EP0404575B1 - Milieu d'enregistrement - Google Patents

Milieu d'enregistrement Download PDF

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Publication number
EP0404575B1
EP0404575B1 EP19900306805 EP90306805A EP0404575B1 EP 0404575 B1 EP0404575 B1 EP 0404575B1 EP 19900306805 EP19900306805 EP 19900306805 EP 90306805 A EP90306805 A EP 90306805A EP 0404575 B1 EP0404575 B1 EP 0404575B1
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EP
European Patent Office
Prior art keywords
layer
liquid crystal
polymer
recording medium
recording
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19900306805
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German (de)
English (en)
Other versions
EP0404575A3 (fr
EP0404575A2 (fr
Inventor
Toshio 502 Taguchi Biruto Konno
Tadayuki Shimada
Atsushi Nakano
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Victor Company of Japan Ltd
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Victor Company of Japan Ltd
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Filing date
Publication date
Priority claimed from JP1160058A external-priority patent/JPH0325735A/ja
Priority claimed from JP1947690A external-priority patent/JPH03223809A/ja
Priority claimed from JP2283490A external-priority patent/JPH03226720A/ja
Application filed by Victor Company of Japan Ltd filed Critical Victor Company of Japan Ltd
Publication of EP0404575A2 publication Critical patent/EP0404575A2/fr
Publication of EP0404575A3 publication Critical patent/EP0404575A3/fr
Application granted granted Critical
Publication of EP0404575B1 publication Critical patent/EP0404575B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/024—Photoelectret layers

