Erasable Imaging Patents (Class 430/19)
  • Patent number: 6103431
    Abstract: A rewritable, color image recording medium composed of a pair of opposed substrates at least one of which is transparent, and an intermediate layer interposed between the substrates. The intermediate layer contains at least one cholesteric liquid crystal compound having a molecular weight of not greater than 2,000 and a glass transition point of at least 35.degree. C., and a photochromic compound. By irradiating the intermediate layer imagewise with the light through the transparent substrate, while maintaining the intermediate layer at such a temperature that the cholesteric liquid crystal compound assumes a cholesteric liquid crystal phase, an image is formed. The image may be fixed by rapidly cooling the recording medium to a temperature lower than the glass transition.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: August 15, 2000
    Assignee: Director-General of Agency of Industrial Science and Technology
    Inventors: Nobuyuki Tamaoki, Hiroo Matsuda, Soyoung Song
  • Patent number: 6090508
    Abstract: An optically anisotropic recording medium and a method of recording and erasing method using the recording medium are disclosed, which comprises the steps of applying heat or light to the recording medium which comprises a recording layer made of optically anisotropic organic thin-film-shaped crystals to raise the temperature of an organic material or which comprises the optically anisotropic organic thin-film-shaped crystals to a recording temperature at which the crystals are fused, performing partial changing of the crystalline state of the crystals by rapidly cooling the recording layer, thereby recording information in the recording layer; and heating the recording layer to an erasing temperature which is lower than the recording temperature, at which the crystals are not fused, but the molecules thereof can be thermally moved.
    Type: Grant
    Filed: August 27, 1997
    Date of Patent: July 18, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Kyoji Tsutsui, Akio Kojima, Masafumi Ohta, Ryohei Miyake
  • Patent number: 6060200
    Abstract: A data processing form for use with photo-sensing apparatus that detect the presence of indicia at indicia-receiving locations on the form. The form is composed of a sheet of carrier material and plurality of indicia-receiving locations. The indicia-receiving locations are defined by a mutable colored composition including a mutable colorant and an ultraviolet radiation transorber such that the indicia-receiving locations are adapted to become substantially undetectable by photo-sensing apparatus upon irradiating the colored composition with ultraviolet radiation at a dosage level sufficient to irreversibly mutate the colorant. The colored composition may be irradiated with radiation in the ultraviolet region of the ultraviolet spectrum.
    Type: Grant
    Filed: February 3, 1998
    Date of Patent: May 9, 2000
    Assignee: Kimberly-Clark Worldwide, Inc.
    Inventors: Ronald S. Nohr, John Gavin MacDonald, Michael Wilfred Mosehauer
  • Patent number: 6048654
    Abstract: A a lithographic printing method comprising repetition of the steps of exposing a printing plate precursor having on the surface thereof a thin layer comprising TiO.sub.2, ZnO or at least one compound selected from the group consisting of RTiO.sub.3 wherein R represents an alkaline earth metal atom, AB.sub.2-x C.sub.x D.sub.3-x E.sub.x O.sub.10 wherein A represents a hydrogen atom or an alkali metal atom; B represents an alkaline earth metal atom or a lead atom; C represents a rare earth atom; D represents a metal atom of the group 5A of the Periodic Table; E represents a metal atom of the group 4A of the Periodic Table; and x represents a number of from 0 to 2, SnO.sub.2, Bi.sub.2 O.sub.3, and Fe.sub.2 O.sub.3 to active light to make the exposed area hydrophilic, and making the hydrophilic area hydrophobic by heat treatment.
    Type: Grant
    Filed: September 14, 1998
    Date of Patent: April 11, 2000
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Takao Nakayama, Seishi Kasai, Takashi Yamada, Koji Kamiyama
  • Patent number: 6030745
    Abstract: An optical recording medium comprising: a substrate having pre-groove for forcing and tracking servo operation; and a recording film formed on the substrate, the recording film having optical properties being changed by applying at least one of a light beam a heating onto a portion of the recording film.
    Type: Grant
    Filed: October 23, 1998
    Date of Patent: February 29, 2000
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Hironori Goto, Hideo Kobayashi
  • Patent number: 6027855
    Abstract: The present invention relates to the field of optical recording materials, in particular, fluorescent compounds and matrices suitable for use in optical memory systems, including three dimensional optical memory systems for READ ONLY MEMORY (ROM). In particular, nonfluorescent Rhodamine B lactams are photochemically transformed into fluorescent Rhodamine B derivatives.
