Abstract: An optical information recording medium provided on a substrate with a recording layer including a dye layer; wherein the dye layer contains a cyanine dye; and the recording layer enables a recording and reproducing to be effected with a laser beam having a wavelength falling within a range of 620 nm to 690 nm; a refractive index "n" of the recording layer being in a range of 1.6 to 4.0 and an extinction coefficient "k" of the a recording layer being in a range of 0.01 to 0.45 when the laser beam having the wavelength is applied thereto; and the recording layer exhibiting a maximum absorption peak wavelength and a second largest absorption peak wavelength falling within a range of 500 nm to 655 nm as measured by means of a visible ultraviolet spectrometer. The dye may be a trimethine-base cyanine dye.

Abstract: An optical recording medium is provided which achieves a higher recording capacity. This optical recording medium includes a base formed of thermoplastic resin which has a thickness ranging from between approximately 0.3 to 1.2 nm, a guide groove formed on the base, at least a reflective film and a phase-change recording layer successively formed on the guide groove, arid a light transmissive layer having a thickness ranging from between approximately 3 to 177 .mu.m. In this optical recording medium, the unevenness .DELTA.t of the thickness of the light transmission layer is set within the range of:.DELTA.t.ltoreq..+-.5.26(.lambda./N.A..sup.4)(.mu.m)wherein N.A. represents a numerical aperture of an optical head device of the optical disk recording and/or reproducing apparatus and .lambda. represents the wavelength of laser light utilized by the optical disk recording and/or reproducing apparatus.

Abstract: An optical recording medium capable of recording and erasing information, includes a first dielectric layer, a recording layer, a second dielectric layer, a light reflection and heat dissipation layer, and an overcoat layer which are successively overlaid on a substrate, the recording layer including a phase-change recording material which includes as constituent elements Ag, In, Sb, Te, and N and/or O with the respective atomic % thereof being .alpha., .beta., .gamma., .delta. and .epsilon. (the total atomic % of N and/or O), which are in the relationship of: 0<.alpha..ltoreq.6, 3.ltoreq..beta..ltoreq.15, 50.ltoreq..gamma..ltoreq.65, 20.ltoreq..delta..ltoreq.35, 0.ltoreq..epsilon..ltoreq.5, provided that .alpha.+.beta.+.gamma.+.delta.+.epsilon.=100, and (2) having a recrystallization upper-limit linear speed in a range of 2.5 to 5.0 m/s. A recording method and a reproduction method, using this optical recording medium, are proposed.

Abstract: A system and method for production of customized compact discs on demand includes acquisition means for acquiring audio data from a plurality of commercial-quality CDs and converting the audio data to digital format; mass storage means, coupled to the acquisition means, for storing the audio data in digital format; indexing means for associating identification data uniquely attributable to the plurality of commercial-quality CDs with their respective audio data in digital format; order processing means for compiling customer data including particularized selection data and shipping data; writing means for recording the customer data to a blank CD; packaging means for labeling the blank CD recorded by the writing means and inserting same in a box for shipment; and production management means, coupled to the mass storage means, indexing means, order processing means, writing means, and packaging means, for controlling production of the customized CDs.

Abstract: A rewritable optical recording disk has a substrate with an increased thickness that is greater than or equal to approximately 1.5 mm and less than or equal to approximately 2.5 mm. The increased thickness of the substrate enhances the flatness of the recording disk relative to a recording plane. In particular, the increased thickness reduces process-induced surface variations such as warpage and tilt, and provides the disk with increased stiffness to resist deflection during use. The enhanced flatness enables data to be recorded on the disk in a consistent manner with greater spatial densities using techniques such as near-field, air-incident recording. The resulting disk thereby yields greater spatial density and data storage capacity.

Abstract: A recordable element includes a substrate, an optical recording layer deposited on the substrate, a light reflecting layer deposited over the recording layer and an interfacial layer having a thickness in a range of 3 to 30 nm and interposed between the recording layer and the reflective layer, the optical recording layer containing Te.sub.a Ge.sub.b C.sub.c H.sub.d O.sub.e where a, b, c, d, and e are the atomic percents such that a+b+c+d+e=100, and wherein 10<a<40, 10<b<60, 5<c<35, 10<d<35, e.gtoreq.0; and the interfacial layer containing Ge.sub.w C.sub.x H.sub.y O.sub.z where w, x, y, and z are atomic percents such that w+x+y+z=100, and wherein 15<w<65, 5<x<35, 15<y<40, z.gtoreq.0. The recording element has its properties changed by heat treatment for a time and temperature selected so as to improve and stabilize its performance.