Definitions

  • the present invention relates to a recording medium for storing a charge image.
  • phase change-type recording medium used as the recording medium in which signals carrying information are recorded thereon by irradiating a recording layer thereof with a beam which is intensity-modulated by the signals to produce physical or chemical changes corresponding to the recording signals.
  • the phase change-type recording medium has been developed as an optical disk (postscript-type disk) on which users are permitted to record information only once or an erasable optical disk for a file memory in office use or other purposes, on which the material (inorganic or organic material), having a configuration with two or more different stable states or phases of optical and/or electrical characteristics (optical transmittance, reflectance, absorption, electrical resistance or other characteristics) which generates transition from one state to another among the stable states, is formed as a recording layer on a substrate by deposition or sputtering.
  • recording media such as, magneto-optical, pit-forming, or bubble or irregularity-forming recording media.
  • the recording medium provided with a charge holding layer capable of photo-modulation for recording thereon the signals carrying information as a charge image of high resolution further has been proposed.
  • the recording medium utilizing dislocation between crystal phases of alloy has poor absorption of heating energy and recording sensitivity.
  • the recording medium composed of organic recording material also has poor recording responses.
  • the recording medium provided with a charge holding layer capable of photo-modulation however has difficulty in holding charges on the charge holding layer in the air for a long time.
  • recording medium composed of a layer of polymer dispersed with a liquid crystal, capable of electrooptically storing an image into insulating polymer matrices, and an electrode joined to, at least, one side of the layer.
  • Such recording medium has already been proposed by the assignee of this application, which is composed by laminating in succession a transparent electrode and the layer of polymer with liquid crystal on a transparent substrate of such as glass, or further laminating a dielectric layer on top of the polymer, or joining at least a photoconductor formed with a transparent electrode thereon, to one side of the layer of polymer with liquid crystal, when recording images.
  • the photoconductor may be joined when manufactured.
  • the image recording is performed in a way that the polymer with liquid crystal or the dielectric layer is scanned by a needle electrode carrying a voltage being made ON/OFF corresponding to the image where a bias voltage is applied between the needle electrode and the transparent electrode of the medium.
  • image recording is performed in a way that a voltage is applied across two transparent electrodes, the photoconductive material and the layer of polymer and liquid crystal being sandwiched therebetween.
  • the image recorded on the recording medium is composed of transparent portion and non-transparent portion (where light is scattered).
  • the recording medium is employed as an image filter (the filter through which light is passed by the transparent portion and light is blocked by the non-transparent portion) installed into a light source and a sensitive material such as a photographic film of silver salt and diazonium sensitized paper for image exposure in an electrophotographic system or an electronic printing system or for a color filter of cyan, magenta and yellow for forming a full-coloured image.
  • an image filter the filter through which light is passed by the transparent portion and light is blocked by the non-transparent portion
  • a sensitive material such as a photographic film of silver salt and diazonium sensitized paper for image exposure in an electrophotographic system or an electronic printing system or for a color filter of cyan, magenta and yellow for forming a full-coloured image.
  • US-A-4675699 discloses an image recording apparatus comprising a pair of substrates and a thermo-optical liquid crystal provided between the pair of substrates. An image can be recorded on this image recording medium by the application of both an electric field and by locally heating the image recording medium containing the liquid crystal.
  • the present invention provides an information memory medium comprising: a memory layer, composed of a polymer member having minute pores and liquid crystal molecules contained therein, one of the two surfaces of the memory layer being exposed or coated with a dielectric layer; a plane electrode laminated to the other surface of the memory layer; and a substrate for supporting the electrode laminated thereto, wherein the electrode is sandwiched between the memory layer and the substrate, wherein the alignment of the liquid crystal molecules is brought into a specific alignment when an electric field is applied thereto which goes beyond a specific threshold level of the liquid crystal molecules with respect to the electric field, and the specific alignment of the liquid crystal molecules remains unchanged after removing the electric field, and wherein the liquid crystals have a melting point lower than that of the polymer of the polymer member.
  • a recording medium 10 and 10a shown in Figs. 1 and 2 respectively is composed of a base substrate 12, a transparent electrode 14 of such as ITO (Indium-Tin Oxide) and a memory layer 16 of polymer dispersed with liquid crystal, and further a dielectric layer 18 in Fig. 2.
  • a transparent electrode 14 of such as ITO Indium-Tin Oxide
  • a memory layer 16 of polymer dispersed with liquid crystal and further a dielectric layer 18 in Fig. 2.
  • An adequate macromolecular material is employed as the base substrate 12, such as a material through which light for reading information is passed if the recording medium is transparent-type.
