US 12,282,155 B2
Optical scanning device, driving method of optical scanning device, and image drawing system
Hirotoshi Yoshizawa, Kanagawa (JP); Shinichiro Sonoda, Kanagawa (JP); Yoshikazu Hishinuma, Kanagawa (JP); and Nobuya Tanaka, Kanagawa (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on May 6, 2022, as Appl. No. 17/738,788.
Claims priority of application No. 2021-101749 (JP), filed on Jun. 18, 2021.
Prior Publication US 2022/0404613 A1, Dec. 22, 2022
Int. Cl. G02B 26/10 (2006.01); G02B 26/08 (2006.01)
CPC G02B 26/101 (2013.01) [G02B 26/0858 (2013.01); G02B 26/10 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An optical scanning device comprising:
a mirror portion that has a reflecting surface on which an incidence ray is reflected;
a first actuator that causes the mirror portion to swing around a first axis which is in a plane including the reflecting surface at a time of a standstill of the mirror portion;
a second actuator that causes the mirror portion to swing around a second axis which is in the plane including the reflecting surface at the time of the standstill of the mirror portion and intersects with the first axis;
a first angle detection sensor that outputs a signal corresponding to an angle of the mirror portion around the first axis;
a second angle detection sensor that outputs a signal corresponding to an angle of the mirror portion around the second axis;
at least one photodetector provided at a position at which reflected light from the mirror portion is receivable; and
at least one processor,
wherein the processor is configured to
provide a first driving signal having a first driving frequency to the first actuator,
provide a second driving signal having a second driving frequency to the second actuator,
derive a first shift time that is a shift time used for correcting a generation timing of a first reference signal representing that the angle of the mirror portion around the first axis is equal to a first reference angle, and is a shift time of a point in time when the angle of the mirror portion around the first axis is equal to the first reference angle with respect to a point in time when the output signal of the first angle detection sensor represents that the angle of the mirror portion around the first axis is equal to the first reference angle, based on an output signal of the photodetector, and
derive a second shift time that is a shift time used for correcting a generation timing of a second reference signal representing that the angle of the mirror portion around the second axis is equal to a second reference angle, and is a shift time of a point in time when the angle of the mirror portion around the second axis is equal to the second reference angle with respect to a point in time when the output signal of the second angle detection sensor represents that the angle of the mirror portion around the second axis is equal to the second reference angle, based on the output signal of the photodetector;
wherein the processor is configured to
derive a first average phase delay time by averaging a first phase delay time of the output signal of the first angle detection sensor with respect to the first driving signal in a plurality of cycles, and
derive a second average phase delay time by averaging a second phase delay time of the output signal of the second angle detection sensor with respect to the second driving signal in a plurality of cycles,
the point in time when the output signal of the first angle detection sensor represents that the angle of the mirror portion around the first axis is equal to the first reference angle is a point in time after an elapse of the first average phase delay time from a point in time when the first driving signal represents that the angle of the mirror portion around the first axis is equal to the first reference angle, and
the point in time when the output signal of the second angle detection sensor represents that the angle of the mirror portion around the second axis is equal to the second reference angle is a point in time after an elapse of the second average phase delay time from a point in time when the second driving signal represents that the angle of the mirror portion around the second axis is equal to the second reference angle.