Abstract: A white decorative member comprising: a substrate; a primary plate layer having a thickness of at least 1 .mu.m and covering the substrate, which is composed of Cu (alloy); an Sn--Cu--Pd alloy plate layer having a thickness of at least 0.2 .mu.m and covering the primary plate layer, which comprises 10 to 20% by weight of Sn, 10 to 80% by weight of Cu and 10 to 50% by weight of Pd as essential components; and a finishing plate layer having a thickness of 0.2 to 5 .mu.m, which is composed of at least one element selected from the group consisting of Pd, Rh and Pt. The decorative member of the present invention does not contain any Ni component, so that, when worn, it does not induce Ni allergy. Moreover, the decorative member which may have white, gold, black or multicolor being a combination of the above colors can be produced at lowered cost.

Abstract: The present invention relates to a printable optical recording medium comprising: a transparent substrate; and at least a recording layer, a reflective layer and a protective layer, a reflective layer or a protective layer and an ink-receiving layer, which layers are in order superposed on said transparent substrate;said protective layer or said ink-receiving layer:(a) containing a hydrophilic and water-insoluble filler having a Mohs hardness of not more than 3;(b) having an arithmetic mean surface roughness Ra on the surface thereof of 0.3 to 2.0 .mu.m; and(c) having a "b" value of the surface thereof of +5 to -5 in Lab color space as a chromaticity.Such printable optical recording medium has a good surface printability and a high whiteness on a printing surface thereof, and is a high chroma of images printed thereon.

Abstract: A side chain liquid crystal polymer and a manufacturing method therefor are provided. Also, an optical recording medium of which recording layer is made of the side chain liquid crystal of the present invention is provided. The side chain liquid crystal polymer expressed by the following formula (V) has excellent processing properties due to its high solubility. Also, due to its high glass transition temperature and low polydispersity, information recorded on a recording layer made of the polymer can be preserved for a long time. In addition, since the recorded type (pit) is even, the error rate is low and the occurrence of jitter noise can be remarkably reduced: ##STR1## where A is either CH.sub.2 or CH.sub.2 --O--(CH.sub.2).sub.m, R is either OCH.sub.3, CN or NO.sub.2, l is 10 to 100, m is 1 to 6, and n is to 20.

Abstract: An optical data storage medium transmissive to a laser beam and formed of a light transmissive substrate that provides mechanical support, and a light transmissive data substrate formed on the substrate. The data substrate is patterned to form block regions that block the laser beam from passing through, and pass regions that allow the laser beam to pass through, such that the blockage or passage of light through the optical storage medium reflects the type of data bits to be stored on the optical medium. In another embodiment a magneto-optical data storage medium which is also transmissive (or partly transmissive) to a laser beam includes a data magneto-optical data substrate formed on a substrate. The data substrate is recordable by patterning a magnetic domain with magnetic fields of opposite directions, such that each magnetic direction reflects the type of data bits to be stored on the optical medium.

Abstract: An optical recording medium has a phase-change recording layer embedded in a stack of thin layers arranged on a substrate. At least one of the dielectric layers adjacent to the recording layer comprises a carbide. The carbide layer is separated from the substrate and/or from a reflecting layer in the stack by a dielectric layer not containing a carbide. The thickness of the carbide layer either lies in a range from 2 to 8 nm or is substantially equal to the thickness of the adjacent dielectric layer.

Abstract: An information carrier has at least two solid material interfaces at which information is, or may be applied and where the information is stored by local modulation of at least one characteristic of the solid material. Reflection of electromagnetic radiation at the interface depends on this characteristic. The information carrier further includes at least one intermediate layer between the two solid material interfaces. The intermediate layer transmits the radiation and is at least predominantly made of either Si.sub.x C.sub.y or Si.sub.v N.sub.w, or both.