  • a material opaque to the light is used if the recording medium is reflection-type having a dielectric mirror allowing the light making a round excursion in the memory layer 16.
  • the memory layer 16 is composed by dispersing a nematic liquid crystal which behaves in its nematic phase at room temperature in the polymer having high volume resistivity and which may be polyester resin, polycarbonate resin, vinyl chloride resin, polyamide resin, polyethylene resin, polypropylene resin, polystyrene resin or silicon resin, each of which has volume resistivity 1014 ⁇ cm or more.
  • a nematic liquid crystal which behaves in its nematic phase at room temperature in the polymer having high volume resistivity and which may be polyester resin, polycarbonate resin, vinyl chloride resin, polyamide resin, polyethylene resin, polypropylene resin, polystyrene resin or silicon resin, each of which has volume resistivity 1014 ⁇ cm or more.
  • the dielectric layer 18 depicted in Fig. 2 also may be thin layer of macromolecular material such as polymers as described above.
  • the followings are examples of the formation of the memory layer 16.
  • Nematic liquid crystal material LIXON 5017 DML (or LIXON 5028) of three grams manufactured by Chisso Co. is applied onto ten weight % chloroform solution of PMMA (Polymethylmethacrylate) of twenty grams. The solution then is stirred and left to settle.
  • PMMA Polymethylmethacrylate
  • a base substrate 12 coated with ITO layer as the transparent electrode 14 sufficiently cleansed is prepared.
  • the chloroform solution of PMMA containing the liquid crystal material is applied onto the transparent electrode 14 by means of a bar-coater to compose the memory layer 16 of 8 micron thickness.
  • any polymer which can be dissolved into solution and formed into a layer and also have high volume resistivity may be used.
  • Polycarbonate and PEI (Polyether Imide) having better transparency are particularly applicable for the purpose. This is also true for the example (2) described later.
  • the recording medium 10 shown in Fig. 1 is thus composed as above.
  • the recording medium 10a shown in Fig. 2 is composed such that the dielectric layer 18 is formed on the memory layer 16 of the recording medium 10 by means of the thin layer of PMMA.
  • Nematic liquid crystal material ZLI4277 of three grams manufactured by Merck Japan Ltd. is applied onto ten weight % chloroform solution of PMMA of twenty grams. The solution then is stirred and left to settle. Other procedures are the same as described in (1).
  • the nematic liquid crystal used in (1) and (2) has such a high resistivity of 1 ⁇ 1013 ⁇ cm. Therefore, image information with high contrast ratio can be read/written from and to the recording medium including the memory layer of polymer and liquid crystal.
  • the nematic liquid crystals used in (1) and (2) contain few ions so that undesirable phenomenon as described above does not occur. Therefore, reading/writing operation of information with high contrast ratio can be performed.
  • the liquid crystals in the memory layer according to the present invention are made in the state that the liquid crystal is enclosed in innumerable pores randomly distributed in the layer of porous polymer.
  • the diameter of the pore is desirably about 0.5 micron or less.
  • liquid crystal which is nematic at a room temperature with high volume resistivity and viscosity can be used for the memory layer of the recording medium according to the present invention for better quality.
  • the liquid crystal with lower melting point than that of the polymer is effective when the recording medium is composed to be capable of erasing recorded information.
  • the melting points 81.6°C of the nematic liquid crystal LIXON 5017 and 102.3°C of the nematic liquid crystal LIXON 5028 described in (1) are both lower than that of PMMA employed as the polymer.
  • Fig. 3 shows the recording system in which a voltage is applied across the transparent electrode 14 of the recording medium 10 and an electrode 24 of a writing head 20.
  • a voltage is applied across the transparent electrode 14 of the recording medium 10 and an electrode 24 of a writing head 20.
  • the electric resistance thereof varies accordingly with the intensity of the optical image.
  • the two dimensional field intensity distribution generated between the photoconductive layer member 22 and the transparent electrode 14 also varies correspondingly with the two dimensional intensity distribution of the optical image due to the voltage applied across the two electrodes.
  • the memory layer 16 of the recording medium 10 has applied to it the electric field, the intensity distribution of which varies accordingly with the optical image.
  • the nematic liquid crystal enclosed in innumerable pores randomly distributed in the polymer of the memory layer is thus oriented accordingly with the intensity of the electric field so that transparency of the memory layer is improved.
  • the state of the liquid crystal thus oriented is not changed even if the electric field is removed.
  • the memory layer is composed such that liquid crystal is enclosed in innumerable pores randomly distributed in the polymer.
  • the liquid crystal thus contained is subject to tension caused by inner wall surface of each pore, smaller the pore, larger the tension of the wall, yet the liquid crystal in such condition exhibits nematic phase under the electric field of up to a certain threshold level.
  • the molecules of the contained liquid crystal are oriented against such tension of the wall in response to the applied electric field of over the threshold level. And it is understood that thus oriented molecules of the liquid crystal are maintained their orientation by the tension of the wall even after the applied electric field is removed.
