Patent ID: 8253766

Claim:
A thermal printer for printing to a print medium at a controlled print speed, comprising: a print head; a paper feed mechanism for conveying the print medium past the print head at the controlled print speed; a print speed change acquisition unit for determining the print speed of the paper feed mechanism and a change in the print speed; an evaluation unit responsive to information from said print speed change acquisition unit for determining if the determined change in print speed exceeds a predetermined threshold value; and a print speed control unit for controlling the print speed of the paper feed mechanism in response to information from said print speed change acquisition unit based upon speed control factors including at least one or more parameters selected from the group consisting of: a temperature of the print head, a printing pattern, an energizing voltage applied to the print head, a print data communication speed and a time required for internal data processing, wherein the print speed control unit limits the print speed to predetermined speed for at least one predetermined time when said threshold value is exceeded.