Abstract: In a rewritable optical information recording medium, a transparent interference layer, a translucent interference layer, a lower protection layer, a recording layer, an upper protection layer, and a reflection layer are formed on a substrate in that order. The transparent interference layer has a reflectance which changes in accordance with a wavelength of a beam incident on the substrate, and the translucent interference layer has a light transmittance smaller than that of the transparent interference layer. In this constitution, by determining appropriate thicknesses of the above-mentioned layers, a reflectance of a non-recorded portion of the recording medium with respect to a reproducing beam can be increased. Further, reflectances of the non-recorded and recorded portions with respect to a recording and erasing beam can be decreased, so that it becomes easy to record and erase information in the recording medium.

Abstract: A system and method for production of customized compact discs on demand includes acquisition means for acquiring audio data from a plurality of commercial-quality CDs and converting the audio data to digital format; mass storage means, coupled to the acquisition means, for storing the audio data in digital format; indexing means for associating identification data uniquely attributable to the plurality of commercial-quality CDs with their respective audio data in digital format; order processing means for compiling customer data including particularized selection data and shipping data; writing means for recording the customer data to a blank CD; packaging means for labeling the blank CD recorded by the writing means and inserting same in a box for shipment; and production management means, coupled to the mass storage means, indexing means, order processing means, writing means, and packaging means, for controlling production of the customized CDs.

Abstract: Artwork is imparted to plastic discs such as CDs, CD ROMs, and DVDs (digital video discs) by exposing a layer of photoresist material on a substrate to light from an original image of the artwork. The material of the photoresist layer is exposed to different depths by different intensity light from different image regions. Where the image is dark, the exposure is to relatively shallow, random depths. Where the image is light, the full thickness of the photoresist layer is exposed. Development of the photoresist layer removes the exposed photoresist material. The surface features of the developed photoresist layer and any uncovered substrate are transferred to a member used in forming a surface of the plastic disc, thereby visibly embossing the image in the disc.

Abstract: In the optical recording medium including a substrate having pregrooves, and a metal recording layer, a buffering layer, a reflecting layer and a protecting layer which are sequentially stacked on the substrate, wherein the buffering layer is formed of an organic material having a low light absorption with respect to a laser beam of 600.about.800 nm, such that light absorption (k) is less than or equal to 1.0 at 650 nm and the light absorption (k) is less than or equal to 0.1 at 780 nm. Therefore, the optical recording medium can be compatible with a compact disc (CD) and have a high reflectivity at longer wavelength than 600 nm.

Abstract: A dye composition for use in optical recording media, comprising at least one cyanine dye having an anion selected from the group consisting of thiocyanate, lactate, hypophosphite, tetracyanonickelate, selenocyanate, trifluromethanesulfonate, ferricyanide, 4-hydroxybutyrate, nitrite, 2-(3',5'-dimethyl-2'-hydroxyphenyl)-2H-benztriazole-4-sulfonate, 1,2-napthoquinone-2-diazide-5-sulfonate and picrate and preferably dissolved in ethyl lactate.

Abstract: An optical recording medium includes a substrate, a first protection layer formed on the substrate, a recording layer formed on the first protection layer, a second protection layer formed on the recording layer, and a reflection heat radiating layer formed on the second protection layer. The recording layer is of a phase-change type in which the recording layer is changed from an amorphous state to a crystal state by a temperature raising and cooling process by projecting a laser beam onto the recording layer. The recording layer has an interface portion interfaced with one of the first and second protection layers. The interface portion has a thermal conductivity lower than that of a remaining portion of the recording layer.

Abstract: A writable compact disk has a plastic substrate, a recording layer, a reflecting layer, and a protective overcoat, the reflecting layer is comprised of a silver-palladium alloy, a silver-copper alloy, or a silver-palladium-copper alloy. By maintaining the palladium component of the alloy less that 15 at. % and the copper component of the alloy less than 30 at. %, the reflectance of the reflecting layer can be similar to the typical gold reflecting layer while jitter and NORP levels can be reduced for illumination power levels exceeding the power normally used to write on the recording layer.

Abstract: A composition suitable for use as a polymer layer disposed on a semi-reflective layer in an optical medium, such as an optical storage medium. The polymer layer includes an acidic component that promotes adhesion of the polymer layer to the semi-reflective layer.