  • Fig. 4 shows a recording system in which a signal source 30 feeds a recording electrode (needle) 32 with electric charges corresponding to analog or digital recording signals.
  • the information is stored in the memory layer 16 as described above by applying an electric field caused between the electrodes 14 and 32 by the fed charges, the intensity distribution of the field varying corresponding with the information to be recorded.
  • the electrode 32 is transferred to scan the recording medium 10 when recording.
  • the recording mediums 10 and 10a according to the present invention comprise the memory layer 16 one surface of which is exposed or covered with the very thin dielectric layer 18. Hence, the writing head 20 or the recording electrode 32 can be brought close to the memory layer 16 as much as possible, so that an electric field applied to the memory layer 16 does not diffuse. This enables the recording with little degradation of the recorded information.
  • Fig. 5 shows a reproduction system in which a light RL is projected onto the recording medium 10 and passed therethrough to be applied to a photoelectric convertor 34 which converts the light RL into electric signals.
  • the light RL may be with large diameter to cover an entire surface of the recording medium and a two-dimensional image sensor may be employed as the photoelectric convertor, or the light RL with small diameter scans the recording medium and is incident to the photoelectric convertor, or a dielectric mirror may be disposed in the recording medium so that the light RL incident thereto is reflected at the dielectric mirror and proceeds to the photoelectric convertor located other side of recording medium 10, or the light RL emitted out from the recording medium is applied to some other devices as it is not as the electric signals.
  • the information recorded in the recording medium can be erased by heating the liquid crystal in the memory layer to a temperature higher than the melting point of the liquid crystal and lower than that of the polymer.
  • the liquid crystal when the liquid crystal is heated as such the liquid crystal exhibits isotopy due to active thermal reaction of the liquid crystal having larger energy than that from the pores in which the liquid crystal is contained. And then the liquid crystal is cooled to become nematic phase. Thus recorded information is erased and the memory layer returns to be opaque.
  • recording media 10b and 10c shown in Figs. 6 and 7 respectively includes the memory layer 16a of polymer and liquid crystal, composed by dispersing liquid crystal which is smectic at a room temperature in the polymer, instead of the memory layer 16 shown in Figs. 1 and 2.
  • the memory layer 16b is composed by dispersing liquid crystal which is smectic at a room temperature in the polymer such as polyester resin, polycarbonate resin, vinyl chloride resin, polyamide resin, polyethylene resin, polypropylene resin, polystyrene resin and silicon resin, each having volume resistivity 1014 ⁇ cm or more.
  • the polymer such as polyester resin, polycarbonate resin, vinyl chloride resin, polyamide resin, polyethylene resin, polypropylene resin, polystyrene resin and silicon resin, each having volume resistivity 1014 ⁇ cm or more.
  • the memory layer 16c is produced as follows. Smectic liquid crystal S6 of three grams manufactured by Merck Japan Ltd. is applied onto ten weight % chloroform solution of PMMA of twenty grams. The solution then is stirred and left to settle. Other procedures are the same as described in (1) of production procedure of the memory layer 16b.
  • the polymer and other components of the recording media 10b and 10c are the same as those of the recording media 10 and 10a shown in Figs. 1 and 2.
  • Behaviour of the smectic liquid crystal in the polymer is the same as that of the nematic liquid crystal described before. However, the smectic liquid crystal is more viscous than the nematic liquid crystal so that higher contrast ratio is obtained in the case of reproduction from the recording media 10b and 10c.
  • the smectic liquid crystal with a melting point lower than that of the polymer is preferable for composing an erasable recording medium.
  • the liquid crystal S6 described above has the melting point of about 60°C which is lower than that of the polymer PMMA.
  • Figs. 8 to 10 show recording/reproduction systems employing the recording medium 10b and their operations are the same as those described with reference to Figs. 3 to 5. Erasing operation is also the same. In Fig. 8, there is a gap between the photoconductive layer member 22 and the surface of the memory layer 16a, however the gap may be omitted.
  • Figs. 11 and 12 show the transmittance of the memory layers 16a and 16 to the wavelength of light, respectively.
  • the curves I each depicted in Figs. 11 and 12 show the transmittance before applying an electric field to the memory layer, the curves II immediately after applying an electric field of 2.5 ⁇ 105 V/cm to the memory layer of the thickness of 8 »m which is applied with electric charges by way of corona electrical charging, the curves III in Figs. 11 and 12, 90 minutes after the application of the electric field applied to the memory layer and the curve IV in Fig. 12 the electric charge is positively neutralized 90 minutes after the application of the charge.
  • the memory layer 16a has better memory function and higher contrast ratio than those of the memory layer 16.
  • recording media 10d and 10e shown in Figs. 13 and 14 respectively includes the memory layer 16b of polymer and liquid crystal, composed by dispersing a mixture of two types of liquid crystal which are smectic and nematic at a room temperature in the polymer, instead of the memory layer 16 shown in Figs. 1 and 2.
  • the followings are examples of the production of the memory layer 16b.
  • the polymer and other components of the recording media 10b and 10c are the same as those of the recording media 10 and 10a shown in Figs. 1 and 2.