    Type: Grant
    Filed: December 12, 1997
    Date of Patent: February 22, 2000
    Assignee: OMD Devices LLC
    Inventors: Natalia T. Sokoluk, Vladimir V. Shubin, Eugene B. Levich, Jacob N. Malkin
  • Patent number: 6022648
    Abstract: Thermochromic materials are incorporated into constructions that facilitate accurate reproductions of monochrome or full-color images having multiple gray levels. The invention utilizes thermochromic materials having different transition temperatures to facilitate their selective activation. The materials may be located in a single layer of a recording sheet, or in multiple layers. The invention also comprises thermal printing apparatus useful in imaging the foregoing constructions, particularly those exhibiting hysteresis.
    Type: Grant
    Filed: March 8, 1996
    Date of Patent: February 8, 2000
    Assignee: Massachusetts Institute of Technology
    Inventors: Joseph M. Jacobson, V. Michael Bove, Jr.
  • Patent number: 6017661
    Abstract: Applications of photoerasable colorant composition include photoerasable price markings for pricing goods, documents such as gaming tickets for securely communicating concealed information, photoerasable paint for temporary markings on terrain and structures such as signs, roadways, trees, and buildings, marking instruments such as pens, and wick or felt markers, ultraviolet light exposure indicators, and dry printing. The photoerasable or mutable colorant composition comprises a mutable colorant and an ultraviolet radiation transorber which, upon irradiation with ultraviolet radiation, interacts with the colorant to irreversibly mutate the colorant and thereby render the colorant substantially colorless. The mutable colorant composition may also include a molecular includant.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: January 25, 2000
    Assignee: Kimberly-Clark Corporation
    Inventors: Jeffrey Dean Lindsay, John Gavin MacDonald, Ronald Sinclair Nohr
  • Patent number: 6010808
    Abstract: A rewritable thermal recording medium of this invention uses a recording material which reversibly changes between an equilibrium state and a quasi-equilibrium state different in color condition from the equilibrium state when a predetermined heat treatment is performed. This rewritable thermal recording medium includes a substrate and a recording layer formed on the substrate. The recording layer has a first region containing a first recording material which takes on lighter color in quasi-equilibrium than in equilibrium, and a second region containing a second recording material which takes on darker color in quasi-equilibrium than in equilibrium.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: January 4, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuyuki Naito, Satoshi Takayama, Takashi Sasaki
  • Patent number: 6001518
    Abstract: A reversible heat-sensitive recording medium has a substrate where a reversible heat-sensitive recording layer and a protective layer are successively formed on top of it. The reversible heat-sensitive recording layer is formed by a reversible heat-sensitive recording material including a leuco dye and a color developing/reducing agent. The color developing/reducing agent is a combination of two kinds of color developing/reducing agents, one with a high color developing ability and the other with high image preservation and stabilization capabilities. The two agents are combined at a ratio between 1:4 to 4:1. Thus a reversible heat-sensitive recording material with a fine color developing ability and high image preservation and stabilization capabilities can be obtained.
    Type: Grant
    Filed: April 9, 1998
    Date of Patent: December 14, 1999
    Assignee: Kyodo Printing Co., Ltd.
    Inventors: Haruhiko Ohsawa, Shin-ichi Koizumi, Hiroyuki Morinaka, Minoru Fujita
  • Patent number: 5989752
    Abstract: A reconfigurable mask for forming erasable patterns is disclosed. The mask includes material having optical properties manipulated by nonphysical means. In a preferred embodiment, the mask includes a liquid crystal array formed by materials that are transparent to the exposure light. A phase-shift mask can also be formed by controlling the refractive index of each cell. The mask can be used to form mask patterns that compensate for overexposure at corners of a mask pattern.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: November 23, 1999
    Inventor: Tzu-Yin Chiu
  • Patent number: 5983028
    Abstract: A usage control device is mounted in an electro-developing type camera with an electro-developing recording medium, by which an image is electronically developed. The electro-developing recording medium has an image recording area and a data recording area. The image is electronically developed and recorded in the image recording area. Data which indicates the number of times that a recording operation of the electro-developing recording medium has taken place, is magnetically recorded in the data recording area. The data recording area is composed of a magnetic recording medium, such as a magnetic tape.
    Type: Grant
    Filed: February 20, 1997
    Date of Patent: November 9, 1999
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventor: Koichi Sato
  • Patent number: 5981115
    Abstract: A reversible thermosensitive recording material which includes a recording layer including a resin, an electron donating coloring agent and an electron accepting coloring developer and in which an image is reversibly formed and erased by appropriately heating and cooling the recording layer, wherein the resin includes a resin crosslinked with the isocyanate compound. The reversible thermosensitive recording material has good image recording/erasing ability, and good durability.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: November 9, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiromi Furuya, Tadafumi Tatewaki, Fumio Kawamura, Kyoji Tsutsui
  • Patent number: 5965333
    Abstract: A thermal recording element comprising a support having thereon a recording layer comprising a J-aggregate derived from an oxonol dye dispersed in a hydrophilic binder.
