An aim of an embodiment is to reduce the volume of power modules, especially for electronic motor control devices. The thin element has an adhesive of a strength to firmly hold the element to a nail, but to enable the element to be peeled away from a nail when desired. Therefore, the emitter means can be placed substantially on the same plane as the image pickup means under the one face M1 of the light transmission means. A second antenna is provided over a second surface of the base.