  • Figs. 15 and 16 show the transmittance of the memory layer 16b and 16 to the voltage applied thereto, respectively. As is obvious from Figs. 15 and 16, the curve for the memory layer 16b starts to rise at about 150 V while about 250 V for the memory layer 16. This means that the memory layer 16b requires less voltage to be operated than the memory layer 16.
  • the memory layer 16 When it comes to the change of transmittance of the memory layer when an electric charge is applied thereto then neutralized, the memory layer 16 has a transmittance change of about 70% while the memory layer 16b about 90%. This results in resolution and contrast ratio being improved if the memory layer 16b is employed.
  • the nematic liquid crystal is not so viscous that orientation of its molecules reduces as time lapse.
  • the nematic liquid crystal requires rather low voltage to be operated.
  • the smectic liquid crystal is so viscous that orientation of its molecules is preferably maintained.
  • the smectic liquid crystal has better memory function.
  • this liquid crystal requires high voltage to be operated.
  • Contrast ratio will be improved by employing the nematic liquid crystal having relatively higher refraction index and anisotropy. Furthermore, liquid crystal which is smectic or nematic at a room temperature is employed in the embodiments, the present invention is applicable at any other temperature by employing optimum liquid crystal depending on the operating temperature.
  • Transmittance (I) is that in the visible range in which light passes through the layer of polymer and liquid crystal immediately after manufacture and before the application of an electric charge
  • transmittance (II) is that in the visible range with the application of an electric charge of 2.5 ⁇ 105 V/cm
  • transmittance (III) is that in the visible range after the application of that electric charge which is subsequently removed.
  • the electric charge applied to the layer is generated by way of corona electrical charging and positively removed by reverse corona electrical charging.
  • curves shown in Fig. 17 are obtained for the recording media W and Y, and those shown in Fig. 18 for the recording media V and X.
  • memory function is evaluated (the smaller the change of the curve III as time elapses, the better the memory function) by measuring the change of the curve III in which the recording media are made transparent by applying an electric charge thereto and then subsequently removing.
  • the curves III in the respective figures indicate the response when 90 minutes have passed after the removal of the charge. It is found that the curves III barely vary in the recording media as shown in Figs. 17 and 18. While it largely varies in the recording medium including nematic liquid crystal as shown in Fig. 19. This results in the recording media V, W, X and Y having better memory function.
  • the configuration of the recording medium, particularly that of an electrode depends on the method of image recording.
  • the recording medium is configured such that the memory layer of polymer containing liquid crystal or a dielectric layer coated over the recording layer is exposed and a flat electrode is laminated to the recording layer.
  • the flat electrode may be transparent or not.
  • the recording medium is configured as such that the memory layer is sandwiched between the two electrodes at least when the recording is performed, and either one of the electrodes is transparent and supported by a transparent substrate.
  • the recording medium is configured as such that a photoconductive layer is contacted to a dielectric layer coated over the memory layer or contacted directly to the memory layer.
  • the photoconductive layer is used to receive the uniform electric charge, one side of the photoconductive layer is configured to be exposed.
  • the photoconductive layer is used to be applied with a voltage to generate a uniform electric field over the memory layer, a flat transparent electrode supported by a transparent substrate if needed, is laminated to one side of the photoconductive layer.
  • the other side of the recording medium is attached with a transparent flat electrode which may be supported by a transparent substrate laminated thereto.
  • the material of the electrode a well known material, such as a vacuum evaporation-layer or sputter-layer of SnO2 and In2O3 (ITO), etc., is employed.
  • a metal such as aluminium is added to that if the electrode does not need to be transparent. Then the electrode is formed by vacuum evaporation and sputtering, etc.
  • the material having volume resistivity of 1014 ⁇ cm or more when not exposed to light and 1012 ⁇ cm or less when exposed is employed.
  • Such materials for the photoconductive layer are as follows: a single material layer of, for example, Se or SeTe, or a photoconductive particles dispersed type in which photoconductive particles made of an inorganic pigment such as CdS exhibiting photoconductivity to light or an organic pigment such as phthalocyanine and quinacridone pigment is dispersed in the polymer, a dye sensitization type in which sensitizing dyes are dispersed or dissolved in photoconductive polymer such as polyvinyl carbazole, a laminated type in which a charge generating layer is laminated to a charge transfer layer for transferring charges generated from the charge generating layer.
  • Such charge generating layer may be composed of thin film of Se or SeTe having a thickness of 1 micron or less, or composed of macromolecular matrix comprising aforementioned pigment or dye, or photoconductive polymer containing such pigment or dye, and such charge transfer layer may be composed of similar materials dispersed or dissolved into the same polymer as mentioned before.
  • Such photoconductive layers can be produced by known methods.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Liquid Crystal (AREA)
  • Optical Record Carriers And Manufacture Thereof (AREA)

