Polaroid Corporation

Zink Imaging, Inc.

Michael A Young

Stephen J Telfer

John L Marshall

Russell A Gaudiana

Larry C Takiff

Robert W Haddock

William T Vetterling

Chien Liu

Edward P Lindholm

Kenneth C Waterman

William C Schwarzel

John M Hardin

Socorro M Ramos

Fariza B Hasan

Dana Frederic Schuh

James R Freedman

Serajul Haque

Robert P Short

Rong C Liang

Stephen R Sofen

Rita S Shon Baker

Yulin Hardin

Stephen Robert Herchen

Iris B Kliman Bloom

Alma J Padilla

An optical disc is described that bears, on one surface, a plurality of color-forming layers that can form a multicolored image when heated in contact with a thermal print head. The color-forming composition comprises color-forming layers and thermally-insulating spacers and is designed such that warping of the optical disc in conditions of changing temperature and humidity is minimized. The compliance of the color-forming composition is such that intimate contact between the thermal print head and the printable surface of the disc can be maintained as one is translated relative to the other. Methods for assembling such an optical disc are provided.

Optical disc with thermally-printable surface

There is described a protective overcoat material comprising from about 40 weight percent to about 85 weight percent of poly(methyl methacrylate) having a Tg above about 100&#xb0; C., from about 10 weight percent to about 50 weight percent of poly(ethyl methacrylate) having a Tg of from about 52&#xb0; C. to about 65&#xb0; C. and about 1 weight percent of a melt flow modifier. Also described are thermal image recording members which include a protective overcoat layer.

Thermographic overcoat layer and thermographic image recording members

A process for producing an image uses an imaging medium comprising an acid-generating layer or phase comprising a mixture of a superacid precursor, a sensitizing dye and a secondary acid generator, and a color-change layer comprising an image dye. The sensitizing dye has first and second forms, the first form having substantially greater substantial absorption in a first wavelength range than the second form. The superacid precursor is not capable, in the absence of the first form of the sensitizing dye, of being decomposed by radiation in the first wavelength range. The secondary acid generator is capable of thermal decomposition, catalyzed by superacid, to form a secondary acid. While at least part of the sensitizing dye is in its first form, the medium is imagewise exposed to radiation in the first wavelength range, thereby causing, in the exposed areas of the acid-generating layer, the formation of superacid. The medium is then heated to cause, in the exposed areas, thermal decomposition of the secondary acid generator, catalyzed by the superacid, and formation of the secondary acid. The components of the acid-generating and color-change layers or phases are then mixed so that the secondary acid causes a change in color of the image dye, and the sensitizing dye is converted to its second form. The acid-generating layer or phase desirably includes a cosensitizer which is a reducing agent less basic than the secondary acid generator.

Imaging medium and process for producing an image

A process for producing an image uses an imaging medium comprising an acid-generating layer or phase comprising a mixture of a superacid precursor, a sensitizing dye and a secondary acid generator, and a color-change layer comprising an image dye. The sensitizing dye has first and second forms, the first form having substantially greater substantial absorption in a first wavelength range than the second form. The superacid precursor is capable of being decomposed to produce superacid by radiation in a second wavelength range, but is not, in the absence of the sensitizing dye, capable of being decomposed by radiation in the first wavelength range. The secondary acid generator is capable of acid-catalyzed thermal decomposition by unbuffered superacid to form a secondary acid. While at least part of the sensitizing dye is in its first form, the medium is imagewise exposed to radiation in the first wavelength range, thereby causing, in the exposed areas of the acid-generating layer, the formation of unbuffered superacid. The medium is then heated to cause, in the exposed areas, acid-catalyzed thermal decomposition of the secondary acid generator and formation of the secondary acid. The components of the acid-generating and color-change layers or phases are then mixed so that the secondary acid causes a change in color of the image dye, and the sensitizing dye is converted to its second form. The acid-generating layer or phase desirably includes a cosensitizer which is a reducing agent less basic than the secondary acid generator.

Imaging medium

An imaging medium comprises a layer, depolymerizable by exposure to actinic radiation and undergoing a reduction in cohesivity upon at least partial depolymerization, disposed adjacent a layer of an imaging material, which has a cohesive strength greater than the cohesive strength of the depolymerizable layer after depolymerization. This medium is imagewise exposed to radiation, thereby causing at least partial depolymerization of the polymer in the exposed areas, so rendering these exposed areas lower in cohesivity than the unexposed areas. The exposed areas of the imaging material are then removed from the depolymerizable layer.

Imaging process, and imaging medium for use therein

The addition, to a thermal imaging medium comprising a color-forming compound which undergoes a change of color upon heating above a color-forming temperature for a color-forming time, the color-forming

Stabilization of thermal images

An imaging medium has at least one color-forming layer comprising a thermal color-forming composition adapted to undergo a change of color upon increase in the temperature of the color-forming layer above a color-forming temperature for a color-forming time, the color-forming layer further comprising a color stabilizer which is a hindered amine light stabilizer or a nitrones. The color stabilizer prevents development of color in the medium during storage before or after imaging, thereby reducing the minimum optical density of the imaged medium and/or color distortion in the image.

Imaging media containing hindered amine light stabilizers or nitrones

Variable density spectacles comprising a pair of superposed iodine stained light polarizing elements, one of such elements being rotatable through an arc of less than 90 degrees to provide changes in the light transmitting functionality of the superposed elements; each of said elements having a light transmittance of from about 42 to 44 percent.

Variable density sunglasses comprising light polarizing elements

Growing community of inventors

Natick, MA, United States of America

Michael A Young