A motor drive apparatus including: a transmission unit carrying-out transmission of an optical signal between a rotation unit for rotating a transmitting and receiving unit and a fixation unit for transmitting reflected light to a control apparatus through a signal line, wherein the transmission unit includes: a tubular shaped lens holding member where a collimator lens is held, and a holding member fixing member having first fixation surface by which the end surface of the lens holding member is fixed and second fixation surface fixed by a surface which is formed to be approximately perpendicular to the direction toward which the optical signal is emanated or the optical signal is light-received the first fixation surface is formed in a spherical shape and the second fixation surface is formed to be approximately perpendicular to the direction toward which the optical signal is emanated or the optical signal is light-received.