Claims (8)

  1. Milieu formant support de mémoire d'information (10) comprenant:
       une couche de mémoire (16) composée d'un élément en polymère ayant des pores minuscules et des molécules de cristaux liquides contenues à l'intérieur de ceux-ci, l'une des deux surfaces de la couche de mémoire étant exposée ou étant revêtue d'une couche diélectrique (18);
       une électrode plane (14) superposée à l'autre surface de la couche de mémoire; et
       un substrat (12) pour supporter l'électrode (14) qui lui est superposée, sachant que l'électrode (14) est intercalée entre la couche de mémoire (16) et le substrat (12),
       dans lequel l'alignement des molécules de cristaux liquides est amené dans un alignement spécifique lorsque est appliqué aux molécules un champ électrique qui dépasse un niveau de seuil spécifique des molécules de cristaux liquides relativement au champ électrique, et l'alignement spécifique des molécules de cristaux liquides reste inchangé après la suppression du champ électrique, et
       dans lequel les cristaux liquides ont un point de fusion inférieur à celui du polymère de l'élément en polymère.
  2. Milieu formant support de mémoire d'information selon la revendication 1, dans lequel le polymère de l'élément en polymère a une résistivité volumique électrique de 10¹⁴ Ωcm ou plus.
  3. Milieu formant support de mémoire d'information selon la revendication 1, dans lequel les cristaux liquides sont smectiques à la température ambiante.
  4. Milieu formant support de mémoire d'information selon la revendication 1, dans lequel les cristaux liquides sont constitués d'un mélange de cristaux liquides ayant des phases smectique et nématique, respectivement, à la température ambiante.
  5. Milieu formant support de mémoire d'information selon la revendication 1, dans lequel lesdits cristaux liquides sont en phase isotopique lorsqu'ils sont chauffés à une température en dessous dudit point de fusion du polymère de l'élément en polymère.
  6. Milieu formant support de mémoire d'information selon la revendication 1, dans lequel ledit substrat (12) est transparent.
  7. Milieu formant support de mémoire d'information selon la revendication 1, dans lequel un couche photoconductrice (24) est en contact électrique avec ladite couche de mémoire (16) pour enregistrer une information optique.
  8. Milieu formant support de mémoire d'information selon la revendication 1, dans lequel ladite couche de mémoire (16) est revêtue de ladite couche diélectrique (18) et une couche photoconductrice (24) est en contact électrique avec ladite couche de mémoire (16) pour enregistrer une information optique.
EP19900306805 1989-06-22 1990-06-21 Milieu d'enregistrement Expired - Lifetime EP0404575B1 (fr)

