US3683382A - Recording medium responsive to force fields and apparatus for recording and reproducing signals on the medium - Google Patents

Recording medium responsive to force fields and apparatus for recording and reproducing signals on the medium Download PDF

Info

Publication number
US3683382A
US3683382A US861019A US3683382DA US3683382A US 3683382 A US3683382 A US 3683382A US 861019 A US861019 A US 861019A US 3683382D A US3683382D A US 3683382DA US 3683382 A US3683382 A US 3683382A
Authority
US
United States
Prior art keywords
particles
web member
field
magnetic
recording medium
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
US861019A
Other languages
English (en)
Inventor
Dale O Ballinger
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.)
Honeywell Inc
Original Assignee
Honeywell Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Honeywell Inc filed Critical Honeywell Inc
Application granted granted Critical
Publication of US3683382A publication Critical patent/US3683382A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/02—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the intensity of light
    • G02B26/026—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the intensity of light based on the rotation of particles under the influence of an external field, e.g. gyricons, twisting ball displays
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/17—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on variable-absorption elements not provided for in groups G02F1/015 - G02F1/169
    • G02F1/172—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on variable-absorption elements not provided for in groups G02F1/015 - G02F1/169 based on a suspension of orientable dipolar particles, e.g. suspended particles displays
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S101/00—Printing
    • Y10S101/37—Printing employing electrostatic force
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/90—Magnetic feature

