US3743382A - Method, material and apparatus for increasing and decreasing the transmission of radiation - Google Patents

Method, material and apparatus for increasing and decreasing the transmission of radiation Download PDF

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Publication number
US3743382A
US3743382A US00133205A US3743382DA US3743382A US 3743382 A US3743382 A US 3743382A US 00133205 A US00133205 A US 00133205A US 3743382D A US3743382D A US 3743382DA US 3743382 A US3743382 A US 3743382A
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transmission
suspension
radiation
level
spectrum
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P Rosenberg
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Research Frontiers Inc
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Research Frontiers Inc
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Assigned to RESEARCH FRONTIERS INCORPORATED, A CORP. OF DE reassignment RESEARCH FRONTIERS INCORPORATED, A CORP. OF DE MERGER (SEE DOCUMENT FOR DETAILS). 9-19-89 - DE Assignors: RESEARCH FRONTIERS INCORPORATED, A NY CORP.
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    • 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

Definitions

  • FIGA A first figure.
  • control devices include mechanical shutters, iris diaphrams of variable opening, wedge shaped filters of variable thickness, liquid crystal light valves, Kerr cells and variable density light valves of the kind which use suspensions of particles in a fluid.
  • control devices When the last-mentioned control devices are opened or partially opened, or operated to increase the transmission of radiation, the transmission is increased simultaneously for all wavelengths, frequencies, and colors, even though the amount of the increase is different for different wavelengths, frequen cies or colors.
  • these control devices are closed or partially closed, or otherwise operated to decrease the transmission of radiation, the transmission is decreased simultaneously for all wavelengths, frequencies or colors, even though the amount of decrease is different for different wavelengths, frequencies or colors.
  • control devices have the effect of either increasing the transmission at all wavelengths or decreasing the transmission at all wavelengths. They cannot be used to'decrease the transmission at some wavelengths and to increase the transmission at other wavelengths. These devices cannot substantially attenuate one color while letting another one pass through, but can only be used to substantially block out all colors (all wavelengths) or none at all.
  • Such a valve that can selectively filter certain wavelengths and transmit others would have substantial use in many industries.
  • a filtering valve such as this can be used in film printing and developing to surpress certain colors while enhancing others.
  • a light valve which acts as an inexpensive filter to filter out certain colors while increasing the transmission of others.
  • FIG. 1 is a graph plotting transmission vs. wavelength for a device of the PRIOR ART.
  • FIG. 2 is a graph plotting transmission vs. wavelengths for the device of this invention.
  • FIG. 3 is a perspective view of the light valve of FIG. 1.
  • FIG. 4 is a cross-sectional view of the valve of FIG. I.
  • the aforesaid Application discloses light valves having thin, transparent walls constructed of flat glass or similar material and separated by a small gap which is filled with a fluid suspension containing small particles distributed therein. These particles will align themselves when a field is placed across the suspension.
  • a thin layer of transparent, conductive material is coated on the inner side of each sheet of glass, either in contact with the substance, or spaced from the substance by a thin, transparent, non-conducting layer.
  • the conductive layers are connected to an energy source by suitable wiring.
  • FIG. I is a graph showing wavelength vs. transmission for a valve of the prior art, a valve containing a suspension where increasing voltage causes increasing transmission, such as the valves discussed in the above Patent Application.
  • wavelength in Angstrom units is plotted along the X axis
  • increasing transmission is plotted along the Y axis.
  • the straight line 1 on the graph represents the transmission of radiation through the valve when no activating voltage is applied to the conductive surfaces. For ease in description, this line has been normalized to the same level of transmission for all wavelengths (20 percent transmission). It will be appreciated that the transmission through the valve in the off condition is not necessarily zero and that is the reason why straight line I is not shown at the position of zero transmission.
  • the curves 2, 3 and 4 represent transmission through the above prior art valves with applied voltages.
  • Curve 2 in FIG. 1 represents the transmission of radiation through the valve at one activating voltage and frequency.
  • Curve 3 represents the transmission of radiation at another voltage and frequency, and curve 4 represents the transmission and still another activating voltage and frequency.