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
JP160058/89 1989-06-22
JP1160058A JPH0325735A (ja) 1989-06-22 1989-06-22 情報記録媒体
JP21944489 1989-08-25
JP219444/89 1989-08-25
JP1947690A JPH03223809A (ja) 1990-01-30 1990-01-30 情報記録媒体の製造方法
JP19476/90 1990-01-30
JP2283490A JPH03226720A (ja) 1990-01-31 1990-01-31 情報記録媒体
JP22834/90 1990-01-31

Publications (3)

Publication Number Publication Date
EP0404575A2 EP0404575A2 (fr) 1990-12-27
EP0404575A3 EP0404575A3 (fr) 1991-04-17
EP0404575B1 true EP0404575B1 (fr) 1995-08-23

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EP19900306805 Expired - Lifetime EP0404575B1 (fr) 1989-06-22 1990-06-21 Milieu d'enregistrement

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EP (1) EP0404575B1 (fr)
DE (1) DE69021789T2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8440509B2 (en) 1997-11-27 2013-05-14 Semiconductor Energy Laboratory Co., Ltd. Method for producing a semiconductor device by etch back process

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9108382D0 (en) * 1991-04-19 1991-06-05 Philips Electronic Associated Opto-electronic memory system
WO2004077136A1 (fr) * 1992-01-10 2004-09-10 Masayuki Iijima Support pour l'enregistrement d'informations et procede d'enregistrement/reproduction d'informations
DE69330060T2 (de) * 1992-10-26 2001-11-15 Dainippon Printing Co Ltd Photoelektrischer Sensor, Informationsaufzeichnungssystem und Methode zur Informationsaufzeichnung
EP0613054A1 (fr) * 1993-02-22 1994-08-31 Matsushita Electric Industrial Co., Ltd. Feuille d'enregistrement électrostatique et procédé d'enregistrement électrostatique
EP0622708B1 (fr) * 1993-04-26 2000-07-12 Dai Nippon Printing Co., Ltd. Détecteur photoélectrique, système d'enregistrement d'information, et méthode d'enregistrement et de reprographie
US5594569A (en) 1993-07-22 1997-01-14 Semiconductor Energy Laboratory Co., Ltd. Liquid-crystal electro-optical apparatus and method of manufacturing the same
US7227603B1 (en) 1993-07-22 2007-06-05 Semiconductor Energy Laboratory Co., Ltd. Liquid-crystal electro-optical apparatus and method of manufacturing the same
JP3390633B2 (ja) 1997-07-14 2003-03-24 株式会社半導体エネルギー研究所 半導体装置の作製方法
JP4014710B2 (ja) 1997-11-28 2007-11-28 株式会社半導体エネルギー研究所 液晶表示装置

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Publication number Priority date Publication date Assignee Title
FR1601599A (fr) * 1968-02-23 1970-08-31
US3935337A (en) * 1973-02-12 1976-01-27 Owens-Illinois, Inc. Preparation of liquid crystal containing polymeric structure
US4675699A (en) * 1985-01-18 1987-06-23 Canon Kabushiki Kaisha Image-recording apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8440509B2 (en) 1997-11-27 2013-05-14 Semiconductor Energy Laboratory Co., Ltd. Method for producing a semiconductor device by etch back process

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EP0404575A3 (fr) 1991-04-17
DE69021789D1 (de) 1995-09-28
DE69021789T2 (de) 1996-01-11
EP0404575A2 (fr) 1990-12-27

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