Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Guo-Fu Zhou

Roel Van Woudenberg

Bernardus A Jacobs

Johannes Cornelis Norbertus Rijpers

Mark Thomas Johnson

Johannes H M Spruit

Alexander Victor Henzen

Hermanus Johannes Borg

Erwin Rinaldo Meinders

James H Coombs

Johannes C Rijpers

Johan P Duchateau

Willibrordus Jurrianus Dijkman

Michael Geoffrey Pitt

A multi-stack optical data storage medium for rewritable recording by a focused laser-light beam, the medium having a substrate with deposited on aside thereof:

Multi-stack optical data storage medium and use of such a medium

The invention relates to a display device comprising electrophoretic particles, a display element comprising a pixel electrode and an associated counter electrode, between which a portion of the electrophoretic particles is present, and a controller for supplying a drive signal to the electrodes to bring the display element to a predetermined black or white state, corresponding to the image information to be displayed. In order to improve the refresh time of the display, the controller is further arranged to supply a preset signal preceding the drive signal comprising a preset pulse representing an energy which is sufficient to release the electrophoretic particles at a first position near one of the two electrodes corresponding to a black state, but is too low to enable the particles to reach a second position near the other electrode corresponding to a white state.

Electrophoretic active matrix display device

An electrophoretic display device () comprising one pixel () with an electrophoretic medium (), electrodes (), as well as drive means () by which the pixels can be brought into different optical states. Some time (thold) after the application of an addressing pulse (Paddress) for setting the brightness level (Rw, Rb) of a pixel (), a restore pulse voltage (Prestore) is applied between the electrodes () for restoring the brightness level of a pixel to the set level (Rw, Rb). The restore pulse may be a set of consecutive pulses to bring the drifted brightness level even more smoothly (i.e. less perceivably) back to the original brightness level.

Electrophoretic display device and driving means for restoring the brightness level

An optical information medium () for erasable recording by means of a laser-light beam () is provided. A substrate () holds a stack () of layers with a phase-change recording layer () between a first dielectric layer () and a second dielectric layer (). A light-absorptive layer () is present proximate the recording layer () and is made of a compound of the formula QR, in which Q is the element Si, Ge, Ti, Zr, Hf, Nb or Ta, R is the element O or N, and 0&#x3c;x&#x2266;2.5, in order to achieve that 0.8&#x3c;A/A&#x3c;1.50, in which Aand Aare the respective quantities of laser-light absorbed in the recording layer () in the crystalline state and the amorphous state at a laser-light wavelength selected from a range of 350-450 nm. Thus high data rates and low data jitters are achieved at this short wavelength range by tuning x to an optimal value during manufacture of the optical information medium.

Optical information medium and its use

A description is given of multi-stack optical data storage medium () for rewritable recording by means of a focused laser-light beam (), said medium () having a substrate () with deposited on a side thereof: a first recording slick () comprising a phase-change type recording layer ()- at least one further recording stack () comprising a phase-change type recording layer (),- a transparent spacer layer () adjacent each further recording stack (). The further recording stack () is sufficiently transmissive to ensure proper sensitivity for reading and recording in the first recording stack (). For this purpose, at least one heat sink layer () made of HfNx, and 1.1=&#xd7;=1.6, is present in at least one of the recording stacks (). The heat sink layer () further ensure proper cooling behavior of the recording layer () of the further recording stack () in order to obtain sufficient recording performance in the further recording stack ().

Multi-stack optical data storage medium and use of such medium

A description is given of a disc-shaped rewritable optical information medium having an IPIM stack ( ) comprising a phase-change recording layer ( ) sandwiched between two dielectric layers ( ), and a metal mirror layer ( ). The thickness of the recording layer ( ) increases gradually with increasing radius r. As a result, the complete erasure time CET of recorded marks decreases from the inner radius r to the outer radius r . Therefore, at a point closer to the outer radius marks can be recorded at a higher linear speed than at a point closer to the inner radius. This effect ensures that the recording medium can be used for recording at a constant angular velocity (CAV).

Rewritable optical information medium

The application relates to methods and devices for determining the optimal erase ( ) and write powers for erasing and writing information on an optical record carrier ( ). These optimal powers are determined from two powers, P ( ) and P ( ), found at specific points, ( ) and ( ), in a curve ( ) where the normalized reflected power ( ) is plotted versus the test power ( ).

Methods of determining the optimal erase and write power, and recording apparatus with devices for said methods

An optical recording medium. The optical recording medium has a substrate and a stack of layers provided thereon. The stack of layers includes a phase change recording layer, having a melting point T , sandwiched between a first and a second dielectric layer. The stack of layers further includes a crystallization-accelerating layer in contact with the recording layer, a reflective layer, and an optional cover layer. The crystallization-accelerating layer may of a binary metal alloy or a semiconductor and has a melting point T at least 250&deg; C. higher than the melting point T of the recording layer and may have a crystal structure similar to the crystalline state of the recording layer.

Optical recording medium and use of such optical recording medium

Rewritable optical information recording medium

A rewritable optical information medium includes a substrate coated with two carbide layers, a phase-change recording layer between two carbide layers, and a light-absorptive layer of a material like Si, Ge, Mo, or W to slow the cooling when scanned with laser light so that the medium can be used for high data rate recording. The material is capable of a user data bit rate of 50 Mbit/s.

A description is given of a rewritable optical information medium having an IPIAIM stack comprising a phase-change recording layer sandwiched between two dielectric layers, a light-absorbing layer of a material like Si, Ge, Mo, or W, a third dielectric layer, and a metal mirror layer. The light-absorbing layer reduces the difference in light absorption between the amorphous state and the crystalline state to a minimum, thus reducing the recording mark distortion. The presence of the light-absorbing layer in this position ensures that the optical phase difference between the amorphous and the crystalline state is almost zero, making the medium suitable for land-groove recording.

A rewritable optical information medium has a phase-change recording layer on the basis of an alloy of Ge--Sb--Te, which composition is situated within the pentagonal area PQRST in a triangular ternary composition diagram. These alloys show a complete erase time of 50 ns or less. CET-values below 45 ns are obtained with alloys situated on the tie-line connecting Te and the compound GeSb.sub.2 Te.sub.4 within the area PQRST. Such a medium is suitable for high speed recording (i.e. at least six times the CD-speed), such as for DVD-RAM and optical tape.

A rewritable optical information medium has a phase-change recording layer (3) on the basis of an alloy of Ge-Sb-Te-O, having the composition (Ge.sub.a Sb.sub.b Te.sub.c).sub.1-d O.sub.d, wherein:

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Eindhoven, Netherlands

Guo-Fu Zhou