Abstract: A movable rack system able to carry out a widthwise shift control of a movable rack without using a sheet rail member to be detected. The system is so configured, that magnets are placed at stop positions of the movable rack on the floor surface as members to be detected, while the movable rack is equipped with magnetic sensors to detect the magnets. When the movable rack stops traveling, the magnetic sensors detect the magnets and compares the detected magnetic intensity to the magnetic intensity detected at the previous stop. If the change exceeds a pre-determined value, namely the widthwise shift exceeding a pre-determined value is detected, a travel route of the movable rack to eliminate the widthwise shift is determined. In the next travel of the movable rack the rotation speeds of the respective driving motors are controlled so that the movable rack follows the travel route.

Abstract: A movable rack system able to carry out a widthwise shift control of a movable rack without using a sheet rail member to be detected. The system is so configured, that magnets are placed at stop positions of the movable rack on the floor surface as members to be detected, while the movable rack is equipped with magnetic sensors to detect the magnets. When the movable rack stops traveling, the magnetic sensors detect the magnets and compares the detected magnetic intensity to the magnetic intensity detected at the previous stop. If the change exceeds a pre-determined value, namely the widthwise shift exceeding a pre-determined value is detected, a travel route of the movable rack to eliminate the widthwise shift is determined. In the next travel of the movable rack the rotation speeds of the respective driving motors are controlled so that the movable rack follows the travel route.

Abstract: A thermal printer including a thermal printer and a thermal head wherein a clearance between the platen and the thermal head is not less than a maximum diameter of one roll of an ink filled ribbon set by a thermal head driving motor. A ribbon cassette is moved to a printing position and, after a printing operation has been completed to another ribbon cassette. A guiding arrangement for positioning the ribbon cassettes in predetermined positions is adapted to be rotatably driven by a ribbon cassette motor and a plate for supplying the ribbon cassette and receiving the ribbon cassetts. The plate is joined to a take-up end portion of the ribbon cassette and the guiding arrangement is adapted to be moved in the forward and rearward direction for supplying the ribbon cassette and receiving the ribbon cassette by a transfer belt which can be moved by a cassette-moving motor.