Sublimation printer

A sublimation printer, comprising:

• a casing;
• a platen roller disposed inside the casing and configured to support a printing medium when the printing medium moves along a first direction or a second direction, wherein the first direction is opposite to the second direction;
• a thermal printing head disposed inside the casing and facing the platen roller, wherein the thermal printing head is configured to transfer dyes of a ribbon onto the printing medium;
• a paper cassette disposed inside the casing and located on a side of the platen roller along the second direction, wherein the paper cassette is configured to accommodate the printing medium and an orthogonal projection of the paper cassette on the casing at least partially overlaps with an orthogonal projection of the platen roller on the casing along the first direction or the second direction;
• and
• a platform disposed inside the casing and located between the paper cassette and the platen roller, wherein the platform is configured to guide the printing medium to move along a direction from the paper cassette to the platen roller, and along the first direction or the second direction, the orthogonal projections of the platform, the platen roller and the cassette on the casing at least partially overlap with each other, wherein the platform is extended from a bottom surface of the casing, and a side of the platform close to the paper cassette has a second height which is less than a height of the paper cassette.