| 摘要 |
PURPOSE:To deflect a light beam over an extremely wide deflection angle range and to reduce the size of a scan recording device by deflecting the light beam twice with two acoustic waves. CONSTITUTION:The optical deflecting device 10 consists of 1st and 2nd AOD (acoustooptic deflector) 11 and 12, a scanning image forming lens 13, etc., and the AODs 11 and 12 are provided with a high-frequency amplifier 19 which applies an AC voltage of high frequency, a VCO 20 which varies the frequency of the voltage continuously, and a phase control circuit 18 which shifts the phase of the AC voltage. The light beam L is diffracted with a 1st acoustic wave 15 and then diffracted with a 2nd acoustic wave 16 for the 2nd time to scan on an object surface 14 through a lens 13. Therefore, an extremely large deflection angle is obtained and an acoustic generation part is positioned on the opposite side across the beam, so the beam after the 2nd diffraction becomes completely parallel light. |