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: October 12, 1999
    Assignee: Eastman Kodak Company
    Inventors: Huijuan D. Chen, Derek D. Chapman, Margaret J. Helber
  • Patent number: 5955225
    Abstract: A reversible thermosensitive composition including a coloring agent and a developer and capable of assuming a colored state and a discolored state depending upon the thermal hysteresis thereof. The developer is a phenol compound represented by the formula: ##STR1## wherein R.sup.1 and R.sup.3 represent, independently from each other, a substituted or non-substituted hydrocarbon group, R.sup.2 represents a substituted or non-substituted aliphatic hydrocarbon group having at least two carbon atoms, with the proviso that the total number of carbon atoms of R.sup.1, R.sup.2 and R.sup.3 is at least 8, X and Y represent, independently from each other, a divalent group having a nitrogen atom or an oxygen atom and r is an integer of between 1 and 3.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: September 21, 1999
    Assignee: Ricoh Company Ltd.
    Inventors: Hiromi Furuya, Masafumi Torii, Masaru Shimada, Fumio Kawamura, Kyoji Tsutsui, Katsushi Sugiyama, Katsuaki Kokubo, Katsuhisa Kamio, Kazuo Hosoda, Masafumi Moriya
  • Patent number: 5945252
    Abstract: The present invention relates to the field of optical recording materials, in particular, fluorescent compounds and matrices suitable for use in optical memory systems, including three dimensional optical memory systems for READ ONLY MEMORY (ROM). More particularly, nonfluorescent peri-phenoxiderivatives of polycyclic quinones are transformed into fluorescent aminoderivatives of anaquinones.
    Type: Grant
    Filed: December 11, 1997
    Date of Patent: August 31, 1999
    Assignee: Memory Devices, Inc.
    Inventors: Natalia T Sokoluk, Vladimir V. Shubin, Eugene B. Levich, Jacob N. Malkin
  • Patent number: 5942377
    Abstract: A reversible thermosensitive composition including a coloring agent and a developer and capable of assuming a colored state and a discolored state depending upon the thermal hysteresis thereof. The developer is a phenol compound represented by the formula: ##STR1## wherein R.sup.1 represents a substituted or non-substituted divalent hydrocarbon group having at least two carbon atoms, R.sup.2 represents a substituted or non-substituted hydrocarbon group, X and Y represent, independently from each other, a divalent group having a hetero atom and r is an integer of between 1 and 3. A reversible thermosensitive recording medium includes a support and a thermosensitive layer including the above composition.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: August 24, 1999
    Assignees: Ricoh Company, Ltd., Miyoshi Yushi Kabushiki Kaisha
    Inventors: Masafumi Torii, Tadafumi Tatewaki, Hiroaki Matsui, Hiromi Furuya, Kyoji Tsutsui, Masaru Shimada, Katsushi Sugiyama, Katsuaki Kokubo, Katsuhisa Kamio, Kazuo Hosoda, Masafumi Moriya
  • Patent number: 5914212
    Abstract: An optical recording medium comprising a substrate having a pre-groove for focusing and tracking servo operation, and a recording film formed on the substrate, the recording film having optical properties which change in response to the application of at least one of a light beam or heat to a portion of the recording film.
    Type: Grant
    Filed: May 25, 1995
    Date of Patent: June 22, 1999
    Assignee: Fuji Xerox Co., Ltd
    Inventors: Hironori Goto, Hideo Kobayashi
  • Patent number: 5888680
    Abstract: An optical recording medium having each of a land and a groove and comprises at least a recording layer, dielectric layers and reflection layer. Recording and erasing of data can be carried out on both land and groove by a phase change between amorphous and crystalline states. The mirror portion may have reflectance characteristics selected from at least one of a reflectance of more than 15% and no more than 35%, when in a crystalline state, and 10% or less, when in an amorphous state. Alternatively, additionally, the depth of the groove may be such as to form an optical path length equal to 1/7 to 1/5 of the wavelength of the reproducing light and the photo-absorbance of the recording layer in the amorphous phase and the photo-absorbance in the crystalline phase may satisfy the following formula, Aa-Ac.ltoreq.10 where Aa is the photo-absorbance (%) of the recording layer in the amorphous phase and Ac is the photo-absorbance (%) of the recording layer in the crystalline phase.