Definitions

  • a recording medium which is responsive to a magnetic or an electrostatic field for recording an input signal thereon having a continuous web of an encapsulating or entrapping material containing a suspension of highly reflective flakes. Exposure to a magnetic or an electrostatic field reorients the preoriented flakes to provide a contrast between the exposed portions of the recording medium and the unexposed portions thereof.
  • FIG. 3 fl v v v vrv v v 38/ 3:
  • the present invention relates to a recording medium; and, more particularly, to a recording medium which responds to a force fields for changing the contrast between that portion of the recording medium exposed to the force fields and the unexposed portions thereof.
  • the shutter technique utilizes a recording medium which is coated with a magnetic material and then exposed to a magnetic field.
  • the magnetic field causes particles within the coating to reorient themselves for providing a transparency through the coating material thus establishing a contrast for visualizing the magnetic field.
  • a paper describing this approach was written by: Suchow, Lawrence, New Method for Making Magnetic Fields Visible. Journal of Applied Physics, (Feb. 1958), 223-224.
  • a chemical agent has been encapsulated in capsules having a brittle shell.
  • the chemical agent is magnetostrictive and undergoes a dimensional change when exposed to a magnetic field. This dimensional change ruptures the brittle shell forming the capsules and allows the chemical agent therein to react with the coating material surrounding the capsule for causing a color change and rendering the magnetic field visible.
  • Still another prior art method of obtaining a visual indication of a force field utilizes a thermoplastic film containing flake-like particles.
  • An optical transparency can be produced by heating the film while applying a pattern of electric fields to locally orient the particles. These fields are controlled by an adjacent photoconductive layer, allowing an input optical image to be recorded.
  • a particle recording medium is not available that will provide sufficient visual contrast between the background, or unexposed portions of a recording medium, and the portions thereof exposed to the force field.
  • the main reason for the lack of sufiicient contrast is that the shutter technique relies on the force field, in most cases a magnetic field, to orient the magnetic particles within the capsules such that electromagnetic energy, in the form of visible light, may be transmitted therethrough. This arrangement is insufficient to provide the necessary contrast; and, therefore,
  • the present invention comes about through a realization that the shutter technique is inadequate.
  • the present invention seeks to replace the shutter technique with a more affective technique which provides a higher contrast between the background and that portion of the recording medium which has been exposed to a force field.
  • Another object of the invention presented here provided a recording medium which is responsive to a magnetic or an electrostatic force field and which responds to that force field by producing a recording trace having a substantially high contrast with respect to the background or unexposed portion of the recording medium.
  • Still another object of this invention provides a recording medium which may be immediately imaged to provide a permanent recording of an input signal that is impervious to abrasive mechanical wear or to chemical reaction and which may be easily erased through the use of a reorienting force field.
  • Yet another object of the present invention is to provide a recording apparatus in which the recording medium of the present invention may be utilized.
  • Yet still another object of thepresent invention provides a recording medium which is useful within a recording apparatus to record and visually display input information and to retrieve that recorded information when required for reproducing it as output information.
  • a further object of this invention provides a means for recording upon a recording medium without creating the necessity for contacting that medium and wherein the recording thereon may be erased and reused.
  • Still a further object of the present invention is to provide a recording medium which may be utilized in place of a recording medium normally used with a pen and ink system thereby eliminating the problems associated therewith, such as clogging of the pen and the inconvenience generally associated with the ink.
  • Yet a further object of the present invention is to provide a recording medium which may be utilized within a high frequency recording system wherein the speed of the recording system may be increased through the reduction of the mass of the writing member and the elimination of the frictional contact
  • FIG. 1 is a perspective view, showing the recording medium of the present invention embodied schematically within a recording apparatus for exposing the recording medium to a force field established in the embodiment of a magnetic field;
  • FIG. 2 is an enlarged cross-sectional view of the recording medium useful in explaining the operation of the present invention
  • FIG. 3 is a perspective view, showing a convenient method for preorienting or erasing the recording medium prior to recording or re-recording;
  • FIG. 4 is an enlarged cross-sectional view of an individual capsule and a flake-like particle during the preorienting operation of FIG. 3;
  • FIG. 5 is an enlarged cross-sectional view of an individual reflective flake-like particle embodied within the present invention.
  • FIG. 6 is a cross-sectional view, similar to FIG. 5, showing a second reflective flake-like particle embodied within the present invention
  • FIG. 7 is a cross-sectional view, similar to FIG. 2, showing a second embodiment of the present inventron
  • FIG. 8 is a cross-sectional view, similar to FIG. 7 showing still another embodiment of the present invention.
  • FIG. 9 is a perspective view, showing a recording apparatus which embodies the recording medium of the present invention.
  • FIG. 1 shows a recording medium 10 including a substrate member 12 and a field sensitive web member 14, sensitive to a force field, such as a magnetic or an electrostatic field.
  • the present invention may be practiced without a substrate 12 wherein the field sensitive web member 14 forms a continuous, self supporting web.
  • the substrate 12, when used, may comprise various materials, such as paper, clear plastic, nonmagnetic foil, or magnetic tape. While any of these materials may be utilized within the present invention, the invention will'be described as if the substrate where a clear plastic, such as polyethylene terephthalale.
  • the present invention does not utilize the shutter technique for creating a transparent coating which is contrasted against a base, as in the prior art.
  • the field sensitive web member 14 is formed from transparent material having a multitude of tiny fluid containing chambers 16 in which chambers suspended highly reflective flake-like particles 18.
  • the fluid containing chamber 16 may be formed by entrapping tiny droplets of fluid and particles in a clear resin which may then be coated upon the substrate 12.
  • the fluid containing chambers 16 may also be formed by encapsulating tiny droplets of fluid and particles within individual capsules which may then be coated upon the substrate 12. While other methods are available, the present invention shall describe the field sensitive web member 14 as formed from individual capsules 16. However, it is to be understood that this is not intended to limit the present invention to this arrangement.
  • the flake-like particles 18 may be formed from paramagnetic or ferromagnetic material, such as iron, nickel or stainless steel; from nonmagnetic material such as aluminum; or from a combination of both magnetic and nomnagnetic materials, such as nickel plated aluminum.
  • paramagnetic or ferromagnetic material such as iron, nickel or stainless steel
  • nonmagnetic material such as aluminum
  • a combination of both magnetic and nomnagnetic materials such as nickel plated aluminum.
  • One of the important features of the particles 18 is that they be substantially flake, disc, plate or leaf-shaped and not acicular, as in the prior art.
  • the present invention shall refer to the particles as flakelike particles, but it is to be understood that this is a descriptive term and not meant to limit the flat, broad shape of the material.
  • the flake-like particles range in surface size from to 50 microns with an average thickness of 1 micron.
  • Each flake-like particle therefore has an aspect ratio between 5 to l i.e., the aspect ratio being the ratio of the surface area to the cross-sectional area of a particle, and 50 to l.