  • the curves are such that when the voltages are increased or decreased, the transmission of radiation at all wavelengths are either all increased simultaneously or decreased simultaneously. These curves uniformly increase and decrease; they never cross each other and they never go below-the straight line (representing the inactivated condition of the valve). The transmission at any wavelength increases as the voltage increases.
  • the transmission of light at that wavelength is greater with a greater applied voltage.
  • the dotted line at 6,000 Angstroms intersects line 4 at a greater transmission value than where it intersects line 2.
  • the transmission is always greater as the applied voltage is increased and the transmission is always greater when a voltage is applied then when no voltage is applied at all (the straight line).
  • the valve When these prior art valves are activated by any applied voltage, the valve becomes optically less dense (transmits more light through it) than when no voltage is applied and this occurs throughout all wavelengths. Still another way of starting this would be to say that density ratio of the prior art valves is always greater than unity.
  • the density ratio is the ratio of the optical density of the light valve in the inactivated condition, to the optical density in the activated condition.
  • FIG. 2 is a graph showing the transmission of a typical light valve in accordance with the present invention; a light valve, which when it is activated, increases the transmission of radiation through it in one part of the spectrum and decreases the transmission through it in another part of the spectrum.
  • percent transmission of radiation is plotted along the Y axis and the wavelength in Angstrom units is plotted along the X axis. This curve is for Example I, which is discussed hereinafter.
  • the straight line 12 in the figure represents the transmission of the inactivated valve normalized to the same transmission for all wavelengths percent). It is not actually the same for all wavelengths in the inactivated state, but for ease in illustration transmission for all wavelengths has been normalized to the same value and transmission in the activated state has been correspondingly changed.
  • the curve represents light transmission of a light valve with an applied voltage of 1,000 volts at a frequency of I kilohertz as discussed in Example I. It will be seen from this graph that when voltage is applied, the transmission in one part of the spectrum (below 4,900 Angstroms) increases above the transmission for the inactivated valve and in another part of the spectrum (above 4,900 Angstroms) decreases below the transmission for the inactivated valve. There is also a point at about 4,900 Angstroms (for this example) where transmission is the same in both the activated and inactivated states. At this point, which is referred to as the crossing point, activating the valve will have no effect on transmission through the valve.
  • the density ratio is greater than unity in one portion of the spectrum (e.g. the blue-violet region) and is less than unity in another portion of the spectrum, (e.g. the green-yellow-orange and red region).
  • the valve then transmits more light in one region when it is activated than when it is inactivated, and transmits less light in another region when it is activated than when it is inactivated.
  • the suspension may be a liquid or a gas, however,
  • the particles may be of any shape.
  • One preferred shape is an elongated rod with a ratio of length to cross-sectional diameter of about 25 to I.
  • ratios may vary from 3 or 4 to l to 50 to or 200 to 1.
  • Titanium dioxide which is used for the particles has a dielectic constant of approximately and two commonly used suspending fluids for titanium dioxide, toluene and isopentyl acetate have dielectic constants of approximately 2 and 5, to result in ratios of about 85 to l, or 34 to I.
  • suspending fluids of high viscosity cause the particles to remain suspended for a longer time.
  • suspensions in high viscosity fluids seem to be slower to react to an activating electric voltage, i.e. a high viscosity suspension is slower to act when an electric field is applied than a lower viscosity suspension.
  • this is not a problem in most applicain a cell.
  • the cell was composed of two sheets of glass, each coated with a thin layer of conductive material, and spaced 33 millimeters apart and held together by a sealant in the same manner as previously described 1 micron) was added to a mixture of isopentyl acetate and nitrocellulose with the latter added to minimize the tions since light valves of the kind described in the in- 5 and as shown in FIG. 3.
  • After the suspension was vention can act in times less than 2 milliseconds. It is placed in the cell, 1000 volts at the frequency of 125 also desirable that the particles and fluid of the suspenkilohertz was applied across the suspension and a tungsion be chemically stable and inert and that they do not ston filament lamp was placed on one side of the cell.
  • the particles include metal oxides, metal salts, alkali hatransmission through the cell when it is activated (on) lides, and alkali oxides.
