Abstract: A photographic contact printing process is disclosed having application in the mass production of replicate video discs from a master disc, and other applications wherein it is desired to replicate micro-detail over a relatively large area. A problem with conventional contact printing from a mask to a photographic medium is one of maintaining intimate contact over a relatively large area since dust, dirt, etc., are almost impossible to completely eliminate in any practical manner. In accordance with the present invention, a contact printing process is provided wherein intimate contact is not necessary for making high quality contact prints. The present invention recognizes that in contact printing information from a master disc to a replicate disc, the contact printing process is significantly less sensitive to imperfect contact between the master disc and the replicate disc if one employs a replicate disc comprising a photosensitive material having a certain optical properties.

Abstract: A dye mixture comprising at least two different unsymmetrical bis[1,2-diphenyl-1,2-ethanedithiolato(2.sup.-)-S,S'] -platinum compounds is disclosed. The mixture is useful in optical recording layers.

Abstract: Telluropyrylium dyes are useful as infrared absorbing dyes in recording elements.

Abstract: Oxoindolizine and oxoindolizinium dyes are useful as radiation absorptive materials in recording elements.

Abstract: Dyes conforming to the structure: ##STR1## wherein R.sub.1 is (CH.sub.2).sub.n or ##STR2## n is an integer from 0-5 and each R is independently selected from the group consisting of straight- and branched-chain alkyl groups of about 1-6 carbon atoms, have a high extinction coefficient at 488 nm and are compatible with common binders such as cellulose-nitrate. These dyes are useful in deformable recording compositions for optical recording elements, e.g., video discs.

Abstract: A recording element is disclosed which is capable of providing high-quality, high information-density recording by thermal deformation. The element comprises a support having thereon a layer of amorphous material. The amorphous material is capable of being thermally deformed to form depressions surrounded by sharply defined ridges when impinged upon by a high energy-density recording beam. The amorphous material comprises either a binder and a dye or a certain solvent-coatable dye, Iosol Red. The amorphous material must have an absorption factor, as herein defined, greater than 20. The depressions which are formed in the described material are such that they are readable by a reading beam which is not absorbed by the material.

Abstract: Improved thermal and mechanical barrier layers coated on the recording layer of an optical recording element are disclosed. The improved layers comprise water-soluble polymers having a glass transition temperature when dry of at least 100.degree. C. and preferably at least 150.degree. C. These barrier layers are easily coated and do not significantly degrade the performance of the element. Optional layers such as spacer layers and topcoat layers coated on the barrier layers are also disclosed.

Abstract: In accordance with the present invention, the optical characteristics of a thermal deformation record device are so altered that the device can be read back using the same beam as was used for recording. Moreover, the read beam can be used for playback at an arbitrarily high power level to enhance the signal-to-noise ratio of the recovered signal and yet not damage the deformation recording.

Abstract: Video information is commonly recorded on a master record device such as a video disc by focussing a modulated recording beam on the master disc and rotating the disc relative to the focussed recording beam. During exposure, the recording beam travels across the rotating master disc so that a spiral track of video information is recorded. Because of the extremely small depth of focus, typically less than a micron, focus maintenance is simplified if the master disc recording surface is optically flat. This requirement has led to the use of a relatively expensive master video disc comprised of optically polished glass, quartz or other rigid material. In accordance with the present invention, a method of recording video information on a master disc is provided which permits the use of an inexpensive flexible master disc comprised of ESTAR or other similar material, and yet which enables an extremely small depth of focus to be accurately maintained.

Abstract: In certain types of printing applications (for example optical or magnetic contact printing) wherein it is desired to transfer imagery from a master device to a replicate device, providing and maintaining close contact between the master device and the replicate device poses certain problems. These problems become even more acute if the surfaces to be contacted are of large area. In accordance with the present invention, close contact over even large areas is obtained between a master device and a replicate device by forming a thin and uniform liquid layer between the master and replicate devices, thus producing a vacuum effect which serves to tightly press the master and replicate devices together.