Mitsubishi Denki Kabushiki Kaisha

Sayoko Hirata

Masaru Ohnishi

Masayuki Tanaka

Kenji Nomura

Sadatoshi Murakami

Satoru Yamasaki

Kenichiro Oka

Hiromi Morimoto

A platen for use in thermal printer of a type designed to effect a printing with the use of at least one thermal print head for printing on a recording medium positioned between the platen and the thermal print head, which platen comprises a generally elongated elastic body having an exterior surface adapted to be brought into contact with the heating elements of the thermal print head assembly with at least the recording medium intervening therebetween, and a layer of porous material lined on the exterior surface of the elastic body and having a hardness greater than that of the elastic body and also having a thermal conductivity lower than that of the elastic body. The thermal conductivity and the porosity of the layer of porous material may be within the range of 0.05 to 0.10 Kcal/m.sup.2 .multidot.hr.multidot..degree.C. and within the range of 50 to 95%, respectively.

Platen for use in thermal printer

A platen for use in a thermal printer of a type designed to effect printing with the use of at least one thermal print head for printing a recording medium positioned between the platen and the thermal print head, which platen comprises a generally elongated elastic body having an exterior surface adapted to be brought into contact with the heating elements of the thermal print head assembly with at least the recording medium intervening therebetween. At least the exterior surface of the elastic body is mixed with a mass of porous fine particles having a hardness greater than that of the elastic body and also having a thermal conductivity lower than that of the elastic body. The thermal conductivity and the porosity of the porous fine particles may be within the range of 0.04 to 0.09 Kcal/m.sup.2.hr..degree.C. and within the range of 60 to 95%, respectively.

A thermal transfer printing method which is performed by the use of a thermal printer including a platen, a thermal print head having at least one heating element and a length of ink carrier ribbon with the recording medium positioned between the thermal print head and the length of ink carrier ribbon, which ink carrier ribbon having a base film and an ink layer, which method includes the steps of pressing the ink carrier ribbon against the platen by the thermal print head with the ink layer brought in contact with the recording medium, heating the heating element to cause that portion of the ink layer, which is aligned with the heating element, to fuse, and causing that portion of the ink layer so fused to partially transfer onto the recording medium when a cohesive force acting internally of the ink layer becomes smaller than an adhesive force acting between the ink layer and the recording medium and, at the same time, smaller than a adhesive force acting between the ink layer and the base film, whereby the cohesive force is substantially destroyed so as to permit the thickness of the ink layer to be substantially split into halves such that one of the halves is transferred onto the recording medium and the other of the halves remains adhering to the base film.

Growing community of inventors

Fukuyama, Japan

Sayoko Hirata