    Type: Grant
    Filed: October 10, 1997
    Date of Patent: March 30, 1999
    Assignee: Toray Industries, Inc.
    Inventors: Gentaro Ohbayashi, Hitoshi Nobumasa, Kunihisa Nagino, Kusato Hirota, Takao Amioka
  • Patent number: 5854710
    Abstract: The invention relates to systems and methods for optical Fourier processing and logic operations based on the discovery that the photoinduced anisotropy of photochromic materials such as bacteriorhodopsin, organic fulgides, azo and fluorescent dyes, phycobiliproteins, rhodopsins, and their analogs, is dependent on the intensity of a polarized actinic beam that illuminates the material and the intensity profile of one or more input beams. This intensity dependence can be used to implement a simple, real-time, self-adaptive optical processing, i.e., spatial filtering, system for Fourier processing of optical input images. This optical processing system can be used to process a wide variety of optical input images, from projected still images to live motion picture images.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: December 29, 1998
    Assignee: University of Massachusetts
    Inventors: Devulapalli V. G. L. N. Rao, Francisco J. Aranda, Joby Joseph, Joseph A. Akkara, Masato Nakashima
  • Patent number: 5837424
    Abstract: A data storage process which includes an erasable high speed, high density, storage medium having a transition metal oxide layer where said oxide layer is capable of undergoing an optically readable chemical change when simultaneously exposed to heat and to light of a selected wavelength. An optically readable image is formed in selected regions of the oxide layer under ambient conditions which include O.sub.2 by simultaneously exposing said layer to heat and to radiation in the blue-green or shorter wavelength spectrum. The image is erased by heating the entire medium using a furnace or by heating selected portions with IR radiation.
    Type: Grant
    Filed: May 1, 1997
    Date of Patent: November 17, 1998
    Assignee: Syracuse University
    Inventors: Joseph Chaiken, Joseph M. Osman
  • Patent number: 5811217
    Abstract: An optical information recording medium, which includes a substrate, and a recording thin film layer provided on the base material and adapted to form variation in an amount optically detectable by absorbing at least laser light so as to record information by partially varying the recording thin film layer and to reproduce the information by optically detecting the variation amount. The optical information recording medium further includes transparent layers each provided in contact with the recording thin film layer, and each of the transparent layers has optical thickness in which, in at least two different wavelengths .lambda., integral multiple of .lambda./2 is added to the thickness giving the large laser light absorption and large optical variation amount, respectively.More specifically, the optically detectable amount is of a reflectance factor variation, and in the different wavelengths .lambda.1 and .lambda.
    Type: Grant
    Filed: June 9, 1994
    Date of Patent: September 22, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Nobuo Akahira, Kenichi Nagata, Eiji Ohno, Kenichi Nishiuchi, Noboru Yamada
  • Patent number: 5804342
    Abstract: A method of making a printing member for providing an erasable bar-code including providing a polymeric substrate having an insert cavity; forming an insert member having a writing surface composed of a non-porous zirconia ceramic ZrO.sub.2 that is alloyed with a secondary oxide selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, a rare earth oxide, and combinations thereof, the non-porous zirconia alloy ceramic having a density of from about 5.6 to about 6.2 g/cm.sup.3 ; and providing an erasable bar-code image on the printing member by imagewise exposing the printing surface to electromagnetic radiation that transforms the printing surface from a stoichiometric to a substoichiometric state, thereby creating a printing surface having both image areas and non-image areas.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: September 8, 1998
    Assignee: Eastman Kodak Company
    Inventors: Gustavo R. Paz-Pujalt, Dilip K. Chatterjee, Syamal K. Ghosh
  • Patent number: 5773182
    Abstract: A light-stable colored composition which includes a colorant and a radiation transorber. The colorant, in the presence of the radiation transorber, is adapted, upon exposure of the transorber to specific, narrow bandwidth radiation, to be mutable. The radiation transorber also imparts light-stability to the colorant so that the colorant does not fade when exposed to sunlight or artificial light.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: June 30, 1998
    Assignee: Kimberly-Clark Worldwide, Inc.
    Inventors: Ronald Sinclair Nohr, John Gavin MacDonald
  • Patent number: 5759447
    Abstract: An erasable optical memory is provided by an erasable bistable photoactive chromophore that is covalently bonded to a polymer microsphere. An azobenzene chromophore that is bonded to the microsphere by an oxygen or NH replacement of chlorine, or a CH double bond to N, is preferred. An array of such microspheres is encoded by applying radiation at a resonant wavelength to induce a conformational change in the chromophores for selected microspheres, and the encoded pattern is read out by detecting changes in either absorption or fluorescence.