  • Some of these materials that 20 is less in one region (between 4900 and 7000 Angare particularly useful are: an oxide of titanium, TiO,; stroms) than when the cell is inactivated (off); and the an oxide of iron, Fe O -H O; and the salt of cobalt, transmission is greater when activated than when inac- CoAl O., cobalt aluminate. tivated in another region (3500 to 4900 Angstroms.
  • EXAMPLE lll Cobalt aluminate was added to a mixture of nitrocellulose and isopentyl acetate in the same manner as with Examples l and ll with cobalt aluminate being substituted for titanium dioxide and iron oxide in those examples.
  • the entire procedure was the same as that of Examples l and II, with the same proportions and the same cell being used with the following results (with the readings in optical density).
  • suspensions of two or more types of particles having different results can be used in the same suspending fluid. They can also be used in mixtures or solutions of two or more fluids.
  • This will produce light valves that have combinations and modifications of the control effects of each individual suspension.
  • An example of this is to mix TiO with Fe O H O to form the suspension. This mixture is then suspended in isopentyl acetate with a protective colloid such as the aforementioned nitrocellulose. The effect of this is to produce a light valve which has a curve of transmission vs. wavelength such as to combine the separate effects of TiO and Fe o H 0 and produce results which fall between the curves of each of the two individual ingrediants.
  • one or more suspensions of the above substances can be combined, mixed, or dispersed into one or more of the suspensions of the conventional substances, such as herapathite, as described in the aforesaid application, Ser. No. 25,541, to make light valves that produce combinations of the effect of the light valve of this invention and the light valves using conventional suspensions.
  • the conventional substances such as herapathite
  • titanium dioxide can be mixed with herapathite
  • iron oxide can be combined with herapathite.
  • valves of this invention can also be used in combination with conventional filters, as for example, the Wratten filters, manufactured by Eastman Kodak Company of Rochester, New York, to create other filtering effects.
  • a filter 8 can be inserted in front of the light valve to filter I out all wavelengths shorter than those of the crossing point (namely, all wavelengths to the left of the wavelengths at which the curve crosses the horizontal straight line) as shown in FIG. 2.
  • the wavelengths longer than 4900 will be able to pass through the valve.
  • those wavelengths FIG. 2 i.e. wavelengths longer than those of the crossing point.
  • the part of the spectrum remaining will then act in a fashion similar to a conventional prior art light valve increasing transmission with increasing voltage. This will have the advantage of a high optical density ratio which gives the advantage of a more complete valve operation.
  • a filter can be used to attenuate only a portion or portions of either or both the decreasing or increasing parts of the spectrum aforementioned to create still different effects.
  • two or more light valves with different suspensions, each with its own characteristic transmission curves, such as those shown in FIG. 2 can be combined in series with the light passing successively through each of them. This will result in a still further variety of color control and color effects. Also, one or more of these valves can be combined with one or more of the conventionally reacting valves such as mentioned in the aformentioned Patent Application to produce a still further variety of color control and color effects.
  • the voltage applied to activate the light valves can either be a DC voltage or an AC voltage, or a pulsed voltage.
  • An alternating type voltage is preferred for most applications because this type of voltage is less likely to produce undesirable side effects such as coagulation, agglomeration, precipitation, or electrochemical destruction of the particles, or migration or plating of the particles on to the electrodes. Any of these will substantially impair the proper operation of the valves.
  • Magnetic fields can also be used either alone or in combination with electric fields to activate the light valve of this invention.
  • the transmission of a light valve of this invention is integrated over the full spectrum, the increased transmission in one portion of the spectrum is partially or fully compensated by the decreased transmission in another portion of the spectrum.
  • the aforesaid compensation can be made such that the integrated radiation energy transmitted by the valves over the entire spectrum remains practically constant as the valve is operated.
  • the total transmitted light energy can be kept constant as the effective color and color balance are varied.
  • the optical density ratio of the valve for white light could be unity or close to unity while the density ratios for certain wavelengths and certain portions of the spectrum could be greater or less than unity.
