Power supply apparatus for performing wireless communication between first circuit and second circuit insulated from first circuit, and image forming apparatus including power supply apparatus

A power supply apparatus comprising:

• a first circuit connected to a predetermined power supply;
• a second circuit insulated from the first circuit;
• an adjustment unit included in the first circuit and configured to adjust power supplied from the predetermined power supply to a load connected to the first circuit;
• a detection unit included in the first circuit and configured to detect a parameter related to the power supplied from the predetermined power supply to the load;
• a first communication unit included in the first circuit and connected to the detection unit, the first communication unit including first wiring as a first antenna, the first wiring electrically connecting a first connection portion of the detection unit and a second connection portion of the detection unit;
• a second communication unit included in the second circuit, and insulated from the first communication unit, the second communication unit including second wiring as a second antenna configured to perform wireless communication with the first antenna, the first wiring being disposed to not contact the second wiring;
• and
• a control unit included in the second circuit and configured to control the adjustment unit based on a detection result of the detection unit, the second wiring electrically connecting a third connection portion of the control unit and a fourth connection portion of the control unit, the detection result being transmitted from the detection unit to the control unit by the wireless communication, the detection unit being configured to operate with power resulting from a voltage generated in the first communication unit due to a voltage output from the control unit to the second communication unit,
• wherein at least a part of a region surrounded by the first wiring and the detection unit overlaps a region surrounded by the second wiring and the control unit in a case where a circuit substrate is seen along a direction perpendicular to a surface of the circuit substrate where the detection unit is disposed, and
• wherein the first wiring includes:
• a first spiral portion spirally disposed on a first surface of the circuit substrate, and
• a first wiring portion on a second surface opposite from the first surface, one end of the first spiral portion being connected to the first connection portion, the first wiring portion electrically connecting the other end of the first spiral portion to the second connection portion.

A communication unit device_comprising:

• a substrate;
• a first antenna disposed on the substrate;
• and
• a second antenna disposed on the substrate, insulated from the first antenna, and configured to perform wireless communication with the first antenna, a region of the first antenna and at least a part of a region of a of the second antenna overlapping each other in a case where the first antenna and the second antenna are seen along a direction perpendicular to a surface of the substrate where the first antenna is disposed;
• a transmitting unit connected to the first antenna and configured to transmit data;
• and
• a receiving unit connected to the second antenna and configured to receive the data from the transmitting unit by the wireless communication.