    Type: Grant
    Filed: December 22, 1995
    Date of Patent: June 2, 1998
    Assignee: Hughes Electronics Corporation
    Inventors: Uzi Efron, Chiung-Sheng Wu, Larry Raymond Dalton, Eli Wiener-Avnear
  • Patent number: 5747225
    Abstract: The invention relates to a light sensing device comprising a spironaphthoxazine dispersed in a layer of gelatin on a base material.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: May 5, 1998
    Assignee: Eastman Kodak Company
    Inventors: Joseph Anthony Manico, Richard Carroll Reem
  • Patent number: 5733693
    Abstract: A data processing form for use with photo-sensing apparatus that detect the presence of indicia at indicia-receiving locations on the form. The form is composed of a sheet of carrier material and plurality of indicia-receiving locations. The indicia-receiving locations are defined by a mutable colored composition including a mutable colorant and an ultraviolet radiation transorber such that the indicia-receiving locations are adapted to become substantially undetectable by photo-sensing apparatus upon irradiating the colored composition with ultraviolet radiation at a dosage level sufficient to irreversibly mutate the colorant. The colored composition may be irradiated with radiation in the ultraviolet region of the ultraviolet spectrum.
    Type: Grant
    Filed: January 2, 1997
    Date of Patent: March 31, 1998
    Assignee: Kimberly-Clark Worldwide, Inc.
    Inventors: Ronald Sinclair Nohr, John Gavin MacDonald, Michael Wilfred Mosehauer
  • Patent number: 5721287
    Abstract: A method of mutating a colorant in a composition which includes a colorant and a radiation transorber by irradiating the composition. The colorant, in the presence of the radiation transorber, is adapted, upon exposure of the transorber to specific, narrow bandwidth radiation, to be mutable. The radiation transorber also imparts light-stability to the colorant so that the colorant does not fade when exposed to sunlight or artificial light.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: February 24, 1998
    Assignee: Kimberly-Clark Worldwide, Inc.
    Inventors: Ronald Sinclair Nohr, John Gavin MacDonald
  • Patent number: 5716674
    Abstract: An information recording layer on a substrate provides a method of recording information by selectively opening the rings of dicyclopentadiene skeletons, thus recording information by forming cyclopentadiene skeletons. The information recorded by the method can be erased by the cycloaddition of cyclopentadiene skeletons. Information can also be recorded or erased by incorporating or eliminating a metal ion from a selectively opened section of a ring of a dicyclopentadiene skeleton after forming an organic thin film comprising the dicyclopentadiene skeleton. Alternatively, after the formation of an organic thin film comprising a cyclopentadiene skeleton, a heterocycle or a benzene ring, a metal ion is incorporated or eliminated from a section between at least two rings of the cyclopentadiene skeleton, the heterocycle or the benzene ring. Thereafter, a metallocene skeleton or a skeleton analogous to the metallocene skeleton is formed or eliminated, thus recording or erasing information.
    Type: Grant
    Filed: September 18, 1996
    Date of Patent: February 10, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tadashi Ohtake, Norihisa Mino, Kazufumi Ogawa
  • Patent number: 5702850
    Abstract: A thermosensitive reversible color-developing and disappearing agent includes an aromatic compound having at least one group of the formula, --SO.sub.2 NHCXNH--, wherein X.dbd.O or S atom, and at least one straight chain alkyl group with 11 or more carbon atoms, and is reactive with a dye precursor in a thermosensitive recording material to thereby record colored images on the recording material upon heating imagewise, and make the colored images disappear upon heating to a temperature lower than the colored image-forming temperature.
    Type: Grant
    Filed: September 13, 1995
    Date of Patent: December 30, 1997
    Assignee: New Oji Paper Co., Ltd.