  • a second important feature of the flake-like particles is that they are highly reflective. Reflectivity or the reflection coefficient is defined as the ratio of the reflected radiant energy which is reflected from a surface to the total incident radiant energy which strikes that to This coefiicient may refer to diffused or to specular reflection and in general varies with the angle of incidence and with the wavelengths of the ambient light. For example, physics handbooks indicate that the reflectivity of polished nickel varies from 0.37 to 0.95 depending on the wavelength of the normally incident light; while steel varies between 0.33 to 0.93.
  • the flake-like particles should be polished to form a reflective surface having an average reflectivity of 0.4 or more. It is also desirable to describe the contrast of the reflective flake-like particles before and after exposure to a force field.
  • the reflection density (D) may be used:
  • the highly reflective, flake-like particles 18 may be formed into the field sensitive web member 14 by placing the flakes in anencapsulating fluid 20.
  • the encapsulating fluid 20 may be one of several fluids such as water, oil or alcohol.
  • a mixture of oils has been utilized including a mixture of magnaflux oil and airoclor oil. These oils have been mixed to match the index of refraction of the material which forms the capsule wall.
  • the highly reflective flake-like particles 18 are placed within the encapsulating fluid and ball milled with a wetting agent until the flakes and encapsulating fluid are completely mixed.
  • the suspension of flakes and oil is then placed in water. Prior to the addition of the encapsulating materials, the pH of the suspension adjusted to above 9.5 and the temperature raised above the gelation temperature.
  • the encapsulating material is then added and the system agitated until the desired droplet size of the oilin-water emulsion is attained.
  • the pH of this system is then reduced to initiate coacervation between the fractions of the polymers.
  • the encapsulating material may be a gum arabic aqueous solution or a gelatin aqueous solution or both. 7
  • the recording medium 10 is shown schematically as it is rolled upon a takeup roller 21 in the direction of the arrow 22.
  • Recording upon the recording medium 10 may be achieved through several methods for establishing a force field, such as a magnetic or an electrostatic field.
  • a magnetic recording field may be established in several ways, such as: by moving a permanent magnet across the recording medium in response to an input signal, by a multistylus recording head having a single stylus actuated as an input signal varies, by utilizing a magnetic recording head, or by a plurality of light sensitive diodes connected to respective ones of a plurality of individual recording stylii and actuated by a light beam responsive to an input signal for energizing one of the stylii.
  • An electrostatic recording field may be established, for example, by placing a charge upon a probe moving adjacent to the recording medium in response to an input signal.
  • Recording in FIG. 1 is achieved simply by a permanent magnet 23 having a flux field represented schematically by the dashed lines 24.
  • the magnet 23 is shown schematically mounted within a collar 25 attached by a cable 26 to suitable driving pulleys 27.
  • the pulleys 27 are driven in response to an-input signal received by an input device 28 which drives the pulleys through a suitable driving mechanism, shown as a dashed line 29.
  • the flux field 24 penetrates the field sensitive we member 14 for reorienting the preoriented highly reflective flake-like particles 18, which in this embodiment are magnetically sensitive.
  • the contrast or net density difference has been found to be over 0.4; where the contrast or net density difference is defined as the difference in reflection density between the area of the recording medium exposed to the magnetic field and the area of the recording medium which has not been exposed to the magnetic field.
  • the highly reflective magnetic flakelike particles 18 are oriented in a position substantially parallel to the plane of the substrate member 12. Obviously, not all flakes are parallel; but statistically more flakes are oriented parallel to the substrate than are otherwise positioned. This orientation may be achieved by several methods, one of which will be described hereinbelow with regard to FIG. 3.
  • the recording trace illustrated in FIG. 1 is shown having a width indicated by X.
  • the reflective, magnetic flake-like particles 18 are reoriented so that some at the center of the magnetic field are substantially perpendicular to the substrate; while others are oriented at an angle to the substrate.
  • the reflective, magnetic flakes 18 are generally reoriented at an angle to the substrate as they attempt to orient parallel to the lines of flux.
  • Incident light rays 30 striking the surface of the recording medium 10 are reflected by the highly reflective, magnetic flakes 18 and returned as reflected light rays 32 in the areas of the recording medium 10 which have not been exposed to the magnetic field.
  • the incident light rays are scattered by the multiple reflective surfaces of the magnetic flakes 18 into the magnetically sensitive web member 14 and there absorbed. This scattering prevents the light rays from being reflected out of the coating thereby creating a contrast.
  • the trace formed by the magnetic field appears as a dark image on a light background.
  • the trace remains as a permanent dark image thereon and is not destroyed by mechanical abrasion, chemical reaction, or electromagnetic energy, such as visible light.
  • the trace demonstrates a considerable memory. It is believed that this memory is brought about by the simple fact that there are no external force acting on the reflective flakes within the capsules which would create realignment. Another explanation for this phenomenon is that the flake-like particles form overlapping shingle-like formations within the irregularly shaped capsules which frictionally engage the inner surfaces thereof and are not easily dislodged unless reexposed to a second force field. Thus, it has been found that the dark image provided upon the recording medium of the present invention remains until erased by a second force field.
  • a second substrate of magnetic oxide such as a strip of magnetic tape, is not necessary to provide a memory, as in some prior art devices. It has also been found that the present invention will provide a read out similar to magnetic tapes. This phenomenon will be further discussed hereinbelow. 7
  • a means is illustrated for preorienting the highly reflective, magnetic flake-like particles 18 within a plane parallel to the plane of the magnetically sensitive web member 14.
  • a fixedmagnetic field is established parallel to one axis of the substrate 12 by a pair of permanent magnets 34.
  • a second magnetic field is produced which combines with the first field to orient the flakes 18 parallel to both axes of the web member 14 and substrate 12.
  • the second magnetic field is formed by a coil 36 having input terminals 38 across which an A.C. signal is applied.
  • a net magnetic vector in the plane of the web 14 is produced by the combined magnetic fields which vector changes direction in response to the variations in the AC.
  • FIG. 4 illustrates a single fluid containing capsule 16 in which a highly reflective, magnetic flake-like particles 18 have been oriented by the flux fields 40 and 42. The method just described for reorientation of the reflective flake-like particles 18 is also utilized to erase a recording trace once established upon the recording medium 12.
  • the reflective flake-like particles 18 illustrated in FIGS. 1 through 4 may be formed from several magnetic materials, such as iron, nickel or stainless steel, as mentioned hereinabove. Through experimentation it has been found that a reflective magnetic flakeconstructed from nickel produces a better contrast while a reflective flake constructed from stainless steel provides a lighter background. However, aluminum flakes have a significantly higher value of reflectance than those mentioned here. As the reflectance essentially determines the amount of contrast which can be obtained between the trace and the background in the present invention, any improvement is of significant value.
  • FIG. 5 illustrates a cross-sectional view of the reflective flake-like particles 18 shown in FIG. 4. When the force field is established by an electrostatic force, the flakes may be constructed from polished aluminum.
  • a charged probe causes an aluminum flake to act as an electric dipole for reorient ing the flake in the presence of the electrostatic field.
