Abstract: A thermal transfer recording apparatus, such as a thermal transfer printer, which winds up at constant speed an ink sheet having ink to be transferred while applying a constant tension to the ink sheet by a DC motor through a speed reduction mechanism, so that the respective rotation speed and torques, when a wind-up roll is of a minimum diameter or a maximum diameter, are computed from the feed speed and tension of the ink sheet to thereby obtain a desired gradient in a chart of the relationship between the torque and the rotation speed of the DC motor, the gradient deciding a reduction ratio of the deceleration mechanism and the driviing voltage of the DC motor being decided. Hence, even though the wind-up roll varies in an external form, variation in tension applied to the ink sheet and that in the feed speed can be restricted.

Abstract: The thermal transfer printer of the present invention prevents slackening of recording paper by exerting a braking force upon a recording paper roll to give a back tension to the recording paper when one of the colors of an ink sheet coated with inks of a plurality of colors is thermal-transfer-printed. The recording paper is unwound from the roll thereof in the forward direction and by rotating the recording paper roll in the backward direction the recording paper is rewound. A roller for carrying the recording paper is stopped or braked at the downstream side of the platen when the recording paper is carried in the backward direction for the thermal transfer printing by the next color.

Abstract: An on-demand type ink jet printer, and an ink droplet projecting device used in this printer are disclosed. This device operates in the following way: a piezo-electric element transmits the pressure generated by its vibration first to the pressure transmitting medium of a non-solid matter; through this medium, the pressure is transmitted to the passive vibrating means being in contact with the ink to be projected, and facing the orifice through which ink is projected, thereby vibrating this vibrating means, and by the pressure generated by the vibration, ink is projected through the orifice. With such a structure, the assembling work of this device is easy; uniform projection characteristics are achieved, and moreover, the problem of air suction with resultant projection failure is eliminated.