DOUBLE LUMINOUS FLUX PICKUP DEVICE

PURPOSE:To detect the double luminous flux in an easy, quick and accurate way, by giving minute displacement control to the optical axis of a collimator lens via a collimator lens holding frame while the optical axis of the collimator lens is deflected. CONSTITUTION:A collimator lens 6 is supported by a holding frame 14 which has a distance (m) between a center axis 20 and a pin 24 fixed by screws 26 and 28 and with the position deflected from the optical axis 18 of the lens 6 by a distance e1. Either one of the screws 26 and 28 is unfastened, and the pin 24 is tilted on the basis of the axis 20. Then the pin 24 is shifted horizontally by an extent of displacement DELTAL. As a result, the axis 18 is also tilted on the basis of the axis 20, and the horizontal shift control degree deltal of the axis 18 is set at a minute amount as deltal=DELTALX(e1/m). Therefore, the direction of optical axis of the double luminous flux is controlled as desired by using a similar collimator lens, a reflector, etc. and in response to the fine adjustment of the optical axis position of the collimator lens. As a result, it is possible to detect the double luminous flux in an easy, quick and accurate way.