  • aluminum flakes provide a recording trace having a high contrast for recording by use of an electrostatic field, the same electrostatic field will affect the magnetic flakes for providing a recording.
  • the aluminum flakes will not react to a magnetic field. It has been found that the recording medium will react faster to an electrostatic field than a magnetic field. That is, a short electrostatic pulse will cause a trace to appear upon a recording medium before a magnetic pulse of the same duration would create a trace. The reason for this is that an electrostatic pulse creates a charge upon the field sensitive web member 14 which remains after the pulse is removed.
  • a reflective flake-like particle 18 which may be formed from aluminum.
  • This aluminum flake has been rendered magnetic by coating it with a magnetic metal film 43, as by vacuum depositing or electroless plating.
  • the film 43 is arranged a few angstroms thick so as to be thinner than the shortest wavelength of visible light. This arrangement preserves the optical properties of the aluminum while rendering the fake magnetic.
  • the high reflectance of aluminum may be utilized in combination with a magnetic field to provide a high contrast recording trace.
  • the sensitive web member 14 is formed from many spherically shaped encapsulating particles 16. Due to the spherical surfaces of the fluid containing capsules 16, the incident light rays are scattered as they reflect from the highly reflective, flake-like particles 18. This is caused by the refraction as the light passes through the walls of the fluid containing capsules 16. To improve this, a second transparent material is placed over the sensitive coating, thereby sandwiching the coating between two transparent substrates.
  • the transparent coating 44 FIG.
  • a second arrangement for accomplishing the improved contrast of the sandwich configuration is to form the field sensitive web member 14 as a single continuous, self-supporting web having flat surfaces, FIG. 8. That is, the mixture of the encapsulating material and the oil-in-water emulsion is rolled into a flat continuous web before the coacervation between the fraction of the polymers is completed. This allows the capsules to be deformed along the outer surfaces thereof for forming a flat continuous surface.
  • the field, sensitive web member 14 is preoriented to align the highly reflective, flake-like particles 18 contained therein in a plane parallel to the plane of the web.
  • the reflective, flake-like particles 18 are realigned for providing a substantial contrast between the preoriented, reflective area which has not been exposed to the force field and that area which has been exposed.
  • the recording paper of the present invention provides an economical medium, costing less than onehalf a cent per square foot.
  • the recording medium responds quickly to a magnetic or an electrostatic field, in less than 3 microseconds, to provide an immediate indication of an input signal thereon. If an input signal is provided in the form of pulses, a pulse duration of less 1.5 microseconds is required to produce a recording. As indicated hereinabove, this pulse is even shorter if provided by an electrostatic field.
  • the field sensitive recording medium of the present invention may be utilized within several recording apparatus.
  • FIG. 9 One example of such an apparatus is illustrated in FIG. 9.
  • the recording medium is illustrated as a continuous belt which is drawn across a pair of rollers 46 by a suitable driving motor 48 in the direction indicated by arrow 50.
  • a recording head 52 such as a multiple stylus head or a magnetic head, is arranged adjacent to the recording medium 10 for recording an analog input signal thereon which is received from input terminals 54.
  • a second recording head 56 may be arranged for recording alphanumeric characters upon the recording medium 10.
  • the recording head 56 is driven by an amplifier S8 and suitable input means 60.
  • the input means provides a display upon the recording medium which may be retained thereon or erased by an erase head 62, similar to that shown in FIG. 3.
  • the information recorded by the recording head 52 may be read by a reproduce head 64 which provides for retrieval of the recorded input information. Thereafter, the signal may be erased by the erase head 62.
  • the reading of the recording medium may be achieved in a manner similar to magnetic tape. That is, the reorientation of the reflective, magnetic flake-like particles 18 within the recording medium 10 provides a discontinuity within the recording medium which may be detected by the magnetic reproduce head 64. It is believed that the initially oriented particles have a net cancellation of any remnant magnetic field induced in the particles 18 by the orienting field while the reoriented particles forming the recorded display exhibit a remnant magnetic field which is not cancelled by adjacent particles and is externally detectable by the magnetic head 64.
  • the present invention may be utilized to provide a recording medium capable of visually displaying input information and capable of reproducing the input information at a later time.
  • a recording medium for recording an input signal comprising;
  • said continuous web being formed from a transparent material; and highly reflective flake-like particles responsive to force fields contained within said continuous web member;
  • said particles being selectively orientable for reflecting ambient wavelengths of electromagnetic energy from said web member and for scattering said ambient wavelengths of electromagnetic energy into said web member thus forming a contrast between areas of said particles reflecting said electromagnetic energy and areas of said particles scattering said electromagnetic energy;
  • said particles being magnetic particles formed from nonmagnetic material having a high reflectance and said nonmagnetic flake-like particles thus formed coated with a thin layer of magnetic material having a thickness less than the shortest wavelength of said electromagnetic energy.
  • a magnetic recording medium comprising:
  • said continuous web member including individually visible transparent capsule means forming said continuous web member
  • said capsule means containing fluid means
  • r l 1 highly reflective, magnetic and flake-like particles suspended within said fluid means oriented to reflect ambient light from said continuous web member except in the areas thereof exposed to a magnetic field recording on said medium wherein said reflective, magnetic and flake-like are reoriented for scattering said ambient light into said continuous web member thus forming a contrast between said areas of said continuous web member exposed to said magnetic field and the unexposed areas thereof:
  • said particles being formed from a nonmagnetic material having a high reflectance and a coating on said material of a thin layer of magnetic material having a thickness less than the shortest wavelength of said ambient light.
  • said web member being formed from transparent material having a plurality of discreet cavities uniformly distributed therein;
  • each of said cavities being completely filled with only a suspension of a plurality of said particles
  • said particles being selectively reorientable by said force field for absorbing said incident wavelengths into said web member to form a contrast between the areas of said web member exposed to said force field and the unexposed areas thereof.
  • a recorder for recording an input signal on a web member having force field responsive, highly reflective, and flake-like particles suspended within said web member comprising:
  • a recorder as 'set forth in claim 6 wherein said means for producing a first field includes means for producing said first field as a fixed predetermined field in the plane of said web member.
  • said means for generating a particle orienting field includes a means for producing a first field within said web member in the area of said flake-like particles and having all field components parallel to the plane of said web member and a means for producing a second field having a component with a periodically varying amplitude and .direction within said web member in the area of said flakelike particles, said component of said second field combining with said first field to form a net field vector having a plane of rotation wholly within said plane of said web member to preorient said particles and an electrostatic charge.
  • a recorder as claimed in claim 11 wherein said means for generating a force field is a magnetic recording head.
  • said continuous web being fonned from a transparent material having a plurality of cavities therein,

