| 摘要 |
PURPOSE:To easily prevent malfunction of a light receiving element by providing an aperture means between the light receiving element and a light emitting element so as to limit an angular range of a light made incident in the light receiving element. CONSTITUTION:An aperture means 27 is provided between light emitting elements 16a-16g provided to part of a main body equipment and light receiving elements 26a-26g provided to the other part to limit the angular range of the light made incident in the light receiving elements 26a-26g. Thus, the light is surely received between the light emitting elements 16a-16g and the light receiving elements 26a-26g corresponding to each other. Thus, malfunction is effectively prevented without increasing the size and cost increase. |