  • the light valve of this invention can be used to control or modify color, color balance, color tones, color values, and color hues in the exposure, processing and printing of color photographic materials. For example, if a color photographic print is too redish, i.e. if red predominates at the expense of blue, the photograph can be printed through the light valve of this invention with the valve adjusted to transmit more of the blue portion of the visible spectrum and less of the red portion of the visible spectrum. Thus, tthe amounts of the blue and red transmissions can be controlled by the valve to modify the color balance of the print as desired.
  • the light valve of this invention can also be used to modify and control color and color balance in duplicating or printing motion picture films from the master or negative film on which the picture was originally made. In this duplicating or printing operation it is usually necessary or desirable to modify the color balance in a different way from scene to scene in order to achieve color realism or for dramatic or artistic effects.
  • the light valve of this invention is highly suited to the Application because it operates rapidly so that a desired change in color balance can be made in the time between the individual frames of the motion picture film.
  • valve which is entirely electrical with no mechanical moving parts, is simple compared to the complicated sets of rotatable and adjustable mirrors, color filters, and lenses that are usual in this application; and further, it is easier to control or program the light valve of this invention than it is to program and control the usual system of mirrors, lenses and filters. The latter is true because the light valve of this invention is controlled and operated by a direct electrical input to the valve with no electromechanical or mechanical moving parts.
  • Light valves according to this invention can also be used to produce illuminated displays which change color.
  • a displayed word can be made to change the color of each of its letters independently as well as flash each letter on and off in any desired sequence of pattern.
  • a pattern or diagram or picture or illustration can have its displayed components or parts or individual symbols changed at will in color, color hue and color intensity.
  • a light valve for controlling the transmission of radiation in the electromagnetic spectrum comprising:
  • a cell having from and rear wall sections spaced apart a distance which is small compared to the lateral dimensions of the sections a fluid suspension in said cell of minute particles dispersed therein capable of having their orientation changed by the application of an electric field to the suspension to change the transmission of radiation through the suspension means for applying an electric field to the suspension between said wall sections in a direction substantially parallel to the direction of transmission of radiation through the suspension and substantially perpendicular to said wall sections, and
  • said suspension being characterized in that it is responsive to said field applied in said direction to decrease the level of transmission of radiation therethrough, in part of the electromagnetic spectrum, below the level of transmission of radiation in this part of the spectrum when said field is not applied to the suspension and to simultaneously increase the level of transmission of radiation therethrough, in another part of the electromagnetic spectrum, above the level of transmission of radiation in this other part of the spectrum when said field is not applied to the suspension.
  • ticles comprise cobalt aluminate.
  • filter means are provided to attenuate the light transmitted through the light valve in that portion of the visible spectrum where the level of transmission of radiation is increased in response to an applied electric field.
  • filter means are provided to attenuate the light transmitted through the light valve in that portion of the visible spectrum where the level of transmission of radiation is decreased in response to an applied electric field.
  • a material for controlling the transmission of radiation in the electromagnetic spectrum comprising a fluid suspension including:
  • suspending medium and a plurality of minute particles dispersed therein capable of having their orientation changed by the application of an electric field to the suspension to change the transmission of radiation through the suspension
  • said suspension being characterized in that it is responsive to said field applied in a direction substantially parallel to the direction of transmission of radiation through the suspension to decrease the level of transmission of radiation therethrough, in part of the electromagnetic spectrum, below the level of transmission of radiation in this part of the spectrum, when said field is not applied to the suspension, and to simultaneously increase the level of transmission of radiation therethrough, in another part of the electromagnetic spectrum, above the level of transmission of radiation in this other part of the spectrum when the field is not applied to the suspension.
  • the minute par- 9. The material of claim 8 wherein the minute particles comprise titanium dioxide.

