8810 results about "Electrophoresis" patented technology

A two-phase electrophoretic medium comprises a continuous phase and a discontinuous phase. The discontinuous phase comprises a plurality of droplets, each of which comprises a suspending fluid and at least one particle disposed within the suspending fluid and capable of moving through the fluid upon application of an electric field to the electrophoretic medium. The continuous phase surrounds and encapsulates the discontinuous phase. The discontinuous phase comprises at least about 40 percent by volume of the electrophoretic medium.

An electrophoretic medium comprises a plurality of particles suspended in a suspending fluid, the particles being capable of moving through the fluid upon application of an electric field to the medium, the fluid having dissolved or dispersed therein a polymer having a number average molecular weight in excess of about 20,000, the polymer being essentially non-absorbing on the particles. The polymer improves the bistability of the display (i.e., the period for which a written image persist without the display being refreshed) but does not greatly increase the viscosity of the suspending fluid, thus keeping the switching time of the display within reasonable limits. The medium may be encapsulated, or may be in the form a polymer-dispersed electrophoretic medium.

An encapsulated electrophoretic medium comprises a plurality of capsules dispersed in a polymeric binder, each of the capsules comprising a capsule wall, a suspending fluid contained within the capsule wall, and a plurality of electrically charged particles suspended in the suspending fluid and capable of moving therethrough upon application of an electric field to the medium, the polymeric binder having a shear modulus of at least about 10 mPa at 20° C., and preferably over the range of 10-50° C.

A two-phase electrophoretic medium comprises a continuous phase and a discontinuous phase. The discontinuous phase comprises a plurality of droplets, each of which comprises a suspending fluid and at least one particle disposed within the suspending fluid and capable of moving through the fluid upon application of an electric field to the electrophoretic medium. The continuous phase surrounds and encapsulates the discontinuous phase. To reduce the humidity sensitivity of the medium, a non-ionizable or crystalline polymer may be used as the continuous phase.

An electrophoretic display comprises a fluid and a plurality of nanoparticles having diameters substantially less the wavelengths of visible light such that, when the nanoparticles are in a dispersed state and uniformly dispersed throughout the fluid, the fluid presents a first optical characteristic, but when the nanoparticles are in an aggregated state in which they are gathered into aggregates substantially larger than the individual nanoparticles, the fluid presents a second optical characteristic different from the first optical characteristic. The electrophoretic display further comprises at least one electrode arranged to apply an electric field to the nanoparticle-containing fluid and thereby move the nanoparticles between their dispersed and aggregated states. Various compound particles comprising multiple nanoparticles, alone or in combination with larger objects, and processes for the preparation of such compound particles, are also described.

In electrophoretic media, it is advantageous to use pigment particles having about 1 to 15 percent by weight of a polymer chemically bonded to, or cross-linked around, the pigment particles. The polymer desirably has a branched chain structure with side chains extending from a main chain. Charged or chargeable groups can be incorporated into the polymer or can be bonded to the particles separately from the polymer. The polymer-coated particles can be prepared by first attaching a polymerizable or polymerization-initiating group to the particle and then reacting the particle with one or more polymerizable monomers or oligomers.

A method for sensing the state of an electrophoretic display includes the steps of applying an electrical signal to a display element, measuring an electrical response for the display element, and deducing the state of the display element from the measured electrical response. Also, the parameters of the display materials are determined using the encapsulated electrophoretic display media as a sensor, either alone or in conjunction with other sensors.

An encapsulated electrophoretic display having a plurality of non-spherical capsules disposed substantially in a single layer on a substrate.

An electrophoretic medium comprises a plurality of one or more types of particles suspended in a suspending fluid. The particles include at least one electrically charged, electrophoretically mobile particle capable of translating through the suspending fluid upon application of an electric field to the medium and at least one magnetic particle. A magnet is disposed adjacent the electrophoretic medium to introduce a threshold resistance to magnetic particle movement.

An electro-optic display comprises first and second substrates and a lamination adhesive layer and a layer of a solid electro-optic material disposed between the first and second substrates, the lamination adhesive layer having a volume resistivity, measured at 10° C., which does not change by a factor of more than about 3 after being held at 25° C. and 45 percent relative humidity for 1000 hours. The electro-optic material is preferably an encapsulated electrophoretic material. Other desirable characteristics of lamination adhesives for use in electro-optic displays are also described.

An electrophoretic display comprises an electrophoretic medium having a plurality of charged particles suspended in a suspending fluid, and two electrodes disposed on opposed sides of the electrophoretic medium. At least one of the electrodes is light-transmissive and forming a viewing surface. The display has a closed optical state in which the charged particles are spread over substantially the entire viewing surface so that light cannot pass through the medium, and an open optical state in which the electrophoretic particles form chains extending between the electrodes so that light can pass through the electrophoretic medium. Insulating layers are disposed between the electrodes and the electrophoretic medium. Similarly electrophoretic displays are provided equipped with color filter arrays or reflectors.

A dielectrophoretic display has a substrate having walls defining a cavity, the cavity having a viewing surface and a side wall inclined to the viewing surface. A fluid is contained within the cavity; and a plurality of particles are present in the fluid. There is applied to the substrate an electric field effective to cause dielectrophoretic movement of the particles so that the particles occupy only a minor proportion of the viewing surface.

The electrophoretic device of the present invention obtains a plurality of different optical characteristics by changing a proportion of number of pixel electrodes supplied with a first voltage and a number of pixel electrodes supplied with a second voltage. The transition of the optical characteristics accompanied by the changes of the proportion is previously obtained as an actual measurement value. The preferable proportion displaying the desired optical characteristic is calculated based on the actual measurement value.

An electronic paper display device, a manufacturing method and a driving method thereof are disclosed. Micro protrusion members are formed at electrodes or at insulating layers. Consequently, the electrophoretic particles are prevented from being securely attached to an upper or the lower structure, and therefore, the quality of pictures is improved, and the contrast ratio of the pictures is increased. The relative sizes and the injection amounts of two kinds of electrophoretic particles are changed such that the relative sizes and the injection amounts of the electrophoretic particles are different from each other. Consequently, the driving voltage is lowered by excessively electrifying the electrophoretic particles of one kind. Protrusions are formed at the corresponding electrode such that a relatively large electric field is distributed around the electrode at which electrophoretic particles are located in the initial stage of voltage application. Consequently, the electrophoretic particles are easily separated from the electrode and moved even at low driving voltage. As such, the voltage level of the driving voltage pulse is lowered. Consequently, it is possible to further increase the response speed of the driving devices and to lower the internal voltage of the devices, thereby reducing the costs related to the driving devices.

Copper chromite particles can advantageously be used as black particles in electrophoretic media and displays. Preferably, the copper chromite particles are coated with a silica coating and a polymer coating.