Ricoh Company, Ltd.

Tetsuya Amano

Yoshihiko Hotta

Atsushi Kutami

Makoto Kawaguchi

Kazumi Suzuki

Fumihito Masubuchi

Kunichika Morohoshi

Toru Nogiwa

Akira Suzuki

Katsuaki Miyawaki

Makoto Obu

Yusuke Takeda

Tsuyoshi Watanabe

Toshio Kawakubo

Yukio Konagaya

Takao Igawa

Tsutomu Kagawa

Tohru Nogiwa

Nobuo Yamada

Kunichika Moroboshi

Akihide Ito

Ryouji Furuta

Satoru Sanpei

Toshihiko Hotta

Katsuyoshi Kodama

Haruhiro Horiuchi

Suzuki Kazumi

A reversible thermosensitive recording material including: a substrate; a recording layer located overlying the substrate and including a crosslinked resin, an electron donating coloring agent and an electron accepting coloring developer; and a protective layer located overlying the recording layer and including a filler and a crosslinked resin, wherein the recording layer achieves a colored state or a non-colored state when appropriately heating and cooling the recording layer, and wherein the reversible thermosensitive recording material has a surface having at least one of a ten-point mean roughness (Rz) not less than 1.5 &mgr;m or a ratio Sm/Rz not greater than 120, wherein Sm represents an average peak-to-peak length of the surface of the recording material.

Reversible thermosensitive recording material, and image recording and erasing method using the recording material

A reversible thermosensitive recording medium has a support, a reversible thermosensitive recording layer of which color tone is reversibly changeable with the application of heat thereto, and a printing layer bearing a printed image A. When an image B is formed in the reversible thermosensitive recording layer by heating the recording layer, the image B completes a single composite image in combination with the printed image A. The method of using the above-mentioned recording medium includes the step of forming an image B in the reversible thermosensitive recording layer by heating the recording layer to an image formation temperature to complete a single composite image in combination with the printed image A.

Method of using reversible thermosensitive recording medium and the reversible thermosensitive recording medium

A reversible thermosensitive recording medium is provided, comprising a supporting substrate, a reversible thermosensitive recording layer and an overcoat layer, formed in the order recited, in which the recording layer changes transparency or color tone reversibly with temperature. The overcoat layer is formed to have a peak temperature of at most 155&deg; C. in a tan &dgr; vs. temperature curve, wherein tan &dgr; is defined by G&prime;/G&Prime;, with dynamic modulus of elasticity represented by G&prime; and dynamic elastic loss represented by G&Prime;. This thermosensitive recording medium is capable of satisfactorily carrying out the formation and erasure of images with a heating device, such as a thermal printhead, and overcoming difficulties such as the occurrence of cracks and portions of the overcoat layer being removed therefrom and then sticking to heating elements of the thermal printhead, which are caused especially by the application of heating pulses for shorter periods of time and/or at increased pressures during repeated image formation and erasure processing.

Reversible thermosensitive recording medium, and image forming and erasing method

A reversible thermosensitive recording medium having a supporting substrate and a reversible thermosensitive recording layer formed on the supporting substrate, being capable of reversibly varying color density depending upon temperature with improved durability, is provided. The recording medium has the rates of changes in recording sensitivity and in erasure sensitivity, which are caused by the immersion in an artificial perspiration liquid, of 50% or less and 80% or more, respectively, and an average maximum particle size of organic materials of 2.5 microns at most.

Reversible thermosensitive recording medium and method for producing the

A reversible thermosensitive recording material which has a substrate and a recording layer formed on the substrate and in which the recording layer assumes a first color state at a first coloring temperature higher than room temperature when the recording layer is heated by applying heat energy in a first color recordable energy range and in which the recording layer then assumes a second color state when heated at a second coloring temperature higher than the first coloring temperature and then cooled, wherein provided that an initial first color recordable energy range is E.sub.1 and a changed first color recordable energy range of the recording material which has been preserved at 35.degree. C. for 48 hours is E.sub.D, a changing rate E.sub.c of a first color recordable energy range, i.e., 100(E.sub.1 -E.sub.D)/E.sub.1, is less than about 35%.

Reversible thermosensitive recording material and method of use thereof

A reversible thermosensitive recording material has a support, and a metal-deposited light reflection layer and a reversible thermosensitive recording layer successively formed on the support, with the reversible thermosensitive recording layer being capable of showing such transparency or color tone that is reversibly changeable depending upon the temperature thereof, and having a thermal pressure level difference of 40% or less, and a thermal pressure level difference change ratio of 70% or less, and the metal-deposited light reflection layer having a corroded area ratio of at most 2% after allowed to stand at 40.degree. C. and 95%RH for 96 hours.