Abstract: A resin composition for polymerization casting containing:20 to 60% by weight of a monomer (1) represented by the formula (1) ##STR1## wherein R.sup.1 stands for a hydrogen atom or a methyl group, R.sup.2 stands for an alkylene group having 2 to 4 carbon atoms, m and n each is an integer of 2 to 5;10 to 40% by weight of a monomer (2) represented by the formula (2) ##STR2## wherein R.sup.3 stands for a hydrogen atom or a methyl group, R.sup.4 and R.sup.5 are the same or different groups and each stands for an alkylene group having 2 to 4 carbon atoms, j and k each is 0 or 1; and5 to 70% by weight of a monomer (3), the monomer (3) being identical with neither monomers (1) nor (2), and containing at least one vinyl group in a molecule thereof.

Abstract: An optical information recording medium which records at shorter laser wavelengths and has excellent light resistance and archival stability includes a supporting substrate and a recording layer coated on the substrate. The recording layer includes a metal chelated azo compound, the azo compound having the general formula (I): ##STR1## wherein X is NR.sup.6 group, oxygen or sulphur, wherein R.sup.6 is hydrogen or alkyl; Y is hydroxy, carboxy, or carbamoyl; each of R.sup.1 -R.sup.5 is independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted alkenyl, alkoxy, amino, halogen, nitro, cyano, trifluoromethyl, or carboxy, with the proviso that all of R.sup.1 -R.sup.5 are not simultaneously hydrogen; and the metal is a metal ion of Groups 3-12 of the Periodic Table.

Abstract: A description is given of an reversible optical information medium comprising a substrate, a first dielectric layer, a phase-change recording layer on the basis of Ge--Sb--Te, a second dielectric layer, and a metal mirror layer. The recording layer comprises an alloy having the composition Ge.sub.50x Sb.sub.40-40x Te.sub.60-10x in atom %, wherein0.166.ltoreq.x.ltoreq.0.444and wherein the layer thickness d.sub.3 of said recording layer ranges between 25 and 35 nm. Such a medium is suitable for high speed recording (i.e. at least twice the CD-speed), and has a large cyclability of at least 10.sup.5 direct overwrite cycles.

Abstract: To protect the optical surface of optical disc information recording media such as a compact disc (CD) or a digital versatile disc (DVD), that surface is coated with a removable layer of a material that does not significantly alter the optical properties of the disc. Whenever the coating layer may have become damaged, it is removed and replaced with a new layer.

Abstract: The present invention discloses an optical recording element having, in the following order, a transparent substrate, a recording layer and a light reflecting layer wherein the recording layer(A) has a real refractive index (N) at 780 nm not less than 1.8 and an imaginary part (k) is not greater than 0.15;(B) comprises a polymeric cyanine dye that (i) has both a weight-average molecular weight greater than 50,000 and a glass transition temperature (Tg) of less than 150.degree. C.; or (ii) has either (a) a weight-average molecular weight greater than 50,000 or (b) a glass transition temperature (Tg) of less than 150.degree. C.; and(C) a thickness greater than 200 nm.

Abstract: The present invention is in the field of optical recording media, and is directed to an optical recording medium which comprises the following layers;a) a grooved transparent substrate (1), superposed byb) a recording layer comprising a partial mirror (2) of a material having a high complex index of refraction which is not within the pentagon defined by the vertices 7.15 - i3.93, 7.15 - i5.85, 8.96 - 6.28, 9.56 - i5.90, and 8.14 - i3.77 in the n,k plane, superposed by a buffer layer (3) comprising a nonliquid-crystalline high-molecular weight material and optionally a dye, superposed by a thick reflective layer (4), together forming a Fabry-Perot wherein the thickness (d) of the buffer layer within the grooves is set so that the reflection of the medium is in the high reflective state, optionally superposed byc) a protective coating (5).By virtue of the partial mirror, the buffer layer, and the thick reflective layer a Fabry-Perot etalon is created.

Abstract: An optical recording medium having a phase-changing material layer served as a recording layer is composed to excellently repeat the rewrite of bits independently of the line speed of the writing light. The amount of the additive to be added to the phase-changing material layer is regulated in relation to the line speed for the write. The additive is added for suppressing the crystallization.

Abstract: An optical recording element is disclosed. The element has a transparent substrate and on the surface of said substrate, a recording layer and a light reflecting layer wherein recording layer comprises a mixture of a metallized formazan dye and cyanine dye and the unrecorded layer is such that the real part of the refractive (n) at 780 nm is greater than 1.8 and the imaginary part (k) is less than 0.15. The metallized formazan dye has a k value of 0.03 to 0.07.