    Inventors: Makoto Nishioka, Kazuo Yamane, Masaki Nishimura, Yoshiyuki Takahashi
  • Patent number: 5700850
    Abstract: A light-stable colored composition which includes a colorant and a radiation transorber. The colorant, in the presence of the radiation transorber, is adapted, upon exposure of the transorber to specific, narrow bandwidth radiation, to be mutable. The radiation transorber also imparts light-stability to the colorant so that the colorant does not fade when exposed to sunlight or artificial light.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: December 23, 1997
    Assignee: Kimberly-Clark Worldwide
    Inventors: Ronald Sinclair Nohr, John Gavin MacDonald
  • Patent number: 5691091
    Abstract: A data storage process which includes an erasable high speed, high density, storage medium having a transition metal oxide layer where said oxide layer is capable of undergoing an optically readable chemical change when simultaneously exposed to heat and to light of a selected wavelength. An optically readable image is formed in selected regions of the oxide layer under ambient conditions which include O.sub.2 by simultaneously exposing said layer to heat and to radiation in the blue-green or shorter wavelength spectrum. The image is erased by heating the entire medium using a furnace or by heating selected portions with IR radiation.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 25, 1997
    Assignee: Syracuse University
    Inventors: Joseph Chaiken, Joseph M. Osman
  • Patent number: 5674649
    Abstract: On one surface of a disk substrate, a first dielectric layer, a thin recording layer, a second dielectric layer and a reflecting layer are cumulatively formed. The second dielectric layer is thinner than the first dielectric layer and is 35-70 nm thick. The reflecting layer is 70-120 nm thick. The total thickness of the four layers is 250-430 nm. The compressive stress of the layers is offset by tensile stress generated by an overcoat resin protective layer, formed on the reflecting layer. A method of using the optical recording medium applies the MCAV (Modified Constant Angular Velocity) recording method which records information by changing recording frequencies in accordance with linear velocity. The linear velocity is 5-12 m/s. A ratio of an inner circumference recording pulse width to an outer circumference recording pulse width is 1.2 or more.
    Type: Grant
    Filed: April 23, 1996
    Date of Patent: October 7, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazumi Yoshioka, Tetsuya Akiyama, Takeo Ohta, Hidemi Isomura
  • Patent number: 5641846
    Abstract: Side-group polymers whose permanently shape-anisotropic side groups carry lateral substituents are particularly suitable, owing to their excellent properties, for optical components which can be employed, in particular, in optical data storage and transfer.
    Type: Grant
    Filed: September 22, 1995
    Date of Patent: June 24, 1997
    Assignee: Bayer Aktiengesellschaft
    Inventors: Thomas Bieringer, Uwe Gessner, Dietrich Haarer, Joachim Rubner, Roland Wuttke, Uwe Claussen, Ralf Ruhmann, Horst Berneth, Sergei Kostromin, Ralf Neigl
  • Patent number: 5635319
    Abstract: There is disclosed a method of successively forming and/or erasing images selectively in different portions of a recording layer of a recording medium which comprises a reversible thermosensitive recording material capable of recording images and erasing the same by reversibly changing the transparency or the color tone of the portions of the recording layer with the application of heat thereto, depending upon the temperature thereof, in such a manner that the same portion of the recording layer is not continuously used for image formation and/or erasure in excess of a predetermined number of times, thereby repeating the use of the recording medium for an extended period of time.
    Type: Grant
    Filed: July 21, 1995
    Date of Patent: June 3, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiko Hotta, Kunichika Morohoshi, Fumihito Masubuchi
  • Patent number: 5614339
    Abstract: Coated objects are recycled by irradiation with a laser beam. The invention is applied to objects (such as documents) that include an entry surface, a surface coated with a coating (such as text or graphics printed with copier or printer toner), and a body interposed between the surface. A laser beam is directed toward a target region of the coated surface, traveling first through the object's entry surface and body, which are translucent or transparent to the wavelength of light contained in the laser beam. The laser beam generates a plasma shock wave at the target region of the coated surface, thereby discharging particles of the coating located near the target region. The discharged printed matter is discharged away from the object, thereby avoiding undesired impregnation of the coating into the object. Discharged coating may be recycled by collection and subsequent reuse.
    Type: Grant
    Filed: August 9, 1995
    Date of Patent: March 25, 1997
    Assignee: Lumedics, Ltd.
    Inventor: Nikolai Tankovich
  • Patent number: 5538822
    Abstract: A method of erasing images recorded in an image recording medium capable of recording images therein and erasing the same therefrom by application of heat thereto includes the step of applying heat to both a front image bearing side and a back side of the image recording medium for erasing images.
    Type: Grant
    Filed: September 27, 1994
    Date of Patent: July 23, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiko Hotta, Kunichika Morohoshi, Fumihito Masubuchi
  • Patent number: 5538823
    Abstract: A thermostable orientation material for liquid crystal alignment including a photopolymerized polyvinyl fluorocinnamate.