Reversible thermosensitive recording material

A reversible thermosensitive recording material has a support and a reversible thermosensitive recording layer formed thereon, capable of reversibly assuming at least two different visible states depending upon the temperature thereof, containing an organic low-molecular weight material and a resin composition in which the organic low-molecular weight material is dispersed, the resin composition including a matrix resin, and a dispersion resin which has a glass transition temperature higher than that of the matrix resin, and having resin aggregates which are separately dispersed in the matrix resin in such a manner that the resin aggregates are associated with the matrix resin.

A reversible thermosensitive recording medium having a supporting substrate and a reversible thermosensitive recording layer formed on the supporting substrate, having the ratio, of two values of light intensity scattered by the recording layer at large angles and small angles, of more than or equal to two, the ratio of the two numbers of particles of low-molecular-weight organic material with the large size to small size, of more than or equal to 2%, and the ratio of the two numbers of the particles with the small size to the total particles, of more than or equal to 10%, is provided which has improved display quality and excellent durability for repeated recording and erasing cycles over an extended period of time.

A reversible thermosensitive recording material which includes a support, and a thermosensitive layer provided on the support and including, as main ingredients, a resin matrix and an organic low molecular weight substance dispersed in the resin matrix, wherein the transparency of the thermosensitive layer reversibly changes depending on the temperature thereof is characterized in that the rate of change in heating temperature for the initiation of transparentization is 13% or less, the rate of change in transparency is at least 50% or the rate of change in film thickness is at least 2%. By heating the reversible thermosensitive recording material, the formation and erasure of images may be suitably effected.

Reversible thermosensitive recording material and method of forming and

A reversible thermosensitive recording medium is composed of a support and a reversible thermosensitive recording layer whose transparency or color reversibly changes by the application of heat thereto formed on the support. The reversible thermosensitive recording layer has a thermal pressure level difference of 40% or less, land a thermal pressure level difference change ratio of 70% or less.

Reversible thermosensitive recording medium and method of producing the

A recording method of forming images on a reversible thermosensitive recording material, by bringing a heating element of a thermal head into pressure contact with the reversible thermosensitive recording material, which is capable of assuming a first colored state when heated to a first temperature which is higher than room temperature, and then cooled, and which is capable of assuming a second colored state when heated to a second temperature which is higher than the first temperature, and then cooled, and relatively moving at least one of the heating element or the reversible thermosensitive recording material, wherein the stress exerted on the reversible thermosensitive recording material per unit area thereof, .sigma.(g/cm.sup.2), which is generated by the pressure contact of the heating element with the reversible thermosensitive recording material and the relative movements of the heating material and the reversible thermosensitive recording material, is represented by formula (I):

Reversible image recording method using reversible thermosensitive

An image recording method for recording information in and erasing recorded information from a display medium which contains a reversible thermosensitive recording material capable of writing information therein and erasing recorded information therefrom by the application of heat thereto, by using a heat application member with round corners, and contacting the surface of the heat application member with the display medium.

Image recording method

A card is composed of a reversible thermosensitive recording portion capable of recording information therein, and an irreversible recording portion capable of recording information therein. An information recording method uses the card in which an numerical information is recorded in the reversible thermosensitive recording portion, and an information which has substantially the same contents as those of the numerical information recorded in the reversible thermosensitive recording portion is recorded in the irreversible recording portion for preventing improper alternation of the numerical information recorded in the reversible thermosensitive recording portion. The numerical information recorded in the reversible thermosensitive recording portion and the information recorded in the irreversible recording portion are recognized by an optical device.

Information recording card, and information recording and recognition

An image recording method of recording information in and erasing recorded information from a display medium which contains a reversible thermosensitive recording material capable of writing information therein and erasing recorded information therefrom by the application of heat thereto, by use of a heat application member with a flat portion by bringing the flat portion into contact with the display medium provided on a supporting base, at least one of the display medium or the flat portion of the heat application member having an elastically deformable portion through which one of the display medium or the flat portion of the heat application member performs elastic deformation and the display medium is capable of coming into close contact with the heat application member.

A reversible thermosensitive recording medium includes a reversible thermosensitive recording layer which is composed of a matrix resin and an organic low-molecular material which is dispersed in the matrix resin, the transparency of the reversible thermosensitive recording layer being reversibly changeable depending upon the temperature of the reversible thermosensitive recording layer, wherein the reversible thermosensitive recording layer has a softening initiation temperature T.sub.A, the organic low-molecular-weight material has a higher crystallization temperature T.sub.B1 which is 80.degree. C. or more and a lower crystallization temperature T.sub.B2, the softening initiation temperature T.sub.A is between the higher crystallization temperature T.sub.B1 and the lower crystallization temperature T.sub.B2, and the higher crystallization temperature T.sub.B1 and the lower crystallization temperature T.sub.B2 satisfies the relationship of T.sub.B1 -T.sub.B2 .gtoreq.40.degree. C.

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Numazu, Japan

Tetsuya Amano