A thermal printer according to an embodiment includes: a platen that has a rotatable columnar shape and that is configured to convey a print medium having various widths, with a central portion in a direction of a rotary shaft as a reference, in a manner of being in contact with an outer peripheral portion; and a print head that is oppositely disposed along the platen, that is pressed by the outer peripheral portion, and that is configured to perform printing by applying heat to the print medium. The platen includes a shaft constituting the rotary shaft and a rubber including the outer peripheral portion provided on an outer periphery of the shaft, and has a first region centered on the central portion and second regions on both outer sides in the direction of a rotary shaft with respect to the first region. A diameter of the platen in the first region and diameters of the platen in the second regions are the same, and a thickness of the rubber in the first region is smaller than thicknesses of the rubber in the second regions.

A method for manufacturing a cylindrical member includes: fixing an end portion of an elastic body to an end portion, in a circumferential direction, of a recess provided in a cylindrical body having a substantially circular shape in cross section, the recess extending along an axial direction of the cylindrical body; and winding the elastic body around the cylindrical body while pressing the elastic body using a pressing member.

A printer includes a platen on which a recording medium is placed, an ink head including a nozzle that discharges ink onto the recording medium placed on the platen and that moves in a main scanning direction, an upstream guide located on an upstream side of the platen in a secondary scanning direction and that guides the recording medium, the upstream guide including an upper surface tilted obliquely downward from a downstream side to the upstream side in the secondary scanning direction, and grit rollers provided in the platen and that move the recording medium in the secondary scanning direction. The upstream guide is recessed from the upper surface of the upstream guide, and includes a concave recess that indicates a position of each of the grit rollers in the main scanning direction so that a position of the grit roller is easily acknowledged when the recording medium is placed on the platen.

A printer includes a platen on which a recording medium is placed, an ink head including a nozzle that discharges ink onto the recording medium placed on the platen and that moves in a main scanning direction, an upstream guide located on an upstream side of the platen in a secondary scanning direction and that guides the recording medium, the upstream guide including an upper surface tilted obliquely downward from a downstream side to the upstream side in the secondary scanning direction, and grit rollers provided in the platen and that move the recording medium in the secondary scanning direction. The upstream guide is recessed from the upper surface of the upstream guide, and includes a concave recess that indicates a position of each of the grit rollers in the main scanning direction so that a position of the grit roller is easily acknowledged when the recording medium is placed on the platen.

A printer as a medium processing apparatus includes a transport path through which a paper being transported passes, a recording head that records on the paper on the transport path, and a platen that forms at least a portion of the transport path as a path forming member with which the paper comes into contact, in which a surface resistance value of the path forming member changes according to an applied voltage of the medium.

A printer as a medium processing apparatus includes a transport path through which a paper being transported passes, a recording head that records on the paper on the transport path, and a platen that forms at least a portion of the transport path as a path forming member with which the paper comes into contact, in which a surface resistance value of the path forming member changes according to an applied voltage of the medium.

A printing unit includes a platen lock mechanism for switching between a locked state and an unlock state of the platen roller; and an urging member for urging the lock arm. The head unit has receiving grooves receiving the platen bearings through an opening. A lock arm presses the platen bearings when the operation lever is at the lock position, and is configured to allow disengagement of the platen bearings from the receiving groove through the opening by being swung from the lock position toward the unlock position side. The lock arm includes a pushing-up arm configured to push the platen bearings from the receiving groove toward the opening side along with movement of the operation lever from the lock position toward the unlock position. An urging member urges the lock arm toward the platen unit side.

A printing unit includes a platen lock mechanism for switching between a locked state and an unlock state of the platen roller; and an urging member for urging the lock arm. The head unit has receiving grooves receiving the platen bearings through an opening. A lock arm presses the platen bearings when the operation lever is at the lock position, and is configured to allow disengagement of the platen bearings from the receiving groove through the opening by being swung from the lock position toward the unlock position side. The lock arm includes a pushing-up arm configured to push the platen bearings from the receiving groove toward the opening side along with movement of the operation lever from the lock position toward the unlock position. An urging member urges the lock arm toward the platen unit side.

Examples of an apparatus to use in a media feeder and a method to use in a media feeder are disclosed herein. An example of the apparatus includes a platen having an input to receive a medium and an output to eject the medium. The example of the apparatus additional includes a re-feed prevention device including a ramp to deflect the medium away from the input of the platen when the medium exits the output of the platen and a hooked end to catch an edge of the medium when curled as the medium exits the output of the platen.

Examples of an apparatus to use in a media feeder and a method to use in a media feeder are disclosed herein. An example of the apparatus includes a platen having an input to receive a medium and an output to eject the medium. The example of the apparatus additional includes a re-feed prevention device including a ramp to deflect the medium away from the input of the platen when the medium exits the output of the platen and a hooked end to catch an edge of the medium when curled as the medium exits the output of the platen.