Imaging apparatus and accessory device

The accessory device to which an imaging apparatus is detachably mounted, the accessory device comprising at least one processor or circuit configured to perform operations of a control unit configured to control communication with the imaging apparatus,

• wherein the accessory device and the imaging apparatus communicate with each other via a first communication line, a second communication line, a third communication line, and a fourth communication line,
• wherein a control signal controlling communication performed via the third communication line is received via the first communication line,
• wherein a first command and a second command are received via the second communication line,
• wherein data is transmitted via the third communication line in response to a reception of the first command, and
• wherein optical data of the accessory device specified by the second command is transmitted via the fourth communication line in response to a reception of the second command.

A communication control method of an imaging apparatus to which an accessory device is detachably mounted, the method comprising:

• performing communication between the imaging apparatus and the accessory device via a first communication line, a second communication line, a third communication line, and a fourth communication line,
• transmitting a control signal controlling communication performed via the third communication line via the first communication line,
• transmitting a first command and a second command via the second communication line;
• receiving data via the third communication line in response to a transmission of the first command;
• and
• receiving optical data of the accessory device specified by the second command via the fourth communication line in response to a transmission of the second command.

A communication control method of an accessory device to which an imaging apparatus is detachably mounted, the method comprising:

• performing communication between the accessory device and the imaging apparatus via a first communication line, a second communication line, a third communication line, and a fourth communication line,
• receiving a control signal controlling communication performed via the third communication line via the first communication line,
• receiving a first command and a second command via the second communication line;
• transmitting data via the third communication line in response to a reception of the first command;
• and
• transmitting optical data of the accessory device specified by the second command via the fourth communication line in response to a reception of the second command.