Abstract: The invention provides a phase change type optical recording medium enabling an increased jitter concomitant with repeated overwriting to be restrained or substantially eliminated. In the optical recording medium comprising a phase change type recording layer on a substrate, the recording layer has a lower dielectric layer in contact with a lower side thereof and an upper dielectric layer in contact with an upper side thereof, and at least one of the upper and lower dielectric layers contains zinc sulfide, and further includes a metal element A that has a standard free energy for forming a sulfide thereof lower than a standard free energy for forming ZnS at 0 to 1,000.degree. C. The ratio of metal element A to all metal elements in the zinc sulfide-containing dielectric layer is less than 2 at %. Metal element A is typically Ce, Ca, Mg, Sr, Ba, and Na.

Abstract: The optical disk writing system disclosed is one in which a data written on an optical data writing medium is verified essentially simultaneously with the writing on the medium. The written data is verified by detecting a timing of the light irradiated on the medium and by measuring return light doses at a rise and a fall of the light irradiated on the medium and comparing the doses thereof with predetermined reference values. The medium used is one which uses a phase transition reversible between a crystal state and an amorphous state for writing/reading/erasing of data on a data writing film and includes, a first protective film, a phase transition type data writing film, a second protective film, a reflection film formed in this order on a transparent substrate.

Abstract: A desired writable optical data recording medium has a transparent substrate 1 where a side wall of a recess is connected to a land surface by a curved surface. A data recording portion of a dye material may be placed only in recesses of a pre-formatted pattern on a transparent substrate, and a reflective layer may be formed on the data recording portion and on the exposed land area between neighboring recesses. The medium can show reflectivity of not less than 65% on reproduction and reduce the cost for manufacturing thereof.

Abstract: An optical disk can provide a sufficiently wide power margin for a recording power even when the optical disk has a high-recording density. The optical disk has a transparent substrate on which a recording layer in which information can be rewritten by at least irradiation of laser beam, a dielectric layer and a thermal conduction control layer are sequentially deposited. The thermal conduction control layer comprises a first low thermal conductivity layer, a first high thermal conductivity layer, a second low thermal conductivity layer and a second high thermal conductivity layer sequentially deposited thereon.

Abstract: A glass substrate for a magnetic disk of the present invention is one in which a laser beam is irradiated on a magnetic recording surface side thereby forming a large number of protrusions thereon to form texture thereon, each of the protrusions having a convex shape, an optical absorption coefficient of a glass with respect to a wavelength of a laser beam at 266 nm being within a range of 20 to 2000 mm.sup.-1, the glass having a composition by weight of:silicon oxide (SiO.sub.2): 58 to 66%,aluminum oxide (Al.sub.2 O.sub.3): 13 to 19%,lithium oxide (Li.sub.2 O): 3 to 4.5%,sodium oxide (Na.sub.2 O): 6 to 13%,potassium oxide (K.sub.2 O); 0 to 5%,R.sub.2 O: 9 to 18% (provided R.sub.2 O=Li.sub.2 O+NaO+K.sub.2 O),magnesium oxide (MgO): 0 to 3.5%,calcium oxide (CaO): 1 to 7%;strontium oxide (SrO): 0 to 2%;barium oxide (BaO): 0 to 2%,RO: 2 to 10% (provided RO=MgO+CaO+SrO+BaO), andiron oxide (Fe.sub.2 O.sub.3): 0.05 to 2%,titanium oxide (TiO.sub.2): 0 to 2%,cerium oxide(CeO.sub.

Abstract: A glass substrate for magnetic disks, obtained by chemical strengthening treatment of a glass consisting essentially of from 50 to 65 wt % of SiO.sub.2, from 5 to 15 wt % of Al.sub.2 O.sub.3, from 2 to 7 wt % of Na.sub.2 O, from 4 to 9 wt % of K.sub.2 O, from 7 to 14 wt % of Na.sub.2 O+K.sub.2 O, from 12 to 25 wt % of MgO+CaO+SrO+BaO, and from 1 to 6 wt % of ZrO.sub.2.

Abstract: An optical information medium comprises a first disc forming information recording layer on a main surface thereof, a second disc being bonded to the first disc at the surface where the information recording layer is formed by way of an adhesive. A hydrophilic resin film is formed on the surface of the disc at the inner peripheral side extending from the center hole to the information non-recording area. The hydrophilic resin film is damp and is rough compared with the other portion formed of non-hydrophilic resin, and it is elastic. The characters, patterns or designs can be printed on the optical information medium using water-base ink, etc. after manufacturing the optical information medium. Further, the hydrophilic resin film is formed on the disc at the portion outside the information recording area.

