Apparatus for thermal printing or embossing

An apparatus for thermal printing or embossing, comprising

• a film conveying section for a carrier film coated with a coloring agent;
• a print support for a printable medium,
• a printhead for selectively heating the carrier film in accordance with a predetermined printed image, so that the coloring agent is transferred from the carrier film to the printable medium in accordance with the predetermined printed image,
• wherein the apparatus further comprises
• a sensor device set up for recording a remaining pattern of the coloring agent on the carrier film after the heating of the carrier film and set up for generating a sensor signal on the basis of the recorded pattern,
• wherein the sensor device comprises
• an image sensor and preferably a light source aligned in a direction of the image sensor, the light source being set up for a purpose of illuminating the carrier film such that the remaining pattern of the coloring agent on the carrier film is recorded as a negative by the image sensor, and
• wherein the image sensor is a line-scan camera.

An apparatus for thermal printing or embossing, comprising

• a film conveying section for a carrier film coated with a coloring agent;
• a print support for a printable medium,
• a printhead for selectively heating the carrier film in accordance with a predetermined printed image, so that the coloring agent is transferred from the carrier film to the printable medium in accordance with the predetermined printed image,
• wherein the apparatus further comprises
• a sensor device set up for recording a remaining pattern of the coloring agent on the carrier film after the heating of the carrier film and set up for generating a sensor signal on a basis of the recorded pattern,
• wherein the sensor device comprises
• an image sensor and preferably a light source aligned in a direction of the image sensor, the light source being set up for the purpose of illuminating the carrier film such that the remaining pattern of the coloring agent on the carrier film is recorded as a negative by the image sensor, and
• wherein the light source comprises light-emitting diodes.

A process for a printed image inspection in thermal printing or embossing, comprising the steps of p1 conveying a carrier film coated with a coloring agent along a section within an apparatus for thermal printing or embossing;

• heating the carrier film in accordance with a predetermined printed image, so that the coloring agent is transferred from the carrier film to a printable medium in accordance with the predetermined printed image;
• recording a remaining pattern of the coloring agent on the carrier film after the heating of the carrier film within the apparatus for thermal printing or embossing
• generating a sensor signal on a basis of the remaining pattern,
• detecting a defective print on a basis of a sensor signal using a logic unit, preferably on the basis of the sensor signal and a printed image signal, wherein the logic unit is set up for a purpose of detecting on a basis of a sensor signal portions on the carrier film on which the coloring agent has remained completely and generating a corresponding print spacing signal.