    Type: Grant
    Filed: February 27, 1995
    Date of Patent: July 23, 1996
    Assignees: Goldstar Co., Ltd., Institute of Physics
    Inventors: Woo S. Park, Hyun H. Shin, Soon B. Kwon, Andrey G. Dyadyusha, Tatyana Y. Marusii, Yuriy A. Reznikov, Anatoliy I. Khizhnyak, Oleg V. Yaroshchuk, Alexandr A. Kolomeytsev, Igor V. Gerus
  • Patent number: 5489494
    Abstract: There is disclosed a method of successively forming and/or erasing images selectively in different portions of a recording layer of a recording medium which comprises a reversible thermosensitive recording material capable of recording images and erasing the same by reversibly changing the transparency or the color tone of the portions of the recording layer with the application of heat thereto, depending upon the temperature thereof, in such a manner that the same portion of the recording layer is not continuously used for image formation and/or erasure in excess of a predetermined number of times, thereby repeating the use of the recording medium for an extended period of time.
    Type: Grant
    Filed: September 9, 1993
    Date of Patent: February 6, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiko Hotta, Kunichika Morohoshi, Fumihito Masubuchi
  • Patent number: 5484686
    Abstract: The present invention provides an optical recording medium using an amorphous-crystalline phase-change for recording and erasing, wherein reflectivity of an optical recording medium-constituting recording film in an amorphous state is larger than that of the optical recording medium-constituting recording film in a crystalline state, or wherein absorptivity of an optical recording medium-constituting recording film in an amorphous state is smaller than that of the optical recording medium-constituting recording film in a crystalline state.
    Type: Grant
    Filed: March 4, 1994
    Date of Patent: January 16, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihito Maeda, Isao Ikuta, Hisashi Andoh, Masaichi Nagai, Yoshimi Katoh, Yoshio Sato, Nobuyoshi Tsuboi, Hiroyuki Minemura
  • Patent number: 5480749
    Abstract: This invention provides a photoswitchable compound comprising interconvertible mirror image units or interconvertible chiral diastereomeric units connected as pendant groups to a stiff polymer having interconvertible left- and right-handed helical portions of its backbone. Further provided by this invention is a photoswitchable compound formed by the method comprising combining an amount of the compound capable of optical activity and capable of changing its optical activity with an amount of a stiff polymer comprised of interconvertible left- and right-handed helical portions. Additionally, this invention provides a method for reversibly storing optical data comprising providing a material comprised of a mixture of a stiff polymer having interconvertible left- and right-handed helical portions and connected units, said units being capable of optical activity and capable of changing its optical activity and irradiating said material with light capable of changing the optical activity of said material.
    Type: Grant
    Filed: September 27, 1994
    Date of Patent: January 2, 1996
    Inventor: Mark M. Green
  • Patent number: 5470690
    Abstract: A stable, image-retaining, optically switchable film produced from a purple membrane in a high-pH polyvinyl alcohol solution forms an optical memory for data storage. The film, when dry, can be exposed to light to convert BR molecules to their M state, which is stable, and which allows long-term image storage. The image can be erased by exposing the film to yellow light to thereby switch all the molecules to the M state, and then a reverse image can be obtained using blue light. By controlling the location and wavelength of the incident light, pixels can be selected and exposed for information storage.
    Type: Grant
    Filed: June 9, 1994
    Date of Patent: November 28, 1995
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Aaron Lewis, Zhongping Chen, Hiroyuki Takei
  • Patent number: 5443940
    Abstract: Disclosed herein is an optical recording material containing a photochromic compound which is expressed in the following general formula (I): ##STR1## where A represents an oxygen atom or a substituted or unsubstituted nitrogen atom, R.sub.1 represents an alkoxy group, R.sub.2 to R.sub.5 represent substituents such as a hydrogen atom, a halogen atom, a hydroxy group, a substituted or unsubstituted alkyl group and the like respectively, and B represents a substituted or unsubstituted thiophene ring, benzothiophene ring, pyrrole ring or indole ring.
    Type: Grant
    Filed: April 14, 1993
    Date of Patent: August 22, 1995
    Assignees: Sanyo Electric Co., Ltd., Kobe Natural Products & Chemicals Co., Ltd.
    Inventors: Fumio Tatezono, Toshio Harada, Masahiro Irie, Meguru Ohara
  • Patent number: 5439777
    Abstract: A recording-reproducing apparatus includes an electrode, a material that changes its intramolecular electron distribution upon the application of electromagnetic wave irradiation and an electric field provided on the electrode, and an electrically conductive probe having a pointed tip. The apparatus projects an electromagnetic wave onto the material, and applies a pulse voltage between the electrode and the conductive probe.