Abstract: A method for transferring colorant from a donor element to a compact disc (CD) includes holding a CD in the focal plane of a focused laser beam with a colorant donor element being positioned in transferable relationship with the CD and focusing a laser beam on the colorant donor element to heat the donor element to a sufficient temperature to transfer colorant to the CD to thereby effect the transfer of colorant from the donor element to the CD.

Abstract: One object of the invention is to achieve a phase change type optical recording medium having high degree of modulation and recording sensitivity, and another object of the invention is to achieve a phase change type optical recording medium having already stable write/read characteristics at the time of the first overwriting. The optical recording medium comprises a recording layer made up of an optical recording material containing given amounts of In, Ag, Te and Sb. In one Raman spectrum embodiment of the optical recording there are a scattering peak I-1 having a Raman shift in a range of 113 to 117 cm.sup.-1 and a scattering peak I-2 having a Raman shift in a range of 123 to 127 cm.sup.-1, said scattering peak I-2 being larger in half-width than said scattering peak I-1. In another Raman spectrum embodiment, there are a scattering peak II-1 having a Raman shift in a range of 105 to 125 cm.sup.-1 and a scattering peak II-2 having a Raman shift in a range of 140 to 160 cm.sup.

Abstract: A phase change optical recording medium having a structure that a phase change optical recording layer and other layers are stacked, wherein the optical recording layer has a microstructure that particles of optical recording material are dispersed in a matrix made from a dielectric, and wherein the optical recording layer meets the condition of Ama<Amc with respect to Maxwell Garnett absorption, where Ama and Amc are the magnitude of Maxwell Garnett absorption of the optical recording layer in the case where the particles are amorphous and crystalline, respectively, so that the optical recording layer meets the condition of Aa*.ltoreq.Ac* with respect to effective absorbance, where Aa* and Ac* are the effective absorbance of the optical recording layer in the case where the particles are amorphous and crystalline, respectively.

Abstract: A recordable optical disk including a transparent substrate; a recording layer formed over the substrate; a reflective layer formed over the recording layer; and a thin metallic interlayer formed on the recording layer at the interface between the reflective layer and the recording layer wherein the thin metal interlayer includes materials selected from the group consisting of Pd, Ni, Sn, Au, In, Te, Si, Ge, and alloys thereof, the interlayer being selected so as to improve the optical disk recording stability without significantly affecting the reflection of a recording light beam passing through the substrate and the recording layer and which is reflected by the reflective layer.

Abstract: An optical information recording medium includes a substrate, and a light absorption layer formed thereon which includes a phthalocyanine compound (I) having a thermal decomposition temperature in a range of 250.degree. C. to 350.degree. C., measured by thermogravimetry with a temperature elevation rate of 10.degree. C. and a phthalocyanine compound (II) having a thermal decomposition temperature in a range of 350.degree. C. to 450.degree. C., measured by thermogravimetry with a temperature elevation rate of 10.degree. C. This optical information recording medium can be produced by providing the light absorption layer, directly or via an intermediate layer, on a substrate with information pits and/or guide grooves being on the surface thereof by film formation coating, providing a light reflection layer, directly or via an intermediate layer, on the light absorption layer by vacuum film formation, and providing a protective layer on the light reflection layer.

Abstract: A phase-change type optical recording medium, wherein (1) recording, erasing and reading of information by irradiating light is possible, and the medium has a structure in which a first protective layer, a recording layer, a second protective layer, and a reflective layer are consecutively deposited in this order on a transparent substrate, (2) the thickness of the first protective layer is in the range of the thickness, where reflectivity of light on irradiating the layer from the side of the transparent substrate exhibits a minimum, .+-.30 nm, and (3) the second protective layer has the absorption coefficient k satisfying the equation as follows0.05.ltoreq.k.ltoreq.2.5.According to the present invention, unevenness of shapes and sizes of the recording pits can be reduced, irrespective of whether the state of the recording layer is crystalline or amorphous.