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Molecular Biology (AREA)
  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
  • Manufacturing Of Magnetic Record Carriers (AREA)
  • Magnetic Record Carriers (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)
  • Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
  • Paints Or Removers (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)
  • Toys (AREA)
  • Photoreceptors In Electrophotography (AREA)
US861019A 1969-05-29 1969-09-25 Recording medium responsive to force fields and apparatus for recording and reproducing signals on the medium Expired - Lifetime US3683382A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US82899369A 1969-05-29 1969-05-29
US86101969A 1969-09-25 1969-09-25

Publications (1)

Publication Number Publication Date
US3683382A true US3683382A (en) 1972-08-08

Family

ID=27125234

Family Applications (1)

Application Number Title Priority Date Filing Date
US861019A Expired - Lifetime US3683382A (en) 1969-05-29 1969-09-25 Recording medium responsive to force fields and apparatus for recording and reproducing signals on the medium

Country Status (6)

Country Link
US (1) US3683382A (enExample)
JP (2) JPS4841221B1 (enExample)
CA (1) CA919764A (enExample)
FR (1) FR2048956A5 (enExample)
GB (2) GB1319047A (enExample)
SE (2) SE363169B (enExample)

Cited By (51)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3803633A (en) * 1972-03-10 1974-04-09 Bell & Howell Co Methods, apparatus and media for magnetically recording information
US3810191A (en) * 1972-10-26 1974-05-07 Honeywell Inc Multi-stylus through field recording head
US3846830A (en) * 1971-10-21 1974-11-05 Honeywell Inc Recording and playback apparatus
US3927930A (en) * 1972-07-10 1975-12-23 Polaroid Corp Light polarization employing magnetically oriented ferrite suspensions
US3947879A (en) * 1974-12-04 1976-03-30 Honeywell Inc. Multi-color recording medium responsive to force fields and apparatus for recording on the medium
US3998160A (en) * 1974-04-17 1976-12-21 Emi Limited Magnetic ink printing method
US4054922A (en) * 1975-05-09 1977-10-18 Kienzle Apparate Gmbh Apparatus for forming an erasable record of the value of a measured quantity
US4125844A (en) * 1976-01-15 1978-11-14 U.S. Philips Corporation Magnetic position marker for a tape recorder using magnetically alignable particles for making the mark
US4203419A (en) * 1976-01-07 1980-05-20 Honeywell Inc. Solar cell
US4326812A (en) * 1979-07-20 1982-04-27 Ing. C. Olivetti & C., S.P.A. Non impact printer
US4366488A (en) * 1980-04-02 1982-12-28 Northern Telecom Limited Read/write arrangement for a magnetic terminal
US4392755A (en) * 1982-02-10 1983-07-12 Extel Corporation Magnetic dot matrix printing
US4392754A (en) * 1982-02-10 1983-07-12 Extel Corporation Magnetic dot matrix printing method and apparatus
US4457723A (en) * 1981-06-11 1984-07-03 Thalatta, Inc. Color changeable fabric
US4659619A (en) * 1981-06-11 1987-04-21 Thalatta, Inc. Color changeable fabric
WO1990003018A1 (en) * 1988-09-01 1990-03-22 Raychem Corporation Indicator for indicating operating state of a device
US5018979A (en) * 1989-11-16 1991-05-28 The Ohio Art Company Magnetic visual display
US5295837A (en) * 1989-11-16 1994-03-22 The Ohio Art Company Magnetic visual display
US5382963A (en) * 1992-09-21 1995-01-17 Xerox Corporation Ink jet printer for magnetic image character recognition printing
EP0556449B1 (en) * 1992-02-21 1997-03-26 Hashimoto Forming Industry Co., Ltd. Painting with magnetically formed pattern and painted product with magnetically formed pattern
WO2000054101A1 (fr) * 1999-03-05 2000-09-14 Seiko Epson Corporation Afficheur pour electrophorese et son procede de production
WO2003035279A1 (en) 2001-10-19 2003-05-01 Superior Micropowders Llc Tape compositions for the deposition of electronic features
WO2003048867A1 (de) * 2001-12-05 2003-06-12 Daniel Bossert Druckverfahren
US20030108664A1 (en) * 2001-10-05 2003-06-12 Kodas Toivo T. Methods and compositions for the formation of recessed electrical features on a substrate
US20030112491A1 (en) * 1995-07-20 2003-06-19 E Ink Corporation Non-spherical cavity electrophoretic displays and methods and materials for making the same
US20030124259A1 (en) * 2001-10-05 2003-07-03 Kodas Toivo T. Precursor compositions for the deposition of electrically conductive features
US20030148024A1 (en) * 2001-10-05 2003-08-07 Kodas Toivo T. Low viscosity precursor compositons and methods for the depositon of conductive electronic features
US20030161959A1 (en) * 2001-11-02 2003-08-28 Kodas Toivo T. Precursor compositions for the deposition of passive electronic features
US20030175411A1 (en) * 2001-10-05 2003-09-18 Kodas Toivo T. Precursor compositions and methods for the deposition of passive electrical components on a substrate
US20030180451A1 (en) * 2001-10-05 2003-09-25 Kodas Toivo T. Low viscosity copper precursor compositions and methods for the deposition of conductive electronic features
US6753830B2 (en) 1998-09-11 2004-06-22 Visible Tech-Knowledgy, Inc. Smart electronic label employing electronic ink
US6776438B2 (en) 2001-08-01 2004-08-17 Hewlett-Packard Development Company, L.P. Magnetic printing media for inkjet and laserjet
US6924781B1 (en) 1998-09-11 2005-08-02 Visible Tech-Knowledgy, Inc. Smart electronic label employing electronic ink
US7116466B2 (en) 2004-07-27 2006-10-03 E Ink Corporation Electro-optic displays
US20070115337A1 (en) * 2005-11-18 2007-05-24 Jds Uniphase Corporation Magnetic Plate For Printing Of Optical Effects
US20080008822A1 (en) * 2001-10-05 2008-01-10 Cabot Corporation Controlling ink migration during the formation of printable electronic features
US7533361B2 (en) 2005-01-14 2009-05-12 Cabot Corporation System and process for manufacturing custom electronics by combining traditional electronics with printable electronics
US7575621B2 (en) 2005-01-14 2009-08-18 Cabot Corporation Separation of metal nanoparticles
US7621976B2 (en) 1997-02-24 2009-11-24 Cabot Corporation Coated silver-containing particles, method and apparatus of manufacture, and silver-containing devices made therefrom
US20110162873A1 (en) * 1997-02-24 2011-07-07 Cabot Corporation Forming conductive features of electronic devices
US8167393B2 (en) 2005-01-14 2012-05-01 Cabot Corporation Printable electronic features on non-uniform substrate and processes for making same
US8334464B2 (en) 2005-01-14 2012-12-18 Cabot Corporation Optimized multi-layer printing of electronics and displays
US8383014B2 (en) 2010-06-15 2013-02-26 Cabot Corporation Metal nanoparticle compositions
US8597397B2 (en) 2005-01-14 2013-12-03 Cabot Corporation Production of metal nanoparticles
US20140111296A1 (en) * 2012-10-24 2014-04-24 Correlated Magnetics Research, Llc System and method for producing magnetic structures
US20140211360A1 (en) * 2009-06-02 2014-07-31 Correlated Magnetics Research, Llc System and method for producing magnetic structures
DE102013015277A1 (de) 2013-09-16 2015-03-19 Schwarz Druck GmbH Orientierung magnetisch orientierbarer Partikel in einer Farbe mit mehreren einander überlagerten Magnetfeldern
US10545622B2 (en) 2016-05-20 2020-01-28 E Ink Corporation Magnetically-responsive display including a recording layer configured for local and global write/erase
US20200085024A1 (en) * 2018-09-13 2020-03-19 Newtonoid Technologies, L.L.C. Static programmable electro-chromic fishing lure
US11221685B2 (en) 2018-12-21 2022-01-11 E Ink Corporation Sub-threshold addressing and erasing in a magneto-electrophoretic writing medium
US11230127B2 (en) 2002-07-15 2022-01-25 Viavi Solutions Inc. Method and apparatus for orienting magnetic flakes