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
  • Optical Filters (AREA)
US00133205A 1971-04-12 1971-04-12 Method, material and apparatus for increasing and decreasing the transmission of radiation Expired - Lifetime US3743382A (en)

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JP (1) JPS5632609B1 (enExample)
CA (1) CA965862A (enExample)
DE (1) DE2217248A1 (enExample)
FR (1) FR2132880B1 (enExample)
GB (1) GB1385505A (enExample)
IT (1) IT957617B (enExample)
NL (1) NL7204866A (enExample)
SE (1) SE377620B (enExample)
ZA (1) ZA722448B (enExample)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4078856A (en) * 1976-03-17 1978-03-14 Research Frontiers Incorporated Light valve
US4164365A (en) * 1972-07-31 1979-08-14 Research Frontiers Incorporated Light valve for controlling the transmission of radiation comprising a cell and a stabilized liquid suspension
US4273422A (en) * 1978-08-10 1981-06-16 Research Frontiers Incorporated Light valve containing liquid suspension including polymer stabilizing system
US4294518A (en) * 1978-11-30 1981-10-13 The Bendix Corporation Dual mode light valve display
US4327970A (en) * 1979-03-21 1982-05-04 Siemens Aktiengesellschaft Display device for optically representing information and a method of operation
US4358743A (en) * 1980-07-09 1982-11-09 Ford Motor Company Light modulator
US4359698A (en) * 1980-07-09 1982-11-16 Ford Motor Company Reflecting type light modulator
US4394068A (en) * 1979-03-20 1983-07-19 Siemens Aktiengesellschaft Fluorescently activated display device with improved sensitivity
US4435732A (en) 1973-06-04 1984-03-06 Hyatt Gilbert P Electro-optical illumination control system
US4639078A (en) * 1984-10-05 1987-01-27 Rockwell International Corporation Optical fiber attenuator and method of fabrication
US4672457A (en) * 1970-12-28 1987-06-09 Hyatt Gilbert P Scanner system
US4739396A (en) * 1970-12-28 1988-04-19 Hyatt Gilbert P Projection display system
US5150257A (en) * 1991-07-29 1992-09-22 Eaton Corporation High reliability, low intensity back lit SR and NVGC indicator assembly
US5398041A (en) * 1970-12-28 1995-03-14 Hyatt; Gilbert P. Colored liquid crystal display having cooling
US5432526A (en) * 1970-12-28 1995-07-11 Hyatt; Gilbert P. Liquid crystal display having conductive cooling
EP0709713A3 (en) * 1994-10-31 1997-03-26 Fujikura Ltd Electrically controlled color display method and device
US6459418B1 (en) * 1995-07-20 2002-10-01 E Ink Corporation Displays combining active and non-active inks
WO2004012002A1 (en) * 2002-07-25 2004-02-05 Luiz Antonio Herbst Junior Adjustable electromagnetic waves filter
WO2006016291A1 (en) * 2004-08-09 2006-02-16 Koninklijke Philips Electronics N.V. Electro-optical suspended particle cell comprising two kinds of anisometric particles with different optical and electromechanical properties
US20100035377A1 (en) * 2006-12-22 2010-02-11 Cbrite Inc. Transfer Coating Method
US20110157683A1 (en) * 2006-10-10 2011-06-30 Cbrite Inc. Electro-optic display
US8501272B2 (en) 2006-12-22 2013-08-06 Cospheric Llc Hemispherical coating method for micro-elements

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19907334A1 (de) * 1999-02-20 2000-08-24 Bayer Ag Elektrochrome Gradientenblende

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US1963496A (en) * 1933-01-16 1934-06-19 Edwin H Land Light valve
US3257903A (en) * 1960-11-21 1966-06-28 Alvin M Marks Electrically responsive light controlling devices employing suspended dipole particles and shear forces
US3322482A (en) * 1965-04-12 1967-05-30 James V Harmon Panel for controlling light transmission by the selective orientation of free particles
US3341274A (en) * 1964-02-04 1967-09-12 Alvin M Marks Electrically responsive light controlling device employing suspended dipole particles in a plastic film

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FR20394E (fr) * 1913-07-15 1917-11-28 Auguste Victor Bollard Murs destinés à s'opposer aux poussées horizontales des masses solides
FR1476194A (fr) * 1965-04-26 1967-04-07 Rca Corp Procédé et dispositifs pour le contrôle des propriétés de substances mélangées avec des cristaux liquides
FR1536032A (fr) * 1967-09-06 1968-08-09 Dispositif de réglage de la lumière sensible à l'électricité
US3612657A (en) * 1970-06-22 1971-10-12 Zenith Radio Corp Light-intensity control device utilizing oriented particles suspended in a gel

