| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical scanner able to ensure a high scanning performance by exerting compensation control through highly accurately monitoring each amplitude and phase difference error in an unexpensive configuration even in use of an MEMS mirror that performs three-wave overlap oscillation. <P>SOLUTION: The MEMS mirror 28 deflects and scans a light beam at a deflection angle θ(t) given by the following expression: θ(t)=A<SB POS="POST">1</SB>sinωt+A<SB POS="POST">3</SB>sin(3ωt+ϕ), in which A<SB POS="POST">1</SB>, A<SB POS="POST">3</SB>, ω is the amplitude of a deflection angle and t is an angle frequency. A BD sensors (signal generators) 33 and 34, which generate signals when the deflection angle θ(t) reaches the predetermined angles θ<SB POS="POST">1</SB>and θ<SB POS="POST">2</SB>in both forward and backward scans, are arranged. Angles θ<SB POS="POST">1</SB>and θ<SB POS="POST">2</SB>are different from each other in absolute value. The absolute value of one of them is almost equal to A<SB POS="POST">1</SB>√3/2. The intervals of signals generated by the BD sensors 33 and 34 are measured, and based on the result of the measurement, A<SB POS="POST">1</SB>, A<SB POS="POST">3</SB>, ϕ are adjusted and controlled. <P>COPYRIGHT: (C)2013,JPO&INPIT |