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5725811B2 (enExample) * 1973-10-19 1982-06-01
US4063296A (en) * 1974-07-08 1977-12-13 Simrad A.S. Method and means for erasing recordings on magnetic paper, particularly for distance measuring equipment
AT343928B (de) * 1976-01-15 1978-06-26 Philips Nv Aufzeichnungs- und oder wiedergabegerat und kassette fur einen aufzeichnungstrager fur ein solches gerat
US5006422A (en) * 1987-08-06 1991-04-09 The Nippon Signal Co., Ltd. Visual magnetic recording medium and method of making the same
US5463492A (en) * 1991-11-01 1995-10-31 Research Frontiers Incorporated Light modulating film of improved clarity for a light valve
DE69232882T2 (de) * 1991-11-01 2003-10-30 Research Frontiers Inc., Woodbury Lichtventil mit einem, eine eingekapselte, flüssige suspension enthaltenden film und herstellungsverfahren für diesen film
US5463491A (en) * 1991-11-01 1995-10-31 Research Frontiers Incorporated Light valve employing a film comprising an encapsulated liquid suspension, and method of making such film
KR960014118B1 (ko) * 1992-01-10 1996-10-14 한국유리공업 주식회사 광편광현탁액이 고분자수지내에 분산된 투과도 가변창용 필름 및 그 제조방법

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2418479A (en) * 1944-02-16 1947-04-08 Du Pont Process for orienting ferromagnetic flakes in paint films
GB830736A (en) * 1958-08-25 1960-03-16 Ernst Voelk An improved magnetic recording and reproducing method and an apparatus for carrying out such method
US2971916A (en) * 1957-01-30 1961-02-14 Ncr Co Microscopic capsules containing magnetizable material
US3013206A (en) * 1958-08-28 1961-12-12 Minnesota Mining & Mfg Magnetic reader
US3106607A (en) * 1960-12-15 1963-10-08 Ampex Apparatus for recording and reproducing images on magnetic tape
US3117065A (en) * 1959-09-02 1964-01-07 Magnetic Film And Tape Company Method and apparatus for making magnetic recording tape
US3171106A (en) * 1961-02-27 1965-02-23 Gen Electric Information storage system
US3181059A (en) * 1961-10-02 1965-04-27 Gerald L Mohnkern Optical polarity indicator for magnetically recorded signals
US3221315A (en) * 1962-06-25 1965-11-30 Ncr Co Magnetic recording medium utilizing microscopic capsules containing magnetic material
US3320523A (en) * 1965-02-01 1967-05-16 Lyne S Trimble Method for visibly indicating and recording magnetic fields
US3370132A (en) * 1963-03-28 1968-02-20 Andrew E. Flanders Polarized magnetic recording

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR767181A (fr) * 1933-01-16 1934-07-12 Soupape à lumière et procédé de fonctionnement
FR1536032A (fr) * 1967-09-06 1968-08-09 Dispositif de réglage de la lumière sensible à l'électricité

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2418479A (en) * 1944-02-16 1947-04-08 Du Pont Process for orienting ferromagnetic flakes in paint films
US2971916A (en) * 1957-01-30 1961-02-14 Ncr Co Microscopic capsules containing magnetizable material
GB830736A (en) * 1958-08-25 1960-03-16 Ernst Voelk An improved magnetic recording and reproducing method and an apparatus for carrying out such method
US3013206A (en) * 1958-08-28 1961-12-12 Minnesota Mining & Mfg Magnetic reader
US3117065A (en) * 1959-09-02 1964-01-07 Magnetic Film And Tape Company Method and apparatus for making magnetic recording tape
US3106607A (en) * 1960-12-15 1963-10-08 Ampex Apparatus for recording and reproducing images on magnetic tape
US3171106A (en) * 1961-02-27 1965-02-23 Gen Electric Information storage system
US3181059A (en) * 1961-10-02 1965-04-27 Gerald L Mohnkern Optical polarity indicator for magnetically recorded signals
US3221315A (en) * 1962-06-25 1965-11-30 Ncr Co Magnetic recording medium utilizing microscopic capsules containing magnetic material
US3370132A (en) * 1963-03-28 1968-02-20 Andrew E. Flanders Polarized magnetic recording
US3320523A (en) * 1965-02-01 1967-05-16 Lyne S Trimble Method for visibly indicating and recording magnetic fields

