, 900 Gaum, outer diameter
A 36φ one was used at a rotation speed of 2200 rpm in the opposite direction to the moving direction of the image holding body. The non-magnetic cylinder has a wall thickness of 1 mm and an outer diameter of 40φ, and has an electrode width of 0.5 mm and an electrode width at a position facing the image holding body.
A 200μ thick polyimide film with electrodes etched at 0.25mm intervals was adhered to the outer surface of the non-magnetic cylinder. The voltage applied to the electrodes was 40V. Under these conditions, the image holding member was transported at a speed of 220 mm/sec. The results are shown in the table below.

[Table] Example 27 Aluminum was vapor-deposited to a film thickness of 800 Å on a 100 μm thick polyester surface, and a 4 μm thick film of the following composition was applied on the aluminum. Barium sulfate with an average particle diameter of 1.0 μm was used as an image holding member. 15 parts of powder, 15 parts of antimony oxide powder with an average particle size of 0.5 μm, and 30 parts of thermosetting phenolic resin were dispersed in a ball mill for 10 hours with 810 parts of methyl ethyl ketone to obtain a dispersed average particle size.
A 0.8 µm mixture was applied using a reverse roll coater and heated at 140°C for 5 minutes. Example 28 In Example 2, calcium carbonate having an average particle size of 0.8 μm was used instead of barium sulfate.

〔Effect of the invention〕

The present invention consists of the above configuration and operation,
A plurality of electrodes separated from the image holding body are arranged so as to face each other in isolation through conductive colored particles, and a voltage is applied between the image holding body and the electrodes to electrically conduct the image holding body surface. In a recording or display method in which a conductive colored fine powder is attached to an image holding member, the image holding member is a diffuser containing at least conductive fine particles in a diffuse reflection layer in which fine particles are dispersed in a binder resin on at least a conductive layer. By laminating reflective layers, it was possible to achieve high contrast and excellent recording or display characteristics in recording or display.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a magnetic stylus type image forming means and an image holding member having a diffuse reflection layer of the present invention. FIG. 2 shows one embodiment of the recording or display method using the image holding member of the present invention, and FIG. 3 similarly shows one of the other embodiments. FIG. 4 is a schematic cross-sectional view showing the structure of the image holding member of the present invention. FIG. 5 is a graph showing the relationship between the specific electrical resistance of the diffuse reflection layer of the present invention and the ratio of surface potential to applied voltage after repeated use. 1... Conductive colored magnetic fine powder, 2... Rotating magnet, 3... Non-magnetic cylinder, 4... Acicular recording electrode, 5
... Image holding body, 6 ... Recording layer (diffuse reflection layer),
7... Conductive support, 8... Transparent plate, 9... Conductive colored magnetic fine powder storage container, 10... Device framework,
11, 11'... Sheet support member, 12... Cleaning member, 13... Recording control unit, 14... Storage device, 15... Original reading device, 16... Back plate,
17... Image forming means, 18... Display section, 19,
19'...roller, 20...writing medium, 21...
Erasing member, 22... Image reading means, 23... Reflective shade, 24... Lamp, 25... Lens, 26...
Photoelectric conversion element, 27...mirror, 28...encoding/decoding circuit section, 29...printer, 30...support body.

Claims (1)

[Scope of Claims] 1. An image holding member and a plurality of divided electrodes are arranged to face each other in isolation via conductive colored fine powder, and a voltage is applied between the image holding member and the electrodes to form an image. In a recording or display method in which electrically conductive colored fine powder is attached to the surface of a holding member, the image holding member is a diffuse reflection film in which fine particles are dispersed in at least a conductive layer and a binding resin laminated on the layer. 1. An image holding member comprising a layer, the reflective layer containing at least conductive fine particles. 2. The image holding member according to claim 1, wherein the conductive fine particles contain at least tin oxide. 3. The image holding member according to claim 1, wherein the conductive fine particles contain at least zinc oxide. 4. The image holding member according to claim 1, wherein the conductive fine particles contain at least antimony oxide. 5. The image holding member according to claim 1, wherein the conductive fine particles contain at least indium oxide. 6. The image holding body according to claim 1, wherein the whiteness of the image holding body is 60% or more. 7. The image holding body according to claim 1, wherein the diffuse reflection layer constituting the image holding body has a specific electrical resistance of 10 ¹² Ω·cm or more.