A noncontact type signal transmission device performs noncontact
transmission of signals between a first member and a second member by
using light. The second member moves along a predetermined orbit relative
to the first member. A plurality of light-emitting devices are arranged on
one of the first and second members. A plurality of light-receiving
devices are arranged on the other of the first and second members. Light
emitted from the light-emitting devices is received by the light-receiving
devices. Beam condensing devices are disposed between the light-emitting
devices and the light-receiving devices. Each beam condensing device has a
function of condensing light from the light-emitting device in a direction
substantially perpendicular to the orbit. The function of each beam
condensing device is to increase the amount of light received by each
light-receiving device and to improve light reception sensitivity.