Cited By (78)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3846830A (en) * 1971-10-21 1974-11-05 Honeywell Inc Recording and playback apparatus
US3803633A (en) * 1972-03-10 1974-04-09 Bell & Howell Co Methods, apparatus and media for magnetically recording information
US3927930A (en) * 1972-07-10 1975-12-23 Polaroid Corp Light polarization employing magnetically oriented ferrite suspensions
US3810191A (en) * 1972-10-26 1974-05-07 Honeywell Inc Multi-stylus through field recording head
US3998160A (en) * 1974-04-17 1976-12-21 Emi Limited Magnetic ink printing method
US3947879A (en) * 1974-12-04 1976-03-30 Honeywell Inc. Multi-color recording medium responsive to force fields and apparatus for recording on the medium
US4054922A (en) * 1975-05-09 1977-10-18 Kienzle Apparate Gmbh Apparatus for forming an erasable record of the value of a measured quantity
US4203419A (en) * 1976-01-07 1980-05-20 Honeywell Inc. Solar cell
US4125844A (en) * 1976-01-15 1978-11-14 U.S. Philips Corporation Magnetic position marker for a tape recorder using magnetically alignable particles for making the mark
US4326812A (en) * 1979-07-20 1982-04-27 Ing. C. Olivetti & C., S.P.A. Non impact printer
US4366488A (en) * 1980-04-02 1982-12-28 Northern Telecom Limited Read/write arrangement for a magnetic terminal
US4457723A (en) * 1981-06-11 1984-07-03 Thalatta, Inc. Color changeable fabric
US4659619A (en) * 1981-06-11 1987-04-21 Thalatta, Inc. Color changeable fabric
US4392755A (en) * 1982-02-10 1983-07-12 Extel Corporation Magnetic dot matrix printing
US4392754A (en) * 1982-02-10 1983-07-12 Extel Corporation Magnetic dot matrix printing method and apparatus
WO1990003018A1 (en) * 1988-09-01 1990-03-22 Raychem Corporation Indicator for indicating operating state of a device
US5112229A (en) * 1989-11-16 1992-05-12 The Ohio Art Company Magnetic visual display
US5018979A (en) * 1989-11-16 1991-05-28 The Ohio Art Company Magnetic visual display
US5295837A (en) * 1989-11-16 1994-03-22 The Ohio Art Company Magnetic visual display
WO1991007287A1 (en) * 1989-11-16 1991-05-30 The Ohio Art Company Magnetic visual display
EP0556449B1 (en) * 1992-02-21 1997-03-26 Hashimoto Forming Industry Co., Ltd. Painting with magnetically formed pattern and painted product with magnetically formed pattern
US5630877A (en) * 1992-02-21 1997-05-20 Hashimoto Forming Industry Co., Ltd. Painting with magnetically formed pattern and painted product with magnetically formed pattern
US5382963A (en) * 1992-09-21 1995-01-17 Xerox Corporation Ink jet printer for magnetic image character recognition printing
US7746544B2 (en) 1995-07-20 2010-06-29 E Ink Corporation Electro-osmotic displays and materials for making the same
US7109968B2 (en) * 1995-07-20 2006-09-19 E Ink Corporation Non-spherical cavity electrophoretic displays and methods and materials for making the same
US8593718B2 (en) 1995-07-20 2013-11-26 E Ink Corporation Electro-osmotic displays and materials for making the same
US7391555B2 (en) 1995-07-20 2008-06-24 E Ink Corporation Non-spherical cavity electrophoretic displays and materials for making the same
US20030112491A1 (en) * 1995-07-20 2003-06-19 E Ink Corporation Non-spherical cavity electrophoretic displays and methods and materials for making the same
US8333820B2 (en) 1997-02-24 2012-12-18 Cabot Corporation Forming conductive features of electronic devices
US7621976B2 (en) 1997-02-24 2009-11-24 Cabot Corporation Coated silver-containing particles, method and apparatus of manufacture, and silver-containing devices made therefrom
US20110162873A1 (en) * 1997-02-24 2011-07-07 Cabot Corporation Forming conductive features of electronic devices
US6924781B1 (en) 1998-09-11 2005-08-02 Visible Tech-Knowledgy, Inc. Smart electronic label employing electronic ink
US6753830B2 (en) 1998-09-11 2004-06-22 Visible Tech-Knowledgy, Inc. Smart electronic label employing electronic ink
US6597340B1 (en) 1999-03-05 2003-07-22 Seiko Epson Corporation Electrophoresis display and its production method
WO2000054101A1 (fr) * 1999-03-05 2000-09-14 Seiko Epson Corporation Afficheur pour electrophorese et son procede de production
US6776438B2 (en) 2001-08-01 2004-08-17 Hewlett-Packard Development Company, L.P. Magnetic printing media for inkjet and laserjet
US6951666B2 (en) 2001-10-05 2005-10-04 Cabot Corporation Precursor compositions for the deposition of electrically conductive features
US20030148024A1 (en) * 2001-10-05 2003-08-07 Kodas Toivo T. Low viscosity precursor compositons and methods for the depositon of conductive electronic features
US20030175411A1 (en) * 2001-10-05 2003-09-18 Kodas Toivo T. Precursor compositions and methods for the deposition of passive electrical components on a substrate
US20030108664A1 (en) * 2001-10-05 2003-06-12 Kodas Toivo T. Methods and compositions for the formation of recessed electrical features on a substrate
US20070117271A1 (en) * 2001-10-05 2007-05-24 Cabot Corporation Methods and compositions for the formation of recessed electrical features on a substrate
US20030124259A1 (en) * 2001-10-05 2003-07-03 Kodas Toivo T. Precursor compositions for the deposition of electrically conductive features
US20070120098A1 (en) * 2001-10-05 2007-05-31 Cabot Corporation Low viscosity precursor compositions and methods for the deposition of conductive electronic features
US20070120099A1 (en) * 2001-10-05 2007-05-31 Cabot Corporation Low viscosity precursor compositions and methods for the deposition of conductive electronic features
US20070125989A1 (en) * 2001-10-05 2007-06-07 Cabot Corporation Low viscosity precursor compositions and methods for the deposition of conductive electronic features
US20030180451A1 (en) * 2001-10-05 2003-09-25 Kodas Toivo T. Low viscosity copper precursor compositions and methods for the deposition of conductive electronic features
US20080008822A1 (en) * 2001-10-05 2008-01-10 Cabot Corporation Controlling ink migration during the formation of printable electronic features
US20080093422A1 (en) * 2001-10-05 2008-04-24 Cabot Corporation Low viscosity precursor compositions and methods for the deposition of conductive electronic features
US7629017B2 (en) 2001-10-05 2009-12-08 Cabot Corporation Methods for the deposition of conductive electronic features
US7524528B2 (en) 2001-10-05 2009-04-28 Cabot Corporation Precursor compositions and methods for the deposition of passive electrical components on a substrate
US7732002B2 (en) 2001-10-19 2010-06-08 Cabot Corporation Method for the fabrication of conductive electronic features
WO2003035279A1 (en) 2001-10-19 2003-05-01 Superior Micropowders Llc Tape compositions for the deposition of electronic features
US20100112195A1 (en) * 2001-10-19 2010-05-06 Kodas Toivo T Method for the fabrication of conductive electronic features
US7553512B2 (en) 2001-11-02 2009-06-30 Cabot Corporation Method for fabricating an inorganic resistor
US20030161959A1 (en) * 2001-11-02 2003-08-28 Kodas Toivo T. Precursor compositions for the deposition of passive electronic features
WO2003048867A1 (de) * 2001-12-05 2003-06-12 Daniel Bossert Druckverfahren
US11230127B2 (en) 2002-07-15 2022-01-25 Viavi Solutions Inc. Method and apparatus for orienting magnetic flakes
US7304787B2 (en) 2004-07-27 2007-12-04 E Ink Corporation Electro-optic displays
US7116466B2 (en) 2004-07-27 2006-10-03 E Ink Corporation Electro-optic displays
US7575621B2 (en) 2005-01-14 2009-08-18 Cabot Corporation Separation of metal nanoparticles
US7749299B2 (en) 2005-01-14 2010-07-06 Cabot Corporation Production of metal nanoparticles
US8167393B2 (en) 2005-01-14 2012-05-01 Cabot Corporation Printable electronic features on non-uniform substrate and processes for making same
US8334464B2 (en) 2005-01-14 2012-12-18 Cabot Corporation Optimized multi-layer printing of electronics and displays
US7533361B2 (en) 2005-01-14 2009-05-12 Cabot Corporation System and process for manufacturing custom electronics by combining traditional electronics with printable electronics
US8597397B2 (en) 2005-01-14 2013-12-03 Cabot Corporation Production of metal nanoparticles
US8668848B2 (en) 2005-01-14 2014-03-11 Cabot Corporation Metal nanoparticle compositions for reflective features
US7717038B2 (en) * 2005-11-18 2010-05-18 Jds Uniphase Corporation Magnetic plate for printing of optical effects
US20070115337A1 (en) * 2005-11-18 2007-05-24 Jds Uniphase Corporation Magnetic Plate For Printing Of Optical Effects
US20140211360A1 (en) * 2009-06-02 2014-07-31 Correlated Magnetics Research, Llc System and method for producing magnetic structures
US8383014B2 (en) 2010-06-15 2013-02-26 Cabot Corporation Metal nanoparticle compositions
US20140111296A1 (en) * 2012-10-24 2014-04-24 Correlated Magnetics Research, Llc System and method for producing magnetic structures
DE102013015277B4 (de) * 2013-09-16 2016-02-11 Schwarz Druck GmbH Orientierung magnetisch orientierbarer Partikel in einer Farbe mit mehreren einander überlagerten Magnetfeldern
DE102013015277A1 (de) 2013-09-16 2015-03-19 Schwarz Druck GmbH Orientierung magnetisch orientierbarer Partikel in einer Farbe mit mehreren einander überlagerten Magnetfeldern
US10545622B2 (en) 2016-05-20 2020-01-28 E Ink Corporation Magnetically-responsive display including a recording layer configured for local and global write/erase
US20200085024A1 (en) * 2018-09-13 2020-03-19 Newtonoid Technologies, L.L.C. Static programmable electro-chromic fishing lure
US11221685B2 (en) 2018-12-21 2022-01-11 E Ink Corporation Sub-threshold addressing and erasing in a magneto-electrophoretic writing medium
US11614809B2 (en) 2018-12-21 2023-03-28 E Ink Corporation Sub-threshold addressing and erasing in a magneto-electrophoretic writing medium
US11934593B2 (en) 2018-12-21 2024-03-19 E Ink Corporation Sub-threshold addressing and erasing in a magneto-electrophoretic writing medium