    Type: Grant
    Filed: February 18, 1993
    Date of Patent: August 8, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Haruki Kawada, Hiroshi Matsuda, Kiyoshi Takimoto, Hiroyasu Nose
  • Patent number: 5432032
    Abstract: A method of writing and reading or writing, reading and erasing information in an optical recording medium is provided in which in an optical recording medium an optically active compound which is an inherently chiral dissymmetric olefinic chromophore is subjected to the action of circularly polarized light or is caused to undergo cis-trans isomerization during writing, is subjected to linearly polarized light during reading, and is subjected to linearly or circularly polarized light or light of a wavelength suitable to effect cis-trans isomerization for erasing.
    Type: Grant
    Filed: August 23, 1993
    Date of Patent: July 11, 1995
    Assignee: U.S. Philips Corporation
    Inventors: Egbert W. Meijer, Bernard L. Feringa, Wolter F. Jager, Ben De Lange
  • Patent number: 5422208
    Abstract: Disclosed is an improvement of a method for erasing a radiation image remaining in a stimulable phosphor sheet which has stored a radiation image and has been irradiated with stimulating rays to read the radiation image. The improvement comprises a first erasing step of irradiating the phosphor sheet with a first erasing light containing a light portion of wavelength in ultraviolet region; and a second erasing step of irradiating the phosphor sheet with a second erasing light containing no light portion of wavelength in ultraviolet region, said second erasing light and said first erasing light being employed in a ratio of amount of light in the range of 15/85 to 45/55. Devices for erasing radiation image appropriately employable in the above-mentioned method are also disclosed.
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: June 6, 1995
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasushi Kojima, Hiroshi Matsumoto
  • Patent number: 5405726
    Abstract: A sheet of paper, plastic or the like on which an image has been formed using a toner that is photochemically decolorizable by absorption of near infrared rays is illuminated with near infrared rays under the state wherein the image is heated to a temperature equal to or higher than the glass-transition temperature of a binding resin of the toner. The color of the toner can thereby be easily and rapidly eliminated. This enables the reuse of the sheet to be realized easily and at a low cost.
    Type: Grant
    Filed: November 10, 1992
    Date of Patent: April 11, 1995
    Assignees: Bando Chemical Industries. Ltd., Showa Denko Kabushiki Kaisha
    Inventors: Yuki Abe, Rikuzou Kouzuki, Masakazu Okamoto, Yasunori Mikata, Masatsugu Tabata, Shigeki Inoue, Sadao Tanimoto, Yoshihiro Uchimoto, Katsumi Murofushi, Yoshikazu Hosoda
  • Patent number: 5399451
    Abstract: An optical recording medium contains a fluorescent material and a photo-reactive bistable quencher. Information is digitally recorded by utilizing the bistable isomers of the photo-reactive bistable quencher by irradiating the medium with a light in the wavelength to be absorbed by the fluorescent material, whereby energy is transferred from the fluorescent material to the photo-reactive bistable quencher. Reading is made by irradiating the medium with a weaker light and detecting the fluorescence emitted by the fluorescent material.
    Type: Grant
    Filed: April 9, 1993
    Date of Patent: March 21, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takashi Hashida, Yoshio Kishimoto
  • Patent number: RE36383
    Abstract: An optical information recording medium is provided in which the active layer is a phase change material capable of absorbing energy and being converted between a substantially amorphous state and a substantially crystalline state. The active layer contains nitrogen, which may be in the form of a nitride or nitrides of the constituent elements of the active layer, or may be a nitrided surface thereof. The inclusion of nitrogen inhibits localized shifting of the active material, which leads to degradation of the recording/erase properties of the medium. The optical recording medium includes a substrate, onto which is deposited in sequence a first dielectric layer, a nitrogen-containing active layer, a second dielectric layer, and a metallic reflecting layer. The second dielectric layer is made thin, so that the cooling rate of the active layer is increased to form a more uniform amorphous state.
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: November 9, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazumi Yoshioka, Takeo Ohta, Masami Uchida, Katsumi Kawahara, Shigeaki Furukawa
  • Patent number: RE36624
    Abstract: The present invention provides an optical recording medium using an amorphous-crystalline phase-change for recording and erasing, wherein reflectivity of an optical recording medium-constituting recording film in an amorphous state is larger than that of the optical recording medium-constituting recording film in a crystalline state, or wherein absorptivity of an optical recording medium-constituting recording film in an amorphous state is smaller than that of the optical recording medium-constituting recording film in a crystalline state.
    Type: Grant
    Filed: January 15, 1998
    Date of Patent: March 21, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihito Maeda, Isao Ikuta, Hisashi Andoh, Masaichi Nagai, Yoshimi Katoh, Yoshio Sato, Nobuyoshi Tsuboi, Hiroyuki Minemura