Induction heated roll apparatus

An induction heated roll apparatus, comprising:

• a roll that is hollow and is rotatably provided about a rotation axis;
• an induction heating mechanism disposed in a hollow space of the roll;
• a temperature sensor provided in the roll and configured to detect a temperature of the roll;
• and
• a signal transmission device configured to transmit a detection signal of the temperature sensor to a temperature control device on a stationary side of the apparatus, in a contactless manner, the signal transmission device including:
• a light transmission unit provided on a rotating side of the apparatus and configured to output light in accordance with the detection signal;
• a light reception unit provided on the stationary side and configured to receive the light from the light transmission unit;
• a rotary transformer including a stationary-side coil and a rotating-side coil that are electromagnetically coupled to each other, and configured to supply power to the light transmission unit in a contactless manner;
• and
• an alternating-current voltage adjustment unit configured to adjust alternating-current voltage to be supplied to the stationary-side coil,
• wherein the stationary-side coil and the rotating-side coil delineate an annular shape that is wound around the rotation axis of the roll, and are provided in a manner facing each other with a gap between the stationary-side coil and the rotating-side coil along a rotation axis direction of the roll, and
• wherein the alternating-current voltage adjustment unit supplies a reference voltage necessary for the light transmission unit to operate, to the rotating-side coil, by adjusting a frequency or an amplitude of the alternating-current voltage.