Abstract: An information recording medium which comprises as a recording layer an information recording thin layer, formed on a substrate directly or via an underlayer, which records and/or reads back information through the use of atomic arrangement change caused by the irradiation of energy beams, a protective layer and at least two reflective layers, the reflective layers including a first reflective layer and a second reflective layer, the materials of which differ in refractive index or extinction coefficient or both, the aforesaid layers being laminated in the order, from the side of light incidence, of the protective layer, the recording layer, an intermediate layer, the first reflective layer and the second reflective layer.

Abstract: An information recording medium composed of 1) a transparent support, 2) a recording layer which is composed of an organic dye and an organic oxidizing agent having a reduction potential on the side nobler than -0.2, and 3) a light-reflecting layer on the recording layer shows improved light-resistance and endurance as well as good recording and reproducing characteristics.

Abstract: Multiple layer laminate element, such as DVD optical recording elements, are disclosed. The laminates include a cured cyanoacrylate adhesive layer in direct contact with a polymeric layer having a chemically bound cure accelerator for the cyanoacrylate.

Abstract: A recordable optical disk including a transparent substrate; a recording layer formed over the substrate; a reflective layer formed over the recording layer; and a thin dielectric interlayer formed on the recording layer at the interface between the reflective layer and the recording layer wherein the thin dielectric interlayer includes materials selected from the group consisting of Ge--C--H, Si--N and InSnSb--O, the interlayer being selected so as to improve the optical disk recording stability without significantly affecting the reflection of a recording light beam passing through the substrate and the recording layer and which is reflected by the reflective layer.

Abstract: A dye mixture having, at 780 nm, a real refractive index not less than 1.8, and an imaginary part not greater than 0.15 and comprising (a) a tetra dye having a metallized azo dianionic dye with a cationic dye counterion and (b) at least one other dye having the structure according to formula I: ##STR1## wherein: A may be equal to or different from A.sup.1, in which each represents an aryl group having 6 to 10 carbon atoms;B may be equal to or different from B.sup.1, in which each ##STR2## R and R.sup.1 represent an alkyl group of C.sub.1 -C.sub.10 or an aryl group having 6 to 10 carbon atoms; andX represents halide, ClO.sub.4, BF.sub.4, PF.sub.6, tosylate and RCOO.

Abstract: An optical information recording medium is here disclosed which comprises a transparent substrate, a recording layer comprising an organic dyestuff on which information can be written by a laser beam, a reflective layer and a protective layer formed in this order on the substrate, the aforesaid optical information recording medium being characterized by containing a pit.multidot.edge control agent for the formation of recording pits, particularly a dyestuff thermal decomposition accelerator in the recording layer. By the addition of the pit.multidot.edge control agent, deviation properties and jitter properties can be remarkably improved, whereby a CD-R medium having a low error rate and good recording properties can be provided. In consequence, stable compatibility with a commercial CD player can be secured.

Abstract: The optical information medium of the invention includes: a first substrate having a first information signal layer; a first reflective film formed on the first information signal layer of the first substrate; a second substrate having a second information signal layer; a second reflective film formed on the second information signal layer of the second substrate; and a photopolymer resin film provided between the first reflective film and the second reflective film for bonding the first substrate and the second substrate with each other.

Abstract: A description is given of an reversible optical information medium comprising a substrate (1), a first dielectric layer (2), a phase-change recording layer on the basis of Ge-Sb-Te (3), a second dielectric layer (4), and a metal mirror layer (5). The recording layer (3) comprises an alloy having the composition Ge.sub.50x Sb.sub.40-40x Te.sub.60-10x, in atom %, wherein0.166.ltoreq.x.ltoreq.0.444and wherein the layer thickness d.sub.3 of said recording layer (3) ranges between 25 and 35 nm. Such a medium is suitable for high speed recording (i.e. at least twice the CD-speed), and has a large cyclability of at least 10.sup.5 direct overwrite cycles.

Abstract: This invention provides phase change media for optical storage based on semiconductors of nitrides of the column III metals. The surface of thin films of these wide bandgap semiconductors may be metallized (by desorption of the nitrogen) by irradiating with photons of energy equal to, or greater than the band gap of these materials, and with power densities beyond a critical threshold value. As a consequence of such writable metallization, these materials are excellent candidates for write once, read many times storage media since the differences in the reflectivity between the metal and its corresponding wide gap nitride are very large. Furthermore, once the nitrogen is desorbed, the written metallic phase can no longer revert back to the nitride phase and hence the media is stable and is truly a write-once system.