Also Published As

Publication number Publication date
JPS4841221B1 (enExample) 1973-12-05
GB1306981A (en) 1973-02-14
SE363169B (enExample) 1974-01-07
DE2065641B2 (de) 1976-09-16
CA919764A (en) 1973-01-23
DE2025409A1 (de) 1970-12-03
SE385243B (sv) 1976-06-14
DE2065641A1 (de) 1974-10-17
FR2048956A5 (enExample) 1971-03-19
GB1319047A (en) 1973-05-31
DE2025409B2 (de) 1975-10-09
JPS4946943B1 (enExample) 1974-12-12

Similar Documents

Publication Publication Date Title
US3683382A (en) Recording medium responsive to force fields and apparatus for recording and reproducing signals on the medium
US3845499A (en) Apparatus for orienting magnetic particles having a fixed and varying magnetic field component
US3221315A (en) Magnetic recording medium utilizing microscopic capsules containing magnetic material
US5006422A (en) Visual magnetic recording medium and method of making the same
JPS5853401B2 (ja) 検出可能なパタ−ンをもつ表面を有する材料層
US3320523A (en) Method for visibly indicating and recording magnetic fields
US3986206A (en) Magnetic recording medium with highly anisotropic particles
US3512170A (en) Thermomagnetic recording and copying method and system
US3245062A (en) Magnetic annealing for information storage
JP2553862B2 (ja) 可視磁気記録シ−ト
US3757353A (en) Information recording by article orientation
US3311903A (en) Process for formation of deformation images in a thermoplastic magnetizable record medium
JP3022749B2 (ja) 磁気記録媒体の製造方法
Bate et al. An experiment on the effect of particle orientation on peak shift in magnetic tapes
CA2080981C (en) Magneto-optical recording method and magneto-optical memory device
Imamura et al. Recording characteristics in magnetography by optical writing
JP2575225B2 (ja) 磁気記録媒体
JP2632275B2 (ja) 磁気記録媒体の製造方法
CA1172894A (en) Process for generating a latent magnetic image
JPH0692078A (ja) 立体磁気記録カード
JP2554078B2 (ja) 磁気記録媒体およびその再生方法
SU1030767A1 (ru) Магнито-оптический носитель записи
JP3192633B2 (ja) 磁気記録媒体及び磁気記録媒体の固定情報の再生方法
JPH09274461A (ja) 磁気表示カード
JPH07287537A (ja) 可視磁気記録媒体