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1963496A (en) * 1933-01-16 1934-06-19 Edwin H Land Light valve
US3257903A (en) * 1960-11-21 1966-06-28 Alvin M Marks Electrically responsive light controlling devices employing suspended dipole particles and shear forces
US3341274A (en) * 1964-02-04 1967-09-12 Alvin M Marks Electrically responsive light controlling device employing suspended dipole particles in a plastic film
US3322482A (en) * 1965-04-12 1967-05-30 James V Harmon Panel for controlling light transmission by the selective orientation of free particles

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4739396A (en) * 1970-12-28 1988-04-19 Hyatt Gilbert P Projection display system
US5398041A (en) * 1970-12-28 1995-03-14 Hyatt; Gilbert P. Colored liquid crystal display having cooling
US5432526A (en) * 1970-12-28 1995-07-11 Hyatt; Gilbert P. Liquid crystal display having conductive cooling
US4672457A (en) * 1970-12-28 1987-06-09 Hyatt Gilbert P Scanner system
US4164365A (en) * 1972-07-31 1979-08-14 Research Frontiers Incorporated Light valve for controlling the transmission of radiation comprising a cell and a stabilized liquid suspension
US4435732A (en) 1973-06-04 1984-03-06 Hyatt Gilbert P Electro-optical illumination control system
US4078856A (en) * 1976-03-17 1978-03-14 Research Frontiers Incorporated Light valve
US4273422A (en) * 1978-08-10 1981-06-16 Research Frontiers Incorporated Light valve containing liquid suspension including polymer stabilizing system
US4294518A (en) * 1978-11-30 1981-10-13 The Bendix Corporation Dual mode light valve display
US4394068A (en) * 1979-03-20 1983-07-19 Siemens Aktiengesellschaft Fluorescently activated display device with improved sensitivity
US4327970A (en) * 1979-03-21 1982-05-04 Siemens Aktiengesellschaft Display device for optically representing information and a method of operation
US4359698A (en) * 1980-07-09 1982-11-16 Ford Motor Company Reflecting type light modulator
US4358743A (en) * 1980-07-09 1982-11-09 Ford Motor Company Light modulator
US4639078A (en) * 1984-10-05 1987-01-27 Rockwell International Corporation Optical fiber attenuator and method of fabrication
US5150257A (en) * 1991-07-29 1992-09-22 Eaton Corporation High reliability, low intensity back lit SR and NVGC indicator assembly
EP0709713A3 (en) * 1994-10-31 1997-03-26 Fujikura Ltd Electrically controlled color display method and device
US6459418B1 (en) * 1995-07-20 2002-10-01 E Ink Corporation Displays combining active and non-active inks
WO2004012002A1 (en) * 2002-07-25 2004-02-05 Luiz Antonio Herbst Junior Adjustable electromagnetic waves filter
WO2006016291A1 (en) * 2004-08-09 2006-02-16 Koninklijke Philips Electronics N.V. Electro-optical suspended particle cell comprising two kinds of anisometric particles with different optical and electromechanical properties
US20070211019A1 (en) * 2004-08-09 2007-09-13 Koninklijke Philips Electronics, N.V. Electro-optical suspended particle cell comprising two kinds of anisometric particles with different optical and electromechanical properties
US20110157683A1 (en) * 2006-10-10 2011-06-30 Cbrite Inc. Electro-optic display
US8233212B2 (en) * 2006-10-10 2012-07-31 Cbrite Inc. Electro-optic display
US20100035377A1 (en) * 2006-12-22 2010-02-11 Cbrite Inc. Transfer Coating Method
US8501272B2 (en) 2006-12-22 2013-08-06 Cospheric Llc Hemispherical coating method for micro-elements

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JPS5632609B1 (enExample) 1981-07-29
ZA722448B (en) 1973-02-28
CA965862A (en) 1975-04-08
NL7204866A (enExample) 1972-10-16
SE377620B (enExample) 1975-07-14
DE2217248A1 (de) 1972-11-30
FR2132880A1 (enExample) 1972-11-24
IT957617B (it) 1973-10-20
GB1385505A (en) 1975-02-26
FR2132880B1 (enExample) 1976-08-06

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