Laser sound head esp. for sound film projector - has laser in tube with lens and two blinds which focus laser onto analogue or digital track on film and minimise distortion factor

摘要

The laser sound head (L) includes a unit [1] that has a cylindrical body within which is contained a laser diode [11]. The laser diode emits red light that passes through a collimator lens [10]. A further head section [12] has a cylinder lens [9] and an objective lens [13] that focuses the beam onto the film [F]. A blind/screen directs the beam onto narrow analogue or digital sound track. The two sections are connected by a bridging element. The transmitted image is received by a photo detector that can be a CCD array [D]. Two blinds/screens (8,15) minimise the distortion factor near the analog film scanner by diminishing the light intensity. Both blinds are pref. free-standing and made from machine cut sheet steel.