| 摘要 |
PURPOSE:To reduce a device in size by making a laser beam for generating a scanning beam incident upon a hologram with an angle sharply shifted from a Bragg angle and applying the laser beam into a rotary body. CONSTITUTION:The laser beam 28 for generating a scanning beam is made incident from the hologram 22 arranged opposed to the scanning beam generating side. The laser beam 28 can be applied into the inside of a holotop 20 by making the beam 28 incident upon the hologram 22 so as to be shifted sharply from the Bragg angle. The applied laser beam 28 is reflected by a parabolic surface mirror 23, turned to a beam 33 parallel with the rotational axis, and after reproducing a hologram, projected as a scanning beam 29. Signal light is turned to a beam 34 almost parallel with the rotational axis by the hologram, focused by a parabolic surface mirror 24 and inputted to an optical detector 27. Said constitution makes it possible to shorten a motor shaft 26 and reduce the device in size. |
